Title of Invention	LIFT INSTALLATION WITH A BUFFER FOR CREATING A ZONE OF PROTECTION IN A LIFT INSTALLATION AND A METHOD OF CREATING A ZONE OF PROTECTION
Abstract	The lift installation comprises a buffer (10) which serves for creating at least one zone of protection in a lift installation, wherein the lift installation comprises a lift cage (15) and a counterweight (23) for the lift cage and the lift cage (15) and the counterweight (23) are movable along paths (VK, VQ). The buffer comprises movable means (14, 14.1) which can be movable into the path (VK) of the lift cage (15) and/or into the path (VQ) of the counterweight (23) in such a manner that the lift cage (15) or the countenA/eight (23) can be brought into mechanical contact with the movable means (14, 14.1) and the buffer (10) of the lift cage (15) or the counterweight (23) is each supported at a predetermined height (Z1.1, Z1.2) above a floor (18) so that a zone of protection can be realised below or above the lift cage (15). (Fig. IE)

Title of Invention

LIFT INSTALLATION WITH A BUFFER FOR CREATING A ZONE OF PROTECTION IN A LIFT INSTALLATION AND A METHOD OF CREATING A ZONE OF PROTECTION

Abstract

The lift installation comprises a buffer (10) which serves for creating at least one zone of protection in a lift installation, wherein the lift installation comprises a lift cage (15) and a counterweight (23) for the lift cage and the lift cage (15) and the counterweight (23) are movable along paths (VK, VQ). The buffer comprises movable means (14, 14.1) which can be movable into the path (VK) of the lift cage (15) and/or into the path (VQ) of the counterweight (23) in such a manner that the lift cage (15) or the countenA/eight (23) can be brought into mechanical contact with the movable means (14, 14.1) and the buffer (10) of the lift cage (15) or the counterweight (23) is each supported at a predetermined height (Z1.1, Z1.2) above a floor (18) so that a zone of protection can be realised below or above the lift cage (15). (Fig. IE)

Full Text	IP 1441 Lift installation with a buffer for creating a zone of protection in a lift installation and a method of creating a zone of protection The subject of the invention is a lift installation with a buffer for creating a zone of protection. A method of creating a zone of protection is a further subject of the invention. Lift installations are usually provided with one or more buffers which are arranged at the shaft floor of a lift shaft in order to stop the lift cage when overrunning the lowermost stopping position in the lift shaft in downward direction and/or when overrunning the uppermost stopping position in the lift shaft in upward direction after transit of a predetermined travel path. This buffer is usually seated below the lift cage and/or the countenA^eight. In order to prevent overrunning of an uppermost stopping position in the lift shaft in upward direction at the latest after transiting a predetermined travel path, buffers can also be arranged at the shaft head above the lift cage. Due to the fact that such buffers have to be arranged at the shaft floor or shaft head directly below or above the lift cage, a specific space requirement results. The shaft head or the shaft floor can therefore only be conditionally utilised for other purposes. In the case of lift installations without a shaft pit, such a standard arrangement of a buffer is not possible, since little space is present underneath the lift cage. A lift installation with a lift shaft, a vertically movable lift cage with counterweight and with buffers is described in PCT Patent Application WO 00/64798-A1. wherein the buffer is disposed not below the lift cage, but near the lift cage at the shaft floor. The lift cage is provided with brackets which impinge on the buffer if an overrun situation arises, i.e. if the lift cage goes beyond the lowermost stopping position at the lowermost storey in downward direction. The lift cage is thereby braked and stopped in a short distance above the shaft floor. An overrun protection against overrunning the uppermost stopping position of the lift cage in upward direction is not proposed in this PCT patent application. The lift installation has a shaft without a pit. A possibility of creating temporary zones of protection for carrying out maintenance and repair operations in the lift shaft at the shaft floor and/or at the shaft head is not disclosed. There is frequently too little space due to constructional or other reasons for a conventional lift installation with a shaft pit and a shaft head. It may be observed that lift shafts without a lift pit and without a lift head are used particularly in the case of subsequent installation or addition of a lift installation in an already existing building. In the case of lift shafts of that kind, but also in the case of conventional lift shafts, there are situations in which it is necessary to create a zone of protection at the upper or lower shaft end. This is so, for example, when the lift installation has to be maintained or checked and when for this purpose an engineer has to go into the shaft. It is important that a system for creating such a temporary zone of protection is safe. There are different proposed solutions for that purpose. The costs and the space requirement for such a system are a further criterion. In addition, a simple checking and maintenance of the system for creating a temporary zone of protection is important. The cost in assembly and the initial aligning of all parts of such a system are also a further criterion which has to be taken into consideration. A lift installation with a lift shaft and a vertically movable lift cage with counterweight is described in European Patent Application EP 0 725 033-A1. Provided at the shaft base is a touch-down device which comprises a pivotable buffer able to be pivoted into the travel path of the lift cage. A zone of protection at the shaft base can thereby be created if needed. As a special form of embodiment there is proposed a combination of a shaft buffer, which is set up outside a path of a lift cage, with a rigid pivot lever pivotable into the path of the lift cage. The lift cage when hitting the pivot lever can thus be braked by the shaft buffer and supported above the shaft floor at a height which lies above the lowermost stopping position of the lift cage. It is a disadvantage of this form of embodiment that it is indeed suitable for creating a zone of protection at the shaft floor, but does not offer any possibility of stopping overrunning of the lowermost stopping position of the lift cage in the lift shaft in downward direction after transiting a predetermined travel path. A possibility of creating a zone of protection at the shaft head is also not provided. A lift installation with a lift shaft, a vertically movable lift cage with a counterweight and a movable support device is described in PCT Patent Application WO 02/051737-A1. The support device is arranged eccentrically at the shaft base between the lift cage and the counterweight and can be moved into the path of the lift cage when necessary. The support device comprises a plate which is pivotably articulated to the shaft floor. If required, this plate is simply pivoted in the direction of the lift cage. Disposed at the lift cage is a buffer which impinges on the plate and stops the lift cage at a predetermined spacing from the shaft floor. A zone of protection at the shaft floor can thereby be created in the case of need. In order to be able to create a zone of protection in the region of the shaft head the lift cage comprises, according to the PCT patent application, a device which is fastened to the roof of the lift cage. This device can be pivoted up and moves against the shaft roof. A zone of protection is thus created at the upper end of the shaft. This PCT patent application is considered to the closest state of the art. It is a disadvantage of this form of embodiment that for creating a zone of protection at the shaft head there is needed a device which is seated on the lift cage. The mass to be accelerated and moved is thereby increased. The present invention has the object of providing a solution which makes it possible to create a zone of protection at the lower or at the upper end of a lift shaft in the case of need. According to the invention this object is fulfilled by the features of claim 1 and the features of method claim 14. Advantageous developments of the lift installation according to the invention are defined by the dependent claims 2 to 13. A development of the method according to the invention is indicated in claim 15. The lift installation according to the invention comprises a buffer, which comprises movable means movable into the path of the lift cage and movable means movable into the path of the counterweight. The movable means movable into the path of the lift cage and the movable means movable into the path of the counterweight can be realised as, for example, a single movable part which is so movable between different positions that it can be brought not only into the path of the lift cage, but also into the path of the counterweight. It is also possible to realise the movable means movable into the path of the lift cage and the movable means movable into the path of the counten^/eight in each instance by different parts movable independently of one another. For example, a first movable part could be so arranged at the buffer that it is movable into the path of the lift cage and a second movable part could be so arranged at the buffer that it is movable into the path of the counterweight. Consequently, the movable means can be brought into a use setting in which they are arranged in such a manner that the lift cage and/or the counterweight can be brought into a mechanical contact with the movable means. It is thereby made possible to be able to selectably support the lift cage or the counterweight in a first or a second predetermined spacing above a floor by a single buffer. The predetermined first spacing and the predetermined second spacing can be different depending on the respective arrangement and form of the buffer or the movable means. The lift cage and the counterweight can accordingly be supported at different heights. In a normal setting of the movable means, the movable means are not disposed in the paths of the lift cage in the counterweight. Consequently, the space available for the lift cage is not restricted when the movable means are brought into the use setting. Due to the fact that selectably the lift cage or the counterweight can each be supported at a predetermined spacing above the floor, the path which the lift cage can travel over is shortened at both ends. Protective spaces are thus created at both ends of the path of the cage. A further form of embodiment of the buffer according to the invention comprises a damping element which is arranged in such a manner that it projects into the path of the lift cage when the movable means are brought into the normal setting, wherein the damping element is constructed in such a manner that the lift cage can be brought into a mechanical contact with the damping element and can be supported at a third spacing above the floor which is smaller than the first predetermined spacing. This form of embodiment is also usable as an overrun protection, which brakes and stops the lift cage on overrunning a lowermost stopping position in downward direction. One form of embodiment of the buffer according to the invention can comprise a damping element which is arranged in such a manner that it projects into the path of the counterweight when the movable means are brought into the normal setting, wherein the damping element is constructed in such a manner that the counterweight can be brought into a mechanical contact with the damping element and can be supported at a fourth spacing above the floor which is smaller than the second predetermined spacing. This buffer can be used as an overrun protection which through mechanical contact with the counterweight brakes and stops the counterweight in downward direction and thus brakes and stops the lift cage on overrunning an uppermost stopping position in upward direction. The buffer can be developed in such a manner that a damping element projects into the paths of the lift cage and the counterweight when the movable means are brought into the normal setting. Thus, solely through selection of the arrangement of a single buffer the lift cage can be prevented from overrunning a lowermost stopping position in downward direction and an uppermost stopping position in upward direction. This form of embodiment is accompanied by the advantage that with a single buffer -depending on the respective selection of the setting of the movable means - the lift cage and/or the counterweight can each be supported at at least two different spacings above a floor. Such a buffer can, if suitably dimensioned, ensure, in a lift installation without a pit, an overrun protection against overrunning a lowermost stopping position of the lift cage in downward direction and against overrunning an uppermost stopping position of the lift cage in upward direction and additionally - in case of an appropriate setting of a movable means - enable creation of temporary protection spaces below and above the lift cage. Details and advantages of the invention are described in the following on the basis of examples of embodiment with reference to the schematic drawings, in which: Fig. 1A shows a schematic plan view of a first form of embodiment of a buffer according to the invention, in a normal state; Fig. 1B shows a schematic side view of the first form of embodiment of a buffer according to the invention, in the normal state; Fig. 1C shows a schematic plan view of the first form of embodiment of a buffer according to the invention, in a use state; Fig. 1D shows a schematic side view of the first form of embodiment of a buffer according to the invention, in the use state, wherein a temporary zone of protection is created; Fig. IE shows a schematic side view of an entire lift shaft with the first form of embodiment of a buffer according to the invention, in the use state, wherein a counterweight is seated on the buffer and a zone of protection is created at the upper shaft end; Fig. 1F shows a schematic side view of the lift shaft with the first form of embodiment of a buffer according to the invention, in the normal state, wherein a countenA^eight is seated on the buffer and overrunning of an uppermost stopping position in upward direction is prevented; Fig. 2A shows a schematic side view of a second form of embodiment of a buffer according to the invention, in a normal state; Fig, 2B shows a schematic side view of the second form of embodiment of a buffer according to the invention, in the normal state; Fig. 2C shows a schematic plan view of the second form of embodiment of a buffer according to the invention, in a use state; Fig. 2D shows a schematic side view of the second form of embodiment of a buffer according to the invention, in the use state, wherein a temporary zone of protection is created at the shaft floor; Fig. 3A shows a schematic plan view of a third form of embodiment of a buffer according to the invention, in a normal state; Fig. 3B shows a schematic side view of the third form of embodiment of a buffer according to the invention, in the normal state, wherein the lift cage travelling downwardly beyond the lowermost stopping position is halted; Fig. 3C shows a schematic plan view of the third form of embodiment of a buffer according to the invention, in a use state; and Fig. 3D shows a schematic side view of the third form of embodiment of a buffer according to the invention, in the use state, wherein a temporary zone of protection is created. Figures 1A to IF show a first form of embodiment of a lift cage with a buffer 10, according to the invention, in different schematic views and in different states. The illustrated buffer 10 is a buffer for supporting a lift cage 15 above the floor 18 of a lift shaft 11. The lift cage 15 is so connected with a counterweight 23 by way of a support means 23.1, for example one or more cables and/or one or more belts, that the lift cage 15 and the counterweight 23 are movable upwardly and downwardly along paths VK and VQ, respectively, in the lift shaft 11. The counterweight, support means, drive pulley for the support means, drive for the drive pulley, guide rails for the lift cage 15 and the counterweight and the other usual elements of a lift installation are not shown in Figures 1A to ID. The buffer 10 has a longitudinal extent substantially parallel to the paths VK and VQ of the lift cage 15 and counterweight 23. It comprises a lower base element 12 and a more slender upper part 13. The buffer additionally comprises movable means 14 and 14.1 which can be moved out of the upper part 13, as indicated in Figures 1C, 1D and IE. In addition, there is provided a drive device (not illustrated) which makes it possible to move the means 14 and 14.1 in each instance between different settings. A control device (not illustrated), which acts on the drive device, makes it possible to check and monitor the positioning of the means 14 and 14.1. The paths VK and VQ are indicated in Fig. IB and ID to IF by dashed lines. The buffer 10 is disposed at least partly between the path VK of the lift cage 15 and the path VG of the countenA^eight 23. For clarification, in Figs. 1A and 1C the projection K1 of the floor 15.1 of the lift cage 15 and the projection G1 of the underside 23.2 of the counterweight 23 are shown each projected onto the shaft floor. The projections K1 and G2 are illustrated by dashed lines in the regions in which they overlap the base area 12.1 of the base element 12 at the shaft floor 18. The movable means 14 and 14.1 are, in the illustrated form of embodiment, constructed to be asymmetrical. The lefthand, trapezium-shaped part 14 projects laterally further out of the upper part 13 than the righthand trapezium-shaped part 14.1. In addition, the movable means 14 and 14.1 are moved to different heights above the shaft floor 18 through the paths VK and VQ: an upper part of the movable means 14 is arranged at a height Z1.1 and an upper part of the movable means 14.1 is arranged at a height Z1.2, wherein Z1.2 is greater than Z1.1 (Figs. 1D and 1E). The buffer 10 is shown in Figures 1A and IB in a so-termed normal state. In the normal state of the buffer, the movable means 14 and 14.1 are disposed outside the paths VK and VG. The respective settings which the movable means 14 and 14.1 adopt in the normal state of the buffer are termed normal setting in the following. Since in the normal state of the buffer 10 the upper part 13 of the buffer 10 does not project into the path VK of the lift cage 15, the lift cage 15 can move to the shaft door 17 of the lower storey without producing a mechanical contact with the buffer 10. In the situation shown in Fig. IB, boarding and disembarkation can take place through the cage door 16 and the shaft door 17. The buffer 10 is illustrated in a so-termed use state in Figures 1C, ID and 1E. In a use state of the buffer the movable means 14 is brought into the path VK and/or the movable means 14.1 is brought into the path VQ, i.e. the movable means 14 and/or the movable means 14.1 is or are disposed in the respective use setting thereof. If the movable means 14 is in its use setting, the lift cage 15 can be brought into a mechanical contact with the means. If the movable means 14.1 is in its use setting, the countenA/eight 23 can be brought into mechanical contact with the means 14.1. If the movable means 14 is brought into its use setting and the buffer 10 is thus disposed in use state, then a mechanical contact of the lift cage 15 with the movable means 14 of the buffer 10 takes place as soon as the lift cage 15 has fallen below a first predetermined spacing, in the present case the spacing Z1.1, with respect to the floor 18. In the case of the illustrated form of embodiment, the lift cage 15 sits by a lower edge on the movable means 14, as shown in Fig. 1D. The buffer 10 together with the movable means 14 and 14.1 is so constructed and arranged that a mechanical contact with the counterweight 23 also takes place when the movable means 14.1 is brought into its use setting and the buffer 10 is thus in the use setting and the counterweight 23 falls below the predetermined spacing Z1.2 with respect to the floor 18. The counterweight 23 is not visible in Figures 1A to ID, since it is disposed at the upper shaft end when the lift cage 15 is disposed at the lower shaft end. Since the lift shaft 11 is a shaft without shaft pit, a zone of protection in the region of the lower shaft end must be able to be created in the case of need. For creating the zone of protection, the buffer 10 is transferred from the normal state to the use state, wherein this takes place in that the movable means 14 is moved out of the upper part 13. The lift cage 15 can now move downwardly until it settles on the movable means 14 and is supported by the buffer 10 at the spacing Z1.1 with respect to the floor 18. In this manner a zone of protection is created below the lift cage 15. The shaft door 17 is arranged in such a manner that a person can enter and/or leave the zone of protection by opening of the shaft door 17. The spacing Z1.1 ensures sufficient distance from the floor 18 in order to enable safe and problem-free working in the zone of protection. A temporary zone of protection in the region of the upper shaft end can also be created by the buffer 10. That is shown in Fig. IE. A schematic longitudinal section through the entire lift shaft 11 is shown in this figure. The lift shaft 11 has four, or more than four, storeys. A shaft door 17 is indicated at the level of each of the storeys. The countenA/eight 23 moves in opposite sense to the lift cage 15 in the lift shaft 11. If the lift cage is disposed at the upper shaft end, then the countenA/eight 23 is disposed at the lower shaft end. In order to create a zone of protection at the upper shaft end, the counterweight is prevented from falling below the spacing Z1.2 relative to the floor 18. As soon as the countenA/eight 23 is seated on the movable means 14.1, the lift cage 15 is also held at a fixedly predetermined spacing from the shaft head. A zone of protection at the upper shaft end thereby results. It is possible to so construct the buffer 10 that the base element 2 also acts as a damping element. In this case, the base element 12 absorbs the kinetic energy of the lift cage 15 or the kinetic energy of the countenA/eight 23 and brakes the lift cage 15 or the countenA/eight 23 when the lift cage 15 and/or the counterweight 23 comes or come into mechanical contact with the buffer 10. This applies not only to the case that the lift cage 15 and/or the counterweight 23 is or are seated directly on the base element 12, but also to the case that the lift cage 15 or the counterweight 23 is seated on the movable means 14 or 14.1. If overrunning of the lowermost stopping position of the lift cage 15 in downward direction takes place, a lower edge of the lift cage 15 seats on the base element 12, as is evident from Fig. IB. The base element 12 acting as a damping element absorbs the kinetic energy of the lift cage 15 and brakes the lift cage 15 until this comes to a stop. In this form of embodiment the buffer 10 can serve not only for creation of zones of protection, but also as an overrun protection. The form of embodiment of Figures 1A to IF is distinguished by the fact that it not only prevents overrunning of the lowermost stopping position of the lift cage 15 in downward direction, but that also an overrunning of the uppermost stopping position of the lift cage 15 in upward direction is arrested. This "emergency case" is illustrated in Fig. IF. A schematic longitudinal section through the entire lift shaft 11 is shown in this figure. The buffer 10 is set in the normal state. Overrunning of the uppermost stopping position of the lift cage 15 in upward direction is now stopped in that the counterweight 23 mechanically interacts with the base element 12 of the buffer 10. Due to the braking and stopping of the counterweight 23 by the buffer 10, the lift cage 15 is prevented from travelling further upwards. In another form of embodiment the drive unit of the lift installation is seated in or directly under the base element 12. In this case the base element would look different in plan view (Figs. 1A and IB). For example, in this case the drive pulley, which is driven by the drive unit, for the support cable would be arranged at the base element 12. It is an advantage of the present invention that it provides different functions with the smallest number of elements and with little space requirement. The base element 12 does not necessarily have to project into the paths VK and VQ if the buffer 10 is to be used exclusively as a device for the creation of protective spaces and does not additionally have to serve as an overrun protection for the lift cage. In this case, the lift cage 15 and the counterweight 23 could not be brought into a mechanical contact with the buffer 10 if the movable means 14 and 14.1 adopt the normal setting. In this case an overrun protection could be realised in that additional buffers, which separately act on the lift cage 15 and/or the counterweight 23 and the dimensions of which are matched to the position of the lowermost and/or the uppermost stopping position of the lift cage 15, are installed in the lift shaft 11. Figures 2A to 2D show - as a second form of embodiment of the invention - a lift installation with a buffer 30 in different schematic views and in different states. The illustrated buffer 30 is a buffer for supporting a lift cage 35 above a floor 38 of a lift shaft 31. The buffer serves as an overrun protection and as means for creation of a temporary zone of protection. The lift cage 35 is so connected with a counterweight that the lift cage 35 is movable upwardly and downwardly along a path VK, and the counterweight upwardly and downwardly along a path VQ, in the lift shaft 31. The counterweight, support means for the lift cage 35 and the counterweight, drive pulley, guide rails and other usual elements of a lift installation are not shown in Figures 2A to 2D. The buffer 30 has a longitudinal extent substantially parallel to the paths VK and VQ of the lift cage 35 and the counterweight. The buffer 30 is so constructed and arranged that it projects at least partly into the path VK of the lift cage and the path VQ of the counterweight. The buffer 30 comprises a lower base element 32, which is designed as a stronger damper, and a more slender upper part 33, which is designed as a weaker damper. The buffer 30 comprises movable means 34 which are seated on the upper part 33 and can be rotated between different settings, as indicated in Figures 2B and 2D. The movable means 34 are symmetrically constructed in the case of the illustrated form of embodiment, i.e. they project out by equal amounts on both sides beyond the upper part 33. The buffer 30 is shown in Figures 2A and 2B in a so-termed normal state. In this case, the movable means 34 is disposed in its normal setting, i.e. it does not project into the paths VK and VQ. In Figures 2C and 2D the buffer 30 is illustrated in a so-termed use state. In this case, the movable means 34 is disposed in its use setting, i.e. it projects into the paths VK and VQ. The buffer 30 is disposed at least partly between the path VK of the lift cage 35 and the path VQ of the counterweight. For clarification, in Figures 2A and 2C the projection K3 of the lift cage 35 and the projection G3 of the counterweight are shown in each instance projected onto the shaft floor. The projections K3 and G3 are illustrated by dashed lines in the regions in which they overlap the base area 32.1 of the base element 32 at the shaft floor 38. In the use state, a mechanical contact of the lift cage 35 with the movable means 34 of the buffer 30 takes place as soon as the lift cage 35 has fallen below a first predetermined space Z3 with respect to the floor 38. In the case of the illustrated form of embodiment, the lift cage 35 is seated by a lower edge on the movable means 34, as shown in Fig. 2D. A temporary zone of protection in the region of the lower shaft end can thereby be created in the case of need. The buffer 30 with the movable means 34 is so constructed and arranged that in the use state a mechanical contact with the counterweight also takes place when the counterweight falls below the predetermined spacing Z3 with respect to the floor 38. The counterweight is not visible in Figures 2A to 2D, since it is disposed at the upper shaft end when the lift cage 35 is disposed at the lower shaft end. The buffer 30 is shown in normal state in Fig. 2B. Since the upper part 33 of the buffer 30 does not project into the path of the lift cage, the lift cage 35 can travel to the shaft door 37 of the lower storey without producing a mechanical contact with the buffer 30. In the situation shown in Fig. 2B, boarding or disembarkation can take place via the cage door 36 and the shaft door 37 when the lift cage adopts the lowermost stopping position at the lowermost storey. If overrunning of the lowermost stopping position of the lift cage 35 in downward direction (not shown in Figures 2A to 2D) now occurs, then a mechanical contact of the lift cage with the base element 32, which is designed as a stronger damper, of the buffer 30 takes place as soon as the lift cage 35 has fallen below a predetermined spacing Z3.1 with respect to the floor 38. In the case of the illustrated form of embodiment the lift cage 35 is then seated by a lower edge on the base element 32. The lift cage 35 can thereby be braked and stopped in the "emergency case". For creation of a zone of protection, the buffer 30 is transferred from the normal state to the use state, wherein this takes place in that the movable means 34 are rotated about an axis of rotation which is aligned substantially parallel to the path VK of the lift cage 35 or to the path VG of the counterweight. The respective setting of the movable means is controlled by means of a drive and a control device acting on the drive. The drive and the control device are not illustrated in the figures. The lift cage 35 can be moved downwardly until it settles on the movable means 34. In this manner a zone of protection is created below the lift cage 35. A shaft door 37 is arranged in such a manner that a person can enter and/or leave the zone of protection by opening of the shaft door 37. The spacing Z3 ensures sufficient distance from the floor 38 in order to enable a safe and problem-free working in the zone of protection. Since in the illustrated form of embodiment there is concerned a lift installation with a shaft pit and since the base element 32 has a longitudinal extent H3, there is created every time a flat zone of protection into which the lift cage 35 cannot penetrate. Even if due to a fault or due to erroneous operation the necessary changeover into the use state is not carried out, a person in the lift shaft cannot be crushed, since a minimum spacing is always given by the height H3 of the base element 32. The base element 32 and/or the lower part 33 has or have a length in the direction of the path VK or VG dependent on the mechanical loading thereof. The load-dependence of this extent substantially determines the capability of the base element 32 or of the upper part 33 of braking and stopping the lift cage or the counterweight when impinging on the buffer 30. In order to indicate the loading of the buffer 30 by the lift cage 35, in Fig. 2D the length of the buffer 30 in the direction of the path VK is illustrated reduced by a distance AZ by comparison with the spacing Z3. In analogous manner the extent of the buffer 30 in the direction of the path VQ is reduced by a height below the spacing Z3 when the countenA/eight loads the buffer 30. A temporary zone of protection in the region of the upper shaft end can also be created by the buffer 30. This state is not, however, shown in Figures 2A to 2D. In order to create a zone of protection at the upper shaft end, the movable means 34 are moved into the path VG of the counterweight and the counterweight is supported by the buffer 30 as soon as the counterweight falls below the spacing Z3 from the floor 38. As soon as the counterweight is seated on the righthand side of the movable means 34, the lift cage 35 is also held at a fixedly predetermined spacing from the shaft head. A zone of protection at the upper shaft end thereby results. Figures 3A to 3D show - as a third form of embodiment of the invention - a lift installation with a buffer 40 in different schematic views and in different states. The illustrated buffer 40 is a buffer for supporting a lift cage 45 above a floor 48 of a lift shaft 41. The buffer serves as overrun protection and as means for creating a temporary zone of protection in a lift installation without a pit, i.e. in a lift installation in which the lowermost stopping level of the lift cage lies at such a short distance above the floor that no space for a shaft pit is present. The lift cage 45 is so connected with a counterweight that the lift cage 45 and the counterweight are movable upwardly and downwardly along paths in the lift shaft 41. The countenA^eight, support means for the lift cage 45 and the counterweight, drive pulley, guide rails and other usual elements of a lift installation are not shown in Figures 3A to 3D. The buffer 40 has a longitudinal extent substantially parallel to the paths of the lift cage 45 and the counterweight. The buffer 40 is so constructed and arranged that it projects at least partly into the path of the lift cage and into the path of the counterweight, depending on the respective state. The buffer 40 comprises a lower base element 43, which is constructed as a stronger damper, and movable means 44, which are seated on the base element 43 and can be rotated, as indicated in Figures 3C and 3D. The movable means 45 are symmetrically constructed in the case of the illustrated form of embodiment, i.e. they project out by equal amounts on both sides beyond the base element 43. The movable means 44 comprise dampers 44.1, which are seated in recesses of the movable means 44. The buffer 40 is shown in Figures 3A and 3B in a so-termed normal state. In this case the movable means 44 and 44.1 are disposed in their normal setting, i.e. they do not project into the paths of the lift cage 45 and the counterweight. The buffer 40 is illustrated in a so-termed use state in Figures 3C and 3D. In this case the movable means 44 and 44.1 are disposed in their use setting, i.e. they project into the paths of the lift cage 45 and the counterweight. The buffer 40 is disposed at least partly between the path of the lift cage and the path of the counterweight. For clarification, the projection K4 of the floor 45.2 of the lift cage 45 and the projection G4 of the underside of the counterweight are shown in Figures 3A and 3C. In the use state, a mechanical contact with the lift cage 45 with the damper 44.1 of the buffer 40 takes place as soon as the lift cage 45 falls below a first predetermined spacing Z4 with respect to the floor 48. In the case of the illustrated form of embodiment the lift cage 45 is seated by a lower edge on the damper 44.1, as shown in Fig. 3D. The buffer 40 is thus eccentrically loaded. A temporary zone of protection can thereby be created in the region of the lower shaft end in the case of need. The buffer 40 with the movable means 44, 44.1 is so constructed and arranged that in the use state a mechanical contact with the counterweight also takes place when the counterweight falls below the predetermined spacing Z4 with respect to the floor 48. The countenA^eight is not visible in Figures 3A to 3D, since it is disposed at the upper shaft end when the lift cage 45 is disposed at the lower shaft end. The buffer 40 is shown in normal state in Fig. SB. Since in the normal state the movable means 44, 44.1 of the buffer 40 do not project into the path of the floor 45.2 of the lift cage 45, the lift cage 45 can travel to the shaft door 47 of the lower storey without producing a mechanical contact with the buffer 40. It is mentioned that in the illustrated state a spacing D between a bracket 45.1 (buffer abutment), which is fastened to the lift cage 45, and the movable means 44.1 exists. In the situation shown in Fig. SB, boarding or disembarkation can take place via the cage door 46 and the shaft door 47. If overrunning of the lowermost stopping position of the lift cage 45 in downward direction (not shown in Figures SA to 3D) now occurs, then a mechanical contact of the bracket 45.1, which is fastened to the lift cage 45, with the means 44 or with the base element 43, which is constructed as a stronger damper, of the buffer 40 takes place. The lift cage 45 can thereby be braked and stopped in the "emergency case". It may be noted that in the case of overrunning the lowermost stopping position of the lift cage 45 the damper 44.1 does not come into use, since the bracket 45.1 produces direct contact with the means 44. The buffer 40 is thus centrally loaded in such an "emergency case". If the movable means 44 and 44.1 adopt the normal setting, then an overrunning of the uppermost stopping position of the lift 45 in upward direction is prevented in that a bracket or another protruding element at the side of the counten/veight facing the shaft door 47 produces a contact with the movable means 44 of the buffer 40. This, too, leads to a central loading of the buffer 40. For clarification, a projection K4.1 of the bracket 45.1 and a projection G4.1 of the said bracket or of the protruding element at the counterweight, each projected onto the shaft floor, are illustrated in Figs. 3A and 3C in each instance by dashed lines. For creation of a zone of protection, the buffer 40 is transferred from the normal state to the use state, wherein this takes place in that the movable means 44 are rotated into the paths of the floor 45.2 of the lift cage 45 and the underside of the counterweight (Figs. 3C and 3D). The necessary changeover can be triggered by, for example, a (key-operated) switch or in electronically controlled manner. In order to create the temporary zone of protection, the lift cage 45 is moved slowly downwardly until it settles on the damper 44.1. A person can enter and/or leave the zone of protection by opening of the shaft door 47. The spacing Z4 guarantees sufficient distance from the floor 48 in order to enable a safe and problem-free working in the zone of protection. A temporary zone of protection in the region of the upper shaft end can also be created by the same buffer 40. However, this state is not shown in Figures 3A to 3D. In order to create a zone of protection at the upper shaft end, the counterweight is prevented from falling below the spacing Z4 from the floor 48. As soon as the counterweight is seated on the damper 44.1 on the righthand side of the movable means 44, the lift cage 45 is also held at a fixedly predetermined spacing from the shaft head. A zone of protection at the upper shaft end thereby results. As indicated in Figures 1D and 1E, the lift cage and the counterweight do not have to be supported at the same height. The form of embodiment according to Figs. 2A to 2D and 3A to 3D can be appropriately modified by a suitable adaptation of the shapes of the movable means 34 and 44 or 44.1. According to the invention the buffer can have a damping characteristic which is specially matched to the case of use. In the case of the third form of embodiment, dampers 44.1 are used which enable a lightly damped seating of the lift cage 35 or of the counterweight on the movable means 44 when a zone of protection is to be created. The movable means 44 are thus treated gently in operation. If the lift cage and/or the counterweight impinges or impinge at high speed on the respective buffer - particularly during overrunning beyond the lowermost or the uppermost stopping position of the lift cage -then, thereagainst, the damping characteristics of the base elements 12, 32 and 43 come into use. The buffer according to the invention can be equipped with special means which allow an asymmetrical loading without the buffer "collapsing" or "deflecting". For this purpose the buffer can be surrounded entirely or partly by a corset-like element or be guided by a special means in order to provide compensation for the bending moments arising due to the eccentric buffer loading. In the case of a part of the form of embodiments the buffer is arranged completely between the lift cage and the counterweight (see, for example, Fig. 3A). In the case of a further form of embodiment the buffer element can be arranged entirely or partly below the counterweight and act directly on the countenA^eight. A movable means of the buffer element then correspondingly acts on the lift cage in the case of need. The cross-section of the buffer can be selected as desired. The buffers 10 and 30 have a substantially round cross-section parallel to the floor of the lift shaft. The buffer 40, thereagainst, has, for example, a square cross-section in the lower region 43. Movement of the movable means of the buffer can take place electromagnetically, hydraulically, pneumatically, manually or by means of a setting motor, depending on the respective form of embodiment. In a further form of embodiment there is used a pit set which comprises a drive/frequency-converter unit, a speed limiter, a fastening for the guide rails and the buffer. Assembly in the lift shaft is thereby appreciably simplified. The present invention is also suitable for use in a lift installation in cantilever disposition. Through the special arrangement and construction of the buffer there results a reduced space requirement by comparison with conventional solutions. The invention is particularly suitable for use in lift shafts which have no or only small shaft pit and shaft head height dimensions. It is an advantage of the invention that regulations for fulfilment of personal protection are maintained and the constructional costs and installation costs, depending on the respective form of embodiment, can be substantially reduced. The movable means 14, 14.1, 34, 44 and 44.1 can be modified in different ways within the scope of the invention. They can be replaced by means which are foldable, pivotable, slidable and/or rotatable out of a basic setting and movable in each instance into the path or paths of the lift cage and/or the counterweight in order to support the lift cage and/or the counterweight at a spacing above the floor. The movable means can also be so constructed by a suitable arrangement that the lift cage and the counterweight can in each instance be supported at different heights. The can be of multi-part or also of integral construction. Patent Claims 1. Lift installation with a buffer (10, 30, 40) for creating at least one zone of protection, wherein the lift installation comprises a lift cage (15, 35, 45) and a countenA/eight (23) for the lift cage and the lift cage (15, 35, 45) and the counterweight (23) are movable along paths (VK, VG), characterised in that the buffer (10, 30, 40) comprises movable means (14, 14.1, 34, 44, 44.1) which are movable into the path (VK) of the lift cage (15, 35, 45) and movable means (14.1, 34, 44, 44.1) movable into the path (VG) of the counteoA^eight (23). 2. Lift installation according to claim 1, characterised in that the movable means (14, 34, 44, 44.1) can be brought into a use setting in which they are arranged in such a manner that a mechanical contact takes place between the movable means (14, 34, 44, 44.1) and the lift cage (15, 35, 45) when the lift cage (15, 35, 45) falls below a first predetermined spacing (Z1.1, Z3, Z4) with respect to a floor (18, 38, 48) and/or that a mechanical contact takes place between the movable means (14.1, 34, 44, 44.1) and the counterweight (23) when the counterweight (23) falls below a second predetermined spacing (Z1.2, Z3, Z4) with respect to a floor (18, 38, 48). 3. Lift installation according to claim 2, characterised in that the movable means (14, 14.1, 34, 44, 44.1) starting from the use setting are movable out of the path (VK) of the lift cage (15, 35, 45) and/or the path (VG) of the countenA/eight (23). 4. Lift installation according to claims 2 and 3, characterised in that the movable means (14, 14.1, 34, 44, 44.1) can be brought into a normal setting in which they are arranged in such a manner that no mechanical contact takes place between the movable means (14, 34, 44, 44.1) and the lift cage (45) when the lift cage (15, 35, 45) falls below the first predetermined spacing (Z1.1, Z3, Z4) with respect to the floor (18, 38, 48) and that no mechanical contact takes place between the movable means (14.1, 34, 44, 44.1) and the counterweight (23) when the countenA/eight (23) falls below the second predetermined spacing (Z1.2, Z3, Z4) with respect to the floor (18, 38, 48). 5. Lift installation according to claim 3, characterised in that the movable means (14, 34^ 44^ 44.1) in the use setting are arranged in such a manner that the mechanical contact between the movable means (14, 34, 44, 44.1) and the lift cage (15, 35, 45) can be realised in such a manner that the lift cage (15, 35, 45) is supported above the floor (18, 38, 48) and a zone of protection exists between the floor (18, 38, 48) and the lift cage (15, 35, 45). 6. Lift installation according to claim 3, characterised in that the movable means (14.1, 34, 44, 44.1) in the use setting are arranged in such a manner that the mechanical contact between the movable means (14.1, 34, 44, 44.1) and the counterweight (23) can be realised in such a manner that the countenA/eight (23) is supported above the floor (18, 38, 48). 7. Lift installation according to claim 6, characterised in that the lift cage (15, 35, 45) together with the counterweight (23) is connected by way of a carrier means (23.1) of such a length, and the counterweight (23) can be supported above the floor at such a height, that a zone of protection exists above the lift cage (15, 35, 45), wherein this zone of protection is preferably disposed between an upper region of the lift cage (15, 35, 45) and an upper end of a lift shaft (11, 31, 41). 8. Lift installation according to one of claims 1 to 7, characterised in that the buffer (10, 30, 40) has an appropriate damping characteristic in order to enable a soft settling when a mechanical contact with the lift cage (15, 35, 45) or with the counterweight (23) takes place and/or that at least an upper part (13, 33, 43) of the buffer (10, 30, 40) is disposed between an area projection (K1, K3, K4) of the lift cage (15, 35, 45) and an area projection (G1, G3, G4) of the counterweight (23) and/or that the movable means (14, 14.1, 34, 44, 44.1) are means which can be folded out, pivotable means, slidable means or rotatable means. 9. Lift installation according to claim 4, characterised in that a damping element (12, 32, 43) is arranged in such a manner that it projects into the path (VK) of the lift cage (15, 35, 45) when the movable means (14, 14.1, 34, 44, 44.1) are brought into the normal setting and that the damping element (12, 32, 43) is constructed in such a manner that the lift cage (15, 35, 45) can be brought into mechanical contact with the damping element (12, 32, 43) and can be supported at a third spacing above the floor (18, 38, 48) which is less than the first predetermined spacing (Z1.1, Z3, Z4). 10. Lift installation according to claim 4, characterised in that a damping element (12, 32, 43) is arranged in such a manner that it projects into the path (VQ) of the counterweight (23) when the movable means (14, 14.1, 34, 44, 44.1) are brought into the normal setting and that the damping element (12, 32, 43) is constructed in such a manner that the counten^^eight (23) can be brought into a mechanical contact with the damping element (12, 32, 43) and can be supported at a fourth spacing above the floor which is smaller than the second predetermined spacing (Z1.2, Z3, Z4). 11. Lift installation according to claim 9, characterised in that the buffer (10, 30, 40) serves as an overrun protection which through the mechanical contact with the lift cage (15, 35, 45) brakes and stops the lift cage (15, 35, 45) when overrunning a lowermost stopping position in downward direction. 12. Lift installation according to claim 10, characterised in that it serves as an overrun protection which through the mechanical contact with the counterweight (23) brakes and stops the counterweight (23) in downward direction and thus brakes and stops the lift cage (15, 35, 45) when overrunning an uppermost stopping position in upward direction. 13. The lift installation according to any one of claims 1 to 12, characterised in that the lift cage (45), the counterweight (23) and the buffer (40) are arranged in a lift shaft (41) without a pit. 14. Method of creating a zone of protection in a lift installation with a buffer (10, 30, 40), which comprises movable means (14, 14.1, 34, 44, 44.1), and with a lift cage (15, 35, 45) which is so connected with a counterweight (23) that the lift cage (15, 35, 45) and the counterweight (23) are movable along paths (VK, VQ), wherein the method comprises the following steps: moving the movable means (14, 34, 44, 44.1) into the path (VK) of the lift cage (15, 35, 45) if there is a need for a zone of protection below the lift cage (15, 35, 45), wherein the zone of protection is created by a mechanical contact of the movable means (14, 34, 44, 44.1) with the lift cage (15, 35, 45), which ensures maintenance of a first predetermined spacing between the lift cage (15, 35, 45) and a floor (18, 38, 48), and moving the movable means (14.1, 34, 44, 44.1) into the path (VG) of the counterweight (23) if there is a need for a zone of protection above the lift cage (15, 35, 45), wherein the zone of protection is created by a mechanical contact of the movable means (14.1, 34, 44, 44.1) with the counterweight (23), which ensures maintenance of a second predetermined spacing between the counterweight (23) andthefloor(18, 38, 38). 15. The method according to claim 14, characterised in that it comprises the following step: movement of the movable means (14, 14.1, 34, 44, 44.1) out of the path (VK, VG) if there is no need for a zone of protection. 16. A lift installation with^ >)uffer substantially as herein described with reference to the accompanying drawings. ^ ^ Dated this 14 day of May 2004

Full Text

IP 1441
Lift installation with a buffer for creating a zone of protection in a lift installation and a method of creating a zone of protection
The subject of the invention is a lift installation with a buffer for creating a zone of protection. A method of creating a zone of protection is a further subject of the invention.
Lift installations are usually provided with one or more buffers which are arranged at the shaft floor of a lift shaft in order to stop the lift cage when overrunning the lowermost stopping position in the lift shaft in downward direction and/or when overrunning the uppermost stopping position in the lift shaft in upward direction after transit of a predetermined travel path. This buffer is usually seated below the lift cage and/or the countenA^eight.
In order to prevent overrunning of an uppermost stopping position in the lift shaft in upward direction at the latest after transiting a predetermined travel path, buffers can also be arranged at the shaft head above the lift cage. Due to the fact that such buffers have to be arranged at the shaft floor or shaft head directly below or above the lift cage, a specific space requirement results. The shaft head or the shaft floor can therefore only be conditionally utilised for other purposes. In the case of lift installations without a shaft pit, such a standard arrangement of a buffer is not possible, since little space is present underneath the lift cage.
A lift installation with a lift shaft, a vertically movable lift cage with counterweight and with buffers is described in PCT Patent Application WO 00/64798-A1. wherein the buffer is disposed not below the lift cage, but near the lift cage at the shaft floor. The lift cage is provided with brackets which impinge on the buffer if an overrun situation arises, i.e. if the lift cage goes beyond the lowermost stopping position at the lowermost storey in downward direction. The lift cage is thereby braked and stopped in a short distance above the shaft floor. An overrun protection against overrunning the uppermost stopping position of the lift cage in upward direction is not proposed in this PCT patent application. The lift installation has a shaft without a pit. A possibility of creating temporary zones of protection for carrying out maintenance and repair operations in the lift shaft at the shaft floor and/or at the shaft head is not disclosed.

There is frequently too little space due to constructional or other reasons for a conventional lift installation with a shaft pit and a shaft head. It may be observed that lift shafts without a lift pit and without a lift head are used particularly in the case of subsequent installation or addition of a lift installation in an already existing building. In the case of lift shafts of that kind, but also in the case of conventional lift shafts, there are situations in which it is necessary to create a zone of protection at the upper or lower shaft end. This is so, for example, when the lift installation has to be maintained or checked and when for this purpose an engineer has to go into the shaft.
It is important that a system for creating such a temporary zone of protection is safe. There are different proposed solutions for that purpose. The costs and the space requirement for such a system are a further criterion. In addition, a simple checking and maintenance of the system for creating a temporary zone of protection is important. The cost in assembly and the initial aligning of all parts of such a system are also a further criterion which has to be taken into consideration.
A lift installation with a lift shaft and a vertically movable lift cage with counterweight is described in European Patent Application EP 0 725 033-A1. Provided at the shaft base is a touch-down device which comprises a pivotable buffer able to be pivoted into the travel path of the lift cage. A zone of protection at the shaft base can thereby be created if needed. As a special form of embodiment there is proposed a combination of a shaft buffer, which is set up outside a path of a lift cage, with a rigid pivot lever pivotable into the path of the lift cage. The lift cage when hitting the pivot lever can thus be braked by the shaft buffer and supported above the shaft floor at a height which lies above the lowermost stopping position of the lift cage.
It is a disadvantage of this form of embodiment that it is indeed suitable for creating a zone of protection at the shaft floor, but does not offer any possibility of stopping overrunning of the lowermost stopping position of the lift cage in the lift shaft in downward direction after transiting a predetermined travel path. A possibility of creating a zone of protection at the shaft head is also not provided.
A lift installation with a lift shaft, a vertically movable lift cage with a counterweight and a movable support device is described in PCT Patent Application WO 02/051737-A1. The support device is arranged eccentrically at the shaft base between the lift cage and the

counterweight and can be moved into the path of the lift cage when necessary. The support device comprises a plate which is pivotably articulated to the shaft floor. If required, this plate is simply pivoted in the direction of the lift cage. Disposed at the lift cage is a buffer which impinges on the plate and stops the lift cage at a predetermined spacing from the shaft floor. A zone of protection at the shaft floor can thereby be created in the case of need. In order to be able to create a zone of protection in the region of the shaft head the lift cage comprises, according to the PCT patent application, a device which is fastened to the roof of the lift cage. This device can be pivoted up and moves against the shaft roof. A zone of protection is thus created at the upper end of the shaft. This PCT patent application is considered to the closest state of the art.
It is a disadvantage of this form of embodiment that for creating a zone of protection at the shaft head there is needed a device which is seated on the lift cage. The mass to be accelerated and moved is thereby increased.
The present invention has the object of providing a solution which makes it possible to create a zone of protection at the lower or at the upper end of a lift shaft in the case of need.
According to the invention this object is fulfilled by the features of claim 1 and the features of method claim 14.
Advantageous developments of the lift installation according to the invention are defined by the dependent claims 2 to 13. A development of the method according to the invention is indicated in claim 15.
The lift installation according to the invention comprises a buffer, which comprises movable means movable into the path of the lift cage and movable means movable into the path of the counterweight.
The movable means movable into the path of the lift cage and the movable means movable into the path of the counterweight can be realised as, for example, a single movable part which is so movable between different positions that it can be brought not only into the path of the lift cage, but also into the path of the counterweight. It is also possible to realise the movable means movable into the path of the lift cage and the

movable means movable into the path of the counten^/eight in each instance by different parts movable independently of one another. For example, a first movable part could be so arranged at the buffer that it is movable into the path of the lift cage and a second movable part could be so arranged at the buffer that it is movable into the path of the counterweight.
Consequently, the movable means can be brought into a use setting in which they are arranged in such a manner that the lift cage and/or the counterweight can be brought into a mechanical contact with the movable means. It is thereby made possible to be able to selectably support the lift cage or the counterweight in a first or a second predetermined spacing above a floor by a single buffer. The predetermined first spacing and the predetermined second spacing can be different depending on the respective arrangement and form of the buffer or the movable means. The lift cage and the counterweight can accordingly be supported at different heights.
In a normal setting of the movable means, the movable means are not disposed in the paths of the lift cage in the counterweight. Consequently, the space available for the lift cage is not restricted when the movable means are brought into the use setting. Due to the fact that selectably the lift cage or the counterweight can each be supported at a predetermined spacing above the floor, the path which the lift cage can travel over is shortened at both ends. Protective spaces are thus created at both ends of the path of the cage.
A further form of embodiment of the buffer according to the invention comprises a damping element which is arranged in such a manner that it projects into the path of the lift cage when the movable means are brought into the normal setting, wherein the damping element is constructed in such a manner that the lift cage can be brought into a mechanical contact with the damping element and can be supported at a third spacing above the floor which is smaller than the first predetermined spacing. This form of embodiment is also usable as an overrun protection, which brakes and stops the lift cage on overrunning a lowermost stopping position in downward direction.
One form of embodiment of the buffer according to the invention can comprise a damping element which is arranged in such a manner that it projects into the path of the counterweight when the movable means are brought into the normal setting, wherein the

damping element is constructed in such a manner that the counterweight can be brought into a mechanical contact with the damping element and can be supported at a fourth spacing above the floor which is smaller than the second predetermined spacing. This buffer can be used as an overrun protection which through mechanical contact with the counterweight brakes and stops the counterweight in downward direction and thus brakes and stops the lift cage on overrunning an uppermost stopping position in upward direction.
The buffer can be developed in such a manner that a damping element projects into the paths of the lift cage and the counterweight when the movable means are brought into the normal setting. Thus, solely through selection of the arrangement of a single buffer the lift cage can be prevented from overrunning a lowermost stopping position in downward direction and an uppermost stopping position in upward direction.
This form of embodiment is accompanied by the advantage that with a single buffer -depending on the respective selection of the setting of the movable means - the lift cage and/or the counterweight can each be supported at at least two different spacings above a floor. Such a buffer can, if suitably dimensioned, ensure, in a lift installation without a pit, an overrun protection against overrunning a lowermost stopping position of the lift cage in downward direction and against overrunning an uppermost stopping position of the lift cage in upward direction and additionally - in case of an appropriate setting of a movable means - enable creation of temporary protection spaces below and above the lift cage.
Details and advantages of the invention are described in the following on the basis of examples of embodiment with reference to the schematic drawings, in which:
Fig. 1A shows a schematic plan view of a first form of embodiment of a buffer
according to the invention, in a normal state;
Fig. 1B shows a schematic side view of the first form of embodiment of a buffer
according to the invention, in the normal state;
Fig. 1C shows a schematic plan view of the first form of embodiment of a buffer
according to the invention, in a use state;

Fig. 1D shows a schematic side view of the first form of embodiment of a buffer
according to the invention, in the use state, wherein a temporary zone of protection is created;
Fig. IE shows a schematic side view of an entire lift shaft with the first form of
embodiment of a buffer according to the invention, in the use state, wherein a counterweight is seated on the buffer and a zone of protection is created at the upper shaft end;
Fig. 1F shows a schematic side view of the lift shaft with the first form of
embodiment of a buffer according to the invention, in the normal state, wherein a countenA^eight is seated on the buffer and overrunning of an uppermost stopping position in upward direction is prevented;
Fig. 2A shows a schematic side view of a second form of embodiment of a buffer
according to the invention, in a normal state;
Fig, 2B shows a schematic side view of the second form of embodiment of a buffer
according to the invention, in the normal state;
Fig. 2C shows a schematic plan view of the second form of embodiment of a buffer
according to the invention, in a use state;
Fig. 2D shows a schematic side view of the second form of embodiment of a buffer
according to the invention, in the use state, wherein a temporary zone of protection is created at the shaft floor;
Fig. 3A shows a schematic plan view of a third form of embodiment of a buffer
according to the invention, in a normal state;
Fig. 3B shows a schematic side view of the third form of embodiment of a buffer
according to the invention, in the normal state, wherein the lift cage travelling downwardly beyond the lowermost stopping position is halted;

Fig. 3C shows a schematic plan view of the third form of embodiment of a buffer
according to the invention, in a use state; and
Fig. 3D shows a schematic side view of the third form of embodiment of a buffer
according to the invention, in the use state, wherein a temporary zone of protection is created.
Figures 1A to IF show a first form of embodiment of a lift cage with a buffer 10, according to the invention, in different schematic views and in different states. The illustrated buffer 10 is a buffer for supporting a lift cage 15 above the floor 18 of a lift shaft 11. The lift cage 15 is so connected with a counterweight 23 by way of a support means 23.1, for example one or more cables and/or one or more belts, that the lift cage 15 and the counterweight 23 are movable upwardly and downwardly along paths VK and VQ, respectively, in the lift shaft 11. The counterweight, support means, drive pulley for the support means, drive for the drive pulley, guide rails for the lift cage 15 and the counterweight and the other usual elements of a lift installation are not shown in Figures 1A to ID.
The buffer 10 has a longitudinal extent substantially parallel to the paths VK and VQ of the lift cage 15 and counterweight 23. It comprises a lower base element 12 and a more slender upper part 13. The buffer additionally comprises movable means 14 and 14.1 which can be moved out of the upper part 13, as indicated in Figures 1C, 1D and IE. In addition, there is provided a drive device (not illustrated) which makes it possible to move the means 14 and 14.1 in each instance between different settings. A control device (not illustrated), which acts on the drive device, makes it possible to check and monitor the positioning of the means 14 and 14.1.
The paths VK and VQ are indicated in Fig. IB and ID to IF by dashed lines. The buffer 10 is disposed at least partly between the path VK of the lift cage 15 and the path VG of the countenA^eight 23. For clarification, in Figs. 1A and 1C the projection K1 of the floor 15.1 of the lift cage 15 and the projection G1 of the underside 23.2 of the counterweight 23 are shown each projected onto the shaft floor. The projections K1 and G2 are illustrated by dashed lines in the regions in which they overlap the base area 12.1 of the base element 12 at the shaft floor 18.

The movable means 14 and 14.1 are, in the illustrated form of embodiment, constructed to be asymmetrical. The lefthand, trapezium-shaped part 14 projects laterally further out of the upper part 13 than the righthand trapezium-shaped part 14.1. In addition, the movable means 14 and 14.1 are moved to different heights above the shaft floor 18 through the paths VK and VQ: an upper part of the movable means 14 is arranged at a height Z1.1 and an upper part of the movable means 14.1 is arranged at a height Z1.2, wherein Z1.2 is greater than Z1.1 (Figs. 1D and 1E).
The buffer 10 is shown in Figures 1A and IB in a so-termed normal state. In the normal state of the buffer, the movable means 14 and 14.1 are disposed outside the paths VK and VG. The respective settings which the movable means 14 and 14.1 adopt in the normal state of the buffer are termed normal setting in the following.
Since in the normal state of the buffer 10 the upper part 13 of the buffer 10 does not project into the path VK of the lift cage 15, the lift cage 15 can move to the shaft door 17 of the lower storey without producing a mechanical contact with the buffer 10. In the situation shown in Fig. IB, boarding and disembarkation can take place through the cage door 16 and the shaft door 17.
The buffer 10 is illustrated in a so-termed use state in Figures 1C, ID and 1E. In a use state of the buffer the movable means 14 is brought into the path VK and/or the movable means 14.1 is brought into the path VQ, i.e. the movable means 14 and/or the movable means 14.1 is or are disposed in the respective use setting thereof. If the movable means 14 is in its use setting, the lift cage 15 can be brought into a mechanical contact with the means. If the movable means 14.1 is in its use setting, the countenA/eight 23 can be brought into mechanical contact with the means 14.1.
If the movable means 14 is brought into its use setting and the buffer 10 is thus disposed in use state, then a mechanical contact of the lift cage 15 with the movable means 14 of the buffer 10 takes place as soon as the lift cage 15 has fallen below a first predetermined spacing, in the present case the spacing Z1.1, with respect to the floor 18. In the case of the illustrated form of embodiment, the lift cage 15 sits by a lower edge on the movable means 14, as shown in Fig. 1D.

The buffer 10 together with the movable means 14 and 14.1 is so constructed and arranged that a mechanical contact with the counterweight 23 also takes place when the movable means 14.1 is brought into its use setting and the buffer 10 is thus in the use setting and the counterweight 23 falls below the predetermined spacing Z1.2 with respect to the floor 18. The counterweight 23 is not visible in Figures 1A to ID, since it is disposed at the upper shaft end when the lift cage 15 is disposed at the lower shaft end.
Since the lift shaft 11 is a shaft without shaft pit, a zone of protection in the region of the lower shaft end must be able to be created in the case of need. For creating the zone of protection, the buffer 10 is transferred from the normal state to the use state, wherein this takes place in that the movable means 14 is moved out of the upper part 13. The lift cage 15 can now move downwardly until it settles on the movable means 14 and is supported by the buffer 10 at the spacing Z1.1 with respect to the floor 18. In this manner a zone of protection is created below the lift cage 15. The shaft door 17 is arranged in such a manner that a person can enter and/or leave the zone of protection by opening of the shaft door 17. The spacing Z1.1 ensures sufficient distance from the floor 18 in order to enable safe and problem-free working in the zone of protection.
A temporary zone of protection in the region of the upper shaft end can also be created by the buffer 10. That is shown in Fig. IE. A schematic longitudinal section through the entire lift shaft 11 is shown in this figure. The lift shaft 11 has four, or more than four, storeys. A shaft door 17 is indicated at the level of each of the storeys. The countenA/eight 23 moves in opposite sense to the lift cage 15 in the lift shaft 11. If the lift cage is disposed at the upper shaft end, then the countenA/eight 23 is disposed at the lower shaft end. In order to create a zone of protection at the upper shaft end, the counterweight is prevented from falling below the spacing Z1.2 relative to the floor 18. As soon as the countenA/eight 23 is seated on the movable means 14.1, the lift cage 15 is also held at a fixedly predetermined spacing from the shaft head. A zone of protection at the upper shaft end thereby results.
It is possible to so construct the buffer 10 that the base element 2 also acts as a damping element. In this case, the base element 12 absorbs the kinetic energy of the lift cage 15 or the kinetic energy of the countenA/eight 23 and brakes the lift cage 15 or the countenA/eight 23 when the lift cage 15 and/or the counterweight 23 comes or come into mechanical contact with the buffer 10. This applies not only to the case that the lift cage 15 and/or the

counterweight 23 is or are seated directly on the base element 12, but also to the case that the lift cage 15 or the counterweight 23 is seated on the movable means 14 or 14.1.
If overrunning of the lowermost stopping position of the lift cage 15 in downward direction takes place, a lower edge of the lift cage 15 seats on the base element 12, as is evident from Fig. IB. The base element 12 acting as a damping element absorbs the kinetic energy of the lift cage 15 and brakes the lift cage 15 until this comes to a stop. In this form of embodiment the buffer 10 can serve not only for creation of zones of protection, but also as an overrun protection.
The form of embodiment of Figures 1A to IF is distinguished by the fact that it not only prevents overrunning of the lowermost stopping position of the lift cage 15 in downward direction, but that also an overrunning of the uppermost stopping position of the lift cage 15 in upward direction is arrested. This "emergency case" is illustrated in Fig. IF. A schematic longitudinal section through the entire lift shaft 11 is shown in this figure. The buffer 10 is set in the normal state. Overrunning of the uppermost stopping position of the lift cage 15 in upward direction is now stopped in that the counterweight 23 mechanically interacts with the base element 12 of the buffer 10. Due to the braking and stopping of the counterweight 23 by the buffer 10, the lift cage 15 is prevented from travelling further upwards.
In another form of embodiment the drive unit of the lift installation is seated in or directly under the base element 12. In this case the base element would look different in plan view (Figs. 1A and IB). For example, in this case the drive pulley, which is driven by the drive unit, for the support cable would be arranged at the base element 12.
It is an advantage of the present invention that it provides different functions with the smallest number of elements and with little space requirement.
The base element 12 does not necessarily have to project into the paths VK and VQ if the buffer 10 is to be used exclusively as a device for the creation of protective spaces and does not additionally have to serve as an overrun protection for the lift cage. In this case, the lift cage 15 and the counterweight 23 could not be brought into a mechanical contact with the buffer 10 if the movable means 14 and 14.1 adopt the normal setting. In this case an overrun protection could be realised in that additional buffers, which separately act on

the lift cage 15 and/or the counterweight 23 and the dimensions of which are matched to the position of the lowermost and/or the uppermost stopping position of the lift cage 15, are installed in the lift shaft 11.
Figures 2A to 2D show - as a second form of embodiment of the invention - a lift installation with a buffer 30 in different schematic views and in different states. The illustrated buffer 30 is a buffer for supporting a lift cage 35 above a floor 38 of a lift shaft 31. The buffer serves as an overrun protection and as means for creation of a temporary zone of protection. The lift cage 35 is so connected with a counterweight that the lift cage 35 is movable upwardly and downwardly along a path VK, and the counterweight upwardly and downwardly along a path VQ, in the lift shaft 31. The counterweight, support means for the lift cage 35 and the counterweight, drive pulley, guide rails and other usual elements of a lift installation are not shown in Figures 2A to 2D. The buffer 30 has a longitudinal extent substantially parallel to the paths VK and VQ of the lift cage 35 and the counterweight. The buffer 30 is so constructed and arranged that it projects at least partly into the path VK of the lift cage and the path VQ of the counterweight.
The buffer 30 comprises a lower base element 32, which is designed as a stronger damper, and a more slender upper part 33, which is designed as a weaker damper. The buffer 30 comprises movable means 34 which are seated on the upper part 33 and can be rotated between different settings, as indicated in Figures 2B and 2D. The movable means 34 are symmetrically constructed in the case of the illustrated form of embodiment, i.e. they project out by equal amounts on both sides beyond the upper part 33.
The buffer 30 is shown in Figures 2A and 2B in a so-termed normal state. In this case, the movable means 34 is disposed in its normal setting, i.e. it does not project into the paths VK and VQ. In Figures 2C and 2D the buffer 30 is illustrated in a so-termed use state. In this case, the movable means 34 is disposed in its use setting, i.e. it projects into the paths VK and VQ. The buffer 30 is disposed at least partly between the path VK of the lift cage 35 and the path VQ of the counterweight. For clarification, in Figures 2A and 2C the projection K3 of the lift cage 35 and the projection G3 of the counterweight are shown in each instance projected onto the shaft floor. The projections K3 and G3 are illustrated by dashed lines in the regions in which they overlap the base area 32.1 of the base element 32 at the shaft floor 38.

In the use state, a mechanical contact of the lift cage 35 with the movable means 34 of the buffer 30 takes place as soon as the lift cage 35 has fallen below a first predetermined space Z3 with respect to the floor 38. In the case of the illustrated form of embodiment, the lift cage 35 is seated by a lower edge on the movable means 34, as shown in Fig. 2D. A temporary zone of protection in the region of the lower shaft end can thereby be created in the case of need.
The buffer 30 with the movable means 34 is so constructed and arranged that in the use state a mechanical contact with the counterweight also takes place when the counterweight falls below the predetermined spacing Z3 with respect to the floor 38. The counterweight is not visible in Figures 2A to 2D, since it is disposed at the upper shaft end when the lift cage 35 is disposed at the lower shaft end.
The buffer 30 is shown in normal state in Fig. 2B. Since the upper part 33 of the buffer 30 does not project into the path of the lift cage, the lift cage 35 can travel to the shaft door 37 of the lower storey without producing a mechanical contact with the buffer 30. In the situation shown in Fig. 2B, boarding or disembarkation can take place via the cage door 36 and the shaft door 37 when the lift cage adopts the lowermost stopping position at the lowermost storey.
If overrunning of the lowermost stopping position of the lift cage 35 in downward direction (not shown in Figures 2A to 2D) now occurs, then a mechanical contact of the lift cage with the base element 32, which is designed as a stronger damper, of the buffer 30 takes place as soon as the lift cage 35 has fallen below a predetermined spacing Z3.1 with respect to the floor 38. In the case of the illustrated form of embodiment the lift cage 35 is then seated by a lower edge on the base element 32. The lift cage 35 can thereby be braked and stopped in the "emergency case".
For creation of a zone of protection, the buffer 30 is transferred from the normal state to the use state, wherein this takes place in that the movable means 34 are rotated about an axis of rotation which is aligned substantially parallel to the path VK of the lift cage 35 or to the path VG of the counterweight. The respective setting of the movable means is controlled by means of a drive and a control device acting on the drive. The drive and the control device are not illustrated in the figures. The lift cage 35 can be moved downwardly until it settles on the movable means 34. In this manner a zone of protection is created

below the lift cage 35. A shaft door 37 is arranged in such a manner that a person can enter and/or leave the zone of protection by opening of the shaft door 37. The spacing Z3 ensures sufficient distance from the floor 38 in order to enable a safe and problem-free working in the zone of protection.
Since in the illustrated form of embodiment there is concerned a lift installation with a shaft pit and since the base element 32 has a longitudinal extent H3, there is created every time a flat zone of protection into which the lift cage 35 cannot penetrate. Even if due to a fault or due to erroneous operation the necessary changeover into the use state is not carried out, a person in the lift shaft cannot be crushed, since a minimum spacing is always given by the height H3 of the base element 32.
The base element 32 and/or the lower part 33 has or have a length in the direction of the path VK or VG dependent on the mechanical loading thereof. The load-dependence of this extent substantially determines the capability of the base element 32 or of the upper part 33 of braking and stopping the lift cage or the counterweight when impinging on the buffer 30. In order to indicate the loading of the buffer 30 by the lift cage 35, in Fig. 2D the length of the buffer 30 in the direction of the path VK is illustrated reduced by a distance AZ by comparison with the spacing Z3. In analogous manner the extent of the buffer 30 in the direction of the path VQ is reduced by a height below the spacing Z3 when the countenA/eight loads the buffer 30.
A temporary zone of protection in the region of the upper shaft end can also be created by the buffer 30. This state is not, however, shown in Figures 2A to 2D. In order to create a zone of protection at the upper shaft end, the movable means 34 are moved into the path VG of the counterweight and the counterweight is supported by the buffer 30 as soon as the counterweight falls below the spacing Z3 from the floor 38. As soon as the counterweight is seated on the righthand side of the movable means 34, the lift cage 35 is also held at a fixedly predetermined spacing from the shaft head. A zone of protection at the upper shaft end thereby results.
Figures 3A to 3D show - as a third form of embodiment of the invention - a lift installation with a buffer 40 in different schematic views and in different states. The illustrated buffer 40 is a buffer for supporting a lift cage 45 above a floor 48 of a lift shaft 41. The buffer serves as overrun protection and as means for creating a temporary zone of protection in

a lift installation without a pit, i.e. in a lift installation in which the lowermost stopping level of the lift cage lies at such a short distance above the floor that no space for a shaft pit is present. The lift cage 45 is so connected with a counterweight that the lift cage 45 and the counterweight are movable upwardly and downwardly along paths in the lift shaft 41. The countenA^eight, support means for the lift cage 45 and the counterweight, drive pulley, guide rails and other usual elements of a lift installation are not shown in Figures 3A to 3D. The buffer 40 has a longitudinal extent substantially parallel to the paths of the lift cage 45 and the counterweight. The buffer 40 is so constructed and arranged that it projects at least partly into the path of the lift cage and into the path of the counterweight, depending on the respective state.
The buffer 40 comprises a lower base element 43, which is constructed as a stronger damper, and movable means 44, which are seated on the base element 43 and can be rotated, as indicated in Figures 3C and 3D. The movable means 45 are symmetrically constructed in the case of the illustrated form of embodiment, i.e. they project out by equal amounts on both sides beyond the base element 43. The movable means 44 comprise dampers 44.1, which are seated in recesses of the movable means 44.
The buffer 40 is shown in Figures 3A and 3B in a so-termed normal state. In this case the movable means 44 and 44.1 are disposed in their normal setting, i.e. they do not project into the paths of the lift cage 45 and the counterweight. The buffer 40 is illustrated in a so-termed use state in Figures 3C and 3D. In this case the movable means 44 and 44.1 are disposed in their use setting, i.e. they project into the paths of the lift cage 45 and the counterweight. The buffer 40 is disposed at least partly between the path of the lift cage and the path of the counterweight. For clarification, the projection K4 of the floor 45.2 of the lift cage 45 and the projection G4 of the underside of the counterweight are shown in Figures 3A and 3C.
In the use state, a mechanical contact with the lift cage 45 with the damper 44.1 of the buffer 40 takes place as soon as the lift cage 45 falls below a first predetermined spacing Z4 with respect to the floor 48. In the case of the illustrated form of embodiment the lift cage 45 is seated by a lower edge on the damper 44.1, as shown in Fig. 3D. The buffer 40 is thus eccentrically loaded. A temporary zone of protection can thereby be created in the region of the lower shaft end in the case of need.

The buffer 40 with the movable means 44, 44.1 is so constructed and arranged that in the use state a mechanical contact with the counterweight also takes place when the counterweight falls below the predetermined spacing Z4 with respect to the floor 48. The countenA^eight is not visible in Figures 3A to 3D, since it is disposed at the upper shaft end when the lift cage 45 is disposed at the lower shaft end.
The buffer 40 is shown in normal state in Fig. SB. Since in the normal state the movable means 44, 44.1 of the buffer 40 do not project into the path of the floor 45.2 of the lift cage 45, the lift cage 45 can travel to the shaft door 47 of the lower storey without producing a mechanical contact with the buffer 40. It is mentioned that in the illustrated state a spacing D between a bracket 45.1 (buffer abutment), which is fastened to the lift cage 45, and the movable means 44.1 exists. In the situation shown in Fig. SB, boarding or disembarkation can take place via the cage door 46 and the shaft door 47.
If overrunning of the lowermost stopping position of the lift cage 45 in downward direction (not shown in Figures SA to 3D) now occurs, then a mechanical contact of the bracket 45.1, which is fastened to the lift cage 45, with the means 44 or with the base element 43, which is constructed as a stronger damper, of the buffer 40 takes place. The lift cage 45 can thereby be braked and stopped in the "emergency case". It may be noted that in the case of overrunning the lowermost stopping position of the lift cage 45 the damper 44.1 does not come into use, since the bracket 45.1 produces direct contact with the means 44. The buffer 40 is thus centrally loaded in such an "emergency case".
If the movable means 44 and 44.1 adopt the normal setting, then an overrunning of the uppermost stopping position of the lift 45 in upward direction is prevented in that a bracket or another protruding element at the side of the counten/veight facing the shaft door 47 produces a contact with the movable means 44 of the buffer 40. This, too, leads to a central loading of the buffer 40.
For clarification, a projection K4.1 of the bracket 45.1 and a projection G4.1 of the said bracket or of the protruding element at the counterweight, each projected onto the shaft floor, are illustrated in Figs. 3A and 3C in each instance by dashed lines.
For creation of a zone of protection, the buffer 40 is transferred from the normal state to the use state, wherein this takes place in that the movable means 44 are rotated into the

paths of the floor 45.2 of the lift cage 45 and the underside of the counterweight (Figs. 3C and 3D). The necessary changeover can be triggered by, for example, a (key-operated) switch or in electronically controlled manner. In order to create the temporary zone of protection, the lift cage 45 is moved slowly downwardly until it settles on the damper 44.1. A person can enter and/or leave the zone of protection by opening of the shaft door 47. The spacing Z4 guarantees sufficient distance from the floor 48 in order to enable a safe and problem-free working in the zone of protection.
A temporary zone of protection in the region of the upper shaft end can also be created by the same buffer 40. However, this state is not shown in Figures 3A to 3D. In order to create a zone of protection at the upper shaft end, the counterweight is prevented from falling below the spacing Z4 from the floor 48. As soon as the counterweight is seated on the damper 44.1 on the righthand side of the movable means 44, the lift cage 45 is also held at a fixedly predetermined spacing from the shaft head. A zone of protection at the upper shaft end thereby results.
As indicated in Figures 1D and 1E, the lift cage and the counterweight do not have to be supported at the same height. The form of embodiment according to Figs. 2A to 2D and 3A to 3D can be appropriately modified by a suitable adaptation of the shapes of the movable means 34 and 44 or 44.1.
According to the invention the buffer can have a damping characteristic which is specially matched to the case of use. In the case of the third form of embodiment, dampers 44.1 are used which enable a lightly damped seating of the lift cage 35 or of the counterweight on the movable means 44 when a zone of protection is to be created. The movable means 44 are thus treated gently in operation. If the lift cage and/or the counterweight impinges or impinge at high speed on the respective buffer - particularly during overrunning beyond the lowermost or the uppermost stopping position of the lift cage -then, thereagainst, the damping characteristics of the base elements 12, 32 and 43 come into use.
The buffer according to the invention can be equipped with special means which allow an asymmetrical loading without the buffer "collapsing" or "deflecting". For this purpose the buffer can be surrounded entirely or partly by a corset-like element or be guided by a

special means in order to provide compensation for the bending moments arising due to the eccentric buffer loading.
In the case of a part of the form of embodiments the buffer is arranged completely between the lift cage and the counterweight (see, for example, Fig. 3A).
In the case of a further form of embodiment the buffer element can be arranged entirely or partly below the counterweight and act directly on the countenA^eight. A movable means of the buffer element then correspondingly acts on the lift cage in the case of need.
The cross-section of the buffer can be selected as desired. The buffers 10 and 30 have a substantially round cross-section parallel to the floor of the lift shaft. The buffer 40, thereagainst, has, for example, a square cross-section in the lower region 43.
Movement of the movable means of the buffer can take place electromagnetically, hydraulically, pneumatically, manually or by means of a setting motor, depending on the respective form of embodiment.
In a further form of embodiment there is used a pit set which comprises a drive/frequency-converter unit, a speed limiter, a fastening for the guide rails and the buffer. Assembly in the lift shaft is thereby appreciably simplified.
The present invention is also suitable for use in a lift installation in cantilever disposition.
Through the special arrangement and construction of the buffer there results a reduced space requirement by comparison with conventional solutions.
The invention is particularly suitable for use in lift shafts which have no or only small shaft pit and shaft head height dimensions.
It is an advantage of the invention that regulations for fulfilment of personal protection are maintained and the constructional costs and installation costs, depending on the respective form of embodiment, can be substantially reduced.

The movable means 14, 14.1, 34, 44 and 44.1 can be modified in different ways within the scope of the invention. They can be replaced by means which are foldable, pivotable, slidable and/or rotatable out of a basic setting and movable in each instance into the path or paths of the lift cage and/or the counterweight in order to support the lift cage and/or the counterweight at a spacing above the floor. The movable means can also be so constructed by a suitable arrangement that the lift cage and the counterweight can in each instance be supported at different heights. The can be of multi-part or also of integral construction.

Patent Claims
1. Lift installation with a buffer (10, 30, 40) for creating at least one zone of protection, wherein the lift installation comprises a lift cage (15, 35, 45) and a countenA/eight (23) for the lift cage and the lift cage (15, 35, 45) and the counterweight (23) are movable along paths (VK, VG), characterised in that the buffer (10, 30, 40) comprises movable means (14, 14.1, 34, 44, 44.1) which are movable into the path (VK) of the lift cage (15, 35, 45) and movable means (14.1, 34, 44, 44.1) movable into the path (VG) of the counteoA^eight (23).
2. Lift installation according to claim 1, characterised in that the movable means (14, 34, 44, 44.1) can be brought into a use setting in which they are arranged in such a manner that a mechanical contact takes place between the movable means (14, 34, 44, 44.1) and the lift cage (15, 35, 45) when the lift cage (15, 35, 45) falls below a first predetermined spacing (Z1.1, Z3, Z4) with respect to a floor (18, 38, 48) and/or that a mechanical contact takes place between the movable means (14.1, 34, 44, 44.1) and the counterweight (23) when the counterweight (23) falls below a second predetermined spacing (Z1.2, Z3, Z4) with respect to a floor (18, 38, 48).
3. Lift installation according to claim 2, characterised in that the movable means (14, 14.1, 34, 44, 44.1) starting from the use setting are movable out of the path (VK) of the lift cage (15, 35, 45) and/or the path (VG) of the countenA/eight (23).
4. Lift installation according to claims 2 and 3, characterised in that the movable means (14, 14.1, 34, 44, 44.1) can be brought into a normal setting in which they are arranged in such a manner that no mechanical contact takes place between the movable means (14, 34, 44, 44.1) and the lift cage (45) when the lift cage (15, 35, 45) falls below the first predetermined spacing (Z1.1, Z3, Z4) with respect to the floor (18, 38, 48) and that no mechanical contact takes place between the movable means (14.1, 34, 44, 44.1) and the counterweight (23) when the countenA/eight (23) falls below the second predetermined spacing (Z1.2, Z3, Z4) with respect to the floor (18, 38, 48).
5. Lift installation according to claim 3, characterised in that the movable means (14, 34^ 44^ 44.1) in the use setting are arranged in such a manner that the mechanical contact between the movable means (14, 34, 44, 44.1) and the lift cage (15, 35, 45) can be realised in such a manner that the lift cage (15, 35, 45) is supported above the floor (18,

38, 48) and a zone of protection exists between the floor (18, 38, 48) and the lift cage (15, 35, 45).
6. Lift installation according to claim 3, characterised in that the movable means (14.1, 34, 44, 44.1) in the use setting are arranged in such a manner that the mechanical contact between the movable means (14.1, 34, 44, 44.1) and the counterweight (23) can be realised in such a manner that the countenA/eight (23) is supported above the floor (18, 38, 48).
7. Lift installation according to claim 6, characterised in that the lift cage (15, 35, 45) together with the counterweight (23) is connected by way of a carrier means (23.1) of such a length, and the counterweight (23) can be supported above the floor at such a height, that a zone of protection exists above the lift cage (15, 35, 45), wherein this zone of protection is preferably disposed between an upper region of the lift cage (15, 35, 45) and an upper end of a lift shaft (11, 31, 41).
8. Lift installation according to one of claims 1 to 7, characterised in that the buffer (10, 30, 40) has an appropriate damping characteristic in order to enable a soft settling when a mechanical contact with the lift cage (15, 35, 45) or with the counterweight (23) takes place and/or that at least an upper part (13, 33, 43) of the buffer (10, 30, 40) is disposed between an area projection (K1, K3, K4) of the lift cage (15, 35, 45) and an area projection (G1, G3, G4) of the counterweight (23) and/or that the movable means (14, 14.1, 34, 44, 44.1) are means which can be folded out, pivotable means, slidable means or rotatable means.
9. Lift installation according to claim 4, characterised in that a damping element (12, 32, 43) is arranged in such a manner that it projects into the path (VK) of the lift cage (15, 35, 45) when the movable means (14, 14.1, 34, 44, 44.1) are brought into the normal setting and that the damping element (12, 32, 43) is constructed in such a manner that the lift cage (15, 35, 45) can be brought into mechanical contact with the damping element (12, 32, 43) and can be supported at a third spacing above the floor (18, 38, 48) which is less than the first predetermined spacing (Z1.1, Z3, Z4).
10. Lift installation according to claim 4, characterised in that a damping element (12, 32, 43) is arranged in such a manner that it projects into the path (VQ) of the counterweight

(23) when the movable means (14, 14.1, 34, 44, 44.1) are brought into the normal setting and that the damping element (12, 32, 43) is constructed in such a manner that the counten^^eight (23) can be brought into a mechanical contact with the damping element (12, 32, 43) and can be supported at a fourth spacing above the floor which is smaller than the second predetermined spacing (Z1.2, Z3, Z4).
11. Lift installation according to claim 9, characterised in that the buffer (10, 30, 40) serves as an overrun protection which through the mechanical contact with the lift cage (15, 35, 45) brakes and stops the lift cage (15, 35, 45) when overrunning a lowermost stopping position in downward direction.
12. Lift installation according to claim 10, characterised in that it serves as an overrun protection which through the mechanical contact with the counterweight (23) brakes and stops the counterweight (23) in downward direction and thus brakes and stops the lift cage (15, 35, 45) when overrunning an uppermost stopping position in upward direction.
13. The lift installation according to any one of claims 1 to 12, characterised in that the lift cage (45), the counterweight (23) and the buffer (40) are arranged in a lift shaft (41) without a pit.
14. Method of creating a zone of protection in a lift installation with a buffer (10, 30, 40), which comprises movable means (14, 14.1, 34, 44, 44.1), and with a lift cage (15, 35, 45) which is so connected with a counterweight (23) that the lift cage (15, 35, 45) and the counterweight (23) are movable along paths (VK, VQ), wherein the method comprises the following steps:
moving the movable means (14, 34, 44, 44.1) into the path (VK) of the lift cage (15, 35, 45) if there is a need for a zone of protection below the lift cage (15, 35, 45), wherein the zone of protection is created by a mechanical contact of the movable means (14, 34, 44, 44.1) with the lift cage (15, 35, 45), which ensures maintenance of a first predetermined spacing between the lift cage (15, 35, 45) and a floor (18, 38, 48), and
moving the movable means (14.1, 34, 44, 44.1) into the path (VG) of the counterweight (23) if there is a need for a zone of protection above the lift cage (15, 35, 45), wherein the zone of protection is created by a mechanical contact of the movable means (14.1, 34, 44, 44.1) with the counterweight (23), which ensures

maintenance of a second predetermined spacing between the counterweight (23) andthefloor(18, 38, 38).
15. The method according to claim 14, characterised in that it comprises the following step: movement of the movable means (14, 14.1, 34, 44, 44.1) out of the path (VK, VG) if there is no need for a zone of protection.

16. A lift installation with^ >)uffer substantially as herein described with reference to the
accompanying drawings. ^ ^
Dated this 14 day of May 2004

Documents:

460-CHE-2004 AMENDED PAGES OF SPECIFICATION 12-03-2013.pdf

460-CHE-2004 AMENDED CLAIMS 12-03-2013.pdf

460-CHE-2004 EXAMINATION REPORT REPLY RECEIVED 12-03-2013.pdf

460-CHE-2004 FORM-3 12-03-2013.pdf

460-CHE-2004 OTHER PATENT DOCUMENT 12-03-2013.pdf

460-CHE-2004 CORRESPONDENCE OTHERS 10-09-2012.pdf

460-CHE-2004 POWER OF ATTORNEY 12-03-2013.pdf

460-che-2004-abstract.pdf

460-che-2004-claims.pdf

460-che-2004-correspondnece-others.pdf

460-che-2004-description(complete).pdf

460-che-2004-drawings.pdf

460-che-2004-form 1.pdf

460-che-2004-form 26.pdf

460-che-2004-form 3.pdf

460-che-2004-form 5.pdf

460-che-2004-other documents.pdf

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Patent Number

256140

Indian Patent Application Number

460/CHE/2004

PG Journal Number

19/2013

Publication Date

10-May-2013

Grant Date

08-May-2013

Date of Filing

14-May-2004

Name of Patentee

INVENTIO AG

Applicant Address

SEESTRASSE 55, CH-6052 HERGISWIL, SWITZERLAND

Inventors:

#	Inventor's Name	Inventor's Address
1	KOCHER, JOHANNES	SONNMATT 12, CH-6044 UDLIGENSWIL, SWITZERLAND
2	HUBER, MARCEL	SCHACHENWEIDSTRASSE 8, CH-6030 EBIKON, SWITZERLAND

PCT International Classification Number

B66B5/28

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	03 405 352.0	2003-05-21	EUROPEAN UNION