Title of Invention	A VALVE MEANS WITH A SOFTSTART FUNCTION
Abstract	A valve means (6) has a softstart valve (21) to provide a softstart function. The softstart valve (21) has principal valve means (25) which are in a position to selectively open or close the connection between a primary duct (4) at a primary pressure and a secondary duct (1). Besides, the softstart valve is in a position to cause a soft start pressure, which is at least initially below the primary pressure, in the secondary duct (1), such softstart pressure obtaining in a softstart duct (25). A control slide (33) of the principal valve means (25) is in position of controlling the connection of the secondary duct (1) both with the softstart duct (2) and also with the primary duct (4) and possesses a drive face (57), which is acted upon by the softstart pressure for switching over the control slide (33). Figure 2.

Title of Invention

A VALVE MEANS WITH A SOFTSTART FUNCTION

Abstract

A valve means (6) has a softstart valve (21) to provide a softstart function. The softstart valve (21) has principal valve means (25) which are in a position to selectively open or close the connection between a primary duct (4) at a primary pressure and a secondary duct (1). Besides, the softstart valve is in a position to cause a soft start pressure, which is at least initially below the primary pressure, in the secondary duct (1), such softstart pressure obtaining in a softstart duct (25). A control slide (33) of the principal valve means (25) is in position of controlling the connection of the secondary duct (1) both with the softstart duct (2) and also with the primary duct (4) and possesses a drive face (57), which is acted upon by the softstart pressure for switching over the control slide (33). Figure 2.

Full Text	--A VALVE MEANS WITH A SOFTSTART FUNCTION-- The invention relates to a valve means with a softstart function comprising a softstart valve having principal valve means able to selectively shut off the connection between a primary- duct siibject to the primary pressure and a secondary duct in a closed position biased by a biasing force or to open up such connection in an open position, the principal valve means being able to be siobjected to the softstart pressure for switching over into the open position and the softstart valve is furthermore capable, when the primary duct is separated, of connecting the secondary duct with a softstart duct, which is subjected or able to be subjected to a softstart pressure which is at least initially less than the primary pressure owing to choke means. A valve means of this type disclosed in the German patent publication DE 91 05 458 Ul comprises a softstart valve with principal valve means constituted by a 2/2 directional valve, such valve means being biased by fluid action and by spring force into a closed position, in which they shut off the primary duct from the secondary duct. In addition to these principal valve means there is a 3/2 directional valve which is able to connect, while bypassing the 2/2 directional valve, the secondary duct with a softstart duct, in which owing to an associated choke means a lower pressure termed the softstart pressure may obtain than in the primary duct. The softstart pressure is, on operation of the 3/2 directional valve, supplied not only to the secondary duct but also simultaneously to the principal valve means, which accordingly are urged toward their open position. On operation of the 3/2 directional valve the secondary duct is consequently supplied with pressure medium at the softstart pressure and owing to the softstart pressure' gradually increasing after a certain time the principal valve means are switched over into the open position so that the secondary duct is supplied at the full flow rate from the primary duct. A valve means operating in a similar fashion is described in the German patent publication DE 20 2004 015 468 Ul. Here as well the softstart valve has two separate valve units to implement the softstart function. The Geiman patent publication DE 1 283 627 B discloses a control valve which in order to avoid having control abutments entails a gradual build up of fluid pressure in of working ducts, which are connected with a load. For this purpose the control slide is driven to perform a switch over movement with a varying speed, choke slots being employed to ensure that at particular transition positions of the control slide there is merely a choked admission of fluid to the working ducts. One object of the present invention is to create a valve means which provides for an economic and compact softstart function. To attain this aim there is a provision such that the principal valve means comprise a control slide which is able to be set in different positions and which is able to control the connection of the secondary duct both with the softstart duct and also with the primary duct and is kinematically coupled with a drive face able to be acted upon by the softstart pressure oppositely to the biasing force also acting on it. While in the prior art to implement the softstart function in addition to the principal valve means at least one further separate valve unit is required, in the present invention the principal valve means alone are responsible for the control of the secondary duct with a gradually waxing pressure level. A single control slide of the principal valve means is in a position of controlling the connection of the secondary duct both with the softstart duct and also with the primary duct and accordingly in a position termed the softstart position to• render possible a choked flow rate and in a position teimed the working position to ensure the full rate at the primary V pressure. The control slide is switched over by the softstart pressure applied by it by means of a drive face, the softstart pressure that goes up during operation owing to the gradual filling of the secondary duct until it reaches a level causing a switch over into the working position. Owing to the concentration of the valve means responsible for the softstart function in a single valve unit the softstart valve may be designed in an extremely compact and economic fashion. There is in addition the possibility of so configuring the softstart valve that it may also be integrated in a valve cluster fitted with several control valves, in particular by the installation on a component mounting face of a fluid distributor in lieu of a control valve or alongside one. If required it is even possible for the housing of control valve to be employed for the design of the softstart valve so that the individual components may be employed more than once, something which further reduces the costs for manufacture and stock holding. Further advantageous developments of the invention are defined in the dependent claims. The valve means may be so designed that the control slide in one working position connects not only the primary duct but furthermore the softstart duct with the secondary duct. The softstart duct therefore need not be separated and may communicate in parallel to the primary duct with the secondary duct. This will as a rule amount to a simplification the design of the softstart valve. A particular advantage arises if the control slide is able to be positioned in a venting position in addition to the softstart position and the working position in which it connects the secondary duct with a venting duct communicating with the atmosphere. In this venting position it is only as regards the primary duct that there is a closed position, since the primary duct is separated both from the secondary duct and also from the softstart duct. Accordingly using the softstart I. valve it is possible to perform a simple venting operation for the secondary duct and any load connected with it. Venting takes place preferably using the control slide. It has for this purpose a transfer duct communicating in the venting position on the one hand with the secondary duct and on the other hand with the venting duct. The passage through the transfer duct is preferably again separately controlled by a valve member arranged in the control slide. The same may obturate the transfer duct, when the control slide assumes a position in which emergence of fluid is undesired. The valve member may be piston-like and in the closed position contact an abutment preferably constituted by an associated valve seat so that it may apply a setting force to the control slide, when for the purpose of switching over of the control slide it is subjected to a control pressure at the rear. The choke means responsible for the at least initially reduced softstart pressure are preferably designed to be adjustable as regards the intensity of the choking action. The means may be a regular component of the softstart valve or be located in a feed duct leading to the softstart duct of the softstart valve of a further component of the valve means, for example in a fluid distributor, if the softstart valve is fitted on or in same. The drive face, preferably arranged directly on the control slide, may delimit a drive space, able to be subjected to the softstart pressure in the housing of the softstart valve. The softstart pressure is preferably supplied to the drive space by way of at least one control duct extending at least in portions thereof in the control slide, and the control duct is connected both in the softstart position and also in the working position with the softstart duct or also with secondary duct, which is at the same pressure. Accordingly a constant maintenance of a setting force acting on the control V slide contrary to the biasing force is ensured. The drive space is best arranged between the drive face associated with the control slide and an abutment piston lying opposite to it and able to be set in relation to the control slide and furthermore also in relation to the valve housing. Owing to the cooperation with the valve housing it delimits the stroke travel of the control slide to set the softstart position. During the following increase in the softstart pressure switched to the drive space it will keep to its position, which is stationary in relation to the valve housing, and will render possible setting of the control slide until a limitation of the stroke travel is caused by associated abutment means, such stroke limitation setting the working position of the control slide. In the follow the invention will be described on the basis of the accompanying drawings. Figure 1 is a perspective representation of a preferred working embodiment of the valve means having a softstart means in accordance with the invention. Figure 2 shows the valve means as in figure 1 adjacent to the softstart interface valve in a cross section taken on the line II - II. Figure 3 represents the softstart valve employed in the arrangement of figures 1 and 2 in an enlarged separate elevation in longitudinal section including the venting position. Figure 4 shows the softstart valve as in figure 3 in the softstart position. Figure 5 shows the softstart valve as in figures 3 and 4 including the working position. The valve means 6 illustrated in figures 1 and 2 is designed in the form of a valve cluster, which comprises an integral, or in the example modular, fluid distributor 7 which is fitted with several of electrically operated control valves 8. The control valves 8 are seated on component mounting faces, which in the drawing are covered over by the components and at which several ducts communicating with the distributor open, which are connected with the valve ducts of the control valves 3 in a conventional fashion. The ducts extending in the fluid distributor 7 comprise a distributor supply duct 12 extending in the longitudinal direction and furthermore, parallel thereto, a first and a second distributor venting duct 13 and 14. These ducts 12, 13 and 14 are respectively joined with each of the control valves 8 for fluid transmission. From each component mounting face there extend furthermore a first and a second distributor working duct 15 and 16, which are able to be connected with loads, not illustrated in detail, for example pressure medium drives to be operated. The action of fluid in the distributor working ducts 15 and 16 is set by the control valves 8, which are able to be electrically controlled by means of a signal transmission means 17 in the fluid distributor 7, such means 17 being only diagrammatically indicated. The fluid distributor 7 is also provided with a softstart valve 21. The preferred design thereof is indicated more particularly in figures 3 through 5. It may for example be attached, preferably in a detachable fashion, to a component mounting face 18 externally on the fluid distributor 7. A direct integration in the fluid distributor 7 would also be possible. On the component mounting face 18 there is a similar constellation of orifices of the ducts extending in the fluid distributor 7, like at the component moiinting faces for the control valves 8. Accordingly the distributor supply duct 12 and the two distributor venting ducts 13 and 14 open at the component mounting face 18. However at the two distributor working ducts a first and a second distributor supply duct 22 and 23 are present, which however may also serve as working distributor supply ducts, when a control valve 8 is installed on the component mounting face 18 at the position of the softstart valve 21. On the contrary there is also a possibility of fitting a softstart valve 21 on at least one of the component mounting faces (carrying a control valve 8) as an alternative to a control valve 8, in which case the associated distributor working ducts 15 and 16 would be employed as distributor supply ducts 22 and 23. This would however be on the basis of there being similar interface dimensions of the control valves 8 and of the softstart valve 21 or an adapter would be required in between. With the aid of the softstart valve 21 it is possible, on putting the valve means 6 into operation, to ensure a slow and smooth build up of pressure in the distributor supply duct 12 supplying the control valves 8. The distributor supply duct 12 is not supplied in a conventional fashion directly by way of a junction opening from an outer face of the fluid distributor 7 with pressure medium, but via the softstart valve 21. The pressure medium, more particularly compressed air, may simultaneously be supplied via the two distributor supply ducts 22 and 23 and comes from a pressure source (not illustrated) supplying the two ducts 22 and 23 with pressure medium at a primary pressure. The softstart valve 21 comprises a valve housing 24 having within it principal valve means generally referenced 25. The principal valve means 25 are activated by the electrically operated pilot valve 26, which is fitted on or in the valve housing 24 and may be supplied by way of an electrical interface 27 with the necessary electrical operating signals. However in lieu of the electrical supply (which is independent of electrical signal transmission means 17, provided in the working embodiment) of the pilot valve 26 the latter may, in the case of a modification of the invention, also be connected with the electrical signal transmission means 17. In the interior of the valve housing 24 there is a slide socket 28 in which a control slide 33 can move in the direction of its longitudinal axis 32. The control slide 33 has a particular configuration, which is more especially indicated in the different section planes in figures 3 through 5. By means of seal means 34, which in the example consist of several annular seal elements arranged with an axial clearance between them and surround the control slide 33 coaxially and are fixed in relation to the housing, the slide socket 28 is divided up into several portions placed axially in sequence, which so open at the outer face of the valve housing 24 that they communicate with orifices of the distribution ducts at the mounting face. As regards details it is a question of secondary duct 1 communicating with the distributor supply duct 12, of a Softstart duct 2 communicating with the first distributor suppy duct, of a venting duct 3 communicating with the first distributor venting duct 13 and of a primary duct 4 communicating with the second distributor supply duct 23. A further duct 5 is joined to the second distributor venting duct 14 but however has no function. It could therefore be omitted. During operation of the valve means 6 the primary pressure supplied to the second distributor supply duct 23 obtains at a constant level in the primary duct 4 of the softstart valve 21 too. The pressure on the other hand obtaining in the softstart duct 2 is however variable and is influenced by a chock means 35 preferably incorporated on the first distributor supply duct 22 in the fluid distributor 7. They are only indicated diagrammatically in figure 2, it having to be mentioned that the choke means 35 are preferably designed to be adjustable so that the intensity of choking set by them may be varied. Owing to the choke means 35 the pressure medium flowing via the first distributor supply duct 22 has its original primary pressure reduced to a relatively lower softstart pressure in conjunction with a reduced flow rate. In a fashion not illustrated in detail the choke means could also be fitted in the softstart valve 21. Furthermore it would be possible to provide a separate choke means, which is placed upstream from the first distributor supply duct 22 or is placed between the softstart valve 21 and the fluid distributor 7. In operation of the valve means 6 the single control slide 33 of the principal valve means 25 bottom, dependent on its position, is able to control the connection of the secondary-duct 1 both with the softstart duct 2 and also with the primary duct 4 and preferably also with the venting duct 3. This renders possible a relatively simple and at the same time compact design of the softstart valve 21. Important details in this respect will in the following be explained more particularly with reference to figures 3 through 5. The generally elongated control slide 33 preferably possesses a cylindrical outline with a number of steps following each other in the longitudinal direction and has an end portion 36 extending into a pilot control chamber 3 7 formed in the interior of the valve housing 24. This chamber can be subjected by way of the associated pilot control valve 26 in a conventional manner to control pressure medium -under a pilot pressure or may be vented to the atmosphere. A pilot control duct 38 opening into the pilot control chamber 3 7 and which is governed by the electrically operated pilot valve 26 (which is preferably designed in the form of an electrically operated solenoid valve) is indicated in the drawing by dotted lines. It communicates on the inlet side with a distributor pilot control duct 42 extending in the fluid distributor 7 or also directly in the interior of the softstart valve 21 with the primary duct 4. The pressure obtaining in the pilot control chamber 37 acts on the associated end face 43 of the control slide 33 and at the same time the feedback face 44 of a piston-like valve member 46 which is guided for movement in the direction of the longitudinal axis of the control slide 33 in an elongated cavity 45 of the control slide 33. , In order to form the cavity 45 the control slide 37 is at least partially tiibular in shape, the cavity 45 being open toward the end face 43 and the floor face 44 facing toward the end face 43. The valve member 46 is consequently constantly \ander the pressure obtaining in the pilot control chamber 27. An annular seal 47 arranged on the outer periphery of the valve means 46 avoids flow of pressure medium between the valve member 46 and the wall of the control slide 33. The valve member 46 is able to be slid within the cavity 45 between an open position as depicted in figure 3 and a closed position indicated in figures 4 and 5 in the direction of the longitudinal 32 in relation to the control slide 33. In the closed position it assumes a position farther removed from the end face 43, which is set because it strikes against a preferably annular abutment 48 in the cavity 45. The open position is set by a further abutment 52, which is axially opposite to the floor face 44 and for example is constituted by a sleeve inserted from the end into the cavity 45. In the case of the valve member 46 it is preferably a question of a valve member for cooperation with a seat. The annular abutment 48 in this case constitutes an annular valve seat 48a cooperating with an end face, opposite to the floor face 44, of the valve member 46, such valve seat dividing up the cavity 45 into cavity portions 45a and 45b lying axially on the one and on the other side of the valve seat 48a. Dependent on the position of the valve member 46 the connection between the two cavity portions 45a and 45b is open or closed. The two cavity portions 45a and 45b constitute portions of a transfer duct 53 extending in the control slide 33 and which opens at one inlet opening 54 at least and at one outlet opening at least at axially spaced positions at the peripheral outer face of the control slide 33. The outlet opening 55 lies on the side of the valve seat 48a facing the valve member 46 while the inlet opening 54 lies at a position past the valve seat 48a. At a second end portion 56, which is opposite to the above mentioned end portion 36, the control slide 33 is provided with a drive face 57 orientated axially opposite to the end face 43. It is preferably of annular configuration and may be more particularly formed directly on the control slide 33. Preferably the drive face 57 is located on a piston-like drive portion 58, which is mounted for sliding motion cooperating with a peripheral sealing action due to sealing means 62, in a preferably cylindrical piston socket 63 formed in the valve housing 24. Axially opposite to the drive face 57 and accordingly axially in front of the second end portion 56 of the control slide 33 there is in the piston socket 63 an abutment piston 64 which is separate from the control slide 33. This piston 64 is also provided with sealing means 65 effective at the peripheral wall of the piston socket 63 so that together with the drive portion 58 it delimits a sealed drive space 66. The abutment piston 64 can slide both in relation to the control slide 33 and as well in relation to the valve housing 24 in the axial direction of the control slide 33. In the case of the relative movement between the abutment piston 46 and the control slide 33 the volume of the enclosed drive space 66 is altered. The drive space 66 and therefore the drive face 57 is, during operation of the valve means 6, able to be acted on by the softstart pressure currently obtaining in the softstart duct and is more particularly constantly acted on. This takes place via a duct 67, marked as a dotted line in figure 4, which extends in portions thereof in the control slide 33 and opens via at least one control pressure tapping opening 68 at the outer peripheral face of the control slide 33. Preferably the control pressure tapping opening 68 is simultaneously constituted by the outlet opening 55. In any case it is so positioned on the control slide 33 that in the case of switching positions still to be described, of the control slide 33 it is joined to the softstart duct 2 or with the secondary-duct 1. It is in this manner that the same pressure obtains in the drive space 66 as in the softstart duct 2 or, respectively, the secondary duct 1. By abutment means 72 and 73 the relative outward movement of the control slide 33 and the abutment piston 46 is limited in the stroke thereof. If the two components move away from each other axially, then after a certain relative travel on the one hand the abutment means 72 and 73 arranged on the one hand on the abutment 46 and on the other hand on the control slide 33 will meet again and will prevent any further relative motion involving axial movement apart. The piston-like abutment means 72 on the piston side, for example in the form of an abutment disk, are located in the working example at the end portion of a preferably cylindrical piston tail 74 on the abutment piston 64, which extends toward the control slide 33 and slides in a control slide socket 75, open toward the drive space 66. The abutment means 73 on the control slide side are in the example constituted by an abutment sleeve 76 inserted and more particularly pressed into the control slide socket 75, same being a permanent component of the control slide 33 and which in the working example also bearing the drive portion 58. By drive means 77 the control slide 33 can be put in a venting position indicated in figure 3. Then it is in its position shifted farthest toward the pilot control chamber 37. The venting position is for example set by the control slide 33 abutting at its end face 43, associated with the pilot control chamber 17, against a terminal wall 78 (on the housing) axially delimiting the pilot control chamber 37. The drive means 77 are in a position of exerting a drive force 79, indicated by an arrow, on the control slide 33. This however does not however happen directly but by the intermediary of the abutment piston 64. The latter is acted on by the drive means 77, same transmitting the drive force 79 by-axial engagement with the control slide 33 to it. In this case the abutment piston 64 and the control slide 33 assume the position in which they are nearest together. The abutment piston 64 may in this case more particularly engage the drive face 57 more particularly directly. Simultaneously the piston tail 74 is inserted into the control slide socket 75 to a maximum extent. Alternatively or in addition force transmission between the abutment piston 64 and the control slide 33 may take place as well by the piston tail 74 terminally engaging the base face, facing it, of the control slide socket 75. For the sake of a better distinction the above mentioned relative position between the abutment piston 64 and the control slide 33 will as well in the following be termed the closest possible position. The drive means 77 in the present embodiment consist of a loading spring means 82. It urges the abutment piston 64 and accordingly the control slide 33 constantly toward the venting position. Preferably it fits through the abutment piston 64 into the hollow piston tail 74 in order at one end to engage its floor 84 and at the other end to engage a second terminal wall 83 of the valve housing. The second terminal wall 83 is opposite to the abutment piston 64 on the axial side opposite to the drive portion 58 and so delimits a drive space 85 accommodating the drive means 77. In the case of an alternative design the spring means 82 is omitted and the drive means 77 comprise a second pilot control valve 26a indicated in chained lines diagrammatically able to supply pressure medium to the drive space in a controlled manner. The supplied pressure medium then acts like the spring means 82 on the abutment piston 64 and accordingly shifts the control slide 33 toward the venting position. In this respect a pressure pulse is sufficient, which the opposite pilot control chambers7 is vented. In the vented position of the control slide 33 the secondary duct 1 may be vented through the transfer duct 53 to the venting duct 33 and therefore to the atmosphere. Accordingly the secondary duct 1 is relieved of pressure and in the working example the distributor supply duct 12 connected to it is also deprived of pressure. The venting flow is indicated in figure 3 by a chained line. It will be clear that the means for ensuring the venting function is so designed that in the venting position the inlet opening 54 communicates with the secondary duct 1 and the outlet opening 55 communicates with the venting duct 3. During the venting phase the valve member 46 assume the open position. Since the pilot control chamber 37 is vented, the second pressure can shift the valve member 46 and lift if from the valve seat 48a. In the venting position of the control slide 33 both the softstart duct 2 and the primary duct 4 too are obturated by cooperation of the control slide 33 with the sealing means 34. In order to activate the softstart valve 21 and to cause a gradual reduction in pressure in the secondary duct 1, by operation of the pilot control valve 26 the pilot control pressure is applied in the pilot control chamber 37. Such pilot control pressure acts on the control slide 33 and shifts same toward the second terminal wall 83. The effective pressure drive area is in this case made up of the end face 43 of the control slide 33 and the floor face 44 in the valve member 46. The latter is included because the pilot control pressure shifts the valve member 46 as far as engagement with the abutment 48, or respectively, the valve seat 48a and accordingly the pressure force acting on the valve member 46 is applied to the control slide 33. This condition is clearly illustrated in figure 4. During this switching over movement the control slide 33 will push along the abutment piston 64 along in front of it against the drive force 79 until the abutment piston 64 hits the second terminal wall 83. In the working en±»odiment this is combined with a compression of the spring means 82. The control slide 33 and the abutment piston 46 are then still located in the closest together position. The position ultimately resulting from the switching over movement of the control slide 33 will appear from figure 4 and will be termed the softstart position. This softstart position is furthermore characterized in that the control slide 33 has produced a fluid connection between the softstart duct 2 and the secondary duct 1. Accordingly the pressure medium will flow as indicated in chained lines in figure 4 from the softstart duct 2 into the secondary duct 1 whence the latter will flow, in the example, into the distributor supply duct 12 in the valve means 6. A further feature of the softstart position is that the control slide 33 assumes a closed position as regards the connection between the secondary duct 1 and the primary duct 4. The secondary duct 1 is therefore shut off from the primary duct 4. The venting duct 3 is also shut off. Transfer of pressure medium between the softstart duct 2 and the primary duct 4 through the transfer duct 53 is prevented owing to the valve member 46 being held in its closed position by the application of fluid. Owing to the connection between the softstart duct 2 and the secondary duct 1 in the latter an increasing pressure level will be built up in the latter. This pressure can theoretically increase up to the primary pressure obtaining upstream from the choke means 35. With the selected setting of the choke means 35 the speed of the pressure build up may be varied. Via the control duct 67 the softstart pressure is, in the softstart position, also supplied to the drive space 66, something which is indicated in chained lines in figure 4. In the working embodiment the tapping of pressure occurs via the control pressure tapping opening 68 positioned on the softstart duct 2. As an alternative it would nevertheless be possible to provide a placement of the control pressure tapping opening 68 such that, in the softstart position, has a position on the secondary duct 1. The position is therefore irrelevant, because in the softstart duct 2 and in the secondary duct 1 there is practically the same pressure. In accordance with the build up of the softstart pressure the drive pressure present in the drive space 66 also goes up. At a certain predetermined level of the drive pressure the control slide 33 switches over into the working position indicated in figure 5. This takes place against the still unchanged biasing force 86, with which the control slide 33 is acted on by the control pressure medium located in the pilot control chamber 37. The pressure level, ultimately responsible for the switching over into the working position, in the secondary duct 1 can be set via the area relationships between on the one hand the drive face 57 and on the other hand the end face 43 and the floor face 44 and also via the pilot control pressure effective for the biasing force 86. For example the switch over threshold may be at a softstart pressure, which is half as large as the primary pressure. However for the setting of the softstart pressure responsible for switching over there is complete freedom. The working position illustrated in figure 5 of the control slide 33 is characterized in that in the connection between the secondary duct 1 and the primary duct 4 there is an open setting. Accordingly in accordance with the chained line in figure 5 pressure medium at the primary pressure level from the primary duct 4 may flow into the secondary duct 1 where it causes the pressure build up as far as the desired working pressure, which is the same as the primary pressure. The working position of the control slide 33 lies axially between the venting position and the softstart position. It is predetermined by the mutually cooperating abutment means 72 and 73. Owing to the pressure built up in the drive space 66 the abutment piston 46 - without any change in relation to the softstart position - is held in an abutment position, in which it bears against the second terminal wall 83 so as to be ,stationary in relation to the housing. Accordingly the drive portion 58 and with it the entire control slide 33 will perform a relative movement in relation to the valve housing 24 and the abutment piston 64 in the case of which the section travels as indicated by the arrow 87 toward the venting position, which is however not reached because the two abutment means 72 and 73 abut each other. Accordingly the working position is defined. In the working embodiment the geometry of the control slide 33 is so chosen that the secondary duct 1 in the working position of the control slide 33 is connected also with the softstart duct 2 as indicated by the thinner chained line in figure 5. This is however not mandatory. The working position is maintained as long as the pilot control chamber 37 gets the pilot control pressure. If the pilot control chamber 37 is vented the pilot control force 86 disappears and the control slide 33 will be shifted back by the drive means 77 into the above mentioned venting position of figure 3. The control duct 67 responsible for the action on the drive face 57 is connected both in the softstart position and also in the working position and during the transition between the two positions with the softstart duct 2 in order to ensure the pressure action on the drive face 57 necessary for the switching over into the working position and the maintenance in the working position; A comparison between figures 4 and 5 will serve to make it clear that the control pressure tapping opening 68 is positioned in each of the above mentioned positions near the softstart duct 2. As regards the working example it may be summarized again that the softstart valve 21 comprises a primary duct 4 svibject to the primary pressure, a secondary duct 1 and a softstart duct 2 subject to a softstart pressure which owing to the choke means 35 is at a level less than the primary pressure. Furthermore it has principal valve means 25, by which the secondary duct 1 may be joined with the secondary duct 2, when the primary duct 4 is separated from it, and comprise a control slide 33 able to be shifted into several positions, and which, against a biasing force 86 is able to be switched over out of a position separating the primary duct 4 from the secondary duct 1 into a working position freeing the connection between these ducts because a drive face 57 provided on it, is subjected to softstart pressure from the softstart pressure 2. The control slide 33 governs in a manner dependent on its position the connection of the secondary duct 1 both with primary duct 4 and also with the softstart duct 2, it being able to be positioned in a softstart position connecting the softstart duct 2 with the secondary duct 1 simultaneously separated from the primary duct 4, from which position it can be switched by action occurring owing to the softstart pressure, of the drive face 57 into the working position. Owing to the softstart valve 21 integrated in the valve means a controlled supply and venting of the valve means 6 is possible without resort to external components. Since the control of the switching positions is caused directly by the pressure action, no electrical pressure sensors are required. The switch over function of the softstart valve 21 can occur in a time and/or pressure dependent fashion. Claims 1. A valve means with a softstart function comprising a softstart valve (21) having principal valve means (25) able to selectively shut off the connection between a primary duct (4) subject to a primary pressure and a secondary duct (1) in a closed position biased by a biasing force (86) or to open up such connection in an open position, the principal valve means (25) being able to be siibjected to the softstart pressure for switching over into the open position, and the softstart valve is furthermore capable, when the primary duct (4) is separated from the secondary duct (1), to connect the secondary duct (1) with a softstart duct (2) , which is svibjected or able to be subjected to a softstart pressure which owing to choke means (35) is at least initially less than the primary pressure, characterized in that the principal valve means (25) comprise a control slide (33) which is able to be set in different positions and which is able to control the connection of the secondary duct (1) both with the softstart duct (2) and also with the primary duct (4), said control slide (33) furthermore being kinematically coupled with a drive face (57), said drive face being able to be acted upon by the softstart pressure oppositely to the biasing force (86) which also acts on the control slide (33) . 2. The valve means according to claim 1, characterized in that the control slide (33) is able to be positioned in a softstart position, in which it connects the softstart duct (2) with the secondary duct (19), said secondary duct (19) in the softstart position being simultaneously separated from the primary duct (4). 3. The valve means according to either claim 1 or claim 2, characterized in that the control slide (33) is able to be positioned in a working position, in which it connects the secondary duct (1) with the primary duct (4). 4. The valve means according to claim 3, characterized in that the control slide (33) in its working position connects the secondary duct (1) both with the primary duct (4) and also with the softstart duct (2). 5. The valve means according to any one of the claims 1 through 4, characterized in that the control slide (33) is able to be positioned in a venting position, in which it connects the secondary duct (1), with a simultaneous separation from the primary duct (4) and the softstart duct (2), with a venting duct (3) communicating with the atmosphere. 6. The valve means according to claim 5, characterized in that the connection present in the venting position between the secondary duct (1) and the venting duct (3) takes place using a transfer duct (53) extending through the control slide (33). 7. The valve means according to claim 6, characterized in that a valve member (46) arranged in the control slide (33) is associated to the transfer duct (53), such valve member being able to open the transfer duct (53) in the venting position of the control slide (33) and to close the transfer duct (53) in the other positions of the control slide (33). 8. The valve means according to claim 7, characterized in that the valve member (46) is piston-like in form and is constantly sxibjected to the pressure present in a pilot control chamber (37) which latter for switching over the control slide (33) is able to be subjected to a pilot control pressure, the valve member (46) being able to be thrust by the pilot control pressure against an abutment (48) arranged on the control slide (33) in order to so apply a setting force to the control slide (33), said abutment (48) in particular being constituted by a valve seat (4 8a). 9. The valve means according to ctny une uj. Lue uxctxina x through 8, characterized by a distributor (7) equipped with several control valves (8), said fluid distributor (7) having a distributor supply duct (12) and at least one distributor venting duct (13) which are respectively connected with the control valves (8), said fluid distributor (7) being fitted with the softstart valve (21), the distributor supply duct (12) being connected with the secondary duct (1), and the primary duct (4) and the softstart duct (2) being respectively connected with a distributor supply duct (22 and 23) opening at an outer face of the fluid distributor (7). 10. The valve means according to claim 9 in conjunction with one of the claims 5 through 8, characterized in that the venting duct (3) of the softstart valve (21) is connected with a distributor venting duct (13). 11. The valve means according to claim 9 or claim 10, characterized in that the fluid distributor (7) is provided with several component mounting faces, from which two distributor working ducts (15 and 16) extending through the fluid distributor (7) are starting, respectively, which are preferably at least partly selectively able to be fitted with a control valve (8) or with a softstart valve (21), the distributor working ducts (15 and 16), in the case of the associated component mounting face bearing a softstart valve (21), being able to be used as the distributor supply ducts (22 and 23). 12. The valve means according to any one of the claims 9 through 11, characterized in that the distributor supply duct (22) , comm\anicating with the softstart duct (2) , is provided with choke means (35) arranged in the distributor supply duct or arranged upstream or downstream from it. 13. The valve means according to any one of the claims 1 through 12, characterized in that the choke means (35) are able to be adjusted as regards their intensity of their choking action. 14. The valve means according to any one of the claims 1 through 13, characterized in that the drive face (57) of the control slide (33) delimits a drive space (66) able to be siibjected to the softstart pressure. 15. The valve means according to claim 14, characterized in that the drive space (66) is connected via at least one control duct (67) with the softstart duct (2) and/or the secondary duct (1) at least when the control slide (33) assumes its softstart position connecting the softstart duct (2) with the secondary duct (1). 16. The valve means according to claim 14 or claim 15 , characterized in that the control duct (67) extends at least in parts thereof in the control slide (33). 17. The valve means according to claim 16, characterized in that the control duct (67) so opens with at least one control pressure tapping opening (68) at a position on the outer periphery of the control slide (33) that this control pressure tapping opening (68) both in the softstart position connecting the secondary duct (1) with the softstart duct (2) and also in the working position connecting the secondary duct (1) with the primary duct (4) communicates with the softstart duct (2) or the secondary duct (1). 18. The valve means according to any one of the claims 14 through 17, characterized in that the drive space (66) is delimited, on the side opposite the drive face (57) , by an abutment piston (46) able to be displaceable both with respect to the control slide (33) and also to the valve housing (24) in the axial direction of the control slide (33), the abutment piston being able to be displaced by the control slide (33), upon movement of the control slide (33) into the softstart position, into an abutting position having a fixed relationship to the housing and simultaneously predetermining the softstart position of the control slide (33), and the abutment piston (46) so cooperates by means of abutment means (72 and 73) with the control slide (33) that it stops the switching over motion of the control slide (33) entailed by an increase in pressure in the drive space when the working position is reached. 19. The valve means according to claim 18, characterized in that the abutment piston (64) is biased or able to be biased by drive means (77) in a direction toward the control slide (33) . 20. The valve means according to claim 19, characterized in that the drive means (77) are constituted by a spring means (82) bearing on the valve housing (24), said spring means getting compressed when the abutment piston (64) is shifted into the abutment position. 21. The valve means according to any one of the claims 18 through 20, characterized in that a piston tail (74) is arranged on the abutment piston (64) plunging coaxially into the control slide (33) , such piston tail preferably having the abutment means (72 and 73) associated with it. 22. The valve means according to any one of the claims 1 through 21, characterized in that the control slide (33) has a terminal end portion (36) plunging into a pilot control chamber (37) which is able to be acted upon by a pilot pressure in order to cause the biasing force (86). 23. The valve means according to claim 22, characterized in that the pilot control chamber (37) is associated with the terminal end portion (36), opposite to the drive face (57), of the control slide (33).

Full Text

--A VALVE MEANS WITH A SOFTSTART FUNCTION--
The invention relates to a valve means with a softstart function comprising a softstart valve having principal valve means able to selectively shut off the connection between a primary- duct siibject to the primary pressure and a secondary duct in a closed position biased by a biasing force or to open up such connection in an open position, the principal valve means being able to be siobjected to the softstart pressure for switching over into the open position and the softstart valve is furthermore capable, when the primary duct is separated, of connecting the secondary duct with a softstart duct, which is subjected or able to be subjected to a softstart pressure which is at least initially less than the primary pressure owing to choke means.
A valve means of this type disclosed in the German patent publication DE 91 05 458 Ul comprises a softstart valve with principal valve means constituted by a 2/2 directional valve, such valve means being biased by fluid action and by spring force into a closed position, in which they shut off the primary duct from the secondary duct. In addition to these principal valve means there is a 3/2 directional valve which is able to connect, while bypassing the 2/2 directional valve, the secondary duct with a softstart duct, in which owing to an associated choke means a lower pressure termed the softstart pressure may obtain than in the primary duct. The softstart pressure is, on operation of the 3/2 directional valve, supplied not only to the secondary duct but also simultaneously to the principal valve means, which accordingly are urged toward their open position. On operation of the 3/2 directional valve the secondary duct is consequently supplied with pressure medium at the softstart pressure and owing to the softstart pressure' gradually increasing after a certain time the principal valve means are switched over into the open

position so that the secondary duct is supplied at the full flow rate from the primary duct.
A valve means operating in a similar fashion is described in the German patent publication DE 20 2004 015 468 Ul. Here as well the softstart valve has two separate valve units to implement the softstart function.
The Geiman patent publication DE 1 283 627 B discloses a control valve which in order to avoid having control abutments entails a gradual build up of fluid pressure in of working ducts, which are connected with a load. For this purpose the control slide is driven to perform a switch over movement with a varying speed, choke slots being employed to ensure that at particular transition positions of the control slide there is merely a choked admission of fluid to the working ducts.
One object of the present invention is to create a valve means which provides for an economic and compact softstart function.
To attain this aim there is a provision such that the principal valve means comprise a control slide which is able to be set in different positions and which is able to control the connection of the secondary duct both with the softstart duct and also with the primary duct and is kinematically coupled with a drive face able to be acted upon by the softstart pressure oppositely to the biasing force also acting on it.
While in the prior art to implement the softstart function in addition to the principal valve means at least one further separate valve unit is required, in the present invention the principal valve means alone are responsible for the control of the secondary duct with a gradually waxing pressure level. A single control slide of the principal valve means is in a position of controlling the connection of the secondary duct both with the softstart duct and also with the primary duct and accordingly in a position termed the softstart position to• render possible a choked flow rate and in a position teimed the working position to ensure the full rate at the primary

V
pressure. The control slide is switched over by the softstart pressure applied by it by means of a drive face, the softstart pressure that goes up during operation owing to the gradual filling of the secondary duct until it reaches a level causing a switch over into the working position.
Owing to the concentration of the valve means responsible for the softstart function in a single valve unit the softstart valve may be designed in an extremely compact and economic fashion. There is in addition the possibility of so configuring the softstart valve that it may also be integrated in a valve cluster fitted with several control valves, in particular by the installation on a component mounting face of a fluid distributor in lieu of a control valve or alongside one. If required it is even possible for the housing of control valve to be employed for the design of the softstart valve so that the individual components may be employed more than once, something which further reduces the costs for manufacture and stock holding.
Further advantageous developments of the invention are defined in the dependent claims.
The valve means may be so designed that the control slide in one working position connects not only the primary duct but furthermore the softstart duct with the secondary duct. The softstart duct therefore need not be separated and may communicate in parallel to the primary duct with the secondary duct. This will as a rule amount to a simplification the design of the softstart valve.
A particular advantage arises if the control slide is able to be positioned in a venting position in addition to the softstart position and the working position in which it connects the secondary duct with a venting duct communicating with the atmosphere. In this venting position it is only as regards the primary duct that there is a closed position, since the primary duct is separated both from the secondary duct and also from the softstart duct. Accordingly using the softstart
I.

valve it is possible to perform a simple venting operation for the secondary duct and any load connected with it.
Venting takes place preferably using the control slide. It has for this purpose a transfer duct communicating in the venting position on the one hand with the secondary duct and on the other hand with the venting duct.
The passage through the transfer duct is preferably again separately controlled by a valve member arranged in the control slide. The same may obturate the transfer duct, when the control slide assumes a position in which emergence of fluid is undesired.
The valve member may be piston-like and in the closed position contact an abutment preferably constituted by an associated valve seat so that it may apply a setting force to the control slide, when for the purpose of switching over of the control slide it is subjected to a control pressure at the rear.
The choke means responsible for the at least initially reduced softstart pressure are preferably designed to be adjustable as regards the intensity of the choking action. The means may be a regular component of the softstart valve or be located in a feed duct leading to the softstart duct of the softstart valve of a further component of the valve means, for example in a fluid distributor, if the softstart valve is fitted on or in same.
The drive face, preferably arranged directly on the control slide, may delimit a drive space, able to be subjected to the softstart pressure in the housing of the softstart valve. The softstart pressure is preferably supplied to the drive space by way of at least one control duct extending at least in portions thereof in the control slide, and the control duct is connected both in the softstart position and also in the working position with the softstart duct or also with secondary duct, which is at the same pressure. Accordingly a constant maintenance of a setting force acting on the control

V
slide contrary to the biasing force is ensured.
The drive space is best arranged between the drive face associated with the control slide and an abutment piston lying opposite to it and able to be set in relation to the control slide and furthermore also in relation to the valve housing. Owing to the cooperation with the valve housing it delimits the stroke travel of the control slide to set the softstart position. During the following increase in the softstart pressure switched to the drive space it will keep to its position, which is stationary in relation to the valve housing, and will render possible setting of the control slide until a limitation of the stroke travel is caused by associated abutment means, such stroke limitation setting the working position of the control slide.
In the follow the invention will be described on the basis of the accompanying drawings.
Figure 1 is a perspective representation of a preferred working embodiment of the valve means having a softstart means in accordance with the invention. Figure 2 shows the valve means as in figure 1 adjacent to the softstart interface valve in a cross section taken on the line II - II. Figure 3 represents the softstart valve employed in the arrangement of figures 1 and 2 in an enlarged separate elevation in longitudinal section including the venting position. Figure 4 shows the softstart valve as in figure 3 in the
softstart position. Figure 5 shows the softstart valve as in figures 3 and 4
including the working position. The valve means 6 illustrated in figures 1 and 2 is designed in the form of a valve cluster, which comprises an integral, or in the example modular, fluid distributor 7 which is fitted with several of electrically operated control valves

8.
The control valves 8 are seated on component mounting faces, which in the drawing are covered over by the components and at which several ducts communicating with the distributor open, which are connected with the valve ducts of the control valves 3 in a conventional fashion.
The ducts extending in the fluid distributor 7 comprise a distributor supply duct 12 extending in the longitudinal direction and furthermore, parallel thereto, a first and a second distributor venting duct 13 and 14. These ducts 12, 13 and 14 are respectively joined with each of the control valves 8 for fluid transmission.
From each component mounting face there extend furthermore a first and a second distributor working duct 15 and 16, which are able to be connected with loads, not illustrated in detail, for example pressure medium drives to be operated. The action of fluid in the distributor working ducts 15 and 16 is set by the control valves 8, which are able to be electrically controlled by means of a signal transmission means 17 in the fluid distributor 7, such means 17 being only diagrammatically indicated.
The fluid distributor 7 is also provided with a softstart valve 21. The preferred design thereof is indicated more particularly in figures 3 through 5. It may for example be attached, preferably in a detachable fashion, to a component mounting face 18 externally on the fluid distributor 7. A direct integration in the fluid distributor 7 would also be possible.
On the component mounting face 18 there is a similar constellation of orifices of the ducts extending in the fluid distributor 7, like at the component moiinting faces for the control valves 8. Accordingly the distributor supply duct 12 and the two distributor venting ducts 13 and 14 open at the component mounting face 18. However at the two distributor working ducts a first and a second distributor supply duct 22

and 23 are present, which however may also serve as working distributor supply ducts, when a control valve 8 is installed on the component mounting face 18 at the position of the softstart valve 21. On the contrary there is also a possibility of fitting a softstart valve 21 on at least one of the component mounting faces (carrying a control valve 8) as an alternative to a control valve 8, in which case the associated distributor working ducts 15 and 16 would be employed as distributor supply ducts 22 and 23. This would however be on the basis of there being similar interface dimensions of the control valves 8 and of the softstart valve 21 or an adapter would be required in between.
With the aid of the softstart valve 21 it is possible, on putting the valve means 6 into operation, to ensure a slow and smooth build up of pressure in the distributor supply duct 12 supplying the control valves 8. The distributor supply duct 12 is not supplied in a conventional fashion directly by way of a junction opening from an outer face of the fluid distributor 7 with pressure medium, but via the softstart valve 21. The pressure medium, more particularly compressed air, may simultaneously be supplied via the two distributor supply ducts 22 and 23 and comes from a pressure source (not illustrated) supplying the two ducts 22 and 23 with pressure medium at a primary pressure.
The softstart valve 21 comprises a valve housing 24 having within it principal valve means generally referenced 25. The principal valve means 25 are activated by the electrically operated pilot valve 26, which is fitted on or in the valve housing 24 and may be supplied by way of an electrical interface 27 with the necessary electrical operating signals. However in lieu of the electrical supply (which is independent of electrical signal transmission means 17, provided in the working embodiment) of the pilot valve 26 the latter may, in the case of a modification of the invention, also be connected with the electrical signal transmission means 17.

In the interior of the valve housing 24 there is a slide socket 28 in which a control slide 33 can move in the direction of its longitudinal axis 32. The control slide 33 has a particular configuration, which is more especially indicated in the different section planes in figures 3 through 5.
By means of seal means 34, which in the example consist of several annular seal elements arranged with an axial clearance between them and surround the control slide 33 coaxially and are fixed in relation to the housing, the slide socket 28 is divided up into several portions placed axially in sequence, which so open at the outer face of the valve housing 24 that they communicate with orifices of the distribution ducts at the mounting face. As regards details it is a question of secondary duct 1 communicating with the distributor supply duct 12, of a Softstart duct 2 communicating with the first distributor suppy duct, of a venting duct 3 communicating with the first distributor venting duct 13 and of a primary duct 4 communicating with the second distributor supply duct 23. A further duct 5 is joined to the second distributor venting duct 14 but however has no function. It could therefore be omitted.
During operation of the valve means 6 the primary pressure supplied to the second distributor supply duct 23 obtains at a constant level in the primary duct 4 of the softstart valve 21 too. The pressure on the other hand obtaining in the softstart duct 2 is however variable and is influenced by a chock means 35 preferably incorporated on the first distributor supply duct 22 in the fluid distributor 7. They are only indicated diagrammatically in figure 2, it having to be mentioned that the choke means 35 are preferably designed to be adjustable so that the intensity of choking set by them may be varied. Owing to the choke means 35 the pressure medium flowing via the first distributor supply duct 22 has its original primary pressure reduced to a relatively lower softstart pressure in conjunction with a reduced flow rate.
In a fashion not illustrated in detail the choke means

could also be fitted in the softstart valve 21. Furthermore it would be possible to provide a separate choke means, which is placed upstream from the first distributor supply duct 22 or is placed between the softstart valve 21 and the fluid distributor 7.
In operation of the valve means 6 the single control slide 33 of the principal valve means 25 bottom, dependent on its position, is able to control the connection of the secondary-duct 1 both with the softstart duct 2 and also with the primary duct 4 and preferably also with the venting duct 3. This renders possible a relatively simple and at the same time compact design of the softstart valve 21. Important details in this respect will in the following be explained more particularly with reference to figures 3 through 5.
The generally elongated control slide 33 preferably possesses a cylindrical outline with a number of steps following each other in the longitudinal direction and has an end portion 36 extending into a pilot control chamber 3 7 formed in the interior of the valve housing 24. This chamber can be subjected by way of the associated pilot control valve 26 in a conventional manner to control pressure medium -under a pilot pressure or may be vented to the atmosphere. A pilot control duct 38 opening into the pilot control chamber 3 7 and which is governed by the electrically operated pilot valve 26 (which is preferably designed in the form of an electrically operated solenoid valve) is indicated in the drawing by dotted lines. It communicates on the inlet side with a distributor pilot control duct 42 extending in the fluid distributor 7 or also directly in the interior of the softstart valve 21 with the primary duct 4.
The pressure obtaining in the pilot control chamber 37 acts on the associated end face 43 of the control slide 33 and at the same time the feedback face 44 of a piston-like valve member 46 which is guided for movement in the direction of the longitudinal axis of the control slide 33 in an elongated

cavity 45 of the control slide 33. ,
In order to form the cavity 45 the control slide 37 is at least partially tiibular in shape, the cavity 45 being open toward the end face 43 and the floor face 44 facing toward the end face 43. The valve member 46 is consequently constantly \ander the pressure obtaining in the pilot control chamber 27. An annular seal 47 arranged on the outer periphery of the valve means 46 avoids flow of pressure medium between the valve member 46 and the wall of the control slide 33.
The valve member 46 is able to be slid within the cavity 45 between an open position as depicted in figure 3 and a closed position indicated in figures 4 and 5 in the direction of the longitudinal 32 in relation to the control slide 33. In the closed position it assumes a position farther removed from the end face 43, which is set because it strikes against a preferably annular abutment 48 in the cavity 45. The open position is set by a further abutment 52, which is axially opposite to the floor face 44 and for example is constituted by a sleeve inserted from the end into the cavity 45.
In the case of the valve member 46 it is preferably a question of a valve member for cooperation with a seat. The annular abutment 48 in this case constitutes an annular valve seat 48a cooperating with an end face, opposite to the floor face 44, of the valve member 46, such valve seat dividing up the cavity 45 into cavity portions 45a and 45b lying axially on the one and on the other side of the valve seat 48a. Dependent on the position of the valve member 46 the connection between the two cavity portions 45a and 45b is open or closed.
The two cavity portions 45a and 45b constitute portions of a transfer duct 53 extending in the control slide 33 and which opens at one inlet opening 54 at least and at one outlet opening at least at axially spaced positions at the peripheral outer face of the control slide 33. The outlet opening 55 lies on the side of the valve seat 48a facing the valve member 46 while the inlet opening 54 lies at a position past the valve

seat 48a.
At a second end portion 56, which is opposite to the above mentioned end portion 36, the control slide 33 is provided with a drive face 57 orientated axially opposite to the end face 43.
It is preferably of annular configuration and may be more particularly formed directly on the control slide 33.
Preferably the drive face 57 is located on a piston-like drive portion 58, which is mounted for sliding motion cooperating with a peripheral sealing action due to sealing means 62, in a preferably cylindrical piston socket 63 formed in the valve housing 24.
Axially opposite to the drive face 57 and accordingly axially in front of the second end portion 56 of the control slide 33 there is in the piston socket 63 an abutment piston 64 which is separate from the control slide 33. This piston 64 is also provided with sealing means 65 effective at the peripheral wall of the piston socket 63 so that together with the drive portion 58 it delimits a sealed drive space 66.
The abutment piston 64 can slide both in relation to the control slide 33 and as well in relation to the valve housing 24 in the axial direction of the control slide 33. In the case of the relative movement between the abutment piston 46 and the control slide 33 the volume of the enclosed drive space 66 is altered.
The drive space 66 and therefore the drive face 57 is, during operation of the valve means 6, able to be acted on by the softstart pressure currently obtaining in the softstart duct and is more particularly constantly acted on. This takes place via a duct 67, marked as a dotted line in figure 4, which extends in portions thereof in the control slide 33 and opens via at least one control pressure tapping opening 68 at the outer peripheral face of the control slide 33. Preferably the control pressure tapping opening 68 is simultaneously constituted by the outlet opening 55. In any case it is so positioned on the control slide 33 that in the case of

switching positions still to be described, of the control slide 33 it is joined to the softstart duct 2 or with the secondary-duct 1. It is in this manner that the same pressure obtains in the drive space 66 as in the softstart duct 2 or, respectively, the secondary duct 1.
By abutment means 72 and 73 the relative outward movement of the control slide 33 and the abutment piston 46 is limited in the stroke thereof. If the two components move away from each other axially, then after a certain relative travel on the one hand the abutment means 72 and 73 arranged on the one hand on the abutment 46 and on the other hand on the control slide 33 will meet again and will prevent any further relative motion involving axial movement apart.
The piston-like abutment means 72 on the piston side, for example in the form of an abutment disk, are located in the working example at the end portion of a preferably cylindrical piston tail 74 on the abutment piston 64, which extends toward the control slide 33 and slides in a control slide socket 75, open toward the drive space 66. The abutment means 73 on the control slide side are in the example constituted by an abutment sleeve 76 inserted and more particularly pressed into the control slide socket 75, same being a permanent component of the control slide 33 and which in the working example also bearing the drive portion 58.
By drive means 77 the control slide 33 can be put in a venting position indicated in figure 3. Then it is in its position shifted farthest toward the pilot control chamber 37. The venting position is for example set by the control slide 33 abutting at its end face 43, associated with the pilot control chamber 17, against a terminal wall 78 (on the housing) axially delimiting the pilot control chamber 37.
The drive means 77 are in a position of exerting a drive force 79, indicated by an arrow, on the control slide 33. This however does not however happen directly but by the intermediary of the abutment piston 64. The latter is acted on

by the drive means 77, same transmitting the drive force 79 by-axial engagement with the control slide 33 to it. In this case the abutment piston 64 and the control slide 33 assume the position in which they are nearest together. The abutment piston 64 may in this case more particularly engage the drive face 57 more particularly directly. Simultaneously the piston tail 74 is inserted into the control slide socket 75 to a maximum extent. Alternatively or in addition force transmission between the abutment piston 64 and the control slide 33 may take place as well by the piston tail 74 terminally engaging the base face, facing it, of the control slide socket 75.
For the sake of a better distinction the above mentioned relative position between the abutment piston 64 and the control slide 33 will as well in the following be termed the closest possible position.
The drive means 77 in the present embodiment consist of a loading spring means 82. It urges the abutment piston 64 and accordingly the control slide 33 constantly toward the venting position. Preferably it fits through the abutment piston 64 into the hollow piston tail 74 in order at one end to engage its floor 84 and at the other end to engage a second terminal wall 83 of the valve housing. The second terminal wall 83 is opposite to the abutment piston 64 on the axial side opposite to the drive portion 58 and so delimits a drive space 85 accommodating the drive means 77.
In the case of an alternative design the spring means 82 is omitted and the drive means 77 comprise a second pilot control valve 26a indicated in chained lines diagrammatically able to supply pressure medium to the drive space in a controlled manner. The supplied pressure medium then acts like the spring means 82 on the abutment piston 64 and accordingly shifts the control slide 33 toward the venting position. In this respect a pressure pulse is sufficient, which the opposite pilot control chambers7 is vented.

In the vented position of the control slide 33 the secondary duct 1 may be vented through the transfer duct 53 to the venting duct 33 and therefore to the atmosphere. Accordingly the secondary duct 1 is relieved of pressure and in the working example the distributor supply duct 12 connected to it is also deprived of pressure. The venting flow is indicated in figure 3 by a chained line. It will be clear that the means for ensuring the venting function is so designed that in the venting position the inlet opening 54 communicates with the secondary duct 1 and the outlet opening 55 communicates with the venting duct 3.
During the venting phase the valve member 46 assume the open position. Since the pilot control chamber 37 is vented, the second pressure can shift the valve member 46 and lift if from the valve seat 48a.
In the venting position of the control slide 33 both the softstart duct 2 and the primary duct 4 too are obturated by cooperation of the control slide 33 with the sealing means 34.
In order to activate the softstart valve 21 and to cause a gradual reduction in pressure in the secondary duct 1, by operation of the pilot control valve 26 the pilot control pressure is applied in the pilot control chamber 37. Such pilot control pressure acts on the control slide 33 and shifts same toward the second terminal wall 83. The effective pressure drive area is in this case made up of the end face 43 of the control slide 33 and the floor face 44 in the valve member 46. The latter is included because the pilot control pressure shifts the valve member 46 as far as engagement with the abutment 48, or respectively, the valve seat 48a and accordingly the pressure force acting on the valve member 46 is applied to the control slide 33. This condition is clearly illustrated in figure 4.
During this switching over movement the control slide 33 will push along the abutment piston 64 along in front of it against the drive force 79 until the abutment piston 64 hits

the second terminal wall 83. In the working en±»odiment this is combined with a compression of the spring means 82. The control slide 33 and the abutment piston 46 are then still located in the closest together position.
The position ultimately resulting from the switching over movement of the control slide 33 will appear from figure 4 and will be termed the softstart position. This softstart position is furthermore characterized in that the control slide 33 has produced a fluid connection between the softstart duct 2 and the secondary duct 1. Accordingly the pressure medium will flow as indicated in chained lines in figure 4 from the softstart duct 2 into the secondary duct 1 whence the latter will flow, in the example, into the distributor supply duct 12 in the valve means 6.
A further feature of the softstart position is that the control slide 33 assumes a closed position as regards the connection between the secondary duct 1 and the primary duct 4.
The secondary duct 1 is therefore shut off from the primary duct 4. The venting duct 3 is also shut off. Transfer of pressure medium between the softstart duct 2 and the primary duct 4 through the transfer duct 53 is prevented owing to the valve member 46 being held in its closed position by the application of fluid.
Owing to the connection between the softstart duct 2 and the secondary duct 1 in the latter an increasing pressure level will be built up in the latter. This pressure can theoretically increase up to the primary pressure obtaining upstream from the choke means 35. With the selected setting of the choke means 35 the speed of the pressure build up may be varied.
Via the control duct 67 the softstart pressure is, in the softstart position, also supplied to the drive space 66, something which is indicated in chained lines in figure 4. In the working embodiment the tapping of pressure occurs via the control pressure tapping opening 68 positioned on the softstart

duct 2. As an alternative it would nevertheless be possible to provide a placement of the control pressure tapping opening 68 such that, in the softstart position, has a position on the secondary duct 1. The position is therefore irrelevant, because in the softstart duct 2 and in the secondary duct 1 there is practically the same pressure.
In accordance with the build up of the softstart pressure the drive pressure present in the drive space 66 also goes up. At a certain predetermined level of the drive pressure the control slide 33 switches over into the working position indicated in figure 5. This takes place against the still unchanged biasing force 86, with which the control slide 33 is acted on by the control pressure medium located in the pilot control chamber 37.
The pressure level, ultimately responsible for the switching over into the working position, in the secondary duct 1 can be set via the area relationships between on the one hand the drive face 57 and on the other hand the end face 43 and the floor face 44 and also via the pilot control pressure effective for the biasing force 86. For example the switch over threshold may be at a softstart pressure, which is half as large as the primary pressure. However for the setting of the softstart pressure responsible for switching over there is complete freedom.
The working position illustrated in figure 5 of the control slide 33 is characterized in that in the connection between the secondary duct 1 and the primary duct 4 there is an open setting. Accordingly in accordance with the chained line in figure 5 pressure medium at the primary pressure level from the primary duct 4 may flow into the secondary duct 1 where it causes the pressure build up as far as the desired working pressure, which is the same as the primary pressure.
The working position of the control slide 33 lies axially between the venting position and the softstart position. It is predetermined by the mutually cooperating abutment means 72 and

73. Owing to the pressure built up in the drive space 66 the abutment piston 46 - without any change in relation to the softstart position - is held in an abutment position, in which it bears against the second terminal wall 83 so as to be ,stationary in relation to the housing. Accordingly the drive portion 58 and with it the entire control slide 33 will perform a relative movement in relation to the valve housing 24 and the abutment piston 64 in the case of which the section travels as indicated by the arrow 87 toward the venting position, which is however not reached because the two abutment means 72 and 73 abut each other. Accordingly the working position is defined.
In the working embodiment the geometry of the control slide 33 is so chosen that the secondary duct 1 in the working position of the control slide 33 is connected also with the softstart duct 2 as indicated by the thinner chained line in figure 5. This is however not mandatory.
The working position is maintained as long as the pilot control chamber 37 gets the pilot control pressure. If the pilot control chamber 37 is vented the pilot control force 86 disappears and the control slide 33 will be shifted back by the drive means 77 into the above mentioned venting position of figure 3.
The control duct 67 responsible for the action on the drive face 57 is connected both in the softstart position and also in the working position and during the transition between the two positions with the softstart duct 2 in order to ensure the pressure action on the drive face 57 necessary for the switching over into the working position and the maintenance in the working position; A comparison between figures 4 and 5 will serve to make it clear that the control pressure tapping opening 68 is positioned in each of the above mentioned positions near the softstart duct 2.
As regards the working example it may be summarized again that the softstart valve 21 comprises a primary duct 4 svibject to the primary pressure, a secondary duct 1 and a softstart

duct 2 subject to a softstart pressure which owing to the choke means 35 is at a level less than the primary pressure. Furthermore it has principal valve means 25, by which the secondary duct 1 may be joined with the secondary duct 2, when the primary duct 4 is separated from it, and comprise a control slide 33 able to be shifted into several positions, and which, against a biasing force 86 is able to be switched over out of a position separating the primary duct 4 from the secondary duct 1 into a working position freeing the connection between these ducts because a drive face 57 provided on it, is subjected to softstart pressure from the softstart pressure 2. The control slide 33 governs in a manner dependent on its position the connection of the secondary duct 1 both with primary duct 4 and also with the softstart duct 2, it being able to be positioned in a softstart position connecting the softstart duct 2 with the secondary duct 1 simultaneously separated from the primary duct 4, from which position it can be switched by action occurring owing to the softstart pressure, of the drive face 57 into the working position.
Owing to the softstart valve 21 integrated in the valve means a controlled supply and venting of the valve means 6 is possible without resort to external components. Since the control of the switching positions is caused directly by the pressure action, no electrical pressure sensors are required. The switch over function of the softstart valve 21 can occur in a time and/or pressure dependent fashion.

Claims
1. A valve means with a softstart function comprising a softstart valve (21) having principal valve means (25) able to selectively shut off the connection between a primary duct (4) subject to a primary pressure and a secondary duct (1) in a closed position biased by a biasing force (86) or to open up such connection in an open position, the principal valve means (25) being able to be siibjected to the softstart pressure for switching over into the open position, and the softstart valve is furthermore capable, when the primary duct (4) is separated from the secondary duct (1), to connect the secondary duct (1) with a softstart duct (2) , which is svibjected or able to be subjected to a softstart pressure which owing to choke means (35) is at least initially less than the primary pressure, characterized in that the principal valve means (25) comprise a control slide (33) which is able to be set in different positions and which is able to control the connection of the secondary duct (1) both with the softstart duct (2) and also with the primary duct (4), said control slide (33) furthermore being kinematically coupled with a drive face (57), said drive face being able to be acted upon by the softstart pressure oppositely to the biasing force (86) which also acts on the control slide (33) .
2. The valve means according to claim 1, characterized in that the control slide (33) is able to be positioned in a softstart position, in which it connects the softstart duct (2) with the secondary duct (19), said secondary duct (19) in the softstart position being simultaneously separated from the primary duct (4).
3. The valve means according to either claim 1 or claim 2, characterized in that the control slide (33) is able to be positioned in a working position, in which it connects the

secondary duct (1) with the primary duct (4).
4. The valve means according to claim 3, characterized in that the control slide (33) in its working position connects the secondary duct (1) both with the primary duct (4) and also with the softstart duct (2).
5. The valve means according to any one of the claims 1 through 4, characterized in that the control slide (33) is able to be positioned in a venting position, in which it connects the secondary duct (1), with a simultaneous separation from the primary duct (4) and the softstart duct (2), with a venting duct (3) communicating with the atmosphere.
6. The valve means according to claim 5, characterized in that the connection present in the venting position between the secondary duct (1) and the venting duct (3) takes place using a transfer duct (53) extending through the control slide (33).
7. The valve means according to claim 6, characterized in that a valve member (46) arranged in the control slide (33) is associated to the transfer duct (53), such valve member being able to open the transfer duct (53) in the venting position of the control slide (33) and to close the transfer duct (53) in the other positions of the control slide (33).
8. The valve means according to claim 7, characterized in that the valve member (46) is piston-like in form and is constantly sxibjected to the pressure present in a pilot control chamber (37) which latter for switching over the control slide (33) is able to be subjected to a pilot control pressure, the valve member (46) being able to be thrust by the pilot control pressure against an abutment (48) arranged on the control slide
(33) in order to so apply a setting force to the control slide (33), said abutment (48) in particular being constituted by a

valve seat (4 8a).
9. The valve means according to ctny une uj. Lue uxctxina x
through 8, characterized by a distributor (7) equipped with
several control valves (8), said fluid distributor (7) having a
distributor supply duct (12) and at least one distributor
venting duct (13) which are respectively connected with the
control valves (8), said fluid distributor (7) being fitted
with the softstart valve (21), the distributor supply duct (12)
being connected with the secondary duct (1), and the primary
duct (4) and the softstart duct (2) being respectively
connected with a distributor supply duct (22 and 23) opening at
an outer face of the fluid distributor (7).
10. The valve means according to claim 9 in conjunction with one of the claims 5 through 8, characterized in that the venting duct (3) of the softstart valve (21) is connected with a distributor venting duct (13).
11. The valve means according to claim 9 or claim 10, characterized in that the fluid distributor (7) is provided with several component mounting faces, from which two distributor working ducts (15 and 16) extending through the fluid distributor (7) are starting, respectively, which are preferably at least partly selectively able to be fitted with a control valve (8) or with a softstart valve (21), the distributor working ducts (15 and 16), in the case of the associated component mounting face bearing a softstart valve (21), being able to be used as the distributor supply ducts (22 and 23).
12. The valve means according to any one of the claims 9 through 11, characterized in that the distributor supply duct (22) , comm\anicating with the softstart duct (2) , is provided with choke means (35) arranged in the distributor supply duct

or arranged upstream or downstream from it.
13. The valve means according to any one of the claims 1 through 12, characterized in that the choke means (35) are able to be adjusted as regards their intensity of their choking action.
14. The valve means according to any one of the claims 1 through 13, characterized in that the drive face (57) of the control slide (33) delimits a drive space (66) able to be siibjected to the softstart pressure.
15. The valve means according to claim 14, characterized in that the drive space (66) is connected via at least one control duct (67) with the softstart duct (2) and/or the secondary duct (1) at least when the control slide (33) assumes its softstart position connecting the softstart duct (2) with the secondary duct (1).
16. The valve means according to claim 14 or claim 15 , characterized in that the control duct (67) extends at least in parts thereof in the control slide (33).
17. The valve means according to claim 16, characterized in that the control duct (67) so opens with at least one control pressure tapping opening (68) at a position on the outer periphery of the control slide (33) that this control pressure tapping opening (68) both in the softstart position connecting the secondary duct (1) with the softstart duct (2) and also in the working position connecting the secondary duct (1) with the primary duct (4) communicates with the softstart duct (2) or the secondary duct (1).
18. The valve means according to any one of the claims 14 through 17, characterized in that the drive space (66) is

delimited, on the side opposite the drive face (57) , by an abutment piston (46) able to be displaceable both with respect to the control slide (33) and also to the valve housing (24) in the axial direction of the control slide (33), the abutment piston being able to be displaced by the control slide (33), upon movement of the control slide (33) into the softstart position, into an abutting position having a fixed relationship to the housing and simultaneously predetermining the softstart position of the control slide (33), and the abutment piston (46) so cooperates by means of abutment means (72 and 73) with the control slide (33) that it stops the switching over motion of the control slide (33) entailed by an increase in pressure in the drive space when the working position is reached.
19. The valve means according to claim 18, characterized
in that the abutment piston (64) is biased or able to be biased
by drive means (77) in a direction toward the control slide
(33) .
20. The valve means according to claim 19, characterized in that the drive means (77) are constituted by a spring means (82) bearing on the valve housing (24), said spring means getting compressed when the abutment piston (64) is shifted into the abutment position.
21. The valve means according to any one of the claims 18 through 20, characterized in that a piston tail (74) is arranged on the abutment piston (64) plunging coaxially into the control slide (33) , such piston tail preferably having the abutment means (72 and 73) associated with it.
22. The valve means according to any one of the claims 1 through 21, characterized in that the control slide (33) has a terminal end portion (36) plunging into a pilot control chamber (37) which is able to be acted upon by a pilot pressure in

order to cause the biasing force (86).
23. The valve means according to claim 22, characterized in that the pilot control chamber (37) is associated with the terminal end portion (36), opposite to the drive face (57), of the control slide (33).

Documents:

4757-CHENP-2008 AMENDED CLAIMS 23-07-2013.pdf

4757-CHENP-2008 CORRESPONDENCE OTHERS 12-06-2013.pdf

4757-CHENP-2008 EXAMINATION REPORT REPLY RECEIVED 23-07-2013.pdf

4757-CHENP-2008 FORM-3 23-07-2013.pdf

4757-CHENP-2008 POWER OF ATTORNEY 23-07-2013.pdf

4757-chenp-2008 abstract.jpg

4757-chenp-2008 abstract.pdf

4757-chenp-2008 claims.pdf

4757-chenp-2008 correspondence-others.pdf

4757-chenp-2008 description (complete).pdf

4757-chenp-2008 drawings.pdf

4757-chenp-2008 form-1.pdf

4757-chenp-2008 form-3.pdf

4757-chenp-2008 form-5.pdf

4757-chenp-2008 pct.pdf

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Patent Number

257161

Indian Patent Application Number

4757/CHENP/2008

PG Journal Number

37/2013

Publication Date

13-Sep-2013

Grant Date

06-Sep-2013

Date of Filing

09-Sep-2008

Name of Patentee

FESTO AG & CO. KG

Applicant Address

RUITER STRASSE 82, 73734 ESSLINGEN,

Inventors:

#	Inventor's Name	Inventor's Address
1	GRZEGORZ, BOGDANOWICZ,	IN DEN STEINEN 17/5, 73760 OSTFIDERN,
2	BRENNER, JAKOB,	BAUMREUTE 54, D-73730 ESSLINGEN,

PCT International Classification Number

F15B11/068

PCT International Application Number

PCT/EP07/0570

PCT International Filing date

2007-01-24

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102006010845.0	2006-03-09	Germany