Title of Invention	DOOR CLOSER
Abstract	The invention relates to all different door closer types, of which all parts like housing (2), eccentric cam disc (1) with driven shaft (3), damping piston (4), spring piston (6) etc., except the spring, are made from plastic material. In this case, the individual parts are manufactured in a procedure without additional cutting, preferably injection moulding, from glass fibre, respectively from carbon fibre reinforced plastic material, and they are automatically assembled without requiring any further retouching work.

Title of Invention

DOOR CLOSER

Abstract

The invention relates to all different door closer types, of which all parts like housing (2), eccentric cam disc (1) with driven shaft (3), damping piston (4), spring piston (6) etc., except the spring, are made from plastic material. In this case, the individual parts are manufactured in a procedure without additional cutting, preferably injection moulding, from glass fibre, respectively from carbon fibre reinforced plastic material, and they are automatically assembled without requiring any further retouching work.

Full Text	DOOR CLOSER The invention relates to a door closer comprising an eccentric cam disc linked to a driven shaft extending out from a housing. The housing is filled with a shock absorbing medium, whereby, seen in the door closer's axis direction, the eccentric cam disc on each side adjoins respectively one pressure roller. Also the eccentric cam disc is engaged in a working connection with a spring piston loaded by a closing spring and is moreover engaged with a damping piston, whereas the piston and the housing consist of oil-proof plastic material. Furthermore, the invention relates to a door closer with a plastic piston presenting an internal toothing, said piston being driven by a pinion arranged on a driven shaft, whereby the driven shaft extends at least on one side out from a housing accommodating the piston and a closing spring. A door closer is known from the Swiss printed patent specification 281 690. Therein the described door closer is suitable for German Standards DIN left hand pivoted or DIN right hand pivoted doors, whereby an existing driven shaft is equipped with a symmetrically executed cam disc which is in contact with the piston and thus with the closing spring. The housing as well as the piston are made from oil-proof plastic material. A door closer species is revealed by DE G 94 13 039 U1, describing a door closer, in which the piston includes an internal toothing. In this case, the toothing and the piston are executed as separate components, and the toothing is preferably made from material other than plastic from which the piston is made. Likewise, at least parts of the pinion being in meshed engagement with the toothing are made partially from metal and plastic material. DE 40 02 889 A1 reveals a door closer, in which the housing is executed as a hollow profile. This hollow profile is executed as single piece and realised from an extruded section made of aluminium alloy or of plastic material. A damping piston composed of a solid body and a thereto connected elastic body made from rubber or plastic material, is described in DE-AS 10 39 886. A piston presenting an external toothing in the form of an inserted toothed rack made from metal or plastic material is found in the US 4,019,222. The object of the invention is to produce a lightweight and inexpensive door closer without any usually required metal removing operation. To solve the problem, the present invention provides a door closer to close a door, said door closer comprising a plastic housing consisting essentially of a plastic material, a plastic drive cam disk consisting essentially of a plastic material and being rotatably disposed in said plastic housing, a plastic output shaft consisting essentially of a plastic material and being disposed to project out a distance from said plastic housing; said plastic drive cam disk being connected to said plastic output shaft to permit transfer of force between said plastic drive cam disk and said plastic output shaft, said plastic output shaft being configured to be operatively connected to a door to permit transfer of force between said plastic output shaft and a door, a plastic spring piston consisting essentially of a plastic material and being slidingly disposed in said plastic housing, a first plastic pressure roller consisting essentially of a plastic material and being disposed between said plastic drive cam disk and said plastic spring piston, said first plastic pressure roller being configured and disposed to rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic spring piston during opening of a door, a spring being mounted in said plastic housing and being disposed to be in contact with said plastic spring piston, said spring being configured and disposed to produce a force to slidingly displace said plastic spring piston during closing of a door, a plastic damping piston consisting essentially of a plastic material and being slidingly disposed in said plastic housing, a second plastic pressure roller consisting essentially of a plastic material and being disposed between said plastic drive cam disk and said plastic damping piston, said second plastic pressure roller being configured to rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic damping piston, at least one of said plastic spring piston and said plastic damping piston being disposed in said plastic housing adjacent to said plastic drive cam disk to provide at least two chambers for containing damping fluid in said plastic housing, said damping fluid being adapted to damp movement of said door closer, at least one of said plastic spring piston and said plastic damping piston being configured to permit flow of said damping fluid between said at least two chambers of said plastic housing, and said plastic housing, said plastic drive cam disk, said plastic spring piston, said plastic damping piston, said plastic output shaft, and said first and second plastic pressure rollers each being configured to exhibit at least substantially the same thermal expansion coefficient. Usually the cylinder walls surrounding the piston have a round outline. This is particularly due to the otherwise required retouching work, as the round shape is the most convenient to realise. However, if it is aimed to manufacture a small inexpensive door closer, that is to say a door closer without a robust structure, then the section of the piston, e.g. of the damping piston and of the spring piston or also the plastic material piston with toothing, may have a different shape than the round section, namely they could have an oval, rectangular, square or quadrangular section. All these shapes can be engineered without any problem from plastic material, as such housings and pistons are made by so-called injection moulding. Thanks to the available plastic materials, these procedures nowadays result in an enormous dimensional tolerance and thus a good fitting precision. Therefore it is also possible to produce at no extra cost for example door closers according to DE 36 45 314 C2 and DE 36 45 315 C2 from plastic material in which piston toothing's teeth present different sizes and a different module. Likewise the opposite toothing of the driven shaft, being in contact with the aforementioned toothing, can be made without any problem from plastic material. With regard to the geometrical sections, such housing must not necessarily be realised as a single piece in injection moulding. It is also possible to produce several segments or even partial segments. These segments or partial segments are assembled respectively joined together via conformed fittings respectively protrusions that match corresponding indentations in the counterpart, which are then durably connected to each other by appropriate procedures like gluing, ultra-sound welding, laser welding or the like. These procedures guarantee that the individual segment's dimensional stability is maintained. Simultaneously the execution of the individual segments of the housing allows also to directly conform or to include in the production process : channels, borings, pockets, valve seats or even the proper valves, without needing any retouching work. Thus the assembly work and the production cost factor is considerably reduced. Usually so-called end caps or covers seal the door closer's end sides, depending on the produced segment according to the inventive idea, these are not necessarily required, as the joining of the individual one sided closed segments allows to consider a pre-assembly of individual pieces. Segments, which can only be closed later, will then receive separate covers. These covers may likewise be connected with the segments respectively with the housing by gluing, ultra-sound welding or the like. In this case, besides covers provided with butt- jointed executions, likewise covers with grooves, undercuts or bayonet-type catches, are possible, thus in this way the assembly times can be reduced when mounting the pieces. Likewise the attachment devices, in form of appropriate borings to mount the ready completed door closer at its final destination can be simultaneously conformed in injection moulding from plastic material without additional cutting. Hereinafter embodiments of the invention are explained in detail with reference to the accompanying drawings which show : Figure 1 : An axial section through a lateral view of an overhead door closer with an eccentric cam disc ; Figure 2 : An axial section through a top view of an overhead door closer according to figure 1 ; Figure 3 : A section through a frontal view of an overhead door closer with an internal toothing ; Figure 4 : A section through a top view on a overhead door closer according to figure 3 ; Figure 5 : A section through a door closer's housing which is composed of individual segments. Figure 6 : A lateral view of two housing halves, comprising two housing segments with a square sectioned piston chamber. Besides the following description of the figures of different embodiment examples according to an overhead door closer, the inventive idea is likewise applicable to floor springs, transom concealed door closers and internal door closers. For the overhead door closers, transom concealed door closers and internal door closers, rods can be used in the form of a rod assembly or an actuation arm in connection with a sliding rail. These parts, sliding rail, actuation arm and rod arm assembly are also made from plastic material having the appropriate stability. The door closer illustrated in figures 1 and 2 presents an eccentric cam disc 1, which is penetrated by a driven shaft 3. In the upper part, the driven shaft 3 is supported inside housing 2 by a driven shaft bearing 17 and in the lower part by a driven shaft bearing 16. In this case, the bearing either consists of sintered material or of a needle bearing respectively a ball bearing. Besides the housing 2, the driven shaft bearings 16 and 17 can also be made of plastic material. On the one side, the curved paths of the eccentric cam disc 1 contact a pressure roller 7, which is supported via an axle 14 inside a damping piston 4 (Fig. 2). On the other side, the eccentric cam disc 1 contacts a pressure roller 8, which is supported via an axle 15 inside a spring piston 6. At the other end of the spring piston 6 abuts a closing spring 13 on the one end and on the other end against a spring counter plate 31. The lateral housing's 2 sides are sealed by covers 18 and 19, which are connected to the housing 2, either by gluing, ultra-sound welding, laser welding or the like. As appropriate channels 20 in connection with valves 29 are required for the control function of a door closer, these have been simultaneously moulded during the production process into the housing 2 without any additional cutting. Inside the damping piston 4 as well as inside the spring piston 6, during production process of these pistons, furthermore return valves 5 have simultaneously been moulded. However, it is also possible to separately produce these return valves 5, whereby in such case they will also consist of plastic material. In order to attach such housing 2 at a door or above a door, an attachment device 28 has been simultaneously moulded within the housing or conformed to the housing during the production process and again without additional cutting. By the method of plastic material processing without any retouching work it is understood that besides the continuous cylinder boring for the damping piston 4, for the spring piston 6 and for the closing spring 13, which are circularly executed in the state of the art, other shapes are possible. These shapes could especially comprise an oval form, which simultaneously means that the closer would be considerably smaller dimensioned, respectively a rectangular or square form. In figure 2, representing a single piece housing, it is obvious that due to the identical material of the damping piston 4 as well as of the spring piston 6 and of the eccentric cam disc 1 with the driven shaft 3, because of warming, caused for example by sun radiation, with such door closer type there will be no problem with thermal expansion, because the used materials have got the same expansion coefficient for all components. This is not accomplished in the state of the art, because when utilising for example steel or light metal in connection with plastic material, these materials all have different thermal expansion coefficients, this circumstance forcibly leads to leakage and failure of such door. In another embodiment example in the figures 3 and 4, a toothed rack door closer with a piston 10 made from plastic material and having an internal toothing 11 is represented. A pinion 12 is in working connection with a toothing 11 whereby the pinion 12 is conformed on the driven shaft 3. In addition to the housing 9, in this embodiment example, the piston 10 with its toothing 11 and the driven shaft 3 with its pinion 12 are likewise made from plastic material. Thus the door closer presents the same characteristics as the one in figures 1 and 2, that means with this door closer warming would not lead either to function failure, as the expansion coefficients are the same. The end sides of the housing 9 are likewise concealed by covers 18 and 19, which are similarly connected to the housing 9 by gluing, ultra-sound welding, laser welding or the like. In case of a floor spring executed completely in plastic material, it is obvious that the cement case for the floor spring is likewise made of plastic material. The embodiment example illustrated in figure 5 shows a door closer housing which is composed of several segments 21 and 22. In this case, it is possible to individually engineer different segments, as for example the segment 22, which is shown as a segment open on one side with conformed attachment devices 28. At their areas to be joined, the segments 21 and 22 are provided with fittings 26 and indentations 27, which will interconnect upon assembly and after subsequent operation to join the segments 21 and 22, they will engage and moreover provide dimensional stable connection. The piston chamber 30 located inside the segments 21 and 22 is closed on the open side of segment 21 by means of a cover 19. Without requiring any additional cutting, a boring 23, for the driven shaft bearing 16 and 17 as represented in figure 1, is moreover simultaneously moulded in segment 21. In addition to the separation into segments 21 and 22, it is possible to subdivide the segments differently, as shown in figure 6. Here we see segments 24 and 25, which are linked in the longitudinal door closer's direction by means of fittings 26 and indentations 27. Simultaneously in this embodiment example of figure 6, the piston chamber 30 is represented as a quadrangular piston chamber. All the aforementioned embodiment examples, which are certainly not complete, are assumed to be door closers of any type, which are assembled without any retouching work on the individual parts and segments. In this case, such assembly may take place in an automated process. The parts manufactured from plastic material, preferably injection moulded without any further retouching work, are connected to each other by gluing, ultra-sound welding, laser welding or the like. The used plastic material may be carbon fibre or glass fibre reinforced plastic. References : 1 Eccentric cam disc 2 Housing 3 Driven shaft 4 Damping piston 5 Return valve 6 Spring piston 7, 8 Pressure rollers 9 Housing 10 Piston 11 Toothing 12 Pinion 13 Closing spring 14, 15 Axles 16, 17 Driven shaft bearings 18, 19 Covers 20 Channel 21,22 Segments 23 Boring for driven shaft 24,25 Segments 26 Fitting 27 Indentation 28 Attachment device 29 Valve 30 Piston chamber 31 Spring counter plate WE CLAIM : 1. A door closer to close a door, said door closer comprising : a plastic housing consisting essentially of a plastic material; a plastic drive cam disk consisting essentially of a plastic material and being rotatably disposed in said plastic housing; a plastic output shaft consisting essentially of a plastic material and being disposed to project out a distance from said plastic housing; said plastic drive cam disk being connected to said plastic output shaft to permit transfer of force between said plastic drive cam disk and said plastic output shaft; said plastic output shaft being configured to be operatively connected to a door to permit transfer of force between said plastic output shaft and a door; a plastic spring piston consisting essentially of a plastic material and being slidingly disposed in said plastic housing; a first plastic pressure roller consisting essentially of a plastic material and being disposed between said plastic drive cam disk and said plastic spring piston; said first plastic pressure roller being configured and disposed to rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic spring piston during opening of a door; a spring being mounted in said plastic housing and being disposed to be in contact with said plastic spring piston; said spring being configured and disposed to produce a force to slidingly displace said plastic spring piston during closing of a door; a plastic damping piston consisting essentially of a plastic material and being slidingly disposed in said plastic housing; a second plastic pressure roller consisting essentially of a plastic material and being disposed between said plastic drive cam disk and said plastic damping piston; said second plastic pressure roller being configured to rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic damping piston; at least one of : said plastic spring piston and said plastic damping piston being disposed in said plastic housing adjacent to said plastic drive cam disk to provide at least two chambers for containing damping fluid in said plastic housing, said damping fluid being adapted to damp movement of said door closer; at least one of : said plastic spring piston and said plastic damping piston being configured to permit flow of said damping fluid between said at least two chambers of said plastic housing; and said plastic housing, said plastic drive cam disk, said plastic spring piston, said plastic damping piston, said plastic output shaft, and said first and second plastic pressure rollers each being configured to exhibit at least substantially the same thermal expansion coefficient. 2. The door closer as claimed in claim 1, wherein : said door closer is one of: a floor-mounted door closer; a frame-mounted door closer; an internal, concealed, door-mounted door closer being configured to be disposed and concealed within a door; and a door closer comprising a plastic connecting arrangement consisting essentially of a plastic material and configured to operatively connect said plastic output shaft to a door, said connecting arrangement being one of : a scissors-type linkage and a slide rail arrangement; each of said plastic spring piston and said plastic damping piston comprises one of: an oval cross section; a circular cross section; a rectangular cross section; and a square cross section; and at least one of said plastic materials is reinforced with one of: glass fibres and carbon fibres. 3. The door closer as claimed in claim 2, comprising at least one of (A) and (B), wherein (A) and (B) comprise : (A) said plastic damping piston comprises a check valve; and said check valve is molded with said plastic damping piston and said check valve and said plastic damping piston together comprise a molded, one- piece structure; and (B) said plastic spring piston comprises a check valve; and said check valve is molded into said plastic spring piston and said check valve and said plastic spring piston together comprise a molded, one- piece structure. 4. The door closer as claimed in claim 3, wherein : said plastic housing comprises fastening devices configured to permit fastening of said door closer to a door or a building structure; said fastening devices and said plastic housing together comprise a molded, one-piece structure; said plastic housing comprises channels and valves to control transfer of damping fluid and borings; said plastic housing, said channels, said valves, and said borings together comprise a molded, one-piece structure having finished surfaces; each of said pistons comprises channels and valves to control transfer of damping fluid and borings; and each of said pistons and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces. 5. The door closer as claimed in claim 3, wherein : said plastic housing comprises a plurality of segments; said segments comprise molded lugs and depressions which correspond to said molded lugs to connect said segments to each other to form said plastic housing; said segments are connected to one another by one of: glue; an ultrasonic weld; and a laser weld; said plastic housing comprises end caps disposed at opposite ends of said plastic housing; said end caps are connected to said plastic housing by one of: glue; an ultrasonic weld; and a laser weld; at least one of said segments comprises a fastening device configured to permit fastening of said door closer to a door or a building structure; said fastening device and its corresponding segment together comprise a molded, one-piece structure; at least one of said segments comprises channels and valves to control transfer of damping fluid; said channels and said valves and their corresponding segment together comprise a molded, one-piece structure having finished surfaces; at least one of said segments comprises a boring; said boring and its corresponding segment together comprise a molded, one-piece structure having finished surfaces; each of said pistons comprises channels and valves to control transfer of damping fluid and borings; and each of said pistons and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces. 6. A door closer to close a door, said door closer comprising : a plastic housing consisting essentially of a plastic material; a plastic pinion consisting essentially of a plastic material and being rotatably disposed in said plastic housing; a plastic output shaft consisting essentially of a plastic material and being disposed to project out a distance from said plastic housing; said plastic pinion being connected to said plastic output shaft to permit transfer of force between said plastic pinion and said plastic output shaft; said plastic output shaft being configured to be operatively connected to a door to permit transfer of force between said plastic output shaft and a door; a plastic piston consisting essentially of a plastic material and being slidingly disposed in said plastic housing; said plastic piston comprising an internal gearing; said plastic pinion being configured ahd disposed to engage with said internal gearing of said plastic piston to slidingly displace said plastic piston during opening of a door; a spring being mounted in said plastic housing and connected to said plastic piston to produce a force to slidingly displace said plastic piston during closing of a door; damping fluid being configured to damp movement of said door closer; said plastic piston being disposed in said plastic housing to divide said plastic housing into at least two chambers for containing said damping fluid in said plastic housing; said plastic piston being configured to permit flow of said damping fluid between said at least two chambers of said plastic housing; and said plastic housing, said plastic pinion, said plastic piston, and said plastic output shaft each being configured to exhibit at least substantially the same thermal expansion coefficient. 7. The door closer as claimed in claim 6, wherein : said door closer is one of: a floor-mounted door closer; a frame-mounted door closer; an internal, concealed, door-mounted door closer being configured to be disposed and concealed within a door; and a door closer comprising a plastic connecting arrangement consisting essentially of a plastic material and configured to operatively connect said plastic output shaft to a door, said connecting arrangement being one of: a scissors- type linkage and a slide rail arrangement; and said plastic piston comprises one of: an oval cross section; a circular cross section; a rectangular cross section; and a square cross section. 8. The door closer as claimed in claim 7, wherein : at least one of said plastic materials is reinforced with one of : glass fibres and carbon fibres; said plastic piston comprises a check valve; and said check valve is molded into said plastic piston and said check valve and said plastic piston together comprise a molded, one-piece structure. 9. The door closer as claimed in claim 8, wherein : said plastic housing comprises fastening devices configured to permit fastening of said door closer to a door or a building structure; said fastening devices and said plastic housing together comprise a molded, one-piece structure; said plastic housing comprises channels and valves to control transfer of damping fluid and borings; said plastic housing, said channels, said valves, and said borings together comprise a molded, one-piece structure having finished surfaces; said plastic piston comprises channels and valves to control transfer of damping fluid and borings; said plastic piston and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces; said internal gearing formation comprises gear teeth of different sizes with different moduli; and said plastic pinion has matching gear teeth complementary with said gear teeth of said internal gearing formation. 10. The door closer as claimed in claim 8, wherein : said plastic housing comprises a plurality of segments; said segments comprise molded lugs and depressions which correspond to said molded lugs to connect said segments to each other to form said plastic housing; said segments are connected to one another by one of : glue; an ultrasonic weld; and a laser weld; said plastic housing comprises end caps disposed at opposite ends of said plastic housing; said end caps are connected to said plastic housing by one of: glue; an ultrasonic weld; and a laser weld; at least one of said segments comprises a fastening device configured to permit fastening of said door closer to a door or a building structure; said fastening device and its corresponding segment together comprise a molded, one-piece structure; at least one of said segments comprises channels and valves to control transfer of damping fluid; said channels and said valves and their corresponding segment together comprise a molded, one-piece structure having finished surfaces; at least one of said segments comprises a boring; said boring and its corresponding segment together comprise a molded, one-piece structure having finished surfaces; said plastic piston comprises channels and valves to control transfer of damping fluid and borings; said plastic piston and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces; said internal gearing formation comprises gear teeth of different sizes with different moduli; and said plastic pinion has matching gear teeth complementary with said gear teeth of said internal gearing formation. 11. A door closer to close a door, said door closer comprising : a plastic housing being formed from a plastic material; a plastic drive cam disk being formed from a plastic material and being rotatably disposed in said plastic housing; a plastic output shaft being formed from a plastic material and being disposed to project out a distance from said plastic housing; said plastic drive cam disk being connected to said plastic output shaft to permit transfer of force between said plastic drive cam disk and said plastic output shaft; said plastic output shaft being configured to be operatively connected to a door to permit transfer of force between said plastic output shaft and a door; a plastic spring piston being formed from a plastic material and being slidingly disposed in said plastic housing; a first plastic pressure roller being formed from a plastic material and being disposed between said plastic drive cam disk and said plastic spring piston; said first plastic pressure roller being configured and disposed to rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic spring piston during opening of a door; a spring being mounted in said plastic housing and being disposed to be in contact with said plastic spring piston; said spring being configured and disposed to produce a force to slidingly displace said plastic spring piston during closing of a door; a plastic damping piston being formed from a plastic material and being slidingly disposed in said plastic housing; a second plastic pressure roller being formed from a plastic material and being disposed between said plastic drive cam disk and said plastic damping piston; said second plastic pressure roller being configured to rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic damping piston; at least one of : said plastic spring piston and said plastic damping piston being disposed in said plastic housing adjacent to said plastic drive cam disk to provide at least two chambers in said plastic housing; said at least two chambers being configured to contain damping fluid to damp movement of said door closer; at least one of : said plastic spring piston and said plastic damping piston being configured to permit flow of damping fluid between said at least two chambers of said plastic housing; and said plastic housing, said plastic drive cam disk, said plastic spring piston, said plastic damping piston, said plastic output shaft, and said first and second plastic pressure rollers each being configured to exhibit at least substantially the same thermal expansion coefficient. 12. The door closer as claimed in claim 11, wherein : said door closer is one of: a floor-mounted door closer; a frame-mounted door closer; an internal, concealed, door mounted door closer being configured to be disposed and concealed within a door; and a door closer comprising a plastic connecting arrangement formed from a plastic material and configured to operatively connect said plastic output shaft to a door, said connecting arrangement being one of: a scissors-type linkage and a slide rail arrangement; each of said plastic spring piston and said plastic damping piston comprises one of: an oval cross section; a circular cross section; a rectangular cross section; and a square cross section; and at least one of said plastic materials is reinforced with one of: glass- fibres and carbon fibres. 13. The door closer as claimed in claim 12, having at least one of (A) and (B), wherein (A) and (B) comprise : (A) said plastic damping piston comprises a check valve; and said check valve is molded with said plastic damping piston and said check valve and said plastic damping piston together comprise a molded, one- piece structure; and (B) said plastic spring piston comprises a check valve; and said check valve is molded into said plastic spring piston and said check valve and said plastic spring piston together comprise a molded, one- piece structure. 14. The door closer as claimed in claim 13, wherein : said plastic housing comprises fastening devices configured to permit fastening of said door closer to a door or a building structure; said fastening devices and said plastic housing together comprise a molded, one-piece structure; said plastic housing comprises channels and valves to control transfer of damping fluid and borings; said plastic housing, said channels, said valves, and said borings together comprise a molded, one-piece structure having finished surfaces; each of said pistons comprises channels and valves to control transfer of damping fluid and borings; and each of said pistons and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces. 15. The door closer as claimed in claim 13, wherein : said plastic housing comprises a plurality of segments; said segments comprise molded lugs and depressions which correspond to said molded lugs to connect said segments to each other to form said plastic housing; said segments are connected to one another by one of: glue; an ultrasonic weld; and a laser weld; said plastic housing comprises end caps disposed at opposite ends of said plastic housing; said end caps are connected to said plastic housing by one of: glue; an ultrasonic weld; and a laser weld; at least one of said segments comprises a fastening device configured to permit fastening of said door closer to a door or a building structure; said fastening device and its corresponding segment together comprise a molded, one-piece structure; at least one of said segments comprises channels and valves to control transfer of damping fluid; said channels and said valves and their corresponding segment together comprise a molded, one-piece structure having finished surfaces; at least one of said segments comprises a boring; said boring and its corresponding segment together comprise a molded, one-piece structure having finished surfaces; each of said pistons comprises channels and valves to control transfer of damping fluid and borings; and each of said pistons and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces. 16. A door closer to close a door, said door closer comprising : a plastic housing being formed from a plastic material; a plastic pinion being formed from a plastic material and being rotatably disposed in said plastic housing; a plastic output shaft being formed from a plastic material and being disposed to project out a distance from said plastic housing; said plastic pinion being connected to said plastic output shaft to permit transfer of force between said plastic pinion and said plastic output shaft; said plastic output shaft being configured to be operatively connected to a door to permit transfer of force between said plastic output shaft and a door; a plastic piston being formed from a plastic material and being slidingly disposed in said plastic housing; said plastic piston comprising an internal gearing; said plastic pinion being configured and disposed to engage with said internal gearing of said plastic piston to siidingly displace said plastic piston during opening of a door; a spring being mounted in said plastic housing and connected to said plastic piston to produce a force to siidingly displace said plastic piston during closing of a door; said plastic piston being disposed in said plastic housing to divide said plastic housing into at least two chambers; said at least two chambers being configured to contain damping fluid to damp movement of said door closer; said plastic piston being configured to permit flow of damping fluid between said at least two chambers of said plastic housing; and said plastic housing, said plastic pinion, said plastic piston, and said plastic output shaft each being configured to exhibit at least substantially the same thermal expansion coefficient. 17. The door closer as claimed in claim 16, wherein : said door closer is one of: a floor-mounted door closer; a frame-mounted door closer; an internal, concealed, door-mounted door closer being configured to be disposed and concealed within a door; and a door closer comprising a plastic connecting arrangement formed from a plastic material and configured to operatively connect said plastic output shaft to a door, said connecting arrangement being one of : a scissors-type linkage and a slide rail arrangement; and said plastic piston comprises one of: an oval cross section; a circular cross section; a rectangular cross section; and a square cross section. 18. The door closer as claimed in claim 17, wherein : at least one of said plastic materials is reinforced with one of : glass fibres and carbon fibres; said plastic piston comprises a check valve; and said check valve is molded into said plastic piston and said check valve and said plastic piston together comprise a molded, one-piece structure. 19. The door closer as claimed in claim 18, wherein : said plastic housing comprises fastening devices configured to permit fastening of said door closer to a door or a building structure; said fastening devices and said plastic housing together comprise a molded, one piece structure; said plastic housing comprises channels and valves to control transfer of damping fluid and borings; said plastic housing, said channels, said valves, and said borings together comprise a molded, one-piece structure having finished surfaces; said plastic piston comprises channels and valves to control transfer of damping fluid and borings; said plastic piston and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces; said internal gearing formation comprises gear teeth of different sizes with different moduli; and said plastic pinion has matching gear teeth complementary with said gear teeth of said internal gearing formation. 20. The door closer as claimed in claim 18, wherein : said plastic housing comprises a plurality of segments; said segments comprise molded lugs and depressions which correspond to said molded lugs to connect said segments to each other to form said plastic housing; said segments are connected to one another by one of: glue; an ultrasonic weld; and a laser weld; said plastic housing comprises end caps disposed at opposite ends of said plastic housing; said end caps are connected to said plastic housing by one of: glue; an ultrasonic weld; and a laser weld; at least one of said segments comprises a fastening device configured to permit fastening of said door closer to a door Or a building structure; said fastening device and its corresponding segment together comprise a molded, one-piece structure; at least one of said segments comprises channels and valves to control transfer of damping fluid; said channels and said valves and their corresponding segment together comprise a molded, one-piece structure having finished surfaces; at least one of said segments comprises a boring; said boring and its corresponding segment together comprise a molded, one-piece structure having finished surfaces; said plastic piston comprises channels and valves to control transfer of damping fluid and borings; said plastic piston and its corresponding channels, valves, and borings together comprise a molded, one-piece structure having finished surfaces; said internal gearing formation comprises gear teeth of different sizes with different moduli; and said plastic pinion has matching gear teeth complementary with said gear teeth of said internal gearing formation. The invention relates to all different door closer types, of which all parts like housing (2), eccentric cam disc (1) with driven shaft (3), damping piston (4), spring piston (6) etc., except the spring, are made from plastic material. In this case, the individual parts are manufactured in a procedure without additional cutting, preferably injection moulding, from glass fibre, respectively from carbon fibre reinforced plastic material, and they are automatically assembled without requiring any further retouching work.

Full Text

DOOR CLOSER
The invention relates to a door closer comprising an eccentric cam disc linked to
a driven shaft extending out from a housing. The housing is filled with a shock
absorbing medium, whereby, seen in the door closer's axis direction, the
eccentric cam disc on each side adjoins respectively one pressure roller. Also
the eccentric cam disc is engaged in a working connection with a spring piston
loaded by a closing spring and is moreover engaged with a damping piston,
whereas the piston and the housing consist of oil-proof plastic material.
Furthermore, the invention relates to a door closer with a plastic piston
presenting an internal toothing, said piston being driven by a pinion arranged on
a driven shaft, whereby the driven shaft extends at least on one side out from a
housing accommodating the piston and a closing spring.
A door closer is known from the Swiss printed patent specification 281 690.
Therein the described door closer is suitable for German Standards DIN left
hand pivoted or DIN right hand pivoted doors, whereby an existing driven shaft is
equipped with a symmetrically executed cam disc which is in contact with the
piston and thus with the closing spring. The housing as well as the piston are
made from oil-proof plastic material.
A door closer species is revealed by DE G 94 13 039 U1, describing a door
closer, in which the piston includes an internal toothing. In this case, the toothing
and the piston are executed as separate components, and the toothing is
preferably made from material other than plastic from which the piston is
made. Likewise, at least parts of the pinion being in meshed engagement with
the toothing are made partially from metal and plastic material.
DE 40 02 889 A1 reveals a door closer, in which the housing is executed as a
hollow profile. This hollow profile is executed as single piece and realised from
an extruded section made of aluminium alloy or of plastic material. A damping
piston composed of a solid body and a thereto connected elastic body made
from rubber or plastic material, is described in DE-AS 10 39 886.
A piston presenting an external toothing in the form of an inserted toothed rack
made from metal or plastic material is found in the US 4,019,222.
The object of the invention is to produce a lightweight and inexpensive door
closer without any usually required metal removing operation.
To solve the problem, the present invention provides a door closer to close a
door, said door closer comprising a plastic housing consisting essentially of a
plastic material, a plastic drive cam disk consisting essentially of a plastic
material and being rotatably disposed in said plastic housing, a plastic output
shaft consisting essentially of a plastic material and being disposed to project out
a distance from said plastic housing; said plastic drive cam disk being connected

to said plastic output shaft to permit transfer of force between said plastic drive
cam disk and said plastic output shaft, said plastic output shaft being configured
to be operatively connected to a door to permit transfer of force between said
plastic output shaft and a door, a plastic spring piston consisting essentially of a
plastic material and being slidingly disposed in said plastic housing, a first plastic
pressure roller consisting essentially of a plastic material and being disposed
between said plastic drive cam disk and said plastic spring piston, said first
plastic pressure roller being configured and disposed to rotate upon rotation of
said plastic drive cam disk to slidingly displace said plastic spring piston during
opening of a door, a spring being mounted in said plastic housing and being
disposed to be in contact with said plastic spring piston, said spring being
configured and disposed to produce a force to slidingly displace said plastic
spring piston during closing of a door, a plastic damping piston consisting
essentially of a plastic material and being slidingly disposed in said plastic
housing, a second plastic pressure roller consisting essentially of a plastic
material and being disposed between said plastic drive cam disk and said plastic
damping piston, said second plastic pressure roller being configured to rotate
upon rotation of said plastic drive cam disk to slidingly displace said plastic
damping piston, at least one of said plastic spring piston and said plastic
damping piston being disposed in said plastic housing adjacent to said plastic
drive cam disk to provide at least two chambers for containing damping fluid in
said plastic housing, said damping fluid being adapted to damp movement of
said door closer, at least one of said plastic spring piston and said plastic

damping piston being configured to permit flow of said damping fluid between
said at least two chambers of said plastic housing, and said plastic housing, said
plastic drive cam disk, said plastic spring piston, said plastic damping piston,
said plastic output shaft, and said first and second plastic pressure rollers each
being configured to exhibit at least substantially the same thermal expansion
coefficient.
Usually the cylinder walls surrounding the piston have a round outline. This is
particularly due to the otherwise required retouching work, as the round shape is
the most convenient to realise. However, if it is aimed to manufacture a small
inexpensive door closer, that is to say a door closer without a robust structure,
then the section of the piston, e.g. of the damping piston and of the spring piston
or also the plastic material piston with toothing, may have a different shape than
the round section, namely they could have an oval, rectangular, square or
quadrangular section. All these shapes can be engineered without any problem
from plastic material, as such housings and pistons are made by so-called
injection moulding. Thanks to the available plastic materials, these procedures
nowadays result in an enormous dimensional tolerance and thus a good fitting
precision.
Therefore it is also possible to produce at no extra cost for example door closers
according to DE 36 45 314 C2 and DE 36 45 315 C2 from plastic material in
which piston toothing's teeth present different sizes and a different module.

Likewise the opposite toothing of the driven shaft, being in contact with the
aforementioned toothing, can be made without any problem from plastic
material.
With regard to the geometrical sections, such housing must not necessarily be
realised as a single piece in injection moulding. It is also possible to produce
several segments or even partial segments. These segments or partial
segments are assembled respectively joined together via conformed fittings
respectively protrusions that match corresponding indentations in the
counterpart, which are then durably connected to each other by appropriate
procedures like gluing, ultra-sound welding, laser welding or the like. These
procedures guarantee that the individual segment's dimensional stability is
maintained. Simultaneously the execution of the individual segments of the
housing allows also to directly conform or to include in the production process :
channels, borings, pockets, valve seats or even the proper valves, without
needing any retouching work. Thus the assembly work and the production cost
factor is considerably reduced.
Usually so-called end caps or covers seal the door closer's end sides, depending
on the produced segment according to the inventive idea, these are not
necessarily required, as the joining of the individual one sided closed segments
allows to consider a pre-assembly of individual pieces. Segments, which can
only be closed later, will then receive separate covers. These covers may

likewise be connected with the segments respectively with the housing by gluing,
ultra-sound welding or the like. In this case, besides covers provided with butt-
jointed executions, likewise covers with grooves, undercuts or bayonet-type
catches, are possible, thus in this way the assembly times can be reduced when
mounting the pieces.
Likewise the attachment devices, in form of appropriate borings to mount the
ready completed door closer at its final destination can be simultaneously
conformed in injection moulding from plastic material without additional cutting.
Hereinafter embodiments of the invention are explained in detail with reference
to the accompanying drawings which show :
Figure 1 : An axial section through a lateral view of an overhead door
closer with an eccentric cam disc ;
Figure 2 : An axial section through a top view of an overhead door closer
according to figure 1 ;
Figure 3 : A section through a frontal view of an overhead door closer with
an internal toothing ;
Figure 4 : A section through a top view on a overhead door closer
according to figure 3 ;
Figure 5 : A section through a door closer's housing which is composed of
individual segments.
Figure 6 : A lateral view of two housing halves, comprising two housing

segments with a square sectioned piston chamber.
Besides the following description of the figures of different embodiment
examples according to an overhead door closer, the inventive idea is likewise
applicable to floor springs, transom concealed door closers and internal door
closers. For the overhead door closers, transom concealed door closers and
internal door closers, rods can be used in the form of a rod assembly or an
actuation arm in connection with a sliding rail. These parts, sliding rail, actuation
arm and rod arm assembly are also made from plastic material having the
appropriate stability.
The door closer illustrated in figures 1 and 2 presents an eccentric cam disc 1,
which is penetrated by a driven shaft 3. In the upper part, the driven shaft 3 is
supported inside housing 2 by a driven shaft bearing 17 and in the lower part by
a driven shaft bearing 16. In this case, the bearing either consists of sintered
material or of a needle bearing respectively a ball bearing. Besides the housing
2, the driven shaft bearings 16 and 17 can also be made of plastic material. On
the one side, the curved paths of the eccentric cam disc 1 contact a pressure
roller 7, which is supported via an axle 14 inside a damping piston 4 (Fig. 2). On
the other side, the eccentric cam disc 1 contacts a pressure roller 8, which is
supported via an axle 15 inside a spring piston 6. At the other end of the spring
piston 6 abuts a closing spring 13 on the one end and on the other end against a
spring counter plate 31. The lateral housing's 2 sides are sealed by covers 18

and 19, which are connected to the housing 2, either by gluing, ultra-sound
welding, laser welding or the like. As appropriate channels 20 in connection with
valves 29 are required for the control function of a door closer, these have been
simultaneously moulded during the production process into the housing 2 without
any additional cutting. Inside the damping piston 4 as well as inside the spring
piston 6, during production process of these pistons, furthermore return valves 5
have simultaneously been moulded. However, it is also possible to separately
produce these return valves 5, whereby in such case they will also consist of
plastic material.
In order to attach such housing 2 at a door or above a door, an attachment
device 28 has been simultaneously moulded within the housing or conformed to
the housing during the production process and again without additional cutting.
By the method of plastic material processing without any retouching work it is
understood that besides the continuous cylinder boring for the damping piston 4,
for the spring piston 6 and for the closing spring 13, which are circularly executed
in the state of the art, other shapes are possible. These shapes could especially
comprise an oval form, which simultaneously means that the closer would be
considerably smaller dimensioned, respectively a rectangular or square form.
In figure 2, representing a single piece housing, it is obvious that due to the
identical material of the damping piston 4 as well as of the spring piston 6 and of

the eccentric cam disc 1 with the driven shaft 3, because of warming, caused for
example by sun radiation, with such door closer type there will be no problem
with thermal expansion, because the used materials have got the same
expansion coefficient for all components. This is not accomplished in the state
of the art, because when utilising for example steel or light metal in connection
with plastic material, these materials all have different thermal expansion
coefficients, this circumstance forcibly leads to leakage and failure of such door.
In another embodiment example in the figures 3 and 4, a toothed rack door
closer with a piston 10 made from plastic material and having an internal toothing
11 is represented. A pinion 12 is in working connection with a toothing 11
whereby the pinion 12 is conformed on the driven shaft 3. In addition to the
housing 9, in this embodiment example, the piston 10 with its toothing 11 and the
driven shaft 3 with its pinion 12 are likewise made from plastic material. Thus
the door closer presents the same characteristics as the one in figures 1 and 2,
that means with this door closer warming would not lead either to function failure,
as the expansion coefficients are the same. The end sides of the housing 9 are
likewise concealed by covers 18 and 19, which are similarly connected to the
housing 9 by gluing, ultra-sound welding, laser welding or the like.
In case of a floor spring executed completely in plastic material, it is obvious that
the cement case for the floor spring is likewise made of plastic material.

The embodiment example illustrated in figure 5 shows a door closer housing
which is composed of several segments 21 and 22. In this case, it is possible to
individually engineer different segments, as for example the segment 22, which
is shown as a segment open on one side with conformed attachment devices 28.
At their areas to be joined, the segments 21 and 22 are provided with fittings 26
and indentations 27, which will interconnect upon assembly and after
subsequent operation to join the segments 21 and 22, they will engage and
moreover provide dimensional stable connection. The piston chamber 30
located inside the segments 21 and 22 is closed on the open side of segment 21
by means of a cover 19. Without requiring any additional cutting, a boring 23, for
the driven shaft bearing 16 and 17 as represented in figure 1, is moreover
simultaneously moulded in segment 21.
In addition to the separation into segments 21 and 22, it is possible to subdivide
the segments differently, as shown in figure 6. Here we see segments 24 and
25, which are linked in the longitudinal door closer's direction by means of fittings
26 and indentations 27. Simultaneously in this embodiment example of figure 6,
the piston chamber 30 is represented as a quadrangular piston chamber.
All the aforementioned embodiment examples, which are certainly not complete,
are assumed to be door closers of any type, which are assembled without any
retouching work on the individual parts and segments. In this case, such

assembly may take place in an automated process. The parts manufactured
from plastic material, preferably injection moulded without any further retouching
work, are connected to each other by gluing, ultra-sound welding, laser welding
or the like. The used plastic material may be carbon fibre or glass fibre
reinforced plastic.
References :
1 Eccentric cam disc
2 Housing
3 Driven shaft
4 Damping piston
5 Return valve
6 Spring piston
7, 8 Pressure rollers
9 Housing
10 Piston
11 Toothing
12 Pinion
13 Closing spring
14, 15 Axles
16, 17 Driven shaft bearings
18, 19 Covers
20 Channel

21,22 Segments
23 Boring for driven shaft
24,25 Segments
26 Fitting
27 Indentation
28 Attachment device
29 Valve
30 Piston chamber
31 Spring counter plate
WE CLAIM :
1. A door closer to close a door, said door closer comprising :
a plastic housing consisting essentially of a plastic material;
a plastic drive cam disk consisting essentially of a plastic material and
being rotatably disposed in said plastic housing;
a plastic output shaft consisting essentially of a plastic material and
being disposed to project out a distance from said plastic housing;
said plastic drive cam disk being connected to said plastic output shaft
to permit transfer of force between said plastic drive cam disk and said plastic
output shaft;
said plastic output shaft being configured to be operatively connected
to a door to permit transfer of force between said plastic output shaft and a door;
a plastic spring piston consisting essentially of a plastic material and
being slidingly disposed in said plastic housing;
a first plastic pressure roller consisting essentially of a plastic material
and being disposed between said plastic drive cam disk and said plastic spring
piston;
said first plastic pressure roller being configured and disposed to
rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic
spring piston during opening of a door;
a spring being mounted in said plastic housing and being disposed to
be in contact with said plastic spring piston;

said spring being configured and disposed to produce a force to
slidingly displace said plastic spring piston during closing of a door;
a plastic damping piston consisting essentially of a plastic material
and being slidingly disposed in said plastic housing;
a second plastic pressure roller consisting essentially of a plastic
material and being disposed between said plastic drive cam disk and said plastic
damping piston;
said second plastic pressure roller being configured to rotate upon
rotation of said plastic drive cam disk to slidingly displace said plastic damping
piston;
at least one of : said plastic spring piston and said plastic damping
piston being disposed in said plastic housing adjacent to said plastic drive cam
disk to provide at least two chambers for containing damping fluid in said plastic
housing, said damping fluid being adapted to damp movement of said door
closer;
at least one of : said plastic spring piston and said plastic damping
piston being configured to permit flow of said damping fluid between said at least
two chambers of said plastic housing; and
said plastic housing, said plastic drive cam disk, said plastic spring
piston, said plastic damping piston, said plastic output shaft, and said first and
second plastic pressure rollers each being configured to exhibit at least
substantially the same thermal expansion coefficient.

2. The door closer as claimed in claim 1, wherein :
said door closer is one of:
a floor-mounted door closer;
a frame-mounted door closer;
an internal, concealed, door-mounted door closer being
configured to be disposed and concealed within a door; and
a door closer comprising a plastic connecting arrangement
consisting essentially of a plastic material and configured to operatively connect
said plastic output shaft to a door, said connecting arrangement being one of : a
scissors-type linkage and a slide rail arrangement;
each of said plastic spring piston and said plastic damping piston
comprises one of:
an oval cross section;
a circular cross section;
a rectangular cross section; and
a square cross section; and
at least one of said plastic materials is reinforced with one of: glass
fibres and carbon fibres.
3. The door closer as claimed in claim 2, comprising at least one of (A)
and (B), wherein (A) and (B) comprise :
(A) said plastic damping piston comprises a check valve; and
said check valve is molded with said plastic damping piston and said

check valve and said plastic damping piston together comprise a molded, one-
piece structure; and
(B) said plastic spring piston comprises a check valve; and
said check valve is molded into said plastic spring piston and said
check valve and said plastic spring piston together comprise a molded, one-
piece structure.
4. The door closer as claimed in claim 3, wherein :
said plastic housing comprises fastening devices configured to permit
fastening of said door closer to a door or a building structure;
said fastening devices and said plastic housing together comprise a
molded, one-piece structure;
said plastic housing comprises channels and valves to control transfer
of damping fluid and borings;
said plastic housing, said channels, said valves, and said borings
together comprise a molded, one-piece structure having finished surfaces;
each of said pistons comprises channels and valves to control transfer
of damping fluid and borings; and
each of said pistons and its corresponding channels, valves, and
borings together comprise a molded, one-piece structure having finished
surfaces.

5. The door closer as claimed in claim 3, wherein :
said plastic housing comprises a plurality of segments;
said segments comprise molded lugs and depressions which
correspond to said molded lugs to connect said segments to each other to form
said plastic housing;
said segments are connected to one another by one of:
glue;
an ultrasonic weld; and
a laser weld;
said plastic housing comprises end caps disposed at opposite ends of
said plastic housing;
said end caps are connected to said plastic housing by one of:
glue;
an ultrasonic weld; and
a laser weld;
at least one of said segments comprises a fastening device configured
to permit fastening of said door closer to a door or a building structure;
said fastening device and its corresponding segment together
comprise a molded, one-piece structure;
at least one of said segments comprises channels and valves to
control transfer of damping fluid;
said channels and said valves and their corresponding segment

together comprise a molded, one-piece structure having finished surfaces;
at least one of said segments comprises a boring;
said boring and its corresponding segment together comprise a
molded, one-piece structure having finished surfaces;
each of said pistons comprises channels and valves to control transfer
of damping fluid and borings; and
each of said pistons and its corresponding channels, valves, and
borings together comprise a molded, one-piece structure having finished
surfaces.
6. A door closer to close a door, said door closer comprising :
a plastic housing consisting essentially of a plastic material;
a plastic pinion consisting essentially of a plastic material and being
rotatably disposed in said plastic housing;
a plastic output shaft consisting essentially of a plastic material and
being disposed to project out a distance from said plastic housing;
said plastic pinion being connected to said plastic output shaft to
permit transfer of force between said plastic pinion and said plastic output shaft;
said plastic output shaft being configured to be operatively connected
to a door to permit transfer of force between said plastic output shaft and a door;
a plastic piston consisting essentially of a plastic material and being
slidingly disposed in said plastic housing;
said plastic piston comprising an internal gearing;

said plastic pinion being configured ahd disposed to engage with said
internal gearing of said plastic piston to slidingly displace said plastic piston
during opening of a door;
a spring being mounted in said plastic housing and connected to said
plastic piston to produce a force to slidingly displace said plastic piston during
closing of a door;
damping fluid being configured to damp movement of said door
closer;
said plastic piston being disposed in said plastic housing to divide said
plastic housing into at least two chambers for containing said damping fluid in
said plastic housing;
said plastic piston being configured to permit flow of said damping
fluid between said at least two chambers of said plastic housing; and
said plastic housing, said plastic pinion, said plastic piston, and said
plastic output shaft each being configured to exhibit at least substantially the
same thermal expansion coefficient.
7. The door closer as claimed in claim 6, wherein :
said door closer is one of:
a floor-mounted door closer;
a frame-mounted door closer;
an internal, concealed, door-mounted door closer being configured to
be disposed and concealed within a door; and

a door closer comprising a plastic connecting arrangement consisting
essentially of a plastic material and configured to operatively connect said plastic
output shaft to a door, said connecting arrangement being one of: a scissors-
type linkage and a slide rail arrangement; and
said plastic piston comprises one of:
an oval cross section;
a circular cross section;
a rectangular cross section; and
a square cross section.
8. The door closer as claimed in claim 7, wherein :
at least one of said plastic materials is reinforced with one of : glass
fibres and carbon fibres;
said plastic piston comprises a check valve; and
said check valve is molded into said plastic piston and said check
valve and said plastic piston together comprise a molded, one-piece structure.
9. The door closer as claimed in claim 8, wherein :
said plastic housing comprises fastening devices configured to permit
fastening of said door closer to a door or a building structure;
said fastening devices and said plastic housing together comprise a
molded, one-piece structure;
said plastic housing comprises channels and valves to control transfer

of damping fluid and borings;
said plastic housing, said channels, said valves, and said borings
together comprise a molded, one-piece structure having finished surfaces;
said plastic piston comprises channels and valves to control transfer
of damping fluid and borings;
said plastic piston and its corresponding channels, valves, and borings
together comprise a molded, one-piece structure having finished surfaces;
said internal gearing formation comprises gear teeth of different sizes
with different moduli; and
said plastic pinion has matching gear teeth complementary with said
gear teeth of said internal gearing formation.
10. The door closer as claimed in claim 8, wherein :
said plastic housing comprises a plurality of segments;
said segments comprise molded lugs and depressions which
correspond to said molded lugs to connect said segments to each other to form
said plastic housing;
said segments are connected to one another by one of :
glue;
an ultrasonic weld; and
a laser weld;
said plastic housing comprises end caps disposed at opposite ends of
said plastic housing;

said end caps are connected to said plastic housing by one of:
glue;
an ultrasonic weld; and
a laser weld;
at least one of said segments comprises a fastening device configured
to permit fastening of said door closer to a door or a building structure;
said fastening device and its corresponding segment together
comprise a molded, one-piece structure;
at least one of said segments comprises channels and valves to
control transfer of damping fluid;
said channels and said valves and their corresponding segment
together comprise a molded, one-piece structure having finished surfaces;
at least one of said segments comprises a boring;
said boring and its corresponding segment together comprise a
molded, one-piece structure having finished surfaces;
said plastic piston comprises channels and valves to control transfer
of damping fluid and borings;
said plastic piston and its corresponding channels, valves, and borings
together comprise a molded, one-piece structure having finished surfaces;
said internal gearing formation comprises gear teeth of different sizes
with different moduli; and
said plastic pinion has matching gear teeth complementary with said
gear teeth of said internal gearing formation.

11. A door closer to close a door, said door closer comprising :
a plastic housing being formed from a plastic material;
a plastic drive cam disk being formed from a plastic material and
being rotatably disposed in said plastic housing;
a plastic output shaft being formed from a plastic material and being
disposed to project out a distance from said plastic housing;
said plastic drive cam disk being connected to said plastic output shaft
to permit transfer of force between said plastic drive cam disk and said plastic
output shaft;
said plastic output shaft being configured to be operatively connected
to a door to permit transfer of force between said plastic output shaft and a door;
a plastic spring piston being formed from a plastic material and being
slidingly disposed in said plastic housing;
a first plastic pressure roller being formed from a plastic material and
being disposed between said plastic drive cam disk and said plastic spring
piston;
said first plastic pressure roller being configured and disposed to
rotate upon rotation of said plastic drive cam disk to slidingly displace said plastic
spring piston during opening of a door;
a spring being mounted in said plastic housing and being disposed to
be in contact with said plastic spring piston;
said spring being configured and disposed to produce a force to
slidingly displace said plastic spring piston during closing of a door;

a plastic damping piston being formed from a plastic material and
being slidingly disposed in said plastic housing;
a second plastic pressure roller being formed from a plastic material
and being disposed between said plastic drive cam disk and said plastic
damping piston;
said second plastic pressure roller being configured to rotate upon
rotation of said plastic drive cam disk to slidingly displace said plastic damping
piston;
at least one of : said plastic spring piston and said plastic damping
piston being disposed in said plastic housing adjacent to said plastic drive cam
disk to provide at least two chambers in said plastic housing;
said at least two chambers being configured to contain damping fluid
to damp movement of said door closer;
at least one of : said plastic spring piston and said plastic damping
piston being configured to permit flow of damping fluid between said at least two
chambers of said plastic housing; and
said plastic housing, said plastic drive cam disk, said plastic spring
piston, said plastic damping piston, said plastic output shaft, and said first and
second plastic pressure rollers each being configured to exhibit at least
substantially the same thermal expansion coefficient.

12. The door closer as claimed in claim 11, wherein :
said door closer is one of:
a floor-mounted door closer;
a frame-mounted door closer;
an internal, concealed, door mounted door closer being configured to
be disposed and concealed within a door; and
a door closer comprising a plastic connecting arrangement formed
from a plastic material and configured to operatively connect said plastic output
shaft to a door, said connecting arrangement being one of:
a scissors-type linkage and a slide rail arrangement;
each of said plastic spring piston and said plastic damping piston
comprises one of:
an oval cross section;
a circular cross section;
a rectangular cross section; and
a square cross section; and
at least one of said plastic materials is reinforced with one of: glass-
fibres and carbon fibres.
13. The door closer as claimed in claim 12, having at least one of (A) and
(B), wherein (A) and (B) comprise :
(A) said plastic damping piston comprises a check valve; and

said check valve is molded with said plastic damping piston and said
check valve and said plastic damping piston together comprise a molded, one-
piece structure; and
(B) said plastic spring piston comprises a check valve; and
said check valve is molded into said plastic spring piston and said
check valve and said plastic spring piston together comprise a molded, one-
piece structure.
14. The door closer as claimed in claim 13, wherein :
said plastic housing comprises fastening devices configured to permit
fastening of said door closer to a door or a building structure;
said fastening devices and said plastic housing together comprise a
molded, one-piece structure;
said plastic housing comprises channels and valves to control transfer
of damping fluid and borings;
said plastic housing, said channels, said valves, and said borings
together comprise a molded, one-piece structure having finished surfaces;
each of said pistons comprises channels and valves to control transfer
of damping fluid and borings; and
each of said pistons and its corresponding channels, valves, and
borings together comprise a molded, one-piece structure having finished
surfaces.

15. The door closer as claimed in claim 13, wherein :
said plastic housing comprises a plurality of segments;
said segments comprise molded lugs and depressions which
correspond to said molded lugs to connect said segments to each other to form
said plastic housing;
said segments are connected to one another by one of:
glue;
an ultrasonic weld; and
a laser weld;
said plastic housing comprises end caps disposed at opposite ends of
said plastic housing;
said end caps are connected to said plastic housing by one of:
glue;
an ultrasonic weld; and
a laser weld;
at least one of said segments comprises a fastening device configured
to permit fastening of said door closer to a door or a building structure;
said fastening device and its corresponding segment together
comprise a molded, one-piece structure;
at least one of said segments comprises channels and valves to
control transfer of damping fluid;
said channels and said valves and their corresponding segment

together comprise a molded, one-piece structure having finished surfaces;
at least one of said segments comprises a boring;
said boring and its corresponding segment together comprise a
molded, one-piece structure having finished surfaces;
each of said pistons comprises channels and valves to control transfer
of damping fluid and borings; and
each of said pistons and its corresponding channels, valves, and
borings together comprise a molded, one-piece structure having finished
surfaces.
16. A door closer to close a door, said door closer comprising :
a plastic housing being formed from a plastic material;
a plastic pinion being formed from a plastic material and being
rotatably disposed in said plastic housing;
a plastic output shaft being formed from a plastic material and being
disposed to project out a distance from said plastic housing;
said plastic pinion being connected to said plastic output shaft to
permit transfer of force between said plastic pinion and said plastic output shaft;
said plastic output shaft being configured to be operatively connected
to a door to permit transfer of force between said plastic output shaft and a door;
a plastic piston being formed from a plastic material and being
slidingly disposed in said plastic housing;
said plastic piston comprising an internal gearing;

said plastic pinion being configured and disposed to engage with said
internal gearing of said plastic piston to siidingly displace said plastic piston
during opening of a door;
a spring being mounted in said plastic housing and connected to said
plastic piston to produce a force to siidingly displace said plastic piston during
closing of a door;
said plastic piston being disposed in said plastic housing to divide said
plastic housing into at least two chambers;
said at least two chambers being configured to contain damping fluid
to damp movement of said door closer;
said plastic piston being configured to permit flow of damping fluid
between said at least two chambers of said plastic housing; and
said plastic housing, said plastic pinion, said plastic piston, and said
plastic output shaft each being configured to exhibit at least substantially the
same thermal expansion coefficient.
17. The door closer as claimed in claim 16, wherein :
said door closer is one of:
a floor-mounted door closer;
a frame-mounted door closer;
an internal, concealed, door-mounted door closer being configured to
be disposed and concealed within a door; and

a door closer comprising a plastic connecting arrangement formed
from a plastic material and configured to operatively connect said plastic output
shaft to a door, said connecting arrangement being one of : a scissors-type
linkage and a slide rail arrangement; and
said plastic piston comprises one of:
an oval cross section;
a circular cross section;
a rectangular cross section; and
a square cross section.
18. The door closer as claimed in claim 17, wherein :
at least one of said plastic materials is reinforced with one of : glass
fibres and carbon fibres;
said plastic piston comprises a check valve; and
said check valve is molded into said plastic piston and said check
valve and said plastic piston together comprise a molded, one-piece structure.
19. The door closer as claimed in claim 18, wherein :
said plastic housing comprises fastening devices configured to permit
fastening of said door closer to a door or a building structure;
said fastening devices and said plastic housing together comprise a
molded, one piece structure;
said plastic housing comprises channels and valves to control transfer

of damping fluid and borings;
said plastic housing, said channels, said valves, and said borings
together comprise a molded, one-piece structure having finished surfaces;
said plastic piston comprises channels and valves to control transfer
of damping fluid and borings;
said plastic piston and its corresponding channels, valves, and borings
together comprise a molded, one-piece structure having finished surfaces;
said internal gearing formation comprises gear teeth of different sizes
with different moduli; and
said plastic pinion has matching gear teeth complementary with said
gear teeth of said internal gearing formation.
20. The door closer as claimed in claim 18, wherein :
said plastic housing comprises a plurality of segments;
said segments comprise molded lugs and depressions which
correspond to said molded lugs to connect said segments to each other to form
said plastic housing;
said segments are connected to one another by one of:
glue;
an ultrasonic weld; and
a laser weld;
said plastic housing comprises end caps disposed at opposite ends of
said plastic housing;

said end caps are connected to said plastic housing by one of:
glue;
an ultrasonic weld; and
a laser weld;
at least one of said segments comprises a fastening device configured
to permit fastening of said door closer to a door Or a building structure;
said fastening device and its corresponding segment together
comprise a molded, one-piece structure;
at least one of said segments comprises channels and valves to
control transfer of damping fluid;
said channels and said valves and their corresponding segment
together comprise a molded, one-piece structure having finished surfaces;
at least one of said segments comprises a boring;
said boring and its corresponding segment together comprise a
molded, one-piece structure having finished surfaces;
said plastic piston comprises channels and valves to control transfer
of damping fluid and borings;
said plastic piston and its corresponding channels, valves, and borings
together comprise a molded, one-piece structure having finished surfaces;
said internal gearing formation comprises gear teeth of different sizes
with different moduli; and
said plastic pinion has matching gear teeth complementary with said
gear teeth of said internal gearing formation.

The invention relates to all different door closer types, of which all parts like housing (2),
eccentric cam disc (1) with driven shaft (3), damping piston (4), spring piston (6) etc.,
except the spring, are made from plastic material. In this case, the individual parts are
manufactured in a procedure without additional cutting, preferably injection moulding,
from glass fibre, respectively from carbon fibre reinforced plastic material, and they are
automatically assembled without requiring any further retouching work.

Documents:

IN-PCT-2000-218-KOL-CORRESPONDENCE 1.1.pdf

IN-PCT-2000-218-KOL-CORRESPONDENCE 1.3.pdf

IN-PCT-2000-218-KOL-CORRESPONDENCE-1.2.pdf

IN-PCT-2000-218-KOL-CORRESPONDENCE.pdf

IN-PCT-2000-218-KOL-FORM 13-1.1.pdf

IN-PCT-2000-218-KOL-FORM 27 1.2.pdf

IN-PCT-2000-218-KOL-FORM 27-1.1.pdf

IN-PCT-2000-218-KOL-FORM 27.pdf

IN-PCT-2000-218-KOL-FORM-27.pdf

in-pct-2000-218-kol-granted-abstract.pdf

in-pct-2000-218-kol-granted-claims.pdf

in-pct-2000-218-kol-granted-correspondence.pdf

in-pct-2000-218-kol-granted-description (complete).pdf

in-pct-2000-218-kol-granted-drawings.pdf

in-pct-2000-218-kol-granted-examination report.pdf

in-pct-2000-218-kol-granted-form 1.pdf

in-pct-2000-218-kol-granted-form 13.pdf

in-pct-2000-218-kol-granted-form 18.pdf

in-pct-2000-218-kol-granted-form 2.pdf

in-pct-2000-218-kol-granted-form 26.pdf

in-pct-2000-218-kol-granted-form 3.pdf

in-pct-2000-218-kol-granted-form 5.pdf

in-pct-2000-218-kol-granted-priority document.pdf

in-pct-2000-218-kol-granted-reply to examination report.pdf

in-pct-2000-218-kol-granted-specification.pdf

in-pct-2000-218-kol-granted-translated copy of priority document.pdf

IN-PCT-2000-218-KOL-PA 1.2.pdf

IN-PCT-2000-218-KOL-PA-1.1.pdf

IN-PCT-2000-218-KOL-PA.pdf

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Patent Number

234235

Indian Patent Application Number

IN/PCT/2000/218/KOL

PG Journal Number

20/2009

Publication Date

15-May-2009

Grant Date

12-May-2009

Date of Filing

14-Aug-2000

Name of Patentee

DORMA GMBH + CO. KG

Applicant Address

BRECKERFELDER STR. 42-48 D-58256 ENNEPETAL

Inventors:

#	Inventor's Name	Inventor's Address
1	TILLMANN, HORST	SIEDLUNG KOHLSTADT 4A D-58256 ENNEPETAL
2	GINZEL, LOTHAR	AM HERMANNSBRUNNEN 26 D-58239 SCHWERTE (DE)
3	GOLLNICK, GÜNTER	FRANFURTER STRASSE 96 D-58339 BRECKERFELD
4	TILLMANN, HORST	SIEDLUNG KOHLSTADT 4A D-58256 ENNEPETAL
5	GINZEL, LOTHAR	AM HERMANNSBRUNNEN 26 D-58239 SCHWERTE (DE)
6	GOLLNICK, GÜNTER	FRANFURTER STRASSE 96 D-58339 BRECKERFELD

PCT International Classification Number

E05F 3/00

PCT International Application Number

PCT/EP1999/09538

PCT International Filing date

1999-12-06

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA