GB2541716A

GB2541716A - Damped hinge

Info

Publication number: GB2541716A
Application number: GB1515261.4A
Authority: GB
Inventors: Chow Chung
Original assignee: BESTKO PREC Ltd
Current assignee: BESTKO PREC Ltd
Priority date: 2015-08-27
Filing date: 2015-08-27
Publication date: 2017-03-01
Anticipated expiration: 2035-08-27
Also published as: CN106481178A; GB201515261D0; CN206256800U; GB2541716B

Abstract

A hinge comprising a housing 1 pivotally connected to a fixture by a coupling including a hinge pivot and a linkage 4, a piston (7 Fig 1) located in a bore in the housing and moveable between first (open) and second (closed) positions along an axis; the linkage comprising a guide 6 is mounted on the head of the piston, the guide 6 having an elongate channel 14 transverse to the piston axis, a contact member 15 16 movable within the channel and pivotally connected to a first member 21 pivotally connected to the housing and a second member 17 pivotally connected to the fixture spaced to the hinged pivot; the contact member moves along the channel between a first position and second position as the hinge is closed (Figs 3-6) and a force exerted by the contact member on the guide urges movement of the piston between the opened and closed positions. The contact may be a roller or toothed gear or pinion. Preferably the piston is a hydraulic and provides a damping force to damp movement between the closed and open positions. The guide channel may have various internal contours (Figs 10-12).

Description

DAMPED HINGE

This invention relates to a hinge for a door or other closure, particularly for a wooden door or a framed glass door. The invention relates particularly but not exclusively to concealed or butt hinges for wooden or metal doors.

Wooden, metal or glass doors are often heavy. Glass doors may be double or triple glazed particularly when intended for exterior use or for chilled rooms. Wooden or metal doors may be very large and may require a robust hinge which provides reliable damped selfclosing avoiding the need for a latch arrangement. GB 2503753 discloses a hinge comprising a housing pivotally connected to a fixture by a coupling; the coupling including a linkage; the housing having a bore therein; a shuttle located in the bore wherein the shuttle is moveable between first and second positions, corresponding to open and closed positions of the hinge; the bore having an internal cavity filled with fluid or gas; a non-moveable baffle located in the cavity to divide the cavity into first and second chambers; a first passageway commimicating between the chambers so that fluid may pass in one direction between the first and second chambers; wherein the shuttle has a head and includes an axial member which extends along the axis of the bore, the head of the shuttle and the axial member being arranged to slide along the bore between the first and second positions; a return passageway extending longitudinally, through the member and communicating between the chambers to provide a restricted flow of fluid between the second and first chambers during movement of the hinge from an open to a closed position; the shuttle being connected to the linkage so that the shuttle moves between the first and second positions as the hinge moves between the closed and open positions; WO2012/07662 discloses a door closer with an accumulator comprising a compressible foam body disposed in a fluid filled chamber. A problem with previously known hinges is that they are relatively long so that a corresponding deep hole must be cut into a door into which they are fitted. Also a relatively large force is necessary to open or close the door.

According to a first aspect of the present invention, a hinge comprises: a housing pivotally connected to a fixture by a coupling; the coupling including a hinge pivot and a linkage; the housing having a bore therein; a piston located in the bore wherein the piston is moveable on an axis between first and second positions, corresponding to open and closed positions of the hinge; the piston having a piston head connected to the linkage so that the piston moves between the first and second positions as the hinge moves between closed and open positions; the linkage comprising a guide mounted on the piston head, the guide including an elongate channel transverse to the piston axis; a contact member constrained to move within the channel, the contact member being pivotally connected to first and second members; the first member being pivotally coimected to the housing; and the second member being pivotally coimected to the fixture at a location in spaced relation to the hinged pivot; arranged so that the contact member moves along the channel between the first position wherein the hinge is opened and a second position wherein the hinge is closed; and wherein a force exerted by the contact member on the guide urges movement of the piston between the opened and closed positions.

The piston preferably provides a force to control or restrain movement between the closed and opened positions. A movement restraining force may be provided to control opening of the hinge. Alternatively or in addition, a movement restraining force may be provided to damp closing of the hinge.

The contact member may comprise a roller movable in the channel. Use of a roller is preferred to reduce friction and wear in use. However, a fixed cylindrical or otherwise shaped member may be used. A cylindrical rod may be employed.

In an alternative embodiment, the contact member may be a toothed gear or pinion, the internal surfaces of the channel including correspondingly shaped toothed racks along which the gear or pinion may roll between the first and second positions. In such an embodiment the distance between the racks is greater than the diameter of the pinion, so that only one rack is engaged at a time.

The channel is preferably perpendicular to the piston axis and preferably has planar parallel faces. The faces may extend orthogonally with respect to the piston axis.

Alternatively, the profile of one or both faces may be non-linear and configured to control the force required to open and close the hinge, as disclosed in more detail below.

In a preferred embodiment, the channel is open at one end and closed at the other end in order to facilitate insertion of the contact member during assembly or maintenance of the hinge.

Preferably the contact member is located at or adjacent the closed end of the channel in the closed position of the hinge and at or adjacent the opened end of the channel in the opened position of the hinge. This arrangement allows a maximum force to be applied to the piston at the closed position in order to maximise damping force applied to the hinge.

The piston may include a piston cap, the guide being releasably secured to the cap. For example, the guide maybe secured by a screw threaded attachment.

The arrangement of the present invention confers several advantages in relation to previously known hinges. Movement of the contact member along a channel which is perpendicular to the piston axis causes the piston to move axially without applying a lateral or twisting force on the piston. The contact member moves in a circular direction relative to the housing. This reduces wear on the piston and allows use of a less robust construction.

The first and second members are preferably connected to the roller or other contact member at a common pivot axis of the roller. This pivot and the pivotal connections of the first member to the housing and the second member to the fixture form a triangular arrangement. The axial distance moved by the common pivot axis of the contact member for each incremental angular movement of the hinge increases exponentially from the fully opened position to the closed position. By this means the volume of fluid displaced by the piston also increases exponentially with increasing angular rotation from the fully opened position to the fully closed position. The volume of fluid displaced for each angular increment increases fi-om the fully opened position to a maximum at the fully closed position. Consequently the damping force reaches a maximum as the hinge approaches the closed position. This arrangement permits use of a less complex construction for the damping hydraulic mechanism.

The first member may be shorter than the second member so that the distance between the pivot axis of the contact member and the pivot axis of the fixture is greater than the distance between the pivot axis of the contact member and the pivot axis of the housing. Use of a relatively short first member allows the extent of travel of the piston to be reduced while maintaining an effective damping force as the closed position is approached.

The present invention permits use of a shorter piston and consequently a shorter housing. A shorter and more powerful but less expensive closing spring may be employed.

Advantageously, the first and second members are fully extended in the fully opened hinge position, forming a held open arrangement which prevents further opening of the hinge. In the held open position the three pivots lie in a straight line so that further extension is not possible.

The members preferably comprise arms having a pivot coupling at each end. The arms may be linear or curved.

In an alternative embodiment, particularly but not exclusively when the hinge is a concealed hinge, the first and second members form a unitary inflexible member having a coupling for the contact member intermediate the ends. The unitary member may be also integral with the fixture.

According to a second aspect of the present invention, a hinge comprises: a housing pivotally cormected to a fixture by a coupling; the coupling including a hinge pivot and a linkage; the housing having a bore therein; a piston located in the bore wherein the piston is moveable on an axis between first and second positions, corresponding to open and closed positions of the hinge; the piston having a piston head connected to the linkage so that the piston moves between the first and second positions as the hinge moves between closed and open positions; wherein the hinge provides a variable motion restraining force during movement from a closed to an open position.

In a first embodiment, the motion restraining force may increase as the hinge is opened. This has the advantage of preventing or reducing the likelihood of a sudden, full outward opening of a door to which the hinge is engaged, reducing the likelihood of shock or injury to a passer-by. Such a hinge may also find application in a windy location to prevent the door from being blown open.

In a seeond embodiment, the motion restraining force may decrease as the hinge is opened. This has the advantage of facilitating use by an elderly, weak or infirm person.

In a third embodiment, the hinge may provide one or two locations at which the movement restoring force is at a maximum in order to reduce or prevent unexpected opening, for example in a public place.

In a fourth embodiment, the channel may include an inward projection, extending away from the hinge axis, adjacent the open position, preventing a door to which the hinge is engaged from being held open. Such an embodiment is useful in making fire doors which are not permitted to be held opened.

In a fifth embodiment, the channel may have a fully closed configuration, being closed at both ends. Such an arrangement provides a limited degree of opening movement dependent on the length of the slot. A kit may comprise one or more hinges as disclosed above, together with interchangeable guides in accordance with the embodiments disclosed above. A plurality of appropriate guides may be selected for each hinge during assembly of the hinge or installation to a door. A hinge may include a linkage comprising a guide mounted on a piston head, the guide including an elongate channel perpendicular to the piston axis, together with two or more guides in accordance with the embodiments disclosed above.

In hinges in which a variable opening motion restraining force is provided, the profile of a surface of the channel facing away from the hinge pivot may be selected as disclosed above.

The hinge pivot may be either concealed or a butt type, exposed between the door and frame in use.

In a first aspect of the invention, a butt hinge has the hinge pivot comprising collars mounted on a hinge pin, is located at a distance from the piston axis greater than the radius of the housing. In this arrangement the collars of the hinge are exposed in use.

In a second aspect, the hinge pivot is located at a distance from the piston axis that is less than the width of the housing so that the hinge is concealed in use. A particularly advantageous embodiment further comprises: the bore having an internal cavity filled with fluid or gas; a non-moveable baffle located in the cavity to divide the cavity into first and second chambers; a first passageway communicating between the chambers so that fluid may pass in one direction between the first and second chambers; wherein the piston includes an axial member which extends along the axis of the bore, the head of the piston and the axial member being arranged to slide along the bore between the first and second positions; a return passageway extending longitudinally, through the member and communicating between the chambers to provide a restricted flow of fluid between the second and first chambers during movement of the hinge from an open to a closed position.

Hinges of this invention may further comprise a stop arrangement to hold the hinge open at a predetermined position.

In more preferred hinges, the first passageway includes a one way valve to restrict flow of fluids as the hinge closes to damp closing of a door in use.

Preferably the one way valve is provided in the baffle. More preferably the one way valve communicates between opposite sides of the baffle. Tlie valve allows flow of fluid from the first chamber to the second chamber during opening of the hinge.

Preferably the bore comprises a cylindrical bore in the housing and the piston comprises a cylindrical member located in the bore.

The piston shuttle includes an axial member which extends along the axis of the bore. The head of the piston and the axial member are arranged to slide along the bore between the first and second positions. A cylindrical cavity surrounds the axial member within the bore. The internal wall of the bore and surfaces of the piston define the cavity in which hydraulic fluid is contained.

The baffle may extend radially from an aperture which receives the axial member to the internal wall of the bore. The baffle provides a seal to the internal wall of the bore preventing passage of fluid around the baffle in use. In this way fluid is forced to pass through the one way valve as the hinge is opened and through the return passageway as the hinge closes.

The stop arrangement may comprise a projection, rebate or other abutment of the piston or linkage arranged to engage a complimentary rebate, projection or other abutment of the housing when the hinge is opened to a predetermined angle.

The projection may comprise a spring loaded ball located in the housing and arranged to be received into a rebate, for example an annular rebate on the exterior of the shuttle or linkage, for example at or adjacent an end of the piston or linkage.

In one embodiment, a pair of rods or other elongate members are located in parallel spaced relation, extending on opposite sides of the shuttle and arranged to engage abutments on the shuttle to retain the shuttle in an open position of the hinge. The abutments may comprise rebates or slots in an outer surface of the shuttle. The abutments may be provided at an end of a shuttle adjaeent a pivot coupling to the linkage.

In preferred embodiment the return passageway may comprise a plurality of channels or bores in the housing communicating between the first and second chambers of the cavity, one or more adjustable valves being provided to control fluid flow within the passageway. Adjustment of the valves may restrict the flow of fluid in the passageway as the hinge moves towards the closed position. This may serve for example to prevent slamming of a door or other closure.

The return passageway extends longitudinally of the axial member. An adjustable valve may be provided at an end of the piston to regulate the flow of hydraulic fluid during closing of the hinge. A hinge may incorporate one or both of the preferred passageway arrangements.

The damping force may be further variable dependent on the angle of the hinge. In order to achieve such variable damping, two or more return passageways may be provided, outlets from the passageways communicating with the first or second chambers being arranged to be closed or opened successively by movement of the piston.

In a preferred embodiment, the two passageways have openings in a chamber located in axially spaced relation so that the piston blocks or unblocks the openings successively during movement between opened and closed positions of the hinge.

The two openings are advantageously located in the first chamber.

Adjustable valves may be provided in the two passageways so that the maximum rate of fluid flow may be adjusted in accordance with a user’s preferences, for example dependent on the size and weight of a door. A hinge in accordance with this invention may further comprise a closing means arranged to urge the hinge into a closed position. A preferred closing arrangement may comprise a helical spring arranged to apply a closing force to a linkage coimecting the housing to the fixture.

The closing means may be located within the housing so that it is integral with a damping means or may comprise a separate hinge unit. For example a door may be mounted on two or more hinges selected from a set of damped hinges, closing hinges, pivot hinges or free swinging hinges, selected as required to meet partieular requirements of the door.

In a preferred embodiment a spring is provided within the housing. A helical compression spring may be located around the piston and arranged to be compressed as the hinge moves to the open position.

The fixture is preferably adapted so that the hinge may be secured to a wall, frame or other permanent structure. The housing may be arranged to be located internally or externally of a door. Alternatively the fixture may be secured to a door and the housing secured to a frame, wall or other structure, for example in a rebate.

The hinges of the present invention confer numerous advantages. The damping arrangement has a minimum of moving parts, and contact surfaces which are liable to wear, in contrast to previously disclosed hinges. An efficient and convenient hold open position may be provided with variable damping as the door approaches a closed position. A minimum quantity of hydraulic fluid may be employed while providing adequate scope for adjustment and control of the application of damping force. Economical manufacture and assembly is facilitated. A kit of complementary damped, closing and freely swinging hinges may be provided for interchangeable use whieh may be required.

The hinges of the present invention may employ compressed air or other gases as a hydraulic fluid in place of oil or hydraulic liquid. References in the specification to fluids or oils should be interpreted accordingly.

The invention is further described by means of an example but not in any limitative sense with reference to the accompanying drawings of which;

Figure 1 is a perspective view of a hinge of this invention;

Figure 2 is an exploded view of the hinge;

Figures 3 to 7 show the hinge in various stages of opening;

Figure 8 is a perspective view of a further hinge of this invention;

Figure 9 is a cross-sectional view of the hinge; and

Figures 10 to 20 show various alternative configurations for the hinge as shown in Figures 8 and 9.

The hinge shown in Figures 1 to 7 comprises a housing (1) comprising a cylindrical body and a mounting bracket pivotally connected to a fixture (2). The housing (1) includes a screw plate (3) for fixing to the edge of a door (not shown). A linkage (4) pivotally connects the housing (1) to an arm (5) extending from the fixture (2). The fixture (2) comprises a first fixing plate (8) arranged to be screwed to a wall, door frame or other support structure, and a second fixing plate (9) adjustably secured to the first fixing plate (8) by means of screws for example (25, 26) mounted in elongate slots in the second fixing plate (9). Rotation of the hinge from the closed to an opened position causes the piston (7) to slide forwardly towards the hinge pivot axis within the housing (1). A damping mechanism is provided by forced circulation of hydraulic fluid within the housing (1) by means of reciprocal motion of the piston (7) within a cylindrical bore provided within the housing. The piston comprises a proximal end (10) located towards the hinge axis and a distal end (11) located away from the hinge axis. An axially extending rod forms a cylindrical member (12) which extends between the proximal and distal ends. The baffle (13) secured to the surface of the bore (27) is fixed to the housing and slidably receives the member (12). The baffle (13) has an axial bore through which the member (12) may slide during operation of the damping mechanism. The inner surface of the bore (27) within the housing provides first (116) and second (117) chambers in which hydraulic fluid is provided. The chambers are connected by a passageway including a one way ball valve (not shown) arranged so that fluid may pass from the second chamber (117) to the first chamber (116) as the piston moves during opening of the hinge, thus during opening of the hinge hydraulic fluid flows freely from the second chamber (117) to the first chamber (116). During closing of the hinge return flow of fluid is prevented by closure of the one way valve.

An axial passageway (115) extends longitudinally of the member (12). Branches of the passageway communicate with the first chamber (116) and second chamber (117) so that a return flow of fluid is possible. The rate of flow of the fluid is restricted by the narrow cross-sectional area of the passage (115). In this way closing of the hinge is damped preventing slamming of a door to which the hinge is attached.

Additional passageways (122) and (119) connect the chambers (116) and (117) together via an adjustable valve (20) formed by needle valves (24,25).

The outlet of passageway (115) communicates with the second chamber (117) so that fluid is forced through adjustable valve (20) and passageway (122) as the piston moves into the hinge opened position. Return of fluid from the valve (20) through passage (119) to opening (129) can be controlled by adjustment of the screw valve.

Passageway (122) with an opening to the first chamber (116) is located distally of the opening (129) and serves to provide an additional passageway for flow of oil during initial stages of closing of the hinge. The flow through passageway (122) may be adjusted by setting the screw (24). Therefore differential damping is obtained dependent on the proximity of the hinge to the fully closed position. A similar arrangement is disclosed in our GB 2503753, the disclosure of which is incorporated into this specification by reference for all purposes.

The linkage shown generally at (4) comprises several components. A guide (6) secured to the head of piston (7) has a transversely extending channel (14) within which a contact member (15) is constrained for transverse movement perpendicular to the piston axis.

The contact member may comprise a rod (16) carrying a roller (15) for rolling engagement with a surface of the channel. Alternatively a rack and pinion arrangement (not shown) may be used. In the Figure 3 embodiment the channel (14) has parallel, planar guide surfaces. A first surface (32) faces distally away from the hinge pivot (30) towards the piston (7), perpendicular to the piston axis. A second surface (33) faces proximally towards the hinge pivot (30), away from the piston and also perpendicular to the piston axis. A first member (4) is pivotally connected at a first end to a pivot on the contact member (15). The first member (4) comprises a pair of arms (17) on each side of the contact member and joined by a cross member (28). The pivot comprises an axial rod (16) of the contact member. A second end of the first member has a second pivot linkage (18) pivotally cormected by a pin (29) to arm (5) integral with the fixture plate (9). Arm (5) is located in spaced relation to the hinge axis. The hinge comprises a hinge pin (30) and collars (31).

Rotation of the hinge plate (9) relative to the housing exerts a pulling or pushing force on the contact member (15,16). A pair of second members (21) are pivotally connected at first ends to the rod (16) of the contact member and are further pivotally connected at a second end (23) to the inner wall of the housing (1).

Two screw needle valves (24, 25) in the head of the piston (7) are accessible through an aperture (26) in the guide (6) to facilitate adjustment of the flow of hydraulic damping fluid.

The pivots (16,18,23) form a triangular configuration as shown in Figure 3B. Successive stages in the movement of the hinge, from the closed to opened configuration as shown in Figures 3 to 7.

Figure 3 shows the fully closed configuration in which the contact member (15, 16) is at the closed end of channel (14). The piston is urged away from the hinge axis fully into the bore (27).

Figures 4 to 7 show successive stages of opening of the hinge. Movement of the pivot (18) on arm (5) away from the guide (6) pulls the contact member (16) away from the closed end of channel (14) towards the open end of the channel. Rotation of second members (21) anticlockwise as shown in Figures 3B to 7B moves the contact member (15) in a circular path so that the piston (7) is urged to move out of the sleeve. Rotation from the Figure 3 position to the first angular orientation of Figure 4 moves the piston by a greater axial distance than during rotation between the Figure 4 and Figure 5 positions. This in turn is greater than the distance between the Figures 5 and 6 positions. This is in turn greater than the distance between the Figures 6 and 7 positions. Therefore the resistance to rotation of the hinge caused by the hinge mechanism decreases as the hinge is opened. Conversely the damping force caused by forced flow of oil or other fluid past the needle valves (24, 25) increases exponentially as the hinge moves from an open to the closed position. This provides for easy opening and damped closing of a door to which the hinge is seeured.

The mechanical advantage provided by the linkage whereby a large movement of the hinge provides a smaller movement of the piston, has the result that a comparatively small force is required to move the piston and actuate the damping mechanism. Therefore a door to which the hinge is attached is easier to open and close than prior art arrangements.

Figures 8 and 9 illustrate an alternative embodiment in which the hinge pin is concealed in use. The arrangement is similar to that shown in Figures 3 to 7, except that the hinge pin (40) is located at a radius from the piston axis which is less than the radius of the housing (1) so that the hinge pin (40) is concealed within a door in use. The first and second members comprise a single unitary inflexible component. The length of the first member is reduced in comparison to the butt hinge of Figures 1 to 7.

Figure 10 shows the linkage of the hinges shown in Figures 1 to 7 and in Figures 8 and 9. The contact member comprising the rod (16) and roller (15) are received in channel (14), having parallel surfaces (32,33) which extend transversely, perpendicular of the piston axis. During opening of the hinge, members (21) rotate (anti-clockwise as shown) causing roller (15) to engage the surface (32) on the proximal side of the channel relative to the hinge pivot, urging the piston outwardly from the housing (1). During this movement one-way valve (34) located in baffle (13) opens, permitting a relatively free flow of fluid from chamber (117) to chamber (116).

During closing of the hinge, the roller (15) engages the surface (33) on the distal side of the channel, pushing the piston into the housing (1). This movement of the piston closes the valve (34) forcing fluid in chamber (116) through the passageways in the piston past the valves (24,25), creating a damping force to resist uncontrolled closing of the hinge. Force applied to the piston during closing increases exponentially as the hinge moves and the members (21) rotate (clockwise as shown) from the opened to the closed position.

Figure 11 shows an embodiment in which the proximal surface (40) is planar but is inclined to both the piston axis and the distal surface (41) of channel (43). Channel (43) has a greater width from the closed end (44) to the open end. Less force is required during opening of the hinge in comparison to the Figure 10 embodiment. The force required to close the hinge is the same as for the Figure 10 embodiment so that efficient damping is achieved during closing. The door may be held open when the first and second members are fixlly extended.

This embodiment is suitable for use by elderly, weak or infirm users without compromising the efficient damping characteristics of the hinge.

Figure 12 shows a further embodiment wherein the proximal surface (50) is inclined so that the open end of channel (51) is at a greater distance from the hinge pivot than the closed end (53). Opening of the hinge creates a greater movement restraining force as roller (54) moves towards the open end of the channel (downwardly as shown). The damping force on closing is the same as in the previous Figures and is adjusted as desired using the needle valves (55,56).

Such a hinge finds particular application in windy conditions or in public places where sudden outward opening of a door is undesirable. The motion restraining force increases linearly as the hinge opens.

Figure 13 shows an alternative embodiment in which the proximal surface (60) is inclined away from the piston so that the channel becomes wider away from the closed end (61). The proximal surface is concave so that the lip (62) extends distally away from the hinge pivot (63).

In this arrangement the hinge is relatively easy to open, in comparison to the Figure 10 embodiment, but exerts a larger movement restraining force as a predetermined opened position is reached. The increased restraining force serves to prevent a door from being fully opened by accident, for example by a gust of wind. Closing of the hinge is the same as for the previous embodiments.

Figure 14 shows a further embodiment in which the proximal surface (65) is convex so that roller (66) encounters and increasing motion restraining force as it moves from the closed end (67) of the channel. When the roller (66) passes an apex (68) of the proximal surface, the force is reduced leading to easier opening as the fully open position is reached. Closing is damped in the same way as for the previous embodiments. The door may be held open when the first and second members are fully extended.

Figure 15 shows a further embodiment wherein the proximal surface of the channel (70) has two concave regions (71,72) joined by a convex region (73). A convex lip (74) is located at the opening of the channel. During opening of the hinge, roller (75) passes successively from the closed end (76) of the channel thiOugh concave region (71) over the apex of convex region (73) and through concave region (72) before encountering convex lip (74). The restraining force to open the door will peak at a predetermined angular position of the door over the apex of convex region (73). Closing of the door is the same as for the preceding embodiments.

Figure 16 shows an embodiment having a proximal surface similar to that of Figure 15 but wherein the distal surface has two convex regions (77,78) connected by a concave region (79). This arrangement provides for a variable motion restraining force to be applied to roller (80) during closing of the hinge in addition to the variable force provided by the proximal surface as described with reference to Figure 15. The charmel (81) has a generally constant width so that lateral width of the roller and contact member within the channel is controlled.

Figure 17 describes a further embodiment in which both proximal and distal surfaces have opposed convex (82,83) and concave (84,85) to provide an alternative variation in the motion restraining force during opening and closing of the hinge.

Figure 18 shows a further embodiment wherein the proximal (86) and distal (87) surfaces are planar parallel surfaces with a convex stop surface (88) provided at the opened position at the mouth of channel (89) to prevent opening of the hinge beyond a predetermined angular orientation. This will also prevent the door from being held open.

Figure 19 shows a further embodiment in which channel (90) has parallel proximal (91) and distal (92) surfaces. The channel is closed at the end corresponding to the opened position of the hinge so that a barrier (93) prevents movement of the roller to a fully opened position of the hinge. In this embodiment the opening of a door to which the hinge is attached is prevented beyond a predetermined angular orientation of the hinge. In further embodiments, various lengths of channel may be used to provide different extents of opening of the hinge.

Figure 20 shows a further emhodiment in which the channel (95) is closed at both ends making a generally elliptical or ovoid cross-sectional configuration. In such an embodiment opening of the hinge beyond a predetermined position dictated by the closed end (96) of the channel (95) prevents unwanted opening of a door to which the hinge is attached. The opening of the door is restrained as roller (97) reaches the opened position due to the concave shape of the proximal surface (98). Pressure required to close the door is also controlled by the concave configuration of the distal surface (99).

Claims

1. A hinge comprising: a housing pivotally connected to a fixture by a coupling; the coupling including a hinge pivot and a linkage; the housing having a bore therein; a piston located in the bore wherein the piston is moveable on an axis between first and second positions, corresponding to open and closed positions of the hinge; the piston having a piston head connected to the linkage so that the piston moves between the first and second positions as the hinge moves between closed and open positions; the linkage comprising a guide mounted on the piston head, the guide including an elongate channel transverse to the piston axis; a contact member constrained to move within the channel, the contact member being pivotally connected to first and second members; the first member being pivotally connected to the housing; and the second member being pivotally connected to the fixture at a location in spaced relation to the hinged pivot; arranged so that the contact member moves along the channel between the first position wherein the hinge is opened and a second position wherein the hinge is closed; and wherein a force exerted by the contact member on the guide urges movement of the piston between the opened and closed positions.

2. A hinge as claimed in claim 1, wherein the piston provides a force to restrain movement between the opened and closed positions.

3. A hinge as claimed in claim 1 or 2, wherein the contact member comprises a roller or a toothed pinion.

4. A hinge as claimed in any preceding claim, wherein the channel is perpendicular to the piston axis.

5. A hinge as claimed in any preceding claim, wherein the channel has planar parallel faces.

6. A hinge as claimed in any of claims 1 to 4, wherein one or both faces has a nonlinear profile configured to control the force required during opening and closing the hinge.

7. A hinge as claimed in any preceding claim, wherein the channel is open at one end.

8. A hinge as claimed in any preceding claim, wherein the first and second members are connected to the roller at a common pivot axis of the roller.

9. A hinge as claimed in claim 8, wherein the axial distance moved on the common pivot axis by the contact member for each incremental angular movement of the hinge increases exponentially from the opened to the closed position.

10. A hinge as claimed in claim 8 or, wherein the first member is shorter than the second member.

11. A hinge as claimed in any of claims 8 to 10, wherein the first and second members are fully extended in the fully opened position to form a held open arrangement.

12. A hinge as claimed in any of claims 1 to 7, wherein the first and second members form a unitary structure.

13. A hinge as claimed in any preceding claim further comprising: a housing pivotally connected to a fixture by a coupling; the coupling including a hinge pivot and a linkage; the housing having a bore therein; a piston located in the bore wherein the piston is moveable on an axis between first and second positions, corresponding to open and closed positions of the hinge; the piston having a piston head connected to the linkage so that the piston moves between the first and second positions as the hinge moves between closed and open positions; wherein the hinge provides a variable motion restraining force during movement from a closed to an open position.

14. A hinge as claimed in claim 13, further comprising: the bore having an internal cavity filled with fluid or gas; a non-moveable baffle located in the cavity to divide the cavity into first and second chambers; a first passageway communicating between the chambers so that fluid may pass in one direction between the first and second chambers; wherein the piston includes an axial member which extends along the axis of the bore, the head of the piston and the axial member being arranged to slide along the bore between the first and second positions; a return passageway extending longitudinally, through the member and communicating between the chambers to provide a restricted flow of fluid between the second and first chambers during movement of the hinge from an open to a closed position.

15. A door mounted on a hinge as claimed in any preceding claim. ,6.' A hinge subsianhaily as hereinbefore described and as illustrated with reference to the accompanying drawings.

15. A hinge as claimed in any preceding claim, wherein the piston includes a piston cap, the guide being releasably secured to the cap.

16. A hinge as claimed in any preceding claim, further comprising: a housing pivotally connected to a fixture by a coupling; the coupling including a hinge pivot and a linkage; the housing having a bore therein; a piston located in the bore wherein the piston is moveable on an axis between first and second positions, corresponding to open and closed positions of the hinge; the piston having a piston head connected to the linkage so that the piston moves between the first and second positions as the hinge moves between closed and open positions; wherein the hinge provides a variable motion restraining force during movement from a closed to an open position.

17. A hinge as claimed in any of claims 1 to 4 which provides a variable motion restraining force during movement from a closed to an open position.

18. A door mounted on a hinge as claimed in any preceding claim.

19. A hinge substantially as hereinbefore described and as illustrated with reference to the accompanying drawings. Amendment to the claims have been filed as follows: CLAIMS

1. A hinge comprising: a housing pivotally connected to a fixture by a coupling; the coupling including a hinge pivot and a linkage; the housing having a bore therein; a piston located in the bore wherein the piston is moveable on an axis between first and second positions, corresponding to open and closed positions of the hinge; the piston having a piston head connected to the linkage so that the piston moves between the first and second positions as the hinge moves between closed and open positions; the linkage comprising a guide mounted on the piston head, the guide including an elongate channel transverse to the piston axis; a contact member constrained to move within the channel, the contact member being pivotally connected to first and second members; the second member being pivotally connected to the housing; and the first member being pivotally connected to the fixture at a location in spaced relation to the hinged pivot; arranged so that the contact member moves along the channel between the first position wherein the hinge is opened and a second position wherein the hinge is closed; and wherein a force exerted by the contact member on the guide urges movement of the piston between the first and second positions.

3. A hinge as claimed in claim 1 or 2, wherein the contact member comprises a roller.

6. A hinge as claimed in any of claims 1 to 4, wherein the channel has two faces and one or both faces has a non-linear profile configured to control the force required during opening and closing the hinge.

7. A hinge as claimed in claim 1 or 2, wherein the contact member comprises a toothed pinion.

8. A hinge as claimed in any preceding claim, wherein the channel is open at one end.

9. A hinge as claimed in any of claims 3 or 4 to 6 when dependent on claim 3, wherein the first and second members are connected to the roller at a common pivot axis of the roller.

10. A hinge as claimed in claim 8, wherein the first member is shorter than the second member.

11. A hinge as claimed in any of claims 1 to 8, wherein the first and second members form a unitary structure.

12. A hinge as claimed in any preceding claim, further comprising: the bore having an internal cavity filled with fluid or gas; a non-moveable baffle located in the cavity to divide the cavity into first and second chambers; a first passageway communicating between the chambers so that fluid may pass in one direction between the first and second chambers; wherein the piston includes an axial member which extends along the axis of the bore, the head of the piston and the axial member being arranged to slide along the bore between the first and second positions; a return passageway extending longitudinally, through the member and communicating between the chambers to provide a restricted flow of fluid or gas between the second and first chambers during movement of the hinge fiOm an open to a closed position.

13. A hinge as claimed in any preceding claim, wherein the piston includes a piston cap, the guide being releasably secured to the cap.

14. A hinge as claimed in any preceding claim, wherein in the open position the hinge pivot, the pivot point between the first member and the fixture and the pivot point between the second member of the housing lie substantially in a straight line.