HINGE

Abstract: A hinge adapted to be fitted between a vehicle body (4) and a pivoted member (2) forming part thereof in which counterbalancing torque spring means (20) is incorporated into the hinge. The torque spring means may be attached at one end to one of the hinge arms (8), the remainder of the spring means tending to coil around the abutment means (23) secured to or formed integrally with the other hinge arm (6), such that the spring is uncoiled as the hinge is closed, thereby generating a restoring force tending to open the hinge.

Description: Title; Hinge Field of the Invention This invention relates to hinges particularly (but not exclusively) for mounting body members such as bonnets, boot lids, and lower tail gates of motor vehicles. Background to the Invention Vehicle body members such as the above, are heavy to lift. Consequently it is known to counter balance their weight by spring-loaded struts or by gas struts, separate from the hinge assemblies and acting between the member and vehicle body at locations remote from the hinge. The use of separate struts gives rise to the need for additional mounting points required for attaching the opposite ends of the strut to the vehicle and may encroach on the usable space within the vehicle. In addition such struts can become permanently damaged due to careless and vigorous treatment of the hinged member. The invention aims to provide a more compact hinge structure for such applications. Summary of the Invention According to one aspect of the invention counterbalancing torque spring means is incorporated into a hinge adapted to be fitted between a vehicle body and an upwardly pivotable member forming part thereof. In one embodiment, one end of the torque spring means is attached directly or indirectly to one of the hinge arms and abutment means is secured to or formed integrally with the other hinge arm around which the remainder of the torque spring means is at least partially coiled, the relative positions of the point of attachment and the abutment means being such as to uncoil the spring means as the hinge is closed thereby to generate a restoring force tending to open the hinge. Preferably, the point of attachment of the torque spring and the said one hinge arm describes a curved path as the hinge arms pivot. Conveniently, the said one hinge arm includes a drum surface (or part thereof) in the region of the hinge point, and the spring end is attached to a point on the said drum surface (or part thereof). The drum surface may have a constant radius of curvature. Where this is the case, different torque/angular displacement characteristics may be obtained depending on whether the centre of curvature is concentric with the axis of the hinge or eccentric thereto. Alternatively, the drum surface may be in the shape of a compound curve having a plurality of radii of curvature to produce different torque/angular displacement characteristics. Whether the drum surface has a varying radius of curvature or constant radius of curvature which is ecentric with the hinge axis, the arrangement is preferably such that the maximum opening torque is exerted by the torque spring means when the hinge is in a closed position. Preferably, the coiling of the torque spring means around the drum surface is opposite to the direction of curvature of the coiling of the torque spring over the abutment means, so that the restoring force is made up of two components, one due to the tendency of the spring to recoil and the other due to the reversal of the curvature of the length of the spring which has been unwound. The invention also provides a hinge which comprises two arms which are movable between an open position and a closed position, and are adapted for respective connection to two relatively movable parts; torque spring means attached directly or indirectly to one arm at a position spaced from the hinge axis; abutment means on the other arm engaged by the spring means the latter tending to coil around the abutment means, wherein the torque spring means is reversibly unwound with closing of the hinge so as to exert a force on the arms to urge them into their open position. Preferably, the torque spring means is attached to a drum surface itself attached to or forming part of the said one arm. In one embodiment, the arms are connected for pivotal movement about a single axis, in which case, one of the arms may be adapted to be attached to a vehicle body and the other arm may be adapted to be attached to a movable body member of the vehicle such as a boot lid. By incorporating a spring into the hinge, the invention enables the two hinged parts to be both hingedly interconnected and biased towards an open position without the need for separate hinge an strut structures. At least part of the spring means may to advantage be interposed between the arms to produce a compact hinge. By interposing all of the torque spring means between the arms so a very compact construction of hinge becomes possible. The invention also lies in a hinge for providing a pivotal interconnection between first and second members, which comprises two parts for respective connection to the first and second members, linkage means pivotally interconnecting the two parts and enabling the latter to be moved between a closed position, in which the two parts lie closely adjacent one another, and an open position, in which the parts are separated, and spring means exerting a force which urges the two members into the said open position thereof, the spring means nesting between the two parts at least when the latter are in their closed position. The linkage means includes at least one rigid strut and the spring means applies a biasing force to a point intermediate the ends of the strut in a direction to urge the strut towards the position it occupies in the open position of the hinge. Preferably the linkage means includes two rigid struts each pivotally connected at its ends to each of the two hinge parts at spaced positions therealong so that the struts and the said hinge form a collapsible quadrilateral linkage. In a preferred embodiment, one strut is shorter than the other and the spring means acts between a point intermediate the ends thereof and the junction of one end of the longer link and one of the two hinge parts. The spring is preferably a torque spring and may comprise a plurality of superimposed elongate spring metal leaves the number being chosen to provide the required restoring force. One or both of the struts may be of bifurcated construction thereby to straddle the hinge parts and provide a very compact form in the closed position of the hinge, which is an important consideration for a boot lid hinge where the available space for the hinge is limited. A hinge according to the invention may be used for a motor vehicle bonnet, tailgate or other similar body member which must be pivotal relative to the vehicle body. The invention also lies in a vehicle having an upwardly pivotable member forming part of the body thereof, mounted thereto by a hinge constructed in accordance with the present invention. Brief Description of the Drawings The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figures 1 and 2 are schematic side views of a hinge according to the first aspect of the invention shown respectively in an open and a closed condition; Figures 3 and 4 are perspective views of the hinge taken from different angles; Figure 5 is a sectional side view of the hinge; Figure 6a is a perspective view from one side of an alternative type of hinge in accordance with the invention; Figure 6b is a sectional side view of the hinge of Figure 6a showing the latter when attached to panels of a vehicle body; Figure 6c is a perspective view from the other side of the hinge of Figure 6a; Figure 7 is a side view of a further alternative type of hinge, shown in its closed position attached to panels of a vehicle body; Figure 8 is an underside view of the hinge of Figure 7 itself partially cut away to show internal detail and with the vehicle body panels removed for clarity; Figure 9 is a cross section of the hinge assembly of Figure 7, on the line III-III, Figure 10 is a side view of the hinge of Figure 7 shown in its open position. Detailed description of the illustrated embodiments The hinge shown in Figures 1 to 4 is intended for use in connecting a car boot lid (partially shown at 2) to a car body part of which is shown at 4. The hinge comprises curved arm 6 attached to the boot lid 2 and an arm 8 attached to the body 4. The arm 8 carries a subframe 9 which, as best seen in Figures 3 and 4, is attached thereto by two blocks 10, 12 attached to opposite side members of a generally rectangular frame 14. One end of the curved arm 6 projects into the central region of the frame 14 and is pivotally connected thereto by a hinge pin 15 which extends between and is supported by the two opposite side members of the frame 14. The frame 14 is also attached to a cylindrical ring 16 part of the curved surface of which is extended laterally to form an arcuate platform 17 which spans the frame 14. A torque spring 20 is secured at one end to the outer surface of the platform 17 by means of a screw 22, and extends tangentially from the arcuate surface 17 to pass below and around a roller 23 carried by the curved arm 6, so as to at least in part encircle the roller. The latter is mounted on the arm 6 by means of a bracket 24 attached to and extending on opposite sides thereof. The restoring force exerted by the uncoiled spring 20 urges the arm 6 in a clockwise direction as denoted by the arrow A in Figure 1. The spring 20 consists of a plurality of superimposed leaves of stainless steel. The number of leaves determines the magnitude of the restoring force acting on the arm 6. The open position of the hinged assembly is shown in Figure 1, and the closed position, in Figure 2. Anticlockwise movement of the arm 6 from the open to the closed position tends to uncoil the spring 20 from around the roller 23 and force it to wrap around part of the curved surface of the ring 16 and platform 17. The centre of curvature of the curved surface 16, 17 does not coincide with the axis of the pin 15. Rotation of the ring 16 about pin axis 15 increases the radius of the point at which the spring first engages the curved surface 16, 17 and thus correspondingly increases the torque applied by the spring 20 on the arm 6 about the pin 15 as the arm 6 is forced in an anticlockwise manner against the action of the spring. Thus, the hinge can be arranged to exert the maximum torque on the arm 6 and the boot lid 2 attached thereto, when the latter is in its lowered, (and therefore is closed position) . As shown in dotted outline in Figure 5, some or all of the ring 16 is optional, where the hinge is only required to provide for pivoting of the boot lid through approximately 90° or less as is usually the case. It can be seen that the extent of opening movement of the arm 6 is limited by the platform 17 which acts as a stop. The hinge shown in Figures 6a to 6c (in its opened position) is intended for use in attaching a downward pivoting lower tailgate 36 to the rear lower sill 38 of a vehicle body (Figure 6b). It will be seen that the tailgate 36 is closed when the hinge is in an open position and open when the hinge is closed. The hinge comprises castings 40 and 42 respectively attached to the sill 38 and an end face 41 of the tailgate 38. The castings 40 and 42 are pivotally connected via a hinge pin 43 which is located at its ends in through bores in opposed flanges 44, 46 of the member 42 and which extends through an integral sleeve 48 on the member 40. The castings 40 and 42 are biassed into the position shown in Figures 6a to 6c (which corresponds to a closed position of the tailgate 38) by a spring 50 attached at one end to a quadrant 52 formed with the member 42, and partially coiled around a roller 54 mounted at its ends on lugs 56, 58 on the casting 40. In the hinge shown in Figures 6a to 6c the spring 50 is attached to the quadrant 52 by a nut and bolt assembly passing through those components. Alternatively the spring 50 may be riveted to the quadrant 52 or may include a generally Z-shaped hook which engages in an aperture (not shown) in the quadrant 52. A tongue 60 provides an extension to the upper curved surface of the quadrant 52 and, with the castings 40, 42 in the position shown in Figures 6a to 6c projects into an aperture 62 adjacent a shoulder 51 in the casting 40. The casting 42 includes a pair of shoulders, one of which is designated 64 in Figure 6a, disposed one an either side of the tongue 62 which in use, engage the casting 40 so as to limit the extent of allowable movement of the hinge. When the tailgate 38 is to be opened it is pivoted downwards, ie in the direction indicated by the arrow B in Figure 6a until the lower edges of the flanges 44, 46 engage the shoulder 51. This causes the spring 50 to uncoil from the roller 54 and partially wrap around the upper surface of the quadrant 52, (and then the tongue 60) and the restoring force exerted by the spring 50 at least partially counteracts the tendancy of the tailgate 38 to fall open under its own weight. Referring now to Figures 7 to 10, an alternative type of hinge which nevertheless still embodies the invention comprises an upper hinge member 110, secured as by welding to the underside of a car boot lid (partially shown at 112), and a lower hinge member 114 secured as by welding to the car bodywork 116 adjacent the upper edge of the aperture which is closed by the boot lid. The members 110 and 114 are pivotally interconnected by two links, namely a shorter link 118 and a longer link 120. The members 110 and 114 and the links 118 and 120 form a collapsible quadrilateral linkage which is movable between the closed (collapsed) position, shown in Figure 7 and the opened or extended position, shown in Figure 10. As can be seen from Figure 8, the link 118 comprises two laterally spaced elements 118a, 118b and the link 120 likewise comprises two laterally spaced elements 120a, 120b. 118a and 118b lie inside the side flanges of the members 112 and 114, while 120a and 120b lie outside the members 112 and 114. A curved plate 122 forming a quandrant is rigidly attached to and spans the two elements 118a and 118b, and one end of a torque spring 124 is rigidly attached to a curved upper surface 126 thereof. The other end of the torque spring 124 partially extends around a pin 128 by which the longer link 120 is pivotally attached to the member 114. The spring 124 consists of three superimposed leaves of stainless steel, and when partially unwound from around the pin 128 as in Figure 9 the effect of the spring is to apply to the link 118 a torque tending to move it in a clockwise direction towards the open position of the hinge (illustrated in Figure 10) in which the spring has once again coiled itself around the pin. Where compactness is important the member 110 can be apertured as at 130 so as to accommodate the thickness of the spring 124 wrapped around the quadrant 122 when the hinge is closed (as in Figure 9), and the member 114 is likewise cut away at 132 to accommodate thickness of the spring as it transfers and encircles the pin 128 in the open position (of Figure 10). The described hinge therefore not only provides pivotal interconnection for the boot lid 112 but also provides a spring force to assist in lifting the boot lid, the magnitude of the spring force being dependent on the material, thickness and number of leaves incorporated in the spring 124. Further, the arrangement of the spring and its nesting between the members 110 and 114 provides a very compact construction, enabling the hinge to be accommodated between the underside of the boot lid 112 and an upper surface of a body panel 116 - so that none of the hinge extends into the boot cavity. The described hinge has an amplitude of pivotal movement of about 60°; but this can be increased to 90°, by appropriate alteration of the geometry of the linkage 118, 120.

Claims: CLAIMS 1. A hinge adapted to be fitted between a vehicle body and pivotal member forming part thereof wherein counterbalancing torque spring means is incorporated into the hinge. 2. A hinge according to claim 1 in which one end of the torque spring means is attached directly or indirectly to one of the hinge arms and abutment means is secured to or formed integrally with the other hinge arm around which the remainder of the torque spring means is coiled, the relative positions of the point of attachment and the abutment means being such as to uncoil the spring as the hinge is closed thereby to generate the restoring force tending to open the hinge. 3. A hinge according to claim 1 or claim 2 in which the point of attachment of the spring end and the hinge arm describes a curved path as the hinge arms pivot. 4. A hinge according to any of the preceding claims in which the said one hinge arm includes a drum surface or part thereof in the region of the hinging point and the spring end is attached to a point on the said drum surface or part thereof. 5. A hinge according to claim 4 in which the drum surface has a constant radius of curvature and the centre of curvature of thereof is ecentric with the hinge axis. 6. A hinge according to claim 4 or claim 5 in which the position of the drum surface relative to the hinge axis is such that the opening torque exerted by the torque spring means on the hinge arms is at a maximum when the hinge is in a closed position. 7. A hinge according to any of claims 4 to 6 in which the coiling of the spring around the drum surface is opposite to the direction of curvature of the coiling of the torque spring around the abutment means, so that the spring restoring force is made up of two components, one due to the tendancy of the spring to recoil and the other due to the reversal of the curvature of the length of the spring which has been uncoiled. 8. A hinge according to claim 7 in which the arms are connected for pivotal movement about a single axis, and are adapted for attachment the one to a vehicle body, and the other one of a trunk lid, bonnet or tailgate of the vehicle. 9. A hinge according to claim 8 in which at least part of the spring means is interposed between the arms thereof. 10. A hinge comprising two arms which are movable between an open position and a closed position and are adapted for respective connection to two relatively movable parts; torque spring means attached directly or indirectly to one arm at a position spaced from the hinge axis; abutment means on the other arm engaged by the torque spring means the latter tending to coil around the abutment means, wherein the torque spring means reversibly unwound with the closing of the hinge so as to exert a force on the arms to urge them into their open position. 11. A hinge for providing a pivotal interconnection between first and second members which comprises parts for respective connection to the first and second members, linkage means pivotally interconnecting the two parts and enabling the latter to be moved between a closed position, in which the two parts lie closely adjacent one another, and an open position in which the two parts are separated, and spring means exerting a force which urges the two members to the said open position thereof, the spring means nesting between the two parts at least when the latter are in a closed position. 12. A hinge according to claim 11 in which the linkage means comprises at least one rigid strut and the spring means applies a biasing force to a point intermediate the ends of the strut in a direction to urge the strut towards the position it occupies in the open position of the hinge. 13. A hinge according to either claim 11 or claim 12 in which the linkage means comprises two rigid struts each links being pivotally connected at its ends to each of the two hinge parts at spaced postions there along so that the struts and the said hinge parts form a collapsible quadrilateral linkage. 14. A hinge according to claim 13 in which one strut is shorter than the other and the spring means acts between a point intermediate the ends thereof and the junction of one each of the longer link and one of the two hinge parts. 15. A hinge according to either claim 13 or claim 14 in which one or both of the two struts is of bifurcated construction thereby to straddle the hinge parts and provide a compact construction. 16. A hinge according to any of claims 11 to 15 in which the spring is a torque spring. 17. A hinge according to any of the preceding claims in which the torque spring means comprises a plurality of superimposed spring metal leaves the number depending on the required magnitude of the restoring force the hinge is to provide. 18. A hinge substantially as described herein with reference to, and as illustrated in. Figures 1 to 5 of the accompanying drawings. 19. A hinge substantially as described herein with reference to, and as illustrated in. Figure 6 of the accompanying drawings. 20. A hinge substantially as described herein with reference to, and as illustrated in. Figures 7 to 10 of the accompanying drawings. 21. A hinge according to any one of the preceeding claims when fitted to a vehicle body so as to support a pivotable member thereof relative to the remainder of the body and provide a counterbalancing force to assist in the lifting the pivotable member relative to the body.

Inventors: ALLPORT WILLIAM SCOTT, HUMPHRIES ROBERT EDWARD, LITTLE JOHN BERNARD, ALLPORT, WILLIAM, SCOTT, HUMPHRIES, ROBERT, EDWARD, LITTLE, JOHN, BERNARD
Applicants: PROFFITT S F & CO, S F PROFFITT & CO LIMITED
Application year: 1991
Main classification: E05F1
IPC codes: E05D5, E05F1