Hinge assemblies

Abstract

 The hinge assembly comprises first (10) and second (12), third (13) and fourth (16) bar-like elements articulated as a four bar assembly for hinging movement, a rotor member (19) mounted to rotate during said hinging movement, an abutment roller (22) radially spaced from said mounted to said rotor member, and a spring (23) in the form of a laminated strip mounted to said rotor member to be wound thereon so as to be stressed by said winding during said hinging movement in a first sense and to be unwound therefrom during hinging movement in a second sense, and extending to be supported against said abutment, so biassing said hinge for movement in said second sense. The assembly is useful in bonnet, boot and tail gate assemblies of motor vehicles.

Description

[0001] The present invention relates to hinge assemblies in which first and second elements are articulated for spring biassed hinging movement.

[0002] Bonnets, boot lids, hatch backs and tail gates of motor vehicles are often provided with means to assist the user in lifting the weight of the component from its closed position to its open position and for retaining the component in its open position. A wide range of means have been employed for this purpose in the past. Gas struts are frequently used to assist the lifting of bonnets, hatch backs and tail gate assemblies. Helical coil springs are frequently used to assist the lifting of boot lids, as are torsion bars.

[0003] None of these means adopted previously is entirely satisfactory. A major problem with gas struts is that the force which they exert varies substantially according to the ambient temperature. A substantial disadvantage of helical springs and torsion bars in connection with tail gate assemblies and boot lids is that they encroach into the useable space of the luggage storage area to a significant extent.

[0004] The invention provides a hinge assembly comprising first and second elements articulated for hinging movement, a rotor member mounted to rotate during said hinging movement, an abutment radially spaced from rotor member, and a spring in the form of strip mounted to said rotor member to be wound thereon so as to be stressed by said winding during said hinging movement in a first sense and to be unwound therefrom during hinging movement in a second sense, and extending to be supported against said abutment, so biassing said hinge for movement in said second sense.

[0005] Hinge assemblies of this kind may be employed in connection with bonnets, boot lids, hatch backs and tail gate assemblies of motor vehicles but may find a wide range of application in other contexts.

[0006] The rotor member is preferably fixed, optionally rotatably, to one of the first and second elements.

[0007] The rotor member preferably has a cylindrical or part cylindrical periphery upon which said spring is wound during said hinging movement.

[0008] Preferably, the spring is a laminated spring, preferably of the kind having a plurality of spring strip layers fixed to one another at each end and of progressively increasing lengths such that when the spring is drawn out, one strip is straight and the others are bowed out progressively by increasing amounts.

[0009] The hinge assembly may include hinge elements other than the first and second elements and may for instance be a four bar mechanism type hinge assembly.

[0010] The invention includes a bonnet (or hood), boot lid (trunk lid), hatch back, or tail gate assembly or more generally any raisable cover member assembly comprising a raisable cover member provided with a hinge assembly according to the invention in which the cover member may be mounted to a suitable support. Of course, two or more such hinge assemblies may be provided.

[0011] The invention includes a motor vehicle provided with a bonnet, boot lid, hatch back, or tail gate assembly mounted by means of hinge assembly as described above.

[0012] The invention will be illustrated by the following description of a preferred embodiment with reference to the accompanying drawing in which the figure shows two positions of the components of a hinge assembly according to the invention viewed from the side.

[0013] As shown in Figure 1, a hinge assembly according to the invention of a four bar mechanism-type comprises a first bar 10 having a bracket 11 extending therefrom to be fixed to for instance a bonnet for a motor vehicle. The assembly further comprises a second bar 12 to be fixed to the body of the motor vehicle. A third bar 13 is articulated to second bar 12 at one end thereof to rotate about an axis 14 and is articulated to first bar 10 to rotate about an axis 15. A fourth bar 16 is articulated to second bar 12 at the second end thereof to rotate about an axis 17 and is articulated to first bar 10 at the end thereof remote from the bracket 11 to rotate about an axis 18. The four bar mechanism-type hinge thus formed can be moved from the position shown in full lines to collapsed position shown in ghost lines in the figure.

[0014] A rotor member or drum member 19 comprises a part cylindrical wall member 20 and a mounting flange 21 and by means of the mounting flange 21 is welded in position on first bar 10. A flanged roller 22 constituting an abutment is fixed in position on second bar 12 with its axis coinciding with the axis of rotation 14 for the third bar 13. A spring 23 comprising a plurality of stainless steel spring strips fixed to each other at each end by bolts (not shown) is fixed to the wall member 20 of the drum 19 at location 24 and passes over the surface of flanged roller 22. The strips which are laminated to form the spring 23 progressively increase in length in the direction going from right to left in the figure so that the natural conformation of the spring is a coil increasing in radius as one progresses clockwise in the figure. A free end portion of the spring passes over the abutment roller 22 and forms a free coil beyond said roller. Alternatively, this portion could be wound round and secured to roller 22 if roller 22 was made rotatable.

[0015] As the hinge mechanism is collapsed into the position shown in ghost lines, the spring is obliged to wind anti-clockwise around the drum 19, thus stressing that end of the spring. Furthermore, that portion of the spring which previously extended loosely as a freely coiled tail beyond the abutment roller 22 is pulled over the surface of the abutment roller to form part of a straight path between the abutment roller and the trailing edge of the cylindrical wall member 20 of the drum 19 so that the string is stressed at that end also.

[0016] The stress induced in the spring by the collapsing of the hinge biasses the hinge to the open position. By selection of the strength of the spring, which may be varied by the number of laminates chosen, a suitable power for the spring biassing of the hinge can be arranged to suit the conditions of use, particularly the weight of the component mounted by the hinge.

[0017] The arrangement shown in the figure is extremely compact and can be incorporated in the hinge of a boot lid, hatch back or tail gate without encroaching significantly on the available luggage space. Its operation will be substantially unaffected by change in ambient temperature.

[0018] By appropriate selection of the geometry of the linkages of the hinge, it is possible to achieve a desirable pattern of force to assist the user. For instance, when the arrangement is applied to a bonnet, it is possible to arrange for there to be relatively little spring biassing effective over the last short period of travel before arriving at the fully closed position so that the bonnet is easy to slam shut to engage the bonnet latch whilst providing a substantial amount of assistance to raise the bonnet and hold it raised once the bonnet has been lifted a short way.

[0019] Although the invention has been described with reference to the characteristics of the embodiment illustrated in the accompanying drawing, many variations and modifications thereof are possible within the scope of the invention.

Claims

1. A hinge assembly comprising first and second elements (12,13) articulated for hinging movement and a spring (23) biassing said movement, characterised in that said assembly further comprises, a rotor member (19) mounted to rotate during said hinging movement and, an abutment (22) radially spaced from said rotor member, and said spring (23) is in the form of a strip mounted to said rotor member to be wound thereon so as to be stressed by said winding during said hinging movement in a first sense and to be unwound therefrom during hinging movement in a second sense, and extending to be supported against said abutment, so biassing said hinge for hinging movement in said second sense.

2. A hinge assembly as claimed in Claim 1, wherein the rotor member is fixed to one of the first and second elements.

3. A hinge assembly as claimed in Claim 1 or Claim 2, wherein the rotor member has a cylindrical or part cylindrical periphery upon which said spring is wound during said hinging movement.

4. A hinge assembly as claimed in any preceding claim, wherein the spring is a laminated spring.

5. A hinge assembly as claimed in Claim 4, wherein said spring comprises a plurality of spring strip layers fixed to one another at each end and of progressively increasing lengths such that when the spring is drawn out, one strip is straight and the others are bowed out progressively by increasing amounts.

6. A hinge assembly as claimed in any preceding claim, further comprising third and fourth elements (10,16) articulated to one another and to said first and second elements to form a four bar mechanism type hinge assembly.

7. A bonnet (or hood), boot lid (trunk lid), hatch back, or tail gate assembly or other raisable cover member assembly comprising a raisable cover member provided with a hinge assembly as claimed in any preceding claim.

8. A motor vehicle provided with a raisable cover member assembly as claimed in Claim 7.

Drawing