Hinges

Abstract: Hinges, especially of the lift-off or demountable type, and primarily for use in vehicles have a resilient element for eliminating vertical free play between the hinge leaves (1, 2) during assembly of the vehicle. In a preferred embodiments the resilient element is incorporated into a spring clip (13) which locates in a groove (8) in the hinge pin (3). Projections (12) from the clip engage a horizontal surface (6) of one of the leaves (1). After final assembly, the special clip (13) may be replaced by a plain clip which may remain in place while the hinge is in service.

Description: This invention relates to a method of mounting a door by means of a hinge as defined in the preamble of claim 1. Such a method is known from US-A-4 858 274 The use of robots in the assembly of vehicle bodies is increasing all the time Where the doors are to be fitted to a body on the assembly line by the use of robots it is known to secure the hinges to the door and to offer up the door to the body, complete with both parts of each hinge, then to insert the screws or other securing means by which the hinge is attached to the body. The hinge may be demountable, not in connection with this stage, but because in a subsequent stage, after the body has passed through the paint shop, the doors may need to be removed for trimming. In one form of hinge currently used there are two vertically spaced coaxial pins. One of them has a groove to receive a spring-ring retaining clip by which the two parts of the hinge are held together. This clip can be removed if the door is to be detached from the vehicle. Especially in hinges made from pressed leaves or knuckles, but even in the case of cast and machined leaves or knuckles there have to be certain tolerances in the dimensions of the parts, and this is particularly necessary where the hinges are to be assembled by automatic machinery. This means there will be a certain amount of vertical play in the hinge. The play does not matter in normal use, i.e. in the finished vehicle, as the weight of the door, bearing down on the one part of the hinge, always takes up the play in one direction, that is to say, with a downward-facing surface on that leaf which is attached to the door in rubbing contact with an upward-facing surface on the leaf attached to the bodywork. A problem arises, however, during assembly by the method described above. When a door, complete with hinge attached, is offered up to the bodywork in the correct orientation, both vertically and horizontally, and then secured in place, it will subsequently drop, on release, by the amount of the tolerance in the hinges. Even though the tolerance may be small, this is not acceptable. One cannot allow for it in the design because it is an unknown variable quantity. Not only does it mean the door is not correctly aligned, but in addition it means that on a given door with two vertically spaced hinges, as the drop is unlikely to be identical in each hinge, all the weight of the door is in practice taken by only one of the two hinges. A hinge for vehicle doors having its leaves biassed into their load bearing condition is disclosed in BE-A-361742. It is, however, the intention behind that hinge to accommodate the effect of loading on the hinge caused by shocks and oscillations in the vehicle frame. DE-A-2504891 discloses a spring clip adapted to compensate for axial free-play and to secure a part mounted on a shaft or peg by engagement in a groove therein. The aim of the invention is to overcome the above-mentioned problems arising in assembly. According to the invention there is provided a method of mounting a door by means of a hinge, the hinge comprising a first leaf adapted for mounting on a door and a second leaf adapted for mounting on a surface adjacent a door opening, each leaf having an abutment surface, the abutment surfaces being arranged to abut one another to transfer the weight of the door from the first leaf to the second leaf when the hinge is in use, the hinge further comprising a pin about which the leaves may rotate relative to one another, and a clip located in a groove in the pin, in which method the first leaf of the hinge is mounted on the door and the second leaf of the hinge is mounted on a surface adjacent the door opening such that the door is correctly aligned with the door opening, the door is removed for further assembly operations by separating the first and second leaves, and after such assembly operations the door is replaced by re-assembling the first and second leaves, whereby the hinge has biasing means comprising at least one resilient projection from the clip arranged to bias the abutment surfaces into contact with one another when the second leaf is not attached to the surface and is suspended from the first leaf during aligning of the door, complete with the hinge attached, with the door opening and in that, after re-assembly, no further adjustment of the hinge leaves is required to ensure that the door is correctly aligned and the clip is replaced by a conventional spring clip to retain the leaves together while the hinge is in service. The biassing means need only be strong enough to overcome the weight of the free leaf or knuckle. Once the door has been mounted on the bodywork the weight of the door is then acting between the two parts of the hinge in the same direction as the resilient device was acting, and so there is now no relative vertical movement in the hinge when the door is released by the robot or other mounting agency (it could be mounted by hand). Instead of being a plain resilient clip which snaps into the groove it could be a clip which is basically similar but which in addition has resilient fingers which bear down on the face of the other part of the hinge. To facilitate its removal the special clip may have an integral laterally extending lug with a hole in it. An example of a hinge assembly according to the invention is illustrated in the accompanying drawings, in which:- Figure 1 is an isometric exploded view, with the door indicated in broken lines; Figure 2 shows an elevation of the assembled hinge; and Figures 3 and 4 are respectively a plan view and side view of the clip. The hinge is of a generally known kind and comprises two leaves or flaps 1 and 2 releasably joined together by two separate vertically spaced coaxial pins 3 and 4. The flap 1 is secured by screws (not shown) to a vehicle door, indicated at 5 and at this stage the hinge is already assembled together with the pin 3 on the flap 2 projecting upwards through a metal-impregnated plastics bush 6 in the flap 1 and the pin 4 on the flap 1 projecting downwards through a similar bush 7 in the flap 2, as shown in Figure 2. An annular groove 8 is formed in the upwardly projecting pin 3 to receive a clip which holds the two parts of the demountable hinge together. In the known hinge this would be a conventional spring ring such as that of the kind sold under the R.T.M. 'Circlip' or a flat sheet metal clip, but we use a different kind of clip, for the reason explained below. The tolerances which are essential in a mass-produced automatically assembled hinge made of pressed components (but also needed even in cast and machined hinges) mean that there is a certain amount of vertical play between the two flaps of the hinge. When it is attached to the door but not to the vehicle the flap 2 will be in its lowest position (using an ordinary clip) so when a robot (or an assembly team) offers up the door to the vehicle bodywork and secures it in place by screws passing through holes 9 in the flap 2, the door will drop, as soon as it is released, by the amount of this play, which is an unknown quantity. As the two hinges are unlikely to have exactly the same amount of play, in practice all the weight will be taken by one of the hinges. To overcome this we use the resilient sheet metal clip 10 shown in detail in Figures 3 and 4. It not only has jaws 11 which engage in the groove 8 but in addition it has a pair of resilient fingers 12 which bear down on the upper face of the flap 1, pulling the flap 2, to which the pin 3 is attached, upwards to the limit of the tolerance. Then when the door is secured to the vehicle bodywork and released it is already in the correct vertical position and does not drop. The fingers need only be strong enough to overcome the weight of the flap 2, and with a range of movement to take up the maximum likely tolerance. A lug 13 is provided to facilitate later removal of the clip, and it may be further extended, as indicated by broken lines in Figures 3 and 4, by a tongue 14 with a hole 15 in it, to make removal easier still. On final assembly of the vehicle it can be replaced by a normal spring ring or clip. It will be understood that the function of the clearance-taking fingers 12 could be performed equally well by another device separate from the clip, for example a wavy washer, and it need not even be on the hinge-pin itself. Because both hinges are secured with the flaps in their final relative vertical positions, regardless of tolerances, the load should, at least in theory, be shared equally; although in practice this ideal may not be achieved, by virtue of the invention it will at least be more nearly approached than with the known methods of assembly.

Claims: A method of mounting a door by means of a hinge, the hinge comprising a first leaf (1) adapted for mounting on a door (5) and a second leaf (2) adapted for mounting on a surface adjacent a door opening, each leaf (1,2) having an abutment surface, the abutment surfaces being arranged to abut one another to transfer the weight of the door from the first leaf (1) to the second leaf (2) when the hinge is in use, the hinge further comprising a pin (3) about which the leaves (1,2) may rotate relative to one another, and a clip (10) located in a groove (8) in the pin (3), in which method the first leaf (1) of the hinge is mounted on the door (5) and the second leaf (2) of the hinge is mounted on a surface adjacent the door opening such that the door (5) is correctly aligned with the door opening, the door (5) is removed for further assembly operations by separating the first and second leaves (1,2), and after such assembly operations the door (5) is replaced by re-assembling the first and second leaves (1,2), characterised in that the hinge has biasing means comprising at least one resilient projection (12) from the clip (10) arranged to bias the abutment surfaces into contact with one another when the second leaf (2) is not attached to the surface and is suspended from the first leaf (1) during aligning of the door, complete with the hinge attached, with the door opening and in that, after re-assembly, no further adjustment of the hinge leaves (1,2) is required to ensure that the door (5) is correctly aligned and the clip (10) is replaced by a conventional spring clip to retain the leaves (1,2) together while the hinge is in service. A method according to claim 1, in which each leaf of the hinge (1, 2) has a pin (3, 4) and a hole (6, 7), the pin (3, 4) of one leaf (1, 2) being received into the hole (7, 6) in the other, at least one pin (3, 4) having a groove (8) for receiving the clip (10). A method according to claim 1 or claim 2 in which the clip (3) is made of resilient material and comprises first and second planar projecting members (11), the facing edges of which are adapted to be received in the groove (8) on the pin (3), each said facing edge having a recess for locating the clip (10) and retaining it in place; and third and fourth projecting members (12) extending adjacent the outer edges of the first and second projecting members (11) and being displaced in a direction normal to the plane of the first and second projecting members.

Inventors: CHEAL JONATHON PAUL, MAYNARD PAUL, CHEAL, JONATHON PAUL, MAYNARD, PAUL
Applicants: BLOXWICH ENG, BLOXWICH ENGINEERING LIMITED
Application year: 1990
Main classification: E05D7
IPC codes: E05D11, E05D7, E05D5, F16B21