HINGE

Abstract: A vehicle door hinge has a first leaf (1) carrying a fixed hinge pin (4), and a second leaf (5) having a bore (7) for receiving the hinge pin, the hinge pin and the bore being adapted to co-operate to permit assembly and separation of the hinge leaves only at a predetermined relative orientation of the leaves. In a preferred em­ bodiment this is achieved by a flat retaining head (4 b ) on the hinge pin passing through a slot (8) in the end of the bore (7).

Description: This invention relates to a hinge suitable, for ex­ ample, for use in mounting a motor vehicle door. In the manufacture of motor vehicles, and in partic­ ular motor cars, it is desirable to attach the doors to the vehicle body before the body is painted, so that the doors can be painted with the body and are therefore a perfect colour match. However, in the subsequent assem­ bly steps, the presence of the doors limits access to the interior of the vehicle, increases the width of the ass­ embly track required, because the vehicle must move with the doors open, and makes the trimming of the door, i.e. the fitting of windows, window winding mechanisms, door locks and handles, and the internal padding and finishing of the door, more difficult. It is therefore desirable to be able to remove the door after painting for separate trimming, and then to refit the completed door when ass­ embly of the vehicle is otherwise complete. With conven­ tional vehicle door hinges, this is difficult to achieve, because the initial fitting of the door requires accurate positioning, and removal of the door would necessitate a second accurate positioning operation, which would add significantly to the vehicle construction cost. The present invention provides a hinge comprising a first leaf having a hinge pin secured thereto, and a se­ cond leaf having a hinge pin boss including a bore for receiving the hinge pin to enable relative pivoting of the leaves, characterised in that the hinge pin and the hinge pin boss are adapted to co-operate to permit assembly and separation of the hinge leaves only at a predetermined relative orientation of the leaves. Preferably the bore opens through an end portion of different cross-section from the remainder of the bore, and the hinge pin carries a head portion linked to the remainder of the pin by a neck portion, the head portion being of substantially the same cross-section as the end portion of the bore so as to be able to pass therethrough at said predetermined orientation, and the neck portion being freely rotatable within the end portion of the bore. The neck portion may be cylindrical with a diam­ eter smaller than that of the remainder of the hinge pin, and the head portion then has a width in one plane through the hinge pin axis substantially equal to the hinge pin diameter and a width in a second plane through said axis at right angles to the first plane equal to the diameter of the neck portion. The hinge of the invention is simple in construc­ tion, but ensures accurate repositioning of the door when removed by separation of the hinges. As mentioned above, such separation is primarily intended to occur during assembly of the vehicle after painting has been completed. At this stage the door is not provided with a door check and so it can swing freely. Advantageously therefore, the hinge is provided with a stop to prevent the door opening too far and possibly hitting the surrounding body work. Additionally, the position of the predetermined orientation of the leaves can be chosen to restrain lifting of the door at a position whereat it might hit against the surrounding body during removal. It is therefore possible to carefully control the exact rotational position at which the door may be removed. In the final stages of assembly of the vehicle, the door is provided with a door check which is arranged to restrain the door from opening sufficiently to reach said predetermined orientation of the leaves so that during the normal sweep of the door the hinge leaves are not separable. Reference is made to the drawings, in which: Figure 1 is a perspective view of a hinge according to a preferred embodiment of the invention; and Figure 2 is a sectional elevation on line A-A in Figure 1. The hinge has a first leaf 1 which is generally L-­ shaped in plan and has a cylindrical boss 2 attached to the shorter arm 1 a of the leaf. The longer arm 1 b of the leaf has two fixing holes 3 therethrough to enable the leaf to be bolted to the vehicle door mounting pillar. The boss 2 extends over approximately half the height of the leaf 1 and has a bore therethrough into which is se­ cured a hinge pin 4 (Figure 2). The hinge pin 4 is se­ cured by interference between a knurled portion 4 a and the bore. The second hinge leaf 5 is also generally L-shaped, the longer arm 5 a of the leaf being welded, in use, to the vehicle door. The shorter arm 5 b carries a cylind­ rical hinge pin boss 6 having a bore 7 therethrough. The bore 7 is initially drilled as a blind bore, which is opened by milling a slot diametrically across the end face of the boss, the slot intersecting the blind bore. The slot 8 has a width less than the diamter of the re­ mainder of the bore. A bush 9, which is suitably formed from a lubricant metallised plastics material, is insert­ ed into the opposite end of the bore 7. The hinge pin 4 is provided at its free end with a head portion 4 b separated by a neck portion 4 c from the remainder of the pin. The neck portion 4 c has a diameter just less than the width of the slot 8 so as to be a close fit therein. The head portion 4 b has a width equal to the diameter of the neck portion, while the dimension in a plane through the pin axis perpendicular thereto is equal to the diameter of the remainder of the pin 4. Thus, the head portion can pass through the bore 7 and through the slot 8 if correctly aligned therewith. The slot 8 is milled in a direction relative to the alignment of the longer arm 5 a of the second leaf 5 such that the head portion 4 b of the hinge pin can only pass through the slot when the hinge leaves are in a predeter­ mined relative orientation which for instance could corr­ espond to the fully-open position of the vehicle door. At any other position, the head portion 4 b engages the boss end on either side of the slot 8 and prevents separ­ ation of the hinge leaves, the neck portion 4 c permitting rotation. In use, the longer arm 5 a of the second leaf 5 of the assembled hinge is welded to the vehicle door, a pair of such hinges being used for each door, in conventional manner. The door is then correctly positioned in the vehicle door frame and the first leaf of each hinge is attached to the door pillar by bolts, which are tightened after final adjustment of the position of the door rela­ tive to the frame. After painting of the vehicle body with the doors, the doors can simply be opened to the correct position to align the head portions 4 b of the pins with the slots 8, and then lifted off for trimming, and to permit finishing of the vehicle body and interior, the first leaves 1 being left undisturbed on the door pillars. In order to prevent the door opening too far and possibly cause damage by hitting the surrounding veh­ icle body, it is possible to provide the hinge with a stop. Conveniently the stop may take the form of a lug 6 a (shown in dotted lines in Figure 1) formed on hinge pin boss 6 which abuts against shoulder 1 c on hinge leaf 1. Finally, the doors are repositioned in the reverse of the operation by which they are removed, and their original precise alignment is resumed without the need for further adjustment. A door check is then fitted to the door to restrain the door opening to its open position whereat it can be lifted off the hinge pins.

Claims: 1. A hinge comprising a first leaf (1) having a hinge pin (4), and a second leaf (5) having a hinge pin boss including a bore (7) for receiving the hinge pin to en­ able relative pivoting of the leaves, characterised in that the hinge pin and the hinge pin boss are adapted to co-operate to permit assembly and separation of the hinge leaves only at a predetermined relative orientation of the leaves. 2. A hinge according to Claim 1, characterised in that the bore (7) opens through an end portion (8) of differ­ ent cross-section from the remainder of the bore, and the hinge pin (4) carries a head portion (4b) linked to the remainder of the pin by a neck portion (4c), the head portion being of substantially the same cross-section as the end portion of the bore so as to be able to pass therethrough at said predetermined orientation, and the neck portion being freely rotatable within the end por­ tion of the bore. 3. A hinge according to Claim 2, characterised in that the neck portion (4c) is cylindrical with a diameter smaller than that of the remainder of the hinge pin, and the head portion (4b) has a width in one plane through the hinge pin axis substantially equal to the hinge pin diameter and a width in a second plane through said axis at right angles to the first plane equal to the diameter of the neck portion. 4. A hinge according to Claim 2 or 3, characterised in that the bore (7) is provided in a boss (6) on the second leaf (5) and in that the end portion of the bore compris­ es a slot (8) cut diametrically across the boss to inter­ sect the blind end of the remainder of the bore.

Inventors: NIPPER, STANLEY C/O I.H.W. ENGINEERING LTD., SHEPHERD, PHILIP CHARLES
Applicants: I.H.W. ENGINEERING LIMITED
Application year: 1985
Main classification: E05D7
IPC codes: E05D7