DOOR CHECKS

Abstract: In order to provide controlled resilient biasing of a movable check roller (13) that roller is mounted on a first leg (15) of a torsion bar (17), the torsion bar (17) having a generally U-shaped portion (18) which lies in a plane which is normal to that of leg (15), and right-angle bend portions (21, 22) restrained to a mounting bracket (1) by hook portions (23) of the bracket. A second roller (14) is conveniently mounted on a second leg (16) of the bar (17). The mounting bracket (1) is of generally S-shape with the rollers being retained between two limbs of the S-shape.

Description: DOOR CHECKS This invention relates to door checks particularly, but not exclusively, door checks intended for use on. the doors of motor vehicles. Vehicle manufacturers and Government bodies are devising increasingly stiff tests which door checks must survive in order to be considered suitable for use. For example, one current test procedure consists of ,.such jecting an unlubricated mechanism to 100,000 operations with the mechanism periodically dusted with desert soil. Whilst there has been a multitude of previous proposals for door checks most of them would not stand up to such arduous tests, or at least the modifications required to meet the tests would be prohibitively expensive. The major problem facing a door check designer is therefore to produce a check which will perform satisfactorily in use yet be inexpensive to manufacture,!, One relatively inexpensive door check arrangement was proposed in our U.K. Patent Specification No. 1247755' in which a contoured check arm extends between a pair of rollers mounted in a bracket, and one of the rollers is resiliently biassed towards the other roller by being mounted on one arm of a torsion bar. Whilst that arrangement has been very successful in practice there is now a requirement for a compact door check which is less costly to produce yet meets the current regulations. According to the invention a door check comprises a contoured check arm adapted to be pivotally secured to a door or door pillar, and a bracket adapted to be secured to a door pillar or door respectively, first and second rollers mounted on or in the bracket with the check arm extending between the rollers, a torsion bar carried by the bracket and comprising substantially parallel first and second legs on which are respectively journalled the first and second rollers, and a substantially U-shaped portion of the bar extending substantially in a plane which is normal to the axes of the legs, the opposite ends of the U-shaped portion being connected by respective angle portions of the bar to the adjacent ends of the respective legs, the arrangement being such that at least the first roller is capable of deflection relative to the bracket, and the bracket is provided with abutment means acting on the bar at or adjacent to the angle portion associated with the first leg to provide a fulcrum for pivotal movement of the first leg. The abutment means ensures that the torsion bar is constrained so that its operating characteristics are closely controlled. In the absence of such an abutment means the U-shaped portion of the bar would be subjected to bending stresses in addition -to torsional stresses, and this could lead to premature failure of the bar in certain circumstances. Since the second roller is mounted on the second leg of the bar it is unnecessary to provide a separate mounting pin for that roller, and this reduces the assembly costs. The abutment means preferably comprises a hook-shaped portion of the mounting bracket. The hook-shaped portion is preferably arranged also to retain the torsion bar against movement relative to the bracket in the axial direction of the legs. The bracket is conveniently formed from sheet material that is bent into an angular S-sape, the rollers are held captive between two of the horizontal limbs of the S, and the hook-shaped portion is part of the third horizontal limb of the S. The second leg of the bar may be restrained to the bracket against lateral movement so that the second roller is held against lateral movement, but if desired the second leg may be permitted to pivot in the manner of the first leg, a second abutment means being provided on the bracket to restrain the angle portion associated with the second leg. A door check for a vehicle in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a plan view of the check in the condition in which the door is closed; Figure. 2 is a side elevation of the check looking in the direction of the arrow A in Figure 1, and without the check arm; Figure 3 is a rear view of the check looking in the direction of the arrow B in Figure 1, but for clarity omitting the check arm; and Figure 4 is an underplan view of a modified check shown mounted in a vehicle. The check comprises a bracket 1 formed from a rectangular strip of sheet metal by bending about five transverse lines so as to be substantially of angular S-shape, as shown in Figure 2, comprising three parallel, horizontally extending walls 2, 3 and 4, and vertical walls 5 and 6 for connection by studs 8 engaging holes 7 to a door or door pillar. The walls 2 and 3 of the bracket 1 are connected by a further vertical wall 9 which is apertured at 10 to receive a contoured horizontal check arm 11 provided with a pivot hole 12 for attachment to a door pillar or door respectively. First and second plain cylindrical rollers 13 and 14 respectively are journalled on parallel first and second legs 15 and 16 respectively of a torsion bar-17 and are located vertically between bracket walls 2 and 3. The torsion bar further comprises a U-shaped portion 18 extending in a plane which is normal to the axes of the legs 15 and 16 and contains the bracket wall 4, the opposite ends 19, 20 of the U portion 18 being connected to the upper ends of the respective legs 15, 16 by respective right-angle bend portions 21, 22. The portions 21, 22 are restrained to the bracket by respective abutment means on the bracket in the form of respective hooks 23, 24. The hooks 23, 24 are formed as laterally spaced projections depending from the free end of wall 4 and, as shown in Figures 2 and 3, the hooks are inclined at an angle of approximately 450 to the axes of the legs 15, 16 with the hook ends directed substantially towards each other. The angling of the hooks helps to retain the torsion bar 17 against movement relative to the bracket in the direction of the axes of the legs 15, 16. The first leg 15 extends through slotted holes 25, 26 provided in the walls 3, 2 respectively to enable the first roller 13 to be deflected in the direction away from the second roller 14, the second leg 16 extending through corresponding round holes 27, 28 in the walls 3, 2 respectively, to hold roller 14 against lateral movement. In Figure 3 the first leg 15 of the torsion bar is shown in full outline in the position it occupies when the rollers engage with the narrow portion of the check arm 11 as shown in Figure 1, and in dotted outline in the deflected position when the rollers engage with a wide portion 29 of the check arm 11. It will be seen that the first leg 15 is pivotally deflected about a fulcrum point provided by the hook 23, by the action of the check arm on the first roller 13. Pivotal deflection of the arm 15 increases the torsional stress in limb 30 of the U portion 18 of the bar. The torsion bar is arranged to have a torsional pre-loading on assembly to the bracket 1. In its free state the lower ends of the legs 15, 16 are arranged almost touching so as to provide on assembly the necessary pre-loading of the roller 13 towards roller 14. Since the portions 21 of the bar are held against relative movement apart by the hooks 23, 24, the U portion. 18 of the. bar is not subjected to substantial bending stresses in use. The hook 23 controls the pivotal movement of the first leg 15 and this control assists in providing a consistent performance in use. This is in contrast to arrangements where the deflecting leg of a spring bar is provided on a relatively unrestrained loop or bend of the bar. The axial spacing of roller 13 from the hook 23 assists in minimising tilting of the roller 13 in use. The deflectable roller 13 is preferably arranged to engage with the smoother side of the arm 11, as shown, but the reverse would be possible. As shown in Figure 1, the wide portion 29 of the check arm 11 is provided with a -recess 31 which is engaged by the roller 14 when the door reaches the fully open condition. However, the recess 31 is spaced from stop faces 32 on the arm such that when the roller 14 is seated in recess 31 the stop faces 32 are spaced slightly from the bracket wall 9. This enables the door to be pushed slightly beyond the normal open condition against resilient biassing of the rollers, to provide a cushioned action when the door opening movement is arrested by the check. Figure 4 shows a modification of the check of Figures 1 to 3, in which parts corresponding to those of Figures 1 to 3 have been given corresponding reference numerals. For convenience of mounting the bracket 1 in a vehicle door of a particular shape the axes of the rollers 13 and 14 are spaced slightly differently from the plane of. vertical walls 5, 6. The pivotal axis of the door is indicated at 35. The slotted holes 25, 26 of the previous arrangement are replaced by open-ended slots, only the slot 26' in wall 2 being shown. In order to provide two hold-open positions of the door the check arm 11 is provided with two spaced apart, recesses 31a and 31b. A mounting bracket 33 is secured to the vehicle body and is pivotally connected at 12 with the check arm 11 which carries a small stop pin engageable with the free end of the bracket 33 to restrict the pivotal movement of the check arm relative to the bracket 33. In a further modification, not shown, the second roller 14 and leg 16 are permitted to deflect in an identical manner to the first roller 13 and leg 15.

Claims: CLAIMS 1. A door check comprising a contoured check arm (11) adapted to be pivotally secured to a door or door pillar, and a bracket (1) adapted to be secured to a door pillar or door respectively, first and second rollers (13, 14) mounted on or in the bracket with the check arm extending between the rollers, a torsion bar (17) carried by the bracket and urging the rollers relatively towards each other, characterised in that the torsion bar (17) comprises substantially parallel first and second legs (15, 16) on which are respectively journalled the first and second rollers (13, 14), and a substantially U-shaped portion (18) of the bar extending substantially in a plane which is normal to the axes of the legs, the opposite end of the U-shaped portion being connected by respective angle portions (21, 22) of the bar to the adjacent ends of the respective legs (15, 16), the arrangement being such that at least the first roller (13) is capable of deflection relative to the bracket (1), and the bracket is provided with abutment means (23) acting on the bar at or adjacent to the angle portion (21) associated with the first leg (15) to provide a fulcrum for pivotal movement of the first leg. 2. A door check as claimed in claim 1 in which the abutment means comprises a hook-shaped portion 4233 of the mounting bracket (1). 3. A door check as claimed in claim 2 in which the hook-shaped portion is shaped to retain the torsion bar (17) against movement relative to the bracket in the axial direction of the legs. 4. A door check as claimed in -any of the preceding claims in which the bracket is formed from sheet material that is bent into an angular S-shape, the rollers are held captive between two of the horizontal limbs (2, 3) of the S, and the hook-shaped portion (23) is part of the third horizontal limb (4) of the S. 5. A door check as claimed in any of the preceding claims in which the second leg (16) of the bar is restrained to the bracket against lateral movement so that the second roller (14) is held against lateral movement.

Inventors: MORRIS, BARRY STANLEY
Applicants: THE BLOXWICH LOCK AND STAMPING COMPANY LIMITED
Application year: 1983
Main classification: E05C17
IPC codes: B60J5, E05C17