| 摘要 |
1494343 Multi-position pivotal mountings ITW Ltd 18 June 1975 [19 June 1974] 27129/74 Heading E2F A pivotal mounting (particularly for the sun visor of an automobile) is formed from two one-piece plastics (e.g. nylon) parts: an outer sleeve 2 with a generally cylindrical bore 10, which is provided with a number of radial undulations 12 spaced around its circumference and an inner generally cylindrical member 13 with a number of radial undulations 20 spaced around the circumference of its outer surface; the number of undulations on each part being unequal. In the embodiment shown a fastener 6 is mounted in a hole in the vehicle body and secured by a pin 8, the interior of member 13 receives a sun visor. There are three projecting longitudinal undulations 12 and sixteen depressed longitudinal undulations 20 designed to provide fortyeight stable relative angular positions of the parts - only one of the projections 12 engaging centrally in a depression 20 at any one time. Either part can carry projections or depressions and there can be more undulations on the sleeve than on the inner member. In modified sleeves the undulations can be longitudinally as well as circumferentially spaced projections (Fig. 7 not shown), or can be helically arranged along the length of the sleeve (Fig. 6 not shown)-each with corresponding depressions on the inner member. In this latter case the hand of the helix is such as to maintain the parts together on relative rotation. Both sets of undulations can have ratchet-like profiles to make relative movement of the parts easier in one direction e.g. upward movement of the visor. The undulations can be arranged to provide even firmer registration at some points than others or a separate snap-fit catch could operate between the pivot parts at such points. |
