| 摘要 |
1,005,616. Cam mechanism. H. L. NAIMER. May 31, 1963 [June 26, 1962], No. 21994/63. Heading F2K. In a cam mechanism for converting the axial movement of a member 20 into an angular movement of a member 22, e.g. to operate a switch, the member 20 acts through a bearing 38 and pressure ring 40 on an intermediate member 21 carrying two or more (preferably four) pairs of rollers 46, 48 respectively engaging first inclined cam surfaces 50 on a fixed member 51 and second inclined cam surfaces 52 on the output member 22. A spring 32 biases the members 21, 20 upwardly and the same spring, or a further spring, biases the member 22 angularly. On depression of the member 20 (e.g. by a solenoid) the descending member 21 is turned helically by the cam engagement 46-50 and, by virtue of the cam engagement 48-52, imparts an increased turning movement to the member 22. The cam surfaces 50, 52 are formed as facial teeth on the members 51, 22 and may or may not be planar. The inclination of the cam surfaces may be relatively steep to reduce contact pressures and allow the use of synthetic materials (super polyamide or thermoplastic) rather than metal in construction. The angular movement of member 22 is limited by interfitting projections 23a, 24a and also by interfitting projections 22a, 51a. The ring 40 may be coupled to the intermediate member 21 by friction or by positive means such as the projections and recesses 21a, 40a shown. In a modification the member 21 has double inclined-plane cam surfaces engaging rollers respectively on the parts 51 and 22. The Specification also describes a construction in which a solenoidactuated intermediate member carries individual rollers which simultaneously engage inclined cam surfaces on a fixed member and on a rotary output member, the construction being illustrated schematically in Fig. 3 (not shown). |
