| 摘要 |
962,740. Gearing elements; cams. HOOVER Ltd. Aug. 16, 1962 [Aug. 17, 1961], No. 29752/61. Headings F2D, F2K and F2Q. A cam mechanism for actuating a cam follower in the form of a pivoted arm 41 carrying a roller 40 comprises a disc 28 driven by a reversible rotary shaft and carrying a dog 33 pivotally mounted on a pin 30 so as to be rocked by its engagement with the cam follower roller 40 between two positions, in each of which it presents to the cam follower a gradually rising leading face and a steeply falling trailing face. The disc 28 is secured to the end face of a wormwheel 25 which has a cut out keyhole-shaped portion 29 forming abutment surfaces 37 for the dog 33. For driving a timing disc 11 for the programme of a dish washer, the arm 41 carries a spring-pressed pawl 46 which engages the toothed periphery of the disc 11 and is urged in an anti-clockwise driving direction by a spring 43. For either direction of rotation of the disc 28, the engagement of the dog 33 with the roller 40 causes the pawl 46 to move back one tooth of the disc 11 and thence, under the influence of spring 43, to index the timing disc 11 forward one step, the pawl 46 then abutting a stop 60. A spring stop 49 prevents backrunning of the disc 11. The cam disc 28 is driven from a reversible electric motor 10 through two trains of worm and worm-wheel gearing 16, 18, 20 and 25. The trains are simi. lar and the teeth of each worm-wheel extend parallel to its axis so that the axis of a fixed shaft 26, on which the worm-wheel 25 rotates, is parallel to the motor shaft 15 which carries the worm 16. |
