| 摘要 |
1,190,956. Retractive switches. BUCHANAN ELECTRICAL PRODUCTS CORP. 1 June, 1967 [22 July, 1966], No. 25437/67. Heading H1N. Apparatus for actuating a limit switch comprises a first member 12 on which limit switch 30 is mounted, a second member 14 rotatably mounted on member 12, an actuating member 18 mounted on member 14, correcting means 16, 26 for actuating switch 30 in response to movement of member 18 and threaded means 32, 34 drivably coupling members 12 and 14 and adapted to rotate member 14 relative to member 12 and to hold member 14 in position when it has been so adjusted. As shown, members 12, 14 are housings and member 18 is an arm carrying roller 20 and mounted on shaft 16 carrying cams 22, 24 depressing cam follower 26, shaft 16 being moved longitudinally by depressing button 92 to depress plate 80 out of a groove on shaft 16 to allow shaft 16 to be moved longitudinally manually, plate 80 re-engaging a groove in shaft 16 to lock it in the selected longitudinal position when button 92 is released. Shaft 16 may be in a position such that cam 22 engages follower 26 so that clockwise rotation of arm 18 operates switch 30, or in a position such that cam 24 engages follower 26 so that counter-clockwise rotation of arm 18 operates switch 30 or in a midposition such that follower 26 is engaged by both cams 22, 24 so that switch 30 is operated by rotation of arm 18 in either direction. On release of the operating force, arm 18 retracts to the mid-position shown under the action of two parallel springs 108 bearing on a U-shaped member 100 bearing on a flat on shaft 16. Housing 14 is secured to housing 12 by a snapring 64 and can be rotated by turning with a screwdriver worm 34 engaging teeth 32, the teeth and worm apart from the screwdriver slot being covered by cover 44. Gaskets 49, 57 and sealing ring 70 provide a water, oil and dirt tight seal. |
