| 摘要 |
1,130,384. Ratchet gearing. MALLORY TIMERS Ltd. 4 Nov., 1966 [16 Dec., 1965], No.4962.3/66. Heading F2Q. In a drive mechanism for a timer having cams 27 on a shaft 26 controlling electrical switches (not shown), a ratchet wheel 25, secured to the shaft 26 and advanced by a tang 23 on a drive member 20 pivotally and slidably mounted on a narrow portion 38 of the shaft 26 by means of a slot 37, is driven at one speed with snap action advancement to drive the cams during a programmed timing cycle, and at a higher speed for rapid advance to or through a particular cycle. For the snap action drive, a motor 11 drives a cam 16, through gears 14, 15, to act on a roller follower 22 on the member 20. The cam moves the member 20 against the force of a spring 18, and then releases it for a rapid driving stroke under the power of the spring 18. For the rapid drive, a motor 34 drives a cam 29 through gears 30-33 to rock the member 20. In an alternative arrangement (Figs. 4, 5, not shown) the second motor 34 and cam 29 are replaced by a solenoid (39) acting on an armature (43) mounted on the member (20). A saw-tooth cam (41) on the shaft of the motor (11) acts on a switch (42) to cyclically energize and de-energize the solenoid (43) to rock the member (20). Instead of the cam (41) and switch (42), an electronic pulsing device may be used to energize the solenoid (39). One of the cams 27 is included in the control of motor 34 or solenoid (39). |
