GB970901A - Improvements in or relating to revolution counters - Google Patents

Abstract

970,901. Clutch control. B. & F. CARTER & CO. Ltd. April 1, 1963 [April 4, 1962], No. 12878/62. Heading F2L. In a revolution counter, an indicator shaft 12b is driven by an input shaft 14 through a worm and wheel 14a, 14b, a shaft 12a, and an electromagnetic clutch 13, an arm 16 carried by the shaft 12b opens a microswitch 15 to disengage the clutch through control means upon predetermined rotation of the indicator shaft 12b from a datum position, and a coil spring 18 secured to a drum 22 on the indicator shaft and to the counter casing and wound up during said rotation returns the indicator shaft to the datum position, the re-engagement of the clutch being sufficiently delayed by a conventional delay mechanism 17. A stop 24 adjustably positioned on a fixed scale 20 lies in the path of a pointer 19 carried by the indicator shaft. Alternatively the stop may be fixed in the counter casing and the indicator scale mounted for rotation with the indicator shaft. In operation, the stop shown is suitably positioned on the indicator scale and the spring 18 moves the pointer into abutment with the stop. Clutch engagement effects rotation of the indicator shaft until the pointer reaches zero scale position when the arm 16 opens the switch 15 to disengage the clutch. The pointer is returned by the spring against the stop during which return the delay mechanism maintains the clutch disengaged. The delay mechanism is variable to provide a delay for all scale settings.