GB735566A - Improvements in and relating to stop devices for mechanisms - Google Patents

Abstract

735,566. Locking rotary elements. SMITH METERS, Ltd., and CHARLES, J. A. April 21, 1953 [April 21, 1952], No. 10030/52. Class 80 (4). A stop device for a rotary shaft 1, Fig. 1, comprises a sleeve 2 with a collar 3 secured to the shaft and a sleeve 5 mounted upon the sleeve 2 'for a certain amount of relative rotation thereto as allowed by a pin-and-slot coupling 7, 8. The collar 3 and sleeve 5 have radially projecting lugs 4, 6 thereon respectively with interengaging helical surfaces so that on movement of a control member 9 axially into the path of lug 6 the initial engagement thereof effects a relative rotation and axial movement of sleeve 5 into full engagement with the member 9 until the pin 7 engages the side of the slot 8 to stop positively the shaft 1. On removal of the control member 9 from the path of lug 6 the shaft 1 can again rotate and the sleeve 5 falls to its original position relative to sleeve 2 by gravity and/or spring pressure. In a modified arrangement shown in Fig. 4 applied to a gas meter prepayment mechanism a sleeve 10 secured to the shaft of a worm 20 which is to be controlled has a gapped flange 11 with which a disc 14 with axially extending parts 16 and inclined cam surfaces 17 co-operates. When a control member 27 is moved axially into the path of disc 14 the latter is first held and moved axially into full engagement with the member 27 until a shoulder 18 of the cam surfaces is engaged to stop rotation of the worm 20. The worm 20 is driven from the meter mechanism and drives the toothed planet carrier 21 of the quantity mechanism and then through a Geneva mechanism 23, 24 a cam 25 which operates a lever 26 carrying the control member 27. This lever may also actuate a gas supply valve, if desired. The worm 20 is released by the control member 27 on reverse movement of the cam 25 effected by the drive from the coin-holder on a prepayment being made.