Patent GB-719858-A (GB)
Title: Improvements in mechanism for converting rotary or reciprocating motion into oscillatory intermittent motion, particularly for use in stencil printing machines
IPC: F16H27/02
Filed: 1950-05-31
Abstract: 719,858. Converting rotary or reciprocating motion into oscillating motion. TENAX TRANSFERS, Ltd. May 31, 1951 [May 31, 1950], No. 12987/51. Divided out of 719,851, [Group XVI]. Classes 80 (1) and 80 (3) [Also in Group XVI] Mechanism for converting a rotary or reciprocating cyclical movement of a driving member into an intermittent oscillatory movement of a driven member comprises an actuating element which is reciprocated by the driving member and a selector member which is operatively coupled to the driven member so as to drive the latter, the selector member having a pair of abutments each movable between an operative and an inoperative position, one of these abutments being engaged, when in operative position by the actuating element when the latter is travelling in one direction so as to move the selector in that direction and the other abutment . being engaged, when in operative position, by the actuating element when the latter is travelling in the reverse direction, and wherein means are provided, operated from the actuating element, for moving the abutments between their operative and inoperative positions such that the selector is moved during selected strokes only of the actuating element As applied to a stencil printing machine (see Group XVI) the mechanism comprises a continuously-driven shaft 23 having a crank 40 thereon adapted to reciprocate a connecting-rod 42 provided with a roller 43: The roller 43 is shown as resting on a member 44 secured to a pair of spaced selector plates 45. These plates are pivoted to arms 48, 49 which are pivoted at their lower ends to the machine frame 1, whereby the plates can move in an arcuate path, limited by adjustable stops 52, 53 which engage the frame 1. Two abutment members 58, 59 mounted between the plates 45 and pivoted thereto at 60, 61, respectively, have rigid arms 67, 68, respectively, pivoted to a link 66, the arrangement being such that when the member 58 is horizontal, the other member 59 is lowered. In the position shown, the selector plates have been moved to the left. On the return movement, the roller 43 rides up the member 59 and strikes the arm 68, so that the member 59 is raised to the horizontal position and the member 58 depressed. When the roller again moves to the left it runs down the member 59 until it drops off the end of the latter on to the member 44. On the subsequent movement of the roller 43 to the right, it engages the end face of the abutment 59 and thus the selector plates 45 are moved to the right. The roller 43 next moves to the left, riding up the inclined abutment 58 to strike the arm 67, and thus the positions of the abutments are reversed. On its return the roller rides along, the abutment 58 and then drops down on to the member 44; it is subsequently moved to the left, engaging the end face of the abutment 58 and thus moving the selector plates 45 to the left into the position shown. Spring-urged plungers 62, 63 in the end faces of the abutments 58, 59, respectively, engage notches in the member 44 to retain and register the abutments when in the horizontal positions. A snap-toggle device 69-74 urges the selector plates 45 into the two extreme positions. Two links 81, 82 pivoted at 46 to the selector plates 45 are connected, respectively, to an internally-toothed annulus 78 and an extension of a planet carrier 79 of an epicyclic gearing 75. The annulus and carrier are freely rotatable on a shaft 77 the carrier having a number of planet wheels 80 which mesh with a sun-wheel 76 and the annulus. The small reciprocating movements of the plates 45 are thus converted into several revolutions of the shaft 77, first in one direction, and then in the other, and the shaft 77 is adapted to drive the inking carriage of the stencilling machine.