GB1185085A - Self-Aligning Slit Mechanism - Google Patents

Abstract

1,185,085. Optical slit diaphragms. PERKINELMER CORP. May 19, 1967 [June 17, 1966], No. 23459/67. Heading G2J. A variable slit mechanism comprises one or two slits each defined by a fixed jaw 16, 17 and a variable position jaw 18, 19 the latter jaw(s) being connected to an actuator by way of a slippable connection. Operation of jaw 18 will be described in detail. An actuating arm 44 is moved clockwise (as seen) so that the edge portion 24<SP>1</SP> of a right angled bracket 22 on which the jaw 18 - e. g. a razor blade - is supported meets a limit pin 60 and is arrested thereby before rotation of the arm, which is following a cam 12, ceases, slippage occuring between the arm and the bracket. Subsequent movement of the arm 44 anti-clockwise moves the jaw 18 towards the jaw 16 which is a mirror surface of a prism 14, until the leading edge 20 of the jaw 18 presses against spacers 62, (64 Fig. 2 not shown), on the mirror. This stops movement of the bracket 22 and also causes the edge 20 to become parallel to the jaw 16 since the jaw 18 can pivot against magnetic attraction about a pin 28. The arm 44 is moved further counter-clockwise to a particular standard position, slippage occurring between the arm and the bracket, thus establishing a standard relationship between the bracket 22 and the arm 44. Subsequent clockwise rotation of the arm 44 in accordance with the contours of the cam 12 gives a predetermined variation in the width of the slit formed by the edge 20 and its reflection in the mirror surface of the prisms. Simultaneous identical variation in the width of the other slit is obtained by the action of a plate 144 driven by the arm 44 on the bracket 23.