Patent GB-724822-A (GB)
Title: Time recording apparatus
IPC: G04F13/02
Filed: 1953-03-27
Abstract: 724,822. Photographic race-timing apparatus. OMEGA, L. BRANDT & FRERE SOC. ANON March 27, 1953 [March 28, 1952J, No. 8552/53: Class 98 (1). [Also in Group XIX] Time-recording apparatus, of the kind in which a photographic film on to which images of moving objects are projected is caused, to move continuously in the same direction and at approximately the same speed as the image, the projection of the image on the film being effected through a slit aperture which is directed to a given line or point past which the objects move, comprises a series of elements each bearing time indications, means to drive the first element continuously and electromagnetic relays controlled by the rotation of the first element and supplying the power to advance the succeeding elements step-by-step, the apparatus including means to project intermittently illuminated images of the conjoint time indications of the elements. As described the invention is applied to a timerecording device for races as described in Specification 673,007 and provides modified means for driving the " seconds," " minutes " and " hour " drums and also provides means for rotating in either direction the slotted light mask for periodically exposing the time indications. A thin cylindrical shutter 8 surrounds a series of four drums 4 to 7, Fig. 3, bearing figures indicating hours, minutes, seconds and hundredths of seconds respectively. The drum 7 is secured to a shaft 23 to which are also secured a gear-wheel 22 and cam 37. The drums 4, 6, 6 are mounted on hollow sleeves 38, 39, 40 respectively carrying ratchet wheels 41, 42, 43, the wheels 42, 43 carrying cams 44, 46. A synchronous motor 15, controlled by an electronic quartz device (not shown), drives through a one-way clutch 16, 17 the drum 7 through its gear-wheel 22, and the shutter 8 through alternative gear trains which may be selected by means of a push-pull control knob according to the desired direction of rotation, preferably so that the shutter moves in the opposite direction to the film. For each revolution of the shaft 23, the cam 37 closes a switch 47 to energize a double-relay 48 causing its armature 50, Fig. 6, to load a spring 46 so that when the cam 37 opens the switch 47 the spring 46 rocks the armature 50 and a pawl 49 carried thereby advances the ratchet wheel 43 one tooth to advance the seconds drum 6 one second division. Movement of the armature 50 is limited by a stop 51, the pawl 49 is guided by a cross-piece 52 finally to lock the wheel 43 against further movement while a retaining pawl 53 prevents the wheel 43 from turning when the pawl 49 goes backwards. The cam 45, Fig. 3, closes a contact 54 when the seconds drum reads 59 so that a double-relay 55, Fig. 6, is energized and -loads a spring 56 so that when the cam 45 opens the circuit through the relay 55 the wheel 42 is driven to advance the minutes drum 5 by means similar to those for the seconds drum. The hour drum 4 is similarly advanced by means of cam 44, contact 57, relay 58 and spring 59. The circuits through the relays 55, 58 are so arranged that relay 55 is only energized when contacts 54 and 47 are both closed and relay 58 when contacts 57, 54 and 47 are all closed in order to synchronize rotation of the drums.