Patent GB-595239-A (GB)
Title: Improvements in or relating to apparatus for recording speed and other magnitudes
IPC: G01P1/12
Filed: 1943-05-12
Abstract: 595,239. Recording-apparatus. LAPCO SOC. ANON. May 12, 1943, No. 7604. Convention date, May 12. 1942. [Classes 106 (iii) and 106 (iv)] An apparatus for recording speed, or other magnitude with respect to time, in which a stylus is reciprocated across a record strip to mark successive ordinates, the lengths of which are proportional to the time required by an operative part of a machine or other device to execute a certain number of revolutions, is characterised in that the stylus is actuated positively in each direction of its movement. As shown in Figs. 1 to 4, for recording the speed of a motor 3, the shaft thereof is coupled by a reducing gear 1 to a shaft 7 which carries cams 8<1>, 8<2> co-operating with contacts 9<1>, 9<2> in circuit with an electromagnet 39 to establish the circuit during one half of each revolution of the shaft 7. The armature 31 is formed as a rocker to shift an intermediate pinion 36, in mesh with a pinion 35 on a shaft 32, from engagement with a pinion 33 into engagement with a pinion 34, the pinions 33, 34 being frictionally mounted on shafts 12, 17. Movement of the shaft 12 is transmitted by the pinions 33, 36 and 35 to the shaft 32 which drives a rack 45 carrying a stylus 46 that is displaced laterally, over a record strip passing over a drum 58, an amount depending on the time taken to attain the velocity or other magnitude to be measured. Shifting of the rocker 31 moves the pinion 36 into engagement with the pinion 34 in order to return the rack and stylus rapidly to initial position. The shafts 12, 17 are driven by a motor 10, Fig. 2, the shaft of which has a driving pinion 13 meshing with a gear 14 loose on the shaft 12 and connected by a spring 15 to a gear 16 fixed on the shaft. The gear 16 meshes with a gear 18 fixed on the shaft 17 and to regulate the movement of the shaft an escapement device 22, 23 and 24 is provided. The speed of the shafts 12, 17 is further regulated by a gear 25 which is in mesh with the gear 14 and acts as a nut on a screwed portion of the shaft 17 to displace an insulated collar 28 to open contacts 30 to stop the motor 10. The shaft 12 through worm gearing 20, 21 a shaft 19 and reduction gearing 59, 60 drives the drum 58. The record strip is fed from a supply roll 64, Fig. 3, over the major part of the periphery of the drum 58 to a take up roll 61 on a spring controlled arm 62. To ensure correct tension a spring controlled brake is provided. The stylus is arranged to record a portion only of the ordinate, a constant length being omitted. For this purpose the rack 45, Fig. 4, has a mutilated part 49 in front of which is a cam extension 53 which at an appropriate time during the return movement moves into a groove 55 on the gear 44 to lock the rack out of engagement while permitting the wheel to rotate to initial position. The limits of movement of the rack are defined by stops 48<1>, 48<2> and a projecting finger 47 on the wheel 44. At the beginning of the recording movement the finger 47 sweeps out a definite angle before it engages the lower edge of the cam 53 whereupon it engages the teeth of the wheel with the rack.