Patent GB-343269-A (GB)
Title: Improvements in and relating to speed indicating and recording instruments
IPC: G01P1/12
Filed: 1930-01-15
Abstract: 343,269. Speed indicators and recorders. MECHANICAL & GENERAL INVENTIONS CO., Ltd., 10, Charles Street, London.-(M.A.G.I.C. Ltd., (France) S.a.r.l., 97, Boulevard Gouvion, St. Cyr, Paris.) Jan. 15, 1930, No. 1493. [Classes 106 (iii) and 106 (iv).] The speed of a machine or vehicle is indicated and recorded by a pointer and stylus driven by a group of three members each with co-operating pins and moved periodically under the control of cam members and associated pawls actuated by the machine or by clockwork or other escapement controlled mechanism. The record, which is made on a prepared surface, is of a temporary nature, means being provided for effacing it at'the end of each rotation of the record disc. An auxiliary device is provided to render the effacing means active if the driving means should fail to operate for any reason. A distance register of the type described in Specification 320,014, [Class 106 (i), Calculating &c.], may be combined with the apparatus. As shown in Fig. 1 a machine-driven flexible shaft 8 carries a pinion 1 adapted to drive a wheel 6 secured to a spring-controlled boss 13, loose on a shaft 14 and having pins 20, 21 on opposite sides for co-operation with a fixed pin 22 and a pin 23 on a second wheel 12 secured to a spring- controlled boss 24 also loose on the shaft 14. A second pin 26 on the wheel 12 co-operates with a pin 27 on an arm 28 secured to a boss 29 fixed to the shaft 14 which is under the control of a spring 30 secured at one end to a fixed point 31 and attached at its other end to a pinion 32 keyed to the shaft 14 which also carries the indicating pointer. Retrograde movement of the wheels 6, 12 is controlled by pawls 7, 10 co-operating with cams 9, 11 secured to a shaft 5 which is provided with a third cam 4 periodically actuating a lever 2 on which the pinion 1 is mounted to throw it into and out of engagement. The shaft 5 has a collar 36 to which is secured one end of a spring 37 the other end of which is in frictional engagement with a collar 38 in driving connection with the machine or clockwork, or suitable electric control device. The rotations of the shaft are regulated by an escapement or other control device 39. To produce a record the pinion 32 drives a rack 40 carrying a stylus 41 that co-operates with a prepared record surface 43, Fig. 2, mounted in a frame 45 provided with peripheral teeth 46 and driven by gearing from the machine. Near the end of each complete rotation a device such as 47, Fig. 4, serves to distribute paint or enamel or other suitable material over the surface to efface the record. The auxiliary device employed to efface the record in the event of a breakdown in the speedometer or its driving connections comprises a rack 60 co-operating with the pinion 32 in such a manner that when the pinion is at its normal position with the pointer 15 at zero the rack is raised to permit a spring-controlled latch 55 to free a pendulum 49. The oscillations of the pendulum due to vibrations in the machine or travelling vehicle cause a paw] 51 to actuate a ratchet wheel 52 in driving engagement with the teeth 46.