Patent GB-276486-A (GB)
Title: Improvements in speed indicating and recording apparatus
IPC: G01P1/12
Filed: 1926-07-21
Abstract: 276,486. Burnham, T. July 21, 1926. Periodic-counter speed indicators with recording-apparatus.-At the end of, say, each minute a chart drum is released to enable it to rotate to the same extent as a coaxial ratchet wheel advanced during that minute by the vehicle and the. chart is then marked by a pricker. The clock is maintained by the vehicle drum in wound condition and continuously shifts the pricker along the drum. The chart, graduated circumferentially for speed in miles per hour and longitudinally for hours 1-12, is mounted on the drum 47 by securing one end beneath a plate 52, Figs. 2 and 7 held to the drum by screws, and the other end to a slotted spindle 50 rotated to stretch the chart by means of a serrated head 55 retained by a spring-plunger detent 56. Th drum is loose on a shaft 33 and carries a spring-influenced lever 60 the roller 59 on.which bears on the edge of a heart-cam 58 fixed to the shaft. Also secured to the shaft is a ratchet wheel 34, Fig. 6 adapted to be advanced intermittently by a tooth 27 on a sleeve 26 rotated by the vehicle the transmission gearing being such that the ratchet wheel is fed one tooth for each 88 ft. traversed. The, vehicle drive is transmitted through a pinion 5 and alternative gear trains 9, 15 and 12, 19, 21 including reversed free wheel devices 10, 13, to a shaft 18 and thence to the driving sleeve 26 and also through wheels 22, 23 to the clock-winding gear. The drive between shaft 18 and sleeve 26 consists of a disc 31 fixed to the shaft and carrying a pin projecting into a cut away in the adjacent disc 28 secured to the sleeve, the pin and cutaway permitting a sudden movement of the sleeve 26 at the driving point by the action of a spring-controlled lever 62 bearing on a pin 29 fixed to the disc 28. The clockwinding gear includes a spur wheel 88 rotated from wheel 23 and carrying a pair of bevel pinions 91 meshing with opposed bevel gears 90, 92. One of these gears is secured to the winding-shaft and the other is connected with a brake-drum 93. The barrel 99 drives a shaft 102 and a train of gears terminating in a fan 114, and secured to the shaft are cam discs 44, 115. At the end of each minute a projection 121 on a disc attached to the seconds spindle of the clock rocks a wire frame 118 to release the fan and so allow the shaft 102 and the cam discs to rotate for one revolution at the end of which the frame is restored by the disc 115 and stops the fan. The cam disc 44 by its rotation rocks a shaft 43, Fig. 8, to retract a detent 70, Fig. 7, thus allowing the drum to take up the setting from the ratchet wheel 34 by means of the roller 59 and heart cam 58. Gearing 73, 76 between the drum and units and tens wheels 78, 82 positions the latter to exhibit the speed. A detent 40, Fig. 6, is subsequently freed by the same cam disc 44 and shaft 43 to permit the ratchet wheel to return to initial position under the action of its spring 36, but previous to this the cam disc 115 allows a spring to rook a shaft' 139, Fig. 7, carrying a plate 141 which is thereby advanced to force the pricker into the chart. The minute spindle 261, Fig. 3, drives a. shaft 124 and pinion 127 gearing with a, rack 128 connected to the pricker carriage 130 which is therefore drawn along in an axial direction to record the speeds with respect to time.