Patent GB-627033-A (GB)
Title: Apparatus for determining and recording the speed of vehicles
IPC: G01P1/07
Filed: 1946-10-07
Abstract: 627,033. Speed - - recording apparatus. McCUTCHEON, J. W. Oct. 7, 1946, No. 29910. Convention date, Oct. 3, 1945. [Classes 106 (iii) and 106 (iv)] [Also in Group XX] Apparatus for determining and recording the speed of vehicles comprises speed recording means, control means for actuating the speed recording means within a predetermined speed range, a photographic camera actuated upon operation of the control means, and means for transmitting an image of the speed recording on to the camera film simultaneously with the actuation of the shutter. A device A, Fig. 1, is placed or suspended alongside a road B and is controlled by cables 186, 187, 188 laid across the road and actuating switches 160, 166 and 178 when a vehicle passes over. The distance between cables 186 and 187 is determined by the calibration of the device A which includes means for timing the passage of a vehicle between these points and indicating this as a speed. Passage of the vehicle over the third cable 188 actuates a camera if the measured speed comes within certain limits, and a picture of the car 191, Fig. 15, showing the number plate, together with a record 192 of the measured speed, the time of day 193, and the instrument identification number 194, is recorded. The camera is included in the upper portion of the device A, the film 23a, Fig. 4, being unwound from a spool 24 by a pin-wheel 27 driven through a Geneva mechanism by an electric motor. An auxiliary manual feed is also provided. After passing through the film gate 28, the exposed film is fed into a light-proof box 30; an associated counter 137 indicates the number of exposures made. Timing mechanism (40). A disc 44, Fig. 9, rotatable in known manner by clockwork, synchronous motor, or other electrical means 41, is started when a vehicle actuates the switch 160, Fig. 1, and stopped by the switch 166. A scale marked on the transparent periphery of the disc 44 indicates the speed of the vehicle against a reticle 54, and this indication is transmitted to the camera by light from a source 51 which is illuminated simultaneously with the actuation of the camera shutter. After being reflected by a prism 47, it passes upward through the disc 44, a lens (not shown) and finally on to the film by a further prism. The momentary illumination of the lamp 51 passes also in the opposite direction through a lens 61 and illuminates a known type of clock together with a hand-set numeral wheel, an image of which is transmitted through another optical system for reproduction on the film. Apart from the photographic recording means, the reading on the disc 44 can be observed by the operator by obtruding a movable prism, against spring means, into the optical system. The disc 44 carries a spring-urged contact button 105 adapted to bridge a pair of arcuate contact strips 103 fixed to the surface of an insulator disc 81 when the latter is raised by a cam 94 operated through an arm 92, Fig. 4, by a solenoid 98. The contacts 103 extend about a quarter of the way round the disc 81 and therefore are bridged only within a certain range of speeds which may be varied by manual rotation of a setting knob (not shown) rotating a worm 86 and worm-wheel 85; this latter turns with a gear 84 in mesh with a gear 79 which carries the disc 81. In this manner contacts 103 can be set to a position in which they are bridged by the button 105 only for speeds, e.g. above 30 m.p.h. By including these contacts in the circuit of the camera shutter actuating relay, therefore, the latter is operated only for vehicles exceeding a speed of 30 m.p.h. After a vehicle has passed over the first cable 186, to prevent the passage of other vehicles subsequently upsetting the recording, a series of contact-operating cams 149 ... 152, Fig. 4, driven by a motor 143 is brought into operation for a complete cycle. Cam 150 immediately opens contacts to prevent a second impulse from the cable 186 from having any effect; cam 152 prepares the circuit which includes the arcuate contacts 103, and cams 149 and 151 control the returning to zero of the dial 44 and the stoppage of motor 143. A three-way switch controls the apparatus to cause operation of the camera shutter for (i) all vehicles travelling above a pre-set speed, (ii) all vehicles travelling below a pre-set speed, or (iii) all vehicles whose speeds are determined.