Patent GB-222201-A (GB)
Title: Improvements in course-indicating and recording apparatus for mechanically propelledroad-vehicles
IPC: G01C17/00
Filed: 1923-06-26
Abstract: 222,201. Collison, H. June 26, 1923. Course-recording apparatus.-Relates to course indicating and recording apparatus for motor road-vehicles, of the kind in which a map and a pointer or scriber are moved at right-angles to each other and are actuated from the road wheels at relative speeds depending on the course being made, the means for varying these relative speeds being controlled by the steering mechanism of the vehicle. The controlling means according to the invention comprise three variable speed devices of the friction type, the driving discs being rotated at a speed proportional to that of the vehicle, while the positions of two of the driven discs on the faces of their driving discs are controlled by the rotary movements of the third driven disc, which is displaced across its driving disc in accordance with the turning movements of the steering road-wheels. Mounted within a casing 2, Figs. 1, 2 and 4, is a shaft 1 driven from the road wheels of the vehicle and connected by worm gearing 6, 7 to a shaft 8 on which is mounted a bevel wheel 15 driving a bevel wheel 16 on a shaft 17 on which is also mounted a friction driving-disc 18. The wheel 16 is mounted on a square portion of the shaft 17 which is capable of limited axial movement through the wheel, the lower end of the shaft being supported by a bearing 19 carried by a pivoted lever 20 provided with a tension spring 22 which urges the shaft upwards to maintain frictional engagement between the disc 18 and the driven disc 23. The disc 23 is slidably mounted on a square shaft 24 and is adapted to be moved across the face of the disc 18 by a fork 46 on a slidable member 47 formed with a slot in which engages a pin 57 carried by an arm 50 fixed to a pinion 51 which is operated by a rack 52 connected by a flexible cable 54 to the steering road-wheel, the disc 23 being thus moved in accordance with the steering of the vehicle. The pin 57 can be adjusted in a slot 49 in the arm 50, in accordance with the wheel base of the vehicle. The shaft 8 is geared to shafts 31, 32 carrying friction driving-discs 38, 39 which are urged into engagement with their driven discs 44, 45 by compression springs 42, 43. The discs 44, 45 are mounted on square shafts 77, 78 the rotary movements of which are respectively communicated to a map and a pointer &c., arranged to move in directions at right-angles to each other. The positions of the discs 44, 45 in relation to their driving discs are controlled by the rotation of the shaft 24 which is geared to two shafts 60, 61 to drive them at equal speeds. These shafts carry arms 58, 59 provided with pins 71, 72 engaging in long horizontal slots in members 73, 74 slidably mounted on supports 75, 76 and pro. vided with forks 107, 108 engaging the discs 44, 45. The arms 58, 59 are at right-angles to each other so that when one of the discs 44, 45 is stationary the other is rotating at its maximum speed. The shaft 60 carries a pointer 64 for indicating on a dial 65 the course for which the instrument is adjusted. For manual adjustment of the setting, a shaft 109 carrying a gear wheel 69 engaging both the wheels 70 and 67 is provided with an external knob 112. The wheel 18 is removed from engagement with the wheel 23 during such adjustment by means of a slidable rod 13 having a wedge surface engaging the lever 20 to depress the bearing 19. The shafts 77, 78 are connected by worm gearing to countershafts 87, 88 which in turn are connected by worm gearing to shafts 95, 96 passing out of the casing through threaded couplings 97, 98. The map and pointer &c. are mounted in a separate casing 121, Figs. 5, 6 and 7, divided by a partition 122. The map 124 is mounted on rollers 117, 118 and passes over guide rollers 129, 130, 132, 133, and a driving roller 131. The rollers 117, 118 are formed with grooves 125 into which the ends of the map are passed, rods 126 then being inserted in the grooves and retained by clips 127. A celluloid &c. strip 141 passes round with the map and over additional rollers 134, 142, the latter being pulled down by springs 142 to keep the strip 14 taut. The strip 141 acts as a driving belt for the rollers 117, 118 and compensates the speeds of these rollers for the varying diameters of the map rolls. The driving roller 131 is mounted on a brass tube 135 projecting through the casing 121, the projecting end carrying a slidable knob 137 provided with a pin engaging a groove in the tube. The knob is also formed with a recessed face having clutch teeth adapted to engage similar teeth on the end of a shaft 138 passing through the tube 135, so that by pulling out the knob, the map can be manually adjusted. At its other end the shaft 138 carries a worm wheel 140 gearing with a worm 145 on a shaft 146 which also carries bevel wheels 149, 150. The wheel 149 meshes with a wheel 151 on a shaft 152 passing through a threaded coupling 154 and adapted to be connected by a flexible shaft to the shaft 95. The pointer 168 is carried by a block 169 having an internally-threaded portion engaging a threaded rod 155 carrying a knob 157 for hand adjustment of the pointer, and also carrying a gear-wheel 159 meshing with a pinion 160 on a shaft 161 which is connected by a flexible shaft to the shaft 96. The block 169 is also drilled to engage a guide rod 170. For rapidly bringing a new section of the map into position when required, the bevel wheel 150 meshes with a wheel 173 on a shaft 174 carrying pinions 175, 176, the latter of which engages the wheel 159, and also, through an intermediate wheel 182, engages a pinion 181 on a shaft 180 carrying a second pinion 179 engaged by the pinion 175. The shaft 180 is connected to a shaft 104, Fig. 2, geared to a shaft 101 which is geared to the shaft 8. Between the wheels 179, 181, which are loosely mounted on the shaft 180, is a clutch member 185 mounted on a square part of the shaft and engaged by the fork of a tie-bar 186 connecting two levers 187, 188 pivoted to the casing 121. Normally both wheels 179, 181 run free, but when a projection 189 on the block 169 engages either of the levers 187, 188 the corresponding wheel is engaged by the clutch and the map and pointer are rapidly moved to the commencement of a fresh strip. For disconnecting the drives from the shafts 95, 96 during such change, the bevel wheel 151, which is freely mounted on its shaft, carries a clutch member 196 adapted to engage a clutch member on the square portion of the shaft 152, the latter member being engaged by one fork of a member 190, the other fork of which engages a clutch member on a square portion of the shaft 161, this clutch member co-operating with a clutch member on tho wheel 160. Connected to the member 190 is a slidable rod 191 carrying at its end a cross member 194 engaging a bar carried by a pinion 195 fixed in the casing and adapted to be rotated by rack teeth on the bar 186. Sliding movement of the bar thus releases the clutches for the wheels 151, 160. For moving the rack 52, Fig. 1, as the vehicle turns, a pulley 197, Fig. 8, is mounted on the stub axle of one of the steering road-wheels, a cable 201 which is an extension of the cable 54 engaging in the pulley. The rack 52 is retracted by a spring 56.