GB1155469A - Camera Crab Dolly - Google Patents

Abstract

1,155,469. Steering vehicles. COLORTRAN INDUSTRIES, Inc. 11 Oct., 1966, No. 45290/66. Heading B7H. A steering arrangement is provided for selectively steering the front, rear or all four wheels in a crab-wise fashion of a camera dolly. Each of the front and rear pairs of wheels is steered through a chain and sprocket transmission, the front wheel transmission including a drive sprocket 110 and the rear wheel transmission including a drive sprocket 112, both sprockets 110 and 112 being rotatably mounted on a shaft 82 provided with a slot 128 in which slides clutch device 132, comprising a lever 136 which can engage slots in either or both the sprockets 110 and 112. Shaft 82 is connected to a shaft 40 which may be rotated by a handle 72 for steering the vehicle. A pin 138 extends through the upper part of the member 132 and rests upon an arm 102 of a yoke 98, the yoke being upwardly urged by a spring 108. Pegs 116, 120 are affixed to the upper and lower arms of the yoke and may be brought to register in holes 118, 122 respectively. For changing the modes of steering, the wheels must be aligned longitudinally of the vehicle to -align the holes 120 and 118 with the pegs 120 and 116 and so that the clutch lever 136 may pass from one slot to another in the sprockets. To select steering of the forward wheels, the yoke 98 is allowed to rise to its upper position, as shown, in which clutch lever 136 engages the slot in sprocket 110, so that this sprocket may now be driven by rotation of shaft 82. Sprocket 112, meanwhile, is prevented from rotation by engagement of peg 120 with hole 122. For steering the rear wheels, the yoke 98 is depressed to its lower position for the clutch lever 136 to engage sprocket 112 and peg 116 to engage hole 118 to prevent sprocket 110 from rotating. In an intermediate position, neither peg 116 nor peg 120 engages its respective hole, and clutch lever 136 is partly in each slot in sprockets 110 and 112 so that they may both be driven. A selector knob 42 is located at the top of shaft 40 which is depressed to select the required steering mode, the knob being connected to a rod 150 extending through the shafts 40 and 82 and bearing upon the top of device 132. A pin 154 is connected to knob 42 and may slide in a slot 156, the correct elevation for the three steering modes being determined by the top of the slot and two horizontal portions 162 and 164. The steering mechanism is mounted beneath a platform 28 of the vehicle and the shaft 40 is mounted in bearings in a frame 34 mounted in sockets 68. The connection between shafts 40 and 82 is readily disengageable so that the upper part of the steering mechanism can be removed by removing the frame 34 from the sockets 68.