Patent GB-1248490-A (GB)
Title: An improved monorail system and a vehicle therefor
Inventor: PETTIT FRANK PHILLIP
IPC: B61C13/04
Filed: 1969-05-21
Abstract: 1,248,490. Overhead monorails. PROJECTS GENERAL OF AMERICA. 21 May, 1969, No. 25841/69. Heading B7L. [Also in Division F2] An overhead monorail comprises a locomotive 10 towing mine cars 12, the locomotive being suspended from an I-section rail 16 by two drive assemblies 17, 18 each consisting of two drive units 40, 42, wherein each unit is universally connected to a support arm 43 which in turn is universally connected to the locomotive body 15 at 57, and a unit consists of a pair of wheels 44 on either side of the rail web running on flange 32, each pair being connected by a link 52 from which is suspended, by pivoted arms 50, a drive wheel support frame 54, the drive wheel 45 being driven by a reversible hydraulic motor, mounted on the frame, and in contact with the lower face of the flange 32, there extending between the arms 50 and the frame 54 further arms 68 such that with the arms 50 inclined and the pivot point 48 and the drive wheel axis on the opposite side of the vertical line P through pivot point 51, the weight of the locomotive body forces the drive wheel into contact with the rail. Tensioning of spring 83 increases the force of contact of the drive wheel on to the rail flange. The cars 12 are suspended from the rail in a similar manner to the locomotive but the drive wheel of each unit and the hydraulic motor are excluded. The body of each car is pivoted to a beam 132 and in its raised position the beam is retained by clips 142. The body may be lowered on cables 135 operable by a hoist 28. The locomotive and each car is provided with a brake 19, 19<SP>1</SP> comprising a frame 90 connected to the top of the locomotive or car, the frame at its upper part dividing to extend around the flange 32 and containing on either side of the web a wedge shaped brake block 94 held above the flange by an arm 118 acted on by a spring 122 and a ram 120. When the fluid is released from the ram the spring urges the arm 118 to adopt the dotted line position whereby the blocks 94 contact the flange and the locomotive or car rides-up on to the blocks which take the weight. The drive wheel hydraulic motors derive fluid from a variable displacement pump 200 driven by an electric motor 202 which may draw its current from collectors mounted on the locomotive. The fluid is drawn by the pump from a tank 203 and an exhaust line 207 is provided. The direction of the pump and the speed is controlled from a position in the locomotive by a lever 210. The drive motors 46 are connected in parallel and for uphill drive fluid is supplied through valve 212 and line 219 and returned through line 220 including check valve 223. For reverse drive fluid is supplied through by-pass line 225. If the fluid pressure is too low a pressure relief valve will close and prevent fluid flow through the motors to the return line 219 thereby preventing rotation of the drive wheels. Braking can be provided by setting the valve 212 into its centre closed position. To operate hoist 28 the valve 212 is set to the HOIST position. The brakes 19, 19<SP>1</SP> have their rams 120 connected in parallel, and an accumulator 242 and check valve 241 are provided in a line thereto. A two-position valve 244 is normally open to permit passage of fluid to valve 244 to hold the brakes off. The accumulator allows successive application of the brake.