Patent GB-911042-A (GB)
Title: Improvements in or relating to vehicle handling mules
IPC: B61J3/08
Filed: 1958-02-03
Abstract: 911,042. Hauling railway wagons. MITCHELL, F. G. Feb. 3, 1959 [Feb. 3, 1958], No. 3489/58. Class 104 (2). In a vehicle handling mule comprising a carriage movable on a track alongside or within the gauge of the vehicle rail track and vehicleengaging member mounted on the carriage for movement between a projected position engaging a vehicle for movement thereof and a retracted position in which the carriages may be moved in one direction below the vehicle, a first set of vehicle-engaging members, movable between projected and retracted positions, are arranged in a projected position to engage and move the vehicle in one direction only and a second set of vehicle-engaging members, movable between projected and retracted positions, apply thrust to the vehicle in the opposite direction, the first set are mounted on the carriage for movement in the projected or retracted positions independently of the movement or position of the second set and a member, operable only when the first set is projected and applying thrust to the vehicle in one direction, moves the second set into its projected position. In the arrangement shown, a mule 10 is propelled by a rope 13 along rails 11 arranged between the normal railway rails 12. Arms 53, 54 carrying wagon wheel (32) engaging rollers 57, 58 and 59, 60 are outwardly biased by tension springs 67, 68 attached via pulleys 65, 66 to extensions 61, 62 of the arms 53, 54. The extensions 61, 62 are also connected to damping devices 63, 64. The rollers 57, 59 are arranged, in the operative position, to engage in a flange or running surface of the wheels 32 and the rollers 58, 60 engage the running surface of the rails 12. The arms 53, 54 are moved inwardly by engagement with the wheels 32 when the mule is moved in the non- driving direction beneath the vehicle, shown in dotted lines on Fig. 3. The tensions 61, 62 engage stops to limit the outward movement of the arms 53, 54. The rope 13 is secured at 14, 15 to the ends of a drawbar 16 which includes a buffer spring 17 and is secured to a cross-head 18 slidably mounted on guide rods 19. When the rope 13, secured at 14, is pulled to move a vehicle by means of rollers 57, 59 engaging the wheels 32, the cross-head 18 is moved forward to raise the rollers 30, 31, carried by pivoted arms 23, 25, by means of links 21, 27, pivoted at one end on the arms 23, 25 and at the other end to the cross-head 18, into the operative position in front of the vehicle axle 33. The rollers 30, 31 are held in the operative position by toggle levers 36, 37 and 40, 41 which are straightened when the cross-head 18 is moved forward so that their centre pivots 38, 39 pass slightly over centre. The toggle levers 36, 37 are stopped against further movement by cams 44, 45. The cams 44, 45 are pivotally secured to the mule by pivots 46, 47 secured to crank members 48, 49 carrying rollers 50. The rollers 50 are forced apart by a blade form track stop 81, located at the desired position in the centre of the track, to swing the cams 44, 45 outwards to move the toggle levers 36, 37 and 40, 41 to their initial position and hence lower the rollers 30, 31. The toggle levers are held in the operative position by tension springs 51, 52. Specifications 860,258 and 860,259 are referred to.