GB1134328A - Mobile gantry crane - Google Patents

Abstract

1,134,328. Steering vehicles. NYDQVIST & HOLM A.B. 22 Feb., 1966 [22 Feb., 1965], No. 7784/66. Heading B7H. [Also in Division B8] In a mobile gantry crane (see Division B8) comprising a crab ortrolley (5) (Fig. 1, not shown) on a cross-member (1) supported at its ends by side members (2) and (3) which are each mounted on a pair of wheels, each of the wheels (A), (B), (C), (D) is turnable about a vertical axis between two positions at right angles to each other under the control of a turning member (18), whereby the crane may travel in a direction longitudinally or transversely of itself and is steerable by steering means co-operable with the turning members to turn the axis of each wheel in a horizontal plane about a vertical axis to steer the wheels whether the crane is moving longitudinally or transversely. On rotation of a steering wheel 21 all the wheels are steered together, pairs of wheels describing common arcs. The steering wheel 21 has a telemotor connection (Fig. 12, not shown) with an hydraulic cylinder 40, on cross-member (1), the piston 42 of which is connected by cables, slidable in sheaths 47, 48, with gear-racks 49, 77 engaging gear-wheels in identical control members 22, 23. Control member 22 comprises a shaft 56 (Fig. 13) to which are secured two cam discs 57, 58, each having two grooves engageable respectively by projections 67, 68 and 69, 70 of two claw clutches 61, 62 mounted on rods 59, 60. The shaft 56 is vertically adjustable by a piston 72, connected hydraulically to the turning member 18, between positions in which the upper grooves and the lower grooves respectively of the discs are engaged by the claw clutches. The grooves are of the correct shape (Figs. 6, 10, 15, 16, not shown) to turn the wheels A, B, C, D as required for longitudinal or transverse movement of the crane. On rotation of the steering wheel 21 the rods 59, 60 and corresponding rods 79, 80 on the other side of the vehicle are moved axially each operating a spool valve (Fig. 17) in a respective valve unit 101, 102, 103 or 104 which controls the flow of hydraulic fluid to. a steering element at the corresponding wheel. Each steering element comprises a cylinder 81 and a piston 83 with rack teeth 85 in mesh with gear teeth 87 on a vertical shaft on which a wheel is mounted. Each vertical shaft also has gear teeth 96 meshing with a rack on a feed-back rod 97 which is connected to one end of a lever 108 (Fig. 17) to which are pivoted at the middle and at the other end the end 107 of the valve spool and the rod 59 respectively. The feed-back rod includes an hydraulic length adjustor comprising a cylinder and piston attached respectively to the two parts of the rod 97 and connected hydraulically to the turning member 18 for adjustment when the member is altered between its longitudinal and transverse travel positions.