GB149720A - Improvements in or relating to lifting-trucks - Google Patents

Abstract

149,720. Spencer, H. E. April 15, 1919. Hand-trucks with lifting frames or platforms adapted to be run under the load, of the kind having a steering-pivot mounted in a member which turns about an horizontal axis during the lifting and lowering movements, are provided with two steering-pivots disposed at an angle to each other so that the axle of the steering- wheels can be turned about a vertical axis in any position of 'the lifting-frame. The truck shown is of the type in which the load-carrying frame A is pivoted as at D<2> to a crank D on the rear axle D<1> and at F<1> to a crossmember F mounted on the steering-wheels. A bar E extends at each side from a pivot D<3> on the crank D to a pivot F<2> on the member F. The frame F is raised and lowered by swinging the member F about the axle L of the steering-wheels, and mav be retained in the raised position by the engagement of a pawl N on the frame A with the member F as described in Specification 149,722. The axle L is coupled to the member F by a kind of Hooke's joint comprising a member H having pivots G, J mounted respectively in the member F and a head K carrying the axie L. The handle-bar M can be made rigid with the head K by the pin-and-slot connexion M<2>, K<1>, K<2> for swinging the member F into the positions shown in Figs. 1 and 2, in which the load frame A is lowered and raised respectively. The axle L can be moved about a vertical axis for steering, in either position of the member F by a combined movement of the members K, H on the pivots J, G. In another construction, Fig. 5, one or other of the two pivots G, J is vertical in the two positions of the member F so that the steering movement of the axle L takes place about only one of these pivots. To prevent the member H from turning sideways about the pivot G in the position shown in Fig. 5, a catch R on the member F may engage a lug S on the member H. This tendency is lessened by carrying the pivot G lower than the axle L, as shown. In this construction the handle M is mounted on the pivot J. In another construction the pivot G is at an angle of 45 degrees, and the pivot J is horizontal in the lowered position ; but m the raised position, the pivot J is vertical so that the steering movement of the axle L takes place only about this pivot in that position. The running axis of the wheels B need not pass through the pivot J, and this axis need not be coincident with that about which the member K turns in the raising and lowering movement. The pivots G, J may be disposed at other angles, and one Provisional Specification states also that the pivots may be in different planes and that a separate lifting and lowering handle may be provided. According to the other Provisional Specification, the invention may be applied to trucks in which there is a second frame which remains in the same position with respect to the wheels.