GB660814A - Improvements in or relating to the steering of wheeled carriers or trolleys - Google Patents

Abstract

660,814. Steering motor vehicles. KING, D.. M. Nov. 8, 1949 [Nov. 8, 1948], No. 28965/48. Classes 79(iii) and 79(v) A wheeled carrier having a steerable wheel is provided on opposite sides with guide wheels, which are rotatable about vertical axes, and capable of transverse movement relative to the carrier, the guide wheels being adapted to contact fixed guide rails on the side of the path of the carrier and means are provided for causing the transverse movement of the guide wheels caused by engagement with the rails to rotate a steering column for the steerable wheel. As shown the invention is applied to a three-wheeled carrier which may be provided with load transporting and for lifting means or may tow loaded trolleys &c. A single driving and steerable wheel 12 is carried in forks 13 integral with the steering column 14 having a hand steering wheel 15. An electric motor 16 supplied from batteries 18 is carried by one of the forks 13 drives the wheel 12 through gearing 17. The wheel 12 is adapted to be steered automatically by electrically or mechanical means. As shown in Figs. 1 and 2, pivoted arms 21 carrying the guide wheels 20 project laterally of the body 10 of the trolley, the wheels 20 being urged outwardly by springs. The wheels 20 are adapted to co-operate with the guide rails its corresponding rail, the arm 21 pivots 22. When one of the rollers 20 engages and a contact thereon actuates a switch to operate a reversible electric steering motor 23 suitably geared to the column 14 to turn the wheel 12 away from that rail, pivoting of the other arm 21 operating the motor 23 in the opposite direction. In a modification the arms 21 are coupled by a rod carrying starter cams to actuate the motor 23. In a further modification the rod directly carries the rollers 20. In an embodiment. Fig. 4, for automatically steering the trolley mechanically a transverse rod 33 carries the guide wheels 34 and a rack 41 engaging the column 14 through gearing 42. A compression spring 36 at each end of the rod 33 bears against a collar 35 and a surface 37 at the end of a transverse rod 38 pivotally connected to a pivoted lever 39, the lever 39 being capable of occupying three positions. With the lever 39 in the position shown the wheels 34 are adapted to co-operate with the guide rails, engagement, between either roller and its corresponding rail causing the rod 33 to move transversely and turn the wheel 12 away from the rail and the spring 36 restoring the wheel 12 to its straight-ahead position when the steering deflection has occurred. When the lever 39 is moved to one of its side positions the rod 33 moves correspondingly and only the one roller at the projected end of the rod 33 is arranged to co-operate with a rail to steer the trolley. In a modification,Fig. 3 (not shown) the rod 38 and the 39 are omitted, the springs 36 bearing against bushes on the body 10 of the carrier instead of the surfaces 37. The embodiment shown in Fig. 4. may be modified for use with an electrically operated steering control system. In another embodiment for either electrical or mechanical steering a single transverse is replaced by two aligned ones. each carrying a roller or if desired two or more guide wheels may be provided on each side of the carrier, each guide wheel having suitable appendent mechanism to provide two or more points of contact with the guide rail.