GB723758A - Improvements relating to coupling units for towing vehicles - Google Patents

Abstract

723,758. Arrangement of wheels and axles. TAYLOR, F. G. July 14, 1953 [Dec. 8, 1952], No. 31026/52. Class 108 (2). A coupling unit for coupling trailer vehicles to towing vehicles comprises an assembly including an attachment element adapted to be secured to the towing vehicle and a coupling element formed or constructed to receive the leading end of the draw-bar of the trailer vehicle in a manner such as to enable a tractive pull to be applied thereto whilst permitting universal angular movement between the coupling unit and the draw-bar within the required range, and dolly wheel means carried by a mounting member pivotally connected with the assembly about a vertical or approximately vertical axis to permit the dolly means to castor when the coupling unit is in use and also displaceable upwardly and downwardly under the control of spring suspension means to enable the latter to bear at least part of the weight presented at the draw-bar of the trailer vehicle. In the arrangement shown, a coupling element formed by a sector-shaped plate 18 carrying a ball member 9, is provided with a pair of guide sleeves 20 united, at their upper ends by a plate 19, which are slidable on spaced vertical guide bars 14 extending between upper and lower projections 12, 13 of a bracket 11, adapted to be secured to a towing vehicle. A further sleeve 21 extends between and through the plates 18 and 19 and forms a guide for endwise movement against a main spring 29 and a check spring 30 of a stem 22 carrying a dolly wheel or wheels 24 mounted on a trailing arm 25. The arm 25 may be mounted to swivel about the stem 22, or may be rigidly fixed to the stem which is rotatable in the sleeve 21 as shown. Buffer springs may be provided at the upper and lower ends of the bars 14. The coupling element may be retained in a raised position by means of a rotatable spindle 33, Fig. 4, engaging at its lower end beneath the plate 19, and carrying at its upper end a spring-loaded plunger engageable with a hole in the projection 12. The bracket 11 may be formed with a pair of arcuate slots, Fig. 5 (not shown), by which the unit may be attached to the towing vehicle and by which the unit may be rotated to an out-ofuse position.