GB2217666A - Self adjusting torsion drawbar - Google Patents

Abstract

A drawbar for a trailer vehicle having twin axles is pivotally attached about a transverse horizontal axis to the trailer via a torsion bar spring coaxial with the pivot axis. This allows all wheels to be in contact with the ground even when negotiating steeply undulating ground. The torsion spring comprises two sets of stacked leaf springs D located inside a cylindrical sleeve B or body B and anchored from freely twisting by bushes C and F, so that it can only twist in torsion. The arms of the 'A' frame of the drawbar are welded to bushes F. <IMAGE>

Description

Self Ajusting Torsion Drawbar Technical Field This invention relates to a self ajusting torsion drawbar to aid twin axle close coupled trailers and caravans on uneven surfaces Background Four wheel twin axle trailers and caravans have a ridgid drawbar and present a problem when leaving a roadway or a reasonable flat surface,my invention is a unit that is easily fixed to eliminate this problem, Example The specification of the invention will now be described by the way of this example with referance to the attached drawing, FIG 1 Shows an exploded veiw of the unit.

A The torsion bar securing bolt, B Main body 1050 x 65 C Inner anchor bush 70 x 55 D Torsion bar 535 x 30 E End nylon bush 150 x 55 F Sleeve 190 x 50 G Grease points flou Total weight of unit. 38 Ibs c Measurements The measurements that show on FIG 11 for this unit would be for a 30 cwt trailer the measurements would alternatelito sujt the size and weight of trailer or caravan in question, .l - ii ! Assembly The anchor bush C fits into center of main body and is lightly secured by bolt A the torsion bar D is then pushed into center square of anchor bush with bolt A tightened a little more to penetrate the indentation on torsion bar the next step is to slide the end nylon bush E into place Finally fit sleeve F into the end of main body so that the torsion barJenters the center square of sleeve and the end levels up with torsion bar, Bolt A can now be firmly tightened one half of main body will now look as FIG 2 on-draweng, FIG 3 The mounting plates can be fixed on at any angle to suit the structure on an existing or new trailer FIG 4 This shows one side of drawbar A frame that connects onto the end of sleeve F and welded at the desired angle, Maintenance This consists of only four grease points G FIG 1 Brakes The braking system is not effected as this is carried out by a cable allowing the brakes to operate when the drawbar A frame is at any angle.

Claims (1)

1. Claims

   With the unit now assembled it is fixed into place under front of trailer the drawbar A frame is then fixed at a desired height of approx 15 19 ins from ground level the A frame will now be very difficult to move up or down and can only be carried out under pressure This enables the trailer running gear to be in contact with the ground surface to enforce the suspension units to carry equal loads WHAT I CLAIM IS A drawbar that is pivotally connected to a trailer to allow free movement but at the same time giving a downward pressure force on the towing vehicle rear wheels A jockey wheel is fitted to the A frame to enable easy coupling and movement of the trailer manually The connection unit from the A frame to the vehicle can be of the 50:'8 or the ring type hitch