SELF-STEERING AND BACKABLE TRAILER

• US 3,561,790 A
• Filed: 10/11/1968
• Issued: 02/09/1971
• Est. Priority Date: 10/11/1968
• Status: Expired due to Term

• Current Assignee: Herman E. Jurgens
• Original Assignee: Herman E. Jurgens
• Inventors: Jurgens, Herman E.
• Application Number:
  US04/766,800
• Time in Patent Office: 851 Days
• US Class Current: 280/476.1
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer

Abstract

A self steering and backable highway trailer consisting of two components: (1) a cargo frame with vertically hinged drawbar at one end and nonswiveling wheels at the other end, and (2) a swivel-mounted front undercarriage or dolly coupled to the frame by a pair of dependent pivot pins spaced apart along the longitudinal axis of the frame and extending through a channeled pressure disc of the dolly. The pins form alternate swivel points for the dolly, on opposite sides of the transverse axle and in each case the functioning pivot point being in the direction of travel taken by the trailer, with the other pivot pin being swingable along an arcuate slot in the disc which slot is radiused from the socketed pivot pin. The pressure disc has two such arcuate channels, each with a central recess-socket so that whichever pivot pin is lodged in a recess-socket changes with direction reversal of the trailer, thus facilitating backing. Selective lock holds forward pin in socket during usual forward towing of trailer to prevent accidental displacement of pins into reverse position.

Claims

1. A two-component trailer of the character described, including:

a first component comprising a body frame supported upon first roller means;

another component comprising an undercarriage bearing a transverse axle carrying second roller means, said undercarriage being spaced from said first roller means and also supporting said body frame;

a pair of upstanding pivot pins each having one end fixedly secured to one of the two components and their other ends each receivable alternately in one or the other of a pair of sockets of the other of said components, said pivot pins being spaced apart parallel to the longitudinal axis of said trailer approximately equidistant on opposite sides of said transverse axle of the undercarriage, and each pivot pin when unsocketed being movable laterally in an arc which is radiused from the socketed pivot pin; and

means responsive to the direction of travel of the trailer for locating the socketed pivot pin in whichever socket is forward to said direction, including pressure plate means carried by one of said components in frictional registration with the other of said components, said pressure plate means being formed with sockets alternately disposed to receive one or the other of said pivot pins upon movement of the pair of pivot pins longitudinal to said trailer, whereby upon the trailer being moved in either direction, said undercarriage is steeringly self-adjusting by seating of one of said pivot pins in the forward socket.

2. The trailer of the preceding claim 1 wherein said pressure plate means is formed with a pair of arcuate channels, each radiused from an edge-located socket open to the other arcuate channel and thus disposed jointly, according to which way the trailer is being drawn, to transiently receive a first pivot pin in a socket of one channel and a second pivOt pin movable along the length of the other arcuate channel, and upon reversal of direction of the trailer to receive said second pivot pin in the other socket and said first pivot pin movable along its arcuate channel.

3. The trailer of the preceding claim 1 which includes selective lock means for retaining one of said pivot pins in its respective socket.

4. The trailer of the preceding claim 1 which includes a vertically pivoted drawbar projecting from the end of said body frame which is supported by said undercarriage.

5. A wheeled structure movable in either direction and comprising a frame supported in part on nonswiveling wheels and in part on a swivel-mounted undercarriage, which undercarriage has alternate pivot means supporting said structure from beneath, said alternate pivot means being shiftable on change of direction toward whichever is the lead direction taken by the wheeled structure, between a pair of alternate, pivot sockets spaced apart lengthwise to the structure, which structure also has associated lateral limit means which restrict lateral pivoting of said undercarriage to a maximum of about 55* on either side of a line through said pivot points.

6. A caster-type unit of limited swivel, characterized by:

a generally horizontal pressure plate formed with a tandem pair of generally vertical, top-opening sockets spaced apart along the direction of travel of said unit;

a roller-carrying axle dependently carried by said pressure plate and located beneath and intermediate said pair of sockets; and

a pair of upstanding pivot pins adapted to have their upper ends fixedly attached to a movable structure which is supported on said pressure plate, and their lower ends received alternately in one or the other of said sockets with the nonsocketed pin movable laterally thereto, whereby said caster may swivel laterally to the extent of possible movement of the nonsocketed pin with turning of the other pin in the socket which is forward to the direction of travel of said axle and unit.

7. The unit of the preceding claim 6 wherein said pressure plate is formed with a complementary pair of transverse, arcuate channels, each radiused from one of said sockets and extending from the convex edge of the other channel, each pivot pin being movable into and out of socket from the adjacent arcuate channel, whereby alternately each one of said pivot pins may lodge in its respective socket while the other member is movable along the other arcuate channel, the particular pivot pin which is thus socketed being self-locating in response to directional movement of the structure which is supported on the pressure plate.