MOVABLE SUBFRAME FOR TRACTOR-TRAILERS

Abstract

A movable subframe for a tractor-trailer includes a pair of spaced-apart, parallel, elongated and longitudinally extending main members. At least two cross members extend between and are attached to the main members, and a retractable pin mechanism selectively positions the subframe beneath a body of a trailer of the tractor-trailer. The retractable pin mechanism includes only two pins, with each pin being located generally centrally along a length of a respective one of the main members of the subframe. Each pin is extendable through an opening formed in its respective main member and a selected one of a plurality of openings formed in a body rail of the trailer, so that when the pins are in an extended or locked position, the retractable pin mechanism provides generally central support for the subframe and for an axle/suspension system which depends from the subframe.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiment of the present invention, illustrative of the best mode in which applicants have contemplated applying the principles, is set forth in the following description and is shown in the drawings, and is particularly and distinctly pointed out and set forth in the appended claims.

FIG. 1 is a top front perspective view of a prior art slider box for a tractor-trailer, showing the retractable four-pin mechanism used to selectively position the slider box along the underside of a trailer body, and further showing depending hangers for suspending axle/suspension systems from the slider box;

FIG. 2 is an enlarged fragmentary side elevational view of a prior art slider tandem, including the prior art slider box shown in FIG. 1, and showing one of two axle/suspension systems, with hidden portions, a tire and brake components represented by broken lines;

FIG. 3 is a reduced-size fragmentary view looking in the direction of lines 3-3 of FIG. 2, with portions thereof represented by broken lines, and showing the prior art slider tandem of FIG. 2 movably mounted on the underside of a trailer body, with the front reinforcing cross member of the slider box of the slider tandem removed;

FIG. 4 is a greatly enlarged fragmentary view taken from the circled area in FIG. 3, and showing one of the pins of the retractable pin mechanism in the locked position;

FIG. 5 is a top front perspective view of a slider box for a tractor-trailer of the present invention, showing the retractable two-pin mechanism used to selectively position the slider box along the underside of a trailer body, and further showing depending hangers for suspending axle/suspension systems from the slider box; and

FIG. 6 is a greatly enlarged fragmentary top perspective view of the retractable two-pin mechanism shown in FIG. 5.

Claims

1. An improved movable subframe for a tractor-trailer, said subframe being selectively movably mounted on a pair of rails mounted on and depending from a body of a trailer of said tractor-trailer, the subframe including a pair of spaced-apart, parallel, elongated and longitudinally extending main members, at least two cross members extending between and being attached to said main members, and a retractable pin mechanism for selective positioning of said subframe beneath said trailer body on said rails, the improvement consisting essentially of a pair of pins, each one of said pins being disposed generally centrally along a length of a respective one of said main members, each one of said pins being extendable through an opening formed in its respective main member and a selected one of a plurality of openings formed in a respective one of said body rails, whereby said retractable pin mechanism provides generally central support for said subframe and for an axle/suspension system depending from the subframe when said pins are in an extended position.

2. The improved movable subframe for a tractor-trailer of claim 1, wherein each said pin is located in a central one-third portion of length of a respective one of said main members.

3. The improved movable subframe for a tractor-trailer of claim 1, wherein each said pin is located adjacent one of said cross members.

4. The improved movable subframe for a tractor-trailer of claim 1, wherein said retractable pin mechanism is pneumatically actuated.

5. The improved movable subframe for a tractor-trailer of claim 1, wherein each said pin includes a D-shaped cross section.

6. The improved movable subframe for a tractor-trailer of claim 1, wherein each said pin includes a round cross section.