Chain Rail Conveyor with Lift Gate

Abstract

A truck cargo lift gate is pivotable between an upstanding and horizontal position. The lift gate carries a low-profile, endless chain conveyor. After the lift gate is pivoted to the horizontal position, the lift gate and the chain conveyor carried thereby may be vertically lowered to the ground with a load on the lift gate.

Claims

1. A truck cargo area having a floor that carries a first endless chain conveyor, and a lift gate that is adjacent to the floor, with the lift gate being pivotable about an axis, from a generally upstanding position to a generally horizontal position, and further, the lift gate carrying a second endless chain conveyor that moves into conveying alignment with the first endless chain conveyor when the lift gate is first pivoted to the generally horizontal position, and still further, after the lift gate has been pivoted to the generally horizontal position, the lift gate is then vertically movable for lowering the lift gate relative to a ground surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In the drawings, like reference numerals and letters refer to the same parts throughout the various views, unless indicated otherwise from content, and wherein:

[0014] FIG. 1 is a side elevation of a cargo truck showing the design disclosed herein;

[0015] FIG. 2 is similar to FIG. 1, but shows a lift gate pivoted to a generally horizontal position; and

[0016] FIG. 3 is similar to FIGS. 1 and 2, but shows the lift gate vertically lowered relative to the position shown in FIG. 2.

DETAILED DESCRIPTION

[0017] Referring now to the attached drawings, FIG. 1 illustrates a typical box truck design, with the box generally shown in dashed lines, indicated by reference numeral 10. Installed on the bed of the truck is a chain rail conveyor system, indicated generally at 12.

[0018] Palletized loads 14, 16, 18, 20, 22, 24 are schematically illustrated as floating slightly above the conveyor 12, with the intent being to illustrate these loads as resting on pallets on the endless chains (not shown) of the conveyor 12. The palletized loads 14, 16, 18, 20, 22, 24 more or less fill the interior of the truck's cargo space 10. As just mentioned, while the pallets are not specifically illustrated, it should be understood that each load 14, 16, 18, 20, 22, 24 is resting on an individual pallet.

[0019] Referring now to the back-end of the cargo space 10 (which is generally indicated by arrow 26), the present design has a drawbridge-type lift gate, or lift platform, indicated generally at 28. The lift gate 28 is designed to be pivoted about an axis that is generally located at the position of arrow 30.

[0020] When the truck is loaded and traveling to customer locations, or the like, the lift gate 28 is in the up position illustrated in FIG. 1. When the truck reaches the customer location, at that point, the lift gate 28 is pivoted down to the horizontal position indicated generally by arrow 32 in FIG. 2.

[0021] When in the horizontal position (see 32 in FIG. 2), the lift gate 28 is more or less co-planar with the truck's bed 12.

[0022] The lift gate 28 carries its own chain rail conveyor 29, similar to what was described in the 011 patent, but shortened to rest on the surface of the lift gate 28. The lift gate's conveyor may be powered in different ways, but in any event, it does not have any type of drive mechanism that extends above its vertical height. In this way, the entire load carried within the truck's cargo space 10 can be moved by the conveyor system, in the manner indicated by arrow 34 in FIG. 2. This leaves the end-most palletized load 24 resting on the lift gate 28.

[0023] At that point, and referring now to FIG. 3, the lift gate 28 and palletized load 24 may be lowered to the ground, as is generally indicated at 36. When the lift gate 28 (and load) are on the ground, the load can be removed by pallet forks (e.g., by forklift or pallet jack) or, alternatively, it may be possible to move the load off the lift gate platform 28 by other means, such as moving the truck or, possibly, activation of the lift gate's independent chain rail conveyor 29.

[0024] With respect to box truck deliveries, in particular, the foregoing design provides certain advantages for unloading cargo when a lift gate is required, such as, for example, allowing for easy unloading of the box truck at multiple locations where there may not be loading/unloading docks or the like. As indicated above, system operation could be made reversible for loading box trucks.

[0025] The foregoing design is currently under development. The purpose of this disclosure is to describe the ideas set forth above with sufficient clarity that they could be designed, developed, and/or built by others; and to provide support and priority for later-filed patent claims that may claim priority benefit of the present disclosure. It is to be understood that the design is under development as of the time of the present filing. As a consequence, the foregoing disclosure is not to be read in a limiting sense. Instead, the limitations of patent coverage are to be defined by the patent claim or claims that follow, the interpretation of which is to be made according to the well-defined doctrines of patent claim interpretation.