Land vehicles: bodies and tops – Bodies – Structural detail
Reexamination Certificate
2001-03-13
2002-08-20
Pedder, Dennis H. (Department: 3612)
Land vehicles: bodies and tops
Bodies
Structural detail
C296S050000, C296S051000, C296S181700
Reexamination Certificate
active
06435604
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to over the road freight vehicles, and more specifically to a novel construction for the rear door frames of large vans and semitrailers. The present rear door frame construction enables a trailer manufacturer to install a single door frame configuration which may be readily adapted to either swinging doors or to an overhead roller door, without requiring a door frame dedicated to each type of door.
2. Description of the Related Art
The trailer manufacturing industry has generally developed certain conventional and specific configurations for various trailer components. While certain differences exist between different trailers, manufacturers have universally tended to construct trailer frames and other components of a relatively large number of relatively simple angle, channel, and other shapes.
Such construction is relatively economical in terms of the materials required, as it requires only a relatively few different readily available stock cross sectional shapes. However, the components must be welded or otherwise assembled together to form the required shapes, and then the finished lengths (posts, headers, sills, etc.) must in turn be assembled to complete the structure. Thus, any savings in material is likely canceled by the labor intensive welding process required to form two or perhaps more linear welds along the length of the frame component assembly. Moreover, the additional time required to fabricate such subassemblies obviously adds considerably to the time required for the construction of a given trailer. The additional labor required for conventional construction results in greater opportunity for error, and resulting requirement for reworking or discarding the improperly constructed component. In addition, such subassemblies constructed of a series of separate stock shapes tend to be heavier than alternative constructions formed of single prefabricated components, and the welds in those built-up subassemblies result in components that are weaker than components formed of single prefabricated lengths of material.
Another problem with conventional trailer frame construction is the development of different frame configurations for different types of trailer doors, as noted further above. A purchaser of a trailer is to a great extent committed to the specific type of door (side hinged or overhead) with which the trailer was originally equipped, regardless of subsequent need or desire.
While it is possible to modify or retrofit a trailer with a different type of door than that with which it was originally manufactured, the process is quite involved, time consuming, and costly. Generally, the rear frame for side hinged doors does not include any means for the installation of lateral tracks or channels for an overhead door, and the frame header does not provide sufficient depth for the mechanism of the overhead door. The frame for an overhead door generally incorporates the lateral door tracks or channels integrally therewith, with the header being relatively deep for the overhead door mechanism. While most customers might prefer side hinged doors due to the higher and slightly wider openings provided, overhead doors might be preferable in certain circumstances, depending upon the space available where the trailer is frequently docked, and other considerations. In any event, once the decision is made as to the type of door to be installed upon a given trailer, it is very difficult to change that door type to an alternative type.
Accordingly, a need will be seen for a universal rear door frame for semitrailers, large vans, and the like, which frame is essentially identical for all trailers and door types. While the present frame may be initially configured for use with side hinged doors, it is a relatively simple matter to fit additional door tracks to the existing door frame to allow the frame to support an overhead door instead. Moreover, the installation of the tracks to the forward surfaces of the side posts and the elimination of the relatively deep header, result in an overhead door having an opening essentially equal to that of the side hinged door, thereby permitting taller and wider loads to be placed in the trailer equipped with the present rear door frame and overhead door. The ease of construction, economy, and versatility of the present universal door frame result in significant advances over other door frames and door installations of the related art.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 3,140,116 issued on Jul. 7, 1964 to William D. Speas, titled “Side-Loading Vehicle,” describes a trailer in which the side panels and roof are supported upon telescoping vertical posts. The posts may be extended to raise the side panels partially, with the side panels then rolling upwardly to overlap immediately beneath the roof, in order to complete the raising of the sides. Speas does not disclose any specific structure for the conventional appearing rear door frame of his trailer, with its apparently conventional side hinged doors.
U.S. Pat. No. 3,211,493 issued on Oct. 12, 1965 to Richard M. Mandel, titled “Bulkhead Structure,” describes various structures providing reinforcement for side hinged and overhead rear doors in trailers and the like. Mandel provides a series of horizontal reinforcements for side doors and vertical reinforcements for overhead doors, in order to reduce damage to such doors due to shifting cargo. Mandel does not disclose any specific structure for the rear door frame of his trailer.
U.S. Pat. No. 3,292,803 issued on Dec. 20, 1966 to Lyle D. Keller et al., titled “Semi-Trailer,” describes a trailer having side hinged front doors and a system for lowering the front of the trailer for loading and unloading the trailer where no dock or ramp is available. Keller et al. provide a pneumatic interlock for the doors in order to assure that the trailer brakes remain locked while the doors are unlocked or open. However, Keller et al. do not specify any particular configuration for the frame of the doors for their trailer, nor do they disclose the adoption of an overhead type door with their trailer.
U.S. Pat. No. 4,652,042 issued on Mar. 24, 1987 to Samuel M. Bader, titled “Design Column And Door System For Highway Trailers,” describes a trailer having a series of telescoping door panels disposed between a series of actuating columns. Each column includes a multiple section telescoping cylinder, to which the edges of adjacent doors are attached. Actuating the cylinders lifts the lower edges of the doors, causing the sections to telescope into one another. This system is not truly an overhead door, in that no tracks extend into the roof for the door, nor is there any provision for side hinged doors in the Bader trailer. Accordingly, Bader does not disclose any specific structure for the universal use of either side hinged or overhead doors, as provided by the present invention.
U.S. Pat. No. 4,659,132 issued on Apr. 21, 1987 to Gerald G. Day, titled “Convertible Beverage Body For Delivery Truck Or Trailer,” describes a trailer having a series of overhead doors installed along the sides and rear of the trailer. The interior of the trailer includes a series of movable panels, providing for side loading of the trailer from ground level or rear loading of the trailer from a raised dock or the like. The Day trailer includes a pair of hinged rear panels which swing inwardly, rather than outwardly as in conventional side hinged doors. The inwardly swinging panels, as well as the other partitions and internal structure, result in considerably less interior volume than available in a trailer utilizing the present rear door frame and side hinged or overhead door therewith. In any event, Day does not disclose any specific structure for either the side or rear door frames or posts in his trailer.
U.S. Pat. No. 4,669,775 issued on Jun. 2, 1987 t
Litman Richard C.
Pedder Dennis H.
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