Freight accommodation on freight carrier – Load bracing means – Brace bar – wall-to-wall
Reexamination Certificate
1999-05-05
2001-02-13
Gordon, Stephen T. (Department: 3612)
Freight accommodation on freight carrier
Load bracing means
Brace bar, wall-to-wall
C410S143000, C410S149000, C410S153000
Reexamination Certificate
active
06186715
ABSTRACT:
FIELD OF THE INVENTION
This invention relates in general to the restraint of cargo and more particularly to cargo bars of the type used in truck bodies to prevent cargo from shifting while in transit.
BACKGROUND OF THE INVENTION
Various types of restraints have been used for restraining the loads which are carried in the trailers of large over-the-road trucks and semi-trailers. Shoring bars are often used in conjunction with tracks that are mounted on the opposite side walls of the truck or trailer body. Cargo bars that do not require tracks are also in widespread use. The cargo bar typically has pads on its opposite ends which bear against the truck walls (or the floor and ceiling) when a jack type ratchet mechanism is operated to lengthen the bar and wedge it in place. Often, a spring system known as a spring foot assembly is installed in the cargo bar to provide it with flexibility as the trailer walls flex. The need for a spring foot assembly increases the cost and complexity of the cargo bar construction.
One of the principal problems with cargo bars is that workers can operate the ratchet so aggressively that the cargo bar can apply excessive force to the trailer walls. At times, serious damage and even destruction of the truck walls can result. This can obviously lead to considerable cost and trouble. Hydraulic devices that have been used to apply the force have been provided with pressure relief systems that relieve the fluid pressure to avoid the application of excessive force. However, hydraulic systems are more complicated, costly, and difficult to use than mechanical cargo bars.
Another problem that has been encountered is that cargo bars can generally be used in only one orientation, with the ratchet handle projecting upwardly. At times, there is an advantage to orienting the cargo bar sideways with the handle projecting to the side for better access when applying and tightening the bar. In existing devices, the pawl of the ratchet mechanism drops to the side of the ratchet housing when the bar is positioned sideways. Then, the pawl cannot properly engage the teeth on the bar and cannot extend the bar as necessary for proper operation. For this reason, cargo bars are generally useful only in a position where the ratchet handle extends upwardly, and this is limiting as to accessibility of the handle.
SUMMARY OF THE INVENTION
The present invention is directed to a cargo bar which is improved in that it is equipped with a mechanical stop that prevents the bar from applying excessive force that could damage the truck walls.
It is a particular feature of the invention that the maximum force that can be exerted by the cargo bar is adjustable as desired. By way of example, the stop can have different settings that accommodate a light, medium, or heavy duty force application, or the stop can be removed altogether to avoid putting a limitation on the force in appropriate circumstances.
It is another object of the invention to provide a cargo bar that can be used in a sideways orientation to enhance the accessibility of the ratchet handle.
A further object of the invention is to provide a cargo bar of the character described that largely makes use of standard available components in order to provide an economical construction.
In accordance with one embodiment of the invention, a cargo bar includes a ratchet housing and a pair of bars that are arranged in line. One of the bars can be extended by operating a reciprocating ratchet handle. The other bar projects from a barrel which cooperates with the ratchet housing and is connected with it by a compression spring. After the bar has been extended between the walls of the truck body (or its floor and ceiling) and the handle is reciprocated additionally, the barrel and ratchet housing are forced closer together to compress the spring.
A pin which serves as a stop for the handle is fitted selectively in sets of holes that are formed in a bracket carried on the barrel. The stop pin thus moves with the barrel and is positioned to interfere with further operation of the ratchet handle when the spring has been compressed to a point selected according to which set of holes the pin is extended through. At this time, the mechanism is exerting the maximum selected force on the truck walls through the compression spring. Additional extension of the cargo bar is prevented by the stop pin which is positioned to prevent additional operation of the ratchet handle. Thus, damage to the truck walls due to excessive force is avoided.
By providing plural positions of the stop pin, the maximum force can be selected as desired, as among selections of light, medium and heavy duty settings, or any other selections that may be appropriate. At the same time, the pin can be removed to eliminate the force limitation altogether.
Other embodiments of the invention provide variations in the specific construction while operating the same in principle.
According to another aspect of the invention, the ratchet housing (or the side of the pawl which is adjacent to the ratchet housing) can be indented (or otherwise deformed) to provide a projection that keeps the pawl from falling against the side of the ratchet housing when the cargo bar is turned sideways. Consequently, the cargo bar can be used in a sideways position without the pawl dropping to a location where it is not able to interact properly with the teeth of the extension bar. This allows the cargo bar to exhibit increased flexibility and versatility because it can be used in a sideways orientation if necessary to provide convenient access to the ratchet handle.
The invention is characterized by a simple and economical construction that is attributable largely to the use of many standard components that are readily available. The spring foot assembly that is required in other cargo bars is not needed, and its expense can be avoided, because the compression spring used in the force limitation mechanism serves the function of allowing the cargo bar to flex with the truck walls for stability purposes.
Other and further objects of the invention, together with the features of novelty appurtenant thereto, will appear in the course of the following description.
REFERENCES:
patent: 4797043 (1989-01-01), Williams, Jr.
patent: 5378095 (1995-01-01), Shultz
patent: 5443342 (1995-08-01), Huang
patent: 5769580 (1998-06-01), Purvis
patent: 5833414 (1998-11-01), Feldman et al.
patent: 5890856 (1999-04-01), Huang
patent: 5944464 (1999-08-01), Cole, Jr.
patent: 5988963 (1999-11-01), Shiau
Gordon Stephen T.
Multiprens C.A.
Shook Hardy & Bacon LLP
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