Land vehicles – Wheeled – Articulated vehicle
Reexamination Certificate
2002-09-06
2004-10-26
Tran, Khoi H. (Department: 3651)
Land vehicles
Wheeled
Articulated vehicle
C414S493000, C414S563000
Reexamination Certificate
active
06808194
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to transporting disabled vehicles and, more particularly, to a recovery unit for hitching a disabled truck tractor to a towing truck tractor.
Due to intense usage of truck tractor and trailer rigs in transporting the bulk of goods and freight over the nation's highways, it is to be expected that tractor breakdown will be a frequent occurrence. Typically, a disabled tractor has to be removed from the highway to a service facility in order for repairs to be made. Removal normally requires towing the disabled tractor by using a large tow truck specially equipped and dedicated for that purpose. However, such tow trucks are expensive and so in many areas of the country there are either none available or there will usually be considerable delay in obtaining the services of one when a breakdown occurs.
Over the years, several attempts have been made to temporarily adapt an ordinary truck tractor to perform such towing tasks in addition to its normal use as part of a tractor and trailer rig. The objective is to eliminate the need to locate a dedicated tow truck in order to remove a disabled tractor from the highway to a service facility. The advantage in being able to use another tractor is that such tractors are found with much greater frequency in all parts of the country than are dedicated tow trucks and thus one would surely be quickly and conveniently available about anywhere the need might arise. Representative of the hoist and towing mechanisms devised in the prior art for this purpose is the recovery unit shown and described in U.S. Pat. No. 4,708,358 (Gehman). Specialized tow trucks for retrieving disabled truck tractors are limited in turning capability when towing a disabled truck tractor. The recovery unit as shown and described in U.S. Pat. No. 4,708,358 simulates a trailer in that the articulated frame locked into the operative position turns like a truck trailer about the pivotal connection between the recovery unit and the fifth wheel of the towing truck.
This recovery unit of U.S. Pat. No. 4,708,358 utilizes at least three hydraulic cylinders coupled to two control valves to effect an unfolding and operative connection to a disabled truck tractor. A major problem in operating the recovery unit constructed as described in U.S. Pat. No. 4,708,358 is the coordination required between the operation of the two control valves operating the respective hydraulic cylinders. Improper coordination would result in the recovery unit binding due to the respective hydraulic cylinders urging pivotal movement about two or more axes. U.S. Pat. Nos. 5,988,664 and 5,845,920, issued to Hill teach that the recovery apparatus can be operated through the use of a single hydraulic cylinder; however, the frame mechanism cannot be compactly folded when being transported from one job site to another. These mechanisms take advantage of the fifth wheel on the towing tractor to convert it for towing a disabled tractor instead of a trailer.
It would be desirable to provide a disabled truck recovery unit that can be utilized with a standard truck tractor to tow a disabled truck tractor over the highway in a safe and effective manner using a single hydraulic actuator to convert the frame mechanism from a compact transport configuration to an operative position to engage the disabled truck tractor.
SUMMARY OF THE INVENTION
It is an object of this invention to overcome the disadvantages of the prior art by providing a disabled truck recovery unit utilizing a single hydraulic cylinder to operate the unit.
It is a feature of this invention that the disabled truck recovery unit incorporates a single hydraulic cylinder cooperable with linkage to convert the frame mechanism from a compact transport configuration to an operative configuration.
It is an advantage of this invention that the construction of the disabled truck recovery unit can be accomplished at less cost than has been previously known.
It is another object of this invention to configure a single hydraulic cylinder and associated linkage to provide the operation formerly accomplished by a truck recovery unit having three hydraulic cylinders.
It is another feature of this invention that the disabled truck recovery unit can be transported in a compact configuration.
It is another advantage of this invention that the hydraulic operation of the disabled truck recovery unit can be effected through manipulation of a single hydraulic control lever.
It is still another advantage of this invention that the disabled truck recovery unit can be constructed with fewer moving parts than has heretofore been known in the art.
It is still another feature of this invention that coordination between multiple hydraulic control valves to effect proper operation of a disabled truck recovery unit has been eliminated through the utilization of a single hydraulic control valve to effect operation of the unit.
It is still another object of this invention to provide a power unit as an integral part of the disabled truck recovery unit to provide operative power for the hydraulic cylinder effecting pivotal movement of the frame to operate the unit.
It is still another feature of this invention that the power unit can be in the form of an electric motor, a gasoline engine, or a diesel engine.
These and other objects, features and advantages are accomplished according to the instant invention by providing a disabled truck recovery unit that is mountable on the back of a standard truck tractor to permit the standard truck tractor to be operable to tow a disabled truck tractor over the highway in a safe and effective manner. The disabled truck recovery unit includes an anchoring frame assembly connected to the standard truck tractor and an attaching frame assembly that can be connected to a disabled truck tractor to permit the towing thereof. The two frame assemblies are pivotally connected and powered by a single hydraulic actuator to convert the frame mechanism from a compact transport configuration to an operative position to engage the disabled truck tractor. A linkage apparatus interconnects the hydraulic cylinder and the frame assemblies to effect proper movement thereof. An engine is mounted on the anchoring frame assembly to provide an independent source of operative power for the hydraulic cylinder.
REFERENCES:
patent: 4838753 (1989-06-01), Gehman et al.
patent: 5722677 (1998-03-01), Lichter
patent: 5845920 (1998-12-01), Hill
patent: 5853283 (1998-12-01), Grant
patent: 5863059 (1999-01-01), Waggoner
patent: 5988664 (1999-11-01), Hill
patent: 6095748 (2000-08-01), Zackovich
patent: 6120051 (2000-09-01), Lichter
Miller Law Group PLLC
Tran Khoi H.
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