Implements or apparatus for applying pushing or pulling force – Hoisting truck – Single throw lever
Reexamination Certificate
2001-08-29
2002-06-25
Hail, III, Joseph J. (Department: 3723)
Implements or apparatus for applying pushing or pulling force
Hoisting truck
Single throw lever
C254S131000, C254SDIG001, C254SDIG004, C254S134000, C254S119000
Reexamination Certificate
active
06409151
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to mechanical jacks. More particularly, the present invention relates to a mechanical jack for use with lifting and for supporting a wide variety of objects.
BACKGROUND OF THE INVENTION
Typically, mechanical jacks are designed for a specific application such as a bumper jack for lifting an automobile, a house jack, a floor jack and others. Such jacks can not be used for different applications other than their intended use for which they were specifically designed. A problem is that if a need for lifting a snow plow blade, a sofa, a desk, a small building, a boat, a snowmobile, an aircraft, a filing cabinet, a stove, a table and other such loads, the user must attempt to locate a specialized mechanical jack for the specific job. This is frustrating since there is no universal mechanical jack which can do several lifting chores. Furthermore, if there were multi-use jacks and even specialty jacks available, the purchase cost would be prohibitive.
A practical mechanical jack, for which there is an unfulfilled need, wherein the mechanical jack capable of being selectively usable for a wide range of lifting applications, is not available.
U.S. Pat. No. 4,205,825 to Stanford shows a jack for snow plow frames. A disadvantage of this patent is that it is bulky, which inherently contributes to its weight, and that it can not be used for lifting objects other than the snow plow frame for which it was specifically designed. Also, the screw component of the jack may be subjected to road sand and salt which could contaminate and possibly jam the screw mechanism making it difficult to crank when in use or rendering it inoperable. Also, no provision on the jack is provided for positioning and for aligning the hoist mounted on the truck with the snow plow. Furthermore, the design is costly.
U.S. Pat. No. 5,335,923 to Langenback et al discloses a snow plow dolly. A problem with this design is that it is specifically adapted to and structurally limited to use for a snow plow blade and can not be practically used to lift and support any other objects. Also, the design is bulky and relies on a jack device in the form of a screw for operation which may be susceptible to road sand and salt which could make it difficult or impossible to operate.
U.S. Pat. No. 4,127,255 to Wooding shows a leverage device for use with a jack which relies on a scissoring leveraging action for raising and lowering an object when the jack is activated. A disadvantage of this device is that it requires a relatively large rectangular frame structure that is interengaged with a lever means with removable bars making it cumbersome to use and expensive to fabricate.
None of the above prior art devices disclose a mechanical jack which has a lever lifting portion and a supporting portion which cooperate with each other without the need for screw or scissor type mechanisms or bulky structural frames and a mechanical jack which is simple in a design and is easy to use.
In view of the above mentioned problems and limitations associated with conventional lifting mechanisms, it was recognized by the present inventor that there is an unfulfilled need for an improved mechanical jack which is simple in design, practical, fun to use and is economically manufactured and which overcomes the disadvantages of the prior art devices.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a new and improved mechanical jack which is conveniently usable for lifting a wide variety of loads which avoids the aforementioned problems of prior art devices.
It is an object of the instant invention to provide a mechanical jack which may be manufactured from readily available materials by conventional manufacturing processes.
It is a further object of this invention to provide a mechanical jack that is simple in design, simple to manufacture, low in cost and fun to use.
It is another object of this invention to provide a mechanical jack which provides a lever lifting means for lifting an object and a supporting means for supporting the lifted object which cooperate with each other.
It is a still a further object of this invention to provide a mechanical jack which can be used to lift and support various objects such as, but not limited to, a snow plow blade, a boat, a sofa, a desk, a small building, a snowmobile, an aircraft, a filing cabinet, a stove, a table and other such loads.
Further objects will become apparent from the following description and claims.
This invention results from the realization that there is a great need for an improved mechanical jack. The resulting invention provides a user the capability of conveniently being able to lift a wide variety of loads without the need to purchase separate jacks for each intended purpose.
The above and the other objects are achieved in accordance with the present invention, which, according to a first aspect, provides a mechanical jack which has a lifting means for lifting an object including a lever, a base and a fulcrum disposed between the lever and the base and a supporting means for supporting the object being lifted including a post pivotally attached to the lever and a rod movably disposed between the post and the lever and the supporting means cooperating with the lifting means.
The second aspect is a special case of the.first aspect of this invention with additional features such as a cup member disposed near the second end of the lever which facillates lifting objects which are inconvenient or difficult to lift. Another feature of the mechanical jack is that a clasp may be disposed near the first end of the lever for use for assisting in the attachment of an object such as a snow plow blade to a “V” plate mounted on a vehicle. Although the mechanical jack can operate without the need for height adjustment; however, preferably, to make the mechanical jack even more functional, height adjusting means for independently adjusting a vertical height of the fulcrum and the post is provided.
According to a third aspect of the invention, disclosed is a method for making a mechanical jack.
According to a fourth aspect of the invention, disclosed is a method for using a mechanical jack.
REFERENCES:
patent: 1511801 (1924-10-01), Coochran
patent: 4127255 (1978-11-01), Wooding
patent: 4205825 (1980-06-01), Stanford
patent: 5335923 (1994-08-01), Langenback et al.
patent: 5713557 (1998-02-01), Kang
patent: 5826857 (1998-10-01), Brack et al.
Birkner Joseph R.
Hail III Joseph J.
Wilson Lee
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