Static structures (e.g. – buildings) – With lifting or handling means for primary component or... – Position adjusting means; e.g. – leveling
Patent
1996-06-28
1997-10-28
Canfield, Robert
Static structures (e.g., buildings)
With lifting or handling means for primary component or...
Position adjusting means; e.g., leveling
521231, 52114, 52117, E04G 120, E04B 282
Patent
active
056807325
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to load bearing support columns, and in particular to an adjustable lifting and shoring jack assembly.
BACKGROUND TO THE INVENTION
Adjustable support posts or columns are well known in the art. Typically, conventional support columns, such as lifting jacks for lifting and supporting of various structures employ a single, threaded support rod disposed in a main column. Many of these assemblies comprise a main column composed of two or more telescoping elements which can be extended and locked at predetermined intervals, such that the column can be adjusted to a length which is slightly shorter than that which is actually required. The threaded support rod, which may either engage an internal screw in the main column or an adjusting nut which bears on the top of the column, is then extended as required to support and/or raise the structure in question.
For example, U.S. Pat. No. 3,027,140 (Holzbach) discloses an adjustable element which is adapted to be quickly and removably fitted to a fixed length column. The disclosed adjustable element comprises an adjusting screw and nut, a bearing plate, and a base plate. The adjustable element is intended to be used in conjunction with a column or post which is obtained separately, and cut approximately to length, by the user, on site.
However, in some cases it is necessary to raise the structure by a substantial distance. For example, when a house or other structure is jacked to permit moving of same, or to raise its foundation, it is frequently found to be necessary to raise the structure by one meter or more. However, conventional jack posts of the type disclosed in U.S. Pat. No. 3,027,140 tend to become unstable, and prone to buckling, due to the extreme length of the adjusting screw extending from the fixed length column portion.
U.S. Pat. No. 4,872,634 (Gillaspy et al) discloses a brace assembly which consists of a main brace and a pair of side braces pivotally attached thereto. The length of the main brace is adjustable by means of threaded couplings mounted on the ends thereof. Each of the threaded couplings consists of a length of threaded rod slidably fitted within the hollow main brace, and a nut which bears against an end surface of the main brace. A mounting bracket is pivotally fitted to the free end of each of the side braces to permit the side braces to be attached to a portion of a member being supported (i.e. a wall), or to some other structure (such as a floor), so as to lend stability to the main brace.
However, since the side braces are of fixed length, the extent to which the main brace can be extended after the side braces have been attached is severely limited. Accordingly, a supporting system such as that disclosed in U.S. Pat. No. 4,872,634 is of limited use in situations where a structure being supported must be lifted through a substantial distance.
Finally, when used to support a structure of substantial weight, a jack post tends to be forced downwards into the earth. Typically, the base plates provided on conventional jack posts do not distribute the weight over sufficient surface area to prevent from undue sinking of the post into soft and/or unprepared earth. Thus the safe and effective use of conventional jack posts is often impossible under these conditions.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an adjustable lifting and shoring jack assembly capable of lifting a load through a substantial distance, and which can be safely and effectively used on soft and/or unprepared earth.
According to an aspect of the present invention, there is provided a lifting and shoring jack assembly comprising: baseplate means, said baseplate means being capable of distributing load forces over a sufficiently large surface area to substantially prevent said jack assembly from sinking into soft earth when subjected to a load; support column means removably disposed on said baseplate means; jack screw means slidably disposed within said support column means a
REFERENCES:
patent: 5271596 (1993-12-01), Holcomb et al.
Canfield Robert
Horton-Richardson Yvonne
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