Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
247 words
A jackable prop comprising: (a) a base, including a transverse plate, and a pair of widely spaced-apart, forwardly-projecting, feet; (b) a pair of spaced-apart, posts each having a polygonal cross-section upstanding from said base; (c) a freely-vertically-movable lifting frame, slidably but not relatively rotatably mounted on said posts, said lifting frame comprising: (i) a pair of bushings, each having a similar polygonal cross-section, each bushing having a length-to-width ratio of at least about 4-to-1 and being freely but not relatively rotatably slidably mounted on a respective said post, each said bushing thus being precluded from slewing with respect to its associated said post and also being inhibited from twisting and jamming when sliding with respect to its associated said post; (ii) a transverse bar interconnecting said bushings; (iii) a pair of forwardly projecting load bearing lifting arms; and (iv) engagement means secured to said transverse bar, said engagement means being adapted to be engaged by disengageable operable elevating means, whereby operation of said disengageable elevating means causes said transverse bar, and hence said load-bearing lifting arms, to be raised against a load applied directly thereon; and (d) manually operated means independent of said elevating means and cooperating between each said bushing and each said associated upstanding post for holding said lifting frame at a predetermined raised vertical position on each associated said post after said lifting frame has been so raised and upon disengagement and removal of said elevating means out of engagement with said engagement means.
Claim 2
Dependent Claim
247 words
A jackable prop comprising: (a) a base, including a transverse plate, and a pair of widely spaced-apart, forwardly-projecting, feet; (b) a pair of spaced-apart, posts each having a polygonal cross-section upstanding from said base; (c) a freely-vertically-movable lifting frame, slidably but not relatively rotatably mounted on said posts, said lifting frame comprising: (i) a pair of bushings, each having a similar polygonal cross-section, each bushing having a length-to-width ratio of at least about 4-to-1 and being freely but not relatively rotatably slidably mounted on a respective said post, each said bushing thus being precluded from slewing with respect to its associated said post and also being inhibited from twisting and jamming when sliding with respect to its associated said post; (ii) a transverse bar interconnecting said bushings; (iii) a pair of forwardly projecting load bearing lifting arms; and (iv) engagement means secured to said transverse bar, said engagement means being adapted to be engaged by disengageable operable elevating means, whereby operation of said disengageable elevating means causes said transverse bar, and hence said load-bearing lifting arms, to be raised against a load applied directly thereon; and (d) manually operated means independent of said elevating means and cooperating between each said bushing and each said associated upstanding post for holding said lifting frame at a predetermined raised vertical position on each associated said post after said lifting frame has been so raised and upon disengagement and removal of said elevating means out of engagement with said engagement means.
Claim 3
Dependent Claim
24 words
The jackable prop of claim 1 wherein said upstanding posts are secured to said transverse plate at the region of said forwardly projecting feet.
Claim 4
Dependent Claim
18 words
The jackable prop of claim 1 wherein said upstanding posts are each secured to a respective, forwardly-projecting, foot.
Claim 5
Dependent Claim
20 words
The jackable prop of claim 1 wherein said lifting frame includes a lifting arm projecting forwardly from each said bushing.
Claim 6
Dependent Claim
23 words
The jackable prop of claim 1 wherein said lifting frame includes a pair of spaced-apart lifting arms projecting forwardly from said transverse bar.
Claim 7
Dependent Claim
23 words
The jackable prop of claim 1 wherein said engagement means comprises a hollow engagement member on the lower surface of said transverse bar.
Claim 8
Dependent Claim
39 words
The jackable prop of claim 1 wherein said holding means comprises the combination of a plurality of vertically spaced-apart apertures through said bushings, and through said posts, and a pin adapted to be inserted through respective aligned said apertures.
Claim 9
Dependent Claim
24 words
The jackable prop of claim 1 including fixed heels projecting rearwardly from the rear of said transverse plate to assist in stabilizing said prop.
Claim 10
Dependent Claim
34 words
The jackable prop of claim 1 including rotatable wheels projecting rearwardly from the rear of said transverse plate, both to assist in stabilizing said prop and to enable it to be more easily moved.
Claim 11
Dependent Claim
11 words
The jackable prop of claim 1 wherein said cross-section is square.
Claim 12
Dependent Claim
14 words
The jackable prop of claim 1 wherein all elements are of hollow square cross-section.
Claim 13
Dependent Claim
19 words
The jackable prop of claim 1 including a lower step adapted to support the base of an elevating means.
Claim 14
Dependent Claim
41 words
The jackable prop of claim 12 wherein said disengageable elevating means is included in combination with said jackable prop, said elevating means being removably disposable between said step and said engagement means for raising said lifting frame relative to said base.
Claim 15
Dependent Claim
14 words
The jackable prop of claim 13 wherein said elevating means is a mechanical jack.
Claim 16
Dependent Claim
14 words
The jackable prop of claim 13 wherein said elevating means is an hydraulic jack.