Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
228 words
In a jacking device including at least one jack installed in a floor pit, said jack comprising at least two horizontally spaced apart parallel pairs of links which are designed for simultaneous movement in two parallel vertical planes, respectively, a mechanism associated with said links for moving them in said planes, and a table supported horizontally on said links, each of said pairs of links consisting of a first link and a second link which are so connected to each other as to form an X-shaped assembly when they are raised to raise said table, said first links which said pairs of links include being parallel to each other, while said second links are also parallel to each other, said links and said mechanism being foldable into said pit when said table is lowered to close said pit, the improvement which comprises: each of said second links having a lower end supported in said pit slidably along one of a pair of sidewalls of said pit, while each of said first links has a lower end supported rotatably in said pit at one end thereof; a horizontal pit cover connected to said second links slidably therewith for closing said pit which is opened when said table is raised; and a mechanism connecting said cover to said second links for causing said cover to slide with said second links.
Claim 2
Dependent Claim
228 words
In a jacking device including at least one jack installed in a floor pit, said jack comprising at least two horizontally spaced apart parallel pairs of links which are designed for simultaneous movement in two parallel vertical planes, respectively, a mechanism associated with said links for moving them in said planes, and a table supported horizontally on said links, each of said pairs of links consisting of a first link and a second link which are so connected to each other as to form an X-shaped assembly when they are raised to raise said table, said first links which said pairs of links include being parallel to each other, while said second links are also parallel to each other, said links and said mechanism being foldable into said pit when said table is lowered to close said pit, the improvement which comprises: each of said second links having a lower end supported in said pit slidably along one of a pair of sidewalls of said pit, while each of said first links has a lower end supported rotatably in said pit at one end thereof; a horizontal pit cover connected to said second links slidably therewith for closing said pit which is opened when said table is raised; and a mechanism connecting said cover to said second links for causing said cover to slide with said second links.
Claim 3
Dependent Claim
61 words
A jacking device as set forth in claim 1, wherein said connecting mechanism comprises: a pair of horizontally spaced apart parallel slidable brackets secured to said cover and each having a slot which is horizontally elongated in parallel to said sidewalls; and a pin projecting from said lower end of each of said second links and received slidably in said slot.
Claim 4
Dependent Claim
72 words
A jacking device as set forth in claim 2, further including a pair of springs each connected between one of said brackets and said pin projecting from one of said second links and lying in parallel to said slot of said one bracket for urging said pin toward one end of said slot to hold said cover out of sliding motion during a part of the sliding motion of said second links.
Claim 5
Dependent Claim
51 words
A jacking device as set forth in claim 3, wherein said cover includes a horizontal portion having an edge extending above said pit at right angles to said sidewalls thereof, and a vertical portion depending from said edge and staying in said pit, said brackets being secured to said vertical portion.
Claim 6
Dependent Claim
52 words
A jacking device as set forth in claim 4, further including a pair of horizontally spaced apart parallel angle bars provided along said sidewalls, respectively, for supporting said cover slidably thereon, each of said bars having a top surface flush with the surface of the floor in which said pit is made.