US3746307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load lifting jacks
Assignee: Aisin Corp
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Filing: 1971-06-23
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Granted: 1973-07-17
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Expires: 1991-06-23
Abstract
Abstract A load lifting jack comprising a pair of guide rails connected in parallel relation with each other by a pin and a connecting member at their both ends so that a rectangular frame is provided, a lifting arm carrying at its one end a load engaging head, a screw shaft rotatably supported within the frame, the screw shaft carrying thereon an internally threaded nut to which the lifting arm is pivoted at its one end, link members pivoted at their one ends with respect to the lifting arm at an intermediate position thereof, a base on which the pair of guide rails is pivotally mounted by the said pin, the base having one or more pairs of aligned notches on its flanged portions with which said one ends of the link members are selectively engageable, and a linking or supporting member which rotatably supports the screw shaft at its one end and inside of the frame but bears the thrust of the screw shaft.
Inventors
- 👤 S Yamazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:38
CPC Classifications
B; B66; B66F; B66F3/00; B66F3/08; B66F3/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
159 words
In combination in a load lifting jack, a pair of guide rails, means connecting said guide rails in parallel relation with each other to provide a rectangular frame, an elongated lifting arm having a load engaging head at one end thereof, a screw shaft rotatably supported within the frame, an internally threaded nut on said screw shaft, means pivotally mounting the other end of said lifting arm on said nut, link members each piVotally connected at one end with said lifting arm at an intermediate position therealong, a base, means pivotally mounting said pair of guide rails with said base, said base having flanged portions with notches spaced along the lengths thereof for selectively receiving the other ends of said link members, a linking member rotatably supporting the screw shaft at its one end thereof and inside of said frame, and means supporting said linking member in relation to said base and in thrust-receiving relation to said screw shaft.
Claim 2
Dependent Claim
159 words
In combination in a load lifting jack, a pair of guide rails, means connecting said guide rails in parallel relation with each other to provide a rectangular frame, an elongated lifting arm having a load engaging head at one end thereof, a screw shaft rotatably supported within the frame, an internally threaded nut on said screw shaft, means pivotally mounting the other end of said lifting arm on said nut, link members each piVotally connected at one end with said lifting arm at an intermediate position therealong, a base, means pivotally mounting said pair of guide rails with said base, said base having flanged portions with notches spaced along the lengths thereof for selectively receiving the other ends of said link members, a linking member rotatably supporting the screw shaft at its one end thereof and inside of said frame, and means supporting said linking member in relation to said base and in thrust-receiving relation to said screw shaft.
Claim 3
Dependent Claim
58 words
A jack according to claim 1, further comprising a guide member fixed with one of said flanged portions and, together with the notched parts of said flanged portions, providing a guide way confining the other end of one of said link members and thereby guiding the lower ends of said link members to selected ones of said notches.
Claim 4
Dependent Claim
57 words
A jack according to claim 1, wherein said means pivotally mounting the other end of said lifting arm on said nut includes two pins extending horizontally from opposite sides of said nut, perpendicular to the axis of the screw shaft, and further comprising rollers of plastic material rotatable on said two pins and within said guide rails.
Claim 5
Dependent Claim
51 words
A jack according to claim 3 wherein said guide rails are U-shaped in cross-section, the said rollers being retained within both guide rails respectively by their upright walls so that the internally threaded nut may be moved in a path provided by the guide rails when the screw shaft is turned.
Claim 6
Dependent Claim
124 words
A jack according to claim 1, wherein one end of said screw shaft protrudes beyond said linking member, wherein said means pivotally mounting said guide rails with said base comprises a pivot pin extending between said rails and in pivotal engagement with said base, and wherein said means supporting said linking member includes a thrust bearing, a nut fast on the protruding end of said screw shaft, said thrust bearing being disposed between said linking member and said nut, two pins extending horizontally from opposite sides of said linking member, perpendicular to the axis of said screw shaft, and two links each connected at one end to the linking member by one of said pins and at the other end to said pivot pin.
Claim 7
Dependent Claim
58 words
A jack according to claim 5, wherein each of said links has at its said other end a nose disposed to rest on said base and stop further relative motion between said rails and said base in one angular direction when the guide rails pivot upwardly about said pivot pin by a predetermined angular amount in said direction.
Claim 8
Dependent Claim
100 words
A jack according to claim 1, wherein said means connecting said guide rails includes a connecting member fixed between said rails at one end of said rails, the other end of said screw shaft protruding beyond said connecting member, and further comprising a driving head fast at said other end of said shaft, said head having diverging outwardly-spreading leafs each with a hole therethrough and at least one of which further has a narrow open-ended slot merging with the hole therethrough, whereby a branch of a driving handle may be entered into and drawn from the hole through the slot.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |