US3857548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pantograph-type jack
Assignee: Individual
•
Filing: 1973-06-28
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Granted: 1974-12-31
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Expires: 1993-06-28
Abstract
Abstract A pantograph-type jack comprising a plurality of upper jack arm assemblies each of which includes a pair of opposite jack arms having inner toothed ends pivoted to a movable load support member and in engagement with each other. The jack has a plurality of lower jack arm assemblies, each of which includes a pair of opposite jack arms having the inner toothed ends pivoted to a stationary base member and in engagement with each other. Spaced movable support blocks are provided for pivotally supporting the outer ends of the jack arms of the upper and lower jack arm assemblies, with one of said support blocks having a center coarsely threaded bore threadedly engaging a first rod while the other support block has a center plain bore which supports a second rod. A sleeve having one end fixedly attached to the adjacent end of the first rod is provided with a finely threaded inner surface that is threadedly engaged by the second rod, which, in turn, is connected to a receiving member 14 for actuating the jack.
Inventors
- 👤 T Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:54
CPC Classifications
B; B66; B66F; B66F3/00; B66F3/08; B66F3/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
206 words
A pantograph-type jack comprising a plurality of upper jack arm assemblies each of which comprises a pair of opposite jack arms having opposingly engaged inner toothed ends pivoted to a movable support member; a plurality of lower jack arm assemblies each of which includes a pair of opposite jack arms having the opposingly engaged inner toothed ends pivoted to a stationary base member; spaced movable support blocks for pivotally supporting the outer ends of said jack arms of said plurality of upper and lower jack arm assemblies, one of said supporting blocks having a center coarsely threaded bore, the other of said support blocks having a plain bore; a first operation rod having a coarsely threaded outer surface in threaded engagement in said one support block; a sleeve having one end portion for fixedly receiving an adjacent inner end of said first operation rod and an other end portion of said sleeve having a finely threaded inner surface; and a second operation rod having a finely threaded outer surface portion in threaded in engagement With said inner threaded surface of the other end portion of the sleeve, said second operation rod further having a plain surface portion received in said plain bore of the other block.
Claim 2
Dependent Claim
206 words
A pantograph-type jack comprising a plurality of upper jack arm assemblies each of which comprises a pair of opposite jack arms having opposingly engaged inner toothed ends pivoted to a movable support member; a plurality of lower jack arm assemblies each of which includes a pair of opposite jack arms having the opposingly engaged inner toothed ends pivoted to a stationary base member; spaced movable support blocks for pivotally supporting the outer ends of said jack arms of said plurality of upper and lower jack arm assemblies, one of said supporting blocks having a center coarsely threaded bore, the other of said support blocks having a plain bore; a first operation rod having a coarsely threaded outer surface in threaded engagement in said one support block; a sleeve having one end portion for fixedly receiving an adjacent inner end of said first operation rod and an other end portion of said sleeve having a finely threaded inner surface; and a second operation rod having a finely threaded outer surface portion in threaded in engagement With said inner threaded surface of the other end portion of the sleeve, said second operation rod further having a plain surface portion received in said plain bore of the other block.
Claim 3
Dependent Claim
28 words
The pantograph-type jack defined in claim 1 wherein said plurality of lower jack arm assemblies is disposed below and inwardly of said plurality of upper jack arm assemblies.
Claim 4
Dependent Claim
36 words
The pantograph-type jack defined in claim 1 wherein said inner ends of the pair of opposite jack arms in each of the upper and lower jack arm assemblies are in the form of a toothed sector.
Claim 5
Dependent Claim
56 words
The pantograph-type jack defined in claim 1 wherein the length of said sleeve is so selected that when said jack is in its permitted highest position, said support blocks are in positions spaced from each other on the opposite sides of a vertical line passing through the center of gravity of a load to be raised.
Claim 6
Dependent Claim
38 words
The pantograph-type jack defined in claim 1 wherein the inner one end portion of said second operation rod is threadedly received in said inner threaded surface of the other end portion of the sleeve to be guided therein.
Claim 7
Dependent Claim
35 words
The pantograph-type jack defined in claim 1 further comprising a pin, said pin fixedly securing the inner end of said first operation rod within said sleeve so that said rod and said sleeve rotate together.
Claim 8
Dependent Claim
38 words
The pantograph-type jack defined in claim 1, in which after said second operation rod has reached a predetermined inner dead end within said sleeve, said first and second operation rods and said sleeve can be rotated in unison.
Claim 9
Dependent Claim
53 words
The pantograph-type jack defined in claim 1 wherein the other end portion of said second operation rod has the plain outer surface and extends through said center plain bore in the support block, the extreme end of said other end portion of the second rod having an operation means receiving member secured thereto.
Claim 10
Dependent Claim
34 words
The pantograph-type jack defined in claim 1 wherein said plurality of upper outer jack arm assemblies comprises two parallel jack arm assemblies and said lower inner jack assemblies comprise two parallel jack arm assemblies.
Claim 11
Dependent Claim
193 words
A pantograph-type jack comprising upper opposing arm having adjacent ends pivotably mounted to a movable load support member, said adjacent ends having engaging tooth sections, the opposite ends of said arms being pivotably mounted to spaced support blocks having aligned bores one of which is a threaded bore, the other of which is a plain bore; lower opposing arms having adjacent ends pivotably mounted to a base member, said adjacent ends having engaging tooth sections, the opposite ends of said lower arms being pivotably attached to said spaced support blocks, respectively, a rod member having a coarsly threaded portion engaging said threaded bore, a connecting member carried at one end of said rod member and rotatable therewith, said connecting member having a finely threaded section, a second rod member having one end rotatably mounted in said plain bore and a finely threaded section thereon engaged with said connecting member; said second rod member rotating within said connecting member a predetermined amount without rotating said first rod member, said connecting member and said first rod member being rotatable with said second rod member after said second rod member is rotated beyond said predetermined amount.
Claim 12
Dependent Claim
193 words
A pantograph-type jack comprising upper opposing arm having adjacent ends pivotably mounted to a movable load support member, said adjacent ends having engaging tooth sections, the opposite ends of said arms being pivotably mounted to spaced support blocks having aligned bores one of which is a threaded bore, the other of which is a plain bore; lower opposing arms having adjacent ends pivotably mounted to a base member, said adjacent ends having engaging tooth sections, the opposite ends of said lower arms being pivotably attached to said spaced support blocks, respectively, a rod member having a coarsly threaded portion engaging said threaded bore, a connecting member carried at one end of said rod member and rotatable therewith, said connecting member having a finely threaded section, a second rod member having one end rotatably mounted in said plain bore and a finely threaded section thereon engaged with said connecting member; said second rod member rotating within said connecting member a predetermined amount without rotating said first rod member, said connecting member and said first rod member being rotatable with said second rod member after said second rod member is rotated beyond said predetermined amount.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |