US4019604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elevating platform apparatus
Assignee: Hyster Co
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Filing: 1975-06-16
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Granted: 1977-04-26
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Expires: 1995-06-16
Abstract
Abstract Apparatus is disclosed for elevating a platform of the type adapted to carry workers, tools, equipment and/or material. Parallelogram boom assemblies support the platform from a mobile frame such that the platform can be raised and lowered in a level attitude. Each boom assembly comprises a compression arm and a tension arm. The two boom assemblies are interconnected by means of a floating frame and a rigid tension member which is arranged to raise and lower the upper boom assembly relative to the floating frame as the lower boom assembly is raised and lowered, respectively, relative to the mobile frame. In one embodiment the upper and lower boom assemblies lie in a horizontal orientation when in their retracted mode. In another embodiment an upstanding support carries the lower boom assembly which inclines downwardly in the retracted position and connects through a floating frame with an upper boom assembly which is formed with a zigzag shape.
Inventors
- 👤 Lyman David Benson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:45
CPC Classifications
B; B66; B66F; B66F11/00; B66F11/04; B66F11/044
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
211 words
In an aerial lift apparatus having a main support frame, the combination of a first parallelogram boom assembly including a pair of elongate parallel first arms mounted at their proximal ends on the support frame and extending at an upwardly inclined angle from the support frame, a floating frame pivotally mounted on the distal ends of the first arms, at least a second parallelogram boom assembly including a pair of elongate parallel second arms pivotally mounted at their proximal ends on the floating frame adjacent said pivotal mounting between the first arms and floating frame, said second arms extending at an angle which inclines upwardly from said base in a direction opposite said inclined angle of the first arms, an end frame pivotally mounted on the distal ends of the second arms, rigid tension link means interconnected between the distal end of one of the first arms and a proximal end of one of the second arms for applying a moment force on the latter to pivot the second boom assembly in an angular direction about the floating frame which is opposite to the angular direction of pivoting of the first arms relative to the main support frame, and means for pivoting the first arms relative to the main support frame.
Claim 2
Dependent Claim
211 words
In an aerial lift apparatus having a main support frame, the combination of a first parallelogram boom assembly including a pair of elongate parallel first arms mounted at their proximal ends on the support frame and extending at an upwardly inclined angle from the support frame, a floating frame pivotally mounted on the distal ends of the first arms, at least a second parallelogram boom assembly including a pair of elongate parallel second arms pivotally mounted at their proximal ends on the floating frame adjacent said pivotal mounting between the first arms and floating frame, said second arms extending at an angle which inclines upwardly from said base in a direction opposite said inclined angle of the first arms, an end frame pivotally mounted on the distal ends of the second arms, rigid tension link means interconnected between the distal end of one of the first arms and a proximal end of one of the second arms for applying a moment force on the latter to pivot the second boom assembly in an angular direction about the floating frame which is opposite to the angular direction of pivoting of the first arms relative to the main support frame, and means for pivoting the first arms relative to the main support frame.
Claim 3
Dependent Claim
116 words
Aerial lift apparatus as in claim 1 in which the first arms are substantially equal length whereby pivoting of such arms relative to the support frame raises and lowers the floating frame in a level attitude, the second arms are of substantial equal length whereby pivoting of the second arms relative to the floating frame raises and lowers the end frame in a level attitude thereof, and the tension link means is sized and positioned to pivot the second arms at a equal angular rate with respect to the angular rate of pivotal movement between the first arms and floating frame whereby the end frame is caused to be raised and lowered without substantial horizontal displacement.
Claim 4
Dependent Claim
92 words
Aerial lift apparatus as in claim 1 in which said support base includes an upstanding post and said first arms are pivotally mounted at their proximal ends to an upper portion of said post for movement between a downwardly inclined retracted position and an upwardly inclined extended position, said floating frame is mounted on and extends upwardly from the distal ends of the first arms, and said second arms are mounted on an upper portion of the floating frame and incline downwardly therefrom when said first arms are in a retracted position.
Claim 5
Dependent Claim
47 words
Aerial lift apparatus as in claim 3 in which said second arms are formed with a portion having a zigzag shape in plan, said zigzag portion being positioned in side-by-side relationship with the first arms for providing clearance therewith when said arms are in their retracted positions.
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) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |