Patent US3893540A successfully refreshed from Google Patents.
US3893540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lifting mechanism
Assignee: Individual
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Filing: 1973-12-07
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Granted: 1975-07-08
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Expires: 1993-12-07
Abstract
Abstract Apparatus for raising and lowering workmen and tools into proximity with elevated structures during construction and repair thereof comprises a platform, a frame and a hydraulicallyactuated linkage assembly connecting the platform to the frame. The linkage assembly comprises an elongated boom assembly pivotally connected to one end of the platform, a compression member assembly pivotally connected to one end of the frame and to the boom assembly, and a tension member assembly pivotally connecting the other end of the boom assembly to the frame. A main hydraulic actuator is connected between the compression member assembly and the frame and operates upon extension to pivot the compression member assembly in one direction to cause the tension member assembly to pivot the boom assembly in the other direction for raising the platform. Auxiliary hydraulic actuator means connects the boom assembly to the platform, and an automatic levelling system is provided to operate the auxiliary actuator means for maintaining the platform level during raising and lowering thereof.
Inventors
- 👤 Robert A Beucher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:05
CPC Classifications
B; B66; B66F; B66F11/00; B66F11/04; B66F11/044
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
173 words
Load lifting apparatus, comprising: a frame, a compression member pivotally connected to said frame at one location, an elongated boom pivotally connected to said compression member, an elongated load support platform pivotally connected to one end of said boom and extending therefrom so as to overlie said boom and said frame for supporting a load moveable on the platform above the frame, a rigid tension member pivotally connected to the other end of said boom and pivotally connected to said frame at another location spaced from said one location, first actuator means connecting said compression member to said frame for pivoting the compression member and causing said tension member to pivot said boom relative to the compression member for raising and lowering said load support, and second actuator means associated with said support and boom for pivoting said support relative to said boom to permit leveling of said support during raising and lowering thereof, whereby said load support platform may be raised and lowered upon extension and retraction of said first actuator means.
Claim 2
Dependent Claim
173 words
Load lifting apparatus, comprising: a frame, a compression member pivotally connected to said frame at one location, an elongated boom pivotally connected to said compression member, an elongated load support platform pivotally connected to one end of said boom and extending therefrom so as to overlie said boom and said frame for supporting a load moveable on the platform above the frame, a rigid tension member pivotally connected to the other end of said boom and pivotally connected to said frame at another location spaced from said one location, first actuator means connecting said compression member to said frame for pivoting the compression member and causing said tension member to pivot said boom relative to the compression member for raising and lowering said load support, and second actuator means associated with said support and boom for pivoting said support relative to said boom to permit leveling of said support during raising and lowering thereof, whereby said load support platform may be raised and lowered upon extension and retraction of said first actuator means.
Claim 3
Dependent Claim
92 words
Apparatus according to claim 1 wherein the pivot connection of said tension member to said frame is spaced from the pivot connection of said tension member to said boom a first predetermined dimension, the compression member to frame pivot connection is spaced from the compression member to boom pivot connection a second predetermined dimension greater than said first dimension; and the pivot connection of said tension member to said boom is spaced from the pivot connection of said compression member to said frame a third predetermined dimension greater than said second-mentioned dimension.
Claim 4
Dependent Claim
79 words
Apparatus according to claim 2 wherein said second dimension is related to said first dimension in a ratio of substantially 1.3/1, and said third dimension is related to said first dimension in a ratio of about 1.7/1, said ratios being determined when the compression member is disposed horizontally and said tension member is disposed at about a 5* downward angle with respect to horizontal and said boom is disposed at about a 6* upward angle with respect to horizontal.
Claim 5
Dependent Claim
32 words
Apparatus according to claim 1 wherein said members are disposed in substantially parallel relation and said one end of said boom overlies the pivot connection of said compression member to said frame.
Claim 6
Dependent Claim
42 words
Apparatus aCcording to claim 4 wherein said first actuator is pivotally connected to said frame at a third location spaced from said first-mentioned frame location and said tension member to frame pivot connection is located intermediate said first and third frame locations.
Claim 7
Dependent Claim
61 words
Apparatus according to claim 5 wherein said first actuator is pivotally connected to said compression member outward of said compression member to frame pivot connection, and said first actuator is inclined with respect to said frame to dispose the line of action of the first actuator transverse to the compression and tension members and in the same direction as the boom.
Claim 8
Dependent Claim
86 words
Apparatus according to claim 6 including a vehicle having a pair of spaced parallel chassis members, said frame including a pair of main frame members fastened to said chassis members and at least one supplemental frame member inclined with respect to said main members and disposed inboard of said chassis members, said tension member being secured to said supplemental frame member at a level below the level of said compression member to frame pivot connection, to afford folding of the apparatus into a compact transport configuration.
Claim 9
Dependent Claim
83 words
Apparatus according to claim 1 including automatic leveling means associated with said second actuator means for maintaining said support level during raising and lowering thereof, said automatic leveling means including an operator mounted to said support, gravity sensing means associated with said operator, and means connecting said operator means to said second actuator means, said operator being operable to extend and retract said second actuator means to maintain said support level as said boom pivots in opposite directions relative to said compression member.
Claim 10
Dependent Claim
68 words
Apparatus according to claim 8 wherein said operator means includes a housing and a rotor mounted for rotation relative to said housing about a horizontal axis parallel to the pivot axis of the support, and said gravity sensing means includes a mass connected to said rotor and depending below its pivot axis for causing said rotor to pivot relative to said housing during pivotal movement of said boom.
Claim 11
Dependent Claim
74 words
Apparatus according to claim 9 wherein said second actuator means includes at least one hydraulic cylinder, and said operator includes rotary valving means associated with said rotor in said housing, said connecting means providing fluid communication to opposite ends of said cylinder for supplying pressure fluid thereto and exhausting pressure fluid therefrom for extending and retracting said cylinder in response to pivotal movement of said housing relative to said rotor and said valving means.
Claim 12
Dependent Claim
49 words
Apparatus according to claim 10 wherein said connecting means includes slave valve means associated with said rotary valving means and connected to said second actuator means and a source of pressure fluid to extend and retract said second actuator means in response to operation of said rotary valving means.
Claim 13
Dependent Claim
43 words
Apparatus according to claim 1 wherein said support is elongated and overlies said boom, and said second actuator means includes a pair of hydraulic cylinders, means pivotally mounting said cylinders outboard of said boom, and means pivotally connecting said cylinders to said support.
Claim 14
Dependent Claim
68 words
Apparatus according to claim 1 wherein said second actuator means includes an hydraulic cylinder, a shaft pivotally connected to said boom adjacent said support pivot connection, a crank arm connected to said shaft, at least one arm secured to said shaft, and at least one link connecting said arm to said support for pivoting the support relative to the boom upon extension and retraction of said hydraulic cylinder.
Claim 15
Dependent Claim
69 words
Apparatus according to claim 1 wherein said second actuator means includes an hydraulic cylinder, a crank having a shaft pivotally connected to said boom adjacent said support pivot connection, at least one arm secured to said shaft and connected to said cylinder, and at least one link connecting said arm to saId support for pivoting the support relative to the boom upon extension and retraction of said hydraulic cylinder.
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) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |