Patent US3595525A successfully refreshed from Google Patents.
US3595525A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable aircraft jack
Assignee: POWERFLOW ENGINEERING AND EQUI
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Filing: 1968-07-15
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Granted: 1971-07-27
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Expires: 1988-07-15
Abstract
Abstract A portable aircraft jack in which a double cylinder hydraulic jack is rigidly mounted at one end of a wheeled trailer which has a towing handle at the opposite end. The rear trailer wheels are mounted on pivot arms connected to the handle by a linkage so that raising the handle will pivot the wheel arms and cause the rear of the trailer to be lowered thus lowering the jack for placement under a vehicle to be lifted. The jack has inner and outer cylinders, each separately supplied with hydraulic fluid, thus leaving one fully operative should the other cylinder fail.
Inventors
- 👤 Edward E Yaste
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:36
CPC Classifications
B; B66; B66F; B66F3/00; B66F3/24; B66F3/25; B66F3/26; B66F3/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
193 words
A hydraulic aircraft jack for mounting on a movable platform comprising: a base having upstanding walls forming a cylinder thereon for receiving a hydraulic piston assembly; a spherical mounting pad inside the base cylinder for supporting a complementary socket; a hydraulic piston assembly comprising an upper piston having first inner cylinder inside of and concentric with a first outer cylinder, a middle piston having a second outer cylinder adapted to engage the outer wall of the first outer cylinder and a second inner cylinder adapted to engage the outer wall of the first inner cylinder, and a lOwer piston having a third outer cylinder adapted to engage the outer wall of the second outer cylinder and a third inner cylinder adapted to engage the outer wall of the second inner cylinder, the third inner an outer cylinders mounted concentrically on a head member, the head member having a spherical socket complementary to the spherical mounting pad so that the piston assembly may pivot about a vertical axis through the spherical pad and within the cylindrical walls of the jack base; and means for supplying hydraulic fluid under pressure to the hydraulic piston assembly.
Claim 2
Dependent Claim
193 words
A hydraulic aircraft jack for mounting on a movable platform comprising: a base having upstanding walls forming a cylinder thereon for receiving a hydraulic piston assembly; a spherical mounting pad inside the base cylinder for supporting a complementary socket; a hydraulic piston assembly comprising an upper piston having first inner cylinder inside of and concentric with a first outer cylinder, a middle piston having a second outer cylinder adapted to engage the outer wall of the first outer cylinder and a second inner cylinder adapted to engage the outer wall of the first inner cylinder, and a lOwer piston having a third outer cylinder adapted to engage the outer wall of the second outer cylinder and a third inner cylinder adapted to engage the outer wall of the second inner cylinder, the third inner an outer cylinders mounted concentrically on a head member, the head member having a spherical socket complementary to the spherical mounting pad so that the piston assembly may pivot about a vertical axis through the spherical pad and within the cylindrical walls of the jack base; and means for supplying hydraulic fluid under pressure to the hydraulic piston assembly.
Claim 3
Dependent Claim
64 words
The hydraulic jack of claim 1 and wherein the means for supplying hydraulic fluid includes a first fluid passage through the head member for supplying hydraulic fluid to the inner cylinder, a second fluid passage through the head member for supplying hydraulic fluid to the outer cylinder, and means interconnecting the fluid passages for equalizing the pressure in the inner and the outer cylinders.
Claim 4
Dependent Claim
115 words
A portable aircraft jack comprising: a wheeled platform for supporting a hydraulic jack at one end thereof, the supporting end of the platform movable between a normal position and a lowered position; a hydraulic jack rigidly mounted at the movable end of the platform, said jack having a base portion which is lowered close to the ground when the platform is lowered, said jack comprising concentric inner and outer telescoping hydraulic cylinders, said cylinders separately supplied with hydraulic fluid under pressure for raising said cylinders, said cylinders provided with means for permitting relative movement of the cylinders with respect to the jack base; and means for supplying hydraulic fluid under pressure to the jack cylinders.
Claim 5
Dependent Claim
115 words
A portable aircraft jack comprising: a wheeled platform for supporting a hydraulic jack at one end thereof, the supporting end of the platform movable between a normal position and a lowered position; a hydraulic jack rigidly mounted at the movable end of the platform, said jack having a base portion which is lowered close to the ground when the platform is lowered, said jack comprising concentric inner and outer telescoping hydraulic cylinders, said cylinders separately supplied with hydraulic fluid under pressure for raising said cylinders, said cylinders provided with means for permitting relative movement of the cylinders with respect to the jack base; and means for supplying hydraulic fluid under pressure to the jack cylinders.
Claim 6
Dependent Claim
116 words
The portable aircraft jack of claim 3 and wherein the hydraulic jack comprises: a base, a first vertical cylinder mounted on the base and adapted for movement about a vertical axis, a second vertical cylinder concentrically affixed inside the first cylinder, a plurality of additional pairs of cylinders concentrically aligned and inserted within said first and second cylinders, so that inner and outer separate hydraulic cylinders are formed thereby, and means for supplying hydraulic fluid to said inner and outer cylinders so that there is equal pressure within the inner and outer cylinders, said means including valve means which will prevent loss of fluid from one of the cylinders if the other cylinder suddenly loses fluid.
Claim 7
Dependent Claim
41 words
The portable aircraft jack of claim 4 and wherein the first vertical cylinder is provided with a spherical socket at one end thereof, and wherein the base has a spherical projection thereon for receiving the spherical socket of the first cylinder.
Claim 8
Dependent Claim
51 words
The portable aircraft jack of claim 4 and wherein the innermost cylinder has a threaded bore therein for receiving a lifting member, and a threaded lifting member received in the threaded bore, said member having a socket at the upper end thereof for engaging a spherical lift pad on an aircraft.
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) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |