US2724572A

US2724572A - Twin hydraulic jack assembly

Info

Publication number: US2724572A
Application number: US239604A
Authority: US
Inventors: Lowell C Weinberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-07-31
Filing date: 1951-07-31
Publication date: 1955-11-22
Anticipated expiration: 1972-11-22

Description

Nov. 22, 1955 L. c. WEINBERG TWIN HYDRAULIC JACK ASSEMBLY 2 Sheets-Sheet 1 Filed July 31, 1951 INVENTOR. Lowell C. Wbinber ATTORNEYS Nov. 22, 1955 1.. c. WEINBERG 2,724,572

TWIN HYDRAULIC JACK ASSEMBLY Filed July 31, 1951 2 Sheets-Sheet 2 J l o J O J WM k G I I K J C v IlllllH H L 1 l -a T. J' l S o J O 2 b 2 INVENTOR. i ifili1i* Lowell C.%imber United States Patent TWIN HYDRAULIC JACK ASSEMBLY Lowell C. Weinberg Redondo Beach, Calif. Application July 31, 1951, Serial No. 239,604

6 Claims. (Cl. 254-89) (Granted under Title 35, U. S. Code (1952), see. 266) The present invention relates generally to hydraulic jacks and specifically to a twin hydraulic jack for use with wheels and tires of aircraft.

In the servicing of aircraft in hangars or on flight decks extreme difliculty has attended the replacement of wheels or tires due to the compact construction of wheel hubs and axles used with retractable landing gear. The hubs and axles are necessarily set close to the rim of the wheels and with the large size tires now in use on aircraft it has been found diflicult to locate a vertically lifting device beneath the axle stub. The large size tires when partially or totally deflated spread out beneath the wheel to a degree which prohibits the use of a hydraulic jack beneath the jacking point on the hub or axle.

The present invention has for its object to provide a hydraulic lifting device which permits vertical lift of an aircraft wheel despite the collapsed and spreadout tire carcass.

Another object of the invention is to provide a. hy draulic jack having an extremely low compressed height and a high-extended height.

A further object of the invention is to provide a hydraulic jack that is readily portable and has wheels which without adjusting or latching to inoperative posi tion do not bear any of the lift load while the jack is in position.

A further object of the invention is to provide a hydraulic jack of inexpensive construction and one capable of lifting large loads as found aboard aircraft carriers.

These and other objects of the invention will be more clearly understood by reference to the accompanying description and drawings in which:

.Fig. 1 shows a partially exploded plan view of the invention.

Fig. 2 shows a cross-sectional view taken on line 2-2 of Fig. 3.

Fig. 3 shows a top plan view, and' Fig. 4 shows a side view in elevation'of the assembled invention.

Referring more particularly to the drawing in which like numerals indicate like parts throughout the several views, in Fig. 1, will be seen a pair of hydraulic jacks having bases 11 securedto bar 12 by angle brackets 13 and 14 (as seen in Fig. 4) at each end of bar 12. Brackets 15 and 16 on bar 12 support a pump 17 which is connected at its outlet end 18 with the distributing valve 19 and at its input end 21 to the oil reservoir 22 by pipe 23. The distributing valve 19 is connected by conduits 24 and 25 to each of the bases 11 by means of connectors indicated at 20.

Bolted to bases 11 are brackets 26 having axles 27 and wheels 28 rotatable thereon.

The hydraulic jacks 10, as shown in Fig. 2, are constructed of outer sleeves 30 screw threaded into the bases 11, inner sleeves 31, and pistons 32, and are extended slidably together by fluid pumped into chambers 33 in the bases 11. As shown in the partially exploded 7 view in Fig. 1 and also in the cross-section view of Fig.

2, the assembled

sleeves

30, 31, and pistons 32 of each jack fit loosely into the caps 35 at each end of the beam 36.

Caps 35 are cylindrical in shape and have their inner ends 37 concave to match and to provide a continuous bearing surface for the convex ends 38 of pistons 32 under conditions of flexing of beam 36 or while one jack 33 in the bases 11. As shown in the partially exploded is extended slightly higher than the other.

Slidable on beam 36 are two

riders

39 and 40, each having depending flanges 41 to prevent them from sliding sideways from beam 36. Rider 39 is a relatively low plate with a hole 42 into which fits pin 43 formed in the base of the load cup 44. Other load cups 45, 46, with identical pins 43, are of diiferent thicknesses and are replaceable with cup 44 in rider 39 or may be used with rider 40 in the hole 48 on top of the adjusting screw 47. Beam 36 has hole 49 at its center for receiving one of pins 43 when one of the cups 44, 45, or 46 are used to bear the weight of the lifted load without the increment of height added by the use of either rider39 or 40.

Each of the

riders

39 and 40 have identical springbased centering pins 51 having the pull-handles 52, the pin 51 of the rider chosen for use coacting with hole 53 in beam 36 to fix the rider in the center of the beam. Load cups 44, 45, 46 have short cables 54 securing them against loss or misplacement.

The purpose of riders 39 and 4t) and load cups 44, 45 and 46 is to provide means for contacting and bearing the lifted load at minimum jack travel regardless of the height of the lifting points of the load from ground level. The height of the lifting point will determine which bearing means is to be used in order that the full vertical jack travel remains and is present to lift the load the required distance. At the lowest lifting point, hole 49 and its load cup is utilized; at an intermediateheight rider 39 is used, and at higher lifting points, rider 40 with its adjusting screw 47 is used. Load cups 44., 45 and 46 are interchangeable with each other in

holes

42, 48, and 49 and have different sized depressions 63 to fit different sized loading points.

In operation, the oil return valve 60 is closed and distributing valve handle 61 is centered to obtain equal flow from pump 17 to each jack 10, and air vent 62 in the top of the reservoir 22 is opened to replenish the oil in pump 17 as it fills the jacks. If one jack lil raises faster than the other or if it is desirable to have one jack higher than the other to accommodate slight irregularities in the deck surface, handle 61 is moved towards the jack requiring the more oil, the particular construction of the .valve 19 permitting the distribution of oil to either or both jacks at will. Depending, upon the distance, deck and the loading point of the axle or hub,

either of

riders

39, or 40, with any one of the loading cups 44, 45, 46 may be used, and the adjusting screw 47 may be used with rider 40 to obtain the greatest amount of lift in each case.

The low compressed height of the beam and its relatively high extended height make it possible to raise the wheels of most aircrafts for easy and speedy wheel or 0 68 is provided for the purpose of permitting the fingers Patented Nov. 22, 1955 having a firm hold on the grip axle, to lift that end of the jack assembly in an upwards motion until the pair of wheels 28 on the opposite end of the jack assembly are in contact with the ground or other supporting surface, and both jack bases 11 are entirely clear of the ground or said supporting surface. The operator can now move the jack assembly to any desired location, simply by pushing or pulling, since the one end of the jack assembly is supported by the pair of wheels 28 at one end and the other end is supported by the firm grip of the operators hand on the axle 27.

The operator can lift either end of the jack assembly thus permitting the placing of the jack under either the right or left hand landing gear of an aircraft from the forward end of the aircraft, and have the lifting beam 36 of the jack assembly next to the aircraft wheel. Upon lowering of the jack off of the wheels, bases 11 provide a substantially immovable or fixed supporting means.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that numerous modifications or alternations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

l. A readily portable hydraulic lifting assembly having a low height and a high lift comprising a pair of hydraulic jacks rigidly secured together in spaced relation by a single straight bar; a base positioned on the lower surface of each'of said jacks; a single hydraulic pump mounted on said bar and operatively connected to each of said jacks; a load transmitting cap surmounting each of said jacks; and a single load receiving beam extending between said caps and rigidly secured thereto.

2. A readily portable hydraulic lifting assembly comprising a pair of hydraulic jacks in spaced relation; a base attached to the lower surface of each of said jacks; a single stragiht bar extending between and rigidly secured to said bases at points spaced above the lower surfaces thereof; a single hydraulic pump mounted on said bar and operatively connected to each of said jacks; a load transmitting cap surmounting each of said jacks; and a single load receiving beam extending between said caps and rigidly secured thereto.

3. A manually portable lifting assembly comprising a pair of hydraulic jacks in spaced relation; a base positioned on the lower surface of each of said jacks; a single straight bar extending between and rigidly secured to said bases at points spaced above the lower surfaces thereof; means for operating said jacks mounted on said bar and operatively connected to each of the jacks, said 4 means comprising a single pump, a hydraulic fluid supply and a single valve for simultaneously controlling the amount of fluid flow to each'jack; a load transmitting cap surmounting each of said jacks; a single load receiving beam extending between said caps and rigidly secured thereto. v

4. A manually portable lifting assembly comprising a pair of hydraulic jacks in spaced relation; a base positioned on the lower surface of each of said jacks; a single straight bar extending between and rigidly securedto said bases at points spaced above the lower surfaces thereof; means for operating said jacks mounted on said bar and operatively connected to each of said jacks; a load transmitting cap removably fitted over each of said jacks; a single load receiving beam extending between said caps and rigidly secured thereto; a series of loading point receiving means of graduated heights movably mounted on said beam.

5. A manually portable hydraulic lifting assembly comprising a pair of hydraulic jacks in spaced relation, each of said jacks having a curved load bearing surface; a base positioned on the lower surface of each of said jacks; a single straight bar extending between and rigidly secured to said bases at points spaced above the lower surfaces thereof; means for operating said jacks mounted on said bar and operatively connected to each of the jacks; a load transmitting cap removably fitted over each of said jacks, the lower bearing face of each cap resting on the curved load bearing surface of the jack and having a matching configuration; and a single load receiving beam extending between said caps and rigidly secured thereto.

6. A manually portable lifting assembly comprising a pair of hydraulic jacks in spaced relation; a base positioned on the lower surface of each of said jacks; a single straight bar extending between and rigidly secured to said bases at points spaced above the lower surfaces thereof; means for operating said jacks mounted on said bar and operatively connected to each of the jacks; and a load transmitting cap removably fitted over each of said jacks; a single load receiving beam extending between said caps andrigidly secured thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,994,942 Calkins Mar. 19, 1935 2,208,221 McCullough July 16, 1940 2,545,403 Wrenn Mar. 13, 1951 2,614,800 Garlinger et a1 Oct. 21, 1952 2,636,715 Gritfin Apr. 28, 1953 FOREIGN PATENTS 7,432 Great Britain 1889 802,202 France June 6, 1936