US1433695A - Lifting jack - Google Patents

Description

. B. BOSTWICK.

LIFTING JACK.

APPLlcAloN FILED :une 2x5, 1920.

m mmm @ma 31,1922,

f Arron/vers.

Patented Unt. 3l, l922.

Jil-a9 i JAMES 1B. EOSTWICK, 0E JERSEY CITY, NEW JERSEY.

MEETING- JACK.

T o aZZ whom t may con-cern.' Y

Be it known-that l, JAMES B. Bos'rwion, a citizen of the United States, and a resident of Jersey City, in the county ofr Hudson and State of `1New Jersey, have invented new and useful lmprovements in Lifting Jacks, of which the following is a specification.

The invention relates vin general to lifting jacks, and more articularly to lifting jacks operated by fluid pressure.

rlfhe objects of the invention are to provide a. combined fluid pressure operated jack and fluid reservoir embodying novel features of construction; to provide such a lifting jack havin a hollow piston of novel construction w ich serves as a reservoir for the fluid under pressure; to obtain a novel construction and arrangement of passages and connections for first charging the reservoir directly with fluid under pressure, subsequently releasing a portion of the fluid from the reservoir behind the piston to elevate the same when it is desired toutlize the jack for lifting purposes, and after such use releasing the fluid pressure from behind the piston into the atmosphere to allow the piston to resume its normal position; to provide ay novel valve means for so charging the reservoir and transferring the fluid therefrom, and to obtain other advantages and .results as may be brought out by the following description. l l

Feferrin to t-he accompanying drawings, in which like numerals of reference indicate the same parts throughout the several views,

Figure l is a vertical longitudinal sectional view through a lifting jack embodying my invention. taken on the line 1-1 of Fig. ll, and showing the piston of the jack in its normal inoperative position;

Figure 2 is a sectional view through the cylinder of the jack, the piston and valve nipple being shown in side elevation andthe piston being shown in an operative position;

Figure 3 1s a top plan view of the j ack;

Figure 4t is an enlarged fragmentary sectional view taken on theline 4:-4 of Fig. l,

and

Figure 5 is a detail view of the j ack head and an extension therefor.

ln the specific embodiment of the invention-illustrated by the drawings, the numeral l designates the lcylinder of the jack which may be constructed of any suitable material such as steel, brass or the like, and which may be formed in any suitable manner as by casting, stamping or machining according to the size of jack desired and the purpose for which the jack is desired. ln the present instance my invention-has been shown embodied in a vehicle jack, and the cylinder l is shown as having one end thereof open and being substantially elliptical in crosssection for the purpose of providing an enlarged area for the base of the jack and also for preventing rolling of the jack when the same is laid upon its side. This elliptical formation of the cylinder also prevents rotation or twistin of a similarly formed pis- 7o ton 2 which is s idably mounted within the cylinder l. l

'llhe piston 2 serves as a reservoir for the Huid under pressure by which the jack is operated, the said piston being shown as hollow in formation and `having at its inner end a conventional packing ring or cup 3 which forms a tight chamber between the inner end of the piston and the cylinder. rl`he kouter end of the piston is closed in any suitable manner as by means of the cap 4 which is provided with a depending flange 5 which overlaps the edge of the cylinder to prevent dust or foreign matter from entering the cylinder.

A fluid conduit pipe 6 extends longitudinally 85 said nuts also serving with a washer 7a to 90 secure the packing cup 3 to the inner end of the piston. rl`he outer end of the pipe 6 projects through the cover 4 and has threaded thereon a cap 8 which closes the outer end of the pipe 6 and serves in conjunction with 95 a clamping nut 9 to secure the cover-4c to the outer end of the piston 2, the said clamping nut 9 also serving with a washer 9a to secure a packing cup l0 between the cover l and the piston to provide a fluid tight joint. A 10o jack head 11 is secured to the Y cap 8 in an)T suitable manner as by a thread connection as shown by Figure l of the drawings, the said jack head serving as a bearing surface for the axle of a vehicle. lt will be obvious that ica the manner of closing the outer end of the piston 2 may be varied as desired, the present construction being only illustrative of one possible construction for this purpose.

The piston 2 is charged with fluid under il@ pressure through an inlet and valve nipple 13 which lhas one end thereof t-hreaded into the cap S and through the side of the pipe 6, the said nipple being provided with a passage 11 opening through the outer end thereof and controlled by a conventional inwardly opening check valve 15. This valve 15 may be of any suitable construction, but in the present instance is shown as comprising a conventional tire-inflating valve 16 normally held against its seat by a spring 1T and having an outwardly projecting stein 18. A tubular duct 19 is threaded through the cover l of the piston into the said passage 1l in the valve nipple 13. and when the inlet valve 15 is connected to a compressed Huid supply the fluid is conducted through the passage 11 and bushing 19 into the piston reservoir Q. 'hen it is desired to use the j ack for jacking up a vehicle. the compressed uid in the piston :2 is conveyed to the chamber 1:2 behind the piston through a passage :20 communicating with the passage 1l and the pipe 6. the said passage 20 being controlled by an inwardly opening check valve 21 similar in construction to ythe valve 15. The valve :21 is provided with afinger button :22 for opening the valve. and when the said button is pushed inwardly the valve 21 is opened to allow the compressed fluid to pass from the piston :2 into the chamber 12 as above described. When the compressed Huid is thus conveyed into the chamber 12 the piston 2 is raised thereby as indicated in Figure 2 of the drawings to jack up the vehicle in the usual way. In order to allow the piston 2 to resume its normal position and lower the vehicle. the compressed uid lin the chamber 12 is permitted to escape into the atmosphere through the pipe 6. passage 2t" and a third inwardly opening check valve .73 in communication with the passage 2U. the said check valve 23 being opened b v pressure upon the finger button Q-l thereof.

The capacity of the piston reservoir Q is preferably such as to contain sutiicient fluid under pressure to operate the jack severalA times. and it will be seen that this is possible through Vthe very slight movement of the piston during its operation. It will also be seen that by reason of the peculiar valve arrangement the piston reservoir can be easily charged bv the attachment of any suitable source of compressed Huid to the inlet valve 15 without effecting any movement of the piston within the cylinder. lTi'hen it is desired to jack up a vehicle it 1s merely necessary to place the jack beneath the axle of the vehicle. press the finger button 22 of the valve '21 to-open the same thus allowing suiicient fluid to enter the chamber 1Q to raise the piston and elevate the vehicle. and when it is desired to lower the vehicle it is merely necessarv to press the linger button Q1 ofthe outlet valve 23 to allow the Huid to escape from the cham ber 12. Owing to the comparatively small passage 2O the escape of the Huid will be comparatively slow so as to gradually lower the vehicle without jerks or jars upon the same. The compressed fluid supply is thus always carried by and within the jack itself so that it is unnecessary to use a hand pump or a,motor operated pump to elevate the piston each time it is desired to use the jack, as is the usual practice with the modern types of pneumatic jacks).

When the jack is to be used in connection with a vehicle the axle of which is a considerable distance above the ljack head 11 when the piston 2 is in its lowermo'st position, a j ack head extension 25 may be pivotally secured to the jack head 11 as shown in Figure 5 of the drawings so as to be swung into operative position upon the top of the jack head as shown in solid lines or thrown into inoperative position as shown in dotted lines. In the present instance this jack! head extension 25 is shown as formed of a single strip of metal bent into the desired form and having one yend thereof pivotally connected at 26 to an extension QT on one end of the jack head 1l, the other end of the strip being returned against the first-mentioned end and resting upon the jack head 11. This extension 25 is particularly desirable in a jack of this type where an unnecessarily long movement of the piston 2 would waste the compressed fluid and reduce the number of times which the jack could be operated by one charging of the piston reservoir 2.

While I have shown and described one possible embodiment of my invention, it will be obvious that many modications and changes can be made in the construction thereof without departing from the spirit or scope of the invention. and I do not desire to be limited in the construction and use of my invention except as required by the following claims when construed in the light of the prior art..

Having thus described the invention. what- I claim is:

l. In a lifting jack. the combination of a, cylinder having a reservoir for Huid under pre'ure within itself. a piston adapted to be operated by said fluid, a nipple secured upon said reservoir and having a main passage one end of which communicates with the cylinder behind said piston and the other end of which is adapted to be connected to a Huid pressure supply. said main passage also communicating intermediate its ends with a passage leading to said reservoir. a valve in said main passage between said last mentioned passage and the said cylinder behind said piston to permit Huid pressure from said reservoir to enter said cylinder to operate said piston, and asecond valve for perfio,

mitting the eXhaust of said fluid pressure from said cylinder.

2. lin a lifting jack, the combination of a cylinder having a reservoir for fluid under pressure within itself, a piston adapted to be operated by said fluid, a nipple secured upon said reservoir and having a main passage one end of which communicates with the cylinder behind said piston and the other end of which is adapted to be connected to a fluid pressure supply, said main passage also communicating intermediate its ends with a passage leading to said reservoir and have ing a by-pass between'said last mentioned passage and said reservoir communicating with the atmosphere. a' valve-in said main" passage between said last mentioned passage and the said cylinder behind said piston to permittluid pressure from said reservoir to enter said cylinder to operate said piston,

and a second valve in said h'y-pass to release the tiuid pressure in said cylinder into the atmosphere.

ln a lifting jack. the combination of a cylinder, a piston in saidcylinder and having a reservoir for fluid under pressure therein. a conduit extending through said reservoir and having one end thereof communicating with the cylinder behind the piston, a main passage one end of -which communicates with the said conduit and the other end of which is adapted to be connected to a fluid pressure supply. a valve for preventing escape of fluid from said supply connection. a second passage communicating with said first mentioned passage and said reservoir, a valve in said first mentioned passage between said second mentioned passage'and the said conduit to control the flow of iiuid pressure from said reservoir into said conduit. and a valved outlet for the fluid pressure in said cylinder behind the piston.

i. ln a lifting jack. the combination of a cylinder, a piston in said cylinder and having a reservoir for fluid 'under pressure therein, a conduit extending through said reservoir and having one end thereof communicating with the cylinder behind the piston. a main passage one end of which communicates with the said conduit and the other end of which is adapted to be connected to a huid pressure supply, a valve for preventing escape of iuid from said supply connection, a second passage communicating with said firstmentioned passage and said reservoir. a valve in said first mentioned passage between said second mentioned passage and the said conduit to control the flow of fluid pressure from said reservoir into said conduit, a by-pass communicating with said main passage and the atmosphere between said conduit and said second mentioned valve, and a third valve in `said by-passl for controlling the exhaust of the ltiid pressure in said cylinder into the atmosphere, 2

|5. "in a. device of the character described, the combination of a cylinder having a reservoir for Huid. under pressure arranged within itself. a piston in said cylinder adapted to be, operated by saidiiuid, said reservoir being normally out, of communication with said piston, a nipple having a passage therein adapted to be connected to a fluid pressure supply, said passage being also adapted to communicate with sa-id reservoir and the atmosphere, an outwardly closing check valve preventing escape of the fluid through said supply connection, a valve controlling communication between said reservoir and said cylinder behind the piston, and a valve for permitting escape, of said iiuid behind the piston through said passage into the at mosphere.

6. ln a lifting jack, the combination of a cylinder, a piston in said cylinder and having a reservoir for fluid under pressure therein. said piston having an inner head. a cover on the outer end of said piston, a pipe extending longitudinally through said piston and having its ends threaded into said inner head and said cover, one end of said pipe projecting beyond said cover, and

the other end opening into the cylinder behind said piston, a cap threaded on the outer end of said pipe to clamp the said cover on said piston, a nipple secured upon said cap and having a passage communicating between the said reservoir in the piston and said pipe, a valve cont-rolling said passage, and means for exhausting the Huid pressure in said cylindei into the air. i

JAMES B. BOSTWECK.

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