US874698A - Hydraulic jack. - Google Patents

Description

No. 874,695. PATENTED DEC. 24, 1907.

' J. W. NELSON.

HYDRAULIC JACK. APPLICATION FILED MAY 21, 1906.

2 SHEETS-SHEET 1. I

Fig f. F

" PATENTED 1330.24, 1907-.

F. i E

J, W. NELSON. HYDRAULIC JACK.

Z J 2% wi /v JAMES W. NELSON, OF NEW YORK, N. Y.

HYDRAULIC JACK.

Specification of Letters Patent.

Patented Dec. 24, 1907.

7 Application filed May'Zl. 1906. Serial No. 317,865-

To all whom it may c ncem:

Be it known that 1, JAMES W. NELSON, a citizen of the United States, and resident of the city of New York, borough of Brooklyn; county of Kings, and State of New York, have invented certain ncw and useful Improvements in Hydraulic Jacks, of which the following is a specification.

This invention relates to hydraulic jacks, and has for its object the provision of a jack which is simple in construction, powerful and dependable in operation, and, particularly,

one which may be quickly and easily released for lowering when relieved of the weight or pressure of the load which it has been the means of raising or moving.

Heretofore very great difficulty has been experienced in releasing the liquid, which has been subjected to pressure to effect the desired results, after the work has been done, in order to move the device and' to contract the extended parts for its application to new work. Such release has been heretofore effected through the employment, even with simple or single pumps, ofan undesirably large number of valves, making the device complicated and thereby increasing both cost of manufacture and difficulties of operation, and sacrificing dependability and ease of repair when inoperative or imperfectly operative through wear or accident.

My invention contemplates, particularly, a construction whereby I am enabled to materially reduce the number of valves employed, not only for the purpose of insuring the proper flow of liquid to and confinement under pressure in the ram-chamber but pro-' viding for its easy and ready releasefrom said ram-chamber and flow back to the storage reservoir, when desired.

With'the above, and other ends in view,

1 my invention consists, generally, in a hydraulic jack comprising the usual storage, pum and ram chambers and provided with nove means for controlling the flow from said storage chamber through said pump chamber to the ram chamber; my invention further consists in means for utilizing the.

same ducts or channels for the passage of hqui-l in both directions, thereby eliminat- 'ing the necessity for separate and independent passages for ingress and egress of the pressure fluid to and from the ram chamber; my invention further consistsin means for positively unseating by one operation all valves which would otherwise check the flow of liquid from said ram chamber back to the storage resevoir to release or lower the jack 5. my invention further consists in means for rendering inoperative the initial inlet valve of a double-pump jack, thereby utilizing the pressure of one of the pumps only, said means being further operative to unseat all the'valves normally preventing back-flow from ram chamber to storage resevoir; my invention further consists in the relative arrangement of valves whereby they may be successively tripped and held off their seats through means acting directly upon one of said valves only, and, particularly, in a superposed or lineal arrangement for this purpose, and, further, in an arrangement which provides independence in automatic action and interdependence in manual control; and my invention further consists in various details of construction and combinations of parts, all as hereinafter more fully described and particularly pointed out in-the claims. V

My invention will be more readily understood by reference to the accompanying drawings, forming a part of this specification, and in which Figure 1 is a central vertical section .of a hydraulic jack embodying my invention.

Fig. 2 is a similar view, on an enlarged scale, 'of the lower or body portion of the same. ,Flg. 3 is a transverse section on the line 33 of -Fig. 2. Figs. 4 and 5 are similar sectional views showing other modifications of the initial intake duct. Fig. 6 is a side view of part of the-head, showing theindicator for, the lowering device.

Referring now to the drawings in detail, numeral 7 refers to a vertical cylinder: secured in the base 8, in which cylinder the tubular ram!) fits and is mounted to move vertically, a tight joint being formed at the top ofthe cylinder by a ring 10 screwed into the upper end of the cylinder.

hollow head 11 is screwedion the upper end of the ram and is provided in its top with an opening which is closed by a screw plug or.

plate 12, said opening having greater diameter than the internal diameter of the ram, for a purpose hereinafter set forth. The ram has a cylindrical bore of uniform diameter from end to end, and into the lower end of this bore in the ram the pum cylinder 13 is screwed. The usual ram pac ring 14 is secured in the lower end of the ram, and is held in place by the packing rings 15 and 16 preferably in such a manner that the bottom of the pump cylinder and the ring 16 are sub stantially flush.

The pumpcylinder. 13 may be said to be cup-shaped, the bore extending from the top 1 of said cylinder to near the bottom thereof.

' This bore comprises two sections, 17 and 18, the upper 18 being of greater diameter than the lower. The piston rod 19 is provided with two pistons, 20 and 21, of different diameters, each correspondingwith the particular section of the pump bore in which it is designed to operate. It is preferable that Y the effective areas of each of the two pistons should be the ,same.

The piston rod 19 extends up into the head 11, where a rock-shaft 23 is mounted, said shaft being provided exteriorly (not shown) any suitable means for attaching or securing thereto a pump handle lever and in- 25 teriorly with a knuckle 24 extending into a head 25, formed on the upper end of the rod 19 or suitably secured thereto, whereby u on rocking the shaft 23 the piston rod 19 wil be longitudinally reciprocated. The pump cylinder is similarly provided with a single bore 26 at one side of and substantially parallel to the pump bore, which bore 26 extends en-' tirely through the pump cylinder from its upper to its lower surface; A valve 27 has a stem 28, preferably triangular in cross-section, which can work up and downin the bore 26, which valve 27 is adapted to close the lower end of the bore 26 and is preferably pressed on its seat, at theflower end of the bore 26, by a spring 29 contained in a chamber 30 in the bottom of. the pump cylinder, whichmhamber is provide with an apertured plug or bonnet 31 secured in the lower end of the opening. Above the upper end of the stem 28, the bore26 is contracted to form a seat for a second valve 32, having a stem 33 also preferably triangular in cross section, mounted to work up and down in said bore. Above the stem 33, the bore 26 is again contractedto form a seat for a similar valve 34, the stem -35 of which extends u ward and into the enlarged up or end 36 of the bore 26. The stems 28 an 33 do not extend to the valves 32 and 34, respectively,

when the latter are seated but terminate a slight distance beneath said valves for a purpose hereinafter described.

The lower section 17 of the pump bore communicates by means of the duct 37 with the bore 26 above the valve 27 and below the valve 31.. The upper section 18 of said bore similar-1y communicates with the valve bore 26, by means of the duct 38, above the valve 31 and below the valve 34.

A valve rod 39 rests on the upper end of the stem 35 of the uppermost valve 34, in the bore .26 and extends upward through an opening in an inwardly. extending bracket 40 in the lower part of the head 11. In the side of this head 11, a plug 41 is screw ed to the inner end of which an angle or bell-crank lever 42 is pivoted in such a manner that one of its arms rests on the upper end of the valve rod 39, while the other is in a path of a screw 43 in the plug41,which has the usual polygonal' pocket. or receptacle 44 for the rotary key 45 or like implement, by means of which said screw can be turned. Obviously, in-

greater pressures on the upper sides of the I valves 34 and 31 will unseat said valves and the liquid will pass said valves and enter both pump chambers through theducts 38 and 37. At the downward stroke, the liquid is forced by the two pistons through, the ducts 38 and 37 into the-valve bore 26' the pressure seating the uppermost valve 34 and unseating the middle and lower valves 31 and 27 The liquid is thus forced into the chamber 49 beneath the ram, which'is raised pnder the well known principles of hydrau- 10s. of water is forced into theram chamber for each stroke of the pump as would be forced with a single piston, and thusrthe ram will It is evident that now twice the amount 4 move a greater distance for the same number of strokes. When the ram has been raised to the point whereit receives the maximum load and it becomes desirable to sacrifice speed to increase the power, the stroke of one interfere with proper action of the valve 34,is turned so that the arrow points to the 2 on the indicator. Byv this operation the valve rod 39 is forced down a distance to depress the stem 35 and unseat and positively hold off its seat the uppermost valve 34, without, however, aflecting action of either of the lower two valves 31 and 27 If now the piston rod is worked up and down, the lower piston operates in the manner previously described, but as the uppermost valve 34 is held off its seat the'water drawn into the space or chamber above the pump.

In other words, the water is moved into and out of the pump chamber 18 without performing any function or work, so that the operator now only pumps one half of the water that is used when both pistons are effective. Furthermore, in case the upper piston becomes defective or inoperative, for any reason whatever, the lower piston operates in the manner just described and the ram of the jack can be raised and lowered and the desired work performed. Similarly, should the lower piston become inoperative, the upper piston alone can be used, as it draws in the water at the up stroke, seats the uppermost valve 34 at the down stroke and at the same time unseats the lower valves 31 and 27 and forces water into the ram chamher] It will be observed that each of the valves I a 34 and31 are free to move off its seat when there is no pressure on its underside, and they are, therefore, normally open check valves. This is important, so far as the rapid operation of the jack is concerned, since they offer no resistance to the passage of the water to the pump bores, as would be the case if they were spring seated like the valve 27.

When it is desired to lower the screw 43 is turned until the valve rod 39 has been forced downward to such an extent as to first unseat the valve 34, which upon further depression of said rod, unseats the valve 31, which, in turn, forces the lower, spring-seated valve 27 off its seat, thus opening and holding open the entire valve bore 26 and permitting the liquid to pass freely back from the ram chamber to the storage reservoir. The proper are or distance through which the screw 43 should be turned may be indicated by the figure 3 on the dial (Fig. 6).

I have shown a bracket 46 suitably secured to or fixed upon the piston rod 19, and provided with an aperture through which the valve rod 39 passes loosely. A pin 47 or the like is secured on the valve rod 39 at such a point that normally the bracket 46 will not contact with said pin, but when the piston rod 19 is forced down beyond the normal and effective downward stroke, said bracket impinges against the pin and forces down the valve rod independently of the lever 4-2. A coil spring 56, surrounding the valve rod and compressed between the top of the pump cylinder and the pin 47, retains said rod in a normally raised and inoperativ position.

If it is desired to lower the ram without using the screw 43, the operator forces down the operating handle, andtherewith the rod 19, beyond end of the normally effective stroke, whereby the bracket 46 depresses the pin 47, and therewith the valve rod 39, sufficiently to unseat the valves in the manner set forth and permit the liquid to flow from the ram chamber back to the storage chamber 48. v

For the purposes pf setting the screw 43 into the desired position it is provided with a dial on the outer end of the screw plug having three indicating marks, as 1 2 3, respectively, whichin connection with the arrow on the outer-end of the screw 43 show the positions of the screw and the consequent respective positions of the valve rod 39 and of the valves in the valve bore 26.

Jacks are not always used in a vertical position and quite frequently must be placed horizontally. In such cases, as the liquid is drawn from the chamber 48, its level may at bore 26. To provide against such contingency, a packing ring, as indicated by dotted lines, may be placed around the lower end of the valve rod 39 at the upper end of the enlarged portion at the top of the valve bore 26, and the liquid admitted to said bore by means of laterally extending channels or ducts. As shown in Fig. 3, the duct 50 may extend laterally from the valve bore 26 to the side of the cylinder, from the outer end of which duct a groove 51 extends to the upper end of the pump cylinder and communicates with the chamber 48. When this construction is employed and the jack placed horizontally, the side of the ram upon which the valve rod is located must be atthe bottom, and as the mechanism for operating the valve rod is on the corresponding side of the case be in a convenient position, it may be preferable to reverse the position of the jack when placed horizontally, so that the side of the head containing the screw plug 41 is at the top. In place of the single duct 50, two lateral ducts 52 and 53 may extend from the side of the cylinder to the valve bore 26, as

the outer end of each duct to the up er end of the pump cylinder. Even with t is construction not all the liquid can be utilized when the jack is placed horizontally, and it may still be better to employ an angle duct 54 (as shown in Fig. 5) extending from the valve der at a point diametrically opposite said valve bore, with a similar groove 55 extending from the outer end of this duct to the upper end of the cylinder.

. he opening in the head'll, closed by the removable cap or plate 12, through which times not reach the upper end of the valve.

bore 26 to the outer face of the pump cylinan arrow or some similar mark and providing head, and the, pump handle, may not in such shownin Fig. 4, and a groove extend from sage cooperating'with the (pump to force liquid the storage or supply chamber 'is filled,

' ering the ram independently of the handle lever is self-contained and as an entirety can 'be inserted by screwing the plug 41 into the orifice therefor in the side of the head 11.

Many modifications of minor details of my improved hydraulic jack will doubtless readily sugges't themselves to those skilled in the art to which it a pertains, and I therefore do not desire to imit my invention to the specific construction herein shown and described.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A self-contained, multiple-pump hydraulic jack having a fluid-passage not including the pump-bores and providing the only means of communication between reservoir and ram-chamber.

2. A multiple-pump hydraulic jack having a valved fluid-passage separate from the pump bores and communicating therewith and means for holding all of the valves oil their seats.

3. A self-contained multiple-pump 3/ draulic jack having a continuous and straiglit fluid-passage from the reservoir to ramchamber and providing the only means of communication therebetween.

4. A multiple-pump hydraulic jack having a fluid passa e from reservoir to ram chamber separate i rom the pump bores and means for controlling the direction of flow through said passage. f

5. A multiple-pump hydraulic jack having a continuous straight fluid-passage from reservoir to ram chamber, valves in said pasfrom sa1d reservoir to sai ram chamber, and means for positively unseating" all of said valves. r

6. A self-contained multipleump hydraulic jack having a single flui -passage from-reservoir to ram chamber, said passage not including the pump chambers but communicating therewith. 7. In a hydraulic jack having a double pump, the combination of a series of'valves controlling flow from reservoir to ram chamber, tlf first of which checks back-fiowfrom one of ,aid pumps only, and means for posi-. tively unseating said first valve, said means bein further operable to positively unseatall 0 said valves. 1 8. A multiple-pump hydraulic jack havin a fluid-passage from reservoir to ram-chamber, said passage not including the pump of sai chambers, and ducts from said passage to to each of said.chambers, said passage and each of said ducts serving'for the flow of liquid in both directions.

l0. Inamultiple-pump hydraulic jackhaving a separate-fiuid-passage from reservoir to ram chamber and ducts connecting said passage with each of the'pump chambers, the combination, with suitable valves in said passa e, of means for positively unseating all dvalves at one operation.

11. In a multiple ump hydraulic jack having a fluidassage om reservoir to ram ohamber'and ucts connecting said passage with each pump chamber, the combination with valves at each end of said passage and intermediate of said ducts, of means for positively unseating all of said valves at one operation.

12. In a multiple ump hydraulic ack having a fluidassage Ir chamber and d with each pump chamber, the comb nation, with valves at each end oi-said passage and intermediate of said ducts, of means for successively unseating said valves in order.

13. In a hydraulic jaclehav'in a doublevoir to ram chamber communicating with each of said pump chambers, the ,combination of an initial inlet valve, a final outlet valve, a valve intermediate of said two charm bers, and means for positively unseating said inlet valve only or a of said valves. 4

15. In a double-pump hydraulic jack, the combination, with a ram containing the pumps and provided with a passage from reservoir to ram chamber communicating with each pump chamber, of a series of superosed valves in said passage, and means acting upon the first va vein said series to positively unseat said first valve only or all of said valves.

16. In a hydraulic jack, the combination, with a ram containing a double-pump and corresponding pump chambers and a straight bore connectin the space above the pump with the space he ow the ram and separately lconnnuni'cating with each of said pump chambers, of a series of superposed valves in said bore, ahd means fer holding one of said valves off its seat, said means beom reservoir to 2am ucts connecting said passage ing further operable to positively unseat all of said valves.

tion, with a ram containing a double-pump and corresponding pump chambers and a straight bore connecting the space above the pump with the space below the ram and separately communicating with each of said pump chambers, of a series of superposed valves in said bore, and means for successively tripping each valve in order and rendering the first or all thereof inoperative.

18. In a hydraulic jack, the combination, with a ram containing a double-pump and corresponding pump chambers and a straight bore connecting the space above the pump with the space below the ram and separately communicating with each of said pump chambers, of three valves in said bore, one controlling inlet thereto, one controlling outlet therefrom, and one intermediate of the passages to the pump chambers, and means for positively unseating the first or all I of said valves.

19. A hydraulic jack having a doublepump and valves for said pumps all contained in a single and separate bore.

20. I 1 a hydraulic jack, the combina tion, with a double-pump, of valves for said pumps in a single and separate valve bore, and means for positively tripping one or all of said valves. t

21. '[n a hydraulic jack, a ram containing a double-pump and corresponding pump bores and valves for said pumpsin a single bore separate from said pump bores but communicating therewith.

In witness whereof, I have signed my name to the foregoing specification in the presence of two subscribing witnesses.

JAMES W. NELSON.

' Witnesses:

HENRY R. BAUER, J. G..Co1- IRAnI.

Images