US1152829A

US1152829A - Hydraulic jack.

Info

Publication number: US1152829A
Application number: US78755613A
Authority: US
Inventors: William Messinger
Original assignee: Individual
Current assignee: Individual
Priority date: 1913-09-02
Filing date: 1913-09-02
Publication date: 1915-09-07
Anticipated expiration: 1932-09-07

Description

W. MESSINGER.

HYDRAULIC JACK.

APPUCATIONVFILED sEPT.2. |913.

PatentedSept. 7, l1915.

2 SHEETS-SHEET,I.

W/TNESSES:

W. MESSINGER.

HYDHAULIG JACK. i APPLlCATION FILED SEPT. 2.1913.

1,1 52,29. Patented Sept. 7, 1915.

2 SHEETS--SHEEI 2.

W/mfssfs.- V WEA/fol? M/f//lm Mess/'larger U A' TED STAT l ENT orricn.

HYDRAULIC JACK.

Specification of Letters Patent.

raeenteasepe. 7,1915.

Application filed September 2,1913. Serial No. 787,556.

Philadelphia and State of Pennsylvania,

have invented certain new and useful Improvements in Hydraulic Jacks, of which the following is a specification.

The principal object of the present invention is to provide a light, portable, compact or small, reliable and durable hydraulic jack which shall be applicable for any purpose where great pressure isrequired and in which the working unit hydraulic pressure may be as high as twenty thousand pounds per square inch or even higher.

Other objects of the invention will appear from the following description and the invention will be claimed at the end hereof, but will be first described in connection with the accompanying drawings forming part hereof and illustrating one embodiment of the invention.

In the drawings, Figure 1 is a top view, principally in section, of a hydraulic jack embodying features of the invention. Figs. 2 and 3, are central sectional views drawn to an enlarged scale and illustrating the suction and pressure valves respectively. Fig. 4, is a sectional view taken on Athe line 4 4 of Fig. 1. Fig. 5,f\i`s a similar view taken on the line 5 5 of Fig. 1, and Fig. 6 is a sectional view on the line 6 of Fig. 5.

In the drawings 1, is a shell or casing provided with a liquid reservoir 2 and with a pressure cylinder 3, completely separated from each other by a partition 4. The shell or casing l is made from a bar of nickel steel by boring the ends thereofto form the cylinder and chamber.

5, is a cap for inclosing the liquid reservoir and it is shown as provided with a illing opening 6.

is the ram which works in the pressure cylinder 3. l

The walls of the cylinder 3, since the cylinder is made of'nickel steel, are thin and are subject to expansionv under the highworking unit hydraulic pressure which can be carried to twenty thousand pounds, or higher, per square inch. Tocompensate for the expansion in this cylinder wall use is y and collar 8 having a cone shaped sea-t into which fits a hollow cone 9 and both ofthese parts are interposed between the base of the cupleather 10 of the ram and the inner end of the ram 7. The area of the face of the cone 9, which is in contact with the cup leather, is such and the cross-sectional area of the collar 8 is also such that under any pressure which may exist in the cylinder the unit stress in the material of the collar will be identical with the unit stress in the cyline der walls, thereby making the expansion of the collar the same as that lof the cylinder and so covering the clearance space produced by high pressure between the exterior of the ram and the bore of the cylinder. This prevents any extrusion of the cup leather past the ram under the force of the high liquid pressure against the leather cup. There is, in fact, a coperation between the ldescribed wedge packing with the thin sec` tion of the cylinder wall by which the use of nickel steel is made possible and desirable, sothat the jack may be made coinparatively small yet sulciently strong to be extremely powerful.

There are ports 11 and 12 disposed on opposite sides of the partition 4 and leading from the liquid reservoir and the cylinder through the wall of the shell or casing l.

From the foregoing description it is evident that the liquid receptacle and the pres'- sure cylinder constitute a single piece or unitary structure. 13, is a body detachably applied, as by means of screws to this untary structure and containing the pump, its

operating mechanism and all the valves and their accessories of the device, so that in case of repairs, renewals or cleaning, the body 13 can be detached and ready access had to the various parts which it carries. Within the body 13 there is a bore or chamber closed by a cap 14 and of relatively large and relatively small diameter. The chamber 15 of relatively large diameter accommodates the rack portion 16 ofthe pump plunger and the chamber 17 of relatively small diameter accommodates the plunger 18' proper. The

parts

16 and 18 are connected together. The plunger, as a whole, presents two working faces, a small one at the end of the part 18 and a larger one at the end of the part 16. The packing 19 and packing a small working area is to provide for moving the ram 17 rapidly with comparatively little power, for example, so as to get it in place and slowly with comparatively great power so as to exert an enormous pressure. The plunger is reciprocated by means of a toothed wheel 23 that can be oscillated by means of a hand lever 24, or other suitable appliance. There is in the body 13 a fluid channel 25, shown as formed by drilling the body in different directions and plugging up the drill holes, although this is not material.

p There are formed through the inner face of the body two openings arranged respectively on opposite sides of the partition 4 and alined with the openings 11 and 12 and communicating with one end of the passage 25. These openings receive the suction valve 26 and the pressure valve 27. Between the body and the casing and around the described openings are washers or rings 28. These consist of parchment paper, the particular usefulness of which lies in the fact that it is not affected by the action of water, oil or other liquid ordinarily employed in hydraulic jacks,land in the fact that it can be used to confine enormously high pressures by virtue of its own strength and because of the exceedingly small thickness in which it can be employed, thereby reducing to a minimum the total pressure which can act upon it tending to ltear it open. The other end of the passage 25 communicates with the small bore 17 and with the large bore 15 of the plunger chamber behind the small working face of the pump plunger and behind the large working face of the pump plunger. There is a valve 29 having a handle 30 which operates to open and close communication between the passage -25 and the larger working surface of the pump plunger. The purpose of this is that when the valve is closed the small area of the pump plunger is eifective for slow motion of the ram, whereas when the valve is'opened the large area of the pump plunger in addition to the small area, is elfective for rapid motion of the ram. The valve 29 is a needle valve. The handle is shown in Figs. 1 and 5 and the valve and its seat in Figs. 4 and 5. The seat is at a, and the valve 29 lets passages 25 and into communication or interrupts communication between them. The passage b is' shown in Fig. 4v as formed partly in the casing and partly in thepacking ring 20 and each part of it is lettered to facilitate following it. The inner end of the valve 29 is solid and the valve moves inward far enough to abut on theseat a and s0 cut off communication between 25 and b, Fig. 6, and the valve moves outward far enough to uncover the seat a and let 25 and b communicate. In Fig. 5, the circle marked 25 is the end of the passage directly in front of the valve. It might have been considered removed in making the section, but it is shown to aid the illustration. Fig. 6 shows how the passage 25 comes through the valve casing and may be covered and uncovered by the valve, and it alsov shows how the passage b is opened when the valve is olf its seat and is closed when the valve is on its seat.

31 and 32 are diagonal relief passages communicating with the liquid reservoir opening 11 and with the pressure cylinder opening 12 and by-passing the

valves

26 and 27 and communicating with a passage 33, which may be opened and closed by the valve 34 having a handle 35, so that by turning the handle 35 it is possible to by-pass the

valves

26 and 27 and establish communication between the liquid reservoir and the cylinder so as to permit of rapid motion of the ram 7 .into its cylinder. y

36, is a tube that may constitute an eXtension of the opening 11 and through which liquid passes from and to the reservoir.

Both the suction and pressure valves consist of a body 37 having a cone-shaped shoulder 38, which by means of a thread 39 can be secured tightly against a corresponding conical seat in the opening in the pump body into which the valve body 37 is screwed. The portion 40 of the valve body adjacent to the seat 38 is undercut so as to permit of free seating and thus a perfect liquid tight joint is obtained without any packing-material. The valve stems 41 are provided with a shoulder 42 having a coneshaped face which fits a corresponding conical seat in the valve body. The valve is guided by means of a long stern 43 which works in a snugly fitting opening in the valve body. Theopening in the valve body provided for thevalve stem is counter-bored for a short distance below the seat as shown at 44 and the conical face on the shoulder of the valve is also abruptly terminated, so as to make the cone portions both on the valve and its sea-t ofthe same length and co-incident when the valve is seated. 45 is a hole or opening drilled longitudinally into the stem and communicating with cross-drilled openings 46 located adjacent to the seat. By this construction liquid always fills the annular recess created by the counter-bore and the instant that the valve lifts off its sea-t the liquid is discharged instantly and uniformly all around the valve seat. This tends to prevent cutting of the seats which might otherwise occur from the high velocity lof the issuing stream if it were localized. The valve seats being formed in separate pieces can be detached from the pump body and renewed without necessitating any machine work or other operations on the pump. The construction of both the pressure and the suction valves is the same, eX- cept that the direction of their seats is reversed and in the case of the pressure valve grit or other foreign substance which mayv lind its way into the liquid medium employed to operate the jack is crushed under the valves without scoring or injuring them and at the next stroke of the plunger the valve seats will be clear of the obstructing materials allowing the valve to become perfectly seated. Scoring or like injury of the valves would produce leakage and make the' jack difficult to maintain in operating condition. Again, hardened valves resist distortion and hence operate successfully under such high unit hydraulic pressure as would distort valves made of such materials as have been heretofore employed or suggested, thus rendering hydraulic jacks ineflicient. Moreover the described substitution of material permits of a great reduction in the size or area of the valves and, of course, a reduction in the area or size of the valves means that the pressure to which they are subjected and which tends to distort them is so reduced that distortion is avoided. In other words, the described substitution of material converts hydraulic jacks which have been substantial failures for uses requiring their transportation and requiring great strength into jacks which are well adapted to .perform such uses and purposes. The elastic limit of hardened steel is high, so that valves and valve seats made of it can work under a high unit pressure within their elastic limit. In consequence, a valve or valve seat may'yield to conform to irregularities in either and thus make a tight valve, without any permanent distortion.

In use the pump plunger is reciprocated by the handle 24. According to the position of the valve 29 either its large or small working surface -operates to draw liquidv from the reservoir 2 past the valve 26 into the passage 25 and into the pump cylinder and to expel the same at each reciprocation of the plunger past the valve 27 behind the ram. When high pressure is applied to the ram the wedge packing 8 9 equali'zes eX- pansion as has been described and permits the jack to operate notwithstanding expanf sion of the walls of the pressure cylinder under the great pressure to which they are subjected. The ram may be permitted to enter the cylinder by manipulating the valve 34 and thus establishing the by-pass around the

valves

26 and 27 and putting the cylinder into direct communication with the reservoir.

It will be obvious to those skilled in the art to which the invention relates that modifications may be made in details of construction and arrangement without departing from the spirit of the invention.

What I claim is:

l. In a hydraulic jack the combination of a pump plunger having a large and a small effective area, a ram and its pressure cylinder, fluid connections from the ram to the small and to the large area, a valve for excluding fluid from and affording it access to the large area and a single pressure valve common to both areas. p

2. In a hydraulic jack the combination of a casing having therein a liquid reservoir and a pressure cylinder and their fluid outlets through the casing, a ram in the pressure cylinder, a pump body having therein a multiple speed pump, connections for each pump speed to the reservoir and pressure cylinder, a valve carried by the pump body for positively closing one of said connections and a single pressure valve common to both pump speeds.

3. In a hydraulic jack the combination of means including a single automatic pressure valve and a single automatic suction valve for operating it at twof different speeds, and a single valve independent of said valves for making one of the speeds both inoperative and ineffective.

4. In a hydraulic jack the combination of a liquid reservoir and pressure cylinder, a pump operatively connected therewith, fluid passages connecting the pump and reservoir and cylinder, and suction, and pressure valves and their seats interposed in the fluid passages. and both made of hardened steel which distorts under high unit pressure making irregularities in contact surfaces of the parts to conform, thereby insuring tightness and which recovers its original form when released from such pressure, whereby the jack can be small and of great power.

5. In a hydraulic jack the combination of a pressure cylinder, a ram, a non-metallic packing, and a radially expansible packing interposed between the non-metallic v packing and the ram to prevent the nonmetallic packing from being forced between the bore of the cylinder and the surface of the ram.

6. In a hydraulic jack the combination of a pressure cylinder of material having a high elastic limit, a ram, a fibrous packing incase@ screw-and-thread connections between th body and Valve seat.

8. In a hydraulic jack the combination of '15 a pressure cylinder, a ram7 a cup packing on the ram and coperating conical rings between the cup packing and ram whereby expansion in the cylinder walls is compensated for.

W'ILLAM MESSINGER. Witnesses:

CLIFFORD K. CAssEL, FRANK E. FRENCH.