US535586A - Brtjch - Google Patents

Brtjch Download PDF

Info

Publication number
US535586A
US535586A US535586DA US535586A US 535586 A US535586 A US 535586A US 535586D A US535586D A US 535586DA US 535586 A US535586 A US 535586A
Authority
US
United States
Prior art keywords
piston
tool
steam
lever
accumulator
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Publication date
Application granted granted Critical
Publication of US535586A publication Critical patent/US535586A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B7/00Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors
    • F15B7/003Systems in which the movement produced is definitely related to the output of a volumetric pump; Telemotors with multiple outputs
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B30PRESSES
    • B30BPRESSES IN GENERAL
    • B30B15/00Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/16Control arrangements for fluid-driven presses

Definitions

  • the subject of this invention is a machine for working wood or metal in which the working stroke is obtained indirect from the pressure of steam by hydraulic means, when the return of the parts is effected exclusively by mechanical means operated only bythe waste steam.
  • This principle is shown as an example of carrying outthe same in the accompanying drawings as shears, in which the movable shearing knife is attached to a movable plunger, which for the working stroke and return slides in a fixed press cylinder.
  • the position at the commencement viz: that of rest, is always the same, but the extent of the working stroke may always be varied by the automatic control of the machine, or the automatic control may be changed to hand control in which case the extent and duration of each stroke can be regulated at Will.
  • the governor influences the stroke of a piston moved by steam power, 1
  • Figures l and la are sections through the apparatus.
  • Fig. 2 is a transverse section through the line oder'
  • Figs. 3 and 3 are plans of Figs. l and la with partial section through the multiplicator.
  • Fig. 4 is a detail view of the device for disengaging the governor.
  • Fig. is a detail View of the valve operating piston.
  • Fig. 6 is a detail view of the water suction valve.
  • Fig. 7 is a detail View of the device for operating the reverse governor when the plunger carrying the movable shearing knife has finished its stroke and returns.
  • Fig. 8 is a detail view of the device for operating such reverse governor when the plunger carrying the shearing knife commences its work.
  • FIG. 9 is a vertical sectional View of the regulating valve interposed between the accumulator and the plunger of the tool showing a portion of the pipe communicating with said plunger.
  • Fig. 10 is a side elevation of the said valve taken from the left in Fig. 9 showing the weighted lever in section.
  • Fig. ll is a top plan View of the valve as shown in Fig. 9, and
  • Fig. 12 is ahorizontal sectional View through the valve casing and"valye proper. All detail views are enlarged as compared with the principal View.
  • the pressure cylinder l is connected with an accumulator G by means of pipes L L.
  • the accumulator G is fitted into a transverse piece H which is connected to the base plate H by means of four columns, Fig. 2.
  • To the base plate H is also fixed the steam cylinder L Z in which moves up and down a piston and piston rod fm, t.
  • the elongated piston rod m, t reaches into the before mentioned accumulator G and forms here the pressure plunger.
  • the spaces in the accumulator G, the pipes and pressure cylinder Z are filled with water or any other suitable iiuid, so that the lift of the piston moving in the cylinder Z operates the plunger carrying the shearing knife b.
  • Two draw bars c are attached to the movable knife b, and carry at their ends the transverse piece d.
  • a pot t' moving upward and downward with the knife and guided in the guiding piece h of the fixed hydraulic cylinder Z.
  • a volute spring g which constantly endeavors to depress, by means of a guiding cylinderfand a connecting rod e, the short end of a lever It pivotable around the pin 7c on h.'
  • the other, longer end of the lever 7c engages with the piston rod m t.
  • the lever la) joins in the up and down movement of the piston sliding in L Z and also the working stroke of the movable shearing knife b.
  • the diameters, and consequently the travel of the plunger m t reaching into G and of the plunger m l The lengths of the arms of the are different.
  • lever 7c are therefore chosen so that they are in a reverse proportion to the surfaces of the plungers m-Z, and fm.
  • the apparatus o, Fig. l, which moves the before mentioned 'circular valve up and down, is shown in detail in Fig. 5 and consists of a cylinder o', a piston o? moving in it, and a control valve 03.
  • the llatter is connected to a hand lever g, pivoted at t', by
  • the said lever carries the governor spindle r.
  • the latter is screw threaded and provided with the projection w, and with the cog wheel v a certain distance therefrom.
  • To the piston rod mt is fixed the ring u, also shown in Fig. 2, en which is pivotally mounted a pin u', having a lug 00 and a lever carrying weights g g.
  • the lug has a tooth, Fig. 4, which is caused by the weights g g to butt against a projection on the ring u, so that always remains horizontal and Vcan only be turned upward after overcoming the weights g g.
  • an oil brake ycataract p is provided which is connected with the valve rod n by means of a lever.
  • the working stroke of the plunger m is effected by water under pressure through themovement of the piston driven upward in L Z by steam.
  • the piston descends again in L Z m must return upward. This is effected by means of the lever la, Athe water, pressed toward Zbeing again pressed backward toward 'G by the plunger moved ⁇ into Z.
  • the return of the plunger into its its original position is effected by mechanical means in this case the lever k operated by' steam.
  • a regulating valve 7c is inserted into the water pressure pipe, Figul, shown in an enlarged scale in Figs. 9 to l2.
  • vsleeve b2 Into the valve casing a2, Figs. 9 and l2, is inserted the vsleeve b2, having a number of perforations k2.
  • a pot CZ? also provided with perforations f 2.
  • the per forations f2 vcorrespond with Lthose 7a2 when (Z2 is in its highest position.
  • the bottom of the pot has small orifices g2 and the pot itself is connected by a spindle e2 to the weighted lever e3.
  • the fluid passing through from G presses against the bottom of the pot @Z2 and, according to the position of the weight e3, the position of the orifices 7a2 and f2 is such that the nuid at its passage therethrough receives at one time a large amount of resistance and at another a less amount of resistance. If d2 is lowered in consequence of excessive velocity, the passage from k2 to f2 becomes narrower by de- IOC grees until they are entirely removed from one another. Then remains only the passage through 'g2 and h2 to k2 for the liquid. The resistance caused thereby reduces the operativevelocity.
  • a suction valve I Fig. 1
  • a tubular valve i', Fig. 6 which is pressed against its seating by the pressure existing in the service pipe L during the piston stroke. The losses by leakage occur during this period.
  • a cog wheel B is j ournaled on one of the pillars F, Figs. l and 3, which engages with a cog wheel U and is operated by a pinion A, axle e' and hand wheel fy.
  • a cog wheel C journaled on m 15 engages with the cog wheel fu on the governor spindle r and is screw threaded on its elongated boss. The latter is screwed into a nut D fixed to the transverse piece E.
  • the cog wheelV The shaft P carries an arm Q, which is brought into the position shown in dotted lines, in Fig. 4, by the rotation of the aXle and turns the counter weights g g and thelug 0c upward at the continued downward move- ⁇ ment of 'm t so that the lug cannot act upon w and is not reversed until reversal is effected by hand through the handle of the lever g. Therefore in this manner the normal position may be changed to a higher place, as may sometimes be desired.

Description

(No Model.) Y e sheets-sheet 1. F. HESSEJIBRU(1I-I` HYDRAULIG MACHINE.
6 Sheets-Sheet 2.
Patented Mar. 12, 1895.
P. HBSSENBRUGH,
HYDRAULIC MACHINE.
(No Model.)
(No Model.) 6 Sheets-Sheet 3.5. F. HESSENBRUGH.
HYDRAULIC MACHINE.
No. 535,586. Patented Mam. 12, 1895.
me umm Enns co. mom-Uma, msumnou. u c l (No Model.) 6 Sheets- Sheet 4.
P. HESSENBRUGH.
. HYDRAULIC MACHINE. No. 535,586. Patented Mar. l2. 1895.
Wz/'Z'nessssz 6 Sheets-sheet 5.
(No Model.)
F. HESSBNBRUCH.
HYDRAULIC MACHINE.
PatentedMar. 12, 1895.
(No Model.) l Y 6 shets-sheet 6.' F. HESSENBRUCH` HYDRAULIC MACHINE. 5 No. 535,586.` Patented Mar. 12, 1895.
Ui nss'es 0 rdm. l )QQ/@5% 5m tartan Samaras PATENT Ormea FRIEDRICH HESSENBRUCH, OF DUISBURG, GERMANY. 4
HYDRAULIC MACHINE.
SPEGFICATION forming part of Letters Patent No. 535,586, dated March 12, 1895.
Application filed May 23, 1894. serlaiNo.' 512,220. (No model.)
TQ aZZ whom, it may concern.-
Be it known that I, FRIEDRICH ,Hassan iBRUCH, director of a public company, residlng at Duisburg, iu the Kingdom of Prussia and German Empire, have invented new and useful Improvements in Hydraulic Machines, of which the following is a specification, reference being had therein to the accompanying drawings.
The subject of this invention is a machine for working wood or metal in which the working stroke is obtained indirect from the pressure of steam by hydraulic means, when the return of the parts is effected exclusively by mechanical means operated only bythe waste steam. This principle is shown as an example of carrying outthe same in the accompanying drawings as shears, in which the movable shearing knife is attached to a movable plunger, which for the working stroke and return slides in a fixed press cylinder. The position at the commencement viz: that of rest, is always the same, but the extent of the working stroke may always be varied by the automatic control of the machine, or the automatic control may be changed to hand control in which case the extent and duration of each stroke can be regulated at Will. The governor influences the stroke of a piston moved by steam power, 1
which piston is used to obtain the necessary compression of the liquid or Water in a cylindrical accumulator.
l In order that myinvention may be the better understood I now proceed to describe the same with reference to the accompanying drawings and to theletters of reference marked thereon.
Figures l and la are sections through the apparatus. Fig. 2 is a transverse section through the line oder', Fig. l. Figs. 3 and 3 are plans of Figs. l and la with partial section through the multiplicator. Fig. 4 is a detail view of the device for disengaging the governor. Fig. is a detail View of the valve operating piston. Fig. 6 is a detail view of the water suction valve. Fig. 7 is a detail View of the device for operating the reverse governor when the plunger carrying the movable shearing knife has finished its stroke and returns. Fig. 8 is a detail view of the device for operating such reverse governor when the plunger carrying the shearing knife commences its work. Fig. 9 is a vertical sectional View of the regulating valve interposed between the accumulator and the plunger of the tool showing a portion of the pipe communicating with said plunger. Fig. 10 is a side elevation of the said valve taken from the left in Fig. 9 showing the weighted lever in section. Fig. ll is a top plan View of the valve as shown in Fig. 9, and Fig. 12 is ahorizontal sectional View through the valve casing and"valye proper. All detail views are enlarged as compared with the principal View.
Into the standardaof the shearing device, Figs. lZL and 3, is fixed the pressure cylinder l in which slides the movable plunger m, Fig. la. To the latter is fixed the movable shearing knife b, which is guided during the operation upward and downward in the standard ct.
The pressure cylinder l is connected With an accumulator G by means of pipes L L. The accumulator G is fitted into a transverse piece H which is connected to the base plate H by means of four columns, Fig. 2. To the base plate H is also fixed the steam cylinder L Z in which moves up and down a piston and piston rod fm, t. The elongated piston rod m, t, reaches into the before mentioned accumulator G and forms here the pressure plunger.
The spaces in the accumulator G, the pipes and pressure cylinder Z are filled with water or any other suitable iiuid, so that the lift of the piston moving in the cylinder Z operates the plunger carrying the shearing knife b.
Two draw bars c are attached to the movable knife b, and carry at their ends the transverse piece d. To the latter is attached a pot t' moving upward and downward with the knife and guided in the guiding piece h of the fixed hydraulic cylinder Z. On the upper bottom of the pot c' rests a volute spring g which constantly endeavors to depress, by means of a guiding cylinderfand a connecting rod e, the short end of a lever It pivotable around the pin 7c on h.' The other, longer end of the lever 7c engages with the piston rod m t. In consequence the lever la) joins in the up and down movement of the piston sliding in L Z and also the working stroke of the movable shearing knife b. The diameters, and consequently the travel of the plunger m t reaching into G and of the plunger m l The lengths of the arms of the are different.
IOO
lever 7c are therefore chosen so that they are in a reverse proportion to the surfaces of the plungers m-Z, and fm.
When the piston L Z ascends, the plunger fm t compresses the fiuid in the accumulator G and b makes its working stroke. However, in consequence of the leakage of the service pipes and joints, part of the fluid is lost. Therefore the stroke is smaller than itshould be theoretically. If the connection between ZJ and the shorter arm of 7c were rigid, the transmission of movement would also,during the working stroke of b, bev not by hydraulic means, but by the lever 7c. In order to avoid this possibility, the volute spring g is inserted between t' andfand is always in tension. If the working travel of the plunger m becomes smaller by loss of power than it should be theoretically the spring will expand somewhat, but vthe completion of the working stroke of b will always be transmitted by hydraulic means from L Z to t m.
It is necessary for the continuous lworking of the machine to lead the steam alternately over and under the piston moving in L Z. For this purpose the machine is provided with an automatic governor er reversing apparatus. Steam vchannels. lead to both ends of the cylinder L Z joining each other and entering the box n. In this box moves acircular valve of known construction which is operated by a steam relay valve apparatus o and the rod n', so as to open, at its highest position, the lower cylinder steam port for the fresh steam entering at n2, while the upper steam port of the cylinder L Z is connected to the atmosphere as indicated at nx. At its lowest Vposition the circular valve connects the upper with the lower cylinder steam prt so that the steam which has previously entered below the piston and at high pressure passes above the piston and causes the latter to descend. The apparatus o, Fig. l, which moves the before mentioned 'circular valve up and down, is shown in detail in Fig. 5 and consists of a cylinder o', a piston o? moving in it, and a control valve 03. The llatter is connected to a hand lever g, pivoted at t', by
means of a rod t. The said lever carries the governor spindle r. The latter is screw threaded and provided with the projection w, and with the cog wheel v a certain distance therefrom. To the piston rod mt is fixed the ring u, also shown in Fig. 2, en which is pivotally mounted a pin u', having a lug 00 and a lever carrying weights g g. The lug has a tooth, Fig. 4, which is caused by the weights g g to butt against a projection on the ring u, so that always remains horizontal and Vcan only be turned upward after overcoming the weights g g.
When the piston, sliding in L Z Fig. l, descends, it strikes the projection w, Fig.v 3. The weights g g, Fig. 4, are attached to the lever carrying them, in such a manner as to produce sufficient momentum to carry the governor spindle r, with them downward whereby the valve 0S is placed in its highest position and the steam enters below the piston o2 of the steam valve relay apparatus, Fig. 5. The circular valve is thereby returned into its highest position n. The fresh working steam can now enter into L Z below the piston, thus effecting a rise of the latter. Before the pistonreaches its highest position in L Z, the lug fr strikes against the cog Wheel c and as it cannot move downward it lifts the latter and the governor spindle r and lowers the valve 03 by means of q and t, so that the circular valve reaches its lowest position at n, thus connecting the space below the piston in L Zwith the space above it, which would cause the lowering of the Whole mechanism while the lowering plunger m would return upwards into its original position.
In Order to insure that the movement of the circular valve sliding in u upward and downward, or vice versa, shall not be too rapid, an oil brake ycataract p is provided which is connected with the valve rod n by means of a lever.
As before mentioned, the working stroke of the plunger m,vi`. e., the movement downward, is effected by water under pressure through themovement of the piston driven upward in L Z by steam. However, when m has arrived at the end of its working stroke and the piston descends again in L Z m must return upward. This is effected by means of the lever la, Athe water, pressed toward Zbeing again pressed backward toward 'G by the plunger moved `into Z. Thus the return of the plunger into its its original position is effected by mechanical means in this case the lever k operated by' steam. l
At the continuous working of the shears, the movement of the machine might be occasionally too quick, because there may not always be dynamic equilibrium between the motor (in this case L Z) and the shears. Therefore yfor the regulation of the operative velocity, a regulating valve 7c is inserted into the water pressure pipe, Figul, shown in an enlarged scale in Figs. 9 to l2.
Into the valve casing a2, Figs. 9 and l2, is inserted the vsleeve b2, having a number of perforations k2. In the sleeve b2 moves a pot CZ?, also provided with perforations f 2. The per forations f2 vcorrespond with Lthose 7a2 when (Z2 is in its highest position. On the outer circumference of d2 'are grooves corresponding to the number 'of holes f2 through which they pass. The bottom of the pot has small orifices g2 and the pot itself is connected by a spindle e2 to the weighted lever e3. The fluid passing through from G, presses against the bottom of the pot @Z2 and, according to the position of the weight e3, the position of the orifices 7a2 and f2 is such that the nuid at its passage therethrough receives at one time a large amount of resistance and at another a less amount of resistance. If d2 is lowered in consequence of excessive velocity, the passage from k2 to f2 becomes narrower by de- IOC grees until they are entirely removed from one another. Then remains only the passage through 'g2 and h2 to k2 for the liquid. The resistance caused thereby reduces the operativevelocity.
Then the plunger m, Fig. l, makes its return journey, there is no pressure over cl2. In consequence the weight resting on e3, Fig. 9, moves the pot d2 into the position shown in Fig. 9, so that the perforations f2 and k2 come into one plane, thus leaving a free passage for the fluid driven back. Further, to counteract the loss of fluid produced by leakage a suction valve I, Fig. 1, is inserted into the service pipe L. It consists of a tubular valve i', Fig. 6, which is pressed against its seating by the pressure existing in the service pipe L during the piston stroke. The losses by leakage occur during this period. When the plunger m, Fig. l, returns into its normal position, the iiuid pressure in L becomes less in consequence of the loss by the leakage, so that the tubular valve f1) descends from its seating and iiuid is allowed to enter from 'i to the same amount as had been lost previously. If equilibrium of pressure has been established between L and i2, the spring t" presses the tubular valve back to its seating.
The foregoing shows that the working plunger m, Fig. l, always executes an equal stroke from its original position. However, this is sometimes not desired. If a short stroke is sufficient, a large stroke means loss of time and power. In order to allow of the adjustment of the stroke, a cog wheel B is j ournaled on one of the pillars F, Figs. l and 3, which engages with a cog wheel U and is operated by a pinion A, axle e' and hand wheel fy. A cog wheel C journaled on m 15 engages with the cog wheel fu on the governor spindle r and is screw threaded on its elongated boss. The latter is screwed into a nut D fixed to the transverse piece E. rlhe pitch of the threads of C and o are in reverse proportion to the diameters of their pitch circles. Both screws are threaded oppositely. In consequence the wheels C and o remain always engaged. For this purpose the width ot tooth of B is suihciently large.
At the rotation ot' y, o and C are screwed either farther up or farther down according to the direction of rotation. In consequence, the lug a: strikes o and reverses the position of the control valve o3, thus reversing the movement of the piston fm t. C in this case forms a limit to the stroke by the ring u on the piston rod striking against C. Thus the extent of the working stroke ot' m may be varied in accordance with a different normal position of starting.
If the Working is not intended to be continuous, but if the working strokes are intended to follow each other at irregular intervals, the lever M, Fig. la, is turned upward, which movement is transmitted `to the shaft P, by means of the shaft N, also Fig. 2, and the bevel wheels O O.
The cog wheelV The shaft P carries an arm Q, which is brought into the position shown in dotted lines, in Fig. 4, by the rotation of the aXle and turns the counter weights g g and thelug 0c upward at the continued downward move-` ment of 'm t so that the lug cannot act upon w and is not reversed until reversal is effected by hand through the handle of the lever g. Therefore in this manner the normal position may be changed to a higher place, as may sometimes be desired.
If M is again turned downward, as shown in Fig. l, the lever q returns also into its original position so that the weights g g act also upon w.
What I claim, and desire to secure by Letters Patent of the United States, is
l. In a hydraulic machine tool the combi nation with a hydraulic press carrying a tool, ot a steam cylinder and piston, a hydraulic accumulator operatively connected therewith and connected with said press for producing the working stroke of the tool and a positive mechanicalconnection between said piston and the tool for returning said tool by steam pressure in said cylinder, substantially as described.
2. In a hydraulic machine tool the combination with a hydraulic press carrying a tool, of a steam cylinder and piston, a hydraulic accumulator Voperatively connected with said piston and connected with said press for producing the working stroke of the tool and a lever for returning said tool connected with said piston and having a yielding connection with said tool, substantially as described.
3. In a hydraulic machine tool, the combination with a hydraulic press carrying a tool, of a steam cylinder and piston, an accumulator operated by said piston and connected with said press, apivoted lever for returning said tool having one end operatively connected with said piston and the other end operatively connected with said tool and a spring interposed between said tool and said lever, substantially as described.
1. In a hydraulic machine tool the combination with the hydraulic press carrying a tool, and the accumulator therefor, of a steam cylinder and piston for operating said accumulator to produce the working stroke ot' said tool, an operating lever connecting said tool with said piston to produce the return movement of said tool, said lever being connected to said tool to move the same positively in a return direction `and having a yielding con- I nection therewith when moving in the opposite direction, substantially as described.
5. In a hydraulic machine tool, the combination with the hydraulic press carrying the tool, of an accumulator for said press and a steam cylinder and piston for operating said accumulator, devices for adjusting the stroke of said accumulator and tool and adjustable devices `for positively limiting the stroke of said accumulator, substantially as described.
6. In a hydraulic machine tool the combi- IOO IIO
- nation with the hydraulic press carrying the tool, of an accumulator for said press, a steam cylinder and piston for operating said accumulator, a governor rod for controlling said cylinder, an arm connected with said piston reversing devices on said rod located in position to be engaged by said arm to reverse the piston, accumulator and tool, a rigid abutment for limiting` the movement of said piston and devices for adjusting said abutment and the reversing devices on said governor rod, substantially as described.
7. In ahydraulic tool the combination with the hydraulic press carrying the tool, the aocumulator therefor, and the steam cylinder and piston for operating said accumulator, of the governing rod for controlling said pis- .ton having a hand operating lever connected therewith, said rod having reversing devices, an arm connected with said piston for engag.` ing said reversing devices and means for moving said arm out of position to be engaged by said reversing devices, to enable the tool to be controlled by said hand lever, substantially as described.
8. In a hydraulic tool the combination with the hydraulic press carrying the tool, of the accumulator therefor andthe steam cylinder and piston for operating said accumulator, of the governor rod for reversing said cylinder provided with projections, a pivoted operating device connected with said piston for engaging said projections, Weights for holding said device in operative position, and a device adapted to be moved into the path of said Weights to remove said pivoted operating device out of position to engage one of the said reversing projections, substantially as described.
In Witness whereof I have hereunto set my hand in presence of two Witnesses.
FRIEDRICH HESSENBRUCH.
Vitnesses:
WM. EssENvvEIN, ALBERT LIEBER.
US535586D Brtjch Expired - Lifetime US535586A (en)

Publications (1)

Publication Number Publication Date
US535586A true US535586A (en) 1895-03-12

Family

ID=2604347

Family Applications (1)

Application Number Title Priority Date Filing Date
US535586D Expired - Lifetime US535586A (en) Brtjch

Country Status (1)

Country Link
US (1) US535586A (en)

Similar Documents

Publication Publication Date Title
US2113115A (en) Hydromechanical press
US2072595A (en) Well pumping apparatus
US535586A (en) Brtjch
US662515A (en) Piston-stroke regulator.
US2227279A (en) Press
US986809A (en) Power-press.
US2184437A (en) Counterbalancing system for oil wells
US556419A (en) james
US34068A (en) Jambs a
US543154A (en) Glass-press
US401795A (en) Caspar schumacher
US1618912A (en) Press
US211427A (en) Improvement in shoe-shaping machines
US604056A (en) leayitt
US642009A (en) Hydraulic press.
US1288472A (en) Form of press.
US117463A (en) Improvement in pumps
US1016070A (en) Press.
US89656A (en) Improvement in hydraulic presses
US34750A (en) Improvement in presses for compressing and baling
US468104A (en) weeks
US53750A (en) Improvement in pumps
US1165174A (en) Mechanism for operating tables for forging-presses, shears, &c.
US1746419A (en) Control mechanism for hydraulic presses
US689552A (en) Pump.