US914169A - Device for generating and applying variable hydraulic pressure. - Google Patents

Description

J. W. NELSON. DEVICE FOR GENERATING AND APPLYING VARIABLE HYDRAULIC PRESSURE.

APPLICATION FILED MAE. 2, 1908.

2 SHEETS-SHEET 1.

IIVVENTOR ATTORNEY rm: mamas PETERS cm, wasmmmuv. n, c.

Patented Mar. 2, 1909.

J. W. NELSON. I DEVICE FOR GBHEBATING AND APPLYING VARIABLE HYDRAULIC PRESSURE.

APPLICATION FILED MAR. 2, 1908.

Patented Mar. 2, 1909. z snnnccs-snnm 2.

IIVVENTOR [0. M

ATTORNEY WITNESSES mt NORRIS PETERS co., WASHINGTON, u c

FFTCE;

JAMES W. NELSON, OF NEW YORK, N. Y.

DEVICE FOR GENERATING AND APPLYING VARIABLE HYDRAULIC PRESSURE.

Specification of Letters Patent.

Patented March 2, 1909.

Application filed March 2, 1908. Serial No. 418,683.

To all whom it may concern:

Be it known that I, JAMEs W. NELsoN, a citizen of the United States, and a resident of the city of New York, borough of Brooklyn, county of Kings, and State of New York, have invented certain new and useful Improvements in Devices for Generating and Applying Variable Hydraulic Pressure, of which the following is a specification.

This invention relates to a paratus for generating and applying hydrau ic pressure with particular reference to devices by means of which an exceedingly wide range of variable pressures may be rendered available from the same generating mechanisms and without varying the operation or operations of such mechanisms.

Among the many practical applications of hydraulic pressure, there is frequent occasion for the employment of a single device or apiaratus which will, when desired, force a very large volume of liquid to the ultimate pressure chamber or chambers under what may be termed a minimum of pressure, yet which will, when desired, be capable of developing an exceedingly high pressure, together with means for rendering available certain intermediate degrees of pressure between the minimum and maximum pressures referred to.

There is obviously a limit to the size and number of pumps which may be employed for practical purposes in what is termed a self-contained hydraulic jack, and there are other reasons in addition to this why it is frequently necessary to separate the pressure generating from the pressure applying means, with suitable connecting conduits therebetween.

The present invention contemplates such separation of the pumps from the ram or rams, with means located in close proximity to the latter to control the effect of the pumping operations.

The present invention further contemplates, for the principal purposes of either great speed or great pressure, as may be desired, and further in order to render more nearly continuous instead of intermittent the generation of pressure, a plurality of ower driven pumps, each of the multiple-o unger type. Under such conditions, it will be apparent that it will be at times inconvenient, if not impracticable, to stop the pumping operations when it is desired to check the application of increased pressure, or to uncouple one or more of said pumps for the purposes of increasing the power at a sacrifice of the volume of liquid delivered under the principles of hydrostatics. herefore, with hydraulic apparatus of this character, in which power or manually driven pumps are designed to be continuously operated, means must be provided for the control of the generated ressures, and such means should obvious y be located in a position where the man in charge thereof may note the progress and effect of the work.

The present invention resides in the provision of means, in connection with the plurality of multiple-piston pumps and one or more pressure applying devices separate therefrom, for consecutively rendering the pumps inoperative, whereby the volume of liquid delivered to the pressure chambers may be in a step-by-step manner reduced and the a plied pressure proportionately increased, said means serving to equalize the pressures at the points of application, to check the application of increased pressure, or finally, to relieve the applied pressures in order to remove or readjust the pressure applying device or devices.

My invention will be more readily understood by reference to the accompanying drawings, forming a part of this specification, in which Figure 1 is a diagrammatic View, artly in section, of a complete apparatus em odying my invention; Fig. 2 is an enlarged longitudinal central section of the pressure-control ling device, and Fig. 3 is a transverse central section of the upper end of Fig. 2.

Referring now to the drawings in detail, numerals 7 and 8 refer, respectively, to separate pump-blocks, preferably mounted upon a common supporting base-plate 9. The pump block 7 is provided with a central pump-bore which comprises an upper portion 10 of larger diameter and a lower por tion 11 of relatively smaller diameter. The piston-rod 12 is provided with a piston head 13 fitting and adapted to reciprocate in the portion 10 of said pump bore, and from the piston 13 projects an extension 14 of the piston-rod which carries at its end the pis ton-head 15 fitting and adapted to reciprocate in the portion 11 of said pump bore. This construction and arrangement is that of a common and well-known type of doublelunger pump. The pump block 8 is simiarly bored and is provided with corresponding pistons carried by the piston rod 16.

While both of these piston-rods may be manually operated by means of separate pump levers, I have shown a shaft 17, which may be journaled in suitable hearings in any desired form of supports, and which may be driven by means of the pulley 18 thereon suitably connected to any suitable source of power. The shaft 17 is provided with a double-crank 19 to which. is pivoted the link 20 whichis similarly pivoted to the end of the piston rod 12. Preferably oppositely disposed on the shaft 17 is the double-crank 21, adapted to similarly reciprocate the piston rod 16 through the interposition of the link 22.

In the pump block 7, a lateral duct 23 leads from the bottom of the larger portion 10 of the pump-bore, below the piston 13, to and through the coupling or connection 24 which is suitably secured to said pump-block and to the end of the pipe 25, which is therefore open through said coupling to the chamber 10. A similar duct 26 leads from the bottom of the smaller portion 11 of the pump-bore, below the piston 15, to

' and throu h the cou lin or connection 27 by means of which the end of the pipe 28 is secured to said pump-block and open to the chamber 11. From the upper and larger pump-chamber in the pump block 8, leads a duct which corresponds to the duct 23 to and through the coupling or connection 29 and thence to the pipe 32. These pumps are without valves, the pump and pressure valves and the means for their control being provided in a separate body or member 33 which may be located near the points where it is desired to apply the generated pressures. This body 33 is preferably of substantially cylindrical shape, and is provided at one end with a central bore 34 which extends approximately half the length of said body. The other end of said body is provided with two smaller bores extending from the end of said body to the bore or chamber 34. Each of these bores is of correspondingly varying diameters, being smallest in diameter adjacent to the bore 34. Referring first to one of said bores, it will be noticed that the portion 35 thereof is at 36 increased in diameter to provide a seat for the valve 37 which has a stem 38 projecting into the bore or chamber 34. The widened portion 39 of said bore is at 40 again increased in diameter to provide a seat for the valve 41 which has a stem 42 extending nearly but under normal conditions not quite to the valve 37. In the widened portion 43 of said bore, below the valve 41, the effective area of said bore is again reduced through the employment of a removable cylindrical plug 44, the end of which provides a seat for the valve 45 which has a stem 46 extending nearly but under normal conditions not quite to the valve 41. The end of this bore is preferably closed and sealed by means of the screw-plug 47 which provides a chamber 48 in which I prefer to mount a spring 49 normally tending to seat the valve 45. In a precisely similar manner, the smaller portion 50 of the other valve hore is at 51 increased in diameter to provide a seat for the valve 52 which has a stem 53 projecting into the bore or chamber 34. The widened portion 54 of said. bore is at 55 again increased in diameter to provide a seat for the valve which has a stem extending nearly but under normal conditions not quite to the valve 52. The portion 58 of said bore is similarly provided with the cylindrical plug 59 the end of which provides a seat for the valve 60 which has a stem ex tending nearly but under normal conditions not quite to the valve 56. A closing and sealing plug 62 provides the chamber 63 in which the spring 64 similarly operates to normally retain the valve 60 in a closed condition. A duct 65 connects the chambers 48 and 63 and equalizes the pressures therein.

From the portion 39 of one of the valve bores, between the valves 37 and 41, leads a duct 65 to and through the arm 67 which is rovided at one end of the device. From the portion 54 of the other valve here, between the valves 53 and 56, leads a corre sponding duct 33 to and through the corresponding arm 69. The end of the arm 67 is screw-threaded for the reception of the coup ling 7 O at the end of the pipe 30, and the end of. the arm 69 is correspondingly provided with means for the reception of the coupling 71 at the end of the pipe 25, these pipes 30 and 25 leading from the upper and larger pump-chambers in the pump-blocks 7 and 8, respectively.

From the portion 43 of one of the valvebores, leads a lateral duct 72 to and through the arm 7 3, upon the end of which is mounted the coupling 74 at the end of the pipe 32. Sin'iilarly, from the portion 58 of the other valve-bore, between the valves '56 and 60, leads duct 75 to and thr ugh the arm 75 which is through the coupling 77 connected to the pipe 28. These pipes 32 and 28, as will be seen, lead from the lower and smaller pump-chambers in the pump-blocks 7 and 8, respectively. From the chamber 48 at the end of one of said valve bores, leads a duct-78 to and through the arm 79, the end of which is adapted to receive the coupling 80 at one end of the pipe 81, the other end to this pipe being provided with the coupling 82 secured to the ram cylinder 83 and open tl'irough the duct 84 to the pressure-chamber 85 below the rain 85. Similarly, from the chamber 63 in the other valve bore, leads the duct 87 to and through the arm 88 which carries the coupling 89 at the end of the pipe 90 which, through the coupling 31, leads in a precisely similar manner to the pressure-chamber in the ram-cylinder 92 underneath the ram 93.

and longitudinal du ct 9. leading; from the chamber 84 to and through the nipple and thence to said source of supply.

The member is provided with a lateral bore thror h the wall thereof leading to said here 3 1-, which is interiorly screw-threaded for the rec ption of the closing and scaling plug 98. .ln this plug 98 is centrally journalod the shaft 99 upon the interior end of which is nuunted the earn 100 and the exterior one of which is provided with head 101 or other suitable means for securing the end of an operating lever 102 by means of which the shaft 99 may be readily and easily rotated. Fitting within the bore 34 and adapted to reciprocate therein, is the short ct inder or tube 103, the lower end of whica is in cooperative positional relation to the ends of the imwardlv projecting stems 38 and 53 of the valves 07 and 52, respectii It will be noticed that irrespective of the retative position of the tubelOS, the ani. end of the latter is always in posi ion to impinse against the ends of said stems. The u, ier end of the tube 103 is preferably provided with an in-turned flange 104 against which acts one end the spring 105 in compression between the inner end of said bore 34- and said flange to normally hold said tube 103 yielding'ly free from contact with the ends of said valve-stems. This flange 104- leaves the central aperture 106, through which liquid may be delivered to the valve bOlGS. The other end of the tube 1.03 is in cooperative positional relation to the cam 100 on the inner end the shaft Under normal conditions. the cam 180 is in such position that under action of the sg'iring 105 the tube 103 held away from contact with the valve-stems and 58. Upon turning the 0U lever 161 to rotate the shaft 99, however, said cam will move the tube 103 to force the same against the action of the spring; 105 and in the direction of the valves in too valve bores.

It will now be apparent that under normal conditions, with the various parts in the position of adjustment illustrated in the drawings, and assuming for the present that the pumps are power-driven, as shown, and the plungers therein reci 31O0f1tfid in alternation, upon the up-stroke of the pistons in the pump 7 partial vacuums willbe created within the chambers 10 and 11 underneath the pistons 13 and 15, respectively. The inequality of pressures thus created will result in a flow of liquid to said chambers through the pipes 25 and 28. In one case, the liquid will flow from the source of supply through the pipe 95 into the bore or chamber 34, and thence past the valve 52, which is unseated, to the duct 68 and the pipe 25, and in the other case in a similar manner from the source of supply past both valves 52 and 55 and thence through the duct to the pipe 28. Upon the stroke of said pistons, the valve 52 ed, the liquid forced by the piston :assi g the valve 55 where it joins with the liquid forced by the piston 15, and the flow from both pump-chambers is directed through the portion 58 of the valve-bore past the valve 60, which is unseated, into the chamber From this chamber, on ac count of the duct 65, the liquid is divided between the pipes 81 and 90, and is forced under equal pressures to the ram-chambers under neath the rams S6 and 93. Reciprocation of the pistons in the pump 8 effects precisely sim'lar results through the other valve here. If the piston-rods are coupled to a rotating shaft in the manner shown in the drawings, the pistons in the pump 7 will make their upward strokes while the piston in the pump 8 are making their downward strokes. This alternation of the effective strokes of the pist res tits in a substantially continuous application of pressure and an exceedingly rapid delivery of liquid to the ram chambers.

SllOUlQl it become desirable to reduce the volume of liquid which is being delivered to the ram chambers, for the purpose of sacrificing speed for increased power, or for any other reason, the workman stationed at the location of the valve-member 33 will turn the lever 102 through an arc SllfllClGDb to operate through the cam 100 to move the tube 1.03 against the action of the spring 105 until the interior end of said tube has imping-ed against the end the stem 38 and positively unseated the valve 37. In order that this valve 37 may be first alone unseated, I make the stem 38 thereof slightly greater in length than the stem 53 of the valve 52 in the portion 50 of the other valve bore. Therefore, the valve 37 may be unseated b movement of the lever 102 through a certain are without interfering with automatic action of the valve 52 or, in fact, with any of the remaining valves in the device.

It will now be apparent that with he valve 37 held off its seat, the liquid which is drawn into the pump-cl v .ber of the pump 8 upon rip-stroke of the piston therein, will, upon down-stroke said pistons, instead of seati 1g the valve 37 and flowing on into the pressure chambers, follow the path of least resistance and re urn past the unseatcd valve 37 into the bore 34*. and thence back to the source of supply. The larger piston in the pump 8 has now been rendered efiectively inoperative, the pressure being generated entirely by the two pistons in the pump which the device is capable.

7 of the remaining smaller piston in the pump 8. Under the principles of hydrostatics, the piston area having been reduced and the applied power remaining the same, a less volume of liquid will be forced to the ram chambers but said liquid will be so forced under increased pressure. Should it become desirable to still further increase the pressure at a sacrifice of the volume of liquid delivered to the pressure chambers, the workmen stationed at the valve member 33 will turn the lever 102 through a slightly greater arc, causing the cam 1 )0 to still further advance the tube 103 until the end thereof has impinged against the end of the stem 53 and unseated the valve 52 as well as the valve 37. It will now be seen that both of the upper and larger pistons in the pumps 7 and 8 have been rendered effectively inoperative, the pressure being generated entirely by the two lower and smaller pistons in said pumps. If desired to still further increase the pressure, the maximum degree thereof of which the device or apparatus is capable of generating may be secured through turning the lever 102 through a still greater arc, causing further movement of the valve 37 to finally impinge against the end of the stem 42 of the valve 41 and positively hold the latter off its seat. The stem 57 of the valve 56 is of such length that the valve 41 may be held off its seat in the manner described without effecting the automatic function of the valve 55. Under the conditions just described, the valves 37 and 52 being held off their seats and both of the upper pistons in the pumps being therefore inoperative, similar unseating of the valve 41 will cause the liquid which has been drawn into the chamber underneath the smaller piston in the pump 8 to be forced back past the unseat-ed valves to the source of supply, instead of being directed to the pressure chambers. Continued operation of the pumping mechanisms under such conditions will render solely effective the stroke of the smaller piston in the pump 7 and thus generate and apply the maximum pressure of Still further rotation of the lever 102 will, in a precisely similar manner, next unseat the valve 55 and thus render wholly ineffective the pumping operations. This might be desirable when the occasion arose to temporarily check the application of increased pressure, to note the effect and progress of the work. With these valves held off their seats, while the pressure in the ram chambers will be maintained, no additional liquid will be forced into said chambers even though the pumping operations be continued. Furthermore, the lever 102 may be turned through a still greater are, causing the valve 41 to impinge against the end of the stem 46 of the valve 45 and positively unseat the latter. This has thereffect, obviously, of opening communication from both ram-chambers to the source of supply. This is done when it is desired to relieve the pressure in the ram-chambers for the purpose of removing or readjusting the pressure applying device or devices. The pressures against the valves 45 and 60 will at times, obviously, be very great. It Willbe apparent that twice the force would be required to unseat both valves as would be required to unseat one thereof. Once started, however, the pressures on both sides of either valve unseated is immediately equalized, and further movement of the same off its seat can be accomplished with but little effort. I therefore continue the relative proportions existing between the lengths of the various valve stems, so that one of the final pressure valves (the valve 45, as shown in the drawings) will be first alone unseated, continued movement of the lever 102 ultimately resulting in the unseating of all the valves in both of the valve bores.

Many modifications of minor details of my improved device for generating and applying variable hydraulic pressures will doubtless readily suggest themselves to those skilled in the art to which it appertains, and I therefore do not desire to limit my invention to the specific construction, location and arrangement of parts as herein shown and described.

I claim as new and desire to secure by Letters Patent:

1. In combination, a plurality of separate mechanisms for generating hydraulic pressures, each thereof comprising a plurality of pressure-generating means, means for applying the generated pressures, and means for rendering effectively inoperative in alternate and consecutive order all of said generating means.

2. In combination, a plurality of separate mechanisms having common actuating means for generating hydraulic pressures, each thereof comprising a plurality of pressuregenerating means, means for applying the generated pressures, and means for rendering effectively inoperative in alternate and consecutive order all of said generating means.

3. In combination, a plurality of separate mechanisms for generating hydraulic pressures, each thereof comprising a plurality of pressure-generating means, a plurality of devices for applying the pressures, and means for rendering effectively inoperative in alternate and consecutive order all of said means and for equalizing the applied pressures.

4. In combination, a plurality of separate mechanisms having common actuating means for generating hydraulic pressures, each thereof comprising a plurality of pressuregenerating means, a plurality of devices for applying the generated pressures, and means for rendering effectively inoperative in alternate and consecutive order all of said generating means and for equalizing the applied pressures.

5. In combination, a plurality of separate mechanisms for generating hydraulic pressures, each thereof comprising a plurality of pressure-generating means, a plurality of devices for applying the generated pressures, and means for rendering effectively inoperative in alternate and consecutive order all of said generating means and for equalizing during operation and finally relieving the applied pressures.

6. In combination, a plurality of separate mechanisms having common actuating means for generating hydraulic pressures, each thereof comprising Within itself a plurality of pressure-generating means, a plurality of devices for applying the generated pressures, and means for rendering effectively inoperative in alternate and consecutive order all of said generating means and for equalizing during operation and finally relieving the applied pressures.

7. In combination, a plurality of multipleplunger pumps, means separate therefrom for applying the generated pressures, and means common to all of said pumps for rendering ineffective the operations of one or more of the plungers.

8. In combination, a plurality of separate pumps, at least one thereof having multiple plungers, means separate from said pumps for applying the generated pressures, and means common to all of said pumps for rendering effectively inoperative one or more of the plungers and one or more of said pumps.

9. In combination, a plurality of1nultiple plunger pumps having common actuating means, means separate therefrom for applying the generated pressures, and means common to all of said pumps for rendering ineffective the operations of one or more of the plungers.

10. In combination, a plurality of separate umps having common actuating means, at east one thereof comprising multiple plungers, means separate from said pumps for applying the generated pressures, and means common to all of said pumps for rendering effectively inoperative one or more of the plungers and one or more of said pumps.

11. In combination, a plurality of multiple-plunger pumps, a plurality of devices separate therefrom for applying the gener ated pressures, and means common to all of said pumps for rendering ineffective the operations of one or more of the plungers and for equalizing the applied pressures.

12. In combination, a plurality of separate pumps, at least one thereof having multiple plungers, a plurality of devices separate from said pumps for applying the generated pressures, and means common to all of said pumps for rendering effectively inoperative one or more of the plungers and one or more of said pumps and for equalizing the applied pressures.

13. In combination, a plurality of multiple-plunger pumps, means separate therefrom for applying the generated pressures, and means common to all of said pumps for rendering ineffective the operations of one or more of said plungers and for finally relieving the applied pressures.

1 1. In combination, a plurality of multiple-plunger pumps, means separate therefrom for applying the generated pressures, and means for consecutively rendering effectively inoperative the plungers in all of said pumps, said means being further operable to relieve the applied pressure.

15. In combination, a plurality of separate pumps, at least one thereof having multiple plungers, means separate from said pumps for applying the generated pressures, and means for consecutively rendering effectively inoperative the plungers in all of said pumps, said means being further operable to relieve the applied pressure.

16. In combination, a plurality of separate pumps, at least one thereof having multiple plungers, a plurality of devices separate from said pumps for applying the generated pressures, and means for rendering said plungers effectively inoperative in consecutive alternation.

17. In combination, a plurality of separate pumps, at least one thereof having multiple plungers, a plurality of devices separate from said pumps for applying the generated pressures, and means for rendering said plungers effectively inoperative in consecutive alternation and for finally relieving the applied pressures during continuance of the pumping operations.

18. In combination, a plurality of multiple-plunger pumps, a plurality of devices separate therefrom for applying the generated pressures, and means for rendering said plungers effectively inoperative in consecutive alternation.

19. In combination, a plurality of multiple-plunger pumps, a plurality of devices separate therefrom for applying the generated pressures, and means for rendering said plungers effectively ino erative in consecutive alternation and fiilally relieving the applied pressures during continuance of the pumping operations.

20. In combination, a plurality of separate pumps, at least one thereof having multiple plungers, a device separate therefrom for applying the generated pressure, a flexible conduit from each pump chamber and to said applying device, said conduits uniting in a member Which is provided With means fcpr controlling the flow through said conuits.

21. In combination, a plurality of separate pumps, at least one thereof having multiple plungers, aplurality of devices for applying the generated pressures, a flexible conduit from each pump chamber andto each of said applyin devices, saidconduits uniting in a mem er which is provided with means for equalizing the applied pressures and for controlling the flow through said conduits.

22. In combination, a plurality of multile-plunger pumps, a device separate thererom for applying the generated pressure, a flexible conduit from each pump chamber and to said applying device, said conduits uniting in a member which is provided With means for rendering effective y inoperative one or more of the plungers, V

23. In combination, a plurality of multiplelunger pumps, a plurality of devices for app ying the generated pressures, a flexible conduit from each pump chamber and to each applying device, said conduits uniting in a member which is provided with means for equalizing the applied pressures and for rendering effectively inoperative one or more of the lungers.

24. n combination, a plurality of multiple-plunger pumps, a device separate therefrom for applying the generated pressure, a flexible conduit from each pump chamber and to said applying device, said conduits uniting in a member which is provided with means for consecutively rendering all of the plungers effectively inoperative.

25. In combination, a plurality of multile-plunger pumps, a device separate thererom for applying the generated pressure,

a flexible conduit from each pump chamber and to said applying device, said conduits uniting in a member which is provided with means for consecutively rendering all of said ipiungers effectively inoperative and for ally relieving the applied pressure.

26. In combination, a plurality of multiplelunger pumps, a plurality of devices for app ying the generated pressures, a flexible conduit from each pump chamber and to each applying device, said conduits uniting in a member which is provided with means for equalizing the app ied pressure and for rendering effectively inoperative one or more of the plungers.

27. In combination, a plurality of multi ple-plunger pumps, a plurality of devices for applying the generated pressures, a flexible conduit from each pump chamber and to each applying device, said conduits uniting in a member which is provided with means for equalizing the app ied pressures, for rendering effectively inoperative one or all of the plungers and for finally relieving the applied pressures.

28. In combination, a plurality of multiple-plunger pumps ,a plurality of devices for applying the generated pressures, a flexible conduit from each pump chamber and to each applying device, said conduits uniting in a member which is provided with means for equalizing the applied pressures, for con' secutively rendering said plungers effectively inoperative and for finally relieving the applied pressures.

29. In combination, a plurality of multiple-plunger pumps, a conduit from each pump chamber which conduits unite in a common pressure-distributing chamber, suitable valves in said conduits, and means common to all of said valves for the manual control thereof.

30. In combination, a plurality of pumps, at least one thereof comprising multiple plungers, aconduit from each pump chamher which conduits unite in a common pressure-distributingichamber," suitable valves in each of said conduits, and means common to all of said valves'for rendering one or more thereof inoperative.

31. In combination, a plurality of pumps, at least one thereof comprising multiple plungers, a conduit from each pump chamsure-distributing chamber, suitable valves in each of said conduits, and means common to all of said valves for rendering one or all thereof inoperative.

32. In combination, a plurality of double pumps, a suitable conduit from each pump chamber, the conduits from each pump uniting in a common passage and said passages uniting in a common pressure-distributin chamber, valves in each of said passages, an means common to all of said valves for unseating the same to render one more of the plungers in said pumps ino erative.

33. In combination, a p urality of double pumps, a suitable conduit from each pump chamber, the conduits from each pump uniting in a common passage and said passages uniting in a common pressure-distributin chamber, valves in each of said passages, an means common to all of said valves for unseating the same in alternate and consecutive order.

34. In combination, a plurality of double pumps, a suitable conduit from each pump chamber, the conduits from each pump uniting in a common passage and said passages uniting in a common pressure-distributin chamber, valves for one pump in each of sai passages, one checking back-flow from one pump chamber, another checking back-flow from the other pump chamber and a third checking bacl -flow from the pressure-distributing chamber, and means for successively unseating said valves'in order.

35. In combination, a plurality of double pumps, a suitable conduit from each pump chamber, the conduits from each pump uniting in a common passage and said passages the various series of valves to unseat the same in alternate and consecutive order.

JAMES W. NELSON.

uniting in a common pressure-distributing chamber, valves for a respective pump in each of said passages, one checking bacleflow from one pump chambeiyanother checking l back-flow from the other pump chamber and 1 Witnesses: a third checking back-flow from the pressure- H. CROOKER, distributing chamber, and means common to JAs. MOORE.

Images