US 2508298 A
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y 1950 v o. J. SAARI 2,508,298
FLUID PRESSURE INTENSIFYING DEVICE Filed April 16, 1948 Stream Patented May 16, 1950 UNITED STATES PATENT OFFICE FLUID PRESSURE INTENSIFYING DEVICE Oliver '3. Sand, Bronx, N. Y. Application April 16, 1948,1SerialNo. 21537 Claims. 1
This invention relates to a hydraulic pressure intensifier, and more particularly to a device for boosting the pressure in a hydraulic fluid line to give a smooth uninterrupted flow without the aidoi additional pumps or motors.
The booster of the invention is easily installed in the pressure line of a .pump, and by increasing the pressure permits the use of smaller ram diameters,.faster advance .and return speeds, and continuous high pressure for holding, deep drawing, etc. The device may be mounted in any posithan without altering its effectiveness.
.Further advantages of the booster are that it may he. used with large volume pumps, and can be used with either variable or constant delivery pumps. The device contains no bearings or packings. to service, and needs no adjustments. ;By its design, thebooster may be produced at low cost and maintained in service over long periods withno maintenance cost.
An object of the invention is. to provide a hydraulic pressure intensifier having the above advantages.
, Another object of the invention is to provide a booster including a pair of interlockedand selfsynchronizing pistons so arranged as to provide delivery of intensified oil pressure at all times.
' These and other objects of the invention will be apparent from the following specification and the accompanying drawing, in which the figure .piston 11,. and similar grooves Ma .and I4?) are provided near the ends of piston I2. Each piston has piston rods [5, l6 and l1, 18. extending from each of its ends and extending into cylinders l5a, |6a, Ila. and la, respectively, these cylinders being of less diameter than cylinders Ma and Ho, and being in communication with the larger cylinders through reduced cylinder portions 20 which are dimensioned to provide for movement of the piston rods but at the same time to seal ofi the large cylinder portions Ha, 1.2a from the smaller cylinder portions |5a lta, etc. Cylinder |5a is connected at its closed end with cylinder Ila by a passage 22 containing. two checkvalves 23,, 24 opening only toward each other A conduit .25 .for the, intensified pressure fluid is. connected to conduit 22 at a point between check valves '23, 24
2 closed ends by a conduit 21 and check valves 28 and corresponding in position and direction of opening to those connecting cylinders "la and Ma. Conduit 21 also communicates with intenslfled pressure. conduit 25 at a point between check valves .28, 29.
Conduits 22 and '21 are connected to and paralleled along most of their lengths by conduits 30, 3|, respectively, each containing a pair of one way check valves 32, 33 and 34, spaced in a manner similar to the check valves 23, 24 and '28,, 29, but operating oppositely to the latter, that is, check valves '32 and 33 permit flow of fluid only toward cylinders |5a and Ila, respectively. Check valves 34 and 35permit flow only toward cylinders IEa and Ma, respectively. Conduits 30 and 3| are both connected at points located between their check valves with a conduit 3-! which receives fluid being fed to the device by a pump or other pressure source (not shown).
Passages and 4| provide communicationbetween the ends of cylinders Ho and the corresponding ends of cylinder |2a, and these two passages both connect with fluid supply passage 31. Conduits 40 and 41 are connected to and paralleled along most of their lengths by passages 42 and 43, respectively, the two latter ,pas-
Cylinders vIlia and 18a are connected-at their 56 sages being connected with a drain conduit 44 which leads, for example, back to the fluid supply tank (not shown).
Conduits 4|], 4|, 42, and 43 communicate with cylinders 5| and 52 which contain movable pistons 53 and 54,, respectively. The openings of passages 40,, 4|, 42 and 43 into cylinders 5| and 52 are spaced along the lengths oi these cylinders and each of the pistons 53, 54 has four openings so positioned that piston 53 While blocking passages 4'0 and 43, permits flow through passages 4| and 42. In the other position of piston 53, it permits fluid flow through passages 40 and 43 and blocks passages 4| and 42. Piston 54 is similarly constructed and operable, except that, as will be explained presently, piston 54 operates out of phase with piston 53.
The right. end of cylinder 5| is connected by a passage 56 with the interior of cylinder Ila near its mid point, and the left end of cylinder 5| is connected by a passage 51 with the left end of cylinder |2a at a point located a short distance from the left end of cylinder I211. The
opening of passage '55 into cylinder '||a is so positioned that the right hand end of piston. gmoves clear of the opening when the pistonmoves to its extreme left hand position. The left end or cylinder 52 is connected by a passage 58 with der that groove |4a will connect passage 59 to drain at 60 when piston I2 is in its extreme right hand position, while groove I 4b will conhect passage 58 to drain at 60 when piston I2 is in its extreme left hand position.
in the case of cylinder Ila, it has-a connection to drain at 6| so positioned that grooveIB will connect passage 56 to drain at 6| when piston II is in its extreme right hand position.
In the phase of operation shown in the drawing, the pressure from the pump (not shown) entering conduit 31 passes through check valve '34 and at the same time through passage 4|,
thus applying pressure to the end of piston rod I6 and to the right end of piston II, causing movement of piston II to the left. The pressure "from the pump also passes downwardly through port 40 into the left end of cylinder I 2a, and at the same time passes through port 30 to open check valve 33 and pass into cylinder I2a which also assists in moving piston rod I1 and piston I2 to the right in the drawing. Access of pressure fluid to the left surface of piston II is prevented by piston 53 so that the pressure on combined areas of piston I 6 and the right end of piston II overcomes pressure tending to open valve 32, thus maintaining this valve closed and forcing piston II and piston rod I to the left v and opening valve 23.
' The pressure in the left end of cylinder I2a passes through conduit 51 as soon as piston I2 has moved far enough to the right to uncover the opening of passage 51 into cylinder I2a so I that the pressure within cylinder I2a passing through conduit 51 passes into the left end of cylinder 5| to move piston 53 to its right-hand position as shown and to maintain it in this position. As long as piston 53 is in its righthand position as shown, it connects the left end of cylinder Ila. through the upper portion of conduit 40 and the upper portion of conduit 42 with the conduit 44 which passes to drain, thus permitting movement of piston II to the left. The fluid in cylinder-I5a passes through check valve 23, forcing this valve open, and then passes through conduit 25 which is the conduit for the fluid under intensified pressure. Check valve 24 prevents passage of the fluid from cylinder I5a into cylinder-Ila. It will be apparent that the pressure of the fluid passing from cylinder I5a to conduit 25 is intensified due to the fact that the pressure on the surfaces of piston II and piston rod I6 is concentrated on fluid in contact with piston rod I5, the left end of cylinder Ila I being connected to drain.
The movement of piston I2 to the right under the pressure of the fluid passing through the lower portion of conduit 40 and through the lower portion of conduit 30 past check valve 33 causes an increase in the pressure in cylinder I8a since the right end of cylinder I2a is coni nected to drain, and the fluid in cylinder I8a. is .forced past check valve 29 into the intensified pressure conduit 25, check valve 28' preventing movement of this fluid through passage 3|. The fluid entrapped within the right-hand end of cylinder |2a during the movement of piston I2 to the right escapes through conduit 43 to the conduit 44 which connects to the drain.
As piston I2 moves to the right, it exposes first the opening of conduit 51 into cylinder I211 to shift piston 53 to the right as described above, and thereafter with further movement of piston I2 to the right, exposes the opening of conduit 58 into cylinder I2a, thereby permitting the incoming fluid pressure from passage 31 to pass from cylinder I2a through conduit 58 to the lefthand end of cylinder 52 so as to urge piston 54 to the right. This movement of piston 54 to the right cannot take place, however, until piston I2 reaches its extreme right-hand position, in which it is shown in the drawing, where it connects the right-hand end of cylinder 52 through conduit 59 and groove 14a in piston I2 to drain through passage 55. When the pressure within the right-hand end of cylinder 52 is thus re leased, the piston 54 is free to move to the right from the position in which it is shown in the drawing. In the right-hand position of piston 54, conduit 40 is blocked, conduit 42 is open, conduit 43 is closed, and conduit 4| is open.
Movement of piston 54 to its right-hand position closes on the flow of fluid from the pump to cylinder IZa through conduits 31 and 40 due to the fact that it blocks conduit 40, but at the same time, it connects the left-hand end of cylinder IEa through conduit 42 to the drain conduit 44. In its right-hand position, piston 54 also connects the right-hand end of cylinder I2a to the incoming fluid pressure conduit 31 since it opens conduit 4| and blocks the connection 43 of the right-hand end of cylinder I20. with drain conduit 44. The fluid pressure entering through conduit 3! then forces open check valve 35 so as to pass into the right-hand end of cylinder I8a, while at the same time the fluid pressure from conduit 3! enters the right-hand end of cylinder I2a through conduit 4|. The combined pressures on the right-hand ends of piston I2 and piston rod I8, and the connecting of the left-hand end of cylinder I 2a through conduit 42 to drain permits the pressure from conduit 31 to force the piston I2 to the left so as to place the fluid within cylinder I'Ia, under intensified pressure, and to force this fluid past check valve 24 into the intensified pressure conduit 25. Check valve 23 prevents the intensified fluid pressure from passing through the upper part of passage 22 into cylinder I5a.
When piston II completes its leftward movement it exposes the opening of conduit 56 into the interior of cylinder I la. and permits pressure from conduit 31 through conduit 4| to pass from the interior of cylinder I la into conduit 56 and thence into the right-hand end of cylinder 5| to urge piston 53 to its left-hand position in which it closes conduit 4|, opens conduit 43, closes conduit 42, and opens conduit 40. This leftward movement of piston 53 occurs at the time when conduit" 51 is connected through the left end of cylinder IZa and through conduit 42 communication with the incoming pressure :con-
duit 31. "The closing of conduit 42 disconnects "drain conduit 44.
no: end of cylinder, 11o from communication with the drain conduit 44, while the opening of conduit 40 permits fluid pressure fromlconduit vi'l'fto enter the left end of cylinder Ha. The
duit'through passage #3 and pressure from pump conduit 31' is passing'into' "both cylinderjfla and the left end of cylinder 'ilu, piston H is therefore forced to move to the right and the fluid entrapped within cylinder ifia is forced past check valve 18 under intensified pressure into the intensiiied pressure conduit 25, meanwhile holding valve '34 closed.
I Returning now to piston 12, the leftward moveinent of piston l2 'after'mcvementof piston to .the right "finaliy brings groove Hi1 into a position to connect conduit 58. with drain "conduit 60, and at the same time to expose the connection of conduit 5.9 with the right-end of cylinder 12w seas to permit the pressure from-conduits 3'! and 4| within the righthand end of cylinder 12a: to pass a through conduit 59 into the righ'thand end of cylinder 52 so as to urge piston 54 toits leithand position, the fluid under pressure inthe lefthanci end of cylinder 52 escaping through conduit 58.
- along groove 1th, and out of drain conduit 60. "With this occurrence, the'iefthand end'oi cylinder 12a is again connected with the pump pressure conduit 31 and the righthand end (if-cylinder "12a is connected through conduit 43 with the movement to the right under the pressure of fluidfrom conduit 31 passing'through conduit 40 into the left end of cylinder Ha. The en- "trapped within cylinder 18a is forced past check valve 29 under intensified pressure into conduit As piston 12 moves to the right it first-passes "the opening of conduit 51 into cylinder m and "til piston H has reached its extreme position 0f "movement to the right in which it connects condu'it 58 through groove 13 with the drain conduit ii, so as to relieve pressure Withinfhdfighfliaald end of "cylinder 51. The movement of "piston so to the right then permits pressure from conduit 51 to pass into the right 'en'dloi cylinder 1 la, and.
permits fluid in the left end oicylinder ita to passput' through the "upper portions of conduitifl and '42 to the drain conduit 34. The .iiuid entrapped within cylinder $541, "is placed under increasedpressure and forced past check valve 23 into intensified pressure conduit 25.
. It will thus be clear from the above description thatthe mode of operation described continues over and over again-as long as the pressure is sup- "plied to conduit 31.
With respeott'o the relative positioning-oi drain duct 60 and the openings offl'uctsfid and 59 into cylinder I'Za, the positioning is such that when piston I2 is in its extreme righthand position,
duct 59 "is oonn'ected't'o duct to andthe left end of piston l2 exposes opening, of conduit into-cylinder-flu. When piston i2 isinits extreme lefthandposition, conduit 58 is in communication by means of groove hit with drain duct Eli and the 'righthand endofpis'ton '12 exposes 'the'openinpof Piston 42 then starts the duct 5! into cylinder m so as to permiticomn unicati-on between duct 59 and the lower end of conduit 4'1. When the piston l2 isin its extreme lefthand position, the-re is, however, no communication between conduit 59 and drain duct 60.
With respect to the positioning of drain duct 6! and the opening of conduit 56 into cylinder l la, the drain duct-til is oifset to the left out of line with the opening into conduit 56 so that when piston 11 is in its extreme lefthand positionthe drain conduit 6| is closed and conduit 5611s in communication through the interior of cylinder 11 a with the upper end of conduit 41. When the piston H is in its extreme rightharnd position,.the opening-of duct: 56 into the interior of cylinder 1 i commnnicateswlth groove 13 which also commun-icaiiesv with drain conduit .64
Itwillhe apparent that thespeed of the pistons 1 Landvl-Z. isv governed by the capacity'of the pump supplying fluid to conduit 31, so that the greater the volume of fluid supply, the greater the speed of the pistons. The spring pressed ball check valves .23, 24,, 28, and 2.9 reduce the pulsation at the stroke reversing intervals to an absolute minimum by preventing. any momentary backflow of the intensifiedpressure 011.
One or more spring loaded detents 10. are used with each of the two piston valves 53 and 54 so as to retain these piston valves in .each of their two positions except when the pressure in one or the other. ends of the cylinders 5|, 521s. suilicient to move the respective piston to its other position. These detents also serve the function of holding the valve pistons 53, 54 in their respective positions regardless of the orientation of the mounting of the pressure intensifier itself. The detents could of course be located in the housing or body Iii to cooperate with depressions in thepistons 53, 5'4. Suitable projections (not shown) on the ends of valve pistons 53 and 54 may be, provided to limit their movement in each direction.
. It should also be apparent that the amount "of intensificationpf the pressure is a function of-the diii'erential-ratio between the surface of'the ends of pistons H and i2 and the surface of the surface area of the ends of each of the piston rods 15, "Hi, H, Hi. The volumetric output of the hydraulic intensifier is of course inversely proportional to the pressure ratio so that, for example,
if the pressure is doubled, the volumetric output is ha lvedporii' the pressure is tripled, the volumetric output d'ecrea'ses to athird of the original intensified pressure could be replaced :by other types of similarly operatmg. check "valves. The
- shape of the main pistons could also be'varied :so
long as each piston has at least two separate fluid pressure areas on each \endso that the separate areas on thexslde of a piston in the direction of movement of the piston can be connected one to the intensified pressure outlet and one torlrain. ilhetannularigrooves ia'hout eachinrain piston could he replaced "by passages through the piston, although this might necessitate maintaining the pistons against rotation.
The form of the invention which 12 have :de-
scribed is but a preferred embodiment, and is not to be considered as limiting the invention to the specific embodiment shown. It is myintention to cover by my patent all variations of the inventionfalling within the scope oi. the claims and outside the prior art.
' areas, second conduit means for connecting one fluid contact area of each side of each piston to said drain outlet, valve means controlling said second conduit means and at least some of said first conduit means, said valve means having positions'for completing the connection of said fluid supply inlet to both areas of one side of each piston to move said piston in a direction away from'that side, while blocking one area of each of the other piston sides from communication with said inlet and connecting said blocked area with said drain outlet, third conduit means connecting the remaining side of each piston with said intensified pressure outlet, and connection reversing means operable by said pistons to shift said valve means to reverse said connections as said pistons approach the limits of their movement in each direction, thereby reversing the direction of movement of said pistons, said valve means comprising two fluid operated valves, each having two positions, first and second cylinders in which said pistons reciprocate, connections to drain positioned in the side wall of each cylinder, said pistons having passages which communicate with one of said drain connections during a portion of the piston movement, said connection reversing means including first and second valve operating fluid passageways connecting the first valve with both end portions of the first cylinder and third and fourth valve operating fiuid pas sageways connecting the second valve with one end portion of each cylinder, the proportioningof said pistons, the positioning of said passages and the positioning of the openings of.said passageways into said cylinders being so related that in ;one extreme position of movement-of; saidfirst 1 piston, the first of the passageways to said first valve is connected to a drain connection by a passage "in said piston while the second passageway to said first valve isin communication through a first end of said cylinder with the piston moving-fluid from said inlet, said first piston in its opposite extreme position putting said first passageway into communication wth the other end of said first cylinder for receiving fluid therefrom and putting said second passageway in communication with a drain connection through a passage in said first piston, said second piston in one extreme position of movement connecting said-third passageway with a drain connection and in its other extreme position putting said third passageway in communication with one end of said cylinder to receive fluid therefrom,'said fourth passageway being connected to said first cylinder at a point positioned between the end of the cylinder andthe opening of the second passageway into the cylinder to receive fiuid from that end of the cylinder during the major portion of the movement of said first piston in both directions.
-2. A device as set forth in claim 1,.saidv fluid operated valves being pistonvalves, valve cylinders in which said valve pistons reciprocate, said first and second passageways being connected to opposite ends of the cylinder of said first piston valve, and said third and fourth 'passageways being connected to opposite ends of the cylinder of said second valve. I f
3. A fluid pressure intensifying device comprising a fluid supply inlet, an outlet for fluid under intensified pressure, an outlet to drain, a pair of main cylindershaving enlarged central portions and reduced end portions, a piston reciprocably mounted in each cylinder, each piston having an enlarged central portion and a reduced end portion slidable in the corresponding cylinder portions, first and second conduits connecting one reduced end portion of one cylinder with a reduced end portion of the othercylinder, third and fourth conduits connecting the other reduced end portions of the two cylinders, a pair of spaced check valves in each of said first and fourth conduits, each check valve opening only toward the other check valve in the same 'conduit,'said check valves permitting fiow only in a direction away from the reduced cylinder portions to which said first and fourth conduits connect, a pair of spaced check valves in each of said second and third conduits, each of said last mentioned check valves opening only away from theother check valve in the same conduit, said last mentioned check valves permitting flow only in a direction toward the reduced cylinder portions to which said second and third conduits connect, a connection from said fluid supply inlet to said second and third conduits at points located between the check valves in each conduit, a connection from said intensified pressure outlet to said first and fourth conduits at points located between the. check valves in each conduit, fifth and sixth conduits paralleling said first and second conduits and connecting the ends of the enlarged portions of the two cylinders which correspond to the reduced ends connected by the first. and second conduits, seventh and eighth conduits similarly connectin the other ends of the enlarged cylinder portions, first and second valve cylinders each intersecting said fifth, sixth, seventh and eighth conduits at spaced positions, a first connection from one end of the first valve cylinder to the interior of the enlarged portion of the first main cylinder at a point located on one side of the center of the cylinder-so asto be uncovered by the piston in that cylinder during the final portion of the movement Ofthat piston toward the end of the cylinder farther removed from said connection, a second connection from the other end ofsaid first valve cylinder to the interior of the enlarged portion of said first main cylinder at a point positioned similarly to said first connection but on the opposite side of the mid point of said cylinder, a third connection from one end of the second valve cylinder to the interior of the enlarged portion of said first main cylinderat a point spaced between said second connection and the endof the main cylinder nearer the second connection, a fourth connection between the other end of said second valve cylinder and the interior of the en larged portion of the second main cylinder at a point positioned to one side of the mid pointloi the cylinder so to be uncovered by the piston, in
said cylinder-during the final portion of its movement toward the endof the. cylinder farther removed from saidjourth connection, means ,carried by said first piston for connecting said first connection to drain at one end piston position and for connecting the second connection to drain in its other end position, means carried by said second piston for connecting said fourth connection to drain when said second piston is in its end position of movement in the direction of the end of the cylinder nearer said connection, a connection from said fluid supply inlet to said fifth and eighth conduits at points located between the intersections of said conduits with said valve cylinders, a connection to drain communicating with said sixth and seventh conduits at points located between the intersections of said conduits and said valve cylinders, and a valve piston in each of said valve cylinders, each of said valve pistons having two positions and having ports located so that each piston blocks said first and third conduits and completes said second and fourth conduits in one position, and blocks said second and fourth conduits and completes said first and third conduits in the other position.
i6 4. A fluid pressure intensifying device as set forth in claim 3, said means carried by said main pistons comprising annular grooves about the peripheries of said pistons.
5. A fluid pressure intensifying device as set forth in claim 3, and spring pressed detent means yieldably retaining said valve pistons in each of their positions.
OLIVER J. SAARI.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 2,274,224 Vickers Feb. 24, 1942 2,293,076 Pointing Aug. 18, 1942 2,336,446 Tucker et al. Dec. 7, 1943 2,442,916 Buchanan June 8, 1948