US2154956A - Hydraulic pressure multiplying mechanism - Google Patents

Description

A ril 18, 1939. H. E. PAGE HYDRAULIC PRESSURE MULTIPLYING MECHANISM Filed May 4, 1938 -llll a I v .i m U 1.0 1 MN QM u I WIN J k Q n mm m o M O J MN 3i 2 115 Patented Apr. 18, 1939 I UNITED STATES PATENT OFFICE 2,154,950 rmmaomc PRESSURE MULTII'LYING This invention relates to hydraulic pressure multiplying mechanisms, and has for its object a simple construction by which a part to be actuated or driven member is quickly moved or operated up against the work by one or two movements of the operating lever, and after the driven member encounters the resistance of the work, heavy pressure is applied by successive operatin movements of the prime mover.

10 It further has for its object a hydraulic pressure multiplying mechanism embodying a shiftable body formed with at least two piston chambers, pistons working in the chambers, one of the pistons being a prime mover, which may be 15 actuated in any suitable manner, or by hand, and a transfer passage between the chambers having means, as a, spring-pressed valve therein with suihcient resistance to normally prevent the transfer of the hydraulic liquid from the smaller or prime mover chamber to the large or power chamber and to permit the flow of the hydraulic liquid from the prime mover to the power chamher, when the driven or actuated part encounters resistance, so that upon preliminarybperation, the driven or actuated part is quickly operated by one or two movements of the prime mover to take up the lost motion between it and the work, and thereafter upon successive reciprocations of the prime mover, the liquid from the prime mover chamber is pumped into the larger power chamber, and the pressure multiplied in..the power chamber, -'to cause the actuated part to apply heavy but slower pressure to the work.

I have here illustrated my invention as fa'ppliedi to a hydraulic lifting jack.

inafter set forth and claimed. v

In describing -this invention, reference is had "to the accompanying drawing, in which likecharacters designate corresponding parts in all the views.

Figure 1 isa longitudinal sectional view through the pressure multiplying mechanism.

4, Figure 2 is a side elevation of a mechanismv 55 vided with a suitable head, not shown, pressing -The invention consists in the novel features and in the, combinations and constructions bere against the vwork to which the pressure is. to be applied, or, in the case of a lack, against 'the article to be lifted.

The body I isformed with piston chambers 4 and 5 extending lengthwise thereof or parallel to the direction 'of the shifting movement of the body I, these chambers being of different diameters, the chamber 5 of larger diameter being a power chamber for applying heavy pressure. 6 and 1 are pistons working respectively in said chambers 4 and 5. The body I is also formed with a reservoir 8 for a hydraulic liquid which communicates through passages 9, In, H, with.

the piston chambers 4, 5 in order to permit the hydraulic fluid to circulate or run or transfer freely from the reservoir to the piston chambers. These pistons are provided with means or are so constructed as to permit the flow-of the fluid from the rear sides to the front or pressure sides thereof, and prevent the flow from the pressure sides to the rear sides. As shown, these pistons are formed with the usual flexible cup-shaped heads. The reservoir is formed with a suitable filler opening l2 closed by a closure I3.

I4 is the transfer passage between the chambers 4 and. 5, this having yielding means therein for normally preventing the transfer of the fluid from the prime mover chamber 4 to the power pressed valve 14 pressing against its seat by a spring IS, the tension of which may be adjusted by means of a suitable adjusting screwor plug.

H. The prime mover piston 13 hasdtsyrod 18 connected to a suitable actuator IQ thiSIbEiHE shown as 'a lever pivoted-at 20 to a shafton a frame, not shown, and having an arm 2| connected through a link 22to' the outer end of the piston rod l8. A suitable'returning spring23is connected to the lever l9 or the arm I2l thereof,

and a stop-pin -24 fixed to the .frame, not shown,

limits the retrograde or return movement of the lever l9.

In the form shown in Figure l, the power piston I has its .rod 25 pivoted or anchored at' 26 to a shaft on the frame, so that the piston I remains stationary and the body I shifts, when heavy pressure is being applied. This is the reverse of the construction shown in Figure 2, in which the power piston is shiftable relatively to the body.

The relative movement of the body and the piston I is transferred to the driven part or lever 2 through suitable mechanism, and in the form shown in Figure 1, the lever 2 has an arm 21 pivoted at 28 to an arm 28 at one end of the shiftable body I. Means is provided for returning the driven part 2 to its starting position, as well as all other Qpvable parts of the machine or mechanism, and also releasable means is provided for holding-the driven part or lever 2 in its operated position. The returning means includes a spring 38 anchored at one end at 3| to a pin on the frame and at its other end at 32 to the shiftable body I. The releasable holding means, as here shown, comprises a valve 34 in a chamber 35 formed in the body I in communication with the reservoir 8 and the piston chambers 4, 5 and normally closing ports or passages 33, 31 leading from the pressure sides of the chambers 5, 4 into the chamber 35 or into the reservoir, this valve being normally closed and operable into open position to release the pressure in the power chamber 5 and prime mover chamber 4 to permit 80 the spring 38 to react and return the parts ,to

their starting positions. The valve 34 is here shown as carried by a stem 38 threading through the rear end of the body I and having a handle 38 at its outer end.

In operation, upon forward movement of the arm 2|, that is, movement to the right, against the action of its returning spring 23, this being effected by moving the operating lever I8 to the left, the prime mover piston 6 will be moved in the piston chamber 4, to the right, but as the oil has no means of escape from the chamber 4 on the pressure side thereof, and the valve I4 is held seated by its spring I6, the body I is shifted to the right, and hence the driven part or lever 2 shifted from its starting position or full-line position. When, however, the lever 2 encounters the resistance of the work and the lever I8 is again actuated or reciprocated, the hydraulic fluid passes the valve I4 through the transfer passage I4 into the larger power chamber 5, reacts against'the piston I, which is held stationary, and effects an additional movement of the body I to the right. The spaces on the pressure sides of the pistons are always kept fllled by reason of the fact that the oil can pass from the rear side to the pressure side of the piston or the cupshaped head of the piston I. As the chamber 5 is of greater capacity than the chamber 4, repeated movements of the piston 6 can be used to build up the pressure in the chamber 5 required to be applied to the lever 2 to perform its work. Because the release valve 34 is closed, the pressure is locked in the pressure ends of both the piston chambers 4, 5, and hence the lever 2 held in any operated position.

However, upon opening of the valve 34 by turning the handle 38, the pressure in the pressure ends of the chambers 4, 5 is released through the passages 35, 31 to the reservoir, so that the returning spring 38 is free to react and restore all parts to their starting positions.

In Figure 2, a construction is shown in which the reservoir and piston chambers, instead of being bored in the block are separate elements and interconnected, and also the smaller .or preliminary closing cylinder only is shiftable, while the power cylinder is stationary or held from shifting movement and the power piston is movable.

In Figure 2, 88 designates the reservoir; 48 the prime mover piston chamber; 58 the power piston chamber; 58 the prime mover piston; and I8 the heavy pressure or power piston, and the stem II thereof is pivoted at I2 to the arm 2I8 of the actuated part or lever 288. 388 designates the returning spring, corresponding to the spring 38. I48 designates the transfer passage or con duit corresponding to the transfer passage I4 (Figure 1), and I the control valve therein, corresponding to the valve Il The reservoir 88 is connected to opposite ends of the cylinder 58 through passages or conduits 88, 8|, conduit 88 having a manually operable valve 82 therein. The reservoir 88 is connected to the rear end or the left end of the piston chamber 48 through a flexible pipe H8. The conduit I48 is also flex- ;ible. The pressure side or right end of the piston chamber 48 is connected to the reservoir through a conduit 388 which is connected to the conduit I48 between the check valve HI and the cylinder 48. The conduit 388 has a release valve 348 therein. The cylinder 58 is pivoted at 258 to the frame. Because of the flexible conduits I I8 and I48, the cylinder 48 can shift relatively to the cylinder 58 and reservoir 88. I

In operation, the piston rod I88 of the prime mover piston 58 is connected to an arm of the operating lever I88, as in Figure 1. The cylinder 48 at its right end is pivoted at 48 to an arm 48 at an angle to and rigid with the arm 2I8 of the actuating member or lever 288. The piston rod II of the power piston I8 is also pivoted to the arm 2". As the cylinder 58 is anchored or pivoted at 238, the piston I8 moves relatively to the cylinder, instead of the cylinder moving relatively to the piston, as in Figure 1.

In operation, upon movement of the handle end of the lever I88 to the left (Figure 2), the piston 58 is moved to the right in the cylinder 48, and as the valve I is held closed by its spring, when there is no resistance to the lifting arm 288, the cylinder 48 shifts to the right, this being permitted by the flexible pipes H8 and I48, and thrusts against the arm 48 lifting the arm 288 against the work. This movement from the fullline position (Figure 2) toward the dotted line position pulls the piston 18 through the rod 1| moving it toward the right end of the cylinder 58, the oil displaced passing the cup-shaped head of the piston I8 into the left hand end of the cylinder 58. When the am 288 encounters the resistance of the work, movement of the actuating lever I88 and hence the piston 88, causes the oil to overcome the spring of the check valve MI and pass through the pipe I48 into the left hand end of the cylinder 58, so that repeated operations of the hand lever I88 and piston 88 pumps the oil into the pressure end of the cylinder 58, moving the piston I8 to the right in short steps and transferring the movement through the piston rod II to the arm 2I8 of the lever 288, thus applying heavy pressure.

During these operations, the valves 348 and 82 are closed, and to release the pressure in the cylinders, these valves are opened and the parts are returned to their starting positions by the spring 388.

What I claim is:

1. In a pressure multiplying mechanism, the combination of a shifta'ble body element including piston chambers, and a reservoir fora hydraulic fluid for supplying the fluid to the chambers, pistons working respectively in the chambers, a part to be actuated, one of said pistons being a prime mover operating to shift the body, a transfer passage connecting the chambers, yieldable means for restraining the movement of the fluid from the prime mover chamber to the other chamber, operable to close said passage during preliminary movement of the prime mover for freely actuating said part, and to yieldingly open when said part encounters resistance causing the fluid to be forced by the prime mover, through the transfer passage into the other chamber and effect relative movement of the body and the piston in said other chamber, and means for transferring the shifting movement of the body and said relative movement to said part.

2. In a pressure multiplying mechanism, the combination of a body element including piston chambers, and a reservoir for a hydraulic fluid for supplying the fluid to the chambers, pistons working respectively in the chambers, a part to be actuated, one of said pistons being a prime mover operating to shift the body, a transfer passage connecting the chambers. yieldable means for restraining the movement of the fluid from the prime mover chamber to the other chamber, operable to close said passage during preliminary movement of the prime mover, for freely actuating said part and to yieldingly open when said part encounters resistance causing the fluid to be forced by the prime mover through the transfer passage into the other chamber and effect relative movement of the body and the piston in said other chamber, means for transferring the shifting movement of the body and said relative movement to said part, and circulating passages between the chambers and the reservoir, said pistons being constructed to permit flow of the liquid from the rear side to the pressure side thereof and prevent'the flow from the pressure side to the rear side.

3. In a pressure multiplying mechanism, the combination of a shiftable body element including piston chambers, and a reservoir for a hydraulic fluid for supplying the fluid to the chambers, pistons working respectively in the chambers, a part to be actuated, one of said pistons being a prime mover operating to shift the body, a transfer passage connecting the chambers, yieldable means for restraining the movement of the fluid from the prime mover chamber to the other chamber, operable to close said passage upon preliminary movement of the prime mover, for freely actuating said part, and to yieldingly open when said part encounters resistance causing the fluid to be forced by the prime mover through the transfer passage into the other chamber and eflect relative movement of the body and the piston in said other chamber, means for transferring the shifting movement of the body and said relative movement to said part, a returning spring arranged to return the actuated part and the other movable parts of the mechanism to their starting positions, and releasable means for holding the same in their operated positions.

4. In a pressure multiplying mechanism, the combination of a body element including piston chambers, and a reservoir for a hydraulic fluid for supplying the fluid to the chambers, pistons working respectively in the chambers, a part to be actuated, one of said pistons being a prime mover operating to shift the body, a transfer passage connecting the chambers, yieldable means for restraining the movement of the fluid from the prime mover chamber to the other chamber operable to close said passage during preliminary movement of the prime mover for freely actuating said part, and to yieldingly open when said part encounters resistance causing the fluid to be forced by the prime mover through the transfer passage into the other chamber and effect relative movement of the body and the piston in said other chamber, means for transferring the shifting movement of the body and said relative movement to said part, a release valve operable to trap the pressure in said chambers, and operable to release the same, and a returning spring for returning the movable parts of the mechanism to their starting positions.

5. In a pressure multiplying mechanism, the combination of a shiftable body element formed with piston chambers extending in a general direction parallel to the shifting movement of the body, and a reservoir for a hydraulic fluid for supplying the fluid to said chambers, the cham-. bers being of different diameters, pistons working respectively in the chambers, a part to be actuated, the piston working in the smaller chamber being a prime mover operating to preliminarily shift the body, a transfer passage connecting the chambers, yieldable means for restraining the movement of the fluid from the prime mover chamber to the other chamber operable to close said passage during preliminary movement of the prime mover for actuating said part and yieldingly open when saidpart encounters resistance, causing the fluid to be forced by the prime mover through the transfer passage to the larger piston chamber and effect relative movement of said part and the piston in the larger chamber, means for transmitting the movement of the body effected by the prime mover piston and said relative movement to the part to be actuated, and means tendingto return the part to be actuated and the movable parts of said mechanism to their starting positions, and releasable means for holding the same in their operated positions.

6. In a pressure multiplying mechanism, the combination of a shiftable body element including piston chambers, and a reservoir for a hydraulic fluid for supplying the fluid to the chamhers, pistons working respectively in the cham bers, a part to be actuated, one of said pistons being a prime mover operating to preliminarily shift the body, a transfer passage connecting the chambers, yieldable means for restraining the movement of the fluid from the prime mover chamber to the larger chamber, operable to close said passage upon preliminary movement of the prime mover for freely actuating said part, and to yieldingly open when said part encounters resistance causing the fluid to be forced by the prime mover through the transfer passage into the larger chamber and effect relative movement of the body and the piston in said larger chamber, means for transferring the shifting movement of the body and said relative movement tov said part, a returning spring arranged to return the actuated part and the other movable parts of the mechanism to their starting positions, a release valve operable to trap the pressure in said chambers and to release the same, and a returning spring for moving the part to be actuated and other movable parts of the mechanism effected by the operation of the prime mover to their starting positions.

7. In a pressure multiplying mechanism, the combination of a shiftable body element including piston chambers of different diameters, and a reservoir for a hydraulic fluid for supplying the fluid to the chambers, pistons working respectively in the chambers, a part to'be actuated, the piston in the smaller chamber being a prime mover operating to preliminarily shift the body, a transfer passage connecting the chambers, yieldable means for restraining the movement of the fluid from the smaller chamber circulating passages between the chambers and the reservoir, pistons including means to permit the flow of liquid from the rear side to the pres- I sure side thereof and prevent the flow in the reverse direction, means tending to return the actuated part and other movable parts of the mechanism to their starting positions, and releasable means for holding the same in their operated positions. I

HERBERT E. PAGE.

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