US2973717A - Booster pump - Google Patents

Description

March 7, 1961 R. M. KENDIG 2,973,717

BOOSTER PUMP Filed Oct. 29, 1957 vgiiim 9801 INVENTOR. Hebert M Kndig' BY f aw 0. A ttoz'ney Robert M. Kendig, Tralford, Pa.,

" a limited volume of fluid 2,973,717 BOOSTER PUMP assignor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Filed Oct. 29, 1957, Ser. No. 693,100 8 Claims. 01.103-152 operating pressures are'maintained throughout the system; a normal operating pressure supplied by a comi pressor, and a high operating pressure supplied by a separate high pressure compressor. In the majority of such systems, space and Weight considerations in addition to' United ta ate t expense makes the additional high pressure compressor 4 impractical.

' According to the invention, there is provided a selfcontained booster pump adapted to he installed ina fluid pressuresystem supplied with fluidunder anormal operating pressure, said booster pump being operative responsively to the normalpressure .to supply limited quantities of fluid at a pressure higher than the normal pressure. The booster pump comprises a minimumof parts including two symmetrically-arranged pairs of diaphragm type pistons of equal effective area operative by said fluid under normal pressure to oscillate a rocker arm and toggle lever to control positioning of pressure inlet valves in such a' manner as to apply normal pressure alternately to first one pair of diaphragm pistons and then the other to cause the opposite pair of diaphragm pistons to boost the normal pressure to the higher pres sure.

It is accordingly the principal i object of: this invention to provide aninexpensivej self-contained and compact boosterpump of small size and weight'operative responsively to' fluid under a normalpressure to supply at a pressure higher than said normal pressure. I v The" above object and, other'objectsfand advantageswill aphragm pistons 13 and 14 being contained in bore 11 and diaphragm pistons '15 and 16 being contained in bore 12. The diaphragm pistons 14 and 16 are clamped around their repective peripheries between the intake portion 2 and the center portion v3 of the casing 1. The diaphragm pistons 13 and 15 are clamped around their respective periphery between the check valve portion 4 and the center portion 3 of the casing 1. Diaphragm pistons 13 and 14 are positioned within the bore 11 in substantially parallel relation and joined by a connecting rod 17 so as to move together. Diaphragm pistons 15 and 16 are positioned within the bore 12 in substantially parallel relation and joined by a connecting rod 18 so as to move together. A plurality of piston chambers 19, 20, 21and 22 are defined by the bores 11 and 12 and the diaphragm pistons, chambers 19 and 21 being defined by bore 11 and respective diaphragm pistons 14 and 13, chambers 20 and 22 being defined by bore 12 and respective diaphragm pistons '16 and 15. V

The connecting rods 17 and 18 of the two pairs of diaphragm pistons are linked together at their respective mid-points by a rockerarm 24'pivota1ly mounted as by a pivot pin 23 on the center portion 3 of the pump body 1 within a rocker chamber 25 connecting the two bores 11 and 12. The outer extremities of the rocker arm 24 .are provided with slots 26 and 27 to receive pins 28 and 29 that extend through holes at the mid-points of the respective connecting rods Hand 18. Separably at- -to a pin 34.fixed at the end of the toggle lever, said pin being movable in an arcuate slot 35 in the arm 30.

The other end of the spring 33 is connected to a pin 36 near the end of the arm 30. Toggle lever 31 is thus become apparent from the"following detailedfldescription Q of a booster pump embodying the invention when read in connection with the accompanying drawing, in ,which the single'figure isa vertical sectionalview, on enlarged scale, of an illustrative embodiment of the booster pump.

Description As shown in the drawing, the booster-pump comprises a sectionalized pump body or casing l'having several por,' 1 'tionsarranged in the followingsequence: an intake portion 2, a center portion'3, acheckgvalve portion d, and a' "compressionheadportion 5, all ofwhich'are secured togetherfby a plurality of through-bolts '6 located in circularly arranged: fashion, atconvenient intervals: around 1 the peripherylofgthej casingj A valve casing se'ction '7 is secured to the intakeiportion 2 by a plurality or; screws j 8, and an outlet casing section 9 is secured to the compression head portions by aplurality ofsscrewsltl.

- Formed withinthetassernbled sections ofytheipump body 1 are 'twoparallel bcres'll and 12,within,eachof which are housed like pairs otdiaphragm pistons, di-

moved' to a position to'the left or to the right of the vertical dependent upon the direction of inclination of the rocker arm 24. The outer end of the toggle lever 31 carries a contact knobor roller 37 for shifting either one of apair of double seatingvalves38 and 39 to an inner seated position defined hereinafter.

The valve '38 is adapted to seattin either an inner (right-hand) position on a seat 40 or an outer (left-hand) position ona seat41 dependent uponthe positioning of the toggle lever 31-and contact knob 37; With the toggle lever 31 in its right-hand position (as shown) thecontact knob 37 thereof engages a contact head 42 connected to the valve 38 by' a stem 43 thereby compressing a valve spring 44 and seating-the valve 38 on the valve seat 40.

With the toggle lever 31in its left-hand position and the contact knob 37 thereof out of engagementwith the contact head 42, the spring 44 biases the valve 38 to its outer (left-hand) position on the'valv'e seat 41',

When the valve 38 is seated on seat 40, communication is established between the pistonchamber 19 and a return pressure sump (not shown) by way of a passage 45, a passage 46, a valve-chamber 47, a passage sur- I roundingthe stem 43, a'return chamber 49 and a 56connected'to said return sump (not shown) When the valve 38jis seated on seat 41, the'just de scribed communication between chamber 19 and a return sump is closed off and communication'established be- :tween an intake pipe'Sl andlpiston chambers 19 a'nd 22 by way' pf passage 52,-va1ve chamber 47, passage 46 and passage 45 to piston chamber,19 and; passage 53 past a non-return check valve'54 to the piston chamber 22.

' The valve 39 is identical to valve 38, having valve seats '55 and 56, a contact head 57 connected to the valve 39 by a stem 58 and a spring 59.

When the contact. knob 37 of the toggle lever 31 engages the contact head 57 to compress the spring '59 and seat valve 39 on seat 55, communication is established between piston chamber 20 and the aforementioned return sump by way of a passage 60, a passage 61, a valve chamber 62, a passage 63 surrounding stem 58, return chamber 49 and port 50 connected to the return sump (not shown).

When the contact knob 37 of the toggle lever 31 is out of engagement with the contact head 57 of valve 39, the spring 59 will bias the valve 39 to seat on seat 56. With the valve 39 seated on seat 56, the just described communication between piston chamber21 is closed oi? and a communication is established between the intake pipe 51 and piston chambers 20 and 21 by Way of passage 64, valve chamber 62, passage 61 and passage 60 to piston chamber 20 and a passage 65 past a non-return check valve-66 to piston chamber 21.

Check valve 54 is positioned in the passage 53 to prevent backflow of fluid under pressure from piston chamber 22 to passage 53. A spring 67 maintains check valve 54 seated when there is no flow of fluid under pressure from passage 53 to piston chamber 22.

Check valve 66 is positioned in the passage 65 to prevent backflow of fluid under pressure from pistonehamber 21 to passage 65. A spring 68 maintains check valve 66 seated when there is no flow of fluid under pressure from passage 65 to piston chamber 21.

A check valve 69 is positioned in a passage 70 between piston chamber 21 and dampening chambers 71 and 72 connected to an outlet pipe 73 thereby preventing backflow of fluid under pressure from the outlet pipe 73 tween piston chamber 22 and dampening chambers 71 and 72 connected to outlet pipe 73 thereby preventing backflow of fluid under pressure from the outlet pipe 73 and dampening chambers 71 and 72 to the piston cham ber 22. A spring 77 maintains the check valve 75 seated when there is no flow of fluid under pressure from the, piston chamber 22 to the outlet pipe 73.

The outlet pipe 73 leading from dampening chamber 72 is utilized to establish communication from the pump to a reservoir or other device (not shown). requiring fluid under high pressure.

Operation In operation, fluid under a normal operating pressure (for example 50 psi.) is supplied to a fluid pressure system in which the illustrated booster pump is connected by the pipe 51. Fluid under 50 psi. pressure (hereinafter called the normal pressure) flows from pipe 1 51 to the passage 64 andthencetassuming toggle lever 31 to be positioned in the right-hand side of vertical) to 1 the valve chamber 62 past'the valve seat 55 of valve 39 which is seated on valve seat56 by spring 59. The fluid at normal pressure flows from the valve chamber 62 to passage 61 and thence to piston chamber 21 via passage 65 past the check valve 66, and also to passage 60 and thence to piston chamber 20.

With fluid at normal pressure in both piston chambers 20 and 21 as just described, the diaphragm pistons 13 and 14 will be moved downward and the pistons 15 and 16 will be moved upward pumping any fluid in the piston chamber 22 out past the check valve 75 to the outlet pipe 73 and forcing any fluid in the piston chamber 19 to the return sump (not shown) via passages 45 and 46, valve chamber. 47, past the valve seat 41 to passage 48..and xetunichamber 49-.and. thence to-the 1101150.

this just described part of the cycle of pumping takes place, the rocker arm 24 is rocked to a position in which the toggle lever 31 will be moved by spring 33 to a position on the opposite side of arm 30 from that shown in the drawing, that is, with the contact knob 37 in a left-hand position engaging the contact head 57 of valve 39, thereby causing the valve-39 to unseat from the valve seat 56, and seat on the valve seat 55. Simultaneously with the seating of valve 37 on seat 55, the spring 44 causes the valve 38 to unseat from the valve seat and to seat on valve seat 41.

With valve 39 seated on valve seat 55 and valve 38 unseated from valve seat 40, fluid at normal pressure from the pipe 51 flows to the valve chamber 47 via the passage 52 and past thevalve seat 40. The fluid at normal pressure flows from the valve chamber 47 via passages 46 and to piston chamber 19, and via passage 53 past the check valve 54 to the piston chamber 22. Fluid at normal pressure in piston chamber 20 remaining from the first part of the cycle of pumping is vented to the return sump (not shown) via passages 60 and 61, valve chamber 62, past the valve seat 56 and stem 58 to the return chamber 49and thence to the return sump via port 50.

From theabove description, it can thus be seen that with piston chambers 19, 21 and 22 supplied with fluid at normal pressure and piston chamber 20 vented to the return sump, a second part of the cycle of pumping is initiated. In. the second part of the cycle of pumping, the diaphragm pistons 15 and-16 will be moved downward by a force in opposition to the force of the pressure in piston chamber 21 of the diaphragm piston 13, said forces being transmitted via the rocker arm 24. Simultaneously with the downward movement of diaphragm pistons 15 and 16, the normal pressure in piston chamber l 19 is tending to move the diaphragm pistons 14 and 13 upwardly against the pressure in piston chamber 21, the

, ing a force on the respective diaphragm pistons 13' and 15,

will also flow to the chambers 71-and 72 past the check ..valves 69 and 75 until the pressure of fluid in said chambers builds up to equal the supply pressure, at which time normal pumping with a boosterefiect begins as hereinafter described.

With the justdescribedmovement of the diaphragm pistons 15 and 16 downward and pistons 13 and 14 upward, the rocker arm- 24 is rocked to a position in which the spring-33 will pivot the toggle arm 31 about the pin 32 with a snapping action such that the contact knob .37 moves to the right-hand position out of engagement with contact head 57 and engaging the contact head 42. With the contact knob 37 in its right-hand position, the valve 38 is seated on the valve seat 40 and unseated from valve seat 41. The spring 59 of the valve 39 will etfect -movement of the valve. 39 to seat on the valve seat 56 and unseat from the valve seat 55.

With the contact knob 37 in its right-hand position,

. and the valves 38 and 39 positioned as described in the previous paragraph, the pump is conditioned again for the first part of the cycle of pumping previously described in which piston chamber 19 is vented to atmosphere and the sum of the normal (S0'p.s.i.) pressure in the two piston chambers'20 and 21 opposes the normal pressure in chamber 22 to pump the fluid in chamber 22 under pressure via passage 70 past the check valve 69 to the outlet-pipe73 to .a-"reservoir not shown. In completing this first part of the cycle of pumping, the rocker arm '24 r and toggle arm 31 is repositioned to set the inlet valves 38 ,and' 39in condition for repeating the previouslydescribed second part of .the cycle of pumping.

It can thusibe-seen that completion of the first part of the pumping cycle conditions the pump for initiation of the second part ofthe pumping cycle, the completion of which conditions the pump for repetition of the pumping cycle etc., until the pressure in the chambers 71' and v 72 and the reservoir (not shown) connected by outlet pipe 73 is equivalent to the total pressure applied by either of the two simultaneously eifective pistons 14 and 6 1, in which each of said piston units comprises'a pair of coaxially spaced pistons connected together by a connecting rod and having an atmospheric pressure chamber therebetween, the axes of movement of said pairs of coaxially spaced pistons being in substantially parallel relation, and in which the opposite extremities of said rocker arm are pivotally connected to said connecting effective pistons is twice the inlet pressure and thus the pump will operate theoretically at least to deliver fluid under pressure at double the pressure of fluid from the inlet. It will be apparent that variations maybe made without invention in theresp'ective areas of the pairs of diaphragm pistons to provide various corresponding ratios of the delivered pressure to the normal pressure other than the theoretical two-to-one ratio effected by the specific structure described.

Having now described the invention, what I claim as new and desire to secure by Letters Patent is:

1; A fluid pressure booster pump for delivering fluid at a pressure higher than and in predetermined ratio to that of the fluid supplied thereto, said pump comprising a casing having a fluid pressure supply inlet passage and a fluid pressure outlet passage, two piston units contained in said casing, each piston unit having a first chamber at one side and a second chamber on the opposing side thereof, a rocker arm pivotally mounted at its mid-point on said casing and connected at opposite extremities thereof to the said piston units respectively so as to transmit a force from one piston unit to the other as said piston units oscillate in opposite directions simultaneously, a pair of valve means each having afirst position and a second position, levermeans connected to said rocker arm and operable responsively to movement of said rocker arm approaching one extremity in one direction to operate one of said pair of valve means selectively to its first posirods respectively.

5. A pressure booster pump according to claim 1, in which each of said piston units comprises a pair of diaphragm pistons fixed in said casing in parallel coaxially spaced relation and having a common piston rod connecting them together, and in which the extremities of said rocker arm are pivotally connected respectively to the said common piston rod of each piston unit between the diaphragm pistons.

6. A fluid pressure booster pump for delivering fluid at a pressure higher than and in predetermined ratio to that of the fluid supplied thereto, said pump comprising a casing having a fluid pressure supply inlet passage and a fluid pressure outlet passage, two piston units contained in said casing, each piston unit having a first chamber at one side and a second chamber on the opposing side thereof, a rocker arm pivotally mounted at its mid-point on said casing and connected at opposite extremities thereof to the said piston units respmtively so as to transmit a force from one piston unit to the other as said piston units oscillate in opposite directions simultaneously, a pair of valve means each having a first position and a second position, lever means connected to said rocker arm and operable responsively to movement of said rocker arm approaching one extremity in one direction to operate tion and the other of said pair-of valve means to its oscillatory movement of said piston units in opposite directions simultaneously, said first chamber of each piston unit being adapted to act as a fluid pressure compression chamber in which fluid contained therein is compressed to a degree according to the sum of supply fluid one of said pair of valve means selectively to its first position and the other of said pair of valve means to its second position, and operable responsively to movement said first position to so control the supply of fluid under pressure from said inlet passage to said first chamber of one of said piston units and said second chamber of the other of said piston units cooperatively with said other of said pair of valve means being operable in its said second position to so control the venting of said second chamber of said one of saidpiston units as to effect movement of said piston units and said rocker arm towards said one extremity in said one direction, and said one of said pair of valve means being operable in its said second position to so control the venting of said second chamber of said other of said piston units cooperatively with said other of said pair of valve means being operable in its said one position to so control the supply of fluid under pressure from said inlet passage to said second chamber of said one of the piston units and said first chamber of Y the said other of the piston units as to effect movement pressure forces from said inlet passage acting on both the said connected piston units to 'eflect delivery to said fluid pressure, outlet passage of fluid at a pressure having' corresponding ratio to the pressure of fluid supplied to the pump via said inlet passage.

2. A fluid pressure boster pump as claimed in a claim 1, in which a non-return valve is provided for each of said first chambers to prevent back-flow of'fiuid under pressure therefrom. v

3. A fluid pressure booster pump, as claimed in claim 1, having a pressure deliverychamber out of which said 7 outlet passage opens, a pressure delivery passagev estab- .lishing communication between each of said compression chambers and said pressure delivery chamber, and nonof said piston units and said rocker arm'toward said other extremity in the opposite direction, said first chamber of each piston unit acting as a fluid pressurecompression chamber in which fluid contained therein is compressed to a degree according to the sum of supply fluid pressure forces from said inlet passage acting on both the said 6, in which are check valvemeans for. preventing back-- flow of fluid pressure from said compression chambers.

8. A fluid pressure booster pump for delivering. fluid at a pressure havinga predetermined higher. pressure than the pressure of fluid'supplied thereto, said pump comprising a casing, a first piston unit and a second piston unit contained in said casing, each piston unit having a first chamber at one side and a'second chamber on the opposite side thereof, rocker arm means pivotally mounted at its mid-point to said casing and connecting said piston 'units so as to transmit force from one piston unit to the other as they move simultaneously in opposite directions, valve means, a plurality of passage means, said valve means operable to one position in which supply of fluid under pressure is eifected to said first chamber of said first piston unit via one of said passage means and to said second chamber of said second piston unit simultaneously via a second passage means, and operative to a second position in which the supply of fluid under pressure is effected to the said second chamber of said first piston unit via a third passage means and to the said first chamber of said second piston unit simultaneously via a fourth passage means to cause fluid pressure forces to act thereon simultaneously in opposite directions, toggle arm means pivotally connected to and operatively controlled by movement of said rocker arm means incidental to movement of said piston units to eflect operation of said valve means to alternately control supply of fluid under pressure to said piston units via said plurality of passage ,means in a manner to cause reversal'of the fluid pressure forces acting thereon thereby to produce oscillatory movement of said piston units simultaneously in opposite direc- 1 tions, said first chamber of each piston unit acting-as a fluid pressure compression chamber means in which fluid supplied thereto via said plurality of passage means under References Cited in the file of this patent UNITED STATES PATENTS 491,116 Keeney Feb. 7, 1893 2,550,678 Deacon May 1, 1951 FOREIGN PATENTS 325,990 Italy Apr. 22, 1935 840,648 Germany. June 3, 1952

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