US1938854A - Pump - Google Patents

Description

Dec. 12, 1933.'

J. L. L. A. A. MOULET PUMP Filed July 18, 1930 5 Sheets-Sheet l ex v, @MU

HrroR/veys.

Dec. l2, 1933.

J. L. L. A. A. MOULET 1,938,854

PUMP

' Filed July 18, 1930 5 sheets-sheet 2 /VVEIYTORI JEH/v L. L. fl. ll. /VlouLeT f7 Tra/e anys. i

Dec. 12, 1933. A.L l.. A. A: MOULET PUMP , 1930 5 Sheets-Sheet 3 Filed July 18 D 12, 1933. J. l.. L. A. A, MouLETl 1,938,854

PUMP

Filed July 18, 1930 5 Sheets-Sheet 4 Dec. 12, 1933. J. l.. A. A. MOULET 1950 5 Sheets-Sheet 5 Filed July 18 Patented Dec. 12, 1933 UNITED STATES PATENT OFFICE France, assignor to Martin, Moulet Cie., Oullins, France Application Iuly 18, 1930, Serial No. 468,883, an in France March 5, y1930 3Claims.

The present invention relates to pumps which are particularly. adapted for pumping petrol, or other liquids which dissolve or otherwise act upon lubricants, and it has for its object to provide a disposition whereby the delivery of the pump is automatically limited or interrupted whenever a. certain resistance opposes the delivery, without the delivery pressure being however allowed to materially vary. This feature is particularly desirable in the case of direct fuel feeding of carburetors for internal combustion engines. In this particular application, the parts controlling the fuel inlet to the carburetor (such as the float and needle valve) oppose a certain resistance to the delivery: in order to insure efficient operation, it is necessary that the flow of the pump should be automatically regulated under the effect of this very resistance, so that the delivery i pressure should remain constant and should not m affect the operative conditions of said controlling y parts u(such as the float and needle valve).

The arrangement according to the invention, which maybe applied in connection with all .types of pump, resides in that one of the walls or one portion of the walls of the pump body is caused to move automatically when the pressure in such pump body reaches a predetermined value, so as to establish a direct communication between the suction and the delivery chambers of the pump, without the vhelp of any conduit or piping, the by-pass flow thus provided being parallel with said movable wall or wall portion in order to prevent the latter from being affected by the momentum of the liquid in motion.

Due to this arrangement, the pumping operation is automatically reduced or stopped inside .the very body of the pump where the volumetric variations take place. Moreover,.friction inside the pump is mostly suppressed; when the pump o isused for pumping petrol or any other lubricant dissolving liquid, the danger of seizing and rapid wear are-thereby considerably reduced.

Another feature oi' the invention consists in using this particular arrangement for the pur- 45 poses of priming the pump or causing the latter to run idle.

Further features ofthe invention will, be disclosed in the following description, with reference 4to the accompanying drawings, which is only a so given by way of example, and in which: l

Fig. 1 is a longitudinal section of a rotary volumetric pump, on line 1-1 of Fig. 4.

Figs. 2 Yand 3 -are transverse sections on lines 2 2 and 3-3 of Fig. 1, respectively. 5s Fig. 4 is a plan view.

Figs. 5 and 6 are transverse sections on lines 5 5 and 6-6 of Fig. 1, respectively.

Fig. '1 shows a modified form of the arrangement shown on Fig. 1.

Fig. 8 shows diagrammatically an axial section co of an embodiment of this invention, as applied to a reciprocating pump, and

Fig. 9` is a transverse section of Fig. 8.

. In the drawings, 1 is the body of the pump, having two bosses inside which are provided a 65 suction valve box 2 and a delivery. valve box 3; the construction thereof will b e hereinafter described.

Inside the body of the pump is secured a sleeve 23 comprising an eccentric cage 23* of large 7o diameter and a smaller portion forming a bearing 231. In eccentric cage 23a is rotatably mounted a drum 24,'integral with a shaft 24'b supported in bearing 23D and whose end has a slit 23 adapted for connection with any operat- 'l5 ing member fitted with a blade engaging slit 23 whereby it is revolved.

Drum 24 has av transverse groovewherein are tted two blades 25 and 26 (Fig. 5) each having one or a plurality of blind holes for housing spiral springs 27 .and 28, which tend to keep the blades or vanes apart from one another and thereby constantly maintain the tips of the vanes in contact with the inner side of eccentric cage A23". Said vanes divide the crescent-shaped in- 85 terval between cage 23'* and drum 24 into'two cells 29' and 29". When rotation takes place in the direction of arrow f, it will be seen that cell 29 is ,connected through a duct 30 with the suction pipe and cell 29b through a duct 31 with the delivery pipe.

Shaft 24* extends through a stuiling-box made of a joint 32 clamped between two surfaces, one belonging to bearing 23b and the other to a '95 spacer 33. Said spacer is applied against the joint by a hollow'nut 34 and a powerful spiral spring 35, housed in nut 34, and adapted to resiliently press spacer 33 against the joint, in order to avoid leakage in case 'of wear of the 100 joint. Nut 34 has a longitudinal groove 34', engaged by the-stem of a set-screw 36.

Spacer 33 also has a longitudinal groove 33, engaged by the stem of a set-screw 37,{and a chamber 33", connected with a circular groove 105 33s, leading through a duct 38 into a cavity wherein is screwed a pressure lubricator. Alternatively said cavity may be stopped by a plug 39, the lubricant being supplied under through a duct connected for instance with lio a pressure lubricating pipe from the engine on which the pump is mounted.

To the body of pump 1 is attached, by means of bolts such as 41, a casing 42 containing an elastic piston or bellows 43 which forms an impervious envelope and has transverse folds so as to expand or retract longitudinally.

One end of the elastic piston has a iluidtight joint with a stationary disc 44, clamped between casing 42 and pump body 1, while its movable end is connected by a disc 45 to a sleeve 46 in which is secured a rod 47. Said rod has a ball-shaped tip held by a hard bearing member 48 in a cup 49 Aintegral with a movable wall or spider 50. Said spider 50 comprises an annular part having an accurately machined and lapped or ground face which ilts accurately the corresponding face, also thoroughly machined and ground or lapped, ofv drum 24 and of the cage. Spider 50 is therefore capable vof imperviously sealing the pump body and constitutes one of the walls or wall portions of said pump boch?.

Spider 50 (Fig. 3) is hollowed out at 50, thus leaving central webs 50* which hold cup 49; the latter fits in a bore provided between two sector- 4shaped bosses 44, 44h at the center of disc 44.

- drum Spider 50 has a hole 50 (Fig. 6) registeringl with a port 44 in disc 44, whereby the inside of the pump body is in communication with the inside of the elastic piston or bellows.

Within sleeve 46 is arranged a spiral spring 51, bearing at one end against a nut, 52, screwed j upon a socket 53 adapted to rotate in casing 42 and at the opposite end against the bottom of sleeve 46, thus constantly tending to contract the elastic piston and to press spider 50 against the ground surfaces of drum 24 and of cage 23.

An adjusting knob .54, attached to socket 53, is adapted to rotate the latter. v Said socket has a shoulder 53", by which it is prevented from moving axially, so that when knob 54 is rotated, ring 52 screwed on the socket is caused to move axially and is prevented from rotating by a screw 55, extending through a bore in casing 42. Said bore has a shoulder 55l adapted to stop the inward motion of the head of screw 55, thereby limiting the inward movement of ring 52.

A rod 56, screwed into sleeve 46, is slidably mounted in socket 53 and has an integral operating knob 57, for imparting longitudinal displacement to said rod.

Casing 42 may be filled with a lubricant, supplied from a lubricator such as 58 and may be drained oli'fthroughal plug such as 59, located at the bottom of the casing.

Fig. 2 shows the construction of the valves. 'Ihe suction valve box has a chamber 2 containing a valve 4 coacting with a valve seat 5.

The lift of saidvalve is limited by a stop member 6 having al ilange resting on a shoulder of chamber 2'A and held in position by a spiral spring 7, bearing on a cap 8 which closes the top part of the valve box, tight sealing thereof being secured by a joint 9.

' The boss forming the suction-valve box is exber 2b, with the interpositlon of an impervious .constantly recede from its seat, thus considerjoint 13. 14 denotes the suction pipe of the Pump.

Boss 3 contains the discharge valve 16, associated with the same elements as the suction valve box.v 22 denotes the delivery pipe of the pumps.

` The operation of the pump is as follows: shaft 24a being imparted a circular motion drives drum 24 inside eccentric cage 23a. Displacement of vanes 25 and 26 produces volumetric variations in cells 29a and 29h. The liquid is sucked up through suction valve box 2 and delivered through delivery valve box 3.

Spider 50 being kept tight against the ground surface of the drum and the cage, both through the action of elastic piston 43 andof spiral spring 51, the inner capacity. of the body of the pump is imperviously closed; the pump works in the manner of an ordinary rotary pump.

Through chamber 33h and ducts 38 and 40, lubricant is supplied to shaft 24a under a pressure which exceeds the pressure of delivery of the pump; lubrication is thus elciently insured, the stufing-.box being constantly soaked with lubricant. Even when the liquid to be pumped is petrol, no seizing can take place in the stuiiingbox.

As long as delivery of the pump remains unobstructed, spider 50 remains tightly pressed against the drum and the cage. However, when the delivery of the pump becomes greater than the demand, the delivery pressure increases, said pressurebeing transmitted to the inside of the elastic piston through holes 50c and 44C. When such pressure reaches a predetermined value, it 110 overcomes the tension of elastic piston 43 and of spring 51, spider 50 recedes from its seat, and a by-pass flow of variable amount takes place, parallel with the movable wall or spider inside the very chamber where the volumetric variation is produced. As a consequence, wall 50 is not aifected by the momentum of the liquid in motion, in contradistinction with what takes place with pumps comprising a by-pass piping and valves, the valves always opening in the direction of the liquid current in the by-pass pipi118.

The delivery of the pump is selected in excess of that required, so that spider 50 will almost and may be used for feeding carbuetors of inter,-

nal combustion engines provided with a con-f stant level fuel tank or with a fuel dosing device.

Suction and discharge valves are required to insure efficient working of the pump at low speeds of rotation, and `in the case oi' a great` height of suction.

In the case of low speeds, the delivery valve opposes any return of liquid from the delivery pipe to the pump and avoids any fall of pressure detrimental to emcient working.

Both the suction and delivery valves open in 145 the same direction thus obviating failing of the pump during temporary stoppage.

Moreover, if rod 56 is imparted a reciprocating motion, a variation of volume is produced inside elastic piston 43, and transmitted through 156 1, with this diiference however that spider is` than the delivery of the pump, which latter may' thus be limited or annulled, the pump then running idle.

The pump may be locked in such position by any suitable means, adapted to keep spider 50 away from its seat.

In some cases, especially when it is desired to preserve the power of an engine at a high altitude, the latter is associated with a compressor adapted to deliver air under varying pressure into the carburetor. In order to obtain eilcient working of the carburetor, the delivery pressure of the fuel to the carburetor should vary simultaneously and by the same amount.

Such'working condition is readily fulillled without any extra mechanism, with the use of the hereinbefore described pumping system. For this purpose, that is in order to balance the pressures on the elastic piston, a pressure equaling that exerted on the carburetor by the compressorA is transmitted to casing 42. By way of example, a special pipe may be provided on the casing, or lubricator 58 or plug 59 may be replaced by a coupling for connecting casing 42 with the compressor discharge end.

It will be readily understood that the elastic piston or bellows may be eliminated, whereby spider 50 would be directly responsive to the) delivery pressure, as shown on Fig. 7, which shows a rotary pump .similar to that illustrated on Fig.

replaced by asolid disc connected with a deformable wall 90 adapted to separate the pump 'may be replaced by a membrane or a deformable partition, etc. while remaining within the scope of the invention.

Moreover, the invention is applicable to pumps of any other types, rotary or reciprocating, volumetric or centrifugal, gear pumps, pumps comprising' a number of movable blocks, arranged within one another and having relative movements producing volumetric variations, etc. Thus, Figs. 8 and 9 illustrate an application of this invention to a reciprocating pump of a conventional typc, in which '10 'denotes the cylinder, '1l the piston, dividing the cylinder into two chambers 10 and '10", '12 the suction valve, 73 the delivery valve and I4 the piston valve. The wall portion '15 is slidably mounted in a guide '10 provided in cylinder '10. Said wall portion is operatively connected with the free end of an elastic piston or bellows '76, through the medium of a sleeve 77. The other end of the elastic piston is attached to a ring 18, clamped between cylinder and casing 79. .A spiral spring 80, housed between the bottom of sleeve '17 and an adjusting socket 81 screwing on a threaded stem 82, presses wall against the piston. A rod 83, fitted with a. knob, is adapted to move wall 75 from the outside. A hole '75a connects top cham-I ber 703 with the inner portion of "the piston.

The operation is identical with that above described inA connection with the rotary pump. The pump being primed, when the piston moves from bottom to top in the direction of arrow f1, liquid is sucked up through valve 72 and discharged through valve 73, and wall 75 bears against the piston as long as the delivery remains unobstructed.

However, when the pressure exceeds a predetermined value, the same being exerted inside the bellows tendsto move wall 75 away from the piston thereby creating direct communication between chambers 70 and 70". y

It should be noted that with this system of pumps, the emcient stroke, causing suctionand delivery, is the upward stroke, while the downward stroke only serves to transfer the liquid from chamber '10 into chamber 70h and to bring back the piston to its lowermost point ready for another emcient stroke.

It will be seen that, during the eillcient stroke,

piston 71 sucks up through one of its faces and delivers through the other, substantially after the manner of the vane in the rotary pump here inbefore described. Also as inthe preceding case, the action of the movable wall section provides direct communication between the suction and delivery sides in the very cavity where volumetric variation takes place, when the pressure reaches a predetermined rate, the liquid flowing in a direction parallel to the movable wall section. v

It should also -be noted that operation o f rod 93 through outside means may cause priming of the pump, with the piston at rest; the pump may' also be put out of operation by keeping the wall section '15 apart from the piston, through the medium of said rod.

Having now described my invention what I claim as new and desire to secure by Letters Patentis:

1. In a pump, the combination of a pump body having a movable wall section, pumping means working along said wall section, a deformable wall operatively connected with said wall section, means whereby the delivery pressure is exerted on one face of said deformable wall and on both sides of said movable wall section, and yielding means for counteracting said pressure.

2. In a pump, the combination' of a pump body having a movable wall section, pumping means working along said wall section, bellows operatively connected with said. wall section, means for connecting the inner side of said bellows with the delivery side of said pump, and resilient means adapted to press on the outer side of said bellows.

3. In a pump, the combination of a pump body l JEAN LoUrs LN ALEXANDRE ALBERT MoULE'r.

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