US2013484A - Pump - Google Patents

Description

sept. 3, 1935.

PUMP Filed Nov. 29, 1952 5 Sheets-Sheet 1 J. A'vAz PUMP Sept. 3; 1935.

Filed Nov. 29, 1952 3 Sheets-Sheet 2 By; I

'Sem' 3, 1935.

PUMP

3 sheets-Shet 3 Filed NOVl 29 IflveNTOF bricant being supplied to one of the said chambers Patented Sept. 3, 1935 UNITED STATES PATENT oFF-ICE PUMP ' Jacques A'i'vaz, Paris.' France Application November 29, 1932. serial No. 644381 i In France December 7, 1931 The present invention'Y relates to a pump for liquids, which is chiey adapted for the supply of fuel to internal combustion engines.

The said pump is principally characterized by able on an axis parallel with the axes of the cylindelrs in which the said pistons operate, and equidistant from the said axes.

In one form of construction, the valve device consists of a single element which is movable in the mam' casing' According to another feature of the invention."- an annular chamber is provided in each` cylinder,

and all of the chambers of the different cylinders are in communition with one another, the luby a drop-feed system.

'I'he said drop-feed system may comprise, for example, a recess formed in one of the pistons and so situated that -it may be alternately connected with the supply of the lubricant under prsure and with the chamberformed injthe corresponding cylinder.

The pressure in the said chambersV is maintained at a givenvalue which exceeds the maximum pressure of the fuel or other `liquid inthe corresponding cylinder,.by any suitable discharge Further as well as the various advantagesof the invention will be set forth in the following description.

In the accompanying drawings, which are given solelyby'way of example:

Fig. 1 is alengthwise section of a pump in conformity to the 1 invention, on the line l-I of Fig. 2;

Fig. 2fis a cross-section the on theu line 2 2 of Fig. 1;

Figs. 3 to 6 are partial sectionsvof modifications of the device controlling the piStODS;

Fig- T is a detail section showing the use of a metallic bellows;

Fig. 8 is a. lengthwise section oiz' a pump, relat.

ing to another form of -valve'device;

Fig. 9 is a partial section-ofthe said valve de-Y Fig. '10 and 11 are respectively a plan vie 1 claim. (ci. 1113-173) and a section of a detail modifcation of thesaid valve device.

In the form of constructionrepre'sented in Figs. 1 and 2, the pump, which can be placed in any di, rection, comprises a metallic mass l of cylin- 5 drical or other shape, to which are secured, by bolts 2 or otherwise, two caps or end portions 3 and. Y.

In the said mass I are formed cylindrical re- 'cesses or lb'ores 5, whose axes :c+-:n are parallel 10 with onev another and are equidistant from the v axis y-y of the mass I. Each cylinder 5 is pref- 1 erably provided with an internal sleeve 5a. In

each sleeve 5a mounted a piston S having a U-shaped head l, and a cam-disc 8 engages 15 all of the heads 1 at its periphery. The said camdisc is keyed to a shaft!) whose axis is :1 -y, and is provided at ill with a projecting part or vlike operating-` device. The said cam 8 has a bent `form, in such manner that during one revolution 20 of the shaft 9, it will give each piston 6 an alternate movement on the axis :1s-:l: of the cylinder 5, corresponding to an amplitude l. The said cam may obviously be forned integral A with the-shaft 9 or may be keyed to the latter, pr further, as shown in 3, it may be pivotally mounted on an axle 50 perpendicular to the axis of rotation `of shaft 9 and maintained by one or more springs 5I which bear for instance on the shaft 9 in such manuel-that when the 'delivery 30 pressure reaches a given value, vsuch springs will be compressed, and the caim'8 will return to the middle position, thus reducing the suction and delivery strokes and providing a' total or partial self-regulation;

In the construction shown in Fig. 4, the cam 8, which does not rotate, is mountedvona bearing. brass 6I), which is in mounted on a partially spherical member El provided on the shaft 9. The said brass 60 is rotated by an arm 62 secured to the shaft and engaged in an aperture 64 formed in a flanged part 650i the said bram. 'I'he said flanged part is urged'by a spring 5|; the brass 60 and its cam 8 will thus oscillate about the centre of the member 6I, under the opposing eifects of 45 the spring 5l and the reactions of the delivery. K

The cam 8 may be further replaced, as shown in Fig. A5, by a ball-bearing having the oblique l position; Vthe outer race I0 of the bearing, which is only; subjected to an alternate movement of 50 oscillation in the directlonof the arrow f1, and

in thecontrarydirection, comprises a. part Il at the periphery, which is engaged inthe heads 1 of f the pistons 6, and this part `Il oscillates in the head 'l after the manner of a roin11a, which latter 55 manner. Each cylinder communicates, at the end opposite the head 1 of its piston 6,' with a channel I3 (Fig. 1) formed in a cylindrical sleeve I4 mounted in the cap 4; said Vsleeve further comprises an annular recess I5. In the said sleeve is rotatablea cylindrical valve I5 whose axis is y-y, and thevalveisrotated by the shaftl'inany suitable manner, for instance by a projection I1 mounted on the cylinder I5 and engaged in a recess I8 in the corresponding end of the shaft 3.

In the surface portion of the cylinder I6 is an annular groove I3 coinciding with the recess I5 in the sleevel 14, which groove is extended by a recess 28 adjacent the outlet ab of the channels l3 formed in the sleeve I6. The length of the recess 2l is such that it communicates at the same time with the channels' I3 of all the cylinders 5 in which the pistons-operate on the delivery stroke. In the cylinder I5 is a port 2I by which its surface portion may communicate with a central conduit 22; said port'is adaptedto coincide with the outlets ab of the channels I3, thus connecting the conduit 22 with the cylinders operating on the admission stroke. The axial conduit 22 is in direct and permanent communication with a conduit 23 by which the liquid fuel is supplied.

The annular reces I5inthesleevel4isinpermanent communication, through a channel 24 with a chamber 25 which is in permanent communication with a conduit 26 by which the liquid fuel, or other liquid, is delivered to the place of use.

The said chamber 25 is further connected, by a channel 21, with the admission conduit 23, but in the idle posion, said channel 21 is closed by a clack-valve 28 whose stem 23 is rigidly secured to the central part of a flexible diaphragm 38, and thus no guiding is necessary. The dia- -phragm. consists of impermeable fabric, sheet metal or the like, and is held at its outer part between the member 4 and a suitable member 3|. The said diaphragm may further consist of a metallic bellows 3l (Fig. '1). In the case of a pump for motors,`a conduit 33 is mounted at 32 on the member 3I, and it leads to the intake manifold of the motor. The p1 in this intake manifold which maybe above or below atmospheric pressure, according to whether superchargers are or are not used for the motor, is thus exerted in the direction of the arrow f? upon the diaphragm 38. This pressure p1 is completed by the adjustable action p1 of a spring 34 mounted between the diaphragm and a ringshaped nut 35, and thus the diaphragm is urged towards the chamber 25 by a pressure p -N+1?.

The surface of the diaphragm 38 is much' larger than that of the valve 28; said diaphragm is substantially parallel to the conduit 24, and thus the current of, liquid issuing from the pump will be practically parallel to said diaphragm.

The pump is completed by lubricating arrange- -masslthe recesses 36 of the other cylinders.

ments. In each Asleeve 5a is an annular recess 35,. and all of the recesses 36 are connected by channels 31 with an annular chamber 38 in the Said chamber 38 is connected by channels 33-40 with a'chamber 4I in which the cam 8 is rotatable. The connection between the chambers 38 and 4I is normally closed off by a. clack-valve 42 urged by a spring 43 whose force is such that the said valve will only be lifted from its seating when the pressure in the chamvber 38 and hence in the recesses 36 reaches a value somewhat exceeding the delivery pressure of the pump.

'I'he supply of fuel to one ofthe recesses 36 (the I other recesses being supplied from the said recess) is assured by the corresponding piston 6 which comprises, Ifor this purpose, a recess 44; this latter, during the -motion of the piston 6, comes successively, but not simultaneously, into coincidencewith the recess .36, and on the other hand, with a. suitable conduit 45 for the supply of lubricant under pressure.

Y The operation of the said pump is as follows. Under the action of the cam 8 which is operated bythe shaft 9, the pistons 6 are given an alternating movement in their cylinders. right-hand stroke (Fig. l) they draw the liquid fuel or other liquid into the cylinder 5, and at this time the valve I6 connects-the intake conduit 23. with the cylinder 5 through the channel 22, the port 2| and the channel I3.

When the piston 5 is on its left-hand stroke (Fig. l) thus driving before it the liquid fuel or other liquid contained in the cylinder 5, the valve I6 connectssaid cylinder 5 with the chamber 25 through the channel I3, the groove 20, the recesses I3 and I5, and the channel 2li.`

The static pressure in the chamber 25 and in the delivery conduit 26 cannot increasey above the above-mentioned force p equal to p1 +112 and exerted in the direction of the arrow f2 upon the diaphragm 30. In fact, when the pressure in the chamber 25 tends to exceed the value p, the diaphragm 30 is moved in the direction contrary to the arrow f2,- and the valve 28 is lifted from its seating, thus connecting the admission with the delivery, and the excess output of the pump will 'thus operate in a. closed circuit. It should be Anoted that due to the position of the diaphragm 30,

which is parallel to the conduit 24, only the elastic pressure ofthe expelled liquid will be exerted upon the diaphragm, to the exclusion of all dynamic eifort due to the current of liquid, as would be the case' if the diaphragm were perpendicular to the current of liquid expelled by the pump.

As the ratio between the surfaces of the diaphragm 33 and of the valve 28 is quite considerable, the diaphragm will hardly be aiected by theA variable pressure prevailing in the admission conduit 23 and acting below the valve 28.

As concerns the lubrication, the piston 6 provided`with the groove 44 serves the purpose of a. drop-feed device; it takes up the lubricant from the channel 45 in which it is at a high pressure, and brings it into .the recess 36, whence it passes throu'gh the channels 31 and the chamber 38 into The pressure of the lubricant in said recesses 36 is maintained below a given value, by the discharge valve 42. This pressure much exceeds the maximumpressure of the fuel or other liquid delivered.

In consequence, the saiduliquid will not'leak around the pistons 6, but on the contrary, the

During the forward, while on the contrary it is very difficultto obtain sufficient non-leaking conditions with the usual apparatus employing pistons or slidevalves. This obviates all diiiicuities with lubrication due to the fact that the petrol dilutes the lubricants and causes gripping of the parts.

The use of pistons allows a considerable suction at the intake end, which is due for instance to the fact that the tanks ae located below the carburettor, which is usually the case for seaplanes, or when operating at low atmospheric pressures at high altitudes.

As above stated, the pump is self-regulating,

with constant pressure at the delivery end, whatever be the output required of the motor. This pressure is also constant, irrespective of the pressure of the surrounding atmosphere due to the altitude, whilst the self-regulating systems usually employed in fuel pumps are only suitable for motors operating near the ground.

The delivery of the pump is constant, thus assuring excellent conditions for the feeding of carburettors in which the float must not be subjected to continual pounding of the'liquid, if a constant level is to be maintained.

It should be further stated that the apparatus has a .very light weight and is of a reduced size.

In the form of construction shown in Figs. 8 and 9, the body I' of the pump is constituted in the same manner as the body I of the pump represented in Figs. 1 and 2, and it is closed at the ends by caps 3"-4'; the cap 4' provides for the entirely free opening of the cylindrical recesses 5' provided in the body I In the cap 4' is mounted the valve device which consists of two circular 1 discs 1li-1I connected together by a metallic bellows 12 which is soldered or otherwise secured to the two discs. A spring 15 urges the disc 10 and 1| respectively upon the body l' and upon the end of the cap l'.

The hubs 13-14, which are mounted at thecentres of said discs, engage a crank-pin 16 mounted in the eccentric position upon thedriving shaft 9' of the pump. Thus the valve device consisting of the discs 1li-1| and the benows 12 will be displaced by an eccentric movement about the axis of the shaft 9', hence successively closing and opening the outer part of the several cylinl drical recesses 5' as shown at 11-18 in Fig. 8.

f Ports 19 in the disc 10 permit, due to the eccentric motion of said disc, to successively establish or cut oil the connection between a chamber in the bellows and the different cylindrical recesses 5" of the pump. Apertures 8| in the hub 14 of the disc 1I provide a permanent connection between vthe chamber 80 and the fuel intake conduit 23.

In order tov maintain each port 18 in coinci- `Adence with its corresponding cylindrical recess -apertures 8l provided in the cap 4' or in a mem- -ber 86 secured thereto.

" The fuel entering through the channel 23 iiows through the apertures 8l into the chamber 80 and thence through the ports 18 into the cylin- V drical recesses 5' which are operating on the admissionstroke (as shown at the upper part of Fig. 8). The fuel ldriven forward out of the cylinders 5' (lower part of Fig. 8) passes through the aperture 18 into the chamber 81 of the cap 4' formed at the exterior of the bellows 12, land issues thence through the channel 24'.

In the case of an excessive pressure at the delivery end, this pressure acts upon the disc 10 which-thus yields, together with the spring 15,

' and hence the delivered fuel is enabled to return I to the admission end through the ports 19 and the chamber 80. This motion of the disc 1li can be obtained without interfering with the disc 1I, by the use of a socket 88 located between the crank-pin 16 and the hubs 13-14 of 'the discs 'l0-1 I. The disc 10 and socket 88 may move together upon the crank-pin 16, due to the ballshaped end of said crank-pin. The socket 88 is rotatable in the hub 14 by reason of its endv 89 which is also ball-shaped.

The disc 18 may be replaced, for example, by

a disc 90, as shown in Figs. l0 and l1, and herein Y the recesses 5' will be successively closed and opened by the inner edge 9| of said disc 90, for

the admission, and by the outer edge 92 for the -delivery will depend solely upon the eccentric position of the disc and are independent of the rotation of the disc 90 about its own axis,

- it is not necessary to provide a device which would prevent the disc 90 from rotating about the crank-pin 16, such for instance. as the' rollers 83 co-operating with the apertures 84- as shown in Fig. 8.

In the embodiment of Figs. 8-9 and lil-ll, the plate 10 or 98 constitutes the actual distributing member. The plate 1| and the bellows 12 are only used in order to form a fluid tight compartment facing said distributing member 10. It is obvious that said compartment may be constituted in any other suitable manner by means y of stationary parts. The plates 10 and 90 mightl also have a larger diameter so as to cover permanently the cylindrical-recesses 5, andapertures would then be provided near the outer edge of said plates in order ,to allow said recesses Vto be. vbrought into and out of communication with chamber 81. j Obviously, the said invention isvnot limited to the forms of construction herein described and representedLwhich are given solely'by way of example.

Having now described m'y invention what I claim as new and desire t'o secure by Letters Patent is:

In a pump in combination a pump body provided with a number of parallel bores opening at one end of said body, a rotatable driving shaft extending through said body, a piston in each of said bores adapted to be reciprocated in said bore, connecting means between said shaft and said pistons whereby said shaft is adapted to reciprocate said pistons in said bores through similar strokes at different stages in the successive bores, a hollow cap for the end of said 70 body on which said 'bores open and provided with.

an inlet opening and outlet opening and leaving` ing means adapted'to urge one of said plates sov against said open end oi said body and the other plate against the en d oi said cap, said distributing member separating in said cap an inlet chamber andan outlet chambercommunicating permanently respectively with said inlet and outlet openings, passages in the plate adjacent said body adapted to be brought into' and out of coincidence with said bores in said body, a hollow socket having one end cylindrical and engagm ing in the plate adjacent said bodvand the other end ball-shaped and engaging n the second plate of saiddistributing member, and a crank-pin eccentrically carried 'by said driving shaft and having a ball-shaped end engaging the inner wall oi said hollow socket, whereby said, crankpin is adapted to drive said socket and the two plates of the distributing member during the rotation of said driving shaft.

JACQUES

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