US1939603A - Pump - Google Patents

Description

D 1933- l A. 1.. R. BERNARD- 1,939,603

PUMP

' Filed Jan. s, 1933 Z'Sheets-Sheet. 1

AugusEFESETs Qen Bernard i ATTOkNlY 2 Sheets-$heet 2 A. L. R. BERNARD PUMP Filed Jan. 5, 1933 Dec. 12, 1933.

Patented Dec. 12, 1933 PATENT OFFICE PUMP Auguste Louis Rene Bernard, Rucil-Malmaison,

France, assignor to the Society Fusion- Moteurs, Rueil-Malmaison, France Application January 5, 1933,'Serial No. 650,332, and in Belgium January 13, 1932 Claims. (Cl. 103-fl1) in accordance with the speed of revolution of I) the engine in connection with which the pump is employed.

According to my invention, I make use for this purpose of a mass 'slidably mounted on a member adapted to move with a velocity interrelated with the velocity of the reciprocating liquid forcing means of the pump and elastically connected with said member in such manner that it tends to move together with it. Therate of flow of the pump is controlled, through suitable means, by the relative displacements that take place between said mass and said member as a result of variations in the velocity of the reciprocating liquid forcing means of the pump.

According to a preferred embodiment of my invention, the member above referred to is a portion of the piston itself.

My invention will be hereinafter more specifically described with reference to the accompanying drawingsv showing, merely by way of example, two preferred embodiments of my in vention and in which:

Fig. l is a vertical axial section of a preferred embodiment of my invention;

Fig. 2 is a vertical axial section of another embodiment.

The general features of my invention that are common to both of the embodiments thereof illustrated in Figs. 1 and 2 respectively are the following:

A suitable frame a, forming, for instance, a fluidtight chamber connected with the fuel sup- ,ply, is fitted with a pump barrel 1), for instance vertical and so disposed that the delivery stroke takes place in an upward direction. Said pump barrel may be of the type usually employed and be provided, at a suitable level, with a feed port 0 opening into said fluidtight chamber and adapted to be coveredby pistond at the beginning of the upstroke thereof.

The upper face of said piston it may be of any desired shape, for instance fiat.

The oppositeor lower end of said piston is provided with a prolonged portion e, for instance cylindrical and coaxial with the pump barrel, that prolonged portion e being so placed that,

higher.

in the course of the reciprocating displacements of the piston, it always-remains outside of the pump barrel b.

A sleeve 1, adapted to be engaged on portion e, is preferably provided with a cylindrical bore very accurately determined in order that it may fit snuglyon said portion e.

The movement of piston d is imparted thereto by a driving organ, such as a cam g, and said piston is pushed against said cam by suitable yield- 5 ing means such as an ordinary spiral spring h, the upper end of which is applied against frame a and the lowerend of which is applied against an annular piece It surrounding piston d and resting against a shoulder -i provided at the lower end of piston d, where portion 6 begins.

Piston d is provided with a conduit 7' opening at one end into the upper face of piston d and at the other end into an opening it provided in portion 6 and adapted to coaet with sleeve 1, the 76 position of said opening It being determined as will be hereinafter described.

Finally, there is provided a mass tending to move together with the pump piston and opera-' tively connected with sleeve 1 in such manner 80 that when the acceleration of the piston during a given portion of the cycle of the pump exceeds a given value, said sleeve is caused, by the inertia of said mass, to move with respect to said portion e and to uncover opening it, thus opening a discharge passage for the liquid under pressure in the pump and therefore stopping the delivery of said pump. It will readily be understood that the uncovering of port It takes place all the earlier in each cycle as the acceleration of the piston is higher. i

According to the nature of the movement imparted to the piston 11 of the pump, the portion of the cycle in the course of which said'mass can be caused to move with respect to the piston by a variation of velocity for the purpose above stated may be either a portion of the compression stroke (upstroke) or a portion of the suction stroke (downstroke). As a matter of fact,

I have found that, it is necessary, for the sake of accuracy of the regulation, to choose the portion of the cycle during which the accelerations are Now, if some controlling means give, during the upstroke of the piston, accelerations that are sufficiently high to give a good regulation, other controlling means are such that the accelerations of the piston during the upstroke are wholly insufficient and it is then necessary that the regulating action should take place during the downward stroke of the piston. The embodiment of Fig. 1 corresponds to the first mentioned case, and the embodiment of Fi 2 corresponds to the second mentioned case.

I will now describe, with reference to Fig. 1, the specific features of an embodiment in which the value of the accelerations during the upstroke of the piston is suflicient for ensuring a satisfactory regulation, either because the pump is driven by a rotating cam the outline of which can be suitably chosen for that purpose or because it is controlled by an oscillating cam which produces a sufliciently quick upstroke.

As shown in Fig. 1, sleeve f is connected to a mass, which may advantageously consist of sleeve f itself, and will be hereinafter referred to as mass f.

A stop, consisting for instance of a shoulder i, is provided on the piston in such manner as to limit the displacement of said mass I along portion e in the direction of the compressing end of the piston. Means are provided for applying said mass against said stop i, said means consisting for instance of a mere spiral spring 1 bearing at its lower end against frame a and at its upper end against an enlarged portion I provided on said mass 1.

Advantageously, instead of having the lower end of spring 1 applied directly against frame a, I provide a support m adapted to be displaced vertically in order to adjust the action of spring I.

For this purpose, support m. (which is for instance given the form of a ring) is rigidly fixed to a rod 11. adapted to slide, within the chamber provided in frame a, in guides formed in said frame. Said rod is provided with a rack q, and a pinion o, keyed to a spindle extending. throughout the wall of said frame, meshes with said rack. Fluidtightness around said spindle is ensured by a stuffing box p,'or any other suitable means. Said spindle carries at its outer end a control lever which can be locked in any desired position.

Port 1: is provided in portion e of the piston rod at a point thereof that is determined according with a hole extending vertically throughout it and to the following considerations:

The strength of spring I and the weight of mass 1' having been suitably chosen, if it be supposed that the pump works in connection with an engine working at a very low speed of revolution, as compared with its maximum speed of revolution (for instance at one half of said maximum speed of revolution), it will be readily understood that said mass 1 remains'constantly applied against shoulder i.

If now, the speedof revolution of the engine increases progressively, the instantaneous veloci- From these considerations, it will be easy to determine, even experimentally, the suitable position of port It in order that, when the engine tends to race, said port may be uncovered suffi-' ciently soon by the inner wall of mass I. When said port I: is uncovered, the fuel forced by the piston is allowed to escape, through conduit d and port 1:, back into the chamber provided in frame a so that the delivery of the pump is stopped sufficiently soon in order to diminish the amount of fuel fed to the engine and therefore to reduce the speed of revolution thereof.

Of course, the end of the injection, which results from the uncovering of port It, will take place all the later as spring I is more compressed. Accordingly it is possible to vary the maximum speed of revolution of the engine by adjusting the vertical position of support m.

Advantageously, I further provide a stop for preventing mass I from moving above a certain level, so that it is stopped at that level during the upstroke and as the piston keeps moving upwardly port In is uncovered, which determines an absolute maximum of the injection.

Said stopping means may be constituted, for instance, as shown in Fig. 1, by a rod 1' carried by frame a in a vertical position and extending downwardly opposite mass f down to a level such that it comes into contact with said mass at the desired time. Preferably, annular member h is provided with a hole for said rod 1' and with a tubular guide 3 for rod r. I

of course, the stopping means that have just been described may be made adjustable vertically in order to adjust the engine, use being then made, for instance, of an arrangement similar with that described in connection with support m.

In order to prevent any damaging of mass ,1 by the shocks to which it is subjected from shoulder i, I provide in one of these two pieces a small housing adapted to receive a corresponding portion of the other one so that, as saidhousing is fille with the liquid that is present in casing a, it acts as a dash pot and deadens shocks. For instance, as shown in Fig. 1, the upper face of mass I may be provided-with a housing so that shoulder i may fit therein with very little play.

Finally, the chamber provided in frame a may advantageously be closed by a push piece t adapted to slide in a fluidtight' manner in a guide u. Said push piece may be driven directly by cam g.

Although the device that has just been described can be made in many different manners, it is believed advantageous to make it as follows:

Frame 0 consists of a block of metal provided'120 adapted to receive the whole mechanism.

A bore is provided in the lateral wall of said block for the passage of the spindle of pinion o.

A bore is also provided vertically in a projec- 123 tion left at the lower end of said block on one side of the first mentioned hole, for guiding the lower end of sliding rod 11, the guiding hole 12 thus provided extending throughout said projection of the block.

A cover w, including guide it is provided for closing both the main hole of the block and hole 12.

Finally the upper end of the main hole is covered by a piece :0 acting as a support for. pump barrel b and carrying a guide 1 for the upper end of rod n.

I will now describe, with reference to Fig. 2, the specific features of an embodiment that corresponds to the cases in which it is. necessary to make use of the downstrokes of the pistons in order to produce the desired regulation of the rate of flow of the pump. Thisjs for instance the case when the pump is controlled through anoscillatlng cam with which the delivery stroke is slower than the suction stroke.

In the embodiment shown in Fig. 2, sleeve 1 is applied against its upper stop (which may for instance consist of an annular element k by a spring N the lower end of which rests on a fixed part integral with frame a and the upper end of 1 1,9saeoa which rests upon a flange provided at the upper part of a cup-shaped member h fixed to sleeve f.

A mass P is mounted with a snug fit about sleeve I.

Said mass f is pushed downwardly by a spring 1" the upper end of which is applied against a piece rigidly fixed to frame a and the lower end of which is applied against an annular piece carried by the upper part of said mass j. Spring l is weaker than spring 1.

Sleeve j and mass 1 are so made that one of them is provided with a housing adapted to receive a corresponding part of the other one, the whole acting as a dash pot. For instance mass f is provided with a cylindrical recess f adapted to receive a projection ,1 of sleeve 1.

The dash pot thus formed is provided with a device through which recess f can be readily filled with the liquid present in the chamber of frame a and in which the mechanism is immersed, but the liquid cannot escape from said recess f or at least cannot escape without undergoing a certain resistance to its outflow. Such a device may, for instance, consist of a ball valve I provided in projection i of sleeve 1. A certain leakage through said valve can be admitted.

Finally, I provide in the chamber formed by frame a a stop 1' adapted to limit the upward displacements of mass 1", said stop being preferably adjustable vertically and consisting, for instance, of a castellated sleeve screwed on the piece that supports pump barrel b and the longitudinal grooves of which serve to the passage of arms k with which 'annular member h is provided inorder that spring It may bear against said element.

The operation of the device is as follows:

If the pump is supposed to work in connection with an engine running with a speed'of revolution that is very small with respect to its maximum speed of revolution, sleeve f, pushed back by its spring I", will tend to move together with portion e of the piston. Mass 1 will also move together with sleeve f. Outlet port It will therefore be uncovered by sleeve 1 only if, at the end of the upstroke of the piston, mass f comes into contact with stop 1 sufllciently early in order that the piston may still have a certain travel to make after mass and sleeve I have been stopped so that port k comes to be uncovered by sleeve 1.

If now the speed of revolution ofthe engine increases progressively, the instantaneous velocities of piston d at corresponding times of the suction stroke increase also. There comes a time when, in the course if the downstroke of 'the piston, mass f" is left behind by projection I of the sleeve, in spite of the action of spring l. Liquid will then be admitted through valve 1 into recess 1oo On the upward strike of the piston the liquid present in said recess cannot escape therefrom, and consequently, mass 1 and sleeve f, on their upward motion,-remain in the respective positions that they occupied at the end of the downstroke, that is with a certain interval between them equal to the distance by which mass f has been left behind in the course of the downstroke as a result of its inertia.

Mass 1 will therefore come into contact with stop 1'" earlier than if recess f were empty. Injection of fuel will therefore be stopped earlier in the cycle and the speed of revolution of the engine will tend to decrease.

Taking thus considerations into account, it

will be easy to determine, even experimentally, the suitable position of port I: in order that, when the engine tends to race, said port may be uncovered sufiiciently soon by the inner wall of sleeve f. When said port It is uncovered, the fuel forced by the piston is allowed to escape, through conduit 7' and port k, back into the cham'berprovided in frame a so that the delivery of the pump is stopped sufficiently soon in order to reduce the amount of fuel fed to the engine and therefore to lower the speed of revolution of the engine.

Of course, the end of the'injection will take place all the later as spring 1" is more compressed. It will therefore be advantageous to provide, for adjusting the compression of said spring, a device analogous to that described for adjusting the compression of spring 1 in the embodiment of Fig. 1.

Likewise, spring I" may also be made adjustable.

Finally, as above stated, the vertical position of stop 1'" should advantageously be adjustable, which willmake it possible to vary the absolute maximum of the rate of feed and also the amount of fuel injected for a given speed of revolution of the engine.

In this embodiment, as in the embodiment of Fig. 1, the lower end of the frame is closed by a push piece If adapied to slide with a fiuidtight fit in guide u. Said push piece may be directly driven by cam g and it is provided with a rod t.

In order to facilitate the assembling and the adjusting of the device, frame a is preferably provided with a door a.

While I have disclosed what I deem to be preferred embodiments of my invention, it should be well understood thatI do not wish to be limited 110 thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of my in vention as comprehended within the scope of the appended claims.

Attention is called to the following points:

The liquid forcing means of the pump is not necessarily a piston. It might be a deformable capsule or membrane.

The regulating mass is not necessarily carried directly by the piston. The necessary condition is that it should be so connected with said piston that its velocity is interrelated with that of the piston. It can, for instance, be carried by a small rod pivoted about a fixed axis and one of the points of which is connected with the piston rod.

The pump is not necessarily driven by a cam.

The regulation of the rate of flow of the pump is not necessarily determined by the velocity of the piston or of organs carried by said piston or connected therewith.

What I claimis:

1. In a pump including reciprocating means for driving the fluid operating in a chamber, said chamber having a fluid inlet and outlet and a pressure relief outlet, a mass movably mounted with respect to said reciprocating means, spring means normally causing said mass to move in unison with said reciprocating means at low speeds, said mass because of its inertia lagging behind said reciprocating member at higher' speeds, said relief outlet being so arranged that it will be opened by a predetermined displacement between the mass and the reciprocating means out of their normal relative positions. 1

2. ma pump including reciprocating means for driving the fluid operating in a chamber, said chamber having a fluid inlet and outlet and a pressure relief outlet, a mass movably mounted with respect to said reciprocating means, spring means normally causing said mass to move in unison with said reciprocating means at low speeds, said mass because of its inertia lagging behind said reciprocating member at higher speeds, said relief outlet being formed in said reciprocating means and being normally covered by said mass, but being uncovered and open when said mass and said reciprocating means are displaced out of their normal relative positions by a predetermined amount.

3. A pump comprising in combination, a pump barrel provided with an inlet port, means for constantly feeding liquid to said inlet port, a piston in said pump barrel provided with a conduit opening into its working face, means for reciprocating said piston in said pump barrel, a prolonged part of said piston provided with a port in its wall connected with said conduit, a sleeve slidably mounted on said part so as to normally cover said port, elastic means for causing said sleeve to tend to move together with said part without any relative displacement with respect thereto, and inertia responsive means, operatively connected with said sleeve, for causing it to tend to move with respect to the prolonged part of the piston, whereby said port can be uncovered when the working speed of the pump exceeds a certain limit, for a period of the cycle that increases progressively with said working speed.

4. A pump comprising in combination, a frame provided with a chamber filled with liquid, a pump barrel provided with an inlet port immersed in said liquid, a piston in said pumpbarrel provided with a conduit opening into its working'face, a cam for reciprocating said piston in said pump barrel, a prolonged part of said'piston provided with a port connected with said conduit, a sleeve slidably mounted on said part so as to normally cover said port, elastic means for causing said sleeve to tend to move together with said part without any relative displacement with respect thereto, a mass operatively connected with said sleeve, for

causing it to tend to move with respect to said prolonged part of the piston, whereby the port can be uncovered when the working speed of the pump exceeds a certain limit, for a period of the cycle that increases progressively with said speed.

5. A pump comprising in combination, a frame provided with a chamber filled with liquid, a pump barrel provided with an inlet port, immersed in said liquid, a piston in said pump barrel provided with a conduit opening into its working face, a prolonged part of said piston, also located in said chamber, and provided with a port in its wall connected with said conduit, a push piece slidably projecting from said chamber in a plunger-like fashion, a cam adapted to cooperate with the outer end of said push piece, elastic means for applying said piston against the inner end of said push piece, a sleeve slidably mounted on said prolonged part of the piston so as to normally cover said port, elastic means for causing said sleeve to tend to move together with said part without any relative displacement with respect thereto, and a mass operatively connected with said sleeve, for causing it to tend to move with respect to said prolonged part of the piston, whereby the port can be uncovered when the working speed of the pump exceeds a certain limit, for a period of the cycle that increases progressively with said working speed.

6. A pump comprising in combination, a pump barrel provided with an inlet port, means for constantly feeding fuel to said inlet port, a piston in said pump barrel provided with a conduit opening into its working face, means for reciprocating said piston in said pump barrel, a prolonged part of said piston provided .with a port in its wall connected with said conduit, a sleeve slidably mounted on said part so as to normally cover said port, means, carried by the portion of said piston located between said sleeve and said pump barrel for pushing said sleeve during the suction stroke of the piston, elastic means for applying said sleeve against the last mentioned means, and a mass integral with said sleeve for causing it to tend to move with respect to said prolonged part of the piston, whereby the port can be uncovered when the working speed of the pump exceeds a certain limit, for a period of the cycle that increases progressively with said working speed.

7. A pump comprising in combination, a frame provided with a chamber filled with liquid, a pump barrel provided with an inlet port, immersed in said liquid, a piston in said pump barrel provided with a conduit opening into its working face, a prolonged part of said piston also located in said chamber and provided with a port in its wall connected with said conduit, a push piece slidably projecting from said chamber in a plunger-like fashion, a cam adapted to cooperate with the outer end of said push piece, elastic means for applying said piston against the inner end of said push piece, a sleeve slidably mounted on said prolonged part of the piston so as to normally cover said port, a shoulder carried by the portion of the piston located between said sleeve and said pump barrel for pushing said sleeve during the suction stroke of the piston, a spring interposed between said frame and said sleeve for pushing said sleeve toward said 'shoulder, a mass integral with said sleeve for causing it to tend to move with respect to said prolonged part of the piston, whereby the port can be uncovered when the working speed of the pump exceeds a certain limit, forv a period of the cycle that increases progressively with the working speed.

8. A pump according to claim 7 further comprising means for adjusting the tension of the last mentioned spring.

9. A pump according to claim 7 further comprising a support for the end of the last mentioned spring that is not in contact with said sleeve, a rod parallel to said piston adapted to slide longitudinally in said chamber and carrying said support, a rack on said rod, a pinion in mesh with said rack, and means for controlling from the outside of said frame the angular position of said pinion.

10. A pump according to claim '7 further comprising stopping means for limiting the displacements of said sleeve in the direction of .the delivery stroke of the piston.

11. A pump according to claim '7 further comprising a rod rigidly fixed to said pump barrel and extending parallel with said piston in the direction of said sleeve so as to limit the displacements thereof in the direction of the delivery stroke of the piston.

12. A pump according to claim '7 further comprising a rod rigidly fixed to said pump barrel and extending in a direction parallel with said piston toward said sleeve so as to limit the displacements thereof in the direction of the delivery stroke of the piston, an annular element provided on said piston and provided with a hole for the passage of said rod, and a tube carried by said annular element for guiding said rod.

13. A pump according to claim '1 in which the sleeve is provided with a recess adapted to receive said shoulder with a snug fit so as to deaden' the shock to which said shoulder is subjected;

14. A pump comprising in combination, a pump barrel provided with an inletgport, means for constantly feeding liquid to said inlet port, a piston in said pump barrel provided with a conduit opening into 'its working face, means for reciprocating said piston insaid pump barrel, a prolonged part of said piston provided with a port in its wall connected with said conduit, a sleeve slidably mounted on said part so as to normally cover said port, means, carried by the the portion of said piston located between said sleeve and said pump barrel for pushing said sleeve during the suction stroke of the piston, elastic means for applying said sleeve against the last mentioned means, a mass slidably mounted on said sleeve, said mass and said sleeve being so arranged that one of them engages in the other onewith a snug fit so as to form between them a chamber 'of variable volume the expansion of which tends to move the mass in the direction of the compressing stroke of the piston with'respect to the sleeve, valve means for admitting liquid into said chamber and preventing v it from escaping therefrom, and a stop, rigidly fixed to said pump barrel, for limiting the displacements of said mass in the direction of the discharge or compression stroke of the piston, and elastic means, weaker than the first mentioned elastic means for preventing said displacements of the mass.

15. A pump comprising in combination, a pump barrel vertically disposed and provided with an inlet port, a piston in said pump barrel provided with a conduit opening in its upper face which is in contact with the liquid in the pump barrel, means for reciprocating said piston in said pump barrel, a prolonged part at the lower end of said piston provided with a port in its wall connected with said conduit, a sleeve slidably mounted on said part so as to normally cover said port, a shoulder carried by the portion of said piston located between the upper face of said sleeve and the lower end of said pump barrel for pushing said sleeve in a downward direction, a springinterposed between said sleeve and a fixed point with respect to the pump barrel for applying said sleeve against said shoulder, a mass slidably mounted on said-sleeve, a recess in the under face of said mass, a shoulder at the lower end of said sleeve adapted to engage said recess with a snug fit so as to form between them a chamberof variable volume, a valve in the last mentioned shoulder for admitting liquid into saidchamber but preventing its escape therefrom, an annular element .rigidly fixed to said pump barrel and adapted to cooperate with the upper face of said mass so as to limit the upward displacements therefrom, and elastic means for urging said mass in a downward direction, said elastic means being weaker than the spring above citedl soaps-1's LOUIS RENE

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