US1768102A - Pump - Google Patents

Description

June 24, 1930. L. H. BELLEM 1,768,102

PUMP

Filed Jan. 24, 1928 2 Shuts-Sheet 2 I1 Z 1? -j 10.9 I

. .E? 'II'II/IIII/III lowil gezlem www- M .fldvrne a InuenZbr Patented June 24, 1930 UNITED STATES PATENT OFFICE your Application filed January 24, 1928, Serial No. 249,113, and in France December 9, 1927.

The present invention relates to improvements in pumps, and more particularly those used for feeding internal combustion engines by means of heavy fuels, but nevertheless, capable of being put to other uses.

The improved pump according to the present invention is of the type comprising a movable cylinder, the discharge end of WlllCh is applied in a fluid-tight manner during a portion of the discharge stroke of the piston, against a discharge orifice formed in the tank containin the liquid to be discharged and in whic the cylinder moves, and this pump is essentially characterized by the fact that it comprises, for the purpose of displacing the cylinder, a cam or its equivalent preferably mounted on the shaft, carrying the pump piston driving eccentric, the profile of said cam and its angular position with respect to said eccentricbeing such that through the intermediary of a suitable kinematic system, said cam, during the suction stroke of the piston,- displaces the cylinder in order to withdraw same from the discharge orifice and, during the discharge stroke of the piston, displaces said cylinder in the opposite direction, in order to apply the same against said discharge orifice.

Means are provided for controlling the amplitude of the portion of the discharge stroke of the piston during which the cylinder remains applied against the discharge orifice, said means, which thus allow the 'pumps discharge to be regulated, consisting according to a particular form of embodir ment in varying the cross-sectional profile of said cam along the width thereof in such manner that the instant at which said cam causes the cylinder to be applied against the discharge orifice varies during the discharge stroke of the pump piston with the cross-section of the cam in use.

- According to aparticular form of embodiment, this .cam is formed by a cylinder having a groove bounded on one side by a generatrix, and on the other side by a helicoidal slope, the two ends of which latter are at an angle of 180 one with respect to the other, said cam ralsmg or lowering a roller which controls the displace: ment of the cylinder through the intermediary of any suitable linkage mechanism, the pumps discharge being regulated by varying the longitudinal position of the cam with respect to the roller. This variation of the relative longitudinal position of the cam with respect to the roller can either be obtained by a longitudinal displacement of the cam on the shaft carrying the same, or by displacing the roller relatively to said cam.

The linkage mechanism interposed between the roller and the cylinder can as sume different forms.

According to one characteristic of the invention, the various driving members of the pistonand the cylinder, are situated in a casing in which the lower end of the cylinder also moves, the upper end of said cylinder moving, as stated above, in the tank containing the liquid to be discharged, said casing and tank being separated by a slightly resilient membrane which is held on its periphery on a bearing in the casing, whilst on its inner side it is attached to the cylinder which is able tomove owing to the resilience of this membrane.

v Various forms of embodiment of the device according to the invention are illustrated diagrammatically and merely by way of example, in the accompanying drawings.

In these drawi s: Fig. 1 is a longitudinal sectional elevation of a first form of embodiment. A Fig. 2 is a view corresponding to Fig. 1, but showing the pump in a difi'erent position.

adapted Y manner against the discharge orifice 11 provi ed with a ball-valve 12, or the position shown in Fig.

2, wherein the end 9 of this cylinder is' withcylinder can drawn from said mouthpiece 10. The displacement of this cylinder 6 is controlled by means of a cam 13 ke ed on the shaft 8 and shown in detail in Figures 5 and 6. 7 As will be seen in these figures, this cam is essentially constituted by a'cylinder in whic a groove is provided bounded on one side by a eneratrix 14 of this cylinder and, on t e 0t er side, by a helicoidal slope, the two ends of which are at an angle of 180 one with ect to the other, the

length of said groove t us varying according to the difierent transverse sections of the cylinder constituting the cam. In other words, th1s cam comprises two concentric cylindrical por tions 15 and 16, the length 0 the inner concentric portion 16 va transverse section of t e cam. The angular position of the cam on the shaft 8 is such that the generatrix 14 corresponds to the upper dead centre of the piston 5. The cam 13 acts on a roller 17 carried by a rod 18 which acts at its upper end on a rocking lever 19, pivoted at 20 and acting at its other end, on a shoulder 21 of the cylinder 6. A spring 22 or its equivalent, constantly acts on the cylinder 6 in order to apply its end 9 against the mouthpiece 10.

In the case,-as illustrated, of apump for feeding internal combustion engines, it is necessary to-separate the tank 3 from the tank 2 in a fluid-tight manner. In the case of Fig. 1, this result is obtained by means of a resilient membrane 23 supported on the outside in'be-arings 24 in the casingll and 'pped on its inner side between a s oulder 25' of the cylinder 6 and a nut 26. The

move by reason of the resilience of this membrane 21 which is capable of being deformed, as shown in Fig. 2.

The mode of operation of the pump 'is as follows:

The piston 5 being at .its u per dead centre, as s own in Fig; 1 the cy 'nder 6, o

to the way inwhic the cam 13 is mounte also occupies its upper position in which its end 9 is app ed against the mouthpiece 10.

As soon as the suction-stroke of the piston 5 begins, the cam 13 which rotates in the direction of the arrow shown in Fig. 5, acts, by means of its outer cylindrical portion 15 on the roller 17 in order toraise The cylinder 6 is also certain interval of time,

enters the upper h 9 ofv the cylinder mouthpiece 10.

according to the be maintained.

. 13 is longitudinally to move relative to this cam. To

this latter.- As a result ofthis raising action, the rocking lever 19 is rocked an said lever acts on the shoulder 21 in opposition to the action of the sprin 22 in or e to bring the cylinder 6 into t e position shown in Fig. 2 in which its end 9 is clear of the mouthpiece 10. It will be remarked that due to the fact that'the outer portion. 15 of the cam is cylindrical, the cyhnder 6 remains stationary in the position shown in Fig. 2 during a during which the oil or other liquid contained in the tank 3 chamber 25 of this cylinder 6. The piston 5, after havinflspassed the lower dead center, begins its charge stroke,- which latter has no other efiect thanv to discharge the oil from the chamber 25 into the tank 3 during such time as the end is not applied against the On the contrary, as soon as the outer cylindrical portion 15 of the cam 13 ceases to be operative and the inner cylindrical portion 16 comes before the roller 17 this latter may fall and, under the action of the spring-22, the cylinder 6 moves upward and-its end,.9 is applied in,a fluidtight manner against the mouthxlisece 10.- T e piston 5 on completing its char stroke, discharges the oil contained in t e chamber 25 through the delivery orifice i 11. It will be readiy understood that by va-- rying the amplitude of-the portion of the stroke of the piston 5 during which the endv 9 is held apphed'against the seat 10, the output of the pum be varied by reason of the fact that t e length of the useful discharge stroke of said piston5 is varied. In the, example shown in Figs. 1 and 2, this result is obtained by 10 tudinally shifting the cam 13 over thesha 8. Depending on the longitudinal position occupied by this cam relative to the roller 17, th1s latter will a longer orshorter interval of time de ing on the length-of the outer cylin 'cal portion 15, said length varying according to the different .t'ransversesections of the cam 13. This latter is shifted longitudinallggy means of an oscillating arm 26 driven 111 without, the cam 13 being mounted on lfiys 27, which allow of its being, longitudin shifted but which constrain 1t to rotate wit 4 the shaft 8.

In the'exampleshown in Fig. 3, the cam fixed and the roller-'17 is adapte this end, its upper end can ivot relativeto the correspondi end 0 the rocking lever 19 and t 's pivoting action is con trolled by the l'nk mechanism 28 actuated from without. Inorder that the roller 17 shall always lie perpendicular to the surface of the cam 13, this latter is slightly curved, the centre of the curvature being-13o its upper-positiondurinf louf preferably near the point about which rotates the roller 17.

An alternative form of construction of the transmission. means interposed between the cam 13 and the cylinder 6 is shown in Fig. 4. According to this alternative, the spring 22 constantly tends to bring the cylinder 6 back into its lower position whilst the rocking lever 19 acts on said. cylinder to apply its end 9 against the mouthpiece 10. In this case, the roove of the cam 13 is replaced by a pro ection of similar shape, that is to say, said projection is bounded in one direction by a generatrix, and in the other direction by a hclicoidal slope. In order to give a certain amount of flexibility to the movement transmitting means, thanks to which the end 9 of the cylinder 6 will always be applied in a fluid-tight manner against the mouthpiece 10, the rod 18 controls the rocking lever 19 through the medium of a spring 30.

It will be remarked that the membrane 23, by reason of its reciprocating motion caused by the displacement of the c linder-6, produces a suction effect which f the ingress of the liquid into the reservoir 3. However, in certain cases, this membrane could be replaced by an ordinary stufiingbox 31, as is the case in Fig. 4. I

The pump according to the invention is particularly adapted for use in feeding internal combustion engines. Considerable advantages accrue from the use of this pump by reason of the fact that the cylinder being positively driven, contrary to the arrangements known heretofore, the said cylinder will always effect its displacement in the desired condition however worn the parts may be. Furthermore, the output of the pump can be very accurately controlled.

Of course, the invention is applicable to the case of multi-cylinder pumps, as shown in Fig. 7 In this case, the eccentrics 7 are keyedon a single driving shaft 8, and the cams 13 are keyed on a parallel shaft8 driven by the shaft 8 by means of the gears 32. The control of the output of the various pumps is obtained by displacing-the shaft 8 longitudinally.

It isevident that the invention has only been described and illustrated in a purely explanatory but by no means limitative manner and that it could be subjected to various modifications in its details without departing from the spirit thereof.

I claim:

1. In a fluid discharging pump, the combination of a cylinder plunging in the liquid to be pumped, a d'ischargepipe in alignment with the axis of said cylinder, said cylinder being displaceable into and out of contact with the edge of the orificeof said discharge pipe, a plunger reciprocating in said cylinder, said plunger discharging fluid acilitates through said discharge orifice when said cylinder contacts'with the edge of said orifice, means fordisplacing said cylinder independently of said plunger, and means, operable both when the pump is stationary and when it is working, for varying the instant at which said cylinder is brought into contact with the edge of said discharge orifice during the discharge stroke of said plunger.

2. In a fluid discharging pump, the combination of a cylinder plunging in the liquid to be pumped, a discharge pipe in alignment with the axis of said cylinder, said cylinder being displaceable into and out of contact. with the edge of the orifice of said dis charge pipe, a plunger reciprocating in said cylinder, said plunger discharging fluid through said discharge orifice when said cylinder contacts with the edge of said orifice, an elongate cylindrical cam having two con centric cylindrical faces connected 'by a generatrix and a helical slope, means for rotating said cam in synchronism with said reciprocating plunger, means, including a roller ridingon the surface of said cam, for displacing said cylinder as said roller passes from one of said cylindrical cam faces to the other, and means for varying the relative positions of said cam and roller axially of said cam wherebythe instants of rise and pipe, 2. plunger reciprocating in said cylinder, said plunger discharging fluid through said discharge orifice when said cylinder contacts with the edge of said orifice, means for displacing said cylinder independently of said plunger, and means, operable both when the pump is stationary and when it is working, for varying both the. instant at which said cylinder is brought into contact with the edge of said discharge orifice during the discharge stroke of said plunger and the time durin which said c linder remains in contact with said edge 0 said discharge orifice.

,4. In a fluid discharging pump, the com-- bination of a cylinder plunging in the liquid to be pumped, a discharge pipe inalignment with the axis of said cylinder, said cylinder being displaceable into and out of contact with the edge of the orifice of said discharge pipe, a plunger reciprocatin in said cylinder, said plunger discharging uid through said discharge orifice when said cylan elongate cam the profile of which varies along its length, means for rotating said cam in synchronism with said reciprocating plunger, means, including a roller riding on the surface of said cam, for displacing said cylinder, and means for varying the relative positions of said cam and roller axially of said cam, whereby the instants of rise and fall of said roller are varied and hence both the instant at which said cylinder makes contact with the edge of said dischar e orifice during the discharge stroke 0 said I plunger and also the duration of said coniloms HENRI LIBERT BELLEM.

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