US2351908A - High-pressure pump - Google Patents

Description

June 20, 1944. BEEH 2,351,908

HIGH-PRESSURE PUMP FiledSept. 18, 1942 5 Sheets-Sheet l ATTORNEY lJune 20, 1944. 1 BEEH HIGH-PRESSURE PUMP 5 Sheets-Sheet 2 Flled Sept. 18, 1942 INVENTOR. 22 A l/ls /BEE/L/ BY fm1 JT M TTORNY June 20, 1944. L BEEH HIGH-PRESSURE PUMP Filed sept. 18, 1942.

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Filed Sept. 18, 1942 L. BEEH HIGH-PRESSURE PUMP 5 Sheets-Sheet 4 June 20, 1944.

L. BEEH 'HIGH-PRESSURE PUMP Filed Sept. 18, 1942 5 Sheets-Sheet 5 [ou/5 (BEEH Y aan fm 4 TToR/VEY Patented June 20, 1944 UNITED STATES PATENT' oFFlcE@ 2,351,908 HIGH-PRESSURE PUMP I Louis Beeh, Long Meadow, Mass.

Application September 18, 1942, Serial No. 458,804

, 19 Claims.

The present invention relates to high pressure pumps for various purposes as, e. g. for supplying i fuel under high pressure to injection-fed internal combustion engines. In' certain conventional pumps of the type herein consideration, metered quantities of a fluid medium are supplied by one plunger, in a predetermined cycle, to a plurality of units such as the cylinders of an internal combustion engine where the consumption of the medium takes place. Pumps for this purpose, in general, are provided with delivery ports and also with means for by-passing excess part quantities, the pump space containing the entrapped iluid from which, per each cycle, the various cylinders of an engine or other units are supplied. Both said ports and by-passing means are controlled by a reciprocating plunger. The minute quantities to be metered in such pumps require extreme accuracy of the measuring devices, viz. the grooves, edges and the like of the plunger controlling the various ports in the pump barrel. Such extreme accuracy is dillicult to obtain because not only the opening and closing of each delivery port must be exactly timed but also the correct timing must be insured with respect to the different delivery ports in relation to each other and to the by-pass ports. Even if owing to excellent workmanship the required accuracy has been originally obtained, wear of the controlling edges of the cooperating metering elements will occur after a relatively short time of operation, owing to the effect of the huid current passing the controlling organs under high pressure, which may reach many thousands of pounds, as necessary in connection with Diesel engines. The result of such wear will be an increase of the 'by-passed portion of the entrapped quantity and,

tion and accessibility of parts, the invention also consists of a particular combination and arrangement of the various elements.

It is, a coincidental advantage `of theA pump having the aforementioned features that a larger amount of individual units such as the cylinders of an engine can be supplied by it with a plunger trating several embodiments thereof by way of example. In the drawings,

Fig. 1 is a top plan view of a pump according to the invention.

Fig. 2 is a cross-section Aalong line 2--2 of Fig. 1.

Figs. 3 and 4 are cross-sections along lines 3-3 and 4 1, respectively, of Fig. 2.

Fig. '5a. is a cross-section of the plunger grooves, and Fig. 5b is a diagrammatic illustration of the relative position of the control grooves andthe delivery ports at various positions of the plunger.

Figs. 6a, 6b and 7a, 7b are illustrations of modiiled groove and port arrangements.

Figs. 8a to d are sections of diierently shaped control grooves of the plunger of the pump.

Fig. 9 is a longitudinal cross-section, similar to Fig. 2, of another embodiment of the invention.

Fig. 10 is.a longitudinal cross-section of the drive9 of plunger andJ barrel at 90 in relation to Fig.

Fig. 11 is a diagrammatic development of the barrel of the embodiment of Fig. 9, showing the arrangement of the delivery ports andthe cooperating control groove of the plunger in Fig. 10.

Fig. 12 is a cross-section of a portion of the plunger with control groove.

Figs. 13a, b and c are front elevations of different forms of the control groove.

Fig. 14 is a front plan view of the top of a modified barrel with its guide element in section.

Fig. 15 is a front plan view of the foot part of ai modified barrel with surrounding parts in sec- Fig. 16 is a longitudinal cross-section of a third embodiment, the driving elements being omitted.

Fig. 17 is a cross-section of the plunger along une n n of Fig. 16. c

Fig. 18 is a diagram showing the relative movement of the plunger in barrel of Fig. 16, in a manner similar to that of Fig. 11.k

Referring now to the drawings, Figs. 1 and 2, thev illustrated embodiment comprises a `.main

body l of substantially cylindrical circumference. Body I is supported by a foot structure 2 provided, in its upper surface, with a circular recess 3 into which body I engages with a bottom flange 4. The parts, thus axially centered. aresecured to each other by means such as screw bolts indicated at 5 in Fig. l. A hollow shell 8 engages a deep recess 1 in the central portion of the top surface 8 of body I and bears on said surface with a flange 9. It is releasably secured to body I by means of bolts I0. 'I'he interior of the shell 6 and recess 1 constitute a primary chamber II for the fluid medium, such as a fuel or a lubricant or even a gaseous medium, depending on the purpose for which the pump is intended to be used. The top of shell 8 is shaped at I2 for the attachment of a pipe I3 to convey fluid from a storage tank (not shown) to the chamber I I.

same inner diameter throughout its entire length except for the lower end portion I6 which is `wider for a purpose to be explained hereinafter.

Intermediate its ends, the barrel forms a peripherally projecting shoulder I1 with which it bears on the bottom surface I8 of recess 1, so that its top portion projects into the chamber II 'I'he lower barrel end projecting from the bottom of body I is externally screw-threaded at I9, and a nut 20 is screwed on such thread so as to secure the barrel to the body I A plunger 2I is arranged in the barrel I5 so as to be reciprocated therein by a cam drive housed within the foot structure 2 in which a shaft 22 is journaled The shaft carries a cam 23 which cooperates with a roller 24 of a tappet 25. The latter has plane faces 28 in engagement with plane guiding faces 21 of an internal projection 28 of the foot structure. In this manner, the parallelism of the axle 29 of the tappet roller 24 with the cam shaft 22 is insured. The tappet has an upper cylindrical projection 38 in engagement with a bore 3I in the lower end of the plunger 2l so as to constitute a thrust bearing and pivot for the plunger which may be turned whereas the tappet is prevented from turning by the guiding faces 21. In the top end of the plunger, a small thrust bearing 32 is embedded, which supports a rod 33 extending up ward into the chamber II. The upper end of the rod carries a cup-shaped part 34 with a flange 35, and a compression spring 36 bears with its one end on said ange 35 and with its other end against the inner top surface' 31 of shell 8. Thus, the plunger 2I can be raised by cam 23 and' lowered by the return spring 36. l

Means are provided to create in the pump a compression chamber in which a predetermined pressure may not be materially exceeded. For this purpose, the barrel-top is closed by an auxiliary plunger 38 with an axial bore 39 through which the rod 33 is passed so as to slide freely therein. 'I'he length of the auxiliary plunger is preferably greater than the stroke of the main plunger 2|. Its head is provided with a flange 49 which in its lowest position abuts against the top rim 4I of barrel I5,so that the auxiliary plunger cannot interfere with the movement of the main plunger 2|. The flange 40 supports a strong compression spring 42 which bears with its other end against the face 31 of the shell 8 and encompasses the aforementioned spring 36. 'I'he compression chamber 43 thus formed in the barrel between the plungers 2l and 38 can communicate with chamber II through a conduit or inlet port 44 in the barrel wall when the plunger 2| is in its lowest position. The two chambers will be disconnected as soon as the upper edge 45 of plunger 2I in the beginning of its upward stroke has passed the inlet port 44, and the quantity of fluid in chamber 43 will then be entrapped between the plungers 2| and 38.

Means are provided to deliver part quantities of the entrapped uid under compression to a plurality of places of consumption in a predetermined sequence and ln metered amounts dursng each cycle of operation of the pump. For this purpose, plunger 2I has a central bore 48 reaching from the top to a transverse bore or slot 41, and an inclined branch 48 laterally of the thrust bearing 32 insures permanent communication of the slot 41 with the chamber 43. A plurality of delivery ports, six in the present embodiment, denoted 49, 50, 5I, 52, 53, and 54, are provided in the wall of the barrel I5. They are so arranged in two opposite axial rows and in staggered relationship that the slot 41 is below the lowest delivery port 49 at the beginning and above the highest delivery port 54 at the end of the upward stroke of plunger 2I, and that the slot passes one of the ports after the other during each stroke. For reasons to be explained hereinafter, I prefer in certain instances to provide in plunger 2I a second transverse slot 55 which is so positioned as to register with the supply port 44 when the plunger is in its topmost position. Each of the delivery ports opens into a delivery conduit in body I. Only two of these conduits, 58 and 51, are visible in Fig. 2 in connection with the ports 53 and 54, respectively. The other conduits 56', 59", 51', and 51" appear in Fig. 3. Each of these conduits is connected by a peripheral groove with its associated delivery port, as e. g. conduit 56" is connected by groove 49" to the delivery port 49.

It will be clear that the quantity of fluid delivered into each delivery conduit per cycle ,will depend on the pressure prevailing in chamber 43, on the resistances owing to the cross-sections of the various ports and conduits, and on the time during which the transverse control slot 41 passes the individual delivery ports, that means, on the shape of the c am 23 for a given R. P. M. of the latter. It is by no means necessary that the quantities delivered through the ports 49 to 54 are equal to each other as it should be if the pump according to the invention is used as a fuel pump for a multiple cylinder engine. If, e. g., the pump is intended to supply a lubricant to various bearings the quantity delivered through the one of the ports 49 to 54 may differ from the other one as required, owing to either the shape of the cam causing the slot 41 to pass the ports with different speed or owing to differences in the dimensions of the ports. It is also clear that both measures may be Itaken at the same time.

Now, in order to vary the vquantity of fluid delivered through each delivery port, it is a known expedient to make the plunger turnable so that different portions of accordingly formed control edges of a plunger recess may come into registry with the delivery ports. The present invention accomplishes this object with other and particularly simple means. It has been stated that plunger 2I can be turned about its axis with the tappet projection 30 as pivot. In order to cause turning of the plunger, the lower portion of the latter is provided with gear teeth 58 which mesh with a rack 59 guided at 80 in the foot structure 2 and projecting therefrom with its end 6|, so that by shifting the rack between two abutments (not shown) the plunger will be adjusted in angular relation about its axis. The widening I6 of the barrel 2| permits the teeth 58 to enter therein during the reciprocating axial movement of the plunger. Turning of the plunger 2| in the indicated manner changes the quantity of uid delivered with the aid of grooves of varying crosssections which are provided on the periphery of the plunger and in communication with the transverse bore or slot 41 as shown in Fig. 5a which is a cross-section of the plunger 2| on the level of the bore of slot 41. It will be seen that the ends of the slot 41 open into peripheral grooves 62 and 63, respectively. Both grooves extend equal arcs in the same anti-clockwise direction and are of gradually decreasing depth. The number of grooves is equal to that of the axial rows in -which delivery ports 49 to 54 are arranged. Fig. 5b shows the delivery ports 49 to 54 in their rela-` tive positions if the inner barrel surface is developed, the one row being formed by ports 49, 5|, and 53 and the other one by ports 50, 52, and 54. The piston grooves 62 and 63 appear in solid lines below the port 49 which position corresponds to the lowest position of the plunger 2|. When the plunger starts its upward stroke, groove 63 is first lifted to the level of port 49 while groove 62 is still below port 56. In the next stepthe different steps being indicated by dash lines of the grooves-groove 62 is in registry with port 50 whereas groove 63 is between ports 49 and 5|. Thus the grooves alternatingly communicate the one with one of the ports of the odd-numbered row, and the other one with one of the ports of the even-numbered row until, finally in the topmost position, both grooves are above port 54. In the illustrated relationship of ports and grooves, the grooves will arrive with their widest portion in front of the ports so that the resistance to iiow is a minimum and, consequently, the delivered quantity a maximum. If now, the

plunger is turned in a clockwise direction in Fig.

5a, it will be clear that narrower cross-sections of the grooves will be positioned in line with the rows of delivery ports with the effect that a smaller quantity of fluid will be supplied to the delivery ports during the passage of the grooves in the course of a plunger stroke.

Although the arrangement of the ports and grooves just described is the preferred one, others are of course possible. Figs. 6a. Vand b illustrate the arrangement of the delivery ports summarily denoted by- 64 in one axial row. In this event the transverse slot of the plunger requires only one radial branch 65 with one peripheral groove 66. In Figs. '7a and b, on the other`hand, the ports 61 are arranged in three axial rows which require three radial slots 68 and three communicating grooves 69 in the plunger. Comparing the different arrangements it will be seen that an increase of the number of axial rows over which the ports are distributed permits a wider spacing of the ports in the same row, and consequently, reduces the danger of leakage between an open and a subsequent closed port without requiring an increase of the length of the plunger stroke. On the other hand, an increase of the number of rows reduces the arc available for the length of each plunger groove, and consequently, de-A creases the possible flneness of quantity adjustment. For this reason the arrangement of Figs. 5a and b is the preferred one.

The control grooves of the plunger may have any desired and suitable shape so as to meet the requirements of a particular engine. This is exemplified in Fig. 8 showing four different groove with the radial slot 65 in its center from which the groove decreases in width towards both ends. Hence by turning a plunger provided with such a. groove beginning from one end position. the quantity of Huid supplied to each delivery port will first be a minimum, and drop down again to a minimum. Such groove is suited e. g. in fuel pumps for certain engines which requireless fuel at top speed than at normal speed. The groove 12 of Fig. 8c is similar to groove 1|. It differs from the latter in that it is directly connected with the bore 46 of the plunger.' In other words, the radial slot present in Figs. 8a and 8b is combined with the groove. Furthermore, the portion 13 of groove 12 on the one side of the widest groove cross-section is shorter than the portion 14 on the other side. Consequently, in the range of portion 13 a greater change of the quantity of delivered fluid is obtained by a given angle of turn of the plunger than in the range of the portion 14. The groove 15 of Fig. 8d nally accomplishes quantity control according to still another law which will be apparent if the change of the groove cross-section from the one to the other end is observed. Although for 5a`and b and 7a. and b may be'shaped in accordance with similar principles.

Means are provided in the Dump according to the invention to relieve the line between the place of fluid consumption and the pump from pressure after each closing of a delivery port in order to avoid certain irregularities which otherwise might occur in the feeding of a machine to which the pump is connected. It is essential from the viewpoint of the present invention that such line pressure relief and the by-passing of fluid required for that purpose is accomplished without reaction on the entrapped quantity of uid from which the delivery ports are supplied. Various ways are possible in order to attain this object, and the illustrated embodiments show preferred examples in this respect. In the embodiment of Figs. 1 and 2 combined delivery and relief valves are used for this purpose, in connection with the delivery conduits in body c The valves being alike in structure, the description will be limited to the valve 16 in connection with conduit 51 and will be given only as far as necessary in order to explain the function of the valve in the present case. For more complete description of the valve reference is made to my co-pending application filed simultaneously herewith and entitled Delivery valve.

Valve 16 comprises an externally threaded body 11 screwed into a cylindrical recess 18 of body so that it seats tightly on the bottom surface 19 of the recess into the center of which conduit 51 opens. An annular space 80 is free between the lower portion of the valve and the wall of the recess 18. The valve body 11 has an axial bore 8| through part of its length from the bottom upwards and with a top extension 82 of reduced diameter, Body 11 is further provided ywith a lateral channel 88 which is closed at the bottom by the surface 19 and opens at the top in an axial projection 84 of the body 11, suitably shaped for the attachment of a pipe line (not shown) leading to the place of consumption of the iiuid from delivery port 54. Two transverse passages 85 and 86, at different levels above surface 19, connect bore 8| and channel 83. Another bore 81 connects the topmost end of the extension 82 with space 88, and a passage 88 in pump body I leads from space 80 into chamber Il. A plunger poppet 89 movable in bore 8| has a rod-like extension 98 which fits slidingly into the bore 82. A spring 9| surrounds rod 90 in bore 8| serving as the spring housing, and tends to urge the poppet 89 to seat on surface 19 so as to close the conduit 51. The lower edge of the -poppet 89 is chamfered so that there is a small annular space 92 of triangular cross-section between the chamfer and the wall of bore 8| when the poppet is on its seat. A bore 93 through the poppet and rod 98 connects the space 92 with the bore extension 82. However, the arrangement is such that with the poppet in its topmost position, the end of the rod 90 bears against the top surface 94 of bore 82 so as to close the top opening of bore 93. Simultaneously, the lateral portion of the top end of the rod closes the opening of bore 81 where it communicates with bore 82. The poppet has furthermore, two control edges 95 and 95. Edge 95 being formed by the aforementioned chamfer is located intermediate passage 85 and surface 19l, and edge 96 being the upper edge of the plunger portion of the poppet, is just below passage 85 when the poppet is seated on surface 19.

The operation of the valve will be explained in connection with the following description of the operation of the pump, wherein it is assumed that the pump is used for injection feeding of a six-cylinder engine. In that event, the projections 84 of the six valves 16 wil1 be connected by pipe lines (not shown) to the injectors of the six engine cylinders in the sequence of their working, and pipe I3 will be connected to a, storage tank from which the chamber 'Il is lled with fuel, preferably under pressure. In the position of Fig. 2 plunger 2| is at the end of its downward stroke so that chamber 43 is filled with fuel entering through port 44. With cam 23 rotating in the direction of the arrow, the plunger will be rapidly lifted in the first part of its upward stroke so as to close port 44 immediatelyl and to build up the desired pressure on the fuel entrapped in chamber 43 against the restraint of the spring 42 bearing on the auxiliary plunger 38. While the plunger 2| continues its stroke the peripheral grooves at the ends of the transverse slot 41 will pass the delivery ports 49 to 54 one after the other, and while one of the grooves is in registry with one of the ports a part of the quantity of fuel entrapped in chamber 43 will be urged through bores 48 and 48, slot 41, and the pertaining groove and port into the associated delivery conduit. Owing to the effect of auxiliary plunger 38 and spring 42 the pressure will remain approximately constant and will be substantially equal for all the part quantities delivered to the six conduits. When fuel is thus forced into one of the delivery conduits, e. g. conduit 51, the pressure acts on the poppet 89 so as to lift it from its seat against the restraint of spring 9| and to press the top end of the rod 98 against the surface 94. While this happens the poppet will rst have decreased the volumetric capacity of spring housing 8| and will have expelled some of the contents of housing 8| into passage 83, that is to say, into the line attached to the valve at 84, until the edge 96 has closed passage 86. Immediately thereafter, the edge 95 will open the passage 85 so thatthe fuel can flow from conduit 51 through space 92 and passage 85 into the attached line. Simultaneously, pressure will be built up in housing 8|. This condition will prevail as long as the flow through the valve continues, i. e. during the period of dynamic fuel pressure. When, however, the plunger groove 82 has passed port 54, the pressure under the valve poppet becomes static so that the combined force of spring 9| and the pressure in housing 8l predominates with the result that the end of the rod 90 separates from surface 94 and thereby opens the top end of bore 93 and also the connection between bores 81 and 82. This establishes a by-pass from conduit 51 through space 92, bores 93, 82. 81, space and passage 88 to chamber Simultaneously, line pressure relief occurs via bore 83 and passage 85 into the space 92 and from there to chamber in'the same way as just explained. During this time, there is still high pressure prevailing in chamber 8|. 'I'his pressure is helpful in bringing the poppet back to its seat. During that part of the movement of the poppet, rst passage 85 wil1 be closed and then passage 88 opened so that the residual line pressure loads the poppet in addition to the force of spring 9|, thereby causing a fast action of the poppet and a rapid decrease of the residual line pressure due to the increase in volumetric capacity of the spring housing 8| when the poppet moves towards its seat. Thus it will be clear that all by-passing and line pressure relief occurs with the aid of valve 18 at the time when delivery port 54 is closed, separately from and without reaction on the fuel entrapped in chamber 43.

Chamber 43 is so dimensioned that there is stil1 some fuel left in the chamber when the plunger reaches its topmost position. This is done to insure that there is a sufficient quantity originally available to supply all the delivery ports 49 to 54 each with the desired quantity of fuel. When the plunger has reached the top end of its upward stroke, further rotation of the cam 23 causes a very rapid downward stroke, owing to the force of the spring 36 acting on the plunger through the intermediary of parts 33 to 35. A vacuum is thereby created in chamber 43 which will be filled again with fuel as soon as the plunger near the end of the downward stroke opens the port 44. When chamber 43 is completely lled and the plunger has reached its lowermost position, the cycle is completed.

It has been stated hereinbefore that another transverse slot 55 may be provided to communicate with port 44 when the plunger is in its topmost position. The provision of this slot is advisable in certain cases for the following reason. If an engine fed by the pump according to the invention vis temporarily operating under conditions where only very little fuel is consumed, chamber 43 will still contain a large quantity at the end of the upward stroke, and the auxiliary plunger 38 will be lifted high above its seat 4|. In consequence, the fuel remaining in chamber 43, in the absence of slot 55, will be under pressure ofthe auxiliary plunger 38 loaded by springy 42, during a part of the stroke equal to the lift offthe auxiliary plunger above its seat. When, now, during the downward stroke of the main plunger 2|, slot 41 passes one of the delivery ports, fuel injection will occur at a time when such injection would interfere with the smooth operation of the engine.

The transverse slot 55 prevents such happening. As soon as this slot comes into registry with port 44 at the end of the upward stroke of the plunger 2|, the fuel remaining in chamber 43 will b e expelled therefrom by auxiliary plunger 38 via the bores 48 and 46, slot 55 and port 44 into the chamber When, then, at the beginning of the downward stroke, port 44 is closed, auxiliary plunger 38 will be on its seat and chamber 43 will be practically empty and free from internal pressure. Immediately thereafter, a vacuum will be created in the chamber 43, so that no delivery to one of the ports 49 to 54 can occur, but that fuel from chamber can rush in through port 44 at the end of the downward stroke. It is obvious that slot 55 should be so formed that communication with port 44 can be obtained regardless of the turning of plunger 2| for the purpose of the quantity control hereinbefore described.

In the pump according to my invention hereinbefore described, the required length of the plunger stroke is equal to the sum of the widths, on the inner barre1 surface, of the ports 49 to 54 and of the slot 41 plus the spacing necessary between, above and below the ports in order to insure the required tightness. No other ports are present which need be considered since by-passing and pressure relief are separate from the pump chamber 43 and not directly controlled by the plunger, although dependent on the plunger movement owing to the diilerences in pressure occurring in the individual delivery conduits on account of the opening and closing of the ports 49 to 54. In other words, there is a certain timed relationship between by-passing and plunger movement, which, however, does not require an additional length of plunger stroke for its control. This fact, and furthermore, the fact that the minute quantities to be dealt with per each cycle require only very narrow ports, and nally, the particular arrangement of the ports in stagger and in cooperation with the plunger grooves of particular form, al1 these contribute to the eifect that the stroke of the plunger in a pump according to the invention can be very short, or that the number of ports served by a plunger having a given length of stroke can be relatively large. This is advantageous, -on the one hand in view of the' short time generally available for each cycle, and on the other hand in view of the desirability of saving pump units if a great number of places of consumption are to be supplied. The pump just described oifers the further advantage that the parts of the pump are simple in design, and that nothwithstanding the provision of means-for bypassing and quantity control, there is practically only one controlling element, namely, the groove of slot 41, which requires a high grade of laccuracy in the making of the plunger, so that the production is facilitated in relation to Dumps of the conventional type. In this respect, the structural feature of a plunger pivoted on a non-rotatably guided tappet and in direct engagement with a rack for its adjustment to accomplish quantity control is considered as particularly valfiedowing to the free raccessibility of the springs and the auxiliary plunger after the removal of onlythe shell 8. Y v

It has been stated hereinbefore, that the present invention contemplates means whereby the number of ports can be further increased without increasing also the length of the plunger stroke, or conversely whereby the plunger stroke can be shortened for the same number of delivery`ports. This can be accomplished according to the invention by a plunger which rotates about its axis while it simultaneously reciprocates in axial direction. The second embodiment illustrated in Figs. 9 to 15 shows these novel features and also illustrates novel means for quantity and timing control. The general structure of this pump is similar to that of Figs. 1 and 2 in many respects.

In order to facilitate the comparison, parts of the second embodiment similar to analogous parts of the first one are denoted with reference characters higher by 100 than those of the first embodiment, whereas basically differing parts have reference numerals in the 200 range. Furthermore, the descriptionof similar parts will not be repeated except as far as necessary for the understanding of the structure and its function.

A body |0| is supported by a foot structure |02 with a recess |03 in its top, and a shell |06 engages recess |01 of body |0| and is carried by the latters top surface |08. The interior of the shell together with recess |01 constitutes the primary fluid chamber with inlet at ||3, and houses the return spring |36 for the positively actuated plunger |2| and spring |42 loading the auxiliary plunger |38. The body |0| is provided with a bore ||4 in which barrel ||5 is axially movable for a purpose to be explained hereinafter. In order to accomplish shifting of the barrel, its lower end portion, projecting from the bottom of body |0I, is provided with an external, square-grooved screw threading 20| engaging the threading of a nut 202. The nut has gear teeth 203 on its periphery and a peripheral groove 204 underneath its top face which bears against the bottom of body |0| A bi-partite anchor ring 205 is secured by means such as screws 205 to the bottom off body |0| and engages said groove 204, whereas a rack |59 engages the nut teeth 203. Rack |59 is' arranged in a manner similar to rack 59 ciA the first embodiment, with the difference, however, that it serves to cause shifting of the barrel ||5 while the rack 59 of the rst embodiment causes turning of the plunger 2|. In order to prevent the barrel from turning when the rack |59 is actuated the top end of the barrel is provided with longitudinal grooves 201, engaged by inner projectlons 208 of a ring 209 which is secured by means not sho'wn to the bottom face ||8 of the body recess |01. Ring 209 has a tubular upward extension 2 I0 encompassing the top portion of the barrel and serving as abutment for auxiliary plunger head |40 in its lowest position. In this manner it is insured that movement of the auxiliary plunger |38 in barrel ||5 does not interfere uable. Also, the servicing of the pump is simpliwith the shifting of the latter. Now it will be clear that actuation of rack |59 will turn nut 202 so as to raise or lower the barrel ||5, which is prevented by ring 209 from moving in another than axial direction, 'I'he barrel ||5 is provided in the present instance with six delivery ports |49 to |54 and an inlet port |44 the arrangement of which will be described hereinafter, and each of the delivery ports is in registry with an associated delivery conduit two of which, |56 and |51, are visible in Fig. 9. Each conduit leads to a relief valve |18 of the same type as valves 16 in Fig. 2, and a passage |30 connects the ring space between body |0| and the lower portion oi' the valve with the primary fluid chamber Underneath ring 209 there is an annular space 2| I surrounding barrel ||5 and in communication on the one hand with chamber by way of a groove 2|2 and on the other hand with inlet port |44 by way of a groove 2 I3. the latter being long enough to maintain its connection with port 44 in any position of the barrel. Plunger I2| movable in barrel ||5 underneath auxiliary plunger |30 is loaded on its top by return spring |33 with the intermediary of the parts |32, |33 and |34. It is provided with an axial bore |45 and with a longitudinal, or rather, a slanting groove 2|4 in its outer surface. Close to its lower end, bore |43 communicates with a supply port |41, destined to supply fluid from bore |43 to the delivery ports |49 to |54. Groove 2|4 extends from the top oi' plunger |2I, that means, from the compression chamber |43 between both plungers at least so far downward that its lower end is on the same level as inlet port |44 when both barrel and plunger are in their lowest positions. A transverse passage 2|5 connects groove 2| 4 with bore |46 so that there is permanent commimication between port |41 and chamber |43 and intermittent communication between chamber |43 and chamber The drive of plunger |2| illustrated in Figs. 9 and comprises means for causing reciprocating movement in axial direction and simultaneously operating means for rotating the plunger. The means for reciprocating the plunger are similar to those of the first embodiment. A cam shaft |22 is journaled in ball bearings 2|5 and 2|1 mounted in the foot structure |02. A cam |23 on said shaft cooperates with a roller |24 whose axle is journaled in a tappet |25, the latter being guided between plane faces |25 of the structure |02 so as to be prevented from turning. A pivot pin extension |30 of the tappet engages in a bore |3| of the lower end of the plunger. The latter has a foot flange 2|0 embodying the upper race of a ball thrust bearing 2|9 whose lower race 20 is constituted by the top face of the tappet. |25. Thus, rotation of the cam shaft |22 by external means will cause the plunger to be lifted to the position shown in Figs. 9 and l0 against the restraint of spring |35, and the latter will force the plunger |2| downward when the roller |24 engages the steep decline 232 of the cam upon further rotation of the shaft. In order to rotate the plunger during reciprocation, a gear wheel 22| keyed to shaft |22 is in mesh with a gear wheel 222 which is connected for common rotation with a miter Wheel 223. The latter is journaled on a bushing 224 secured to the foot structure by a bolt 225, and meshes with a second miter wheel 226 held in its position between the lower surface of nut 202 and a bearing surface 221 provided on a part of the foot structure |02. The plunger |2| is connected to miter wheel 22B by long splines 228 so that it will be taken along when the latter rotates but can move in relation thereto in axial direction. In order to give sumcient freedom for the axial movement of the ,splined portion of the plunger, the lower portion ||6 of the barrel bore has a larger diameter than the upper part. The transmission ratio of the gear and miter wheels will generally be such that the plunger completes one revolution during the time of one cycle of reciprocation. However, extraordinary arrangements of the various Ports of barrel and plunger are conceivable which may require a dineret transmission ratio.

The arrangements of the various ports is shown in Fig. 11 in a diagrammatic development of the inner surface of barrel ||5 with the slots and groove of the plunger |2| superimposed thereon in dinerent positions. In order to distinguish them from each other, solid lines are used in connection with the barrel and dash-lines are used in connection with the plunger. The figure shows the total width of the inner barrel surface. meaning that in the actual cylindrical shape the two lines :r and :c coincide. The six delivery ports |43 to |54 appear on an inclined line equally spaced from each other. The port |54' on the left side of line z is a repetition of port |54 in order to show a complete cycle of movements which will be described with reference to Fig. 11. The inlet port |44 is vertically above port I5| and on a level slightly higher than that of port |54. However, it will be understood that the relative position of port |44 to the other ports can be freely selected provided that no part ofthe plunger groove 2|4 periodically communicating with port |44 communicates with any one of the other ports during the plunger movement. From Figs. 9 and l2, the latter being a vertical cross-section of a portion of plunger |2|. it will be clear that the port |41 has an upward extension 230 of 'tion of port |41 shown in Fig. 13a has a substantially triangular shape, so that the cross-section of the passage through the plunger wall decreases from a maximum. to zero considering various levels upward from the inner port center. Port |41 is shown, in Fig. 11, in various of its positions, a, b, c, d, e, in relation to the delivery ports |43 to |54. Such relative positions will occur when the plunger is rotated in the direction of the arrow Z and, simultaneously reciprocated under the action of the cam |23. Similarly, the positions of plunger groove` 2|4 in relation to the barrel inlet port-i 44 are shown as they occur coincidentally with the illustrated positions of port |41, and the coordinate positions are denoted with the same reference letter, meaning that when port |41 is in the position a in which it registers with port |54, the top end of groove 2| 4 and the top face of the plunger |2| will be in the position a" and the bottom end of the groove will be in the position a'. 'I'he dotted line R, finally, indicates the path on which the center of port |41 will move in relation to the ports |49 to |54 during one complete cycle owing to the uniform rotation of the plunger and its simultaneous re- 'ciprocation according to the shape of cam |23 shown in Fig. 9. Following now one complete cycle from the position of Fig. 9, the port |41 is in registry with barrel port |54 so that iluid in the manner described in connection with the first embodiment is delivered to valve |15 via conduit |51. The plunger |2| is in its topmost position with roller |24 on the peak 23| of cam |23. This is the position indicated by a in Fig. 11 and it will be noticed that groove 2|4 with its end a' is far above the barrel inlet port |44. A short period follows in which there is practically no axial movement of the plunger, in which, however, the plunger |2| continues to rotate, while the auxiliary plunger |33 lifted from its seat |4| continues to force fluid through ports |41 and |54, unti1 the one has passed the other owing to the rotation of plunger |2|. Immediately thereafter, the plunger |2| with roller |24 on the decline 232 of cam |23 drops abruptly, in consequence whereof the volumetric capacity of chamber |43 will be increased so that auxiliary plunger |38 is restored to its seat and a. vacuum created in chamber |43. When during that drop the port |41 has reached its position b. plunger groove 2|4 is turned and lowered so that its end in position b' is in registry with port |44 and that iiuid from chamber can enter chamber |43. Owing to the inclined arrangement of groove 2| 4 as clearly shown in Fig. 1l registry is maintained while the plunger continues its downward stroke until port |41 is in the position c and the lower groove end at c'. Again there is a short period in -which practically no vertical movement occurs, in which, however, the continued rotation separates groove 2I4 from inlet port |44` leaving chamber |43 completely filled to its maximum capacity. Immediately thereafter, the plunger rises on a rather steep portion of cam |23 so as to compress the chamber contents until in the position d registry of port |41 with the lowest delivery port |49 is reached. From there on the peripheral and axial movement of the plunger is substantially uniform so that port |41 in position e passes port |50 and similarly the subsequent ports until with port |41 again in its position a the cycle is completed. It is. of course, possible to make the path R between |49 and |54 other than straight lined, e. g. stepped by applying a cam having a different shape. A cam of such type has been shown in Fig. 2 where the outline of the cam 23 comprises alternating inclined and circular portions. Fig. l1 clearly illustrates the claimed advantage offered by the novel combination of a rotatory and reciprocatory drive of the plunger |2|. Although the barrel ports |49 to |54 are widely spaced from each other, they are extremely close to each other in the vertical projection so that notwithstanding ample security against leakage the plunger stroke can be shortened to a minimum. l

In order to provide for quantity control means are provided to shift the barrel ||5 in an axial direction as hereinbefore described in connection with the threading nut 202, rack |59, grooves 201 and projections 200 of ring 209. Notwithstanding the axial shift of the barrel, the delivery ports stay in communication with their coordinate delivery conduits by grooves extending downwardly from each port on theouter surface of the barrel, so for instance, port |54 whose associated groove 234 maintains the communication with conduit |51 even if the barrel is raised in relation to body 0|. When this happens port |54 will be on a level with a portion of the triangular groove 230 of plunger port |41 when the latter and port |54 come into the same axial plane in the course of the plunger rotation. Such portion of the groove 230, however, offers only a restricted passage to the fluid with the effect that the delivered quantity is reduced; Similarly, the quantity passing the other delivery ports will be decreased at the same rate. Hence, quantity control ycan be attained by actuating rack |59 to adjust the barrel position in the vertical between a maximum prevailing when the barrel port |54 in the illustrated position comes to register with the full cross-section of port |41, to a minimum of zero when port |54 is above the top end of the groove 230. A

Considering the shape of port |41 with groove 230 in Fig. 13a and assuming that rotation of the plunger occurs in the direction of the arrow r in Fig. 13, it will be clear that the vertical, i. e.

right-hand, side will meet each delivery port always at the same point o! time of a cycle no matter what the position of the barrel may be. Consequently, the timing of thebeginning of the feeding remains constant. Contrary thereto, the timing of theend of the feeding will be changed owing to the inclination ofthe left-hand side of the triangle. In fact, feeding will be ended the earlier the higher the barrel is positioned. Hence, the shape of the groove is instrumental in changing the timing as well as Ithe feeding, but not independently from each other. Figs. 13b and c, illustrate by way of example grooves whose cross-section as of Fig. 12 is the same, whose front elevations, however, differ in that the groove 230' of Fig. 13b allows for quantity control without change of timing, whereas groove 230" of Fig. 13e accomplishes quantity control and change of the timing of the beginning of the feeding.

Another means for a combined quantity and timing control is illustrated in Fig. 14v showing the barrel 'top and guide ring in a modified form. In this modification the top of the barrel |l5' is provided with grooves 201 which are arranged in the form of a high pitch helix rather than parallel to the axis as the grooves 201 in Fig. 9. The projections 208' of the ring 209 are shaped so as to engage these grooves. In all other respects the structure is the same as in Fig. 9. Now, it will be clear that raising of the barrel ||5' will cause a simultaneous turning owing to h the nut effect of the projections 208' in engagement with the helical grooves 201'. Consequently, quantity control with the aid of barrel ||5' will be accompanied by an advancing or retarding of the feeding depending on the direction of the threading constituted by the grooves 201'.

If it is desired to accomplish timing control Without quantity control, the grooves 201 at the top end of the barrel and the projections 208 of ring 209 can be dispensed with and the barrel be made so as to be turned by the rack |59 in a manner similar to that of the first embodiment where the rack 59 serves to turn the plunger 2|. Such modification is shown in Fig. 15 in which barrel H5" is provided with a collar 236 bearing against the bottom surface of body |0| and held in position by the bi-partite, recessed ring 231. This ring is secured to body 0| by means of the screws 238 so that the barrel can turn with the collar in the recess 239. The lower end of the barrel is provided with gear teeth 240 which are in mesh with the rack |59, and the miter wheel 226 is positioned between the lower end face of the barrel ||5" and the face v221 of the foot structure |02. In all other essential respects the design of the modified pump is similar to thatl described with reference to Figs. 9 and 10. When the barrel I5" is turned by actuation of the rack |59 the points of the cycle of operation at which the port |41 is in registry with the delivery ports |49 to |54 of the barrel will be shiftedv either backward or forward dependingl on the direction in which the rack is moved. It will be clear, that in that event the grooves in connection with the delivery ports will be arranged in peripheral rather than axial direction as shown at 234' in connection with delivery port |50. Also, the inlet groove of the piston should be formed in accordance with the possible movement of the barrel. This, however, appears so obvious in view of the foregoing description that no additional explanation or illustration is required The embodiment illustrated in Figs. 9 and 10 is 8L preferable to the embodiment of Figs. l and 2,

notwithstanding its more complex drive if the number of ports is relatively high orsif it is imperative to reduce the plunger strokfto: aminiilcing any length of the axial stroke for this purpose.

In the embodiments of my invention hereinbefore described, by-passing and line pressure relief are accomplished with the aid of a valve responsive to differences in pressure occurring in a delivery conduit at or after the end of the feeding'period of such conduit. A similar result can be obtained with the aid of a timed valving means whereby each delivery conduit will be temporarily connected to the primary fluid chamber immediately or at least shortly after the conduit has been disconnected from the compression chamber of the pump. In its preferred form, this timed valve is a slide valve constituted by a portion of the rotating and reciprocating plunger so that one valving element is sufilcient to accomplish the by-passing for all delivery conduits of the pump. This is illustrated in Fig. 16 showing a pump of the general type ofFlg. 9, with a rotating and reciprocating main plunger and a, barrel shiftable in,axial direction for quantity control. Since the drives of plunger and barrel are like those of Fig. 9, only the actual pump is illustrated in Fig. 16, the drives being broken away in order to avoid repetition in the drawing. In Fig. 16 such parts which are of the same design as analogousparts occurring in Fig. 9 are denoted by the same reference character whereas differing parts have reference numerals above 300.

The embodiment of Fig. 16 comprises the body |0| on foot structure |02 and with an axial bore ||4 in which the barrel H5 can be shifted axially by means of its threading nut 202, andrack |53 while being guided by the projections 208 engaging the grooves 201 in the top portion of the barrel. Ring 209 provided with the projections 203 has an upward tubular extension 2| 0 whose top face serves as a seat for an auxiliary plunger, all as described more thoroughly in connection with Fig. 9. The arrangement of the main plunger 30| and of the auxiliary plunger 302 with cooperating springs 303 and 304 differs from that of Fig. 9 inasmuch as both plungers are hollow and the main plunger return spring 303 is located interiorly of the plungers whereas only the spring 304 bearing on the head 305 of the auxiliary plunger 302 is arranged in a shell 306 similar to shell |06 of Fig. 9. It is to be understood, however, that the arrangement o1' spring 303 in the hollow of the plungers is merely a modification whereby some top space can be saved, and that as far as the plungers and springs are concerned the arrangement of Fig. 9 may be used here as well. Shell 303 is screwed into a threading 301 provided in the side wall of recess |01 in body |0|. I'he interior of the shell 306 and the recess |01 constitute the primary fluid chamber The top end of the spring 303 engages directly the top face 303 of the bore 303 of the auxiliary plunger, whereas the lower end of the spring, interiorly of the hollow space 3|0 of the plunger 30|, bears upon a disc 3|I whose lower 75 face constitutes the top race of a thrust ball bearing 3|2. The lower race of the bearing is formed by the bottom face 3|3 of the space 3|0. The

drive of the plunger 30| is exactly like that of the plunger |2| in Fig. 9, only the splines 223, the

miter wheel 223, and part of the cam-operated tappet |23 being visible in Fig. 16.

The primary iiuid chamber has its inlet at the top where a threading ||2 permits attachment of a pipe (not shown). The chamber is in permanent communication, via groove 2 I2, with annular space 2|| which in turn is permanently connected through groove 2|3 with inlet port |44 of the barrel III, no matter whether the latter is adjusted to a higher or lower position. The barrel is also provided with delivery ports 341 to 334. In the present embodiment, there are eight such ports rather than the six shown in the other embodiments. However, it is to be understood that here as well as there any suitable number of delivery ports may be used. The delivery ports 341 to 334 are provided with downward extensions 234 which communicate each with a coordinate delivery conduit in the body I. Only two of these conduits, namely conduits |53 and |51, are visible in Fig. 16. In the illustrated embodiment each conduit is provided with a relief valve 3|4 adapted at 3| 5 for connection to a pipe line not shown, the relief valve being of a type disclosed in my co-pending application Serial No. 409,663 filed September 5, 1941. However, other types of valves may be used or even no valve in which event the conduit |51 may be directly connected to a pipe leading the fluid passing through conduit |51 to the place oi' consumption. 'I'he valve is immaterial from the viewpoint of the operation of the pump of Fig. 16 because, as it will be explained here inafter, by-passing and line pressure relief is attained by means in connection with plunger 30| rather than by means of a valve of the type 13 of Fig. 2 or |13 of Fig. 9. In addition to the mentioned ports, barrel H5 is also provided with one relief port 3|3 with an upward groove extension 3|1. It is immaterial where on the periphery of the barrel the port 3|6 is located. However, a relief conduit 3|3 must be so arranged in body IOI that it connects, in any position of the barrel, port 3|3 with the primary fluid chamber III, either directly or via the groove 3| 1, or with a storage tank (not shown) or other device of relatively low interior pressure for which purpose the threading 330 can be used after removal of the plug 33|. It goes without saying that the vertical leg of the conduit 3|8 should be closed or omitted if port 3 I0 is connected to a storage tank.

From the foregoing description of the hollow structure of the plungers 30| and 302 it will be apparent that the entire inner spaces 309 and 3|0, together with that portion of the barrel H5 which is between the lower face of the auxiliary plunger and the top face of the main plunger, except for the space occupied by the spring 303. can be illled with uid and consequently considered as the compression chamber 3|3 of the pump. Two ports in the wall of plunger 30|, namely an inlet slot 320 and a supply port 32|, are so arranged that they periodically connect the chamber 3|9 to ports in the barrel, the slot 320 effecting the connection with the inlet port |44, and the supply port 32| effecting the connection with the ports 341 to 354. Inlet slot and supply port may be shaped similarly to the corresponding elements 2|4 and |41 described in connection with Figs. 9, 12, and 13. However,

vthe slot 320 will be in its position g', and groove it is by no means necessary that slot 320 reaches the top rim of plunger It is sumcient that the slot eiect communication between port |44 and the inner space 3|0 of plunger 30|, from a selected point of the downward stroke to the end of that stroke. 'I'he plunger 30|- is also provided in its outer surface with a peripheral groove 322 and a vertical groove 323. The groove 322 is so wide and so located that there is permanent communication between it and the barrel relief port 3|! no matter how barrel and piston are positioned at any time. The lower end of groove 323 communicates with groove 322. rhe width of groove 323 may be approximately equal to that of any one of the ports 341 to 354. and its length is so selected that. during the movement of plunger 30|, it can communicate with the highest delivery port, i. e. port 354 of the barrel. even if the latter is in its topmost position. In peripheral relation, the groove 323, as shown in Fig. 17, preferably lags behind the port 32| a short distance, e. g. half that of two consecutive delivery ports of the barrel, when the plunger rotates. Considering the location of the groove 322 it will be noticed that plunger 30| need be tight in barrel ||5 only against low pressure, because any leakages occurring will lead downward into the groove 322 which is in permanent communication with chamber ||I or the storage tank in which only low pressure prevails.

The operation of the pump according to Fig. 16 will be explained in connection with the diagram of Fig. 18 which is similar to Fig. l1. The lines y and u' border one complete development of the inner surface of the barrel H5. and the portion on the left-hand side of line y' is a repetition of a portionof such development. The arrangement of the barrel ports 341 to 354 is similar to that described in connection with Fig. 11. The ports 352, 353, and 354 appearing twice in the drawing, are provided with a prime where they occur at the left of line y'. In addition thereto, barrel port 3|0is indicated approxi-- mately underneath port 350. It is assumed that the barrel is in its lowest position. Dash-lines are used for the superimposed elements of the plunger 30| shown in two different positions. The dotted line R. indicates the path of the port 32|, and arrow Z the sense of the plunger rotation. From the diagram in connection with Fig. I6 it is apparent that in the rst position shown 'in which the plunger is at the end of its upward stroke, the plunger port 32| at f is in yregistry with delivery port 354 so that the fluid willv be forced by auxiliary plunger 302 under the action of spring 304 and against the restraint of spring 303, being weaker than the first-named, from chamber 3|0 into the conduit |51. The pressure built up in that conduit will open valve 3|4 so that injection at the connected place 'of uid consumption will occur. At that time. the inlet port |44 of the barrel is closed sincethe plunger. slot 320 in its position f' is high above port |44. Similarly, fluid passage through barrel port 3|0 is blocked since the plunger groove 323 in position f is half way between ports 353 and 354. During the following downward stroke of .the plunger, port 32| travels along line R first closing port 354 and nalhr reaching the position g approximately half way between ports 354 and 341. In the meantime. slot 320 has established connection between chamber and chamber,

3|3 so that fluid can enter owing to the vacuum created in chamber 3|9. When port 32| is at g,

323 in its position g" in which it is in registry with port 354. Thereby connection will be established from chamber through conduit 3I8, port 3|6, grooves 322 and 323, and port 354 to the conduit |51 which just had received its full quantity of fluid and still is under the interior pressure built up therein by the pump. Owing to the established connection any excess fluid in conduit |51 will be drained into the chamber and line pressure relief occurs so that the pressure in conduit |51 can decrease to that of said chamber. further explanation in consideration of what has been stated in connection with the foregoing description that upon continuation of the plunger movement rst ports |44 and 354 will be closed and port 341 will be openedso that uid from chamber 3|9 can pass through that port. Port |44 stays closed for the remainder of the cycle.

When port 32| is half way between ports 341 and f 348 groove 323 will be in registry lwith port 341 so that by-passing and line pressure relief takes place for the delivery conduit connected thereto. In -a similar manner and with similar effect, the remaining ports, ,one after the other, will be in registry first with port 32| and then with groove 323 until the cycle is completed and a new cycle commences.

The embodiment last described oilers the, advantage that no particular by-passlng and relief valve of the type of valve 13 is required. Furthermore, groove 322 being instrumental in the -lay-passing, coincidentally is a means to aid in the sealing of the plunger in the barrel. Of course, a peripheral groove rwithout longitudinal extension -but with a connection to the primary fluid chamber by means of a drainas shown in Fig. 16 may be applied in the first and second embodiment for sealing purposes. Similarly, such groove with drain may be present in a pump according to the invention in the event vthat the means for lay-passing and line lpressure relief are not needed, as it may be the case, e. g. if the pump is used for pressure lubrication rather than for fuel injection or similar purposes.

From the foregoing description of several embodiments it will be clear that the separation of the means for lay-passing and line pressure relief from the actual pumping means opens the way for shortening the length of the plunger stroke required so that more places of fluid consumption can be served with a given length of stroke. This is particularly the case if a combined rotary and reciprocatory movement is imparted to the main plunger. A movable barrel, either turnable or axially shiftable or both, is a convenient means in connection with the rotatable plunger to adjust timing and/or control the delivered quantities. Furthermore, the abovementioned separation makes it possible to simplify the elements for metering the delivered fluid with the eiect'that the required accuracy can be much more easilyy attained. Additional advantages have been stated in the course ofthe description.

It will be apparent to those skilled in the art that manyv alterations of the structures herein described and illustrated by way of example are possible within the spirit of my invention. In particular, many of the modications described in connection with one ofthe illustrated embodiments may be applied to another one, and specific features of the one may be substituted It will be understood without with said conduits and with a place of low iluid pressure, and temporarily operative to drain fluid from each conduit after disconnection of its associated port from the pump chamber.

2. A pump comprising acylinder with pump chamber therein and a plurality of deliver ports on diierent levels, a plunger movable in said cylinder and ported to connect temporarily said delivery ports, one afterthe other, to the pump chamber, a conduit for each of said ports and in communication therewith to convey pumped fluid to the outside, and a valve in each conduit and in connection rwith a place of low uid pressure, each valve being responsive to a pressure drop in the associated conduit so as to drain fluid therefrom after disconnection of the associated port from the pump chamber.

3. A pump comprising a cylinder with a pump chamber therein and a plurality of delivery ports on different levels, a plunger movable in said cylinder and ported to connect temporarily, said delivery ports, one after the other, to said pump chamber, 'a delivery conduit for each of said delivery `ports and in communication therewith .to convey pumped fluid to the outside, a drain conduit, a slide valve between said delivery conduits and said drain conduit and connectedwith said plunger for synchronous operation so as to opposite direction, said main plunger being ported to connect temporarily one ot said delivery ports after the other'to the space between said main plunger and said auxiliary plunger.

6. In a pump oi' the type described the combination of a stationary top structure, a. barrel having a plurality of delivery ports on diilerent levels, a turnable and reciprocatable main plunger movable' therein,v` a cam drive to move said plunger axially in one direction, an auxiliary plunger opposite saidmain plunger in said barrel, both said plungers being hollow with their openingstowards each other, a thrust bearing on the bottom of the hollow of said main plunger, a first compression spring within said plungers ybetween said thrust bearing and the top oi said hollow of said yauxiliary plunger, a second compression spring, stronger than the first one between the top of said auxiliary plunger and said stationary structure, and a port in the wall of said main plunger to connect temporarily one Y of said delivery ports after the other to the inconnect temporarily said drain conduit to veach delivery conduit consecutively after the disconnection of its associated delivery port from the pump chamber.

' 4. A pump comprising a iluid storage chamber, a cylinder with a pump chamber therein, said cylinder being provided .with a plurality of delivery ports on diierent levels andV Iwith an inlet port communicating with said storage chamber, a plunger movable in said cylinder and ported to connect temporarily said pump chamber to said storage chamber at both ends of its compression stroke, and tosaid delivery ports one after the other during said stroke, a conduit for each of said delivery ports andin communication therewith to convey pumped uid to the outside, ,and valving means connected with said conduits and with said storage chamber and temporarily operative to drain fluid from each vconduit consecutively after disconnection of its associated delivery port from the pump chamber.4

5. In a pump of the type described a'stationfv ary structure, a barrel with a plurality of delivery ports on different levels, a main plunger movable in said barrel, a` cam drive to move said plungerv axially in one direction, van auxiliary plunger opposite saidmain plunger in said barrel and provided with an axial bore, a first compression spring between said stationary structure and said auxiliary plunger, a thrust bearing on top of'said main plunger, a headed rod resting with its foot end on said thrust bearing, and a secondvcpfmpression` spring between' the head of said rod and said stationary structure terior of` said plungers and barrel.

7. In a pump of the type described a barrel having a plurality of delivery ports on different levels, a main plunger in said barrel, said plunger having an axial bore through a portion of its length and in communication with the barrel space, a peripheral groove of a depth decreasing towards at least one of its ends, and a transverse connection between said Ibore and the widest portion of said groove, means to reciprocate said plunger axially to establish temporary connection between 'the barrel space and said delivery ports one after'the other, means to turn the `plunger to bring a selected portion of said groove in registry with said ports, and a springbiased auxiliary piston in said barrel in opposi- 4tion tosaid main plunger.

8. A pump comprising a housing having a plurality of delivery conduits, a barrel embodying a pump chamber interiorly -of said housing and having delivery ports on different levels and circumferentially spaced from each other, said ports being-in'comrnunication Awith said conduits respectively,` a rotatableand reciprocatable plunger in saidl barrel and being ported so as to connect temporarily said 'r delivery ports, one after the other, with the pump chamber, a drive for said plunger to rotate it uni-directionally about its axis and simultaneously to reciprocate it in axial direction once during each revolution, and operative means to alter fthe position of the lbarrel in said housing relatively to the moving plunger.

9. A pump comprising a. housing having a plurality of delivery conduits, a barrel embodying a pump chamber interiorly of said housing and having delivery portsondiiferent levels and circumerentially spaced from each other, said ports being incommunication with said conduits respectively, a reciprocatable and rotatable plunger -in said barrel and having a port so as to connect temporarily said delivery ports, one after the other, with the pump chamber, a drive for said plunger to rotate itvuni-directionally about its axisand simultaneously to reciprocate it in axial direction once during each revolution, operative means in connection with the barrel to alter the position of the ,barrel in the housing,

and tending to move the main plunger in the and means to guide said barrel non-rotatably in an axial direction.

10.V A pump comprising a housing having a plurality'of delivery conduits, a barrel embodying a pump chamber interiorly of said housing and having an exteriorly toothed portion, said barrel being provided with delivery ports on dierent levels and circumferentially spaced from each other, saidports being in communication with said conduits respectively, a reciprocatable and rotatable plunger in said barrel and having a port so as to connect temporarily said delivery ports, one after the other, with said pump chamber.

a drive for said plunger to rotate it uni-directionally about its axis and simultaneously to reciprocate it in axial direction once during each revolution, and a rack in engagement with-said toothed portion ofthe barrel to turn the barrel for adjustment.

1l. A pump comprising a housing having a plurality oi delivery conduits, a barrel embodying a pump chamber interiorly of said housing and having delivery ports on diierent levels and in communication with said conduits respectively,

y said ports constituting longitudinal grooves where 12. In a pump of the type described the combination of a barrel embodying a pump chamber and having a plurality of ports arranged in a helical line, a plunger movable in said barrel, a cam drive for reciprocating the plunger, a gear drive for rotating the plunger during reciprocation, and means in interengagement with both said drives for interdependent timing of recprocations and revolutions of said plunger, said plunger being provided with a port so as to connect temporarily the delivery ports, one after the other, rwith the pump chamber during a cycle of rotation and reciprocation.

i3. A device as claimed in claim l2 wherein said drives comprise a shaft, a cam on said shaft, a tappet engaging said cam and embodying a pivot and thrust bearing for said plunger, a gear wheel secured to said shaft, a mlter wheel splined `to said plunger so as to permit axial movement of the plunger relatively to said miter wheel, and additional wheels to transmit rotation from said gear wheel to said miter wheel.

14. In a pump of the type described the combination of a barrel embodying a pump chamber and having a plurality of delivery ports on different levels and circumierentially spaced from each other, and an inlet port communicating with a uid storage chamber, a plunger movable in said barrel and having a supply port and an inlet slot, -both said port and said slot being in communication with said pump chamber, a gear drive for rotating and a cam drive for reciprocating said plunger, the cam of said drive having a iirst portion so formed that said supply port temporarily is in registry with said delivery ports, one after the other, during the compression stroke, a second portion so formed that registry between said inlet port and said inlet slot is established during the return stroke, and a third portion so formed that said inlet port and f inlet slot will be separated at the end of the return stroke during a period in which there is substantially only rotation of said plunger.

ing a housing having a plurality of delivery conduits opening in an axial bore of the housing on a substantially helical line, a barrel embodying a pump chamber and being adjustable within said housing bore, said barrel having delivery ports in communication with said conduits respectively, said ports being groove-shaped at the outside of the barrel so as to stay in communication with said conduits when said barrel is moved in a predetermined manner, and a plunger in said barrel having a port in communication with the pump chamber, said port being so shaped at the outside of the plunger as to form a groove with decreasing cross-section, and a drive for rotating and reciprocating said plunger whereby a plunger groove portion selected by adjustment of the barrel will temporarily register with said delivery ports, one after the other, during a cycle of the plunger movement;

16. A pump, comprisixm a barrel embodying a pump chamber and having a plurality of delivery ports on diil'erent levels, a plunger reciprocatable in said barrel and having a first port so as to temporarily connect said delivery ports, one after the other, with said pump chamber, and a second port so as to temporarily connect each delivery port to ailuid storage chamber while said delivery port is disconnected from said pump chamber after the passage of said first plunger port, the spacing of said first and second port from each other in the direction of the plunger movement being smaller than the spacing of two consecutive delivery ports but wider than the dimension of the delivery ports in said direction.

17. A pump, comprising a barrel'embodying a pump chamber and having a plurality of delivery ports on different levels, and a drain port below the lowest one of said delivery ports and in connection with a low pressure chamber, a plunger reciprocatable in said barrel and so ported as to temporarily connect said delivery ports, one after the other, to said pump chamber, said plunger having also a circumferential groove underneath vthe plunger port and of a width of at least the length of the plunger stroke plus the -width of said drain port so as to stay in permanent communication with said drain port.

18. A pump, comprising a barrel embodying a pump chamber and having a plurality of delivery ports arrangedon a helical line, said barrel having also a drain port underneath the lowest delivery port and in connection with a low pressure chamber, and a rotatable and reciprocatable plunger in said barrel, said plunger having a supply port in communication with said pump chamber, a circumferential groove of such a location and width as to maintain its permanent communication with said drain port, and a longitudinal groove in connection with said circumferential groove and of such a` width, length and location as to temporarily register with each delivery port shortly after it has been passed by said supply port.

19. A pump comprising a housing provided with a plurality of delivery conduits and a drain conduit in connection with a low pressure chamber, a movable barrel embodying a pump chamber, means for shifting said barrel in said housing, said barrel having a plurality of delivery ports arranged on a helical line and in permanent communication with said delivery conduits respectively, and having also a drain port underneath the lowest delivery port and forming, on the outside oi' the barrel, a groove extending 15. In a pump 0f the type described comprls- 75 in the direction in which said rbarrel is shiftcircumferential groove and of such a width, lengt: and location as to temporarily resister with eao delivery port shortly after it has been passed b said supply port. means for continuously rotat ing said plunger, and means for reciprocatin said plunger once during each of its revolutiom Louis nana.

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