US3178888A

US3178888A - Plural output pump

Info

Publication number: US3178888A
Application number: US273084A
Authority: US
Inventors: Andrew T Hampton
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-04-15
Filing date: 1963-04-15
Publication date: 1965-04-20
Anticipated expiration: 1982-04-20
Also published as: GB1027973A

Description

April 20, 1965 A. T. HAMPTON 3,178,888

PLURAL OUTPUT PUMP Filed April 15, 1963 3 Sheets-Sheet 1 IP1 A .INVENTOR. ANDREW THAMPTON By Ms A 770EMEY$ HARE/5, Mach, Ruassu. & KERN A ril 20, 1965 A. T. HAMPTON PLURAL OUTPUT PUMP 3 Sheets-Sheet 2 Filed April 15 1963 INVENTOR A/voxesw 7.- HAMPTON 5r Hi5 Arraeweys HARE/6, K/EcH, Russsu. & K52

April 20, 1965 A. T. HAMPTON 3,178,888

PLURAL OUTPUT PUMP Filed April 15. 1963 3 Sheets-Sheet 3 HYDRAULIC FLU/D OTHER HYDRAULIC FLU/D esszevom FLU/D RESERVOIR v ga INVENTOR ANDREW ZHA MPTOA/ B) H/5 ATTOE/l/A'YS HARE/5, K/EcH, Russfiu, 6 KER/v United States Patent 3,178,888 PLURAL OUTPUT PUM? Andrew T. Hampton, Burbank, Calif., assignor of one-half to George R. Soseman, Burbank, Calif. Filed Apr. 15, 1963, Ser. No. 273,084 20 Claims. (Cl. 60-52) The present invention relates in general to what might be termed a plural output pump, and a primary object is to provide, in a single, unitary device driven by a single power source, an apparatus for pumping two or more fluids at the same or different output pressures and at the same or different volumetric rates.

Still more particularly, a basic object of the invention is to provide a plural output pump, having the foregoing characteristics, which includes: fixed-displacement or fixed-volume-delivery primary pump means; fluid-operated variable-displacement or variable-volume-delivery secondary pump means operable by the output of the primary pump means; and means for selectively delivering the outputs of the primary pump means and the secondary pump means to external, primary and secondary fluid-operated apparatuses, which may be the same or different apparatuses. Since the secondary pump means is a fluid-operated pump means driven by the output of the primary pump means, it will be understood that the single power source mentioned, which may be a suitable motor, such as an electric motor, is connected to and drives the primary pump means only.

A plural output pump of the foregoing nature may be utilized in a wide variety of ways. For example, the output of the primary pump means may be used solely to operate the secondary pump means, or it may be used solely to operate an external fluid-operated apparatus or apparatuses, or it may be divided between the secondary pump means and such external fluid-operated apparatus or apparatuses. The output of the secondary pump means, when such pump means is operated by the output of the primary pump means, may be delivered to any desired external fluid-operated apparatus or apparatuses. Preferably, the primary pump means has a constant output at a relatively high volume and a relatively low pressure, e.g., up to 1500 psi The variable output of the secondary pump means may be at the same pressure and volume as that of the primary pump means, or it may be at a higher pressure and a lower volume, or at a lower pressure and a higher volume.

Another important object of the invention is to provide a plural output pump wherein the primary pump means comprises a plurality of primary pumping units and means for actuating them in sequence, and wherein the secondary pump means comprises a plurality of fluidoperated secondary pumping units respectively connected to and sequentially operable by the outputs of the primary pumping units. With this construction, the combined outputs of the primary pumping units and the combined outputs of the secondary pumping units are both relatively steady.

A further object of the invention is to provide a plural output pump wherein the outputs of the fluid-operated secondary pumping units may be combined, or grouped in sets of one or more. With this construction, a single fluid, or a number of fluids up to the number of secondary pumping units, may be pumped by the secondary pump means, which is an important feature.

Considering the present invention more specifically now, an object thereof is to provide a plural output pump which includes: fixed-displacement primary pumping devices respectively having primary pump inlets and respectively having primary pump outlets; means for sequentially actuating the primary pumping devices; priice mary-pump inlet means communicating with the primary pump inlets for supplying fluid to the primary pumping devices; primary-pump outlet means common to and communicating with the primary pump outlets for receiving fluid discharged by the primary pumping devices; primary-pump outlet check valves respectively disposed between the primary pump outlets and the common primary-pump outlet means; variable-displacement fluidoperated motors equal in number to the number of the primary pumping devices; the motors respectively having motor inlets respectively communicating with the primary pump outlets upstream from the primary-pump outlet check valves; secondary pumping devices equal in numher to the number of, and respectively connected to and driven by, the motors; the secondary pumping devices respectively having secondary pump inlets and respectively having secondary pump outlets; secondary-pump inlet means communicating with the secondary pump inlets for supplying fluid to the secondary pumping devices; and secondary-pump outlet means communicating with the secondary pump outlets for receiving fluid discharged by the secondary pumping devices.

With the foregoing construction, the fluid pumped by the primary pumping devices may be utilized solely to operate the respective fluid-operated motors, or some or all of the fluid discharged by the primary pumping devices may be diverted from the common primary-pump outlet means to an external fluid-operated apparatus or apparatuses. Similarly, the secondary pump inlets and the secondary pump outlet may be interconnected to handle a single fluid, or they may be grouped in sets of one or more to handle a corresponding number of secondary fluids separately. These may be discharged at pressures the same as, or higher or lower than, the primary-fluid output pressure from the primary pumping devices.

Still another important object of the invention is to provide variable-displacement fluid-operated secondary pumping units which are of the reciprocating type and which are arranged circumferentially about and extend in the direction of the axis of the plural output pump of the invention. More particularly, an object in this connection is to provide variable-displacement fluid-operated secondary pumping units respectively comprising motor pistons having secondary pump pistons aligned therewith and connected thereto, the various motor-pump piston combinations being circumferentially arranged about and reciprocable parallel to the axis of the plural output pump.

Yet another important object of the invention is to provide a plural output pump of the foregoing nature having all its components in a single housing to form a single, unitary, compact device.

An additional object is to provide a plural output pump having circumferentially arranged primary pumping de vices comprising either radially reciprocable plungers,

or adjacent vanes of a pump having circumferentially sta tionary, radially movable vanes and eccentric means for sequentially radially displacing the vanes so as to sequentially vary the volumes of the intervane spaces between paired adjacent vanes. In either case, each primary pumping device has a variable-volume chamber of fixed displacement, such chamber comprising a cylinder and plunger in one instance and an intervane space in the other.

A further important object of the invention is to provide means for returning the combined outputs of primary fluid from the primary pumping devices to a reservoir through a throttling means which dissipates the energy therein'in the form of heat in the event that no secondary fluid or fluids are being accepted from the secondary pumping devices. Thus, during interruptions in the delivery or deliveries of secondary fluid or fluids from the secondary pumping devices, the plural output pump of the invention provides, in effect, a. clutch which permits the secondary pump means to stall while the primary pump means continues to operate, this being an important feature. While the secondary pump means is stalled, the motor-pump piston combinations thereof merely float in intermediate positions. This mode of operation holds true irrespective of Whether the secondary-fluid outputs from one, some or all of the secondary pumping devices are shut down. In the case of a partial shutdown, only the corresponding secondary pumping devices stall, theremainder continuing to operate as long as the primary-fluidoutputs from the corresponding primary pumping devices are available for the purpose.

, The foregoing objects, advantages, features and results of the present invention, together with various other 013- jects, advantages, features and results thereof which will be evident to those skilled in the pump art in the light of this disclosure, may be achieved with the exemplary embodiments of the invention described in detail hereinafter and illustrated in the accompanying drawings, in which: 1

FIG. 1 is a longitudinal sectional view of a plural output pump which embodies the invention;

FIGS. 2 and 3 are transverse sectional views respectively taken along thearrowed lines 22 and 33 of FIG. 1;

FIG. 4 is a mirror image of a, view taken along, the arrowed line 44 of FIG. 1;

FIGS. 5 and 6 are transverse sectional views respectively corresponding to FIGS. 3 and 4, but illustrating another embodiment of the invention;

FIGS. 7 and .8 are enlarged, fragmentary sectional views respectivelytaken along the arrowed lines 7--7 and' 8-8 of FIG. 5;

FIG. 9 is a fragmentary longitudinal sectional view similar to the left end of FIG. 1, but illustrating an alternative embodiment of the invention;

FIG. 10 is a transverse sectional view taken along the arrowed line 1010 of FIG. 9; and 7 FIGS. 11 and 12 are diagrammatic views illustrating possible applications of the plural output pump of the invention.

Plural output pump Referring initially to FIG. 1 of the drawings, the plural output pump of the invention isdesignated generally therein by the numeral 20 and includes a single housing 22 shown as composed of

cylindrical wafers

24, 26, 28 and 30 suitably secured together, as by circumferentially spaced, longitudinal screws 32 anad'"34. The pump 20 also includes a suitable mounting bracket 36 secured to the housing wafer 24, as by'circumferentially spaced, longitudinal screws 38. v

Basically, the plural output pump 20 of the invention comprises a fixed-displacement primary pump means or,

section 40, and a fluid-operated,variable-displacement, secondary pump means or section 42 operated by the output of the primary pump means. In the particular construction illustrated, the primary pump means 40 is located in the housing wafers 24 and 26, being located primarily in the housing wafer24, while the secondary pump mean 42 occupies the

housing wafers

26, 28 and 30.

The primary pump means 40 includes a plurality of fixed-displacement, primary pumping devices or units 44 which are radially oriented and which are circumferentially' spaced apart about the central axis of the plural output pump 20. The primary pumping units 44 respectively include plungers 46 radially reciprocable in bores 48. Springs 50 engaging the plungers 46 adjacent'their outer ends bias the inner ends of the plungers into engagement with a bearing 52 on an eccentric 54. The latter is carried by an input or drive shaft 56 coaxial with the central axis of the pump 20 and journalled in

bearings

58 and 60. The input shaft 56- may be driven by any suitable power source, such as an electric motor, not shown.

The primary pump section 40includes primary-pump inlet means 62 for supplying fluid to inlets 64 of the primary pumping unit-s 44. The inlet means 62 is shown as including an inlet passage 63 which may be connected, as by an inlet line 65, to a reservoir 66,'FIGS. 11 and 12, or other suitable fluid source. Preferably, the fluid in the reservoir 66 is ordinary hydraulic fluid, i.e., oil, although any other fluid suitable for the purpose may be used.

.- The primary pump inlets 64 are shown as formed in the respective plungers 46, andcommunicate with the inlet passage 63 through the bearing and through inlet 64 during the pumping or working stroke of the corresponding plunger 46, it being .understood that the -working strokes of the plungers are the outward strokes thereof. During the .return or inward stroke of each plunger 46, the corresponding inlet check valve 70 tends to'open to admit additional fluid into the bore 48 outwardly of such plunger. V

Formed in the housing 22 are primary pump outlets 72 communicating with the bores 48 radially outwardly of the plungers 46 and receiving the respective outputs of the primary pumping units 44. The respective outlets 72 have branches 74 which lead to and communicate with a common primary-pump outlet means 76 through primary-pump outlet check valves 78 biased toward closed positions by springs 80. It will be understood that the outlet check valves 78 tend to open during the working strokes of the corresponding plungers 46, and

close during the return strokes thereof. The primarypump outlet means 76 consists of a manifold formed in the housing 22 and having an outlet passage 82 in communicationtherewith- This outlet passage hasconnected theretoan outlet line 84 leading back to the reservoir 66 and/or to some external, fluid-operated apparatus or apparatuses to be actuated by the combined ,outputs of the fixed-displacement primary pumping units 44. Possible external'connections to the primary pump means 40 will be discussed hereinafter in connection with FIGS. .11 and 12 of the drawings.

The secondary pump means orv section 42' includes a plurality of variable-displacement, fluid-operated secondary pumping units equal in number to the number of primary pumping units 44. The secondary pumping units 90, which. are circumferentially spaced apart about and 1 I drawings, the left ends of the motor cylinders 96 communicate with the respective primary pump outlets ,72 so that the respective outputs of the primary pumping units 44 cyclically bias the respective motor pistons 94 to the right. The motor pistons 94 are constantly biased to the left by a relatively low fluid pressure which acts on the right ends thereof and which is much less than the output pressures-of the primary pumping units 44. Considering how this fluid pressure for producing the returnstrokes of the motor pistons 94 is created, the right ends of the motor cylinders 96, as viewed in FIG. 1 of the drawings, communicate with a central manifold 98 through radial ports 100. The central manifold 98 is formed by one end of an axial bore 102-containing a piston 104 biased axially toward the primary pump section 40 by a spring 106. The piston 104 carries, as an axial extension thereof, a throttle valve 108 in an axial passage 110 leading from the primary-pump outlet means 76 to the manifold 98.

Considering the operation of the throttle valve 108, thecombined output pressure from the primary pumping units 44 acts to bias the throttle valve 108 toward a closed position in opposition to the action of the spring 106. Thus, an increase in the pressure in the primary-pump outlet means 76 tends to increase the restriction to flow from such outlet means to the manifold 93, and vice versa, thereby maintaining in the manifold 98 a substantially constant pressure which is low as compared to the output pressure of the primary pump means 40. This relatively low pressure is applied to the right ends of the motor pistons 94, as viewed in FIG. 1 of the drawings, to effect the return strokes thereof during the return strokes of the respective plungers 46.

When the primary pump means 40 is shut down, the spring 106 seats an O-ring 112, or the like, on the piston 104, around the adjacent end of the axial passage 110 to prevent back flow from the manifold 98 into the primarypump outlet means 76. The purpose of this is to prevent contamination of the primary fluid circulating through the primary pump means 40 by the secondary fluid or fluids being pumped by the secondary pump means 42.

One of the motor cylinders 96 has a port 114 in communication therewith on the low pressure side of its motor piston 94. A surge chamber, not shown, may be connected to this port to damp any pressure pulsations on the low pressure sides of the motor pistons.

In addition to the fluid-operated motors formed by the motor pistons 94, the secondary pumping units 90 include secondary pumping devices in the form of secondary pump pistons 129. Preferably, the secondary pump pistons 120 are integral parts of the plungers 92, and thus integral parts of the respective motor pistons 94. The secondary pump pistons 120 are shown as reciprocable in secondary pump cylinders or bores 122 which are preferably formed in removable liners 124.

In the particular construction illustrated throughout the drawings, the secondary pump pistons 120 are smaller in diameter than the motor pistons 94. Consequently, the secondary-fluid output pressures from the secondary pumping units 90 are higher than the corresponding primary-fluid output pressures from the primary pumping units 44. The ratios of the secondary-fluid output pressures to the primary-fluid output pressures depend, of course, on the ratios of the diameters of the motor pistons 94 and the secondary pump pistons 120. However, it will be understood that by substituting plungers 92 having different ratios of the diameters of the motor pistons 94 and the diameters of the secondary pump pistons 120, any desired ratios between the primary-fluid output pressures and the secondary-fluid output pressures may be achieved. Thus, the secondary-fluid output pressures may be equal to or lower than the corresponding primary-fluid output pressures, instead of higher.

Also, the ratios of the secondary-fluid output pressures to the corresponding primary-fluid output pressures need not be the same for all of the secondary pumping units 90. In other words, one or more of the secondary pumping units 99 may amplify the corresponding primary-fluid output pressures, one or more may decrease them, and one or more may produce secondary-fluid output pressures equal to the corresponding primary-fluid output pressures. (However, the primary-fluid output pressures from the primary pumping units 44 are preferably all made equal by making the diameters of all of the plungers 46 the same.)

As will be apparent, any desired ratios of secondaryfluid output pressures to primary-fluid output pressures from the primary pumping units 44 may be achieved by substituting for the plungers 92 and the liners 124 shown plungers and liners having correspondingly larger or smaller secondary pump pistons 120 and secondary pump cylinders 122. if desired, the diameters of the motor pistons 94 and the motor cylinders 96 can be increased or decreased also, but this is normally not necessary.

In the particular embodiment of the invention presently under consideration, the secondary pump means 2 is designed to pump a single fluid, i.e., all of the secondary pumping units pump the same fluid. Thus, the housing 22 is provided therein with secondary-pump inlet means 128 and secondary-pump outlet means 130 common to all of the secondary pumping units 90, i.e., communicating with all of the secondary pump cylinders 122. The inlet means 128 consists of an annular manifold which is supplied with the single fluid to be pumped through an inlet passage 131 and an inlet line 132. The inlet means 128 communicates with all of the secondary pump cylinders 122 through spring-biased inlet check valves 134. As will be understood, these check valves tend to open during the return strokes of the motor piston 94 and close during the Working strokes thereof. The common secondary-pump outlet means 130 consists of a central manifold discharging into a central outlet passage 135 and an outlet line 136. The various sec-.

ondary pump cylinders 122 communicate with the outlet means 130 through spring-biased outlet check valves 138. As Will again be apparent, these check valves close during the return strokes of the motor pistons 94 and open during the working strokes thereof.

Operation of pump 20 with external connections of FIG. 11

Turning to FIG. 11 of the drawings, illustrated therein is one possible environment in which the plural output pump 20 of the invention might be used. In this instance, the inlet line 65 to the primary pump section 40 is connected to the reservoir 66, while the outlet line 84 is connected to an adjustable bypass valve 140. The latter leads to a control valve 142 and a fluid-operated motor 144 in series therewith, or back to the reservoir 66 through a return line 146. The motor 144 is connected to the reservoir 66 by a return line 148. A pressure gauge 150 is interposed between the bypass valve and the control valve 142 to indicate the primary-fluid pressure.

To adjust this system, the control valve 142 is closed and the bypass valve 140 is adjusted to obtain the desired primary-fluid pressure, as indicated by the gauge 150. The bypass valve 140 thus provides the means of determining the maximum output pressure of the secondary pump 42.

The secondary pump section 42 is shown as having its inlet line 132 connected to a reservoir 152 of any suitable fluid to be pumped. The outlet line 136 of the secondary pump means 42 is connected, through a control valve 154, to any desired fluid-operated apparatus 156. A gauge 157 indicates the secondary-fluid pressure.

As a matter of convenience, the fluid handled by the primary pump section 40 will be regarded as ordinary hydraulic fluid, and the fluid handled by the secondary pump section 42 will be regarded as paint, in which case the apparatus 156 may be a paint spray gun, or the like. The operation of the plural output pump 20 of the invention Will now be considered in this setting.

First of all, it will be assumed that the bypass valve 140 is so adjusted as to provide a high resistance to flow of the output of the primary pump means 40 back to the reservoir 66, and that the control valve 142 is also set to provide a high restriction to flow, or is closed. It will also be assumed that the control valve 154 for the output of the secondary pump means 42 is open.

Under such conditions, substantially the full output of the primary pump means 40 is used to operate the secondary pump means 42, very little of the primary fluid discharged by the primary pump means 40 being returned to the reservoir 66 through the bypass valve 140. Thus, there is very little circulation of hydraulic fluid through the primary pump means 40, the amount circulated being only enough to replenish any leakage and to replenish that which returns to the reservoir through the bypass valve 140.

With the foregoing circumstances obtaining, the fluid I plunger 46 reciprocates, it being understood that the maximum displacement of each motor piston 94 is equal to the maximum displacement of the corresponding plunger-46. Under these conditions, of course, the secondary pump pistons 120 pumppaint, or other fluid;

from the reservoir 152 to the spray gun, or other apparatus, 156. t

7 If the control valve 154 is now partially closed, 'so as I to restrict the secondary-fluid output of the secondary pump means 42, the strokes of the motor pistons 94 are correspondingly shortened. Any excess primary fluid is returned to the reservoir 66 through the bypass valve 140, which throttles the return flow to dissipate the excess energy in the form of heat.

Should the control valve 154 be closed completely, the motor pistons 94 merely stall in intermediate positions, all of the primary-fluid output of the primary pumping units 44 being returned to the reservoir 66 through the bypass valve 140, which dissipates all of the energy in the form of heat.

Thus, in the setting outlined, the output of the secondary pump section 42 is variable, ranging from zero to the maximum of which it is capable. zero, the displacements of the secondary pumping units 90 are zero, these displacements being a maximum when the output of the secondary pump means 42 is at its maximum. Irrespective of such variations in the delivcry of the secondary pump means 42,' the displacements of the primary pumping units 44 are constant. When the delivery of the secondary pump means 42 is reduced below its maximum, any excess primary fluid is returned to the reservoir 66 through the bypass valve 140 to dissipump is ideally suited for such things as paint spraying" operations, where variations in delivery and/or complete interruptions in delivery are essential.

Additionally, allor part of the primary-fluid output of the primary pump means 40 may be diverted to the fluidoperated motor 144 by appropriately opening the control valve 142. The motor 144 may be utilized to operate any desired apparatus, such as an agitator, not shown, for paintin the reservoir 152 in the particular exemplary application of the invention currently being considered. Alternatively, the fluid-operated motor 144 maybe utilized to operate any desired apparatus. It will be understood that as long as only part of the primary fluid is being diverted to the fluid-operated motor144, the remainder of the outputs of the primary pumping units 44 may be utilized to operate the secondary pumping units 90, at reduced displacements of, and with variations and/ or interruptions in the outputs of the secondary pumping units.

Summarizing, all of the output of the primary pump means 40 may be utilized to operate the secondary pump means 42, with variations and/ or interruptions in thedelivery from the secondary pump means, or part or all of the output of the primary pump means may be diverted to some external fluid-operated apparatus, such as the' fluid-operated motor 144. Thus, the present invention provides an extremely versatile apparatus capable of being used in a variety of different ways.

In FIG. 12 of the drawings, the plural output pump 20 of the invention is shown in a somewhat different set- When the output is 8.. ting. In this instance," the inlet lines 65 and 132' of both the primary pump means 40' and the secondary pump means 42 are connected to a hydraulic fluid reservoir 160. The outlet line 84 of the primary pump means 40 is connected to an adjustable bypass valve 162 which diverts any excess primary-fluid output back to the reservoir through'a return line 166. The bypass valve 162 normally directs the primary-fluid output of the primary pump means'40 through a control valve 164 and a check valve 168 into a line 170 to which the outlet line 136 of the secondary pump means 42 is connected, a pressure gauge 171 being connected between the valves 162 and 164 to indicate the primary-fluid pressure. It will be understood that the bypass valve162 and the control valve -164 respectively correspond to and perform the same functions as the bypass valve and the control valve 142.

The'line 170, and a return line 172 to the reservoir 160, lead to a three-position selector valve 174 controlling a double-acting hydraulic ram'176 throughlines 178 andv 180 leading to opposite ends of the ram. As will be apparent, in the position shown, the selector valve 174 blocks flow to and from the ram 176. If the selector valve'174 isimoved downwardly, it respectively connects the

lines

178 and 180 to the lines and 172 to operate the ramin one direction. If the selector valve 174 is moved upwardly, it respectively connects the lines 178 and to the lines 172 and 170 to reverse the ram 176.

Considering the operation of the plural output pump 20 of the invention in the setting of FIG. 12, if the bypass valve 162 is set to provide a high resistance to return' flow of the primary-fluid output of the primary pump section 46 to the reservoir 160, and if the control valve 164,is closed, the full primary-fluid output is available to operate the secondary. pump section 42 in the eitherdirection, depending upon the position of the se-- lector valve 174. If the latter is in its of]? position, or if the sequence valve and the manualvalve 187 are closed, then the secondarypump section 42 is stalled, whereupon the entire primary-fluid output of the primary pump means 4%) is returned to the reservoir 160 and is throttled' by the bypass valve 162, its energy being dissipated in the form of heat.

On the other hand, by setting the control valve 164 in a position such that it directs the primary-fluid output from the primary pump means 40 into the line 170 through the check valve 168, assuming that the sequence valve 185 and the manual valve 187 are closed, the primary-fluid output may also be utilized to actuate'the ram 176 in either direction. When the output of the primary pump means 40 is utilized in'operating the ram 176 in this fashion, the secondary pump section 42 is stalled until the ram encounters a predetermined resistance. When this occurs, a primary-fluid back pressure results which, through a control line 183, opens the pressureoperated sequence valve 185 in the output line 136 of the secondary pump section 42. Under these conditions, since the sequence. valve 185 is .open, the secondary pump section 42 is no longer stalled, so that all of the primaryfluid output is used to operate the secondary pump section 42 to deliver fluid to the ram 176, the secondary pump section being inoperative for this purpose until the sequence, valve is opened. It will be noted that thecheck valve 168' prevents the output of the secondary pump section 42 from returning directly to the reservoir 160 through the control valve 164' and the bypass valve 162. The manual valve 187 in parallel with the sequence valve 185 is normally closed, but may be opened to bypass the sequence valve if desired.

The foregoing external connections for the plural output pump 2% are well suited to utilizing the ram 176 to operate a hydraulic press, for example. In such a press, a high speed stroke requiring only low pressure is desirable until the work is contacted, a low speed stroke requiring high pressure being desired thereafter. By diverting the entire primary-fluid output of the primary pump means 40 to the ram 176, a relatively large volume of fluid at a relatively low pressure is available to produce the desired high speed initial portion of the stroke of the hydraulic press. When the ram 176 encounters resistance, the full primary-fluid output from the primary pump means is available to operate the secondary pump means 42. The latter, with the particular construction hereinbefore described, then delivers a relatively low volume of high pressure fluid to effect the final or working portion of the stroke of a hydraulic press, for example. When the final portion of the working stroke of the hydraulic press has been completed, the secondary pump means 42 stalls, whereupon the entire primary-fluid output is diverted back to the reservoir 169, its energy being dissipated in the form of heat by the bypass valve 162.

Thus, with the particular external connections shown in FIG. 12 of the drawings, the plural output pump 20 of the invention is capable of stroking a fluid-operated reciprocatory-type apparatus at different speeds.

Summary of operation In addition to the environments of use illustrated in FIGS. 11 and 12 of the drawings and hereinbefore described, various other applications of the plural output pump 20 of the invention are possible. In each instance, the primary-fluid outputs of the primary pumping units 46 are constant, and may be utilized solely or partially to operate the respective secondary pumping units 90, or may be utilized solely or partially to operate some external fluid-operated apparatus or apparatuses, or may be dissipated in the form of heat. Similarly, the variabledisplacement secondary pumping units 90 may be operated at their full displacements, at partial displacements, or at zero displacements. Numerous possible applications of these potential modes of operation of the primary and secondary pump means 40 and 42 will occur to those skilled in the art.

Plural output secondary pump section 42 Turning to FIGS. 5 to -8 of the drawings, it is possible, as hereinbefore outlined, to utilize the secondary pump section 42 as a plural output section capable of handling a number of different fluids up to the number of secondary pumping units 90. In the particular embodiment illustrated in FIGS. 5 to 8 of the drawings, the secondary pumping units 90 are divided or grouped into two sets, one comprising two of the secondary pumping units and the other three.

Considering how the foregoing is accomplished, the annular secondary-pump inlet means 128 is simply plugged at two points, by

plugs

182 and 184, to isolate two of the inlets leading to the secondary pump pistons 120 from the other three. The secondary pump pistons 120 of the set of two have their inlets supplied with one secondary fluid through the inlet passage 131. The secondary pump pistons 120 of the set of three have their inlets supplied with another secondary fluid through a special inlet passage 186.

The secondary pump pistons 12% of the set of three have their outlets all in communication with the central outlet passage 135. The other two have their outlets connected to a special, off-center outlet passage 188 through branch passages 199.

Thus, with the foregoing construction, one secondary fluid is handled by two of the secondary pump pistons 120, and another secondary fluid is separately handled 19 by three of the secondary pump pistons. This separate handling may be continued to the points of ultimate use or disposal of the two secondary fluids, or the two secondary fluids may be mixed by any suitable apparatus if desired, various treatments being possible.

It will also be understood, as previously suggested, that the inputs to and outputs from the secondary pump pistons may be divided or grouped in sets of various numbers, ranging from the total number of secondary pump pistons down to one.

It will also be understood that in addition to grouping the secondary pump pistons 120 into sets, the secondary pump pistons of each set may provide a diflerent secondary-fluid output pressure. This may be accomplished by varying the ratio of the diameters of the motor and

secondary pump pistons

94 and 120 from set to set. For example, one possibility might be to have two sets of two of the secondary pump pistons 120 and a third set of one. The two sets of two might be utilized to pump different paint ingredients at low volumes and high pressures and the set of one might be utilized to pump a very large volume of air at a rather low pressure, the two paint ingredients and the air being mixed in a suitable spray gun, or the like. Various other possibilities will also occur to those skilled in the art.

Alternate primary pump section 200 Turning to FIGS. 9 and 10 of the drawings, illustrated therein is an alternative primary pump means or section 290 which can be substituted for the primary pump means or section 40. Basically, the primary pump section 200 is of the sliding vane type having circumferentially spaced, circumferentially stationary, radially slidable vanes 202 biased inwardly by springs 204 into engagement with an eccentric 206 on a drive or input shaft 208 corresponding to the input shaft 56.

Each pair of adjacent vanes 202, and the eccentric 206, cooperate to provide a fixed-displacement primary pumping device or unit 210, these primary pumping units being circumferentially spaced apart about the central axis and being actuated sequentially by the eccentric. The displacements of the intervane spaces are equal to the maximum displacements of the motor pistons 94. The respective intervane spaces communicate directly with the adjacent ends of the motor cylinders 96, as clearly shown in FIG. 9 of the drawings, and thus serve also as primary pump outlets corresponding to the primary pump outlets 72.

Each primary pumping unit 210 includes an inlet check valve 212 and an outlet check valve 214 communicating with the corresponding intervane space. The inlet check valves 212 receive primary fluid from a primarypump inlet means 216 by Way of an inlet line 218. There is also a common primary-pump outlet means 220 leading to an outlet line 222, the outlet check valves 214 being interposed between the intervane spaces and the outlet means 220 so that they are downstream from the connections between the intervane spaces and the motor cylinders 96. In other words, using terminology consistent with that employed in connection with the primary pump means 4t), and regarding the intervane spaces as constituting their own primary pump outlets, the primary-pump outlet check valves 214 are respectively disposed between the primary pump outlets and the common primary-pump outlet means 220.

It will be understood that the mode of operation of the primary pump means 209 is basically the same as that of the primary pump means 40. For example, if the primary-fluid output from the primary pump means 200 is throttled, and the secondary-fluid output from the secondary pump means 42 is unobstructed, the cyclically and sequentially varying primary-fluid pressures in the intervane spaces will cyclically and sequentially act on the motor pistons 94 to produce the maximum strokes thereof. If the demand on the secondary pump means 42 is savages fluid output from the primarypump means 260 is diverted to some other fluid-operated apparatus, the stroke 'of themotor pistons 9 3' of the secondary pump means 42 will be correspondingly shortened or reduced to zero, as the case may be. Thus, the plural output pump of the invention,

when equipped with the alternative primary pump means 269, may be utilized in the same Ways as when equiped' with the primary pump means 49.

Although exemplary embodiments of the invention have been disclosed herein .for purposes of illustration,

it will be understood that various changes, modifications and substitutions may be incorporated therein without departing 'from'the spirit of the invention as defined by the claims which follow. a

I claim: 7 g

1. In a vplural outputpump, the combination of:

' (a) fixed-displacement primary pumping devices respectively having primary'pump inlets and respectively having primary pump outlets;

(b) means for sequentially actuating said primary pumping devices;

(c) primary-pump inlet means communicating with said primary pump inlets for supplying fluid to said primary pumping devices;

(d) primary-pump outlet means commonto and communicating with said primary'pump outlets for receiving fluid discharged by aid primary pumping devices;

(e) primary-pump outlet check valves respectively disposed between said primary pump outlets and said common primary-pump outlet means;

7 (f) variable-displacement fluid-operated motors equal in number to 'the number of said primary pumping devices;

(g) said motors respectively having motor inlets respectively communicating with said primary pump outlets upstream from said primary-pump outlet check valves;

* (11) secondary pumping devices equal in number to' said primary pump'inlets for supplying fluid to said primary pumping devices;

7 (d) primary-pump outlet means common to and communicating with said primary pump outlets for re- :ceiving fluid discharged by said primary pumping devices;

(e) primary-pump outlet check valves respectively disposed between said primary pump outlets and said common primary-pump outlet means; t

(f) variable-displacement fluid-operated motors equal in number to the number of said primary pumping devices;

(11) secondary pumping devices equal in number to the number of, and respectively connected to and driven by, said motors;

(i) said secondary pumping devicesrespectively having secondary pump inlets and respectively having secondary pump outlets; g g

(j) secondary-pump inlet means communicating with saidsecondary pump inlets for supplying fluid to said secondary pumping devices; and

7 (k) secondary-pump outlet means communicating with said secondary pump outlets 'forxreceiving fluid discharged by said secondary pumping devices.

3. In a plural output pump, the combination of:

(a) fixed-displacement primary pumping devices respectively having primary pump inlets and respectivelyv having primary pump outlets;

(b) means for sequentially actuating said primary pumping devices; x V

(c) primary-pump inlet meanscomm'on to and communicating with said primary'pump inlets for sup- I plying fluid to said primary pumping devices;

(at) primary-pump outlet means common to and communicating with said primary pump outlets for receiving fluid discharged by-said primary pumping devices; I I

(e) primary-pump outlet check valves respectively dis- 7 f posed between said primary pump outletsand said common primary-pump outlet means;

, (f) variable displacement fluid-operated motors equal i (g) said 'motors respectively having motor inlets respectively communicating with said primary pump outlets upstream from said primary-pump outlet check valves;

(h) secondary pumping devices equal in number to the number of, and respectivelyconnected to and driven by, said motors; 7 v

(i) said secondary pumping devices respectively hav- 7 ing secondarypump inlets and respectively having secondary pump outlets;

(j) secondary-pump inlet means common to and communicating with said secondary pump inlets for supplylng fluid to said secondary pumping devices; and

(k) secondary-pump outlet means common to and communicating With said secondary pump outlets for I6C6lVl1'1g fluid discharged by said secondary pumping devices. 7 v

4. In a plural output pump, thecombination of:

(a) fiXed-displacementprimary pumping devices respectively having primary pump inlets and respectively having primary pump outlets;

(b) means for sequentially actuating said' primary pumping devices;

(0) primary-pump inlet means common to and communicating with said primary pump inlets wfor supplying fluid to said primary "pumping devices;

(d) pr mary-pump outlet means common to and commumcating with said primary pump outlets for rece1v 1ng fluid discharged by said primary pumping devices; a

(e) primary-pump outlet check valves respectively disposed between said primary pump outlets and said common prrmary pump outlet means;

(f) variallajle-dtispliilcement fluid-operated motors equal mnumerotenum devices; I, ber of said primary pumping (g) said motors respectively having motor inlets.re-

spectively communicating with said primary pump outlets upstream from said primary-pump outlet check valves;

(12) secondary pumping devices equal in number to the number of, and. respectivelyconnected to and driven by, said motors;

(i) said secondary pumping devices respectively having secondary pump inlets and respectively having secondary pump outlets;

(j) secondary-pump inlet means respectively communi-' (k) secondary-pump outlet means respectively communicating with sets of one or more of 'said sec- V ondary pump outlets for respectively receiving fluid discharged by said corresponding sets of secondary pumping devices.

5. In a plural output pump, the combination of:

(a) fixed-displacement primary pumping devices respectively having primary pump inlets and respectively having primary pump outlets;

(b) means for cyclically actuating said primary pumping devices in sequence;

() primary-pump inlet means common to and communicating with said primary pump inlets for supplying fluid to said primary pumping devices;

(d) primary-pump outlet means comm-on to and communicating with said primary pump outlets for receiving fluid discharged by said primary pumping devices;

(f) variable-displacement, reciprocating-type, fluid-operated motors equal in number to the number of said primary pumping devices;

(g) said motors respectively including motor pistons and respectively having motor inlets communicating with said primary pump outlets upstream from said primary-pump outlet check valves;

(h) whereby the respective outputs from said primary pumping devices cyclically tend to displace said motor pistons in one direction to produce working strokes there-of;

(i) means biasing said motor pistons in the opposite direction for effecting return strokes thereof;

(j) reciprocating-type secondary pumping devices equal in number 'to the number of said motors and respectively including secondary pump pistons connected to and driven by said motor pistons;

(k) said secondary pumping devices respectively having secondary pump inlets and respectively having secondary pump outlets;

(l) secondary-pump inlet means communicating with said secondary pump inlets for supplying fluid to said secondary pumping devices; and

(m) secondary-pump outlet means communicating With said secondary pump outlets for receiving fluid discharged by said secondary pumping devices.

6. In a plural output pump, the combination of:

(b) means for cyclically actuating said primary pumping devices in sequence;

' (c) primary-pump inlet means common to and communicating with said primary pump inlets for supplying fiuid to said primary pumping devices;

(d) primary-pump outlet means common to and communicating with said primary pump outlets for receiving fluid discharged by said primary pumping devices;

(2) primary-pump outlet check valves respectively dis- '(h) whereby the respective outputs from said primary pumping devices cyclically tend to displace said motor pistons in one direction to produce working strokes thereof;

(i) means biasing said motor pistons in the opposite direction for eflecting return strokes thereof;

(j) reciprocating-type secondary pumping devices equal in number to the number of said motors and respectively including secondary pump pistons connected to and driven by said motor pistons;

(k) the cross sectional area of at least one of said secondary pump pistons differing from that of the motor piston to which it is connected;

(m) secondary-pump inlet means communicating with said secondary pump inlets for supplying fluid to said secondary pumping devices; and V (n) secondary-pump outlet means communicating with said secondary pump outlets for receiving fluid discharged by said secondary pumping devices.

7. In a plural output pump, the combination of:

(b) means for cyclically actuating said primary pumping devices in sequence;

(c) primary-pump inlet means common to and communicating with said primary pump inlets for supplying fiuid to said primary pumping devices;

(f) variable-displacement, reciprocating-type, fluidoperated motors equal in number to the number of said primary pumping devices;

(h) whereby the respective outputs from said primary pumping devices cyclically tend to displace said m0- tor pistons in one direction to produce working strokes thereof;

(1') means biasing said motor pistons in the opposite direction for effecting return strokes thereof;

(j) reciprocating type secondary pumping devices equal in number to the number of said motors and respectively including secondary pump pistons connected to and driven by said motor pistons;

(k) the cross sectional area of at least one of said secondary pump pistons being less than that of the motor piston to which it is connected;

(m) secondary-pump inlet means communicating with said secondary pump inlets for supplying fluid to said secondary pumping devices; and

(n) secondary-pump outlet means communicating with said secondary pump outlets for receiving fluid discharged by said secondary pumping devices.

8. In a plural output pump, the combination of:

(a) primary pump means including fixed-displacement primary pumping devices circumferentially spaced about an axis and respectively having primary pump inlets and respectively having primary pump outlets;

(b) actuating means for cyclically actuating said primary pumping devices in sequence;

(c) primary-pump inlet means common to and communicating with said primary pump inlets for supplying fluid to said primary pumping devices;

(d) primary-pump outlet means common to and communicating with said primary pump outlets for receiving fiuid discharged by said primary pumping devices;

(2) primary-pump outlet check valves respectively disspaced about tor pistons .in one axial direction to produce working strokes thereof; a (j) means biasing said motor pistons in the opposite axial direction for eifec'ting return strokes thereof; 7

(k) reciprocating-type secondary pumping devices I 7 equal in number to the number of saidlmotors and respectively. including secondary pump pistons aligned with and connected to and driven by'said I with saidusecondary pump inlets for supplying fluid to said secondary pumping devices; and (n) secondary-pump outlet means communicating with said secondary pump outlets for receiving fluid discharged by said secondary pumping devices.

9. Ina plural output pump, the combination of:

(a) a housing havingan axis;

(b) fixed-displacement primary. pumping devices in said .housing' and circumferentially spaced-about said axis and respectively having primary pump inlets and respectively having primarypurnp outlets;

(0) means in said housing for cyclically actuatingsaid. primary pumping devices in sequence; v i (d) primary-pump inlet means in said housing common to and communicating with said primary pump inlets for supplying fluid to said primary pumping devices;

(e) primary-pump outlet means in said housing common to and communicating with said primary'pump outlets for receiving fluiddischarged by said primary pumping devices;

(f) primary-pump outlet check valves in said housing and respectively disposed between said primary pump outlets and said common primary-pump outletmeans;

(g) variable displacement, reciprocating type fluidoperated. motors equal in number to the numberof said primary pumping devices; T

(h) said motors being disposed in said housingand being circumferentially spaced. about and oriented parallel to said axis;

(i) said motors respectively including motor pistons and respectively having motor inlets communicating with said primary pump outlets upstream from said primary-pump outlet check valves;

(j) whereby the respective outputs from said'prirnary pumping devices cyclically tend to displace said motor pistons in one axial direction to produce working strokes thereof;

(k) means insaid housingbiasing said motor pistons in the opposite axial'direction for eflecting return strokes thereof; a

g (l) reciprocating-type secondary pumping devices in 10. Ina plural output pumpythe'combination of:

(a) a housing having an axis; I

(b) fixed-displacement primary pumping devices in said housing and circumferentially spaced about said axis and respectively having primary pump inlets and respectively having primarypump outlets;

(0) means in said housing for cyclically actuating said primary pumping devices in sequence;

(d) primary-pump inlet means in said housing common to and communicatingiwith said primary pump inlets for. supplying fluid to'said primary pumping devices;

(e) primary-pump outlet means in said housing common to and communicating with said primary'pump outlets for receiving fluid dischargedby said primary pumping devices;

(f) primary-pump outlet check valves in said housing and respectively disposedbetween said primary pump outlets and said common primary-pump outlet means;

(g) variable-displacement, reciprocating-type, fluid-operated motors equal in number to the number of said primary pumping devices;

(11) said motors being disposed in said housing and being circumferentially spaced about and oriented parallel tosaid axis; I

(i) said motors respectively including motor pistons and respectively having motor inlets communicating with said primary pump outlets upstream from said primary-pump outlet check Vales;

(j) whereby the respective'outputs from. said primary pumping devices cyclically tend to displace said motor pistons in one axialdirection'to produce working strokes thereof;

(k) means in said housing biasing said motor pistons in the opposite axial direction for eflecting return strokes thereof, including means for applying to said motor pistons fluid pressures less than the fluid pressures of said outputs from said primary pumping devices;

(I) reciprocating-type secondary pumping devices in said housing and equal in number to the number of said motors and respectively including secondary pump pistons aligned with and connected to and driven by said motor pistons;

(m) said secondary pumping devices respectively having secondary pump inlets and respectively having secondary pump outlets;

(n) secondary-pump inlet means in said'housing and communicating with said secondary pump inlets for supplying fluid to said secondary pumping devices; and

(o) secondary-pump outlet means in said housing and communicating with said secondary pump outlets for receiving fluid discharged by said secondary pumping devices.

11. In a plural output pump, the combination of:

(a) primary pump means including fixed-displace ment primary pumping devices circumferentially spacedvabout an axis and respectively having primary pump inlets and respectively having primary pump outlets;

(b) actuating means for cyclically actuating said primary pumping devices in'sequence;

(d) primary-pump outlet means common to and communicating with said primary pump outlets for receiv- 17 ing fluid discharged by said primary pumping devices;

( variable-displacement, reciprocating-type, fluidoperated motors equal in number to the number of said primary pumping devices;

(g) said motors being circumferentially spaced about and oriented parallel to said axis;

(h) said motors respectively including motor pistons and respectively having motor inlets communicating with said primary pump outlets upstream from said primary-pump outlet check valves;

(i) whereby the respective outputs from said primary pumping devices cyclically tend to displace said motor pistons in one axial direction to produce working strokes thereof;

(j) means biasing said motor pistons in th eopposite axial direction for effecting return strokes thereof;

(k) reciprocating-type secondary pumping devices equal in number to the number of said motors and respectively including secondary pump pistons aligned with and connected to and driven by said motor pistons;

(m) secondary-pump inlet means communicating with said secondary pump inlets for supplying fluid to said secondary pumping devices;

(n) secondary-pump outlet means communicating with said secondary pump outlets for receiving fluid discharged by said secondary pumping devices; and

(o said primary pumping devices including radially reciprocable plungers.

12. In a plural output pump, the combination of:

(11) said motors respectively including motor pistons and respectively having motor inlets communicating With said primary pump outlets upstream from said primary-pump outlet check valves;

(1') whereby the respective outputs from said primary pumping devices cyclically tend to displace said motor pistons in one axial direction to produce working strokes thereof;

(j) means biasing said motor pistons in the opposite axial direction for effecting return strokes thereof;

(0) said primary pump means comprising circumferentially stationary, radially movable vanes and said actuating means comprising eccentric means for varying the volumes of the intervane spaces between paired adjacent vanes cyclically and sequentially, the pairs of vanes defining said intervane spaces respectively constituting said primary pumping devices.

13. In a plural output pump, the combination of:

(11) means for sequentially actuating said primary pumping devices;

(0) primary-pump inlet means communicating with said primary pump inlets for supplying fluid to said primary pumping devices;

((1) primary-pump outlet means common to and communicating with said primary pump outlets for receiving fluid discharged by said primary pumping devices;

(1) variable-displacement fluid-operated motors equal in number to the number of said primary pumping devices;

(g) said motors respectively having motor inlets respectivelycommunicating with said primary pump outlets upstream from said primarypump outlet check valves;

(h) secondary pumping devices equal in number to the number of, and respectively connected to and driven by, said motors;

(i) said secondary'pumping devices respectively having secondary pump inlets and respectively-having secondary pump outlets;

(j) a primary fluid operated apparatus; and

(k) means interconnecting said primary-pump outlet means and said primary fluid operated apparatus for selectively delivering at least a part of the combined outputs of said primary pumping devices to said primary fluid operated apparatus.

14. In a plural output pump, the combination of:

(b) means for sequentially actuating said primary pumping devices;

(h) secondary pumping devices equal in number to ,(iyg i d secondary pumping device s,respeetivelyhav ing secondary pumpinlets and respectively having secondary pump outlets; f i

(j) a primaryfluid operated apparatus;

(k) means interconnecting said primary-pump outlet means andsaidpn'marytfluid operated apparatus for selectivelydeliveringat'least a part of the combined outputs of said primary pumping devices to said primary fluid operated apparatus;

(1) at least one secondary fluid operated apparatus differing from said primary fluid operated apparatus; and a (m) means for selectively delivering the output of at least one of said secondary'pumping devices to said secondary fluid operated apparatus.

(a) primary pump means comprising alplurality of primary pumping units and .means "for actuating them in sequence;

(b) secondary pump 'means comprising a plurality of variable-displacement fluid operated, secondary pumping, units respectively connected to :andsequentially operable by the outputs of said primary pumping units;

(c) a primary fluid operated apparatus;

(d) means interconnectingsaid primary pumping units for selectively delivering at least a part of the combined outputs thereof to said primary fluid operated apparatus; l a

(e) at least one secondary fluid, operated apparatus;

(f) means for selectively'delivering the output of at outlet check valves communicating withione end of said primary pump cylinder;

(b) means for reciprocating said primary pump piston in said primary pump cylinder; and" (c) variable-displacement secondary pump means for pumping a secondary fluid, including a secondary pump cylinder one end of which communicates with 15. In a plural output pump system, the. combination of:

said one end of said primary pump cylinder between said primary inlet and outlet check valves, a floating secondary pump piston reciprocable in said secondary pump cylinder by the primary fluid in response to reciprocation of said primary pump piston .in said primary pump cylinder; and secondary'inlet and outlet check valves communicating with the der, a primary pump piston reciprocablein; said,

primary pump cylinder, and primary inlet and outlet check valves communicating with .oneend of said primary pump cylinder;

(b) means for reciprocating said primary pump piston' in said primary'pump cylinder;

(c) variable-displacement secondary pump means for pumping a secondary; fluid, including a secondary pump cylinder one end of which communicates with said one end of said primary pump cylinder be-.

tween said primary inlet and outlet check valves,

a floating secondary pump, piston reciprocable in said secondary pump cylinderbythe primary-fluid in response to reciprocation of said' primary pump 'piston, in. saidprimary pumpcylinder, and secondary inlet and outlet check valves communicating with the other. end of .said secondary pump cylinder; and

(d) means for selectively bleeding off the primary fluid output of said primary pump means so 'as to selectively vary thestroke of said. secondary pump piston, andthus the outputof saidsecondary pump means. I

18. In a'plural output pump, the combination of:

(a) fixed-displacement primary pumping .devices respectively having primary pump inlets and respectively having primary pump outlets;

(b) means for sequentially actuating said primary .pumping devices;

(c) primary-pump inlet means communicating with said primary pump inlets for supplying fluid to said primary pumping devices; I I

(d) primary-pump outlet means common to and communicating with'said primary pump outlets for-receiving fluid discharged by :;said primary pumping devices; i i v (e) primary-pump outlet checkivalves respectively disposed between said primary pump outlets and said common primary-pump outlet means;

(g) said'motors respectively having motor inlets respectively communicating with said primary pump outlets upstream fromv said primary-pump outlet check valves; T p

(h) secondary pumping devices equal in number to the number of, and respectivelyconnected to and driven by,said motors; p 7

(i) said secondary pumping devices respectively havingsecondar'y pump inlets and respectively having secondary-pumpoutlets; and V i (j) means for connecting at least two of said secondary pump inlets to, different fluid sources.

19.tIn a pump, the combination of:

(a) fixed-displacement primary pump means for pumping a primary fluid and having a'variable-volume 'chamber of fixed displacement, said chamber having a primary inlet provided with a primary inlet check valve, andhaving a primaryout-let provided with a primary outlet check valve;

(b) means for actuating said primary pump'means to vary the volume of said chamber; and

V (c) variable-displacement secondary pump means for pumping a secondary fluid, including a secondary pump cylinder one end of which communicates with said chamber betweensaid primary inlet and outlet check valves, including a floating secondary pump 7 piston reciprocable in said secondary pump cylinder by the primary fluidin response to actuation of said primary pump means, and including secondary-inlet and outlet check valves communicating with the other end'of said secondary pump cylinder. 7 20. In a plural output pump, the combinationof: (a) primary pump means comprising a plurality of fiXed-displacementprimary pumping units and means gor actuating them in sequence'to pump a'primary uid; 1 e (b) secondary pump means comprising a plurality of variable-displacement fluid-operated secondary pumping units respectively connected to and sequentially operable by the primary-fluid outputs of said primary pumping units to pump at least one secondary fluid;

and I (0) means for simultaneously varying the displacements of said secondary pumping units to simultaneously vary the secondary-fluid outputs thereof, com- Y prising means interconnecting'said primary pumping units for selectively bleeding off the combined primary-fluid outputs thereof.

References Cited by the Examiner UNITED STATES PATENTS 2,006,572 7/35 Herrmann 103-9 2,103,530 12/37 Henry 6052 2,282,977 5/42 Mast 6052 2,461,235 2/49 Raymond 103182 X 22 2,462,931 3/49 Anderson 103-9 X 2,851,953 9/58 Peterson 1034 X 3,018,902 1/62 Minty 6097 X FOREIGN PATENTS 518,840 2/31 Germany.

JULIUS E. WEST, Primary Examiner.

EDGAR W. GEOGHEGAN, Examiner.

Claims

1. IN A PLURAL OUTPUT PUMP, THE COMBINATION OF (A) FIXED-DISPLACEMENT PRIMARY PUMPING DEVICES RESPECTIVELY HAVING PRIMARY PUMP INLETS AND RESPECTIVELY HAVING PRIMARY PUMP OUTLETS; (B) MEANS FOR SEQUENTIALLY ACTING SAID PRIMARY PUMPING DEVICES; (C) PRIMARY-PUMP INLET MEANS COMMUNICATING WITH SAID PRIMARY PUMP INLETS FOR SUPPLYING FLUID TO SAID PRIMARY PUMPING DEVICES; (D) PRIMARY-PUMP OUTLET MEANS COMMON TO AND COMMUNICATING WITH SAID PRIMARY PUMP OUTLETS FOR RECEIVING FLUID DISCHARGED BY SAID PRIMARY PUMPING DEVICES; (E) PRIMARY-PUMP OUTLET CHECK VALVES RESPECTIVELY DISPOSED BETWEEN SAID PRIMARY PUMP OUTLETS AND SAID COMMON PRIMARY-PUMP OUTLETS MEANS;