US2342088A - Pump - Google Patents

Description

A. RAPPL Feb. 15, I944;

PUMP

Filed July 27, 1940 2 Sheets-Sheet 1 mMm mm m mm R @m m% mm Mm l A M 5 m 5% Q a PUMP ' Filed July 27, 1940 2 Sheets-Sheet 2 -l/ Z0 9 0 19 J ,1 1d

5 52 15 AA/ro/v 1525 Patented Feb. 15, 1944 PUMIP Anton Rappi, Buffalo, N. Y., assignor to Trico Products Corporation, Buffalo, N. Y.

Application July 27, 1940', Serial No. 347 937 20 Claims.

This invention relates to a pump for use in the generation of fluid pressure.

The novel fluid displacing means of my invention involves fundamentally the provision of a movable fluid impelling member of novel form in association with a pumping chamber whose interior wall is also of novel form whereby the fluid impelling member and the chamber wall cooperate to provide a plurality of pump chambers which are successively expanded and contracted in size by virtue of movement of the impelling member in the chamber. A primary object. of my invention is to provide a fluid displacing pump which will operate in an efficient and continuous manner and one whose construction is practical and economical.

In one form of my invention the casing of the chamber above mentioned is mounted for to. and fro movement to permit cooperation between the impelling member and the walls of the pumping chamber in a practical and eflicient manner. In such form the casing for the pump chamber itself maycomprise a second piston for a second pumping unit, a suitable casing being disposed, about such second piston to complete the second pumping unit.

In the specific embodiment of my invention which is depicted in the drawings and described in the ensuing specification the two pumping units referred to are provided with separate valving means whereby the fluids pumped by the two pumping units may be of different characteristic from each other. By the application of mechanical skill the valving arrangement there shown might be modified to'merge the streams of fluid pumped by the two pumping units in such manner that their action would be cumulative and supplementary one to the other.

In pumps constructed according to the teachings of my invention the pumping impulses are,

comparatively speaking, of relatively small amplitude and high frequency whereby the streams of fluid pumped, whether they be one or two diffeernt fluids, are nearly constant in volume and not accompanied by pulsating or surging to the extent that such pulsating and surging is present in pumps heretofore in practical use.

In the drawings:

Fig. 1 is a vertical cross sectional iew taken along the axis of rotation of the drive shaft thereof with the wall of the crank case of an internal combustion engine illustrated fragmentarily;

Fig. 2 is a cross sectional View taken generally along line IIII of Fig. l but with the rotary driving element in cross section;

Fig. 3 is an end view of the device taken fromthe left. as viewed in Fig. 1 and with portions broken away to better illustrate the fluid p'assage;

Fig. 4 is a cross sectional view taken along the line'IV-IV of Fig. 1;

Fig. 5 is across sectional view taken along line V-V of Fig. 1;

Fig. 6 is a cross sectional view taken approximately along the line 6-6 of Fig. 2

Fig. 7 is a detailed perspective-view of a valving element;

Fig. 8' is a similar View of the opposite side of such valvingelement; and' Fig. 9-- is a fragmentary diagrammatic view similar to Fig. 2 but with the elements thereof shown in another phase of cycle of operation.

In. the drawings the numeral I9 designates a casing element having a wall It and an open side opposite the wall, such open side being normally covered by a closure plate; I2 which, with the casing IE1, forms a compartment for housing pumping means. Within such compartment there is disposed a piston element t3 which, in the exemplary form, comprises a swinging vane which is pivoted as upon the pin M- which has its opposite ends supported in the wall I! of the casing Ill and in the closurerplate l2 respectively. It will be noted from a consideration of Fig. 2 that the end of the piston l3 which is adjacent the pivot pin I l is of relatively short radius struck from the pivot as a center and such end seats against a portion of the casing 10, which has a like curvature to provide a constant seal between the piston t3 and the casing H1 at this point throughout the pivotal movements of the piston.

At its opposite end the piston l3 has a projection i5 whose terminus isv likewise arcuate and struck from the center of the pivot pin it to engage a similarly curved portion of the interior of the casing in so that at this point also the piston is constantly in sealing engagement with the interior of the casing l6. These arcuate engagements together with the fact that the piston 13, in thickness, extends the full distance between the wall ll of the casing and the closure plate I 2-, results in the provision of a pair of pump chambers l9 and 20 at opposite sides of the piston as appears in Fig. 2.

The piston I3 is adapted, in a manner which will: presently appear, to oscillate about the pivot pin M to successively and alternately expand and contract the chambers l9 and 2H and suitable means, which will presently be described, are provided for utilizing such alternate expansion and contraction for the pumping of fluid. While a swinging vane type of piston has been shown and described, it will appear that the principles of my invention may be pursued in struc tures embodying a reciprocating piston or one of any other suitable form.

The medial portion of the piston I3 may be formed with a somewhat bulbous enlargement for the reccptionof means forming a second distinct but associated pumping unit which may, by suitable modification, be utilized to pump additive quantities of the same fluid as is being pumped by the first pump unit but which, in the illustrated example, is arranged to pump a second and distinct fluid. In the present embodiment of my invention such second pumping unit is utilized for producing alternating movements of the piston I3 for operating the first-described pumping unit. A chamber for such second pumping unit is formed, as appears best in Fig. 2, by providing an opening in the piston or vane I3 as at 24. In the form of the invention which is illustrated, such opening has substantially parallel side walls joined by curving end walls. This description of the shape of the opening 22 is approximately only as will presently appear.

The closure plate I2 is provided with a portion 26 which is disposed substantially centrally thereof and extends in a direction away from the casing ID. The portion 26 cooperates to support the entire pump assembly and, further, provides bearing for a drive shaft 21 for the device. As viewed in Fig. 1, the right-hand end of the shaft 21 is broken away but that end is adapted to be connected with any suitable form of drive means for rotating the shaft 21. In one embodiment the right-hand end of the shaft 21', as viewed in Fig. 1, may be provided with a gear for engagement with a cooperating gear on the camshaft of an internal combustion engine with which the pumping device is associated. The supporting wall 28 which is fragmentarily indicated in Fig. 1 will in such case be a portion of the crank case of such engine.

A fluid displacing element or piston 29 is secured to the shaft 21 for rotation therewith and to this end the displacing element 29 is formed with an opening for receiving the shaft 21, such opening being counterbored to a larger diameter at its left end, as viewed in Fig. 1, for receiving a valving element 33.

The fluid displacing element 29 has a contour which presents three lobes or protuberances which in the illustrated embodiment are equally spaced about the element 29, the intermediate portions of the contour of the element being such that the overall dimension of the element 29 is very nearly constant, considered from various angles in the plane of rotation of the element 29. In one form this end may in general be attained by forming the three equally spaced lobes of relatively small arcs, the side of the element 29 which is opposite each lobe being arcuate and having its center of curvature approximately coincident with the center of curvature of the lobe, although in actual practice certain compensation must be made for the swinging nature of the alternating movement of the piston I3 in the illustrated embodiment.

With the fluid displacing element 29 in the position illustrated in Fig. 2, that is with one of its lobes coinciding with the vertical center line and the other two symmetrically, disposed about said center line, the piston I3 which serves as a pump housing for the fluid displacingelement 29 is likewise centrally disposed and the pump chambers I9 and 20 which the piston I3 forms with the casing I9 are of equal size, that is they are at midway points in their relative conditions of expansion and contraction. As the fluid displacing element 29 is rotated in a clockwise direction, as viewed in Fig. 2, it will be seen that the lower left-hand lobe of the fluid displacing element 29 will move upwardly and to the left, as seen in that figure, while the lower right-hand lobe will move downwardly and likewise to the left, with the other lobe of that figure moving along the upper curved portion of the contour of the opening 24 in the piston I3. Such movement of the fluid displacing element 29 will cause the piston I3 to move to the left about its pivot I4 until the lower left-hand lobe of Fig. 2 reaches the horizontal center line of the axis of rotation of the fluid displacing element 29 at which time the curved side of the fluid displacing element 29 which lies directly opposite this lobe will be in engagement with the right-hand wall of theopening 29. This position represents the extreme left-hand position of the piston I3 as viewed in Fig. 2 and in this position the pump chamber I9 will be in its state of maximum contraction while the pump chamber 20 will be in its maximum condition of expansion.

Continued rotation of the fluid displacing element 29 will cause the lobe, which appears at the lower left-hand corner of the piston element 3| in Fig. 2, to move upwardly and to the right, while the lobe which is at the top center of the fluid displacing element 29 in Fig. 2 will by this time engage the right-hand side wall of the opening 29 and move downwardly and to the right until it in turn reaches a point where it coincides with the horizontal center line of the axis of rotation of the fluid displacing element 29 at the right-hand sideof the opening 24 whereupon the piston I3 will be in its extreme right-hand position and the pump chamber I9 will be fully expanded and the pump chamber 29 fully contracted.

Continuous rotation of the piston element 29 will therefore result in each of the three lobes of the fluid displacing element 29 imparting to the piston I3 both a left and a right-handmovement during each rotation of the fluid displacing element 29 with the result that each pump chamber I9 and 29 will be expanded and contracted to its maximum degree three times during each rotation of the piston element 29, this movement resulting in six complete pump chamber expansion and contraction cycles per revolution of the fluid displacing element 29.

The manner in which these expanding and contracting pumping movements are utilized in the displacement of fluid by the provision of suitable valve and conduit means for the fluid being pumped will now be described.

An axial bore 30 leads from the left end of the shaft, as viewed in Fig. l, to a point substantially medially thereof where it meets a transverse opening 3I which registers with a transverse opening 32 in the bearing portion 26. The openings 39, 3| and 32 cooperate to form a fluid discharge passage for the pump chambers I9 and 29 in a manner which will presently appear.

The portion of the shaft receiving opening which is adjacent the counterbore is provided with oppositely disposed notches as at 35. The notches 35 receive a pair of pins 36 which are secured in the shaft 27 adjacent its left end and radiate: front oppositessides theienf. It will be seen; that-the shaftzzl is';to': beassembledinto the,

displacing: element: 2.9:. from thetleft; as; viewed in;

Fig. 12, to. permit: introduction. of. the radiating pins: 36 into" the. notches 35.. 1

Subsequent to the introduction of: the shaft.

27: intothe displacing: element 29 the valving element 33". is disposed inxthe counterbore'v provided therefor in the; displacing. element. The valving' element 33 is. cup-shaped: in form: and has a pair of protuberanceszatits rim: portion for engagement in theadgiacentends of the notches so that when in assembled position the shaft 21', the displacin element 29-, and the valving elementSSJ rotateas a unit. The cup-shapedT-valwing element is shown in detail in Figs. 7 and 8- and comprises an annular portion 31. and anact as an integralunit in the embodiment of theinvention illustrated inthe drawings."

Theend wall 38' has three equally spaced fluid passages extending therethrough. as at $0, and, in

addition, is provided with a blind recess 4"! which comprises three divergent" arms disposed midway between the several ports No-partof the recess 4| extends through the'endwall' 3S and the radiating arms thereof serve to selectively connect fluid passagesforme-d; in the. wall ll of the casing In to coperate. in properly valvin'g the pump chambers l9 and" 20' in a manner which will now be described Fluid communication. with; the pump chambers l9 and 20- is gained by'meansof passages 34 and lfiwhich lead therefrom respectively, and, as appears best in Fig. 3;. open respectively injpassages and' 4''!" which terminate. in. ports 48. and 39, respectively. The port's'48 and 4'9. open into. the interior face of the. Wall H of the casing It]. Disposed between the ports..al8 and. 49 and like wise opening into the inner face of. the wall H is aport 51- to which may be connected 2. conduit 52' which will: constitute a" fluid inlet conduit to the pump chambers 18' and 2!};

It has been stated" that the valving element33 rotates with the fluid displacing element 29 and the shaft 2-1 and it will therefore appear from a consideration of the foregoing description that for a certain period during its rotation a fluid passage 40 of the valve element will pass over and be in communication with the port 48 in. the face and during such period the p umpv of the wall ll chamber 19 will be connected for exhausting fluid through passages 44 and 4B,.the port 48, and

opening 50, thence through the. bore 30 and the transverse element 3| in theshaft 2?, and through the opening 32. in. the portion 26 of' the closure plate 12. Obviously. the valving element 33 will be so related with respecttothe displacing element 29 that the foregoing. connection between the port 48 and. the opening 40 is established during movement of the piston E3 to the left, as seen in Fig. 2, to contract the pumpchamber 19.

At the same time the radiating arm of the blind recess 8! which is disposed opposite the nected by convex faces.

through the port 5 i, the blind recess 4i the port $9 and the passages 47 and 45. Continued rotation ofj'the fluid; displacing element 29 and the valving'element 33 breaksthestated connections and reverses the connection of the. ports. 48: and.

4-9;so.that.they are connectedto a source of inlet fluid and with the exhaust passages respectively. It will be noted that the respective inlet and exhaust connections of the chambers: I 9 and 20 arereversed during everyone-sixth revolution of the displacing element 29 to provide for proper valving of the. three complete pumping cycles which. are executed by each of the pumpcham-.

hers iii and 283 during a single rotation of the shaft 21'; the-fluid displacing element 29 and the valving'element 33.

It has already been set forth that the displacing element 29 in the illustrated embodiment, and as is best shown in Fig. 2, is provided with three lobes or projecting portions which are con- The resultant contour is that of a three-lobedcam with the lobes substantially equally spaced about the cam surface and the cooperation of the element 29 as a drive member for the piston !3 has previously been described. As its designation implies, however, the fluid displacing element 29 has a dual function and serves also,

and communicate with intake and discharge passages 6! and 62 respectively which extend'through the-piston element l3 and terminate at the adjacent face of the closure plate [2. or non-adjacent side of the closure plate I 2 is shown in Fig, 4, but the somewhat rectangular inletand discharge passages 63 and 64' respectively which extend from the piston engaging face of the closure plate I2 through such closure plate may be seen in Fig. '4 and terminate in variously formed elongate openingsnumbered 65, 65, 6'5 and 63. The last mentioned openings are specially formed to cooperate with a discharge fluid and inlet fluid collecting plate 10, shown in detail in 5, which is provided for merging fluid passing 6t and also for merging the fluid passing through the two inlet passages 63 to provide a single ultimate discharge passage and a single ultimate inlet passage adjacent the wall 28 of the internal. combustion engine crankcase referred. to previously."

To this end, the collecting plate 10 has, in the surface which abuts the closure plate l2, two inlet openings ii and 12 which communicate respectively with portions of the elongate openings 68 and 66 respectively, which in turn lead from the inlet ports 63. merged at the side of the collecting-plate, which is away from the closure plate l2, by a depression M which is best shown in Fig; 5.

In a similar manner, the face of the collecting platelmwhich is adjacent to the closure plate 12,

3. iven. opening 4i); servestobridge amtconnectthe: port: and" the port 51;, the latter: ofwhich: is connected with a fluid source so thatfluidi flowsv into the then enlarging pump. chamber 2i]v in cooperation with the opening 24 of the piston I3, as a second pumping. unit; 7 Each convex face of the displacing ele-' ment 2% cooperates with changing portions of the p the piston element l3 to the parts in the position illustrated inv pairs of alternately disposed I intake and discharge ports 59 and respectively lead from the interior Wall .of the opening 24.

The reverse through the two discharge passages The openings H and 12 are is provided with a-pair of openings I5 and I5 which register with portions of the elongate openings 65 and 6'! respectively which lead from the discharge passages 6 The openings I5 and I6 are also merged at the face of the plate III, which is away from the closure plate I2, by a depression 'I'I.- Fluid inlet and discharge conduits will be associated with the wall 28 of the crank case of the engine in such manner as to communicate with any part of the depressions I I and 11 respectively.

The casing II], the closure plate I2, and the fluid collecting plat ID, are held in assembled position with respect to each other with a plurality of screws Bil and the entire assembly may be secured against the wall 28 of an internal combustion engine crank case by means of screws BI.

The operation of the displacing element 29 in the opening 24 of the piston I3 with respect to its fluid displacing function will now be described. The pumping chambers 55, 56 and 51 previously referred to are transitory in their nature and are referred to merely as a convenient starting point in the description of operation. Ina sense they come into being and perform a singlepumping cycle of intake and exhaust, then cease to exist, giving way to other pumping chambers inthe rotation of the displacing element 29 inthe chamber 2 The opening 2 6 in the piston I3 is developed or generated from the displacing element 29 and is so formed that its opposite side walls, as seen in Fig. 2, are always contacted by the displacing element 29, Either a lobe or an intermediate curving face of the displacing element 29 is always in abutment with each of the approximately straight side walls of the opening 2d. Further, ,each of the three lobes of the displacing element 25 traverses the curving portions at the upper and lower ends of the opening it and remains in frictional engagement therewith throughout its travel along both the upper and lower curving portions from one side wall of the opening 24 to the other.

' With the displacing element 29 in the position I in which it is illustrated in Fig. 2 and rotating in a clockwise direction, the pumping chamber 55 is being enlarged and fluid is being drawn thereinto through the upper left-hand inlet port 53. At the same time the pumping chamber 56 is being contracted and fluid is being expressed therefrom through the upper right-hand exhaust port 69. At this same point in the cycle of operation, the pumping chamber 51 has been filled with fluid through the lower right-hand inlet port 59 and such fluid is being transferred to a point where it will be expressed from the chamber 57 through the lower left-hand exhaust port 60.

Fig. 9 is a diagrammatic view similar to Fig. 2 but with the fluid displacing element 29 in a position in advance of that illustrated in Fig. 2, and it will be noted therefrom that pumping chamber is of greater area than in Fig. 2, the pumping chamber 56 is approaching a state of total exhaustion, the pumping chamber 51 has moved to a position of communication with the lowerleft-hand exhaust port and fluid is being expressed therefrom, and a new pumping chamber 35 has been created at the lower right-hand portion of the chamber 24 and is in communication withthe lower right-hand inlet port 59 and drawing fluid therethrough.

As the approaching lobe of the displacing element29 reaches the upper right-hand exhaust port 60, the pumping chamber 56 is in a state of total exhaustion and in fact ceases to exist, giving place to the new pumping chamber 85. In subsequent rotation of the displacing element 29, the pumping chamberf5'! is likewise totally compressed when the next succeeding lobe of the displacing element '29 reaches the lower lefthand port 60, in turn giving way to a new pumping chamber which forms at the upper left-hand intake 59 in the same manner as in the case of the pumping chamber 85. It will be noted from the foregoing that at some periods in the cycle of rotation of the displacing element 29 in the formance of the other in that the portion of the oil which is the medium being pumped by the displacing element 29 is forced through a groove 81 formed in the faceof the piston I3 which is adjacent the wall II of the casing I0, such oil traveling along the bearing of the pivot pin I4 and subsequently outward through a groove 88 formed in the opposite face of the piston I3 whereupon the oil serves to lubricate and provide a fluid seal for the piston I3 at its opposite point of arcuate engagement with the casing II).

The exhaust passages 62 extend entirely through the piston I3 and at the wall II of the casing I0 intersect a circular oil groove 90 formed in the face of the piston I3 to further assist in the provision of an oil seal for the pumping unit formed by the piston I3 and the casing Ill. The inlet passages 6| stop short of the wall II of the casing II) to prevent withdrawal of sealing lubricant therefrom. In the embodiment illustrated in the drawings the external pumping unit comprising the piston I3 and the casing I0 is used to create a partial vacuum, usually for the operation of the automotive accessories, and the air pumped thereby isexhausted into the internal combustion engine crank case. In this way sealing lubricant which passes from the oil pumping unit to the air pumping unit is ultimately returned to the engine crank case.

Various modifications may be made in the structure which is described by way of example without departing from the spirit or scope of the invention which is tobe considered as limited only by the appended claims.

I claim:

1. In a fluid pump, a casing having an open ing therein comprising a continuous non-circular wall, a rotatable piston comprising a camlike element disposed in said opening for rotation therein on an axis coincident with its geometric center and having three lobes, the wall of said opening being so formed that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumpmg chambers, means permitting limiting body movement of said casing but preventing rotation thereof, said casing being formed with inlet and exhaust passages, the rotation of said piston being adaptedto successively expand said pumping chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaust passages to pump fluid in a substantially continuous flow.

-2. ln a fluid pump, a casing having an opening therein comprising a continuous non-circular wall, a rotatable piston therein comprising a cam-like element disposed in said opening for rotation therein about a fixed axis and having three lobes, the continuous wall of said opening forming a closed figure having substantially parallel side wall portions and curving end wall portions connecting the side wall portions, said-casing being mounted for guided movement transverselyito said parallel side wall portions and said opening being so shaped and proportioned with respect to the lobes of the piston that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, said casing being formed with inlet and exhaust passages,

the rotation of said piston being adapted to the side opposite such lobe approximately 0011- centric and the wall of ,said opening being so formed that the three lobes of the piston are substantially permanently in contact with" said 'wall during rotation of said piston to form a plurality of pumping chambers, means permitting limited body movement of said casing but preventing rotation thereof, said casing being formed with inlet and exhaust passages, {the rotation of said piston beingadapted to successively expand said pump chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaust passages to'pu'mp fluid 'in a substantially con- 4.'In a fluid pump, a-casing having an opening therein comprising a continuous non-circular wall, a rotatable piston therein comprising a cam-like element disposed in said opening for rotation therein and having three lobes, the continuous mm of said opening forming a closed figure having substantially parallel side wall portions-and curving end wall portions connecting the side wall portions and the piston having three arcuate lobes and three arcuate sides connecting the lobes with the radius of each lobe and the radius of the side opposite such lobe approximately concentric, said casing being the region of the exhaust passages to pump fluid in a substantially continuous flow.

- 5. Ina fluid pump, a casing having an opening therein comprising a continuous non-circular wall, a rotatable piston therein comprising a cam-like element disposed in said opening for rotation therein on an axis coincident with its geometric vcenter and having a plurality of lobes of odd number, the continuous wall of said opening forming a closed figure having substantially parallel side wall portions and curving end wall portions connecting the said wall portions and the piston having arcuate lobes and arcuate sides connecting the lobes with the radius-of each lobe and the radius of the side opposite such lobe approximately concentric, said casing being mounted for guided movement transversely to said ,paralle'l side wall portions and said opening beingso shaped and proportioned with respect to the lobes of the piston that the lobes of the piston are substantially permanently in contactwith said wall during rotation of said piston to form a plurality of pumping chambers, meanssupporting said casing for limited body movement but preventing rotation thereof, said casing being formed with inletandexhaust passages, vthe rotation of said piston being adapted to successively expandsaid pump chambers in theregion of the inlet passages and contract said pumping chambers in the region of the exhaustpassages to pump fluid in a substantially continuous flow.

6. In a fluid pump, a 'movably mounted pump oasing, a piston rotatable on an axis coincident with its goemetric center comprising a cam having three lobes-said casing having an opening therein having a continuous non-circular wall, saidrotatable-piston being. disposed in said opening for rotation therein, said opening being so formed that the-three lobes of said piston are substantially permanently in contact with said Wall during'rotation of said piston to form a' plurality of pumping chambers, said wall being'formed with inlet and exhaust passages, the rotation of said pistonabeing adapted to successively expand said pumping chambers in the regionof, the inlet passages andcontract said pumping chambers the regioniof the exhaust passages to pump fluid in a substantially continuous flow.

7. In a fluid pump, a casing and a piston disposed for to and fro movement therein, fluid conduit means for communication with the interior of said casing at opposite sides of said piston and valve means for controlling such communication, and a second pump comprising an opening formed in said piston and having a continuous non-circular wall, and a rotatable piston comprising a cam-like element having three lobes, the continuous wall of said openingbeing so formed that the three lobes of said rotatable "piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality'of pumping chambers and toimpart-to 'and'fro movement tosaid first mentionedpiston during rotationof the rotatable piston, the first mentioned piston being formed with inlet and exhaust passages for said ing being so shaped and proportioned with respect to the lobes of the piston that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to successively expand said pump chambers in the region of the inlet passages and contract said pmnping chambers in the region of the exhaust passages to pump fluid in a substantially continuous fiow.

9. In a fluid pump, an oscillatable casing having an opening therein comprising a continuous non-circular wall, a rotatable piston therein comprising a cam-like element disposed in said opening for rotation therein and having a plurality of lobes of odd number, the, continuous Wall of said opening forming a closed figure having substantially parallel side wall portions and curving end wall portions connecting the side wall portions and the piston having arcuate lobes and arcuate sides connecting the lobes with the radius of each lobe and the radius of the side opposite such lobe approximately concentric, said casing being oscillatable in a direction transverse to said parallel side wall portrons and said opening being so shaped and proportioned with respect to. the lobes of the piston that the lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to successively expand said pump chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaust passages to pump fluid in a substantially continuous flow.

10. In a fluid pump, mounting said casing for limitedj pivotal movement about a fixed axis, said casing having an opening therein comprising a continuous noncircular wall, a piston rotatable about a fixed axis and comprising a cam-like element disposed in said opening for rotation therein and having three lobes, the wall of said Opening being so formed that the three lobes of the piston are substantially permanently in contactwith said wall during rotation of saidpiston to form a plurality of pumping chambers, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to successively expand said pump chambers in the region of the inlet passages and contract said a pumping chambers in the region of the exhaust passages to pump fluid in a substantially continuous fiow.

11. In a fluid pump, a casing and means mounting said casing for limited pivotalmovement about a fixed axis, said casing having-an opening therein comprising a continuous noncircular wall, a piston therein rotatable about a fixed axis and comprising a cam-like element disposed in said opening for rotation therein a casing vand meansand having three lobes, the continuous wall of said opening forming a closed figure having substantially parallel side wall portions and curving end wall portions connecting the sidewall portions and the piston having three arcuate lobes and three arcuate sides connecting the lobes with the radius of each lobe and the radius of the side opposite such lobe approximately concentric, said opening being so shaped and proportioned with respect to the lobes of the piston that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to suecessively expand said pump chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaust passages to pump fluid in a substantially continuous fiow.

12. In a fiuid pump, a casing and a rotatable piston therein, said casing having an opening for receiving said piston, said opening, as viewed along the axis of rotation of the piston, having substantially parallel side wall portions and curving end wall portions connecting said side wall portions to form an uninterrupted wall surface, said casing being mounted for movement in a direction transverse with respect to said parallel side wall portions, said rotatable piston having three lobes, said opening and said piston being so proportioned that the three lobes are adapted to traverse said uninterrupted wall surface in substantially continuous contact therewith, said lobes cooperating with said wall surface to form pump chambers between successive lobes, and inlet and exhaust passages formed in said casing and communicating with saidpump chambers in the region of their successive expansion and contraction.

13. In a fluid pump, a casing and a piston disposed therein, means mounting said piston for pivotal rocking movement about a fixed axis,

fluid conduit means for communication with the interior of said casing at opposite sides of -said piston and valve means. for controlling such communication, and a second pump comprising an opening formed in said piston and having a continuous non-circular wall, and a rotatable piston comprising a cam-like element having three lobes, the continuous wall of said opening having parallel side wall portions engageable by said rotating piston to impart alternating pivotal movement to said first mentioned piston, said rotatable piston and said opening being so formed that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers,,the first mentioned piston being formed with inlet and exhaust passages, the rotation of said rotatable piston being adapted to successively expand said'pump chamber in the region of the inlet passages. and contract said pumping chambers in the region of the exhaust passages. I 14. In a fluid pump, a casing having an opening therein comprising a'continuous non-circular wall, a rotatable piston comprising a camlike element disposed in said opening for rotation therein on an axis coincident with its geometric center and having three lobes, the wall of said opening being so formed that the three lobes of the piston are substantially permanen'tly in contact with said wall during r'ota tion of said piston to form a plurality of pumping chambers, means supporting said casing for guided to and fro movement by engagement of the lobes of the piston with the wall of said opening, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to successively expand said pumping chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaust passages to pump fluid in a substantially continuous flow.

15. In a fluid pump, a casing having an opening therein comprising a continuous non-circular wall, a rotatable piston comprising a camlike element disposed in said opening for rotation therein on an axis coincident with its geometric center and having three lobes, said opening having substantially parallel side wall portions and curving end wall portions connecting said side wall portions to form a substantially uninterrupted wall surface and said opening being so formed that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, means supporting said casing for guided to and fro movement by engagement of the lobes of the piston with the side walls of said opening, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to successively expand said pumping chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaustpassages to pump fluid in a substantially continuous flow.

16. In a fluid pump, a casing having an opening therein comprising a continuous non-circular wall, a rotatable piston comprising a camlike element disposed in said opening for rotation therein on an axis coincident withits geometric center and having three lobes, the wall of said opening being so formed that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, means supporting said casing for oscillation by engagement of the lobes of the piston with the wall of said opening, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to successively expand said pumping chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaust passages to pump fluid in a substantially continuous flow.

17. In a fluid pump, a casing having an opening therein comprising a continuous non-circular wall, a rotatable piston comprising a camlike element disposed in said opening for rota tion therein on an axis coincident with its geometric center and having three lobes, said opening having substantially parallel side wall portions and curving end wall portions connecting said side wall portions to form a substantially uninterrupted wall surface and said surface being so formed that the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, means supporting said casing for oscillation by engagement of the lobes of the piston with the wall of said opening, said casing being formed with inlet and exhaust passages, the rotation of said piston being adapted to successively expand said pumping chambers in the region of the inlet passages and contract said pumping chambers in the region of the exhaust passages to pump fluid in a substantially continuous flow.

18. In a fluid pump, a casing mounted for guided to and fro movement, a rotatable piston comprising a cam-like element having three lobes, said casing having an opening receiving said piston for rotation therein, the wall of said opening having opposed side walls spaced a distance equal to the greatest diamctrical dimension across said piston whereby said casing is moved to and fro by rotation of said piston therein, the end walls of said opening being generated by the movement of the piston lobes therealong during the to and fro movement of said casing, whereby the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, said casing being formed with passages for taking in and exhausting fluid, the rotation of said piston being adapted to successively expand and contract said pumping chambers to pump fluid in a substantially continuous flow.

19. In a fluid pump, a rotatable piston comprising a cam-like element having three lobes, a casing having an opening receiving said piston for rotation therein and having av pivot spaced from said opening to permit'oscillation of said casing, the wall of said opening having opposed side walls spaced a distance equal to the greatest diametrical dimension across said piston whereby said casing is moved to and fro by rotation of said piston therein, the end walls of said opening being generated by the movement of the piston lobes therealong during the to and fro movement of said casing, whereby the three lobes of the piston are substantially permanently in contact with said Wall during rotation of said piston to form a plurality of pumping chambers, said casing being formed with passages for taking in and exhausting fluid, the rotation of said piston being adapted to successively expand and contract said pumping chambers to pump fluid in a substantially continuous flow.

20. In a fluid pump, a casing mounted for guided to and fro movement, a rotatable piston comprising a cam-like element having three arcu-ate lobes and three arcuate sides connecting the lobes with the radius of each lobe and the radius of the side opposite such lobe approximately concentric, said casing having an opening receiving said piston for rotation therein, the wall of said opening having opposed side walls spaced a distance substantially equal to the sum of the said two radii whereby said casing is moved to and fro by rotation of said piston therein, the end walls of said opening being generated by the movement of the piston lobes therealong during the to and fro movement of said casing whereby the three lobes of the piston are substantially permanently in contact with said wall during rotation of said piston to form a plurality of pumping chambers, said casing being formed with passages for taking in and exhausting fluid, the rotation of said piston being adapted to successively expand and contract said pumping chambers to pump fluid in a substantially continuous flow.

ANTON RAPPL.

Images