US1765360A

US1765360A - Rotary pump

Info

Publication number: US1765360A
Application number: US166548A
Authority: US
Inventors: Baumann Adolph
Original assignee: BBC Brown Boveri France SA
Current assignee: BBC Brown Boveri AG Germany; BBC Brown Boveri France SA
Priority date: 1926-02-18
Filing date: 1927-02-07
Publication date: 1930-06-24
Anticipated expiration: 1947-06-24

Description

A. BAUMANN 1,765,360

ROTARY PUMP June 24, 1930.

Filed Feb. '7, 1927 3 Sl'xeets-heefr. 1

AQ BAUMANN June 24, 1930.

ROTARY PUMP Filed Feb. '7, 1927 3 Sheets-Sheet 2 A. BAUMANN June 24, 1930.

ROTARY PUMP Filed Feb. 7, 1927 3 Sheets-Sheet 3 l; ffii/Iliff.

Asif? s:

@.Yitlllllllnffl.

. lill. lil Il!! Patented June Z4, 1930 UNITED STA-TES ..ADOLPH BA'UMANN, OF BADEN, SWITZERLAND, ASSIGNOR T0 AKTIENGESELLSCHAFT i 'BROWN'. BOVERI'GU CIE., OF BADEN, SWITZERLAND, JOINT-STOGK COMPANY 0F SWITZERLAND ROTARY Puur Application led February 7, 1927, Serialv No.

This invention relates to rotary pumps,l and it has particular relation to pumps in which the liquid is impelled in an -elastic tube by means of a suitable impeller member that progressively compresses the tube and squeezes the Huid along the same.

The pumps of the foregoing type as known heretofore, have proven delicient on account of the excessive wear of the hollow tube in which the liquid is being impelled the limitations in respect to the pressure under which such pumps could operate; the necessity of packing means and stuiiing. boxes; and other drawbacks incident to the'manufacture and operation of the same.

Among the objects of the' present invention is to provide a pump of this type which overcomes the deficiencies of the prior-art devices of this character, and is readily adapted for economical manufacture.

The features of my'inventi'on which I be` lieve -to be novel, will appear more clearly from the following descriptionof various simple exemplications of my invention, .reference being made to the accompanying drawings in which,A Y

Fig. 1 is a vertical sectional view of a pump to which my invention pertains;

Fig. 2 is ahorizontal sectional view'of the pump in Fig. 1 along the lines II--II;

. Fig. 3 is a vertical sectional view through a pump exemplifying my invention; F ig. iis a horizontal sectional view'of the pump in Fig. 3 along the line IV--IV'g Fig. 5 is a detailed sectional view through a portion of the impeller tube and the adj acent housing along the line V-V in Fig. 3; 'Figs 6 to 10 are sectional views similar to Fig. 5 illustrating various modifications of the construction of the impeller tube and of the mounting thereof; Figs. l1 and 12 are views similar to Fig. 3 illustrating modifications of the invention;

Fig. 13 is a view similar to Fig. et illustrating another modification of the invention;

Fig. 14: is a detailed sectional view of one vform of a compression valve used in my im-v proved pump; and,

A Figs. 15 and 16 are views similar to Fig. 1

trated in the arrangement of .sively contact with the tube 5 and gradually?, `0 roll flat a portion thereof, in the directionf-v 166,548, and in- Germany February i8, 1926.

The operating principle of the type of pump to which my, invention relates is i1lus`- In the inner chamber 1 of a pump casing 2 having a fluid inlet 3 and an outlet 4, 1s I dispose and elastic tube 5 of rubber, ori-60' the like. One end of the ltube is fitted into the inlet opening; the tube being disposed adjacent to the circular walls'of the cham;

ber 1, and having its other end `terminate y near the outlet .4. An impeller member 6 255 lin the formof rollers? .arranged to be rotated by a crank member 8- through a shaft" 9 extending through the casing, is sorarranged within the chamber as to progresfrom the inlet 3 toward the outlet 4,. This action of the roller members 7' thus, .to a cer- I tain extent, squeezes the liquid inthe direction towards the outlet 4, thereby forcing the i liquid towards the delivery side 4 of the pump. The two' rollers 7 of the impeller member are so arranged that as one rollerv is leaving the elastic tube 5, the other is just beginning the compression cycle at the point ofthe tube adjacent the pump inlet 3, thereby preventing backward iiow of the iuid.

A pump. made as described above has a number of disadvantages outlined above, and

'it is among the objects of the present inven- 85 tion to so improve this type of pump as to greatlyincrease'its field of application and at the same time permit its economic manufacture. v

One .of the disadvantages of the prior-art 9'0 pump is the excessive wear of the iexible impeller tube 5 by reason of 'the squeezing or pinching action that takes' place in the operation of the prior-art vpumps ofthis e aracter. One Jfeature of my invention is the provision of an improved type of impeller tube having combined therewith a special lining or insert for increasing its resistance to the wear incident to the movement of the roller or impellerthereon for reduc- 10o Figs. 1 and 2.

casing walls, or through the inner chamber of the casing, or through the lining associated with the impeller tube.

A further feature of the invention resides in the improved means for holding the impeller tube in position withinthe casing through the action of the elastic lining, and through the suitable mounting means asso-` ciated therewith. i

Another feature of the .invention resides in the arrangement for causing the elastic impeller tube to return to its expanded con- -dit1on after the passage of the roller over a portion thereof, and theitilization of a partial vacuum or underpressure in the crank case of the pump for this purpose. Other features of the invention reside in the provision of an impeller tube that extends directly through between the inlet of the pump and the outlet thereof, thusV permitting complete segregation of the fluid that is being impelled in the pump from the crank case.

' This arrangement avoids the necessity for pressure-tight packings and stuffing boxes at the point where the impeller shaft is'to lead through the walls of the pump casing.-

lt also prevents the admixture of` grease, 011, or other lubricating substances and the like, that may be employed in the ,pump mechanism to the iuid that is being Vimpelled through the pump.

A distinct feature of the invention is the provision of an improved compression valve at the delivery endl of the impeller tube of the pump. l Y

Still other features of my invention reside in the utilization of the partial vacuum withi in the crank case' chamber for withdrawing the working Huid in case the elastic impeller tube should become leaky; the utilization of auxiliary rollers for preventing excessive expansion or inflation of the portions of the impeller tube in whichthe liquid is being compressed; and other features which will appear more clearlyvfrom the further description of the several forms of the invention.

Referring to Figs. 3 and 4, the impeller tube 5 has its intake end 11 directly attached to the intake or suction pipe l2, and its delivery end 13 isdirectly connected to the delivery pipe 14, a compression valve l5 being includedin the connection between the deliveryend of the tube and the delivery pipe thespace adjacent the same,`

Lveaeee 14. The two ends of the impeller tube are preferably so brought out fromthe circular ortion of.the casing 2 as to avoid sharp ends or angles.

The impeller tube 5 is made of an elastic flexible material, such as rubber, and so arranged as to vretain its expanded, open or hollow shape. It is mounted within the cas-l ing so as to form a substantially circular annular body having its outer surface backed against the circular'inner walls of the casing. The impeller member 7 in the .form of a roller, is supported on a crank member 8 and driven by the shaft Qin counter-clockwise direction, the roller surface pressing the inner wall of the impeller tube 5 against the wall of the casing 2. As the resultvof this action of the impeller member the tube is attened at the portion where'the impeller member presses against it, the oint of flattening traveling progressively rom near the intake end ll of the tube toward the delivery end 13 thereof, thereby forcing the fluid within the tube in the direction of the arrows 16.

In order to preserve the flexible impeller tube andprevent its ra id destruction incident to the cylical action of the impeller member 7, the tube is provided with a specialinsert or lining 21, which is so arranged as to hold the tube fixed in its operating position, with its outer walls against the walls of the casin 2, and furthermore, to permit complete co lapsing of the tube under the action of the impeller member 7 without introducing sharp bends in the tube walls, and excessively straining the same.

There are a variety of constructions permitting an arrangement of the tube to secure the foregoingobjects. In the construction of Figs. 3 and 4, the lining is formed in the shape of a substantially circular flat ring arranged inside the tube adjacent the outer wall thereof, the sides of the circular rim forming somewhat enlarged rounded beads lying adjacent to the exterior and side walls I of the impeller tube, as shown at the righthand side of the view in Fig. 4. This lining may be made of substantially rigid material, but l prefer to have it made elastic, but less iexible than the tube. It may, for instance, be made of a rubber body that is harder than the walls of the tube 5. The rigidity of-the lining will in most cases be suflicient to hold the tube in shape against the walls of the casing 2.l However, if necessary, the tube may be additionally secured against the casing by bolts 22 which clamp the lining towards the casing walls.

The particular shape of the lining in the interior of the tube shown in the drawing is so chosen that when the inner wall of the tube is collapsed inwardly and pressed outwards, the inner surface of the lining is substantially co-extensive with the inner surface mensen of the vtube portion which is to'be pressedv against said lining surface. ln other words,

Y the total outer surface of the lining is substantially equal to the inner area of the tube when in collapsed condition, as shown in the lefthand side of the view in Fig. 4. This arrangement prevents pinching of the tube walls while compressed by the impeller member. It also secures Very complete impelling action, since it permits complete compressing or sealing off of the tube under the action of the impeller member pressing against the inner walls of the tube. In this way the suction and delivery spaces of the pump are completely separated and undesirable reverses of the flow are prevented.

The outer surface of the roller 7 is so shaped as to substantially conform to the inner periphery of the lining, or the collapsed condition of the tube when it is pressed against the lining, respectively. In the preferred arrangement the width of the lining is so chosen that only a relatively limited portion of the tube at the interior side thereof is subjected to the action of the roller, and is moved between the open and the collapsed position, respectively, the side walls of the tube and the exterior thereof being sustantially free from any strains.

Under some operating conditions the pressure in the portion of the tube between the impeller and the compression valve 15 .may

be so large as to tend to produce excessive inflation of the elastictuba 1n order to prevent, and safeguard against, such excessive inflation, I provide -the tube w'ith speciall frneans for limiting the inward radial movement of the innerwalls of the impeller tube. Such means may have. the form of a plurality of guide rollers 25 carried on an eXtension of the crank-8, opposite the impeller roller 7. While the impeller roller is so mounted that the outer surface thereof, contacts with the surface of the tube when in collapsed condition, the guide rollers are so arranged asto contact with the impeller tube when it is in open or undeformed condition.

As shown in the detailed view of Fig.' 5, the-lining 21 may be made hollow with a chamber 31 in the interior thereof to permit circulation of a liquid in order to cool the impeller tubeand the associated portions of the pump, or for any-other purpose, such as to bring the fluid that is impelled in the pump f in a heat-exchanging relation with another fluid. Cooling of the impeller tube is very often desirable, particularly where the temperature conditions are such that the constant bending of the iiezrible tube produces therein sufficient friction losses as to cause a temperature rise beyond an allowable value.

Fig. 5 shows the impeller tube in collapsed or deformed condition, the dash-dotted line' corresponding to the undeformed condition of the tube after the roller has moved to clamp the, impeller tube in place against the outer casing walls. By reason of the particular shaping ofthe inner surface of the lining and the roller, the tube will be collapsed without pinching the side portions thereof between the roller and the casing walls, and at 'the same time a complete closure of the tube at the point where'the roller acts thereon will be obtained.

Additional cooling of the tube and the associated portions of the pump may be secured b circulating through the interior of the cgamber 1 a suitable fluid, for instance, by

means of a pipe connection indicated at 35.-

In the preferred arrangement of my invenvand the lining, and serve to additionally y tion the pressure within the crank-case chamber 1 around 'the impeller tube 5, is maintained below the pressure of the fluid lwithin the impeller-tube. rlhis partial vacuum or pressure difference between the interior of the impeller tube and the exteriorl thereof, will assist the tube in returning toits normal undeformed or expanded position after the roller which flattens the same has passed to another portion. lt will also protect against leakage of the tube and lead away any portions cf the fluid that may getinto the crankcase chamber through a leak. l

In Figs- 6 to 10, there are shown a number lof modiiications of the tube mounting and the associated lining.` ln the construction of Fig. 6 a result similar to that obtained with the arrangements of Figs. 3 and 4 is obtained by making the lining in thev form of two rings, 41 and 42, of rubber or similar elastic material. The

rings

41, 42 are disposed opposite each other adjacent the side walls of the tube and are held in place within the tube between the side walls 43 of the casing which partially overlaps the elastic tube and the lining, like in the mounting of tires in motor car Wheels. With such arrangement no further attachment of the lining and. the tube is required.

In the modication of Fig. 7 the tube anti the lining constitute a unitary body', a reinforced suitably shaped portion of the tube taking the place of a separate lining.v

Fig. 8 shows an arrangement for supporting the tube and the lining in annular grooves vbeads for Clamping in the annual grooves of the side walls of the casing similar in construction to 'that of Fig. 7.

In the form of the invention shown in Fig. 10, the impeller-tube does not have the form of a closed integral tube, but it has a iexible portion which constitutes the inner wall of the impeller tube, and has its sides 46 clamped to the side walls 47 of the lining which constitutes the other portion of the impeller tube. The clamping of the flexible portion' of the impeller tube to the lining is effected by the overlapping portions of the casing walls at 48.

In the form of the invention shown in Fig. 11, the impeller tube is made in the form of a substantially closed ring 51 which is split at the top 52 where the two ring ends meet and abut against each other. In this construction the suction or intake sideV 53 and the delivery side 54 of the pump of the impeller tube are separated by enlarged portions 54 of the lining. The lining ismade of two halves which may be separately inserted into the tube through the ends thereof at the point 52 where it is split, the enlarged portions of the lining at 54 -servingas plugs to close the two ends of the tube.. The lining is suitably clamped to the casing walls by the bolts 22, a sleeve 55 being fitted over the two tube ends at the point where they meet to hold these portions securely in place.

The'entire arrangement is such that when the inner wall of the impeller tube is considered in collapsed position adjacent to the inner surface of the lining, it will have a. substantially circular surface around thecenter of rotation of the impeller member 7. With the foregoing construction the impeller roller 7 remains continuously in contact with the iexible tubular member, whereas, in the arrangement shown in Figs.- 3 and 4, the roller had to pass over a gap at the portion between I A the intake and delivery endsof the impeller tube.

In the form of the invention shown in 12, bot-h the tube and the lining form a complete circle, whereas, in the construction shown in Fig. 11 the impeller tube is of somewhat elongated shape. In the construction of Fig. 12, the inner surface of the tube is tightly secured to the lining at 56, by cementling, rivetin ,or otherwise, in order to separate the delivery and suction portions of the impeller tube. The circular construction of the ring is helpful in preserving the flexible tubular member and extending the life thereof.

Both in the-.constructions of Fig. 11 and Fig.l2, the suction and delivery pipes are back-flow o connected to the ends of the tube by means of

radial attachments

57 and 58 disposed in radial direction in a manner similar to the valves of pneumatic tires of automobiles and the like.

The form of the invention shown in Fig. 13 is particularly suitable for high pressures,

. the casing 61 being so shaped as to practically enclose and surround the entire outer walls of the impeller tube 5, leaving only a comparatively narrow gap 62 through which the impelling roller 7 may press against the tube and impel the liquid therein.

'In this construction the casing walls 61 are shown provided with hollow passages 63 adjacent to the portions where they contact with the impeller tube 5 to permit circulation of additional cooling liquid through said passages, or for any other heat-exchanging operations.

The direct connection of the two ends of the impeller tube to the suction pipe and the 'delivery pipe, respectively, as shown in Figs. 3, etc., is very desirable from the viewpoint of maintaining the iiuid that is impelled by the pump completely segregated from the moving mechanisms of the pump and of dispensing with packings, stutting boxes, and the like. The working Huid is thus entirely enclosed by an air tight elastic compression chamber entirely dispensing with glands, stutin boxes, and the like.

In the preferred embodiment of the invention, I provide in the delivery end of the impeller tube a compression valve, such as indicated at Fi s. 3 and 11, in order to prevent the liquid into the impeller tube in case a leak should develop therein, and also in order to avoid continuous subjection of the impeller ytube to the full pressure of the Ycompressed fluid. The provision of the comcompression valve, is utilized.

The compression valve, as shown in Fig. l 3, is formed by an enlargement 71 of the elastic lining 21 near the delivery end oi the impelling tube. This enlargement 71 constitutes a substantially circular body which has a hollow tubular chamber 72 at its upper end. The delivery pipe 14 is directly connected to the upper end of the tubular chamber 72 which is provided at its lower end with a plurality of perforations 73 extending radielly outward through the walls of the chamber.` The delivery end 13 of the impeller tube is fitted over` the enlarged portion 71 of the lining 'and forms an enclosure aroundl the space provided with the perforations 73.

In operation, the liquid compressed inthe impeller tube by the action of the impelling roller 7 will be impelled towards the delivery end of the impeller tube, and cause said end against the to be im'iated at the space around the perforations 73, thus delivering the fluid through said perforations into the hollow chamber l752. and therethrough into the delivery pipe 14;. 4A suitable clamping ring 75 around'the 'delivery end 13 of the impeller tube may serve to hold the same sealed to the adjacent portions of the valve.

In Fig. 14 is shown another valve construction comprising a tubular valve chamber 81 having a threaded outer surface over which the delivery end 13 of the impeller tube is fitted and held clamped by means of a ring 82. A closure member 83 is held pressed co-operating valve seat in the valve chamber 81 by means of a spring 85 which is held in a co-operating portion 86 of the valve to permit the adjustmentl of the spring 85 in a familiar manner. The valve chamber is held in place within the pump cas-v ing by means of a sritable flange 87. The insert 21 within the tube has an enlarged portion 88 at the end thereof adjacent to the lower'part of the valve chamber 81 in order 25 to make the dead space at the endl of the compression part of the impeller tube as small as possible, as seen in the drawing in which the impeller tube 5 is shown in deformed position, being pressed down by the impelling roller 7 corresponding to its position at the end of the compression cycle. The shape of the impeller tube in undeformed condition is indicated by the dash-.dotted line 89.

One of the reasons for the excessive wear of lthe impeller tube in the pumps as made heretofore, is the tangential pull on the material behind the roller and the tendency to form a wave in front of the roller, the latter leading very often to puckering and pinching of the tube.

In accordance with my invention the impeiling means are so designed withv respect to the impeller tube as to eliminate this drawback. To this end I so correlate the size and the shape of the impeller means with respect to the dimensions and shape of the impeller tube that the movement of the roller on the tube is not accompanied by any forces tending t0 pull the tube walls in a direction in which 5o it would cause the formation of folds, or the like. In theconstruction shown in Figs. 3,

etc., Iattain this object by making the di- .'ameter of the im elling roller 7 substantially e ual or larger t an one-halfv of the internal diameter of the tube when in depressed condition.

In Fig. 15 there is illustrated diagrammatically the case where the diameter of the impelling roller 7 is half the diameter of the base circle 5 upon which it is rolled, corresponding to the tube5 in the deformed condi tion. The curve described by a point 93 on the roller circle 7 is in this ease a hypocycloid in the shape of a straight radially-extending In the case illustrated by 16- wherein the diameter of the rolling circle is more than one-half the diameter of the base circle 5', l

the curve described b a point 93 on the rolli ing circle is acurve hypocycloid 92 which contact with the tube without applying any pressure to the walls thereof. -Under such conditions the walls of the tubes would be subjected only to radial forces corresponding to the arrow 95, and would be free from tangential stresses.

I-Iowever, if the roller is pressed against the elastic tube, the material of the latter will be rolled out in the direction of the roller motion, even if n0 sliding should occur. Accordingly, there will be a tendency to form puckers and the tube walls will be subjected to a certain amount of tangential pull, which would be, however, only aI fraction of the pull ,that would be present in case the diameter of the roller were made' less than one-half of the diameter of the base circle.

By making the diameter of the roller greater than one-half the diameter of the base circle, the foregoing rolling action can be completely compensated as seen from the diagrammatic view in Fig. 16. In the latter case the point 93 will not move in radial direction, but will be forced backward, thus offsetting the force component which tends to move the material in forward direction when compressed by the roller. By suitably dimensioning the roller, the formation of puckers may thus be completely prevented, and the useful life of the tube extended.

My invention is susceptible of many other I modifications than those described and speciiically pointed out hereinabove, and it is my desire that the appended claims be given a broad construction commensurate wlth the scope of my invention which, as shown hereinabove, not only avoids the difficulties met in the prior-art constructions, but embodies in addition a number of features which greatly extend the usefulness of the'type of pump under consideration. .,l .l

The particular construction of the pump in which the impelled fluid is completely se regated from contact with the rotating or ot er Amoving members of thepump mechanism,

safeguards the fluid against contamination with the impurities, such as oil, grease, etc. This' feature makes the pump particularly suitable for impelling chemically active fluids the pump also particularly adapted for use in connection with poisonous substances, as the escape of such substances is positively excluded. vThe absence of packings and points of leakage makes the pump also very effective for producing high vacua.

I claim as my invention:

l. In a pump comprising a tubular impeller chamber of elastic material and means for propelling fluid through said chamber by successively flattening portions of said tubular chamber in the direction in 'which the fluid is to be moved, means associated with and disposed in said chamber and providing for complete closure of any section thereof Without introducing sharp bends into the flexible Working Walls thereof.

2. In a pump comprising an impeller tube having an-elastic wall and impeller means for progressively closing sections of said tube by successively compressing portions of the flexible Wall in the direction in which the fluid is to be impelled, means associated with and disposed in said tube to constitute a relatively stable support for the flexible Wall thereof when in depressed condition.

Si. In a pump comprising an impeller tube having an elastic Wall and impeller means for progressively closing sections of said tube by successively compressin portions of the flexible walls in the direction in which the fluid is to be impelled, means associated with said tube to constitute a relatively stable sup port for the flexible Walls thereof when in depressed condition, said support being rounded to prevent sharp bends in the flexible portions of the tube.

4. In a pump comprising an impeller tube having a flexible wall portion and impelling means for progressively closing said' tube by successively compressing the flexible walls thereof in the direction in which the fluidis to be impelled, a lining associated with said vtube to act as a support forvsaid flexible Wall when in deformed condition, said lining bein relatively rigid with respect to the flexible portions of said tube and permitting complete flattening of sections o said tube without introducing sharp bends in the flexible por-A 4 tions thereof.

6. `In a pump comprising an impeller tube having a flexible Wall portion and impelling means for progressively closing said tube by successively compressing the flexible wall thereof in the direction in which the fluid is to be impelled, a lining associated with said tube to act as a support for said flexible Wall when in deformed condition, said lining be` ing relatively rigid with respect to the flexible `.portions of said tube and permitting complete flattening of sections of said tube without introducing sharp bends in the flexible portions thereof, and means associated with said lining for cooling the same.`

7.- In a pump comprising an impeller tube means for progressively closing said tube by successively compressing the flexible Wall thereof in the direction'in which the fluid is to be impelled, a-liningassociated Withsaid when in deformed condition, said lining being relatively rigid with respect to the flexible portions of said tube and permitting complete flattening of sections of said tube. -vvitliout introducingsharp bends in the flexible portions thereof, said lining having a hollow conduit for circulating therethrough a fluid in heat-exchanging relation therewith.

8. In a ump comprising an impeller tube having a exible wall portion and impelling meansfor progressively closing said tube by v9. In a pump comprising an impeller tube.

having a exible Wall portion and means for impelling a fluid in said tube by progressively flattening sections of said tube in the direc- .80 having a. flexible Wall portion and impelling,

.85 tube to act as a support for said flexible Wally liti tion in which the fluid is to be impelled, a

substantially rigid casing having Walls supporting the `portions of said tube a ainst which the flexible portions thereov are pressed, and means for holding the portions of said tube adjacent to the Walls of the casing in substantially rigid condition thi-oughout the operation thereof. f

10. In a pump, a substantially circular casing, a substantially annular impeller tube adjacent to the Walls of said casing, means for holding one Wall of said tube in substantially rigid position against the Walls of said casing, the opposite Wall of said tube being relatively flexible and arranged to be compressed against the rigid Wall .portion to permit complete flattening of the sections of rigid position against the walls of said cas ing, the opposite wall of said tube being rela- -to said tube as to tively flexible and arranged to be compressed against the rigid wall portion to permlt complete flattening of the sections of said tube, 1m eller means arranged to be driven lalong sai tube to successively flatten portions there-l of in the direction in which the fluid is to be' impelled, said tube being so shaped and supported as to prevent sharp bends in the leXile portions thereof under the action of saidimpeller means, bead members, extendine along said tube, and'means associated with said casin for clamping said bead members thereto to old said tube in position. v-

12. In a pump, a substantially circular casing, a substantially annular impeller tube ad\ jacent to the walls of said' casing, means for holding one wall of said tube in substantially rigid position against thewalls of said casing, the opposite wall of said tube being rela-' tively flexible and arranged to be compressed against the rigid wall Aportion to permit complete flattening of the sections of said tube, impeller means arranged to be driven along said tube to successively flatten portions thereof in the direction in which the fluid is to be impelled, said tube being so shaped and supported as to prevent sharp bends in the flexible portions thereof under the action of said impeller means, bead members extending along said tube, and means associated with said casing for clamping said bead members thereto to hold said tube in position, said impeller means being so arranged with respect substantially eliminate tangential pull of the iexible tube walls incident to the progressive movement of the impelling means. l

13. In a rotary pump comprising a substantially circular impeller tube, a fluid intake connection at one end of said tube and a fluid delivery connection at another end of said'tube, said tube being collapsibleto permit successive closure of the sections thereof in the direction from the intake end tc the delivery end thereof -to impel the fluid, an impeller roller movable on said tube to progressively close sections thereof and impel the fluid towards the delivery end of said tube, said impeller roller being so dimensioned. with respect to the path on which it rolls that the force component exercised by said roller on the co-operating Walls of said tube is permit successive Athereof in the direction from said tube,

directed substantially walls of said tube in un eformed condition.

stantially circular impeller tube, a fluid intake connection at one end of said tube and a fluid delivery connection at another end :of said tube, said tube being collapsible ,y to

closure of the sectionsv the intake end to the delivery end thereof to impel the fluid, an impeller roller movable on said tube'to progressively close sections thereof and impel the fluid towards the delivery end of said tube, said impeller roller being so dimensioned with respect to the path' on which it rolls asto substantially eliminate pull on the erpen'dicular to the 14. In a `rotary pump comprising a sub# flexible portion of said tube in the directionv of the movement of the roller.

15. In a rotary pum comprising a substantially circular impe ler tube, a fluid intake connection at one end yof said tube and a fluid delivery connection at another end of said tube, said tube being .collapsible to permit successive closure of the sections thereof'in the direction from 'the intake end to the delivery end thereof to impel the Huid,

an impeller roller movable on said tube to progressively close sections thereof and impel the fluid towards the delivery end of saidtube, the curvature of said roller being'so related to the curvature of the path onl which it rolls as to substantially eliminate forces tending to pull the flexible walls of said tube in the direction of the impeller movement.

16. In a rotary pumip comprisinga subst-antially circular lmpeller tube, take connection at one end of said tube and a fluid delivery connection at another end of said tube being collapsible to Vpermit successive closure of the sections thereof Ain the direction from the intake end to the delivery end thereof to impel the fluid, an impeller roller movable on said tube to progressivel close sections thereof and impel the fluid towards the delivery end of said tube, said impeller roller being so dimensioned with res ect to the path on which it rolls that the orce exerted vby a point o'f the roller on the cooperating walls of the tube is directedsubstantially perpendicular to said path or in a direction back thereof.

17. In a rotary pump comprising a substantially circular impeller tube, a fluid intake connection at one end of said tube and a fluid delivery connection at another `end of said tube, said tube being collapsible to permit successive yclosure of the sections thereof inthe direction from the intake end to the delivery end thereof to impel the fluid, an impeller roller movable on said tube to progressively close sections thereof and impel the fluid towards the delivery end of said tube, the diameter of said roller being equal to one-half or more than the diameter of the a fluid in-` path on which it isarranged to'roll on said tube.

18. In a pump comprising a casing and an impeller tube disposed within said casing, a fluid intake connection at vone point of said tube and a fluid delivery connection at another point of said tube to direct Circulation impeller tube disposed Within said casing,`

a fluid intake connectionat one point of said tube and a fluid delivery connection at another point of said tube to direct circulation of said fluid under substantial segregation from the other portions of said casing, said tube having a flexible wall arranged to be progressively compressed, and impeller means for progressively compressing portions of said flexible wallin the direction from the intake point of said tube to the de- 4liver point thereof to impel a fluid towardslsaid delivery point, said casing exterior of said tube being maintained. at a pressure below the pressure of the duid within said tube. 20. In a pump, an impeller tube having l a fluid intake connection at one point thereof and a fluid delivery connection at another point thereof, said tube having a flexible wall permitting successive flattening of portions of said tube between the intake point'and the delivery point to impel the fluid therein, an impeller means successively acting on said portions of the flexible wall toimpel said @incasso ment to said impeller meansand'said guide means along said tube.

22. In pump apparatus, a collapsible fluidimpeller tube, means for effecting yprogressive collapsing of said tube from the inlet end to the outlet end thereof, and valve means y disposed within and cooperating with the outlet end of said tube to prevent backward flow of fluid with respect thereto.

23. In pump apparatus, a collapsible fluidimpeller tube, means for 'effecting' progressive collapsing of said tube from the inlet end -to the outlet end thereof, and a member disposedwithin the outlet end of sa'id tube and providing a valve seat for such end, said outlet end cooperating with said member in such manner as to provide a valve action with respect to said tube to prevent backward fluidflow in said tube while permitting of forward fluid-flow therein. Y

24. In pump apparatus, a fluid-impeller tube having a collapsible wall, means for effecting progressive collapsing of said tube from the inlet end to the outlet end thereof,

and supporting means for said wall disposed within said tube, the end of said supporting means adjacent the outlet end of said tube cooperating with the latter to provide a valve action with respect to said tube preventing backward fluid-flow therethrough while permitting of forward fluid-flow through the same.

.In testimony whereof I have hereunto subscribed my name at Zurich, Switzerland, on the 13th day of January, A. D. 1927.

vADOLPI-I BAUMANN.

, los

fluid and compress the same in the portion of the tube between said impeller means and y the delivery point thereof, and guide means l for supporting the undeformed Iportions of said impeller tube to prevent excessive inflation thereof under the action of the pressure of the fluid in the interior thereof.

21. In a pump, an impeller tube having a fluid intake connection and a fluid delivery connection, said tube having a flexible wall permitting successive flattening of portions of said tube to impel a fluid within the same, impeller means for progressively compressing the flexible portions of said tube and impel said fluid, and guide means acting against the flexible portions of said tube outside the portion 'compressed by said impeller means to `prevent excessive inflation of said tube incident to the compression of fluid there'- in, and means imparting a progressive move-