US2696173A - Fluid pump - Google Patents

Description

Dec. 7, 1954 T. JENSEN 2,696,173

FLUID PUMP Filed Dec. 23, 1950 4 Sheets-Sheet l INVENTOR Tfiormod Jensen ATTOR J5 5 T- JENSEN FLUID PUMP Dec. 7, 1954 4 Sheets-Sheet 2 Filed Dec. 23, 1950 INVENTC'J'R Thai-mod Jensen M m I 1 ATT RN T. JENSEN FLUID PUMP Dec. 7, 1954 4 Sheets-Sheet 3 Filed Dec. 25, 1950 T. JENSEN FLUID PUMP Dec. 7, 1954 4 Sheets-Sheet 4 Filed Dec. -23, 1950 INVENTOR Thormodfemen United States Patent-O FLUID PUMP Thormod Jensen, Laurelton, N. Y.

Application December 23, W50, Serial No. 202,493 14 Claims. (or. 105-449 This invention relates to pumping and force feeding; and, more: in particular to pumps of the type wherein a fluid). e. g. a. liquid, is impelled through a. flexible tube by compressing the tube progressively from one end. to the other using rollers to perform the compressing operation...

Pumps and force-feeding arrangements have been provided inthe past whichare of the general nature. of those constituting. the. illustrative embodiments of the invention.v However, the prior devices. have been somewhat unsuccessful commercially particularly in fields where reliability of action is important, and. where the parts. are apt to be subjected to abuse which causes excessive wear and breakage of the. parts. For example, pumps have been. proposed. for pumping or feeding liquids which must be kept from contact with the metal parts of the pump or from contact. with the air, because such contact will: damage either the pump parts. or because such contact is objectionable for sanitary reasons. When these. pumps have been. of the type where the liquid passes through a flexible tube of rubber (or another elastomer), the' tubes: have been subjected to such severe. treatment that they have broken frequently, thus rendering the pump inoperative. When the pump is used as. an important component of a processing system and the breakdown of the. pump stops the operation of the. entire sys+ tem, then the objectionable features of the prior pumps have; made them unsatisfactory from. a commercial standpoint. In practice, the breakdown. of such pumps is. apt to occur at the times when they are handling maximum loads which, of course,v are the times when breakdown is; most objectionable; As: a result of difiiculties such as those discussed above, the pumps of the. character referred. to. above have been considered. unsatisfactory for many uses.

It is. an object of the present invention to overcome the difliculties which have been encountered in the past and to provide. improved constructions and modes of operation, and to provide extremely efficient and dep n a p ati n with devices of the character de scribed above.- It is a further object to render such devices useful under circumstances where excessive repair and replacement costs. are objectionable and where the interruption of operation must be avoided. These and other objects will be. in part obvious and in part pointed out below. It is to be noted that the scope of this in- I ventioni is not. limited by the description of the specific embodiment-s but departures may be made therefrom as covered by the appended claims.

One aspect of the present invention may be said to lie in providing a pumping device of the class described wherein a fluid is passed through a tube by squeezing the tube. with rollers which are positively driven and rotated as. they pass along the tube. The tube is formed of an el'astomer, illustratively rubber, and the construction and operation are such that an improved operation is obtained with minimum wear and strain on the tube.

In the. drawings;

Figure 1 is a side elevation of one embodiment of the invention comprising a pump mounted on a support or base. together with its driving motor and speed-reduction mechanism;

Figure 2. is a front elevation of the pump of Figure 1, with the front plate removed;

Figure 3. is an enlarged section on the.line 3-.3 ofn 2;

Figure 4 a view simllar to a portion of Figure but on an enlarged scale and wi h Parts broken away to show detailsof construction;

Figure 5 is an enlarged sectional viewof the elastic tu e;

Figure 6 is a view similar to Figure 2 but showing another embodiment of the invention;

Figure 7 is a sectional view on the line 7'-7 of Figure 6; and,

Figures 8 and 9 are side elevations with parts broken away of two other embodiments of the invention.

Referring particularly to Figure 1 of the drawings, there is shown to the left apump 2 which is driven throughgear reduction mechanism 4 by anelectrical motor 6 with the driving connection from the motor being through a pair ofpulleys 8 and 10 and a V-belt 12. These elements are mounted on abase 14 with the pump and the gear reduction mechanism and itsplate 96 being rigidly clamped to the base and with the motor being adjustably mounted so that the speed of the pump can be adjusted. Accordingly, clamped to the base is a pair ofbrackets 16 and 18 which have a pair ofshafts 20 extending therebetween. The motor in turn is rigidly mounted on a pair ofbrackets 22 which are freely slidable onshafts 20. Ascrew shaft 24 is threaded through the right-hand bracket 22 and is rotatably mounted inbracket 18 and at the right the screw shaft carries ahand wheel 26.. Ashand wheel 26 is turned so as to movemotor 6 to the right, belt 12v rides down between the sides of the variable speed.pulley 10 so that the effective radius of the pulley is reduced and the speed at which the pump is driven is reduced.

Thegear reduction mechanism 4 drives pump 2 directly (see the right-hand portion of Figure 3) through ashaft 28 to which is keyed thecentral hub 30 of a web 32 (see Figure 1 and 4). The pump has a casing 29 which is a rigid rectangular shell havingside plates 31 and 33, a back frame member (see Figure 3), a top frame plate 37 (see Figure 4) and a removable front plate 39 (see Figure 1).Web 32 has three equally- .Spacedradial arms 34 and mounted respectively on these arms are threeswingable roller arms 36. As best shown in Figure 3, eacharm 36 carries at its extreme end. aroller shaft 38 which is rigidly clamped by aset screw 40, and mounted upon each of these shafts is aroller 42 which has acylindrical roller portion 44 and agear portion 46. Each of the rollers is held in place on its shaft by acollar 48 which is clamped in place by a set screw 50, and each roller is provided at its ends with bearingcollars 52, 54. Eacharm 36 also carries acam roller 56 upon acam roller shaft 58 which is. rigidly mounted in the arm; this permits the releasing of the rollers from the tube in a manner to be discussed below.

Referring to the lower portion of Figures 3 and 4, the pump is provided with a pair of anvil blocks 60 and. 62 (Figure 3) which are positioned side-by-side and present a tube clamping oranvil surface 64 which (see. Figure 4) extends from astraight portion 66 at the right, downwardly with. asemi-cylindrical portion 68 and (see Figure 2) thence upwardly with astraight portion 70 at the left. Thissurface 64 provides a continuous surface against which atube 72 is held and is squeezed progressively by therollers 42. Referring to Figure 5, thetube 72 is formed by a simplecylindrical rubber tube 74 which is enclosed within a muchthinner tube 76 which extends downwardly and also encloses asolid rubber strip 78.Blocks 60 and 62 are cut away to provi'cle a recess forstrip 78 and the portion of thethin tube 76 which extends between the blocks as shown and surrounds thestrip 78.

Blocks 60 and 62 are rigidly clamped together (by a pair ofbolts 80 shown in Figure 2) sothat a firm anchor is provided for thethin tube 76. This anchor extends (Figure 2) along the entire extent of theanvil surface 64 from the top ofsurface 66 at the right downwardly and to the left and upwardly to the top ofsurface 70. The ends. of tube 74- project upwardly beyond the ends oftube 76 and the right-hand end is rigidly clamped to ametal connecting ferrule 82'. by a. clamp 84. As. shown best in Figure 4, ferrule 82v is. externally threaded and is adjustably clamped by a pair-of nutsufi and 83 to atop frame plate 37 which is slotted at 90 from its front edge (Figure 2) to permitferrule 82 to be slid out when the nuts are loosened.Ferrule 82 is flattened at its sides so as to be held from turning in the slot. A block 92 (Figure 1) is filled into the slot between the ferrule and thefront plate 39 so as to close the opening, and block 92 is supportgl by athin plate 94 which is clamped in place by nut Similarly, the left-hand end (Figure 2) oftube 74 is attached to a connecting ferrule 81 by aclamp 83; and the ferrule is adjustably clamped by a pair ofnuts 85 and 87 in aslot 89 inplate 37. The slot is closed by ablock 91 supported by aplate 93.

Thefront plate 39 is clamped in place by twohand bolts 97 havingknobs 99 and threaded into theback frame member 35. Eachbolt 99 extends loosely through the front plate and carries a collar 101 (see Figure 2) which rests against the front face of the clampingblock 60. Whenbolts 99 are tightened they hold the front plate rigidly in place and they also hold the blocks tightly in place. However, whenbolts 99 are removed, the front plate is also removed and blocks 60 and 62 are no longer clamped in place. As will be referred to below,tube 72 may be replaced readily by removing thesebolts 99 in the front plate and simply loosening the nuts 85, 86, 87 and 88 which clamp theferrules 81 and 82.

Theback frame member 35 is cut away and provided withinternal gear teeth 100 so as to form aring gear 98. This back plate is clamped tightly to the edge of aplate 96 upon which thegear reduction mechanism 4 is mounted. During operation gears 46 are rotated around thering gear 98 and the intermeshing of the gear teeth causes the gears to rotate. This, in turn rotatesrollers 42 so as to cause the rollers to compresstube 72 progressively along theanvil surface 64 starting at the top ofportion 66, thence downwardly and aroundportion 68, and upwardly alongportion 70. The rollers are positively rotated with the result that the roller climbs along the tube. The roller is of sufficient diameter to insure that the tube is not subjected to objectionable abuse. Thus, referring to Figure 4, the roller at the right is shown moving along the tube and the size and relationship of parts is such that the tube is completely closed, and yet is not strained excessively. As the roller moves clockwise, the Zone of compression moves. With this embodi ment, there are two rollers in complete engagement with the tube at all times so that a segment of the tube is positioned between two compressed zones of the tube.Ferrule 82 is connected to a liquid supply and ferrule 81 is connected to a liquid outlet. tinually supplied with liquid so that as a roller moves downwardly and the tube behind the roller is no longer compressed, the tube is refilled with liquid. After a rotation of one hundred twenty degrees, the next roller engages the tube thus trapping a predetermined quantity of the liquid. The liquid is therefore pumped in predetermined quantities from the inlet to the outlet. It has been found that this pumping action may be carried on against a substantial pressure head or back pressure without damage to the pump or without loss of the advantages of operation referred to above. As shown best in Figure 3, thetube 72 remains at the center ofroller 44, primarily because of the anchor attachment. As discussed above, this anchor attachment is formed by theouter tube 76 andstrip 78 clamped betweenblocks 60 and 62. This anchoring permits easy compression of the tube and yet holds the tube beneath the rollers.

As pointed out above, each of therollers 42 is mounted upon a swinging arm 36 (see Figure 4). During the operation of the pump these arms are maintained in the position shown by acentral cam 102 which is engaged by thecam rollers 56.Cam 102 has three identical cam surfaces for the respective cam rollers, each including anarcuate surface 104, atangential portion 106 and an arcuate portion or dwell 108. There is also astop portion 110 which limits the counter-clockwise rotation of the cam when the cam is moved to the position shown in Figure 4.Cam 102 has a hub 112 (see Figure 3) by which the cam is rotatably mounted on ashaft 114 andshaft 114 has anextension 116 at the left upon which is mounted ahand wheel 118.Hand wheel 118 is interlocked withhub 112 and is held in place by aremovable collar 120.Shaft 114 also has asleeve extension 122 which extends to the right betweenshaft 28, and the Thus,ferrule 82 is con- 4hub 30 ofweb 32 and a single key 124keys shaft 28 toshaft 114 and also tohub 30.

When it is desirable to remove the tube as discussed above, for example, to replace it with another tube, thehand wheel 118 is turned clockwise (see Figure 4) so that each of the arcuate portions or dwells 108 is at itscam roller 56. The resiliency of the tube urges therollers 42 toward their retracted position and the tube is no longer compressed. Thehand wheel 118 is then removed and, as indicated above, the front plate is removed. The nuts 85, 86, 87 and 88 are then loosened and the entire unit comprising the tube and its ferrules and theblocks 60 and 62 is slid out from the pump casing. It is contemplated that a substitute unit be available for replacement. The replacement can therefore be made very rapidly. As indicated above, this is quite important from the standpoint of commercial use where the pump is apt to cause diificulties because of excessive wear or breakage of parts.

Under some circumstances, there is a tendency for the tube to become heated, particularly where the operation is rapid. This is objectionable not only because it may cause deterioration, but also because it is important to avoid heating some liquids as they are passing through the pump. Accordingly, as shown at the upper righthand portion of Figure 2, provision is made to supply water to therollers 42 as they move toward thetube 72. Thus, adjacent ferrule 82 awater supply pipe 124 is rigidly mounted inplate 37 by a pair ofnuts 126 and 128.Pipe 124 is connected to a water supply and is provided with a flow control valve not shown. Water drips constantly from the end ofpipe 124 downwardly into the path of therollers 42. The water is carried by the rollers and flows off ontotube 72. The supply of water is so controlled that the rollers and the tubes are maintained wet without there being an excess of water which would drain from the bottom of the pump. The compressing of the tube creates heat which evaporates the water, thus cooling the tube. Furthermore, the water acts as a lubricant so as to reduce the friction between the rollers and the tube. Under some circumstances other liquids may be used so as to give a relatively greater or lesser cooling or lubricating effect. Aguard plate 130 is positionedadjacent gear 98 and tends to protect the gear from spattering water.

In the embodiment of Figure 6, sixrollers 142 are provided instead of the three shown in Figures 1 to 5 and they are mounted in fixed relationship upon aweb 144. Referring to Figure 7, thetube 146 is positioned on ananvil block 148 havingintegral side flanges 150 and 152. These side flanges confine the tube to the compressing zone of the rollers and the action is similar to that of the embodiment of Figures 1 to 5.

Figure 8 shows another embodiment of the invention which is adapted for a horizontal arrangement of the elastic tube. Therein is shown anoval casing 154 and a substantially straightelastic tube 156 mounted within arigid support 158.Tube 156 is attached at one end to anadjustable inlet ferrule 160, and at the other end toadjustable outlet ferrule 162. Nuts 164 and 166 secure inlet ferrule withinsupport 158, andnuts 168 and 170 similarlysecure outlet ferrule 162.Clamps 172 and 174 secure the ends oftube 156 to the respective inlet and outlet ducts. Shouldelastic tube 156 expand or contract to an undesired degree, with use or different conditions of service, this may be compensated for by adjustment of the inlet or outlet ferrules, which are then re-locked into position by the nuts indicated.

Withincase 154 is a pair ofsprockets 176 which are driven by a motor (not shown).Teeth 178 of each ofsprockets 176 engage the links of aperipheral drive chain 180. Fixedly positioned around the outer periphery ofcasing 154 is agear rack 182, the teeth of which engage the gearedportions 184 ofrollers 186.Rollers 186 are carried on and driven by chains at. the center of the rollers; thus, motion ofchains 180 moves therollers 186 around the periphery ofcasing 154, thereby engaging the geared portion 184- of said rollers withrack 182 and providing predetermined planetary motion of said rollers within the casing. The rollers contacttube 156, compress portions thereof and drive liquid therethrough, while minimizing the frictional contact of the rollers and tube.

Figure 9 shows an embodiment of the invention for vertical flow which comprises anelastic tube 190 pcsitioned between twoadjacent casings 194 having coacting sets ofrollers 196 which are driven by chains and sprockets (not shown) around the periphery of their respective casings, in a manner similar to that described in connection with Figure 8. One pair ofrollers 196, one from each casing portion of the pump, contactselastic tube 190 simultaneously and propels the liquid within the tube towards its outlet.Tube 190 is mounted within asupport 198 which is cut away to permit free engagement ofrollers 196 with said tube. The arrangement of other parts of the pump is substantially similar to that of Figure 8.

While this invention is not limited to any special kind of elastic tube, I presently prefer a tube construction as shown in Figure 5, wherein the inner portion is made of soft rubber and the outer portion is made of soft rubber; or, under some circumstances,tube 76 is a cotton hose. However, this construction may be varied to suit particular needs and uses. Thus, one may use various kinds of elastorners for particular purposes, such as synthetic rubbers and elastic plastic materials so long as the tube made is collapsible, resilient and elastic, non-deleterious to the liquid it contains or vice versa, and is resistant to linear deformation.

I claim:

1. A pump of the character described which comprises, a rigid outer casing, a collapsible resilient tube supported within said casing, an adjustable inlet duct means and an adjustable outlet duct means mounted on said casing and connected with the respective ends of said tube, means for maintaining said tube in predetermined alignment within said casing and presenting a surface against which said tube may be compressed, a plurality of rollers adapted to travel along and to compress said tube, means for moving said rollers radially into compressing relationship with the tube, and roller drive means providing positive rotation of said rollers as they move along said tube.

2. In a pump of the character described, the combination of, a casing, a tube assembly within said casing and comprising a flexible tube which is generally U-shaped, an anvil block presenting a compressing surface along said tube, anchor means attaching said tube to said anvil block substantially throughout the length of said compressing surface, attaching means removably attaching said anvil block and with the said tube to said casing, and attaching means including ferrule means connected to the ends of said tube and comprising inlet and outlet ducts and clamping means clamping said ferrule means to said casing.

3. Apparatus as described inclaim 2 which includes, a roller assembly comprising roller mounting means and a plurality of rollers mounted thereon'adapted to be rotated about an axis coincident with the axis of the curved portion of said compressing surface, each of said rollers including a gear portion and a cylindrical roller portion which is adapted to engage said tube, and a rack with which the gear portions of said rollers engages to rotate the rollers as they are moved along said tube.

4. A pump as described inclaim 3 wherein said casing is rectangular and has a top wall through which said ferrule means extends, and means to releasably urge said rollers radially outwardly into compressing relationship against said tube.

In a pump of the character described, the combination of, a casing construction including a top plate having a pair of spaced slots in one edge thereof, a pair of ferrules removably positioned within said slots, a substantially U-shaped tube positioned within said casing and having its ends connected respectively to said ferrules, a spider assembly rotatably mounted centrally with respect to said casing, a plurality of rollers mounted on said spider assembly and adapted to move for a substantial arc in contact with said tube, block means presenting a compressing surface extended along the side of said tube opposite the side contacted by said rollers whereby said tube is compressed by said rollers.

6. Apparatus as described inclaim 5 wherein said spider assembly comprises a central spider having three equally spaced radial arms, three roller arms pivotally connected respectively to the ends of said radial arms and each carrying one of said rollers, and cam means which is adapted to swing said arms radially outwardly into the compressing relationship with the tube.

7. Apparatus as described inclaim 6 wherein said cam means comprises a central rockable cam which is adapted to swing through an arc with respect to said roller arms between one extreme wherein each roller arm is presented with a high cam surface and another extreme wherein said roller arm is presented with a low cam surface, and three cam rollers mounted respectively on said roller arms and adapted to ride on said cam surfaces.

8. Apparatus as described in claim 7 wherein said block means comprises a pair of blocks which have mating surfaces substantially in alignment with the center of said tube and said mating surfaces are cut away to provide an anchoring recess which is narrow adjacent said tube and has a cylindrical portion remote from said tube, and anchor means for said tube comprising a thin-walled flexible tube and a flexible strip positioned within said cylindrical portion of the recess.

9. Apparatus as described inclaim 8 which includes, removable means holding said pair of blocks rigidly together, and releasable means clamping said blocks to said casing.

10. Apparatus as described inclaim 9 wherein said casing includes a front plate which is clamped in place simultaneously with the clamping in place of said pair of blocks, and a pair of cover blocks attached respectively to said ferrules and closing said slots within which said ferrules are positioned.

11. Apparatus as described inclaim 10 wherein said casing includes a back plate which is provided with an annular rack extending substantially parallel to said tube, and wherein each of said rollers has gear means rigidly fixed with respect thereto and meshing with said rack.

12. Apparatus as described in claim 7 which includes, means to supply water to the rollers as they approach said tube whereby the tube and rollers are lubricated and the tube is cooled, and a hand wheel to operate said cam means.

13. In apparatus of the character described, the combination of, a rectangular casing having a top plate, a pair of ferrules removably mounted in said top plate, a flexible tube positioned within said casing and having a substantially U-shape with its ends connected respectively to said ferrules, a compressing block presenting a compressing surface to said tube along an arcuate portion thereof and radially outwardly with respect to the tube, a spider rotatably mounted to rotate about an axis coincident with the axis of said arcuate portion, a plurality of rollers carried by said spider and each including a roller portion which is adapted to engage and compress said tube against said compressing surface and a gear portion, and a fixed rack meshing with said gear portions through their path adjacent said arcuate portion of the tube.

14. Apparatus as described in claim 13 wherein said block has integral side flanges which tend to retain said tube on said compressing surface.

References Cited in the file of this patent UNITED STATES PATENTS

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