1. A PUMP DESIGNED TO CREATE A HIGH VACUUM PRESSURE IN A CHAMBER IN WHICH AN INDUSTRIAL OPERATION IS TO BE PERFORMED COMPRISING: (A) A RIGID AIR-TIGHT CYLINDRICAL CASE, (B) A FLEXIBLE ENDLESS TUBE, HAVING A BODY, CROWN AND BASE PORTION, THE TUBE BEING DISPOSED INSIDE THE CASE AND EXTENDING COMPLETELY ABOUT THE INSIDE SURFACE OF THE CYLINDRICAL WALL OF THE CASE WITH SAID CROWN PORTION ATTACHED THERETO, (C) THE BODY PORTION OF THE TUBE INCLUDING A STRAIN MEMBER COMPOSED OF A LAYER OF TRANSVERSELY EXTENDING CORD, (D) A SHORT LENGTH OF THE TUBE, RELATIVE TO ITS LENGTH, BEING CLOSED AIR-TIGHT, SAID TUBE BEING PROVIDED WITH A FIRST INLET, ADJACENT ONE SIDE OF THE SHORT LENGTH, COMMUNICATING WITH SAID CHAMBER AND AN OUTLET, ADJACENT THE OTHER SIDE OF SAID SHORT LENGTH, COMMUNICATING WITH THE ATMOSPHERE,
April 6, 1965 F. B. PFEIFFER 3,176,622
Filed June 6, 1962 3 Sheets-Sheet 1 F IG.6 2 ,f6
/7 INVENTOR f FRED B. PFEIFFER April 6, 1965 F. B. PFElr-FER PUMP 3 Sheets-Sheet 2 Filed June 6, 1962 INVENToR. FRED B. PFEIFFER April 6, 1965 F. B. PFEIFFER PUMP 3 Sheets-Sheet 5 Filed June 6, 1962 JNVENTOR. FRED PFEIFFER United States Patent O- 3,176,622 PUMP This invention relates `generally to pumps. More particularly, the invention relates to pumps comprising a lcylindrical case, a iiexible tube within the case and extending about and attached to the inner surface of the outer circumferential wall of the case. The tube having an inlet and an outlet projecting through the casing walL and means for progressively exerting moving pressure along the tube from theinlet to the outlet.
Pumps, incorporating the features referred to above, have failed to meet commercial success probably dueto their power consumption and faulty performance.
it is therefore an object of the present invention to provide an improved pump that is low in power consumption, of low -construction cost, and having traveling airtight-contact means that eliminates the leakage or back-flow into the tube of the fluid being pumped.
Another object of the invention is to provide a pump capable of creating a very high vacuum in a compartment required in certain present day scientific and industrial processes, such for example, as depositing a thin coat of metal on iilm. p
A further object of the inventiomwhen lthe pump is operated as a vacuum pump, isv to create a vacuum pressure within the pump `case and to maintain such pressure by connection of the space, -within the case, to the pump vacuum line. A
A still further and important object of the invention is to provide a pump, of its type, that has positive means adapted to pull the baise wall of the tube away from the crown Wall thus insuring the re-opening of the tube, after it has been closed, by the moving pressure members.
Yet another object of the invention is to reinforce the wall of the tube with strain members so that the wall may be thin and ofer little resistance to the pressure members thereby saving power consumption.
These and other objects will be apparent in View of the following detailed description of the invention considered with the attached drawings.
In the drawings: v p K FiG. l is a perspective view of a pump comprising the present invention and shown connected to a tank from which air is being pumped, a portion of a sump below the tank being removed to show some details of construction; Y
FlG. 2 is an enlarged sectional view taken on line 2-2 of FG. 1;
FlG. 3 is a sectional vie-W taken on line 3 3 of FIG. 2;
FlG. 4 is a perspective view of the rotor shown in HG. 2;
FIG. 5 is a perspective view of .a bellcrank shown in FIG. 2, mounted `on arms of the rotor;
FIG. 6 is a sectional view of the tube of the pump shown in its molded shape; and
HG. 7 is an enlarged view illustrating the tube shown in FIG. 6 as it appears when drawn open by a substantially inextensible component of the tube.
In the present invention a pump, indicated generally by reference numeral 10, includes a casing 11 having a cylindrical outer wall 12 and a cover i3V attached to the casing in airtight relation therewith lby means ofbolts 14 and sealing gasket 9 as will be seen by, reference to FIG.
3. Rotatable pump mechanism is mounted within the casing on a shaft 41 driven by motor S and journalled in bearings 42 and 43 as will also be seen by reference Y 3,176,622v Patented Apr. 6., 1965 ICC to FIG. 3. A packing glandA 44 makes an airtightseal between the shaft'and the casing.
A molded tube 17, shown in detail in` FIG. 6 is mounted in a -dovetailed recess formed in the inner surface Aof wall 12 a portion 16 of lthe tubeV being formed for that purpose. As illustrated portion 16 includes circumfer- -entially extending cords 20 embedded in rubber. It is -to be understood that the element'Zt) may be a spirally wound wir-e embedded rubber that has been compounded to permit only' enough distortion to permit portion 16 to enter the dovetail recess. The invention also contemplates the use of a suitable .adhesive in the dovetailed recess and if found desirable att-aching portion 16 posed of nylon andrubber 21 of tire tread type rubber,
however, the particular construction described is'by way of example only and the track may consist of any ruaterial found satisfactory. Y
The wall of tube 17 comprises a rubber lining 23, transversely extending cords 24 land, outer rubber cover 25.` The tube isV prepared for molding in -any usual manner known to the rubber industry-and if found -desirable the tube body proper `and its portions 16 and 1S may be molded and vulcanized separately and united by cement and/or cement and a second vulcanization as will be understood by thosefamiliar with the art of molding tubes. The molded shape of the tube `as shown in FG. 6 is important and it is to be noted that portions 16 .and 1S are wider than the tube body proper and that the tube bodyhas a flattened crown and base portion to which portions 16 and 13 are respectively attached. Also that each lateral side 2.6 and 27 are so formed as to bring the inner surface of the Vtube into Y contact for a short distance. The importance of these features will Vbe understood as the descriptioncontinues. By reference to FIG. 2 it will be seen that an inlet 61 and an outlet 62, for tube 17, ane yclosely spaced and that .the tube issealed `at 7 between the inlet and outlet with a bolt 2 anchoring the tube at that areaagainst radially inwardly movement. Alsothat a third opening 63a communicates with the inside o-f the tube for a purpose to be explained later herein.
As indicated above a rotator referred .to generally as 40 (see FIG. 4) is mounted on and driven by shaft 41 and includes spaced frames 5 ando havingbearings 45 and tied together by cross-arms 46 which have tapped -bolt holes 47 to receive bolts 48 for controlling a rooking movement of bell crank 49, best shown in FIG. 5.
Each of the four bell-cranks 49 have spaced parallel sides 3 and 4 joined by a cross-bar 50 having a bolt hole 51 through which the bolts 48 extend through bolt holes 47 of each cross-arm 46 whereby the bell crank move'- ment is controlled on rotator 40'. By reference to FIG. 2 it will be seenthat a spring 60 is interposed between the bolt head and cross-bar 50 and the opposite end of the bolt is in threaded relation with cross-arm 46 of the rotator 40. Mounting holes 52 and 52a are disposed in the bell crank as shown and are mounted on the rotator by means of pin 53. Pressure roller 56 is mounted on shaft 55 disposed in bearings 54 and 54a in the sides` 3 and 4 of the bell-crank respectively.
3 A pipe 69 extends from the top of the sump to the pump casing where it is joined in airtight relation to the inlet 61 of tube 17. Pipe 70 establishes communication between the bottom of the sump and pipe 69.
The present inventionprovides means for creating a vacuumpressure within the pump case about the tube 17 andto this end tube 17 communicates with the inside of the case 11 through openingv 63a of the tube and opening 63 through the case joined .by a pipe 6317 as will -be seen by reference to FIGS. `l, 2 and 3. Afcheck valve 1 in pipe 63h to limit the direction of ow therein from the casing to the tube.
It is to be understood that all openings through case 11 and all connections are sealed airtight by any of well known expedients.
Operation The rotor 40 of the pump is driven by motor 8. The four pressure rollers 56 are preferably so disposed as to have each diametrically opposite another so as to relieve shaft 41 of any whipping or radial stress which is important in that it reduces wear on the shafts bearings and packing gland. The rollers are biased by springs 60 which may be adjusted by tightening or loosening bolts 48. The rollers are adapted to progressively press the wall of tube 17 into airtight contact. In the present example `the 0.D. of the inside of tube 17 is 10 and its I.D. 9%. The diameter of roller 56 is 2" and each is so mounted as to press the tube closed before the compression of the springs have reached there limit thereby providing a resilient mounting for the rollers to acommodate variations in the thickness of the tube and make possible the passage of Vforeign material through thek Y ,will take when the tube is under pressure from the rollers.
This'is important as the ,slightest leak by the compressed area of the tube will materially reduce the vacuum pressure sought. f l
The operation ofthe track portion 18, of the tube'17, is vital or at least a highly important feature of the invention in that it is relatively inextensible. Accordingly as the four rollerspress the track radially outwardly the track moves radially linwardly between the rollerspsince the total length of the track cannot change appreciably. This movement of the track pulls the tube base radially inwardly from its molded diameter whereby collapse of kthe tube between the rollers is made impossible during a pumping operation.
When pumping is initiated by rotation of kshaft 41 and the rollers 56 are in the position shown in FIG. 2 it will be seen that the tube comprises four compartments A, B, C 'and D, with compartment A communicating with the inlet opening andA compartment D with the outlet or discharge opening while compartment C communicates with opening 63a which in turn communicates with the inside of the pump casing through opening 63 (see FIGS. l and 3).
, Asthe rollers move about the base of the tube against track 18 the tube is progressively closed whereby a travel.- ing air-tight contact barrier isy provided. Starting with `compartment A iilled with airvfrom tank 65 through the' piping -for that purpose, the roller 56 moves over the intake ,opening andcompartment A becomes an air tight compartment between the last mentioned roller and the next preceding roller and in eiect becomes compartment B. In like manner each said compartment moves with its defining rollers in to the position `of the preceding compartment. Thus when a roller moves over the intake compartment A becomes Ycompartment B and this latter compartment becomes a closed moving `compartment until it becomes exposed to outlet opening 63a'when it 4 becomes, by function, compartment C. Compartment C moves forward until its rear end moves by opening 63a when it becomes compartment D communicating with discharge opening 62.
Air that enters compartment A is forced through the tube and discharged lat 62. Since the air comes from closed unit tank 65 it will be seen that a vacuum pressure will be created in the tank and that the pump construction avoids back-flow from the discharge opening beyond the approaching roller. Thus the eiiiciency of the pump is very high and power consumption low due to small amount of back-flow to be removed.
As a vacuum pressure is created in tube 17 the compartment C communicating with the inside of the casing 11 outside of the tube evacuates air from the casing creating vacuum therein equal to that within the tube whereby pressure external of the tube which would tend to collapse the tube is avoided and maintenance of the Vacuum in the casing is assured against any leakage of air into the cas= ing.
The exhaust fan 67 over the sump impels any residual molecules, that settle into its iield from the tank, into the inlet line of the pump. The movement of air through pipe 61a to the pump draws any air that hasfreached the bottomv of the sump into line 61a through outlet pipe 70.
The present invention avoids the vacuum chamber being subjected to fumes given oi from metallic elements of the pump. Such fumes interfere seriously with such Voperations as depositing a metal coating on lms by vacuum process.
The pump 10 is useful for pumping iiuid or liquid but obvious when used for this purpose such components as the tank 65, sump and its elements, pipe 61111 and the elements for evacuating air from the casing would be omitted. Y While a preferred embodiment of the invention has been shown and described it will be understood that changes and modifications may be made therein without departing from the spirit of the invention or the scope of the subjoined claims.
What is claimed is:
1. A pump designed to create a high vacuum pressure in a chamber in which an industrial operation is to be performed comprising: I
(a). a rigid air-tight cylindrical case,
(b) a exible endless tube, having a body, crown and base portion, the tube being disposed inside the case and extending completely about the inside surface of the cylindrical wall of the case with said crown portion attached thereto, l
(c) the body portion of the tube including a strain member composed of a layer of transversely extending cord,
(d) a short length of the tube, relative to its length, being closed air-tight, said tube being provided with a iirst'inlet,l adjacent one side of the short length, communicating with said chamber and an outlet, adjacent the other side of said short length, communicating with the atmosphere,
(e) a driven rotor including at least` three equispeed pressure rollers mounted in the case, means adapted to activate the rollers and to resiliently force the rollers against and lengthwise of the tube, thereby pressing the tube airtight shut under each roller, dividing the opening of the tube into a plurality of separate compartments that travel longitudinally of the tube under the inuence of the rollers, said tube being provided with a second inlet and being in communication with a closed compartment of the tube, and communicating with the inside of the case through means including piping outside the case,
(f) said traveling compartments successively communicating with said inlets andY outlets, and
(g),said baseportion having an endless flexible substantially inextensible roller track attached thereto.
2. In a pump designed to create high vacuum pressure in a chamber n which an industrial operation is to be performed comprising;
(a) an air-tight cylindrical case,
(b) an endless llexible tube Within and attached to the cylindrical Wall ofthe case,
(c) said tube being molded and comprising a tube body portion with cylindrical attachment means formed on its radially outer side and a continuous cylindrical track formed on its radially inner side,
(1) said attachment means being composed of reinforced rubber,
(2) said track comprising reinforced rubber and being substantially longitudinally inextensible,
(3) said tube body portion comprising an inner and an outer layer of rubber and a transversely extending cord strain member,
(4) the tube body having attened crown and base portions and, lateral side portions molded to the shape the tube assumes when under the iniiuence of pressure rollers,
(5) the tube having a short closed portion, `relative to the length of the tube, bolted to the case, said tube being provided with an inlet and outlet closely adjacent the closed portion, the inlet communicating with the chamber in which said operation is to be performed and the outlet is to the atmosphere,
(6) said tube being provided with a second inlet, the latter communicating with the inside of the case through means of piping outside the case,
(7) said second inlet being in fluid communication with a compartment of the tube that is sealedoi by the pressure rollers from said rst mentioned inlet `and outlet,
(l) having a plurality of radially extending arms with at least three equi-spaced spring biased pressure rollers thereon mounted in the case, and
(2) said rollers being adapted to travel in spaced relation longitudinally about the tube and progressively press the tube Wall shut thereby creating not less than three traveling compartments Within the tube as the rotor revolves, one of said compartments being sealed off by the pressure rollers from said inlet and outlet.
3. A pump designed to create a high vacuum pressure in a chamber in which an industrial operation is to be performed comprising:
(a) a rigid air-tight case,
(b) a molded emble tube disposed inside said case,
(c) said tube having a crown and a base portion,
(d) means joined to said crown adapted to attach the tube to the case,
(e) an endless flexible inextensible roller track attached to said tube base,
(f) said tube having a short length, relative to the tube length, permanently closed air-tight, said tube being provided with a lirst inlet closely adjacent one side of said short length and communicating with the chamber in which the commercial operation is to be performed, and an outlet closely adjacent the other side of said short length communicating with the atmosphere,
(g) a rotor,
(l) having a plurality of radially extending arms with at least three equi-spaced spring-biased pressure rollers mounted thereon,
(2) said rollers being adapted to travel in spaced relation longitudinally about the tube and progressively press the tube Wall .air-tight shut, thereby creating traveling closures and compartments Within the tube as the rotor revolves, one of said compartments being sealed-off from said inlet and outlet by the pressure of said rollers.
(h) the inside surface of the tube having circumferentialiy extending lateral portions molded to substantially the shape the inside lateral surface of the tube assumes under the influence of said rollers, and
(i) piping, external of the case, joining an inlet to the tube through the crown thereof, to an outlet from the inside of the case, said latter inlet being generally located opposite to the said closed tube portion, said piping having a check valve in the line whereby the riovv through the piping is from the inside of the case to the inside ofthe tube.
References Cited bythe Examiner UNITED STATES PATENTS 664,507 IZ/GO Singer 2SC-168 1,765,360 6/30 Baumann 103-149 2,693,766 ll/54 Seyler 10S-149 2,909,125 lG/59 Daniels 103-149 2,926,835 3/60 Lorenz 230-45 2,928,353 3/60 Murray l03-l49 2,95 8,455 l l/ 60 Steinhertz et al 230--45 2,977,890 4/61 Seyler l03--l49 2,982,225 5/ 61 Thompson 10S-149 2,987,004 6/61 Murray l03l49 3,067,692 12/52 Brikich 103-149 3,163,178 9/63 Thompson 193-149 FOREiGN PATENTS 628,785 9/49 Great Britain.
669,809 4/52 Great Britain.
341,261 ll/ 59 Switzerland.
.5 LAURENCE V. EFNER, Primary Examiner.