US 3485180 A
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Description (OCR text may contain errors)
Dec. 1969' c. H. WICKENBERG ET AL 3,485,180
DOUBLE-ACTING PUMP FOR GAS 0R LIQUID Filed May 28, 1968 Fig.2.
INVENTOR H. WICKENBERG 1 .ZIJII/ I CHESTER SIGFRID M. OLOFSSON ATTORNEY.
3,485,180 DOUBLE-ACTING PUMP FOR GAS R LIQUID Chester H. Wiclrenberg, 890 Ford Ave., Elgin, Ill.
60120, and Sigfrid M. Olofsson, Box 5880, Munkedal, Sweden Filed May 28, 1968, Ser. No. 733,228 Int. Cl. F04b 19/02, 21/04 US. Cl. 103158 2 Claims ABSTRACT OF THE DISCLOSURE SUMMARY OF THE INVENTION Known types of double-acting pumps usually include a piston which is reciprocal to a cylinder sealed at both ends and through which one end wall projects a piston rod. The cylinder is divided by the piston into two chambers which serve alternately as pumping chambers. In order to facilitate the operation of this arrangement a valve is provided which alternately opens the connection between the chamber which is serving as the pumping chamber as well as the pump outlet. This valve arrangement is complicated and highly expensive and difiicult to manufacture and maintain.
The object of the present invention is to provide a double acting piston pump which is simple and inexpensive to manufacture, reliable in function and which can be used for pumping either liquids or gas.
This object is achieved by means of the present invention which is mainly characterized by the arrangement and construction of a piston which resides within a cylinder with the piston having a relatively wide clearance between its periphery and the inner wall of the cylinder. The piston includes a self-contained valve means comprising a sealing ring that is selectively positioned into sealing contact with the inner wall of the cylinder and moves relatively within an annular peripheral groove provided by the piston to open communication with either one of the pumping chambers defined thereby.
GENERAL DESCRIPTION The invention will best be understood by reference to the accompanying drawings in which there is shown the preferred form of construction.
FIG. 1 shows a side elevational detailed view of the double acting pump of this invention;
FIG. 2 is a fragmentary detailed sectional view of a modified piston valve as can be associated within the present invention; and
FIG. 3 is a fragmentary detailed section view of a modified valve sealing means.
FIG. 1 illustrates a double-acting pump which consists of a cylinder 1 which is capable of reciprocating movement over a stationary piston 2. One end 3 of the cylinder 1 is provided with a handle 4 which facilitates the moving of the cylinder 1 over the stationary piston 2. The opposite end wall 5 of the cylinder is provided with a center opening 5' through which a hollow piston rod 6 projects. The piston rod 6 is mounted between and has its opposite ends closed by the piston 2 and a support plate 7, the latter providing an outlet 7', which has open communication nited States Patent 0 with a hose 8 through which the working medium of the pump is exhausted.
The cylinder 1 is divided by the piston 2 into two pumping chambers 9 and 10 which can be alternately placed in communication with the piston rod 6. To accomplish the above function the diameter of the piston 2 is less than the inner diameter of cylinder 1 so that there is a clearance formed between the circumferential edge of the piston 2 and the inner wall of the cylinder 1.
Formed in the vertical peripheral edge surface of the piston 2 is an annular groove 12 into which is positioned a sealing ring 13. This sealing ring 13 has a diameter less than the area between the side walls of the groove 12 so that it has a limited vertical movement therein. Also formed in the piston 2 are a plurality of passages 11 which extend between the annular groove 12 and intake ports 11' formed in the upper end of the piston 2.
Each of the pumping chambers 9 and 10 are provided with suction openings 14 and 17 provided with valve arrangements 15 and 18, respectively. As shown in FIG. 1 the lower pumping chamber 9 has provided in the end wall 5 of the cylinder 1 a number of apertures 14 which serve as suction openings disposed about the piston rod 6. Circumferentially extending about the piston rod 6 is an inner annular wall 16' which supports a retaining member 16 in a spaced relation to the end wall 5 of the cylinder 1. Between the end wall 5 and the retainer member 16 and defined by the annular wall 16 is a chamber 15 which houses a sealing ring 15 frictionally mounted on the piston rod 6.
The top wall of the cylinder 1 is provided with a plurality of suction holes 17 which have open communication with the upper pumping chamber 10. The top Wall of cylinder 1 also provides a ring 18' extending circumferentially about a mounting stud 17 upon which is fixedly secured a flexible diaphragm 18 that normally closes the suction holes 17.
In the position shown in FIG. 1 the cylinder 1 has commenced its vertical movement caused by moving the cylinder 1 away from the support plate 7. Because of the friction between the piston rod 6 and the sealing ring 15, such ring 15 will have been moved downwardly through the chamber 15 against the bottom wall 5 so as to seal the apertures 14 formed therein to prevent the acting medium within the pumping chamber 9 from escaping therethrough. It should also be noted that the pressure created within the reducing pumping chamber 9 will assist in pressing the ring 15 downward upon the wall 5 to seal the openings 14 formed therein.
By the upward movement of the cylinder 1 the sealing ring 13 which exerts frictional pressure against the inner wall of the cylinder 1 will be caused to move into abutment with the upper inner wall surface of the groove 12 so as to effect a seal between that portion of the annular groove 12 and the inner wall of the cylinder 1. This movement of the sealing ring 13 within the annular groove 12 provides a gap between the sealing ring 13 and the lower wall surface of the groove 12 and opens communication between the pumping chamber 9 and the passages 11 formed in the piston 2. Thus as the cylinder 1 is caused to move vertically as seen in FIG. 1 the medium in the pumping chamber 9 is forced through the passages 11 and into the hollow piston rod 6 and into the hose 8 for exhaust through the nozzle 19.
During the upward movement of cylinder 1 relative to the piston 2 the vacuum created in the enlarging pumping chamber 10 will cause the flexible diaphragm 18 to flex inwardly and expose the openings 17 formed in the top wall 4 to admit air therethrough into the chamber 10.
Upon downward movement of the cylinder 1 the sealing ring 13 will be caused to move in abutment with the lower wall surface of the groove 12 and thus expose the passages 11 to the pumping chamber 10 forcing the medium therein out of the pump. The back pressure created by this movement of the cylinder 1 will effectuate the sealing of the flexible diaphragm 18 on the openings 17 to close the same to prevent the escapement of the medium therethrough. The downward movement of the cylinder 1 will cause the sealing ring 15 to move into abutment with the retainer 16 opening communication with the openings 14 formed in the bottom wall 5 of the cylinder 1 to admit air into the enlarging pumping chamber 9.
FIG. 2 illustrates a modified embodiment of the valve arrangement in the piston 2 which alternately connects the pumping chambers 9 and 10 with the hollow piston rod 6. Passing from each of the pumping chambers 9 and 10 to the interior of the piston rod 6 are passages 20 and 21, respectively. The mouths of the passages 20 and 21 are suitably situated opposite each other in the side wall of the piston rod 6. Located within the upper end of the piston rod 6 is a bell-shaped valve member 22 which lies against the inner wall of piston rod 6 and covers the mouths of the passages 20 and 21.
When using the pump as shown in FIG. 2 the medium pressure in one or the other passage 20 and 21 (depending on relative direction of movement between cylinder 1 and piston 2) will increase and deflect the wall of the valve member 22 away from one of the passages allowing the medium to flow into the hollow piston 6. Thus upward movement of cylinder 1 as viewed in FIG. 2 would effect opening passage 20 while downward movement of the cylinder 1 would open passage 21.
In FIG. 3 the piston 2 as shown is provided with a sealing ring 23 which is substantially U-shaped in cross-section with the open portion thereof turned in toward the base of the annular groove 12. The U-shaped sealing ring 23 fits within the groove 12 without any appreciable pressure against the upper and lower walls thereof, and the edges of the sealing ring 23 are free to be deflected away by the pressure prevailing in either one of the pumping chambers 9 and 10 to permit the medium to pass about the sealing ring 23 and flow into the passages 11 and out of the piston rod 6.
The above description has been made with respect to an air pump, but it should be understood that the invention so described can be applied to a pump intended for other gases as well as for liquids without departing from the scope of the present invention.
While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limitedto the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.
Having thus described our invention, what we claim as new and desire to protect by Letters Patent is:
1. A double-acting piston pump for a gas or liquid medium including a hollow cylinder and a piston therein dividing the cylinder into two pumping chambers with the cylinder and piston movable relative to each other to change the volume of the pumping chambers wherein the improvement comprises:
(a) a hollow piston rod closed at one end by the piston;
(b) passages formed through said piston providing open communication with said hollow piston rod and the pumping chambers;
(c) valve means carried by said piston for selectively sealing one oi the pumping chambers against open communication with the hollow piston rod while simultaneously permitting open communication with the other pumping chamber; and
(d) said valve means comprises a flexible bell-shaped gasket which normally closes the passages formed in said piston with a portion of the bell-shaped gasket being deflected away from one of the passages by the increasing exhaust pressure of the medium in one of the pumping chambers as said cylinder is moved relative to said piston.
2. The pump of claim 1 further defined by having pressure responsive valve members at opposite ends of the hollow cylinder for admitting the medium into one or the other pumping chambers in response to the directional movement of the cylinder with respect to the piston.
References Cited UNITED STATES PATENTS 90,940 6/1869 Forrester 103l58 309,662 12/1884 Stoufler 103-188 711,654 10/1902 Byars 103-190 1,278,264 9/1918 Weinman 103192 1,830,258 11/1931 Bohnenblust 103192 FOREIGN PATENTS 483,009 7/ 1951 Italy. 742,293 11/1943 Gennany.
HENRY F. RADUAZO, Primary Examiner US. Cl. X.R.