US 3489099 A
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Jan. 13, 1970 HUFF'SMITH, SR
PISTON-TYPE PUMP FOR USE WITH HIGHLY VISCOUS FLUIDS Filed July 10, 1968 INVENTOR Charles S. Huffsmirh,Sr.
BY I /QMW 9' 0% ATTORNEYS United States Patent 3,489,099 PISTON-TYPE PUMP FOR USE WITH HIGHLY VISCOUS FLUIDS Charles S. Hulfsmith, Sr., Metuchen, N.J., assignor to Wood Industries, Inc., Plainfield, N.J., a corporation of Virginia Filed July 10, 1968, Ser. No. 743,718 Int. Cl. F04b 21/04, 21/08; B67d /50 U.S. Cl. 103-178 5 Claims ABSTRACT OF THE DISCLOSURE A pump for highly corrosive and viscous fluids having a housing adapted to be submerged in a bath of fluid, a piston vertically slidable in the housing, check valve means on the piston controlling flow of fluid into a pressure chamber of the housing and side ports in the housing through which fluid may flow into the pressure chamber and into and out of the housing to agitate the bath as the piston moves.
BACKGROUND OF THE INVENTION This invention relates to a pump and more specifically to a positive displacement pump for pumping a highly viscous, corrosive fluid.
Many industries have need for a positive displacement pump that will meter and pump a highly viscous fluid. For example, in the newspaper industry, offset plates are developed using a developer fluid which is corrosive with many metals and which is very viscous, both characteristics of which make the developer fluid difficult to pump. It is desirable when pumps are used that they be made with a minimum of moving parts in order to keep the expense of manufacture and repair at a minimum. It is further desirable that the pump unit be capable of ready disassembly for cleaning. It is also a desirable feature that the capacity of the pump be easily and accurately varied in order that delivery of the pump will be varied.
It is therefore an object of my invention to provide for a pump construction which will meet the aforementioned requirements. Broadly my pump comprises a pump housing adapted to be submerged in a bath of highly viscous fluid. The pump housing has a plurality of ports spaced vertically in the side wall of the housing which are adapted to be closed by the side walls of a piston which is movable vertically within the housing. The piston in turn has a side port adapted to communicate with the ports in the housing and with an end port in one end of the piston. A moveable check valve means is connected to the piston and is adapted to close the end port upon the down stroke of the piston and to open the end port upon the up stroke of the piston. The bottom of the piston forms a pressure chamber with the bottom of the housing such that as the piston moves on its down stroke, fluid within the pressure chamber will be ejected there from while at the same time fluid will be caused to flow into and out of the ports in the housing whereby the bath of fluid is agitated. During the up stroke of the piston, the check valve means opens allowing fluid to flow into the pressure chamber through the ports in the housing and the ports in the piston. Means are provided for varying the stroke of the piston in order to vary the pump capacity and the piston itself is made of a material having lubricant properties and which is non-corrosive to the material being pumped.
DESCRIPTION OF THE DRAWINGS FIGURE 1 is a partial cross-sectional view of a pump constructed according to --my invention wherein the piston is shown on the up stroke; and
3,489,099 Patented Jan. 13, 1970 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGURE 1, there is illustrated a sump 1 of a fluid system in which a pump housing 2 is submerged. Housing 2 has a nipple 3 on the bottom end thereof extending through the bottom of the sump and to which a nut 4 is screwed to hold the housing in the sump.
A piston 5 is slidable within the housing and is preferably made of a plastic material having lubricant properties, as for example Teflon, a product of the Du Pont Corporation. Use of such material also minimizes any corrosion that might occur since it is chemically and physically inert to many solutions.
The housing has first and second ports 6 and 7 in the side walls thereof with the ports being vertically spaced while the piston has a port 8 which is of suflicient length to overlap ports 6 and 7 as shown in FIGURE 1. The piston is also provided with an end port 9 at its bottom end which is in communication with port 8.
Port 9 is adapted to be closed by a moveable check plate 10 which is moveably mounted on the piston by means of pilot rod 11 which extends through passage 12 of the piston. The end of the pilot rod opposite the check plate end has an enlarged head 13 which prevents the rod from falling through the piston and to limit movement of the plate away from port 9.
A pressure or pumping chamber 14 is formed between the bottom of the piston 5 and the bottom of the housing and has on opening 15 in the bottom thereof leading to the nipple 3 on which a conduit may be connected to lead to the area where the fluid is to be pumped.
The piston 5 has a piston rod 16 pivotably connected to the upper end thereof by a pin 17. The other end of the rod 16 is mounted in a rod housing 18 which is pivotably connected by a pin 19 to a powered rotary shaft 20. The effective length of the rod 16 may be varied by loosening screws 21 on the housing so that the rod may be moved in or out of the housing. Varying the length of the rod will in turn vary the capacity of the pump which is determined by the downward movement of the piston from the position shown in FIGURE 1 to the limit of its downward stroke as shown in FIGURE 2, If the capacity of the pump is to be increased, the effective length of the piston rod is increased.
The operation of the pump is as follows. As the piston moves on its up stroke as shown in FIGURE 1, the check plate 10 will move downward under the pressure of atmospheric pressure and of the fluid pressure within the sump 1 above the level of the plate. Fluid will then flow into the housing through port 7, into port 8 and thence through port 9 into the chamber 14. Any liquid trapped in the housing on the top of the piston will fiow through the upper port 6 as the piston rises until the side walls of the piston close the port. This flow out of port 6 assists in agitation of the fluid Within the sump.
On the down stroke of the piston, the piston will move down to contact the check plate which is held in position by reason of its resistance to move in the fluid within the housing. On the initial portion of the down stroke, fluid is forced through both ports 6 and 7 which assists in agitation of the fluid within the sump. When the bottom part of the piston reaches the point shown in FIGURE 1 at which the pressure chamber is sealed from the port 7, fluid will begin to be ejected from the chamber 14.
The piston and housing assembly may readily be disassembled for cleaning and repair. The piston rod merely has to be loosened from the rod housing whereby the piston and rod may then be lifted from the pump housing. The check plate assembly may be easily disconnected from the piston by screw 11' which is threaded on the end of the rod 11. The housing itself may be readily disassembled from the sump by loosening screw 4.
No packing or sealing rings are necessary in the pump construction shown since the piston comprises a plastic having lubricating qualities. A further advantage of having the piston made of such a plastic material is that there is no danger of damage to the pump in the event that it runs dry since there is no need for the liquid being pumped to provide any lubricating function.
It is apparent that because of the positive displacement action of the piston moving in a pressure chamber and also because of the large ports utilized, that the pump may handle fluids having a variety of viscosities. Further,
housing adapted to be submerged in a bath of viscous V fluid, a moveable piston having a vertical stroke within said housing and forming a pressure chamber with the bottom of the housing, first and second ports in the side wall of said housing wherein said first ports are positioned above said second ports, a side port in the side wall of said piston adapted to communicate with said first and second ports when said piston is at the upper part of its stroke and to be sealed by the side walls of said housing when the piston is at the lower part of its stroke, an end port in the end of said piston in communication with said side port and adapted to communicate with said pressure chamber, and moveable check valve means carried by said piston adapted to close said end port during the down stroke of the piston and to open said end port on the upper stroke of the piston whereby fluid will flow into said pressure chamber through said end port, side port and first and second ports when said piston is moving on its up stroke and whereby fluid will flow into and out of said first and second ports on the down stroke of said piston to agitate fluid in the bath.
2. A pump according to claim 1 wherein said piston is connected by a piston rod to a rotary shaft and said piston rod is adjustable in length to vary the stroke of the piston within the housing and thus the capacity of the pump.
3. A pump according to claim 1 wherein said check valve means comprises a check plate connected to said piston by means of a pilot rod which extends through and is moveable with respect to said piston and wherein said pilot rod has means thereon for limiting its movement with respect to said piston.
4.,A pump according to claim 1 wherein said piston is made of a plastic material having lubricant properties.
5. A pump according to claim 1 having means on the housing to position the pump within a sump of a fluid system.
References Cited UNITED STATES PATENTS 326,409 9/1885 De Volin 103-178 815,301 3/1906 Manzel 103-37 1,180,221 4/1916 Adams 222385 1,455,235 5/1923 Townsend et a1. 103-178 2,503,478 4/1950 Grime 222385 1,699,194. 1/1929 Junkers 103154 1,849,490 3/1932 Junkers 10337 3,059,586 10/1962 Brailsford 103-216 3,125,004 3/1964 White 1031 14 3,396,873 8/1968 Nef 222-385 HENRY F. RADUAZO, Primary Examiner US. Cl. X.R.