Background of the Invention
The present invention relates generally to a pumping valve and, in particular, to a pumping valve for pumping viscous fluid, such as cream, at atmospheric pressure from a fluid-holding container.
In the past, viscous fluids were removed from fluid-holding containers in a number of different ways. In one prior art system, the viscous fluid was maintained in a container under pressure and a simple control valve was mounted on the container. Upon opening of the valve, the pressurized fluid, e.g., cream, flowed out. However, installation of such a valve is expensive, since it required pressurizing equipment as well as necessary safety equipment usually associated with materials under pressure.
In another type of system, a pumping valve has been used. In this valve, the spout is mounted on the valve plunger and is movable with this valve plunger during the pumping action. As a result, spillage takes place since it is difficult to align the moving spout with the container.
A substantial improvement was achieved with the valve of my prior U.S. Pat. No. 4,953,758. The valve disclosed in this patent permitted pumping fluids at atmospheric pressure from a fluid-holding container with minimal or no spillage. The valve of this patent is easy to operate.
The valve disclosed in my U.S. Pat. No. 4,953,758, comprises a valve body having a valve chamber and a plunger connected to a piston that is slidably received in the valve chamber. The plunger and piston are biased by a spring toward the top of the chamber. A flexible seal is provided on the piston and is biased to a position in which it seals an exit passage of the valve. A spout is connected by a channel to the top of the chamber. A one-way check valve is provided in the valve chamber to prevent flow of fluid outwardly through the inlet opening. The depression of the plunger causes movement of the piston downward through the chamber. This causes fluid in the chamber to press down on a one-way check valve at the bottom of the chamber which prevents fluid from flowing out of the chamber and back into the container. When the check valve prevents fluid from leaving the chamber, the movement of the piston causes sufficient pressure on the flexible seal to cause it to open so that fluid below the seal flows past the seal and into the portion of the valve chamber above the seal. The release of the plunger causes movement of the plunger upward to its initial position due to the bias spring. During this upward movement the fluid is pumped out of the valve through the channel and spout. Additional fluid also enters into the bottom portion of the valve chamber from the fluid-holding container due to the vacuum created by the movement of the piston.
The valve of my U.S. Pat. No. 4,953,758, while performing quite satisfactory, is relatively complex in manufacture and assembly because it has a relatively large number of parts.
Summary of the Invention
The object of the present invention is a pumping valve which is effective in operation and, at the same time, is economical in manufacture and is easily assembled.
The object of the invention is achieved by providing a valve including a plunger connected by a shaft to a piston in a fluid chamber. The top of the fluid chamber is connected by a channel to a spout. A plunger hub is slidably mounted on the plunger shaft above the piston and has a plurality of openings extending through it. When in engagement with the hub, the top of the piston seals the holes in the hub. A resilient member is mounted on the periphery of the plunger hub and a spring biases the piston and the plunger hub upwardly. The resilient member has a diameter slightly larger than the diameter of the fluid chamber, so the resilient member frictionally engages the circumferential wall of the fluid chamber.
Upon depression of the plunger, the plunger shaft and piston move downward in the fluid chamber, allowing the flow of fluid around the piston toward the upper part of the fluid chamber. However, because of the frictional engagement between the fluid chamber walls and the resilient member, the hub does not move. Instead, the plunger shaft slides through it until a pin on the shaft engages the hub and begins to push it down. With the piston out of contact with the hub, fluid flows around the piston and through the openings in the hub into the upper portion of the fluid chamber. Upon release of the plunger, a spring located in the lower portion of the fluid chamber, pushes the piston upward, and the frictional engagement of the resilient member with the walls of the fluid chamber holds the hub in place until the piston can close and seal the holes in the hub. The piston moves together with the plunger hub toward its initial position. During this movement the fluid above the hub is pumped out of the fluid chamber through the channel and spout. Substantially at the same time, additional fluid enters from the fluid-holding container into the bottom of the fluid chamber due to the vacuum created by movement of the piston/hub combination to their initial position. The plunger is received in a cavity in the upper part of the valve body. This cavity is separated from the fluid chamber by a seal which is constantly biased by a spring located in the plunger-receiving cavity. This spring also presses on the plunger to assist in biasing the plunger and piston to their initial position.
Brief Description of the Drawings
The above-mentioned and other features and objects of this invention and the manner of obtaining the same will become more apparent and the invention itself will be best understood from the following detailed description of the preferred embodiment when read in conjunction with the accompanying drawings; wherein:
FIG. 1 is a front elevational view of the pumping valve according to the present invention;
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1 at an enlarged scale in the initial position of the plunger;
FIG. 3 is a partial cross-sectional view similar to that shown in FIG. 2, but with the plunger in an operating position in which fluid is able to flow through the openings in the hub; and
FIGS. 4A and 4B are, respectively, side and elevational views of the plunger hub.
Detailed Description of the Preferred Embodiment
FIG. 1 shows a pumping valve (10) for pumping fluid at atmospheric pressure from a fluid-holding container (not shown). The valve (10) comprises an elongate valve body (12) having a circumferential wall (14). A plunger or push button (16) is received in a chamber (40) at one end of the valve body (10), and a material receiving segment (18) for connecting the valve to a fluid-holding container is received at the other end of the valve body. The valve body (12) has an outer thread (20) for receiving a nut (22) for attaching the valve (10) to the fluid-holding container.
The valve body defines a fluid chamber (24) having a seat (26) separating the fluid chamber (24) from a channel (24b). The valve body (12) has an inner opening (28) at the nozzle receiving end with an inner thread for receiving a threaded portion of the material receiving segment (18). A side opening (30) in channel (24b) is provided for connecting the channel to a spout (32). The spout (32) has an internal passage (32a) connected with the channel (24b) of the fluid chamber (24). Sealing O-rings (34 and 36) are located between the nozzle (18) and the valve body (12), as well as between the spout (32) and the valve (12) respectively. The valve body (12) has an inner shoulder (38) separating the fluid flow channel (24b) from an axial cavity (40) for slidably receiving the plunger (16). The valve body (12) also has an upper concave circumferential flange (42 designed to facilitate grasping of the plunger (16), and lower circumferential flange (44) designed to cooperate with a gasket (not shown) to seal the valve to the fluid-holding container.
A plunger assembly (46) has a piston (58) that is displaceable in the valve chamber (24). The piston is connected to a plunger shaft (48) that extends through the channel (24b) and into the plunger-receiving cavity (40). The plunger shaft (48) has a threaded end portion (50) which may be threaded into an axial threaded opening of the plunger (16) for connection therewith. The plunger assembly (46) further includes a plunger hub (52) having a disk-shaped portion (54) which is slidably received on the plunger shaft (48). The disk portion (54) has a diameter which is slightly less than the diameter of the fluid chamber (24). A resilient washer (56) is circumferentially mounted on the portion (54). The diameter of the resilient washer (56) is slightly larger than the diameter of the fluid chamber (24) so that the resilient washer frictionally engages the wall (14).
The disk portion (54) has a plurality of circumferential openings (54a) extending therethrough. The piston further includes a sealing washer (62) for sealing the opening in the disk portion. The sealing washer (62) is fixedly mounted on the plunger shaft (48) at an upper surface of the piston (58) for joint displacement therewith. The sealing washer (62) is supported between the flange (60) of the piston (58) and the disk portion (54) of the hub (52). A spring (64) is used to bias the piston and hub into engagement with the seat (26) at the top of the fluid chamber. The spring (64) is supported in the fluid chamber (24) in the groove (68) of the surface of nozzle (18) and extend to the flange (60) of the piston (58).
The plunger-receiving cavity (40) is sealed from the fluid chamber (24) by a seal (70). To constantly bias seal (70) into engagement with the shoulder (38), a spring (74) is arranged in the cavity (40) and extends between an end surface of the plunger (16) and a washer (72) abutting the seal (70). This spring (74), along with spring (64), helps to bias the plunger assembly (46) to its initial position. The washer (72) may be the same washer disclosed in U.S. Pat. No. 4,953,758, incorporated herein by reference thereto.
The operation of the pumping valve, according to the present invention, will be given for the sake of completeness. Upon depression of the plunger (16), the plunger assembly (46) is moved downward. This causes the piston (58), together with the sealing washer (62),to move downward, but the plunger hub (52) remains in place because of the frictional engagement of the resilient washer (56) with the walls of chamber (24). Further, downward movement of the plunger assembly (46) causes fluid in chamber (24) to flow around the piston head (58). A pin (66) in shaft (48) comes into contact with the top of hub (52) and causes hub (52) to begin to move downward. At this time, the disk portion (56) moves away from the seat (26), and the sealing washer (62) on piston (58) is away from the disk portion, as shown in FIG. 3. In this position, fluid in the fluid chamber is able to flow through the openings (54a) in the disk portion from the lower portion of the fluid chamber (24) toward the upper portion thereof.
Upon release of the plunger or push button (16), the plunger assembly moves in the opposite direction. As the piston continues, the sealing washer (62) on top of piston (58) abuts against the disk portion (54), blocking fluid flow though the openings (54a). Upon further movement of the plunger assembly (46) upward, the fluid is pumped from the upper portion of chamber (24) through the channel (24b) and passage (32a) of the spout (32) to the outside of the valve (12). At the same time, fluid from the fluid-holding container flows through the passage (18a) of the material receiving segment (18) into the lower portion of the fluid chamber (24) due to the vacuum created therein upon upward movement of the piston/hub combination.
While a particular embodiment of the invention has been shown and described, various modifications thereof will be apparent to those skilled in the art. Therefore, it is not intended that the invention be limited to the disclosed embodiment or the details thereof, and that departures may be made therefrom which fall within the spirit and scope of the invention as defined by the appended the claims.