Pump priming apparatus

A pump priming apparatus including a housing through which fluid object material may be urged to flow, the housing including an intake portion and a pumping portion downstream from the intake portion. The apparatus further includes a piston assembly carried for reciprocation in the housing, the piston assembly and the housing being configured such that a partial vacuum is developed in the pumping portion of the housing as the piston assembly moves through the pumping portion of the housing toward the intake portion of the housing and such that the partial vacuum is substantially released upon the movement of the piston assembly into the intake portion of the housing, thereby causing the fluid object material in the intake portion of the housing to flow into the pumping portion of the housing.

BACKGROUND OF THE INVENTION

In order to remove fluid material from a container of such material, and particularly in the event that the container of fluid material contains substantially more fluid material than is needed at any given point in time, the fluid material is typically pumped out of the container in the desired quantity. This holds true for a variety of fluid materials, including but not limited to highly viscous lubricating fluids such as high viscosity grease. However, in order to pump such materials from a container, the material must first be drawn into the pumping device. This initial drawing in of material into the pumping device is referred to by those of ordinary skill in the art as “priming” the pump. In sum, in order for a pump to effectively remove fluid from a container, the pump must first be primed. When the fluid material is highly viscous, the sheer inertia of the still fluid is substantial and such inertia must be overcome in order to prime the pump. Therefore, to prime a pump with highly viscous fluid, the priming mechanism of the pump must impart enhanced force on the fluid.

Prior art pump priming mechanisms address the problem of priming pumps with highly viscous fluid materials in a variety of ways. One such way is the creation of a partial vacuum which is then released, causing a sudden equalization of air pressure that urges the high viscosity material into the pump. As used herein, the term “partial vacuum” means an air pressure lower than an ambient air pressure.

One prior art example of the utilization of sudden release of a partial vacuum for pump priming is U.S. Pat. No. 4,249,868 to Kotyk. The Kotyk patent discloses a pump with a priming mechanism designed to address the problem of pumping high viscosity material. In the Kotyk pump, the piston travels within a cylindrical valve, which in turn travels within the pump cylinder. When the piston completes a downstroke, the cylindrical valve blocks the inlet of the pump. On the upstroke, the piston creates a partial vacuum within the cylindrical valve until the piston reaches the top of the cylindrical valve and lifts the valve such that the inlet is reopened. Upon the reopening of the inlet, the partial vacuum in the cylindrical valve is released and the sudden equalization of pressure causes the fluid material at the inlet to rush into the cylindrical valve before proceeding into the succeeding stages of the pump.

In contrast to Kotyk and other partial vacuum priming devices in the prior art, the pump priming apparatus of the present invention provides a simple piston and cylinder structure to accomplish the priming without the need for additional parts that ultimately add expense to the construction and maintenance of the pump while diminishing its reliability.

SUMMARY OF THE INVENTION

One embodiment of the invention is a pump priming apparatus including a housing through which fluid object material may be urged to flow, the housing including an intake portion and a pumping portion downstream from the intake portion. This apparatus embodiment of the invention further includes a piston assembly carried for reciprocation in the housing, the piston assembly and the housing being configured such that a partial vacuum is developed in the pumping portion of the housing as the piston assembly moves through the pumping portion of the housing toward the intake portion of the housing and such that the partial vacuum is substantially released upon the movement of the piston assembly into the intake portion of the housing, thereby causing the fluid object material in the intake portion of the housing to flow into the pumping portion of the housing.

Another embodiment of the invention is a method of priming a pump for pumping fluid object material, the method including the steps of providing a pump priming apparatus comprising a housing through which fluid object material may be urged to flow, the housing including an intake portion and a pumping portion downstream from the intake portion. Additional steps of this method embodiment of the invention include placing the intake portion of the housing in the fluid object material to be pumped, creating a partial vacuum in the pumping portion of the housing, substantially releasing the partial vacuum in the pumping portion of the housing, thereby causing the fluid object material to flow from the intake portion of the housing into the pumping portion of the housing, and pumping the fluid object material out of the pumping portion of the housing.

Yet another embodiment of the invention is a pump priming apparatus including means for carrying a flow of fluid object material therethrough, the carrying means including an intake portion and a pumping portion downstream from the intake portion. This apparatus embodiment of the invention further includes means for urging the fluid object material through the carrying means, the urging means and the carrying means being configured such that a partial vacuum is developed in the pumping portion of the carrying means as the urging means moves through the pumping portion of the carrying means toward the intake portion of the carrying means, and such that the partial vacuum is substantially released upon the movement of the urging means into the intake portion of the carrying means, thereby causing the fluid object material in the intake portion of the carrying means to flow into the pumping portion of the carrying means.

Yet another embodiment of the invention is a method of priming a pump for pumping fluid object material, the method including the steps of providing a pump priming apparatus comprising a means for carrying a flow of fluid object material therethrough, said carrying means comprising an intake portion and a pumping portion downstream from the intake portion. Additional steps of this method embodiment of the invention include placing the intake portion of the carrying means in the fluid object material to be pumped, creating a partial vacuum in the pumping portion of the carrying means, substantially releasing the partial vacuum in the pumping portion of the carrying means, thereby causing the fluid object material to flow from the intake portion of the carrying means into the pumping portion of the carrying means, and pumping the fluid object material out of the pumping portion of the carrying means.

DETAILED DESCRIPTION

Referring now to the drawings,FIG. 1illustrates a pump priming apparatus10according to an embodiment of the present invention. The basic components of the pump priming apparatus10are the cylinder11, the piston rod12, and the piston13. The piston13is carried on one end of the piston rod12, which reciprocates in the cylinder11during operation of the pump priming apparatus10. The cylinder11is provided with a threaded portion14for interfacing with an adjacent section of the pump (not shown). The cylinder11has a proximal end15and a distal end16; the proximal end15includes the threaded portion14of the cylinder11. A pumping portion20of the cylinder11is adjacent to the proximal end of the cylinder11, while an inlet portion21of the cylinder11is adjacent to the distal end16of the cylinder11. The inlet portion21defines a plurality of inlet ports22for allowing fluid material (not shown) to flow into the cylinder11. The inlet ports22allow the fluid material to flow into the cylinder11when the distal end16of the cylinder11is resting on the bottom of a container (not shown) of fluid material.

Turning now toFIG. 2, the construction of the piston13is shown. A disc valve23comprises the central portion of the piston13. The disc valve23includes a upper valve portion24having a upper major valve surface25facing toward the piston rod12and a lower valve portion26having a lower major valve surface30facing away from the piston rod12. A chamfer31sloping radially outward from the periphery of the upper valve portion24to the periphery of the lower valve portion26results in the diameter of the upper valve portion24being smaller than the diameter of the lower valve portion26. The valve23defines a centrally disposed port32that enables the fastening of the valve23as part of the piston13. Furthermore, as shown inFIG. 3, the valve23defines a weep hole33for preventing the piston13from seizing in the cylinder11, as described further below.

Turning back toFIG. 2, the piston13further includes a washer34and a hexagonal nut35, which engage the upper and lower major valve surfaces25,30, respectively, when the piston13is fully assembled. The washer34and the nut35each define respective centrally disposed ports36,40that align with the centrally disposed port32defined by the valve23when the piston13is assembled.

Still referring toFIG. 2, the piston13is fastened to the piston rod12as follows. A piston-engaging end41of the piston rod12carries a threaded bolt shank42. An internally threaded sleeve43is provided for receiving the bolt shank42. The bolt shank42and the sleeve43are screwed together and carry the piston13by insertion through the centrally disposed ports32,36,40of the valve23, the washer34, and the nut35of the piston13.

Turning now toFIGS. 4,5,6, and7, the piston rod12, the piston13, and the interior of the cylinder11are more visible and four successive stages of one complete downstroke of the piston13are shown. It can be seen from these drawings that the inner diameter of the pumping portion20of the cylinder11is smaller than the inner diameter of the inlet portion21of the cylinder11. This variance in the inner diameter of the cylinder11is directly related to the outer diameter of the piston13. Specifically, the outer diameter of the piston13is nearly equal to the inner diameter of the pumping portion20of the cylinder11, but is smaller than the inner diameter of the inlet portion21of the cylinder11.

This variation in the inner diameter of the cylinder11and its relation to the outer diameter of the piston13enables a pressure differential and equalization to occur during the movement of the piston13in the cylinder11. As the piston13moves on a downstroke beginning from the proximal end15of the cylinder (FIG. 4) through the pumping portion20of the cylinder11(FIG.5), a partial vacuum is developed in the pumping portion20of the cylinder11. As the piston13continues its downstroke toward the distal end16of the cylinder11by moving into the inlet portion21of the cylinder11(FIG.6), the partial vacuum in the pumping portion20of the cylinder11is substantially released and the pressures in the pumping portion20and the inlet portion21suddenly equalize, forcing the fluid material in or near the inlet portion21of the cylinder11to be drawn into the pumping portion22of the cylinder11.

The weep hole33(FIG. 3) defined by the valve23allows a small amount of air and/or fluid material in the cylinder11to flow back and forth between the pumping portion20and the inlet portion21of the cylinder11(FIGS.4,5,6,7) as the piston13moves within the cylinder11. This small air and/or fluid material flow helps prevent the partial vacuum created in the cylinder11during operation of the apparatus10from becoming so strong as to cause the piston13to be immobilized in the cylinder11. However, the flow enabled by the weep hole33does not detract from the above-described priming action of the apparatus10.

After the piston13reaches the distal end16of the cylinder11to complete its downstroke (FIG.7), the piston13begins its upstroke in the cylinder11by traveling back toward the proximal end15of the cylinder11. The order of the piston positions discussed above and shown inFIGS. 4,5,6, and7need only be reversed to view various stages of the upstroke motion of the piston13. On its upstroke, the piston13forces the fluid material in the cylinder11, and especially the fluid material in the pumping portion20of the cylinder11, out of the cylinder11through an opening44in the proximal end15of the cylinder11and into an adjacent section of the pump (not shown).

Although the above description and the accompanying drawings describe embodiments of the cylinder, piston, and valve of the present invention that are cylindrical and/or annular in shape, similar results may be achieved with elements of varying shapes, so long as the seal between the valve on the piston and the pumping portion of the pump priming apparatus is sufficient to create the desired partial vacuum in the pump priming apparatus and so long as the partial vacuum may be released to cause the flow of fluid material into the pump priming apparatus. Similarly, the composition of the various elements of the pump priming apparatus may also vary so long as the necessary functions of those elements are still served.

A pump priming apparatus is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims.