Patent Application
20060165540
The present invention relates in general to priming pumps for use with a fuel delivery system. The priming pump cooperates with a base structure having a fuel inlet, a fuel outlet, and a fuel flow valve positioned partially in the base and cooperating with components of the priming pump to determine whether fuel flows through the priming pump or by-passes the priming pump.
More specifically, the present invention relates to the use of a spring-biased control knob for a priming pump, the control knob being positionable in either a locked position or a priming position. When the control knob is in the locked position, the fuel flow valve is opened and the fuel flow by-passes the priming pump and travels directly to a downstream, remote location. In this open condition, the priming pump of the present invention adds little, if any, flow restriction or what would be considered a minimum flow restriction. When priming is required or desired, the described control knob is rotated to an unlocked position and moves under a spring-biasing force to an up position. With the control knob in this position, the fuel flow valve is closed and any straight fuel flow through the base from the fuel inlet to the fuel outlet is blocked and the incoming fuel flow is redirected through the priming pump. A downward stroke of the control knob pushes the fuel within the priming pump out through the outlet opening of the base.
Current priming pumps that are used in fuel systems, excluding the present invention, are generally considered to be restrictive relative to the flow that is permitted or blocked and typically require additional systems and structures for the requisite fuel routing. Obviously, these additional requirements add both size and cost to the overall system. With the rapid development of modular fuel systems, greater attention has been directed to the need for a less restrictive, more easily operated, fuel priming pump. The priming pump of the present invention addresses these considerations in a novel and unobvious manner.
A priming pump for a fluid system according to one embodiment of the present invention cooperates with a base component defining a flow inlet, a flow outlet, and including a flow control valve positioned between the flow inlet and flow outlet. The priming pump comprises a housing located atop the base with an inlet valve compartment, an outlet valve compartment, and a plunger chamber that is in flow communication with the inlet and outlet valve compartments. Flow into and out of the priming pump housing is controlled in part by an inlet flow valve positioned in the inlet valve compartment and in part by an outlet flow valve positioned in the outlet valve compartment. The priming pump includes a control knob assembled to a plunger that is positioned in the housing and is configured to encircle the plunger chamber. The control knob is axially movable toward the base and is connected to the flow control valve such that the flow control valve is positionable by the control knob in either a direct-flow orientation or alternatively in a by-pass orientation. When the flow control valve is in the direct-flow orientation, flow from the flow inlet is routed directly through the flow control valve to the flow outlet. When the flow control valve is in the by-pass orientation, fluid is drawn into the plunger chamber by way of the inlet flow valve as the control knob moves upwardly. Fluid is pushed out of the plunger chamber through the outlet flow valve as the control knob moves downwardly.
One object of the present invention is to provide an improved priming pump for a fluid system.
Related objects and advantages of the present invention will be apparent from the following description.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Referring to
A fuel-in passageway 26 is defined by base 21 and connects the fuel inlet 22 with the interior of priming pump 20. A fuel-out passageway 27 is defined by base 21 and connects the fuel outlet 23 with the interior of priming pump 20. As is illustrated in
The flow-control valve 25 is constructed and arranged so as to permit fuel flow from the fuel inlet 22 directly to the fuel outlet 23 without introducing any flow restrictions when the priming pump 20 is in the closed and locked position of
As is illustrated, control knob 31 is spring-biased such that unlocking the control knob from the priming pump housing results in the upward axial movement of control knob 31 in an automatic fashion and this movement in the upward direction corresponds to a first step or portion of the overall fuel pumping action. As the control knob 31 moves in an upward direction due to the action of spring 42, an interior plunger 41 moves in that same direction, creating a low pressure area and thus suction so as to draw fuel in to chamber 32 of priming pump 20 by way of passageway portion 26b and ball valve 33. On the down stroke of control knob 31, fuel within chamber 32 is pushed out of the priming pump by way of ball valve 34 and passageway portion 27b. As would be understood, the fuel enters by way of inlet 22 and travels through portion 26a before flowing into chamber 32. Similarly, from portion 27b, the exiting fuel travels through portion 27a to fuel outlet 23.
Ball valves 33 and 34 are each constructed with a valve seat 35, ball 36, flow outlet 37, and biasing spring 38. The inverted orientation of the two ball valves means generally that as one valve opens, the other valve closes and vice versa. In use, when priming is desired, the control knob is released from its locked condition and, as it is turned, it positions the flow-control valve 25 in a closed or blocking orientation, as illustrated in
After a quantity of fuel is drawn into chamber 32, the next step in the priming process is to initiate the downward stroke by pushing knob 31 axially in the direction of base 21. This action causes plunger 41 to push the quantity of fuel out of chamber 32 against both the ball 36 in valve 33 and against ball 36 in valve 34. After the initial suction is created within chamber 32 by the upward movement of the control knob, ball 36 in valve 33 returns to its seated position against valve seat 35. Once fuel enters to offset the pressure differential within chamber 32, the biasing spring 38 has sufficient force to overcome any offsetting pressure and returns the ball 36 to valve seat 35. As such, with the downward stroke of control knob 31, there is no flow path through or across ball valve 33. However, on the opposite side, spring-biased ball 36 in valve 34 is able to be moved by the pressure force exerted by the fuel and the downward stroke of control knob 31. Since this downward force is greater than the offsetting force from biasing spring 38, ball valve 34 opens. This allows the fuel within chamber 32 to flow to the fuel outlet 23, as previously described. While a small portion of the quantity of fuel in chamber 32 may be retained in the small space above ball 36 in valve 33, the majority of that quantity of fuel in chamber 32 is pushed out of priming pump 20 through the fuel outlet 23 in base 21.
At the end of the downward stroke, spring 42 automatically returns knob 31 to its upward position. This action draws in another quantity of fuel into chamber 32 by way of ball valve 33, thus repeating the cyclic process in an automatic or near-automatic fashion. The only manual interaction is to push the control knob in a downward direction and to decide at what point the control knob would be placed in its locked position or released from its locked position. As this quantity of fuel is being drawn in for the second cycle, the biasing spring 38 in ball valve 34 returns the ball 36 to a closed position against seat 35 and the priming pump 20 is then ready for the delivery of another quantity of fuel from within chamber 32 out through fuel outlet 23. At the end of any downward stroke of control knob 31, if no further fuel is to be pumped for the purposes of priming, the control knob is simply turned so as to lock the control knob in a downward position at which time valve 25 is returned to an open position (see
The construction of priming pump 20, excluding base 21, includes the referenced housing 46 that is located atop base 21 and defines the plunger chamber 32, an inlet valve compartment 47 for housing ball valve 33, and an outlet valve compartment 48 for housing ball valve 34. As would be understood, compartments 47 and 48 separately communicate with chamber 32, but are otherwise isolated from each other. Housing 46 is attached to base 21 in a secure and leak-free manner. Plunger 41 is positioned inside chamber 32 and the plunger shaft 48 extends out of the housing.
As would be understood from the
While the locking of control knob 31 in the down position is able to be accomplished in less efficient ways, the preferred design, according to the present invention, is illustrated in greater detail in
Upper portion 60 is configured with an L-shaped channel 62 including an axial or vertical section 63 and a connected circumferential or horizontal section 64. The control knob 31 includes a radially inwardly extending rib 65 that is received by and travels in channel 62. The circumferential extent of section 64 is approximate 90 degrees. The closed end 66 includes an axially raised space 67 (see
When control knob 31 is to be locked in its down position, it is pushed down toward base 21 until lower edge 72 is adjacent upper surface 73. During this axial movement of control knob 31, rib 65 travels in channel 62 with a close clearance fit. When the control knob 31 is pushed to its lowest point of travel, rib 65 is aligned with section 64 and this enables the control knob to be rotated in a clockwise direction approximately 90 degrees. This locks the control knob in the down position. In order to release control knob 31 from its locked position, it must first be pushed downward very slightly so as to move rib 65 out of space 67 and then rotate the control knob in a counterclockwise direction until rib 65, as traveling through section 64, reaches section 63. At this point, since axial travel would now be permitted, the biasing spring takes over and, through that spring force, pushes upwardly on the control knob 31 in an automatic fashion.
The ninety degrees of rotation for control knob 31 is important so that the flow control valve 25 will be positioned in the by-pass orientation (see
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
