Food metering and dispensing device

A pump apparatus for an adjustable metering and dispensing pump apparatus for food products including a product piston moving in a product cylinder, the product cylinder being connected to a food hopper and a dispensing nozzle. The pump apparatus also includes a cylindrical valve moving within a central aperture in the product piston to selectively open and close passageways also in the product piston which communicate with intake and outlet ports connected to the product cylinder. The valve is attached to a valve piston moving within a valve piston cylinder and the valve piston cylinder is attached to a source of compressed air, to a sensor and to a control assembly. The control in turn is connected to a foot switch to allow an operator to initiate a cycle of the pump apparatus. The valve piston reciprocates both the valve piston and the product piston, however, while the valve moves directly with the valve piston, the product piston is connected with a lateral pin mounted in an elongated lateral slot formed in the product piston resulting in a delayed movement of the product piston. A screw is mounted to the valve piston cylinder to abut the valve piston in an adjustable manner so that the valve piston stroke is changeable resulting in a corresponding change in the volume of a food product in a product chamber in the product cylinder.

CROSS REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a pump apparatus and more particularly to a pump apparatus having a valve within a piston for a metering and dispensing device that may be used for food products, the device being very efficient, reliable and simply constructed as well as easy to use and to wash.

2. Description of the Related Art

Dispensers for food products are known in the food industry. For example, a dispenser for barbecue sauce is constructed with a piston in a cylinder, an intake check valve and an outlet check valve. A major problem with this dispenser is that the food product being transmitted includes chunks which clog the check valves and require frequent cleaning. This procedure is very time consuming and thus the dispenser is not practical.

BRIEF SUMMARY OF THE INVENTION

The difficulties encountered with previous dispensers has been overcome by the present invention. What is described here is a pump apparatus including a cylinder for containing a piston and for forming a product chamber, the cylinder having a longitudinal axis, an inlet and an outlet, a piston mounted in the cylinder, the piston having first, second and third apertures, a valve mounted in one of the piston apertures and having first, second and third lateral apertures and a connecting structure which allows both the piston and the valve to reciprocate together and allows the valve to move while the piston is stationary.

There are a number of advantages, features and objects achieved with the present invention which are believed not be available in earlier related devices. For example, several advantages are that the pump apparatus is a simply constructed, reliable, efficient and cost effective. Other features are that the pump apparatus is easy to operate, easy to maintain and easy to clean.

A more complete understanding of the present invention and other objects, advantages and features thereof will be gained from a consideration of the present description which provides a written description of the invention, and of the manner and process of making and using the invention, set forth in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same in compliance with Title 35 U.S.C. section 112 (first paragraph). Furthermore, the following description of a preferred embodiment of the invention read in conjunction with the accompanying drawing provided herein represents an example of the invention in compliance with Title 35 U.S.C. section 112 (first paragraph), but the invention itself is defined in the attached Claims section attached hereto.

While the present invention is open to various modifications and alternative constructions, the preferred embodiment illustrating the best mode contemplated by the inventor of carrying out his invention is shown in the various figures of the drawing and will be described herein in detail pursuant to Title 35 U.S.C. section 112 (first paragraph). It is understood, however, that there is no intention to limit the invention to the particular embodiment, form or example which is disclosed herein. To the contrary, the intention is to cover all modifications, equivalent structures and methods, and alternative constructions falling within the spirit and scope of the invention as expressed in the appended Claims section attached hereto, pursuant to Title 35 U.S.C. section 112 (second paragraph).

Referring now toFIGS. 1-4, there is illustrated a food metering and dispensing device10having a mounting frame12, a food hopper14connected to the frame, an adjustable metering pump assembly16mounted to the frame, a tube or hose18connecting an inlet port20of the pump assembly16to the hopper14, a nozzle assembly22connected to an outlet port24of the pump assembly16, a control assembly26mounted to the frame for operating the pump assembly in a predetermined manner and a pneumatic foot switch28for starting a cycle of the pump assembly. The apparatus10, as shown, is a mobile unit intended to dispense a food product, such as tomato sauce for a pizza topping, either at non periodic intervals, if the pizza is made only after an order is received, or as part of an assembly line if packaged pizzas are being prepared.

The frame12includes an upstanding post30,FIGS. 5 and 6, supported by four legs32,34,36,38mounted to four casters40,42,44,46,FIG. 1. Extending from one of the legs36is a pair of hooks48,50,FIGS. 5 and 6, that is used to store the foot switch28,FIG. 1, when the apparatus is not in use. A pneumatic line52,FIGS. 2 and 3, extends from the foot switch to the control assembly26for transmitting a signal from the foot switch.

It is to be understood that a wall switch (not shown) may be substituted for the foot switch or the apparatus may operate automatically, for example, as part of an assembly line by connecting the device (without the foot switch) to a sensor (not shown) so that a signal is generated every time a pizza presents itself at a selected location. In such circumstances, the casters may be removed, if desired. Or, the casters may be retained because they may be convenient for moving the device to a washing station. Because food is being processed by the device, all parts of the device coming into contact with the food product must be detached and/or disassembled, usually once a day, for washing in a prescribed manner well know to those skilled in the food preparation field.

The food hopper14,FIG. 7, includes a cylindrical upper portion53and a cone shaped lower portion54. The lower portion is connected to the tube18. A bracket56is fastened to the hopper and is used to mount the hopper to the frame12. A hose lock nut58connects the tube to the hopper and provides an easy and quick mechanism to remove the tube from the hopper to allow both to be washed. The other end of the tube18is connected to the inlet port20,FIGS. 2-4, of the pump assembly16. Another hose lock nut60,FIG. 3, is provided so that the tube may be easily and completely disconnected and washed.

Attached to the outlet port24of the pump assembly is the nozzle assembly22. The nozzle assembly includes a second or outlet tube or hose62,FIG. 2, and an end piece64. When in use, the end piece is placed above a food substrate, such as a pizza crust, the pump assembly activated, and the food product, in this case, tomato sauce, is applied to the pizza crust. A hose lock nut66is used to connect the outlet tube62to the outlet port24of the pump assembly16. Another hose lock nut68is used to connect the end piece64to the tube62.

Referring now toFIGS. 8-13, the adjustable metering pump assembly16is shown in more detail. The pump assembly includes a pump apparatus, itself including a product cylinder70for forming a product chamber72between its inner surface and a top surface74of a product piston76. A shaded region78symbolizes a food product in the product chamber. The product piston has a longitudinal axis79,FIG. 14, and includes a longitudinally directed, centrally located internal aperture or opening80. The pump apparatus includes a cylindrically shaped valve82with a threaded opening83, the valve being located to move longitudinally in a reciprocal fashion in the opening80of the product piston. A valve piston86threadedly secured to the valve is mounted in a valve piston cylinder88and provides structure to move the valve82in the reciprocal motion in the product piston central opening80.

The product piston has a lateral aperture or slot90formed at an end portion92of the product piston. A connecting structure in the form of a pin94is mounted laterally in the lateral slot90, and causes the product piston to be reciprocated in the product cylinder70. The lateral slot90is partially formed by first and second end surfaces96,98spaced apart in a longitudinal direction of the product piston, and the lateral pin94moves between the first and the second end surfaces. The lateral pin94is also connected to the valve82through a first lateral aperture99formed in the valve. This structural arrangement allows the valve being moved by the valve piston86to reciprocate relative to the product piston, and the product piston to reciprocate relative to the product cylinder, but the product piston's movement occurs only after the lateral pin engages one or the other of the slot end surfaces96,98. During the time that the lateral pin is traveling with the valve and between the end surfaces of the slot90, the product piston is stationary even though the valve82within the product piston continues to move.

The valve piston86reciprocates in the valve piston cylinder88in response to a fluid, usually air or water, though preferably air, either entering a first port100to cause a food product intake or entering a second port102to cause a food product evacuation. The valve piston is directly connected to the valve82, and, through the lateral pin94, the valve aperture99and the lateral slot90, to the product piston76. Appropriate tubes104,105,FIG. 3, are attached to the fluid ports100,102and a tube106is attached to a source of fluid, such as an air compressor107. A sensor is included in the control assembly to sense when the valve piston reaches the end of a stroke and to signal the control assembly to send air to the opposite side of the valve piston so as to reverse direction.

A screw110, a gripping pin112and a lock knob114is used to adjust the stroke of the valve piston86. The screw abuts the valve piston at the end of its intake stroke for causing the valve piston to have a shorter or a longer stroke, as desired. This mechanism allows the selective shortening and lengthening of the stroke of the product piston76and thereby adjusts the volume, less or more, of the product chamber72. It is understood that other structures may be used to adjust the stroke of the product piston.

It may now be observed that the valve piston86, the valve cylinder88and the screw110do not ordinarily come into contact with food product and so they form a sealed unit that may be cleaned on the outside but there is usually no need to disassemble the unit. Once the screw position is set, the lock knob114is used to restrain the screw from inadvertently changing positions and thereby changing the volume of the product chamber. It is now understood that an operator has a simple and easily manipulated structure to quickly adjust the volume of the product chamber and assure that the volume will remain constant.

The product cylinder70has a tubular shape and is covered by two end caps, a mid end cap120and a far end cap122, mounted at respective product cylinder ends124,126. U-shaped connector pins130,132are used to attach the end caps to the product cylinder through appropriate openings, such as the openings134,136,138,140,141in the product cylinder, and aligning openings142,144,146,147in the end caps. Fixed to the cylinder are the intake port20and the outlet port24which are connected by the hose lock nuts60,66to the tubes18and62, respectively.

O-ring seals150,152,154are provided around the far end cap122and the product piston76. Another o-ring seal160is provided for the valve piston86. A set of screws162,164,166,168are used to attach the mid end cap120to one end170of the valve cylinder88and to a bracket172. Another set of screws180182,184,186is used to connect another bracket190at the other end192of the valve cylinder. It should be noted that by simply removing the U-shaped pins130,132and unscrewing the hose lock nuts60,66the pump elements in contact with food product, such as the product cylinder70, the far end cap122and the product piston76are separable from the rest of the pump assembly for washing.

The product piston76is described in detail inFIGS. 14-20. The product piston has a cylindrical shape with the first centrally located, longitudinally directed, internal aperture80and an outer circumferential surface202. Two longitudinally directed apertures or grooves204,206are formed in the outer surface202. The product piston also includes second and third longitudinally directed, but off-center, internal apertures208,210spaced from each other and from the first internal aperture80although they are in communication with the first internal aperture by lateral portions212,214, seeFIGS. 14,15,19and20.

The product piston further includes two lateral internal apertures216,218, each in communication with one of the second and third longitudinally directed internal aperture208,210and with one of the grooves204,206as well as with the first longitudinally directed internal aperture208. The two lateral apertures216,218are spaced from each other in a longitudinal direction and they are radially offset from one another as well by about ninety degrees, seeFIGS. 14,15,19and20. The grooves204,206are also offset by about ninety degrees as are the second and third internal apertures208,210, seeFIG. 18.

It is now appreciated that two passageways are formed in the product piston, first an intake passageway represented by the arrows220,FIG. 19, and including the groove204, the lateral aperture216, across the first central aperture80, into the lateral portion212and the second aperture208. The second or outlet passageway represented by the arrows222,FIG. 20, includes the third aperture210and the lateral portion214, across the first central aperture80, into the lateral aperture218and along the groove206.

The passageways are completed by product paths or lateral apertures230,232,FIGS. 10 and 11, in the valve82. The two lateral valve apertures230,232are spaced from one another in a longitudinal direction and are also offset from one another by about ninety degrees, seeFIGS. 21aand21b. The valve moves back and forth in the central internal aperture80of the product piston76, and the second aperture230of the valve during intake aligns as will be explained below, with the intake passageway220. During evacuation, the second aperture misaligns with the intake passageway. When the second lateral aperture230of the valve is in alignment with the intake passageway220, the second aperture230is adjacent to the lateral aperture216and to the lateral portion212of the product piston76. When the lateral aperture230of the valve is misaligned with the intake passageway212, the valve is in a transition movement or the other third lateral aperture232of the valve is aligned with the outlet passageway222where the third lateral aperture232is adjacent to and aligned with the lateral aperture218and the internal portion214of the product piston76. The third lateral aperture232operates in a similar though opposite manner from the second lateral aperture230as will be explained in relation toFIGS. 21-24.

The product piston also has a front end surface240, a rear end surface242, an anti-rotation opening244in the rear surface, and two circumferentially directed grooves246,248in the outer surface202for receiving the two o-ring seals152,154. The product piston further includes the lateral slot90for receiving the lateral pin94. The valve82also has the first lateral aperture99for also receiving the lateral pin94. In this manner, the force causing movement of the valve piston86is transmitted to the valve82, from the valve to the lateral pin94, and from the lateral pin to the product piston76, except for the delay of motion caused by the free movement of the lateral pin94in the elongated lateral slot90of the product piston. It is not until the lateral pin moves into contact and abuts either the end surface96or the end surface98around the lateral slot that the product piston also is moved in the same direction and at the same rate as the valve piston, the valve and the lateral pin. An anti-rotation pin252,FIG. 11, is connected to or integral with the screw162and is inserted into the opening244of the product piston to prevent rotation of and to align the product piston.

Because of contact with food product, the material of the product cylinder, the product piston, the valve, the lateral pin, the far end cap, the U-shaped pins, the tubes, and the hopper are made of stainless steel or plastic, such as the plastic sold under the brand DELRIN.

The control assembly26is operated by the foot switch28and is used to start a pump cycle of the adjustable metering pump assembly16. The control assembly receives a signal from the foot switch and activates the control assembly to send compressed air to one side of the valve piston cylinder to cause retraction of the valve piston. First, food product in the product cylinder is expelled. When the valve piston reaches its extended position, the sensor, which monitors air escaping from the air port not being supplied by the compressor, signals the control assembly to reverse the air flow from one side of the valve piston to the other. The valve piston retracts as does the product piston and a suction or low pressure is created in the now expanding product chamber72. This causes a movement of food product situated in the hopper at atmospheric pressure to flow through the tube18to the intake port20of the pump assembly and along the intake passageway220. The position of the screw110determines how far back or how far the retraction of the valve piston goes. The volume of the product chamber72is thus filled with food product, and a cycle is completed. When the operator activates the foot switch again, a new cycle begins. The control assembly then causes air to be injected to the other side of the valve piston to cause a compression stroke of the product piston76. This forces the food product to move along the outlet passageway222, through the outlet port24, along the tube62and to eject through the end piece64of the nozzle assembly22.

The operation of the pump assembly is illustrated inFIGS. 21-24, where each page of figures shows an end view of the pump assembly, in the lower center of the page and is designatedFIGS. 21,22,23and24, and two section views, disposed at forty-five degree angles, taken from the end views, each section at an offset of ninety degrees from the other, and are designatedFIGS. 21a,21b,22a,22b,23a,23b,24aand24b. The cycle of the pump assembly begins with the valve piston86, the valve82, and the product piston76, at their most retracted positions as shown inFIGS. 21aand21b.

Referring toFIGS. 21aand21b, air has already entered the port100,FIG. 21b, so as to push the valve piston86to an abutting position against the screw110. The valve is positioned such that the intake passageway220is open allowing food product to be sucked through the intake port20as the product piston was retracted. The food product has moved along the groove204, the lateral aperture216, the second valve aperture230, the lateral portion212and through the second longitudinal aperture208so as to discharge into the product chamber72in the product cylinder70.

In theFIG. 21bconfiguration of the pump assembly, the product chamber should be full of food product. The lateral pin94is positioned abutting the end wall98of the lateral slot90of the product piston. As can be seen inFIG. 21a, the outlet passageway222is closed because the third lateral aperture232of the valve is not aligned with either the third longitudinal aperture210or the lateral aperture218in the product piston.

Referring now toFIG. 22b, the cycle continues by having air enter the port102. This pushes the valve piston86away from the screw110. The valve82is moved to a position such that the outlet passageway222,FIG. 22a, is opened so that food product in the product chamber72is ready to be pushed through the outlet port24. In theFIG. 22bconfiguration of the pump assembly, the product chamber is still full of food product. The lateral pin94has moved away from the end wall98of the lateral slot90of the product piston and has approached the end wall96. However, as can be seen, the product piston has not yet moved from its position inFIG. 21b.

The length in the longitudinal direction of the lateral slot90of the product piston between the end walls96and98has allowed the lateral pin to move freely in relation to the product piston. Nevertheless, the intake passage way220has been closed because the second lateral aperture230of the valve is no longer in alignment with either of the second longitudinal aperture208or the lateral aperture216in the product piston.

Moving on toFIGS. 23aand23b, the cycle continues by having air at a pressure above ambient continue to enter the port102, so as to push the valve piston86to a position furthest from the screw110. The valve82is in a position such that the outlet passageway222is still open because of the longitudinal length of the groove206. InFIG. 22a, the groove206is at one end of its travel and inFIG. 23a, the groove206is at the other end of its travel. During the whole time that the groove206travels, it remains in an open alignment with the outlet port24.

Also during this travel time, the product piston moves to compress the product chamber72so that food product is pushed out through the outlet port24. To accomplish this, the food product is pushed through the third longitudinal aperture210, into the lateral portion214, through the third lateral aperture232of the valve, into the lateral aperture218and along the groove206so as to be discharged through the outlet port24. The lateral pin94,FIG. 23b, is positioned abutting the end wall96of the lateral slot90of the product piston. As may be seen inFIG. 23b, the intake passageway220remains closed because the second lateral aperture230of the valve is not aligned with either the second longitudinal aperture208or the lateral aperture216in the product piston.

Finally, moving on toFIG. 24b, the cycle continues by having higher pressure air enter the port100, so as to push the valve piston86toward the screw110. The valve82is moved to a position such that the intake passageway220is opened. This allows food product to be sucked through the intake port20as the product piston retracts. In theFIG. 24bconfiguration of the pump assembly, the product chamber72is essentially empty of food product although food product is about to enter. The selected portion of food product previously in the chamber has already been dispensed. It should be noted that the lateral pin94has moved away from the end wall96of the lateral slot90of the product piston and has approached the opposite end wall98.

As can be seen, even though the valve and the valve piston have moved from theFIG. 23bpositions, the product piston76is still stationary and has not yet moved from its position inFIG. 23bbecause of the free travel of the lateral pin94in the lateral slot90. Also, because of the longitudinal length of the groove204, it always remains in open communication with the inlet port20, just as the groove206always stays in open communication with the outlet port24, as the product piston moves from the configuration inFIG. 24bto the configuration inFIG. 21b. The outlet passageway222, however, has been closed because the third lateral aperture232of the valve is no longer in alignment with either the longitudinal aperture210or the lateral aperture218in the product piston.

The stroke of the product piston may be three inches to provide about ten ounces of tomato sauce and the longitudinal distance of the grooves204,206may be about one and a half inches.

The pump apparatus comprising the valve, the product piston and the pin are simply constructed, reliable and relatively inexpensive. In fact, the entire metering and dispensing device is simply constructed, reliable and efficient and is a cost effective device for metering and dispensing a food product. The device is also easy to operate, easy to maintain and east to clean. The pump apparatus can operate with food product that typically measures in the range of three to twelve on a Bostwick Consistometer. The pump apparatus can also be used to pump non-food product and product outside the above Bostwick range and even product that cannot be measured by the Bostwick Consistometer.

The above specification describes in detail the preferred embodiment of the present invention. Other examples, embodiments, modifications and variations will, under both the literal claim language and the doctrine of equivalents, come within the scope of the invention defined by the appended claims. For example, changing the size or placement of the valve, or of the valve piston, or of the product piston or the structure of the hopper or of the frame are still considered to be equivalent structures. Further, they will come within the literal language of the attached Claims. Using water or any other fluid instead of air to drive the valve piston or using different hoses are still considered equivalent structures. Also, a compressor may be incorporated in the control assembly should the user not have a central compressed air supply readily available. Or, a mechanical actuator operated by a small electrical motor may move the product piston back and forth and the control assembly would have an electric circuit. The pump assembly may also be operated manually by using a handle or a lever or similar element. In addition, it should be noted that the lateral apertures230,232may be replaced with circumferential grooves spaced from one another in an axial or longitudinal direction, rather than through-holes as shown and explained above. It is intended that the term “aperture” used here covers both through-holes and grooves as well as equivalent structures because all that is required is selective product paths through or around the valve so that product moving through the product piston goes from the inlet to the product chamber and from the chamber to the outlet. The use of a pin94in the aperture99of the valve and the slot90of the product piston may be replaced with shoulders and/or washers or other mechanisms to provide for the delaying movement of the product piston while being driven by the reciprocating movement of the valve. By way of another example, the valve may be elongated to extend into the product chamber. A snap ring around the valve at the extended end and another snap ring or shoulder near the other end of the valve which are engageable with surfaces of the product piston may be used to allow both free travel of the valve without travel of the product piston and combined travel of both the valve and the product piston. Using different attachment mechanisms for the brackets or different pin designs also are considered equivalent. Still other alternatives will also be equivalent as will many new technologies. There is no desire or intention here to limit in any way the application of the doctrine of equivalents nor to limit or restrict the scope of the invention.