Many restaurants, food service providers and restaurant chains strive to make their products consistent in order to control costs but also because patrons expect menu items to be consistent, regardless of where a particular menu item is purchased or which employee prepared it. Prepared food product consistency is difficult to achieve if different processes are used to prepare the product, as often happens when different employees of a restaurant use different amounts of ingredients to prepare the same item.
One way to help achieve food product consistency is to use the same ingredients, in the same amount. Prepared menu items can be made consistent by preparing an item using the same amount of each ingredient. Seasonings and toppings that are applied to a food item either before or after it is cooked are often applied in different amounts by different employees. Butter and margarine are considered herein to be toppings.
Many restaurants and restaurant chains offer breakfast foods that include English muffins. Many restaurants offer English muffins with toppings that are applied by the restaurant and thereafter served to a customer.
Consistently applying the same amount of butter or margarine to an English muffin is time consuming and problematic because of the surface roughness of an English muffin. A method and apparatus by which a liquid or melted butter or margarine, or other liquid food product can be consistently applied to food products like English muffins would be an improvement over the prior art.
Reference is made to the accompanying figures.
Viscosity is an internal property of a liquid that offers resistance to flow. In a sense, viscosity is liquid friction.
Viscosity is the inverse of fluidity, i.e., viscosity=1/fluidity. The unit of measure of viscosity is centipoise. 1 centipoise (cp)=0.01 dyne-sec/cm2. The higher the coefficient of viscosity, the higher is the liquid's viscosity. Viscosity is also dependent upon temperature however. In general, the viscosity of a liquid varies inversely with the liquid's temperature. The higher the temperature of a liquid, the lower will be its viscosity. At room temperature, butter has a viscosity of about 50,000-75,000 cp. Melted butter on the other hand has a lower viscosity of about 1,000 up to about 5,000 cp.
Virtually any liquid with a viscosity of between about 1 cp up to about 100,000 cp can be dispensed using the dispenser disclosed herein but whether a liquid can be dispensed can also depend on a liquid's thixotropic characteristics.
Thixotropy is a property of various gels that become fluid when disturbed, such as by shaking Thixotropic means that a liquid's viscosity decreases as stress on the liquid increases. Substances which are thick like a solid, but which flow like a liquid when a sideways force is applied to them, are called thixotropic.
A thixotropic fluid undergoes a decrease in viscosity with time, while it is being subjected to constant shearing. Ketchup and mayonnaise are examples of thixotropic materials. Mayonnaise has a viscosity of about 28,000 cp; ketchup has a viscosity of about 75,000 cp. They appear thick or viscous, but can nevertheless be pumped because they are thixotropic.
The preferred embodiment of the dispenser 10 is comprised of a rigid container 12, preferably made of molded plastic or molded fiberglass. The container 12 has a top portion that is also referred to as a top part 14. The top part 14 has a shape reminiscent or suggestive of a rectangular parallelepiped, which is well known to be a six-faced polyhedron all of whose faces are parallelograms lying in pairs of parallel planes and wherein the faces of the polyhedron meet at right angles.
The top part 14 is hollow and has an open top 16, as can be seen in
The parallelepiped-shaped top part 14 has a bottom edge identified by reference numeral 18. The bottom edge is joined to, attached to, or formed with, a substantially funnel-shaped portion 20. The bottom edge 18 of the top part 14 corresponds to the top edge of the funnel-shaped portion 20.
The funnel-shaped portion 20 has a bottom edge 22, which is joined to, attached to, or formed with, a substantially cylindrical discharge portion 24. The bottom edge 22 of the funnel-shaped portion also corresponds to the top edge of the discharge portion 24.
As can be seen in
Fluid food products are dispensed from the dispenser 10 by grasping a handle 32 attached to one side of the rigid container 12 and depressing a tab 82, which is one end of a piston actuator 34, not visible in
As can be seen in
The protuberances 31 have relatively small diameter dispensing holes 29, which are covered by dispensing valves 30, such as the ones disclosed in U.S. Pat. No. 5,339,995, issued Aug. 23, 1994. The dispensing valves 30 are identified in the '995 patent by reference numeral 3. The contents of U.S. Pat. No. 5,339,995 are therefore incorporated herein in its entirety, as are the contents of U.S. Pat. No. 5,439,143 and U.S. Pat. No. 5,213,236.
Liquid and liquid food in the rigid container 12 is dispensed from the holes 29 and through the dispensing valves 30 using a pump assembly 40 inside the discharge portion 24. The pump assembly 40 is comprised of a holding cup 42, which fits inside a cylindrical interior portion of the discharge portion 24, and a piston assembly 52 that reciprocates up and down inside the cup 42. The cylindrical interior portion of the discharge portion 24 is hereafter referred to as a cylinder 36 inside the discharge portion 24.
As stated above, the cup 42 fits snugly into the cylinder 36 formed into the inside of the discharge portion 24. The holding cup 42 therefore does not move in the cylinder 36. As best seen in
The inside diameter of the cup 42 is selected to receive a piston assembly 52 best seen in
The piston assembly 52 moves downward in response to downward force exerted on the piston assembly 52 through the piston actuator 34. The piston assembly 52 moves upward in response to an upward force exerted on the piston assembly 52 by a coil-type piston return spring 66, which forms part of the piston assembly 52.
As best seen in
As mentioned above, the piston actuator 34 is essentially a beam, one end of which fits loosely into a hole formed into one side of the rigid container 12, the other end of which is formed to extend over the user handle 32. As can be seen in
Referring now to
As can be seen in the figures, the top 50 of the cylinder 48 that comprises the cup 42 is open. The cylinder 48 has an inside diameter selected to receive the piston assembly 52 into the open top 50 of the cylinder 48 and to permit the piston assembly 52 to freely move up and down in the cylinder 48. The cup 42, container 12 and piston assembly 52 are configured such that when the piston assembly 52 is at or near the top 50 of the cup 42, the level of the “bottom” of the fluid in the container 12 is above the cup 42 and above the piston assembly 52. A check valve in the piston assembly 52 allows fluid from the container 12 to flow into the cup 42 until the cup 42 is full. Downward force on the push rod 54 closes the check valve in the piston assembly 52 and drives the piston assembly downward in the cup 42, against fluid that flowed into the cup 42 while the first check valve was open.
A second check valve 90 is operatively coupled to the hole 46 in the bottom 44 of the cup 42. The second check valve 90 is normally closed until a downward force exerted on the second check valve 90, through the captured fluid in the cup 42, is great enough to open the second check valve 90. When the second check valve 90 opens, fluid in the cup 42 flows through the hole 46, out of the cup and into the discharge portion 24. Additional force on fluid that flows into the discharge portion 24 from the cup will drive the fluid in the discharge portion 24, into holes 29 formed in the bottom 26 of the discharge portion 24 and through the dispensing valves 30 that cover and seal the holes 29.
The first check valve 51 is comprised of a relatively thin, substantially planar rigid disk 56 having a central hole 58, a stopper 60 which moves up and down in the central hole 58, and the hemispherical cup 72. The disk 56 has an outside diameter slightly less than the inside diameter of the cup 42 so that the disk 56 can freely translate up and down, i.e., reciprocate, inside the cup 42 but also be able to force or drive fluid out of the cup 42 in response to force applied to the piston assembly 52. A groove 53 is preferably formed into the peripheral edge of the disk 56. The groove 53 is sized, shaped and arranged to receive an O-ring 55, which improves the seal between the disk 56 and the inside surface of the cylinder 48 of the cup 42. The O-ring 55 is, of course, preferably made of a pliable material suitable for use with food products and the material from which the dispenser parts are made.
The hole 58 that extends through the disk 56 has a predetermined diameter, selected to freely receive the stopper 60. The stopper 60 has a round and substantially planar, disk-like bottom end 64. Four, L-shaped prongs 61 extend “upwardly” from the planar bottom end 64 and have a predetermined length, which is selected such that when the stopper 60 is installed in the disk 56, the vertical portions the L-shaped prongs 61 extend through the hole 58 in the disk 56 and are able to extend to the top of the inside surface of the cap 72. The top of the vertical portions of the L-shaped prongs 61 define a top end 62 of the stopper 60. The stopper 60 is preferably molded from a plastic that is sufficiently flexible to allow for the insertion of the prongs into the hole.
While the top end 62 of the stopper 60 extends into the cap 72, the bottom 64 of the stopper 60 contacts the top end 68 of the coil-type piston spring 66. The bottom end 70 of the spring 66 works against the bottom 44 of the cup 42. The characteristics of the spring 66 are selected in order to be able to push the disk 56 and the stopper 60 upwardly and away from the bottom 44 of the cup 42, when there is no downward force applied to the piston assembly 52 by the piston actuator 34.
As best seen in
The prongs 61 of the stopper 60 and the diameter of the hole 58 are selected so that the stopper prongs 61 fit loosely inside the hole 58. The loose fit of the stopper prongs 61 thus allows the stopper 60 to move up and down in response to forces applied to it by the hemispherical cup 72 and the coil spring 66.
The first coil spring 66, which is located below the bottom end 64 of the stopper 60 and above the bottom of the cup 42, applies an upward force against the bottom end 64 of the stopper. When the horizontal portions 63 of the L-shaped prongs 61 engage the bottom face of the disk 56 due to the upward force from the spring 66, the same force is transmitted through the stopper 60 to the disk 56, push rod 34 and the piston actuator 34.
In
When the cap 72 is driven downward, it eventually meets the top surface of the disk 56. Since the inside diameter of the hole 58 through the disk 58 is less than the inside diameter of the cup 72, the cup 72 effectively covers and closes the hole 58 in the disk 56 when the cup 72 meets the top surface of the disk 56. When the hole 58 is closed, fluid in the container 12 cannot flow into the cup 42. An optional O-ring 57, formed of a soft, pliable material suitable for use with a food product, is therefore sized and shaped to fit around the prongs 61 of the stopper 60. The O-ring 57 is placed between the disk 56 and the cap 72 to enhance the seal between the cap 72 and the disk 56 when the cap 72 is driven downwardly and into engagement with the disk 56.
As mentioned above, the first coil spring 66 biases or urges the stopper 60 upwardly. When the stopper 60 is pushed upwardly, the top end 62 of the stopper 60 pushes against the hemispherical cap 72. If the force from the coil spring 66 is greater than downward force applied through the cup, as happens when a user releases the user actuating tab 82, the cap 72 is moved upwardly and away from the disk 56, opening the first check valve 52, by exposing the hole 58 in the disk 56 to liquid inside the container 12.
The volume of the cup 42 below the disk 56 and above the planar bottom 44 of the cup 42 defines a maximum volume that can be captured inside the piston. As mentioned above, captured liquid is considered to be liquid that flows into the cup 42. Fluid in the cup is “captured” in the cup 42 when the first check valve 52 closes. The first check valve 52 closes when the cap 72 is pushed downwardly and into engagement with the top of the disk 56, closing the hole 58. Captured fluid in the cup 42 is translated downwardly in the cup 42, through the hole 48 in the bottom 44 of the cup 42, into the bottom 26 of the discharge portion 24 and out of one or more holes 29 formed into the bottom 26 of the discharge portion 24, by the application of additional downward force on the cap 72 via the push rod 54/user actuating tab 82.
A second check valve 90 is provided at the bottom of the cup 42. The second check valve 90 is configured to open and allow fluid to flow out of the cup 42 and into the discharge portion 24 in response to downward force applied to liquid in the cup 42 from the piston assembly 52. The second check valve 90 closes when the piston assembly 52 moves upward in the cup, i.e., away from the bottom of the cup 42. It thus prevents fluid from being drawn up into the cup 42.
As best seen in
A second coil spring 96 is located below the bottom of the stopper 94 and above the bottom 26 of the discharge portion 24 to bias the stopper 94 upwardly. When the second planar disk 92 portion of the second stopper 94 is biased against the bottom 44 of the cup 42, the hole 46 in the bottom 44 of the cup 42 is sealed.
The second spring 96 is compressed downwardly and the hole 46 opened when hydrostatic pressure inside the cup 42 exceeds the force applied to the planar disk 92 by the second spring 96. Stated another way, when the hydrostatic force applied to a fluid product inside the cup 42 exceeds the force applied to the planar disk 92 of the second stopper 94, the planar disk 92 will be urged downwardly and away from the planar bottom 44 of the cup 42. Liquid inside the cup 42 is thereafter driven through the hole 46 and into the discharge openings 29 formed in the bottom 26 of the discharge portion 24.
The disk 56 and cup 42 are configured such that the disk 56 fits snugly in the cup 42. Upward movement of the disk 56 will thus create a negative pressure inside the cup 42. Negative pressure, i.e., a partial vacuum, inside the cup 42 will slow the disk's upward movement, but a negative pressure inside the cup 42 will also draw liquid from the container 12 into the cup 42 through the hole 58. When downward force/pressure is released, the spring will overcome the partial vacuum and allow the assembly to return to its quiescent or starting position.
In
In
Additional hydrostatic pressure drives the liquid 100 completely down into the discharge portion and out of the discharge opening 30 as shown in
The pump assembly 40 is in reality a positive displacement pump. Its displacement on each actuation, and hence the volume of liquid that is dispensed on each actuation of the piston actuator 34, is a function of the diameter of the cup 42 and the length of the stroke of the piston assembly 52 in the cup 42. The volume of liquid that is dispensed on each actuation can therefore be selectively controlled, i.e., changed by a user, by limiting the piston assembly 52 travel in the cup 42. The volume of a cylinder is defined by: V=π r2h=π(d/2)2h, where r=inside radius of a cylinder, d=diameter of a cylinder, h=height of cylinder or stroke
The pump displacement limiter 120 shown in
Reducing the downward travel distance of the actuator 34 by the height of the lobes 124, 126 and 128 reduces the piston assembly 52 stroke length in the cup 42 accordingly. Reducing the piston assembly stroke length, reduces how much liquid is dispensed each time that the piston actuator 34 is depressed. By controlling the piston stroke travel using discrete distances defined by the different lobes, the limiter 120 in
The thumbscrew 142 has a threaded shank 144, which extends through a slot 145 formed into the actuating tab 82. The thread on the shank 144 mate with and engage a threaded hole 146 that extends through the flat lip 147 surrounding the open top 16. Rotating the head 143 of the screw 142 causes the screw 142 and screw head 143 to move up and down in the threaded hole 146, relative to the lip 147.
In
Those of ordinary skill in the art will recognize that clearances between the side wall of the cup 42 and cylinder 36 that the piston 40 translates in will allow material inside the rigid container to leak past and settle at the bottom 26 of the discharge portion 24. An accumulation of the material will eventually leak through the discharge openings 30 unless a closure is provided to retain the liquid inside the discharge openings. An effective dispensing valve is disclosed in U.S. Pat. No. 5,439,143, which is entitled “Dispensing Valve for Packaging.” The '143 patent issued on Aug. 8, 1995, the term of the patent subsequent to May 25, 2010, was disclaimed. The contents of the '143 are incorporated herein in their entirety.
An additional dispensing valve is disclosed in U.S. Pat. No. 5,339,995 which issued Aug. 23, 1994, and which is entitled, “Dispensing Valve for Packaging.” The contents of the '995 patent are also incorporated herein in its entirety.
Descriptions of the structure and operation of the dispensing valves 110 depicted in
The foregoing description is for purposes of illustration only. The true scope of the invention is set for in the appurtenant claims.