Abstract:
A pinch valve for use with a liquid dispensing cabinet is comprised of a tube pinching device configured to translate between an open position and a closed position and an electrically powered linear actuator configured to provide a valve opening force to the tube pinching device, The pinching device is coupled to a spring device configured to apply a valve closing force to the tube pinching device. The pinch valve is additionally comprised of an operator handle facilitating manual opening of the tube pinching device. The pinching device is rotatable in the valve body. The valve body has a front surface heat sink against which a tube pinching force is applied by a tube pinching device and a rear surface with a concavity configured to receive a tube carrying a heat transferring fluid. The tube pinching device can be operated electrically or manually.

Description:
BACKGROUND 
     A pinch valve is a valve operable with a flexible tubing or hose, and which is capable of pinching the tube or hose using a tube-pinching mechanism. Pinch valves are typically full bore, linear action valves that can be used in an off/on manner. Some pinch valves, however, can be used in a variable position or throttling service. 
     Pinch valves are used in many medical and pharmaceutical applications. They are also used in food dispensing applications because a main advantage of pinch valves is that they facilitate cleanliness, excellent drainage, and ease of cleaning. In addition to cleanliness, another advantage of pinch valves is their operation speed. Most pinch valves are simply on-off valves; they open and close a flexible tube using a pinch bar that moves between two positions. Moving a pinch bar through two, fixed locations can be done quickly, especially if the pinch bar is moved by an electrically-actuated solenoid. 
     Electromechanical closure of a pinch valve is typically accomplished by activating a solenoid to draw a spring-biased bar or gate against an elastomeric sleeve or tube, thereby cutting off fluid flow through the tube or sleeve. Some prior art pinch valves are fluid actuated wherein the pinching action is accomplished by air or hydraulic pressure placed on the elastomeric sleeve or tube. 
     A problem with prior art pinch valves, especially those used with dairy products, is that they do not facilitate the installation and removal of a bulk container. Stated another way, prior art pinch valves typically require disassembly to install and/or remove a tube passing through them and also for cleaning. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a refrigerated dispenser for liquids; 
         FIG. 2  is a close-up view of the front of the dispenser shown in  FIG. 1 ; 
         FIG. 3  is a perspective view of the underside of the dispenser shown in  FIG. 1 , viewed from its front and showing three separate pinch valve assemblies; 
         FIG. 4  is a perspective view of the underside of the dispenser shown in  FIG. 1 , viewed from its rear and showing the three separate pinch valve assemblies and the pinch bars used with each; 
         FIG. 5  is another view of the bottom of the liquid dispenser  10 , but with a horizontal lower panel removed; 
         FIG. 6  is a side view of the structure shown in  FIG. 5 ; 
         FIG. 7  is a side view of one pinch valve; 
         FIGS. 8A ,  8 B and  8 C are views of a heat sink; 
         FIG. 9  is a view of the front side of the valve body. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a refrigerated liquid dispenser  10 . The dispenser  10  is comprised of a cabinet  100  having a top  101 , a bottom  102 , a right side  103 , a left side  104 , a front side  106  and an opposing rear side  108 , not visible in  FIG. 1 . A refrigerated interior  110  is sized, shaped and arranged to enclose and refrigerate three liquid containers  112 ,  114  and  116 . Access to the refrigerated interior  110  is provided by a hinged top door  118  and a hinged front door  120 . The top door  118  and the front door  120  enable the liquid containers  112 ,  114  and  116  to be replaced and/or refilled. In one embodiment of the dispenser  100 , the containers  112 ,  114  and  116  are the containers disclosed and claimed in the applicant&#39;s co-pending patent application serial number 13/169,339 entitled “Liquid Dispenser with Storage Tanks,” filed on Jun. 27, 2011, and which is incorporated by reference herein in its entirety. 
     In one embodiment, the liquid containers  112 ,  114  and  116  are formed of a rigid plastic. Each one has a top opening as described in the aforementioned co-pending patent application and is thus refillable. Each container has two opposing side walls, a front side and an opposing rear side, a top having a refill opening and a bottom. Barely visible in  FIG. 1  are short drain cylinders  130  that extend downwardly from the container bottoms. The drain cylinders are connected to a flexible tube  128  that extends downward in front of a horizontal lower panel  111  that extends across the front  106  of the cabinet  100 . The tube  128  also extends through a pinch bar of pinch valve. Liquid in the containers  112 ,  114  and  116  will thus flow by gravity through the drain cylinders and tubes  128  unless the tubes  128  are closed by a pinch valve. Liquids are controllably dispensed by pinching and un-pinching the flexible tubes  128  using a pinch valve described herein. 
     As described below, a pinch valve configured for use with the liquid dispenser  10  is comprised of a tube pinching device and an electrically powered solenoid or other linear actuator. The tube pinching device is preferably comprised of a pinch bar described in the applicant&#39;s co-pending patent application serial number 13/169,509 entitled, “Pinch Bar,” filed on Jun. 27, 2011, and which is also incorporated by reference herein in its entirety. 
       FIG. 2  is an isolated view of a portion of the front of the liquid dispenser  10  depicted in  FIG. 1 . The drain cylinders  204  in the container bottoms are inserted into flexible tubes  128 . The tubes  128  extend downwardly from the drain cylinders  204  and “under” a horizontally-oriented, user-operable pinch valve handle  200 . Stated another way, the tubes  128  extend downwardly but between a horizontal pinch valve handle  200  and a valve body, not visible in  FIG. 2  but detailed below. 
     Three handles  200 A,  200 B and  200 C are shown in  FIG. 2 . The handle  200  is a substantially flat or planar, rectangle, having a central region  202  open to facilitate grasping the handle  200  by an operator. 
     Each handle  200 A,  200 B and  200 C is attached to an elongated rod  300 , which extends into a lower panel  111  that extends across the front of the dispenser. A spring device, not visible in the figures because it is inside the Pinch Bar, biases the elongated rod  300  and the handle  200  attached to the rod  300 , inwardly vis-à-vis the cabinet  100 . Stated another way, the bias force from a spring inside the Pinch Bar urges the rod  300  and handle  200  in a direction that is away from a user of the dispenser  10  and toward the rear side  108  of the cabinet  100 . 
     As described in the aforementioned co-pending patent application, each handle  200  is formed to also provide a relatively narrow pinching edge  206 . The spring bias force is thus directed through a relatively narrow area defined by the pinch edge  206 , which faces a fixed valve body, not readily visible in  FIG. 1  or  FIG. 2 . The pinching edge can thus be considered as focusing the force provided by the aforementioned spring, through the handle  200  to the pinching edge  206  of the handle  200 . When a flexible tube  128  is placed between the pinching edge  206  and a fixed surface, the closing force on the rod  300  will tend to pinch the tube  128  closed. The bias or valve closing force on the rod  300 , which is provided by the aforementioned spring device, is thus considered herein to be a valve closing force. Stated another way, the aforementioned spring device provides a valve closing force. 
     The pinching edge or surface  206  is preferably a narrowing of a side or edge of the handle  200  that faces a valve body surface. Such an edge can have different cross sections or profiles, such as those shown in  FIG. 7  of the applicant&#39;s co-pending “Pinch Bar” application. 
     An important aspect of the aforementioned “Pinch Bar” is that the valve closing force can be overcome electrically or manually. The open central region  202  is thus large enough to allow at least one human finger to be inserted into the central region  202  to facilitate pulling the handle  200  and the pinching edge  206  away from a valve body against which the pinch surface  206  applies a pinching, closing force to a flexible tube  128 . 
     In an alternate embodiment, the elongated rod  300  can be bent or “L-shaped” as shown in  FIGS. 2 and 3  of the co-pending patent application Ser. No. 12/885,641, filed Sep. 20, 2010, entitled “Pinch Valve.” The content of application Ser. No. 12/885,641 is incorporated herein by reference in its entirety. 
     As used herein, the terms “spring” and “spring device” refer to any device that returns to an original shape after being compressed or stretched. Because of their ability to return to their original shape, springs are used to store energy. A spring can be formed as a coil or a strip. A twisted or twistable rod or bar can also act as a spring and sometimes referred to as torsion bar. A torsion bar is a flexible spring that can be moved about its axis via twisting. It works by resisting the torque placed on it. When one end of the bar is affixed to an object that cannot be moved, the other end of the bar is twisted, thus causing torque to build up. When this happens, the torsion bar is resistant to the torque and will quickly go back to its starting position once the torque is removed. 
       FIG. 3  is a perspective view of the underside of the liquid dispenser  10 , i.e., looking upwardly at the bottom of the refrigerated portion of the cabinet  100 , but from a point located in front of the cabinet  100 . Three pinch valves  350  are shown. Each pinch valve  350  is comprised of the aforementioned “Pinch Bar”  360  described in the co-pending patent application but not visible in the figure and, an electrically actuated solenoid or linear actuator device  370 . 
     A spring device in the pinch bar portion of the pinch valve  350  exerts a valve closing force on the pinching surface  206  through the elongated rod  300 , also not visible, both of which comprise the aforementioned “Pinch Bar.” In order for the pinch valve  350  to be opened electrically, and thereby dispense liquids electrically, a solenoid/linear actuator  370  is utilized. The solenoid/linear actuator  370  is a device configured to provide a force directed against the base portion  706  of the spring stop  700  of the pinch bar  360 . The force applied by the solenoid  370  is thus in a direction that is opposite the direction of the valve closing force, i.e., forwardly and away from the rear  108  of the cabinet and toward the front  106  where a person would operate the liquid dispenser  10 . The valve opening force provided by the linear actuator  370  is applied to the base portion  706  through a push rod  380  that is mechanically coupled to the armature of the linear actuator  370  but not connected or mechanically attached to the Pinch Bar. The push rod  380  is not attached or connected to the Pinch Bar so that enables the Pinch Bar to be physically removed from the horizontal lower panel  111 . 
       FIG. 4  is another view of the bottom of the liquid dispenser  10  but viewing the underside from a point that is behind the front of the cabinet  100 . The rod actuator  400  described in the aforementioned co-pending “Pinch Bar” extends through the lower panel  111 . The push rods  380  can be seen impinging the base portion  706 . 
       FIG. 5  is a close-up view of the pinch valves shown in  FIG. 4 . The horizontal lower panel  111  is also removed in  FIG. 5  to show how each pinch bar  360  and its corresponding solenoid  370  effectuates a pinch valve that is operable electrically and manually. Two push rods  380 A and  380 B are drawn as being shorter than the third push rod  380 C. Similarly, the third spring stop portion  700 C of the third Pinch Bar  360 C is depicted as being shorter than the first spring stop portion  700 A of the first Pinch Bar  360 A and the second spring stop portion  700 B of the second Pinch Bar  360 B. And, the third handle  200 C is depicted as being further away from the front of the cabinet  100  and a valve body  500 . In this case, the flexible tube  128  is not pinched at all. The first handle  200 A is depicted as being closest to the front of the cabinet  100  and a valve body  500  against which the flexible  128  is pinched closed by the valve closing force provided by a spring device inside the pinch bar  360 A. The second handle  200 B is depicted similarly as the first handle  200 A. The longer third push rod  380 C depicts actuation of the third solenoid  370 C and its application of a valve opening force through the push rod  380 C and into the base portion  706  of the pinch bar  360 C. 
     As described in the applicant&#39;s co-pending patent application Ser. No. 12/885,641 entitled “Pinch Valve” and which was filed Sep. 20, 2010, and which is incorporated by reference, each solenoid can be computer controlled and is able to drive a corresponding push rod  380 A,  380 B and  380 C forwardly, i.e., in a direction that is away from the back side  108  of the cabinet  100  and into the bottom end or base portion  706  of a pinch bar  360  responsive to an electric signal applied to the solenoid. The valve opening force provided by the solenoids thus acts in a direction that opposes the valve closing force because it acts in a direction that is away from the rear side  108  of the cabinet  100  and toward where a person using the liquid dispenser would be standing and operating the pinch valves to dispense liquids. 
       FIG. 6  is a side perspective view of the structure shown in  FIG. 5 . The pinch valves  360 A- 360 C are held in place in the valve body  500  by a somewhat L-shaped spring-loaded clip  600 . The short leg  602  of the L-shaped retaining clip  600  has an edge  606  that engages a notch  428  formed into the outside surface of the rod actuator  400  and provides a detent that holds the Pinch Bar  360  in the valve body  500 . Pushing the long leg of the retaining clip  600  disengages the edge  606  from the notch  428 , which permits the pinch valves to be pulled out of the valve body  500  and the lower panel  111 . 
       FIG. 7  is a side view of one pinch valve  350  for use with the cabinet  100  depicted in  FIG. 1 . The pinch valve  350  is comprised of a valve body  500  having a front face or side  702  and an opposing rear face or side  704 . The pinch bar  360  described above extends through a lower portion  720  of the valve body  500 . A heat sink  800  is fixed in a top portion  724  of the valve body  500 . 
       FIG. 8A  is a perspective view of the heat sink  800 , which is made of a thermally-conductive material such as aluminum, copper or brass. The heat sink  800  has a top surface  802 , a bottom surface  804 , a front face  806 , which when installed into the valve body receives and abuts a flexible tube  128 . The heat sink  800  also has a rear face  810  opposite the front face  806 , a right side  812  and a left side  814 . 
       FIG. 8B  is a top view of the heat sink  800 . The right side  812  and left side  814  can be seen in  FIG. 8B  as substantially planar. The front face  806 , however, has a channel  816  sized to receive a tube  128  that dispenses liquid from a container  112 ,  114  or  116 . In one embodiment the channel  816  has a cross sectional shape (when viewed from the top) that is an arc of a circle. In another embodiment the channel  816  is an arc of an ellipse. 
     The channel  816  in the front face  806  of the heat sink  800  is considered herein to be a concavity, inasmuch as the channel  816  is concave vis-à-vis the front face  806 . The channel  816  has a width  818  as shown, and a depth  820  sufficient to receive a flexible tube  128  that extends from a container  112 ,  114  and  116  and restricts the tube&#39;s side-to-side translation as the tube is pinched and un-pinched. 
       FIG. 8C  is a right-side view of the heat sink  800 . The top face  802  and the bottom face  804  can be seen to be substantially planar. The front face  806  can be seen in  FIG. 8C  as having a second, recessed lower front face  822 , that is itself substantially vertical, substantially planar and setback into the body of the heat sink  800  from the upper front face  806  by a distance substantially equal to the depth  820  of the channel  818 . A chamfer  824  provides a transition from the upper or extended face  806  backwardly, i.e., toward the rear side  810 , to the recessed lower front face  822 . The recessed lower front face  822  is the surface against which a pinching force is exerted by a pinch bar or a pinching edge  206 . 
     The back face  810  of the heat sink  800  has a second, horizontally-oriented channel  826 , which is also considered herein to be a concavity. The cross sectional shape of the second channel  826  (when viewed from either side) is an arc of a circle. The second channel  826  has a depth and a width configured to mate with the outside surface of a length of tubing (not shown but well known in the art) which carries a heat transfer fluid, such as a compressed and cooled gas used in a refrigeration system evaporator coil. In another embodiment, a tube fit into the second channel  826  carries a hot liquid. The mechanical attachment of a refrigeration coil or a heating coil into the second channel  826  provides a direct thermal and mechanical coupling of the heat sink  800  to a heat-absorption fluid or a heat source fluid. 
     In another embodiment, the back face  810  is smooth and has attached to it, the cold side of a Peltier device, not shown but well known in the art. In another embodiment, the channel  826  formed in the back face  810  has an electric heating element attached to it, which provides heat energy into the heat sink  800 . In yet another embodiment, a smooth back face  810  has the hot side of a Peltier device attached to it, which also provides heat energy into the heat sink  800 . Regardless of whether the heat sink  800  back face  810  is attached to a source of heat energy or a heat sink, the direct, mechanical coupling of the heat sink  800  to a heat transfer device, such as an evaporator coil, a Peltier device, or a heating element, significantly improves heat transfer to and from liquids in a flexible tube  128  that abuts the front face  806 / 822 . 
       FIG. 9  is a view of the front side of the valve body  500 . A substantially L-shaped rod  300  passes through a removable shaft seal  1000  in the valve body  500 . The seal  1000  prevents liquids from migrating into the valve body  500  along the rod  300 . 
     As described in the co-pending Pinch Valve application, the pinch bar shown in  FIG. 9  has an axis around which the pinch bar can rotate in order to facilitate the removal and/or installation of a tube from and into the pinch valve. 
     In  FIG. 9 , a J-shaped handle is sized, shaped and arranged such that a user can pull the pinch bar away from the valve body  500 . 
     The foregoing description is for purposes of illustration only. The true scope of the invention is set forth in the appurtenant claims.