Abstract:
A two-piece pinch valve is disclosed. A first piece or part of the valve is fixedly installed into a dispensing cabinet. A second piece or part having a movable pinch bar that pinches and un-pinches a tube is installable into and removable from the first piece by hand. Removal of the second piece from the first pieces allows a tube to be directly installed into the pinch valve. Installation of the second piece into the first piece configures the valve for operation. The second piece is installed into slots in the first piece. The slots and engaging protuberances on the second piece enable the second piece to be locked in place.

Description:
BACKGROUND 
     A pinch valve is a valve that is 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. However, some pinch valves 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 advantages of pinch valves include 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. 
     A problem with prior art pinch valves, especially those used with a liquid dispenser is that they do not facilitate the installation and removal of the bulk containers from which liquids are dispensed. Stated another way, prior art pinch valves typically require disassembly to install and/or remove a tube passing through them and also for cleaning. Disassembling a prior art pinch valve is difficult and time consuming. A pinch valve that can be disassembled quickly and easily would be an improvement over the prior art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a dispenser for liquids; 
         FIG. 2  is a front elevation view of the liquid dispenser; 
         FIG. 3A  is a front elevation view of a liquid dispenser, the door of which is removed; 
         FIG. 3B  is a perspective view of a dispensing tube inserted into the first part of the pinch valve; 
         FIG. 4  is a close-up view of a refrigerated liquid dispenser compartment and depicting how the tank is placed directly into the compartment; 
         FIG. 5  is a perspective view of the clamp section of the pinch valve; 
         FIG. 6A  is a perspective view of the frame section of the pinch valve; 
         FIG. 6B  is an exploded view of the frame section of the pinch valve; 
         FIG. 7A  is a perspective view of the latch; 
         FIG. 7B  is a top view of a heat sink in the pinch valve frame section; 
         FIG. 7C  is a right-side view of a heat sink in the pinch valve frame section; 
         FIG. 8A  is a perspective view of a preferred embodiment of a removable clamp part of the pinch valve; 
         FIG. 8B  is a perspective view of the clamp body and pinch bar; 
         FIG. 8C  is a perspective view of the open interior of the clamp body; 
         FIG. 8D  is a perspective view of the pinch bar viewed from the apex ridge; 
         FIG. 8E  is a perspective view into the open sides of the pinch bar; and 
         FIG. 9  is a perspective view of the assembled clamp section. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a perspective view of a refrigerated liquid dispenser  100 . The dispenser  100  is comprised of a cabinet  102  having a left side  104 , a right side  106 , a top  108 , a bottom  110  and a front side  112 . The front side  112  is comprised of a door  114  attached by a hinge (not visible in  FIG. 1 ) to the right side  106  of the cabinet  102 . Refrigeration equipment comprised of a compressor, condenser and a fan are enclosed inside a refrigeration equipment compartment  116  located below a refrigerated storage compartment  120 , which is located behind the hinged door  114 . 
       FIG. 2  is a front elevation view of the liquid dispenser  100  with the door  114  open to reveal the inside of the refrigerated storage compartment  200 . The refrigerated storage compartment  200  has a left side  202 , a right side  204 , a top  206 , a bottom  208  and a rear panel  209 . The sides, top and bottom are thermally insulated. The insulation is not shown but well-known to those of ordinary skill in the art and further discussion of it is omitted for brevity. 
     The bottom  208  of the refrigerated storage compartment  200  has a front edge  212  into which slots  214  are formed. The slots  214  receive pinch valves described below. The pinch valves are comprised of two pieces. A first part is fixed in a slot  214 . The second part of the pinch valve is removable from the first part in order to allow a flexible tube extending downwardly from a liquid storage bin in the refrigerator storage compartment  200  to be received directly into the first part of the valve wherein the tube is pinched and un-pinched. 
       FIG. 3A  is a front elevation view of a liquid dispenser  100 , the door  114  of which is removed to reveal a refrigerated compartment  300  having two liquid storage tanks  302  side-by-side in the compartment  300 . The top  301  is hinged to a back side of the cabinet  102  to allow tanks  302  to be refilled without having to remove them from the compartment  200 . 
     The tanks  302  shown in  FIG. 3A  are known in the art. They are plastic, substantially rectangular in shape and with an open top  304  into which liquid can be poured. The tanks have bottoms  309  with openings, not visible in  FIG. 3A  but from which flexible plastic tubes  310  extend downwardly from short and relatively rigid cylinders. The tube from the left-side tank  302  is shown passing through an assembled pinch valve  314 . The tube from the right-side tank  302  is shown passing through the aforementioned first part  316  of the pinch valve, i.e., the second part of the valve is removed. 
     Controllably dispensing liquid from the tanks  302  requires the flexible plastic tubes  310  to be opened and closed. Opening and closing the flexible tubes  310  is accomplished using a pinch valve  314 , which is considered herein to be a full bore control valve that uses a pinching effect to obstruct fluid flow. 
     A problem with many prior art pinch valves is that they require a tube to be threaded through the valve. Threading a tube through a pinch valve means passing the flexible tube through a pinch valve in a manner akin to inserting a strand through a small opening. Threading a tube through a prior art pinch valve usually requires manipulating the tube through the valve from the top by bending folding. It is time consuming, tedious and usually requires supporting a relatively heavy, liquid-filled container. 
     The pinch valve  314  disclosed herein is comprised of two sections or portions that can be quickly and easily separated from each other without tools or special equipment in order to enable a dispensing tube  310  to be inserted directly into the “valve,” i.e., without having to feed or thread a tube through the valve  314 .  FIG. 3B  shows a dispensing tube  310  from a tank inserted into a substantially U-shaped first part of the valve  314 , which is preferably fixed into a slot  210  formed in the front edge  212  of the bottom  208  of the refrigerated compartment using an adhesive. 
     The first part of the valve  314  is referred to herein as a frame section  316 . When viewed from above or below, the frame section has a shape reminiscent of the upper case Arabic letter “U.” Its shape is also reminiscent of the Greek letter “Π” which is also known as “pi.” When viewed from above or below, its shape is also reminiscent of the mathematical symbol for intersection (∩) and union. A second section that is removable from the frame section  316  is referred to as a removable clamp section. The clamp section is described below. For brevity, such shapes (∩, U, Π) and equivalents thereof are collectively referred to hereinafter as U-shaped or substantially U-shaped. 
       FIG. 4  depicts a tank  306  in the compartment  300  and its associated flexible tube  310  descending downward after being placed directly into the first part  410  of the pinch valve  314 . The tube  310  can be seen in its entirety, extending, downwardly from the bottom  309  of the tank  306  a distance of between about six and about ten inches.  FIG. 4  also shows that there is no structure or mechanism through which the tube  310  needs to be placed or threaded. The tube is simply placed into a substantially U-shaped frame portion or section  316 . The frames section  316  is considered herein to be a first part of the pinch valve  314 . 
     The bottom  309  of the tank  306  rests on a support plate  400 . The support plate  400  has a side wall  402  that defines an air gap  404  below the support plate  400  and above the bottom  208  of the storage compartment  200 . The notch  210  formed at the front edge  212  of the bottom  208  is configured to receive the pinch valve assembly that is comprised of the aforementioned U-shaped frame section  316 , which receives a clamp section that is removable from the frame section  316 . 
       FIG. 5  is a perspective view of the clamp section  504 , shown removed from the frame section  316  and inclined at an angle relative to the horizontal bottom surface  208  of the refrigerated storage compartment  200 . The frame section  316  is considered herein to be comprised of two opposing and substantially parallel sides  506  and  508 , which are spaced-apart from each other by what is considered herein to be a third side  510  extending between the two opposing sides  506  and  508 . 
     When the clamp section  504  is held at an angle as shown, protuberances  512  that extend outwardly from sides  514  of the frame section  316  can be slid into two, opposing grooves  516  formed into the opposing sides  506  and  508  of the frame section  316 . The removable clamp section  504  is slid down the grooves  516  to a substantially circular cutout located near the bottom of the U-shaped frame section sides  506  and  508 . The cutout is identified by reference numeral  618  in  FIG. 6A . When the protuberances reach the cutout  618 , the frame section  504  can be rotated forwardly, i.e., toward the tube  310 . 
     Cantilevered arms  516  extend from the third side  510  of the frame section  316 . They are configured to engage an edge  518  of a clamp  520  located at the top  804  of the clamp section  504 . When the clamp section  504  is slid down the grooves  516  to the cut-out  618  and when the clamp section  504  is rotated forwardly, the arms  516  and clamp  520  lock the clamp section  504  in place in the frame section  316 . 
     In a preferred embodiment, the third side  510  of the frame section  316  is formed by wide, base section portions of the first side  506  and the second side  508 . As stated above, both of the sides of the frame section have a slot formed in them to receive the clamp section, which is also referred to herein as a second part of the pinch valve. 
     The slot  618  formed into each side of the frame section  316  that receives a protuberance extending from a side of the clamp section  504  is referred to herein as a clamp receiving slot  618 . The clamp-receiving slot  618  in the first side of the U-shaped frame section  316  faces or opposes a clamp-receiving slot in the opposite second side of the U-shaped frame section  316 . The clamp-receiving slots  618  in the sides of the frame section  316  enable the clamp section  504  to be slid upwardly and removed from the frame section  316  and thereafter slid downwardly for re-installation into the frame section  316 . The ability to quickly and easily remove the clamp section  504  from the frame section  316 , without tools, enables a dispensing tube  310  to be placed into and removed from the pinch valve frame section  316  directly, i.e., without having to thread or feed a tube  310  through a pinch bar mechanism as prior art pinch valves require. 
     A dispensing tube  310  is removed from the pinch valve by de-latching the clamping arms  516  from the edge  518  of the clamp  520  and rotating the clamp section  504  outwardly, i.e., away from the tube  310  and refrigerated compartment  220  and sliding the clamp section  504  upwardly and out of the clamp receiving slots  516 . After the clamp section  504  is removed from the frame section  316 , a tube in the frame section  316  can be removed directly from the frame section  316  because the frame section  316 , being U-shaped, has an open passageway between the two opposing side walls  506  and  508 . 
     The first side  506 , second side  508  and third side  517  of the frame section  316  are considered herein as being substantially U-shaped, i.e., they have a shape reminiscent of the Arabic letter “U.” The open space between the two opposing sides and “in front of” the third side defines an open passageway that receives a tube  310  of a liquid container. 
     The frame section depicted in  FIG. 5  is actually an assembly of three separate components shown in  FIGS. 6A and 6B .  FIG. 6A  is a perspective view of a frame section  600  assembled.  FIG. 6B  is an exploded view of the frame section  600  depicted in  FIG. 6A . 
     Referring to both  FIGS. 6A and 6B , the frame section  600  is comprised of a left side or portion  602 , an opposing left side or portion  604  and a thermally-conductive body  606  enclosed by end sections  622  of the left portion  602  and right portion  604 . The thermally-conductive body  606  conducts heat. It is referred to hereinafter as a heat sink for brevity because its function is to carry heat away from (sink) a flexible tube in the pinch valve. In an alternate embodiment, however, wherein liquid in a tube  310  is to be kept warm or hot, the thermally-conductive body  606  carries heat toward a flexible tube in the pinch valve but is nevertheless still considered to be a heat sink. 
     Referring now to  FIG. 6B , both sides  602  and  604  have a base portion or section  622  having a horizontally-oriented notch  608  the horizontal side walls  610  of which are separated from each other by a vertical distance great enough to receive the heat sink  606  between them. A front face  605  opposite the base portion  622  is formed with an opening  614  into a clamp-receiving slot  612  formed into the left side portion  602  and right side portion  604 . 
     The clamp-receiving slot  612  receives protuberances that extend outwardly from the sides of the aforementioned removable clamp section  504 . The clamp-receiving slot  612  has a width dimension (orthogonal to the length of the clamp-receiving slot  612 ) and a depth into the sides of the clamp sections. The width and depth of the clamp receiving slot  612  are selected to provide a slip fit to a substantially rectangular protuberance  512  from the side wall  514  of a clamp section  504 . The clamp receiving slot  612  thus receives the clamp section  504  into the frame section  316 . 
     As shown in  FIG. 6B , the clamp receiving slots  612  have an opening  614  at the front faces  605  of both the left side  602  and right side  604 . The slots  612  angle downwardly from the opening  614  and terminate at substantially circular receiving holes or cut outs  618  located at what is considered to be the bottom of the clamp-receiving slot, which is also near the bottom  616  of the left side  602  and the bottom  616  of the right side  604 . 
     (The right side  604  of the frame section  600  is a mirror image of the left side  602 . When the left side  602  and right side  604  are assembled as shown in  FIG. 6A , the right side  604  has a clamp receiving slot and cut out directly opposite the clamp receiving slot  612  and cut out  618  formed in the left side  602 . Only the opening  620  of the clamp receiving slot  612  formed into the right side  604  is visible.) 
     When the left side  602  and the right side  604  are assembled together with the heat sink  606  enclosed between them, the assembled frame section  600 , which is depicted in  FIG. 6A , can be seen to have two opposing and spaced apart sides  602  and  604  and a third side  623  formed in part by the heat sink  606  enclosed within the slots or notches  608  therein. The side walls  610  of the notch  608  and the heat sink  606  thus form the third side  623  of the U-shaped frame section  600 . The horizontal separation distance between the opposing sides  602  and  604  defines an open passageway  630 , which is the open space between the opposing and spaced apart side walls  602  and  604  and in front of the third wall or side  623 . 
       FIG. 7A  is a perspective view of the heat sink  606 . The heat sink  606  is made of a thermally-conductive material, examples of which include aluminum, copper or brass. The heat sink has a top surface  700  a bottom surface  702  opposite the top surface  700 , a front face  704 , which when installed into the clamp section  504  abuts a flexible tube  310 , a rear face  706  opposite the front face  704 , a right side  708  and a left side  710 . 
       FIG. 7B  is a top view of the heat sink  706 . The right side  708  and left side  710  can be seen in  FIG. 7B  as substantially planar. The front face  704 , however, has a channel  712  sized to receive a tube  310 . In one embodiment the channel  712  has a cross sectional shape (when viewed from the top) which is an arc of a circle. In another embodiment the channel  712  is an arc of an ellipse. The channel  712  has a width  714  and a depth  716  sufficient to receive a flexible tube  310  that extends from a liquid holding tank  302  and which tends to locate or fix a tube  310  into the center of the frame section  316 . An advantage of having a channel  712  formed into the front face over a flat surface is that a tube  310  located into the channel  712  will tend to stay in the channel  712  while the tube  310  is being pinched and un-pinched. 
       FIG. 7C  is a right-side view of the heat sink  606 . The top face  700  and the bottom face  702  can be seen to be substantially planar. The front face  704  has a second and recessed lower front face  720 , that is substantially vertical, substantially planar and setback into the body of the heat sink  606  from the upper front face  724  by a distance substantially equal to the depth  716  of the channel  712 . The extended face or projecting face  724  transitions to the recessed face  720  by a chamfer  722 . The recessed lower front face  720  is the surface against which a pinch bar in the clamp part of the pinch valve  314  exerts a compressive, pinching force on the flexible tube resting in the channel  712 . 
     The back face  706  of the heat sink  606  has a second, horizontally-oriented channel  726 . The cross sectional shape of the second channel  726  (when viewed from either side) is either an arc of a circle or an arc of an ellipse. The second channel  726  has a depth and a width configured to mate with the outside surface of a length of tubing of a refrigeration system evaporator coil, not shown but well known to those of ordinary skill in the mechanical art. The mechanical attachment of a refrigeration coil into the second channel  726  provides a direct thermal mechanical coupling of the heat sink  606  to an evaporator coil of a refrigeration system. In another embodiment, the back face  706  is smooth and has attached to it, the cold side of a Peltier device. In another embodiment, the channel  726  formed in the back face  706  has an electric heating element attached to it, which provides heat energy into the heat sink  606 . In yet another embodiment, the channel  727  has a tube through which a hot or heated liquid is passed and which provides heat energy into the heat sink. In yet another embodiment, a smooth back face  706  has the hot side of a Peltier device attached to it, which also provides heat energy into the heat sink  606 . Regardless of whether the heat sink back face  706  is attached to a source of heat energy or a heat sink, the direct, mechanical coupling of the heat sink  606  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  310  that abuts the front face  704  and which is held in the first channel  712 . The shape of the first channel being substantially similar to the shape of a tube  310  increases the surface areas of the tube  310  and heat sink  606  through which heat can be conducted. 
       FIG. 8A  is a perspective of a preferred embodiment of a removable clamp part, renumbered in  FIGS. 8A and 8B  starting with reference numeral  800 . The clamp part  800  depicted in  FIG. 8  is identical to the clamp part identified by reference numeral  504  in  FIG. 5  and which is shown in  FIG. 5  as ready for removal from, or insertion into, the clamp portion  502 . 
     In  FIG. 8A , the clamp part  800  is comprised of a clamp body  802  the shape of which is reminiscent of a rectangular parallelepiped or cuboid. One side of the cuboid-shaped clamp body, which is not visible in  FIG. 8A , is open. The open side of the clamp part  800  is best seen in  FIG. 8B , wherein the clamp part  800  is depicted with the open side facing upwardly. 
     Referring now to both  FIGS. 8A and 8B , the clamp body has a top side  804  a bottom side  806  a right side  808  and a left side  810 , not visible in  FIG. 8A . A front side  812  faces an operator of the valve when it is installed in the refrigerated cabinet. 
     A curved handle  814  extends downwardly from the bottom side  806 . The bottom side  806  is thus formed with a slot, which the handle  814  projects outwardly from and translates in. The handle  814  has a bottom end  820  and an opposing top end  822 . The curvature of the handle  814  allows the top end  822  to extend into an open side  826  of a wedge-shaped pinch bar  824  with the bottom end  820  extending away from the cabinet facilitating actuation of the valve by lifting or depressing the handle  814 . 
     The top end  822  of the handle  814  is mounted into a pyramidal or wedge-shaped pinch bar  824  using a pin  828  that extends through the right side  808  and the left side  810  of the clamp body  802 . The pin  828  also extends through an elongated slot  830 , which extends through the right side  832  of the pinch bar  824  and the left side  834  of the pinch bar  824 . 
     The elongated slot  830  can be seen as bordered by two substantially cuboid-shaped protuberances  836 A and  836 B extending outwardly from the right side  832  of the pinch bar  824 . An identical set of protuberances extend from the left side  834  but cannot be seen in  FIG. 8B . The protuberances  836 A and  836 B are separated by a distance slightly greater than the width of two cuboid extensions  838 A and  838 B, which extend from the left interior side  810  and the right interior side  808  of the clamp body  802 , i.e., into the open interior space  840  of the clamp body  802 . 
     With regard to the clamp body  802  and more particularly the pinch bar  824 , the distance separating the left side  834  from the right side  832  of the clamp body  824  is less than the separation distance between the left side  810  and the right side  808  of the clamp body  802 . The pinch bar  824  is thus able to freely translate back and forth (as shown in  FIG. 8A ) or up and down as shown in  FIG. 8B  responsive to bias exerted on the bottom face  844  of the pinch bar  824  by two coil springs  842 . The springs  842  bias the pinch bar  824  outwardly from the interior space  840  of the clamp body  802 , which is toward the lower flat face  720  of the heat sink  606 . 
     The pinch bar  824  translates back and forth on a track or slide comprised of the protuberances  836 A and  836 B that extend outwardly from the opposite sides of the pinch bar  824 . The protuberances  836 A and  836 B ride against the side walls of the cuboid extensions  838 A and  838 B from the left and right sides  810  and  808  of the clamp body  802 . 
     The pin  828 , which also extends through the elongated slot  830 , provides a pivot for the top end  822  of the handle  814 . Upward or downward movement of the bottom end  820  of the handle  814  drives the pinch bar  824  backwardly, against the force exerted on the pinch bar  824  by the springs. Upward or downward movement of the bottom end  820  of the handle  814  thus causes the pinch bar  824  to be retracted inwardly into the clamp body releasing or un-pinching a hose  310  in the frame portion. 
       FIG. 8C  is a perspective view of the open interior  840  of the clamp body  802 . The open slot  816  in the bottom face  806  described above and which accommodates vertical translation of the handle is visible in  FIG. 8C  as are the protuberances  838 A and  838 B that extend inwardly from the left side  810  and right side  808  of the clamp body  804 . 
     A hole  845  through the two opposite sides is sized and configured to receive the pin  828  around which the top end  822  of the handle  814  pivots. A clamp  846  with an edge  847  is formed at the top  804  of the clamp body  802 , extending upwardly from the top side  804  to provide a latch for cantilevered arms that extend from the third side of the U-shaped clamp portion. 
       FIG. 8C  shows one of two substantially rectangular-shaped protuberances  848  located near the open side of the cuboid-shaped clamp body  802 , away from the front face  812  and close to the bottom face  806 . The protuberances  848  are dimensioned to slide freely into the clamp receiving slots  612  described above and shown in  FIGS. 6A  and  6 B. The rectangular shape of the protuberances  848  allows them to slide up and down the slots  612 . When the protuberances  848  are rotated in the aforementioned cut-outs  618 , their rectangular shape precludes them from sliding out of the clamp receiving slots  612 . 
     The protuberance length is less than the diameter of the cut-out  618  formed at the bottom of the clamp receiving slot. The protuberance length is chosen such that when the protuberances  848  are inside the cut out  618  and rotated by even a small angle, as happens when the clamp body is latched into place, the protuberance length prevents the clamp body  802  from sliding upwardly, i.e., out of the frame section. Rotation of the clamp body  602  in the frame section to a latched position thus locks the clamp body into the frame section. 
       FIG. 8D  is a perspective view of the substantially wedge-shaped pinch bar  824  viewed from the apex edge  850 . The elongated slot  830 , which rides over the pin  828 , extends through both the left side  834  and the right side  832 . The substantially rectangular-shaped protuberances  836 A and  836 B that extend outwardly from the sides can define a slot  830  between the two protuberances  836 A and  836 B. 
       FIG. 9  is a perspective of the assembled clamp section, viewed from the top of the open side of the clamp body  802 . A pair of holes  902  are formed into the opposing sides  808  and  810  of the clamp body to receive optional roll pins, not shown. The function of this feature is to limit the travel of the lever  814  to one direction. A similar pair of holes  904  located below the pin  828  can receive a second stop pin (not visible) the function of which is to limit the travel of the handle in an opposite direction. Insertion of a pin through the upper holes  902  or lower holes thus limits the travel of the lever to only an upwardly or downwardly direction. A pin through either pair of holes  902  and  904  preventing the top surface  906  of the handle  814  from rotating in one direction or the other around the pivot point  828 . A pin in the upper holes  902  prevents the handle  814  from being upwardly lifted. A pin in the lower holes  914  prevents the handle  814  from being depressed downwardly. 
     The pin  828  around which the pinch bar  824  rotates functions as an axle. Upward or downward movement of the end of the handle  814 , relative to horizontal, causes the wedge-shaped pinch bar  824  to translate toward or away from the third side of the U-shaped clamp section. The upward or downward handle movement thus pinches and un-pinches a plastic tube in the clamp section. 
     In a preferred embodiment, the handle  814  is formed of a stamped metal. The frame section is comprised of an injection molded plastic such as nylon or fiberglass. The clamp section  504  is also comprised of an injection molded plastic such as nylon or fiberglass. The heat transfer body or heat sink  606  is preferably comprised of a thermally-conductive material such as brass, copper or aluminum. 
     Those of ordinary skill in the art will recognize that the pinch valve described above has a valve frame that is open and capable of directly receiving a tube from a liquid reservoir without having to feed or “snake” the tube through a pinch bar assembly as prior art valves require. Moreover, the third side or back side of the frame section can be shaped with the side walls to provide a substantially concave shape which will locate a flexible tube directly in front of the pinch bar. 
     The heat sink or thermally conductive body being thermally and mechanically coupled to a heat transfer device such as those described above provides improved heat transfer over prior art devices. Such a feature assists in providing temperature stability to liquids trapped in a plastic tubing above the pinch valve keeping liquids therein hot or cold as necessary. Heat transfer through the thermally conductive body being by way of conduction rather than radiation or convection provides more thermal heat transfer than prior art pinch valves provide. 
     The foregoing description is for purposes of illustration only. The true scope of the invention is set forth in the appurtenant claims.