Patent Publication Number: US-2017367370-A1

Title: Freezing Cylinder Beater

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Benefit is claimed of U.S. Patent Application No. 62/095,882, filed Dec. 23, 2014, and entitled “Freezing Cylinder Beater”, the disclosure of which is incorporated by reference herein in its entirety as if set forth at length. 
    
    
     BACKGROUND 
     The disclosure relates to dispensing of frozen confectionary products such as soft-serve ice cream, ice milk, frozen yogurt, artificial substitutes therefor, and the like. More particularly, the disclosure relates to dispensing valves for dispensers of such product. 
     Frozen confection dispensing systems are commonly used in the food service industry. An exemplary system configuration comprises a cabinet containing a mixing vessel (e.g., hopper) for mixing the confection. From the mixing vessel, the confection passes to a freezing vessel (e.g., a freezing cylinder). An air pump may add air to the mix. A refrigeration system may refrigerate the confection in the mixing hopper and freeze the confection in the freezing cylinder (cooled to a frozen or semi-frozen state). 
     The cabinet may contain one or more stages of pumps for driving the confection from the vessel to a delivery head/valve assembly. An exemplary pump is positioned between the mixing upper and freezing cylinder, with a rotary action of a beater of the freezing cylinder acting as a further pump. An exemplary valve assembly is mounted on the front of the cabinet. The valve assembly typically has a downward-facing outlet for discharging the confection into a bowl, cup, cone, or the like. The valve may be manually-actuated (e.g., via a lever pivotable upward or downward about a transverse hinge axis from an off condition to a dispensing condition). The valve assembly body is often called a “door” mounted over a hole in the front face of the cabinet. 
     An exemplary beater comprises helical blade driven by a motor to rotate about an axis the rotation causes the blade to drive product toward an inlet port in the rear surface of the door. A fixed baffle may extend rearward from the door to prevent accumulation of a stagnant mass of product within the interior of the helix. Examples of such baffles and beaters are seen in U.S. Pat. No. 7,278,276 of Boyer et al., issued Oct. 9, 2007 and US Patent Application Publication 2013/0068331 of Matz et al., published Mar. 21, 2013. 
     SUMMARY 
     One aspect of the disclosure involves a frozen product dispensing apparatus comprising a refrigeration system and a freezing cylinder. A source of the product or precursors of the product is coupled to an inlet of the freezing cylinder. An outlet valve has an open condition for discharging product from the freezing cylinder. A beater assembly is within the freezing cylinder and has an axis and an outer helical member. A motor is coupled to the beater assembly for driving rotation of the beater assembly about the axis so that when driving said rotation in a first direction, the outer helical member drives product toward the outlet valve. The beater further comprises an inner helical member within the outer helical member. 
     In one or more embodiments of any of the foregoing embodiments, the inner helical member has a spiral opposite to the outer helical member. 
     In one or more embodiments of any of the foregoing embodiments, the inner helical member is mounted to rotate as a unit with the outer helical member. 
     In one or more embodiments of any of the foregoing embodiments, the inner helical member has a spiral in the same direction as the outer helical member and the inner helical member is mounted to rotate opposite to rotation of the outer helical member. 
     In one or more embodiments of any of the foregoing embodiments, the inner helical member is mounted to remain stationary in operation. 
     In one or more embodiments of any of the foregoing embodiments, the outer helical member has a helix angle decreasing from a rear end toward a front end. 
     In one or more embodiments of any of the foregoing embodiments, the outer helical member is a blade integral to a frame having features for removably mounting wiper blades. 
     In one or more embodiments of any of the foregoing embodiments, the inner helical member has a blade integral to a shaft and an open cup at one end. 
     In one or more embodiments of any of the foregoing embodiments, the inner helical member, shaft, and open cup are a unitary non-metallic piece. 
     In one or more embodiments of any of the foregoing embodiments, the outlet valve comprises an outlet valve body. An axle has a first portion in threaded engagement with the outlet valve body and a second portion received in a compartment of the inner helical member. 
     In one or more embodiments of any of the foregoing embodiments, the beater assembly axis is within 10° of horizontal in a normal operational condition. 
     In one or more embodiments of any of the foregoing embodiments, wherein the outlet valve comprises: an inlet; an outlet; and a valve element. The valve element is shiftable between: a first condition providing communication between the inlet and the outlet; and a second condition blocking communication between the inlet and the outlet. 
     In one or more embodiments of any of the foregoing embodiments, an actuator is coupled to the valve element and manually engagable by a user to shift the valve element between the first condition and the second condition. 
     In one or more embodiments of any of the foregoing embodiments, the actuator comprises a lever, the lever being shiftable from a neutral condition to respective first and second lever conditions to, respectively, shift the valve element to the valve element&#39;s first and second conditions. 
     In one or more embodiments of any of the foregoing embodiments, a cabinet has a front, wherein the source is within the cabinet and the valve is mounted on the front. 
     In one or more embodiments of any of the foregoing embodiments, the apparatus is in combination with the confectionary product, the confectionary product being a frozen confectionary product. 
     In one or more embodiments of any of the foregoing embodiments, a method for operating the apparatus comprises: running the motor to drive said rotation in said first direction so that the outer helical member drives the product toward the outlet valve and the inner helical member drives product away from the outlet valve. 
     In one or more embodiments of any of the foregoing embodiments, the method further comprises opening the outlet valve from a closed condition to the open condition so as to discharge product from the freezing cylinder. 
     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a soft-serve freezer. 
         FIG. 2  is a right side view of the freezer of  FIG. 1 . 
         FIG. 3  is an isolated vertical/axial sectional view of a subassembly of freezing cylinder, beater/scraper, valve, and transmission. 
         FIG. 3A  is an enlarged view of a forward end of the subassembly of  FIG. 3 . 
         FIG. 4  is a view of the forward end of  FIG. 3A  in a discharging condition. 
         FIG. 5  is a view of the subassembly of  FIG. 3  absent the freezing cylinder. 
         FIG. 6  is a first view of a central beater helical member (screw) of the combination of  FIG. 3 . 
         FIG. 7  is a second view of the beater screw of  FIG. 6 . 
         FIG. 8  is an isolated vertical/axial sectional view of a second subassembly of freezing cylinder, beater/scraper, valve, and transmission. 
         FIG. 9  is an isolated vertical/axial sectional view of a third subassembly of freezing cylinder, beater/scraper, valve, and transmission. 
     
    
    
     Like reference numbers and designations in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
       FIGS. 1&amp;2  show a soft-serve freezer  20  which is formed as a modification of an existing model C708 Soft-Serve Freezer of Taylor Company (a division of Carrier Commercial Refrigeration, Inc.) of Rockton, Ill. However, other freezers may be similarly modified (including other general configurations and multi-flavor or other variations on the illustrated or other configuration). The freezer comprises a cabinet  22  having a front  24 , a back  26 , a base or bottom  28 , a top  30 , and respective left and right sides  32  and  34 . An upper portion of the cabinet front is formed by a panel  36  to which a dispensing valve assembly  38  is mounted. The exemplary top includes a removable cover/lid  40 . The lid  40  covers a mixing hopper  42  for receiving and mixing the confection or its ingredients (e.g., having an agitator  44  (driven for rotation about an axis  500 ) and having an air injection pump  46 ). 
     A refrigeration system  50  (e.g., a vapor compression-expansion cycle) is provided to refrigerate the confection in the hopper. A freezing cylinder  52  is located between the hopper  42  and the valve assembly  38 . The freezing cylinder contains a beater assembly (beater/scraper assembly)  53  (driven for rotation about an axis  502 ). The axis  502  is generally horizontal (e.g., within 10° of horizontal in a normal operating condition, more particularly within 5°). The refrigeration system includes appropriate heat absorption heat exchangers to cool the hopper  42  and freezing cylinder  52  to appropriate temperatures and maintain those temperatures. The heat absorption heat exchangers (which absorb heat in the normal mode (as distinguished from defrost mode, cleaning mode, or pasteurization mode)) may be integrated with the hopper  42  and cylinder  52 . A compressor of the refrigeration system is schematically shown as  54 , a normal mode heat rejection heat exchanger (e.g., condenser) as  56 , its associated fan as  58 , and an expansion device as  60 . Also schematically shown are an electric motor  62  and a transmission  64  for driving the rotation of the beater assembly. 
       FIG. 3  is an isolated vertical/axial sectional view of the valve assembly  38 , freezing cylinder  52 , beater assembly  53 , and transmission  64 .  FIG. 4  is a view of a combination of the valve assembly  38 , beater assembly  53 , and transmission  64 . 
     The exemplary valve assembly  38  serves as a door which closes the downstream end of the freezing cylinder. The exemplary valve assembly  38  is mounted via hand-actuated screws  72  ( FIG. 1 ) to permit removal and reinstallation for system cleaning. The valve assembly includes a door/valve body  74  ( FIG. 3 ) which may be machined of an alloy (e.g., food-grade stainless steel) or molded of a food-grade plastic (e.g., polybutylene terephthalate (PBT)). In lieu of a prior art baffle assembly, an axle  76  extends from an aft face/surface  78  of the body  74 . The door/valve body  74  includes an inlet  80  for receiving the confection from the freezing cylinder and an outlet  82  for dispensing the confection into bowls, cups, cones, and the like. 
     The exemplary valve assembly  38  is a manually-actuated valve which the user may actuate via rotating a lever  84  (e.g., via a handle  86  at a distal end of a lever arm (driving arm)  88 ) about a lever axis  510 . The lever, in turn, controls movement of a piston-like valve member (element)  90  within a vertical bore (valve compartment)  92  of the valve body  64 .  FIG. 3A  further shows the axle  76  mounted to a central boss  94  along the rear of the valve body  74 . In the exemplary embodiment, the central boss  94  is threaded and, in the baseline prior art, receives a threaded baffle. Use of the axle  76  with such a door allows retrofit of existing freezers. 
     The axle  76  is concentrically received within the beater/scrapper assembly ( 53  of  FIG. 2 ). A nozzle/cap  95  ( FIG. 1 ) may be secured to the body at the outlet  82 . For example, there may be snap-fit engagement with an outwardly open channel of an outlet boss  96  ( FIG. 3A ). The cap may have an interior surface of a cross-section selected to provide a desired extrusion profile (e.g., a star-shaped cross-section or a fluted cross-section). When present, the downstream rim of the cap may alternatively be regarded as forming an outlet. 
       FIG. 4  shows the lever rotated downward into an open/dispensing condition wherein a flow  520  may pass from the inlet to the outlet. 
       FIG. 3  shows the freezing cylinder  52  as comprising an inner wall  120  extending from a forward end closed by the door to a rear end closed by a domed end  122 . The exemplary domed end  122  comprises an inlet  124  for receiving product via a conduit  126  (e.g., from the hopper  42  or from a pump or other source). 
     The freezing cylinder  52  includes an outer wall  130  with a space between the inner wall and the outer wall defining a heat exchanger (e.g., the heat rejection heat exchanger (evaporator) of the vapor compression refrigeration system  50 ). 
     The beater/scraper assembly  53  comprises a drive shaft  140  extending through the domed end  122  and coupled to the transmission  64  and motor to drive rotation of the beater assembly. In conventional manner, the shaft  146  is keyed to engage a rear end plate  150  of the beater/scraper assembly ( FIG. 5 ). An outer helical beater/scraper assembly  152  is mounted to the plate  150  extending forward therefrom. The assembly  152  comprises an outer helical member  154  supported by longitudinally-extending struts  156  and  158 . The struts  156  and  158  are held to each other by a series of clamps  160 . Some of these clamps  160  may mount the outer helical member  152 . For example, the struts and clamps may form a frame integral to the outer helical member. Some of these clamps  160  may also mount one or more wiper assemblies  170 ,  172 . In this example, there are two wiper assemblies diametrically offset from each other for balance and axially offset so as to provide full axial coverage. The wiper assemblies each comprise a wiper frame  174  removably mounting a longitudinal wiper blade  176  for wiping the inner diameter (ID) surface of the inner sidewall  120 . 
     One or more stirring rods  180  may extend from the aft face of the plate  150  to maintain movement of material adjacent the freezing cylinder inlet  124 . 
     The outer helical member  152  is generally helical/spiral with a first sense of direction and extending from a rear/upstream end  190  to a forward/downstream end  192 . When rotated in a first direction  530  about the freezing cylinder axis  502 , the outer helical member  152  drives product forward (flow  540 ) within the freezing cylinder. When the valve  38  is open, the outer helical member will drive product through the valve inlet port  80  and thus out the valve outlet port  82 . The exemplary helix angle of the outer helical member may progressively change from end to end. In this example, the helix is relatively shallower near the forward end and relatively steeper (more nearly longitudinal) near the rear end. 
     The beater assembly also includes an inner helical member or screw  200 . The exemplary inner helical member is non-metallic (e.g., polyoxymethylene or other acetal homopolymer or other engineering thermoplastic). 
       FIG. 6  shows the inner helical member extending from a rear end  202  to a forward end  204 . The exemplary rear end  202  comprises an internal socket  206  that acts as a keying feature receiving a complementary end portion  208  ( FIG. 3 ) of the shaft  140  to drive rotation along with the outer helical member as a unit. The exemplary inner helical member  200  comprises a unitarily molded combination of a central shaft  210  and a helical blade portion  212  wrapping the shaft and extending between a rear end portion  212  bearing the compartment  206  and a forward end portion  214  forming a cup having a compartment  216  ( FIG. 7 ) rotatingly receiving the rear end portion of the boss  76 . The inner helical member (i.e., its blade portion) is of opposite sense spiral to the helix of the outer helical member (i.e., if one corresponds to a left handed thread, the other corresponds to a right handed thread). When the beater/wiper assembly is rotated in the first direction  530  about the axis  502 , the inner helical member  200  drives product rearward (flow  542 ) thus cooperating with the outer helical member  190  to provide a recirculation. The recirculation helps maintain product consistency during longer intervals between each dispensing. 
     Manufacturing methods and materials may otherwise be the same as those of any baseline system. Similarly, use parameters of the baseline system may otherwise be the same. A notable addition is the molding of the inner helical member  200  (e.g., injection molding). 
     An alternative less ambitious reengineering/remanufacturing of a baseline unit involves replacing the fixed baffle of the baseline unit with a fixed inner helical member  300  ( FIG. 8 , e.g., of opposite sense to the outer helical member). The surfaces of the blade portion of the inner helical member may help drive product rearward via a pumping action driven by the outer helical member. The exemplary member  300  has a threaded end portion  302  that threads directly into the rear door boss of the baseline door. An opposite rear end  304  of the member  300  may be a free end (shown) or may be in rotationally sliding relation with a fixed member (not shown) or an end of a shaft rotating with the outer member. Otherwise, geometry and manufacture may be as noted above for the inner helical member  200 . 
     An alternative more ambitious reengineering/remanufacturing would involve providing a transmission or other arrangement for counterrotation of the inner helical member  400  ( FIG. 9 ) and the outer helical member. In such a situation, the inner helical member and outer helical member would be of like sense to each other. This may be provided by configuring the transmission (gearbox)  420  with concentric counter-rotating output shafts  422  (driving the outer helical member) and  424  (driving the inner helical member). In this example, the inner helical member  400  forward end may be as noted for the member  200 . The aft end  404  may have keyed interfitting with the forward end of the inner shaft (e.g., a faceted compartment in the end  404  receiving a complementary faceted end  406  of the shaft). 
     Although an embodiment is described above in detail, such description is not intended for limiting the scope of the present disclosure. It will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. For example, when implemented in the engineering of an existing system configuration or the remanufacturing of an existing system, details of the existing system or configuration may influence or dictate details of the particular implementation. Accordingly, other embodiments are within the scope of the following claims.