Abstract:
A house appliance for making soft serve ice cream comprises a motor driven auger in a housing. The auger, which has spiral land, is contained in a work chamber having longitudinal grooves or longitudinal ribs upon which the lands ride. Recirculation and mixing of ingredients produces a smooth, soft serve product.

Description:
[0001]    This application claims priority of Provisional Application Serial No. 60/349,703 filed Jan. 22, 2002, which in turn claims priority of Provisional Application Serial No. 60/310,723 filed Aug. 7, 2001.  
         [0002]    The subject invention relates to the art of ice cream processing devices and, more particularly, to a processing appliance for softening ice cream for use in the home. 
     
    
     
       INCORPORATION BY REFERENCE  
         [0003]    Reed, U.S. Pat. No. 4,506,988; Levine, U.S. Pat. No. 4,637,221; Carlson, U.S. Pat. No. 4,708,489; and Verkler, U.S. Pat. No. 4,828,398 are incorporated herein by reference as background art.  
         BACKGROUND OF THE INVENTION  
         [0004]    Processing appliances for softening ice cream have been provided before now, and generally, as shown in Carlson &#39;489 for example, have a container that is adapted to hold the ingredients that are to be processed, such as hard packed ice cream, and a rotatable auger that is fed into the container thereby displacing and working the ingredients, such as hard packed ice cream, therein to soften or otherwise blend them. Generally, the container and the auger are axially spaced from one another providing access to the opening of the container for filling it with the ingredients to be softened. Once all of the ingredients have been put into the container, the rotatable auger can be started and introduced into the container either by axial displacement of the auger or by axial displacement of the container. Such devices are typically large and generally employ complicated mechanisms to move the auger or the container axially into engagement with the other components to blend and soften the ice cream. As such, these devices are not suitable for home use.  
           [0005]    Ice cream softening appliances for use in the home have been provided before now and generally, as shown in Verkler &#39;398 for example, have a container for holding ice cream and other ingredients and a rotatable auger that engages the edible ingredients in the container and thereby the causes the blending and softening of them. The device in Verkler &#39;398 includes an axially stationary auger supported on a frame and driven by a belt through the output of an electric motor. Initially, the container is axially displaced away from the auger providing access to the top of the container for the input of ingredients, such as hard packed ice cream. Once the ingredients have been put into the container, the auger started and the container is axially displaced toward the auger moving the ingredients and the auger into engagement with each other, facilitating the softening and blending of the ingredients.  
           [0006]    In each of the foregoing devices, the auger has one or more lands that resemble large screw threads spirally extending along the axis of the auger. Before the engagement of the auger with the container, the rotating auger is fully exposed and could cause injury should an operator&#39;s hand or piece of clothing get caught by the auger. Additionally, the mechanisms employed by the foregoing devices to move the container and the auger into engagement with each other expose the operator to pinch-points and other possible causes of injury. This is a significant disadvantage of these prior devices.  
           [0007]    In commercial applications, the danger of injury may be minimized through training and supervision of the operators of such equipment. However, in devices intended and suitable for use in the home, such as Verkler &#39;398 for example, training and supervision are generally not possible. This is a significant disadvantage of devices intended for use in the home.  
           [0008]    It will be appreciated that the containers in the foregoing devices include an inside surface that defines the work chamber. The product in the work chamber is displaced by the movement and rotation of the auger as it enters the work chamber. Once the auger is fully engaged with the container in the work chamber, the ingredients to be softened are sheared by the action of the auger relative to the inside surface of the work chamber. However, as the ingredients become softened and their temperature increases, the ingredients increasingly slip around the smooth inside surface of the work chamber. This reduces the efficiency of the auger by reducing the shearing action of the products between the auger and the work chamber. As such, the ingredients must be processed for an extended period to ensure that they will be sufficiently blended and that the final product will be smooth with a minimal number of hardened lumps in it.  
         SUMMARY OF THE INVENTION  
         [0009]    In accordance with the present invention, a processing appliance for softening ice cream and other ingredients for use in the home is provided that avoids or minimizes the problems and difficulties encountered with the use of devices of the foregoing character, while promoting or maintaining the desired safe operation, simplicity of use, durability of construction, and economy of manufacture. More particularly in this respect, a processing appliance for softening ice cream and other ingredients for use in the home according to the invention includes a rotatable auger supported on a base that provides rotation thereto through an electric motor, a hopper for holding the ingredients, such as hard packed ice cream, a plunger assembly for urging the ingredients into engagement with the auger, and a nozzle for dispensing the softened and blended product. The hopper is supported on the base and has a processing portion that is generally coaxial with the auger. Extending transversely from the processing portion is a receiving portion. The receiving portion has an opening toward the top of it and is adapted to hold the ingredients before being processed by the auger. Adjacent the processing portion of the hopper and supported thereon coaxially with the auger is a nozzle. The nozzle has an opening at the end of it for the dispensing of the softened and blended product. The ingredients in the receiving portion of the hopper are urged toward the processing portion of the hopper and the auger by a rod and piston that is suitably adapted to travel the receiving portion.  
           [0010]    The auger engages and is driven by the rotatable output of the base. The auger is a generally cylindrical screw with a tapered front end that has an outside profile defined by one or more lands spirally extending along the length of it. It will be appreciated that the lands have a lead defined as the axial distance traveled per revolution of the auger and that the lead of the lands may vary along the length of the auger. The cross-sectional area of the grooves of the auger may vary along the length of the auger.  
           [0011]    The processing portion of the hopper includes an inside surface defining a processing passage. The nozzle also includes an inside surface defining a nozzle passage. The processing and nozzle passages together define a work chamber in which the auger is at least partially encapsulated, and in the preferred embodiment the auger is entirely encapsulated except for the portion exposed to the receiving portion of the hopper. Additionally, the nozzle may be adapted to force the softened and blended product to be dispensed in a downward direction out of the nozzle.  
           [0012]    The work chamber defined by the inside surfaces of both the processing passage and the nozzle passages create an envelope that is closely fitted to the outside profile of the auger. A plurality of grooves extend longitudinally along the inside surface of both the processing passage and the nozzle passage. These grooves will provide the necessary rifling effect for displacing the ingredients forward by means of a rotating auger, and they will also create less wasteful space between the lands and grooves of the auger and the inside surface of the processing and nozzle passages. As such, a shorter auger and work chamber may be employed to provide the same blending and softening action. However, instead of grooves a plurality of ribs may extend longitudinally along the inside surface of both the processing passage and the nozzle passage. In this embodiment, the auger would ride on the ribs in the work chamber such that small pockets are formed between two adjacent ribs, the inside surface of the processing passage or the nozzle passage and the lands and grooves of the auger. These small pockets would provide significantly increased shearing action and recirculation of the ingredients being softened and blended over a work chamber that does not include such longitudinal ribs.  
           [0013]    In operation, the ingredients to be blended and softened, such as hard packed ice cream, are placed into the hopper, the motor is energized and the plunger assembly is used to urge the ingredients into engagement with the auger. The piston of the plunger assembly is displaced through the receiving passage by pumping the handle of a ratcheting mechanism that rests atop the hopper. The lands and grooves of the auger shear the ingredients from the receiving portion of the hopper and carry them around the processing portion and along the auger into the nozzle portion filling the pockets between the ribs as the final, blended product is displaced. The action of the auger recirculates the product in and out of these pockets, increasing the shearing action of the ingredients as they travel toward the output end of the work chamber in the nozzle. A smooth, softened and blended product is extruded out of the end of the nozzle, resembling a product such as a soft serve ice cream that one gets at a commercial soft serve stand. It will be appreciated that the ingredients blended and processed by the subject device may include fillers such as cookies, fruits and/or candy. These fillers may be placed in alternate layers with the other ingredients in the receiving portion of the hopper and processed as discussed above, providing a soft serve product having the filler material broken up and blended within it.  
           [0014]    Additionally, it will be appreciated that the subject device is intended for use with ingredients such as frozen ice cream. As such, the hopper, including both the receiving portion and the processing portion, and the nozzle may be insulated by air spaces or another suitable insulating medium to help in keeping the ingredients being processed near their freezing temperature during the entire process.  
           [0015]    Accordingly, it is an outstanding object of the present invention to provide a processing appliance for softening ice cream for use in the home having a work chamber and auger arrangement of increased efficiency so that the size of the device may be minimized.  
           [0016]    Another object is the provision of a processing appliance of the foregoing character in which the auger is fully encapsulated by the work chamber to minimize the possibility of injury to the operator of it.  
           [0017]    Another object is the provision of a processing appliance of the foregoing character in which the auger and work chamber are axially stationary, eliminating the need for complicated mechanisms to move the auger and work chamber into engagement with each other.  
           [0018]    Another object is the provision of a processing appliance of the foregoing character that is easy to operate, and simple to assemble, disassemble and clean.  
           [0019]    A further object is the provision of a processing appliance of the foregoing character that comprises a minimal number of parts having a durable yet simple structure, thereby promoting the economic production of the appliance. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    The foregoing objects, and others, will in part be obvious and in part more fully pointed out hereinafter in conjunction with a written description of the preferred embodiments of the invention illustrated in the accompanying drawings in which:  
         [0021]    [0021]FIG. 1 is a pictorial view from the front of a fully assembled ice cream softening appliance in accordance with the present invention;  
         [0022]    [0022]FIG. 2 is a pictorial view from the back of a fully assembled ice cream softening appliance in accordance with the present invention;  
         [0023]    [0023]FIG. 3 is a pictorial view of the appliance in FIG. 1 shown with the ice cream processing portion disassembled from the base;  
         [0024]    [0024]FIG. 4 is a pictorial view of the processing portion of the device in FIG. 3 shown partially disassembled;  
         [0025]    [0025]FIG. 5 is a pictorial view from the end of the hopper showing the processing and nozzle passages;  
         [0026]    [0026]FIG. 6 is an enlarged pictorial view of the processing portion showing the grooves that extend longitudinally along the inside of the processing portion;  
         [0027]    [0027]FIG. 7 is a pictorial view showing the inside surface of the processing portion;  
         [0028]    [0028]FIG. 8 is a pictorial view of the auger in accordance with the present invention;  
         [0029]    [0029]FIG. 9 is an enlarged pictorial view of part of the auger shown in FIG. 6 illustrating the variations in the lead of the auger;  
         [0030]    [0030]FIG. 10 is a pictorial view of part of the auger in accordance with the present invention illustrating the variations in the cross-sectional area of the grooves of the auger;  
         [0031]    [0031]FIG. 11 is a pictorial view of part of the plunger assembly in accordance with the present invention;  
         [0032]    [0032]FIG. 12 is a pictorial view of the present invention showing the plunger assembly;  
         [0033]    [0033]FIG. 13 is a pictorial view of part of the plunger assembly as shown in FIG. 12;  
         [0034]    [0034]FIG. 14 is a cross-section view of the plunger assembly at the top of a stroke;  
         [0035]    [0035]FIG. 15 is a cross-section view of the plunger assembly in the middle of a stroke; and,  
         [0036]    [0036]FIG. 16 is a cross-section view of the plunger assembly at the bottom of a stroke. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0037]    Referring now in greater detail to the drawings, in which the showings are for the purpose of illustrating preferred embodiments of the invention only, and not for the purpose of limiting the invention, FIGS.  1 - 3  of the drawings illustrate an ice cream processing appliance  10  having abase  12 , a hopper  14 , a nozzle  16 , and a plunger assembly  18 . A motor  20  is housed in the front of base  12  and receives electrical power from a household power outlet through a cord  22  and a switch  24 . Motor  20  transmits rotational output to an output shaft  26 , which extends between the front and back of base  12 .  
         [0038]    [0038]FIG. 3 illustrates ice cream processing appliance  10  showing hopper  14 , nozzle  16 , plunger assembly  18  and auger  28  removed as an assembly from base  12 . Base  12  also includes a hopper support  30  and a hopper support connection  32 .  
         [0039]    In FIG. 4, a portion of plunger assembly  18  and auger  28  are shown disassembled from hopper  14  and nozzle  16 . Plunger assembly  18  includes a piston  34  and a rod  36  having a knob  38  and a shaft  40 . As can be seen in FIGS. 4 and 11, piston  34  includes an auger engaging surface  76  with a plurality of ribs  78 .  
         [0040]    Hopper  14  has a receiving portion  42  and a processing portion  44 . As shown in FIGS.  1 - 4 , receiving portion  42  generally comprises a cylindrical tube  46  with an inside wall  41  defining a receiving passage  48 . Cylindrical tube  46  includes a first end  43  and a second end  45 . However, the receiving portion may also be comprised of a flared wall  47  terminating at a receiving opening or rim  50  that inclines away from first end  43  of cylindrical tube  46  to help in funneling ingredients into receiving passage  48 . Piston  34  of plunger  18  is complimentary to receiving passage  48  and tube  46  and fits loosely within tube  46  to permit travel of the piston along passage  48 . In addition, at second end  45  of cylindrical tube  46  there may be a ramp, not shown, to help guide the ingredients into a process opening  79  (FIG. 7) leading to processing passage  80  and in the direction of the rotation of auger  28 . Piston  34  is peripherally defined by at least one wall extending generally longitudinally with and corresponding to receiving passage  48 . At least one wall of piston  34  extends between a top  75  and bottom  76  surface. The bottom surface or processing surface  76  is adapted to urge ice cream and other ingredients into engagement with auger  28 . Processing surface  76  of piston  34  includes a plurality of ribs  78  extending longitudinally in the direction of auger axis a.  
         [0041]    As shown in FIGS.  3 - 5 , processing portion  44  of hopper  14  includes a generally circular wall  52 , extending transversely to cylindrical tube  46 . Wall  52  has an inside surface  54  defining a processing passage  80  about axis a, as best seen in FIGS. 6 and 7. Semicircular wall  52  extends between two end walls  56  and  57 . One end wall  56  engages hopper support connection  32  of base  12  such that hopper  14  is supported thereon. The other end wall  57  engages a nozzle connector  58  at the connection end of nozzle  16  that supports nozzle  16  on hopper  14 . Opposite the nozzle connector, nozzle  16  terminates at an output end or end wall  60  having an output orifice  62 . Output orifice  62  is adapted, for example, by means of an elbow, to direct the product downward as it is extruded through nozzle  16 . Alternatively, the output end may have an output orifice generally coaxial, not shown, with nozzle passage  82 .  
         [0042]    As best seen in FIGS.  5 - 7 , nozzle  16  includes a wall  70 , for example, a frustoconical wall, extending between nozzle connector  58  and end wall  60 . Wall  70  has an inside surface  72  defining a nozzle passage  82  that extends along axis a, coaxially with processing passage  80  of hopper  14 . Processing passage  80  of processing portion  44  and nozzle passage  82  of nozzle  16  define a work chamber within which auger  28  is encased. As seen in FIG. 5, a plurality of longitudinally extending grooves  74  extend along both inside surface  72  of nozzle  16  and inside surface  54  of processing portion  44  of hopper  14 . Auger  28  is driven by output shaft  26  through drive shaft  64 . It will be appreciated that the outside profile of auger  28 , which is defined by lands  66 , will loosely fit within the work chamber such that radially extending pockets will exist between the lands of the auger and the inside surfaces of both nozzle  16  and processing portion  44  of hopper  14 . These pockets will extend axially along processing passage  80  and nozzle passage  82 . Alternatively, extending along the inside surfaces of nozzle  16  and processing portion  44  there may be a plurality of longitudinally extending ribs, not shown, instead of grooves  74 .  
         [0043]    As shown in FIGS.  8 - 10 , auger  28  has a drive shaft  64  having a connection portion  65  extending from one end  63 . Connection portion  65  of drive shaft  64  engages output shaft  26 , which in turn rotates auger  28 . Auger  28  also includes a plurality of lands  66 , each spaced apart from the other by a groove  68 , as best seen in FIGS.  8 - 10 . The auger spirally extends along axis a. Each of grooves  68  has a root radially inwardly displaced from lands  66  of auger  28 . It will be appreciated that lands  66  of auger  28  have a lead defined by the axial displacement of it per revolution of the auger and that the lead of lands  66  may be variable along the length of the auger. Additionally, auger  28  may include serrations, scallops, or breaks  67  on or along lands  66 . As best seen in FIG. 10, the depth and the corresponding cross-sectional area of grooves  68  of auger  28  may be variable along the length of the auger.  
         [0044]    As best seen in FIGS.  11 - 13 , plunger assembly  18  comprises piston  34 , rod  36 , hopper cover  89 , a spring-loaded pawl  90 , a pivot pin  92 , a lever  94 , and an axle  96 . Lever  94  is generally U-shaped with a handle  98  connected to ends  101  and  103  of two legs  100  and  102 , respectively. The other ends  105  and  107  of legs  100  and  102 , respectively, are connected to the ends of axle  96 , which is housed in hopper cover  89 . Spring-loaded pawl  90  is attached to axle  96 . On the back side of shaft  40  of rod  36  is a linear array of angled teeth  99  adapted to receive pawl  90 . Further, pawl  90  has a clip  104  that extends vertically from pivot pin  92 . There is a recess  106  on the back side of rod  36 , just above teeth  99 , adapted to receive clip  104 . Pressing clip  104  against rod  36  and into recess  106  causes spring-loaded pawl  90  to rotate about pivot pin  92  and to disengage from teeth  99 , thus permitting rod  36  and piston  34  to be pulled by knob  38  in a vertical direction. This allows the user to move plunger assembly  18  in an upward direction and out of receiving portion  42  of hopper  14  and to insert the ingredients into receiving portion  42  of hopper  14  for processing.  
         [0045]    In operation, as shown in FIGS.  14 - 16 , ingredients will be placed in receiving portion  42  of hopper  14 , and plunger assembly  18  will be placed onto the hopper. Lever  94  should be in its most vertical position. As lever  94  is manually rotated in a downward direction and away from the vertical position, axle  96  rotates. With pivot pin  92  acting as a fulcrum point for pawl  90 , the rotation of axle  96  causes pawl  90  to move downward until it engages with angled teeth  99 . Once pawl  90  is engaged with angled teeth  99 , rod  36  and piston  34  will advance downward in receiving portion  42  of hopper  14 . Angled teeth  99  are adapted to allow motion in one direction only. Thus, as lever  94  is manually rotated in an upward direction and to a vertical position, pawl  90  does not engage with teeth  99  and simply moves up rod  36 . During the upstroke, rod  36  and piston  34  remain stationary. Accordingly, as lever  94  is rotated in alternating clockwise and counterclockwise directions about axle  96 , piston  34  is displaced from the top to the bottom of receiving portion  42 . This downward displacement causes engaging surface  76  of piston  34  to engage the various ingredients in receiving portion  42  and to urge them into processing portion  44 .  
         [0046]    In another embodiment (not shown), the ingredients may be urged through the receiving portion and into the processing portion of the hopper by means of a plunger assembly having a handle, a pinion gear, a rack gear, a disengagement cam, an engagement cam, an axle, a one-way shaft clutch, a hopper cover, and a shaft. The handle is connected to both ends of the axle. The pinion gear is attached to and rotates about the axis of the axle. The rack gear is on one side of the shaft, which extends vertically through a hole in the hopper cover. A piston is attached to the bottom of the shaft. The disengagement cam has a cam surface, and the engagement cam has a cam surface. When the handle is rotated about the axle to a vertical, upwardly extending position, it comes into contact with the cam surface. This contact causes the axle to shift laterally and, in turn, causes the pinion gear to disengage from the rack gear. Thus, when the handle is in its most vertical position, the plunger assembly may be freely pulled in an upward direction and out of the receiving portion to allow for ingredients to be placed into the receiving portion for processing. When the handle is rotated about the axle and away from a vertical position, it comes into contact with the cam surface. This contact causes the axle to shift laterally and, in turn, causes the pinion gear to engage the rack gear. The pinion gear is thus able to rotate and cause the rack gear to move vertically downward. In this process, the shaft and the piston will advance downward through the receiving passage. The one-way shaft clutch acts to allow pinion gear rotation when the handle is rotated from a vertical position, while preventing pinion gear rotation when the handle is rotated to a vertical position. Accordingly, as the handle is manually rotated in alternating clockwise and counterclockwise directions about the axle, the piston is displaced from the top to the bottom of the receiving portion. This downward displacement causes the engaging surface of the piston to engage the various ingredients in the receiving portion and to urge them into the processing portion.  
         [0047]    While considerable emphasis has been placed herein on the structures and structural interrelationships between the component parts of the embodiments disclosed, it will be appreciated that other embodiments of the invention can be made and that many changes can be made in the embodiments illustrated and described without departing from the principals of the invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted as merely illustrative of the present invention and not as a limitation.