Patent Publication Number: US-9420917-B2

Title: Method for blending food or beverages

Description:
FIELD OF THE INVENTION 
     The present invention relates to methods of operating food preparation machines, particularly electrical blenders for preparing smoothies, milkshakes, protein shakes and other blended beverages. 
     BACKGROUND OF THE INVENTION 
     Blended fruit smoothies, milkshakes and protein shakes are becoming increasingly popular among health conscious people. In these blended drinks, fresh fruits and/or vegetables can be mixed together with, if desired, vitamins and protein supplements to provide fresh nutritious foods in a convenient, portable form. 
     While it is advantageous to blend carefully selected ingredients at the peak of their freshness, it is often not practical to do so. To have fresh fruits and vegetables available every day, for example, one may need to frequently go shopping for such fruits/vegetables, give the fruits/vegetables time to ripen and then make sure that the fruits/vegetables do not over ripen. Moreover, working with fresh fruits and vegetables usually generates organic wastes, is often messy and inevitably requires clean up. This means a lot of time and attention. 
     In a fast moving society, there is a demand for a fresh, nutritious blended drink that can be selected and prepared quickly. Better yet, such a fresh, blended drink should be available at a place that can be easily accessed, such as a convenience store or one&#39;s home. 
     F&#39;Real Foods, LLC has made a business of making fresh, nutritious smoothies and milkshakes available at easily accessible locations, such as convenience stores. F&#39;Real Foods starts with fresh ingredients, such as fresh fruits and milk, which it pre-blends into smoothies and milkshakes. The pre-blended smoothies and milkshakes are then frozen in sealed cups before they are shipped to convenience stores at many different locations. The frozen pre-blended smoothies and milkshakes are then stored in a freezer at the convenience store next to a commercial size blending machine. When the convenience store customer wants a fresh smoothie or milkshake, the customer simply selects the desired frozen, pre-blended smoothie or milkshake from the convenience store freezer, tears the seal off the top of the smoothie/milkshake cup and then places the smoothie/milkshake cup in a blending machine cupholder built into the blending machine. The customer can then start the commercial sized blending machine to blend the frozen smoothie/milkshake to a desired consistency. 
     F&#39;Real Foods, LLC has numerous U.S. patents and U.S. published patent applications pertaining to its commercial size blending machine and processes for preparing smoothies/milkshakes, including U.S. Pat. Nos. 5,803,377; 5,962,060; 6,041,961; 6,326,047; 6,474,862; 6,465,034; 6,527,207; 7,144,150; 7,520,658 and 7,520,662 as well as U.S. Published Patent Application Nos. 2011/0088558; 2011/0088568 and 2011/0090756. 
     The popularity of F&#39;Real Foods, LLC&#39;s convenience store smoothies and milkshakes has led to a demand to make the same sort of smoothies and milkshakes available for home use. Nonetheless, creating a smoothie/milkshake blender for home use poses a much different set of design problems than creating a smoothie/milkshake blender for commercial use. For example, space is often in short supply inside a kitchen at home. While a convenience store blender can be made to be tall, a homeowner will often want a blender at home to fit within a tight space between an upper kitchen cabinet and a lower kitchen cabinet. Moreover, a convenience store blender should be made of heavy duty materials, such as stainless steel, to withstand repeated, rugged use. By contrast, such a heavy duty, stainless steel blender would be too expensive for most homeowners. While homeowners appreciate having a rugged, reliable blender, they would want such a blender to be lighter in weight and less expensive than the blenders used in convenience stores. Thus, there is a demand in the art for a rugged blender for home use that is compact in size and can still blend frozen smoothies/milkshakes reliably. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a method for blending food or beverages, preferably using a blender that is compact enough for home use, rugged enough to blend frozen beverages, simple for homeowners to use and safe. The blender of the present invention preferably includes an upper housing, with a front housing door, that covers the moving blending machinery and prevents injury to the user. The blender also preferably includes a cupholder receiving area which allows the user to safely insert a frozen beverage cup inside a cupholder for blending. When the cup and cupholder are properly inserted in the cupholder receiving area, a start button will preferably light up to indicate that the blender is ready to blend the frozen contents in the cup. When the user then presses the start button, a cupholder lip will be grasped by the clamping jaw of an elevator assembly to lift the cupholder upward. As the cupholder is lifted upward, a cup cover will be pressed over the top opening of the cup to prevent spillage during blending. The elevator assembly will then continue to lift the cupholder upward until the rotating cutter blades of a spindle assembly make contact with the frozen beverage. The rotating cutter blades of the spindle assembly will cut through layers of the frozen beverage while the cupholder continues to be lifted until the cupholder has been lifted to the point where the rotating cutter blades are mixing frozen beverage at the bottom of the cup. To achieve a desired consistency for the smoothie/milkshake, the elevator assembly may raise and lower the cupholder multiple times while the rotating cutter blade of the spindle assembly is in operation. When the desired consistency of the smoothie/milkshake is obtained, the elevator assembly lowers the cupholder back to its original position in the cupholder receiving area of the blender. At that point, the user can remove the cupholder from the blender, separate the cup from the cupholder and then enjoy the blended smoothie/milkshake from the cup. 
     The blender of the present invention has several preferred features which allow it to perform safely and reliably. For example, in order to prevent the cup from spinning inside the cupholder when the rotating cutting blades are blending the frozen beverage, both the cup and cupholder preferably have complementary anti-rotational surfaces. The anti-rotational surfaces of the cup preferably include vanes that protrude from the bottom of the cup. These vanes mate with complementary vanes on the bottom of the cupholder to prevent the cup and cupholder from rotating with respect to one another when the rotating cutter blade is in operation. As additional safety features, sensors or switches are preferably built into the blender to make sure the cupholder is properly positioned and the front housing door is latched in a locked, closed position before the rotating cutter blade starts moving. In order to make sure that the cupholder is raised during blending in a reliable, even way, dual lead screws of the elevator assembly are preferably actuated by a single motor to lift the cupholder. 
     To facilitate cleaning, the front housing door can be opened to expose the spindle and lead screw assemblies. The spindle assembly can be easily removed for cleaning by turning a quick release coupling member at the top of the spindle assembly and then pulling the spindle assembly downward. A cup cover is constructed on the spindle assembly to reduce the need for blender cleaning. As the elevator assembly begins to pull the cupholder upward during operation, the spindle assembly cup cover firmly attaches to the top of the cup to prevent beverage from splashing out during blending. When the elevator assembly pulls the cupholder upward and the clamping jaw presses the cup cover over the top of the cup, a lever lock mechanism ensures that the cup cover stays clamped to the cup. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a preferred blender of the present invention before the cup and cupholder are placed in the cupholder receiving area. 
         FIG. 2  shows a perspective view of the blender of  FIG. 1  after the cup and cupholder have been placed in the cupholder receiving area. 
         FIG. 2A  shows a perspective view of an alternative blender embodiment where the cupholder is integrated into the blender. 
         FIG. 3  shows how the preferred blender of the present invention can fit into the tight space between an upper cabinet and a lower cabinet in a typical kitchen. 
         FIG. 4  shows a perspective view of a preferred form of cupholder; 
         FIG. 5  shows how a cup can be inserted into the  FIG. 4  cupholder; 
         FIG. 6  is a bottom view of a cup illustrating a preferred form of anti-rotational surface; 
         FIG. 7  is a top view of the  FIG. 4  cupholder illustrating a complementary anti-rotational surface; 
         FIG. 8  is a side cross-section view of a preferred blender of the present invention illustrating proper initial positioning of the cupholder before blending; 
         FIG. 9  is a frontal view of a preferred blender of the present invention with the front upper housing door open before insertion of a cupholder; 
         FIG. 10  is a frontal view of the preferred blender in  FIG. 9  after a cupholder is inserted into the cupholder receiving area; 
         FIG. 11  is a frontal view of the preferred blender in  FIG. 9  after the clamping jaw presses the spindle cup cover against the top of the cup; 
         FIG. 12  is a frontal view of the preferred blender in  FIG. 9  as the dual lead screws in the elevator assembly lifts the cupholder during blending. 
         FIG. 13  is a frontal view of the preferred blender in  FIG. 9  as the cupholder reaches its maximum height during blending. 
         FIG. 14  is a chart conceptually illustrating how the cupholder is moved up and down during blending. 
         FIG. 15  is a cross-section view of a preferred spindle assembly of the present invention; 
         FIG. 16  is a cross-section view of an alternative spindle assembly embodiment of the present invention; 
         FIG. 17  is a perspective view of the preferred blender in  FIG. 9  illustrating the spindle assembly in its locked position; 
         FIG. 18  is a perspective view of the preferred blender in  FIG. 9  illustrating how the spindle assembly can be turned to an unlocked position; 
         FIG. 19  is a perspective view of the preferred blender in  FIG. 9  illustrating how the spindle assembly can be pulled down for removal and cleaning after it is turned to an unlocked position; 
         FIG. 20  is a perspective view of the preferred blender in  FIG. 9  illustrating removal of the spindle assembly from the blender; 
         FIG. 21  is a section view of a portion of the elevator assembly, including the clamping jaw; 
         FIG. 21A  is a front view of an alternative embodiment for a portion of the elevator assembly; 
         FIG. 22  is a perspective section view of the drive nut connecting a lead screw with the lower clamping jaw in the elevator assembly; 
         FIG. 23  is a perspective view of the  FIG. 22  drive nut; 
         FIG. 24  is a perspective section view of the locking mechanism of the  FIG. 21  clamping jaw; 
         FIG. 25  is a top view of the belts and pulleys that connect the spindle and dual lead screw motors to the spindle and lead screws; 
         FIG. 26  is a rear view of the spindle and lead screw motors as well as their belts and pulleys; 
         FIG. 27  shows an electrical block diagram for the preferred blender of the present invention; 
         FIG. 28  is a flow chart illustrating the general steps from the user&#39;s perspective to prepare smoothies and milkshakes using the preferred blender of the present invention; 
         FIG. 29A-D  is a logic flow chart illustrating the steps from the microcontroller&#39;s perspective to prepare smoothies and milkshakes using the preferred blender of the present invention; and, 
         FIG. 30  is a perspective view of an alternative embodiment where the cup and cupholder can be raised and lowered by dual lead screws without the presence of a clamping jaw. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a preferred blender  10  of the present invention as it would be viewed from the outside. This blender  10  has an upper housing  12  and a cupholder receiving area  16 . The upper housing  12  encloses the moving parts of the blender  10  and, in order to prevent injury to the user, the upper housing  12  blocks the user from touching the moving parts while those moving parts are in operation. On the front of the upper housing  12 , there is a hinged front housing door  20  that can be opened by pressing the front door latch  22 . This front housing door  20  allows the user to access the moving parts of the blender  10  for cleaning and maintenance while those moving parts are not in operation. In contrast to the upper housing  12 , the cupholder receiving area  16  is preferably open in order to allow a product to be inserted under the upper housing  12  before blending. In the preferred embodiment, the cupholder receiving area  16  preferably consists of stand  19  which connects the cupholder receiving area base  18  to the upper housing  12 . Those of skill in the art will, nonetheless, recognize that other designs can be used for the cupholder receiving area  16  so long as a product can be inserted under the upper housing  12  before blending. 
       FIG. 2  shows how a cupholder  30  can be inserted into the cupholder receiving area  16  of the blender  10 . The product to be blended, such as a frozen smoothie, milkshake or protein shake, is preferably inside the cupholder  30  itself or within a cup  40  ( FIG. 5 ) that is placed within the cupholder  30 . Those of skill in the art will recognize that other sorts of containers besides cupholder  30  and/or cup  40  can be used to hold the food or beverage product so long as the container fits within the cupholder receiving area  16  and can be operated upon by the blender machinery. While the blender  10  of the present invention is constructed to be rugged enough to blend frozen food and/or beverage products, those of skill in the art will readily recognize that the food products do not need to be frozen. For example, the blender  10  of the present invention can also blend beverages having fresh, unfrozen fruits, vegetables and/or dairy products. Nonetheless, if the food and/or beverage products to be blended are frozen, it is preferred that water, milk or other liquid be added on top of the frozen food and/or beverage products before blending to place less strain on the blending machinery and to produce a better product consistency. This added liquid is preferably within the range of 5 to 30% by volume as compared with the volume of the frozen food and/or beverage. In some embodiments, the blending machinery may even include a sensor to sense whether sufficient liquid has been added before blending and, if not, remind the user to add liquid. 
     A start button  24  is preferably located on the front housing door  20  of the upper housing  12 . In a preferred embodiment, the start button  24  will light up briefly (e.g., for 5 seconds) with a green color when the blender is plugged into an electrical outlet and light up briefly again with a green color when a cupholder  30  has been properly inserted within the cupholder receiving area  16 . In an alternative embodiment, the start button  24  can light up in a different color, such as red, when the blender  10  is not yet ready for operation. This alternative embodiment is less preferred because the start button will be lit up for longer periods and thus draw more electricity. In the preferred embodiment, pushing the start button  24  will only activate the blender  10  for operation when the start button  24  is or has been green in color. Determining whether the blender  10  is ready for operation will preferably depend on such factors as whether the front door latch  22  is properly closed and whether the cupholder  30  has been placed in its proper position in the cupholder receiving area  16 . In a further alternative embodiment, a visual display (not shown) can be included on the front door  20  near the start button  24  that tells the user in words why the blender  10  may not yet be ready for operation. For example, the visual display can tell the user to close the front door latch  22  or correctly position the cupholder  30 . 
       FIG. 3  illustrates how the blender  10  of the present invention might be positioned between an upper cabinet  50  and a lower cabinet  52  in a typical kitchen at home. In some home kitchens, the distance between the upper cabinet  50  and the lower cabinet  52  can be 18 inches or less. To accommodate its use in such tight kitchen spaces, the preferred blender  10  of the present invention has been designed to be as compact as possible. For example, the cupholder receiving area  16  has been designed to allow the cup  40  and cupholder  30  to be slid in horizontally. This is a distinguishing feature between the preferred blender  10  of the present invention and the much taller blenders currently in commercial use by F&#39;Real Foods. In F&#39;Real Foods&#39; commercial blenders, the cupholder is built into the commercial blender so that a cup having frozen beverage is placed into the commercial cupholder from above while the cupholder is attached from below to the commercial blender. In order to make the blender  10  of the present invention as compact as possible, there is not enough space to allow the cup  40  to be placed into the cupholder  30  from above while the cupholder  30  is attached from below to the blender  10 . Instead, the cupholder  30  in the present invention is preferably separate from the blender  10 . For the present invention, the cup  40  is preferably placed in the cupholder  30  outside the blender  10  so that the combined cup  40 /cupholder  30  can be horizontally inserted together into the cupholder receiving area  16 . 
       FIG. 2A  illustrates an alternative embodiment where the blender  10  has the same compact size, but has the cupholder  30  being attached to an extension of the blender  10 , rather than separate from the blender  10 . In the  FIG. 2A  embodiment, two rails  29  are used to attach the cupholder  30  to the blender  10 . The rails  29  are preferably telescoping so that the cupholder  30  can be horizontally pulled out and then pushed into the cupholder receiving area  16  as the rails  29  expand and contract. Preferably, the cupholder  30  is permanently attached to the rails  29  in this embodiment so that it will never be inadvertently separated from the blender and misplaced. As those of skill in the art will recognize, though, the cupholder  30  could also be separable from the rails  29 , which would have the advantage of making the cupholder  30  easier to clean. 
       FIG. 4  provides a close up view of a preferred form of cupholder  30  of the present invention. As those of skill in the art will recognize, the cupholder  30  can do more than simply hold a cup with food or beverage. For example, as previously noted, the food or beverage can be placed directly within the cupholder  30  thereby obviating the need to also use a cup. Further, if one wanted to use the blender  10  of the present invention to mix non-food products, such as paints, the cupholder  30  could be used to hold those non-food products. For these reasons, the cupholder  30  acts as a product positioning device whether that product is contained in a cup or not. 
     In its preferred form, the cupholder  30  of the present invention preferably has a generally cylindrically shaped body  32  having a bottom  33  and open top  35 . A cupholder upper lip  34  is preferably formed along the upper edge of the cupholder body  32 . The cupholder upper lip  34  preferably has an overhanging front portion  36  that allows a user to slide his or her fingers underneath the overhang to conveniently push the cupholder  30  into the cupholder receiving area  16  or pull it out. The cupholder  30  preferably also has substantially straight side edges  39  to prevent the cupholder from rotating during the blending process. While  FIG. 4  shows the substantially straight edges  39  on the upper lip  34  of the cupholder, the substantially straight side edges  39  could also be formed on other parts of the cupholder  30 , such as the cupholder bottom, and still achieve the same anti-rotational function. On the sides of the cupholder lip  34  are preferably two lip indentations  38  which allow a user to grip the cup  40  when it is inserted into the cupholder  30  and easily remove the cup  40  from the cupholder ( FIG. 5 ). A presence indicator  37  is preferably placed at the rear of the cupholder lip  34 . In one embodiment, the presence indicator  37  can take the form of a magnet which can be sensed by the blender  10  to indicate that the cupholder is properly positioned in the cupholder receiving area  16 . 
       FIG. 5  illustrates how a cup  40 , having upper lip  41 , can be placed in the cupholder  30  before they both are inserted into the cupholder receiving area  16  of the blender  10 . In one preferred embodiment, the cup  40  contains frozen food or beverage product. In that preferred embodiment, frozen food or beverage fills the cup between one half and three quarters of the way from the bottom of the cup to the top of the cup. In this preferred embodiment, liquid is added on top of this frozen food or beverage to facilitate the blending process but, again, space is left between the top of the fluid and the top of the cup  40  before blending. It is helpful to leave space at the top of the cup because the food or beverage tends to expand in volume during blending as air is whipped into the mixture. Leaving room at the top prevents the blended food or beverage from overflowing and thereby creating a mess that needs to be cleaned. Rings  42  or other markers can be placed on the cup to tell the user the maximum height recommended for adding liquid. 
       FIG. 6  shows a bottom perspective view of a preferred cup  40  of the present invention having an anti-rotational surface  44 . Anti-rotational surfaces  44  which can advantageously be used in the blender  10  of the present invention are described in U.S. Published Patent Application No. 2010/0108696 and U.S. Pat. No. 6,041,961, the disclosures of which are hereby incorporated by reference. In a preferred form, as described in U.S. Published Patent Application No. 2010/0108696, the cup&#39;s anti-rotational surface  44  preferably has multiple vanes  46  which protrude downward from a generally flat bottom cup surface  45 . The vanes  46  are each preferably substantially triangular in cross-section and extend outwardly from a protruding center portion  48  such that no two vanes  46  are angularly separated by 180 degrees. The protruding sides of the vanes  46  are preferably steep to better seat the anti-rotational surface  44  in a complementary cupholder anti-rotational surface  60  ( FIG. 7 ) and also to create a drive surface  49  which locks the anti-rotational surfaces  44 ,  60  together. In some embodiments, the drive surface  49  of the vanes  46  forms an overhanging surface. To help the anti-rotational surfaces  44  properly seat in the cupholder  30 , a protruding rim  43  can be formed around the periphery of the vanes  46 . 
       FIG. 7  is a top view looking down into the base of the cupholder  30  and illustrating the complementary anti-rotational surface  60  of the cupholder  30 . In a preferred embodiment, the anti-rotational surface  60  of the cupholder  30  also has vanes  62  of substantially triangular cross-section. As illustrated in  FIG. 8 , when the cup vanes  46  contact the cupholder vanes  62 , the leading triangular apexes of the respective vanes  46 ,  62  will tend to deflect the vanes  46 ,  62  away from one another and cause gravity to fully drop the cup  40  into the cupholder  30 .  FIG. 8  illustrates how the anti-rotational surfaces  44 ,  60  of the cupholder  30  and cup  40  engage with one another so that their respective vanes  46 ,  62  intermesh on the same horizontal plane. After the vanes  46 ,  62  have intermeshed, those vanes  46 ,  62  prevent the cup and cupholder from rotating with respect to one another as the food or beverage product is being blended in the cup  40 . Of course, in those embodiments where the food or beverage product is blended in the cupholder  30  without use of a cup  40 , there would be no need for the complementary anti-rotational surfaces  44 ,  60 . 
     In addition to showing complementary anti-rotational vanes  46 ,  62 ,  FIG. 8  also shows how the cupholder&#39;s magnetic presence indicator  37  can interact with a cupholder presence sensor  68 . If the cupholder presence sensor  68 , for example, senses a strong enough magnetic field coming from magnetic presence indicator  37 , it can send a signal to a microcontroller  140  ( FIG. 27 ) in the blender indicating that the start button  24  should temporarily light up in the color green to indicate to the user that the blender can be activated for blending by pushing the start button  24 . By contrast, if the cupholder presence sensor  68  fails to sense a strong enough magnetic field, it can send a signal or fail to send a signal to microcontroller  140  indicating that the start button  24  should not be activated. In addition to, or as an alternative to the magnetic presence sensor  68 , other mechanical or electro-mechanical means, such as a switch, can be employed to determine whether the cupholder  30  is properly positioned so that the start button  24  can be activated. 
       FIGS. 9-13  illustrate the progression of steps involved in blending frozen food or beverage into, for example, a smoothie, milkshake or protein shake using the blender  10  of the present invention. To better understand how the blending machinery works, these steps are illustrated with the front housing door  20  in an open position. Nonetheless, as previously noted, the blending machinery, for safety reasons, should not be operated with the front housing door  20  open. As such, for purposes of understanding the operation of the blender  10  of the present invention, one should assume that the front housing door  20  would be closed when the steps in  FIGS. 9-13  take place. 
       FIG. 9  illustrates how the elevator assembly  80  has its clamping jaw  90  and the spindle assembly  70  has its cup cover  74  in their lower most resting positions before the cupholder  30  is inserted into the cupholder receiving area  16  to begin the blending process.  FIG. 10  illustrates the next step of having the user insert the cupholder  30 , preferably including a cup  40  having frozen food or beverage, into the cupholder receiving area  16 . The cupholder  30  should be inserted so that the upper lip  34  of the cupholder rests within the lower clamping jaw  94  of the elevator assembly  80 . At this point in the process, there has not yet been any motorized movement of the blender  10 . 
       FIG. 11  illustrates the beginning step of motorized blending. After the start button  24  is pushed to begin activation of the blender  10 , the elevator assembly  80  pulls the lower clamping jaw  94  upward using its motorized dual lead screws  82  to the point where the lower  94  and upper  92  clamping jaws come together to firmly secure the cupholder  30  and clamp the cup cover  74  of the spindle assembly  70  against the top of the cup  40  to prevent food or beverage from spilling out during blending. 
     In  FIG. 12 , blending of the food or beverage product is taking place. At the bottom of the spindle assembly ( FIG. 15 ), there are preferably rotating cutting blades  72  that are used to cut through and blend the food or beverage product. While rotating cutting blades  72  are the preferred blending tool for the present invention, particularly where the food or beverage to be blended is frozen, those of skill in the art will recognize that other blending tools, such as whisks, may also be used in appropriate circumstances. In the preferred blender  10  of the present invention, the rotating cutting blades  72  remain at a constant, predetermined height while the cupholder  30  moves up and down. As the elevator assembly  80  moves the cupholder  30  up and down, the rotating cutter blades  72  operate at different levels of the food or beverage product. For example, in the position shown in  FIG. 12 , the rotating cutting blades  72  would be blending at a level which is one quarter to one half of the way down through the food or beverage in the cup  40  or cupholder  30 . To achieve even blending and good consistency, the rotating cutting blades  72  should work at all levels of the food or beverage present in the cup  40  or cupholder  30 .  FIG. 13  illustrates what happens when the elevator assembly  80  raises the cupholder  30  to its highest point. When the cupholder  30  reaches its highest point, the rotating cutting blades will be spinning at or near the bottom of the cup  40  or cupholder  30 . 
     When the cupholder  30  is subsequently lowered, the progression of steps is the opposite of those shown in  FIGS. 9-13 . In other words, the cupholder  30  begins at the highest level as shown in  FIG. 13  and gradually is lowered to the positions shown in  FIG. 12 ,  FIG. 11  and then  FIG. 10 . To get the best blending and consistency, the cupholder  30  is preferably raised and lowered multiple times while the rotating cutting blades  72  are spinning and before the cupholder  30  is released from the clamping jaw  90  as shown in  FIG. 10 .  FIG. 14  illustrates one such multiple pass protocol. In the  FIG. 14  protocol, the cupholder  30  is raised and lowered twice by the elevator assembly  80  before the cupholder  30  is released in the resting or “home position”. In the  FIG. 14  embodiment, the “home position” corresponds to the cupholder position illustrated in  FIG. 10 , the “low position” corresponds to the cupholder position illustrated in  FIG. 11  and the “high position” corresponds to the cupholder position illustrated in  FIG. 13 . 
       FIG. 15  shows a cross-section view of the preferred spindle assembly  70  of the present invention. The spindle assembly  70  preferably includes a quick release coupling member  75 , a rotating shaft  76 , cup cover  74  and rotating cutting blades  72 . The quick release coupling member  75  connects the spindle assembly  70  to a spindle pulley  122  ( FIG. 25-26 ). To facilitate cleaning of the spindle assembly  70 , the quick release coupling member  75  allows the spindle assembly  70  to be quickly detached from the blender  10  as illustrated in  FIGS. 17-20 . Rotating motion generated by the spindle motor  120  ( FIG. 26 ) is translated to the rotating cutting blades  72  through the rotating shaft  76  of the spindle assembly  70 . The rotating shaft  76  is preferably housed in an outer sleeve  78  for structural/alignment purposes and to keep the shaft free from food/beverage particles. Slidably attached to the outside of the outer sleeve  78  and trapped between the quick release coupling member  75  and the rotating cutting blades  72  is a moveable cup cover  74 . The purpose of the cup cover  74  in the preferred embodiment is to press onto the top lip  41  of the cup  40  in order to prevent food or beverage from spilling out of the cup  40  or cupholder  30  during blending. The cup cover  74  is preferably constructed from a combination of a hard plastic base  87  and a soft plastic or rubber seal  89 . The hard plastic base  87  maintains a resilient shape for the cup cover  74  while the soft plastic or rubber seal  89  makes a tight, flexible fit with the top of the cup  40 . Alternatively, the cup cover  74  can be molded from a single plastic to reduce costs. As illustrated in  FIGS. 11-13 , the cup cover  74  is clamped to the top of the cup  40  by the clamping jaw  90  before blending and moves up and down the outer sleeve  78  of the spindle assembly  70  with the clamping jaw  90  during blending. 
     At the bottom of the spindle assembly  70  are the rotating cutting blades  72 . The purpose of the rotating cutting blades  72  is to cut through the food or beverage during blending, particularly if they are frozen. While most of the non-electrical parts of the blender  10  of the present invention are preferably made from plastic, the rotating cutting blades  72  are preferably made from a rust proof metal, such as stainless steel. In the preferred embodiment, the rotating cutting blades  72  include radially extendable cutting blades  73  (see also,  FIG. 21 ). One embodiment of these radially extendable cutting blades  73  is disclosed in U.S. Pat. No. 6,527,207, the disclosure of which is hereby incorporated by reference. The purpose of the radially extendable cutting blades  73  is to compliment the rotating cutting blades  72  by adjusting to sections of the cup  40  or cupholder  30  with different radiuses. For example, most cups are not perfectly cylindrical, but rather have a larger radius at their top than at their bottom. The cup  40  illustrated in  FIG. 5  shows a cup with this sort of varying radius. By having radially extendable cutting blades  73  complimenting the rotating cutting blades  72 , the radially extendable cutting blades  73  can extend their blending radius to the edge of the cup  40  even though that radius changes from the top of the cup to the bottom of the cup. 
       FIG. 16  shows an alternative embodiment for the spindle assembly  70  of the present invention which further includes a spindle assembly spring  83  and illustrates a spindle connector  77  which connects the rotating shaft  76  of the spindle assembly to the spindle assembly pulley  122 . The spindle assembly spring  83  is useful for pressing the cup cover  74  against the top of the cup  40  in those embodiments, for example, that do not have a clamping jaw  90  to perform that function (see, e.g.,  FIG. 30 ). The disadvantage of this spindle spring  83  embodiment, as compared with the preferred clamping jaw  90  embodiment, is that, in the alternative spindle spring embodiment  83 , the spring  83  will compress as the cup cover  74  and cupholder  30  are raised during blending thereby creating a variable load on the dual lead screw motor  126  ( FIG. 26 ) as compared with a more constant load that the clamping jaw  90  creates. 
       FIGS. 17-20  illustrate how the spindle assembly can be quickly and easily removed from the blender  10  of the present invention for periodic cleaning. To begin the removal process, one must first open the front housing door  20  by unfastening the front door latch  22 .  FIG. 17  illustrates the spindle assembly  70  in its locked, operational position after the front housing door  20  has been opened. To make sure the spindle assembly  70  is in a proper locked, operational position before blending, the preferred blender  10  of the present invention uses a combination of a peg  29  on the front housing door  20  and a complementary opening  79  on the quick release coupling member  75  of the spindle assembly  70 . In order for the front housing door  20  to close, the peg  29  must fit into its complementary spindle assembly opening  79 . If the peg  29  and opening  79  are not properly aligned, the front housing door  20  will not close due to the interference of peg  29  with the surfaces adjacent to opening  79 . Alternatively, as those of skill in the art will recognize, the parts can be reversed so that the peg is on the spindle assembly  70  and the opening is on the front housing door  20 . As previously noted, if the front housing door  20  is not closed, the blender  10  will preferably be prevented from operating. 
     As shown in  FIG. 18 , removal of the spindle assembly  70  from the blender  10  requires, in the preferred embodiment, that the quick release coupling member  75  be turned to the right to place it in an unlocked position. As shown in  FIG. 19 , after the quick release coupling member  75  is in an unlocked position, it can be pulled down to detach the spindle assembly  70  from the rest of the blender  10 . Finally, as shown in  FIG. 20 , the spindle assembly  70  can be pulled away altogether from the blender  10  to allow it to be cleaned. Reattaching the spindle assembly  70  to the blender after it has been cleaned is simply a matter of repeating the steps shown in  FIGS. 18-20  in reverse order. While one mechanism for removing the spindle assembly  70  from the blender has been illustrated, those of skill in the art will recognize that other mechanisms can be used to remove the spindle assembly  70  from the blender  10 . 
       FIG. 21  shows a cut away, section view of the elevator assembly  80 . In its preferred form, this elevator assembly  80  includes clamping jaw  90 , dual lead screws  82 , clamping jaw drive nuts  100 , clamping jaw springs  95  and a clamping jaw lever lock mechanism  110 . The clamping jaw  90  includes upper clamping jaw  92  and lower clamping jaw  94 . As can be most clearly seen in  FIG. 21 , the “upper” clamping jaw  92  is actually a U-shaped part that fits into a U-shaped annular space in “lower” clamping jaw  94 . While part of lower clamping jaw  94  is physically lower than the upper clamping jaw  92 , there is also a portion of lower clamping jaw  94  that wraps around the outside of upper clamping jaw  92  at the same height as upper clamping jaw  92 . The purpose of upper  92  and lower  94  clamping jaws is to collectively clamp onto the upper lip  34  of the cupholder  30  using opposing surfaces  113 ,  114  and press the cup cover  74  of the spindle assembly  70  against that upper lip  41  of the cup  40  (see also,  FIG. 11 ). This clamping action is aided by clamping jaw springs  95  which continually bias the upper clamping jaw  92  downward. Once the cupholder  30  is firmly secured by the clamping jaw  90  and the cup  40  is covered, the clamping jaw  90  can raise and lower the cupholder  30  during the blending process through the actions of the dual lead screws  82 . 
       FIG. 21A  shows a slightly modified form of the  FIG. 20  elevator assembly  80 . In the  FIG. 21A  embodiment, wings  87  are attached to the lower clamping jaw  94  in such a way that they will vertically constrain the cup lip  41  during blender operation so that the cup  40  will stay in the cupholder  30 . If the rubber seal  89  of the cup cover  74  fits tightly to the cup lip  41 , it can cause the cup cover  74  to stick to the cup  40 . Consequently, when the blending process is finished and the lower clamping jaw  94  is returned to the “home position”, the cup cover  74  may cause the cup  40  to be pulled out of the cupholder  30 . If so, it will be more difficult for the user to remove the cupholder  30  and cup  40  from the blender  10  once the blending process is finished. The wings  87  in the  FIG. 21A  embodiment vertically constrain the cup lip  41  in such a way that the cup lip  41  will separate from the cup cover  74  when the lower clamping jaw  94  is returned to the “home position” and, thus, the cup  40  and cupholder  30  will always remain together while they are in the blender. 
     Returning to  FIG. 21 , using dual lead screws  82  is the preferred way to raise and lower the cupholder  30  in the blender  10  of the present invention. If only a single lead screw were used on one side of the clamping jaw  90 , cantilevered loads with resulting moments and torque would be created on the opposing side of the clamping jaw  90  by the pull of gravity and by the resistance of the product being blended by the blender  10 . This torque would not only lead to greater wear on the elevator assembly  80  but could cause the elevator assembly  80  to jam or break and, for that reason, a single lead screw is not preferred. By using a lead screw  82  on each side of the clamping jaw  90  turning at the same rate, the clamping jaw  90  is raised and lowered without significant cantilevered moments. Using at least two lead screws allows for reliable operation and a longer life for the blender  10  of the present invention. To have the dual lead screws  82  turn at the same rate, the dual lead screws  82  are preferably connected to the same motor  126  ( FIG. 26 ). In the preferred embodiment, pulleys  83  of the top of each lead screw  82  are connected to each other and the dual lead screw motor  126  through a common belt or chain  84  ( FIG. 25 ). As the dual lead screw motor  126  turns, the pulleys  83  on each lead screw  82  are turned at the same rate. As those of skill in the art will recognize, the movement of the dual lead screws  82  can alternatively be synchronized through the use of gears (not shown) rather than a belt or chain  84 . 
     The dual lead screws  82  are each attached to the lower clamping jaw  94  through clamping jaw drive nuts  100 . A clamping jaw drive nut  100  is more clearly shown in  FIGS. 22 and 23 . The drive nut  100  has an interior thread  101  which wraps around and meshes with the thread  86  of the lead screw  82 . While the dual lead screws  82  are preferably constructed from machined metal, such as stainless steel, the drive nut  100  can be formed from either metal or plastic. The drive nut  100  is connected to the lower clamping jaw  94  through the interaction of the U-shaped channel  103  on the drive nut  100  with a matching protrusion  97  on the lower clamping jaw  94  as well as cross shaped protrusions  104  on two sides of the drive nut  100  which fit into openings  99  on the lower clamping jaw  94 . The lower clamping jaw openings  99  are preferably oval in shape to allow a small degree of angular and horizontal translational movement for the cross shaped protrusions  104 . To the extent the drive nuts  100  and lead screws  82  are not perfectly machined or suffer wear over time, the small degree of angular and horizontal translational movement allowed by the drive nut cross shaped protrusions  104  and oval openings  99  will help avoid any binding action as the clamping jaw  90  is driven up and down the lead screws  82 . As those of skill in the art will recognize, other shapes for the drive nut protrusions and lower clamping jaw openings can be used to allow a small degree of angular and horizontal translational movement. For example, the drive nut protrusion can be circular in shape and fit within a larger oval opening. 
       FIG. 24  shows a cut-away view of the clamping jaw lever lock mechanism  110 . The purpose of the clamping jaw lever lock mechanism  110  is to hold the upper  92  and lower  94  clamping jaws together as they are raising and lowering the cupholder  30  during blending while allowing the lower clamping jaw  94  to release from the upper clamping jaw  92  when the blending process is finished so that the user can easily remove the cupholder  30  from the blender  10  to enjoy the blended food or beverage product. The lever lock mechanism  110  accomplishes this objective through the interaction of lever lock mechanism biasing spring  119  with lever  117  and upper locking tube  115 . During the blending process (see,  FIGS. 11-13 ), the biasing spring  119  presses down on the lever  117  to wedge the upper locking tube  115  and, thereby, the lower clamping jaw  94  into a locked position. When the upper locking tube  115  is so wedged, the upper  92  and lower  94  clamping jaws travel up and down together as one piece, thereby firmly holding the cupholder  30  in place during blending. When the blending has been completed and the upper clamping jaw  92  drops down to its lowest position (see,  FIG. 11 ), a shelf  118  ( FIG. 8 ) built into the upper housing  12  will push the lever  117  upward to overcome the force of the biasing spring  119  and thereby allow the upper locking tube  115  to move freely. In this release position, the lower clamping jaw  94  can vertically separate from upper clamping jaw  92 . In addition, when the lever  117  is pushed up into the horizontal release position, the lever  117  holds the upper clamping jaw  92  stationary while the lower clamping jaw  94  travels downward to the “home position.” This vertical separation allows the cupholder  30  to be freely removed and reinserted. At the beginning of the next blending process after the cupholder  30  has been reinserted, the dual lead screws  82  will raise the lower clamping jaw  94  until it reconnects with the upper clamping jaw  92  and continues its upward movement to the point where biasing spring  119  again presses the lever  117  into its downward locking position so that the upper  92  and lower  94  clamping jaws are locked together during blending. 
       FIG. 30  shows an alternative elevator assembly embodiment that does not rely on a clamping jaw  90  to hold the cupholder during blending. In the  FIG. 30  embodiment, the cupholder  132  is part of an elevator bracket assembly  130  which connects the cupholder  132  to lead screw nuts  136  through bracket arms  134 . To blend food or beverage using this alternative embodiment, one places the cup  40  with the food or beverage into the top of the cupholder  132 . The interaction of the dual lead screws  82  with the lead screw nuts  136  can then raise and lower the elevator bracket assembly  130  during the blending process. As in the preferred embodiment, the spindle assembly (not shown) remains in a fixed position while the food or beverage cup  40  is moved up and down. As compared with the preferred embodiment, this alternative embodiment is more simple to manufacture. Nonetheless, this alternative embodiment has the disadvantage of requiring more space because, as in the F&#39;real commercial blenders, the cup  40  must be inserted into the cupholder  132  from above. This means that the alternative embodiment blender must be large enough to provide room for the cup  40  to be inserted into the cupholder  132  from above. 
       FIGS. 25 and 26  are cut-away top and rear views, respectively, of the blender  10  of the present invention illustrating the preferred location and operation of the spindle motor  120  and the dual lead screw motor  126  ( FIG. 26 ). A spindle belt or chain  129  preferably connects a pulley  124  on top of the spindle motor  120  with a pulley  122  coupled to the spindle assembly  70 . It is through this spindle belt or chain  129  that rotational energy from the spindle motor  120  translates into turning the rotating shaft  76  and rotating cutting blades  72  of the spindle assembly  70 . In the preferred embodiment, associated with the spindle motor  120  is a spindle motor encoder  121  which detects and helps control the speed of the spindle motor  120 . As previously noted, the dual lead screw belt or chain  84  connects the dual lead screw motor  126  to the dual lead screws  82  through their respective pulleys  128 ,  83 . Like the spindle motor  120 , the dual lead screw motor  126  also has a dual lead screw motor encoder  127  to detect and help control the operation of the dual lead screw motor  126 . By detecting the angular position of the dual lead screw motor, the dual lead screw motor encoder  127  can, in conjunction with microcontroller  140  ( FIG. 27 ), calculate the vertical position of the clamping jaw  90 . To overcome the potential cumulative effect of occasional missed encoder counts, a “home” sensor  145  ( FIG. 26 ) is preferably used with the encoder  127  to ensure that the clamping jaw  90  always returns to the same starting “home position” at the end of the blending cycle. In alternative embodiments, the position of the clamping jaw  90  can be determined through, for example, a combination of “high position”, “low position” and “home position” sensors that are positioned along the travel path of the clamping jaw  90 . Where multiple sensors are used in these positions, the microcontroller would not need to rely upon a dual lead screw motor encoder  127 . These sensors could, for example, be electrical or electro-mechanical devices, such as magnets activating “Hall Effect” sensors or switches. 
       FIG. 27  is an electrical block diagram for the blender  10  of the present invention. The blender of the present invention preferably receives its power from an alternating voltage source, such as a household electrical outlet. Those of skill in the art will recognize, though, that other electrical sources could be used, such as batteries. A switch, such as an “on/off” switch (not shown) may be present on the blender  10  to shut off power to the blender  10  when the blender is not in use. The start button  24  on the front door housing  20 , in some embodiments, can serve as such an “on/off” switch. For the reasons previously noted, the blender is prevented from operating if the front housing door  20  is in an open position. In the preferred embodiment, the front door latch  22  acts as a switch  131  to prevent electricity from reaching the motorized parts of the blender  10  if the front door latch  22  is open. Rectifiers  134 ,  135  are preferably used to convert alternating current into direct current for the spindle motor  120 /spindle motor control  121 A as well as dual lead screw motor  126 /dual lead screw motor control  127 A. Transformer  133 /Logic Power Circuit  141  are preferably used to step down the voltage to more usable levels, particularly for the microcontroller  140 . The microcontroller  140  receives numerous inputs to allow it to safely operate the blender  10  of the present invention, including inputs from cupholder sensor  68 , the start button  24 , clamping jaw “home” sensor  145  ( FIG. 26 ), the dual lead screw motor encoder  127 , the spindle motor encoder  121  and a vibration detection transducer  149 . For example, the cupholder  30  must be sensed in the proper position by cupholder sensor  68  before blending can take place. Assuming that the latch  22  is properly closed and the cupholder is sensed to be in the correct position, the microcontroller  140  preferably lights up, at least temporarily, the start button  24  and/or an LED display  143  near the start button  24  to tell the user that the blender is ready for operation. The microcontroller  140  then waits until the user presses the start button  24  to begin blending. The vibration detection transducer  149  senses whether the blender is undergoing excessive vibration indicative of improper use. For example, if the user fails to add liquid to a frozen beverage before blending, the frozen beverage can form a thick slurry which adheres to the rotating cutting blades  72  of the spindle assembly  70  during blending and, in some instances, causes excessive vibration of the blender. If excessive vibration is sensed by the vibration detection transducer  149 , the spindle motor  120  will preferably be stopped and the clamping jaw  90  will be returned to its “home position” (i.e., so that the rotating cutting blades  72  will be disengaged from the food or beverage in the cup). After a period of time, the microcontroller  140  can reset to allow continued operation of the blender. The vibration detection transducer  149  can take a number of forms, including an accelerometer, a switch or a microphone. 
     To perform the blending process, the microcontroller  140  sends signals to the dual lead screw motor control  127 A to have the dual lead screw motor  126  turn the dual lead screws  82  to raise and lower the cupholder  30 . Simultaneously, the microcontroller  140  will have the spindle motor control  121 A operate the spindle motor  120  so that the food or beverage is being blended as the cupholder  30  is moved up and down. During the blending process, the microcontroller  140  can receive inputs from, in the preferred embodiment, the dual lead screw motor encoder  126  and the “home position” sensor  145  so that the microcontroller  140  can tell the dual lead screw control  127 A to have the dual lead screw motor  126  initiate movement, reverse movement or stop movement, as appropriate. 
       FIG. 28  illustrates the steps a user would typically go through to prepare smoothies and milkshakes using the blender  10  of the present invention when the blender is first used. First, the user will plug in the blender [ 150 ]. Preferably, after the blender is plugged in, an “on/off” switch or the start button  24  will light up, at least temporarily, to show the user that the blender  10  is ready for operation. As a safety feature, the blender will not operate if the front door is open [ 152 ,  153 ]. If the spindle assembly  70  has not yet been installed, the user will need to open the front housing door [ 151 ] to install the spindle assembly  70  into the quick release coupling [ 154 ]. After the spindle assembly has been properly installed, the user closes the front housing door [ 155 ]. The user can then remove the cupholder from the cupholder receiving area [ 156 ] so that a cup with frozen food or beverage can be placed in the cupholder [ 157 - 160 ]. To prevent contamination, the cup with frozen food or beverage preferably has a tear off seal that must be removed to expose the frozen food or beverage [ 157 ]. In the preferred embodiment, the user then adds liquid, such as water or milk, to the frozen food or beverage up to a recommended level to facilitate the blending process [ 158 ]. At this point, the user may also add mix-ins, such as fresh fruit or protein powder. The cup should then be dropped into the cupholder so that the anti-rotational surfaces of the cup and cupholder can engage with one another [ 160 ]. After the anti-rotational surfaces have engaged, the cup/cupholder are slid horizontally into the cupholder receiving area so that cupholder lip  34  is between the upper and lower clamping jaws [ 161 ]. In the preferred embodiment, the start button or an LED display will tell the user if the cupholder has been properly inserted [ 162 ]. After proper insertion, the user can press the start button  24  to initiate the blending routine [ 163 ], which then takes place automatically [ 164 ] without any further work by the user. When the blending process has been completed, the clamping jaws will release the cupholder so that the user can remove the cupholder from the blender [ 165 ] and enjoy the blended food/beverage in the cup after the cup is removed from the cupholder [ 166 ]. 
       FIG. 29A-D  summarizes the blending process of the present invention from the perspective of the blender  10  and, particularly, its microcontroller  140 . Before blending takes place, the microcontroller  140  preferably uses the “home position” sensor  145  to sense whether the clamping jaw  90  is in the proper starting or “home position” [ 170 ]. If not [ 172 ], the dual lead screw motor will be activated to move the lower clamping jaw down to the proper “home position” [ 174 ]. Once the lower clamping jaw  94  is confirmed to be in the “home position” and the microcontroller confirms that the cupholder is properly inserted between the upper and lower clamping jaws [ 175 ], the blender can be activated by pressing the start button  24 . After the start button  24  is then pushed, the microcontroller  140  activates the dual lead screw motor  126  to start raising the lower clamping jaw  94  of the elevator assembly [ 176 ]. The ramped geometry on the underside of the front door  20  and cupholder lip  34  urge the cupholder  30  into the correct position, if it is not already there [ 177 ]. The lower clamping jaw  94  is then raised from its “home position” until it locks with the upper clamping jaw  92  and, in the process, firmly clamps the cupholder lip  34  as well as presses the cup cover  74  against the cup lip [ 180 ]. At this point, in the preferred embodiment, the microcontroller  140  uses information received from the dual lead screw motor encoder  127  to calculate when the clamping jaw  90  reaches the “low position” [ 182 ]. When the clamping jaw  90  is in the “low position”, the microcontroller  140  can start the blending process through activation of the spindle motor [ 184 ]. 
     The spindle motor  120  continues to blend the food or beverage in the cup or cupholder as the elevator assembly lifts the cupholder upward [ 186 ]. Since the rotating cutting blades of the spindle assembly are in a fixed position, those rotating cutting blades will blend progressively lower levels of the food or beverage as the cup and/or cupholder are raised by the elevator assembly [ 186 ]. As the clamping jaw  90  of the elevator assembly reaches its highest position, the microcontroller  140  determines that the “high position” has been reached using its dual lead screw encoder  127  or, in some embodiments, it receives a signal from a “high position” sensor [ 190 ]. This determination causes the microcontroller  140  to stop the dual lead screw motor from continuing to raise the clamping jaw [ 192 ]. After a brief pause, the microcontroller  140  directs the dual lead screw motor  126  to begin lowering the clamping jaw and cupholder [ 194 ]. As the clamping jaw and cupholder are lowered between the “high” and “low” positions, the rotating cutting blades will blend progressively higher levels of food or beverage in the cup and/or cupholder. The dual lead screw motor continues lowering the clamping jaw and cupholder until the microcontroller  140  determines that the clamping jaw  90  has reached the “low position” [ 196 ]. After reaching the “low position”, the microcontroller  140  instructs the dual lead screw motor  126  to stop lowering the clamping jaw and cupholder if further blending is desired [ 198 ]. During the raising and/or lowering process as blending takes place, the microcontroller  140  can monitor the amount of current used to make sure it does not exceed pre-determined limits [ 195 ,  203 ]. If the pre-determined current limit is exceeded, the microcontroller will temporarily slow travel or reverse the direction of travel [ 197 ,  204 ]. 
     In the preferred embodiment, the rotating cutting blades pass through the food or beverage multiple times before the blending is complete (see  FIG. 14 ). For example, if two complete cycles are desired, the microcontroller  140  will direct the dual lead screw motor to raise the clamping jaw and cupholder for a second time [ 198 ] until the microcontroller determines that the clamping jaw has again reached the “high position” [ 200 ]. At that point, the dual lead screw motor  126  will lower the clamping jaw and cupholder for a second time [ 202 ] until the microcontroller determines that the “low position” has again been reached [ 206 ]. In this two cycle embodiment, the blending will now be complete so that the microcontroller can turn off the spindle motor [ 208 ]. To allow the user to access the blended food or beverage, the dual lead screw motor  126  will further lower the clamping jaw from the “low position” to the “home position” [ 210 ] which will simultaneously separate the upper clamping jaw  92  from the lower clamping jaw  94  and remove the cup cover  74  from the cup lip  41 . As the “home position” is reached, the microcontroller  140  will stop the dual lead screw motor [ 212 ] so that the user can remove the cupholder with the blended food or beverage product while none of the blender motors are operating. 
     In the foregoing specification, the invention has been described with reference to specific preferred embodiments and methods. It will, however, be evident to those of skill in the art that various modifications and changes may be made without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative, rather than restrictive sense; the invention being limited only by the appended claims.