Patent Publication Number: US-2019167041-A1

Title: Food processing machine and associated bowl and drive arrangement

Description:
TECHNICAL FIELD 
     This application relates generally to commercial food processing machines commonly utilized for mixing and cutting food products, and more particularly to a bowl and drive arrangement for a mixer-cutter type food processing machine. 
     BACKGROUND 
     Existing commercial food processing machines include a drive motor, a transmission, a food processing tool, a shaft, a bowl, and a dynamic seal. The motor is mounted underneath the bowl, and the motor shaft passes upward through an opening in the bottom of the bowl. To prevent leakage of water or fluids or other material during food processing, a dynamic seal is used to seal against the motor shaft. In particular, a dynamic seal is associated with the opening in the bottom of the bowl and includes a radially inward facing seal portion that contacts the radially outward facing surface of the drive shaft. The dynamic seal may be restrained in place by the mixing tool, but can be removed. 
     Dynamic seals are more prone to wear than stationary seals, and dynamic seals can be damaged by debris, chemicals, and thermal cycling. The dynamic seals can also be misplaced (or not replaced) by the operator during or after sanitation cleaning of the food processing machine. Dynamic seals are thus more sensitive to variations in operator training and proficiency. Such issues can lead to undesired water or fluid leakage downward through the bottom opening of the bowl toward the drive system. 
     It would be desirable to provide a commercial food processing machine that eliminates the need for a dynamic seal. 
     SUMMARY 
     In one aspect, a food processing machine includes a mixer body including a stand and a bowl support pivotally mounted on the stand for selective pivot about a horizontal axis. A bowl is mounted atop the bowl support for pivot with the bowl support, the bowl includes a bottom wall with an opening therein, the bowl having an upper edge, wherein a bowl height is defined by a linear distance from the opening to a height of the upper edge. A tubular member is fixed to the bowl and extends upward from the opening and within the bowl. The tubular member includes a lower end and an upper end, the lower end in a stationary sealed arrangement with the bottom wall of the bowl, the stationary sealed arrangement extending around the opening, wherein a tube height is defined by a linear distance from the opening to a height of the upper end of the tubular member, wherein the tube height is least thirty percent of the bowl height. A drive is mounted below the bowl support for pivot with the bowl support. The drive includes a rotatable drive shaft extending upward through the opening of the bottom wall of the bowl and upward through the tubular member. The rotatable drive shaft includes an upper end, wherein a drive shaft height is defined by a linear distance from the opening to a height of the upper end, wherein the drive shaft height is greater than the tube height and less than the bowl height. 
     In another aspect, a food processing machine includes a mixer body including a stand and a bowl support. A bowl is mounted atop the bowl support, the bowl including a bottom wall with an opening therein, the bowl having an upper edge, wherein a bowl height is defined by a linear distance from the opening to a height of the upper edge. A tubular member is fixed to the bowl and extending upward from the opening and within the bowl, the tubular member including a lower end and an upper end, wherein a tube height is defined by a linear distance from the opening to a height of the upper end of tubular member, wherein the tube height is less than the bowl height. A drive is mounted below the bowl support, the drive including a rotatable drive shaft extending upward through the opening of the bottom wall of the bowl and upward through the tubular member, the rotatable drive shaft including an upper end, wherein a drive shaft height is defined by a linear distance from the opening to a height of the upper end, wherein the drive shaft height is greater than the tube height and less than the bowl height. 
     In another aspect, a food processing machine includes a mixer body including a stand and a bowl support pivotally mounted on the stand for selective pivot about a horizontal axis. A bowl is mounted atop the bowl support for pivot with the bowl support, the bowl including a bottom wall with an opening therein. A tubular member is connected to the bowl and extending upward from the opening and within the bowl, the tubular member including a lower end and an upper end, the lower end in a stationary sealed arrangement with the bottom wall of the bowl, the stationary sealed arrangement extending around the opening. A drive is mounted below the bowl support for pivot with the bowl support, the drive including a rotatable food processing component drive shaft extending upward through the opening of the bottom wall of the bowl and upward through the tubular member, wherein the rotatable food processing component drive shaft includes an upper end that is above an upper end of the tubular member. 
     In a further aspect, a food processing machine includes a mixer body including a stand and a bowl support. A bowl is mounted atop the bowl support, the bowl including a bottom wall with an opening therein, the bowl having an upper edge, wherein a bowl height is defined by a linear distance from the opening to a height of the upper edge. A tubular member is formed separate from the bowl and is connected to the bowl, the tubular member extending upward from the opening and within the bowl, the tubular member including a lower end and an upper end, wherein a tube height is defined by a linear distance from the opening to a height of the upper end of tubular member, wherein the tube height is less than the bowl height. A drive is mounted below the bowl support, the drive including a rotatable drive shaft extending upward through the opening of the bottom wall of the bowl and upward through the tubular member, the rotatable drive shaft including an upper end, wherein a drive shaft height is defined by a linear distance from the opening to a height of the upper end, wherein the drive shaft height is greater than the tube height and less than the bowl height. 
     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 perspective view of a food processing machine; 
         FIG. 2  is a front elevation of the food processing machine; 
         FIG. 3  is partial cross-section showing an in bowl drive arrangement of the food processing machine; and 
         FIGS. 4 and 5  are cross-sections showing an alternative embodiment of an in-bowl drive arrangement. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-3 , a food processing machine  10  includes a mixer body  12  with a stand or frame  14  to which a bowl support  16  is pivotally mounted for selective pivot about a horizontal axis  18 . A bowl  20  is mounted atop the bowl support  16  for pivot with the bowl support, and a bowl tilt lever  21  facilitates tilting of the bowl support and bowl. The bowl typically remains in a fixed position on the bowl support during use and cleaning operations. A see through bowl cover  22  is mounted to a pivot arm  24  that is pivotable about a horizontal axis  26  enabling the cover to move from a lowered bowl covering position to a raised bowl access position per movement path  28  in  FIG. 2 . Both the lowered and raised positions of the arm  24  and cover  22  are shown in  FIG. 2  for illustration purposes. A latch member  30  can be engaged with the distal end of the pivot arm  24  when the pivot arm is in the lowered position in order to secure and hold the cover in place during food processing operations. 
     A drive  40  (e.g., motor or motor and transmission) is mounted below the bowl support  16  and is connected to the bowl support so as to pivot with the bowl support. A limit bar  42  extends between two opposed uprights  44  of the stand  14 , and the drive  40  abuts the limit bar  42  when the bowl support, bowl and drive are in an upright working position. The limit bar  42  prevents pivot of the bowl support, bowl and drive out of the upright position in one pivot direction  46 , while permitting pivot of the bowl support out of the upright position in an opposite direction  48 . 
     A control box  50  is provided with associated start switch  52 , stop switch  54 , and timer control  56 , which may enable jog, run and timed settings for the machine. 
     The bowl  20  includes a bottom wall  60  with a central opening  62  therein that aligns with the axis of a drive shaft  76  that extends upward through the opening. Here, the opening  62  is located in a slight downward depression of the bowl bottom wall. The bowl has an upper edge or rim  64 , which may or may not include a pouring lip. A bowl depth or height H B  is defined by a linear distance from the opening  62  to a height of the upper edge  64 . A tubular member  70  is removably connected to the bottom wall of the bowl and extends upward from the opening  62  and within the bowl. The tubular member includes a lower end  72  and an upper end  74 , with the lower end  72  in a stationary sealed arrangement with the bottom wall  60  of the bowl. The stationary sealed arrangement extends around the bottom wall opening  62 . A tube height H T  is defined by a linear distance from the opening  62  to a height of the upper end  74  of tubular member. 
     A rotatable drive shaft  76  extends upward from the drive  40  through the bottom wall opening  62  and upward through the tubular member  70 . The rotatable drive shaft  76  includes an upper end  78 , and a drive shaft height H DS  is defined by a linear distance from the opening  62  to a height of the upper end  78 . As shown, the drive shaft height H DS  is greater than the tube height H T  and less than the bowl height H B . Thus, the top of the drive shaft  76  extends above the top of the tube  70 . By way of example, the tube height H T  may be at least thirty percent (e.g., at least forty percent, at least fifty percent, at least sixty percent or at least seventy percent) of the bowl height H B . 
     Here, the tubular member  70  includes a bottom flange  80  that is held stationarily adjacent the inner surface of the bottom wall  62  about the periphery of the opening  62  for the purpose of sealing. The flange  80  may directly contact the surface of bottom wall  60  for sealing, or a stationary annular sealing gasket may be sandwiched between the flange  80  and the bowl bottom wall  60 . The connection between the tubular member and the bowl bottom wall may be via a fastening system (e.g., threaded studs at the bottom of flange  80  extending down through corresponding stud openings in the bowl bottom wall, with nuts at the underside of the bowl connected to the studs), but other variations are possible. 
     A food processing attachment  90  can be engaged on the upper end  78  of the tubular member, with the food processing attachment including a tubular wall  92  that extends downward alongside, but spaced from, an outer surface of the tubular member  70 . In order for fluid or other material within the bowl to reach the opening  62  in the bottom wall  60 , the fluid must pass upward along a gap  94  between the inner surface of the tubular wall  92  and the outer surface of the tubular member  70 , and then downward through along a gap  95  between the tubular member  70  and the drive shaft  76 . This arrangement creates a circuitous path that will limit leakage. Moreover, with proper sizing of the height of the tubular member  70 , the upper end or edge of the tubular member will be maintained above a normal height of material within the bowl. 
     As shown, an upper end  78  of the drive shaft  76  is threaded. The food processing attachment  90  is disposed over the upper end of the drive shaft with the upper end  78  of the drive shaft extending above a top of the food processing attachment. The upper part  91  of the food processing attachment may be keyed to the upper end of the shaft for rotation with the shaft. A handle member  96  is threadedly engaged to the upper end  78  of the drive shaft to retain the food processing attachment on the drive shaft  76 . The handle member  96  can be unthreaded and removed to permit removal and replacement of the food processing attachment (e.g., for cleaning or where different types of attachments are provided). 
     The subject stationary sealed arrangement provided above reduces failure and misplacement issues associated with prior dynamic seals. The arrangement also facilitates cleaning by enabling the food processing tool to be removed and taken to a sink, while at the same time the bowl can be cleaned (e.g., liquid in the bowl but below the top of the tubular member) without the liquid passing through the bottom opening of the bowl. 
     It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible. For example, in alternative embodiments, a bottom portion of the tubular member may threadedly engage with a corresponding threaded portion of the bowl bottom to provide removability, or the tubular member  70  may twist fit/lock to the bottom wall of the bowl for removability or a bottom portion (e.g., the flange) of the tubular member may be welded to the bowl bottom wall (although the removable variations are preferred). 
       FIGS. 4 and 5  show an exemplary embodiment in which the bottom portion of the tubular member  70 ′ threadedly engages with a corresponding threaded portion of the bowl bottom. Here, the threaded engagement is with a mount hub  110  that is mounted to the bowl bottom wall  60  by studs  112  that extend downward from the mount hub, through openings in an annular sealing gasket  114  and then through openings in the bottom wall  60 . The studs  112  are threaded at least below the bottom wall  60  so that nuts  116  can be used to secure the mount hub  110  in place with a downward pressure against the sealing gasket  114 . The mount hub  110  may, for example, be of metal (e.g., stainless steel) and the sealing gasket  114  may, for example, be a nitrile gasket. An upper section  118  of the mount hub is externally threaded and the tube  70 ′ includes a lower tube mount  120  that is internally threaded to so that the tube  70 ′ threads onto the mount hub, with an O-ring  122  provided therebetween for sealing. Here, the O-ring  122  is positioned within an annular recess of a lower section  124  of the mount hub, but protrudes upward beyond the top of the recess to assure sealing contact with a downwardly facing surface portion of the tube mount  120 . In this embodiment, the drive shaft  130  is in the form of a two-piece drive shaft that includes a lower section  132  and an upper section  134 . The lower section extends from the drive and passes upward through the bowl bottom wall opening  62  and a central opening  119  in the mount hub  118 , then upward through the cylindrical wall of the tube  70 ′. The upper section  134  is threadedly connected to the lower section  132 . The upper end  136  of the upper section  134  passes through an opening in the top part  138  of the tube  70 ′ and can receive a handle (not shown) in a manner similar to that described above. The embodiment also provides a circuitous path, including gaps  94  and  95 , through which material must flow to reach the opening  62  in the bowl bottom wall. 
     Still other variations are possible.