Patent Publication Number: US-2010123290-A1

Title: Shaft seal arrangement of a chocolate fountain

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a chocolate fountain, and more particularly, to an improvement of a shaft seal arrangement of a chocolate fountain. 
     2. Description of the Related Art 
     As shown in  FIGS. 1 through 4 , a few of chocolate machines  10  disclosed by C. Liang Wu include a base  11  on which a basin  12  is disposed. A motor  13  is installed therein. An auger  15  is driven by the motor  13  via a transmission shaft  14  in rotation within a cylinder  16 . As a result, the melted chocolate within the basin  12  can be brought upward along the cylinder  16  at the center in a screwed way to the top  17  of the chocolate fountain. Thereafter, the melted chocolate flows from the top back to the basin  12 . When the melted chocolate flows along the tiers, a chocolate waterfall effect is created. 
     No matter whether the motor  13  is laterally arranged ( FIG. 2 ) or vertically arranged ( FIG. 3 ), a shaft seal  19  has to be mounted at the connection between the transmission shaft  14  and the auger  15  for preventing the melted chocolate within the basin  12  from leakage. As shown in  FIG. 4 , the conventional shaft seal  19  includes a rubber sleeve  191  within a shaft hole at the bottom of the basin  12  through which the transmission shaft  14  passes. The rubber sleeve  191  is elastically and tightly mounted at the periphery of the transmission shaft  14  for preventing the melted chocolate (illustrated by dots) within the basin  12  from leakage. 
     After used for a long period, the shaft seal  19  of the shaft seal  19  creates a fatigue of elasticity such that the melted chocolate will leak into a bearing  192 , thereby reducing the service life thereof. Moreover, the melted chocolate may leak into the base  11 . Even, it may overflow from the housing and cause much trouble. Therefore, the conventional shaft seal requires further improvements. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide a shaft seal arrangement of a chocolate fountain that prevents the melted chocolate from leaking from the seal. 
     Another object of the invention is to provide a shaft seal arrangement of a chocolate fountain that possesses a pushing resilience constantly pushing the transmission element against a resilient spacer such that a long-term forcing effect to protect from leakage is ensured. 
     In order to achieve the above-mentioned object, a shaft seal arrangement of a chocolate fountain in accordance with the invention is interposed between the transmission shaft and the screw rod and includes a spring, a holding sleeve, an elastic sleeve, a supporting body, a drive shaft, a compression ring, and a resilient spacer: 
     The spring is received within an annular groove of the bearing seat. The annular groove is formed externally and concentrically to the bearing. 
     The holding sleeve is made of metallic material such as copper and U-shaped. A through hole is formed at the center of the holding sleeve such that the transmission shaft passes through the through hole without contact therewith. A flange is extended from the periphery of the holding sleeve and positioned on the top of the spring. 
     The elastic sleeve is downward tapered and includes a greater opening at the top thereof. A bottom portion of the elastic sleeve is mounted on the internal wall of the holding sleeve. The top of the elastic sleeve includes a flanged surface extended outward and positioned on the bearing seat. 
     The supporting body includes a through hole at the center thereof. The transmission shaft passes through the without contact therewith. The supporting body is mounted both on the internal wall of the bottom portion of the elastic sleeve and on the holding sleeve. 
     The drive shaft includes a bottom portion fixed in a coupling hole at the top of the transmission shaft such that the drive shaft is movable with the transmission shaft. The drive shaft further includes an upper portion fitting into a connection groove of the screw rod. An n-shaped disc body is extended outward from the middle portion of the drive shaft for covering the supporting body. 
     The compression ring is interposed between the bearing seat and the bottom of the basin and compressed against the top of the flanged surface of the elastic sleeve. Moreover, the compression ring includes a recessed portion at the internal wall thereof. 
     The resilient spacer is received within the recessed portion and disposed at the bottom of the basin. Moreover, the resilient spacer includes a mounting hole tightly positioned around the circumference of the drive shaft in such a way that the resilient spacer sits on the top of the n-shaped disc body. The elastic sleeve and the resilient spacer are preferably made of rubber. The material should not be restricted thereto. Any other equivalent materials are applicable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accomplishment of this and other objects of the invention will become apparent from the following descriptions and its accompanying figures of which: 
         FIG. 1  is a perspective view of a conventional chocolate fountain; 
         FIG. 2  is a cutaway view of the conventional chocolate fountain; 
         FIG. 3  is a cutaway view of another conventional chocolate fountain; 
         FIG. 4  is an enlarged cutaway view of the conventional shaft seal of a chocolate fountain; 
         FIG. 5  is a perspective view of a preferred embodiment in accordance with the invention; 
         FIG. 6  is a cutaway view of the preferred embodiment in accordance with the invention; 
         FIG. 7  is an enlarged cutaway view of the main structure according to  FIG. 6 ; and 
         FIG. 8  is an enlarged cutaway view of the main structure according to  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     First of all, referring to  FIG. 5 , a preferred embodiment of a shaft seal arrangement of a chocolate fountain in accordance with the invention includes a base  20  with a basin  21  positioned thereon, and a cylinder  30  fixed at the center of the basin  21  with a fixing portion  32  at the bottom thereof. A screw rod  40  is positioned within the cylinder  30 . A plurality of step-shaped tiers  31  are mounted on the periphery of the cylinder  30 . A top portion  33  is positioned on the top of the cylinder  30 . 
     As shown in  FIG. 6 , a motor  50  is disposed within the base  20 . A transmission shaft  51  is driven by the motor  50  via a transmission tooth disc  52 . A fixing seat  60  is positioned at the top of the motor  50 . A bearing seat  61  is disposed at the top of the fixing seat  60 . A bearing  62  is interposed between the bearing seat  61  and the transmission shaft  51 . 
     The above-mentioned configuration belongs to the prior art and is not the object of the invention so that no further descriptions are given hereinafter. The invention features that a shaft seal arrangement  70  adapted to the chocolate basin  21  is interposed between the transmission shaft  51  and the screw rod  40 . 
     As shown in  FIGS. 6 through 8 , the shaft seal arrangement  70  includes a spring  71 , a holding sleeve  72 , an elastic sleeve  73 , a supporting body  74 , a drive shaft  75 , a compression ring  76 , and a resilient spacer  77 . 
     The spring  71  is received within an annular groove  63  of the bearing seat  61 . The annular groove  63  is formed externally and concentrically to the bearing  62 . 
     The holding sleeve  72  is made of metallic material such as copper and U-shaped. A through hole  721  is formed at the center of the holding sleeve  72  such that the transmission shaft  51  passes through the through hole  721  without contact therewith. A flange  722  is extended from the periphery of the holding sleeve  72  and positioned on the top of the spring  71 . 
     The elastic sleeve  73  is downward tapered and includes a greater opening at the top thereof. A bottom portion  731  of the elastic sleeve  73  is mounted on the internal wall of the holding sleeve  72 . The top of the elastic sleeve  73  includes a flanged surface  732  extended outward and positioned on the bearing seat  61 . 
     The supporting body  74  includes a through hole  741  at the center thereof. The transmission shaft  51  passes through the  741  without contact therewith. The supporting body  74  is mounted both on the internal wall of the bottom portion  731  of the elastic sleeve  73  and on the holding sleeve  72 . 
     The drive shaft  75  includes a bottom portion  751  fixed in a coupling hole  53  at the top of the transmission shaft  51  such that the drive shaft  75  is movable with the transmission shaft  51 . The drive shaft  75  further includes an upper portion  752  fitting into a connection groove  41  of the screw rod  40 . An n-shaped disc body  753  is extended outward from the middle portion of the drive shaft  75  for covering the supporting body  74 . 
     The compression ring  76  is interposed between the bearing seat  61  and the bottom of the basin  21  and compressed against the top of the flanged surface  732  of the elastic sleeve  73 . Moreover, the compression ring  76  includes a recessed portion  761  at the internal wall thereof. 
     The resilient spacer  77  is received within the recessed portion  761  and disposed at the bottom of the basin  21 . Moreover, the resilient spacer  77  includes a mounting hole  771  tightly positioned around the circumference of the drive shaft  75  in such a way that the resilient spacer  77  sits on the top of the n-shaped disc body  753 . The elastic sleeve  73  and the resilient spacer  77  are preferably made of rubber. The material should not be restricted thereto. Any other equivalent materials are applicable. 
     The material of the supporting body  74  is selected from a group consisting of carbon, graphite, Teflon, and wearproof ceramics. The material of carbon is preferred. The top of the supporting body  74  is provided with a ring groove  742  for minimizing the contact with the n-shaped disc body  753 . 
     Moreover, the bottom of the resilient spacer  77  is provided with a plurality of projecting ring ribs  772  arranged concentrically to one another for creating a multiple sealing effect and reducing the frictional surface. 
     The operation of the shaft seal arrangement of a chocolate fountain in accordance with the invention is shown in  FIG. 8 . Based upon the above-mentioned configuration of the invention, the transmission shaft  51  and the drive shaft  75  are driven by the transmission tooth disc  52  such that the screw rod  40  within the basin  21  is rotated. At that time, the spring  71  constantly provides an upward resilience that acts on the holding sleeve  72  to force the supporting body  74  against the bottom surface of the n-shaped disc body  753  of the drive shaft  75 . As a result, when the drive shaft  75  and the n-shaped disc body  753  are rotated, an upward pushing force is maintained so as to constantly force the n-shaped disc body  753  in sealed contact with the resilient spacer  77 . Even when the supporting body  74  has been worn out, the spring  71  constantly provides an upward resilience that constantly pushes the supporting body  74  upward against the n-shaped disc body  753 . The elastic sleeve  73  is made of elastic material and will be moved with the supporting body  74 . 
     The shaft seal arrangement of a chocolate fountain in accordance with the invention provides an excellent shaft-sealing effect such that the melted chocolate within the basin can be prevented from downward leakage, thereby ensuring a smooth operation of the transmission element as well as a prolonged service life. 
     Many changes and modifications in the above-described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.