Abstract:
A spice or peppercorn grinder including a cylinder body; an L-grooved barrel in the cylinder body; a top cap connected to a pressure drum slidably mounted in the L-grooved barrel, a rotatable ∞-shaped open-end long tube provided in a lower space of the pressure drum and engaged with a screw-shaped long axis assembly provided rotatably in the L-grooved barrel, so that when the ∞-shaped open-end long tube moves downwardly with the pressure drum, the screw-shaped long axis is caused to rotate in a certain direction, the other end of the screw-shaped long axis assembly being provided with a pinion; a compression spring being provided between the seat of the L-grooved barrel and the bottom of the pressure drum; a gear-toothed ring transmission mechanism being provided beneath the L-grooved barrel; a grinding plate assembly being provided on the cylinder bottom and being driven by the gear reduction apparatus to rotate in one direction to grind spices or peppercorns. The peppercorn grinder can be either operated with two hands or operated on a table with a single hand and can grind peppercorns only by pushing down the top cap gently. Moreover, the top cap can be free running of step change with a braking action relative to the pressure drum without interfering with normal operation.

Description:
The present application claims convention priority from Chinese patent applications nos 02204365.9 of Jan. 28, 2002 and 02252556.4 of Sep. 6, 2002. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to grinders, in particular to a spice or peppercorn grinder. 
   2. General Background of the Invention 
   At present, a generally available and commonly used peppercorn grinder is shaped like a long cylinder and require an operator to operate it with two hands. When using the conventional grinder, the operator grasps the cylinder body with one hand while it rotates and presses a top cap of the grinder with the other hand which forces peppercorns stored in the top cap to be pushed against a crushing plate in order to be crushed. 
   A main drawback of the above grinder is its operation requires the operator forcibly to rotate the top cap which is a more laborious work and is not suitable for elderly or weak persons. Further, the said grinder has been designed to be operated by two hands of an operator, which is very inconvenient for a disabled operator who may not be able to operate such a grinder. 
   Therefore, it would be desirable to improve the known spice or peppercorn grinder so that it can be operated with a single hand in an up-and-down pressing manner. Meanwhile, even if people habitually rotate the top cap in a conventional manner, it would be desirable to prevent the connection between the top cap and a pressing cylinder from being broken, since this may damage the peppercorn grinder. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing, an object of the invention is to provide a spice grinder which can be either operated with two hands or operated on a table with a single hand and which allows a user to grind spices or peppercorns simply by repeatedly and gently pushing down a top cap of the grinder, thereby saving labor. 
   Another object of the invention is to provide a labor-saving spice grinder operated by an up-down pressing motion, a top cap of the grinder being capable of free or stepped rotation, so that rotation thereof does not damage the grinder. 
   In order to achieve the above objects, the invention provides a spice grinder comprising:
         a cylinder body with a top and a bottom, a cylinder cap being provided on the top and a cylinder bottom being detachably connected on the bottom; an L-grooved barrel in the cylinder body, the barrel having an L-groove on a side thereof and a stepped hole formed in a bottom thereof, the L-groove having a lower cross groove;   a top cap connected with a pressure drum slidably mounted in the L-grooved barrel, the pressure drum being divided into an upper space and a lower space by a baffle, the lower space being closed by a cover plate, the baffle and the cover plate having a coaxial central through-hole, the pressure drum having a projection on its side, the projection being guided in the L-groove of the L-grooved barrel such that when it follows a rotation of the pressure drum it enters the lower cross groove of the L-groove, thus keeping the pressure drum in position;   a ∞-shaped open-end long tube provided in the lower space of the pressure drum and being able to rotate in the pressure drum and the through-hole of the cover plate, the ∞-shaped open-end long tube having a flange that is upwardly and downwardly moveable in the lower space of the pressure drum such that when it reaches the cover plate of the pressure drum, its rotation is limited by a braking means provided between an upper surface of the flange and a lower surface of the baffle;   a screw-shaped long axis assembly rotatably located in the stepped hole of the L-grooved barrel, a screw-shaped long axis on one end of the screw-shaped long axis assembly being engaged with an internal thread of the ∞-shaped open-end long tube, such that when the ∞-shaped open-end long tube moves downwardly with the pressure drum, the screw-shaped long axis is rotatable in one direction, and when the ∞-shaped open-end long tube moves upwardly with the pressure drum, the ∞-shaped open-end long tube is caused to rotate about the screw-shaped long axis in a reverse direction, an opposed end of the screw-shaped long axis assembly being provided with a pinion;   a compression spring provided between a seat of the L-grooved barrel and a bottom of the pressure drum, the compression spring biasing the pressure drum upwardly;   a gear-toothed ring transmission mechanism provided in the cylinder body and positioned under the L-grooved barrel, the transmission mechanism being connected transmissively with the pinion of the screw-shaped long axis assembly to obtain a driving force of high torsion moment; and   a grinding plate assembly provided on the cylinder bottom, the grinding plate assembly being connected with the gear-toothed ring transmission mechanism and being driven by the gear-toothed ring transmission mechanism to rotate in one direction for grinding spices.       

   In the above-mentioned grinder, it is preferable to provide, between the top cap and the pressure drum, a top cap connecting device which can allow the top cap to rotate freely or in a stepped manner relative to the pressure drum, and thus to provide a braking action. Further, in the context of the use of the term “∞-shaped” herein, the term is used to describe the cross-section of the opening in the L-grooved barrel which receives the screw-shaped long axis for providing relative rotary motion. The actual cross-sections must be complementary to allow for sliding action however, may be varied in cross-section from rectangular to such as curved or bulbous lobes. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the present invention and to show how it may be carried into effect, reference shall now be made by way of example to the accompanying drawings, in which: 
       FIG. 1  is a longitudinal section view of a peppercorn grinder of the invention; 
       FIG. 2  is a front view of the peppercorn grinder of the invention; 
       FIG. 3  is a sectional view of a pressure drum; 
       FIG. 4  is a sectional view of a ∞-shaped open-end long tube; 
       FIG. 5  is a sectional view of an L-grooved barrel; 
       FIG. 6  is a side view of the L-grooved barrel; 
       FIG. 7  is a front view of a screw-shaped long axis; 
       FIG. 8  is a sectional view of a cylinder body; 
       FIG. 9  is a sectional view taken along line  9 — 9  in  FIG. 1 , showing a gear-toothed ring transmission mechanism; 
       FIG. 10  is a top view of the toothed ring; 
       FIG. 11  is an exploded perspective view of a grinding plate assembly; 
       FIG. 12  is a top view of a toothed grinding pan; 
       FIG. 13  is a top view of a screw pressure wheel; 
       FIG. 14  is a side view of the screw pressure wheel; 
       FIG. 15  is a sectional view of a cylinder bottom; 
       FIG. 16  is a sectional view of a top cap connecting device being capable of free running of step change according to an embodiment; 
       FIG. 17  is a top view of a lower cover of the top cap connecting device; 
       FIG. 18  is a sectional view taken along line  18 — 18  of  FIG. 17 ; 
       FIG. 19  is a longitudinal section view of a pressure drum connected with the top cap connecting device; 
       FIG. 20  is a top view of the pressure drum of  FIG. 19 ; 
       FIG. 21  is a plan view of an embodiment of a brake connection wheel for the top cap connecting device; and 
       FIG. 22  is a sectional view taken long line  22 — 22  of FIG.  21 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to FIG.  1  and  FIG. 2 , the main members of the peppercorn grinder according to the invention are shown. The peppercorn grinder comprises a top cap  1 , a pressure drum  2  connected with the top cap  1 , the pressure drum  2  being inserted into a cylinder body  3  provided on its outer surface with a curved portion for comfortable holding by a user, the cylinder body  3  being covered by a cylinder cover  31  and the cylinder body  3  being connected with a cylinder bottom  4  including a grinding plate. To use the grinder, a user first opens the cylinder body  3  and puts peppercorns or other spices into the grinding plate on the cylinder bottom  4 . The cylinder body  3  is then remounted on the cylinder bottom  4  and the user may grind peppercorns or spices through pressing and moving the top cap  1  up and down. The lower part  32  of the cylinder body  3  may be formed as a transparent cylinder wall through which a state of the peppercorns or spices being ground in the cylinder may be observed. 
     FIG. 3  is a sectional view of the pressure drum  2  which has both a lower space  29  and an upper space  23  divided by a baffle  21 , the baffle  21  being provided with a hole  24  that allows a ∞-shaped open-end long tube to be positioned in the lower space  29  and kept in the lower space  29  by a cover plate  25  having a hole  26  that is coaxial with the hole  24 . The baffle  21  is provided with a rib  27  on its bottom surface. A projection  28  is formed on the outer circumference of the bottom of the pressure drum  2 . 
   Referring to  FIG. 4 , the ∞-shaped open-end long tube  7  has a flange  71  near its bottom and the upper surface of the flange  71  is provided with a recess  72  which may match with the rib  27  in the lower space  29  of the pressure drum  2  such that when the ∞-shaped open-end long tube  7  is put in the lower space  29  of the pressure drum  2 , the flange  71  on the ∞-shaped open-end long tube  7  may move up and down in the lower space  29 , and when the flange  71  bears against the bottom surface of the cover plate  25  of the lower space  29 , the rib  27  engages with the recess  72  to limit rotation of the ∞-shaped open-end long tube  7 . The ∞-shaped open-end long tube  7  has a ∞-shaped opening  73 . 
   Referring to FIG.  5  and  FIG. 6 , an L-grooved barrel  99  has on its one side an L-groove comprising a vertical groove  91  and a lower cross groove  92 . There is in the inner bottom of the L-grooved barrel  99  a recess  93  used to store a compression spring  5 . Moreover, the L-grooved barrel  99  has a stepped circular hole  94  at a center of its bottom. When a long axis  81  of a screw-shaped long axis assembly  8  (see  FIG. 7 ) passes through the stepped circular hole  94 , a flange  83  of a connection seat  82  on a tail of the long axis  81  is just positioned on a stepped hole  95  of the stepped circular hole  94  and a pinion  84  on one end of the connection seat  82  emerges from the bottom surface of the L-grooved barrel  9 . 
   Thus, the pressure drum  2  may be mounted on the L-grooved barrel  99 , which has received the spring  5  and the screw-shaped long axis assembly  8 . Then, the long axis  81  of the screw-shaped long axis assembly having passed the L-grooved barrel  99  may be inserted into the ∞-shaped opening  73  of the ∞-shaped open-end long tube  7  (see FIG.  4 ). In addition, the projection  28  on the bottom of the pressure drum  2  can be inserted along the vertical groove  91  of the L-groove in the L-grooved barrel  99 . Therefore, when the top cap  1  is pressed down, the pressure drum  2  will move up and down along the L-grooved barrel  99  and cannot rotate. As for the function of the lower cross groove  92 , it is used when the pressure drum  2  is pressed down and the projection  28  is transferred laterally into the lower cross groove  92  to lock the top cap  1  and the pressure drum  2  in the pressed down position when the grinder is not being used, which may provide space-saving advantages for storage. 
     FIG. 8  is a sectional view of the cylinder body  3  in which a hollow cylinder portion  31  is used to receive the assembled L-grooved barrel  99 . In the bottom of the hollow cylinder portion  31  of the cylinder body  3  there is provided a toothed ring  101  (see FIG.  10 ). Two positioning pins  102  on the bottom of the toothed ring  101  are inserted into two small holes  32  in the bottom of the cylinder body  3  respectively to fix the toothed ring  101  non-rotationally on the cylinder body  3 . A circular hole  103  at the center of the toothed ring  101  is coaxial with a circular hole  33  of the cylinder body  3  and the cylinder body  3  has a curved outer circumference  34 . 
     FIG. 9  is a sectional view taken along the line  9 — 9  of  FIG. 1. A  gear-toothed ring transmission mechanism  10  is shown in FIG.  9 . The gear-toothed ring transmission mechanism  10  includes a toothed ring  101  and a rotary disk  104  rotatably mounted on an inner circumference of the toothed ring  101 . A cylindrical long tube  105  on one side surface of the rotary disk  104  is rotatably provided in the circular hole  103  at the center of the toothed ring  101  and in the circular hole  33  in the bottom of the cylinder body  3 . The cylindrical long tube  105  has an inner hole  106  of a square section. 
   There are three pinions  107  rotatably mounted on a side surface  104  of the rotary disk opposed to the cylindrical long tube  105 . These three pinions  107  on the rotary disk  104  mesh respectively with the internal teeth of the toothed ring and simultaneously mesh together with the pinion  84  of the screw-shaped long axis assembly  8  positioned at the center of the rotary disk  104 . The structure of gear transmission of the peppercorn or spice grinder has been described in the above. 
   Referring again to  FIG. 1 , the lower portion  32  of the cylinder body  3  is connected with the cylinder bottom  4  that is provided with the grinding plate assembly  13 . By lifting the cylinder body  3 , peppercorns or other spices may be put on the grinding plate assembly  13 . 
   Referring to  FIG. 11 , the grinding plate assembly  13  includes a square shaft mandrel  15 , a three-blade iron sheet  16 , a small spring  17 , a toothed grinding pan  181  with symmetric notches, a screw pressure wheel  19  and a locking block  20 . When assembling the grinding plate assembly  13 , firstly the small spring  17  is sleeved on the square shaft mandrel  15 , then the square shaft mandrel  15  is passed through a circular hole at the center of the three-blade iron sheet  16  and the screw pressure wheel  19  is put in the toothed grinding pan  181  with symmetric notches. Next, a threaded end  151  of the square shaft mandrel  15  is inserted in a square hole  191  of the screw pressure wheel  19 . Finally, a locking block  20  is screwed onto the threaded end  151  to prevent the screw pressure wheel  19  from falling out. The grinding plate assembly  13 , after having been assembled, may be mounted in a stepped hole  41  of the cylinder bottom  4  (see FIG.  15 ). On either side of the center of the bottom of the cylinder bottom  4  there is respectively a screw hole  42 . After the grinding plate assembly  13  has been put in the stepped hole  41  of the cylinder bottom  4 , in order to prevent the grinding plate  13  from falling out, each of two screws  21  may be passed through a corresponding opening of an L-shaped iron sheet  220  then screwed in a corresponding screw hole  42  of the cylinder bottom  4  to fix the L-shaped iron sheet  220 . The L-shaped iron sheet  220  has in its center a small recess  221  to support the threaded end  151  of the square shaft mandrel  15 , and thus the grinding plate assembly  13  is fixed and will not be moved horizontally during its rotation which otherwise would decrease the grinding efficiency. Now, the whole structures of both the gear transmission and the grinding plate assembly have been already assembled. 
   When using the peppercorn grinder, one can open the connecting parts of the cylinder body  3  and the cylinder bottom  4 , and put peppercorns on the grinding plate  13  before combining these two parts again together. When the top cap  1  is pressed down, the pressure drum  2  moves downward by means of the projection  28  being guided along the vertical groove  91  of the L-shaped groove on the L-grooved barrel  99  and presses the compression spring  5 , meanwhile the ∞-shaped open-end long tube  7  received in the pressure drum  2  will be under the action of pushing the screw-shaped long axis  8  to cause the flange  71  of the ∞-shaped open-end long tube  7  to move upward and bear against the lower surface of the baffle  21  of the pressure drum  2 , so that the rotation of the ∞-shaped open-end tube  7  is restricted and the screw-shaped long axis  8  can be rotated as the pressure drum  2  continues to be pushed downward. During this rotation, the pinion  81  on one end of the screw-shaped long axis  8  will also be rotated; however, as mentioned above, the pinion  81  meshes together with the three pinions  107  and so drives the three pinions  107  as well as the rotary disk  104  to rotate along the inner wall of the toothed ring  101 . 
   The three pinions  107  drive the long tube with a square inner hole  106  so as to rotate through the rotary disk  104  and to drive the square shaft mandrel  15  in rotation so as to cause the peppercorns or spices to fall into a slot between the toothed grinding pan  181  and the screw pressure wheel  15  and to be crushed under rotation of the screw pressure wheel  19  so the effect of grinding peppercorns or spices can be realised. 
   In the above, the structure of an embodiment of a pressing-type grinder according to the invention has been described. In the structure shown in  FIG. 1 , the connection between the top cap  1  and the pressure drum  2  is fixed so that the top cap  1  cannot rotate relative to the pressure drum  2 . If the top cap  1  is forcibly rotated, the connecting part between the top cap  1  and the pressure drum  2  may be broken or it may damage the inner members of the grinder. 
     FIGS. 16-22  show an embodiment according to the invention wherein, in the connection structure of the top cap, the top cap is capable of free running of step change relative to the pressure drum. Referring to  FIG. 16 , a top cap  100  comprises an upper cap member  101  and a lower cap member  102 , the two members being joined together along their outer circumferences either by means of a mutual fastening or an adhesive. A pressure drum  200  may be rotatably passed through the lower cap member  102  and then connected fixedly with a brake connection wheel  300 . Through the engagement of the brake connection wheel  300  and the lower cap member  102 , the top cap  100  may be free running of step change relative to the pressure drum  200  and have a braking action. The details of the members will be described in the following. 
   FIG.  17  and  FIG. 18  are respectively a longitudinal top view and a sectional view of the lower cap member  102  of the top cap  100 . The bottom of lower cap member  102  has a circular hole  103 , the undersurface of the bottom of the lower cap member  102  is provided with a stepped hole  104  being coaxial with the circular hole  103  and on the inner side surface  105  of the bottom of the lower cap member  102  there is formed a brake ring  106  that is coaxial with the circular hole  103 . On an inner peripheral surface  107  of the brake ring  106  there are formed a plurality of small recesses  108  distributed equidistantly along a circumference. The number of the small recesses is unrestricted according to the invention and is nine, for example, in this embodiment as shown in FIG.  17 . The shape of the section of the portion in the inner peripheral surface  107  between the recesses  108  may be an arc and is preferably a line for improving the brake effect. The brake ring  106  has a top surface  109 . 
   FIG.  19  and  FIG. 20  show respectively a longitudinal section view and a top view of the pressure drum  200  connected with the connection structure of the top cap shown in FIG.  16 . The pressure drum  200  has a flange  202  near the top of the cylinder body  201  and the top of the pressure drum  200  has three cylindrical pins  203  distributed along the circumference equidistantly and projecting upwardly. A circular ring  204  is formed on the upper portion of the flange  202  and a small circular ring  206  with a diameter of its outer peripheral surface  205  being less than that of the circular ring  204  extends upwardly from the circular ring  204 . The small circular ring  206  has a top surface  207 . When the pressure drum  200  penetrates into the circular hole  103  from the bottom of the lower cap member  102 , the flange  202  of the pressure drum  200  bears against the stepped hole  104  of the lower cap member  102 , thus the circular ring  204  may rotatably engage with the circular hole  103  of the lower cap member  102 , the upper surface  208  of the circular ring  204  lies flush with the inner surface  105  of the bottom of the lower cap member  102 , and the top surface  207  of the small circular ring  206  lies flush with the top surface  109  of the brake ring  106  of the lower cap member  102 . 
   FIG.  21  and  FIG. 22  show respectively a plan view and a sectional view of the brake connection wheel  300 . On the circular plate-like connection wheel  300  there are provided three mounting holes  301  distributed circumferentially and equidistantly which are formed to match with the three cylindrical pins  203  on the pressure drum  200  respectively. On the bottom surface  302  of the circular plate-like connection wheel  300  there is provided at least one segmental stub  303 . In this embodiment there are shown three segmental stubs  303  and they are distributed circumferentially and equidistantly between each two of the three mounting holes  301 . Each segmental stub  303  has a central long hole  304  with its inner arc side  305  integrally connecting with the bottom surface  302  of the connection wheel  300  and its outer arc side  306  separating from the bottom  302  of the connection wheel  300  for enhancing the elastic action of the outer arc side  306 . The outer arc side  306  is designed to rotate in cooperation with the inner peripheral surface  107  of the brake ring  106  of the lower cap member  102 . On the outer arc side  306  there is formed a projection  307  which may be snap-fitted with the small recess  108  of the brake ring  106 . 
   Now referring again to  FIG. 16 , the assembling of the connection structure of the top cap is described. The pressure drum  200  penetrates into the circular hole  103  from the bottom of the lower cap member  102 , the flange  202  of the pressure drum  200  bears against the stepped hole  104  of the lower cap cover  102  and the upper surface  208  of the circular ring  204  of the pressure drum  200  lies flush with an inner side surface  105  of the bottom of the lower cap member  102 . The bottom surface  302  of the brake connection wheel  300  is disposed downwardly on the lower cap member  102  to cause each of the cylindrical pins  203  of the pressure drum  200  to insert into a corresponding mounting hole  301  of the connection wheel  300  and the segmental stub  303  of the connection wheel  300  is disposed in the space formed between the inner peripheral surface  107  of the brake ring  106  of the lower cap member  102  and the outer peripheral surface  205  of the small circular ring  206  of the pressure drum  200  to cause the bottom surface  302  of the connection wheel  300  to bear closely against the top surface  109  of the brake ring  106  of the lower cap member  102 . After the assembling process described as above, the lower cap member  102 , the pressure drum  200  and the brake connection wheel  300  will be connected together. The lower cap member  102  may rotate relative to both the pressure drum  200  and the connection wheel  300 . By means of the elastic outer arc side  306  of the segmental stub  303  of the connection wheel  300  as well as the projection  307  on the elastic outer arc side  306  being snap-fitted with the small recess  108  in the brake ring  106  of the lower cap member  102 , a certain brake action may be generated with respect to the relative rotation between the lower cap member  102  and the pressure drum  200 . However, under a forcible action of the external force, the free running of step change will be realised. Thus, it is not only possible to prevent the top cap from arbitrarily unceasingly running free so as to interfere with the operation of grinding, but is also possible to prevent damage from being caused to the grinder due to any inadvertent rotation.