Abstract:
The rotary shaft of a juicer motor is braked by engaging an arch-shaped braking piece against the peripheral sidewall of a circular block that is mounted on the rotary shaft exteriorly of the motor shell for simultaneous rotation with the rotary shaft.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to juicers, and more particularly to a juicer having a brake. 
   2. Description of the Related Art 
   Referring to  FIGS. 5–7 , a conventional fruit and vegetable juicer  90  is comprised of a housing base  91 , a motor  92 , a razor (not shown), a cooling fan  94 , a rotary shaft  93 , a linkage  95 , a spring  98 , and an actuating bar  99 . The motor  92  is mounted inside the housing base  91 . The rotary shaft  93  is connected with the razor (not shown) and the cooling fan  94 , having two ends extending outwards. The linkage  95  is pivotally mounted at a bottom side of the motor  92  for pivotal movement between a first position and a second position, having a brake  96  extending into the motor  92  and a braking piece  97  mounted on the brake  96  and approaching the rotary shaft  93 . When the linkage  95  is moved to the second position, the braking piece  97  works on the rotary shaft  93 . The spring  98  is mounted between the linkage  95  and the motor  92  for generating resilience, which drives the linkage  95  to pivot towards the second position. The actuating bar  99  is pivotally mounted on the housing base  91 , having an end  991  either engaging a side of the linkage  95  to keep the linkage  95  at the first position or being moved away from the linkage  95  to enable the spring  99  to drive the linkage  95  to move to the second position where the braking piece  97  works on the rotary shaft  93  of the motor  92  to stop the rotation of the rotary shaft  93 . 
   However, because the current juicer is gradually structurally miniaturized and its motor is gradually upgraded to a high-power motor, the linkage  95  of the aforementioned juicer  90  takes much more time to frictionally stop the rotary shaft  93 , thereby failing to effectively brake the high-power motor  92 . 
   SUMMARY OF THE INVENTION 
   The primary objective of the present invention is to provide an improved juicer, which can quickly stop the rotation of a rotary shaft of its motor. 
   The foregoing objective of the present invention is attained by the improved juicer, which is comprised of a housing base, a motor, a circular block, a linkage, a springy member, and an actuating member. The housing base includes a space inside and at least one pivoting seat located in the space. The motor is mounted inside the space of the housing base, having a shell and a rotary shaft, which has two ends running respectively through a top side and a bottom side of the shell. The circular block has an axial hole for running through by the rotary shaft. The linkage is pivotably mounted on the bottom side of the shell of the motor for pivotal movement between a first position and a second position, having a braking piece and a driven portion. The braking piece is located at a side of the linkage for frictionally engaging against the circular block while the linkage is located at the second position. The springy member has two ends connected respectively with the linkage and the shell of the motor for generating resilience that drives the linkage to move towards the second position. The actuating member includes a driving bar extending into the shell of the motor and located on the pivoting seat for pushing against the driven portion of the linkage to keep the linkage at the first position, and is pivotable relatively to the shell of the motor for disengaging the driving bar away from the driven portion. Therefore, the linkage can be moved to the second position by the resilience of the springy member to brake the rotary shaft of the motor. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a first preferred embodiment of the present invention having its bottom side facing upwards. 
       FIG. 2  is a bottom view of the first preferred embodiment of the present invention, showing that the actuating member is located at the first position. 
       FIG. 3  is similar to  FIG. 2 , showing that the actuating member is located at the second position. 
       FIG. 4  is an exploded view of a second preferred embodiment of the present invention having its bottom side facing upwards. 
       FIG. 5  is an exploded view of a second preferred embodiment of the present invention having its bottom side facing upwards. 
       FIG. 6  is a bottom view of the conventional juicer. 
       FIG. 7  is a side view of the conventional juicer. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a juicer  1  constructed according to a first preferred embodiment of the present invention is comprised of a housing base  10 , a motor  20 , a circular block  30 , a linkage  40 , a springy member  50 , a cooling fan  60 , and an actuating member  70 . 
   The housing base  10  is provided inside with a space  11  and two pivoting seats  111  located inside the space  11 . 
   The motor  20  includes a shell  21  fastened to the housing base  10  inside the space  11  and located between the two pivoting seats  111 , a rotary shaft  22  having two ends running through a top side and a bottom side  211  of the shell  21 , a hook-like first lug  212  and a hook-like retaining member  213  formed respectively at two peripheral edges of the bottom side  211 , and a sleeve portion  221  formed on the rotary shaft  22  and having a non-circular cross-section. 
   The circular block  30  includes an annular sidewall and an axial hole  31 , which has a cross-section corresponding to that of the sleeve portion  221 , being fitted onto the sleeve portion  221  of the rotary shaft  22  through the axial hole  31 , such that the circular block  30  is synchronously rotatable with the rotary shaft  22 . 
   Referring to  FIGS. 2 and 3 , the linkage  40  is embodied as a sheety member, including an arched portion  41  recessed inwards from a side thereof and corresponding to the annular sidewall of the circular block  30  in shape, a corresponding arched braking piece  412  mounted on the arched portion  41  and facing the sidewall of the circular block  30 , a pivot hole  43  formed at an end thereof, a driven portion  44  formed at the other end thereof, and a second lug  45  protruded at a side thereof. The linkage  40  is pivotally mounted to the bottom side  211  of the shell  21  of the motor  20  by bolt  46  inserted through the pivot hole  43  so as to pivot between a first position ( FIG. 2 ) and a second position ( FIG. 3 ). When the linkage  40  is located at the second position, the braking piece  42  is moved to frictionally engage against the peripheral sidewall of the circular block  30 . In addition, the linkage  40  is located between the retaining member  213  and the bottom side  211  of the shell  21 . 
   The springy member  50  is embodied as an extension spring, having two ends connected respectively with the second lug  45  of the linkage  40  and the first lug  212  of the shell  21 , for generating resilience that drives the linkage  40  to pivot towards the second position. 
   Referring to  FIG. 1  again, the cooling fan  60  is fastened to a free end of the rotary shaft  22  and located outside the circular block  30  for dissipating the heat generated in the motor  20 . 
   The actuating member  70  is embodied as a U-shaped bar having two distal ends  71  and  72  extending respectively into the housing base  10  and is pivotally mounted to the pivoting seats  111  for pivotal movement relatively to the housing base  10 . The actuating member  70  includes a driving portion  73  perpendicularly extending from one distal end  71  thereof for pushing the driven portion  44  of the linkage  40  upon the pivotal movement of the actuating member  70  to further drive the linkage  40  to be either securely positioned at the first position or away from the driven portion  44  to pivot to the second position by the springy member  50 . 
   The operation for the juicer  1  of the present invention is recited below. When the driving portion  73  of the actuating member  70  is moved to contact against the driven portion  44  of the linkage  40 , the linkage  49  is securely positioned at the first position and the braking piece  42  keeps spaced from the circular block  30 ; meanwhile, the circular block  30  is rotated synchronously with the rotary shaft  22 . As soon as the driving portion  73  is moved away from the driven portion  44 , the resilience of the springy member  50  drives the linkage  40  to be located at the second position, and the braking piece  42  frictionally engages against the circular block  30  in rotation, thereby braking and quickly stopping the rotary shaft  22  from rotation. 
   Therefore, in comparison with the conventional juicer, the circular block  30  has larger braking area for the braking piece  42  than the rotary shaft  22  in the present invention to enhance the friction and actuation between the braking piece  42  and the circular block  30 , thereby stopping the rotation of the motor  20 . 
   In addition, the retaining member  213  prevents the linkage  40  from one end thereof turnup or disengagement from the normal pivoting range. In other words, the braking piece  42  can securely contact against the circular block  30  to prevent the juicer  1  from brake failure. 
   Referring to  FIG. 4 , the juicer  2  constructed according to a second preferred embodiment of the present invention is similar to the first preferred embodiment but different by that the circular block  80  and the cooling fan  81  are formed in one piece by injection molding, thereby shortening the assembly time of the juicer  2  and further reducing the production cost of the same.