Abstract:
A juicer includes a linkage assembly operated with a pusher and a trigger assembly for allowing power to be supplied to motor. The linkage assembly includes a pressure component set in the end of the opening of feed tube. The pressure component is connected with a follower lever, the follower lever installed in the inside of the feed tube an be moved up and down. The trigger assembly includes some signal generators installed in the bottom of the follower lever and some inductors installed in juicer base are corresponded to the signal generators. The inductors are connected electrically with motors control circuit. The present invention avoids trouble from lengthy wires in circuit connection and shortens running length of the trigger assembly and lowers cost and machining accuracy.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a juicer. 
         [0002]    Nowadays, juicers on sale generally include a safety mechanism which is used to enlarge the opening size of the feed tube. When user puts away pusher, the safety mechanism can shut off motor power and the cutter of juicer can be stopped as well, so it will be more safety for user. In general way, some safety mechanisms include a micro switch set in the base and a trigger assembly set in container or feed tube. Because of fatigue wear of mechanical structure, it will happen that the micro switch can not be triggered after pusher is inserted into the feed tube. On the other side, the gap between micro switch and trigger assembly will be increased due to long time friction, it will influence the normal using. In addition, the running length of micro switch is so short, so that the accuracy of trigger assembly is needed to be high, indirectly, it will increase the cost of juicer. For example, Chinese patent whose published NO. is CN200980565Y discloses a safety mechanism of vegetable-fruit machine characterized that a magnetic switch is set inside the feed tube, the magnetic switch is connected electrically to motor, a magnetic driving unit is set in the pusher, when the pusher is inserted into the feed tube, the magnetic switch receives the signal of the magnetic driving unit so that the power is on, oppositely, power will be off due to the pusher is gotten away from the feed tube. But there is a defect in above patent, because of the magnetic switch is set on the top of the feed tube, it needs some long wires for the connection of the switch and circuit board or power outlet, so the wires are so complicated and bad for assembly, that the cost will be higher. Meanwhile, the patent has another embodiment whose switch is micro switch connected to elastic assembly. And the driving unit has a protruding part protruded outside the feed tube. The protruding part will move the micro switch to turn on power after the pusher is inserted into the feed tube. That will be related to the matter of reliability and service life. There is a kind of technology about juicer&#39;s safety mechanism illustrated that a magnetic switch is set in base and a magnetic matters are set in big feed tube and pusher. When the pusher has been installed, the magnetic matter will trigger the magnetic switch for power on. Even if the above design can remove the connected complication of wire, but if the pusher has not been installed yet, when outside magnetic matter closed the big feed tube to be outside interference, which will turn on the magnetic switch for motor on, so it is dangerous for the above wrong running existing in juicer. 
       BRIEF SUMMARY OF THE INVENTION 
       [0003]    An object of the present invention is to settle shortages of the existing technology, to provide a juicer which can be more reliable and safer. 
         [0004]    A juicer, include a base, a motor, a cover, a pusher, a linkage assembly and a trigger assembly. The base defines a receiving cave therein for receiving a cutter and food to be processed. The motor is used for driving the cutter. The cover is fixed on the base, a feed tube extendes upwardly from the cover and acting as an entrance for the food. The pusher is configured to be inserted into the feed tube to push the food into the receiving cave. The linkage assembly is configured at the feed tube. The trigger assembly is connected to the linkage assembly and configured for generating a trigger signal to start the motor. The linkage assembly includes a pressure component and a follower lever. The pressure component is movable connected to the feed tube and close the opening of the feed tube; the follower lever is rotatably connected to the pressure component, and can be moved up and down; the trigger assembly includes two or more signal generators connected to the end of the follower lever and three or more inductors configured at the base; at least one weakest area of signal exist between the two or more signal generators, and the three or more inductors are placed face to face with the two or more signal generators and the at least one weakest area, respectively; the three or more inductors are connected electrically with the motor&#39;s control circuit. 
         [0005]    Preferably, the pressure component includes a first link and a second link, a terminal of the first link is rotatably connected to the feed tube, the other terminal of the first link is rotatably connected to a terminal of the second link, the other terminal of the second link is rotatably connected to the follower lever, the side wall of the feed tube defines a hole which is right against the connection joint between the first link and the second link, the connection joint extends into the inside of the feed tube, and can be moved downwardly by the pusher when the pusher is inserted in the feed tube; when the connection joint is moved downwardly the follower lever is pushed by the second link to move downwardly accordingly. 
         [0006]    Preferably, an elastic element is set between the follower lever and the cover in order to lift the follower lever upwardly when the pusher is removed from the feed tube. 
         [0007]    Preferably, the elastic element is spring which is depressed between the follower lever and the cover. 
         [0008]    Preferably, the inductors are magnetic sensors, the signal generators are magnets. 
         [0009]    Preferably, the magnets are placed side by side at a distance, a weakest area of signal exists between the magnets, the magnetic sensors are placed face to face with the magnets and the weakest area of signal, respectively. 
         [0010]    Preferably, the magnetic sensors are magnetic reed switches. 
         [0011]    Preferably, the inductors is configured inside or outside the base. 
         [0012]    Comparing with the conventional juicer, the invention has the following advantages: 
         [0013]    (1) It can avoid the trouble of linkage complication of wires due to the non-contact trigger unit of magnetic switches and inductors. So that it lowers the trigger unit&#39;s running length and lowers machining precision and lowers the cost of production. 
         [0014]    (2) It can avoid the wrong running of juicer by outside magnetic matters, because of it utilizes the magnetic inductors and the magnet to form switch to control motors driving. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective view of a juicer in according to a first embodiment of the present invention. 
           [0016]      FIG. 2  is an enlarged view of A of  FIG. 1 . 
           [0017]      FIG. 3  is a diagram of inductors and magnet units in according to the first embodiment of the present invention, three inductors sit against two magnets and the weakness area “O” between the two magnets. 
           [0018]      FIG. 4  is a cross-sectional view of a part of the juicer of  FIG. 1 , the pusher is not inserted into the feed tube and the signal generators does not been triggered by the inductors in according to the first embodiment 
           [0019]      FIG. 5  is an enlarged view of B of  FIG. 4 . 
           [0020]      FIG. 6  is a cross-sectional view of a part of the juicer of  FIG. 1 , the pusher is inserted into the feed tube and the signal generators has been triggered by the inductors in according to the first embodiment 
           [0021]      FIG. 7  is a cross-sectional view of a part of a juicer in according to a second embodiment of the present invention, a pusher is not inserted into a feed tube and a signal generators is not been triggered by the inductors. 
           [0022]      FIG. 8  is another cross-sectional view of the part of the juicer of  FIG. 7 , the pusher has been inserted into the feed tube and the signal generators has been triggered by the inductors in according to the second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    Embodiments of the present invention will be described in detail below, with reference to the accompanying drawings. 
       Embodiment I 
       [0024]    Referring to  FIG. 1 , a juicer in according to a first embodiment of the present invention mainly includes a base  6  and a cover  7  fixed on the base  6 . A feed tube  71  is configured on the cover  7 . A pusher  1  matched the feed tube  71  is removable inserted in the feed tube. A cutter (not shown in the view) is set in the base and under the feed tube  71 . The same to the conventional juicers, the cutter is driven by a motor which is controlled by a control circuit. 
         [0025]    Referring to  FIG. 2  to  FIG. 4 , the juicer also includes a linkage assembly  2  and a trigger assembly  3  connected to the end of the linkage assembly  2  The trigger assembly  3  is configured for generating trigger signals for the motor. 
         [0026]    The linkage assembly  2  is configured at the outside wall of the feed tube  71  and the cover  7 . In detail, the linkage assembly  2  is settled in a case  8  attached to the outside wall of the feed tube  71  and the up-surface of the cover  7 . 
         [0027]    The linkage assembly  2  includes a pressure component  21 , a follower lever  22  and an elastic element  23 . Referring also to  FIG. 5 , the pressure component  21  includes a first link  211  and a second link  212 . A terminal of the first link  211  is removable connected to the inside wall of the case  8 . The other terminal of the first link  211  is rotatably connected to a terminal of the second link  212  via a hinge joint. The other terminal of the second link  212  is rotatably connected to the follower lever  22  via a hinge joint. The side wall  711  of the feed tube  71  defines a hole  712  which is right against the connection joint  213  between the first link  211  and the second link  212 . In the embodiment, the hole  712  is close to the opening  71  of the feed tube  71 . The connection joint  213  extends into the inside of the feed tube  71 , and can be moved downwardly by the pusher  1  when the pusher  1  is inserted in the feed tube  71 . When the connection joint  213  is moved downwardly the follower lever  22  is pushed by the second link  212  to move downwardly accordingly. 
         [0028]    The follower lever  22  is substantially L-shaped, it includes a first part which is connected to the end of the pressure component  21  and can move up and down along the outside wail of the feed tube  71 , and a second part which extends perpendicularly from the end of the first part and is substantially parallel to the up-surface of the cover  1 . 
         [0029]    The elastic element  23  sits between the end of the first part of the follower lever  22  and the up-surface of the cover  7 , and is depressed by the follower lever  22 . When the pusher  1  is removed from the feed tube  71 , the elastic element  23  lift up the follower lever  22  and let the connection joint  213  stay in the top of the hole  712  (see  FIG. 5 ). When the pusher  1  is inserted in the feed tube  71 , the follower lever  22  moves downwardly, the elastic element  23  is further compressed, and the connection joint  213  stays in a lower space of the hole  712  (see  FIG. 6 ). 
         [0030]    The trigger assembly  3  includes a signal generator  31  connected to the end of the linkage assembly  2  and a signal receiver  32  configured at the base  6 . The signal generator  31  moves along the follower lever  22 . When the follower lever  22  moves to the lowest point, the signal receiver  32  can receive the signal sent from the signal generator  31 . When the follower lever  22  moves upwardly from the lowest point to a preset level, the signal receiver  32  can not receive the signal sent from the signal generator  31 . When the signal receiver  32  receives the signal from the signal generator  31 , the signal receiver  32  will generate and send a trigger signal to the control circuit to start the motor, such that the motor operates to drive the cutter of the juicers to rotate. 
         [0031]    In the embodiment, the signal generator  31  includes a first magnet  311  and a second magnet  312 , and the signal receiver  32  includes three magnetic sensors  321 ,  322 ,  323  as inductors. The first and second magnets  311 ,  312  are straight bars and parallel with each other. Furthermore, the first and second magnets  311 ,  312  are placed in opposite polarity and have a certain distance between each other, thus that there is a weakest area “O” existing between the first and second magnets  311 ,  312 , and the magnet force in the weakest area “O” is nearly zero. 
         [0032]    The three magnetic sensors  321 ,  322 ,  323  are connected electrically with the motor&#39;s control circuit. The three magnetic sensors  321 ,  322 ,  323  are configured right against the ends of the first and second magnets  311 , 312  and the weakest area O, thus that when the signal generator  31  is lowered to a predetermined height, the magnetic sensors  321 ,  322  can senses the magnetic force from the first and second magnets  311 ,  312 . In the embodiment, the magnetic sensors  321 ,  322 ,  323  are a first magnetic reed switch, a second magnetic reed switch and a third magnetic reed switch, respectively. 
         [0033]    When the follower lever  22  moves down to a preset position, the magnet unit  31  enters the induction area of the signal receiver  32 . The first magnetic reed switch  321  and the second magnetic reed switch  322  detect the magnetic force (in other words, receive signals from the first and second magnets  311 ,  312 ) of the first and second magnets  311   312  respectively, while the third magnetic reed switch  323  dose not receive any signal from the weakest area “O”. The magnetic sensors  321 ,  322  generate predetermined electrical signals accordingly, and the control circuit starts the motor. On the other hand, electronic system of the juicer should preset that only when receiving the above signal condition, the signal receiver  32  will let power on to achieve the motor running. 
         [0034]    When the follower lever  22  moves up and the magnet unit  31  leaves the induction area of the signal receiver  32 , the first, second and third magnetic reed switches  321   322 ,  323  can not detect the magnetic force (in other words, do not receive signals) of the first and second magnets  311 ,  312 . There is no predetermined electrical signals output from the signal receiver  32 , and the control circuit will not start the motor. 
         [0035]    When there are interference signals, thus as a magnet comes close to the juicer (when the pusher  1  has not been inserted into the feed tube  71 ), one or two or all of the magnetic sensors  321 ,  322 ,  323  will detect the magnetic force from the magnet and generate electrical signals accordingly. Because a interference signal that causes the magnetic sensors  321  and  322  generate electrical signals at the same time with the magnetic sensor  323  does not rarely exists, it means it will not reach the preset signal condition for the control circuit to start the motor. So it can avoid the wrong running of juicer by outside magnetic matters and make the juicer be safer. 
       Embodiment II 
       [0036]    Referring to  FIG. 7  to  FIG. 8 , embodiment II is similar to Embodiment I on structure. But it&#39;s different from the position of the trigger assembly  3 . In the Embodiment I, the inductors  31  and the signal receiver  32  are installed outside the base  6  and the cover  7  of the juicer. However, in the Embodiment II, the signal receiver  32  is installed inside the base  6  and below the cutter. The follower lever  22  moves the magnet unit  31  downward as long as reaching the induction area, the signal receiver  32  senses signal from the magnet unit  31  so that the control circuit is power on and the motor and cutter run. The above design is aimed at avoiding magnetic signal interference outside. Via setting the signal receiver  32  inside the base and because of effective barrier by the housing and other parts of the juicer, any outside magnetic matters could not close the signal receiver  32  so that the invention can be effective to prevent wrong motor start from magnetic signal interference outside and to be safer for users. 
         [0037]    The above statement represents a typical operation of the invention. The invention should not be limited within the scope of the above detailed statement only. It will be appreciated that various modifications may be made to the embodiments described above. To the person skilled in the art, other changes and modifications which are based on this invention could be made, such as to change the number or the shape or the type (photosensor or thermistors or electromagnetic wave etc.) of the signal generator and inductor. The idea of this invention and the above stated possibilities shall all be protected under this patent application.