Abstract:
The current invention discloses a food-drying device that includes a container, a drying assembly having a plurality of bores, and a drive mechanism. The drying assembly is disposed in the container and is capable of being rotated relative to the container. The drive mechanism rotates the drying assembly relative to the container. The drive mechanism includes a reciprocating handle movable between a first position and a second position along a linear direction, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion of the drying assembly from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position.

Description:
FIELD OF THE INVENTION 
     This invention relates to food-drying device with drive mechanism, and the related drive mechanism, particularly those for converting reciprocating movement of a user to rotation motion of the object to be driven. 
     BACKGROUND OF THE INVENTION 
     In many cases, it is desirable to dry washed food, for example to avoid making watery salad, and such food-drying devices or salad spinners are known. Typically, such device has a container, in which a drying assembly having a plurality of bores, for example a basket, is disposed. The drying assembly can be rotated relative to the container. A drive mechanism for rotating the drying assembly relative to the container is provided, while the drive mechanism is usually integrated with the cover of the container. The drive mechanism is typically actuated by a handle. 
     Salad spinners in U.S. Pat. No. 5,865,109 and U.S. Pat. No. 7,621,213 have a drive mechanism that includes a reciprocating handle movable along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion of the drying assembly. However, the drive mechanism in these salad spinners only allow movement of the reciprocating handle in one direction to be converted to rotary motion of the drying assembly. That is, force applied by the user in another direction of the reciprocating movement of the reciprocating handle is wasted as such is not converted to rotary motion of the drying assembly. 
     Although the drive mechanism of the salad spinners of U.S. Pat. No. 5,992,309 is able to convert reciprocating movement of the handle to rotary motion of the drying assembly, in fact the user can apply force in one direction of the reciprocating movement. Movement of the handle in another direction of the reciprocating movement only occurs when force is no longer applied. Therefore, the user can only apply force in one direction of the reciprocating movement of the reciprocating handle for conversion to rotary motion of the drying assembly 
     Therefore, there is a need to devise cleverer drive mechanism that can more effectively convert force applied by a user during reciprocating movement of the handle to rotary motion of the drying assembly. 
     Objects of the Invention 
     Therefore, it is an object of this invention to resolve at least one or more of the problems as set forth in the prior art. Particularly, it is an object of the current invention to provide food-drying devices that can more effectively covert force applied by a user during reciprocating movement of the handle to rotary motion of the drying assembly. As a minimum, it is an object of this invention to provide the public with a useful choice. 
     SUMMARY OF THE INVENTION 
     Accordingly, this invention provides a food-drying device including a container; a drying assembly having a plurality of bores, said drying assembly disposed in the container and capable of being rotated relative to the container; and a drive mechanism for rotating the drying assembly relative to the container. The drive mechanism includes a reciprocating handle movable between a first position and a second position along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion of the drying assembly from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position. The conversion mechanism includes a slot assembly having ratchet teeth along two edges defining a slot, said slot assembly being coupled to the reciprocating handle, and said slot having a first end corresponding to the first position, and a second end corresponding to the second position. 
     Preferably, the conversion mechanism includes an output gear being coupled to the drying assembly; a drive gear meshing with the ratchet teeth such that said slot assembly rotates the drive gear between the first end and the second end; and a clutch gear meshing with the drive gear, said clutch gear engaging the output gear when the drive gear is between the first end and the second end, and disengaging the output gear when the drive gear is at the first end or the second end. The ratchet teeth and the drive gear are arranged such that when the reciprocating handle changes direction of movement when the drive gear reaches the first end or the second end, the ratchet teeth can continue to rotate the drive gear, preferably in the same direction. 
     More preferably, at least a portion of the ratchet teeth along the two edges is movable when the drive gear reaches the first end or the second end and is biased to engage the drive gear. Alternatively, the drive gear have flexible gears that mesh with the ratchet teeth, said flexible gears are movable when the drive gear reaches the first end or the second end and are biased to engage the ratchet teeth. 
     Even more preferably, the at least a portion of the ratchet teeth along the two edges is positioned at diagonally opposing ends of the two edges, and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch. Alternatively, entire portion of the ratchet teeth along the two edges is movable and is biased to engage the drive gear as two movable racks, said movable racks having respective pivotal points being positioned diagonally opposing each other along the slot, and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch. 
     Optionally, the drying assembly has an open end opposing a closed end, and the closed end has at least one additional rim to increase weight of the closed end. 
     It is another aspect of this invention to provide a drive mechanism for driving a device, that includes a reciprocating handle movable between a first position and a second position along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position. The conversion mechanism includes
         an output gear;   a slot assembly having ratchet teeth along two edges defining a slot, said slot assembly being coupled to the reciprocating handle, and said slot having a first end corresponding to the first position, and a second end corresponding to the second position;   a drive gear meshing with the ratchet teeth such that said slot assembly rotates the drive gear between the first end and the second end; and   a clutch gear meshing with the drive gear, said clutch gear engaging the output gear when the drive gear is between the first end and the second end, and disengaging the output gear when the drive gear is at the first end or the second end
 
wherein at least a portion of the ratchet teeth along the two edges is movable when the drive gear reaches the first end or the second end and is biased to engage the drive gear.
       

     It is another aspect of this invention to provide a drive mechanism for driving a device that includes a reciprocating handle movable between a first position and a second position along a path, and a conversion mechanism for converting reciprocating movement of the reciprocating handle to rotary motion from force supplied by a user to actuate the reciprocating handle moving from the first position to the second position, and from force supplied by the user to actuate the reciprocating handle moving from the second position to the first position. The conversion mechanism includes
         an output gear;   a slot assembly having ratchet teeth along two edges defining a slot, said slot assembly being coupled to the reciprocating handle, and said slot having a first end corresponding to the first position, and a second end corresponding to the second position;   a drive gear meshing with the ratchet teeth such that said slot assembly rotates the drive gear between the first end and the second end;   a clutch gear meshing with the drive gear, said clutch gear engaging the output gear when the drive gear is between the first end and the second end, and disengaging the output gear when the drive gear is at the first end or the second end
 
wherein the drive gear have flexible gears that mesh with the ratchet teeth, said flexible gears are movable when the drive gear reaches the first end or the second end and are biased to engage the ratchet teeth.
       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the present invention will now be explained by way of example and with reference to the accompanying drawings in which: 
         FIG. 1  shows an exploded view of an exemplary food-drying device of this invention; 
         FIG. 2  shows the enlarged view of the drive mechanism of the food-drying device of  FIG. 1 ; 
         FIG. 3  shows yet another exploded view of the drive mechanism of the food-drying device of  FIG. 1  without showing the reciprocating handle; 
         FIG. 4  shows the arrangement of the slot assembly and the drive gear of the drive mechanism of the food-drying device of  FIG. 1 ; 
         FIG. 5  shows the connection of the drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of this invention; 
         FIGS. 6   a  and  6   b  show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of  FIG. 1  when the slot assembly is at one end point; 
         FIGS. 7   a  and  7   b  show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of  FIG. 1  when the slot assembly is moving out of the end point in  FIG. 6 ; 
         FIG. 8  shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of  FIG. 1  when the slot assembly is approaching the other end point in  FIG. 6 ; 
         FIG. 9  shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of  FIG. 1  when the slot assembly is about to reach the other end point in  FIG. 6 ; 
         FIG. 10  shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of  FIG. 1  when the slot assembly enters the other end point in  FIG. 6 ; 
         FIGS. 11   a  and  11   b  show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of  FIG. 1  when the slot assembly reaches the other end point in  FIG. 6 ; 
         FIG. 12  shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of the food-drying device of  FIG. 1  when the slot assembly is moving out of the other end point in  FIG. 6 ; 
         FIG. 13  shows the exploded view of the drive mechanism of another embodiment of this invention; 
         FIG. 14  shows the exploded view of the drive mechanism of yet another embodiment of this invention; 
         FIG. 15  shows yet another exploded view of the drive mechanism of  FIG. 14  only showing the slot assembly and the drive gear; 
         FIGS. 16   a  and  16   b  show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of  FIGS. 14 and 15  when the slot assembly is at one end point; 
         FIGS. 17   a  and  17   b  show the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of  FIGS. 14 and 15  when the slot assembly is moving out of the end point in  FIG. 16 ; 
         FIG. 18  shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of  FIGS. 14 and 15  when the slot assembly enters the other end point in  FIG. 16 ; 
         FIG. 19  shows the relationship between the slot assembly, drive gear, clutch gear, and output gear of the drive mechanism of  FIGS. 14 and 15  when the slot assembly is moving out of the other end point in  FIG. 16 ; 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     This invention is now described by way of examples with reference to the figures in the following paragraphs. Objects, features, and aspects of the present invention are disclosed in or are apparent from the following description. It is to be understood by one of ordinary skilled in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. List 1 is a list showing the parts and respective reference numerals in the figures. 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 List 1 
               
             
          
           
               
                   
                 Reference numeral 
                 Part name 
               
               
                   
                   
               
               
                   
                 100 
                 Food-drying device 
               
               
                   
                 200 
                 Drive mechanism 
               
               
                   
                 201 
                 Top cover 
               
               
                   
                 202 
                 Reciprocating handle 
               
               
                   
                 204 
                 Fixed frame 
               
               
                   
                 206 
                 Slot assembly 
               
               
                   
                 207 
                 Slot 
               
               
                   
                 208 
                 Ratchet teeth 
               
               
                   
                 208a 
                 Ratchet teeth with reduced pitch 
               
               
                   
                 210 
                 Movable pitch module 
               
               
                   
                 211 
                 Elastic spring plate 
               
               
                   
                 212 
                 Pivot point 
               
               
                   
                 220 
                 Drive gear 
               
               
                   
                 230 
                 Clutch gear 
               
               
                   
                 232 
                 Clutch gear swing slot 
               
               
                   
                 240 
                 Output gear 
               
               
                   
                 270 
                 Drive mechanism bottom cover 
               
               
                   
                 280 
                 Drying assembly connecting plate 
               
               
                   
                 300 
                 Drying assembly 
               
               
                   
                 400 
                 Container 
               
               
                   
                 506 
                 Slot assembly 
               
               
                   
                 508 
                 Movable ratchet teeth rack 
               
               
                   
                 508a 
                 Ratchet teeth with reduced pitch 
               
               
                   
                 511 
                 Coil spring 
               
               
                   
                 512 
                 Pivot point 
               
               
                   
                 606 
                 Slot assembly 
               
               
                   
                 608 
                 Ratchet teeth 
               
               
                   
                 620 
                 Drive gear 
               
               
                   
                 622 
                 Drive gear flexible gear 
               
               
                   
                 624 
                 Drive gear elastic spring plate 
               
               
                   
                 626 
                 Flexible gear swing slot 
               
               
                   
                 628 
                 Flexible gear pivot point 
               
               
                   
                   
               
             
          
         
       
     
     The exploded view of a first exemplary food-drying device  100  of the current invention is shown in  FIG. 1 . The food-drying device  100  has a drive mechanism  200  for rotating the drying assembly  300 , which is in the form of a basket having a plurality of bores in this particular embodiment. The drying assembly  300  is contained in a container  400 . The drive mechanism  200 , the drying assembly  300 , and the container  400  can be in any desire shape, for example the general quadrate shape as shown in  FIG. 1 , or general cylindrical shape. Naturally, the drive mechanism  200 , the drying assembly  300 , and the container  400  should match each other or at least be able to accommodate each other. 
     The reciprocating handle  202  in the exemplary food-drying device  100  in  FIGS. 1 and 2  is able move between a first position and a second position along a path, in this particular example being a linear path. However, this path can be curved as in U.S. Pat. No. 5,865,109 and U.S. Pat. No. 7,621,213 if desired. The design of the reciprocating handle  202  is not important as long as it can be moved linear in a reciprocating manner. The first position and the second position correspond to the two end points of the aperture of the top cover  201 . The reciprocating handle  202  is coupled to a slot assembly  206 , which is actuated by the reciprocating handle  202 . The slot assembly  206  can be actuated to move in the same direction when a user actuates the reciprocating handle  202 , or in the opposite direction if desired, subject to how the slot assembly  206  is coupled to the reciprocating handle  202 . An optional fixed frame  204  is provided in the exemplary food-drying device  100  to limit the slot assembly  206  to move along the path. 
     As shown in  FIGS. 2 and 3 , the slot assembly  206  has ratchet teeth  208  along two edges that define a slot  207 . The slot  207  has a first end that corresponds to the first position, and a second end that corresponds to the second position of the reciprocating handle  202 . As shown in  FIG. 4 , a drive gear  220  meshes with the ratchet teeth  208  in the slot  207  such that when the slot assembly is actuated as the reciprocating handle  202  is actuated, the drive gear  220  is rotated. As shown in  FIG. 5 , a clutch gear  230  meshes with the drive gear  220 , the clutch gear  230  engaging an output gear  240  when the drive gear  220  is between the first end and the second end, and disengaging the output gear  240  when the drive gear  220  is at the first end or the second end by means of the clutch gear swing slot  232  (shown in  FIG. 3 ), as in other clutch mechanisms for converting reciprocating motion to rotatory motion. The output gear  240  is coupled to the drying assembly  300  through the drying assembly connecting plate  280  for rotating the drying assembly  300 . For the convenience of assembly, all components can be assembled on an optional drive mechanism bottom cover  270 . 
     The ratchet teeth  208  and the drive gear  220  are arranged such that when the reciprocating handle  202  changes direction of movement when the drive gear  220  reaches the first end or the second end, the ratchet teeth  208  can continue to rotate the drive gear  220 . Otherwise, the drive gear  220  will be jammed when reaching the first end or the second end during the reciprocating movement. The detail of various arrangements to achieve this will be discussed below. 
       FIG. 4  shows one of such arrangements, in which at least a portion of the ratchet teeth  208  along the two edges is movable when the drive gear  220  reaches the first end or the second end, and is biased to engage the drive gear  220 . In this specific embodiment, the movable portion of the ratchet teeth is in the form of a movable pitch module  210 , which is biased to engage the drive gear  220  by respective elastic spring plates  211  (as shown in  FIG. 3 ), which can be replaced by any suitable biasing means like spring. More specifically, the movable portion of the ratchet teeth  208  along the two edges is positioned at diagonally opposing ends of the two edges, and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch  208   a . It was found that if only ratchet teeth with reduced pitch are provided at the first end or the second end, then drive gear  220  may not be able to be driven by the ratchet teeth smoothly after reaching the first end or the second end during the linear reciprocating movement. 
       FIGS. 6 to 12  show how the arrangement in  FIG. 4  works, in which the relationship between the slot assembly  206 , drive gear  220 , clutch gear  230 , and output gear  240  of the drive mechanism  200  of the food-drying device  100  is shown. In  FIGS. 6   a  and  6   b , the slot assembly  206  is at an upper end point, which can be viewed as the initial position in the sequence in  FIGS. 6 to 12 . As shown in  FIG. 6   b , the clutch gear  230  and output gear  240  are disengaged. In  FIGS. 7   a  and  7   b , when the reciprocating handle  201  is actuated by a user, the slot assembly  206  is caused to be moved out of the end point in  FIG. 6  in a downward direction, and the drive gear  220  is rotated clockwise accordingly. This causes the clutch gear  230  to move about the clutch gear swing slot  232  in a clockwise direction to engage the output gear  240 , such that when the drive gear  220  is rotated, the output gear  240  is also rotated through the clutch gear  230 . In  FIG. 8 , the slot assembly  206  is moved further downward to approach the lower end point, and the slot assembly  206  is about to reach the lower end point in  FIG. 9 . In  FIG. 10 , the slot assembly  206  enters the lower end point in  FIG. 6 , in which the movable pitch module  210  “concedes” or is moved when the drive gear  220  presses against this movable pitch module  210 . This movable pitch module  210  is arranged to pivot such that it only concedes when the drive gear  220  approaches the movable pitch module  210  from a forward direction when the drive gear  220  approaches the first or second end of the slot  207 . On the other hand, when the drive gear  220  approaches the movable pitch module  210  from a backward direction such that when the drive gear  220  is leaving the first or second end of the slot  207 , this movable pitch module  210  remains stationary. More specifically, the movable pitch module  210  pivots about a pivot point  212  (as shown in  FIG. 3 ) that is distant from the first or second end of the slot  207  and in proximity to the slot  207 . In  FIGS. 11   a  and  11   b , the slot assembly  206  reaches the lower end point, in which the movable pitch module  210  “retracts” or returns to its normal position as the drive gear  220  approaches the end of the slot  207 . As shown in  FIG. 11   b , the clutch gear  230  and output gear  240  are disengaged as the clutch gear  230  is moved in an anti-clockwise direction by the output gear  240  as the drive gear  220  does not drive at this end point. In  FIG. 12 , the slot assembly  206  is moving out of the lower end point by changing the direction of the linear motion. The cycle in  FIGS. 6 to 12  then repeats in a reversed direction. 
     The drive gear  220  does not have full set of teeth to mesh with the slot assembly  206 , but only half set of teeth. This allows the teeth of the drive gear  220  to engage with one of the racks in the slot  207  except at the first end and the second end. 
     It will be noted in  FIGS. 6 to 12  that the movable pitch module  210  is biased to engage the drive gear  220  at all times. 
       FIG. 13  shows another arrangement alternative to that shown in  FIGS. 4 to 12 . The components in  FIG. 13  that are the same as those in  FIGS. 4 to 12  are indicated by the same reference numbers. In this embodiment, entire portion of the ratchet teeth along the two edges of the slot assembly  506  is movable and is biased to engage the drive gear as two movable racks  508 . The movable racks  508  having respective pivotal points  512  being positioned diagonally opposing each other along the slot  207 , and the ratchet teeth at other diagonally opposing ends of the two edges have reduced pitch  508   a . In the particular example in  FIG. 13 , the movable racks  508  are biased by coil springs  511  positioned at the other end of the pivot point  512 . This alternative embodiment works in a manner similar to that shown in  FIGS. 4 to 12 . 
       FIGS. 14 and 15  show yet another arrangement alternative to those shown in  FIGS. 4 to 13 . The components in  FIGS. 14 and 15  that are the same as those in  FIGS. 4 to 13  are indicated by the same reference numbers. In this embodiment, the ratchet teeth  608  along the two edges of the slot  607  of the slot assembly  606  are not movable, and have no ratchet teeth with reduced pitch. Instead, the drive gear  620  has flexible gears, in this example being two sets of flexible gears  622  that mesh with the ratchet teeth  608 . The two sets of flexible gears  622  are movable when the drive gear  620  reaches the first end or the second end, and are biased to engage the ratchet teeth  608  by drive gear elastic spring plate  624 . The flexible gears  622  pivot about flexible gear pivot points  628  and within the flexible gear swing slots  626 . The flexible gear pivot point  628  and the flexible gear swing slot  626  of each set of one set of flexible gears  622  are positioned diagonally opposing the other respective flexible gear pivot point  628  and the flexible gear swing slot  626  of the other set of flexible gears  622 . 
       FIGS. 16 to 18  show how the arrangement in  FIGS. 14 and 15  works, in which the relationship between the slot assembly  606 , drive gear  620 , clutch gear  230 , and output gear  240  is shown. In  FIGS. 16   a  and  16   b , the slot assembly  206  is at one upper end point, which can be viewed as the initial position in the sequence in  FIGS. 16 to 18 . As shown in  FIG. 16   b , the clutch gear  230  and output gear  240  are disengaged. In  FIGS. 17   a  and  17   b , when the reciprocating handle  201  is actuated by a user, the slot assembly  606  is caused to be moved out of the end point in  FIG. 16  in a downward direction, and the drive gear  620  is rotated clockwise accordingly. This causes the clutch gear  230  to move about the clutch gear swing slot  232  in a clockwise direction to engage the output gear  240 , such that when the drive gear  220  is rotated, the output gear  240  is also rotated through the clutch gear  230 . In  FIG. 17   a , the slot assembly  606  is about to leave the upper end point and is going to move downward, the flexible gears  622  “concede” or are moved when the ratchet teeth  608  presses against the flexible gears  622 . The flexible gears  622  are arranged to pivot such that they always face the end of the slot  607  that they will be approaching. In  FIG. 18 , the slot assembly  606  is about to reach the lower end point, in which the flexible gears  622  again “concede” or are moved when the ratchet teeth  608  presses against the flexible gears  622 . In  FIG. 19 , the slot assembly  606  reaches the lower end point when the direction of the motion along the linear path is about to be changed. The cycle in  FIGS. 16 to 19  then repeats in a reversed direction. 
     As shown above, various arrangements of the current invention effectively convert force applied by a user in both directions of the reciprocating motion of the handle to rotation motion of the drying assembly, thereby enhancing the conversion efficiency and the performance of the food-drying device. 
     Further, salad spinners give little or no consideration to the design of the drying assembly. It was found that adding extra mass round the rim at the bottom of the drying assembly can enhance the stability of the operation. That is, the closed end of the drying assembly prefers to have at least one additional rim  302  to increase weight of the closed end to enhance performance of the salad spinners. 
     While the preferred embodiment of the present invention has been described in detail by the examples, it is apparent that modifications and adaptations of the present invention will occur to those skilled in the art. Furthermore, the embodiments of the present invention shall not be interpreted to be restricted by the examples or figures only. It is to be expressly understood, however, that such modifications and adaptations are within the scope of the present invention, as set forth in the following claims. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the claims and their equivalents.