Abstract:
A cartridge includes a base, a tray and a latching element. The base has a boss. The tray is slidably mounted on the base. The base has a cartridge spring corresponding to the tray. The cartridge spring provides the tray a resilient force. The latching element has an eccentric hole that receives the boss of the base. A spring connects the latching element to the base so that the latching element can secure the tray to the base or release the tray from the base. It enhances the retaining of the tray so that even when the cartridge is impacted by an external force, the tray can still be kept closed. The cartridge of the invention provides advantages such as being highly stable, having fewer components, is easy to assemble, and costs less than prior art models.

Description:
BACKGROUND OF THE PRESENT INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a cartridge, and more particularly to a cartridge that does not tend to open when subjected to an external impact, and therefore has improved stability. 
     2. Description of the Related Art 
     A conventional cartridge, such as Taiwan Patent No. 307148 published on Jun. 1, 1997, discloses an automatic drawer that includes a tray and a handle. The tray has a track piece and a lid engaged with the track piece. The track piece has a track rail with a recess. A block comes to be embedded in the lid by the sliding movement of a resilient element which is mounted between the lid and the block. The handle has a swinging arm which has a sliding rod. By means of securely mounting the tray in a desk, the handle is securely mounted opposite to the drawer and extends into the tray. After the drawer is pushed, the sliding rod first moves along the track rails of the tray and is then positioned in the recess of the track rail so that the drawer can be opened. When the drawer is pushed again, the sliding rod moves out of the recess and withdraws from the track rail so that the drawer can be closed. 
     However, when the conventional drawer is pushed a first time, the tray cannot be held securely and can be accidentally opened. Specifically, when the drawer is subject to an external impact, the drawer tends to open, resulting in poor stability. Besides, the conventional drawer needs significant number of components, which translates to increased costs and labor. 
     SUMMARY OF THE INVENTION 
     One object of the invention is to provide a cartridge that can securely hold a tray even when the cartridge is impacted by an external force, and therefore has improved stability. 
     Another object of the invention is to provide a cartridge that has fewer components, is easy to assemble and therefore costs less. 
     In order to achieve the above and other objectives, the cartridge of the invention includes a base, a tray, and a latching element. The base has a boss. The tray is slidably mounted on the base. The base has a cartridge spring corresponding to the tray. The cartridge spring provides the tray a resilient force. The latching element has an eccentric hole that receives the boss of the base. A spring connects the latching element to the base so that the latching element can secure the tray to the base or release the tray from the base. It enhances the retaining of the tray so that even when the cartridge is impacted by an external force, the tray can still be kept in a closed status when not being used. The cartridge of the invention provides advantages such as high stability, fewer components, and fast and ease of assembly with an overall lower cost. 
     To provide a further understanding of the present invention, the following detailed description illustrates embodiments and examples of the present invention, this detailed description being provided only for illustration of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a cartridge according to one embodiment of the invention; 
         FIG. 2  is a perspective exploded view of a cartridge according to one embodiment of the invention; 
         FIG. 2A  is a detailed perspective view of a boss in a cartridge according to one embodiment of the invention; 
         FIG. 3  is a perspective view of a latching element according to one embodiment of the invention; 
         FIG. 4  is a perspective view of a latching element according to one embodiment of the invention taken from a different angle of view from  FIG. 3 ; 
         FIG. 5  is a schematic view of a first action of operation according to one embodiment of the invention; 
         FIG. 6  is a schematic view of a second action of operation according to one embodiment of the invention; 
         FIG. 7  is a schematic view of a third action of operation according to one embodiment of the invention; 
         FIG. 8  is a schematic view of a fourth action of operation according to one embodiment of the invention; 
         FIG. 9  is a schematic view of a fifth action of operation according to one embodiment of the invention; 
         FIG. 10  is a schematic view of a sixth action of operation according to one embodiment of the invention; and 
         FIG. 11  is a schematic view of a seventh action of operation according to one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Wherever possible in the following description, like reference numerals will refer to like elements and parts unless otherwise illustrated. 
     Referring to  FIG. 1  through  FIG. 4 , the cartridge of the invention includes a base  10 , a tray  20 , and a latching element  30 . 
     The base  10  can be a base provided with at least one tray  20 , for example a work desk, a multi-functional processor, or a printer. In a case in which the base  10  is a multi-functional processor, a spring receiver  11  is formed inside the base  10  opposite to the tray  20 . An opening  111  is formed at a front end of the spring receiver  11  to communicate with the interior of the spring receiver  11 . The spring receiver  11  further has a cartridge spring  12 . 
     The base  10  has a column-shaped boss protruded from the base  10 . A slot is formed around the boss  13 . On a top of the boss  13  is formed a recess  131  which has a protrusion  132  with a slanting top surface  133 . The base  10  further has a retainer  15  having a round-profile fixing hole  151 . 
     The tray  20  can be a drawer or a paper box. In one embodiment of the invention, the tray  20  is a paper box for holding paper. The tray  20  is disposed on the base  10  in a manner in which the tray  20  is able to slide back and forth along the base  10 . A rib  21  protrudes from a rear of the tray  20  in a manner to correspond to the cartridge spring  12  so that the rib  21  is allowed to penetrate through the opening  111  of the spring receiver  11  to stretch into the spring receiver  11  and push against the cartridge spring  12 . The cartridge spring  12  applies a forward force to the tray  20 . 
     A first rib  22  and a second rib  23  are configured to protrude from a bottom of the tray  20 , spaced away from each other at a distance. The first rib  22  is an L-shape and has a propping part  221  corresponding to the latching element  30 . The second rib  23  has a bent part  231  extending along the first rib  22 . The bent part  231  has a hook  232  protruding there from. 
     The latching element  30  has a free front end and a resilient hooking part  31  extending from the free front end. The latching element  30  further includes a stopper  32  and a ring part  33 . The stopper  32  has a triangle shape and is connected to one side of the latching element  30 . A guiding face  321  extends from the stopper  32  toward the resilient hooking part  31  at a certain angle from the direction of the resilient hooking part  31 . The ring part  33  has a substantially ellipse shape, and is connected to the latching element  30  at the opposite side to the stopper  32 . The ring part  33  has an eccentric hole  331  on an interior of which a flange  332  is formed. When the eccentric hole  331  receives the boss  13 , the flange  332  comes to abut against the boss  13  so that the latching element  30  is pivotally connected to and rotated against base  10 . A slanting face  333  is formed on a bottom of the flange  332  to correspond to the slanting top surface  133 . 
     An L-shaped leg  34  extends from a bottom of the ring part  33 . The leg  34  has a round-profile fixing hole  341 . The leg  34  penetrates through the slot  14  and the fixing hole  341  to reach one end of the spring  16 . The other end of the spring  16  connects to the fixing hole  151  of the retainer  15 . The latching element  30  thereby fixes the tray  20  to the base  10  or the released tray  20  from the base  10 . 
     Referring to  FIG. 5 , from a top view of the cartridge of the invention, the leg  34  of the latching element  30  connects to the spring  16 . The spring  16  drives the latching element  30  to resiliently move, forcing the latching element  30  to move back and forth on one predetermined path. 
     Referring to  FIG. 6  and  FIG. 7 , when the tray  20  is to be closed, the tray  20  is pushed toward a rear of the base  10  so that the first rib  22  of the tray  20  is driven to be against the guiding face  321  of the stopper of the latching element  30 . The first rib  22  drives the latching  30  to move along the guiding face  321  so that the latching element  30  pivotally rotates against the boss  13  clockwise. After the flange  332  of the latching element  30  rotates over the protrusion  132  of the boss  13 , the latching element  30  is drawn by the spring  16  so that the slanting face  333  of the flange  332  cooperates with the slanting top surface  133  of the protrusion  132  to engage the flange  332  with the protrusion  132 . Thereby, the latching element  30  is securely propped onto the boss  13 . After the first rib  22  passes by the stopper  32 , the propping part  221  stops the latching element  30  from rotating. 
     Referring to  FIG. 8 , when the latching element  30  is securely propped by the boss  13  and stopped by the first rib  22 , the tray  20  keeps sliding backward until the bent part  231  comes to contact the resilient hooking part  31  of the latching element  30  and makes the resilient hooking part  31  resiliently deformed. At this time, the hook  232  of the bent part  231  comes into one side of the latching element  30 . Meanwhile, the rib  21  at the rear of the tray  20  comes into the spring receiver  11  through the opening  111  to reach against the cartridge spring  12 . 
     Referring to  FIG. 9 , when the tray  20  is released, the rib  21  of the tray  20  is applied with a resilient force by the cartridge spring  12  so that the whole tray  20  is driven to move forward. At this moment, the latching element  30  lies against the propping part  221  of the first rib  22 , and the second rib  23  drives the latching element  30  to move forward. Thereby, the flange  332  of the latching element  30  departs from the protrusion  132  of the boss  13 , and the hook  232  of the bent part  231  comes to engage with the resilient hooking part  31  of the latching element  30 . The popping part  221  of the first rib  22  remains stopped by one side of the latching element  30 . Thereby, the latching element  30  forces the tray  20  to be secured inside the base  10 . 
     Referring to  FIG. 10  and  FIG. 11 , when the tray  20  is to be withdrawn from the cartridge, the tray  20  is pushed again to slide backward and thus to press the cartridge spring  12 . When the first rib  2  of the tray  20  is back to the rear of the latching element  30  and thus releases the latching element  30 , the latching element  30  is drawn by the spring  16  to rotate counterclockwise. The resilient hooking part  31  of the latching element  30  is released from the hook  232  of the bent part  231  and thereby the tray  20  is released. The latching element  30  which is drawn by the spring  16  returns to its original position as shown in  FIG. 5 . At this moment, the cartridge spring  12  at the rear of the tray  20  applies a resilient force to the tray  20  to force the tray  20  to move forward a certain distance. In this way, the base  10  is driven to open. 
     Thereafter, the tray  20  can be drawn out of the base  10 . When the tray  20  is drawn out, the first rib  22  is pushed to be against the rear of the stopper  32  to drive the latching element  30  to rotate counterclockwise, which allows the tray  20  to be easily drawn out. After the first rib  33  completely passes the latching element  30 , the latching element  30  is driven to rotate clockwise by the spring  16  to return to its original position as shown in  FIG. 5 . 
     Therefore, the cartridge of the invention can be closed when the tray  20  is pressed at first time, and opened when pressed a second time. The cooperation of the latching element  30  with the ribs  22 ,  23  of the tray  20  offers the releasing and securing of the tray  20 . The spring  16  provides a resilient force to the latching element  30  to force the latching element  30  to move on a predetermined path. When the tray  20  is closed, the resilient hooking part  31  of the latching element  30  engages with the hook  232  of the second rib  23 , and the propping part  221  of the tray  20  is stopped by one side of the latching element  30 . This enhances the retaining of the tray  20  so that even when the cartridge is impacted by an external force, the tray  20  can still be kept in a closed status. The cartridge of the invention provides advantages such as being highly stable, has fewer components, and is fast and easy to assembly. 
     It should be apparent to those skilled in the art that the above description is only illustrative of specific embodiments and examples of the present invention. The present invention should therefore cover various modifications and variations made to the herein-described structure and operations of the present invention, provided they fall within the scope of the present invention as defined in the following appended claims.