Patent Publication Number: US-2010113110-A1

Title: Link assembly with springs which can be extended and contracted and slider assembly having it

Description:
FIELD OF THE INVENTION  
     The present invention relates to an extendable and retractable link assembly with springs and a slider assembly for a slide type cellular phone having the same and, more particularly, to a thickness-reduced link assembly capable of making a cellular phone slim and a slider assembly having the same. 
     BACKGROUND ART  
     Referring to  FIG. 5 , there is shown a link assembly for use in a slider assembly of a conventional slide type cellular phone having a pair of link plates, which is disclosed in the publication of Korean Utility Model Registration No. 20-0363295. For the purpose of enhancing durability, the link assembly  300  shown in  FIG. 5  makes use of a pair of link plates  310  and a pair of tension springs  320  in place of a torsion spring that has been used to maintain the up and down states of a slide plate in the conventional slide type cellular phone. The link plates  310  have an identical shape and are restrained with each other by means of guide protrusions  313  slidably inserted into guide slots  312 . A pair of tension springs  320  is retained in place by means of spring locking portions  314  formed at one end of each of the link plates  310 . Each of the link plates  310  has a hinge portion  311  with a through-hole, the hinge portion  311  being rotatably attached to a fixed plate or a slide plate of a cellular phone through a pivot pin. 
     The conventional link assembly  300  of this configuration suffers from a problem in that the spring locking portions  314  of the link plates  310  are often bent and are difficult to manufacture due to their elongated shape and reduced strength. Furthermore, additional components such as the guide protrusions  313  and the like are needed to slidably restrain the link plates. A difficulty is encountered in an assembling process, because the annular end rings of the tension springs  320  are to be fitted to the spring locking portions  314 . Moreover, the annular end rings of the tension springs  320  fitted to the spring locking portions  314  may physically interfere with a flexible printed circuit board and may cause damage thereto if they are moved out of place. Particularly, the annular end rings of the tension springs  320  have a great size, which poses a problem in that the link assembly becomes thick and the cellular phone cannot be manufactured into a slim type. 
     DETAILED DESCRIPTION OF THE INVENTION  
     Technical Problems  
     It is an object of the present invention to provide a link assembly capable of solving the afore-mentioned problems inherent in the prior art and a slider assembly for a slide type cellular phone having the link assembly. 
     Another object of the present invention is to provide a slim and easy-to-manufacture link assembly capable of improving the coupling structure between springs and a link plate and a slider assembly for a slide type cellular phone having the link assembly. 
     Solution to the Technical Problems  
     In accordance with one aspect of the present invention, there is provided an extendable and retractable link assembly comprising: 
     a link plate including a base end portion and at least one spring receiving channel extending from the base end portion in a longitudinal direction of the link plate; 
     a link frame coupled to the link plate in a removal-free manner, the link frame including a base end portion and at least one spring support rod extending from the base end portion of the link frame into the spring receiving channel of the link plate for sliding movement relative to the spring receiving channel; and 
     at least one spring having a first end received within the spring receiving channel of the link plate and a second end into which the spring support rod of the link frame is inserted. 
     In accordance with another aspect of the present invention, there is provided a slider assembly for a slide type cellular phone comprising: 
     a fixed plate attached to one surface of a body of the cellular phone, the fixed plate having a guide portion; 
     a sliding plate attached to one surface of a cover of the cellular phone in a facing relationship with the fixed plate, the sliding plate coupled to the fixed plate for rectilinear sliding movement along the guide portion of the fixed plate; and 
     an extendable and retractable link assembly rotatably attached to the fixed plate and the sliding plate for applying a biasing force to the fixed plate and the sliding plate, wherein the link assembly comprises: 
     a link plate including a base end portion and at least one spring receiving channel extending from the base end portion in a longitudinal direction of the link plate, the base end portion of the link plate having a through-hole through which a pivot pin is inserted to attach the link plate to one of the fixed plate and the sliding plate; 
     a link frame coupled to the link plate in a removal-free manner, the link frame including a base end portion and at least one spring support rod extending from the base end portion of the link frame into the spring receiving channel of the link plate for sliding movement relative to the spring receiving channel, the base end portion of the link frame having a through-hole through which a pivot pin is inserted to attach the link frame to the other of the fixed plate and the sliding plate; and 
     at least one spring having a first end received within the spring receiving channel of the link plate and a second end into which the spring support rod of the link frame is inserted. 
     Advantageous Effects  
     Use of the compression springs in the link assembly of the present invention eliminates the need to form spring locking portions. This makes it possible to manufacture the link assembly by an injection molding method in a simple and easy manner. 
     With the present invention, it is possible to reduce the thickness of the slider assembly by improving the structure of coupling portions of the link assembly coupled to the slider assembly. This helps make a slide type cellular phone slim. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  is a perspective view showing a link assembly in accordance with one embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the link assembly shown in  FIG. 1 . 
         FIG. 3  is an exploded perspective view showing a slider assembly for a cellular phone provided with the link assembly shown in  FIG. 1 . 
         FIGS. 4A ,  4 B and  4 C are views for explaining different operation states of the slider assembly shown in  FIG. 3 . 
         FIG. 5  is a perspective view illustrating a conventional link assembly. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION  
     Preferred embodiments of a link assembly and a slider assembly having the same in accordance with the present invention will be described in detail hereinafter with reference to the accompanying drawings. 
     First, description will be made on a link assembly.  FIG. 1  is a perspective view showing a link assembly in accordance with one embodiment of the present invention and  FIG. 2  is an exploded perspective view of the link assembly shown in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , the link assembly includes a link plate  10 , a link frame  20  and a plurality of springs  30 . The link plate  10  has a pair of laterally spaced-apart guide channels  1 , a plurality of spring receiving channels  3  arranged between the guide channels  1  and a through-hole formed through the thickness of the link plate  10 . A plurality of compression springs  30  is received within the spring receiving channels  3  in a mutually separated state. The spring receiving channels  3  extend from a base end portion of the link plate  10  in a longitudinal direction so that the springs  30  can be received within the spring receiving channels  3 . Although the spring receiving channels  3  correspond in number to the springs  30  in the present embodiment, a single wide spring receiving channel for receiving a plurality of springs may be formed to extend in the longitudinal direction of the link plate  10 . In this case, a plurality of longitudinally-extending spaced-apart ridges may be formed in the single spring receiving channel so that the springs can be separated from one another by the ridges. 
     The guide channels  1  are formed at the lateral opposite ends of the link plate  10  to extend along the longitudinal direction of the link plate  10 . Stopper juts  2  are formed in the entrance portions of the guide channels  1 . The stopper juts  2  are shaped and arranged to engage with the below-mentioned lugs  12  of a guide rods  11 , thereby preventing removal of the guide rods  11  from the guide channels  1 . 
     One surface of the base end portion of the link plate  10  is recessed to reduce the thickness of the base end portion. This means that the base end portion of the link plate  10  is thinner than the tip end portion thereof. The through-hole  7  is formed in the base end portion of the link plate  10 . A below-mentioned pivot pin  115  is inserted into the through-hole  7  to rotatably secure the link plate  10  to the slider assembly described below. The pivot pin  115  is provided with an enlarged head having a specified thickness. The reason why the thickness of the base end portion of the link plate  10  is reduced by recessing one surface of the base end portion is to provide a space in which the head of the pivot pin  115  can be received without increasing the thickness of the slider assembly as a whole. 
     The link frame  20  includes a plurality of spring support rods  13 , a pair of guide rods  11  and a through-hole  17  formed through the thickness of the link frame. The spring support rods  13  are designed to extend from a base end portion of the link frame  20  in a longitudinal direction and arranged side by side along a transverse direction of the link frame  20  so that they can be slidably inserted into the corresponding spring receiving channels  3  of the link plate  10 . 
     The guide rods  11  are formed at the lateral opposite ends of the link frame  20  so that they can be slidably inserted into the guide channels  1  of the link plate  10 . The guide rods  11  are provided at their distal ends with lugs  12  engageable with the stopper juts  2  formed in the guide channels  1  of the link plate  10 . When inserted into the guide channels  1 , the guide rods  11  allow the link frame  20  to make smooth sliding movement along the link plate  10 , at which time the spring support rods  13  make sliding movement within the spring receiving channels  3 . As the link frame  20  is slid in such a direction that the spring support rods  13  go out of the spring receiving channels  3 , the lugs  12  of the guide rods  11  come into engagement with the stopper juts  2  of the guide channels  1 , thereby preventing removal of the link frame  20  from the link plate  10 . 
     One surface of the base end portion of the link frame is recessed to reduce the thickness of the base end portion. The through-hole  17  is formed in the base end portion of the link frame  20 . A pivot pin  105  is inserted into the through-hole  17  to rotatably secure the link frame  20  to the slider assembly described below. The direction in which the pivot pin  105  is inserted into the through-hole  17  is opposite from the direction in which the pivot pin  115  is inserted into the through-hole  7 . The recessed surface of the base end portion of the link frame  20  is arranged on the opposite side from the recessed surface of the base end portion of the link plate  10  so that the thickness of the slider assembly can be kept small even when the pivot pins  105  and  115  with the enlarged head are inserted into the through-holes  7  and  17 . 
     The springs  30  are received within the spring receiving channels  3  of the link plate  10  and the spring support rods  13  of the link frame  20  are inserted into the corresponding springs  30 . In other words, the springs  30  have first ends  23  received within the spring receiving channels  3  and second ends  21  into which the spring support rods  13  are inserted. If the link plate  10  and the link frame  20  are pushed to move toward each other, the link frame  20  is slid toward the link plate  10  while compressing the springs  30 . If the pushing force is removed, the link frame  20  is slid away from the link plate  10  into the original position by the pressure of the springs  30 . 
     Next, description will be made on the slider assembly.  FIG. 3  is an exploded perspective view showing a slider assembly for a cellular phone provided with the link assembly shown in  FIG. 1  and  FIGS. 4A ,  4 B and  4 C are views for explaining different operation states of the slider assembly shown in  FIG. 3 . 
     Referring to  FIG. 3 , the slider assembly includes a fixed plate  110 , a sliding plate  120  and a link assembly  40  for applying a biasing force to the fixed plate  110  and the sliding plate  120 . The fixed plate  110  is fixed to one surface (the front surface) of a body of a slide type cellular phone and is provided with guide portions  101  formed on the opposite side edges thereof. 
     The sliding plate  120  is fixed to one surface (the rear surface) of a cover of the slide type cellular phone in a facing relationship with the fixed plate. The sliding plate  120  is provided with slider portions  111  formed on the opposite side edges thereof. The slider portions  111  are slidably fitted to the guide portions  101  of the fixed plate  110  so that they cam make rectilinear sliding movement along the guide portions  101 . 
     The link assembly  40  is the same one as shown in  FIG. 1 . The link frame  20  of the link assembly  40  is rotatably attached to the fixed plate  110  of the slider assembly by the pivot pin  105  inserted into the through-hole  17 . Likewise, the link plate  10  is rotatably attached to the sliding plate  120  of the slider assembly by the pivot pin  115  inserted into the through-hole  7 . 
     If a force is applied to the sliding plate  120  in the direction designated by an arrow  121  in  FIG. 4A , the sliding plate  120  is slid along the fixed plate  110  in the direction of the arrow  121 . At this time, the springs  30  are compressed so that a restoring force can be accumulated in the springs  30 . When the sliding plate  120  is moved to the position illustrated in  FIG. 4B , the springs  30  are compressed into the smallest size, at which time the restoring force accumulated in the springs  30  becomes greatest. If the sliding plate  120  is further pushed in this state, the accumulated restoring force of the springs causes the sliding plate  120  to move in the direction designated by an arrow  123  in  FIG. 4C . 
     The embodiment shown and described hereinabove should not be construed to limit the scope of protection of the present invention. The scope of the invention shall be limited only by the subject matters recited in the claims. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention defined in the claims. 
     INDUSTRIAL APPLICABILITY  
     The link assembly and the slider assembly incorporating the same can be advantageously applied to a slide type cellular phone.