Patent Publication Number: US-7586054-B2

Title: Switch assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Application No. 2003-52432, filed on Jul. 29, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a switch assembly. More particularly, the present invention relates to a switch assembly having a shuttle function and a button function in an integrated form. 
     2. Description of the Related Art 
     An electronic product, such as a video cassette tape recorder (VCR), a video tape recorder (VTR), or a digital video disk player (DVDP), is provided with a plurality of manipulation knobs to manipulate functions of the electronic product. The manipulation knobs are for various operations of, for example, playing, fast-forwarding, re-winding, pausing and stopping, according to the on/off state of the switches installed on a printed circuit board (PCB). However, because there are so many different manipulation knobs, the size of the product must be oversized. Recently, an integrated switch assembly has been developed to solve the problem by selectively manipulating a plurality of functions. 
       FIG. 1  is a cross section view showing a conventional switch assembly, and  FIG. 2  is an exploded perspective view of  FIG. 1 . As shown in  FIGS. 1 and 2 , a conventional switch assembly  100  includes a shuttle unit  120  and a plurality of tact switches  131  and  132  disposed on a printed circuit board (PCB)  110 , a shuttle knob  140  operating the shuttle unit  120 , and a button knob  150  for turning on/off the tact switches  131  and  132 . The conventional switch assembly  100  further includes a board holder  160  and a button knob holder  170  interposed between the tact switches  131  and  132  and the button knob  150 . 
     The plurality of tact switches  131  and  132  are arranged in a radial direction with respect to the shuttle unit  120  rotatably disposed on the PCB  110 . The plurality of tact switches  131  and  132  are located at predetermined intervals and signals the performance of different functions, namely, playing, stopping, pausing, or inserting/ejecting. The board holder  160 , located on the front surface of the PCB  110 , where the tact switches  131  and  132  are located, compensates for a stepped width between the tact switches  131  and  132  and the PCB  110 . 
     When assembled with the button knob holder  170 , the button knob  150  is connected to the front surface of the PCB  110  where the board holder  160  is disposed. The button knob holder  170  is provided with a plurality of poles  171  and  172  protruding therefrom and corresponding to the tact switches  131  and  132  fixed to the PCB  110 . As a side of the button knob  150  is pressed, the poles  171  and  172  of the button knob holder  170  turn on/off the corresponding tact switches  131  and  132 . The shuttle knob  140  is connected to the shuttle unit  120  to rotate 360° in either a clockwise direction or a counter-clockwise direction. The button knob  150  includes a plurality of tension ribs  155  spaced from the shuttle knob  140  by a predetermined distance. For example, a user can adjust the volume of sound by rotating the shuttle knob  140 . 
     However, the conventional switch assembly  100  has a complicated construction requiring assembly of the shuttle knob  140 , the button knob  150 , the button knob holder  170 , and the board holder  160  with the shuttle unit  120 . Therefore it is difficult to disassemble the switch assembly  100 , which increases manufacturing costs. Particularly, since the shuttle unit  120  is a single unit integrating a plurality of components therein, it has to be manufactured as an original equipment manufacturer (OEM) part, resulting in increased manufacturing costs. 
     Also, if a malfunction occurs in the relatively expensive shuttle unit  120 , the entire switch assembly  100  has to be replaced causing increased maintenance costs. 
     SUMMARY OF THE INVENTION 
     The present invention has been developed in order to solve the above problems in the related art. Accordingly, it is an aspect of the present invention to provide a switch assembly having a simplified construction capable of facilitating assembling/disassembling and, particularly, reducing manufacturing and maintenance costs. 
     Another aspect of the present invention is to provide a switch assembly with a compact design to reduce the size of a product. 
     Still another aspect of the present invention is to provide a switch assembly that makes operating an electronic product more convenient for a user. 
     The above aspects are achieved by providing a switch assembly comprising first and second tact switches disposed on a printed circuit board (PCB) at a predetermined interval. The switch assembly comprises a shuttle body having a pair of tension ribs including a first tension rib and a second tension rib located in parallel to each other, to turn on/off the first and the second tact switches; and a knob holding shaft between the first and the second tension ribs; a manipulation knob connected to the knob holding shaft of the shuttle body, rotating between a position where the manipulation knob presses one of the first and the second tension ribs to operate the corresponding tact switch and a position where the manipulation knob releases the tension rib. The switch assembly further includes a spring member connected to the knob holding shaft of the shuttle body to elastically press the manipulation knob to the releasing position. 
     The manipulation knob may comprise a pair of operating portions outwardly protruding from the manipulation knob in a radial direction, having a predetermined angle between each operating portion, and operating with the first and the second tension ribs of the shuttle body, and a connection portion extending from the manipulation knob in an axial direction and connected to the shuttle body. 
     In other embodiments, the first and the second tension ribs of the shuttle body each may comprise a protrusion upwardly protruding toward the manipulation knob, and an inclined portion formed at a predetermined inclination angle with respect to the protrusion and inwardly curved, contacting the operating portion of the manipulation knob. 
     In other embodiments, the shuttle body may have a guide hole or recess formed therein, to receive the connection portion of the manipulation knob and restrict the movements of the connection portion within a predetermined range. 
     In other embodiments, the operating portions of the manipulation knob each may include a pair of locking protrusions locked by opposite ends of the spring member, which exerts an elastic biasing force toward the releasing position. 
     In other embodiments, a third tact switch may be further disposed on the PCB, and the shuttle body further includes a third tension rib interposed between the first and the second tension rib to operate with the third tact switch, and the third tension rib is elastically deformed when pressed by the manipulation knob positioned at the release position, thereby turning on the third tact switch. 
     In other embodiments, the shuttle body may be provided with an elastic supporting rib which elastically supports the manipulation knob such that the third tension rib is placed at a position to turn off the third tact switch. 
     In other embodiments, the switch assembly may further comprise a shuttle ring interposed between the manipulation knob and a front panel of an electronic product which exposes a part of the manipulation knob to the outside. 
     In a preferred embodiment, the switch assembly further comprises a shuttle ring interposed between the manipulation knob and a front panel of an electronic product which exposes a part of the manipulation knob to the exterior of the electronic product. 
     The above aspects and other advantages are achieved by providing a switch assembly comprising a manipulation knob, and a shuttle body integrally formed with a knob holding shaft to which the manipulation knob is rotatably connected, and a plurality of tension ribs positioned within a rotating radius of the manipulation knob to be selectively deformed by the manipulation knob. 
     Furthermore, the switch assembly may further comprise a spring member connected to the knob holding shaft to return the manipulation knob to an original position. 
     In addition, the switch assembly may further comprise a plurality of tact switches fixed onto a printed circuit board (PCB) to be turned on/off by the plurality of tension ribs. 
     Finally, the shuttle body may be formed by injection molding. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The above aspects and other advantages of the present invention will be more readily understood in connection with the following description of an exemplary embodiment of the present invention with reference to the accompanying drawings, in which: 
         FIG. 1  is a cross sectional view showing a conventional switch assembly; 
         FIG. 2  is an exploded view of  FIG. 1 ; 
         FIG. 3  is a front view showing an electronic product on which a switch assembly is mounted according to an exemplary embodiment the present invention; 
         FIG. 4  is a partially exploded perspective view of  FIG. 3 , in which the construction of the switch assembly is more specifically illustrated; 
         FIG. 5  is an enlarged view of part ‘A’ of  FIG. 4 ; 
         FIG. 6  is a partial cross sectional view of  FIG. 3  taken along line V-V; 
         FIG. 7  is a view of  FIG. 4  in an assembled state, in which the manipulation knob is connected to the shuttle body; 
         FIG. 8  is a rear elevation view of  FIG. 7 ; 
         FIG. 9  is a plan view of  FIG. 8 , which shows the tact switches and the tension ribs located on the PCB; and 
         FIG. 10  is a rear elevation perspective view showing the manipulation knob. 
     
    
    
     In the drawing figures, it will be understood that like reference numerals refer to like features and structures. 
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT 
     Hereinafter, a switch assembly according to an exemplary embodiment of the present invention will be described in greater detail. 
       FIG. 3  is a front view showing an electronic product having a switch assembly mounted therein according to an embodiment of the present invention,  FIG. 4  is a partially exploded perspective view of  FIG. 3 ,  FIG. 5  is an enlarged view of the part ‘A’ of  FIG. 4 , and  FIG. 6  is a partial cross section view taken along the line V-V of  FIG. 3 . As shown in these drawings, an electronic product  1  includes a case body (not shown) having an opening formed in a front portion thereof, and a front panel  3  blocking the opening of the case body. The case body has embedded a plurality of parts and a printed circuit board (PCB)  11 . A switching assembly  17 , tact switches  21 ,  22 ,  23 ,  24 ,  25 , and  26 , and display unit  28  are preferably located on the PCB  11 . 
     As shown in  FIG. 3 , a door  4  and a display window  5  are located in a center portion of the front panel  3  and located one above the other, and the door  4  vertically pivots to be opened and closed. For example, through the door  4 , a medium such as a video tape or a disk is inserted or ejected. The display window  5  is made of a transparent material to expose an operating state displayed on the display unit  28  to the outside. Functions keys  6  protrude through the display window  5  to perform functions of recording, adjusting a channel or adjusting a screen by turning on/off the respective tact switches  26 . 
     The front panel  3  is also provided with a power button  13  and an eject button  14  located on one side of the door  4  and the display window  5 . An external input unit  15  having a plurality of external input ports is preferably located under the power button  13  and the eject button  14 . Knob holes  7 ,  8 , and  9  are formed in the front panel  3  on the side opposite the powerbutton  13  and the eject button  14 . The knob holes  7 ,  8 , and  9  allow manipulation knobs  71 ,  84 , and  85 , which form the switch assembly  17 , to protrude through the front panel  3 . 
     As shown in  FIG. 4 , the front panel  3  has a plurality of connection ribs  10  located at predetermined intervals along the length of the rear edge panel  3 . The connection ribs  10  include a connection hole or a hook. If the connection rib  10  has a connection hole, the connection ribs  10  are connected to the case body using an extra connection member (not shown). Meanwhile, if the connection rib  10  has a connection hook, the connection ribs  10  are connected to the case body using a hook hole formed in the case body. 
     Referring to  FIGS. 4 and 5 , the switch assembly  17  according to a preferred embodiment of the present invention includes the plurality of tact switches  21 ,  22 ,  23 ,  24 ,  25 , and  26  disposed on the PCB  11 , a shuttle body  20  to be mounted on the front panel  3 , and the manipulation knob  71  movably connected to the shuttle body  20  for shuttle rotation. It is preferred that the switch assembly  17  further includes a spring member  81  for returning the manipulation knob  71  to an original position. 
     The tact switches  21 ,  22 ,  23 ,  24 ,  25 , and  26  disposed on the PCB  11  individually perform separate functions. For example, if the first and the second tact switches  21  and  22  are designed to perform the fast-forwarding and rewinding functions, the third switch  23  may be located between the first and the second tact switches  21  and  22  to perform another predetermined function. Also, the fourth and fifth tact switches  24  and  25  are located outside of the second tact switch  22  to perform functions such as pausing and stopping. 
       FIG. 7  is a view showing the switch assembly  17  of  FIG. 4  in an assembled state,  FIG. 8  is a rear elevation view of  FIG. 7 , and  FIG. 9  is a plan cross sectional view of  FIG. 8 , which shows the main parts of an exemplary embodiment of the present invention more specifically. Referring to  FIGS. 7 and 8 , the shuttle body  20  includes a frame  20 ′ fixed to the front panel  3  (not shown), and a first and a second tension ribs  31  and  32  operating with the first and the second tact switches  21  and  22  (not shown), and a knob holding shaft  51  connected to the manipulation knob  71 . 
     The first and the second tension ribs  31  and  32  extend from a lower portion of the frame  20 ′ toward the first and the second tact switches  21  and  22  (not shown) in parallel to each other. The first and the second tension ribs  31  and  32  are elastically deformable in a vertical direction with respect to the frame  20 ′. As the first and the second tension ribs  31  and  32  are elastically deformed to a lower portion, they turn on/off the corresponding first and the second tact switches  21  and  22  (not shown). 
     In  FIG. 8 , the first and the second tension ribs  31  and  32  respectively include protrusions  41  and  42  upwardly protruding from the connected portions to the frame  20 ′, and inclined portions  47  and  48  formed at the ends of the protrusions  41  and  42 . The inclined portions  47  and  48  are shaped in arc pattern with respect to the knob holding shaft  51 , and maintained at a predetermined angle with respect to the corresponding protrusions  41  and  42 . The inclined portion  47  and  48  are pressed and released by an operating portion  72  of the manipulation knob  71 , which will be described in greater detail below, thereby being elastically deformed in a forward or a backward direction. Accordingly, the first and the second tension ribs  31  and  32  are elastically deformed in unison with the inclined portions  47  and  48 . 
     Meanwhile, between the first and the second tension ribs  31  and  32  is provided a third tension rib  33  extending toward the third tact switch  23  (not shown). Like the first and the second tension ribs  31  and  32 , the third tension rib  33  has a protrusion  43  upwardly protruding to operate with the manipulation knob  71 . The protrusion  43  is elastically deformed backward when being pressed at the front portion and in association with this, the third tension rib  33  is elastically deformed to turn on/off the third tact switch  23 . 
     Fourth and fifth tension ribs  34  and  35  operating with the fourth and the fifth tact switches  24  and  25  (not shown) may be located outside the second tension rib  32 . Like the first to the third tension ribs  31 ,  32 , and  33 , the fourth and the fifth tension ribs  34  and  35  have protrusions  44  and  45  upwardly protruding. The manipulation knobs  84  and  85  (shown in  FIG. 7 ) are connected to the protrusions  44  and  45  of the fourth and the fifth tension ribs  34  and  35  to be exposed to the outside through the knob holes  8  and  9  formed in the front panel  3 . When the manipulation knobs  84  and  85  are pressed backward, the fourth and the fifth tension ribs  34  and  35  are elastically deformed in unison with the protrusions  44  and  45 , thereby turning on/off the corresponding tact switches  24  and  25  (not shown). 
     Meanwhile, the knob holding shaft  51  is located in the center above the first and the second tension ribs  31  and  32 . The knob holding shaft  51  extends from a plate surface of the shuttle body  20  in a forward direction, and has a shaft hole  51   a  formed in a center thereof. Also, guide recesses  61  and  65 , each forming a pattern of a partial arc, are located around the knob holding shaft  51  opposite to each other. The ends of each guide recess  61  and  65  prevent excessive normal/reverse rotations of the manipulation knob  71 . 
     Referring now to  FIG. 9 , a boss  63  protruding in an arc pattern is located between the knob holding shaft  51  and the guide recesses  61  and  65  (shown in  FIG. 8 ). A spring recess for housing a spring member  81  is formed between the boss  63  and the knob holding shaft  51 . The spring member  81  may be a torsion spring. The boss  63  has a predetermined cutting part formed on a lower portion of the boss  63  to hold opposite ends  82  and  83  of the spring member  81  downward. The opposite ends of the spring member  81  held by the cutting part are elastically deformed only in a compressed direction. 
     Preferably, the shuttle body  20  with the above construction is integrally formed by injection molding. Referring back to  FIG. 8 , the first and the second tension ribs  31  and  32  may take various forms that are capable of directly operating with the operating portions  72  and  73  of the manipulation knob  71  without the protrusion  41  and  42  and the inclined portions  47  and  48 . For example, in order to be operated by the operating portions  72  and  73  of the manipulation knob  71 , the first and the second tension ribs  31  and  32  each have an inclined surface formed along the length of their front surface. 
     Meanwhile,  FIG. 10  is a rear elevation view showing the manipulation knob  71 . As shown in  FIG. 10 , the manipulation knob  71  includes a rotary shaft  75  connected to the shaft hole  51   a  of the knob holding shaft  51 , the operating portions  72  and  73  operating with the first and the second tension ribs  31  and  32 , and connecting portions  76  and  77  movably received in the guide recesses (holes)  61  and  65 . The rotary shaft  75  protrudes toward the shuttle body  20  (not shown) along a center axis of the manipulation knob  71  to be rotatably connected to the shaft hole  51   a  of the knob holding shaft  51  (as shown in  FIG. 5 ). The manipulation knob  71  is rotatably connected to the knob holding shaft  51  and is partially exposed to the outside of the front panel  3 . A knurling  78  is preferably formed around the circumference on the outer surface of the manipulation knob  71  for the user to grip. 
     The connection portions  76  and  77  are provided in pairs and extend from the rear end of the manipulation knob  71  toward the shuttle body  20 , and have hooks  76 ′ and  77 ′ protruding outward from the ends of the connection portions  76  and  77 , respectively. The connection portions  76  and  77  are received in the guide recesses or holes  61  and  65  of the shuttle body  20  to shuttle-rotate along the length of the guide recesses or holes  61  and  65 . The hooks  76 ′ and  77 ′ are formed at the end of connection portions  76  and  77  are hooked into the guide holes or recesses  61  and  65  to prevent the manipulation knob  71  from being turned further than the length of the guide recesses or holes  61  and  65 . 
     The operating portions  72  and  73  are provided in pairs and protrude outward from the outer surface of the manipulation knob  71  in a radial direction. Operating portion  72  is a predetermined distance from operating portion  73 ; the predetermined distance corresponding to the angle between the opposite ends  82  and  83  of the spring member  81 . Also, the operating portions  72  and  73  have contact protrusions  72 ′ and  73 ′ formed at their ends to contact the inclined portions  47  and  48  of the first and the second tension ribs  31  and  32 . Referring to  FIGS. 7 and 8 , the first and the second tension ribs  31  and  32  shuttle-rotate in the normal/reverse directions, the contact protrusions  72 ′ and  73 ′ move in unison with the inclined portions  47  and  48  of the first and second tension ribs  31  and  32 . As the contact protrusions  72 ′ and  73 ′ move along the inclined portions  47  and  48  in the normal/reverse directions, they press or release the first and the second tension ribs  31  and  32 , thereby turning on/off the corresponding tact switches  21  and  22 . 
     Referring now to  FIG. 9 , the operating portions  72  and  73  have locking protrusions  72 ″ and  73 ″ protruding toward the spring member  81 . The locking protrusions  72 ″ and  73 ″ operate with the opposite ends of the spring member  81  received in the spring recess of the shuttle body  20 . That is, the opposite ends  82  and  83  of the spring member  81  elastically press the locking protrusions  72 ″ and  73 ″ toward the outside so that the manipulation knob  71  is maintained at a position to press and release the first and the second tension ribs  31  and  32 . 
     In order to assemble a switch assembly  17  having the above construction, first, the spring member  81  is received in the spring recess of the shuttle body  20 . Next, the rotary shaft  75  of the manipulation knob  71  is inserted into the shaft hole  51   a  of the knob holding shaft  51  of the shuttle body  20 . At this time, it is important that the locking protrusions  72 ″ and  73 ″ of the operating portions  72  and  73  correspond to the opposite ends  82  and  83  of the spring member  81  at the outside. Accordingly, due to the elasticity of the spring member  81 , it is possible for the manipulation knob  71  to shuttle-rotate between a position where the manipulation knob  71  releases the first and the second tension ribs  31  and  32  and a position where the manipulation knob  71  presses the first and the second tension ribs  31  and  32 . 
     The shuttle body  20 , assembled with the manipulation knob  71 , is fixed to the rear surface of the front panel  3 . The frame  20 ′ of the shuttle body  20  has a connection recess (reference numeral  27  of  FIG. 8 ) formed along its longitudinal direction into which the shuttle body  20  is fixed. A plurality of connection members (not shown) formed on the rear surface of the front panel  3  are connected to the connection recess so that the shuttle body  20  is fixed to the front panel  3 . It is preferred that a shuttle ring (reference numeral  91  of  FIG. 4 ) is located between the front panel  3  and the shuttle body  20 . The shuttle ring  91  aids in smooth rotation of the manipulation knob  71 , which extends through the knob hole  7  in the normal/reverse directions to the exterior of the front panel  3 . 
     Meanwhile, the tact switches  21 ,  22 ,  23 ,  24 ,  25 , and  26  are fixed onto pre-set positions on the PCB  11 . The PCB  11  has tact switches  21 ,  22 ,  23 ,  24 ,  25 , and  26  installed on it and is connected to a predetermined position on the bottom of the case body. Accordingly, as the front panel  3  is assembled with the case body, the first and the second tension ribs  31  and  32  of the shuttle body  20  correspond to the first and the second tact switches  21  and  22  located on the PCB  11 . 
     A user can grip the manipulation knob  71  positioned at a press-release position and shuttle-rotate it in the normal/reverse directions. During the shuttle rotation of the manipulation knob  71 , the operating portions  72  and  73  elastically deform the first and the second tension ribs  31  and  32 . Then, the first and the second tact switches  21  and  22  are turned on/off to perform the corresponding functions. Thus, when the user ceases applying force to the manipulation knob  71 , the spring member  81  returns to the press-release position by the recovering force thereof. 
     When a user presses the manipulation knob  71  backward, the third tension rib  33  is elastically deformed to turn on/off the third tact switch  23 . It is preferable not to elastically deform the third tension rib  33  freely by the manipulation knob  71 . In this embodiment, an elastic supporting rib (a reference numeral  29  of  FIG. 7 ) is formed at a position corresponding to the third tension rib  33  with respect to the knob holding shaft  51 . The elastic supporting rib  29  presses the manipulation knob  71  forward, thereby preventing the third tension rib  33  from operating freely. 
     According to embodiments of the present invention as described above, assembling and disassembling of the switch assembly  17  becomes easy and simple because the shuttle body  20  is integrally formed with the knob holding shaft  51  by the injection molding and the tact switches are located on the PCB. Accordingly, manufacturing costs and maintenance costs can be reduced. 
     Also, the switch assembly  17  with a simple compact construction reduces the overall size of a product and allows the user to manipulate it with ease and convenience. 
     The foregoing embodiment and advantages are merely exemplary and are not to be construed as limiting the present invention. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.