Abstract:
A printed circuit board retaining device for restricting the movement of a printed circuit board to which tactile switches are mounted. The printed circuit board retaining device having components that prevent lateral movement of the printed circuit board with respect to a bracket in which the printed circuit board is mounted. These components provide a force that counters forces created by the activation of switches directly mounted to the main printed circuit board.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of applicant&#39;s Ser. No. 09/084,933 filed in the U.S. Patent &amp; Trademark Office on May 28, 1998, now U.S. Pat. No. 6,370,031, and assigned to the assignee of the present invention. 
    
    
     CLAIM OF PRIORITY 
     This application makes reference to, incorporates the same herein, and claims all rights accruing thereto under 35 U.S.C. §119 through my patent applications entitled PCB Movement Restriction Device And Monitor Comprising The Same earlier filed in the Korean Industrial Property Office on the day of May 28, 1997 and there duly assigned Ser. Nos. 1997/12284, 1997/12280, 1997/12283, and my patent application entitled PCB Movement Restriction Device And Monitor Comprising The Same earlier filed in the Korean Industrial Property Office on the Nov. 26, 1997 and there duly assigned Ser. No. 33435/1997. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to monitor components and, more specifically, to a securing device for a printed circuit board that restricts the movement of the printed circuit board and thus simplifies the use of tactile switches that are attached to the printed circuit board. 
     2. Background Art 
     Generally, monitors can support tactile switches using one of two methods. One method of attaching tactile switches to a monitor is to mount the switches on a separate printed circuit board from the main printed circuit board. A second method used to support tactile switches in monitors is to attach the switches directly to the main printed circuit board. The monitor that has the various switches installed on the main printed circuit board has the advantage of having fewer parts that need to be assembled during the monitor assembly process. However, one disadvantage of mounting the tactile switches directly to the main printed circuit board is that the mounting of the printed circuit board requires more accuracy and a more secure mounting method to ensure the proper operation of the switches. 
     A monitor with tactile switches installed on the main printed circuit board may be constructed using a front cover that is fixed to a first bracket that supports a cathode ray tube. The rear cover is attached to the rear side of the front cover. The main printed circuit board has a multitude of electric devices and tactile switches that input commands to the main printed circuit board that processes video signals. A second bracket is fixed to the first bracket and supports the main printed circuit board. A stand allows the monitor to rotate through a predetermined range of motion with respect to a user. A bottom member is affixed to the underside of the second bracket and is engaged with the top of the stand. The main printed circuit board is secured to the second bracket by a plurality of fasteners. 
     There are many difficulties with the monitors of the contemporary art that utilize printed circuit boards that have attached switches. For example, when the tactile switches are pressed, the main printed circuit board, on which the tactile switches are mounted, moves slightly within the second bracket due to manufacturing and tolerance errors. This results in the printed circuit board being progressively misaligned. Additionally, since the main printed circuit board makes contact with the inner surfaces of the second bracket, an increased amount of time is required to secure the main printed circuit board onto the second bracket when the second bracket is deformed. This increases the precision of tolerances required to manufacture a bracket that supports a printed circuit board that has mounted switches. Furthermore, if the tactile switch is mounted to the printed circuit board in a position closer to the rear of the monitor than specified in the design, then the tactile switches will not be pressed directly even when a function switch, positioned on the front cover, is pressed. If the tactile switches are installed on the printed circuit board too close to the front of the monitor, then the tactile switches and the function switches will always be in contact. Thus, even when the main printed circuit board is accurately installed, the placement of the tactile switches on the printed circuit board is critical. Thus, a monitor that has function switches mounted on the main printed circuit board can have difficulty functioning properly and avoiding malfunctions. 
     As such, I believe that it may be possible to improve on the contemporary art by providing a bracket for monitors that has improved securing characteristics for a printed circuit board, that allows switches to be mounted directly to the main printed circuit board without undergoing progressive misalignment, that simplifies the assembly process by allowing the switches to be attached to the printed circuit board during the manufacturing process of the printed circuit board, that has enough elastic resilience to prevent the tactile switches from fracturing when an excessive amount of force is provided, and that actually guide the printed circuit board into the proper position on the bracket during the monitor assembly process. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved main printed circuit board retaining device for monitors. 
     It is another object to provide a main printed circuit board retaining device for monitors that allows switches to be mounted directly to the printed circuit board without the board undergoing progressively increasing misalignment as the buttons are used. 
     It is still another object to provide a main printed circuit board retaining device for monitors that has improved printed circuit board securing characteristics. 
     It is yet another object to provide a main printed circuit board retaining device for monitors that simplifies the monitor assembly process by allowing the switches to be mounted ahead of time on the main printed circuit board prior to the assembly of the monitor and thus avoiding the difficulties in precise switch positioning. 
     It is still yet another object to provide a main printed circuit board retaining device for monitors that has enough elastic resilience to prevent the switches that are directly mounted on the printed circuit board from fracturing when an excessive amount of force is provided while securing the printed circuit board in the correct position relative to the supporting bracket. 
     It is a further object to provide a main printed circuit board retaining device for monitors that guides the printed circuit board into position on the bracket during the assembly process, thus further simplifying the manufacturing process as printed circuit boards bearing switches need to be more precisely placed within the monitor housing than printed circuit boards that do not have tactile switched directly mounted. 
     These and other objects can be achieved, by providing a printed circuit board retaining device that may be constructed using a bracket with side walls to hold the printed circuit board in place. The bracket can either use abutments in the side walls or a locker device to secure the printed circuit board to the bracket. The tactile switches that are mounted to the printed circuit board are maintained in a stable position relative to the chassis due to the side walls of the bracket. 
     One type of abutment that can be used to retain the printed circuit board in the bracket is to have a multitude of protrusions projecting inwards from the side walls. Preferably, the protrusions are formed as an integral unit with the side walls. The protrusions exert a force onto the printed circuit board that prevents the printed circuit board from separating from the bracket. The protrusion can be easily manufactured using a tool to exert a force on the bracket that deforms the side walls of the bracket. However, the protrusion must not project inward from the side wall so far as to interfere with the mounting of the printed circuit board. 
     Alternatively, the board restraining device can be a flap formed by cutting out a part of the side wall and bending it inwards. In this case, it is preferable to provide a groove at a side of the printed circuit board or configure the side profile of the printed circuit board so that the movement of the printed circuit board is restricted by the flap. The bracket may be designed to have an inclined surface that can guide the printed circuit board into position during the assembling process. 
     The side walls can be manufactured so that the flap is merely a cut out section of the side wall that is bent inwards, thus the side wall provides support for the flap. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A more complete appreciation of this invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
     FIG. 1 is an exploded perspective view of a monitor having tactile switches mounted on the printed circuit board; 
     FIG. 2 is a schematic cross-sectional view of the monitor of FIG. 1; 
     FIG. 3 is a perspective view of a printed circuit board retaining device as constructed according to the principles of the present invention; 
     FIG. 4 is a cross-sectional view of the printed circuit board retaining device of FIG. 3 as taken along the line  3 - 3 ′; 
     FIG. 5 is a cross-sectional view of a monitor with the printed circuit board retaining device of FIG. 3; 
     FIG. 6 is a perspective view of a printed circuit board retaining device as constructed according to a second embodiment of the present invention; 
     FIG. 7 is a perspective view of a printed circuit board retaining device as constructed according to a third embodiment of the present invention; 
     FIG. 8 is a perspective view of a locker device that, along with the corresponding bracket, comprises a fourth embodiment of the present invention; 
     FIG. 9 is a perspective view of a locker device that, along with the corresponding bracket, comprises a fourth embodiment of the present invention; and 
     FIG. 10 is an exploded perspective view illustrating the use of a locker device to secure a main printed circuit board to a bracket. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning now to the drawings, FIGS. 1 and 2 illustrate a monitor that has tactile switches installed on the main printed circuit board. The monitor may be constructed using front cover  4  that is fixed to first bracket  11  that supports cathode ray tube  2 . Rear cover  9  is attached to the rear side of the front cover. The covers combine to form a chassis that encloses degaussing coil  15  that eliminates magnetic fields that are generated by cathode ray tube  2 . Main printed circuit board  13  has a multitude of electric devices and tactile switches  6  that are used to input commands to the printed circuit board. Buttons  5  protrude through front cover  4  and are aligned with tactile switches  6 . Second bracket  12  is fixed along one edge to first bracket  11  and supports the main printed circuit board. Stand  16  allows the monitor to rotate through a predetermined range of motion with respect to a user. Bottom member  14  is affixed underneath second bracket  12 . 
     A printed circuit board retaining device as constructed according to the first embodiment of the present invention is shown in FIG.  3 . Printed circuit board  13  is installed within bracket  12 . When printed circuit board  13  is mounted the side surfaces  70  abut protrusion  18 . Switches  6  are aligned with perforation  72  in front wall  12 - 1  of bracket  12  to allow the switches to be depressed when buttons  5  (FIGS.  1  and  2 ), that are located on the front cover  4  (FIGS.  1  and  2 ), are depressed. Tactile switches  6  are installed on the front of printed circuit board  13 . Bracket  12  has protrusions  18  that restrict the movement of the main printed circuit board  13 . FIG. 4 is a cross-sectional view of the printed circuit board retaining device, i.e., protrusions  18 , of FIG. 3 as taken along the line  3 - 3 ′. 
     Referring again to FIGS. 3 and 4, protrusions  18  are provided on the front wall  12 - 1  and rear wall  12 - 4  of bracket  12 , and at least two pairs of protrusions  18  are provided on both the right wall  12 - 2  and left wall  12 - 3  of the bracket  12 . Thus, when printed circuit board  13  is installed on bracket  12 , protrusions  18  exert a force on sides  70  of printed circuit board  13  that retains the printed circuit board  13 , hence restricting lateral movements of printed circuit board  13 . 
     A cross-section of a monitor having the first embodiment of the printed circuit board retaining device is shown in FIG.  5 . Protrusions  18  abut the sides  70  of the printed circuit board  13  to restrict the printed circuit board  13  from moving laterally. After printed circuit board  13  is mounted on bracket  12 , a plurality of fasteners (not shown) are used to secure printed circuit board  13  against bracket  12 . The fastener can be any one of solder, a bolt, a rivet, a screw, or an adhesive. 
     FIG. 6 shows a printed circuit board retaining device as constructed according to a second embodiment of the present invention. Flap  19  and inclined surface  18 , located above the flap, are formed by cutting a portion of the side wall and then bending the cut portion inward. Groove  13 A in the printed circuit board is fitted over flap  19  and inclined surface  18 . Voids  71  and  73  are created when flap  19  and inclined surface  18  are formed by cutting a portion of bracket  12 . When installing printed circuit board  13 , the inclined surface  18  contacts an edge of groove  13 A and guides printed circuit board  13  into position. Then, groove  13 A is placed over the flap  19  and printed circuit board  13  is installed in the appropriate position within bracket  12 . Switches  6  are aligned with perforation  72  in bracket  12  to allow the switches to be depressed when buttons  5  (FIGS. 1,  2  and  5 ), that are located on the front cover  4  (FIGS. 1,  2  and  5 ), are depressed. If excessive force is exerted on the printed circuit board via tactile switches  6  and buttons  5 , flap  19  moves backwards due to the elastic nature of the flap. This prevents the fracturing of tactile switch  6 . Thus, printed circuit board  13  will return to its normal location once the excess force is removed. 
     FIG. 7 shows a third embodiment of the printed circuit board retaining device as constructed according to the principles of the present invention. Switches  6  are aligned with perforation  72  in bracket  12  to allow the switches to be depressed when buttons  5  (FIGS. 1,  2  and  5 ), that are located on the front cover  4  (FIGS. 1,  2  and  5 ), are depressed. Many of the features are same as those described relating to the second embodiment above. Perforation  74  is formed when flap  19  and inclined surface  18  are cut out of bracket  12 . One difference, however, is that a cut-line  20  starting from the portion connecting flap  19  and bracket  12  is formed. Due to the cut-line  20 , the flap can be bent more flexibly than the flap of the second embodiment. This allows the flap to respond to smaller forces exerted on the printed circuit board via the tactile switches. 
     FIG. 8 shows a locker device for use in cooperation with a bracket  12  to form the fourth embodiment of a printed circuit board retaining device. The locker device has body  38 , lateral sides  32  and rectangular support slants  30 . A gap  76  is formed between body  38  and clip  25  by a horizontal member  75  connecting clip  25  to body  38 . An edge of bracket  12  is inserted inside gap  76  to secure the locker device to bracket  12 . Resilient clip  25  and horizontal member  75  are integrally formed with body  38 , wherein clip  25  is disposed apart from and along a back portion of body  38 . Support slants  30  are symmetrically positioned and are slanted downwards so that groove  64 , in the printed circuit board  13  shown in FIG. 10, can easily fit over support slants  30 . Support walls  30 - 1  extend vertically downward from support slants  30  and contact the edges of groove  64  in printed circuit board  13  shown in FIG.  10 . Thus, securing the printed circuit board  13  after the board is placed in position over the locker device  23 . 
     A fifth embodiment of a printed circuit board retaining device is shown in FIG.  9 . This locker device  41  has a cavity  42  positioned below support slants  50  and above locker tab  55 . Gap  76  is formed by horizontal member  75  and clip  45 . An edge of bracket  12  is inserted inside gap  76  to secure the locker device  41  to bracket  12 . This locker device differs from the locker device of FIG. 8 in that support slants  50  are made of a resilient material. The resilience of support walls  77  is increased due to the cavity  42  positioned underneath the support slants  50 . Accordingly, spacing between support walls  77  can be slightly larger that the gap formed in groove  64  of printed circuit board  13  shown in FIG.  10 . 
     FIG. 10 illustrates the securing of a printed circuit board  13  with a retaining device that uses locker device  23 . When the printed circuit board  13  is in position, switches  6  are aligned with perforation  72  in bracket  12  to allow the switches  6  to be depressed when buttons  5  (FIGS. 1,  2  and  5 ), that are located on the front cover  4  (FIGS. 1,  2  and  5 ), are depressed. The lateral sides  32  of body  38  of locker device  23  are guided by guide pins  40  that protrude from the side wall  12 - 3  of bracket  12 . Locker device  23  may be manufactured using a plastic or rubber molding process. An insert hole  51  is provided in the bottom of bracket  12  and is aligned with a notch  61  formed in side wall  12 - 3 , thus enabling the bracket  12  to engage with the locker device  23 . Side wall  12 - 3  fits into gap  76  and horizontal member  75  engages cut out portion  61  to prevent locker device  23  from moving in a lateral direction. Locker tab  35  is received in insert hole  51  to assist in the securing of the printed circuit board  13 . 
     To secure printed circuit board  13  to bracket  12  using one of the two disclosed retaining devices that use a locker device, locker device  23  ( 41 ) should be aligned at a predetermined location along bracket  12 . Then, the locker device  23  ( 41 ) is moved downwards and inserted into hole  51  in the bracket. The sides of locker device  23  ( 41 ) are guided into precise position by guide pins  40  of bracket  12 . When printed circuit board  13  is aligned at a predetermined location above bracket  12 , the printed circuit board can be inserted within bracket  12  and supporting slants  30  ( 50 ) pass through groove  64  of printed circuit board  13 . It should be apparent that printed circuit board could comprise a second groove  64  on an opposite side thereof, thus bracket  12  would include a second notch  61  and guide pins  40  and a second locking device would be utilized. 
     Although this preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. It is also possible that other benefits or uses of the currently disclosed invention will become apparent over time.