Patent Publication Number: US-5291172-A

Title: Noise absorber

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a noise absorber for enclosing wires of electronic equipment therein to absorb electric noises generated within the equipment and to prevent noises generated outside the equipment from running through the wires into the equipment. 
     A conventional noise absorber surrounds an outer periphery of wires with ferrite or other magnetic material, thereby absorbing electric noises running through the wires. Such a noise absorber comprises coupling devices molded of magnetic material. The coupling devices are in the shape of a cylinder cut in half along an abutment face including the axis thereof. The coupling devices are housed in cases provided in a container made of a synthetic resin. When the container is closed, the coupling devices made of magnetic material contained within the case enclose the wires therein in order to absorb electric noises. Such a noise absorber is secured to a chassis or a printed board by engaging an engaging portion disposed at its bottom with a second engaging member on a top of a stand which is screwed onto the chassis or the substrate. 
     Although such a noise absorber can be fixed to a printed board and a housing, the stand of the noise absorber occupies a lot of space, thereby hampering placement of the noise absorber. Moreover, in repairing or other occasions where the noise absorber needs to be removed, the engaging portions between the stand and the noise absorber are difficult to reach since the stand is positioned at the bottom of the noise absorber. Thus, the mechanism for fixing the noise absorber needs to be further improved 
     SUMMARY OF THE INVENTION 
     Wherefore, an object of the invention is to provide a noise absorber which can be easily installed at a desired location and has improved operability. 
     In order to achieve the above object, a noise absorber according to the invention comprises coupling devices molded of magnetic material, a container for containing the coupling devices, and a stand or support member. Each of the coupling devices is a cylinder divided in half along an abutment face including the axis thereof so as to enclose an outer periphery of wires of electronic equipment. When combined with each other, their abutment faces are closely abutted. The container is openable by a hinge. When the container is closed, the coupling devices made of magnetic material enclose the wires, thereby absorbing electric noises running through the wires. The container is provided with a first engaging portion. The stand comprises a second engaging portion for engaging the first engaging portion, a support portion for supporting the container at a flank thereof, and a bottom face which is substantially at the same level as a bottom of the container when the first and the second engaging portions engage one another. 
     In the noise absorber with the structure specified above, the container and the stand are integrally combined by engaging a first engaging portion of the container and a second engaging portion of the stand. When the container and the stand are combined, a bottom surface of the container and the bottom face of the stand are substantially at the same level. The support portion of the stand supports the container at the flank. Thus, the stand is integrally connected to the flank of the container and the container can be fixed on a chassis or a printed board while it is supported by the stand. Since the stand is provided on the same level as the container, the height of the noise absorber as a whole is minimized. Thus the noise absorber is advantageous for use in a location with limited space. Moreover, since the stand is provided at the flank of the container, the stand is easily accessible for removal from the chassis or the printed board, thus facilitating disassembly of the container. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing the structure of a noise absorber of a first embodiment according to the present invention. 
     FIG. 2 is a plan view of a container of the noise absorber. 
     FIG. 3 is a bottom plan view of the container. 
     FIG. 4 is a side view of the container. 
     FIG. 5 is a side sectional view of the container. 
     FIG. 6 is a front view of upper case of the container. 
     FIG. 7 is a rear view of the lower case of the container. 
     FIG. 8 is a sectional view of the container taken along the line 8--8 of FIG. 2. 
     FIG. 9 is a sectional view of the container taken along the line 9--9 of FIG. 2. 
     FIG. 10 is a plan view of a stand of the noise absorber 
     FIG. 11 is a bottom plan view of the stand. 
     FIG. 12 is a side view of the stand. 
     FIG. 13 is a sectional view of the stand taken along the line 13--13 of FIG. 10 
     FIG. 14 is a front view of the stand. 
     FIG. 15 is a rear view of the stand. 
     FIG. 16 is a sectional view of the stand taken along the line 16--16 of FIG. 10. 
     FIG. 17 is a sectional view of the noise absorber in a mounted condition. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of a noise absorber according to the present invention will now be explained hereunder referring to the drawings. 
     As shown in FIG. 1, a noise absorber of the invention comprises ferrite pieces 1 and 3, a container 5 and a support member or a stand 7. Each of the coupling members or the ferrite pieces 1 and 3 is in the shape of a cylinder divided in half along abutment faces which lie in a plane defined by the axis of the cylinder so as to enclose wires when combined with one another. The ferrite pieces 1 and 3 have indentations (not shown) in their side faces for receiving a projection 15 and other protrusions of the container 5 as described later. The container 5 comprises a first upper case 11 and a second lower case 13 interconnected by a hinge 9 for housing the ferrite pieces 1 and 3, respectively. As shown in FIGS. 2 through 9, the container 5 has a projection 15 and protrusions 17, 19 and 21 on an inner peripheral surface of the upper case 11. The projection 15 engages the corresponding indentation of the ferrite piece 1, thereby supporting the ferrite piece 1 inside the upper case 11. The protrusions 17, 19 and 21 offset the allowance of the outer dimension of the ferrite piece 1. The upper case 11 is provided with a disposing space or opening 23 within which a leaf spring 24 is disposed as shown in FIG. 17. The leaf spring 24 presses or biases the ferrite piece 1 against the opposite ferrite piece 3 such that the end faces of the ferrite pieces 1 and 3 intimately abut one another. The upper case 11 is also provided with an engaging hook 29 on a first latch end for closing the container 5 and a first protective frame 27 on the same end for protecting the engaging hook 29. The protective frame 27 has an opening 25 for releasing a hook receiver 45 of the lower case 13 from the engaging hook 29 of the upper case 11. Handles 31 axially extend from both opposed sides of the latch end of the upper case 11. 
     In the same manner as the upper case 11, as shown in FIG. 2, the lower case 13 is provided with a projection 33 and protrusions 35, 37 and 39. The projection 33 engages a corresponding indentation provided in a side of the ferrite piece 3, thereby supporting the ferrite piece 3 inside the lower case 13. The protrusions 35, 37 and 39 offset the allowance of the outer dimension of the ferrite piece 3. The lower case 13 is also provided on a first latch end with a hook receiver 45 for receiving and engaging the engaging hook 29 of the upper case 11 and further, with a second protective frame 43 for protecting the hook receiver 45 and an engaging hook 51 of the stand 7. The protective frame 43 has an engaging aperture 41 for engaging the engaging hook 51 of the stand 7. Handles 47 axially extend from both opposed sides of the first latch end of the lower case 13. 
     As shown in FIGS. 10 through 16, the stand 7 comprises the engaging hook 51 located at the center facing toward the front of a base 50 of the stand 7. Side walls 55 and 57 are provided on respective sides of the engaging hook 51. The side walls 55 and 57 have support surfaces 53 which have a curvature substantially corresponding to the curvature of the outer peripheral surface of the upper and lower cases 11 and 13. The side walls 55 and 57 are connected and reinforced by a connecting member or board 59 therebetween. As shown in FIG. 12, the side walls 55 and 57 are partly hollowed out to form scoops 61. A securing aperture 63 is formed in a rear portion of the base 50 to receive a fixing or securing member M, such as a rivet, for fixing the stand 7 to a chassis or a printed board. As shown in FIG. 17, a bottom surface 65 of the base 50 is substantially at the same height as a portion of a bottom surface 13a of the container 5 when the stand 7 is integrally connected to the container 5. Thus, the container 5 and the stand 7 are secured on the same plane while maintaining the relative positions thereof. 
     In operation, as shown in FIG. 17, by engaging the engaging hook 29 of the upper case 11 with the hook receiver 45 of the lower case 13, the container 5 is closed. The ferrite pieces 1 and 3 are intimately abutted on their abutment faces to form a cylinder. Wires are located at a predetermined position such that the wires are disposed in a hollow central section 70 defined by the ferrite pieces 1 and 3. Once the stand 7 has been fixed on a chassis or a printed board by the fixing member M, the container 5 is connected to the stand 7 by engaging the engaging aperture 41 of the second protective frame 43 with the engaging hook 51 of the stand 7. The container 5 can be closed either before or after connection to the stand 7. The container 5 may be connected to the stand 7, by engaging the engaging aperture 41 with the engaging hook 51, prior to fixing the stand 7 on the chassis or the printed board by inserting fixing member M in the aperture 63. 
     When the noise absorber, with the container 5 and the stand 7 integrally connected, is mounted to the chassis or a substratum, the bottom surface 65 of the stand 7 and the bottom surface 13a of the container 5 are at the same height. The support surfaces 53 of the stand 7 cover a flank support portion of the container 5. Since the stand 7 is contiguous to the flank support portion of the container 5, the support surfaces 53 and the bottom surface 13a of the container 5 cooperate such that container 5 is secured to the chassis or the printed board. Moreover, since the stand 7 is provided at the flank support portion of the container 5 without elevating the container 5, the height of the noise absorber as a whole is reduced. Therefore, the noise absorber can be mounted in a location with limited space. Further, since the stand 7 is provided at the flank support portion of the container 5, the noise absorber can be easily disassembled for repairing or other occasions by removing the stand 7 from the chassis or the printed board. 
     The invention has been described above with reference to a preferred embodiment shown in the drawings. Modifications and alterations may become apparent to one skilled in the art upon reading and understanding the specification. Despite the use of the one embodiment for illustration purposes, it is intended to include all such modifications and alterations within the scope and the spirit of the appended claims. 
     In this spirit, it should also be noted that in the embodiments as shown and described, the bottom surface 65 of the stand 7 and the bottom surface 13a of the container 5 are substantially at the same height. However, the noise absorber is also advantageous even when the container 5 is slightly larger making the level between the bottom surface 65 and the bottom surface 13a a little different. In this case, when the stand 7 is fixed to a chassis by the fixing member M, the stand 7 deflects, thus forcing the stand 7 and the container 5 to be firmly secured to the chassis and preventing backlash.