Abstract:
A modular interface connection system having a receiver and a test adapter. The receiver includes a non-circular torsion shaft for providing improved strength and ease of assembly and a cover for providing safety. The test adapter has a frame, a shield, and one or more bushings, which provides easy access to contacts, patchcords and modules in the test adapter for troubleshooting, repairs and maintenance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Provisional application No. 60/330,887, filed Nov. 2, 2001; Related application Ser. No. 10/042,332 for a modular test adapter for rapid action engagement, filed Jan. 11, 2002. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates broadly to electrical connectors and more particularly to that specialized class of connectors, which are increasingly required in computer interface equipment. Such equipment requires the frequent placement of individual test adapters with their multiple ranks and files of minute electrical contacts in operative engagement with the coacting electrical contacts of receivers. It is imperative that the receiver contacts and individual test adapter contacts engage with precision to minimize wear and to prevent damaging the delicate and expensive equipment. 
     2. Description of the Related Art 
     One example of prior art interface systems was disclosed in U.S. Pat. No. 4,329,005, entitled “Slide Cam Mechanism for Positioning Test Adapter in Operative Relationship with a Receiver,” which was assigned to Virginia Panel Corporation. In the &#39;005 Patent, the receiver included an inner frame and outer walls. Between the outer walls and adjacent side of the receiver frame were placed fixed hanger plates provided with straight slots and interior slides having coacting cam slots. The slides were driven by a hand lever and attached round torsion shaft with connected linkage having an over-dead-center locked position. The individual test adapter, or ITA, had four split roller dual bearings or rollers on common dry lube sleeves that would rotate oppositely during the camming action to minimize friction. The individual test adapter rollers rested on dwell shoulders of the cam slots and then descended through the straight slots during movement of the slides of the receiver to produce positive straight-on engagement of the test adapter and receiver multiple contacts. The slides had elongated linear guide bearings with dry lube pads for precision free movement. The slides were connected to a cylindrical torsion shaft via linkage. 
     Various covers and housing for interfaces are known. Several Virginia Panel products, PN&#39;s 410112341 and 410112458, use a box housing with detachable cover plates. Virginia Panel PN 410112394 and 410112454 have an L-shaped enclosure with a removable, hinged cover. The L-shaped cover also uses detachable cover plates to access connections underneath the covering. Flat cover ITA enclosures, such as Virginia Panel PN 410112286 and others, with a removable cover plate that mount to the ITA with screws are well known. 
     Another prior art system sold by Virginia Panel Corporation included a receiver that included slides similar to those disclosed in the &#39;005 patent but used pins at two corners, diagonal from one other, on the receiver. These pins inhibited vertical movement of the ITA in the receiver to produce straight-on engagement. This prior art system, shown in FIG. 6, included machined siderails  501  and a cylindrical torsion shaft. 
     Although these devices generally functioned well and provided advantages over prior devices, the devices did not provide users with convenient access to the connectors and wires of a test adapter after the test adapter had been assembled. Such access may be desirable to perform troubling shooting tasks and repairs on the test adapters. Further, the devices included many components, including some machined parts, which contributed to expense and increased time for manufacturing and assembling the products. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above circumstances and has as an object to provide an improved connection interface system having fewer parts and that is easier and less expensive to manufacture and assemble. A further object of the invention is to provide easier access to contacts and wiring for troubleshooting and repairs. 
     Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of this specification illustrate some embodiments of the invention and, together with the description, serve to explain the objects, advantages, and principles of the invention. In the drawings, 
     FIG. 1 is a front perspective view of a preferred embodiment of modular interface system in accordance with the present invention. 
     FIG. 2 is an isometric view of a preferred embodiment of a modular interface system in accordance with the present invention. 
     FIG. 3 is a perspective view of a preferred embodiment of a portion of a receiver of a modular interface system in accordance with the present invention. 
     FIG. 4 is a rear perspective view of a preferred embodiment of a modular interface system in accordance with the present invention. 
     FIG. 5 is an assembly drawing of a preferred embodiment of a receiver (without a cover) of a modular interface system in accordance with the present invention. 
     FIG. 6 is a front view of a receiver of a prior art interface connection device sold by Virginia Panel Corporation. 
     FIG. 7 is a top view of a preferred embodiment of an assembled receiver of the present invention. 
     FIG. 8 is a side view of a preferred embodiment of a receiver of the present invention with its cover removed. 
     FIG. 9 is a side view of a preferred embodiment of a test adapter cover of the present invention. 
     FIGS. 10 a, b , and  c  are side, cross-sectional, and top views of a preferred embodiment of a portion of the linkage used on a receiver of the present invention. 
     FIG. 11 a  illustrates a second side view of an embodiment of the present invention. 
     FIG. 11 b  illustrates a cross-sectional view of a preferred embodiment of the complimentary mating surfaces of the present invention. 
     FIG. 11 c  illustrates a cross-sectional view of an alternative embodiment of the complimentary mating surfaces of the present invention. 
     FIG. 12 illustrates a preferred bushing placement of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A preferred embodiment of the present invention is shown in FIGS. 1-5. The interface connection system or device includes two basic components, a receiver  100  and a test adapter  300 . The receiver  100  typically is connected to automatic test equipment and the test adapter is typically connected to a unit under test. An interface connection system of the present invention with the test adapter  300  in a mated position with the receiver  100  is shown in FIGS. 1 and 4. 
     The receiver  100  includes a variety of sub-components, which are shown in FIGS. 2,  3 ,  5 ,  7  and  8 . The aluminum receiver frame  110  includes a number of holes  114  in opposing ends for use in securing modules in the receiver frame  110 . Standard modules such as those used with prior art interface systems and that are readily available on the market may be used with the receiver of the present invention. Guide pins  115  are placed as one or more corners of the receiver frame  110  for guiding a test adapter into the receiver  100 . In a preferred embodiment, the receiver frame  110  has two guide pins  115  placed at comers diagonal from one another. 
     Slides  120  in this particular embodiment are made from flat metal plates. Each has two guide slots  124  and two Cam slots  122 . The slides are mounted onto the receiver frame  110  using shoulder screws  112  and washers  118 . A washer  118  and a bearing  117  are placed onto each shoulder screw  112 . The shoulder screw  112  is then inserted through a guide slot  124  in a slide  120  such that the bearing  117  on the shoulder screw is within the slot  124  in the slide  120 . The shoulder screw  112  is then screwed into a hole  116  in the receiver frame  110 . Each shoulder screw  112  has a bearing  117  on it to permit its respective slide  120  to move linearly along the length of the receiver frame  110 . Other embodiments for the slides  120  are of course possible and contemplated for use with the present invention, including a system having two or more slides  120  on each side of the receiver frame  110  in which each slide  120  includes a single cam slot  122  and is mounted on a single bearing  117  to provide non-linear reciprocation of the slide  120 . 
     Each slide  120  in the preferred embodiment also includes a hole  121  in one end for receiving a bearing surface  167  of first link  166  which in turn is connected to the receiver frame  110  via a second link  162 . The first link  166  has two bearing surfaces  167 ,  168 . The second link  162  has a non-circular opening  163  for receiving a mating, non-circular torsion shaft  150 , a bearing surface  164  for insertion into hole  115  in the receiver frame  110 , and a hole  165  for receiving a bearing surface  168  of the first link  166 . The non-circular torsion shaft  150  provides stable connections to the handle  130  and the second link  162  without the use of or need for pins while still transmitting torque. Linkage  162 ,  166  connects the non-circular torsion shaft  150 , to the receiver frame  110 . The linkage  162 ,  166  design with incorporated bearing surfaces  164 ,  167 ,  168 , reduces the number of parts needed in receiver and interface test adapter design. 
     In the preferred embodiment, the non-circular torsion shaft  150  and non-circular opening  163  are square. However, other shapes having angles and planar surfaces, for example, triangles, octagons, a star shape, a criss-cross, and the like, allow the shaft to engage because of its shape, and avoids the need for pins or other additional parts and securing mechanisms. It will additionally be appreciated by one skilled in the art that it is not necessary for the entire torsion shaft  150  to have the non-circular shape. Rather, the ends of the torsion shaft that fits with the handle  130  and the links  162 ,  166 , as further described below, is the minimum portion which must have a torque-transmitting, e.g., non-circular, shape. A spacer  169  also is placed upon the torsion shaft  150  on one side of the receiver frame  110  for spacing a handle  130  from the receiver frame  110 . 
     The handle  130  in the preferred embodiment has a recessed form in the preferred embodiment such that it comprises a first portion  131  having a non-circular hole near one end for receiving the non-circular torsion shaft  150 , a second portion  132  extending at an angle away from the receiver frame  110 , and a third portion  134  parallel to the first portion. Other embodiments may, of course, use handles of other forms, including a straight handle. A plastic or rubber grip  138  may be placed on the handle  130  such as is shown in FIG.  5 . The grip  138  in the preferred embodiment has indentations  139  for accommodating a user&#39;s hand. 
     Once the torsion shaft  150  is inserted into the non-circular hole in the handle, the handle  130  is welded onto the torsion shaft  150 . A cover  200  is placed over the receiver frame  110 , slides  120 , linkage  162  and  166 , spacer  169  and torsion shaft  150 . The cover  200  includes a slot  220  such that the torsion shaft  150  extends through the slot  220  and the handle  130  remains outside the cover  200 . The cover  200  further has openings or slots  230  for permitting test adapter pins  320  to enter into the receiver  200 . The cover provides safety and aesthetic functions by covering the linkage  162  and  166  and slides  120 . The cover may be secured to the receiver frame  110  in a variety of different ways, including a lip structure for snapping the cover  200  onto the receiver frame  110  or screws. 
     The test adapter  300  includes a frame  310 , one or more bushings  350 , and a shield  400 , or cover. The test adapter frame  310  is made from a metal such as aluminum and includes holes  312  for mounting standard modules  314  such as used in the prior art and are readily available in the market. Two pins  320  are mounted on each side of the test adapter frame  310 . When the test adapter  300  is engaged in the receiver  100 , the test adapter pins  320  enter into the openings of the cam slots  122  in the slides  120 . When the handle  130  is closed, the slides  120  move and the test adapter pins  320  are forced into the face of the receiver  100 . The test adapter frame  310  has holes (not shown) at one or more corners for receiving guide pins located on the receiver frame  110 . In a preferred embodiment, the test adapter frame  310  has two holes placed at corners diagonal from one another. 
     The test adapter frame  310  and shield  400  include complimentary mating surfaces  316 ,  420 , which allow the test adapter frame  310  to receive the shield  400  while they are removably engaged. As illustrated in FIGS. 2,  11   a , and  11   b , the test adapter frame  310  includes a tongue  316  structure for engaging with the shield  400 . The shield  400  includes a cover body  410  and a groove structure  420 . The tongue and groove structure  316 ,  420  slide together, permitting the shield  400  to be removed from the test adapter quickly and easily to perform troubleshooting, repairs, and maintenance to the contacts, wires, and modules mounted in the test adapter  300 . FIG. 11 b  is the cross-sectional view of a mated tongue and groove structure  316 ,  420  taken at line I of FIG. 11 a.    
     The shield  400  can be made from a wide variety of materials. Preferably, an insulator, e.g., thermal plastic, is used. However, other nylon, ceramic, or polymer, i.e., thermoplastic, materials may be used. Additionally, the shield  400  can be made from material that further provides EMI shielding for the electrical connections between the receiver  200  and the test adapter  300 . Shielding may be provided by embedding conductive material within the shield  400  or by applying conductive material to the shield surface. Preferably, the shield  400  is formed from a 6/6 nylon with 13-30% glass and 10% stainless steel, having the property of being an insulator with some conductivity. 
     The complimentary mating surfaces  316 ,  420  of the shield and the test adapter frame preferably mate closely, so that when the shield  400  is installed on the test adapter frame  310 , the juncture between is also an effective EMI shield for electrical connections housed within the receiver  200  and the test adapter  300 , and EMI does not leak through the engaged tongue and groove structures  316 ,  420 . 
     Referring to FIG. 11 c , an alternative embodiment of the complimentary mating surfaces  316 ,  420  for a shield  400  with EMI shielding properties is illustrated. The complimentary mating surfaces  316 ,  420  form a butt joint. An EMI gasket  500  is placed in a groove  316  and is positioned between the complimentary mating surfaces,  316 ,  420 . At least one fastener  510 , for example a screw, is inserted in pre-drilled, threaded holes (not shown) in the shield  400  and test adapter frame  310 . Where EMI protection is not needed, the shield  400  can simply be screwed to the test adapter frame  310 . Although the fastener illustrated in the preferred embodiment is a screw, it will be appreciated that other fasteners, such as latches, or quick turn fasteners may be used. 
     Another alternative embodiment of the complimentary mating surfaces  316 ,  420  for a shield  400  with EMI shielding properties, not shown, includes flat complimentary mating surfaces  316 ,  420 . The EMI gasket  500  in the form of a flat tape is placed on either complimentary mating surface  316 ,  420 . The shield  400  is secured to the test adapter frame  310  with at least one fastener  510 , sandwiching the EMI gasket  500  between the test adapter frame  310  and the shield  400 . 
     Although the embodiment of FIGS. 2,  11   a ,  11   b , and  11   c , illustrate the complimentary mating surfaces  316 ,  420 , using a tongue and groove structure, it will be appreciated by those skilled in the art that a variety of structures can be used to secure the shield  400  to the test adapter frame  310  and provide EMI shielding, while still being easily removed when performing troubleshooting, repair, or maintenance. It will be further appreciated by one skilled in the art that the complimentary mating surfaces  316 ,  420  can be engaged in a variety of ways besides sliding without departing from the scope of the present invention. 
     Additionally, it will be appreciated that by those skilled in the art that, being complimentary, the complimentary mating surfaces can be reversed between the shield  400  and the test adapter frame  310  without departing from the scope of the present invention. For example, the groove may be located on the test adapter frame  310  and the tongue may be located on the shield  400 . Similarly, the complimentary mating surfaces  316 ,  420  can be reversed between the shield  400  and the test adapter frame  310  in alternative embodiments of complimentary mating surfaces  316 ,  420 . 
     At least one bushing  350  is mounted to the test adapter frame  310 . Bushings  350  are mounted to the test adapter frame  310  using screws (not shown) placed through holes  352 . The bushings  350  accommodate wires extending from contacts in modules placed in the test adapter frame  310 . The bushings  350  may further include a clamp structure (not shown) for securing the wires extending out of the test adapter  300 . The bushings  350  are mounted to the tested adapter frame  310  so that the bushing  350  remains in place to support and protect the accommodated wires extending from contacts in modules placed in the test adapter frame  310 , regardless of whether the shield  400  is installed on the test adapter frame  310  or removed during any troubleshooting, repair, or maintenance activities. Alternatively, the bushings  350  can be formed integrally with the test adapter frame  310 , or are otherwise fixed to the test adapter frame  310  so that the shield  400  can be removed without releasing the wires from the bushings  350 . 
     Referring to FIG. 12, a preferred placement of the bushing  350  is illustrated. The test adapter frame  310  is positioned in a vertical plane shown by line II. The bushings  350  of this embodiment are angled as depicted by line III. An angle, α, is formed measuring the distance the bushing  350  is angled away from the vertical plane. If the bushing is also vertical, any wire bundles extending from the bushing  350  block a worker&#39;s access to test equipment directly behind the wire bundle. If the bushing extends perpendicular to the vertical plane, wire bundles would also extend straight out from the vertical plane, making it difficult for workers to reach around the wire bundles or otherwise get close to the interface test adapter without accidentally de-mating any connections. Setting the bushing at an angle allows a worker access to test equipment directly behind the bushing  350  without disturbing the wiring in the bushing  350 . The angle α is a value between 0 degrees and 90 degrees from the vertical plane of line III. Preferably, the angle α measures 5-25 degrees from the vertical plane of line III, and more preferably, 10 degrees, ±1 degree from the vertical plane of line III, to provide sufficient space from the vertical plane without extending away from the vertical plane so far that the wires are difficult to work around. 
     The foregoing description of the preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiment was chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and the entirety of their equivalents.