1. Field of the Invention
The invention is directed in general to an angled coaxial cable connector and more specifically to such a connector that makes use of an insulation displacement termination method to minimize assembly time and connector size.
2. Discussion of Related Art
Coaxial cable connectors often have a right-angle, or some other angle, design to facilitate electrical engagement with connection ports or printed circuit boards. This can eliminate the need to significantly bend the cable, and thereby possibly damage the connection between the connector and cable, when making the electrical engagement. Typical right-angle coaxial cable connectors use traditional methods of terminating the cable in the connector such as soldering and crimping. Both have advantages and disadvantages. In the soldering method, the size of the connector can be relatively small because the cable is brought in perpendicular to an axis of the interface between two contact sections. However, this procedure is time consuming and often hazardous. The crimping method is faster and non-hazardous in comparison to the soldering method. There are two types of crimp configurations. One requires two contacts, resulting in increased component count. The other requires only one contact, but the cable has to be bent, so this method requires a longer connector length due to the bend radius of the cable.
One way of doing away with the need for two separate terminals crimped or soldered together to provide the right angle turn within the connector is disclosed in co-pending U.S. patent application Ser. No. 11/016,919, filed Dec. 21, 2004. A connector assembly has first and second main components. A terminal crimped on an end of a coaxial cable is inserted through the second component and secured in the first component when the two components are in a straight or in-line configuration. The cable is secured to the second component. Then the second component is rotated relative to the first component to bend the cable and transform the assembly into a right-angle connector.
U.S. Pat. No. 4,632,486 provides an example of how insulation displacement terminals have been used in coaxial cable connectors. A ribbon-type coaxial cable has its outer jacket and each conductive sheath stripped back from the inner insulation layer and signal wire. The cable is inserted into and secured by adhesive within a first housing part of insulating material. A second, separate housing part also made of insulating material contains female terminals having insulation displacement contact portions at one end. The insulation displacement contact portions protrude from the second housing part. When the two housing parts are guided together the insulation displacement contact portions cut through the inner insulation layers to contact the signal wires and electrically connect the signal wires with the female terminals. While the method disclosed in this patent may provide a solution for terminating ribbon-type coaxial cables, it requires a large, two-piece connector and does not address problems associated with connectors requiring center contact terminals with concentric outer terminal sockets. A smaller size, lower component count connector with a fast termination method would provide a significant improvement to these existing types of connectors.
Accordingly, it is an object of this invention to provide a right-angle coaxial cable connector that is as small as a contact interface and cable size will allow.
Another object of the invention is to eliminate the need for soldering and crimping methods for terminating the inner conductor of the cable.
A further object of the invention is to minimize the number of connector components while incorporating a fast termination method.
In carrying out this invention in the illustrative embodiment thereof, an electrically conductive, one-piece connector housing has a first, main cylindrical section for receiving a terminal device and a second, barrel section for receiving an end of a coaxial cable. The sections have intersecting interiors. The coaxial cable end is stripped to expose the inner insulation layer and a cut-back part of the outer conductive sheath is flared outward. The stripped end of the cable is inserted through the barrel section into the first section. A cable stop positions the cable end in a specific, proper location for electrical connection with the terminal device. This location can be visually confirmed by looking into the first section. Then a ferrule is used to crimp the flared sheath around the barrel section, securing the cable to the connector housing.
The cable stop can be provided by a projection within the first housing section against which the insulating layer of the cable end abuts. The projection creates a space between an inner conductive core or signal wire of the cable end and the conductive housing, electrically separating the core of the cable from the housing. Alternatively, the cable stop can be provided as an extension of a dielectric member associated with the terminal device.
The terminal device comprises an inner contact terminal having a female terminal part at one end and insulation displacement blades at an opposite end. The inner terminal is held within the dielectric member. An outer socket or contact is fit around the dielectric member. In one possible assembly process, the inner terminal, dielectric member and outer contact are secured together in fixed position. Press-fitting the outer contact into the first section of the connector housing causes the insulation blades on the inner terminal to cut through the insulation layer of the cable and physically and electrically contact the core.
In another possible assembly process, the dielectric member with the extension for providing a cable stop is press-fit into the first housing section before insertion of the cable end. The inner terminal is movable within the dielectric member, and after the cable end is positioned in the correct location the inner terminal with the insulation displacement blades is forced into electrical contact with the cable core. The outer contact is separately press-fit into the first housing section, either after the electrical connection is made or simultaneously with a single tool stroke acting on both the outer contact and inner terminal.
The invention enables the size of the connector to be reduced. It allows use of an insulation displacement termination method for faster termination of coaxial cables. There is a reduction in the number of components and the assembly process can be automated. These advantages combine to result in a low-cost and easier to assemble connector.
This invention, together with other objects, features, aspects and advantages thereof, will be more clearly understood from the following description, considered in conjunction with the accompanying drawings.
Referring now to
A connector body or housing 30 according to the present invention is shown in
The interior of the main section 32 comprises a series of chambers decreasing in internal diameter from the terminal mating end 34 to adjacent the cable receiving end 36. A first chamber 44 extends from the terminal mating end 34 back partially along the main section to an inclined step or ledge 46. A second chamber 48 stretches along the main section from the first chamber to an inclined step 50. A third chamber 52 extends from the step 50 along the main section to a first radial wall 54. A fourth chamber 56 continues back along the main section to a second radial wall 58. A dome-shaped depression 60 is formed in the radial wall 58 adjacent the second end of the main section 32.
The fourth chamber 56 intersects with the internal passage 42 through the barrel section 38 of the housing 30 at an opening 62 in an annular wall 64 of the chamber. On an opposite side of the fourth chamber from the opening 62, there is a cable stop surface formed by a protruding projection 66 at the junction of the annular wall 64 and the radial wall 58.
The purpose or function of the projection 66 is depicted in
As shown in
The different cross-section views of
The inner center contact terminal 72 has a first end 80 in the form of a female terminal part 82 and a second part or end 84 comprising insulation displacement surfaces or blades 86. The terminal 72 is illustrated as being stamped or otherwise manufactured in one piece and is made from an electrically conductive metal such as brass or stainless steel. The female terminal part 82 could alternatively be formed as a male terminal, depending on the type of terminal the connector housing 30 is meant to mate with. A center part or portion 87 of the terminal 72 has longitudinally spaced sets of resilient retention barbs 88, one set at a forward end adjacent the female terminal part 82 and another set at a rearward end adjacent the blades 86, for securing the terminal in the dielectric member 76. The retention barbs are depicted as angled cut-outs from the center portion 87. The center portion 87 also includes an orientation projection 89 adjacent the barbs at the forward end.
The dielectric insert or member 76 may be made from a material such as Nylon, Teflon, polybutylene-terephalate or any of a variety of extruded plastics. It comprises a first cylindrical segment 90, a second cylindrical segment 92 larger in outer diameter but shorter in length than the first cylindrical segment, and a short lip or rim element 94 on the opposite side of the second segment 92 from the first segment 90. The rim element 94 has a rounded or beveled edge 95. A ledge 96 is formed where the first segment 90 joins the second segment 92, and a radial stop surface 98 is formed at the juncture of the rim element 94 and second segment 92. As best seen in
The dielectric member 76 has a central passage 104 passing through it, with a narrower inner portion 106. Each end of the narrower portion 106 provides a stop surface 108 against which the retention barbs 88 of the center contact terminal 72 catch when the terminal 72 is pushed into the dielectric member. A slot 109 in an inner wall of the narrower passage portion 106 interacts with the orientation projection 89 on the center portion 87 of the terminal to orient and guide the terminal into the proper position. In the fully inserted, locked position, the female terminal part 82 extends through the first segment 90 of the dielectric member 76, the center portion 87 of the terminal is clamped by the retention barbs 88 within the narrower portion 106 of the passage through the member, and the insulation displacement blades 86 extend out of the rim segment 94 of the member.
The outer female socket or contact 74 is constructed to accept a standard male connector (not shown) for mating with the female terminal 72. Like the terminal 72, it may be stamped and bent or otherwise manufactured in one piece from a conductive metal such as brass or stainless steel. The contact 74 has a ring element 110 with an inner annular surface 112 and an outer surface 114. A first end 116 of the ring element is sized to receive the dielectric member 76. Spring fingers 118 extend from the ring element 110 for receiving the male connector through a second end 120.
The outer surface 114 of the ring element 110 adjacent the first end 116 has a short guide protuberance 122. The inner surface 112 of the ring element has a longitudinal rib (not shown in order to illustrate the channel 102 on the outer surface 100 of the second segment 92 of the dielectric member 76 in cross-section) and tabs 124 bent inward into an interior of the ring element. The tabs 124 are spaced from the first end 116 of the ring element 110 at a distance equal to the length of the second segment 92 of the dielectric member.
The dielectric member 76 (with the secured inner contact terminal 72) is inserted through the first end 116 of the outer contact 74. The channel 102 is aligned with the rib on the inner surface of the ring element 110 to orientate the insert and prevent rotation of the member relative to the outer contact. The outer surface 100 of the second segment 92 of the member is press-fit into the ring element until the ledge 96 abuts against the bent tabs 124.
The assembly of the terminal device 70 with the connector housing 30 is done in an automated process. A tool inserts the ring element 110 of the outer contact 74 through the first chamber 44 after aligning the guide protuberance 122 with the slot 69 (as shown in
Referring to
The main section 32 of the connector housing is modified to have a first chamber 134 adjacent the terminal mating end 34, a second, intermediate chamber 136 with a longitudinal slot 138 in its inner wall, and a third chamber 140 intersecting with the internal passage 42 through the barrel section 38 of the housing. The third chamber 140 is sized such that the rim segment 94 and its extended portion 130 of the dielectric member 76 can be press-fit into the chamber 140, with the extended portion 130 located across the chamber from the opening 62 of the passage 42. Recesses 142 are formed in a top or end wall 144 of the third chamber 140 directly aligned with the blades 86 of the terminal 72.
The connector housing main section 32 also includes an outer indentation 146, allowing the ferrule 24 to be brought in closer to a longitudinal center-line of the main section and thereby enabling the barrel section 38 to be shorter. This reduces the overall length of the connector. As illustrated in
The dielectric member 76 with the inner terminal 72 in the initial position within the member is first inserted into the main section 32 of the connector housing 30. The rim element 94 with its extended portion 130 is press-fit into the third chamber 140, holding the dielectric insert within the housing. The coaxial cable end 14 is then pushed through the barrel section 38 of the housing until it crosses the chamber 140 in the main section and abuts against the extended portion 130. The assembler then looks through the window 148 to make sure the cable end is contacting the dielectric member and electrically isolating the cable core 22 from the connector housing. If the inspection confirms this condition, the ferrule 24 is crimped over the braid 18 onto the barrel section to secure the cable to the connector housing in the correct position.
The outer female socket or contact 74 is generally of the same construction as in the first embodiment except that it includes a relatively short appendage 150 extending from the first end 116 of the ring element 110. The appendage 150 is positioned to close or cover the window 148 when the outer contact 74 is press-fit into the intermediate chamber 136 of the main section 32 after the dielectric member and cable end are assembled in the housing 30. The guide protuberance 122 on the outer contact is aligned with the slot 138 and the tool forces the ring element 110 of the outer contact into the intermediate chamber. The appendage 150 covers the window 148 internally as best illustrated in
In the last assembly step, the inner center contact terminal 72 is pressed toward the cable end 14 by exerting force on a push area 152 within the female terminal part 82. The insulation displacement blades 86 cut through the insulation layer 20 of the cable and make electrical contact with the core 22 as the set of retention barbs 88 adjacent the female terminal part abut against the associated stop surface 108 formed by the shortened narrower inner portion 132 of the passage through the dielectric member. This completed assembly is shown in
In one alternative assembly process, the inner center contact terminal 72 can be forced to terminate the cable prior to press-fitting the outer contact into the main section of the housing. This would have the benefit of allowing viewing of the cable termination by the blades 86 before the window is covered by the outer contact appendage 150.
Since minor changes and modifications varied to fit particular operating requirements and environments will be understood by those skilled in the art, this invention is not considered limited to the specific examples chosen for purposes of illustration. The invention is meant to include all changes and modifications which do not constitute a departure from the true spirit and scope of this invention as claimed in the following claims and as represented by reasonable equivalents to the claimed elements.
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