US 3353144 A
Description (OCR text may contain errors)
NOV. 14, 1967 R. J. BRooKMAN PATCHCORD ASSEMBLY Filed Jan. 2l, 1966 FIC. 2
INVENTOR. RQNALD om BRQQKMAN' BY ommwwwn Patented Nov. 14, 1967 3,353,144 PATCHCORD ASSEMBLY Ronald John Brookman, Harrisburg, Pa., assigner to AMP Incorporated, Harrisburg, Pa. Filed Jan. 21, 1966, Ser. No. 522,227 1 Claim. (Cl. 339-217) ABSTRACT F THE DISCLOSURE A patchcord assembly is provided having a conductive shell with a plurality of cantilever members extending therefrom for grounding the patchcord when inserted into a board member. An insulating insert is provided for protecting the cantilever members against over-stress and for supplying a partial restoring force thereto.
This invention relates to the art of electrical connectors and more particularly to a new and novel plug contactor or patchcord for use with coaxial or shielded wire.
A principal object of the present invention is to provide a plug contactor which is durable and reliable in operation while being relatively inexpensive to produce.
Another object is to provide a plug contactor which will exhibit excellent electrical characteristics after repeated insertions into and withdrawals from a plugboard.
Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purpose of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.
In the drawings, in which like reference numerals refer to like parts:
FIGURE 1 is a perspective view of a plug contactor made in accordance with the teachings of the present invention; and
FIGURE 2 is a longitudinal cross-sectional view of the plug contactor of FIGURE l.
Referring now to the figures there is shown a plug contactor of the present invention which is received in an aperture 12 of a board member 14. Board member 14 may be a portion of a connector block or may be part of a plugboard assembly having hundreds or thousands of apertures such as 12 into which large numbers of contactors 10 may be inserted to, in effect, program connections between leads such as 16 and thereby between computer components connected to such leads. The contactor 10 effectively terminates lead 16 in a manner to be described. Board 14 may be of an insulating material such as phenolic resin or diallyl phthalate and normally has a thin conductive sheet such as 18 on one side thereof to effectively terminate the shielding of each patchcord cable in common with the shielding of all the other patchcords.
The coaxial or shielded cable 16 typically comprises a center conductor 20 surrounded by a cable dielectric 22. A shielding layer 24 is disposed around the dielectric 22 and is covered by the outer insulating sheath 26.
The contactor 10 comprises a central pin member 28 which is effectively terminated to the center conductor 20 of the cable. A generally cylindrical metallic outer shell 30 is effectively terminated to the cable shield or braid 24 by means of a ferrule assembly. The ferrule assembly comprises an outer ferrule member 32 disposed around the circumference of the outer shell 30 at the rearward end thereof and an inner ferrule member 34 disposed within the end of the outer shell 30. An eyelet member 36 having an upturned flange 38 is disposed between the cable dielectric 22 and the braid 24 and eooperates with the inner and outer ferrule members to effect a termination. Radial force applied to the outer ferrule member 32 will cause the shell 30 to be securely fastened between the ferrules 32 and 34 and will cause the braid 24 to be secured between ferrule 34 and eyelet 36 thus allowing the outer conductive path of the cable to be carried by the braid and through the shell member 30.
The rearward portion of shell 30 and the ferrule assembly is surrounded by an insulating boot 40 which serves the dual function of providing external insulation to the contactor in the termination area and also to provide a means for manually grasping the contactor and inserting it into or withdrawing it from a plugboard. The boot 40 is provided with strain relief portions 42 and 44 and an intermediate finger grasping portion 46.
The outer shell 30 is provided with a circumferential ridge 48 which serves as an abutment for the forward end of the boot to prevent damage to the boot and also serves as a means for limiting the insertion of the contactor into the board. The shell is further provided at its forward end with a series of spaced longitudinal fingers 50 having detents 52 at the ends thereof. The detents 52 join the fingers 50 at a radially extending portion 54, the portion 54 serving to seat against the forward face of the board 14 when the contactor is inserted therein. The detents 52 and portions 54 will engage the conductive sheet 18 and thus effect a termination of the conductive path extending through the cable braid.
Within the shell 30 and surrounding the central pin member 28 is an insulating insert 56 which is retained in position relative to the shell 30 by a plurality of dimples 58. Insert 56 is provided at its rearward end with an enlarged bore 60 for accommodating an enlarged end portion 62 on the pin 28 to thus retain the pin in position. A further insulating insert 64 is disposed within bore 60 and abuts against the end 62 of the pin 28 and against the flange 38 on eyelet 36 to thus maintain the various parts in their assembled position. Insert 56 is provided with a flange portion 66 which meets the shell 30 at the point where the fingers 50 are secured to the cylindrical portion of the shell. As can be seen the fingers Si) function generally as a plurality of cantilever beams. The flange 66 serves as a pivot point about which the fingers 50 may rotate during insertion and withdrawal of the contactor.
The diameter of the cylindrical portion of shell 30 and the fingers 50 thereof is generally equal to or slightly less than the diameter of the aperture 12 in the board 14. However the diameter of the detents 52 lat the radially extending portion 54 is greater than the diameter of aperture 12 and therefore these portions will be cammed inwardly d-uring insertion and withdrawal of the contactor. To allow for this inward camming movement of the detents 52 and thus the lingers 50 the insert is provided with a pair of relieved portions 68 and 70 separated by a circumferentially extending flange 72. The outer diameter of flange 72 is less than the inner diameter of fingers 50 and thus permits the lingers to move inwardly. However the flange 72 limits the extent to which the fingers may move in order that the fingers will not become overstressed during insertion or withdrawal. Further the flange 72 provides a partial restoring force to the fingers 50 in that the flange will tend to force the fingers radially outward into firm engagement with the aperture in the conductive sheet 18.
At the forward end 'of insert 56 there is provided an enlarged end 74 which insures that no short will occur between the outer conductive path carried by the shell 30 and the inner conductive path carried by the central pin member 28. The end 74 further provides a means for guiding the contactor into the aperture 12 and prevents accidental damage to the detents S2 during insertion, such damage being possible if a detent 52 would contact the rearward face of the board 14 and be -bent outwardly rather than being inserted into the aperture.
If the insert 56 was not provided with the Harige 72 the contact lingers 50 would eventually become overstressed and lose their resiliency thus resulting in a poor electrical connection between the lingers and the conductive sheet 18. A buildup in manufacturing tolerances could result in an oversized contactor and an undersized aperture which would mean that the fingers 50 would be cammed inwardly further than would be desired and this excess movement of the fingers 50 could very well exceed the design specifications of the fingers. The addition of ange 72 provides a simple and inexpensive means for insuring long life of the fingers 50 and excellent electrical terminations.
Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be dened in the following claim when viewed in their proper perspective against the prior art.
What is claimed is:
In a plug contactor adapte-d for use with shielded cable including a central pin member adapted to be terminated to the center conductor of the cable and a conductive shell adapted to be terminated at one end to the shielding of the cable and having at its other end a plurality of cantilever members each carrying a detent adapted for radial movement to latch the contactor Within a board, the improvement comprising an insulating insert disposed between said shell and said pin member, said insert having a portion adjacent the fixed end of said cantilever members with a diameter approximately equal to the insi-de diameter of said cantilever members to thus serve as a pivot point for said cantilever members, said insert further having an enlarged end section disposed beyond the end of said conductive shell, said enlarged end serving to insulate said cantilever members from said central pin member and further serving to guide said plug contactor into an aperture in the board, a ange disposed on said insert between said pivot portion and said enlarged end, said ange lying beneath said cantilever members and having an outer diameter slightly less than the inside diameter of said cantilever members whereby said cantilever members are normally out of Contact with said flange, said insert having a radially relieved section adja- 0 cent said flange and underlying the free ends of said cantilever members to permit inward radial movement of said cantilever members, said flange serving to limit the inward movement of said cantilever members and to Vprovide a partial restoring force thereto to displace said 5 detents radially outward into` contact with the board.
References Cited UNITED STATES PATENTS o 836,805 11/1906 Dozier 339-217 2,711,011 6./1955 Weisberg 29-206 2,983,895 5/1961 Pasik 339-217 3,112,977 12/1963 Long et al 339-217 3,284,755 ll/l966 Mummey et al 339-217 MARVIN A. CHAMPION, Primary Examiner.y R. S. STROBEL, AssistantExan/zz'rzen