US 3252127 A
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Description (OCR text may contain errors)
y 7, 1966 A. s. WOODWARD 3,252,127
PLUG CONTACT Filed Oct. 5, 1963 g sh t s t 1 I ave n20 r J5! rihur S Woodward, by
y 7, 1966 A. s. WOODWARD 3,252,127
PLUG CONTACT Filed Oct. 5, 1963 2 Sheets-Sheet 2 E EIEHEHIEWEHIEH E-THEE Iuve for flrihur 'S. Woodward,
United States Patent 1 3,252,127 PLUG CONTACT Arthur S. Woodward, Natick, Mass., assignor to United- Carr Incorporated, a corporation of Delaware Filed Oct. 3, 1963, Ser. No. 313,584 4 Claims. (Cl. 339-217) contact.
A primary object of the present invention is to provide efiicient, easy axial insertion or axial withdrawal of a plug when the insertion or withdrawal forces are applied at the base, and having means of preventing axial Withdrawal when the forces are applied at the terminal end of the plug.
Another object of the present invention is to provide a contact spring means having a configuration formed to prevent axial withdrawal on application of pressure at a terminal end.
Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.
In the drawings:
FIG. 1 is a side elevation of the contact assembly;
FIG. 2 is a side elevation of the spring element of the assembly shown in FIG. 1;
FIG. 3 -is a section and part elevation of the assembly of FIG. 1 broken off and engaged with a jack panel and a template;
FIG. 4 is a section, partly in elevation, showing the contact of FIG. 1 broken off and partially engaged in a template panel and also a section of the jack panel;
FIG. 5 is a side elevation, partly in section, of the assembly shown in FIG. 1 with the plug cover removed; and
FIG. 6 is a section, partly in side elevation, of a series of the contacts shown in FIG. 1 engaged with a mating board and with a programing board.
Referring to the drawings, there is shown, in FIG. 1, a broken-off view of a programing patch cord assembly. This plug assembly comprises a cover 10, a body element 12, a spring member 14, and a wire lead 16. The cover 10 is formed of a material having insulating qualities and the applicant has discovered that a vinyl plastic is excellent for forming this part. 1
The spring member 14 comprises a series of four legs connected at one terminal end to form a bight portion 18. Each pair of legs is in opposed relation to each other and a pair will be referred to as the engagement legs 20 and the remaining two legs as the guide legs 22. The engagement legs 20 are in opposed relation to each other as are the guide legs 22 and each of the legs are spaced from the other to form -a cage. Each of the engagement legs 20 and the guide legs 22 comprises a terminal end integral with the bight portion 18 and extending away from the bight portion 18 to form an obtuse angular portion 24 having a diverging portion and a converging portion. The converging portion is directed toward the axis of the spring member 14. Integral with the converging portion is a second diverging portion 26 formed with a second converging portion 27 in a second angle portion 25 which is more acute than the angle formed by the obtuse angular portion 24. The leg then continues as a free terminal end 34, which is substantially in parallel relationship with the axis of the spring member 14. The area defined by the angle formed by the converging portions and the second diverging portions 26 delineates a throat area or volume 30. The width of the legs 22 and 20 is reduced to form a connecting portion 32 at the throat area 30.
The body element 12 is formed of an electrically conductive material, such as brass and comprises a base 3,252,127 Patented May 17, 1966 portion 36 having a generally tubular configuration closed at one end from which a pin portion 38 extends. A channel or trepan 40 is formed adjacent to and circumscribing the point of jointure between the pin portion 38 and the base portion 36. The pin portion 38 comprises a solid cylindrical rod of substantially less diameter than the remaining portion of the body element 12 and has a free arcuate terminal end 42. A circumferential groove 44 is formed intermediate the free terminal end 42 and the beginning of the body element 12.
The cover 10 is formed of a non-conductive material 7 having a certain amount of elasticity, is generally tubular in configuration and has a series of spaced, circumferential ribs 46 formed around its external surface. A head collar 48 is formed around and adjacent one of the terminal ends of said cover 10 and at the other terminal end a base collar 50 is formed.
The terminal ends 34 of the spring member 14 are engaged with the body element 12 by collapsing the wall of the trepan 40 inwardly toward the axis of the body element 12 thereby placing the spring element 14 in a fixed relation thereto. In a relaxed or non-engaged position the circumferential center line (i.e. at the knuckle formed by the converging portion 24 and the diverging portion 26) of the throat is aligned just to the rear of the groove 44. The bight 18 is spaced from the terminal arcuate end 42 of the pin 38, and the legs 20 and 22 form a cage about the pin 33.
A wire lead 16 is inserted into the tubular channel formed by the tubular body element 12 at the end opposite from the pin 38. The body element 12 is then crimped at one or two predetermined points (FIG. 5) to lock the bared lead electrically with the body element 12. It is also possible to crimp the body element 12 in another area (FIG. 5) about the insulation of the lead 16. Obviously, the lead 16 is an insulated type which has insulation removed from the end in engagement with the body element 12.
To engage the cover 10 with the assembly of the body element 12 and the spring member 14, it may be integrally molded about the body element 12 and lead 16 so that the head collar 48 may be aligned adjacent the external point of juncture between the trepan and the terminal ends 34 of the spring. Preferably, the head collar 48 will cover any exposed area of the base portion 36 which may occur. The base collar will cover a portion .of the lead 16 making -a dust proof and water proof covering at that point. Naturally, the cover 10 may be slipped over the body element 12 if required.
To engage the patch cord assembly to a template 52 and a jack panel 54, it is first engaged with a stepped hole 56 formed in the template 52. The stepped hole 56 is open at both ends and has a shoulder 58 formed intermediate the open ends. One opening of the stepped hole 56 is slightly less in diameter than the knuckle diameter of the second angular portion 25. During the insertion, the diverging portion 26 is flexed toward the axis of the spring element 14 thereby increasing the acuity of the obtuse angular portion 24 and in turn moving the center line of the throat "30 into annular alignment and engagement with the groove 44. This action reduces the knuckle diameter of the second angular portion 25 formed by the diverging portion 26 and the converging portion 27 sufficiently to allow entrance into the stepped hole 56. When the surface adjacent to the trepan 40 abuts the template 52, the relationship of the second angle portion 25 to the shoulder 58 is such as to allow the obtuse angle portion 24 to return to its original state. This fact in turn allows the effective knuckle diameter of the second angle portion 25 to return to its original diameter thereby lockingthe assembly with the template 52 as shown in FIG. 3. The internal diameter of the hole '56 is greater above the shoulder 58 than below. If an axial force were now applied to the bight portion 18 of the spring member '14, the resultant action would increase the locking action of the second angle portion ZSagamst the shoulder 58 of the template 52 by increasing or urging the increase of the knuckle diameter. It is, therefore, apparent that the only efiicient force of withdrawal must be applied at a point remote from the bight portion 118 and on or beyond the cover '10 in a manner which is the exact reversal of the manner and function of insertion.
The programming assembly, which includes the programming patch assembly and the template 52, can now be engaged with a jack panel '54 without fear of accidentally pushing the patch cord assembly from the engagement with the template 25. Furthermore, any accidental pressure against the bight 18 will have little or no disengagement effect on the programming assembly whether this may occur by accidental dropping on a floor or table or by hand. When it is accidentally dropped with the bight portion 18 in contact with a solid surface, the bight portion 18 will be forced against the free terminal end 42 of the pin portion 38 which will increase the acuity of the obtuse angle portion '24. This, in turn, reacts on the diameter of the throat area 30 which in turn attempts to reduce itself. Since the throat area 30 surfaces are bearing on the solid surface of the pin portion 18 rearward of the groove 44, this force is transmitted to the second angle portion whose knuckle diameter is urged to increase within the limits of the stepped hole 56 and thereby once again further locking the assembly to the template.
When the programming assembly is engaged with the jack panel 54, the bight portion 18 is inserted into a jack 60 with the following results. The obtuse angle portion 24 has a knuckle diameter greater than the inter nal diameter of the jack 60; therefore, after insertion,
this knuckle diameter is reduced to approximately the internal diameter of the jack 60 which in turn creates two forces, one of which increases the space, between the bight part 18, and the free terminal end 42 and'the second of which reduces the throat area diameter with the results set forth above. It is important that when the throat surfaces are in engagement with the groove 44 that the legs remain spaced from each other, this is assisted by connecting portion 32.
While there has been illustrated and described one preferred embodiment of the invention, it should be understood that the invention is best defined by the following claims.
1. An electrical plug for engagement with a jack or the like, said plug comprising a cover, a body element, a spring member and a wire lead, said spring member comprising a bight portion and at least two legs having portions in spaced, opposed relation and extending from said bight portion, each of said legs having a first angular portion integral with said bight portion and a second angular portion integral with said first angular portion and being more acute than said first angular portion, said body element having a base portion, means engaging said legs and means for engaging said lead and said cover circumscribing in abutting relation said body elemen and said body element having a pin, said pin having a free terminal end and extending from said base portion, between said legs and spaced therefrom and an annular groove formed on said pin intermediate said free terminal end and said base portion.
2. A plug as set forth in claim 1 wherein each of said first angular portions has a converging portion directed at the axis of said spring member and each of said second angular portions has a diverging portion integral with said converging portion to form a third angular portion adapted to engage said annular groove.
3. The combination of a plug and a template said plug comprising a cover, a body element, a spring mem her and a wire lead, said spring member comprising a bight portion and at least two legs having portions in spaced, opposed relation and extending from said bight portion, each of said legs having a first'angular portion integral with said bight portion and a second angular portion integral with said first angular portion and being more acute than said first angular portion, said body element having a base portion, means engaging said legs and means for engaging "said lead and said cover circumscribing in abutting relation said body element, and said body element having a pin, said pin having a free terminal end and extending from said base portion between said legs and spaced therefrom and an annular groove formed on said pin intermediate said free terminal end and said base portion, said template having an aperture formed therethrough, said aperture having an internal shoulder and said secondangular portion engaging said shoulder.
4. An electrical plug for engagement with a jack or the like, comprising a cover, a body element, a spring member, and a wire lead, said body element having a base portion and a pin extending therefrom, said spring member having at least one leg engaging said base portion and having a free terminal end and having a first angular portion in close proximity to said terminal end and a second angular portion of more acuity than said first angular portion and lying intermediate said first angular portion and said base portion, said cover circumscribing in abutting relation said body element and said body element engaging said wire lead.
References Cited by the Examiner UNITED STATES PATENTS 2,191,297 2/1940 Olson 339 252 2,244,975 6/ 1941 Tinnerman -5 2,398,684 4/1946 Woodward 339-252 3,008,118 11/1961 Mavity 339-217 FOREIGN PATENTS 577,456 5/ 1933 Germany.
PATRICK A. CLIFFORD, Primary Examiner,