US 3120989 A
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Description (OCR text may contain errors)
Feb. 11, 1964 R s, sQLoRow ETAL 3,120,989
ELECTRICAL SOCKET CONTACT Filed April l0, 1961 2 Sheets-Sheet 1 ATTORNEY Feb- 11 1964 R. s. soLoRow ETAL 3,120,989
ELECTRICAL. SOCKET CONTACT Filed April l0 1961 2 SheetS-Shee 2 &\A\\\\\\\\\\\\\\ I X k\\\\\\\\\\\\\\\ FIG.8
USSFLL S SoLoeou SH/MUM? K3660/Ff@ INVENTORS ATTORNEY United States Patent C) 3,126,989 ELECTRICAL SOCKET CONTACT Russell S. Solorow, Norwalk, Conn., and Seymour Rosenfeld, Bronx, N.Y., assignors to Burndy Corporation, a I corporation of New York Filed Apr. 10, 1961, Ser. No. 101,785 3 Claims. (Cl. 339-256) This invention relates to electrical connectors and more particularly to socket type contacts for connector assemblies.
Socket type contacts, which are adapted to receive a mating pin type contact, are well known in the electrical connector art. Such contacts are frequently used in multiple contact assemblies, an example of which is disclosed in the Dupre and Rogoff United States Patent 2,710,384.
These contacts were originally permanently molded into the dielectric housing of the connector assembly. Later they were removably retained in mounting bores in the housing by means of locking panels or individual snap rings fitted over the contacts after they were inserted into the housing. Recently the contacts have been provided with individual latching springs which permit the contacts to be individually inserted and removed from the housing. These springs are customarily mounted to the periphery of the contact, or pass through the periphery of the contacts, to engage locking shoulders on the inside of the mounting bores in the housing. These latching springs may additionally be provided with a mating pin retention function.
While these external latching springs serve their purpose admirably, when the contacts are external to the housing the latching springs are occasionally snagged by foreign objects, damaging or removing the spring from the contact. Therefore, it has been found that it is desirable to mount the latching spring in the mounting bore in the dielectric housing and to utilize a smooth contact which is free from snagable projections.
For maximum strength and high dimensional accuracy it is desirable that the socket contact be formed of solid stock.
To prevent the entry of an oversize probe or contact, which might distort or otherwise damage the socket interior, or the pin retention spring, it is desirable that the contact be provided with what is commonly known as a closed entry or a front annulus of fixed diameter only large enough to pass the mating pin.
To provide proper contact pressure it is necessary to utilize a retention spring which extends into the socket and applies a force to the mating pin. Preferably it should be nonintegral with the body so that it may be designed with describable mechanical characteristics without regard to the spring materials electrical characteristics. However, the spring should be easily assembled and secured to the socket.
It is, therefore, an object of this invention to provide a socket type contact without external projections having a closed entry and a separate pin retention spring of unique characteristics.
A feature of this invention is a tubular socket with a spring insert disposed entirely inside said socket.
These and other objects of my invention are accomplished and new results obtained as will be apparent from the devices described in the following speciiication, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:
FIG. 1 is a side View in cross-section of a socket contact embodying this invention, the contact being in an unfinished state;
FIG. 2 is a partial end cross-sectional View taken along line 2-2 of FIG. 1;
3,120,989 Patented Feb. 11, 1964 lCC FIG. 3 is a side view in partial cross-section of the socket contact of FIG. l in a finished state, but prior to the assembly therein of a contact spring;
FIG. 4 is a partial side view in partial cross-section of the socket contact of FIG. 1, with a contact spring assembled therein, together rwith a mating contact pin.
FIG. 5 is a perspective View of the contact spring of FIG. 4;
FIG. 6 is a perspective View of a modified version of the contact spring of FIG. 4;
FIG. 7 is a perspective view of another modilied version of the contact spring of FIG. 4; and
FIG. 8 is a partial side view in cross-section of a modied version of the socket contact of FIG. 3.
As may be seen in FIGS. 1 through 4, the socket contact 1t) is formed as shown of solid stock with a central bore 12 in a pin contact receiving portion or socket 14, a body portion having a shoulder portion 16 and a tapered portion 1S, a conductor receiving portion 20, and a conductor insulation receiving portion 22. An annular slot 24 may be formed by counterboring the end of the central bore 12 to form a rst shoulder 26 as shown in FIG. 1, and then rolling the end 28 of the socket to form a second shoulder or ridge 30 as shown in FlG. 4. The second shoulder may be rolled to an internal diameter equal to that of the central bore 12 as shown in FIG. 3. After counterboring, but before rolling, a longitudinal slot or keyway 32 may be broached in the surface of the bore 12. The contact material may be selected for good electrical conductivity and easy machinability characteristics.
As may be seen in FIGS. 4 and 5, a pin contact retention spring 5t) may be formed from sheet metal as a loop or C having two legs 52a, 52h and a medial and perpendicularly extending arcuate tail 54. The spring material may be selected for its resilient characteristic.
FIG. 6 illustrates a modified version of a pin Contact retention spring 6) formed from wire stock in the form of a loop 62 with a perpendicular and arcuate tail 64.
FIG. 7 illustrates another modified version of a pin contact retention spring 7G formed from wire stock in the form of a loop 72 with two perpendicular and arcuate tails 74a and 74h.
As is shown in FlG. l4, the two legs 52a, 526 of the spring 50 may be compressed and snapped into the annular slot 24 while the tail 54 is slid into the longitudinal slot 32. The tail 54 of the spring 50 is arcuate and a portion thereof resiliently projects into the bore 12. In a similar manner (not shown) springs 60 and 70 may be disposed in the socket.
It will be seen that the rolled portion 28 provides a solid annulus at the front end of the bore or" a fixed diameter which may be equal t0 that of the bore 12, and thus provides the closed entry feature. The roll may be tapered to form a cone shaped entrance way for the inserted pin P, and will obstruct oversize pins or probes. When the pin P is inserted into the socket bore 12 it will be biased by the spring tail 54 into good electrical contact with the inner surface of the bore 12, while the spring tail 54 is conversely biased into slot 32. It will also be seen that should an undersize probe be inserted into the socket and wobbled around therein, the springr portion 54 will be able to retract into slot 32 without suffering any permanent set or other damage.
If it is desired to have the spring 50 easily removable from the socket 14, then diametrically opposite slots (not shown) may be cut through the roll 28 to permit the insertion of a tweezer type tool to compress the legs 52a and 52b of the spring Si! so that the spring may be extracted.
As an alternative to the rolling of a closed entry and spring retaining shoulder, a sheet metal cup 84), as shown in FIG. 8 may be eyeletted, staked or otherwise secured to the socket.
If desired, one or more annular beads A and B may be rolled onto the inner surface of the contact to provide small contact areas of high pressure. yThe inner diameter of the closed entry ridge dened by shoulder 30 may be made substantially equal to the diameter of these beads, as shown in FIG. 4.
I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other Ways Without departing from the spirit of my invention, and therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, since the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.
1. A unitary socket type contact assembly comprising a body member including a longitudinal mating contact pin receiving bore therein, an annular recess in the wall of said bore, and a longitudinal recess in the Wall of said bore having an integral base surface, said annular recess and longitudinal recess intersecting; and a resilient member disposed entirely Within said bore, including a first portion and a second portion substan tially perpendicular thereto; said first portion disposed in said annular recess, and said second portion disposed in part in said longitudinal slot and in part in said bore and adapted to be resiliently pressed gainst said longitudinal recess base surface by a mating contact pin inserted in said bore.
2. A socket type contact assembly comprising: a unitary body member having an interior Wall defining a longitudinal pin contact receiving bore adapted to receive and electrically contact a mating contact pin inserted therein; said interior Wall including therein an annular channel, and a longitudinal channel intersecting said annular channel and having an integral base surface; a resilient spring member disposed entirely Within said bore including a iirst elongate portion and a second circularly formed portion substantially perpendicular thereto; said second portion disposed in said annular channel; said rirst portion disposed in part in said longitudinal channel and in part in said bore, and adapted to be resiliently pressed into said longitudinal channel against said base surface by a mating contact pin inserted into said bore.
3. The socket assembly of claim 2 wherein said bore is circular in cross section and includes an internal bead on its inner Wall adapted to circumferentially Contact a mating Contact pin inserted therein, and said bore has an open end having a solid annulus which includes an inwardgoing bead having an inner diameter equal to the inner diameter of said bore bead.
References Cited in the file of this patent UNITED STATES PATENTS