US2572448A - Electrical connector having a resiliently biased automatic latch - Google Patents

Description

Oct. 23, 1951 E. s. CHILLD 2,572,448

ELECTRICAL CONNECTOR HAVING A RESILIENTLY BIASED AUTOMATIC LATCH Filed Jan. 29, 1949 5 Sheets-Sheet l 3 Sheets-Sheet 2 INVENTOR. f/(f/Fffi" a". 07/10 BY ATTORNEY E. S. CHILD Oct. 23, 1951 ELECTRICAL CONNECTOR HAVING A RESILIENTLY BIASED AUTOMATIC LATCH Filed Jan. 29, 1949 Oct. 23, 1951 E. s. CHILD 2,572,448

ELECTRICAL CONNECTOR HAVINGA RESILIENTLY BIASED AUTOMATIC LATCH Filed Jan. 29, 1949 3 Sheets-Sheet 3 AT T ORNEY Patented Oct. 23, 1951 ELECTRICAL CONNECTOR HAVING A RE- SILIENTLY BIASED AUTOMATIC LATCH Everett S. Child, Barrington, R. I., assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application January 29, 1949, Serial No. 73,621

8 Claims. 1

This invention relates to an improved electrical terminal adapted to be connected to a like terminal and a protecting cap for such terminal. The subject matter disclosed and claimed herein is a continuation-in-part of my former application Serial No. 717,646, filed December 21, 1946, now abandoned.

The locking connection is useful for preventing electrical cable terminals from becoming separated and also for retaining them in tight engagement to form a fluid tight seal for the completely enclosed electrical contacts and locking member. Electrical terminals having the above characteristics are particularly useful for connecting power lines and communication cables which are subjected to outdoor weather conditions, and to being pulled over the ground or other rough handling. Such conditions require the electrical contacts to be sealed against water and dirt, and that all external projections be eliminated to prevent the connection from catching fixed objects. In order to protect the terminals against damage from handling and moisture before they are connected, the terminals are provided with protective caps.

Among the objects of this invention is to provide a locking connection between separable lengths of an electrical cable which has a smooth outline, and a water-proof enclosure for the locking mechanism and electrical contacts. Another object is to protect the unconnected cable terminal.

A further object is to make the connected parts alike so that each interlocks with the other.

A still further object is to provide a construction that can be readily coupled and uncoupled without the use of tools.

The foregoing and other objects of this invention will be more clearly understood by referring to the following description, and the accompanying drawings, in which:

Fig. 1 is a cross-sectional view of an electrical terminal comprising one part of the connection embodying this invention, taken on line l--l of Fig. 2.

Fig. 2 is an end view of the terminal shown in Fig. 1;

Fig. 3 is a view of the disconnected locking connection, showing the two like parts, one of which is incorporated in each of the terminals;

Fig. 4 is a view of the parts shown in Fig. 3 after being connected;

Fig. 5 is an end view of one part of the locking connection shown in Fig. 3, with an outer sleeve added;

Fig. 6 is an elevational View of the guiding and aligning member of the locking connection;

Fig. 7 is a view of the member shown in Fig. 6, but turned through an angle of Fig. 8 is a cross-sectional view of a cable terminal taken on line 8-8 of Fig. 2, and showing a similar cross-section of a protective cap for the terminal;

Fig. 9 is a cross-sectional view similar to that shown in Fig. 8, but showing the protective cap secured on the cable terminal;

Fig. 10 is an elevational view of the engaging end face of the protective cap;

Fig. 11 is a longitudinal cross-section of a modified form of a terminal embodying this invention taken on line |l--ll of Fig. 12;

Fig. 12 is an end view of the terminal shown in Fig. 11; and

Fig. 13 is a cross-section of two like terminals being connected.

An embodiment of the invention is shown in Figs. 1 to 10 of the drawings as an electrical cable terminal. As both of the terminals are alike onl one complete terminal is illustrated and described in connection with the modification in Figs. 1 to 10. Referring particularly to Figs. 1 and 2, the terminal I0 is provided with male and female contact members ll and 12, respectively, which are arranged in a circle around one part 13 of a locking connection I4. When two of the terminals I!) are connected together, the male contact members ll of one terminal telescope within the female contact members I2 of the other terminal, while the like parts I3 of the locking connection engage one another, as shown in Fig. 4, and thereby secure the terminals l0 together. The contact terminals H and i2 and the parts [3 of the locking connection are enclosed in a soft or deformable resilient waterproof casing I5, which may be made of a rubber or rubber-like composition. An annular ridge [6 is formed on the end face of each of the terminals. The resilient ridge It on one terminal abuts against the ridge on the other terminal lil when they are connected, and form a waterproof seal around the contact members and the locking connection 14.

The contact members II and [2 are supported in hard pressed fiber discs I1, and a conductor l8 extending from a cable I9 is connected to each contact member. The cable l9, containing a plurality of the conductors l8, passes through and is anchored to a base ring 20, which supports the locking connection parts l3 by means of a yoke 2| extending upwardly from the ring Zil. A

brass sleeve 22 extends around the outer end of part l3 from the end of the yoke 2| to the end of the rubber casing [5. The water-proof rubber casing I is molded around and encloses the bases of the contact members II and I2, the sleeve 22, the end of the cable l9, and the rigid supports therefor. The contacts and connected metal parts are thereby electrically insulated b! the rubber 15.

The separated parts [3 of the locking connection Hi are shown in Fig. 3 in their relative positions prior to their engagement with one another. central aligning and guiding member 23- around which is located three projections 24 provided with overhanging shoulders forming locking hooks 25. The radial faces 25.0f the projections,

24 are inclined to the axis of the circle about which they are arranged. The inclination is' in the nature of a helix and as shown herein it hasa left handtwist. Thealigning and guiding member 23 has generally the shape of a'half cylinder. As shown in Figs. Band '7, the outer end of the member 23 is provided with a fiat side 21, and has a sector shaped recess 28- extending inwardly therefrom.

In order to connect two of the terminals It together, the faces of the'terminals are brought towards each other with the flat ends 2'! of the guiding and aligning members 23 in sliding contact. When the terminals are so oriented by the fiat ends 27, the male contact members H are axially aligned with and arranged in posi tion to extend into the female members 62'. It

will be noted that since'the ends of the male members H extend outwardly beyond the ends of the locking projections 23 and female members I2 (which latter ends are at the same. level) the telescoping action of themale and female contact members will begin before the ends of the locking projections 24 on the respective terminals begin to mesh with one another. Upon pushing the faces of the terminals closer together, the locking projections 22 on one terminal extend into the space 29 between and mesh with those of the other.

v The longitudinal axes of the male and female contact members are parallel to the axis of the cable terminal, and such contact members on opposed terminals engage'each other. in a straight line motion, whereas the radial faces 26 of the locking projections 23 arearrangedat an angle to or spirally in reference to the axis of the terminal, and such projections on opposite terminals engage each other in a spiral motion. Due to the angular arrangement of the faces 26 in respect to the axes of the contact members I1 and I2, and the sliding helical movement of the opposing faces 26 of the projections 22 on one another, as the terminals are pushed together, torsional strains are set up in the rubber between the locking members '24 and the contact members in the terminals. The contact members I I and [2 being mounted in soft resilient rubber, they are permitted to move against the resistance of the rubber about the locking projections and through the radial angle required for the hooks on the projections 2 of each terminal to pass axially inwardly beyond one another. When the hooks 25 are opposite each other, the resilient action of the rubber casing [5, resulting from the torsional strains, forces the overhanging faces of the hooks into locking engagement as shown in Fig. 4, by rotating the parts relatively to each other as indicated by the arrows A. The sealing Each of the parts [3 is provided with a or other suitable material.

ridges It are thus pressed into tight engagement with each other and they form a fluid proof seal between the faces of the terminals. The seal extends completely around their outer margin.

The torsional strains in the rubber casing l5 maintain the locked connection, until some outside force or forces turn one-terminal in respect to the other in the direction opposite to the arrows A, in Fig. 4, so as to overcome the resilient action of the rubber body l5, and at the same time pull the terminals away from one another. This may be done by grasping the terminals, one with each hand, and rotating and pulling the terminals apart as indicated.

When the locking connections 14 are being pushed together, the'rotation of one with respect tothe other takes place after the flat ends 21 pass over one another, and then one half of each end rotates into the angular recess 28, on the guiding and aligning members 2'3. When the terminals H) are pulled apart, the rotation of the aligning. and guiding members 23 in the direction of the arrows A ceases when the fiat ends 21 of the respective terminals in begin to engage one another, and in that position they are again parallel.

Figs. 8 to 10 disclose a cable terminal In, similar to that shown in Figs. 1 and 2, and also discloses a protective cap 30-for the cable terminal. by a chain 3! in order that it may be held in readiness to engage the cable terminal l0 when one cable terminal is separated from another.

The cap Sitcomprises projections 32 which are adapted to telescope with the hollow, or female contact members l2 inthe cable terminal 10.

Two or more of the projections 32 are looselyanchored in a rigid disc 33-on a circle about the center of the disc, which-may be made of metal is formed by inserting the flanged ends 34-of the projections 32 into slots 35, which extend from the edge of the disc radially inward. The width of the slots 35 is greater than the diameter of the ends 34 between the flanges 36 and 31 which are spaced from each side of the disc 33. The ends 34 of the projections 32 and the disc 33 are embedded in a body 33 of a soft rubber-like ma' terial, which is molded around these members in such a manner that the outer ends 39 of the projections 32 have some resilient movement in respect to the disc 33, but is normally retained by the rubber in alignment with the hollow female contacts I2. Three locking projections 40 are rigidly secured to the disc 33 on a circle concentric with the circle on which the projections 32 are arranged. Such locking projec-- tions are identical with, and adapted to interlock with the lockin projections 24 on the terminal i0. jections 40 there isarranged a guiding member 4|, which is similar to, but slightly different in shape from, the guiding member 230i the cable terminal IE]. As shown in. Fig. 1f), the guiding member 4! has a sector shaped cross-sectional area throughout, and coversan are slightly less than that of a semi-circle. The outside angle tween the radial sides (and 43 (Fig. 10) is the same as the outside angle between the radial sides of terminalguide member 2] opposite the recess 28, and is greater than by the amount the locking projections 45 must rotate during their axially directed engaging motion with the terminallocking projections .24.-

The cap 30 is assembled on the terminal; lfljin;

The cap 33 is attached to the cable l9 The loose anchorage- Within the circle of the locking prosomewhat the same manner heretofore described for the connection of two of the like terminals [0. The construction of the cap is slightly different from the construction of the cable terminal Ill, and because of such difference, the coaction of the cap and terminal differs slightly from the co-action between two terminals during their locking movements. In the case of the cap 30 the guide member is not provided with a flat diametrical end like the end 21 on the cable terminal I0, and the ends of the telescoping projections 32 do not extend beyond the ends of the lockin projections 48. In connecting the cap 30 to the terminal H), the side 42 of the cap guide member 4| is placed against the flat end 21 of the terminal guide member 23, and as cap 38 is moved towards the terminal l0, first the locking projections 40 extends into the spaces 29 between the corresponding looking projections 24 of the cable terminal, and then the projections 32 begin to telescope with the female contacts I2. There is suflicient play or tolerance in the fit of the parts to permit the initial telescoping action of the parts 48, 24 and 32, 12, respectively, to take place without setting up any strains in the rubber. After engagement of the projections 32 and the contacts I 2, the relative helical sliding movement between the inclined faces 44 and 26 in opposition to the straight line or axial movement of the projections 32 into the contacts l2, sets up torsional strains in the rubber 38 and I5. As the axial engaging movement is continued, the projections 48 are rotated in a counter-clockwise direction (as viewed in Fig. 8) in respect to the projections 24 and against the resilient resistance of the rubber transmitted through the projections 32. When the locking hooks 45 on the projections 48 pass over the locking hooks 25 on the projections 24, the resilient action of the projections 32 rotates the projections 48 in a clockwise direction so that the hoolm interlock one another in the position shown in Fig. 9.

When the cap 30 is connected to the terminal 10, the outer edge 46 on the cap 38 engaged the perimeter of the casing l5 and the outside of the sealing ridge l6, and thereby forms a liquid-proof seal between the contacting parts, and encloses the electrical contacts II and [2. When so connected, the outer edge 46 and ridge l6 are deformed under compression against each other, but for clarity of illustration such deformity is not indicated in the drawings. The enclosure formed by the cap 38 protects the electrical terminals from mechanical injury and damage from moisture during the handling of the cables while two like cable terminals ID are disengaged.

A modified form of an improved electrical terminal embodying this invention is shown in Figs. 11 to 13 of the drawings, in which the locking projections for retaining the two like cable terminals in their connected relationship are placed on a circle circumscribed about the electrical contacts, instead of being placed within the circle on which the electrical contacts are located. This form of terminal is also provided with a different type of aligning and guiding member, as will be hereinafter described.

Referring to Figs. 11 and 12, the electrical contacts are resiliently mounted in a deformable soft rubber, or rubber-like body 41, which is secured to a sleeve 48, on which an outer ring of locking projections 49 are formed. The locking sleeve 48 is secured to a metal yoke 58. A rubber casing 5| surrounds the locking sleeve 48 and the yoke 50 and is bonded to the latter. The casing 5| extends downwardly over the cable jacket 52 to which it is bonded so as to unite the terminal parts to the cable end. The conductors 53 extend from the end of the cable jacket 52 into the yoke 50, and are connected to the respective electrical contacts.

The end face 54 of the rubber body 41 is provided with a semi-cylindrical projection 55 within which the female contacts 56 are embedded. The end face is also provided with a complementary semi-cylindrical recessed portion 51 within which are mounted male electrical contacts- 58. The electrical contacts 56 and 58 are initially mounted in a fiber disc 59, and are placed in a mold together with the locking projection sleeve 48. The rubber composition 4'1 is then placed in the mold and vulcanized around the contacts and within the sleeve 48. A vulcanized bond is thereby formed between the rubber and such parts. The sleeve 48 may be then secured to the yoke 58 in any suitable manner, as by a pressed fit, or by riveting. The conductors 53 are then soldered on to the projecting ends of the contacts 56 and 58, and such assembly is placed in a mold, in which the, outer casin of rubber 5! is vulcanized to the yoke and to the cable jacket 52.

The locking projections 49 are provided with helically inclined cam surfaces 80, at the inner end of which is formed overhanging locking shoulders 8!. As shown in Fig. 13, when two like cable terminals are being connected, the diametrical side 62 of the elevated semi-cylindrical portions of the rubber bodies 47 are first engaged with one another. The diametrical sides 62 forming aligning and guiding members, which are adapted to align the male contacts 58 on one terminal with the female contacts 56 on the other terminal when such sides are matched together as shown in Fig. 13. As the terminals are forced together in the direction of their axes, the cam surfaces 68 engage one another after the contacts on the respective terminals have begun to telescope, and with the continued inward or connecting movement of the terminals the cam surfaces slide over each other and rotate, or displace the telescoping contacts in respect to the locking projections. When the ends of the cam surfaces are reached, the locking shoulders 6! on the opposite terminals slide over each other in a counter rotating movement due to the resilient energy stored in the rubber body 41 by the rotative movement of the cams 68. The terminals are thus locked together, and will remain so locked until the operator turns the casings 5| of the respective terminals in the direction of rotation produced by the cam surfaces so as to disengage the over-hanging shoulders 5! on the respective locking projections from each other. After the shoulders 5! have been disengaged, the terminals may be pulled apart by the operator. When the shoulders 6| of the locking projections 49 are in engagement, the ends 53 of the casing are tightly pressed together and form a fluid tight seal.

While the preferred embodiments of this. invention have been disclosed herein, it will be understood that the details of its construction may be changed without departing from the spirit of the invention and the scope of the appended claims.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. An electrical terminal adapted to be coniieoted t'o alike terminal, said terminal 'compr-i's-- ing abody of soft resilient rubber-like material, a plurality of maleand female electrical contacts resiliently mounted in said body and being spaced so that said male contacts on one terminal ar adapted to telescope with the female contacts on the other terminal, locking projections mounted in said body, said projections on one terminal having helical cam faces adapted to slide on. like facesof the other interlocking terminal and circumferentially displace said telescoping contacts with respect to said projections in opposition. to the resilient resistance of. said body during the? inward telescoping movement of said contacts, and overhanging shoulders at the inner ends of. said faces adapted tointerlock With correspond.- ing shoulders onathe other liketerminal under the resilient reaction; of saidibody.

2. An; electrical terminal adapted to be connectedand locked toalike terminal, said terminal. comprising a deformable resilient rubber-like body of material, a plurality of electrical contacts, resiliently mounted on a circle in said body, said contacts on one terminal being adapted to slide over the contacts of the other terminal in the direction of the axis of said circle, locking projections connected to said rubber body and spaced from said contacts on a circle circurnscribed about said axis, said projections on one terminal having helical cam surfaces adapted to slide on like cam surfaces of the locking projections on the other terminal and thereby radially displace the contacts of the interlocking terminals inopposition to the resilient resistance of said rubber-like body during the connecting movemeritv of said contacts, and overhanging shoulders at the inner ends of said cam surfaces adapted to interlock with corresponding shoulders of the other projections of the-like terminal under the resilient reactionof saidresilient rubber-like body at the end of said connecting movement of said terminal.

3. An electrical terminal as in claim 1, wherein said locking projections are located on a small circle, and anaxial guide is fixed in said circle and extends beyond the initial point of engagement of said'other elements of said terminal and is adapted to slide over the corresponding-element of the mating terminal during the connecting operation.

4. An electrical terminal as in claim 1, whereinsaid locking projections are located on an inner circle concentric with said contacts, an axial guide locking terminal for initially aligning said male contacts on one terminal with said female contacts on the other terminal, and the lengths of said guides, contacts and locking projections being proportioned to cause said members to err-- gage each other in the order last named during the terminal connecting operation.

5. In combination, an electrical cable terminal and a protective cap therefor, said terminal com-- prising a resilient rubber-like cylindrical body of waterproof material forming a casing; said terminal comprising a plurality of electrical con tacts and locking projections mounted respectively on outer and inner concentriccircles in said terminal body, said contacts and locking projectionsbeing resilientlysupported by said casing.

so that. the .contacts are adapted-to be moved relatively'with respectto said locking projections; saidlo'cking'projections having spirally inclined faces provided with looking notches, said protective cap comprising a body, pins anchored in said body and adapted to telescope with said terminal contacts by a straight'line axial movement, looking' projections anchored in said cap body, saidlast mentioned locking projections corresponding to and adapted to interlock with said terminal locking projections upon moving along said spirally inclined-faces against the resilient resistance offered by the straight line' telescoping movement of said-pins with said terminal contacts.

6. Incombination, an electrical cable terminal andia' protective cap therefor, said terminal and cap each comprising-'2'. resilient rubber-like cylindrical body of water-proof material forming a casing, said. terminal comprising a plurality of electrical contacts and locking prbje'c'tio'ns mounted respectively'on outer and inner concentric circles in said terminal body; a guide member wholly Within said inner circle" and rigidly connected'to' said' locking projections, said contacts and'locking projections being resiliently supported sothat the contacts are adapted to be moved relatively with respect to said locking projections; said locking projections having. spirally inclined faces provided with notches, said protective cap comprising a guide member adapted toslide and rock on said terminal guide member, projections adapted to telescope with said terminal contacts, locking projections corresponding to and'adapted to interlock with said terminal locking projections, all of said projections and the guide? member of said cap being mounted in said cap body, and said cap body having an outer peripheral sealing edge which is adapted'to contact witha corresponding sealingedge on said terminal body'vvhen said cap is interlocked with said terminal.

'7. An electrical terminal adapted to be connectedand locked to alike terminal, said terminal comprising a deformable resilient rubberlike body of material having elevated and depressed end face portions, a plurality of female contacts resiliently, mounted and substantially embedded in said elevated portion of said body, a plurality of male contacts resiliently mounted in said depressed portion, said contacts on one terminal being adapted to make slidingcontact with the contacts" of the other terminal during the connecting and disconnecting movements of said terminals, locking projections connected to said'rubber body and spaced from said contacts on a circle surrounding said elevated and dc pressedend face portions, said projections on one terminal having'helic'al cain'surfaces adapted to slide on like cam surfaces of the locking projections on the other: terminal and thereby rotate said locking projections on one terminal in respect to those on the othertermina-l and displace the contacts of the'interlocking terminals in op position to the resilient resistance of said rubber.- like body during the connecting movement of said contacts, and overhanging shouldersat the inner ends of said cam'surfaces' adapted to inter-' lock with corresponding shoulders on the other like terminal under the resilient reaction of said resilient rubber-like body at the end of said connecting movement of said terminals.

8. An electrical terminal adapted to be con nected and locked to' a like: terminal comprising a deformable resilient rubber-like body of material having-semi cylindricali elevated and do pressed. end face-= portions=provided. with dram eters of the same size and lying in the same plane, a plurality of female contacts substantially embedded in said elevated portion, a plurality of male contacts mounted in said depressed portion, said female and male contacts being adapted to telescope with the respective male and female contacts of the like terminal during the connecting movement of said terminals, locking projections secured to said rubber-like body and spaced from said contacts on a circle surrounding said elevated and depressed end face portions, helical cam surfaces on said locking projections adapted to slide over the cam surfaces of the like terminal and rotate the telescoping male and female contacts in respect to said locking projections during the connecting movement of said terminals, and overhanging shoulders at the inner ends of said cam surfaces adapted to interlock with corresponding shoulders on the other like terminal under the resilient reaction of said rubber-like body at the end of said connecting movement of said terminals,

EVERETT S. CHILD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS-

Images