US3233204A

US3233204A - Automatic interlocking electrical connector

Info

Publication number: US3233204A
Application number: US309488A
Authority: US
Inventors: Jr William W De Vore
Original assignee: Harvey Hubbell Inc
Current assignee: Harvey Hubbell Inc
Priority date: 1963-09-17
Filing date: 1963-09-17
Publication date: 1966-02-01
Anticipated expiration: 1983-02-01

Description

Feb. 1, 1966 w. w. DE VORE, JR 3,233,204

AUTOMATIC INTERLOCKING ELECTRICAL CONNECTOR Filed Sept. 17, 1965 HI'IURNEYS.

United States Patent 3,233,204 AUTOMATIC INTERLOCKING ELECTRICAL CONNECTOR William W. De Vere, Jr., Palos Verdes Estates, Calif.,

assignor to Harvey Hubbell, Incorporated, Bridgeport,

Conn, a corporation of Connecticut Filed Sept. 17, 1963, Ser. No. 309,488 Claims. (Cl. 339-45) This invention relates to two-part electrical cable connectors and, more particularly, to such connectors of the interlocking type.

Interlocking electrical cable connectors are widelyused wiring devices which usually consist of two parts, a connector body portion and a connector cap. The body of the connector encloses female electrical contacts and the cap includes male electrical contact blades which extend therefrom and are inserted into the female contacts when the cap and body are mated. The male blades are somewhat L-shaped so that a laterally projecting lug is formed on each blade. The body of the connector includes a front wall having slots for receiving the blades. The cap is mated with the body by inserting the contact blades into the corresponding slots. The contact blades thereupon make electrical connection with the female contacts within the body. The cap is then rotated relative to the body and this causes the lug on each of the contact blades to move into a position out of alignment with its associated slot and behind the front wall of the body. This takes place without interrupting the electrical connections between contacts of the cap and body, and the connector parts are thereupon locked together so that they are no longer separable by simply attempting to pull them apart axially. In order to unlock the connector parts, they must be rotated in the opposite direction from which they were originally rotated to lock them, which realigns the blades with the slots so that the cap may be separated from the body by .pulling them apart axially.

In the prior art connectors of the type described, a positive rotating force must be applied to the connector parts in order to elfect initial interlocking. In order to eliminate the requirement for manual actuation of the interlocking means, there have been provided in prior art devices auxiliary means for automatically rotating the cap and body relative to one another during the time they are being mated. However, most of the devices heretofore proposed have had certain deficiencies. For one thing, such devices have been relatively complex and, accordingly, are somewhat expensive to manufacture. Another drawback of prior art automatic interlocking connectors is that many of them do not allow for misalignment of the male blades relative to each other, which sometimes occurs in practice.

Accordingly, it is a primary object of this invention to provide an improved automatic interlocking electrical connector. Other objects are to provide such a connector which is inexpensive to manufacture, which has few parts, and which automatically adjusts to the alignment of the male contact blades of the connector cap. Other objects, features, and advantages of this invention will be more apparent from the following description, the appended claims, and the figures of the attached drawing, wherein:

FIG. 1 illustrates in side elevation a two-part electrical connector embodying the invention in unconnected condition;

FIG. 2 is a sectional view on an enlarged scale of the body of the connector of FIG. 1 taken substantially along the line 22 of FIG. 1;

FIG. 3 is a sectional view taken substantially along the line 33 of FIG. 2, but showing the connector parts during their connection;

FIG. 4 is a transverse sectional view illustrating the operation of the interlocking means of the connector parts as they are connected;

FIG. 5 is a view similar to FIG. 4 illustrating the interlocking motion of the interlocking means of the connector parts; and

FIG. 6 is an exploded prespective view showing the construction of the major operating elements of the interlocking means of the connector of the invention.

In FIG. 1 there is illustrated a two-part electrical connector comprising a connector cap 10' and a connector body 12. The cap and body are each provided with a suitable cable clamp 14-14 for mechanical connection to electrical cables 1616. The cap 10 is of generally cylindrical shape and from one planar surface there projects a plurality of male electrical contact line blades 18 and a grounding blade 18'. Each of blades 18, 18' is connected within cap 10 in the usual manner to one of the electrical conductors of the cable 16.

The body 12 is also of generally cylindrical configuration. It includes a cylindrical base 20 of a suitable di electric material. The base 20 is surmounted by a main body portion 22 which is also in the form of a cylinder and is secured to base 20 by means of suitable screws 24 which are threaded into a metallic shell or end plate (not shown) which also supports the cable clamp 14. The base 29 and body portion 22 define a plurality of internal compartments therein which enclose. the required electrical female contacts. Main body portion 22 also includes a front wall 26 having a plurality of arcuate slots 28, each positioned to receive an individual one of the

male contact blades

18, 18. The blades 18, 18' are of the interlocking type and are of generally L-shaped construction, having a laterally projecting lug 3% which defines an inwardly facing shoulder 32. The shoulder 32 is designed to engage the inner surface of front wall 26 and interlock the cap 10 and body 12.

Projecting inwardly from the front wall 26 of main body portion 22 is a raised boss 34 (FIG. 3) which has a square opening 35 axially therethrough from the outer surface of front wall 26. Circularly arranged around this boss and mechanically supported by base 20 are a plurality of U-shaped electrical female spring contacts 36. Contacts 36 are positioned in the usual fashion slightly radially offset from the center lines of corresponding slots 23 to receive the male contact blades 18, 18' after they are inserted into the slots and to maintain electrical contact when the cap 10 is rotated clockwise, relative to its direction of advancement toward body 12. A square retaining shaft 38 is contained within the square opening 35 in boss 34. Shaft 38 includes an enlarged cylindrical head 46 at one end and a rounded threaded portion 40 at its other end which is designed to threadedly engage a nut 42 disposed in a suitable counter-sunk opening 44 in front wall 26.

The interlocking means actuating mechanism of this invention is positioned around the retaining shaft 38 between its head 46 and the flat surface 47 of boss 34. This mechanism consists of a rigid .plastic material lower drive arm 48 and a rigid plastic material upper drive arm 50, separated from one another by means of a metallic spacer 52. The lower drive arm 48 comprises a central ring portion 54 having a circular opening of larger diameter than the diagonal dimension of the retaining shaft 38. Ring portion 54 carries a cam 56 having a downwardly facing sloping cam surface 58. The upper drive arm 50 is of generally similar construction as lower drive arm 48 and also comprises a central ring portion 60 defining a circular opening greater than the diagonal dimension of retaining shaft 38. Ring portion 60 carries a cam 62 having a downwardly projecting sloping cam surface 64. The primary difference between upper drive arm 50 and lower drive arm 48 is that the dimensions of the cams 55ts2, measured axially of the center line of the connector body, are such as to position the

cam surfaces

58, 64 so that they are substantially equally spaced from the front wall 26. Thus, the cam 62 is longer than cam 56, and, in fact, overlaps the central ring portion 54 of the lower drive arm 43.

The spacer 52 is mounted on retaining shaft 3%, separates the upper and lower drive arms 48, 50 and is generally cylindrical, but has a central opening 66 resembling an oval with two opposing straight sides (see FIG. 4). The straight sides of the opening 66 engage opposite surfaces of the square retaining shaft 38 so that the spacer is restrained from rotational movement relative to the shaft. The curved ends of the oval opening 66, however, are spaced from the sides of the retaining shaft 38.

Positioned within the circular opening of lower drive arm ring portion 54 and around retaining shaft 38 is a coiled torsion lower drive spring 68. The end 63a of lower drive spring 68 is disposed near boss 34 and bent radially outwardly to extend through a suitable radial opening within ring portion 54- of the lower drive arm The other end 68b of the lower drive spring 68 is bent axially and extends along the retaining shaft 38 and into one curved end of the oval opening an in spacer 52. The lower drive spring 68 is conditioned and mounted so as to tend to maintain the lower drive arm and its cam 56 in the position illustrated in FIGS. 2 and 3.

An upper torsion drive spring '76, somewhat similar to spring 68, is positioned between the rpper drive arm ring portion tit and the square retaining shaft 38. Spring lib is provided with one end 'l'tla which is bent axially along retaining shaft 38 and extends into the other curved end of the oval opening in spacer 52. The other end 705 of upper drive spring 7t? is bent radially outwardly to extend into a radial opening '72 in the ring portion an. Upper drive spring 7% is conditioned and mounted so as to tend to maintain the upper drive arm and its cam 62 in the position illustrated in FIGS. 2 and 3.

Operation of the automatically interlocking connector of this invention may be best understood by reference to FIGS. 3, 4 and 5. In FIG. 3, the axially advancing male contact blades 13 projecting from connector cap are shown as initially engaging the cam surfaces 58, 64, respectively, of the cams of lower and upper drive arms 48 and 59. It should be noted that a corner 19 of each con tact blade 18 opposite the corner on its lug 36 engages a cam surface. As the contact blades are inserted further through slots 28, their increased engagement with the cam surfaces generates a rotational component of force on the cams and forces the lower drive arm 48 and the upper drive arm 59 to rotate substantially simultaneously in a counterclockwise direction relative to the advancing cap against the increasing resistance exerted by the drive springs. Spacer 52 remains fixed to the retaining shaft 38 and may be operatively considered an extension of-the retaining shaft.

FIG. 4 is a somewhat schematic view looking down relative to FIG. 3, and illustrates the manner in which the lower and upper drive arms are cammed as the contact blades 18 are axially advanced. As the upper and lower drive arms are forced to rotate, they tension the coiled springs, and the springs exert greater and greater resistance counter forces. Sufiicient axial advancement of cap it) eventually allows the shoulder 32 on each of the contact blades 13 to clear the inner surfac of thefront wall 26 and, at about the same time, corners 19 of blades 18 that have ridden on the cam surfaces pass the curved portions of

surfaces

58 and 64 and engage straight portions 58 and 6 thereof, respectively. As the shoulders 32 have cleared the inner surface of front wall 26, the cap it) is free to rotate clockwise relative to its direction of advancement. The drive arms are driven by the individually tensioned coil springs, which release their stored energy, so as to rotate the blades 18 and drive their shoulders .32

behind front wall 26, locking the cap and body together. This position is illustrated in FIG. 5.

In order to separate cap 10 from body 12, it is merely necessary to rotate the cap relative to the body in the opposite direction to that which effects interlocking. This causes a corner 19 of each of blades 18 to force its associated straight portion of the cams to rotate. Continued rotation moves the cams back into their position wherein they are axially aligned with slots 18, as shown in FIG. 4, allowing the blades 18, 13' to be withdrawn through slots 28 by a slight axially separating pull apart, after which the corners 19 pass onto cam surfaces 53 and 64 and the latter cam the contact blades 18 axially away from body 12.

It will now be seen that the invention provides an electrical connector body having therein a pair of cams which are positioned to engage the advancing male contact blades of an electrical connector cap and effect initial automatic interlocking. It should also be noted that the cams produce powered ejection of the contact blades on disconnection of the cap and body. The cam surfaces of the cams are integral portions of respective drive arms which are independently mounted on a single retaining shaft and are powered by separate springs, and accordingly,

misalignment of an inserted contact blade has no adverse affect on the operation of the device for the cams operate independently. By reason of this invention, automatic interlocking of electrical connector parts can be easily achieved. The device of the invention is simple in construction having few moving elements.

It will be apparent that a number of variations and modifications may be made in this invention, without departing from its spirit and scope. For example, the inventio-n, has been illustrated and described as embodied within a cylindrical connector body. However, this is not a limiting feature as the device may be built into any type of suitable connector part, for example, into a boxlike electrical receptacle, as distinguished from a cylindrical connector body. Furthermore, the materials of which the invention are constructed may be varied. It is important, of course, that the male contact blades not be short circuited and for this reason, it is desirable to construct the upper and lower drive arms of a suitable dielectric material, such as any suitable plastic. Metallic carns could be used, however, if suitable insulating means is employed. Other variations and modifications of the invention will be apparent to those skilled in the art. Accordingly, it is to be understood that the invention is not limited to the construction specifically described herein and that it is limited only by the scope of the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. An interlocking electrical connector comprising: a body of electrical insulating material; a front wall on said body defining a plurality of circumfercntially aligned spaced arcuate openings therethrough; a raised central boss supported by said front wall within said body and extending on an axis falling substantially intermediate said openings; a retaining shaft supported at a first end by said boss and extending on an axis normal to said front wall from the common center of a circle on which said openings are disposed, the second end of said shaft spaced from the inner end of said boss and including an enlarged head; a first blade positioning means adjacent the inner end of said boss, mounted for controlled partial rotation about said shaft; a second blade positioning means adjacent said head, mounted for controlled partial rotation about said shaft independent of said first positioning means; each of said first and second blade positioning means including an inclined cam surface positioned to intercept an interlocking male contact blade inserted in an associated one of said openings and initially be rotated thereby but thereafter to rotate said blade, each of said cam surfaces being of a length such that said blade leaves the inclined portion of said cam surface prior to reaching its position of maximum insertion into said body; a first coiled torsion spring intermediate said first blade positioning means and said shaft and having a first end secured to said first blade positioning means; a second coiled torsion spring intermediate said second blade positioning means and said shaft and having a first end secured to said second blade positioning means; and securing means interconnecting said shaft and the second ends of each of said first and second springs; said springs arranged to bias the inserted blades rotationally into an interlocking position relative to said front wall on the blades reaching a predetermined amount of insertion.

2. The connector of claim 1 wherein said securing means comprises a spacer atfixed to said shaft between said first and second positioning means.

3. The connector of claim 2 wherein said shaft has at least one flat side and wherein said spacer defines an opening therein having at least one fiat side mating non-rotatably with said shaft.

References Cited by the Examiner UNITED STATES PATENTS 2,635,131 4/1953 Greatbatch 339-41 X 3,066,276 11/1962 Hubbell et al 339-189 FOREIGN PATENTS 705,485 4/1941 Germany.

ALBERT H. KAMPE, Primary Examiner.

JOSEPH D. SEERS, Examiner.

Claims

1. AN INTERLOCKING ELECTRICAL CONNECTOR COMPRISING; A BODY OF ELECTRICAL INSULATING MATERIAL; A FRONT WALL ON SAID BODY DEFINING A PLURALITY OF CIRCUMFERENTIALLY ALIGNED SPACED ARCUATE OPENINGS THERETHROUGH; A RAISED CENTRAL BOSS SUPPORTED BY SAID FRONT WALL WITHIN SAID BODY AND EXTENDING ON AN AXIS FALLING SUBSTANTIALLY INTERMEDIATE SAID OPENINGS; A RETAINING SHAFT SUPPORTED AT A FIRST END BY SAID BOSS AND EXTENDING ON AN AXIS NORMAL TO SAID FRONT WALL FROM THE COMMON CENTER OF A CIRCLE ON WHICH SAID OPENINGS ARE DISPOSED, THE SECOND END OF SAID SHAFT SPACED FROM THE INNER END OF SAID BOSS AND INCLUDING AN ENLARGED HEAD; A FIRST BLADE POSITIONING MEANS ADJACENT THE INNER END OF SAID BOSS, MOUNTED FOR CONTROLLED PARTIAL ROTATION ABOUT SAID SHAFT; A SECOND BLADE POSITIONING MEANS ADJACENT SAID HEAD, MOUNTED FOR CONTROLLED PARTIAL ROTATION ABOUT SAID SHAFT INDEPENDENT OF SAID FIRST POSITIONING MEANS; EACH OF SAID FIRST AND SECOND BLADE POSITIONING MEANS INCLUDING AN INCLINED CAM SURFACE POSITIONED TO IN TERCEPT AN INTERLOCKING MALE CONTACT BLADE INSERTED IN AN ASSOCIATED ONE OF SAID OPENINGS AND INITIALLY BE ROTATED THEREBY BUT THEREAFTER TO ROTATE SAID BLADE, EACH OF SAID CAM SURFACES BEING OF A LENGTH SUCH THAT SAID BLADE LEAVES THE INCLINED PORTION OF SAID CAM SURFACE PRIOR TO REACHING ITS POSITION OF MAXIMUM INSERTION INTO SAID BODY; A FIRST COILED TORSION SPRING INTERMEDIATE SAID FIRST BLADE POSITIONING MEANS AND SAID SHAFT AND HAVING A FIRST END SECURED TO SAID FIRST BLADE POSITIONING MEANS; A SECOND COILED TORSION SPRING INTERMEDIATE SAID SECOND BLADE POSITIONING MEANS AND SAID SHAFT AND HAVING A FIRST END SECURED TO SAID SECOND BLADE POSITIONING MEANS; AND SECURING MEANS INTERCONNECTING SAID SHAFT AND THE SECOND ENDS OF EACH OF SAID FIRST AND SECOND SPRINGS; SAID SPRING ARRANGED TO BIAS THE INSERTED BLADES ROTATIONALLY INTO AN INTERLOCKING POSITION RELATIVE TO SAID FRONT WALL ON THE BLADES REACHING A PREDETERMINED AMOUNT OF INSERTION.