Twist-lock connector

This application is based on and claims priority to U.S. Provisional Application No. 60/300,460, filed on Jun. 26, 2001. Provisional Application No. 60/300,460 is incorporated herein by reference in its entirety.

The present invention relates to electrical connectors. More particularly, this invention relates to twist-lock electrical connectors.

Electrical connectors are disclosed, e.g., in U.S. Pat. Nos. 3,552,777; 3,786,396; 4,029,953; 4,070,080; 4,074,927; 4,148,542; 4,191,443; 4,284,313; 4,296,992; 4,431,244; 4,548,458; 4,703,988; 4,875,715; 5,082,454; 5,181,860; 5,192,219; 5,454,728; 5,569,053; 5,722,847; 5,823,811; 5,984,721; 6,087,918; 6,104,960; 6,143,983; 6,168,212; 6,176,746; 6,290,525; 6,299,473; and 6,350,139. Twist-lock electrical connectors are disclosed, e.g., in U.S. Pat. Nos. 3,552,777; 4,029,953; 4,703,988;. 5,181,860; 5,722,847; 5,984,721; 6,087,918; 6,143,983; 6,168,212; 6,290,525; and 6,350,139.

Twist-lock electrical connectors are mechanically assisted connectors utilizing rotary motion. Such connectors are typically used to prevent power plugs from accidentally disengaging.

Conventionally, twist-lock electrical connectors are manufactured by separately molding each component of the connector and then combining the components in an assembly process. In some twist-lock connectors, the components are held together by a piece-retaining ring. In other twist-lock connectors, the components are held together by a locking ring integral to the connector housing. In connectors of the latter type, the locking ring is snapped over the connector housing with a high force.

A drawback to conventional twist-lock connectors is that two tools (i.e., molds) are required to produce the components, thereby raising reliability and cost issues.

Another drawback to twist-lock connectors is that the individual components tend to come apart, frequently resulting in loss of one or both components.

Accordingly, a primary object of this invention is to provide an interlocking twist-lock electrical connector which is formed in a single mold, i.e., the individual components or parts are formed simultaneously in the same mold and are disposed in an interlocking state in the molded connector.

A further object of this invention is to provide a twist-lock electrical connector which is cost-effective to make.

Yet another object of this invention is to provide a twist-lock electrical connector which is of durable and reliable construction and wherein the individual components do not tend to come apart.

A still further object of this invention is to provide a twist-lock electrical connector which does not require any tools to perform the locking operation.

These and other objects are achieved in the present invention.

The present invention provides a molded twist-lock connector containing:

a cylindrical connector housing having: (i) an axial bore with a first open end for receiving a first tubular body and an opposite second open end for receiving a second tubular body; (ii) a side wall defining the axial bore and having an inner surface and an outer surface, the side wall being configured to fittingly engage the first and second tubular bodies; and (iii) a plurality of outwardly projecting tabs formed in the outer surface of the side wall; and

a cylindrical locking collar concentrically disposed around a portion of the connector housing, the locking collar having: (i) first and second open ends; (ii) an axial bore for receiving the portion of the housing and being defined between the first and second open ends; (iii) a side wall defining the axial bore and having an inner surface and an outer surface, the inner surface being configured to fittingly engage the outer surface of the side wall of the connector housing; and (iv) a plurality of circumferentially-elongated slits formed in the side wall of the locking collar, the slits being disposed complementary to the tabs formed in the connector housing and being dimensioned and shaped to slidably engage the tabs therein, the tabs being slidably movable within the slits so as to render the locking collar rotatable from an unlocked position to a locked position, the unlocked position of the collar existing when the tabs abut against a first lateral side of the slits and the locked position of the collar existing when the tabs abut against an opposite second lateral side of the slits;

wherein the connector is in an unlocked state when the locking collar is disposed in the unlocked position and in a locked state when the collar is disposed in the locked position.

In the twist-lock connector of this invention, the connector housing and the locking collar are molded in the same tool (mold) as one part. Once the molding process is complete, the connector housing and the locking collar become interlocking parts, free to move independently of one another but restricted in movement by design limits. No assembly is required, and only one molding tool is needed. In addition, the interlocking components do not come apart or become lost. The connector is ready to use when shipped, thus saving time. No tools are required to perform the locking operation.

The connector of this invention is suitable for use in a variety of electrical applications, particularly in the automotive industry.

FIG. 1 is a side view of the twist-lock connector of this invention.

FIG. 2 is a front view of the twist-lock connector of this invention.

FIG. 3 is a cross-sectional view taken along the line A—A of the twist lock connector shown in FIG. 2 .

The twist lock connector of this invention will be described with reference to FIGS. 1-3. In the Figures, the connector is generally designated by the reference numeral 1 . The term “tubular bodies” will be used to broadly describe the electrical components which can be joined using the connector of this invention. Non-limiting examples of tubular bodies include, e.g., complementary connector bodies, plugs, receptacles, sockets and the like.

Connector 1 is composed of two primary components: a connector housing 2 and a locking collar 3 .

Connector housing 2 is a cylindrical structure having first and second open ends 4 , 5 ; an axial bore 6 extending between the first and second ends, and a side wall 7 defining the axial bore. First and second ends 4 , 5 are disposed to receive first and second tubular bodies (not shown).

A plurality of outwarding projecting tabs 8 are formed in an outer surface 7 A of connector housing side wall 7 . Preferably, outer surface 7 A has two tabs 8 formed therein, more preferably two diagonally opposed tabs 8 . Tabs 8 are preferably flat structures extending perpendicularly from outer wall surface 7 A.

In a particularly preferred embodiment, housing 2 has a step-like configuration composed of a front cylindrical section 9 and a back cylindrical section 10 . The outer diameter of section 9 is larger than the outer diameter of section 10 , resulting in the presence of an annular flat ledge 11 (constituted by a rear annular surface of section 9 ) (see FIG. 2) disposed between sections 9 and 10 . In this embodiment, tabs 8 are preferably formed in front section 9 .

Side wall 7 of housing 2 is configured to fittingly engage the first and second tubular bodies joined by means of the connector of this invention.

In a preferred embodiment, outer surface 7 A of side wall 7 will contain in a forward surface 12 of front cylindrical section 9 thereof a plurality of holes 13 shaped and dimensioned to receive corresponding protrusions (not shown) disposed on an outer surface of a first tubular member (not shown). Preferably, surface 12 will have three holes 13 formed therein in a circumferentially-equidistant fashion. Furthermore, inner surface 7 B of side wall 7 will preferably have formed therein at a rear surface 14 of front section 9 a longitudinal rib 15 (see FIG. 3) to fittingly engage a corresponding longitudinal rib (not shown) disposed in the first tubular member.

Preferably, a plurality of longitudinal ribs 16 will be formed on outer surface 7 A at back cylindrical section 10 (see FIG. 1) to fittingly engage corresponding longitudinal ribs (not shown) disposed on an inner surface of a second tubular member, e.g., a complementary connector body (not shown). Preferably, ribs 16 will be disposed in a circumferentially-equidistant manner on outer surface 7 A.

Locking collar 3 is a cylindrical structure concentrically surrounding a portion of housing 2 . Collar 3 is composed of first and second open ends 17 , 18 ; an axial bore 19 for receiving the portion of the housing and being defined between ends 17 and 18 ; a side wall 20 defining the axial bore; and a plurality of circumferentially-elongated slits 21 formed in side wall 20 . Side wall 20 has an inner surface 20 A and an outer surface 20 B, the inner surface being configured to fittingly engage the outer surface 7 A of side wall 7 of connector housing 2 .

Preferably, locking collar 3 has a step-like configuration composed of a cylindrical front section 22 and a cylindrical back section 23 . The outer diameter of front section 22 is larger than the outer diameter of back section 23 . Thus, an annular flat ledge 24 (constituted by a rear annular surface of front section 22 ) is formed between sections 22 and 23 .

As stated above, axial bore 19 of collar 3 concentrically surrounds a portion of connector housing 2 . Preferably, bore 19 surrounds housing 2 such that front section 22 of collar 3 surrounds a rear portion 25 of the front section 9 of housing 2 and back section 23 of collar 3 surrounds back section 10 of housing 2 .

Slits 21 in collar 3 are located complementary to tabs 8 formed in housing 2 and are dimensioned and shaped such that tabs 8 are slidably engaged or seated within slits 21 . Slits 21 have a generally rectangular configuration with two lateral sides 21 A, 21 B and two longitudinal sides 26 A, 26 B. Two opposite material recesses 27 A, 27 B are formed along longitudinal sides 26 A, 26 B, respectively, of each slit. Preferably, recesses 27 A. 27 B are formed along an intermediate portion of the longitudinal sides of slits 21 , as shown in FIG. 1 .

Tabs 8 are slidably movable within slits 21 from a first lateral side 21 A of slit 21 to an opposite lateral side 21 B of the slit. Thus, lateral sides 21 A and 21 B functions “stops” to the movement of tabs 8 within slits 21 .

The ability of tabs 8 to slidably move within slits 21 renders the locking collar 3 partially rotatable relative to connector housing 2 . The movement of tabs 8 from lateral side 21 A to lateral side 21 B causes the collar to rotate from an “unlocked” position to a “locked” position. More specifically, the collar is disposed in its “unlocked” position when the tabs 8 abut lateral side 21 A and disposed in its “locked” position when the tabs abut lateral side 21 B.

When collar 3 is disposed in its “unlocked” position, connector 1 is in an “unlocked” state, and when the collar is disposed in its “locked” position, the connector is in a “locked” state.

The angular distance over which the collar 3 rotates corresponds to the distance between the lateral sides 21 A, 21 B of slits 21 , i.e., the length of slits 21 . Preferably, the length of each of slits 21 is such that the angle at which the collar rotates from its unlocked position to its locked position ranges from about 30° to about 45°.

In collar 3 , front cylindrical section 22 has an inner wall 22 A and an outer wall 22 B, and back cylindrical section 23 has an inner wall 23 A and an outer wall 23 B. Inner walls 22 A and 23 A are configured to fittingly engage an outer wall (not shown), of a second tubular body, e.g., a complementary connector body (not shown). Preferably, inner walls 22 A and 23 A will have formed therein a plurality of (preferably two, more preferably two diagonally opposed) gradual camming ramps (not shown) terminating in step portions 28 (see FIG. 1 ), wherein the ramps are designed to engage corresponding camming-receiving surfaces (not shown) of a complementary connector body (not shown) or other tubular body.

Also preferably, the outer wall 23 B of back section 23 of collar 3 will have formed therein a plurality of (preferably three) holes 29 which are designed to receive therein corresponding protrusions (not shown) of a complementary connector body (not shown).

Preferably, the outer wall 22 B of front section 22 of collar 3 will have formed therein at least two pairs of U-shaped longitudinal grooves 30 (preferably two diagonally opposite pairs of grooves 30 ) to facilitate gripping and rotation of collar 3 .

In the process of making the connector of this invention, the connector housing and the locking collar are simultaneously formed in a single mold. In other words, the connector is formed as a unit in a single mold, with the tabs being engaged within the slits upon formation of the connector. Tool steel is brought in from four directions and positioned so as to separate the mold cavity section used to form the connector housing from the mold cavity section used to form the locking collar. Two injection ports are incorporated in the tool so that plastic material can be injected into the two isolated- mold cavity sections. Each mold cavity section has its own gate. Although Gated separately, the two mold cavity sections are filled simultaneously with the plastic used to form the parts. Once the molding process is complete, the connector housing and the locking collar are removed from the mold as a single device wherein the housing and the collar are interlocked by virtue of the retaining tabs of the housing being seated within the circumferential slits of the collar. Although interlocked, the housing and the collar are free to move independently of one another.

The connector of this invention is particularly useful in automotive applications.

All references cited in the instant specification are hereby incorporated by reference herein.