This invention relates generally to electrical connectors and is particularly directed to an electrical connector having a locking feature for increased safety and security.
In some applications, such as environments including hazardous, combustible or explosive gases, referred to as “Zone II” applications, it is desirable to have a secure coupling between male and female electrical connectors so that the connectors cannot be inadvertently disconnected which can cause a possible arc or inadvertently interrupt the operation of a machine on a production line. Thus, it is desirable to have a locking feature in such connectors. However, in the case of an urgent matter or simply for convenience, it is also desirable that the two connectors may be disconnected by a tool which is normally in the immediate area. A common blade screw driver is such an acceptable, convenient tool, but its application to a connector in an unlocking procedure, must be convenient and safe.
The present invention relates to an electrical connector assembly comprising a male and a female connector. For convenience, one connector, which may be either the male or female, is referred to as the “first” connector, and the other connector is referred to as the “second” connector. The first connector includes a retainer spring for releasably securing the two connectors together.
The electrical connectors with which the illustrated embodiment is concerned are plug type connectors. In particular, the connecting element may be pins (on one connector) and sleeves on the other. Typically, a plug type connector is connected at the end of a cable including an outer insulating sheath. As used herein, “forward” refers to the direction of insertion of a connector (whether it is the male connector or the female connector). Thus, both connectors are moved in the “forward” direction in order to accomplish connection. Second, the term “axial” refers to the axis of a cable which passes through the center of the connector and the term “radial” refers to a direction in a plane perpendicular to the “axis” as defined. Thus, male and female plug connectors are assembled or “connected” by passing the two connectors, each in a “forward” direction along an “axial” line passing through the center of both connectors. These terms are for convenience and clarity of description and not intended to be limitations of the invention. In the illustrated embodiment, the female connector has socket elements for receiving associated connector pins on the male connector.
The first connector (male or female) includes a generally annular retainer spring having a circular base or ring and inwardly (i.e., centrally) projecting flexible tines which are inclined slightly in the direction of insertion of the second connector. The inner edges of the tines define an opening for receiving and coupling to the outer surface of a cylindrical insert of the second connector. As the second connector is assembled to the first connector, the cylindrical insert of the second connector engages the tines of the retainer spring and deflects the tines of the retainer spring in the direction of insertion of the second connector, thereby enlarging the receiving opening formed by the distal ends of the tines, and admitting the second connector to the coupling position. Upon insertion, the distal ends of the tines lock against the outer surface of the second connector (in the illustrated embodiment, by means of a peripheral rim) thereby preventing separation of the two connectors.
The first connector has an axially slidable member referred to as an inner sleeve, which is provided with a forward flange (“forward” in the direction of connection of the first connector), in the form of an annular wall. The forward flange or annular wall of the inner sleeve, in the connected position of the connector, engages a forward portion of a spring actuator or release sleeve which unlocks the two connectors through the use of a common tool such as a blade screw driver.
The outer sleeve of the first connector is received on the inner sleeve, and the outer sleeve includes a rear wall which fixes the outer sleeve against movement in an axial (connecting) direction, but permits free rotation of the outer sleeve about the axis of the connector.
The inner sleeve is also freely rotatable. The outer sleeve has a first plurality of openings, each extending in a circumferential direction over a limited distance, and the inner sleeve has a second plurality (preferably different in number from the first plurality of openings of the outer sleeve) which also extend circumferentially over a limited distance. The openings on the outer sleeve and the openings on the inner sleeve are constructed and arranged so that at least one pair of openings (that is, one on the outer sleeve and one on the inner sleeve) align to form a space sufficient to receive the blade of a common tool, such as a screw driver. Each of the first plurality of openings disposed on the circumferential, cylindrical side wall of the outer sleeve includes a respective first reaction surface at the forward end of each opening. Similarly, each of the second plurality of openings disposed on the circumferential, cylindrical side wall of the inner sleeve includes a respective second reaction surface at the rear end of each opening. The first reaction surfaces on the outer sleeve are axially spaced from the second reaction surfaces on the inner sleeve.
When the second connector is assembled to the first connector, the plug of the second connector engages the tines of the retainer spring of the first connector and displaces inner portions of the tines in the direction of insertion, thereby bending the tines so that the inner edges of the tines form an enlarged opening for receiving the plug of the second connector. The plug of the second connector may include a circumferential rim which passes beneath the opening tines of the first connector; and the tines engage the rear end of the circumferential rim to lock the two connectors together.
The spacing between the second reaction surfaces on the inner sleeve (which extend generally in a radial plane) and the first reaction surfaces on the outer sleeve (which also extend generally in a radial plane) is such as to receive the blade of a common, generally available tool such as a screw driver. The distance between the two reaction surfaces (one on the rear portion of an opening on the inner sleeve and the other on the forward portion of an opening on the outer sleeve) when the openings are aligned defines a space which is approximately equal to the width (i.e., shorter dimension) of the blade of the tool.
Thus, when the blade of the uncoupling tool is inserted through corresponding aligned openings, one in the outer sleeve and one in the inner sleeve, one lateral edge of the lower end portion, or tip, of the tool blade engages a reaction surface of an opening on the inner sleeve and the opposite lateral edge of the blade engages a reaction surface on the outer sleeve. When the tool is then twisted about its longitudinal axis (i.e., along a radius of the two connectors), the inner sleeve is moved rearwardly relative to the first connector (i.e., in the direction of connection for the second connector). This forces the inner sleeve of the first connector rearwardly, and the forward flange of the inner sleeve engages a forward surface of the actuator sleeve, causing the actuator sleeve to engage inner end portions of the tines of the retainer spring and urge them rearwardly to enlarge the opening formed by the inner end portions of the tines of the retainer spring, thus freeing the plug of the second connector so that it may be removed from the first connector.
In the illustrated and preferred embodiment, there are three equally spaced openings disposed about the circumference of the outer sleeve and four equally spaced openings disposed about the circumference of the inner sleeve. Preferably, the size, number and spacing of the openings on the inner and outer sleeves is such that there is always one slot on the outer sleeve which is aligned with one slot on the inner sleeve to provide a space to receive a disconnecting tool having a blade-type edge.
The openings on the outer sleeve (sometimes referred to as the “outer openings”) are arranged axially such that a forward (i.e., in the direction of connection) edge of the outer openings is spaced forwardly of a rear edge of the aligned openings on the inner sleeve to provide an axial space sufficient to receive the leading edge of the blade of the disconnecting tool.
For clarity, the blade of a flat screw driver (i.e., as opposed to a Phillips screw driver) has two relatively short, flat sides and two relatively long, flat sides. The two long sides provide bearing surfaces for engaging the slot of a screw and applying torque. When the tool is inserted into the aligned openings of the inner and outer sleeves of the connectors of the present invention, one bearing surface of the tool (the one facing the direction of insertion of the first connector) lies adjacent the reaction surface on the forward edge of the slot in the outer sleeve, and the opposing bearing surface of the tool lies adjacent a reaction surface on the rear edge of the radially aligned slot on the inner sleeve.
By turning the tool (in the manner for inserting or removing a fastener), the inner sleeve of the first connector is moved rearwardly. The inner sleeve includes a member (a circular peripheral flange in the illustrated embodiment) which engages and translates the actuator sleeve axially rearwardly (i.e., in the direction of disconnection). The actuator sleeve of the connector includes an inner frusto-conical bearing surface which engages the tines of the spring to force the tines to an unlock, or release, position, freeing the latched second connector and permitting its removal.
The connectors may be assembled together without the tool. During connection, a leading portion of the insert of the second connector forces the tines of the locking spring forward in the direction of insertion of the second connector such that the tines “open” to form an enlarged receiving opening. When an outer peripheral rim on the insert of the second connector passes beneath the inner edges of the tines on the locking spring, the tines spring back to form a reduced opening, thereby engaging the rear surface of the peripheral ridge on the insert extension of the second connector, and locking the two connectors together in the assembled, operative position.
As indicated above, to disconnect the connector, the tool is inserted into aligned openings, one on the outer sleeve, and the other on the inner sleeve. The tool is then twisted to translate the spring release actuator which forces the tines to the open or unlock position so that the second connector may be removed manually.
Referring first to
The housing 12, as seen in
Referring now to the female connector 11 shown in
The insert 30 of the female connector 11 includes a rear section 31A (to the right in
Still referring to
A spring mount 37, also having a generally cylindrical (or sleeve-like) shape, is attached to a receiving sleeve 59 of the female connector 11 and is received within the spring actuator 34. The spring actuator 34 is also formed, generally, as a surface of revolution, and it includes an outer wall 38.
The spring actuator 34 also includes an annular forward wall 39 which lies in a radial plane and extends about the plug extension 17, and it is then formed rearwardly into a cylindrical wall portion 42 which lies adjacent and receives the plug extension 17 of the male connector 10 when the male connector is inserted into the female connector 11. At the right side of the inner cylindrical wall 42, there is formed a frusto-conical lip forming an actuating wall or extension 45 which extends generally rearwardly and inwardly of the female connector 11 (that is toward the right and axially inwardly in
As seen in
Referring now to
Still referring to
Turning now to the outer sleeve 27 (
On the inner surface of the forward portion wall 26 of the outer sleeve 27 is an annular groove or recess 63. The recess 63 receives an annular barbed portion 65 on the outer surface of the inner sleeve 32. Comparing
Turning now to the structure which permits actuation of the spring actuator 34 from the locking position of
Turning now to
When the screw driver blade 90 is rotated back to its original position as shown in
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without the departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications that fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
Number | Date | Country | |
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61159720 | Mar 2009 | US |