US3778569A

US3778569A - Electrical connector with safety switch

Info

Publication number: US3778569A
Application number: US00213943A
Authority: US
Inventors: A Newman; C Haun
Original assignee: Empire Products Inc
Current assignee: Cooper Industries LLC
Priority date: 1971-12-30
Filing date: 1971-12-30
Publication date: 1973-12-11
Anticipated expiration: 1990-12-11
Also published as: CA983075A

Abstract

An insulated electrical connector comprising a male member and female member, having a movable member integral with one of said members, and adapted for movement upon the interengagment of the said male and female members, said movement causing the activation of a series connected current interrupting switch.

Description

United States Patent [1 1 Newman et al.

[ ELECTRICAL CONNECTOR WITI-l SAFETY SWITCH [75] Inventors: Albert P. Newman; Clem Edward Haun, both of Cincinnati, Ohio [73] Assignee: Empire Products, Inc., Cincinnati,

Ohio

[22] Filed: Dec. 30, 1971 [21] Appl. No.1 213,943

521 US. Cl. zoo/51.09 [51] 4 Int. Cl II0lr 33/30 [58] Field of Search 200/50 B, 51.09, ZOO/51.07, 51.08

[56] References Cited UNITED STATES PATENTS 2,441,465 5/1948 Bauroth ZOO/51.09

J6\ g, 1 1 (1:) ft7/ J $\TTXY l\ M U Eff: ,5

[111 3,778,569 Dec. 11, 1 973 Appleton ZOO/51.09

Primary Examiner-David Smith, Jr. Attorney-John W. Melville et al.

[57] ABSTRACT An insulated electrical connector comprising a male member and female member, having a movable member integral with one of said members, and adapted for movement upon the interengagment of the said male and female members, said movement causing the activation of a series connected current interrupting switch.

9 Claims, 4 Drawing Figures ELECTRICAL CONNECTOR WITH SAFETY SWITCH BACKGROUND OF THE INVENTION connector elements to supply mechanical union and, as

well, good electric contact between cable termini. By cam interconnection is meant the provision of a cam surface in one connector, and cam surface engaging means in a mating connector, interconnection being effected when there is mutual rotation of the connectors in such manner that the engaging means is brought into firm contact with the cam surface.

A feature of the kind of connector described is that each connector element may be wholly contained within an insulating body. When interconnection between connector elements is made, the insulating bodies may be also united to protect the connectors from water or other media with which it might be harmful for the connectors to come into contact. Nothing external to the insulating bodies is required for secure interconnection between connector elements. Connection and separation of connectors may thus be carried out while good insulating protection for the connector means is maintained. j

The type of electrical connector described finds use with all sizes of cables. In practice, however, it has been found that where larger size cables are joined, difficulties in maintaining union of connectors under field conditions arise. Where cables are joined by mutual rotation, a force tending towards counter-rotation of the cable connectors 'is set up. The effect of this force becomes more pronounced in cables of larger diameter, and actual separation of connectors has occured under conditions of use. Separation results where there is some increase in the counter-rotation force exerted, and inevitably an increase will occur where there is movement of the cable. Such movement, whether itbe in the connection or premature separation, is potentially dangerous. For example, the connectors of the type described are used in handling electricity in excess of 1000 volts. It will be appreciated that a premature connection or separation could be destructiveto equipment, and even fatal to an operator.

The present invention provides means for preventing such accidents by incorporating in said connector a movable member adapted to activate a series connected interrupting safety switch. Only when said connector is substantially fully engaged will current flow through the connector.

While it must be acknowledged that means to interrupt current flow are known, such as a fuse or circuit breaker in the ordinary house electrical wiring system, such means are independently activated. This is not the case herein. Activation of said switch is achieved only by the interconnecting action of the male and female members of the said electrical connector.

Thus, where the prior art sought primarily to devise means to lock the electrical connector against premature movement therein, the present invention has gone one step further in providing a safety interlock switch which de-energizes the circuit if accidental disengagement of the connectors occur.

SUMMARY OF THE INVENTION This invention relates to an insulated electrical connector assembly, and more particularly to an assembly wherein a movable member is provided therein for activating a series connected current interrupting safety switch. The connector assembly comprises a female member and male member interengagable therewith, wherein said female member is characterized by a plunger adapted to move along the axis therein, such that in the depressed condition, caused by the interengagement with said male member, said plunger will activate a switch to permit the flow of current through said connector assembly.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a top perspective view illustrating an insulated female member of the electrical connector assembly according to the present invention, and an uninsulated male member for interengagement therewith.

FIG. 2 is a partial longitudinal section through the female member shown in FIG. 1.

FIG. 3 is a partial longitudinal section similar 'to FIG. I

2, but illustrating a modification to the plunger assembly within the electrical connector assembly.

FIG. 4 is a side view of the plunger assembly illustrated in FIG. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings where like reference characters designate corresponding parts or elements throughout the several views, FIG. 1 shows the general relationship of the components, prior to assembly. For convenience, the female connector 10 has been illustrated completely, with a surrounding insulating jacket or sleeve 12, microswitch l4, and electric cable 16. In contrast to this, the male connector 18 is represented solely by the inserting end 20, the function of which in this invention will be described in greater detail hereinafter. It should be understood that typically, said male connector is provided with an insulating jacket which overrides a portion 12a of the jacket or sleeve 12 on said female connector. Finally, means are typically provided on said male connector for securing an electric cable thereto, such that when said male and female connectors are joined together, electric current may be transmitted through the assembly.

With respect to the construction of the latter, it will be noted that the male connector includes a main body portion 22 along with the inserting end 20. The main body portion 22 is typically provided with a depression at the rear end thereof with a longitudinally extending hollow cylindrical portion fixed to the said rear portion. Generally this is formed of a soft material such as copper or the like and it is adapted to receive the bared end of the cable and be suitably connected thereto such as by crimping or the like. Alternatively, the main body portion may be extended and be provided with a hollow bore into which the bared end' of the cable is inserted.

But in either case, electric current may be brought to the male connector portion 18.

The inserting forward end 20 of male connector 18 includes a generally cylindrical portion which is split longitudinally thereof as indicated at 24 to define lower and upper portions. This longitudinal splitting provides a certain degree of resilience to the connector. The degree of movement or a control of the resiliency may be effected by including a spring or separating means within the split, or by including a set screw (not shown) which is threaded into one portion and abuts the other within said split. However, it should be understood that the male connector may be solid without the splitting, but that some means to provide resiliency within the connection is preferable.

While a number of different locking mechanisms may be used with the invention herein, the one that is shown is a cam-groove arrangement. It will be observed at the inserting end 20 of the male connector 18 that said end is'provided with a longitudinally extending cut-out portion 26 which joins with a circumferentially extending cut-out groove 28. The groove 28 is characterized by a changing depth in a clock-wise direction. That is, the groove has a maximum depth at the tangent point with cut-out portion 26 and a minimum depth where it joins the outer surface of the portion 20 at the opposite side thereof. Groove 28 serves as a cam groove for receiving a suitable portion of the cooperating electrical connector means to be described later, so as to enable cooper- .ating portions of the two electrical connector means to obtain maximum pressure therebetween and minimum electrical resistance while at the same time locking the connectors and 18 together.

The female connector is characterized by the cylindrical portion 30, and is electrically connected to cable 16 and insulated by insulator l2. Connection is made by inserting male connector 18 into the cylindrical portion 30 of the female connector 10. As explained above, the male connector is provided with the longitudinal cut-out portion 26, the depth of which is such as to permit the joining of the respective connector despite the presence of a radially inwardly extending projection 32. The projection 32 is adapted to be disposed within the circumferentially extending cam groove 28 of the male connector whereupon relative rotation between the two connectors causes the projection 32 to ride along the cam groove until further movement is prevented. Under such conditions, the electrical connector is locked.

Normally, in the absence of a circuit break, electrical power would be passing through the assembly at the moment of mating contact between the respective connectors. However, the present invention prevents any premature power start-up until such time as full and complete contact is made between the respective connectors. Such means will presently be described.

Referring particularly to FIG. 1, it will be observed that the tip 34 of the inserting end has been angled or is skewed as to the axis of the connector.

Whilethe male is so constructed, the female connector has been modified by the inclusion of a central bore 36 throughout the length thereof. Said bore is characterized by a plunger section 38 and a spring portion 40 whose diameter is less than found in the plunger section 38. Into said bore, a plunger assembly, such as shown in FIG. 4, is provided.

The plunger assembly is characterized by a threaded rod 42 mounted within a compression spring 44. At one end of the rod a cylindrical plug 46 is pinned 47 onto the rod. Said plug is characterized by a diameter which permits it to slide within the plunger portion 38. Finally, the face 48 is angled or skewed to the axis thereof very much in the manner of the face 34 of the male connector 18. The plunger assembly operates by sliding or reciprocating within the connector. Rotation thereof is prevented by projection 37 in slot 38, see FIGS. 24. Thus, the forward movement of said plunger assembly is determined by the amount of rotation of face 34 on non-rotating face 48.

At the opposite end of the rod, a contact tip 50 is threaded onto the rod which when activated will cause the microswitch 14 to be placed in the on position. While it is generally desirable to make the tip 50 of non-conductive material, such as plastic, this is not wholly necessary as there is no electrical contact with the microswitch 14.

The inward movement, or the movement of the rod compressing spring 44, is checked by the shoulder intersecting bore portions 38 and 40. To keep the rod from withdrawing completely from the bore, the tip 50 is larger than the counterbore. That is, the inner shoul- 'der 52 prevents the rod from being withdrawn completely.

Returning now to the interengagement of the respective connectors, it will be recalled that themale connector is inserted in the female connector so that the projection 32 rides along the cut-out portion 26 until 7 the projection reaches the groove 28. At this point, the connectors are rotated relative to one another such that the angled surface or face 34 rides against the angled face 48 of the plunger assembly. The relative motion between these two surfaces is a cam like motion which causes the plunger assembly to advance towards the microswitch 14. As the plunger rod moves inwardly, the tip 50 contacts the arm 54 thereby depressing it causing the microswitch to move from a normally open position to a normally closed position. This microswitch may operate or activate a solenoid coil which in turn operates the contactors of a high capacitor motor starter or similar device. In other words, no electricity will be caused to pass through said connector until such time as the microswitch is rendered operative by said plunger assembly. The time delay between initial contact of the connector members and activation of the solenoid coil, or the length of the plunger stroke, may be varied by axially moving the safety switch 14. Said switch is mounted in such a manner that the switch base 14a is threaded on extension 51. Thus, the axial position of the switch may vary or be temporarily fixed by moving the threaded nut 53 along the extension 51.

FIG. 3 represents a modification to the plunger assembly shown in FIGS. 2 and 4. Here the plug 60 has a flat face and is operated by the inserting of the male member. However, in each case the plunger assemblies rely upon the compression spring to maintain the extended position, and the shoulders on the members at the threaded ends to limit the depth of the plunger movement.

It will be observed in FIGS. 2 and 3, that the microswitch is mounted on the threaded portion of the conductor head. By so arranging the microswitch, it should be apparent that it can be moved axially of the connector to change the time delay in which electrical contact is made. In other words, as the microswitch is moved closer to the fully extended position of the plunger assembly, it should be apparent that little movement is needed in which to activate the microswitch.

Finally, it will be seen that a slanted flange has been incorporated on the female member of the assembly to facilitate mounting thereof on an electrical panel. It should be apparent that the flange can be mounted in a manner perpendicular to the axis of the housing or connector or, as a matter of fact, on the male member itself. in addition, while the preferred description has illustrated the plunger assembly in the female member, it should be made clear that it could be provided in the male member as well.

As this invention may be embodied in several forms, as believed evidenced from the above, without departing from the spirit or essential characteristics thereof, the present embodiments are illustrative and not restrictive, and since the scope of the invention is defined by the appended claims, all changes that fall within the metes and bounds of the claims or that form their functional'as well as conjointly cooperative equivalence are 1 therefore intended to be embraced by those claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An insulated electrical connector assembly having a series connected interrupting safety switch in combination therewith, said connector assembly comprising a male and a female contact, said female connector having forward and rearward ends and an axial bore, an insulative jacket surrounding said female contact, said male connector comprising an elongated element having forward and rearward ends and being surrounded by an insulative jacket, said forward end of said male contact being axially insertable in said female contact bore from said forward end thereof to a fully seated position and being rotatable therein, said series connected interrupting safety switch having an actuator shiftable between switch-on and switch-off positions, means to bias said safety switch to said switch-off position, mounting means affixing said switch to said rearward end of one of said male and female contacts, a plunger mounted in said one of said male and female contacts and being coaxial therewith, said plunger having a forward end and having a rearward end extending beyond said rearward end of said one of said male and female contacts, said plunger being axially shiftable between a 'rearward switch-on position wherein said rearward end switch actuator to assume said switch-off position,-

means to bias said plunger to said switch-off position, said other of said male and female contacts having a surface in abutting relation-ship with said forward end of said plunger when said male contact is in said seated position within said female contact bore, said abutting surface and said forward plunger end being so configured as to shift said plunger to said switch-on position upon rotation of said male contact in said seated position to a predetermined rotative position.

2. The structure claimed in claim 1 wherein said switch mounting means is adjustable axially of said plunger whereby to adjust said plunger switch-on position.

3. The structure claimed in claim 1 including means to lock said male contact within said female connector against axial withdrawal therefrom, said locking means being such that when said male contact is fully seated 5 within said female contact it is rotatable between a locked position and an unlocked position, said locked position corresponding to said predetermined rotative position of said male contact whereby when said male contact is in said unlocked position said plunger is in said switch-off position and when said male contact is in said locked position said plunger is in said switch-n position.

4. The structure claimed in claim 1 wherein said switch mounting means is affixed to said rearward end of said female contact, said plunger being nonrotatively mounted in said female contact bore and being coaxial therewith, said rearward end of said plunger extending beyond said rearward end of said female contact.

5. An insulated electrical connector assembly having a series connected interrupting safety switch in combination therewith, said connector assembly comprising a male and a female contact, said female connector having forward and rearward ends and an axial bore, an insulative jacket surrounding said female contact, said male contact comprising an elongated element having forward and rearward ends and being surrounded by an insulative jacket, said forward end of said male contact being axially insertable in said female contact bore from said forward end thereof to a fully seated position and being rotatable therein, said series connected interrupt safety switch having an actuator shiftable between switch-on and switch-off positions and being biased to said switch-off position, mounting means affixing said switch to said rearward end of one of said male and female contacts, a plunger non-rotatively mounted in said one of said male and female contacts and being coaxial therewith, said plunger having a forward end and a rearward end extending beyond said rearward end of said one of said male and female contacts, said plunger being axially shiftable between a rearward switch-on position wherein said rearward end of said plunger contacts and shifts said switch actuator to said switchon position and a forward switch-off position wherein said rearward plunger end permits said switch actuator to assume said switch-off position, means to bias said plunger to said switch-off position, said other of said male and female contacts having a surface in parallel 50 abutting relationship with said forward end of said plunger when said male contact is in said seated position within said female contact bore, said forward end of said plunger and said abutting contact surface lying in a plane non-parallel with and forming an angle of less than 90 to said plunger and bore axes whereby upon rotation of said male contact, while in said seated position, said abutting end and surface will cooperate to shift said plunger to said switch-on position.

6. The structure claimed in claim 5 wherein said switch mounting means is affixed to said rearward end of said female contact, said plunger being nonrotatively mounted in said female contact bore and being coaxial therewith, said rearward end of said plunger extending beyond said rearward end of said female contact, said surface parallel to and abutting said forward end of said plunger comprising a surface on said forward end of said male contact.

7. The structure claimed in claim 6 wherein said plunger comprises a shaft having enlarged forward and rearward ends, said female contact bore at the rearward end of said female contact having a reduced diameter forming an annular shoulder within said bore, said means to bias said plunger to said switch-off position comprising a helical compression spring mounted on said plunger shaft with one end abutting said shoulder and the other end abutting said enlarged forward end of said plunger.

8. The structure claimed in claim 6 wherein said switch mounting means is adjustable axially of said plunger whereby to adjust said plunger switch-on position.

9. The structure claimed in claim 6 including means to lock said male contact within said female contact

Claims

1. An insulated electrical connector assembly having a series connected interrupting safety switch in combination therewith, said connector assembly comprising a male and a female contact, said female connector having forward and rearward ends and an axial bore, an iNsulative jacket surrounding said female contact, said male connector comprising an elongated element having forward and rearward ends and being surrounded by an insulative jacket, said forward end of said male contact being axially insertable in said female contact bore from said forward end thereof to a fully seated position and being rotatable therein, said series connected interrupting safety switch having an actuator shiftable between switch-on and switch-off positions, means to bias said safety switch to said switch-off position, mounting means affixing said switch to said rearward end of one of said male and female contacts, a plunger mounted in said one of said male and female contacts and being coaxial therewith, said plunger having a forward end and having a rearward end extending beyond said rearward end of said one of said male and female contacts, said plunger being axially shiftable between a rearward switch-on position wherein said rearward end of said plunger contacts and shifts said switch actuator to said switchon position and a forward switch-off position wherein said rearward plunger end permits said switch actuator to assume said switch-off position, means to bias said plunger to said switchoff position, said other of said male and female contacts having a surface in abutting relation-ship with said forward end of said plunger when said male contact is in said seated position within said female contact bore, said abutting surface and said forward plunger end being so configured as to shift said plunger to said switch-on position upon rotation of said male contact in said seated position to a predetermined rotative position.

3. The structure claimed in claim 1 including means to lock said male contact within said female connector against axial withdrawal therefrom, said locking means being such that when said male contact is fully seated within said female contact it is rotatable between a locked position and an unlocked position, said locked position corresponding to said predetermined rotative position of said male contact whereby when said male contact is in said unlocked position said plunger is in said switch-off position and when said male contact is in said locked position said plunger is in said switch-on position.

4. The structure claimed in claim 1 wherein said switch mounting means is affixed to said rearward end of said female contact, said plunger being non-rotatively mounted in said female contact bore and being coaxial therewith, said rearward end of said plunger extending beyond said rearward end of said female contact.

5. An insulated electrical connector assembly having a series connected interrupting safety switch in combination therewith, said connector assembly comprising a male and a female contact, said female connector having forward and rearward ends and an axial bore, an insulative jacket surrounding said female contact, said male contact comprising an elongated element having forward and rearward ends and being surrounded by an insulative jacket, said forward end of said male contact being axially insertable in said female contact bore from said forward end thereof to a fully seated position and being rotatable therein, said series connected interrupt safety switch having an actuator shiftable between switch-on and switch-off positions and being biased to said switch-off position, mounting means affixing said switch to said rearward end of one of said male and female contacts, a plunger non-rotatively mounted in said one of said male and female contacts and being coaxial therewith, said plunger having a forward end and a rearward end extending beyond said rearward end of said one of said male and female contacts, said plunger being axially shiftable between a rearward switch-on position wherein said rearward end of said plunger contacts and shifts saiD switch actuator to said switch-on position and a forward switch-off position wherein said rearward plunger end permits said switch actuator to assume said switch-off position, means to bias said plunger to said switch-off position, said other of said male and female contacts having a surface in parallel abutting relationship with said forward end of said plunger when said male contact is in said seated position within said female contact bore, said forward end of said plunger and said abutting contact surface lying in a plane non-parallel with and forming an angle of less than 90* to said plunger and bore axes whereby upon rotation of said male contact, while in said seated position, said abutting end and surface will cooperate to shift said plunger to said switch-on position.

6. The structure claimed in claim 5 wherein said switch mounting means is affixed to said rearward end of said female contact, said plunger being non-rotatively mounted in said female contact bore and being coaxial therewith, said rearward end of said plunger extending beyond said rearward end of said female contact, said surface parallel to and abutting said forward end of said plunger comprising a surface on said forward end of said male contact.

9. The structure claimed in claim 6 including means to lock said male contact within said female contact against axial withdrawal therefrom, said locking means being such that when said male contact is fully seated within said female contact it is rotatable between a locked position and an unlocked position, said locked position corresponding to said predetermined rotative position of said male contact, said abutting end and surface being such that when said male contact is in said unlocked position said plunger is in said switch-off position and when said male contact is in said locked position said plunger is in said switch-on position.