US3235682A - Explosion proof electrical connector operable upon engagement of plug and receptaclehalves - Google Patents

Description

Feb. 15, 1966 H. P. PAPwoRTH 3,235,682

EXPLOSION PROOF ELECTRICAL CONNECTOR OPERABLE UPON ENGAGEMENT 0F PLUG AND RECEPTACLE HALVES Filed Feb. 24. 1964 5 Sheets-Sheet l Feb. 15, 1966 H. P. PAPWORTH 3,235,682

EXPLOSION PROOF ELECTRICAL CONNECTOR OPERABLE UPON ENGAGEMENT OF PLUG AND RECEPTACLE HALVES Filed Feb. 24, 1964 3 Sheets-Sheet 2 INVENTOR. HUGH P. PA PWORTH ATTORNEY.

Feb. 15, 1966 H. P. PAPwoRTH 3,235,682

EXPLOSION PROOF ELECTRICAL CONNECTOR OPERBLE UPON ENGAGEMENT OF PLUG AND REGEPTACLE HALVES Filed Feb. 24, 1964 3 Sheets-Sheet 3 FIG. IO

INVENTOR. HUGH P. PAPWORT H ATTORNEY.

United States Patent O 3,235,682 EXPLOSIGN PROOF ELECTRICAL CGNNECTOR OPERABLE UPON ENGAGEMENT F PLUG AND RECEPTACLE HALVES Hugh P. Papworth, Syracuse, N.Y., assigner to Crouse- Hinds Company, Syracuse, N.Y., a corporation of New York Filed Feb. 24, 1964, Ser. No. 346,749 3 Claims. (Cl. 20D-51.09)

This invention relates to and has as a general object a new and improved explosion proof electrical connector.

In hazardous locations which may be dened as locations in which the surrounding atmospheres contain sufiicient quantities of flammable vapors, gases, or highly combustible dusts, to create explosive mixtures, it is necessary to use explosion proof electrical devices. However, due to the fact that the different vapors, gases and dusts have different ignition temperatures, and when exploded produce different pressures, the various types of atmospheres containing different type of explosive mixtures have been categorized by fire underwriter groups, or the like, and electrical devices must be approved for use in the various classes before they can be installed in locations which contain the various mixtures of explosive gases.

The National Electrical Code categorizes the locations in which the hazards are due to flammable vapors or gases, as Class I, and those in which the hazards are due to combustible dusts as Class II. This classication is further broken down according t0 groups as follows:

containing ethyl ether This invention is directed to an electrical connector designed for use in Class I, Group B, and as will be seen from the above-set-forth classification, which is generally arranged in order of most hazardous gases, first, and least hazardous mixtures last, Group B gases rank second in hazard.

Accordingly, it is a more specific object of the invention to provide a new and improved explosion proof electrical connector of the plug and receptacle type which may be safely employed in atmospheres containing explosive mixtures of Class I, Group B, gases.

As is well known in the art, one of the leading methods of manufacturing explosion proof equipment is to design the equipment so that any explosion created by arcs, static sparks, or any other type of electrical ignition is confined within an enclosure which is of suiiicient physical strength to withstand the momentary high pressure created by the explosion and wherein the leakage paths from the enclosure are of suflicient length and closeness to lower the temperature of the gases to beneath the ignition point of the surrounding hazardous gas mixture. Such paths are termed flame-quenching paths in the art, and have taken the form of threaded paths wherein the iiame or hot gas must follow a long tortuous route from the enclosed area or explosion proof 3,235,632 Patented Feb. 15, 1966 chamber to the outside atmosphere, or wherein the path is smooth, but the tolerances are held sutiiciently close, and the length of the path is suiiiciently long to provide the necessary llame-quenching and cooling eifect.

In large current conducting devices, it has heretofore been necessary to use heavy cast iron housings, to enclose electrical equipment, so as to contain any explosion created by an electrical ignition of the hazardous mixture within the enclosure by an arc or static spark. For

example, where circuit breaking devices were desired in Class B locations, it has been necessary to utilize large heavy weight enclosures for the circuit breaker, and a plug mechanically interlocks with a receptacle carried by the breaker so that the plug cannot be withdrawn from the receptacle until the circuit breaker is operated to break the circuit. In such an arrangement any explosion created by the ignition of gases in the circuit breaker enclosure caused by the arc generated by the operation of the breaker is contained within the breaker housing or enclosure. Such combination circuit breakers and interlocked plug and receptacles are not only of great size and weight, they are in addition very expensive.

Accordingly, it is a more specific object of the invention to provide a circuit breaking electrical connector which is relatively compact, and explosion proof, yet at the same time is reliable and simple in operation and economical to manufacture.

It is further desirable that circuit breaking electrical connectors of this general type .be arranged so that the receptacle contacts are electrically dead when the plug is disengaged from the receptacle. This prevents shock hazard and further eliminates the possibility of the receptacle contacts being accidentally engaged by a metallic substance so as to create an electric arc.

Accordingly, it is a further object of the invention to provide a new and improved dead front explosion proot electrical receptacle.

All known prior devices of this general type, both explosion proof and dead front have operated in one of two general manners. The first type of such connectors is that wherein the plug is inserted in the receptacle to cause an electrical engagement of the plug and receptacle contacts and the plug is then rotated, which rotation serves to connect power to the receptacle contacts, and in turn to the plug contacts. Such devices are difficult and expensive to make, and further it is extremely difficult to construct the switching chamber in a manner so as to meet the standards of fire underwriters and the like, for Group B gases. The second general type of such prior'art connectors are those wherein the plug carries a switch operator so that upon insertion of the plug into the receptacle, whereby the plug and receptacle contacts are engaged, the operator carried by the plug engages cooperable operating means in the receptacle, so that upon rotation of the plug operator, the switching is effected to connect the power to the receptacle contacts, and again, in turn to the plug contacts. This type of device becomes very cumbersome and expensive to manufacture because of the independent operator and co-operable operating means carried by the plug and receptacle, respectively.

Accordingly, it is a more specific object of this invention to provide a unique and novel circuit breaking electrical connector of the explosion proof dead front variety, wherein the receptacle contacts are normally disengaged from the power contacts and upon axial insertion of the plug into the receptacle in a straight non-rotating fashion, the receptacle and plug contacts are rst engaged, and upon continued axial insertion of the plug power contacts are connected to the receptacle contacts to complete the circuit to the plug contacts (the order being reversed upon withdrawal of the plug), and wherein the connection between the power contacts and the receptacle contacts takes place in an explosion proof chamber, into which the inner ends of the receptacle contacts extend.

The invention consists in the novel features and constructions and the method hereinafter set forth and claimed.

lIn describing the invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

In the drawings:

FIGURE 1 is an elevational cross-sectional view of the preferred embodiment of the plug and receptacle of the invention wherein the plug is shown in axial alignment with, but separated from the receptacle.

FIGURE 2 is a sectional view similar to FIGURE 1, but wherein the plug has lbeen shown as fully inserted into the receptacle.

FIGURE 3 is a View taken looking in the direction of the arrows of line 3 3 of FIGURE l.

FIGURE 4 is a view taken looking in the direction of the arrows of line 4 4 of FIGURE l.

FIGURE 5 is a View taken looking in the direction of the arrows vof line 5 5 of FIGURE 1.

FIGURE 46 is an elevational view with parts broken away and parts in section of a portion of the receptacle.

FIGURE 7 is a View taken looking in the direction of arrows of line 7 7 of FIGURE 6.

FIGURE 8 is an end view looking to the right `of FIGURE 6.

FIGURE 9 is an end view looking to the left of FIG- URE 6 with portions broken away and portions in section.

FIGURE 10 is a view of the laid-out surface of an ele-ment of the invention.

FIGURE 11 is an elevational view of an explosion housing for the receptacle of the invention, shown mounted in an electrical conduit system.

Referring to FIGURE l, the plug housing or shell, is generally indicated at 10, and is made up of a forward portion 12 which is open at its rearward end, and internally threaded, as at 14. The forward end of the portion 12 is reduced in diameter to form a shoulder 16 and extends axially forward from the shoulder 16 to form the plug skirt 18. Received in the portion 12 and abutting against an internal shoulder 19 is a dielectric insert 2t), in which are mounted a plurality of pin type electrical contacts 22. The contacts 22 are of the conventional variety having an annular groove to receive an O-ring 23, and are provided with an axial slot 24 at their forward edge and an electrical conductor receiving socket 26 at their rearward end.

While the number of the contacts 22 has been shown to be S, it will be understood that any suitable number of contacts may be carried by the insert 20. Carried in a central rectangular slot 30 formed in the dielectric insert is a helical actuator 32 which extends through a reduced aperture communicating with the slot Si) and formed in the forward end of insert 2t). The actuator terminates at its forward end within the plug skirt 18, and is formed with a portion 34 located in a plane 90 out of the phase with the plane of the portion 32, whereby the helical surfaces 36 and 38 serve to join the portion 34 to the portion 32. The portion 32 extends beyond the inner end of the insert 20, as do the sockets 26 of the contacts 22. Power conductors, generally indicated at 34, are introduced into the sockets 26 and are mechanically fixed therein by any suitable means, as for example by set screws 33 (see also FIGURE 3). The inner end of the helix actuator 32 is apertured to receive a pin 38 to maintain the actuator in the dielectric piece 20. A second dielectric piece 40 provided wth a central cored-out portion 42, and through apertures 44 for the contact sockets 26, abuts a gasket 45 and the iirst dielectric insert 2t) and is maintained in this position by a rearward shell portion 46, which is externally threaded to mate with the threads 14 in the shell portion 12, and is fixed in threaded engagement by set screw 47. The shell portion 46 may, if desired, be provided with a threaded aperture closed by a plug, so that a sealing compound may be introduced into the plug, rearwardly' of the insert 40 to seal the power conductors 34 in the plug 10.

Referring to FIGURE 3, it will be seen that the plug contacts 22 are asymmetrically positioned in the insert 2B in a preselected arrangement to aid in polarizing the plug and receptacle. Finally, it will be seen in FIGURE l, an internally threaded coupling nut 50 is carried on the portion 12 of the plug 10 between the shoulder 16 and tiange S2 formed on the portion 46 for a purpose to be hereinafter described.

Referring again to FIGURES 1 and 2, the receptacle is generally designated by the reference numeral 6d, and is received in the forward portion 62 of a housing (to be shown in detail hereinafter) open at its rearward end to permit introduction of the power conductors 68. The outer end of portion 62 is threaded complementally to the threads on the plug coupling nut 50 to permit the nut to be attached thereto.

A cylindrical dielectric insert is received in the portion 62 of the receptacle housing by means of the annular threaded ring 82 carried by the insert 80, and an internally complementally threaded portion 84 in the housing 62.

The forward portion of the insert 80, which may be termed a silo is formed of a plurality of cylindrically cored-out portions 86, in which are received a plurality of receptacle contacts of the socket type, to receive the plug contacts 22. Again, thereceptacle contacts 90 are shown to be 5 in number, and are positioned complementally to the positioning of the plug contacts, but it will be understood that any suitable number of receptacle contacts can be carried by the receptacle, and they may be positioned in any suitable arrangement.

One of the receptacle contacts, indicated by the reference numeral 92, extends rearwardly through the insert 80 to the rear face 94 thereof, and is drilled at its inner end to receive a pin portion 96 formed on a ground contact 9S, which is provided at its rearward end with a socket 109 to receive a ground lead, or conductor 102. The ground conductor 102 is iixedly mounted in the socket by the set screw 104. As best seen in FIG- URE 1, the dielectric insert Sti is formed with the annular skirt portion 196, which is interiorly cored, so as to form an explosion proof switching chamber M98. This chamber is closed by a second dielectric piece 110, which is aflixed to the skirt 196 by means of threaded fasteners 112, which pass through insert 110, and are received in tapped holes formed with axially extending ribs or thickened portions in the ring 106 (see FIGURE 5). A plurality of shouldered bridging contacts 114 are carried by the dielectric piece 110 by any suitable means, and the bridging contacts are connected to the power conductors 68 by the set screws 104. As best seen in FIGURES 1, 2 and 5, the insert 110 is formed with a raised portion 111 on its rear surface in which the apertures for the hot contacts 114 are formed, and a raised portion 115, in which the aperture for the ground contact 98 is formed.

Connected to the interior end of the bridging contacts 114, each of which are formed with a socket aperture 116, are the rearward pin type ends 113l of power connecting contacts formed at their forward or inner end with butt type contact faces 122. The power connecting contacts 120 are moved axially by means to be hereinafter described, to move the contact faces 122 into abutting engagement with contact faces 124 formed on the rearward inner end of the receptacle contacts 90. As best seen in FIGURE 2, the power connecting contacts 120 have been moved axially from the position shown in FIG- URE 1 to engage their contact faces 122 with the contact faces 124 of the receptacle contacts 9i). As will also be seen in FIGURE 2, the plug contacts 22 are engaged in the aperture or socket 91 formed in the receptacle contacts, all

whereby the power is connected from vthe leads 68 through the connector to the leads 34 carried by the plug.

The insertion and axially inward movement of the plug into the receptacle 60 operates the means which effect the axial motion of the power connecting contacts 120. Referring to FIGURES 3 to 9, inclusive, this means will next be described. As best seen in FIGURES 1 and 2, the dielectric insert 80 is provided at its center with an aperture 130 which extends through the insert 80 into the inner end thereof, where it enters the chamber 108 formed by the attachment of the rear insert piece 110 to the dielectric insert 80. The central aperture 130 is threaded as at 132, intermediate its ends to receive a complementally threaded portion`134 of a cylinder 136.

The forward portion of the cylinder 136 is provided with a central cylindrical aperture 138 for a purpose to be hereinafter described, and the rearward portion of the cylinder terminates in a stub shaft 140 to reduced diameter. As best seen in FIGURES 1 and 2, the rearward end of the stub shaft 140 is received in an aperture 142 formed in the rearward dielectric piece 110' in order t0 provide a pilot bearing for the rotation of cylinder 136. The stub shaft 140 is provided at its inner end with a through aperture 143, and a cam actuator 144 formed with a central aperture 146 corresponding to the diameter of the stub shaft 140 is received on the shaft 140 and affixed thereto by means of a roll pin 148, which passes through a pair of radial apertures 150 formed on the inner end of the actuator 144 and the through aperture 142 formed in the stub shaft 140, all whereby the cam actuator 144 will rotate with the shaft 140 upon rotation of the cylinder 136.

As best seen in FIGURE 10, which is a layout of the surface of the cam actuator 144, the actuator is provided with three cam tracks 152, 154, and 156, located 120 degrees apart. Cam track 154, which is representative of all cam tracks, is made up of an axially extending portion 158 which is provided at its upper end portion with a circular depressed portion 160 forming a detent aperture for a purpose to be hereinafter described. The remainder of the cam track 154, indicated at 162, extends circumferentially and in spiral fashion along the surface of the actuator 144, and terminates at its inner end in a further detent depression 164. The detents 160 and 164 are located 90 degrees apart, thus describing the rotational limit of the actuator 144, as will be hereinafter understood. As best seen in FIGURE 6, the cam tracks 152, 154 and 156 are formed by relieving the surface of the carn actuator 144, so that the -bottom portion of the tracks is below the surface of the actuator 144, and the detents 160 and 164 are located below the surface of the cam tracks.

Referring again to FIGURES l and 2, it will be seen that the power connecting contacts 120 are carried by a carrier plate 170, which is composed of a pair of identical formed pieces 172 and 174 to permit assembly of the contacts 128 to the plate 17 0. As best seen in FIGURE 6, the connection of the contacts to the plate is effected by means of a snap ring 176 which is connected to the shank portion of the contact 128, and the snap ring 176 is carried in the chamber 178 formed by the hollowed-out inner portions of the pieces 172 and 174 forming the carrier plate. The butt contact portion 122 of contact 120 is enlarged so as to provide a shoulder and the outer face of the carrier plate 17@ to yieldingly bias the contacts to the position shown in FIGURES 1 and 6, wherein the ring 176 engages the underside of the carrier plate piece 174. As will be obvious, this yieldable mounting of the power contacts 120 is necessary to compensate for variations and irregularities in the manufacture and assembly of the receptacle so that each of the contacts 126 will fully engage each of the contacts 98 through their contact faces 122 and 124.

As best seen in FIGURE 9, the pieces 172 and 174 forming the carrier plate 170 are provided with three radially extending apertures, one of which is shown in the broken away sections in FIGURE 9, and is indicated by the reference numeral 184. Mounted in the apertures 184 are three detent pins 186, which are yieldingly urged into the central aperture 188 formed in the carrier plate 170 by means of compression springs 190 carried in the apertures 184 between the rearward end of the pins 186 and the bottom of the apertures 184. As will be understood, these detent pins engage and ride in the cam tracks 152, 154, and 156, formed in the surface of the cam actuator 144. Accordingly, upon rotation of the cylinder 136, the cam actuator 144 will be rotated 90l degrees and through the means of the cam tracks 152, 154 and 156, and the detent pins 186, which are normally received in the detents will pass along the spiral leg 162 of the cam tracks, and into the detents 164. The carrier plate will be moved forwardly in the chamber 108 formed by the dielectric inserts 110- and 80, to effect connection of the power contacts 120 with the receptacle contacts 90. Reverse rotation of the cylinder 136 will reverse the action and return the detent pin 186 to the detents 160, thus separating the power and receptacle contacts.

The rotation of the cylinder which may also be termed an actuator 136, is effected -by the insertion of the plug in the receptacle. Referring to FIGURES 6, 7 and 8, the forward end of the cylindrical aperture 138 formed in the cylinder 136 is closed by a guide piece 192. The guide piece 192 is formed on its forward face with a rectangular aperture 194 having a beveled entrance complemental in dimension, but oversize, to the rectangular dimension of the forward portion 34 of the helical actuator 32 carried by the plug 10. The guide piece 192 is pro-vided with a pair of radial apertures 195 extending normally to the guide aperture 194, and the forward end of the cylinder 136 is provided with a pair of radial apertures 198, to receive a pair of roll pins 260 to fixedly connect the guide piece 192 to the cylinder 136. The cylinder 136 is provided with an annular channel 202, in which a gasket 204 is received, the gasket 284 engaging the aperture 138 formed in the dielectric insert 80.

. As will be understood, when the plug skirt 18 having an axially extending keyway 206 is properly orientated, and inserted into the receptacle housing 60, so that the polarizing lug 208 enters the keyway 206, the forward portion 34 of the helical actuator 32 will enter the rectangular guide aperture 194 of the guide piece 192 carried by the cylinder 136. Continued inner movement of the plug 1t) into the receptacle 60 will, due to the helical portions 36 and 38 on the helical actuator, cause rotation of the cylinder 136, as the forward portion 34 of the helical actuator is received in the aperture 138 formed in the cylinder 136. As will be understood, this will effect a 90 rotation of the cylinder 136, and in turn a 90 rotation of the actuator 144 carried thereby, The rotation of the actuator 144 will, through the agency of the detent pins 186, carried by the carrier plate 170, effect a forward movement of the carrier plate 170, and the power contacts 120 carried thereby.

For assembly purposes, the detent pins 186 pass along the axial portions 158 of the cam tracks 152, 154 and 156, and when they reach the inner end thereof, they will snap into the detent apertures or depressions 160. Accordingly, rotation of the actuator 144, as above set forth, will cause the pins 186 to move out of the detents 160 and along the spirally extending portions 162 of the cam tracks until the detent pins 186 are received in the detent depressions 164 formed at the inner end of the cam tracks. At this point, the power contacts have moved from the position shown in FIGURE 1 to the position shown in FIGURE 2, so that the contact faces 122 thereof are in engagement with the contact faces 124 carried by the rearward ends of the receptacle contacts 90. As also seen in FIGURE 2, the plug 10 is at this point fully inserted in the receptacle 60 with the plug contacts 22 in full engagement with the sockets 91 formed in the receptacle contacts 90, and the helical actuator 32 has passed fully through the guide aperture 194 formed in the guide piece 192, carried by the forward end of the cylinder 136. As will be obvious, withdrawal of the plug from the receptacle will effect the reverse operation causing the power contacts 120 t-o first separate from the receptacle contacts 90, and thereafter the plug contacts 22 will be Withdrawn from the sockets 91 formed in the receptacle contacts.

It will be therefore understood, that the plug contacts are in mechanical and electrical engagement with the receptacle contacts prior to the engagement of the power contacts, with the inner end of the receptacle contacts, and the plug and receptacle contacts stay in such engagement until the power contacts have been separated from the inner ends of the receptacle contacts, and power has been thereby disconnected from the plug contacts. The engagement of the contact faces 122 and 124 takes place l within an arc retaining sleeve 212 carried by the inner end of the receptacle contact apertures formed in the dielectric piece 80. These arc containing sleeves may be of any suitable material, and serve to aid in extinguishing the electrical arc caused by the separation of the contact faces 122 and 124.

It will be understood and be apparent from the description thus far, that any and all electrical arcing will take place within the sleeves 212 and the chamber 108. The receptacle contacts 90 are molded, or otherwise suitably imbedded in the dielectric piece 80, so as to prevent the forward leakage of any high temperature gases or ame from the interior of the unit cau-sed by ignition of explosive gases in the chamber 108 during the contact separation operation. A flame tight path is also provided by the engagement between the threads 134 on the cylinder 136, and the threads 132 formed in the aperture 130 of the dielectric piece 80, so that there is no ame path from the arching chamber 108 forwardly through the receptacle 60.

The rearward portion of the receptacle is mounted in an explosion proof conduit housing, so that any rearward flame or high temperature gas travel or path is prevented. The mounting of the rear portion of the receptacle is best seen in FIGURE ll, wherein the empty receptacle shell portion 62 is shown as being one leg 220 of a Y-type conduit housing, or fitting 222. The other leg 224 of the iitting 222 is provided at its opposite ends with threaded apertures to receive threaded conduit nipples 226 and 228. T-he nipple 228 is fixed in place in the leg 224 of the housing 222 by set screw 230, carried by a threaded aperture formed in ear 232 formed on the leg 224, adjacent the threaded aperture there-of,

In actual installation, a sealing fitting is placed on either the top or bottom of the installation, one of which is indicated at 234. Finally, the fitting 222 is provided with a wire pulling aperture 236, which is closed by a threaded cover 238 to facilitate the connection of the power leads to the receptacle.

It will be understood therefore, from the description of the installation of fitting 222, that the receptacle is connected to a power supply in an explosion proof manner, so that any rearward escape of hot gases, or flame caused by the ignition of explosive gases in the arcing chamber 108 of the receptacle are continued within the fitting 222, in a manner which will permit their escape to the surrounding atrnosphere only after they have sutiiciently cooled to prevent an ignition of the surrounding atmosphere. The shell 62 of leg 220 is provided with one or more grounding straps 210 mounted in axial recesses 242 formed in the interior wall of shell 62 and adapted to engage plug skirt 18 to ground the plug housing in the conventional manner.

It is to be understood that, while the receptacle 60 has been shown as being formed in the leg 220 of a conduit fitting, this showing is by way of illustration only, to indicate a suitable arrangement for use in hydrogen laden atmospheres, and in other less hazardous atmospheres the receptacle 60 may be differently formed, and in fact may be formed in a manner whereby it is connected to a cord, so as to form with the plug 10 a cord connector unit.

Also it is to be understood that the detailed showing of the manner of construction of the plug and receptacle are illustrative only, and details thereof may be varied in any suitable manner without departing from the essence of the invention, and accordingly, the scope of the invention is to be limited only by the appended claims.

l What is claimed is:

1. An electrical connector comprising a plug half and a receptacle half, said halves adapted to be telescopically engaged, plug current carrying contacts carried by said plug half, and receptacle current carrying contacts carried by said receptacle half, said plug and receptacle contacts being complementally positioned in said halves so as to axially engage upon axial engagement of said halves, said Vreceptacle being formed with an explosion proof chamber, said receptacle current carrying contacts extending into Vsaid chamber, a power supply contact mounted in said receptacle in axial alignment with each of said current carrying receptacle contacts and being axially spaced therefrom, said power supply contacts being connected to a power supply, a power connecting con tact mounted in said explosion proof chamber in axial alignment with each of said receptacle contacts, like ends of said power connecting contacts having axially slidable engagement with said power supply contacts, the opposite ends of said power connecting contacts being normally spaced from said current carrying receptacle contacts, contact actuating means mounted in said explosion proof chamber, means carried by said plug cooperable with said contact actuating means upon engagement of said plug and receptacle halves to effect axial movement of said power connecting contacts into engagement with said receptacle current carrying contacts to connect the same to said power supply contacts.

2. An electrical connector comprising a plug half and a receptacle half, said halves adapted to be telescopically engaged, plug current carrying contacts carried by said plug half, and receptacle current carrying contacts carried by said receptacle half, said plug and receptacle contacts being complementally positioned in said halves so as to axially engage upon axial engagement of said halves, said receptacle being formed with an explosion proof chamber, said receptacle current carrying contacts extending into said chamber, a power supply Contact mounted in said receptacle in axial alignment with each of said -current carrying receptacle contacts and being axially spaced therefrom, an annular member mounted in said explosion proof chamber, a power connecting contact carried by said annular member and axially aligned with each of said current carrying receptacle contacts, like ends of said power connecting contacts having axially slidable engagement with said power supply contacts, the opposite ends of said power connecting contacts being normally spaced from said receptacle current carrying contacts, an actuator mounted in the receptacle and being operatively connected to said annular member, said actuator and said plug half having co-acting means operable upon axial engagement of said halves to effect movement of s-aid annular member to move said power connecting contacts into engagement with said current carrying receptacle contacts, and upon disengagement of said halves to move said power connecting contacts axially out of engagernent with said current carrying receptacle contacts.

3. An electrical connector comprising a plug half and a receptacle half, said halves adapted to be telescopically engaged, plug current carrying cont-acts carried by said plu-g half, and receptacle current carrying contacts carried by said receptacle half, said plug and receptacle contacts being complementally positioned in said halves so as to axially engage upon axial engagement of said halves, said receptacle being formed with an explosion proof chamber, said receptacle current carrying contacts extending into said chamber, a power supply contact mounted in said receptacle in axial alignment with each of said current carrying receptacle contacts and being -axially spaced therefrom, an actuator mounted in the receptacle for rotation yabout the axis thereof and having a portion extending into said explosion proof chamber, an annular member in said chamber encircling said actuator, a power connecting contact carried by said annular member and -axially aligned with each of said current carrying receptacle contacts, like ends of said power connecting contacts having axially slidable engagement with said power supply contacts, the opposite ends of said power connecting contacts being normally spaced from said current carrying receptacle cont-acts, said actuator and plug half having co-acting means operable upon axial engagement of said half to eiect rotation of said actuator in a rst direction and upon disengagement of said half to effect rotation of said actuator in the opposite direction, said actuator and annular member having co-acting cam means operable upon rotation of said actuator in said first direction to move said power connecting contacts axially into engagement with said receptacle current carrying contacts, and upon rotation of said actuator in said opposite direction to move said power connecting contacts axially lout of engagement with said receptacle current carrying contacts.

References Cited by the Examiner UNITED STATES PATENTS 1,686,347 10/ 1928 Scheuerman 20G-51.09 2,951,138 8/1960 Petrino 200-153 3,078,435 2/ 1963 Berry 339-111 KATHLEEN H. CLAFFY, Primary Examiner.

BERNARD A, GILHEANY, Examiner.

Claims (1)

1. AN ELECTRICAL CONNECTOR COMPRISING A PLUG HALF AND A RECEPTACLE HALF, SAID HALVES ADAPTED TO BE TELESCOPICALLY ENGAGED, PLUG CURRENT CARRYING CONTACTS CARRIED BY SAID PLUG HALF, AND RECEPTACLE CURRENT CARRYING CONTACTS CARRIED BY SAID RECEPTACLE HALF, SAID PLUG AND RECEPTACLE CONTACTS BEING COMPLEMENTALLY POSITIONED IN SAID HALVES SO AS TO AXIALLY ENGAGE UPON AXIAL ENGAGEMENT OF SAID HALVES, SAID RECEPTACLE BEING FORMED WITH AN EXPLOSION PROOF CHAMBER, SAID RECEPTACLE CURRENT CARRYING CONTACTS EXTENDING INTO SAID CHAMBER, A POWER SUPPLY CONTACT MOUNTED IN SAID RECEPTACLE IN AXIAL ALIGNMENT WITH EACH OF SAID CURRENT CARRYING RECEPTACLE CONTACTS AND BEING AXIALLY SPACED THEREFROM, SAID POWER SUPPLY CONTACTS BEING CONNECTED TO A POWER SUPPLY, A POWER CONNECTING CONTACT MOUNTED IN SAID EXPLOSION PROOF CHAMBER IN AXIAL ALIGNMENT WITH EACH OF SAID RECEPTACLE CONTACTS, LIKE ENDS OF SAID POWER CONNECTING CONTACTS HAVING AXIALLY SLIDABLE ENGAGEMENT WITH SAID POWER SUPPLY CONTACTS, THE OPPOSITE ENDS OF SAID POWER CONNECTING CONTACTS BEING NORMALLY SPACED FROM SAID CURRENT CARRYING RECEPTACLE CONTACTS, CONTACT ACTUATING MEANS MOUNTED IN SAID EXPLOSION PROOF CHAMBER, MEANS CARRIED BY SAID PLUG COOPERABLE WITH SAID CONTACT ACTUATING MEANS UPON ENGAGEMENT OF SAID PLUG AND RECEPTACLE HALVE TO EFFECT AXIAL MOVEMENT OF SAID POWER CONNECTING CONTACTS INTO ENGAGEMENT WITH SAID RECEPTACLE CURRENT CARRYING CONTACTS TO CONNECT THE SAME TO SAID POWER SUPPLY CONTACTS.

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