US2732531A - Lockable electric connector - Google Patents

Description

1956 E. V.'JANOW|EC LOCKABLE ELECTRIC CONNECTOR Filed March 18, 1953 I N V EN TOR. fax 420 K/qwawz-z United States Patent LOCKABLE ELECTRIC CONNECTOR Edward V. Janowiec, Minneapolis, Minn.

Application March 18, 1953, Serial No. 343,124

3 Claims. (Cl. 339-75) This invention relates to lockable electric connectors and more particularly to electric connectors adapted to cooperate in locking engagement with conventional devices at the terminals of electrical conductors.

It is an important object of the invention to provide for an electrical connector which will easily and efiiciently cooperate in locking engagement with the perforate prongs of standard electrical plugs.

It is another object of the invention to provide for an adaptor which may be introduced between a conventional electrical connector having perforate prongs and a conventional connector such as a receptacle so as to lock the connectors together physically and electrically even though the connectors may have become so worn and loose as not of themselves to furnish a good frictional union.

It is still another object of the invention to provide a locking mechanism in a female electrical connecting device which can be secured to and released from the standard perforate prongs of a male connector by simple manipulation of opposed lateral pin members in cooperation with the perforate openings of the prongs.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to similar parts throughout the several views and in which:

Fig. 1 is a vertical sectional view of a double connector or adaptor secured to a standard prong plug and to a standard wall receptacle, portions thereof being broken away and others shown in full line;

Fig. 2 is a top elevation of the adaptor shown in Fig.

1, the plug and receptacle not being shown;

Fig. 3 is an end view of the adaptor of Figs. 1 and 2 looking in the direction of arrows 3-3 of Fig.2;

'Fig. 4 shows a simplified form of the invention havinga. screw type plug and a female outlet embodying myinvention and attached to a standard pronged plug; and

Fig. 5 shows an alternate form of my invention wherein the female connector is attached to a standard prong plug by resilient latching means.

My invention is adapted to be used with an ordinary male electrical plug indicated generally at P, the said plug being equipped with electric leads terminating in electrical contacts with prong members 11 which extend outwardly in spaced parallel relation and have one perforation in each at 12, as'shown in Figs. 1, 4 and 5. In the form shown in Figs. 1, 2 and 3, my invention is also adapted to be used with a female plug element or receptacle R having openings or passageways 13 in spaced parallel relation and surface contacting members 14 disposed therein and connected with electric leads 15.

My invention comprises an electrical connector or adaptor having a dielectric body 16' which is preferably cylindrical in shape and of adiameter in the order of that of the plug P. The dielectric body 16 is provided with spaced parallel openings or passageways 17 which are adapted to receive the prong extensions of the plug Patented Jan. 24, 1956 P in the usual manner. Lying within the passageways or ablyof the spring-pressed type having a urshaped bend 19 being constructed of conducting material such as spring brass. The inner ends of the contacts 18 are electrically connected with the contacts 14 of the receptacle R.

Disposed adjacent the passageways or openings 17 and within the dielectric body 16 are latching means L which consists in at least one locking pin 20 and preferably two as shown in Fig. 1, the latching means in 'the form thereshown comprising an elongated bolt or pin 21 threadably engaged with an opening 22 which is formed in the dielectric body 16 and communicating with the opening or passageway 17 in a lateral direction. opening 22 at its juncture with the passageway or opening 17 is spaced inwardly fromthe outer orifices 23 of the passageways 17 for a distance substantially equal to the distance from the forward face 24'of the pronged plug P to the perforations 12. Thus when the pronged plug P is inserted its full distance into-the passageways or openings 17 the perforations 12 will be exactly aligned with the openings 22 and with the elongated pins 21. The outer ends of the latching means 20 comprises dielectric heads or knobs 25 which are preferably knurled or serrated as shown for easy gripping. The latching means 20 may be advanced or retracted from the passageway or opening 17 so that the elongated ends 21 will engage the perforations 12 in locking engagement. When it is' desired to release the locking engagement the latching means may be merely retracted by unscrewing thereof. In the form shown in Figs. 1, 2 and 3, the electrical connector likewise has prong members 26 which are adapted to be locked in the openings 13 of the receptacle R. The prongs 26 lie in slotted passageways or openings 27 which are of a width somewhat larger than the width of the prongs 26. The inward ends of the prongs 26 are pivotally and electrically connected by such means as screws 28 to the contact members 18. Access openings 29 may be formed in the outer wall of the dielectric body 16 so as to insert the pivotal screws 28 into threaded engagement with tapped openings 30 in the medial portion of the dielectric body 16. Referring now to Fig. 2, the

prongs 26 are shown in'side view'and the degree of movement within the slot 27 is clearly shown. One edge of each of the prongs 26 may be toothed or serrated as at 31, the toothed or serrated edges being in opposed relation one with the other as shown. Abutment means 32 are adapted to cooperate with the edges of the prongs 26 which are opposed to the toothed or serrated portions 31. The abutment members 32 may be formed somewhat similar to the latchingrneans 20 and comprise-6 an elongated threaded pin portion 33 and -a dielectric thumb screw or head 34. The elongated threaded pin portion 33 is threadably engaged with an opening in alignment with the rear edge of each of the prongs 26. As

the abutment means 32 are advanced against the rear edge of prongs 26, they are thrown out of their normal Fig.3.

Fig. 4 shows a simplified form of my invention in which the conventional pronged plug P is inserted into' a screwplug 35 having a central contact member 36 and a conducting threaded butt 37.- The contacting elements 38 lie within openings or passageways 39 and are respec tively connected to the central contact 36 and the conducting threaded butt '37; The latching means 20 may be identical with the form shown in Fig. 1, being screw 1 The threaded through openings 40 in the side of the dielectric body 41 so as to cooperate With the perforate openings 42 formed in the prongs 43 of the conventional plug P. It is understood, of course, that one latching or locking pin 2'0 may be Successfully employed to prevent the withdrawal of the pronged plug P although I prefer the dual arrangement in order to more firmly effect the union of the prongs 4 3 with the respective contact members 38. It is also to be understood that openings or recesses 42a may be formed in all of the dielectric bodies herein described for each of the knobs or manual contacting members so as to insure against human contact with the metal parts which are designedto come in contact with the prongs, contacts or other portions of the electrical conducting system. The abutment means and latching means may thus have their dielectric knobs situated within the recesses 42a to such a distance that no metallic portion will be exposed even when these members are in retracted position.

Fig. shows another form of the invention in which the actuation of the locking or latching means is effected by pressing resilient latching means rather than screwing and unscrewing the projecting pin from the prong re ceiving openings or passageways. Here again the connector is adapted to receive the perforate prongs 44 of the conventional electric plug P, the perforation 45 being formed at a standard distance from the outer face 46 as previously described. In the form shown in Fig. 5, a dielectric body 47 has openings or passageways 48 which lie in spaced parallel relation, each having therewithin an electrical contact member 49, it being understood that the hidden prong and contact members are the same as the one theredisclosed. Each of the contact members 49 is connected with an electrical conductor 50 which may in turn be connected with an electrical circuit as is common in the art. The dielectric body has a hollow portion 51, the wall portions of which contain grooves 52 in opposed relation. Sloping areas 53' and 54 are likewise formed about the space 51 so as to retain the latching or locking means 55 as shown in Fig. 5. More specifically, the latching or locking means 55 comprises a rocking arm 56 each of which has an offset fulcrum 57 lying within the opposed grooves 52. The rocking arm 56 terminates outwardly in an L-shaped extension 58- which extends through an opening 59, one at each side of the dielectric body 47. A dielectric knob 6t) is attached to each of the outwardly extending L-shaped ends 58 for manual pressing thereon. The inner end of the rocking arm 56 bears an offset pin 61 which is adapted to be projected into the perforation 45 of prong 44 at each side of the pronged plug P. Resilient means such as compression spring 62- is interposed between the rock ing arms 56 rearwardly of the fulcrum 57 and may be positioned against displacement by short bosses 63 extending inwardly from the rocking arms 56.

In the use of my invention, the operation of the form shown in Fig. 4 will be first described. My electrical connector indicated generally at 35 is inserted into a screw socket to establish electrical contact through the terminals 36 and 37. It is, of course, understood that any other standard type of electrical connection may be employed in the form shown. After having thus beenpositioned, the latching or locking means may be unscrewed sufiiciently to retract the threaded pin 40 from the passageway or opening 39. Where two such latching or locking means are employed, the opposed pin is likewise retracted. The conventional pronged plug P is then inserted so that the perforations 42 align themselves with the laterally positioned pins 40 and in contact with the spring contacts 38. The latching members are then screwed inwardly so that the pins 40 engage the perforations 42 while maintaining the electrical contact between the prongs and the spring contacts 38. When thus positioned, the plug P will be so securely locked in its electrical contact that considerable force can be applied d to the lead cord 10 without disengaging the electrical contact.

In the form shown in Fig 5, the dielectric manual knobs 60 are depressed against the compression springs 62 which causes each of the rocking arms 56 to pivot about the fulcrum 57 and to cause the abutment or pin 61 to retract from each of the openings or passageways 48. When thus retracted the pronged plug P is inserted into the openings with the perforations 45 in alignment with the abutments 61. The dielectric abutments or knobs 60 are then released from their converging position and the abutments or pins 61 will spring into position so as to be in locking engagement with the perforations 45. The compression spring 62 will constantly urge the abutments or pins 61 so as to maintain the locking engagement until the knobs 60 are again converged against the force of the compression spring 62. The form shown in Fig. 5 is somewhat more convenient in that the dual latching means is actuated by a single movement rather than requiring screwing in and screwing out of the individual latching or locking members.

The combined form of invention shown in Figs. 1, 2 and 3 has the additional value of providing a connector or adaptor which can be inserted between a conventional male and female electrical plug. Thus where the connection is no longer firm, as is often the case with long extension lines, my adaptor or connector can be inserted between the standard plugs so as to lock them together. The locking or latching means 20 is retracted and advanced in the same manner as previously described so as to lock the standard pronged plug P in electrical connection with the adaptor or connector as shown. The prongs 26 of the adaptor are then inserted into the standard receptacle R which may be any female electrical connector such as a slotted plug or wall receptacle whereupon the abutment means 32 are employed to deliber ately misalign the prongs 26 with a constant pressure, the magnitude of which is required to effect a locking engagement with the plug or receptacle. When it is desired to remove the prongs 26, the abutment means 26 are again retracted and the teeth or serrations 21 of the prong 26 will move out of engagement with the openings or passageways 13.

In the form of my invention shown in Fig. 4, it will be observed that a positive locking action is obtained upon screwing in the latching or locking pin 20 and that even in the absence of a perforate opening 42 there still will be a binding action upon the sides of the prongs 43. It is thus within my contemplation to provide for the binding or locking of pronged plugs even though they may not have perforations. In such event, the locking action will not be a positive latching operation but will rather be a frictional binding one. The form shown in Fig. 5 will, ofcourse, not adapt itself to a binding action but is to be used with only those types of pronged plugs in which perforations are formed.

it may thus be seen that I have devised a useful type of electrical connector or adaptor which is simple and efficient in construction and operation and will positively lock together electrical contacts in standard construe tion which otherwise might, through wear or undue tension thereon, become easily disconnected. The foregoing hasbeen accomplished while maintaining easy release from the locked position of said electrical connecting device.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope ofmy invention.

What-I claim is 2 1. An electrical connector for establishing an electrical circuit between conducting leads comprising, a dielectric body having a pair of spaced openings therein terminating outwardly in orifices which are adapted to receive the perforate prongs of a standard electric plug, an electrical contact member in each of said openings, each contact member being connectable to a conductor, a locking pin pivotally mounted adjacent each of said spaced openings and having a laterally formed end projectable against resilient pressure into each of said openings, a portion of each of said locking pins extending outwardly through said body for manual depression thereof whereby said projecting portion will be retracted for insertion of said perforate prong plug and may be released to permit each of said locking pins to engage the respective perforations of said prong plug to opera tively lock the electrical plug to the electrical connector.

2. An electrical connector for establishing an electrical circuit between conducting leads comprising, a dielectric body having a pair of spaced openings therein each terminating outwardly in an orifice which is adapted to receive a perforate prong of a standard electric plug, an electrical contact member in each of said openings, eachcontact member being connectable to a conductor, a rocker arm disposed within said dielectric body and pivotally engaged therewith, said rocker arm having a laterally extending locking pin adjacent one of said openings, and in alignment with an opening of a perforate pronged plug when inserted thereinto, said rocker arm further having a lateral extension extending outwardly from said dielectric body and resiliently urged in its outward direction, whereby upon depression of said lateral extension and insertion of a perforate pronged plug into said spaced openings, said locking pin will be automatically projected into a pronged perforation upon release of said depressed extension for firmly locking said pronged plug in electrical engagement with said electrical contact members in each of said openings.

3. An electrical connector comprising a dielectric body having a pair of spaced openings formed therein, each of said openings terminating outwardly in an orifice adapted to receive a perforate prong of a conventional electrical plug, an electrical contact blade in each of said openings and adapted for spring-pressed electrical contact with a perforate prong of the conventional electric plug, each contact member being connectable to a conductor in a circuit, a locking abutment positioned in an opening laterally at one side of at least one of said spring contact members and normally adapted to enter into the perforate opening of the corresponding perforate prong and thereby lock the electric plug in conducting relation with the contact members in the openings of the dielectric body, a passageway formed through the References Cited in the file of this patent UNITED STATES PATENTS 1,158,708 Mulligan Nov. 2, 1915 1,536,688 Osborn May 5, 1925 1,941,374 Weisberg Dec. 26, 1933 1,976,501 James Oct. 9, 1934 1,979,958 Clark Nov. 6, 1934 1,988,489 Gunthorp Jan. 22, 1935 2,047,623 Felts July 14, 1936 2,274,798 Kostal Mar. 3, 1942 2,307,592 Kuklman Jan. 5, 1943 FOREIGN PATENTS 289,213 Germany Dec. 5, 1914

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