Lockable electrical cord connector unit

Information

  • Patent Grant
  • 6428339
  • Patent Number
    6,428,339
  • Date Filed
    Wednesday, December 6, 2000
    24 years ago
  • Date Issued
    Tuesday, August 6, 2002
    22 years ago
Abstract
A lockable electrical cord connector unit having a cylindrical connector housing made of electrically non-conductive material. A locking control ring telescopes over the connector housing and it is mechanically connected to structure within the connector housing that allows male electrical connector members extending from the housing to be locked into a female electrical socket. In an alternative embodiment the connector housing may have female sockets that can lock onto a male electrical terminal by using the same locking control ring structure. A second alternative embodiment provides for the connector housing to be an adaptor having male electrical terminal prongs extending from one end and having a female electrical socket formed in its other end. The locking ring allows both ends to be locked to mating electrical terminals.
Description




BACKGROUND OF THE INVENTION




The invention relates to an electrical connector and more specifically to one that can be locked onto either a male electrical terminal or a female electrical terminal.




Extension cords have been used for many years to lengthen the cord of an electrical device so that it can be connected to a remote power supply or receptacle. One end of the extension cord has a female socket that is sized to engage with a plug located on the cord of the electrical device while the other end of the extension cord is formed with a plug which is adapted to engage with a socket located at the power supply.




Quite often, while the user is moving the electrical device or when the extension cord or the cord of the device becomes entangled or caught, the extension cord will become disconnected from the device or the power supply. When this occurs, the user is forced to discontinue operations and to reestablish the electrical connection, thereby adding additional time to complete the task. Another problem is that the extension cord partially disconnects from the receptacle and has hot electrical contacts exposed to the user and the environment. In this situation, a person may accidently touch the electrical contact and sustain injuries or the electrical contacts may short and cause a fire and/or damage to the device, power supply or user.




In order to prevent the extension cord from becoming disconnected from the electrical device, users have often resorted to means such as tying a knot in the cord of the device and the socket end of the extension cord to isolate the plug/socket connection from induced stress. This method, is time consuming, and can damage the insulation surrounding the conductor, and shortens the effective life of the cord.




To overcome the above disadvantages, extension cords have been designed with a variety of locking mechanisms to securely connect the extension cord to the device or power supply. One such extension cord is shown in U.S. Pat. No. 4,085,991. It utilizes structure allowing engagement of the apertures formed in the prongs of a male electrical plug. Once engaged, the two members cannot be pulled apart and there is structure for releasing that engagement. A similar method of locking a connector onto the male prong of a male electrical plug is illustrated in U.S. Pat. No. 5,352,132.




Other prior art patents of interest are the following. The Chesler U.S. Pat. No. 3,691,327 discloses a circuit-closing adaptor having a key-operated lock means that closes the electrical circuit when the key is in the lock and which opens the circuit when the key is removed from the lock.




The Sherman U.S. Pat. No. 4,167,658 is directed to an electrical lock having a housing carrying a pair of prongs to be mounted in a conventional wall socket. It has a key operated cam in the housing that makes and breaks one of the contacts and latching means carried by that contact that mechanically locks onto the plug prong. The Solomon U.S. Pat. No. 4,579,410 is directed to a security attachment for an electrical plug that is effective to prevent unauthorized use and to readily permit authorized use.




The Windsor Jr. U.S. Pat. No. 4,875,874 is directed to a rotatable electrical connector arrangement for the secure snag free interlocking of the socket female end member of an electrical power extension cord, to the plug or male end member of an electrical power implement, or to any related device having a male plug member fixed to its power cord. The Torok U.S. Pat. No. 5,108,301 is directed to a locking electrical cord connector that securely attaches at both the male and female ends.




It is an object of the invention to provide a novel lockable electrical cord connector unit that can be installed on the end of the electrical cord of an electrical device.




It is also an object of the invention to provide a novel lockable electrical cord connector unit that will prevent accidental disconnection.




It is another object of the invention to provide a novel lockable electrical cord connector unit that will prevent downtime previously caused by the electrical connections pulling apart.




It is an additional object of the invention to provide a novel lockable electrical cord connector unit that will reduce the cost of labor caused by downtime delays.




It is a further object of the invention to provide a novel lockable electrical cord connector unit that is easy and fast to install.




It is also an object of the invention to provide a novel lockable electrical cord connector unit that is inexpensive to manufacture and market.




It is another object of the invention to provide a novel lockable electrical cord connector unit that is safer since it prevents partial disconnection and exposed contacts.




It is also an object of the invention to provide a novel lockable electrical cord connector unit that will prevent the possibility of an electrical short that could cause a fire.




SUMMARY OF THE INVENTION




The lockable electrical cord connector unit has been designed with a basic component, an elongated cylindrical connector housing having a front wall structured as a female electrical terminal or as a male electrical terminal. The rear wall of the connector housing can have either a bore hole for receiving the end of an extension cord or it can be structured as a male electrical terminal. A substantially semi-circular groove extends around the outside of the bottom half of the connector housing to opposing positions near its mid point. A cylindrical bore extends inwardly from the front wall of the connector housing and extends a substantial portion of the length of the connector housing and in some cases its entire length. A ground cylinder is telescopically received in the cylindrical bore. An eccentric control pin has its front end connected to the ground cylinder and its rear end is connected to a control pin guide that is attached to the inner surface of a locking control ring that telescopes over the connector housing. The locking control ring can be rotated through a range of approximately 180 degrees which would cause the ground cylinder to rotate at the same time. When the connector housing has the mating male and female wedge structure incorporated in its interior, a male electrical plug that has been inserted into the front end of the connector housing can be locked in its female socket by the rotation of the locking control ring in one direction and it may be released by rotation in the opposite direction. Where a male electrical structure is either extending from the front wall or the rear wall of the connector housing, the rotation of the locking control ring will cause the ground pin to be rotated in such a manner that it will lock into a ground receptacle into which it has been inserted.




Utilizing the basic connector housing structure and the locking control ring, one embodiment of the lockable electrical cord connector unit can have its rear end connected to an extension cord and its front end structured as a female receptacle for a male electrical terminal plug. Using the same basic connector housing and the locking control ring structure, a second embodiment can be assembled with an extension cord connected to its rear end and its front end can be structured with projecting male conductor blades and a ground pin. A third embodiment using the same basic connector housing structure and the locking control ring can be produced in the form of an adaptor having a female front end and a male rear end. The exact manner in which the different embodiments function is fully described later in the specification.











DESCRIPTION OF THE DRAWINGS





FIG. 1

is an exploded front perspective view of the novel lockable electrical cord connector unit showing an embodiment having a female receptacle in the front wall of the connector housing;





FIG. 1A

is a rear elevation view of the ground tube inserted into the rear end of the ground cylinder;





FIG. 1B

is a vertical cross section taken along lines


1


B—


1


B of

FIG. 1A

;





FIG. 2

is a horizontal cross sectional view taken through the connector housing and also showing an extension cord attached thereto;





FIGS. 3A-3C

are schematic front elevation views of the connector housing showing how the lobe of the cam member travels to raise and lower the male wedge as it travels from an unlocked position to a fully locked position;





FIG. 4

is an exploded front perspective view of a first alternative embodiment of the lockable electrical cord connector unit having male electrical terminal members extending from the front wall of the connector housing;





FIG. 5

is a side elevation view of the eccentric locking ground pin and the ground pin cylinder with portions broken away for clarity;





FIGS. 5A-5C

schematically show the eccentric locking ground pin as it travels between its unlocked position and its locked position;





FIG. 6

is a horizontal cross sectional view through an adaptor embodiment of the lockable electrical cord connector unit;





FIG. 7

is a vertical cross section view taken along lines


7





7


of

FIG. 6

;





FIG. 8

is an end elevation view taken along lines


8





8


of

FIG. 7

;





FIG. 9

is a cross sectional view taken along lines


9





9


of

FIG. 7

;





FIG. 10

is a cross sectional view taken along lines


10





10


of

FIG. 7

; and





FIG. 11

is a rear end elevation view taken along lines


11





11


of

FIG. 7

, respective sockets.











DESCRIPTION OF THE PREFERRED EMBODIMENT




The first embodiment of the lockable electrical cord connector unit will now be described by referring to

FIGS. 1-3

of the drawings. The lockable electrical cord connector unit is generally designated numeral


16


and it has as its primary component connector housing


18


having a longitudinally extending X-axis.




Connector housing


18


has a front wall


20


, a rear wall


21


, a top side


22


, a left side


23


, a right side


24


and a bottom side


25


. A cavity or chamber


27


is formed in the interior of connector housing


18


. A pair of laterally spaced sockets


29


and


30


are formed in front wall


20


for removably receiving the male prongs of an electrical plug. A first pair of elongated electrical terminal members


32


and


33


are supported in cavity


27


with their respective front ends adjacent the rear ends of the respective sockets


29


and


30


so that they would be placed in electrical contact with the laterally spaced male prongs of an electrical connector when the male prongs are inserted into the respective sockets.




An extension cord


35


has a male electrical plug


37


connected on its rear end. The front end of extension cord


35


passes through an aperture


38


in rear wall


21


. Electrical conductor wires


40


and


42


along with a ground wire


41


pass through the length of extension cord


35


. Electrical conductor wires


40


and


42


are soldered or otherwise connected to the rear ends of electrical terminal members


32


and


33


. Ground wire


41


is connected by a ground clip terminal


43


to an annular ground clip channel


44


on the rear end of cylinder ground tube


45


. Ground tube


45


has a bore hole


46


having a L-axis.




Part of cavity


27


in connector housing


18


forms an open space


47


immediately forward of support platform


48


that is formed in the interior of connector housing


18


. Male wedge


49


reciprocally telescopes up into and retracts from female wedge


50


and both captured in open space


47


. An opening


52


is formed in top surface


22


for removably receiving wedge assembly retaining cover


53


. When in its assembled position, wedge assembly retainer cover


53


presses downwardly upon spring


54


to keep a downward pressure on female wedge


50


. As male wedge


49


is pushed upwardly, it causes the legs of female wedge


50


to be spread apart with a sufficient force that they press outwardly upon the respective electrical terminal members


32


and


33


and rigidly lock the male prongs of an electrical plug that has been inserted through the respective sockets


29


and


30


. A pair of screws


56


pass through the respective apertures


57


in wedge assembly retainer cover


53


and are locked into the threaded bore holes


58


in support platform


48


.




Connector housing


18


has an eccentric control pin slot


60


in its outer surface that has an arc of approximately 180 degrees. An eccentrically located bore hole


62


having a K-axis extends through front wall


20


and through at least most of the length of connector housing


18


. Bore hole


62


communicates with the inner edge of slot


60


. Ground cylinder


64


is telescopically received into bore hole


62


and cam member


65


that is formed on the front end thereof aligns with the bottom of open space


47


immediately beneath male wedge


49


. Ground cylinder


64


has an eccentric L-axis that receives ground tube


45


. This structure is best described by referring to

FIGS. 1A and 1B

.

FIG. 1A

is a rear elevation view of ground cylinder


64


that has a concentric K-axis and ground tube


45


that has an eccentric L-axis. The front end of bore hole


62


has an enlarged aperture


66


which allows cam member


65


to pass inwardly therethrough. Outer disk


61


has a bore hole


63


having a L-axis and a transversely extending threaded bore


66


for receiving threaded screw


67


. Bore hole


63


aligns with a bore hole in ground cylinder


64


and bore hole


46


in ground tube


45


for receiving the ground pin of a male electrical plug.




A threaded bore hole


74


receives the top end of an eccentric control pin


75


whose bottom end is connected to control pin sleeve


76


. Control pin


75


and control pin sleeve


76


are positioned in slot


60


so that they may travel through a range of approximately 180 degrees as ground cylinder


64


is rotated. Locking control ring


78


has an eccentric control pin guide recess


77


formed on its inner surface. A pair of longitudinally aligned bore holes


79


align with aperture


80


in control pin sleeve


76


for receiving pin


81


. When locking control ring


78


is telescopically received on connector housing


18


at its proper position and connected to pin


81


, a 180-degree rotation of locking control pin


75


will be possible due to the arcuate configuration of slot


60


. This will cause eccentric ground cylinder


64


to rotate through the same number of degrees thereby causing male cam member


65


to push upwardly on male wedge


49


into the spreadable legs of female wedge


50


. This will lock the male prongs of a male connector plug rigidly within connector housing


18


.

FIGS. 3A-3C

illustrates the manner in which cam member


65


travels and ground tube bore hole


46


travels. A reverse rotation of locking control ring


78


will lower male wedge cam


65


and disengage female wedge


50


and male wedge


49


from locking engagement with the inner surface of electrical terminal members


32


and


33


. The ground pin of a male connector plug that is inserted into bore hole


46


will also be rigidly locked to connector housing


18


when locking control ring


78


is rotated approximately 180 degrees. A rear cover ring


83


telescopes over the rear end of connector housing


18


and is secured in position by a set screw


84


that passes through the respective threaded aperture


85


and threaded bore


86


. Front cover ring


88


telescopes over the front end of connector housing


18


and is secured in position by set screw


89


that passes through the respective threaded apertures


90


and


91


.




A first alternative embodiment of the lockable electrical cord connector unit is illustrated in FIGS.


4


and


5


-


5


C and it is generally designated numeral


100


. It has a cylindrical connector housing


102


made of electrical non-conductive material having a front end


103


, a rear end


104


, a top surface


105


, a left side


106


, a right side


107


and a bottom surface


108


. A cavity


110


is formed in connector housing


102


and an aperture


112


is formed in top surface


105


for removably receiving a removable assembly cover


114


. The interior of cavity


110


would have a support platform with a pair of longitudinally spaced threaded bore holes such as illustrated in FIG.


2


. Screws


116


passing through threaded apertures


117


would secure the assembly cover to housing


102


.




An extension cord


120


could have its rear end connected to a power tool, a male electrical plug or a female electrical plug. The front end of extension cord


120


passes through an aperture


122


in rear wall


104


. Extension cord


120


has electrical conductor wires


124


and


125


and a ground wire


126


. Front wall


103


has a pair of laterally spaced sockets through which pass electrical terminal members or blades


128


and


129


. A bore hole


131


in front wall


103


having an eccentric K-axis extends inwardly at least most of the length of connector housing


102


for receiving eccentric ground pin cylinder


132


. An arcuate slot


134


extends approximately 180 degrees around the bottom of connector housing


102


with its inner end in communication with bore hole


131


.




Eccentric ground pin cylinder


132


has a longitudinally extending bore


134


having a K-axis. An elongated conductor rod


135


has a locking ground pin


136


formed on its one end and it has an annular ground clip channel


138


formed on its other end. A rotating ground clip terminal


139


is connected to the end of ground wire


126


and it is detachably secured onto ground clip channel


138


. A threaded bore hole


141


is formed in the bottom surface of ground pin cylinder


132


for receiving the eccentric control pin


142


. The bottom end of control pin


142


is connected in the top end of control pin sleeve


143


. A control sleeve set pin


144


passes through bore hole


145


of control pin sleeve


143


. Eccentric locking ground pin


136


has a flat surface


147


along its one side. When eccentric locking ground pin


136


is inserted into a mating female electrical socket, flat surface


147


faces downwardly. When it is rotated approximately a half rotation, the eccentric locking ground pin rotates off center and locks itself in the socket thus preventing the disconnecting of the connector housing therefrom.

FIGS. 5A-5C

schematically show how the eccentric locking ground pin travels first from its completely unlocked position in

FIG. 5A

to its completely locked position in FIG.


5


C.




A locking control ring


155


has a recessed control pin guide


157


formed on its inner surface for receiving the bottom end of control pin sleeve


143


. Control sleeve set pin


144


passes through the longitudinally aligned bore holes


158


to lock control pin sleeve


143


therein. Rotation of locking control ring


155


through approximately 180 degrees causes control pin sleeve


143


to travel radially throughout that same angulation and cause ground pin cylinder


132


to rotate about its K-axis. In one extreme position of locking control ring


155


, locking ground pin


136


will be free to enter or be removed from its appropriate female socket. At the other end of the rotation of locking control ring


155


, locking ground pin


136


will be locked so tightly in the receptacle socket that connector housing


102


cannot be removed. A rear cover ring


160


has a set screw


161


that is threaded into aperture


162


and threaded bore hole


163


. A front cover ring


165


has a set screw


166


that is threaded into a bore hole


167


and threaded bore hole


168


.




A second alternative embodiment of the lockable electrical cord connector unit is illustrated in

FIGS. 6-11

. It is an adaptor connector unit that has a female receptacle structure on its front end and male connector structure on its rear end. These respective locking structures function exactly the same as the two previously discussed embodiments. The locking adaptor unit is generally designated numeral


172


. It has a connector housing


174


having a front wall


175


, a rear wall


176


, a top surface


177


and a bottom surface


178


. A pair of laterally spaced sockets


180


are formed in front wall


175


. A first pair of electrical terminal members or blades


182


are mounted in the top surface of support platform


183


. Their front ends are aligned with the sockets


180


to receive the prongs of a male electrical connector. Rear wall


176


has a laterally spaced pair of bore holes


185


. A second pair of electrical terminal members or blades


187


have their front end connected to the rear end of the respective first pair of electrical terminal members


182


. The rear ends of the second set of electrical terminal members


187


pass through the respective bore holes


185


. A cavity


190


is formed in front of support platform


183


for receiving male wedge


192


, female wedge


193


and the lobe of cam member


194


. Connector housing


174


has an X-axis around which the locking control ring


196


rotates. Rear cover ring


197


and front cover ring


198


are rigidly secured to the outer surface of connector housing


174


in the same manner as described with the first two embodiments.




As seen in

FIG. 7

, a bore hole


200


extends inwardly from rear wall


176


and it has a longitudinally extending K-axis. An eccentric ground cylinder


202


having an eccentric locking ground pin


203


extending from its rear end is received in bore hole


200


. Ground pin


203


has an eccentric L-axis. The front end of ground cylinder


202


has a bore hole


210


for receiving the ground terminal of a male electrical plug. Spaced forwardly of ground cylinder


202


is cam member


194


having its aligned bore hole and a cap plug


212


also having an aligned bore hole through which the ground pin of a male electrical can pass.




A retainer cap


214


is received in an aperture in the top surface of connector housing


174


and it is secured in place by screws


216


that are threaded into bore holes


217


in the support platform


183


. Connector housing


174


has a radial slot


220


that extends for about 180 degrees and through which passes eccentric control pin sleeve


222


. Control pin sleeve


222


is connected by pin


224


to the control pin guide on the inner surface of locking control ring


196


. The control pin extending upwardly from control pin sleeve


222


is screwed into the bottom surface of ground pin cylinder


202


. Rotation of locking control ring


196


provides a locking action simultaneously to each end of the electrical cord connector unit


172


. In one sequence, the rear end of the unit has the ground pin


203


rotated in the socket in which it is inserted. Because it is eccentric, it locks in its uppermost position to form a locked tight connection. With the same rotation of ground pin cylinder


202


, cam member


194


drives male wedge


192


up into female wedge


193


causing its arms to spread tightly against the inner surface of the electrical terminal members or blades


182


which then grabs the male blades of a male connector sufficiently tight enough that they cannot be removed from the connector housing


174


.

FIG. 8

is a rear elevation view showing the eccentric L-axis of bore hole


213


.

FIG. 9

shows how cam member


194


forces male wedge


192


up into female wedge


193


to force the inner sides of electrical terminal members


182


outwardly and lockingly grip the prongs of a male electrical plug.

FIG. 10

shows how locking ring


196


rotates eccentric ground cylinder


202


.

FIG. 11

is a rear elevation view showing eccentric locking ground pin


203


.



Claims
  • 1. A lockable electrical cord connector unit comprising:a connector housing having a front wall, a rear wall, a top surface, a bottom surface, a left side and a right side; said connector housing being made of electrically non-conductive material; said connector housing having a longitudinally extending X-axis; a cavity formed in said connector housing; a first pair of laterally spaced sockets formed in said front wall of said connector housing for removably receiving the male prongs of an electrical plug; a first pair of elongated electrical terminal members each having a front end and a rear end; means for supporting said respective first pair of elongated electrical terminal members with their respective said front ends adjacent said respective sockets so they would be placed in electrical contact with the laterally spaced male prongs of an electrical connector when the male prongs are inserted into said first pair of sockets; wedge means reciprocally mounted in said cavity so that said wedge means can travel back and forth between said first pair of elongated terminal members from a first position in which the male prongs of an electrical plug are free to travel in and out of said pair of laterally spaced sockets and a second position that locks the respective male prongs of an electrical connector against said respective first pair of electrical terminal members; and means for actuating movement of said wedge means between said first position and said second position comprising a locking control ring having a front end, a rear end and an inner surface; said locking control ring being telescopically mounted over said connector housing so that it may be rotated with respect to said connector housing between a locked position and an unlocked position.
  • 2. A lockable electrical cord connector unit as recited in claim 1 further comprising an electrical extension cord having at least two electrical conductor wires each having a front end and a rear end; a male electrical plug is connected to said rear end of said electrical conductor wires; said front end of said electrical extension cord passing through an aperture in said rear wall of said connector housing and said two respective electrical conductor wires being connected to said respective rear ends of said first pair of elongated electrical terminal members.
  • 3. A lockable electrical cord connector unit as recited in claim 2 wherein said electrical extension cord has a ground wire having a front end and a rear end; said front wall of said connector housing having an electrical ground terminal socket formed in said front wall of said connector housing; first electrical ground connector means located in said connector housing for electrically connecting said front end of said ground wire of said electrical extension cord to said electrical ground terminal socket.
  • 4. A lockable electrical cord connector unit as recited in claim 1 wherein said inner surface of said locking ring has a recessed eccentric control pin guide.
  • 5. A lockable electrical cord connector unit as recited in claim 4 wherein said means for actuating movement of said wedge means further comprises a cylindrical bore hole having a longitudinal K-axis extending inwardly from said front wall of said connector housing; an eccentric cam ground cylinder having a front end, a rear end and an outer surface is rotatably mounted in said cylindrical bore hole.
  • 6. A lockable electrical cord connector unit as recited in claim 5 wherein said means for actuating movement of said wedge means further comprises a radially oriented control pin having an inner end and an outer end; said inner end being captured in said outer surface of said cam ground cylinder and said outer end having means fixedly connecting said outer end in said eccentric control pin guide in said inner surface of said locking ring; said outer surface of said connector housing having an arcuate control pin slot that communicates with said cylindrical bore hole and said eccentric control pin passes through said control pin slot during arcuate travel of said control pin.
  • 7. A lockable electrical cord connector unit as recited in claim 1 wherein said wedge means comprises a male wedge member aligned to reciprocally enter and withdraw from a female wedge member in response to rotation of said locking ring around said connector housing.
  • 8. A lockable electrical cord connector unit as recited in claim 1 wherein said top surface of said connector housing has a wedge retainer cover aperture formed therein that communicates with said cavity in which said wedge means is mounted; a wedge retainer cover is removably mounted in said wedge retainer cover aperture.
  • 9. A lockable electrical cord connector unit as recited in claim 1 further comprising a front cover ring and a rear cover ring that are telescopically mounted over said connector housing respectively in front of and behind said locking control ring; and means for securing said front ring cover and said rear cover ring to said connector housing to prevent rotation with respect to said connector housing.
  • 10. A lockable electrical cord connector unit comprising:a connector housing having a front wall, a rear wall, a top surface, a bottom surface, a left side and a right side; said connector housing being made of electrically non-conductive material; said connector housing having a longitudinally extending X-axis; a cavity formed in said connector housing; an aperture formed in said rear wall of said connector housing; an electrical extension cord having two electrical conductor wires and an electrical ground wire and each of said wires having front ends that extend in through said aperture formed in said rear wall of said connector housing and into said cavity in said connector housing; a first pair of laterally spaced apertures formed in said front wall of said connector housing; a first pair of elongated electrical terminal members each having a front end and a rear end; said respective front ends of said electrical terminal members extending forwardly through said respective first pair of laterally spaced apertures; means connecting said rear ends of said respective electrical terminal members to said respective front ends of said two electrical conductor wires within said cavity in said connector housing; a ground pin having a front end, a rear end and a longitudinally extending K-axis; said front end of said ground pin extending forwardly from said front wall of said connector housing; means connecting said rear end of said ground pin to said front end of said ground wire within said connector housing; and means for rotating said ground pin about said K-axis once said ground pin has been inserted into the ground socket of a female electrical receptacle.
  • 11. A lockable electrical cord connector unit as recited in claim 10 wherein said top surface of said connector housing has a wedge retainer cover aperture formed therein that communicates with said cavity in said connector housing; a wedge retainer cover is removably mounted in said wedge retainer cover aperture.
  • 12. A lockable electrical cord connector unit as recited in claim 10 wherein said means for rotating said ground pin comprises a locking control ring having a front end, a rear end and an inner surface; said locking control ring being telescopically mounted over said connector housing so that it may be rotated with respect to said connector housing between a locked position and an unlocked position.
  • 13. A lockable electrical cord connector unit as recited in claim 12 further comprising a front cover ring and a rear cover ring that are telescopically mounted over said connector housing respectively in front of and behind said locking control ring; and means for securing said front ring cover and said rear cover ring to said connector housing to prevent rotation with respect to said connector housing.
  • 14. A lockable electrical cord connector unit as recited in claim 12 wherein said inner surface of said locking ring has a recessed eccentric control pin guide.
  • 15. A lockable electrical cord connector unit as recited in claim 14 wherein said means for rotating said ground pin further comprises a cylindrical bore hole having a longitudinal K-axis extending inwardly from said front end of said connector housing and an eccentric ground pin cylinder having a front end, a rear end and an outer surface is rotatably mounted in said cylindrical bore hole.
  • 16. A lockable electrical cord connector unit as recited in claim 15 wherein said rear end of said ground pin is mounted in said front end of said ground pin cylinder.
  • 17. A lockable electrical cord connector unit as recited in claim 16 wherein said means for rotating said ground pin further comprises a radially oriented control pin having an inner end and an outer end; said inner end being captured in said outer surface of said ground pin cylinder and said outer end having means for fixedly connecting said outer end in an eccentric control pin guide in said inner surface of said locking ring; said outer surface of said connector housing having an arcuate control pin slot that communicates with said cylindrical bore hole and said eccentric control pin passes through said control pin slot during arcuate travel of said control pin.
  • 18. The lockable electrical cord connector unit as recited in claim 1 further comprising a second pair of laterally spaced apertures formed in said rear wall of said connector housing; a second pair of elongated electrical terminal members each having a front end and a rear end; said respective front ends of said second pair of elongated electrical terminal members extending forwardly through said respective second pair of laterally spaced apertures; means connecting said rear ends of said respective second pair of electrical terminal members to said respective rear ends of said first pair of elongated electrical terminal members; a ground pin having a front end, a rear end and a longitudinally extending L-axis; said front end of said ground pin extending forwardly from said rear wall of said connector housing.
  • 19. The lockable electrical cord connector unit as recited in claim 18 wherein said front wall of said connector housing has an electrical ground terminal socket formed therein.
  • 20. The lockable electrical cord connector unit as recited in claim 19 further comprising means connecting said rear end of said ground pin to said electrical ground terminal socket formed in said front wall of said connector housing.
  • 21. The lockable electrical cord connector unit as recited in claim 20 wherein said means for actuating movement of said wedge means between said first position and said second position also functions to rotate said ground pin extending from said rear wall about said L-axis once said ground pin has been inserted into the ground socket of a conventional female electrical receptacle.
  • 22. The lockable electrical cord connector unit as recited in claim 21 wherein said means for actuating movement of said wedge means comprises a locking control ring having a front end, a rear end and an inner surface; said locking control ring being telescopically mounted over said connector housing so that it may be rotated with respect to said connector housing between a locked position and an unlocked position.
  • 23. A lockable electrical cord connector unit as recited in claim 22 wherein said wedge means comprises a male wedge member aligned to reciprocally enter and withdraw from a female wedge member in response to rotation of said locking ring around said connector housing.
  • 24. A lockable electrical cord connector unit as recited in claim 22 wherein said inner surface of said locking ring has a recessed eccentric control pin guide.
  • 25. A lockable electrical cord connector unit as recited in claim 24 wherein said means for actuating movement of said wedge means further comprises a cylindrical bore hole having a longitudinal K-axis extending inwardly from said front wall of said connector housing; an eccentric cam ground cylinder having a front end, a rear end and an outer surface is rotatably mounted in said cylindrical bore hole.
  • 26. A lockable electrical cord connector unit as recited in claim 25 wherein said means for actuating movement of said wedge means further comprises a radially oriented control pin having an inner end and an outer end; said inner end being captured in said outer surface of said cam ground cylinder and said outer end having means fixedly connecting said outer end in said eccentric control pin guide in said inner surface of said locking ring; said outer surface of said connector housing having an arcuate control pin slot that communicates with said cylindrical bore hole and said eccentric control pin passes through said control pin slot during arcuate travel of said control pin.
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Number Name Date Kind
3891289 Hanke Jun 1975 A
4136919 Howard et al. Jan 1979 A
4375307 Rock Mar 1983 A
4627681 Hong Dec 1986 A
5286213 Altergott et al. Feb 1994 A
5336103 Herboldsheimer Aug 1994 A
5893772 Carmo et al. Apr 1999 A
5941724 Reed Aug 1999 A
6039591 Marsh et al. Mar 2000 A
6234823 Fuess May 2000 B1