CA2166819C - Electrical plug with lever for disengagement from a mating receptacle - Google Patents
Electrical plug with lever for disengagement from a mating receptacle Download PDFInfo
- Publication number
- CA2166819C CA2166819C CA002166819A CA2166819A CA2166819C CA 2166819 C CA2166819 C CA 2166819C CA 002166819 A CA002166819 A CA 002166819A CA 2166819 A CA2166819 A CA 2166819A CA 2166819 C CA2166819 C CA 2166819C
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- Canada
- Prior art keywords
- lever
- plug
- gudgeon
- openings
- receptacle
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
- H01R13/62—Means for facilitating engagement or disengagement of coupling parts or for holding them in engagement
- H01R13/629—Additional means for facilitating engagement or disengagement of coupling parts, e.g. aligning or guiding means, levers, gas pressure electrical locking indicators, manufacturing tolerances
- H01R13/633—Additional means for facilitating engagement or disengagement of coupling parts, e.g. aligning or guiding means, levers, gas pressure electrical locking indicators, manufacturing tolerances for disengagement only
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- Details Of Connecting Devices For Male And Female Coupling (AREA)
Abstract
An electrical plug or similar device includes a plug body and a lever connected thereto adapted to reduce the force required to disengage the plug from a mating receptacle. The lever is suitably adapted to provide a mechanical advantage that decreases with the degree of rotation of the lever about its fulcrum. The arrangement is particularly described in relation to low profile plugs.
Description
ELECTRICAL PLUG WITH LEVER FOR
DISENGAGEMENT FROM A MATING RECEPTACLE
FIELD OF INVENTION
This invention . relates to electrical plugs. It is particularly S described in relation to low profile electrical plugs for use with AC
convenience receptacles, but is it not necessarily restricted thereto.
BACkONOUr~D OF INVENTION
Electrical plugs such as those used for connecting to convenience outlet receptacles typically comprise an insulating body member and a pair of conductor blades which project forwardly from the bottom face of the body member. A third conductor may also be used to provide a ground connection.
In one common type of North American plug, the body member is elongated along the axial direction of the blades, which"permits the body member to be grasped for removal of the plug from the receptacle. There have been a number or proposals to provide these plugs with handles to facilitate their removal from receptacles.
_2_ In another type of plug, the body member has a relatively low profile which does not permit the body member to be grasped easily for removal of the plug.
It is old and well known to provide flush-fitting electrical devices such as fuse holders with a fold flat handle. In U.S. Patent 2,507,092 (Cline), there is described a low profile electrical plug with a fold flat handle.
The removal of electrical plugs from receptacles may require an appreciable physical force to be applied through a grasping action, which is difficult for physically infirm persons.
It is an object of this invention to provide electrical plug devices which incorporate means to facilitate their removal from receptacles.
It is another object of this invention to provide electrical plugs wherein the effort required for their removal from a receptacle may be significantly less than that which is required to pull the plug from the receptacle.
It is still another object oi~ihis invention to provide electrical plugs which do not necessitate their being grasped in order to be removed from a receptacle.
,n It is yet another object of this invention to provide removal means of the foregoing type which is particularly adapted for use with low profile plugs.
In accordance with a broad aspect of this invention, in an electrical plug comprising a low profile insulating-housing which may otherwise be referred to as the body, with at least one conductor blade projecting from a bottom fac~a thereof for inserting into a receptacle therefor, and a wire connector exiting the body generally parallel to that bottom face, there is provided a lever, and pivot means mounting the lever to the body for rotation about a fulcrum between a first stored position wherein the lever is diposed within the low profile of the body, and a second position wherein the lever is upstanding. The lever includes a lever arm having a first end which, when the lever is disposed in its second position, exterids below the bottom face of the housing. Accordingly, the rotation of the lever from its first position to its second position will, when the plug is in engaged relationship with a receptacle, cause the first end of the lever arm to bear upon the receptacle and urge the plug into disengaged relation with the receptacle. It will be appreciated that the words "bottom face" and "above" as used above and throughout the specification to describe the plug and its use are used in a ~'~~~1 relative sense to facilitate description, together with the terms "top", "end", "left"
and "right" rather than in any absolute sense.
Suitably and preferably, the mechanical advantage of the lever is substantially greater than one, and conveniently may be in the range of about 1.5 to about 10. Also suitably and preferably, the lever will provide a variable mechanical advantage, preferably one which decreases as the lever is rotated from the first position to the second position. In accordance with the preferred embodiment the range changes from an initial value of about 5 to a final value of about 2, but the range may be increased or decreased as desired.
Accordingly, the force necessary to move the lever from its first position through an initial arc of about i0° may be relatively low. Once the lever has been moved through this initial arc, it becomes more accessible so that a greater force can be applied. At no time does the application of the rotating force require that the plug or the lever he grasped in any manner, and the force applied may be restricted to a pushing force, which is usually more readily applied by physically challenged persons than ~ba pulling force, particularly where this must be accompanied by a grasping action.
Suitably, the variable mechanical advantage is provided by shaping the first end of the lever arm as a yam.
~~ ~~~ ~ 9, Also suitably, the lever will comprise two lever arms connected together remote from the first end thereof by a bight, with the lever arms in parallel relationship. Preferably, the bight includes an outwardly facing portion that is upwardly outwardly inclined to facilitate the application of a rotating force thereto when the lever is in its first position.
The insulated housing of the plug will normally include a flank wall which intersects the bottom face about a substantial portion of the periphery thereof. Suitably and preferably, the lever arms and the bight when in the stored position will be contiguous with the flank wall along substantially the whole of the length of the lever. Desirably, the lever and the flank wall will be provided with co-operating means which prevent the rotation of the lever beyond its first position.
Preferably, the lever arms are attached to the insulating body by gudgeon pins integrally formed with the lever arms, which rotate in gudgeon openings provided in the body. In accordance with the preferred embodiment, the gudgeon pins and openings have a complementary shape serving to capture the gudgeon pins and prevent their withdrawal from the gudgeon openi~~gs along the axis thereof.
~'he most commonly adopted receptacles for domestic use in North America are formed as duplex pairs, with a standard modular interval between the outlets of approximately 38.20 mm. (1.50 in.), and it is a common expedient to ensure that a plug inserted into one outlet of the receptacle will not intertere with a plug in the adjacent outlet. With low profile plugs wherein the wire cord will normally exit from the plug body along an axis in a plane parallel to the face of the plug, the angle subtended by the axis within this plane will be selected so that the wire cord does not form an impediment to an adjacent outlet.'~Suitably, this angle will be not greater than about 60° relative to an axis passing through the conductor blades of the plug. In the instant lever- off plugs, the operation of the lever of one plug must not be significantly impeded by the adjacent plug. Generally speaking, this condition will be ensured where the fulcrum of the lever subtends an angle within the range of about 90° to about 45° with the axis passing through the conductor blades, with 90° being preferred. In accordance with the preferred embodiment wherein the lever comprises a pair of lever arms interconnected by a bight, the lever has an outwardly facing flank which extends over a circular arc of about 230°, the diameter of which arc is marginally less than the modular spacing of the duplex outlets, and the axes of the wire cord and of the fulcrum may be varied within the above limits without conflict.
The foregoing objects and aspects of the invention, together with other objects, aspects and advantages thereof will be more apparent from a consideration of the following description of the preferred embodiment thereof taken in conjunction with the drawings annexed hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings-FIG. 1 Shows a plug in accordance with the invention in perspective view from the top, front, right side;
FIG.2 Shows the plug of FIG. 1 in top elevation;
FIG. 3 Shows the plug of FIG. i in bottom elevation;
_g_ FIG. 4 Shows the plug of FIG 1 in right side elevation;
FIG.5 Shows the plug of FIG. 1 in front elevation;
FIG. 6 Shows the body of the plug of FIG. 1 in right side elevation before assembly with the lever;
FIG. ' Shows the lever of the plug of FIG. 1 in bottom elevation befiore assembly with the plug body; and FIGS. 8 - 10 Show in schematic form, the plug of FIG.1 in assembled relationship with a receptacle and the progressive action of the lever in the removal of the plug from the receptacle, with hidden detail 2~~8~1'9 shown in dashed outline.
FIG. 11 Shows a pair of plugs engaged in a duplex receptacle which is shown in dashed outline;
FIGS 12 - 13 Are similar to FIG. 3, but show different embodiments of the plug.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings Iri detail, a plug in accordance with the invention is identified generally therein by the numeral 10. Plug 10 comprises an insulating body 12 having a bottom face 14, a top face 16 and a flank wall i8 extending therebetween. A pair of conductor blades 20, 22 project downwardly from bottom face 14, and a wire cord conductor 24 extends from body 12 and attaches thereto over rearward portions of flank wall 18 by means of a strain relief 26; the conductor wires of cord 24 connect to conductor blades 20, 22 within body 12 in a conventional manner which is not illustrated.
Conductor blades 20, 22 have a transverse axis 32 passing therethrough, and ~~~~g~9 wire cord conductor 24 exits from body 12 along an axis 34 which extends in a plane parallel to the plane of bottom face 14.
Plug 10 further comprises a lever 40 which includes a pair of mirror image lever arms 42 interconnected by a bight 44. A gudgeon pin 46 extends from each of lever arms 42 in opposed relationship. Gudgeon pins 46 include at the distal end thereof, a head portion 50 of enlarged diameter. A
pair of circular gudgeon openings 52 are formed in body 12 on a notional axis 54 which is disposed intermediate blades 20, 22 within body 12, adjacent the centre of resistance of engagement of the plug with a receptacle as will be referred to subsequently at greater length. Gudgeon openings 52 communicate with flank wall 18 and are respectively intersected by a pair of T shaped slots 56, which also intersect bottom face 14. Lever 40 is assembled onto body 12 by urging gudgeon pins 46 along slots 56 until the gudgeon pins snap in to the gudgeon openings 52, so that notional axis 54 then defines a fulcrum 60 of the lever 40.
LEVer 40 is rotatable about fulcrum 60 between a first stored, position, as seen in FIGS. 1 - 5, wherein the lever does not project below the plane of bottom face 14, and a second position, as seen in FIG. 10, wherein the rearward end 70 of the lever projects below the bottom face.
The over-rotation of lever 40 beyond the first position is precluded by providing the forward end portion 72 of flank 18 with an upwardly rearward inclination, which will form an abutment for a similarly inclined portion 74 on the inwardly facing wall surface' of bight 44. The bottom surtace of bight 44 is upwardly forwardly inclined at 76 to facilitate the application of a force F
to lever 40 when it is desired to remove plug 10 from engagement with a receptacle R. As best considered with reference to FIGS. 8 -10, a receptacle R has electrical contacts C with a gripping portion disposed at a distance D
below the upper surface S of the receptacle. The plug 10 has conductor blades 20, 22 with a length L. Typically L is about 17 mm and D is not less than about 50% of L. Accordingly, the blades 20, 22 may be inserted a distance of about 9 mm into the receptacle R before any significant resistance is encountered, and the length of the blades engaged by contacts C is approximately 8 mm. As a corollary of this, the withdrawal of plug 10 from its fully seated position in receptacle R by a distance of L - D equal to about 8 mm will disengage the blades 20, 22 from the grip of contacts C, and will k permit the further withdrawal of the plug from the receptacle without any substantial resistance. Desirably, lever 40 will be dimensioned such that when in its second position, the lever end will project a distance of about 50% of the length L of blades 20, 22, or about 8 mm in this exemplary embodiment. Lever 40 is provided with a cam surface 80 which is arranged to progressively decrease the mechanical advantage of the lever with the degree of rotation thereof from the first position to the second position. The effect of this is to minimize the force F that is necessary to rotate lever 40 when the lever is at or adjacent its first position, wherein it will be generally flush with the surtace S of receptacle R and less readily accessible than when it is more upstanding from the receptacle R and the body 12 of plug 10. Suitably, for a plug 10 for use with a standard North American 15 amp receptacle, the mechanical advantage will change in the range of about 5:1 to about 2:1. Experimentally, the force F applied to the forward extremity of lever 40 in a tangential direction to the motion of the lever was determined to be about 2.25N adjacent the first position of the lever, and this increased to about ~S.SN adjacent the second position. This contrasts with a force of about i1N which was required to be applied along the axial direction of insertion of blades 20, 22 to release the blades of plug 1n~ from engagement with the contacts C of receptacle R.
Lever 40 has an outwardly facing flank 80 which describes a circular arc extending over an angular interval of approximately 260°, and has a diameter d equal to 36.60 mm. (1.44 in.), which is somewhat less than the intermodular spacing of 38.20 mm. (1.50 in.~ between two outlets O of a duplex pair of receptacles P shown in FIG. i l, whereby the body 12 of one plug 10 engaged in one outlet will not interfere with the body of another plug engaged in the adjacent outlet irrespective of the angular rotation of the plug body with respect to the duplex outlet. This angular rotation will of course be set by the axis 32 of conductor blades 20, 22. The axis of fulcrum 60, being at right angles to blade axis 32, will ensure that the inclined surface 76 of lever 40 through which the force F is applied to rotate the lever, is not impeded, and the axis 34 of wire cord 24 and strain relief 26, being collinear with the blade axis 32, will ensure that the wire cord will not intertere with a plug 10 engaged in an adjacent outlet O of the duplex pair P.
The inter-relationships of the blade axis 32, wire cord axis 34 and of the fulcrum 60 may be changed, however, while avoiding inter-plug interference. Thus, with reference to FIG. 12, the blade axis 132 of a plug i is intersected at an angle of approximately 45° by the fulcrum 160 and by the wire cord/strain relief axis 134, and with reference to FIG. 13 the blade axis of a plug 210 is intersected by the fulcrum 260 at an angle of 90° and by the wire/corc~ strain relief at an angle of about 45°. In this last embodiment a ground pin 282 is also provided, although it will be appreciated that a similar V
ground pin could have been provided if desired in each of the embodiments.
The foregoing embodiments are illustrative only of the invention and not limitative thereof. It will be appreciated that many other variations may be made, some of which may be preferred according to particular circumstances, and it is intended that all changes be encompassed by the Claims appended hereto.
DISENGAGEMENT FROM A MATING RECEPTACLE
FIELD OF INVENTION
This invention . relates to electrical plugs. It is particularly S described in relation to low profile electrical plugs for use with AC
convenience receptacles, but is it not necessarily restricted thereto.
BACkONOUr~D OF INVENTION
Electrical plugs such as those used for connecting to convenience outlet receptacles typically comprise an insulating body member and a pair of conductor blades which project forwardly from the bottom face of the body member. A third conductor may also be used to provide a ground connection.
In one common type of North American plug, the body member is elongated along the axial direction of the blades, which"permits the body member to be grasped for removal of the plug from the receptacle. There have been a number or proposals to provide these plugs with handles to facilitate their removal from receptacles.
_2_ In another type of plug, the body member has a relatively low profile which does not permit the body member to be grasped easily for removal of the plug.
It is old and well known to provide flush-fitting electrical devices such as fuse holders with a fold flat handle. In U.S. Patent 2,507,092 (Cline), there is described a low profile electrical plug with a fold flat handle.
The removal of electrical plugs from receptacles may require an appreciable physical force to be applied through a grasping action, which is difficult for physically infirm persons.
It is an object of this invention to provide electrical plug devices which incorporate means to facilitate their removal from receptacles.
It is another object of this invention to provide electrical plugs wherein the effort required for their removal from a receptacle may be significantly less than that which is required to pull the plug from the receptacle.
It is still another object oi~ihis invention to provide electrical plugs which do not necessitate their being grasped in order to be removed from a receptacle.
,n It is yet another object of this invention to provide removal means of the foregoing type which is particularly adapted for use with low profile plugs.
In accordance with a broad aspect of this invention, in an electrical plug comprising a low profile insulating-housing which may otherwise be referred to as the body, with at least one conductor blade projecting from a bottom fac~a thereof for inserting into a receptacle therefor, and a wire connector exiting the body generally parallel to that bottom face, there is provided a lever, and pivot means mounting the lever to the body for rotation about a fulcrum between a first stored position wherein the lever is diposed within the low profile of the body, and a second position wherein the lever is upstanding. The lever includes a lever arm having a first end which, when the lever is disposed in its second position, exterids below the bottom face of the housing. Accordingly, the rotation of the lever from its first position to its second position will, when the plug is in engaged relationship with a receptacle, cause the first end of the lever arm to bear upon the receptacle and urge the plug into disengaged relation with the receptacle. It will be appreciated that the words "bottom face" and "above" as used above and throughout the specification to describe the plug and its use are used in a ~'~~~1 relative sense to facilitate description, together with the terms "top", "end", "left"
and "right" rather than in any absolute sense.
Suitably and preferably, the mechanical advantage of the lever is substantially greater than one, and conveniently may be in the range of about 1.5 to about 10. Also suitably and preferably, the lever will provide a variable mechanical advantage, preferably one which decreases as the lever is rotated from the first position to the second position. In accordance with the preferred embodiment the range changes from an initial value of about 5 to a final value of about 2, but the range may be increased or decreased as desired.
Accordingly, the force necessary to move the lever from its first position through an initial arc of about i0° may be relatively low. Once the lever has been moved through this initial arc, it becomes more accessible so that a greater force can be applied. At no time does the application of the rotating force require that the plug or the lever he grasped in any manner, and the force applied may be restricted to a pushing force, which is usually more readily applied by physically challenged persons than ~ba pulling force, particularly where this must be accompanied by a grasping action.
Suitably, the variable mechanical advantage is provided by shaping the first end of the lever arm as a yam.
~~ ~~~ ~ 9, Also suitably, the lever will comprise two lever arms connected together remote from the first end thereof by a bight, with the lever arms in parallel relationship. Preferably, the bight includes an outwardly facing portion that is upwardly outwardly inclined to facilitate the application of a rotating force thereto when the lever is in its first position.
The insulated housing of the plug will normally include a flank wall which intersects the bottom face about a substantial portion of the periphery thereof. Suitably and preferably, the lever arms and the bight when in the stored position will be contiguous with the flank wall along substantially the whole of the length of the lever. Desirably, the lever and the flank wall will be provided with co-operating means which prevent the rotation of the lever beyond its first position.
Preferably, the lever arms are attached to the insulating body by gudgeon pins integrally formed with the lever arms, which rotate in gudgeon openings provided in the body. In accordance with the preferred embodiment, the gudgeon pins and openings have a complementary shape serving to capture the gudgeon pins and prevent their withdrawal from the gudgeon openi~~gs along the axis thereof.
~'he most commonly adopted receptacles for domestic use in North America are formed as duplex pairs, with a standard modular interval between the outlets of approximately 38.20 mm. (1.50 in.), and it is a common expedient to ensure that a plug inserted into one outlet of the receptacle will not intertere with a plug in the adjacent outlet. With low profile plugs wherein the wire cord will normally exit from the plug body along an axis in a plane parallel to the face of the plug, the angle subtended by the axis within this plane will be selected so that the wire cord does not form an impediment to an adjacent outlet.'~Suitably, this angle will be not greater than about 60° relative to an axis passing through the conductor blades of the plug. In the instant lever- off plugs, the operation of the lever of one plug must not be significantly impeded by the adjacent plug. Generally speaking, this condition will be ensured where the fulcrum of the lever subtends an angle within the range of about 90° to about 45° with the axis passing through the conductor blades, with 90° being preferred. In accordance with the preferred embodiment wherein the lever comprises a pair of lever arms interconnected by a bight, the lever has an outwardly facing flank which extends over a circular arc of about 230°, the diameter of which arc is marginally less than the modular spacing of the duplex outlets, and the axes of the wire cord and of the fulcrum may be varied within the above limits without conflict.
The foregoing objects and aspects of the invention, together with other objects, aspects and advantages thereof will be more apparent from a consideration of the following description of the preferred embodiment thereof taken in conjunction with the drawings annexed hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings-FIG. 1 Shows a plug in accordance with the invention in perspective view from the top, front, right side;
FIG.2 Shows the plug of FIG. 1 in top elevation;
FIG. 3 Shows the plug of FIG. i in bottom elevation;
_g_ FIG. 4 Shows the plug of FIG 1 in right side elevation;
FIG.5 Shows the plug of FIG. 1 in front elevation;
FIG. 6 Shows the body of the plug of FIG. 1 in right side elevation before assembly with the lever;
FIG. ' Shows the lever of the plug of FIG. 1 in bottom elevation befiore assembly with the plug body; and FIGS. 8 - 10 Show in schematic form, the plug of FIG.1 in assembled relationship with a receptacle and the progressive action of the lever in the removal of the plug from the receptacle, with hidden detail 2~~8~1'9 shown in dashed outline.
FIG. 11 Shows a pair of plugs engaged in a duplex receptacle which is shown in dashed outline;
FIGS 12 - 13 Are similar to FIG. 3, but show different embodiments of the plug.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings Iri detail, a plug in accordance with the invention is identified generally therein by the numeral 10. Plug 10 comprises an insulating body 12 having a bottom face 14, a top face 16 and a flank wall i8 extending therebetween. A pair of conductor blades 20, 22 project downwardly from bottom face 14, and a wire cord conductor 24 extends from body 12 and attaches thereto over rearward portions of flank wall 18 by means of a strain relief 26; the conductor wires of cord 24 connect to conductor blades 20, 22 within body 12 in a conventional manner which is not illustrated.
Conductor blades 20, 22 have a transverse axis 32 passing therethrough, and ~~~~g~9 wire cord conductor 24 exits from body 12 along an axis 34 which extends in a plane parallel to the plane of bottom face 14.
Plug 10 further comprises a lever 40 which includes a pair of mirror image lever arms 42 interconnected by a bight 44. A gudgeon pin 46 extends from each of lever arms 42 in opposed relationship. Gudgeon pins 46 include at the distal end thereof, a head portion 50 of enlarged diameter. A
pair of circular gudgeon openings 52 are formed in body 12 on a notional axis 54 which is disposed intermediate blades 20, 22 within body 12, adjacent the centre of resistance of engagement of the plug with a receptacle as will be referred to subsequently at greater length. Gudgeon openings 52 communicate with flank wall 18 and are respectively intersected by a pair of T shaped slots 56, which also intersect bottom face 14. Lever 40 is assembled onto body 12 by urging gudgeon pins 46 along slots 56 until the gudgeon pins snap in to the gudgeon openings 52, so that notional axis 54 then defines a fulcrum 60 of the lever 40.
LEVer 40 is rotatable about fulcrum 60 between a first stored, position, as seen in FIGS. 1 - 5, wherein the lever does not project below the plane of bottom face 14, and a second position, as seen in FIG. 10, wherein the rearward end 70 of the lever projects below the bottom face.
The over-rotation of lever 40 beyond the first position is precluded by providing the forward end portion 72 of flank 18 with an upwardly rearward inclination, which will form an abutment for a similarly inclined portion 74 on the inwardly facing wall surface' of bight 44. The bottom surtace of bight 44 is upwardly forwardly inclined at 76 to facilitate the application of a force F
to lever 40 when it is desired to remove plug 10 from engagement with a receptacle R. As best considered with reference to FIGS. 8 -10, a receptacle R has electrical contacts C with a gripping portion disposed at a distance D
below the upper surface S of the receptacle. The plug 10 has conductor blades 20, 22 with a length L. Typically L is about 17 mm and D is not less than about 50% of L. Accordingly, the blades 20, 22 may be inserted a distance of about 9 mm into the receptacle R before any significant resistance is encountered, and the length of the blades engaged by contacts C is approximately 8 mm. As a corollary of this, the withdrawal of plug 10 from its fully seated position in receptacle R by a distance of L - D equal to about 8 mm will disengage the blades 20, 22 from the grip of contacts C, and will k permit the further withdrawal of the plug from the receptacle without any substantial resistance. Desirably, lever 40 will be dimensioned such that when in its second position, the lever end will project a distance of about 50% of the length L of blades 20, 22, or about 8 mm in this exemplary embodiment. Lever 40 is provided with a cam surface 80 which is arranged to progressively decrease the mechanical advantage of the lever with the degree of rotation thereof from the first position to the second position. The effect of this is to minimize the force F that is necessary to rotate lever 40 when the lever is at or adjacent its first position, wherein it will be generally flush with the surtace S of receptacle R and less readily accessible than when it is more upstanding from the receptacle R and the body 12 of plug 10. Suitably, for a plug 10 for use with a standard North American 15 amp receptacle, the mechanical advantage will change in the range of about 5:1 to about 2:1. Experimentally, the force F applied to the forward extremity of lever 40 in a tangential direction to the motion of the lever was determined to be about 2.25N adjacent the first position of the lever, and this increased to about ~S.SN adjacent the second position. This contrasts with a force of about i1N which was required to be applied along the axial direction of insertion of blades 20, 22 to release the blades of plug 1n~ from engagement with the contacts C of receptacle R.
Lever 40 has an outwardly facing flank 80 which describes a circular arc extending over an angular interval of approximately 260°, and has a diameter d equal to 36.60 mm. (1.44 in.), which is somewhat less than the intermodular spacing of 38.20 mm. (1.50 in.~ between two outlets O of a duplex pair of receptacles P shown in FIG. i l, whereby the body 12 of one plug 10 engaged in one outlet will not interfere with the body of another plug engaged in the adjacent outlet irrespective of the angular rotation of the plug body with respect to the duplex outlet. This angular rotation will of course be set by the axis 32 of conductor blades 20, 22. The axis of fulcrum 60, being at right angles to blade axis 32, will ensure that the inclined surface 76 of lever 40 through which the force F is applied to rotate the lever, is not impeded, and the axis 34 of wire cord 24 and strain relief 26, being collinear with the blade axis 32, will ensure that the wire cord will not intertere with a plug 10 engaged in an adjacent outlet O of the duplex pair P.
The inter-relationships of the blade axis 32, wire cord axis 34 and of the fulcrum 60 may be changed, however, while avoiding inter-plug interference. Thus, with reference to FIG. 12, the blade axis 132 of a plug i is intersected at an angle of approximately 45° by the fulcrum 160 and by the wire cord/strain relief axis 134, and with reference to FIG. 13 the blade axis of a plug 210 is intersected by the fulcrum 260 at an angle of 90° and by the wire/corc~ strain relief at an angle of about 45°. In this last embodiment a ground pin 282 is also provided, although it will be appreciated that a similar V
ground pin could have been provided if desired in each of the embodiments.
The foregoing embodiments are illustrative only of the invention and not limitative thereof. It will be appreciated that many other variations may be made, some of which may be preferred according to particular circumstances, and it is intended that all changes be encompassed by the Claims appended hereto.
Claims (20)
1. ~An electrical plug including a low profile insulating body having a bottom face; at least one conductor blade projecting downwardly therefrom for insertion into a receptacle therefor to provide an electric interconnection therewith, and a wire cord exiting said body generally parallel to said bottom face;
a lever:
pivot means mounting said lever to said insulating body for rotation about a fulcrum between a first, stored, position wherein said lever is diposed within the low profile of said body and a second, upstanding, position;
said lever comprising a lever arm having a first end which, when said lever is in said second position, projects below the plane of said bottom face;
rotation of said lever from said first position to said second position thereby causing said first end of said lever arm to bear upon a receptacle when said plug is in engaged relationship therewith to urge said plug towards a disengaged relationship with said receptacle.
a lever:
pivot means mounting said lever to said insulating body for rotation about a fulcrum between a first, stored, position wherein said lever is diposed within the low profile of said body and a second, upstanding, position;
said lever comprising a lever arm having a first end which, when said lever is in said second position, projects below the plane of said bottom face;
rotation of said lever from said first position to said second position thereby causing said first end of said lever arm to bear upon a receptacle when said plug is in engaged relationship therewith to urge said plug towards a disengaged relationship with said receptacle.
2. ~A plug as defined in Claim 1 wherein said lever is arranged to decrease the mechanical advantage thereof as said lever is moved from said first position to said second position.
3. ~A plug as defined in Claim 1 wherein said first end of said lever arm is provided with a cammed surface portion serving to decrease the mechanical advantage of said lever as said lever is moved from said first position to said second position.
4. ~A plug as defined in Claim 1 wherein said lever has a variable mechanical advantage in the range of about 5 to about 2.
5. ~A plug as defined in Claim 1 wherein said first end projects below said bottom face when said lever is in said second position by a distance equal to about one half of the length of said conductor blade.
6. ~A plug as defined in Claim 1 wherein said lever arm is one of a pair of similar lever arms comprising said lever, said lever further comprising a bight interconnecting said lever arms in parallel relationship remote from said first end.
7. ~A plug as defined in Claim 6 wherein said bight includes an outwardly facing portion that is outwardly, upwardly inclined to facilitate the actuation of said lever arm from said first position towards said second position by a force which is manually applied to said lever without necessitating the grasping of said lever.
8. ~A plug as defined in Claim 6 wherein said insulating body includes a flank wall intersecting said forward face and wherein said lever when in its first position is contiguous with said flank wall along substantially the whole of the length of said lever.
9. ~A plug as defined in Claim 6 wherein said lever and said flank wall are provided with co-operating means to prevent the rotation of said lever beyond said first, stored position.
10. ~A plug as defined in Claim 6 wherein said pivot means comprises a gudgeon pin integral with each said lever arm and a pair of gudgeon openings in said body within which said gudgeon pins are respectively received and a pair of slots respectively extending between said bottom face and said gudgeon openings along which said gudgeon pins are movable into engagement with said gudgeon openings for capture therein.
11. ~A plug as defined in Claim 6 wherein said plug comprises two said blades extending downwardly from said bottom face along parallel axes and wherein said fulcrum is disposed intermediate said axes.
12. ~A plug as defined in Claim 10 wherein each said gudgeon pin is enlarged in diameter adjacent the distal end thereof to form a head and wherein said slots have a T-shape cross-section to permit the passage of said head therealong, said head serving to prevent the release of said gudgeon pins from said gudgeon openings along the axis of said gudgeon openings.
13. ~A plug as defined in Claim 11 wherein said blades have a common transverse axis and said fulcrum intersects said common transverse axis at an angle of between about 45° to about 90°.
14. ~A plug as defined in Claim 13 including a wire cord and a strain relief surrounding said wire cord at the juncture thereof with said body, said strain relief having an axis therealong which intersects said transverse axis at an angle from 0° to about 60°.
15. A low profile electrical plug comprising an insulating body having a bottom surface, at least one conductor blade projecting downwardly from said bottom surface; a top surface generally opposed to said bottom surface;
and a flank wall connecting said bottom surface to said top surface;
a lever comprising a pair of lever arms interconnected by a bight;
pivot means mounting said lever to said body rotation between a first position and a second position;
said lever when in said first position being contiguous with said flank wall and totally contained within the low profile of said body so as not to project either above said top surface or below said bottom surface;
each of said arms including a lever end portion which when said lever is moved towards said second position projects below said bottom surface so as to bear upon a receptacle when said plug is in engaged relationship therewith and thereby upon said plug towards a disengaged relationship with said receptacle.
and a flank wall connecting said bottom surface to said top surface;
a lever comprising a pair of lever arms interconnected by a bight;
pivot means mounting said lever to said body rotation between a first position and a second position;
said lever when in said first position being contiguous with said flank wall and totally contained within the low profile of said body so as not to project either above said top surface or below said bottom surface;
each of said arms including a lever end portion which when said lever is moved towards said second position projects below said bottom surface so as to bear upon a receptacle when said plug is in engaged relationship therewith and thereby upon said plug towards a disengaged relationship with said receptacle.
16. A plug as defined in Claim 15 wherein said bight includes an outwardly facing portion that is outwardly, upwardly inclined to facilitate the actuation of said lever arm from said first position towards said second position by a force which is manually applied to said lever without necessitating the grasping of said lever.
17. A plug as defined in Claim 15 wherein said lever and said flank wall are provided with co-operating means to prevent the rotation of said lever beyond said first, stored position.
18. A plug as defined in Claim 15 wherein said pivot means comprises a gudgeon pin integral with each said lever arm and a pair of gudgeon openings in said body within which said gudgeon pins are respectively received and a pair of slots respectively extending between said bottom face and said gudgeon openings along which said gudgeon pins are movable into engagement with said gudgeon openings for capture therein.
19. A plug as defined in any of claims 15 - 18 wherein said plug comprises two said blades extending downwardly from said bottom face along parallel axes and wherein said fulcrum is disposed intermediate said axes.
20. A plug as defined in Claim 18 wherein each said gudgeon pin is enlarged in diameter adjacent the distal end thereof to form a head and wherein said slots have a T-shape cross-section to permit the passage of said head therealong, said head serving to prevent the release of said gudgeon pins from said gudgeon openings along the axis of said gudgeon openings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US37588895A | 1995-01-20 | 1995-01-20 | |
| US08/375,888 | 1995-01-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2166819A1 CA2166819A1 (en) | 1996-07-21 |
| CA2166819C true CA2166819C (en) | 2004-09-07 |
Family
ID=23482783
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002166819A Expired - Fee Related CA2166819C (en) | 1995-01-20 | 1996-01-09 | Electrical plug with lever for disengagement from a mating receptacle |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2166819C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102820588A (en) * | 2011-06-07 | 2012-12-12 | 株式会社伊连特 | Plug with separation means |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3870312A1 (en) * | 2018-10-26 | 2021-09-01 | 3M Innovative Properties Company | A system having a battery powered blower unit for a powered air purifying respirator and an electrically powered accessory |
-
1996
- 1996-01-09 CA CA002166819A patent/CA2166819C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102820588A (en) * | 2011-06-07 | 2012-12-12 | 株式会社伊连特 | Plug with separation means |
Also Published As
| Publication number | Publication date |
|---|---|
| CA2166819A1 (en) | 1996-07-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20130109 |