Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
  • H01R4/24—Connections using contact members penetrating or cutting insulation or cable strands
  • H01R4/2404—Connections using contact members penetrating or cutting insulation or cable strands the contact members having teeth, prongs, pins or needles penetrating the insulation
• • 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
  • H01R13/56—Means for preventing chafing or fracture of flexible leads at outlet from coupling part
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R2103/00—Two poles
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R24/00—Two-part coupling devices, or either of their cooperating parts, characterised by their overall structure
  • H01R24/28—Coupling parts carrying pins, blades or analogous contacts and secured only to wire or cable
  • H01R24/30—Coupling parts carrying pins, blades or analogous contacts and secured only to wire or cable with additional earth or shield contacts

Definitions

• This invention relates to an electrical coupling device, and in particular, but not exclusively, it relates to a 3-pin, 13 amp fused nlug.
• the conductor-locatin means comprises a pair of jaws which are hinged together, which pair of jaws is inserted into its associated recess either with its hinged end first (for example as described with -reference to Figures 7 and 8a. - 8c_) or with the end of the pair of jaws remote from its hinged end first.
• U.S. Patent No. 4,14.8,54.0 it has been proposed to employ a pair of jaws of metallic material as the conductor- locating means (as described with reference to Figure 17).
• the present invention aims to provide an electrical coupling device which has a greater ability to tolerate mis use of the kind just referred to. Disclosure of the Invention
• each of said jaws comprises at least one metallic member which, in use of the coupling device, at least partially displaces the insulating material of the conductor, whereby enhanced contact pressure between the conductor-piercing member and the pierced conductor is achieved by said at least one metallic member bearing substantially directly on the con ⁇ ducting material of the insulated conductor.
• the jaw-receiving member may be arranged, as in the case of the recess described in I..S. Patent No. 4,148,540, to exert a camming action on the pair of jaws to urge the jaws towards one another as they are advanced into the aw-receiving member.
• displacement of the insulating material of the conductor may take place at least partly due to the camming action of the jaw-receiving member, although some displacement of the insulating materia may take place at the time of inserting the conductor betwg the two jaws prior to advancement of the jaws into the jaw- receiving member.
• the jaw-receiving member may be dimen ⁇ sioned so that it can receive the pair of jaws, with the insulated conductor located between the jaws, without exerting any camming action on the jaws, and simply pre ⁇ vents any substantial separation of the jaws as the conduc ⁇ tor is pierced by the piercing member.
• dis ⁇ placement of the insulating material of the conductor may take place entirely during insertion of the conductor between the two jaws prior to advancement of the jaws into the jaw-receiving member.
• slight expansion of the conductive portion of the insulated conductor due to the penetration of the conductor by the piercing member, may result in further displacement of insulating material from the conductor by said metallic • members.
• said at least one metallic member of each jaw is positioned so that, when the two jaws are inserted into the awrreceiying member, said metallic member- of one jaw is disposed opposite said metallic member of the other • jaw and said piercing member is located either in the region between these two opposed metallic- members or closely adjacent to said region.
• Said jaws may be formed entirely of metallic material, for example stamped from metallic sheet material, said at least one metallic member then being formed as a projection, for example a rib, formed integrally with the conductor- locating surface of the jaw.
• the two jaws are joined together to form a substan ⁇ tially U-shaped cradle for the reception of the insulated conductor, which cradle may be entered into the jaw- receiving member either with the open end or the closed end of the cradle first.
• the closed end of the cradle is provided with one or more apertures for the passage of the conductor-piercing member when the jaws are advanced into the jaw-receiving member.
• the confronting surfaces of the two limbs of the cradle, which limbs form the two jaws of the cradle, are each provided with a pair of spaced-apart, inwardly-projecting ribs disposed substantially at right angles to the closed end of the cradle, each of these ribs forming one of said metallic members.
• these ribs may be stamped in the limbs at the time of forming the cradle.
• each of said jaws may be made partly of plastics material which is clipped or otherwise secured to a metallic insert which provides said at least one metallic member.
• the two jaws may be hinged together, the hinge being formed in the metallic insert and/or in the plastics material.
• an electric plug of the kind comprising an electrically-insu- 5 lating contact-carrying portion, at least one metallic con ⁇ tact pin carried by and extending from said contact- carrying portion, a metallic conductor-piercing member electrically connected to said pin, a pair of conductor- locating jaws for the reception of an insulated conductor 10 which s to be electrically connected to said pin, and.
• each 15 of said jaws comprises at least one metallic member which, in use Qf the plug, at least partially displaces the insulating material of the conductor, whereby enhanced contact pressure between the conductor-piercing member and the pierced conductor is achieved by said at least one 20 metallic member bearing substantially directly on the con ⁇ ducting material of the insulated conductor.
• an electric plug in accordance with this last- mentioned aspect of the invention may have a single contact pin or two contact pins-, the main interest of this aspect ⁇ 5 of the invention lies in the field of 3-pin plugs, in partic ⁇ ular 3-pin, 13 amp fused plugs.
• Figure 1 is an exploded perspective view of the base and conductor-locating jaws of a known 3-pin, 13 amp fused electric plug,
• Figure 2 is a perspective view of the pins and fuse of the plug shown partly in Figure 1
• Figure 3 is a perspective view of an alternative form of a pair of conductor-locating jaws for use in the plug of Figures 1 and 2
• Figure is a perspective view of the pair of jaws Figure 3 with one jaw partly broken away to reveal the inner construction
• Figure 5 is a sectional view, taken on the line V-V of Figure 4, through one of the jaws
• Figure 6 is a sectional end view of the pair of jaws of Figures 3-5 with an insulated conductor between the jaws
• Figure 7 is a sectional view showing a first stage of entering the pair of jaws of Figures 3 - 6 into the jaw- 0 receiving member of an electric plug
• Figure 8 is a view similar to Figure 7, but showing the pair of jaws fully inserted into the jaw-receiving member
• Figure 9 is a sectional view taken on the line IX-IX of Figure 8
• 5 Figure 10 is a view similar to Figure 7 but showing an alternative way of inserting the pair of jaws
• Figure 11 is a partly sectioned end view of a metallic insert forming part of another pair of conductor-locating jaws for use in the plug of Figures 1 and 2, 0 - Figures 12 and 13 are sectional views taken on the lines XII-XII and XIII-XIII, respectively, of Figure 11,
• Figure 14 is a sectional view, taken on the line XIV-XIV of Figure 15, of a pair of jaws comprising the insert of Figures 11 to 13, the pair of jaws being shown ? partly inserted into one of the recesses of the plug of Figures 1 and 2,
• Figure 15 is a sectional view taken on the line XV-XV of Figure 14, and
• Figure 16 is aperspective view of a further pair of conductor-locating jaws for use in the plug of Figures 1 and 2. Modes for carrying out the Invention
• Figure 1 shows part of a 13-amp, 3 pin electric plug of the kind shown in Figures 3 and 4 of U.S. Patent No. 4,148,540 but adapted to receive conductor-locating jaws of the general kind shown in Figures 7 and 8a. - 8c_ of that
• the plug illustrated comprises a base 1 moulded from electrically-insulating material and carrying neutral, live and earth pins 2, 3 and 4, respectively, which are shown in more detail in Figure 2.
• the numeral 5 designates a 3-core insulated electric cable with outer insulation 6 removed from one end thereof to reveal insulated neutral, live and earth wires 7, 8 and 9, respectively.
• the insulated wires 7, 8 and 9 are rec ⁇ eived between pairs of jaws 10a, 10b_, 11a, llb_ and 12a., 12b_, respectively, the wires being inserted into conductor- locating slots 13, 14 and 15, respectively, defined by rec ⁇ esses of substantially semicircular cross-section provided in confronting portions of the jaws 10a, 10b_, 11a, llb_ and 12a.,.12b_, respectively.
• the jaws, of each pair are hinged together at their lower ends (as viewed in Figure 1), there being two apertures 10_c, llc_, 12c_ through the hinged ends of the respective pairs of jaws.
• Metallic insulation-piercing means are located .in recesses 20, 21 and ' 22, respectively, provided in the upper portion of the base 1.
• Each of these insulation- piercing means comprises a pair of co-planar blades 17a,- 17b_, 18a., l ⁇ b_ and 19a., 19b_, respectively (see Figure 2).
• the piercing means 17 and 19 are electrically and physically connected to the pins 2 and 4, respectively.
• the piercing means 18 is formed from a metallic strip which is bent, at its end remote from the blades 18a, l8b_, into the shape of a clip 23.
• Another metallic strip 24, bent into the shape of a clip 25 is electrically and physically connected to the pin 3.
• the clips 23 and 25 receive a fuse 26 to com- plete an electrical circuit from the pin 3 to the blades. 18a, 18b.
• the pairs of jaws 10a, 10b_, lla, llb_ and 12a, 12b_ are made of synthetic resin material and adequate contact pressure between the conductiv portions of the conductors 7, 8 and 9 and the blades 17a, 17b_, I ⁇ a ⁇ , l8b_ and 19a., 19b_, respectively, is achieved for all normal usages of the plugs.
• severe mis-use of the plug can result in deterior ation of. the insulating sheath of the conductors, and also of the jaws themselves.
• Figures 3 to 5 show a pair of jaws of metallic material, for example brass, ' for use in place of the pairs of jaws employed in the plug of Figures 1 and 2.
• This pair of jaws is in the- form of a U-shaped cradle, generally designated by the reference numeral 27, the limbs 28., 29 of which constitute the two jaws of the pair.
• Figure 6 shows the cradle 27 with an insulated conduc ⁇ tor 7 inserted between the limbs 28, 29, resulting in the free ends of these limbs being forced slightly apart and the ribs 31 penetrating partly into the insulation 32 of the conductor 1.
• a chute may be arranged to guide the- conductor into the clamped cradle, and this chute may be provided with projections to initiate removal of insulation from the conductor prior to its entry into the cradle.
• Figure 7 shows the cradle 27, with an insulated con ⁇ ductor 7 between its limbs, being entered into the recess 20 of the base 1 of the plug of Figures 1 and 2.
• Figure 8 shows the cradle 27 . and the conductor 7 fully inserted into the recess -20, the conductor-piercing blade 17b_ having passed through the conductor.
• the side walls of the recess 20 urge the limbs 28, 29 of the cradle closer together so that the ribs 31 penetrate further into the insulation 32 of the conductor, as shown more clearly in Figure 9, in the immediate vicinity of the regions where the blades 17a, 17b_ penetrate the ' conductor.
• the recess 20 is shallower ' than shown, so "that the tips of the blades 17a., 17b_ are substantially level with the plane of the open top of the recess, it may be necessary to guide the cradle 27 as it is entered into the recess 20, to ensure that the blades 17a, 17b_ pass centrally through the conductor 7. Such guidance may be provided by a jig 33, show in chain lines in Figure 7, temporarily positioned over the recess. When the cradle 27 is fully inserted into the recess 20 the piercing blades 17a, 17b. will then pass through the holes 30 and can be bent over against the closed end of the cradle to assist in securing the cradle in recess.
• Figure 10 shows how the cradle 27 may be inserted into the recess 20 with its closed end first.
• the piercing blades 17a, 17b_ pass through and may be guided by 5 the holes 30 in the cradle before penetrating the conductor 7.
• cradle 27 Once the cradle 27 has been fully inserted into the recess 20, it may be difficult to remove it again without the use of special tools. It is therefore anticipated i ⁇ that the cradle 27. will find its main application in the field of non-rewirable plugs. Consequently, when cradles 27 are used ih the recesses 20 - 22 of the plug of Figures 1 and 2 a cover (not shown) may be moulded over, or secured permanently to, the base 1 to cover the open ends of the 5 recesses.
• the cradle 27 is employed in a rewirable plug-, it is possible to make provision to facilitate removal of the cradle from the recess 20.
• the ' recess 20 may -be provided with a groove as described with reference 0 to Figure 14 of U.S. Patent No. 4,148,540 to enable a screw-driver to be used to prise the cradle from the recess.
• the cradle is dimensioned so that there is substantially no urging 0 together of its limbs 28, 29 by the side walls of the recess 20 when the cradle is inserted into the recess.
• displacement of insulating material from the con ⁇ ductor 7 is effected only during insertion of the conductor 7 into the cradle, prior to insertion of the cradle into the recess.
• FIGs 11 to 13 show a metallic insert forming part of another pair of jaws for use in place of the pairs of jaws employed in the plug of Figures 1 and 2.
• This metallic insert is again in the form of a substantially U-shaped cradle, stamped from metallic sheet material, which is gener ally designated by the numeral 35.
• This cradle comprises two limbs 36, 37 joined by a web 38, each of the limbs 36, 37 being of channel section, as seen in Figure 12 for the limb 36.
• the limb 36 comprises a pair of spaced-apart arms
• each of the arms 39, joined h a web 40, and the limb 37 comprises a pair of spaced-apart arms 41 joined by a web 42.
• the edge of each of the arms 39 lying remote from the web 40 there is a substantially semicircular recess 3.
• the corres ⁇ ponding edge of each of the arms 4l there is a similar recess 44.
• the metallic cradle 35 forms an insert in a pair of jaw portions 45 3 46 of plastics material, which are hinged to one another by hinge portions 47 moulded integrally with the two jaws.
• Each of the jaw portions 45, 46 has a conductor-locating slot of substantially semicircular cross-section in its inwardly-facing surface, the slot
• FIG. 48 of the jaw portion 45 being seen in Figure 15- Figure 14 shows the pair of jaw portions 45, 46 assembled on the metallic cradle 35 and partly inserted into the .recess 20 in the base 1, the jaw portions, having been squeezed to- gether, against the bias of the web 38 of the cradle 35, with the insulated conductor 7 lying in the conductor-locating slots of the jaw portions and in the recesses 43 and 44 of the cradle 35.
• the piercing blades 17a, 17b_ pass through holes 49, 50 formed in the hinged end of the jaws between the hinge portions 47 and the metallic web 38 of the cradle 35.
• the blades 17_a, 17b then penetrate the conductor 7 in regions between opposed arms 39 and 40 of the cradle 35.
• the cradle recesses 4 * 3 and 44 are dimensioned so that their surfaces are forced into the insulation 32 of the con ⁇ ductor 7 as the pair of jaws is forced into the recess 20.
• the surface of the recesses 43 and 44 bear on the conductive portion of the conductor 7 either directl or through a thin residual layer of the insulation 32.
• the arms 39 and 41 may be provided with slits 51 which give the arms a degree of resilience, which has the additional advantage that the pair of jaws can accommodate conductors of different sizes.
• the cradle 35 o complementing the conductor-locating recess 43, 44 of the cradle, and of providing convenient handling means for squeezing the limbs of the cradle 35 . together and pressing the jaws down into the recess 20.
• Figure 16 shows a further pair of jaws for use in place of the pairs of jaws employed in the plug of Figures 1 and 2.
• This pair of jaws is made entirely of metallic material and comprises two spaced-apart U-shaped cradles 52, 53 joined by a common web 54.
• the cradle 52 comprises two spaced- apart L-shaped arms 55 joined to the web 54
• the cradle 53 comprises two shaped-apart L-shaped arms 56 joined to the web 54.
• Confronting edges of the limbs 57 of the arms 55 are provided with substantially semicircular conductor- locating recesses 58, and the corresponding edges of the limbs 59 of the arms 56 are provided with similar conductor- locating recesses 60.
• the web 4 is provided with holes 61 for the passage of the conductor-piercing blades 17a., 17b_ ( Figure 2) when the pair ⁇ f jaws is inserted into the recess 20 ( Figure 1).
• edges of the recesses 58, 59 bite into the insulation of the conductor located in the recesses so that these edges bear against the conductive portion of the conductor either directly or through a very thin residual layer of insulation.
• the pair of jaws shown in Figure 16 is particularly suitable for use in non-rewirable plugs.
• the limbs 57 and 59 may be. provided with slits (not shown), similar to the slits 51 in Figure 11, to give these limbs a degree of resilience. -
• the pairs of jaws are inserted into a recess in a base of electrically-insulating material, it will be appre.c- iated that the jaws may be .received in other forms of jaw- receiving members, for example metallic ones physically and electrically connected to the pins 2 and 4 and the fuse clip 23.

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• Connections By Means Of Piercing Elements, Nuts, Or Screws (AREA)

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ID=10527392

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• 1982
  • 1982-01-12 EP EP82900214A patent/EP0098262A1/de not_active Withdrawn
  • 1982-01-12 WO PCT/GB1982/000005 patent/WO1983002531A1/en unknown

Non-Patent Citations (1)

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