Patent GB-956118-A (GB)
Title: Improvements in or relating to electrical connectors and to methods of and apparatusfor making electrical connections
IPC: H01R43/04
Filed: 1963-01-30
Abstract: 956,118. Making electrical connections. AMP Inc. Jan. 30, 1963 [Feb. 5, 1962], No. 3753/63. Heading B3A. [Also in Division H2] A method of making an electrical connection between a conductor and a post by a connector having a width between opposed faces less than the combined thickness of the post and the conductor when slidably engaged on the post, comprising positioning the conductor transversely of the post at one end thereof, sliding the connector thereon to engage the conductor and move it with the connector along the post to trap and urge the conductor between the opposed faces of the connector and post. A connector of e.g. steel or plastics, comprises a stepped web portion 1 bounded by curved sidewalls 2, a pair of tabs 6 struck up from a rectangular slot in a web extension 5, a recess 7a and a forward tab 7. The end of an insulated conductor is positioned transversely of an anvil 12 having a T-shaped extension 13, a sharp upper edge 16, and a central notch 15 of a width greater than the core diameter of the conductor and a connector is positioned in a recess 18 of a channel-shaped plunger 17. The plunger is lowered to push the connector on to the anvil and pinch the insulation between the recess 7a, continued movement of the plunger causes the insulation to be partially severed against the edge 16 followed by circumferential tearing due to the conductor being gripped between the extension 5 and in the concave recess formed by the tabs 6. Finally, the core 22 is pulled into the notch 15 and from the severed section of the insulation, and compressed between the web surface 4 and anvil and thence on to a post 10 positioned beneath the anvil to complete the connection, Fig. 26. The web 1 moves either elastically or plastically to accommodate the conductor core. The connector and conductor so assembled may be removed from the post as a unit for servicing. An alternative form of connector for use with small wire sizes, e.g. up to A.W.G.24 (Fig. 9), comprises a channelsection with inturned portions 25, ribs 28 to improve the contact pressure applied to the conductor by the connector and a frusto conical insulation support portion 26. The connector may be assembled directly on to a modified form of post 29 having a central tongue 30 or tapered faces over which the insulation is severed and the core dragged to strip the insulation during the assembly thereof. Conductors having vinyl, P.T.F.E., varnish or no insulation covering may be used and in some instances coverings such as P.T.F.E. may flow from between the core and the post to such an extent that a conducting contact is obtained without stripping of the insulation. A hand tool for making connections using connectors according to Fig. 1, comprises a section 33 having a pistol grip portion 32, an intermediate section 35 engaging a rib 34 on the section 33 and a top section 37. The connector is inserted through an aperture 57 in the section 35 with its tab 7 extending rearwardly of the tool and the recess 64 of a plunger 62 the opposite end of which is pivotally connected to the end of a pneumatically operated piston 68 biased in a rearward direction by a spring 72 within a cylinder attached to the rear of the tool. The plunger is slidable along ribs 34, 43 and within a channel 36 of a section 35. The connector straddles the rib 43 of a block 41 and the tool is aligned with a post 10 the end of which engages the notch of a spring hose 53 to hold the post on a support 46 and against the forward edge of an anvil 48. A conductor 21 is inserted downwardly through a bore 44 until a length equal to a connector length projects beyond a notch 50 in the anvil 48 and a trigger 82 depressed to operate via a control valve the piston 68 to move the plunger forward and push the connector over the wire and effect a connection on the post as above. In a modification an apparatus having connector and conductor feeding means and suitable for wiring panels having a plurality of interconnected terminal posts comprises an inner frame block 100, positioned in a bottom plate 122, suspended for limited swinging motion on rods 102 attached to a top frame plate 112. An upright plate 136 having a cut-away portion 140 and a T-shaped anvil portion 142 is fixed in the slot 134 of the block and a recess 150 in the upper face thereof houses a vertically slidable block 151 having feet 152 about which a pair of flat springs 154 are located having serrated ends 156 arranged on opposite sides of the slot 134 centre line. A tongue 160 protrudes from a guide block 158 located in the front of the block 151 in alignment with the plate 136. The connector strip feed comprises a spring biased feed pawl assembly pivotally mounted on a bell-crank 176 reciprocated by a pneumatic cylinder means 182 and a spring-loaded frictional drag lever 183 housed in a pair of blocks 166 having an arcuate passageway 168 and attached to the main frame block. The leading connector of the strip is fed on to the T-shaped extension 208 of an adjustable feed slide 202 reciprocable along the face 206 of the plate 136 and within the slot 134 and biased by a spring 198 in the loading position and advanced by a pneumatic cylinder means 190 via a slidable carriage assembly 186. A channel-shaped plunger 216 aligned with the anvil 42 is connected for vertical reciprocating movement via a shoe assembly to a pneumatic operating means 228 and is provided with an enlarged recess 233 and a notch 234 in the web of the channel to accommodate a connector and its insulation support notch 26. A wire or conductor feeding mechanism is pneumatically operated in a manner similar to that of the connector feed unit and comprises two pneumatically-operated fingers 266, 272 which clamp the wire fed from a reel 132 in the bores 258, 260 of slide 244 and web 239 of a bracket respectively. A wire carrier tube 246 is clamped to the slide 244 and a square cross-section nose portion 252 is adapted to be slidably received in the notch 157 of the block 151. In operation, the apparatus is supported on its legs 124 over a post and positioned thereto by a pair of opposed inclined pneumatically-operated holding finger 290 having straight edge and convex end portions which engage the post and due to the camming action of the convex portions thereon tilt the frame block assembly 100 into alignment therewith. The conductor is clamped by the finger 266 in the slide 244 which is advanced to pull the conductor off the reel until the feed tube 246 with the conductor therein is a connector length past the anvil 142 and the clamp released, clamp finger 272 is then actuated to clamp the conductor in the bore 239 and the feed carriage retracted by exhausting of the cylinder 284. The connector slide 202 is subsequently advanced to shear the leading connector thereon from the strip against the edge 212 and the remaining lower tab from the connector against the edge 214 of the tongue 160. Continued movement of the slide 202 pushes the connector into the recess 233 with its side walls engaging the sides of the channel. 232, the plunger is next moved downwardly to push the connector off the slide 202, which is then retracted, against the conductor which is pushed down the anvil 142 to sever the insulation therefrom prior to making a connection as before on the post 10. Before the connector engages the post the fingers 290 are retracted and the clamp finger 272 released to allow the connector to be pulled through the feed tube. Leads connecting more than one post are initially connected to the first post, as above, and the apparatus positioned over the second post, a length of conductor is paid out and the clamp 266 operated to secure the conductor, the slide 244 advanced an increased distance until the conductor is gripped below the slide 244 (see Fig. 39) and between the serrated edges 156 and further movement of the slide effected to shear the core and insulation between edges 306, 304. Subsequently, the tube 246 is withdrawn and the plunger operated as before. Multiple connections may be made on a single post by stacking. The severed tabs and pieces of insulation are suitably removed by an air blast. The unit may be controlled manually or by a system of solenoid valves, controlled by cams or switches.