BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a strip of insulation displacement contact blocks in accordance with the prior art.
FIG. 2 is front perspective view of a strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 3 is a rear perspective view of a strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 4 is a rear view of a strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 5 is a side view of an insulation displacement contact which may be used in accordance with an embodiment of the invention.
FIG. 6 is a top view of an insulation displacement contact block in accordance with an embodiment of the invention.
FIG. 7 is a bottom perspective view of a strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 8 is a bottom perspective view of an insulation displacement contact block in accordance with an embodiment of the invention.
FIG. 9 is a top perspective view of an insulation displacement contact block in accordance with an embodiment of the invention.
FIG. 10 is a side view of a punch down tool which may be used in accordance with an embodiment of the invention.
FIG. 11 is side perspective view of a punch down tool which may be used in accordance with an embodiment of the invention.
FIG. 12 is a front perspective view of a punch down tool and strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 13 is a rear perspective view of a punch down tool and strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 14 is a top view of a strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 15 is a top perspective view a circuit board including strips of insulation displacement contact blocks and shields in accordance with an embodiment of the invention.
FIG. 16 is a rear perspective view of a cover and a strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
FIG. 17 is a rear perspective view of a cover and a strip of insulation displacement contact blocks in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
Shown in FIGS. 2-4 is a strip 100 of insulation displacement contact blocks 102 (102a, 102b, 102c, 102d) in accordance with an embodiment of the invention. Focusing on block 102a, though it should be clear that each block includes the same structural components, each block 102 includes a base 106. Base 106 has a substantially flat portion 116 on a wire insertion side (FIG. 3) of block 102 and a bent portion 108 defining three surface areas on a wire termination side (FIG. 2) of block 102. Extending upwardly from base 106 are three walls 110, 112, 114 defining a first and second wire insertion openings 174, 176 as discussed more completely below. Walls 110, 112, 114 may be made of plastic or of another insulative material.
Shown in FIG. 5 is an insulation displacement contact 130 including a base portion 134 and a termination portion 132. Termination portion 132 may be inserted into a circuit board (FIG. 15) and used to mechanically and electrically mate insulation displacement contact 130 with the circuit board and possibly a jack. Extending upwardly from base 134 are tines 136. Tines 136 include sharp edges 140 that define an entrance of a wire insertion path 138.
Referring to FIG. 6, walls 110, 112, 114 define punch tool clearance cavities 122 which may be used to receive a punch down tool discussed more completely below. Walls 110, 112, 114 further define a wire insertion cavity 118 which provides an area for a technician to insert a wire into block 102a. By defining a wire insertion cavity 118 on one side of block 102, more stability is provided for an inserted wire and punch down tool.
With continuing reference to FIG. 6, insulation displacement contacts 130 are installed in block 102a so that a short edge 144 of each insulation displacement contact 130 faces, and is in the same plane as, an edge 144 of an adjacent contact 130. The inventors have discovered that, as edges 144 of contacts 130 are shorter than sides 146, disposing edges 144 so that they face one another, significantly reduces crosstalk of data communicating within each block and between adjacent blocks. FIG. 7 shows a bottom view of strip 100 and further illustrates the facing of edges 144 of contacts 130. FIG. 7 also shows support pads 148 which are spread apart on a bottom of block 102 and may be used to provide stability for block 102a.
FIG. 8 shows a bottom view of contact block 102a and still further illustrates the placement of contacts 130 and edges 144. Also shown is a stand-off isolation element 150 which may be used to further reduce communication between terminals 130 within a single block 102a. Ramps 152 may be used to facilitate support and placement of terminals 130 within block 102.
FIG. 9 shows wire notches 154 which may be used to retain a wire inserted into block 102a before the wire is punched down by a punch down tool. After the wire is punched down, wire support flanges 156 may be used to maintain and inhibit movement of the wire.
An example of a punch down tool 160 is shown in FIGS. 10 and 11. Punch down tool 160 includes a handle 162 and a punch down portion 164. Punch down portion 164 includes a wire trim side 166 and a wire push side 168. Wire push side 168 has a cross-sectional area matching punch down tool clearance cavities 122 (FIG. 6) so that punch down tool 160 may be received by block 102. FIGS. 12 and 13 show punch down tool 160 being used to punch and trim a wire 170 inserted into block 102b. A recess 172 (FIG. 13) may be cut out of wire push side 168 so as to allow room for wire 170. As base 106 of block 102 includes a flat portion 116, additional support is provided for punch down tool 160 when used. FIG. 14 shows wire 170 punched down into block 102b. Insulation displacement contacts 130 are disposed edge to edge and are shown piercing and retaining wire 170. Furthermore, wire retention flanges 142 retain wire 170 within block 102b.
Thus, the following steps may be followed to insert a wire into an insulation displacement contact block in accordance with an embodiment of the invention. An assembler may place wire 170 into wire insertion cavity 118 (FIG. 6) on a wire insertion side of contact block 102. The assembler will continue inserting wire 170 so that it rests on wire notches 154 (FIG. 9). Thereafter, punch down tool 160 (FIG. 12) is used to punch down the wire into the contact block. Sharp edges 140 of tines 136 (FIG. 5) pierce the insulation of the wire and wire retention flanges 142 (FIG. 14) retain the wire within block 102.
Referring again to FIG. 2, each block 102 includes a first wire insertion opening 174 and a second wire insertion opening 176 defined by walls 110, 112 and 114. A center of first and second opening 174, 176 within each block may be spaced apart from one another by a distance of, for example, between 0.080 and 0.200 inches. A tie bar 104 may be used to orient and place a plurality of blocks 102, for example four bocks, relative to one another. Tie bar 104 is designed to facilitate insertion and handling of blocks 102 into a circuit board. For example, a length of tie bar 104 may be designed so that a distance from a center of first opening 174 in a first block (e.g. block 102b) to a center of first opening 174 in a second block (e.g. 102c) is 0.390 inches. A height of each block 102 may be designed so as to allow for an automatic triggering of punch down tool 160 when tool 160 is used.
Tie bar 104 allows an assembler or assembly machine to easily place a plurality of blocks onto a circuit board while maintaining relative positions of the blocks. Alternatively, each block may be easily broken off from the tie bar and used individually or in smaller groups. For example, a single block may be used as a ground or power outlet. Two blocks may be used for a wall or phone outlet, etc. Such flexibility in insulation displacement contact blocks is generally not available in the prior art.
FIG. 15 shows 4 strips 100 (100a, 100b, 100c, 100d), each including four contact blocks 102 disposed on a circuit board 178. Circuit board 178 allows for electrical communication, such as through electrical traces, between blocks 102 and jacks 186. Each block 102 may have an associated shield 180 disposed external to the block. Shield 180 has three sides so as to shield each block from internal cross talk from neighboring blocks in the same channel or strip and from crosstalk from adjacent channels (e.g. adjacent strips 100a, 100b)—sometimes referred to as alien or exogenous crosstalk. An opening on one side of shield 180 allows an assembler to insert a wire into a block 102. Shield 180 is inserted into circuit board 178 through the use of a projection and opening 182. In this way, all shields 180 are placed at a common voltage potential.
Blocks 102 alone can communicate at speeds of 500 MHz without significant undesired crosstalk. Prior art devices could not handle such speeds without a shield. These shields increase the cost of such devices. With shield 180, blocks can communicate at speeds of 1000 MHz without significant undesired crosstalk—a speed not available with prior art insulation displacement contact devices. Some prior art devices include a shield within the insulation displacement contact block itself. Such placement of the shield means that more holes are required in the circuit board yielding a more expensive board. Moreover, the prior art is completely devoid of shielding between communication channels—e.g. between strip 100a and strip 100b. Clamps 184 may be used to retain wires to board 178 and minimize movement of the wire relative to blocks 102. Strips 100 may be disposed staggered from one another as shown so as to further minimize crosstalk.
FIG. 16 shows a cover 190 which may be used in accordance with an embodiment of the invention. Cover 190 includes a base portion 192 and downwardly extending tabs 194. In the figure, four tabs 194 are shown on each of the wire insertion side and wire termination side of strip 100. Tabs 194 includes slots 196 effective to receive wires 170. As show most clearly in FIG. 17, cover 190 may be fit over strip 100 such as by, for example, snap fitting. When disposed over strip 100, cover 190 may be used to prevent accidental removal of terminated wires and may provide additional security for wire connections. Slots 198 disposed in base portion 192 allow space for walls 110, 114 of block 102. Slots 198 also enable cover 190 to be broken apart and used for an individual block 102.
Having described the preferred embodiments of the invention, it should be noted that the scope of the invention is limited only by the scope of the claims attached hereto and obvious modifications may be made without departing from the scope and spirit of the invention.
Patent Application
20080050980
