The field of this invention is tools for wiring telephone and data circuits or the like.
Insulation displacing type connectors mounted in and part of a circuit board were introduced several decades ago and are commonly used in terminating telephone or high-speed data wires. An insulated end portion of each wire is forced between a pair of knife blades of an associated connector. A hand piece applies an impact force to a tool body which in turn forces the wire between the connector blades.
Forcing the wire into the connector causes the knife blades to cut into the insulating cover of the wire, so that there is then an electrically conductive engagememnt of the wire with the connector blades. Remnants of the insulation surrounding the contact area are purposely left in place so as to protect the contacts against moisture and/or corrosion. When the wire end is properly seated between the connector blades it is then also necessary to cut off a protruding end portion of the insulated wire. That operation is performed concurrently by forcing the wire between the contacts, with a blade edge carried on the forward end of the tool body.
One standard circuit board having insulation displacing type connectors is known as a “110 Block”. A tool for use with that type of circuit board is known as a “110 Blade”, and has a forward end portion with a U-shaped opening to partially encircle the end of the wire while forcing the wire between the knife blade contacts of the insulation displacing connector. During operation of a “110 Blade” tool the U-shaped opening is parallel to the common plane of the conductive knife blade contacts, but is perpendicular to the longitudinal axis of the wire being inserted into the connector. That type of tool also has a cutting edge extending perpendicular to the U-shaped opening in the forward end portion of the tool, for cutting off an end portion of the conductor wire as it is being secured to the connector block. A 110 Tool with replaceable cutting blade is disclosed and claimed in my copending application Ser. No. 10/836,508 filed Apr. 29, 2004.
Another standard circuit board with insulation displacing type connectors is known as a “66 Block”. A tool for use with that type of circuit board is known as a “66 Blade”. The forward end of the tool body has an essentially planar locator opening that receives and surrounds a pair of knife blade contacts of the connector block whose plane is then common to the plane of the opening. The conductor which is to be inserted between the blades of the connector block is placed across the forward end of the tool body, perpendicular to the locator opening. With forward movement of the tool body the conductor is forced between the knife blades of the connector while at the same time the blades are confined and squeezed by the locator opening of the tool body.
The 110 Blade tool is sometimes referred to as having a male tool type of action while the 66 Blade tool is sometimes referred to as having a female type of tool action.
A 66 Blade type tool is shown in the Mason patent No. 03883.31-6 in which the tool body and cutting blade for cutting off the protruding end portion of the conductor are made as an integral member to perform both the positioning and wire cutting operations.
A 110 Blade type of tool is shown in U.S. Pat. No. 4,161,061 to Mason et al issued July 17, 1979. The tool body including a cutting blade for cutting off the protruding end portion of the conductor is made as an integral member to perform both the positioning and wire cutting operations.
Tool bodies for both 110 type tools and 66 type tools have typically been made as an integral steel casting including both the wire positioning end and the wire cutting end portion and blade, which is then machined, heat treated, and ground. Experience has shown that such tool bodies used in the impact type of tool system frequently have to be discarded because of wear and/or damage to the cutting edge of the blade. Experience has also shown that a dull or damaged cutting edge requires a high level of force which may then cause damage to the circuit board, or a bad wire connection.
Another example of prior art is shown in U.S. Pat. No. 6,615,480 issued Sep. 9, 2003 to Murphy, relating to both 110 Blade tools and 66 Blade tools. According to that patent a blade that performs the wire cutting operations is formed as a separate member and is then permanently attached to its supporting tool body by ultrasonic welding, insert molding, riveting, or gluing. When the blade becomes worn the entire tool would presumably be thrown away.
According to my invention a separate and replaceable cutting blade is removably attached to a supporting cast tool body. In my WIRE END INSERT 66 TOOL WITH REPLACEABLE CUTTING BLADE a cast metal or metal injected molded, or other injected molded tool body, is used to position the end of an insulated wire between the knife blade contacts of an insulation displacing type of connector terminal. The tool body also has an elongated flat surface for receiving and supporting a replaceable cutting blade, and at its forward end has an essentially planar locator opening to receive and surround a pair of knife blade connector contacts whose plane is then common to the plane of the locator opening.
An important feature of my invention is that the replaceable cutting blade is made from a material that is able to provide a sharper cutting edge, and therefore achieves a sharper and cleaner cut on the end of the insulated wire being terminated. Another important feature of my invention is that the replaceable cutting blade accommodates for the ease of grinding for different cutting blade configurations. My replaceable cutting blade is preferably made of a good grade of tool grade steel. This cutting action reduces the force required to cut the insulated wire, resulting in less damage to the circuit board to which the connector is being attached. The tool body need not be heat treated or have a secondary grinding operation.
Further in accordance with the presently preferred embodiment of my invention I attach the removable blade to the tool body at two different points along the length of the blade. This is preferably accomplished by using a fastening screw near the rearward end of the blade and a locator/positioning pin near its forward end.
An advantage of my invention is that the cutting blade may be replaced without having to replace the tool body with which the blade is used. A technician working in the field can carry smaller replacement blades instead of the larger and heavier tool bodies, and does not have to carry complete replacement tools. The smaller blades can also be made readily available, which results in a considerable saving.
The presently illustrated preferred form of my invention is primarily intended for use in tool systems of the impact type; that is, tool systems including a hand piece to generate an impact that is imparted to the tool body. However, it is also feasible to use this new invention by way of a screwdriver type arrangement, with a blade set on the end of a screwdriver type mechanism and the force being imparted directly by the technician.
Referring now to
The operative tool portion 130 also has an elongated generally flat surface 10 for supporting my replaceable cutting blade 150. To the rear of central opening 12 a threaded screw hole 16 is provided, as part of the mechanism for fastening my removable cutting blade in place. A riser or locator pin 18 is formed forward of central opening 12 on the forward end portion of flat surface 10. Side flanges 14 and 15 are provided on the left and right sides of elongated flat surface 10 on its forward end portion and adjacent the locator pin 18.
In the forward end portion 130 of tool member 100 the elongated locator opening 140 has a plane essentially parallel to the elongated flat surface 10. Opening 140 has side walls 142, 144, as shown in
My elongated essentially flat blade member 150 when supported on the elongated flat surface 10 of the metal body 100 is in essentially parallel relationship to the plane of the elongated locator opening 140. Blade member 150 has a forward end with a cutting edge 158 thereon which extends beyond the locator opening 140. Two separate fastening means secure the replaceable blade member at two different points along its length to the flat surface 10 of the elongated body 100.
For fastening the blade 150 to the tool body 120 the rearward end portion of blade 150 has an opening 152 formed therein. A threaded screw hole 16 in surface 10 located rearwardly of the opening 12 is adapted to receive a screw 160 passing through the hole or opening 152 to fasten the blade in place on tool 100. The locator pin or riser 18 formed on the forward end of flat surface 10 of the tool body engages another opening 155 in the forward end of blade member 150 to further support the blade.
On the forward end of flat surface 10 of the tool body 100 a pair of side flanges 14, 15, are formed. When blade 150 is secured in place by the screw 160 it is laterally positioned by the side flanges, as well as by the locator pin-18. My blade member is preferably manufactured according to Japanese Industrial Standard (JIS) with an Rc of 57 to 60. Alternatively, it can be made of a very hard insulating ceramic material.
In an alternate form of my invention as shown in
In another alternate form of my invention the section 120 of elongated body 100 may be omitted. The remaining portion of the tool may then be used as “no cut” when blade 150 has been removed or not yet attached.
Although the presently preferred forms of my invention have been disclosed herein, it will be understood that other modifications should be apparent to those skilled in the art, and that the scope of my invention is to be judged only by the appended claims.
100 elongated tool body
110 central mounting block
120 non-cutting, wire seating end
130 wire seating and wire-engaging end
140 contact locator opening
10 elongated generally flat surface
12 with a central opening (square in this embodiment)
14, 15, side flanges on left and right sides of surface 10
16 threaded screw hole rearward of 12
18 riser or locator pin forward of opening 12
150 replaceable cutting blade
152 opening in blade rear end portion
155 opening in forward end portion of blade 150
158 sharp cutting edge of blade
160 screw to fasten blade 150 to surface 10
140 contact locator opening
200 conductor wire
210 left connector blade
212 connector right blade
220 alternate form of blade
224 major cut on blade 220
226 minor cut on blade 220
This application claims priority of my copending U.S. patent application Ser. No. 10/836,508 filed Apr. 29, 2004 as well as my U.S. Provisional Application Ser. No. 60/514,047 filed Oct. 24, 2003, the priority of which is also claimed in Ser. No. 10,836,508.