Abstract:
An improved impact tool head having separate and distinct pressing and cutting blades integrally molded therein. The impact tool head allows for independent and optimal material and dimensional design of the pressing blades and the cutting blades to minimize impact damage to a terminal block and to ensure longer useful tool life. Also, through the use of multiple components, the impact tool head is readily adaptable to a wide variety of different terminal block configurations. Furthermore, sets of pressing blades and sets of cutting blades may be formed with each set comprising a continuous piece of material in order to simplify manufacturing and to ensure uniformity of production. Additionally, the integral molded structure is designed to allow post-molding sharpening of the cutting blades in order to ensure blade uniformity to further improve blade durability.

Description:
TECHNICAL FIELD 
     The present invention relates generally to tools employed in the telecommunication industry for seating and cutting the free ends of wires inserted into resilient telephone wire terminal receptacles such as the AT&amp;T/Lucent Technologies RJ-45/M-series type jacks. It is more particularly directed to a new and improved wire-insertion and cutting tool head, geometrically configured to match a resilient telephone wire terminal receptacle such that when pressure is applied to the head from a source such as a handle, the head will provide means by which to seat and cut multiple wires that have been inserted into the wire terminal receptacle. Thus, with one impact, a multiplicity of wires may be simultaneously seated into a wire terminal receptacle and cut. 
     BACKGROUND OF THE INVENTION 
     Tools for terminating electrical conductors at terminal clips or blocks are widely used in the telephone industry. Currently, there is a wide variety of such instruments, generally serving the purpose of cutting and seating individual telephone wires. Examples of a few such tools may be found in U.S. Pat. Nos. 5,832,603; 5,758,403; 5,628,105; 4,656,725; and 4,161,061 and the patents cited therein. 
     Typical impact tools include an elongated handle and an impact head for cutting and seating wires in a terminal block. Such a handle may contain a hammer element and a compression spring arranged such that the spring actuates the hammer, causing it to strike the impact head. Thus, the hammer provides an impact force that causes the impact head to cut and seat the wires into the terminal block. In operation, the impact head is aligned with, and pushed into, a terminal block. As the handle is pressed, the spring is released, forcing the hammer against the impact head. The force stored in the spring is thus translated into the impact head, thereby forcibly cutting and seating one or more wires in the terminal block. In place of handles, some impact tools utilize electric motors to provide the impact force; thereby reducing the manual strength required to seat and cut the wires in a terminal block. 
     With the increasing complexity of terminal blocks and the need for technicians and craftspersons to efficiently use their time, a need arose to develop means by which multiple wires can be cut and seated simultaneously. Early solutions to this problem, although providing great improvements over prior single-wire seating and cutting techniques, have met with limited success. 
     Examples of these solutions include wire-insertion and cutting heads such as those employed by AT&amp;T model 788J1 and Seimens model S788J impact tools. Illustrations of these tools, which comprise separate wire-insertion and seating blade support blocks and knife blade support blocks are provided in FIGS. 1 and 2, respectively. The wire-insertion and seating blade block includes a plurality of slotted copper wire-insertion blades  1  captured within respective slots  3  formed in a region of the base block  5  and extending into respective standoffs  7  in the wall of the base block  5 . A base region  9  with ribs  11  is formed on one side of the wire-insertion and seating blade block in order to accept the knife blade support block. The knife blade support block  21  is made of an injection molded insulating material and contains a plurality of razor blade-like cutting knives  23  securely retained therein. Depressions  25  are molded into the base of the knife blade support block  21  in order that the ribs  11  of the wire-insertion and seating blade block may be received such that the wire-insertion and seating blade block and knife blade support block  21  may be maintained in an operative relationship during use. FIGS. 3 and 4 demonstrate this impact head in an operative relationship with a terminal receptacle  31  during normal operation. As depicted, the dimensions of the impact head are chosen such that the contacts  33  in the terminal receptacle  31  are bridged by the slotted copper wire-insertion blades  35  of the wire-insertion and seating blade block  37 . When the impact head is actuated, the wire  39  is pressed against the bottom surface  41  of the slot in the terminal receptacle  31  and the end of the wire  43  is severed by the cutting knives  23  of the knife blade support block  21 . During this process, the contacts cut into the wire jacket  45 , electrically contacting the wire  39 . Unfortunately, the experience of technicians and craftspersons has revealed a major shortcoming of this design, as depicted in FIG.  5 . In this case, the impact head has been actuated but did not cut the wire. This problem is the result of the two-piece design of the impact head and the associated play between the parts. Even when the two pieces are properly aligned, a small amount of play is allowed therebetween. Furthermore, small particulate pieces of matter such as plastic from the terminal block or pieces of wire insulation may become lodged between the impact head pieces, causing malfunction. Additionally, this problem may be caused or exacerbated by failure to properly align the impact tool with the terminal receptacle. Any wires remaining uncut must be individually severed with the use of a separate tool. 
     An attempt to correct these shortcomings is disclosed in U.S. Pat. No. 5,836,069 and U.S. Pat. No. 5,628,105, the first being to an impact tool head having a plurality of unitary pressing and cutting blades and the second being to a wire termination tool in which the impact tool head is incorporated. In order to solve the problem of misalignment between parts, this impact head included an injection-molded piece with a plurality of integrally formed wire-seating and cutting blades. Thus, the misalignment problems associated with the two-piece impact head design were overcome. 
     In order to construct the one-piece impact head, as detailed in U.S. Pat. No. 5,836,069, a plurality of integrally formed wire-seating and cutting blades  60  such as the one shown in FIG. 6 are positioned in a molded support block  70  as shown in FIG. 7, such that they are aligned in a generally parallel fashion. The final assembly for an impact head of this type is shown in FIG.  8 . The use of this impact head in alignment with a terminal receptacle of a termination block is demonstrated in FIG.  9 . This design&#39;s main advantage is that the cutting blade is forced to remain in alignment with the rest of the tool, thus eliminating the problem of uncut wires due to play between the parts. Although this design increases the wire-cutting reliability of the impact head, it suffers from several important drawbacks. First of all, the integrally formed wire-seating and cutting blades, because of their integral nature, must be fabricated from a material that is functional for both cutting and seating wires. As such, the material must be soft enough to minimize damage to the terminal receptacle, yet be hard enough to provide a durable cutting instrument. Because damage minimization and durability as a cutting surface are somewhat conflicting requirements, a manufacturer must make a compromise between the two functions when choosing materials. Second, the design of the integrally formed one-piece impact head is such that post-fabrication sharpening of the blades is not practical. Consequently, differences in blade length due to positioning variations of the integrally formed wire-seating and cutting blades in the mold results in a more rapid dulling of some blades than of others. As some blades dull and others remain sharp, it is likely that not all of the wires will be cut with one impact, and therefore, multiple impacts will be required to cut and seat the wires in a terminal. Multiple impacts not only require additional time and labor but may also cause structural damage to the terminal head. Furthermore, dull blades require a more powerful impact for successful cutting, which may cause structural damage as well. Third, because this design requires the placement of a plurality of integrally formed wire-seating and cutting blades in the mold prior to fabrication, consistent alignment is difficult and manufacture is costly. 
     The invention disclosed herein overcomes these difficulties by providing a one-piece integrally molded impact head having distinct pressing and cutting blades which can be chosen from different materials to optimize the seating and cutting functions independently. Additionally, the dimensions of the pressing and cutting blades may be independently chosen to optimize their effectiveness in their distinct roles. Furthermore, the integral molded structure is designed such that the blades may be sharpened after the molding process is complete, thus ensuring blade uniformity for improved durability. Finally, the design of the impact tool head disclosed herein, because of its multi-component nature, is readily adaptable to different terminal block configurations, and may optionally be made to press wires into the grooves of only one terminal ridge and to cut the wires on only one side of the terminal ridge. Thus, the impact tool head disclosed herein provides an improved device for cutting and seating wires in the same terminal blocks as the prior-art tools just described, such as a Lucent 110-type terminal block. Further, the present invention may economically constructed such that it may cut and seat wires across a plurality of terminal ridges in a Lucent 110-type terminal block, thus providing for further improvement over the prior-art tools. 
     SUMMARY OF THE PRESENT INVENTION 
     In accordance with the present invention, an improved impact tool head having separate and distinct pressing and cutting blades integrally molded therein is presented. This impact tool head allows different materials to be chosen for the pressing blades and for the cutting blades. Thus, it provides the ability to optimize both the pressing and the cutting processes independently without the compromises necessitated by having separate blocks for the pressing and cutting blades or by the use of a single uniform material piece for both the pressing and cutting blades. Additionally, sets of pressing blades and sets of cutting blades may be formed, each set comprising one continuous piece of material in order to reduce manufacturing costs and to ensure uniformity of production. Also, by allowing the pressing blades and cutting blades to be formed separately, adjustments in the dimensions of each may be made independently of the other. Thus, it is possible to ensure optimal design of each and to adapt the design to the needs of a variety of terminal block configurations. Furthermore, the integral molded structure is designed to allow post-molding sharpening of the cutting blades in order to ensure blade uniformity for improved durability. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of wire-insertion and seating blade block of a conventional two-piece wire-insertion and cutting impact head assembly; 
     FIG. 2 is a perspective view of a knife blade support block of a conventional two-piece wire-insertion and cutting impact head assembly; 
     FIG. 3 is a diagrammatic representation of an operationally combined wire-insertion and seating blade block and knife blade support block of a conventional two-piece wire insertion and cutting impact head assembly of FIGS. 1 and 2, operatively aligned with a terminal receptacle of a terminal block; 
     FIG. 4 is a diagrammatic representation of an operationally combined wire-insertion and seating blade block and knife blade support block of a conventional two-piece wire insertion and cutting impact head assembly of FIGS. 1 and 2, operatively aligned with, and actuated against, a terminal receptacle of a terminal block demonstrating the wire insertion and seating blades and knife blades in operative contact with a wire; 
     FIG. 5 is a diagrammatic representation of an operationally combined wire-insertion and seating blade block and knife blade support block of a conventional two-piece wire insertion and cutting impact head assembly of FIGS. 1 and 2, demonstrating the unwanted deflection of a knife around a wire jacket; 
     FIG. 6 is a perspective view of the prior art unitary wire seating and cutting blade used in a unitary element impact tool head; 
     FIG. 7 is a front view of an embodiment of the prior art unitary element impact tool head demonstrating the operative positioning of the unitary wire-seating and cutting blades shown in FIG. 6; 
     FIG. 8 is a perspective view of an embodiment of the prior art unitary element impact tool head utilizing a plurality the of the unitary wire-seating and cutting blades shown in FIG. 6; 
     FIG. 9 is a diagrammatic representation of the prior art unitary element impact tool head demonstrating its use operatively aligned with, and actuated against a terminal receptacle of a terminal block such that it is operative to seat and cut a wire; 
     FIG. 10 is a perspective view of a preferred embodiment of an assembled impact tool head according to the present invention; 
     FIG. 11 is a front view of an embodiment of a set of four of separate and distinct pressing blades according to the present invention; 
     FIG. 12 a  is a front view of an embodiment of a pair of separate and distinct pressing blades according to the present invention; 
     FIG. 12 b  is a side view of an embodiment of a pair of separate and distinct wire-pressing blades according to the present invention; 
     FIG. 13 is a perspective view of a pre-assembly embodiment of a wire-cutting blade set according to the present invention; 
     FIG. 14 is a cutaway side view demonstrating the operative alignment of the separate and distinct wire-pressing blades and wire-cutting blades within the impact tool head according to an embodiment of the present invention; 
     FIG. 15 is a cutaway front view demonstrating the operative alignment of the separate and distinct wire-pressing blades and wire-cutting blades within the impact tool head according to an embodiment of the present invention; 
     FIG. 16 is a perspective view of an example of a terminal block with which the impact tool head of the present invention would be used; 
     FIG. 17 is a diagrammatic representation of the impact tool head demonstrating its use operatively aligned with, and actuated against a terminal receptacle of a terminal block such that it is operative to seat and cut a wire; 
     FIG. 18 is a perspective view of a second preferred embodiment of the impact tool head in a configuration including one set of cutting blades and individual pressing blades; 
     FIG. 19 is a cutaway side view of a second preferred embodiment of the impact tool head as shown in FIG. 18 operatively aligned with, and actuated against a terminal block. 
    
    
     DETAILED DESCRIPTION 
     A perspective view of a preferred embodiment of an assembled impact tool head according to the present invention is shown in FIG.  10 . The impact tool head is of generally rectangular shape, including a support block body  101  formed of an injection-moldable and suitably resilient insulating material, preferably a plastic material such as liquid crystal, ryton, ultem, or mineral filled nylon. The support body block  101  includes a longitudinal groove  103  formed in the body material and extending along the length of the support body block  101  between end faces  105  and  107 . The longitudinal groove  103  opens on a generally planar surface  109  and is sized to accommodate a multiple terminal wire cable within the terminal block. Pairs of pressing blades  111  reside perpendicular to, and on either side of the longitudinal groove  103 . The tops of the pressing blades  111  are substantially planar with the generally planar surface  109 . Cutting blade portions  115  extend perpendicularly beyond the generally planar surface  109  and abut the pressing blades  111  opposite the longitudinal groove  103 . In this particular embodiment, shoulders  117  are formed adjacent the cutting blade portions  115  and opposite the pressing blades  111  on the generally planar surface  109  to allow the impact tool head to be grasped within an impact tool. The dimensions of the individual pieces of the impact tool head may be chosen to allow usage with differently sized and configured terminal blocks. 
     Two versions of a pre-assembly embodiment of wire-pressing blades according to another version of the invention are shown in FIGS. 11 and 12, respectively. The version of FIG. 11 demonstrates the manufacture of four wire-pressing blades in one unit and the version of FIG. 12 a  and FIG. 12 b , respectively, demonstrate front and side views of the manufacture of two wire-pressing blades as a single unit. The pressing blades  111  are formed of a resilient material sufficiently durable to endure many impacts, e.g. beryllium copper, a carbon composite, or other sufficiently hard material. The material of the pressing blades  111  is preferably chosen to avoid chemical interaction with the cutting blades  115 . The pressing blades  111  each include a first pressing surface  119  and a pressing surface  121  separated by a straddle portion  123  which forms a substantially U shape therebetween. The dimensions of the straddle portion  123  are chosen such that the first pressing surface  119  and the second pressing surface  121  press a wire into a terminal slot without contacting or damaging the terminal contacts during operation (FIGS. 16 and 17 with their accompanying explanations will provide further information in this regard). In the embodiments of FIGS. 11 and 12, sets of pressing blades are formed as a single piece, connected by a center portion  125  having a breakable portion  127 . Notches  129  and  131  may be formed in the center portion  125  on either side of the breakable portion  127  to permit easy removal after molding so that electrical conduction is impossible between adjacent pressing blades. This is necessary to prevent electrical shorting between adjacent conductors in a terminal block during operation of the impact tool head. The pressing blades  111  further include seating portions  133 , which preferably include locking holes  135  through which injection-moldable material flows and hardens during molding to fixedly hold the pressing blades  111  in place within the impact tool head. FIG. 12 b  provides a side view of a pair of wire-pressing blades according to the invention in order to more specifically show the relationship between the pressing blades  111 , the center portion  125 , the breakable portion  127 , and the notches  129  and  131 . Additionally, the thickness  137  of the pressing blades  111  is chosen to allow for optimal fit when pressing wires into a slot in particular terminal block. 
     A pre-assembly embodiment of a wire-cutting blade set  150  according to the invention is shown in a perspective view in FIG.  13 . The set of wire-cutting blades  150  is formed of a hardened material such as 440C steel, and includes a breakaway portion  152  from which extend one or more cutting blades  154  each including a cutting blade portion  115  with a bevel-shaped cutting end  156  formed thereon. An arched locking portion  158  is formed between the breakaway portion  152  and the bevel-shaped cutting ends  156  along the cutting blade portions  15  in order to help hold the wire-cutting blade set  150  rigidly in place within the impact head after the molding process. The arched locking portion  158  preferably takes the shape of a roughly 90-degree arc, as shown in the figure. Also, the cutting blades  154  are preferably formed as individual blades as shown in FIG. 13, but could be formed as a single, wider, blade. Between the arched locking portion  158  and the breakaway portion  152 , breakaway notches  160  are preferably formed to allow for easy removal of the breakaway portion after the molding process is complete. 
     Cutaway side and front views demonstrating the operative alignment of the wire-pressing blade pairs  111  and the wire-cutting sets  150  within the impact tool head of the present invention are presented in FIGS. 14 and 15, respectively. In manufacture, a mold cavity of an injection mold apparatus is preloaded with one or more pairs of pressing blades  111  and two wire-cutting blade sets  150  such that the breakable portion  125  of the pressing blade pairs  111  (see FIGS. 11 and 12) resides in the portion of the mold which will form the longitudinal groove  103  of the impact head; such that the pressing blade pairs  111  reside so that after molding they will be substantially planar with the generally planar surface  109  of the impact tool head; and such that the after molding, the bevel-shaped cutting ends  156  of the wire-cutting blade sets  150  extend perpendicularly beyond the generally planar surface  109  of the impact tool head. The number of pressing blade pairs  111  equals the number of cutting blade portions  115  in each wire-cutting blade set  150  (see FIG.  13 ). The exact number of pressing blade pairs  111  and cutting blade portions  115  is tailorable to the requirements of a particular terminal block. Additionally, dimensions of the wire-pressing blade pairs  111  and the wire-cutting blade sets  150  may be chosen for compatibility with a particular terminal block. These dimensional choices include not only the overall scale, but also the dimensions of particular features of the individual pieces, e.g. adjustment of the depth of the straddle portion  123  of the pressing blades  111  to accommodate different wire contacts or of the length of the cutting blade portions  115  of the wire-cutting blade sets  150  to vary the distance by which the bevel-shaped cutting ends  156  extend beyond the generally planar surface  109  of the impact tool head. During the molding process, various means for attaching the impact tool head may be included, depending on needs of the impact device with which it is to be used, e.g. threaded holes in the molding material, shoulders  117  formed adjacent the cutting blades  115  and opposite the pressing blades  111  (see FIG.  10 ), etc. After molding, the breakable portion  125  (see FIGS. 11 and 12) is removed from the longitudinal groove  103  of the impact tool head to clear it from obstruction. The breakaway portions  152  of the wire-cutting blade sets  150  are also removed. 
     A perspective and partial cut-away view of an example of a terminal block with which the impact tool head of the present invention would be used is shown in FIG.  16 . In this particular case, the terminal block shown is configured as a Lucent RJ-45 terminal block. However, the impact tool head of the invention can be configured compatibly with any geometrically similar configuration. As shown in the figure, the terminal block is of a generally block shape, and includes a two substantially planar ridges  200  formed on either side of a longitudinal wire receptacle  202 . A plurality of wire terminal grooves  204 , each including an electrically conductive contact  206  therein, are formed in the substantially planar ridges  200 . Individual wires  208  from a multiple-wire cable  210  are placed in an operative relationship with the wire terminal grooves  204  as shown, such that they may be pressed and cut by the impact tool head. The terminal block of the example further includes longitudinal anvil-ridge portions  212  along its exterior, positioned to act as anvils against which the individual wires  208  may be cut as they are seated in the terminal grooves  204 . The electrically conductive contacts  206  are designed such that they penetrate and form an electrical connection with the individual wires  208  as they are seated within the terminal grooves  204 . 
     A diagrammatic representation of the impact tool head demonstrating its use in operative alignment with, and actuated against a terminal receptacle of a terminal block of the type shown in FIG. 16, such that it is operative to seat and cut a wire in a wire terminal groove of the terminal block is presented in FIG.  17 . Here, the dimensions of the impact tool head have been selected to fit the particular terminal block such that the distance  250  between the wire-cutting blade sets  150  provides sufficient clearance for the terminal block body  252  to fit and to be guided therebetween. The height  254  by which the pressing blade pairs  111  extend from the support body block  101  is chosen such that when the impact tool head is actuated against the terminal block, the pressing blade pairs  111  extend into the wire terminal grooves  204  of the terminal block (see FIG.  16 ), pressing the individual wires  208  into them. Also, the dimensions of the straddle portions  123  of the pressing blades pairs  111  are chosen such that they do not contact the electrically conductive contacts  106  (see FIG.  16 ), but still press the individual wires  208  onto the electrically conductive contacts  106  with sufficient force to cause the electrically conductive contacts  206  to penetrate and electrically contact the individual wires. Furthermore, the distance  256  by which the cutting blades  150  extend beyond the generally planar surface  109  of the impact tool head (see FIG. 1 also) is chosen such that when the impact tool head is actuated against the terminal block, the cutting blades  150  cut the wires  208  against the longitudinal anvil-ridge portions  212  of the terminal block (see FIG. 16 also), leaving wire clippings  258 . Additionally, the longitudinal groove  103  of the impact tool head is geometrically configured to accommodate the multiple-wire cable  210  residing in the longitudinal wire receptacle  202  of the terminal block. 
     The multiple component design of the impact tool head disclosed herein, although described above in a configuration compatible with an RJ-45 terminal block, is readily adaptable to other terminal block configurations. An example of a second preferred embodiment of the impact tool head is a design for use with a single strip of a Lucent 110-style terminal block is shown in perspective view in FIG. 18, utilizing one set of cutting blades  302  and pressing blades  300  configured as unitary pressing blades set into the impact tool head block  304 . A cutaway drawing of the second preferred embodiment of the impact tool head aligned with, and actuated against, a single strip of a Lucent 110-style terminal block is shown in FIG.  19 . In this figure, the impact tool head  304  is actuated against the terminal block  306 , causing the cutting blades  302  and the pressing blades  304  to respectively seat and cut a terminal wire  308  therein. Using an impact tool head with this configuration, a number of wires may be seated and cut at one time along a strip. Additionally, though not shown in the figures, the impact tool head disclosed herein may be adapted to seat and cut wires along two or more strips of a terminal block having a configuration geometrically similar to that of a Lucent 110-type terminal block. 
     As can be seen by the preferred embodiments above, the design of this impact tool head may be easily adapted to the requirements of many more terminal blocks than presented. Thus, foregoing descriptions of the preferred embodiments of the invention have been presented for purposes of illustration and description. It is neither intended to be exhaustive nor to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.