US 3309768 A
Description (OCR text may contain errors)
March 21, 1967 F. E THOMPSQN CABLE CUTTER FOR SIMULTANEOUSLY FERFORMING A PLURALITY OF SPACED CUTS 2 Sheeis-$heet 1 Filed D90. 2, 1964 INVENTOR.
FRANKLIN E. THO MPSON A? TO R N EYS March 39%? F. E. m-mmmww CABLE CUTTER FOR SIMULTANEOUSLY PERFORMING A PLURALITY OF SPACED CUTS Filed Dec. 2, 1964 2 Sheets-Sheet 2 INVENTOR.
FfifiuNKLIM E. THOM PSON United States Patent Ofiice 3,369,768 Patented Mar. 21, 1967 3,309,768 CABLE CUTTER FOR SIMULTANEOUSLY PERFORNHNG A PLURALITY F SPACED CUTS Franklin E. Thompson, 744 San Pablo, Sunnyvale, Calif. 94087 Filed Dec. 2, 1964, Ser. No. 415,543 3 Claims. (Cl. 30-911) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
This invention relates to apparatus for cutting and Stripping cables and in particular to apparatus for cutting and stripping coaxial cables.
There are of course a Wide variety of devices for cutting and stripping the insulation from a single-conductor wire. The problem is more complicated in connection with multiconductor cables such as coaxial cables. The reason for the difiiculty is that a coaxial cable has both an inner conductor and an outer conductor. The two conductors are concentrically arranged with the outer conductor being cylindrical in form and surrounding the inner conductor, with a sleeve of insulating material separating the two conductors. In addition, there is an outer sleeve of insulating materials surrounding the outer conductor.
In order to prepare a coaxial cable for use with conventional coaxial connectors and for other uses it is necessary to cut through and remove the outer insulation, the outer conductor and the inner insulation to expose -a length of the inner conductor at the extreme end of the cable. In addition it is necessary to cut through and remove a portion of the outer insulator to expose a length of the outer conductor adjacent the exposed inner conductor. In order to accomplish this task in the past it has been customary to use conventional single cutters in two operations, one to bare the inner conductor and a second operation to bare the outer conductor. In addition apparatus has been proposed having two cutters for performing the operation in one step. However, such prior apparatus has not been a complete solution to the problem.
In accordance with this invention, there is provided a novel cable stripper employing a pair of cutting arms and a cable-holding arm. The cutting arms are preferably mounted on either side of the cable-holding arm and are provided with cutters which are spaced from each other along the length of a piece of cable held in the cable-holding arm. Pivot means are provided interconnecting the three arms so that the cutting arms may be pivotally moved to simultaneously bring their associated cutters into engagement with the cable at spaced points along the length thereof.
It is an object of the present invention to provide a two-blade cutter and stripper wherein the depth of each cut is adjustable separately from the depth of the other cut.
Another object of the invention is to provide a twoblade cutter and stripper wherein it is a simple matter to adjust the distance between the two cuts.
A further object of the invention is to provide a cutter and stripper for coaxial cables which will bare both the inner and outer cable in a single operation and yet is an entirely integral single structure not requiring any auxiliary equipment. A related object of the invention is to provide in such a device a means for automatically establishing the desired length of the exposed inner conductor and further for changing this adjustment to meet different requirements.
An additional object of the invention is to provide a two-blade cutter and stripper wherein each of the blades is separately movable towards the cable to be cut. In this way it is possible to make both cuts with a single rotation of the cutters relative to the cable and at the same time the force required to make the cuts is relatively small because each of the cutters is working from the outside into the cable as the cable is rotated. This arrangement gives an extremely versatile and easy to use construction.
Another obejct of the invention is to provide a twoblade cutter and stripper which is adjustable to accommodate cables having different diameters.
Another object of the invention is to provide a twoblade cutter and stripper which does not become clogged with stripped material after a cutting and stripping operation is performed.
These and other objects and features of advantage will become more apparent from the following detailed description wherein reference is made to the accompanying drawings in which:
FIGURE 1 is a perspective view showing a cutter and stripper according to the invention in the position its various parts occupy after a cutting action has been completed.
FIGURE 2 is a side elevational view showing various parts of the device rotated relative to each other to give a clear picture of the construction of each of the parts. It should not be understood that operation of the device requires that the parts be rotated to the extreme positions shown in FIG. 2.
FIGURE 3 is a side elevational view of the device on the scale of FIG. 1 and again showing the parts in the position they occupy after a complete cutting operation has been performed.
FIGURE 4 is a side elevational view of a length of cable which has been cut and stripped with the apparatus shown in the drawings.
FIGURE 5 is a top view of the apparatus as shown in FIGS. 1 and 2 and showing a length of cable which has been cut and stripped with the apparatus and then inserted back into the apparatus to show the relation of the various parts.
FIGURE 6 is a cross sectional view on the lines 66 of FIG. 5; and
FIGURE 7 is a cross sectional view on the lines 7-7 of FIG. 5.
Referring in more detail to the drawings the cutter and stripper apparatus comprises a cable holding member 1 and two cable cutting members 2 and 3. The holding member and the two cutting members are pivotally interconnected by a pivot pin 4. The holding member 1 is simply an elongated bar or arm, and the cable-. engaging surface of the member is formed by either one of two holes 7 and 8 drilled adjacent the left end of the holding member. The holes 7 and 8 are used alternatively depending on the size cable to be cut, as will be hereinafter described in detail. The holding member 1 is drilled at a location spaced substantially from the holes 7 and 8 to receive the pivot pin 4. In addition the holding member is drilled on the opposite side of pivot pin 4 from the holes 7 and 8 to receive an abutment or stop pin 9 which extends on both sides of the holding member.
The cutting member 2 is an arm shaped member which is bored to receive the pivot pin 4. A cutting blade 12 is attached to the left end of the arm 2 as shown in the drawings. By way of example, blade 12 can be a conventional type of blade known as an X-Acto blade number twenty-four. Blade 12 is received in a recess 13 formed in the side of arm 2 and is held in place by a plate 14 having a ridge 15 which fits into the recess 13. Plate 14 is attached to the cutv s9 ting arm 2 by means of a number of screws 16. The right end of arm 2 is shaped to provide a relatively thin portion 17. One reason for the reduced portion 17 is to provide a proper hand grip. Thus, when the device is grasped around its right end by the right hand, the palm of the hand will engage the top of arm 2, and the fingers will engage the bottom of arm 1. The reduced portion 17 avoids any possibility of the fingers pressing upwardly on the bottom of arm 2. Another reason for the reduced portion 17 is to provide proper positioning for an abutment screw 18 which is threaded in a bore P19 in the thin portion 17. Screw 18 is positioned at substantially the same radial distance from the pivot pin 4 as is the abutment member 9, whereby screw 18 is engageable with the pin 9 to provide a positive fixed limit to the relative rotation of the holding arm 1 and the cutting arm 2. Screw 18 has a hexagonal recess in its upper end to facilitate turning. The left ends of cutting arm 2 and the plate 14 are given matching recessed shapes to provide a groove 20 in which the cutting edge of the blade 12 is received.
The cutting arm 3 is exactly the same as the cutting arm 2 except that the blade receiving recess is on the opposite side. Thus, the cutting arm 3 is provided with a cutting blade 22 which is exactly the same as blade 12. Blade 22 is received in a recess 23 and is held therein by a plate 24 provided with a raised portion 25 which fits in the recess 23. The plate 24 is held in place by a plurality of screws 26. It will be noted that screws 26 also hold two additional plates 27 and 28 in place. The left end of the cutting arm 3, plate 24 and plate 27 are all given matching recessed shapes to provide a groove 29 in which the cutting edge of blade 22 is received and in which a cable in the apparatus will also be received. The function of plate 28 is to provide a stop against which the end of the cable is engageable to fix the length of inner conductor which will be stripped. The function of plate 27 is to provide a spacer for determining the distance between blade 22 and plate 28. If a longer or shorter length of exposed inner conductor is desired the plate 27 is simply removed and replaced by a wider or narrower spacer plate. The right end of cutter arm 3 is provided with a portion 30 of reduced width in the same manner and for the same purpose as the reduced portion 17 on arm 2. Thus, the reduced portion 30 on cutting arm 3 is provided with a stop screw 31 which is threaded in a bore 32. The screw 31 is positioned on arm 3 at substantially the same radial distance from the pivot pin 4 as the abutment 9 is positioned in the arm 1 and operates in a manner similar to that described above for screw 18 to control the limit of movement of arm 3. The screw 31 has a hexagonal recess at its upper end to facilitate turning. In order to provide a smooth acting pivot and yet one which is easily removable, the pin 4 is threaded internally to receive a cooperating screw 33.
In order to operate the apparatus which has been previously described, the cable holding arm 2 is positioned so that. the hole 7 or 8 which is closest to the cutting blades 12 and 22 is of substantially the same diameter as the cable to be cut. For example, in the arrangement shown in the drawings the device is adjusted for cutting a cable having substantially the same diameter as the hole '8. FIG. 4 shows a conventional coaxial cable 36 having an inner conductor 37 and an outer conductor 38. The left end of the cable in FIG. 4 is shown prior to the cutting and stripping operation, and the right end is shown after the operation has been completed.
In order to cut and strip a cable such as 36, the holding arm 1 is rotated clockwise relative to the cutting arms 2 and '3 a sufiicient distance so that the hole 8 clears the cutting blades :12 and 22. It is then possible to insert the uncut end of a cable through the hole 8 until the end of the cable abuts the stop plate 28. Then,
holding the apparatus in one hand positioned to the right of pivot pin 4, it is simply necessary to squeeze the right ends of cutting arms 2 and 3 toward the right end of the cable holder 1 and to rotate the apparatus relative to the cable which is held in the opposite hand. The relative rotation of the apparatus and the cable can be obtained by rotating either the apparatus or the cable or a combination of both. The scissors action which results because of pivot pin 4 thus forces the cable carried in the hole 8 into engagement with the cutting edges of blades 12 and 22. It will be noted that the cutting edges of blades 12 and 22 are slanted at a substantial angle so that the cutting edges move into the cable with a slicing action.
Stop screws 18 and 31 are adjusted to the precise position required to make the desired cut. For example, as shown in the drawings the abutment screw 18 is screwed out farther than the abutment screw 31 so that as seen best in FIG. 3 the cutting blade 12 can not move up toward hole 8 as far as cutting blade 22. The reason of course for the difference in adjustment is that blade 22 must cut deeper than blade 12. More specifically, blade 22, must cut through the outer insulation, through the outer conductor 38 and through the inner insulation down to the inner conductor 37. In contrast the blade 12 need only cut through the outer insulation down to the outer conductor 38. After the cable has been rotated at least once while pressure has been applied to compress the right ends of arms 1, 2 and 3 together all of the necessary cutting will have been accomplished. It is then a simple matter to withdraw the cable. If the cable is withdrawn while the cutting blades 12 and 22 are held in place the edges of the blades will strip the cut material from the cable. It is also possible to turn the holding arm 1 slightly clockwise relative to the cutting arms 2 and 3 and then remove the cable, in which case the cut material can then be stripped by hand. In either case it should be noted that the apparatus is so designed that no stripped material will clog it.
Although specific details of the present invention are shown and described herein, it is to be understood that modifications may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims. For example, the distance between the blades 12 and 22 can be changed by adding spacing washers on the pivot pin 4 between the holding member :1 and the cutting members 2 and 3, or holding member 1 can be replaced by another holding member having a different thickness.
Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:
1. A cable cutter, comprising:
a cable holding arm;
a first cutting arm on one side of said holding arm;
a second cutting arm on the other side of said holding arm;
said holding arm and said first and said second cutting arms having longitudinal axes which are substantially parallel to each other;
a cable-engaging surface on said holding arm for receivinga length of cable disposed substantially perpendicular to said axes of said arms;
a cutter attached to each of said cutting arms, said cutter being spaced from each other along the length of said cable; and
pivot means interconnecting all three of said arms,
said first and said second cutting arms being pivotable about said pivot means to bring said cutters into spaced engagement with a length of said cable in said cable-engaging surface of said holding arm.
2. Apparatus in accordance with claim 1 in which said cutters are located adjacent one end of each of their associated cutting arms, said cable-engaging surface is located adjacent one end of said holding arm,
5 6 and said pivot means is located in a portion of said arms References Cited by the Examiner intermediate the ends thereof; UNITED STATES PATENTS a stop member secured to said cable holding means 927 345 7/1909 Furlong on the other side of said pivot means from said 2704000 3/1955 Miner cable-engaging surface and extending laterally from 2752676 7/1956, Trickle each side of said cable holding means; and u cooperating abutting means secured to each of said FOREIGN PATENTS cutting arms for engagement with said stop mem- 705,668 3/1954 Great Britain.
her to control the limit of pivotal movement of each of said cutting arms to thereby control the 10 movement of said cutters relative to said cable in 2,695,537 11/1954 Imman et 81. said cable-engaging surface 2,871,739 2/1959 Granzow. 3. Apparatus in accordance with claim 1 including 2,903,064 9/1959 Blonder. spacer means posltioned between said first and said sec- 15 3 089 367 5/1963 Schluten ond cutting arms to vary the spacing between said cutters to thereby vary the relative points of engagement WILLIAM FELDMAN Prlmary Exammerof said cutters with said cable. MYRON C. KRUSE, Examiner.
References Cited by the Applicant D. 199,088 9/ 1964 Hurlbut.