Abstract:
Wire processing apparatus particularly adapted to perform operations on wires having a central conductor with multiple, coaxial covering layers. The apparatus includes an electronic memory for storing values commensurate with the lengths from a terminal end of the wire to the positions of cuts to be made through the plurality of coating layers, and a plurality of threaded shafts individually movable by manual manipulation of mechanical elements to control the depths of each cut. The threaded shafts are mounted upon a turret which is movable both rotationally and axially with respect to the wire being processed. The electronic memory is preferably adapted to receive inputs representing parameters of sequential steps in each of two processing operations, and to perform such operations alternately, upon different wire ends, upon successive actuations of the apparatus. A further feature of the apparatus is an arrangement permitting the force exerted on the wire by a pair of gripping members to remain substantially constant over a range of different wire diameters. A stepper motor is mechanically linked to the gripping members and is indexed from a fixed starting position by a selectively variable number of steps to bring the gripping members to the wire-engaging position.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to so-called wire processing apparatus wherein a coated, filamentary member, such as an electrical wire or optical fiber, is clamped in a fixed position while blade means sever the coating layer(s) and strip the severed slug(s) from the member. In a preferred form, the apparatus of the invention is operable to successively sever and strip a plurality of coating layers from the filamentary member. Although it will be understood that the present invention, and related prior art equipment, may be used with many types of filamentary workpieces, for simplicity of discussion the workpiece will be considered an electrical cable having a central core and a plurality of coating or covering layers of electrical insulation, magnetic shielding, and the like, i.e., such as a coaxial cable, and will be referred to as a “wire” throughout the following written description. 
     A wide variety of equipment has been devised for the purpose of severing and stripping coating layers from coaxial cables, and other wires with a plurality of coating layers. Such equipment may be constructed for entirely manual operation, fully automated operation, or some combination of the two. Examples of fully automated cutting/stripping machines may be found in U.S. Pat. Nos. 5,111,720, 5,243,882, and others, wherein values representing a plurality of lengths (from the end of the cable to the longitudinal position of the cut) and radial depths of successive cuts, each through a different covering layer, may be entered via a keypad and stored in electronic memory. Upon actuation, the equipment proceeds automatically to make successive cuts through the covering layers at the lengths and depths stored in memory. 
     It is a principal object of the present invention to provide apparatus for successively cutting through a plurality of layers of a coaxial cable at different lengths and depths with some settings entered by an operator and stored in a purely mechanical manner with other settings entered and stored electronically. That is, the principal object of the invention is to provide novel and improved hybrid or semi-automatic apparatus for cutting through a plurality of covering layers at various lengths and depths of cuts. 
     Another object is to provide apparatus for gripping a wire with a substantially constant force over a range of wire diameters as cutting and stripping of covering layers is performed. 
     A further object is to provide wire processing apparatus with means for storing two sets of values relating to lengths of cuts and/or other variables and for performing functions commensurate with each set of values alternately on two different wire ends. 
     Still another object is to provide novel and improved means for mechanically storing a plurality of radial depths of cuts to be made in covering layers of a coaxial cable and for implementing successive cuts at the mechanically stored depths. 
     Other objects will in part be obvious and will in part appear hereinafter. 
     SUMMARY OF THE INVENTION 
     The wire processing apparatus of the invention includes a pair of reciprocating gripping jaws which are initially separated for axial insertion therebetween of a coaxial cable, or the like. After the apparatus has been initialized, as described later, the cable is inserted until its terminal end contacts blade means which subsequently effect the cutting operation. The jaws are then pivoted toward a closed position by operation of a linear actuator to move a wedge to rotate the jaws until they grip the cable. The actuator is programmed to move the wedge, and thereby move the jaws, by a distance commensurate with the diameter of the wire being clamped. That is, the distance of movement of the actuator is variable in accordance with the wire diameter to ensure that the gripping force is sufficient to prevent movement of the cable as axial forces are exerted thereon while avoiding excessive gripping forces. 
     The apparatus includes a pair of blades having cutting edges movable toward and away from one another to effect cutting through the covering layers on the cable. The blades are initially in a closed position, i.e., the cutting edges of the blades are substantially in mutual contact, and serve as a stop means for contact by the end of the cable to establish the limit of axial insertion thereof. Arms carrying the blades are then pivoted to rotate the blades to an open position, i.e., to separate the cutting edges, and the cutting mechanism, including the blades, is moved axially of the cable to position the blades adjacent the axial portion of the cable where the first cut is to be made. The distance of axial movement of the blades, i.e., the “length of cut,” is controlled by a stepper motor acting on a lead screw to move a carriage upon which the cutting means are mounted. Electrical signals provided to the stepper motor for establishing the lengths of each of a plurality of successive cuts are controlled by an electronic memory which stores values entered by an operator via a keypad on the apparatus, in conventional manner. 
     The depth of a cut, i.e., the distance of radial movement of the blades toward the axis of the cable, is determined by the axial position of a stop member which physically contacts and axially moves a conical cam member to effect radial movement of the blades. A rotatable turret is fitted with a plurality of threaded shafts and a fixed shaft. All of the shafts have axes parallel to the axis of rotation of the turret and are spaced equally therefrom. The threaded shafts are engaged in respective nuts which are manually rotatable for reciprocal, axial movement of the shafts, thereby providing individual, selective positioning of the terminal end of each shaft. The turret is indexed by a linear actuator between four rotational positions. The terminal end of a different one of the four shafts (three selectively, axially movable, one fixed) is positioned in alignment with the member which effects radial movement of the blades in each of the four turret positions. The turret is mounted on a carriage which is movable in a direction parallel to the axes of the shafts. The carriage moves a fixed distance, between predetermined rear and forward positions, upon each actuation. Thus, the extent of radial movement of the blades (depth of cut) is controlled by the position of the end of the shaft in alignment with the cam member. The turret is rotatably indexed after each cut is completed to position the end of a different shaft in alignment with the cam member, the fixed shaft always being in this position, with the carriage in its forward position, at the beginning of each cycle to establish the initialized (fully closed) position of the blades. The nuts which adjust the axial positions of the threaded shafts to establish the desired depths of cuts are manually accessible through an opening in the top of the apparatus housing. 
     A unique keypad is provided for entry by an operator of values and control functions. Among other features, the keypad permits entry of a first plurality of cutting and/or strip lengths for sequentially severing and fully or partially removing a plurality of coating layers on one end of a wire, and a second plurality of values for sequential cutting/stripping operations on the other end of the wire. Of course, the wire is removed from the clamping means, reversed end-for-end and replaced in the clamping means between the first and second sequence of operations. 
     The foregoing and other features of construction and operation of the invention will be more readily understood and fully appreciated from the following detailed disclosure, taken in conjunction with the following detailed description and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a housing for apparatus embodying the invention; 
     FIG. 2 is a plan view of the apparatus of FIG. 1 with the housing cover removed; 
     FIG. 3 is a side elevational view of the apparatus of FIG. 2; 
     FIGS. 4 through 7 are fragmentary, perspective views, some exploded and some partly in section, of various portions of the apparatus; 
     FIG. 8 is a front elevational view of certain elements; 
     FIGS. 9A and 9B are plan views of the element of FIG. 8, together with other elements, in two positions of relative movement; and 
     FIG. 10 is a plan view of an example of the keypad layout. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, an example of apparatus for processing elongated, filamentary members such as coaxial cable is seen in FIG. 1, denoted generally by reference numeral  10 . Apparatus  10  includes an external housing having upper and lower sections  12  and  14 , respectively, wherein both mechanical and electrical components are housed. Power cord  16 , for connection to an appropriate AC source, extends from the housing. Transparent safety shield  18  is hingedly attached to upper housing section  12  for movement between covering and uncovering positions with respect to openings  20  and  20   a.  A workpiece such as wire  21  extends through opening  22  in shield  18  when the latter is in the covering position as covering layer(s) on the cable are cut and, if desired, stripped from the cable. Actuation or cycling button  23  is provided on the front surface of lower section  14 . Keypad  24  and display window  25 , described later in more detail, are provided on the top surface of upper housing section  12  for entering values to be stored in an electronic memory within the housing, and for effecting other control functions. 
     Components housed within lower section  14  are shown in plan view in FIG.  2  and in side view in FIG.  3 . Circuit board  26 , transformer  28  and fan  30  are contained in the upper (as viewed from the top in FIG. 2) part of section  14 , transformer  28  being secured to plate  29 . An additional circuit board (not shown) is preferably mounted on the lower surface of upper housing section  12 , directly under keypad  24 . A pair of gripper members  32 ,  32 ′ are mounted at what is termed the forward side of apparatus  10 , i.e., the right side as viewed in FIG. 2, upon the ends of rods  34 ,  34 ′, respectively. Rods  34 ,  34 ′ are rotatably supported in forward and rear end plates  36  and  38 , respectively, of a fixed frame within lower housing section  14 . Outer carriage  40  and inner carriage  42  are each mounted for reciprocal movement toward the forward and rear sides of the apparatus. As explained later, inner carriage  42  moves together with outer carriage  40 , but is also movable with respect thereto. 
     Cutting mechanism, indicated generally by reference numeral  44 , is mounted rearwardly of gripper members  32 ,  32 ′ upon hollow shaft  46  which is rotatably mounted upon outer carriage  40 . Cutting mechanism  44  includes a pair of blades having opposed cutting edges and mounted upon the forward ends of respective, pivotally mounted arms  48 ,  48 ′. Rollers carried at the rear ends of arms  48 ,  48 ′ are spring biased into contact with the surface of member  50 , essentially flat on the top and bottom and tapered on the sides, which is slidably mounted upon hollow shaft  46  for axial movement relative to arms  48 ,  48 ′. Member  50  is connected by pin  52 , extending through elongated slots in hollow shaft  46 , to rod  54  which is positioned within hollow shaft  46 . Axial movement of rod  54  moves member  50  to rotate arms  48 ,  48 ′ and effect movement of the blades toward and away from one another. Member  50  is shown in FIG. 2 in its forwardmost position, wherein the blades are fully closed with their cutting edges in mutual contact. Construction and operation of cutting mechanism  44  is entirely conventional, corresponding essentially to that disclosed in U.S. Pat. No. 4,993,147, incorporated by reference herein, although further details relating conventional portions of the cutting mechanism to novel elements of the present invention appear hereinafter. 
     Movement of various elements of apparatus  10  is effected by one electric motor and four linear actuators, also known as stepper motors. Electric motor  56  is mounted upon outer carriage  40  for rotation of pulley  58 , connected by belts  60  to pulley  62  for rotation of cutter mechanism  44 . Stepper motor  64  is mounted upon outer carriage  40  and operates upon axially stationary lead screw  66  to effect reciprocating movement of the outer carriage. Stepper motor  68  is mounted upon inner carriage  42  and operates upon lead screw  70  to effect reciprocating movement of the inner carriage relative to outer carriage  40 . Stepper motor  72  and wedge  74  are fixedly mounted upon frame member  76  which is slidably mounted on rods  34 ,  34 ′; operation of motor  72  acts upon lead screw  77  to move wedge  74  in forward and rear directions to operate gripper jaws  32 ,  32 ′, as described later. Stepper motor  78  is mounted on inner carriage  42  and has an output shaft connected to rotatable turret  80  to index the latter between four positions, as also described later in more detail. Turret  80  carries fixed shaft  83  and three nuts  82 ,  82 ′,  82 ″, each engaging a respective threaded shaft, one of which, indicated by reference numeral  84 , may be seen in FIG. 2, the other two being shown in later Figures. Additional reference numerals, denoting elements described later, also appear in FIGS. 2 and 3. 
     Having thus generally described various components in fully assembled condition, attention is now directed to FIGS. 4, et seq., where further details of construction and operation of these and other components will be more readily apparent. Fixed frame  37 , shown separately in FIG. 4, is provided by base plate  39  with rigidly affixed, vertically disposed end plates  36  and  38 . Frame  37  is affixed to the lower wall of housing section  14  by bolts passing through openings  39   a  in base plate  39 . L-shaped bracket  86  is affixed to base plate  39 , and rotatable shafts  34 ,  34 ′ are mounted in bearings in end plates  36  and  38 , as previously mentioned. Lead screws  66  and  77  are each rotatably mounted at one end upon, and extend from, end plate  38 . It will be noted that lead screw  77  forms one portion of a rod having a smooth, cylindrical portion  77   a  which, as described later, extends slidably through an opening in a wall of outer carriage  40 . 
     Turning now to FIG. 5, outer carriage  40  is seen to comprise four rigidly connected walls, namely, front and back walls  88  and  88 ′, respectively, and side walls  90 ,  90 ′. Blocks  92  and  94 , having respective openings  92   a  and  94   a,  are affixed to and extend inwardly from the inside surface of side wall  90 ′. Motor  56  and stepper motor  64  are shown exploded away from their fixed mountings upon the inner surfaces of front and back walls  88  and  88 ′, respectively. The following through openings are provided in front plate  88 : opening  46   a  for bearings  46   b  (FIG. 6) in which shaft  46  of the cutting mechanism is journaled, openings  34   a,    34 ′ a  for rods  34 ,  34 ′, opening  56   a  for the shaft of motor  56  and surrounding small openings for screws to attach the motor to wall  88 , and openings  96  to provide clearance for the forward ends of three of the four shafts on turret  80  which are aligned with openings  96  when the turret is moved, with inner carriage  42 , from its rear to its forward position. Through openings  34   b,    34 ′ b,    66   a,    92   b  and  94   b  are provided in rear wall  88 ′. Limit switch  98 , having forwardly disposed contact button  98   a  is fixedly mounted at the upper portion of the inside junction of walls  88 ′ and  90 ′. Limit switch  99 , having rearwardly disposed contact button  99   a  (FIGS. 2 and 3) is affixed to the lower rear corner of the outer surface of side plate  90 ′. 
     In FIG. 6, outer carriage  40  is shown in combination with inner carriage  42  and portions of cutter mechanism  44  and turret  80  carried thereon. Inner carriage  42  is seen to consist of an essentially T-shaped plate  100 ; stepper motor  68  is mounted on the rear surface and limit switch  102 , having forwardly disposed contact button  102   a,  is mounted on a side surface of plate  100 . The shafts of stepper motor  78  and turret  80  extend through opening  78   a  in plate  100  and are connected to one another for rotational indexing of the turret by the motor. Flange  78   b  of stepper motor  78  is spaced rearwardly from plate  100 , being connected thereto by rod  78   c  so that the motor and turret shafts rotate, rather than the motor itself. Rods  92   c  and  94   c  extend slidably through openings  92   b  and  94   b  in end wall  88 ′ and through openings  92   a  and  94   a  in blocks  92  and  94 , the forward ends of the rods being fixedly mounted in openings  92   d  and  94   d  in plate  100 . Thus, as stepper motor  68  is actuated to travel forwardly and rearwardly upon lead screw  70 , inner carriage  42  moves, together with rods  92   c  and  94   c  and block  104  which is carried upon rod  92   c,  relative to outer carriage  40 . The elements mounted upon plate  100 , i.e., stepper motors  68  and  78 , turret  80  and elements carried thereon, and switch  102  move relative to the outer carriage and to cutter mechanism  44 . Lead screw  70  extends through opening  70 ′ in plate  100  since the plate moves as screw  70  remains stationary. 
     Fixed frame  37  and outer carriage  40  are shown in FIG. 7 in combination with the wire clamping elements. As previously mentioned, gripper members  32 ,  32 ′ are fixedly mounted on the forward ends of rods  34 ,  34 ′, respectively, with collars  103 ,  103 ′ restraining axial movement of the rods. Thus, the V-shaped gripping jaws of gripper members  32 ,  32 ′ are moved toward and away from one another as rods  34 ,  34 ′ are rotated in opposite directions. Arms  104 ,  104 ′ are fixedly connected to rods  34 ,  34 ′, the lower ends of the arms being biased by spring  106  into contact with the tapered sides of wedge  74 . As arms  104 ,  104 ′ are rotated by forward and rear movement of wedge  74 , rods  34 ,  34 ′ are rotated to move gripper members  32 ,  32 ′ into and out of engagement with a wire positioned therebetween. Wedge  74  is affixed to frame member  76 , upon which stepper motor  72  is mounted, as previously mentioned. Rods  34 ,  34 ′ extend slidably through sleeve portions  108 ,  108 ′ which are integral with frame member  76 . Limit switch  109 , having rearwardly directed contact button  109   a  (FIGS. 2 and 3) is also carried by frame member  76 . As stepper motor  72  is actuated to move in forward and rear directions on lead screw  77 , frame member  76  and wedge  74  are likewise moved to actuate the gripping mechanism. With this arrangement, the distance of forward movement of the elements from an initial, “home” position, and thus the spacing of the gripping surfaces of gripper members  32 ,  32 ′ at the forwardmost position of wedge  74 , is commensurate with the number of steps which stepper motor  72  is indexed. The initial, rearmost position of frame member  76  is established by contact of rearwardly directed button  109   a  of contact switch  109  with bracket  86  on fixed frame  37 . 
     Turret  80  is shown in enlarged, front elevation in FIG. 8, together with a fragment of plate  100 . The turret includes four arms  110 ,  110   a,    110   b,  and  110   c  at 90 degree intervals. Shaft  83  extends loosely through a passageway in arm  110 , and threaded shafts  84 ,  84 ′, and  84 ″ extend through passageways in arms  110   a,    110   b,  and  110   c,  respectively. Circular nuts  82 ,  82 ′ and  82 ″ are positioned in recesses in arms  110   a,    110   b,  and  110   c,  respectively, in threaded engagement with shafts  84 , 84 ′ and  84 ″, respectively. Thus, manual rotation of nuts  82 ,  82 ′ and  82 ″ moves shafts  84 ,  84 ′, and  84 ″ axially with respect to turret  80 . Set screw  112  extends through one side of arm  110 , into the passageway wherein shaft  83  is positioned, to permit axial adjustment of shaft  83  when screw  112  is backed off and to fix the axial position of shaft  83  when screw  112  is tightened against the shaft. This is considered a factory or technician-performed adjustment; that is, the axial position of shaft  83  is not intended to be changed by an operator of apparatus  10  and is considered to be fixed during normal cutting/stripping operations. Set screws  114 ,  114 ′ and  114 ″, on the other hand, have knurled heads for manual engagement by an operator to back off these screws as the operator turns nuts  82 ,  82 ′ and  82 ″ to adjust the axial positions of shafts  84 ,  84 ′, and  84 ″ to set up the apparatus for normal operation in the manner described later. 
     Referring now to FIGS. 9A and 9B, turret  80  is shown in its forward and rear positions, respectively, relative to elements of cutter mechanism  44 . Forward and rear, linear movement of turret  80  is effected by operation of stepper motor  68  to travel upon lead screw  70 , thereby moving inner carriage  42  upon which the turret is mounted. When apparatus  10  is ready to receive a workpiece (wire), inner carriage  42  is in its forward position of FIG. 9A wherein the forward end of fixed shaft  83  contacts the rear end of cutter mechanism shaft  54 , moving member  50  to its forwardmost position and rotating arms  48 ,  48 ′ to fully close blades  116 ,  116 ′, i.e., to bring the cutting edges of the blades substantially into mutual contact. The wire is axially inserted, through shield opening  22  and the space between the gripping surfaces of gripper members  32 ,  32 ′, which are initially in the open or most widely spaced position, until the terminal end of the wire contacts blades  116 ,  116 ′. The operator then presses cycling button  23  to begin the sequence of operations resulting in cutting and, if desired, stripping of a plurality of covering layers. During the ensuing sequence of operations, which takes place without further intervention by the operator, turret  80  is moved by stepper motor  68  to the rearward position of FIG. 9B, wherein shafts  83 ,  84 ,  84 ′ and  84 ″ are removed from clearance openings  96  to permit rotation of turret  80  by stepper motor  78 . 
     Upon actuation, stepper motor  72  travels along lead screw  77  to move frame member  76  and wedge  74  forwardly from its initial position by a distance commensurate with a value previously entered into electronic memory by the operator. This value is selected as a function of the outside diameter of the wire so that the gripping force exerted by gripper members  32 ,  32 ′ is sufficient to hold the wire during cutting/stripping operations, but is not an excessive force which might damage the wire. When the wire is securely clamped, stepper motor  68  is actuated to travel upon lead screw  70 , moving inner carriage  42  and turret  80  from the position of FIG. 9A to that of FIG.  9 B. Turret  80  is moved by a distance indicated by letter D, which is non-variable; that is, motor  68  is indexed by the same number of steps upon each actuation in both directions of movement. As turret  80  moves to its rearward position, the biasing force of spring  48   a,  urging the rollers on arms  48 ,  48 ′ toward one another, causes member  50  to slide rearwardly on hollow shaft  46 , thereby moving blades  116 ,  116 ′ to the fully open position, spaced by a distance greater than the diameter of the clamped wire. Substantially simultaneously with actuation of stepper motor  68 , motor  56  is actuated to rotate cutter mechanism  44 . 
     With the elements in their positions of FIG. 9B, stepper motor  78  is actuated to rotate turret  80  by 90 degrees. Referring again to FIG. 8, turret  80  is movable in 90 degree increments to any of four positions. In the position shown, fixed shaft  83  is at position I. Assuming turret  80  rotates in a counterclockwise direction (as viewed in FIG.  8 ), shaft  83  will be in position IV after indexing once, and will be at positions III and II upon successive further indexings. The shaft in position I is axially aligned with shaft  54  of the cutting mechanism. With the blades in the open position, stepper motor  64  is actuated to travel on lead screw  66 , moving outer carriage  40  forwardly upon rods  34 ,  34 ′ by a distance which has been entered by the operator and stored in electronic memory as the length (from the terminal end of the clamped wire) of the first cut. Stepper motor  68  is then actuated again to move turret  80  (inner carriage  42 ) forwardly to the position of FIG.  9 A. During such movement, shaft  84 , which is now in position I, contacts the end of shaft  54 , moving member  50  axially to pivot arms  48 ,  48 ′ and move blades  116 ,  116 ′ toward one another. When inner carriage  42  (turret  80 ) reaches its forwardmost position, the spacing of the blade cutting edges, i.e., the depth of the cut, is a function of the position of the front end of shaft  84 . This position has been manually set by the operator, in a manner described later, and thus mechanically stored to produce the desired depth of cut. 
     Upon completion of the first cut, at the electronically stored length and mechanically stored depth, motor  56  is deactuated to stop rotation of the cutter mechanism. If desired, the blades may then be opened by a small amount to prevent scraping the central conductor or other wire layer as the severed slug is fully or partially pulled from its initial position; such opening is performed by rearward movement of inner carriage  42  by a portion of the total number of steps which stepper motor  68  is indexed to move the carriage to its terminal position. Stepper motor  64  is then actuated to move outer carriage  40  and the cutter mechanism in the rearward direction by a distance previously entered by the operator as the desired strip or pull length, if any. Stepper motor  68  is then actuated to move inner carriage  42  to its terminal rearward position, thereby fully opening blades  116 ,  116 ′, and motor  56  is actuated to resume blade rotation. Outer carriage  40  is then moved forward by stepper motor  64  to position the blades at the second length of cut. Inner carriage  42  is moved forward, bringing shaft  84 ″ into contact with shaft  54 , thereby moving the blades radially to the second, mechanically stored depth of cut. After the final cut/pull operation, stepper motor  72  is returned to its terminal rear (“home”) position, thereby releasing clamping members  32 ,  32 ′ to permit withdrawal of wire  21 . Motor  56  is again actuated to dislodge any debris from the blades as stepper motor  68  moves inner carriage  42  rearwardly to fully open the blades. Blade rotation is stopped and stepper motor  64  moves outer carriage  40  to its home position (if it is not already there after the final pull operation). Stepper motor  78  indexes turret  80  to its home position, with shaft  83  in position I, aligned with shaft  54 . 
     The illustrated embodiment of apparatus  10  permits the operator to manually adjust the axial positions of three shafts, thereby mechanically storing the depths of three successive cuts to be made in the covering layers of the clamped wire, although it will be readily apparent that either more or less than three adjustable shafts may be provided to make the capabilities of the apparatus commensurate with its intended use. Manual adjustment of shafts  84 ,  84 ′,  84 ″ is effected while turret  80  is in its forward position (FIG.  9 A), wherein the set screw and nut associated with the shaft in position I (FIG. 8) is manually accessible through opening  20 . Turret  80  is moved to its rear position, rotationally indexed to position the desired shaft in position I, and returned to its forward position for manual adjustment by sequential actuation of stepper motors  68 ,  78  and  68  in response to a single keypad actuation, as explained later in more detail. After backing off the set screw of the shaft in position I, a gauge (e.g., a pre-stripped wire corresponding to the wire to be processed) is placed between the blade cutting edges and the nut is rotated manually in the appropriate direction, thereby moving (or allowing spring  48   a  to move) shaft  54  until the blade edges lightly contact (or are slightly spaced from) the gauge. The set screw is then advanced back into contact with the threaded shaft, fixing its axial position relative to turret  80  and mechanically storing the depth of cut produced by moving inner carriage  42  to its terminal forward position with the adjusted shaft in alignment with shaft  54 . 
     It may be useful to note that the four described limit switches  98 ,  99 ,  102  and  109  are provided only to establish “home” positions of the four corresponding stepper motors, principally during set-up and power-up of apparatus  10 . That is, they are not in use during the described sequence of wire processing operations. The home rotational position of turret  80 , with fixed shaft  83  in position I is established by contact of protrusion  110   a′  on the rear side of turret arm  110   a  with contact button  102   a,  as shown in FIG.  2 . It is also noted that springs  66   a  and  70   a  surround lead screws  66  and  70 , respectively, to pre-load stepper motors  64  and  68  in accordance with conventional practice. 
     The steps performed by an operator in preparing the machine for performing a specific sequence of processing steps may be best understood by reference to the example of keyboard layout shown in FIG.  10 . The layout preferably includes a pictorial example of a wire having three covering layers X, Y, and Z coaxially surrounding a central conductor. Opposite ends of the wire are referred to as A and B, with keys bearing these letters positioned in proximity to the pictured wire ends. The significance of this arrangement and the versatility which it adds to operation of apparatus  10  is explained later. To enter a program of values corresponding to successive operations to be carried out at each step, the operator presses the A button (or it is automatically activated at power-up) and then presses the “Step 1” button at the right side of the keypad. This actuates stepper motors  68 ,  78  and  68  in sequence to move inner carriage  42  to its rear position, rotate turret  80  to place arm  110   a  in position I, and move the inner carriage back to its forward position. Set screw  114  and nut  82  are now manually accessible through opening  20 , and the position of shaft  84  is adjusted in the manner previously described to mechanically store the depth of the first cut. The operator then presses the “strip length” button and enters the value on the numeric portion of the keypad corresponding to the length of the first cut. 
     Values corresponding to the parameters represented by the buttons in the horizontal row under the AB buttons (or default values for these parameters) may then be sequentially entered by the operator for Step 1 of the processing operation. The “pull length” button represents the distance of linear travel of the blades in pulling or stripping the severed layer from its original position, the “step back” button corresponds to a distance of outward, radial travel of the blades after cutting to the pre-set depth and before beginning the pull/strip linear travel, the “cut dwell button sets the time for which the blades continue to rotate after reaching the cutting depth before rotation is stopped, and the “blade speed” button sets the speed of radial movement of the blades (i.e., the speed of stepper motor  68 ). After entering all Step 1 values, the operator then presses the “Step 2” button, which indexes turret  80  to permit manual adjustment of the depth of the second cut. The operator then proceeds to make the manual adjustments and keypad entries for the second and third steps of the operation and apparatus  10  is then ready, upon pressing cycling button  23 , to perform the complete sequence of steps on a wire end. 
     It is sometimes required that the length(s) of cut(s), and possibly other parameters be different at opposite ends of a wire, although the depths of the cuts remains the same. In such situations, the operator may press key A and manually store the depths of cuts and electronically store other parameters in the manner just described. The operator then presses the B key and enters another sequence of values corresponding to the parameters indicated by the horizontal row of keys to be performed at end B. When successive processing operations are to be performed alternately according to programs A and B, the operator presses the “AB alternate” button before commencing the first operation. When the apparatus has completed the sequence of steps at end A, and the elements returned to their initial positions with the gripper members released, the wire may be withdrawn, reversed end-for-end, and reinserted until the terminal end of the wire contacts the blades. Upon the next actuation, the apparatus effects the processing operations previously entered and stored electronically for end B. The depths of the cuts, of course, are the same at both ends, corresponding to the mechanically stored values resulting from manual adjustment of the threaded shafts by the operator prior to initial actuation. It will be understood, of course, that the alternating (A and B) sets of parameters may be performed on the ends of two different wires, if desired, rather than on opposite ends of the same wire, provided that the depths of suts be the same in both sequences. 
     Further options are provided by the buttons in the vertical column on the left side of the keypad. Programs (e.g., relating to processing parameters for a particular type of wire) may be stored in and recalled from memory using the top two buttons. The “clamp pressure” button provides the operator with a plurality of choices of the distance of travel of stepper motor  72  to vary the spacing of the clamping jaws in the fully closed position. The “wire guide” button allows entry of values corresponding to the wire guide (a bushing having an opening corresponding to the diameter of the wire to be processed) which is installed at the front of cutting mechanism  44  as described in U.S. Pat. No. 4,993,147; entering this number may assist in locating a previously entered program for the type of wire used with this wire guide and/or may be electronically tied to the “clamp pressure” value to make this pressure correspond automatically to wire diameter. The “blade rotation” button permits the operator to select either clockwise or counterclockwise rotation of the blades. The “blade change” button is pushed to place the elements in position for installation of new blades in the manner of U.S. Pat. No. 4,993,147, and the “password” and “counter” buttons provide means for limiting access to the programming controls and for counting the number of processing operations, respectively. 
     From the foregoing it will be understood that the present invention provides a useful and versatile form of wire processing apparatus with means for electronically storing and automatically performing many processing functions and parameters, although entering a plurality of successive cutting depths is performed entirely manually and stored mechanically. Linear movement of inner carriage  42  between two distinct, forward and rear positions effects radial movement of the cutting blades to cutting depths determined by the operator-adjusted axial positions of a plurality of threaded shafts. The predetermined positions of the inner carriage are established by the number of steps by which stepper motor  68  is indexed, a value which is a permanent, non-adjustable and non-variable part of the permanently installed software of apparatus  10 . Although manual setting of the elements which control the depths of cuts is more time-consuming than entering and storing values electronically, the manual settings are continuously variable, i.e., an analog operation, and not subject to preselected resolution limits of a digital procedure.