Abstract:
In order to give the device proposed for preparing electric wires and/or cables for installation a sensitive feel, it is designed with two outer grips ( 1,2 ) disposed opposite each other and at least one inner arm ( 3,4 ) mounted on one of the outer grips ( 1,2 ). A link element ( 50 ) holds the first outer grip ( 1 ) by a first bolt ( 6′ ), the second outer grip ( 2 ) by a second bolt ( 9′ ) and the inner arm ( 3,4 ) by at least one additional bolt ( 7′,8′ ) located in the link element ( 50 ) between the first and second bolts ( 6′,9′ ). A multiple joint ( 5 ) of this kind enables both of the outer grips ( 1,2 ) and their associated inner arms ( 3,4 ), together with their tool parts ( 11,12; 13,14; 15,16 ), to be pressed against each other and for the outer grips ( 1,2 ) to be moved different distances towards each other and also different distances with respect to the inner arm ( 3,4 ).

Description:
BACKGROUND OF THE INVENTION 
     The present invention concerns a wire stripper comprising at least two legs fastened together at one end by a pivot like the legs of a pair of tweezers. The pivot is complex and comprises at least two pins accommodated in an intermediate component. There is one tool component at at least the other end. 
     A device of this genus is known from DE 42 21 500 C1. It comprises two legs fastened together like the legs of a pair of tweezers by a double articulation. Wire-cutting components are positioned at the free end of the legs remote from the articulation. 
     This device has been proven effective. Still, in order to remove the insulation from the wire, so much force must be applied to slide the insulation off with the legs squeezed together as to render the overall procedure difficult. Furthermore, thin wires can be torn apart. 
     Wire-stripping pliers are known from WO 90/10 323 A1. They comprise an upper and a lower leg, each of which merge at one end into a handle. The upper leg accommodates a holder that holds one wire-cutting component. The other wire-cutting component is mounted on the lower leg. There is a drawback to these pliers. The wire-cutter holder executes a translation when the handles are squeezed together, which makes it difficult to work with a fine touch. 
     There is accordingly a need for an improved device of the aforesaid genus that will allow reparation of electrical wires and cables with a fine touch during installation. 
     SUMMARY OF THE INVENTION 
     According to the invention, the legs are first and second outer legs secured to the intermediate component by first and second pins, one of outer legs accommodating a working leg which is secured by an additional pin between the first and second pins to form a complex articulation that allows the two outer legs to be squeezed together with the working legs inside and with their working components together. 
     The particular advantages of the present invention derive from the squeezed-together outer legs applying all the force necessary as they move toward each other. The working leg, articulated at the complex articulation between the outer legs, is accordingly “supported” in its execution of the same motion. The complex articulation is a triple articulation. Between one of the outer legs and the working leg, the distance between the pins associated with the outer legs and the pins associated with the working leg as part of a lever. It is accordingly possible to apply the forces needed while the working leg is moving with a fine touch and with exactness. 
     There are two possible types of working leg. It can be either an inner leg or an inner-leg piston. 
     If the working leg is an inner leg, it will have at least one guidance recess and travel along a guidance recess in the first outer leg (the upper leg). The inner leg and the first outer leg will accordingly act as one leg when both legs are held like the legs in a pair of tweezers and when the two outer legs are squeezed together. If on the other hand a sliding motion is executed, both legs will act as separate components. If only the inner leg does the work, the complex articulation can be a triple articulation. 
     This action is exploited when the tool components function like the wire-cutting components in a wire stripper. In this event, one wire-cutting component is mounted with a gripping jaw facing it on the opposing end of the inner leg, with a third pin extending through that end, and the other wire-cutting component with another gripping jaw facing it on the opposing end of the other outer leg. The inner leg will not, as it slides along with the adjacent outer legs, slide as far in relation to the second outer leg (the lower leg) as the (upper) outer first leg does in relation to it. The actual removal of the cylinder of insulation from the wire will be carried out by the (lower) second outer leg and the inner leg. 
     To ensure smooth relative motion on the part of the legs, the second leg accommodates a cog, part of which has a curved leg guidance surface. 
     The cog can engage a leg-guidance recess in the inner leg. 
     The inner leg can, in accordance with its intended function, be either an insulation-removal leg or an insulation slide-off leg. In this event the legs will differ in length by a specific increment, the insulation-removal leg being longer than the insulation slide-off leg. In this event, as the insulation-removal leg slides, the separated cylinder of insulation will entirely slide off the wire. In contrast, the insulation slide-off leg will slide the separated insulation along the wire and away from the point of incision without removing it. Since the separated cylinder of insulation remains on the wire, this approach is especially appropriate for strands. The section of cylinder remaining on the wire can be used to twist the strands for later connection. This method will protect the fingers more effectively than known methods can. 
     It will be of advantage for at least part of one leg-guidance opposing surface on the insulation slide-off leg to be beveled. This will allow effective application of the force-times-distance relationship to the displacement of the separated cylinder of insulation. 
     If the working leg is an inner-leg piston, it can be secured in the second outer leg by a guidance piston. The guidance piston will effectively travel forward in a slot or similar structure inside the outer leg as the two outer legs slide relative to each other. If only the inner-leg piston is involved, the complex articulation can be a triple articulation. 
     If on the other hand an appropriately designed inner leg is employed along with the inner-leg piston, the complex articulation will be a quadruple articulation. A quadruple articulation can also act like a triple articulation if an outer leg is appropriately combined with an inner leg or inner-leg piston. 
     The inner-leg piston can accommodate at least one crimping plunger. The squeezing plunger can enter at least one crimping bushing accommodated in one wall of the second outer leg. The result is a crimping tool that can be used to crimp bushings inserted over the free ends of the stripped wire. The lever reduction ensures that both the crimping and insulation stripping can be executed both forcefully and with a fine touch. 
     The crimping bushings are components of a guidance rod that bridges the walls of the second outer leg. The guidance rod extends through guidance recesses in the inner-leg piston. The crimping bushings are engineered such that the guidance rod is a solid cylinder. A bore is bored in one end of the rod and then slit to allow the particular crimping plunger to force bushings inserted in the round recess against the wire. 
     There is a moving surface on the opposing free end, which a fourth pin extends through, of the inner-leg piston that moves against a separating knife in one wall of the second leg. 
     Since the moving surface can be forced forward by the inner-leg piston, it constitutes in conjunction with the separating knife a line-or-cable cutting mechanism. The inner-leg piston, secured by the fourth pin, moves forward, like the inner leg, slower than the two outer legs in all its operations. The fourth pin between the pins associated with the first and second outer legs allows a fine touch and forceful motion of the inner-leg piston. 
     To facilitate movement of the two outer legs with respect to each other, these legs are provided with gripping elevations and gripping depressions for the thumb on one side and for the fingers on the other. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     One embodiment of the present invention will now be specified with reference to the accompanying drawing, wherein 
     FIG. 1 is a schematic perspective illustration of a wire stripper with a quadruple articulation, 
     FIG. 2 is a schematic perspective illustration of the wire stripper illustrated in FIG. 1 disassembled and exploded, 
     FIGS. 3 through 5 illustrate the wire stripper illustrated in FIG. 1 at various stages of operation, and 
     FIG. 6 illustrates a stranded wire being processed with an insulation slide-off leg. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The wire stripper illustrated in FIG. 1 comprises two outer legs  1  and  2 , an inner leg  3 , an inner-leg piston  4 , and a quadruple articulation  5 . Quadruple articulation  5  is designed with an intermediate component  50  articulatedly accommodating outer leg  1  in a bearing  6 , inner leg  3  in a bearing  7 , inner-leg piston  4  in a bearing  8 , and outer leg  2  in a bearing  9 . 
     A spring  10  inserted in intermediate component  50  rests against the inner surface of outer leg  2  to secure components  1  through  4  in their tweezers-like disengaged position. Outer legs  1  and  2  are concave halves accommodating at least inner leg  3 , inner-leg piston  4 , and quadruple articulation  5 . 
     The aforesaid individual components of the wire stripper will now be specified with reference to FIG.  2 . 
     Outer leg  1  is, as specified hereintofore, at least partly concave and accommodates an outer-leg recess  23 . The front of outer leg  1  is provided with an inner-leg accommodation recess  30  that matches the cross-section of inner leg  3 . Behind inner-leg accommodation recess  30 , at least one guidance component  25  and  26  extends into outer-leg recess  23 . 
     The guidance component can be a web, a rail, a bolt, or a similar structure. Mounted on the forwardmost third of its outer surface is a gripping elevation  36  with a gripping depression  38  sloping gently away from the front of it. Gripping elevation  36  and gripping depression  38  facilitate operation of the wire stripper. Facing each other in the wall of the rear of outer leg  1  are two bores  6 ″ for accommodating bearing  6 . 
     Illustrated below outer leg  1  are two different embodiments of inner leg  3 , one of them in the form of an insulation-removal leg  31  and the other in that of an insulation slide-off leg  32 . 
     The front of each leg  31  and  32  is provided with a wire-cutting component  11 . 1  and  11 . 1 ′. In front of each component  11 . 1  and  11 . 1 ′ is a gripping jaw  12 . 1  and  12 . 1 ′. Behind each component  11 . 1  and  11 . 1 ′ and within each leg  31  or  32  is at least one guidance recess  27  and  28  or  27 ′ and  28 ′ in the form of a longitudinal groove. The guidance components  25  and  26  in outer leg  1  engage and guide recesses  27  and  28  or  27 ′ and  28 ′. The particular inner leg  3  in outer leg  1  is accordingly secured and guided. Approximately half-way along each leg  31  and  32  is a leg-guidance recess  22  and  22 ′. A bore  7 ″ that accommodates bearing  7  extends through the end of each leg  31  and  32 . Legs  31  and  32  at least to some extent match the recess  23  in outer leg  1 . 
     With respect to design and shape, accordingly, insulation-removal leg  31  is similar to insulation slide-off leg  32 . They differ, however, in length, with insulation-removal leg  31  being an increment D longer than insulation slide-off leg  32 . The length of increment D depends on the particular application. Another difference is that the leg-guidance opposing surface  29 ′ on insulation slide-off leg  32  is at least partly beveled or curved. The leg-guidance opposing surface  29  on insulation-removal leg  31  on the other hand has only a straight rounding off of its leg guidance recess  22 . 
     Inner-leg piston  4  is illustrated below the two embodiments of inner leg  3 . It is made of plastic and is essentially rectangular in section. Mounted in the middle are guidance recesses in the form of slanting guidance slots  17 . 2  and  18 . 2 . Slanting at the same angle in the vicinity of these slots are plunger-holding components  15 . 3  and  16 . 3 . Each accommodates a crimping plunger  15 . 2  and  16 . 2 . At the front, the body of inner-leg piston  4  merges into a guidance piston  34 . Mounted on its free end is a motion separating surface  14 . Motion-separating surface  14  is of metal and can accordingly be machined. If the entire inner-leg piston  4  is made of metal in contrast to the other function-defining components of the wire stripper, motion separating surface  14  will be part of it. If inner-leg piston  4  is plastic as far as guidance piston  34 , motion-separating surface  14  will be part of an inserted metal piece. Crimping plungers  15 . 2  and  16 . 2  are also metal and, if inner-leg piston  4  is metal, will be part of it. If, on the other hand, plastic is employed, the particular crimping plunger  15 . 2  or  16 . 2  will be inserted in the also plastic plunger-holding components  15 . 3  and  16 . 3 . Mounted on the end of inner-leg piston  4  toward motion-separating surface  14  is a bore  8 ″ for accommodating bearing  8 . 
     Outer leg  2  is illustrated below inner-leg piston  4 . 
     Outer leg  2  is also at least partly concave and has an outer-leg recess  24 . Accommodated in the front of outer leg  2  is the cutter  11 . 2  of the wire-stripping tool  11 . In front of it is a gripping jaw  12 . 2 . The cutter of a jacket-removing tool can in particular be positioned behind cutter  11 . 2  as well as on the opposing outer leg  1 . 
     A transverse web extends through outer leg  2 . A separating knife  13  is accommodated in outer leg  2  behind its wall  2 ′. Separating knife  13  constitutes in conjunction with the motion separating surface  14  on inner-leg piston  4  a cable cutter. Approximately in the middle is a guidance inner-leg recess  35 . Matching recess  35  is a guidance web  35  mounted on insulation removal leg  31  or insulation slide-off leg  32 . 
     Behind guidance inner-leg recess  35  is a cog  21 . One side of cog  21  has an at least partly curved leg-motion guidance surface  20 . The leg-motion guidance surface  20  on cog  21  travels over a specially designed leg-guidance opposing surface  29  on the insulation slide-off leg. Next to cog  21  is an equally high guidance surface  19 . Guidance surface  19  is slightly curved. Guidance surface  19  and guidance inner-leg recess  35  constitute part of a sliding surface as the individual legs move and hence facilitate the sliding motion of the wire stripper. 
     Accommodated in wall  2 ′ behind components  19  and  21  is a sloping recess. In this vicinity, walls  2 ′ extend between guidance rods  17 . 1  and  18 . 1 . Opposing these guidance rods, inner-leg piston  4  moves in such a way that crimping plungers  15 . 2  and  16 . 2  travel over the sloping recess. Crimping plungers can enter crimping bushings  15 . 1  and  16 . 1 . Crimping plungers  15 . 2  and  16 . 2  are designed with the solid guidance rods  17 . 1  and  18 . 1  bored and accordingly slotted. The advantage of this design is that the crimping bushings  15 . 1  and  16 . 1  cannot be displaced at an angle during crimping. A bore  9 ″ for accommodating bearing  9  extends through end of outer leg  2  facing wire-cutting component  11 . 2 . Inner-leg piston  4  can be inserted in the resulting outer-leg recess  24 . 
     All components, except for the wire-stripping tool,  11 . 1 ,  11 . 2  cable cutter,  13 ,  14  crimping tools  15 . 1 ,  15 . 2 ,  16 . 1 ,  16 . 2 , pin bearings  6 - 9 , and spring  10 , are plastic. The use of plastic facilitates molding the specially shaped parts of the individual legs. A specially hardened steel is used for the excepted components. The other components can made of iron, brass, copper, or even a hard plastic. 
     Intermediate component  50  is illustrated next to inner-leg piston  4 . Bearing-accommodation bores  7 ″,  8 ″, and  9 ″ extend through intermediate component  50 . Spring  10  is accommodated in one wall of this component  50 . The end of intermediate component  50  that can be inserted into outer leg  2  is rounded. The other end is rounded off merging into a straight surface. Outer leg  1  can rest on the straight surface. Although intermediate component  50  can be solid, the illustrated embodiment is hollow and open along one side. 
     How the wire stripper is assembled will now be specified. Inner leg piston  4  is inserted into lower outer leg  2 . Intermediate component  50  is then inserted into recess  24  of outer leg  2  and the pin  9 ′ is inserted into the bore  9 ″. Inner-leg piston  4  is now connected to intermediate component  50  by inserting pin  8 ′ 0  through bore  8 ″. 
     Outer leg  1  is now positioned on intermediate component  50  and connected to it by inserting pin  6  into bore  6 ′. 
     Since there are three possible embodiments of inner leg  3 , the insulation-removal leg  31  in one can now be connected to intermediate component  50  by inserting pin  7  into bore  7 ′. If this connection is to be permanent, insulated wires can now be stripped of insulation with the wire-stripper. 
     Insulation slide-off leg  32  can also be connected instead of insulation-removal leg  31  to intermediate component  50  by inserting pin  7  into bore  7 ′. This version makes it possible in particular to prepare stranded wires for connection. 
     To make the wire stripper more universal in application, insulation removal leg  31  and insulation slide-off leg  32  can be alternatively connected to intermediate component  50 . 
     How the wire stripper works will now be specified with reference to FIGS. 3 through 6. 
     Insulation slide-off leg  32  is employed for inner leg  3  in the wire stripper illustrated in FIG.  1 . In the initial state with all the legs opposing one another like the legs of a pair of tweezers, the point of insulation slide-off leg  32  extends out of inner-leg accommodation recess  30 . Wire-cutting components  11 . 1 ′ and  11 . 2  rest parallel with their gripping jaws  12 . 1 ′ and  12 . 2  forward. 
     The motion separating surface  14  of inner-leg piston  4  is separated from separating knife  13 , as are crimping plungers  15 . 2  and  16 . 2  separated from the crimping bushings  15 . 1  and  16 . 1  on crimping tool  15  and  16 . This state will be evident from FIG.  3 . 
     If the adjacent legs are now squeezed together, the point of the rounded leg-motion guidance surface of cog  21  will come to rest against the appropriately prepared leg-guidance opposing surface  29 ′. Its sloping position and slight roundness will bring blades  11 . 1 ′ and  11 . 2  together. Leg-motion guidance surface  20  of the cog  21  will move along leg-guidance opposing surface  29 ′. This operation will cut through a cylinder  41  of insulation around a stranded wire  40  while leaving the strands  42  intact. 
     Outer legs  1  and  2  are reliably secured in gripping depressions  38  and  39  and forced forward and toward each other by thumb pressure against gripping elevation  36 . During this displacement, outer legs  1  and  2  travel farther toward each other than in relation to the insulation slide-off leg  32  and inner-leg piston between them. Since bearing  6  is farther away from bearing  9  than they are from the bearings  7  and  8  between them, the powerful sliding motion of the outer legs is transmitted with a fine touch to insulation slide-off leg  32  and inner-leg piston  4 . The different paths traveled by the legs will be evident in that insulation slide-off leg  32 , previously extending out of upper outer leg  1 , is now entirely inside it. The sliding motion of insulation slide-off leg  32  in relation to outer leg  2  is facilitated by the friction bearing provided for the outward-facing guidance web  35 ′ by guidance surface  19 . The guidance web  35 ′ in guidance-leg recess  35 ′ also ensures correctly aimed forward motion on the part of insulation slide-off leg  32 . Controlled displacement of insulation slide-off leg  32  in outer leg  1  is ensured by the guidance components  25  and  26  sliding in guidance recesses  27 ′ and  28 ′. 
     Once the final displacement state is attained, the cylinder of insulation separated at the area of incision from the rest of the insulation is displaced as illustrated in FIG. 6 from strands  32  by a specific length determined by the distance from bearing  7  at cutter  11 . 1 ′. Since the trimmed end of cylinder  41  of insulation has not been entirely slid off strands  42 , it can be exploited to twist the strands. This eliminates the often very painful twisting with the thumb and fingers. Once the strands have been twisted, the trimmed end of cylinder  41  of insulation is drawn off manually. A bushing can now be slipped over the twisted end and secured with crimping tool  15  and  16 . The crimping is executed by displacement of outer legs  1  and  2 . In the final state, illustrated in FIG. 5, crimping plungers  15 . 2  and  16 . 2  extend far enough into crimping bushings  15 . 1  and  16 . 1  to ensure proper crimping. 
     A displacement of outer legs  1  and  2  in relation to each other and hence also of inner-leg piston  4  in relation to outer leg  2  allows separating knife  13  and motion-separating surface  14  to cut through wire and cable. 
     If insulation-removal leg  31  is employed instead of insulation slide-off leg  32 , the motion of outer legs  1  and  2  in relation to insulation-removal leg  31  and inner-leg piston  4  will occur as hereintofore specified. Since, however, insulation removal leg  31  is increment D longer than insulation slide-off leg  32 , leg  31  will travel farther than lower outer leg  2 . The trimmed-off cylinder  41  of insulation will be entirely removed from the strands  42  below a one-piece wire and accordingly ready to connect. 
     REFERENCE NUMBERS 
       1 . outer leg 
       2 . outer leg 
       2 ′. wall 
       3 . inner leg 
       4 . inner-leg piston 
       5 . quadruple articulation 
       6 ,  7 ,  8 , &amp;  9 . bearings 
       6 ′,  7 ′,  8 ′, &amp;  9 ′. pins 
       6 ″,  7 ″,  8 ″, &amp;  9 ″. bearing bores 
       10 . spring 
       11 . wire-stripping tool 
       11 . 1  &amp;  11 . 1 ′. cutter of the wire stripping tool 
       11 . 2 . cutter of the wire stripping tool 
       12 . 1  &amp;  12 . 1 ″. gripping jaw 
       12 . 2 . gripping jaw 
       13 . separating knife 
       14 . motion-separating surface 
       15  &amp;  16 . crimping tool 
       15 . 1  &amp;  16 . 1 . crimping bushing 
       15 . 2  &amp;  16 . 2 . crimping plunger 
       14 . 3  &amp;  16 . 3 . plunger-holding component 
       17 . 1  &amp;  18 . 1 . guidance rod 
       17 . 2  &amp;  18 . 2 . guidance slot 
       19 . guidance surface 
       20 . leg-motion guidance surface 
       21 . cog 
       22  &amp;  22 ′. leg-guidance recess 
       23  &amp;  24 . outer-leg recess 
       25  &amp;  26 . guidance component 
       27  &amp;  27 ′ and  28  &amp;  28 ′. guidance recess 
       29  &amp;  29 ′. leg-guidance opposing surface 
       30 . inner-leg accommodation recess 
       31 . insulation leg 
       32 . insulation slide-off leg 
       33 . jacket-removal tool 
       34 . guidance piston 
       35 . guidance-leg recess 
       35 ′. guidance web 
       36  &amp;  37 . gripping elevation 
       38  &amp;  39 . gripping depression 
       40 . strands 
       41 . cylinder of insulation 
       42 . core 
       50 . intermediate component 
     D. length increment