Abstract:
A device for forming a pointed wire tip on the ends of wires is provided. The device has receiving elements for receiving a wire, and heating device. The device stretches the wire causing the wire to taper and break resulting in the formation of a pointed wire tip at the point of breakage.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a device as well as a procedure for forming a point on the ends of wires. 
     Particularly when retracting wires in wire drawing machines, it is necessary to form a point on the ends of the wires to be retracted so that same can be threaded into the next respective die. 
     A device for forming points on wire tips is already known in which the ends of the wires to be pointed are cold-formed between two rollers. The surfaces of the rollers have slots with increasing groove depth so as to produce a rounded cross-section of a wire end progressing essentially pointed. 
     Forming wire tips with said known device is, however, costly and time-intensive. Moreover, pointed wire tips manufactured with such a device exhibit burrs which are often unwanted. 
     It is thus the task of the present invention to produce a device for forming points on the ends of wires which is economical to manufacture, enables fast and burr-free wire end tips, and which can be flexibly adapted to different wire diameters. 
     The task is solved by a device for the forming of points on the ends of wires in accordance with the present invention. 
     In accordance with the present invention, a device is in particular provided for the forming of points on the ends of wires which comprises a first and a second means for the receiving of a wire, as well as a heating device and a means for stretching the wire according to predetermined conditions. 
     The heating device is preferably configured as an electric resistance heater or electrical heating means. Especially preferred is the heating means comprising at least one first contact point as well as at least one second contact point, respectively at least one first pole and at least one second pole. Said poles are preferably connected to a transformer. By means of these poles, hereinafter referred to as contact points, each heating means comes into contact with one respective section of the wire to be pointed. Hereby, a voltage drop occurs between said contact points, meaning especially within said wire, so that a current flows through the conductive wire, thereby inducing a heating of the wire in the section between the contact points. 
     According to the present invention, the heating means may also be of a different configuration. 
     The wire is braced against the first as well as the second receiving means. Said first and/or second receiving means respectively preferably comprises a clamping means in which the wire is clamped. Said clamping means can be configured as clamping pliers or be disposed with a rotatable, wedge-shaped disc as well as an adjustable lever having a conical point, whereby said disc is particularly configured as a tractive disc. Said tractive disc can preferably be operated either manually, or by a drive means comprising a motor, or in some other way. The clamping means may also be of a different configuration. 
     The heating device is such designed and arranged that the wire becomes heated between the first and the second receiving means. 
     Preferably, said first electrical contact point of said electrical heating means, respectively resistance heater, is disposed on said first receiving means and said second electrical contact point of said electrical heating means, respectively resistance heater, is disposed on said second receiving means. 
     It is also preferred that said electrical contact points are not disposed on said first receiving means or said second receiving means, which preferably are provided with clamping means for clamping the wire, or that only one of said receiving means has an electrical contact point. 
     According to the present invention, a further means is provided which stretches the wire in the heated section according to predefined conditions, in particular doing so in a longitudinal direction to the wire axis. 
     Especially preferred is using the inventive device as follows: By means of the heating device, configured in particular as a resistance heater, a section of wire in an area between the first and the second receiving means is heated. To this purpose, it is especially provided that the poles, respectively electrical contact points of said resistance heater are arranged on said first receiving means as well as on said second receiving means. The wire is preferably heated long enough to reach incandescence. During this heating or after having been heated, a means is utilized to stretch the wire in the heated section. 
     The first and the second receiving means, respectively the first and the second contact point, are preferably arranged to be relatively movable with respect to one another. 
     Especially preferred is that the first receiving means, respectively the first electrical contact point, is fixedly arranged and the second receiving means, respectively the second electrical contact point, is arranged to be rotatable or axially displaceable. The second contact point is particularly preferably arranged on the second receiving means such that upon axial mobility, said receiving means likewise displaces axially and upon rotation, the second receiving means follows a circular path. 
     This stretching of the heated, respectively incandescent section, can in particular induce that the wire initially tapers and ultimately breaks off. This tapering, respectively breaking off, results in a pointed wire tip. The configuration of the pointed wire as well as the length of the pointed segment can be influenced in different ways. For example, by varying the distance between the electrical contact points or the voltage of the resistance heater, respectively the temperature which the heating means generates in the wire, or the length of heating time, in particular in conjunction with the magnitude and duration of the force generated in the wire, or in other ways. 
     Preferably, the first contact point is arranged on a clamping member of said clamping means of said first receiving means such that the electrical contact point is pressed against the wire when the clamping member stresses the wire. 
     It is preferred, in corresponding manner, that a second contact point is arranged on a second clamping member of said clamping means of said second receiving means. 
     The clamping member is preferably disposed with a threading in which it is led. 
     It is preferred that said first receiving means and/or said second receiving means is configured as a clamping means and in fact in such a way that wires of different diameters or wires having differing cross-sectional geometries may be clamped. 
     The device according to the present invention can be used for forming points on various types of wire materials such as, for example, superconductor, CrNi, German silver, or wires made from other types of material. 
     The inventive device can furthermore be used with wires having different cross-sectional profiles such as triangular, rectangular, polygonal, or rounded or other cross-sectional profile configurations. 
     The inventive device may be integrated in a wire drawing machine or may be a separate device which, for example, can be moved on rollers or by other similar means. 
     The inventive device can in particular be used to form points on wires which are drawn in rough drawing processor, whereby the wire diameter is preferably between a range of 2 mm-8 mm. The device according to the present invention is however also preferred for wires of other diameters. 
     The second receiving means, which is preferably disposed with a second electrical contact point, is movable relative the first receiving means via a drive means such as a motor or the like, or manually. 
     SUMMARY OF THE INVENTION 
     The present invention especially provides for heating a wire at a predetermined section and particularly in such a manner that it glows reddish and is subsequently stretched in at least the area of this section in the longitudinal direction of the wire axis such that the wire initially tapers and ultimately breaks off, forming a pointed tip at the end of the wire. 
     In a particularly preferred procedure of the present invention, the wire is heated by means of an electrical resistance heater. 
     In a preferred procedure of the present invention, the wire is clamped between two points separated by a clearance and is heated in the (or in one) intermediate region between said two points. The wire is then subsequently stretched, wherein one clamping point is moved relative the other clamping point. This induces the wire to taper and break off, forming a pointed wire tip. 
     The present invention is not to be limited by either its preferred embodiments nor by the examples as given. 
     In the following, the invention will be described in greater detail using exemplary, nonrestricting embodiments of the present invention, which show: 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a schematic view of an exemplary inventive embodiment; 
     FIG. 2 a sectional view along the  2 — 2  line from FIG. 1; 
     FIG. 3 a sectional view along the  3 — 3  line from FIG. 1; and 
     FIG. 4 a sectional view along the  4 — 4  line from FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows an inventive device  1  for forming a point on the ends of wires comprising a housing  10 , a first receiving means  12  as well as a second receiving means  14 . A wire to be pointed is received in the respective area suggested by dashed lines  16 ,  18 , respectively  20 ,  22  of said first receiving means  12 , respectively said second receiving means  14 , and extends between said areas. 
     The first receiving means  12  comprises a first clamping member  24 . Said first clamping member  24  is led (which is not shown in FIG. 1) into a threading and has radial cantilever arms  26 ,  28 ,  30 ,  32 , which serve to facilitate operability. 
     The second receiving means  14  comprises a second clamping member  34 , likewise led (not depicted in FIG. 1) into a threading and having radial cantilever arms  36 ,  40 ,  42 ,  44 . 
     Said second receiving means furthermore comprises a disk-shaped support  46  which is rotatably mounted on a swivel joint  48 . 
     Electrical contact points are respectively arranged on said clamping members  24 ,  34 , said contact points being connected to a transformer. When an electrical voltage is applied to the contact points, the (not shown) wire is heated at a section between the first receiving means  12  and the second receiving means  14 . During this heating or subsequent to this heating, lever  50  can turn in the rotational direction indicated by arrow  52 , which induces a rotation of the disk-shaped support and thus a change in the distance of clamping member  34  from clamping member  24 . When the wire reaches a suitable temperature, the rotational motion induces a stretching of the wire without a large application of force, whereby the wire profile tapers and breaks off, forming a pointed tip at the end of the wire. 
     FIG. 2 shows a sectional representation along the  2 — 2  line from FIG. 1 in revolved view. 
     Said first clamping member  24  is connected to component  64  by means of threading  60  as well as by means of counter-threading  62 . A rotation of component  24  about its axis induces that, upon the corresponding rotational direction, facing end  66  of said first clamping member  24 , functioning as a clamping jaw, is moved toward surface  68  functioning as a counter clamping jaw. Facing end  66  is furthermore an electrical contact point which is connected (not shown) to a transformer. 
     The wire to be pointed can be received, respectively clamped, in the intermediate region  70  between said facing end  66  and said surface  68 . 
     FIG. 3 shows a sectional view along the  3 — 3  line from FIG. 1 in partial sectional view. 
     The second clamping member  34  comprises a threading  80  at its outer periphery, which extends into a threading  82  of component  84  so that upon the corresponding rotational direction, facing end  86  of said second clamping member  34 , which also functions as a second electrical contact point, moves toward surface  88  so that the wire arranged in intermediate region  90  between said facing end  84  and said surface  86  can be clamped. 
     FIG. 4 shows a sectional view along the  4 — 4  line from FIG.  1 . 
     FIG. 4 depicts in particular the rotational mounting of disk-shaped support  46 . 
     Said disk-shaped support comprises a first plate  100  as well as a second plate  102  which are non-rotatably coupled together by means of connecting elements such as screws  104 . 
     Second plate  102  has a through opening  106  into which a cylindrical end  108  of component  110  extends. Component  110  is non-rotatably connected to housing  10  by means of the appropriate mounting, such as screws  112 . 
     It is to be noted that other configurations for the rotatable mounting of support  46  are also preferred. 
     List of Reference Numerals 
       1  inventive device 
       10  housing 
       12  first receiving means 
       14  second receiving means 
       16  dashed line 
       18  dashed line 
       20  dashed line 
       22  dashed line 
       24  first clamping member 
       26  radial cantilever arm 
       28  radial cantilever arm 
       30  radial cantilever arm 
       32  radial cantilever arm 
       34  second clamping member 
       36  radial cantilever arm 
       38  radial cantilever arm 
       40  radial cantilever arm 
       42  radial cantilever arm 
       46  disk-shaped support 
       48  swivel joint 
       50  lever 
       52  arrow 
       60  threading 
       62  counter-threading 
       64  component 
       66  facing end 
       68  surface 
       70  intermediate region 
       80  threading 
       82  threading 
       84  component 
       86  facing end 
       88  surface 
       90  intermediate region 
       100  first plate 
       102  second plate 
       104  screw 
       106  opening 
       108  cylindrical end 
       110  component