Wiring pens
BACKGROUND OF THE INVENTION 
     The invention relates to tools having an elongate pen-shaped body through which, in use, an electrically conducting wire is lead from a supply. The wire is carried by the tool to a tip of the tool where the wire emerges and may be used for wiring together manually electrical components mounted on a circuit board. Such a tool is referred to hereinafter as a wiring pen. 
     In a previously proposed wiring pen, the wire passes through a continuous closed bore in the body from the supply to the tip. When the wire emerging from the tip of the wiring pen breaks, either deliberately or accidentally, it generally does so at the tip. It is a disadvantage of such a previously proposed wiring pen that in order to move the wire forward so that a free end emerges from the tip, the wire must be manually gripped and fed. In addition, a deliberate attempt to break the wire can be frustrated by the breaking effort pulling wire from the supply rather than breaking the wire. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to mitigate the above noted disadvantage. 
     According to the invention there is provided a wiring pen including an elongate pen-shaped body. A bore extends through the body from one end of the body to a tip at the other end of the body for the passage of a wire to the tip. A slot is formed in the body so that the bore leads to one end of the slot and continues from an opposite end of the slot to the tip. A slider is slidable in and along the slot. A tongue is formed on the slider and, in a separated position of the tongue and the slider in which the tongue is spaced from the slider, providing a path between the tongue and the slider for wire to pass to the tip. The slider and the tongue are relatively movable from the spaced position towards one another to close the path and grip the wire therebetween. The slider, in this closed position, is slidable in the slot to move the gripped wire forward to the tip. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     An embodiment of the invention is shown, by way of example, in the accompanying drawings in which: 
     FIG. 1 is a plan view from above of a wiring pen, 
     FIG. 2 is an elevational view of one end of the wiring pen of FIG. 1, 
     FIG. 3 is an elevational view of the other end of the wiring pen of FIG. 1, 
     FIG. 4 is a sectional view of the line Z--Z of FIG. 2, 
     FIG. 5 is a plan view from beneath of the wiring pen, 
     FIG. 6 is a partial perspective view, partially in section, showing a slider of the wiring pen, and 
     FIGS. 7a, 7b, 7c are three partial longitudinal cross-sections of the wiring pen showing together three stages in the operation of the slider. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to FIGS. 1 to 5, the wiring pen includes an elongate body 10 with a pointed tip 11 at one end and a pair of parallel ears 12 having lugs 13 for locating and holding a reel of electrically conducting wire 21 (FIG. 4) at the other end. The body 10 and ears 12 are preferably injection moulded from a plastics material. 
     The body 10 is formed with a bore 15 extending therethrough and a slot 14 extending in the direction of the length of the body 10 and so arranged that the bore leads into one end of the slot and from the other end of the slot (see FIG. 4). The slot has parallel walls and a base and includes a widened portion at the end thereof remote from the tip 11 (see FIG. 4). 
     The slot 14 carries a slider 16 which is formed with two channels 17 in sliding engagement with two guides 18 formed on the body. The upper surface of the slider 16 is provided with a knurled surface which is inclined towards the tip 11 (see FIG. 6). The slider 16 is supported on a tongue 19 formed on the slider 16 and a hole 20 is provided in the connection between the tongue 19 and the slider 16. The channels 17 are so dimensioned as to allow the movement of the slider into and out of the slot 14. As best seen in FIGS. 7a, 7b, 7c, a spring strip 22 extends from the end of the slot 14 remote from the tip 11 into the widened portion of the slot end, in the position shown in the drawings prevents sliding movement of the slider 16 into the widened portion. 
     In use, a wire 23 from the reel of electrically conducting wire 21 is threaded through the bore 15. If the slider 16 is pushed forwards, the wire 23 can be pushed between the under-surface of the slider 16 and the upper surface of the tongue 19, through the hole 20 and through the continuation of the bore 15 to emerge at the tip 11. If, having passed the wire 23 through bore 15 to the slot 14, passage of the wire 23 through the hole 20 is found difficult, the spring strip 22 can be flexed to allow the slider 16 to be slid into the widened portion where it disengages from the guides 18 and can be removed from the slot 14. The wire 23 can then be threaded through the hole 20 and through the continuation of the bore 15 to emerge at the tip 11. The slider 16 can then be replaced in the slot 14 and pressed downwards and forwards over the spring strip 22 to re-engage with the guides 18. The tip 11 may be removable and this will make threading easier in exceptionally difficult cases. 
     The wire 23 is used to connect electrical components on a circuit board (not shown). When the wiring is complete, the slider 16 is drawn back by hand in the direction shown by the arrow 24 in FIG. 7a. The slider 16 is then depressed by manual pressure on the knurled surface and the under-surface of the slider 16 and the upper-surface of the tongue 19 grip the wire. The wire can then be snapped without drawing further wire from the reel. 
     The wire normally snaps at the tip 11. In order to provide a short length of wire at the tip 11 to commence or recommence wiring, the slider 16 is depressed by manual pressure on the knurled surface, as shown in FIG. 7b, to grip the wire between the upper surface of the tongue 19 and the under-surface of the slider 16. The slider 16 is then moved towards the tip 11 by pushing the knurled surface to draw wire from the reel and forward it so that a short length of wire emerges from the tip 11. The slider 16 is then released and the wire is no longer gripped thus allowing wire to be withdrawn from the reel during the wiring operation.