METAL TIE
The invention relates to a tie formed of metal and use¬ ful, for example, 'for tying together a bundle of cables or other elements.
Cable ties formed of plastics material are known,such a tie comprising a strap portion provided on one side with a series of transverse ratchet serrations, and an aper¬ tured head at one end of the strap: the strap is passed around the bundle of cables to be tied and the free end of the strap is passed through the head for a pivoted pawl within the head-aperture to interlock with the rat¬ chet serrations on the strap. Although these plastics ties have been satisfactory for their purposes, there are situations where metal ties are needed.
In accordance with this invention, there is provided a metal tie, comprising an elongate strip of metal which is formed with apertures at intervals along its entire length, and a metal head member attached to one end of said strip, the head defining an aperture for the free end of the strip to be passed through and having a tang which projects at an angle across the head-aperture and in the direction of insertion of the free end of the strip, such that the tang will locate into the apertures of the strip and prevent retraction of the strip from the head.
in a preferred embodiment of this metal tie, the head- aperture extends in the lengthwise direction of the strip
so that the free end of the strip is inserted through the head-aperture flat against the portion of strip which is. adjacent the head.
The metal tie of this invention has the particular advan- tage that its apertured-strip may be cut to required len¬ gth (either in the factory of by the user) from a reel or other supply of the apertured strip material of inde¬ finite length, then have the head member attached to one of its ends. This attachment may be effected by welding, or simply by inserting one end of the strip through the head and bending it back on itself to lock to the head.
Embodiments of this invention will now be described by way of examples only and with reference to the accompany¬ ing drawings, in which:
FIGURE 1 is a plan view of one embodiment of metal tie, on an enlarged scale;
FIGURE 2 is a longitudinal section through the tie on the line II-II of Figure 1;
FIGURE 3 is a cross-section of the tie on the line III- III of Figure 1;
FIGURE 4 is a longitudinal section through the head member of the tie, showing attachment to the apertured strip by passing the latter through the head and simply bending it back on itself;
FIGURE 5 is a cross-section similar to that of Figure 3, but showing the head member attached to the apertured strip the other way up;
FIGURE 6 is a plan view of a portion of apertured strip with modified shape to its apertures; and
FIGURE 7 is a plan view of a modified head member having strengthening ribs and two locking tangs.
Referring to the drawings, there is shown a tie formed of steel.and comprising an elongate, flexible strip 10 of 0.01 inch (0.25mm) thickness and 7mm width and formed with identical transverse, rectangular apertures 12 at regular intervals.along its entire length, the tie fur¬ ther comprising a head 14 attached to one end of the strip 10. The head 14 defines an aperture 1'6 for the free end 15 of the strip to be passed through it in the direction indicated by the arrow: in the example shown this direc¬ tion is parallel to the length of the strip and such that the inserted, free end of the strip will lie flat against the head-end portion of strip.
The head is formed from strip or sheet steel bent to define the aperture. From one wall of the head, a tang 18 is pressed out to lie at an angle, inclined across the aper¬ ture and extending generally in the strip-insertion direc¬ tion. In the example shown, the tang is pressed out from a wall of the head which lies parallel to and is spaced from the head-end portion of the strip, i.e. a wall of the head which is on the opposite side of the aperture 16 from the strip. Also in the example shown, the head is formed from a separate strip of steel which has been bent into generally rectangular shape (Figure 3) and had its end portions welded to the main strip 10 on its under¬ side.
In use of the metal tie shown in Figures 1 to 3, the strip 10 is passed around the bundle of cables (or other element or elements) to be tied and its free end 15 is passed thro¬ ugh the head aperture 16 in the direction of the arrow in Figures 1 and 2. Initially the extreme end of the strip 10 strikes the tang 18, applying pressure to the tang to
deflect it sufficiently to allow the strip 10 to be advan¬ ced. The extreme end of the tang then presses against and slides over the surface of strip 10, until tfre first aperture 12 of strip 10 reaches the tang. Under the influ- ence of its own slight springiness, the tang locates into tiiis aperture 12, but is then deflected away again when the trailing edge vof that aperture strikes the tang. This sequence repeats for the successive apertures 12 until the tie has been tightened as required. Then, if any force is applied to withdraw the strip 10 from the head in the opposite direction, tang 18 will locate in an aperture (if it is not already so-located) and the trailing edge of that aperture will strike the tang and ride up the rear surface 18a of the tang: the tang will now effecti- vely lock the strip 10 against withdrawal.
The metal tie is designed and intended so that the strip 10 may be cut to length from a reel or like supply of aper¬ tured strip material of indefinite length, then have the separate head member attached to it. The attachment may be effected by welding as mentioned above and may be carried out either in the factory, or in the field by the user. Alternatively, and as shown in Figure 4, the attachment may be effected by inserting the one end of the strip (duly cut to required length) through the head and simply bend- ing it back on itself to lock to the head. This form of attachment may again be carried out either in the factory by the manufacturer, or in the field by the user.
Figure 5 shows an alternative mode of attaching the head member to the strip, wherein the head is turned the other way up and its main wall (from which the tang 18 projects) is welded to the upper side of the strip.
The tie is not limited to the dimensions mentioned above
for the examples shown in Figures 1 to 5. For example, the apertures 12 may be closer together to provide finer adjustment of the tie when tied. The aperture 12 may be rounded at their opposite ends 12a_ as shown in Figure 6: this is found to improve the tensile strength of the strip relative to a strip having apertures with sharp corners. For some applications, a wider strip may be required: in this case, the head may be strengthened by the provi¬ sion of longitudinal ribs 20 as shown in Figure 7 and two tangs 18 may be provided one after the other.
In all examples, the strip 10 and the head member may be coated with a polymeric material to protect the user's hands, and the tied cables, from any sharp edges of the metal elements, and also as protection against corrosion.