THIS INVENTION relates to a device for tensioning and securing fastening cords, straps, bands, ropes and the like.

More particularly the invention relates to such a device which, according to the scale to which it is made and the material of which it is made, may be used variously for tensioning and securing string or tape binding parcels, straps or ropes binding bundles of items together, or cables or ropes for securing loads on vehicles, for example.

According to the invention there is provided a device for tensioning or taking up slack in a flexible strap or other filamentary element comprising a lever, a drum formation, as herein defined, extending transversely from the lever along a first axis, the drum formation defining a passage for a strap or other filamentary element extending through said drum formation transversely to said axis, said lever carrying a retaining member remote from said drum formation and extending from the lever in the same direction as said drum formation, the arrangement being such that a strap or like filamentary member passed through said passage can be tensioned, or the slack therein taken up, ^* by rotating the device about said axis, by means of said lev-er, to wind the strap or other filamentary member around the drum formation, and said retaining member thereafter engaged with a part of the strap or other filamentary member extending from the drum formation, to prevent reverse rotation of the device about said axis with consequent unwinding of the strap or other filamentary member, and wherein said retain-

ing member incorporates an anti-tamper closure which can be closed around the strap to prevent disengagement of the retaining member from the strap and which closure cannot readily be released once closed, without specialised equip¬ ment or without inflicting obvious damage on the device.

An embodiment of the invention is described below by way of example with reference to the accompanying drawings in which:-

FIGURE 1 is a perspective view showing a device embodying the invention in use in tensioning a strap,

FIGURE 2 is a plan view and FIGURE 3 a side elevation view of the device of Figure 1 ,

FIGURE 4 is a view in section along the line IV-IV in Figure 2 showing an anti-tamper closure closed,

FIGURE 5 is a sectional view, corresponding to Figure 4, but showing the anti-tamper closure open,

FIGURE 6 is a side elevation view of the device, from the opposite side from Figure 3 and

FIGURE 7 is a schematic sectional view of the device in use.

Referring to the drawings, the device comprises an elongate ^" lever arm 10 from which extends, adjacent one free end of the arm 10, a drum formation 12. The drum formation 12 extends along an axis, indicated at 14, which is substantially perpendicular to the longest dimension of the arm 10. The drum comprises a hub portion disposed between two flange portions, namely a flange portion 16 integral with the arm 10 and a flange portion 18 on the opposite end of the drum portion from the flange 16.

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As best shown in Figures 2 and 6, the flange portion 18 and the drum portion are each bisected by a planar -slot 20, the plane of the slot 20 including the axis 14, so that the slot extends diametrically with respect to the axis 14. Thus, each half of the drum portion, with its associated half of the flange portion 18 forms a respective projection projecting transversely from the arm 10, the slot 20 being defined between these projections.

A lashing strap 24 to be tightened can be passed through the slot 20 to extend at right angles to the axis 14 and the device rotated about the axis 14 to wind the lashing strap around the drum portion, in the space between the flanges 16 and 18, in the manner illustrated in Figures 1 and 7.

In order to hold the device in position once the desired tension has been reached, the other end of the lever arm 10 is provided with an integral retaining member 26, adapted to receive and hold the portion of the strap 24 extending from the drum along the side of the arm 10. The retaining member comprises a finger 28, projecting laterally from the arm 10 in the same direction as the drum formation, i.e. substantially parallel with the axis 14, the finger 28 being disposed at the end of the arm 10 remote from the drum formation 12 and being integral with the arm. Hingedly connected to the free end of the finger 28 is a closure plate 30. In use, in its closed position, the closure plate 30 overlies the finger 28, to define, between the finger 28 and closure plate 30, a shallow channel which r-ecei ^' ves the strap 24. In the open position, illustrated in Figure 5, the plate 30 is swung away from the finger 28 to allow the appropriate part of the strap 24 to be placed between the finger 28 and closure plate 30 before the closure plate 30 is swung into its closed position to trap the strap between the finger 28 and closure plate 30.

The closure plate 30 is designed to snap into its closed position in such a manner as to make it impossible or difficult to open the closure plate once again without breaking or physically damaging the retaining member so that, for example, the recipient of a package bound by straps tensioned and secured using a number of devices of the type illustrated will be able to tell readily whether some unauthorised person has opened the package or has attempted to do so.

In the embodiment illustrated, the snap-action is obtained by so designing the retaining formation that, in the closed position, the edge of the closure plate 30 forms a tapering nose or detent which engages under a shoulder or recess formed in the wall of the arm 10 from which the finger 28 projects. The arrangement is such that when the closure plate is swung down towards the arm 28 to trap the strap between the plate 30 and the arm 28, the nose of the plate 30 rides over the adjoining surface of the arm 10, in the manner of a cam, resilient distortion of the device under the forces arising from such camming action allowing the closure plate to move into its closed position where the nose of the plate 30 slips into said recess to be retained therein. The opening 32 as shown in Figure 4 is merely a cavity left by a mould insert, used in moulding the device, to afford the recess or shoulder against which the nose of the locking plate 30 locates.

Since the object of the anti-tamper device is simply to ensure that a clear indication is provided when the tensioning device has been undone, the device is so designed that the structure will withstand the forces arising during normal closure of the closure plate 30 over the strap 24 but will break visibly, rather than simply opening without damage, if, for example, an attempt is made to pry the closure plate 30 open.

It will be clear that various other arrangements may be provided, alternatively, to meet the same objective. Thus, for example, the free end of the closure plate 30 might carry a stud of "harpoon" or "arrow-head" section which, when the closure plate is closed, deforms it sufficiently to pass through corresponding holes formed in the arm 28, the "barbs" of the harpoon or arrow-head studs springing out against the under face of the arm 28 when the closure plate has been fully closed, to prevent re'-opening of the closure plate.

The opposing surfaces of the closure plate 30 and the finger 28, or one or other of these surfaces may be toothed, knurled or ribbed in order to grip the strap 24.

The arm 10 may be used as a handle by which a parcel or bundle of items bound by a strap 24 tensioned by the device may be carried. Alternatively a separately formed handle may be provided integral with the arm 10.

The device illustrated may be made in various sizes, for example a small version 2cm - 3cm long may be used for tensioning and securing parcel string or tape, ^' while a larger version, such as that shown, may be 10cm-12cm long and may be used for securing larger bundles with stouter straps.

The embodiment illustrated is formed as a one-piece injection moulding in a suitable plastics material, such as nylon, but it will be appreciated that variants may be made of metal, for example of steel or aluminium, or of plastics reinforced with glass fibres or carbon fibres.