Patent Description:
Prior art cable tie arrangements have a periodic arrangement of raised elements which extend along the length of a strap. These raised elements engage an extension in a locking head to bundle cables or similar in a ratchetting manner. However, as the tension in the strap is determined by the spacing between the raised elements this results in poor or loose bundling.

Document <CIT> discloses tie-wraps of practically infinite length that can be cut to any desirable size at the time of use. To use the tie-wrap, the user cuts a piece from the flexible strap bundle and inserts its ends into a locking part and pulls one or both ends of the strap until it is tightly wrapped around the object. In some embodiments the ends of the strap may enter the locking part from one side or from multiple sides. The locking part or the strap may have a single pawl or multiple pawls which are made of plastic, metal, or other materials.

The present invention seeks to address at least some of these issues.

Aspects of the invention are set out in the independent claim. Dependent claims describe optional features.

According to a first aspect of the invention, which is defined in claim <NUM>, there is provided a cable tie arrangement for bundling one or more elongate members, the cable tie arrangement comprising:.

Advantageously, the planar surface has a raised central portion. Preferably, the strap comprises a second raised central portion on an opposed side of the strap to the first raised central portion.

Advantageously, the opposed teeth are arranged to engage the raised central portion.

Advantageously, the continuous strap comprises a second planar surface opposed the first planar surface. Preferably, the second planar surface is arranged substantially the same as the first planar surface.

Advantageously, the locking head comprises one or more shoulders for guiding the continuous strap through the opening.

Advantageously, the metal locking element circumscribes the opening.

Advantageously, the locking head comprises inter-engaging elements for engaging with a further corresponding locking head.

Advantageously, the strap has a thickness and the opposed teeth define a gap extending perpendicularly therebetween, and wherein the gap is substantially twice the thickness of the strap.

The present description provides also a locking head for use in a cable tie arrangement according to the invention, the locking head comprising:.

A magazine comprising a plurality of locking heads for use in a cable tie arrangement according to the invention is also described.

A reel of continuous strap for use in a cable tie arrangement according to the invention is also described.

The described example embodiment relates to cable ties used for bunding a plurality of component, such as, cables, wires, conduits and the like.

Certain terminology may be used in the following description for convenience only and is not limiting. The words 'right', 'left', 'lower', 'upper', 'front', 'rear', 'upward', 'down', 'downward', 'above' and 'below' designate directions in the drawings to which reference is made and are with respect to the described component when assembled and mounted (e.g. in situ). The words 'inner', 'inwardly' and 'outer', 'outwardly' refer to directions toward and away from, respectively, a designated centreline or a geometric centre of an element being described (e.g. central axis), the particular meaning being readily apparent from the context of the description.

Through the description and claims of this specification, the terms 'comprise' and 'contain', and variations thereof, are interpreted to mean 'including but not limited to', and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality, as well as, singularity, unless the context requires otherwise.

The invention is not restricted to the details of any foregoing embodiments.

<FIG> illustrate an exemplary cable tie arrangement <NUM> with two elongate elements 1A, 1B, for example, wires, cables, tubes, pipes or similar. The illustrated cable tie arrangement <NUM> includes a locking head <NUM> and a section of a continuous strap <NUM> looped around the elongate elements 1A, 1B. The continuous strap <NUM> includes a supply section <NUM> which passes through an opening <NUM> of the locking head <NUM>. In some cases, the supply section <NUM> is fed from a supply 'S' of strap material, for example, a reel <NUM> of strap material as shown in <FIG>. The continuous strap <NUM> also includes a looped section <NUM> which circumscribes the elongate elements 1A, 1B to bundle the elongate elements 1A, 1B on one side of the locking head <NUM>, and an end section <NUM> which passes through the opening <NUM> in the locking head <NUM>. The supply section <NUM>, the looped section <NUM> and the end section <NUM> are shown as forming a continuum from one section to the other section. As shown in <FIG>, the supply section <NUM> passes from a first side of a plane 'P' defined by the locking head <NUM> to a second side of the locking head <NUM> in a first direction A1 (see <FIG>), and the end section <NUM> passes from the second side of the plane to the first side through the locking head <NUM> in a second direction opposed to the first direction A1.

<FIG> is a perspective view of the cable tie arrangement of <FIG> with parts of the locking head <NUM> omitted.

With reference to <FIG>, a locking element <NUM> is provided in the locking head <NUM> that is designed to restrict relative movement between the supply section <NUM> and the end section <NUM> within the opening <NUM> of the locking head <NUM> in order to securely bundle the plurality of elongate members 1A, 1B. The illustrated locking element <NUM> comprises metal, but it would be apparent that in other cases the locking element <NUM> may contain other materials in addition to metal. The locking head <NUM> includes a body in which the locking element <NUM> is inserted. The body of the locking head <NUM> defines the opening <NUM> and the locking element <NUM> includes a body <NUM> designed to circumscribe the opening <NUM> in the locking head <NUM>. While the opening <NUM> is shown as substantially rectangular and the overlapping supply section <NUM> and end section <NUM> have a corresponding cross-section, it would be apparent that this was not essential. In some cases, the opening <NUM> can have other cross-sections which correspond to the cross-section of the strap <NUM>. The locking element <NUM> includes a pair of teeth <NUM> designed to engage the supply section <NUM> and the end section <NUM>. In particular, the teeth <NUM> grip or bite into a smooth planar surface of the strap <NUM>. The planar surface of the strap <NUM> may extend across the entire width of the strap <NUM> or a portion of the strap <NUM> as will be explained below. While the teeth <NUM> are shown extending across partially across the width of the strap <NUM>, it would be apparent that the teeth <NUM> may extend across the entire width of the strap <NUM>. The term "smooth" should be understood as meaning free of protrusions, racks or similar elements which are raised from the surface of the strap <NUM>. An advantage of the present invention is a smooth strap allows for better bundling of elongate elements 1A, 1B, as the strap <NUM> can be tightened optimally based on the overall cross-section of the elongate elements 1A, 1B and by the teeth <NUM> biting into the planar surface. This is in contrast to prior art straps, where extensions engage the raised protrusions or racks of a strap, rather than the main surface of the strap which results in poor or loose bundling.

<FIG> shows a side view of the locking element <NUM>. With reference to <FIG>, the locking element <NUM> is formed of a plate having a thickness X1, an overall width X5 (taken as the horizontal distance in the orientation shown in <FIG>) and an overall height X4 (taken as the vertical distance in the orientation shown in <FIG>). The teeth <NUM> extend at an acute angle relative to a plane defined by the body <NUM> of the locking <NUM>. The example locking element <NUM> shown in <FIG> has the teeth <NUM> extending at an angle A1 relative to an axis normal to the plane of the body <NUM>. A gap X3 is formed between the free ends of the teeth <NUM>, and the space between the base of the teeth <NUM>, the base being where the teeth <NUM> connect to the body <NUM>, is at a distance X6. The teeth <NUM> have a width X7 and protrude from the body <NUM> by <NUM> (taken as the difference between X2 and X1). The body <NUM> forms an annulus around the opening <NUM> and has a first inner width X8 and a second inner width X9. The different inner widths X8, X9 of the body <NUM> help to accommodate the strap <NUM>, particularly, where the strap <NUM> has one or more peripheral portions <NUM> (see <FIG>) as will be explained below. It would be apparent that the dimensions provided are merely examples of suitable dimensions for a strap <NUM> having corresponding dimensions. A similar locking element <NUM> could be designed with variations on these dimensions either with respect to the absolute values provided herein, or the ratios between the values provided herein. As shown in <FIG>, the teeth <NUM> have a face <NUM> which is substantially perpendicular to an insertion direction D1 of the strap <NUM> (see <FIG>). An edge of each tooth <NUM> which defines the face <NUM> can be considered to form a blade which engages the surface of the strap <NUM> and grips the strap <NUM> when inserted into the locking head <NUM>.

As shown in <FIG> the locking head <NUM> body can also include shoulders <NUM> to guide either or both of the supply section <NUM> and the end section <NUM> of the strap through the opening <NUM>. While four shoulders <NUM> are shown, it would be apparent that this was merely exemplary and that one or more shoulders <NUM> could be provided to achieve the same function. While the shoulders <NUM> are shown at opposed corners of the opening <NUM> it would be apparent that this was not essential and that other arrangements would be suitable for guiding the strap <NUM>.

<FIG> is a cross-sectional view of the locking head <NUM> of <FIG>. The locking element <NUM> is shown inserted in the body of the locking head <NUM> and the teeth <NUM> are angled to allow the strap <NUM>, or a section <NUM>, <NUM> thereof, to pass in a first direction D1, but not in a second direction opposed to D1. The teeth <NUM> of the locking element <NUM> extend into the opening <NUM> and have a curved base section which extends from a substantially perpendicular angle relative to the first direction D1, to an acute angle relative to the first direction. A buttress or supporting portion <NUM> of the body of the locking head <NUM> is also shown in <FIG>. This helps to resist motion of the strap sections <NUM>, <NUM> in the second direction by abutting the teeth <NUM>, thereby stiffening the teeth <NUM> and increasing the resistance of the locking head <NUM> to motion of the strap sections <NUM>, <NUM> in the second direction. While a single solid supporting portion <NUM> is provided for each tooth <NUM>, it would be apparent this was not essential and the supporting portion <NUM> may be formed of a plurality of supporting portions <NUM>. Similarly, the supporting portion <NUM> may only extend partially along the length of each tooth <NUM>. For example, supporting the base section entirely and only supporting a part of the remaining tooth <NUM> as shown in <FIG>.

<FIG> illustrate a cross-sectional view of different exemplary straps 50A, 50B, 50C. As shown in <FIG>, the strap 50A has a substantially rectangular cross-section defining an overall width W3 and thickness T3. The overall thickness of the strap 50A T3 is approximately <NUM> and the overall width W3 is approximately <NUM>. An alternative exemplary strap may have an overall width W3 of approximately <NUM> and an overall thickness T3 of approximately <NUM>. However, it would be apparent these were merely exemplary dimensions and the straps described herein may have other dimensions. It would be apparent the gap X3 between the teeth <NUM> corresponds to twice the thickness T3 of strap 50A, as the supply section <NUM> and the end section <NUM> overlap in the opening <NUM>. In some cases, the gap X3 may be between one and two times the thickness T3 of the strap 50A, as this may provide a more robust grip on the ends <NUM>, <NUM> of the strap in the opening <NUM> as the teeth <NUM> are deformed by the sections of strap 50A passing therebetween. It would be apparent that the gap X3 would be greater than the strap 50A thickness T3. The strap 50A is also shown having a raised central portion <NUM> which provides the planar surface against which the teeth <NUM> can engage the strap sections <NUM>, <NUM>. The teeth <NUM> extend across substantially the width of the raised central portion <NUM>. In some cases, the teeth <NUM> may also extend across a part of the whole of the peripheral portion <NUM>. Peripheral portions <NUM> are adjacent the central portion <NUM> and extend substantially along the length of the strap 50A. The peripheral portions help to align the central portion <NUM> within the opening <NUM> and facilitate good engagement between the teeth <NUM> and the central portion <NUM>. The raised central portion <NUM> has a width W4 that is greater than or equal to half the width X7 of the tooth <NUM>. For example, the raised section may have a width of <NUM>. By way of example, each of the peripheral portions <NUM> has a width W1, W2. The central portion <NUM> is raised relative to the peripheral portion <NUM> on a first side by a distance T1 and a second side by a distance T2. It would be apparent that the peripheral portions <NUM> do not need to have the same dimensions and that T1 and T2 may be different to one another, and that W1 and W2 may be different to one another. The opening <NUM> is designed to accommodate the peripheral portions <NUM> between the shoulders <NUM>. In some cases, only the raised central portion <NUM> engages the teeth <NUM>. It would be apparent that the raised central portion <NUM> may only be raised on a single side of the strap 50A, such as shown in <FIG>. As the strap 50A is looped back on itself such that the supply section <NUM> and end section <NUM> overlap and abut one another in the opening <NUM>, the abutting sides of the supply section <NUM> and end section <NUM> need not have a raised section <NUM>. In some cases, the strap 50A may have a uniform cross section, such that there is no raised central portion <NUM>. However, in either case, by angling the teeth <NUM> towards one another in the opening <NUM>, the supply section <NUM> and the end section <NUM> are squeezed in the opening <NUM>. This further enhances the frictional engagement of the teeth <NUM> against the smooth surface of the strap 50A. <FIG> illustrates an alternative exemplary strap 50B having a raised section <NUM> only on a single side of the strap 50B. The raised section <NUM> is narrower than that illustrated in strap 50A. For example, the raised section <NUM> of strap 50B is less than or equal to half of the width X7 of the tooth <NUM>. It would be apparent that strap 50A may include a similarly narrow raised section <NUM>. <FIG> illustrates a further exemplary strap 50C having no raised portions. Strap 50C has a substantially rectangular cross-sectional profile.

<FIG> is a perspective view of an exemplary cable tie assembly <NUM>. The cable tie assembly <NUM> includes a reel <NUM> with six continuous straps 50A-50F shown mounted thereto. Each strap 50A-50F may have any of the features described above in relation to the strap of <FIG>. A continuous strap <NUM> enables the looped section <NUM> to have any length, and thus allows for a greater range of elongate members 1A, 1B to be bundled. The assembly <NUM> also includes a magazine <NUM> of locking heads, and a single "active" locking head 200A through which a supply section <NUM> and an end section <NUM> of one of the straps 50A - 50F extends in the manner described above. The elongate members 1A, 1B have been omitted from the looped section <NUM> for clarity. Once a user has finished with a given strap, for example strap 50A, they can simply draw a new strap, for example 50B, through the next "active" locking head from magazine <NUM>. This provides a more efficient cable tie arrangement than previous arrangements, as additional straps 50A-50F and/or magazines <NUM> can be pre-loaded in a given cable tie tool so the user does not have to spend time loading individual locking heads <NUM>, <NUM> or straps <NUM> when on site. It would be apparent that locking head <NUM> may be used in the cable tie assembly <NUM> in the same manner as locking head <NUM>.

<FIG> are perspective views of an alternative locking head <NUM>. The locking head <NUM> has an opening <NUM> and a locking element <NUM> which function in a similar manner as opening <NUM> and locking element <NUM> described above. As shown in <FIG>, the locking element <NUM> circumscribes the opening <NUM> and teeth <NUM> extend from the body <NUM> into the opening <NUM> to grip the strap sections <NUM>, <NUM> that pass through the opening <NUM> so that the sections <NUM>, <NUM> can be pulled through the opening <NUM> in a first direction but are resisted from being pulled through the opening <NUM> in the opposite direction. A supporting portion <NUM> is also provided which functions in a similar manner to supporting portion <NUM> described above.

The locking head <NUM> is also shown having a pair of tabs <NUM> and a pair of protrusions <NUM> which engage corresponding tabs <NUM> and protrusions <NUM> on an adjacent locking head <NUM>. While the tabs <NUM> and protrusions <NUM> are formed on the same sides of the locking heads <NUM> from which the teeth <NUM> extend (i.e. the upper and lower sides as shown in <FIG>), it would be apparent this was not essential and that the protrusions <NUM> and tabs <NUM> may be formed on different sides to those from which the teeth <NUM> extend. It would also be apparent that the tabs <NUM> and protrusions <NUM> were merely one example of suitable inter-engaging mechanical elements that allow one locking head <NUM> to be releasably connected to a second locking head <NUM>.

Claim 1:
A cable tie arrangement (<NUM>) for bundling one or more elongate members (1A, 1B), the cable tie arrangement comprising:
a continuous strap (<NUM>) having a planar surface free of any racks, and
a separate locking head (<NUM>; <NUM>) defining an opening (<NUM>; <NUM>) and having a metal locking element (<NUM>; <NUM>) comprising a pair of opposed teeth (<NUM>) extending into the opening and arranged to engage the strap in the opening, the pair of opposed teeth including a first tooth and a second tooth, and
wherein, in use, the continuous strap comprises a looped section (<NUM>) arranged to bundle one or more elongate elements on a first side of the locking head, and the looped section has an end section (<NUM>) and a supply section (<NUM>) extending through the locking head to a second side of the locking head in a first direction,
wherein the opposed teeth are arranged to engage the planar surface of the end section and the supply section to prevent movement of the end section and the supply section in a second direction opposed to the first direction and to allow movement of the supply section in the first direction, and
wherein the opposed teeth extend towards one another in the opening, so as to press the end section and the supply section together in the opening
characterised in that the locking head (<NUM>; <NUM>) comprises first and seconding supporting portions (<NUM>) for abutting each of the opposed teeth (<NUM>), respectively, the first supporting portion extending partially along a length of the first tooth and the second supporting portion extending partially along a length of the second tooth, thereby helping to resist motion of the end section (<NUM>) and the supply section (<NUM>) in the second direction.