TIE STRIPS

Abstract: An integrally formed tie strip (10) is formed with a series of apertures (14), at respective locations that are spaced apart in succession along the strip, and is formed with a series of laterally projecting latch members (11), at respective locations that are spaced apart in succession along the strip, for resisting withdrawal from one of the said apertures after having been passed therethrough.

Description: TIE STRIPS The present invention relates to tie strips, for example cable ties. Tie strips are used to secure items together in a relatively quick and easy manner. For example, tie strips can be used to bundle cables together laterally, or to secure a tree to a stake. One conventional tie strip is generally in the form of a length of flexible material having an apertured head portion, at one end, and a tail portion which can be passed through the aperture of the head portion and has a series of laterally projecting latch portions for preventing withdrawal from the said aperture. In use, the tie strip is placed around the items to be secured and the tail portion is inserted into the aperture of the head portion. The tail portion is then pulled through the head portion to tighten the tie strip around the enclosed items. The latch portion(s) cooperate with the head portion in the manner of a ratchet, permitting such tightening of the strip, in the form of a closed loop, and preventing it from becoming loose thereafter. One disadvantage of such a tie strip is that the part of the tail that has been pulled through the head is wasted material. According to the present invention there is provided an integrally formed tie strip having portions formed to define a series of apertures through the strip, at respective locations that are spaced apart in succession therealong, and having portions formed to define a series of laterally projecting latch members, at respective locations that are spaced apart in succession along the strip, for resisting withdrawal from one of the said apertures after having been passed therethrough. A preferred embodiment of such a strip is made of a semi-rigid resiliently bendable material, and is provided with a series of spring portions, at respective locations that are spaced apart in succession along the strip, formed by parts of the strip that extend transversely with respect to its longitudinal axis, whereby resilient bending of the said parts when the strip is subjected to an applied longitudinal tension affords resilient longitudinal extension of the strip. In the stretched condition the strip portion formed to define a selected one of the said latch members at one end region of the strip can be passed through a selected one of the said apertures so as to form a closed loop whereafter on relaxation of the applied tension the loop will tend to contract whilst the selected latch member prevents withdrawal thereof from the selected aperture. Alternatively, this strip portion formed to define a selected one of the said latch members at one end region of the strip can be passed through a selected one of the said apertures / so as to form a closed loop, in an unstretched condition. In such a preferred embodiment the said portions defining the latch members may be separate from the said portions defining the apertures and from the said spring portions, the said spring portions being separate from the said portions defining the apertures. Alternatively, the said portions defining the apertures may comprise the respective said portions defining the latch members. In another alternative form, the said portions defining the apertures comprise the respective said spring portions. In a further alternative form, the said spring portions comprise the respective said portions defining the latch members. An advantageous form of the preferred embodiment of the present invention consists of a strip comprising a series of unit cell portions connected one to the next along the strip, each of the said unit cell portions being formed to define at least one of the said latch members and to define one of the said apertures and to provide one of the said spring portions. The aperture of each unit cell portion in a relaxed condition thereof may have one or more relatively narrow portions that extend transversely across the strip, in a main plane thereof, so that application of longitudinal tension to the strip causes the aperture to open up longitudinally of the strip so as to facilitate the passage therethrough of another such unit cell portion of the strip. Each of the said unit cell portions is preferably generally cardioid in form, when the strip is free of longitudinal tension, having at one end thereof a re¬ entrant part and having at the other end thereof an apical part connected, except at the said one end of the strip, to a central region of the re-entrant part of the next unit cell portion in the series, whereby respective lobe portions of each unit cell portion, which lobe portions are located to opposite sides of the said central region of the unit cell portion, provide respective such latch members. Alternatively each of the said unit cell portions may have the general form of an isosceles triangle, a mid-portion of each of the sides of which is displaced inwardly of the triangle so as to be concave outwardly thereof when the strip is free of longitudinal tension, the apex of each of the said unit cell portions, except that at the said one end of the strip, being connected to the mid-point of the base of the next unit cell portion of the series, whereby respective portions of the triangle adjacent to the base angles thereof provide respective such latch members that are barb¬ like in form. Reference will now be made, by way of example, to the accompanying drawings, in which: Fig. 1 shows a plan view of part of a tie strip embodying the present invention; Fig. 2 shows a side elevational view of the part illustrated in Fig. 1; Fig. 3 shows, to a smaller scale, a plan view of a length of the tie strip of Fig. 1; Fig. 4 shows a side elevational view corresponding to Fig. 3 ; Fig. 5 shows, to an enlarged scale, a diagrammatic isometric view of part of the tie strip of Fig. 3 ; Fig. 6 shows a plan view of a length of tie strip according to a second embodiment of the present invention; Fig. 7 shows a side elevational view corresponding to Fig. 6; Fig. 8 shows a diagrammatic perspective view of part of a tie strip according to a third embodiment of the present invention; Figs. 9(a) and 9(b) show, to a smaller scale, a length of the tie strip of Fig. 8, in relaxed and tensioned states respectively; Figs. 10 and 11 show side views of a tie strip, embodying the present invention, at successive respective stages of an operation to secure a bundle of wires (shown in cross-section) by means of the tie strip; Fig. 12(a) shows a plan view of a part of a first modified form of the tie strip of Fig. 8; Fig. 12(b) shows a sectional view corresponding to the line B-B of Fig. 12(a) ; Fig. 13 shows a diagrammatic perspective view of part of a second modified form of the tie strip of Fig. 8; Fig. 14(a) shows a plan view of a part of a third modified form of the tie strip of Fig. 8; Fig 14 (b) shows a side elevational view corresponding to Fig. 14(a); Figs. 15(a) and 15(b) show respective plan and side elevational views of a tie strip according to a fourth embodiment of the present invention; Figs. 16(a) and 16(b) show respective plan and side elevational views of a tie strip according to a fifth embodiment of the present invention; Figs. 17(a) and 17(b) show respective plan and side elevational views of a tie strip according to a sixth embodiment of the present invention; Figs. 18(a) and 18(b) show respective plan and side elevational views of a tie strip according to a seventh embodiment of the present invention; Figs. 19(a) and 19(b) show respective plan and side elevational views of a tie strip according to an eighth embodiment of the present invention; Figs. 20(a) and 20(b) show respective plan and side elevational views of a tie strip according to a ninth embodiment of the present invention; Figs. 21(a) and 21(b) show respective plan and side- elevational views of a tie strip according to a tenth embodiment of the present invention; Figs. 22(a) and 22(b) show respective plan and side elevational views of a tie strip according to an eleventh embodiment of the present invention. Figs. 1 and 2 show a single unit cell portion 1 of the tie strip of Figs. 3 and 4. Two such unit cell portions 1 are shown in Fig. 5. The unit cell portion 1 is generally cardioid in form, when the tie strip in which it is incorporated is free of longitudinal tension. Accordingly, the unit cell portion 1 has a re-entrant part 13 joined to an apical part 15 by opposite side parts 12, which parts bound an aperture 14 passing through the unit cell portion. To opposite sides respectively of the re¬ entrant part 13 are two lobe portions 11 of the unit cell portion 1, which lobe portions provide respective latch members directed away from the apical part 15 of the unit cell portion 1. A multiplicity of such unit cell portions 1 are connected together in series to form a generally flat tie strip 10 shown in Figs. 3 and 4, the apical part 15 of each unit cell portion (except that at the extreme left-hand end of the strip as viewed in Fig. 3) being connected to a central region of the re-entrant part 13 of the next unit cell portion 1 of the .series. Alternatively, there may be straight parts 16 of the strip between two such unit cell portions 1, as shown in Figs. 6 and 7. These straight parts 16 are used to provide an increased length of strip without the need to provide more unit cell portions than is necessary for the particular application for which the tie strip is to be used. The tie strips shown in Figs. 3 to 7 are made of a semi-rigid resiliently bendable material. They are formed integrally, for example by injection moulding of a thermosetting or thermoplastic material or by stamping from a blank. More specifically, for example, the strip could advantageously be made of Nylon 66, or of a polyamide derivative, or alternatively of steel or even titanium. The dimensions of the unit cell portions and the length of an integrally formed tie strip consisting of such portions will vary in dependence upon the application for which the tie strip is to be used. Typically, such a unit cell portion used in a Nylon tie strip for securing cables would desirably be about 8mm in length, approximately 8mm in width and between 2mm and 3mm in thickness. Such unit cell portions could advantageously be used to produce a tie strip having a length between 0.5m and lm. Such a length of tie strip is preferably stored in the form of a roll. When a tie strip is required for use, an appropriate amount can be cut from the roll. An alternative form of unit cell portion is shown in Fig. 8. This unit cell portion 1' has the general form of an isosceles triangle, a mid-portion of each of the sides of which is displaced inwardly of the triangle so that these sides are concave outwardly of the triangle when the tie strip incorporating the unit cell portion 1' is free of longitudinal tension. Base angle portions 11' of the triangle provide barb-like latch members. Such a tie strip 10', having a longitudinal axis 100, is shown in Figs. 9(a) and 9(b), being made up of a series of these unit cell portions 1', the apex 15' of each of which, except that at one end of the strip, is connected to the mid-point of the base 13' of the next unit cell portion in the series. Parts of each unit cell portion 1' , for example the base 13' , extend transversely with respect to the longitudinal axis 100 of the strip concerned, thereby providing the strip with a series of spring portions, at respective locations that are spaced uniformly apart in succession along the strip, so that resilient bending of the parts concerned can afford resilient longitudinal extension of the strip when it is tension longitudinally. Figs. 9(a) and 9(b) show the generally flat strip 10' in a relaxed and a tensioned state respectively. The aperture 14' of the unit cell portion 1' , in its relaxed state, has relatively narrow portions 16' that extend transversely across the strip, in the main plane thereof, so that application of longitudinal tension to the strip causes the aperture to open up longitudinally of the strip, thereby facilitating the passage therethrough of another such unit cell portion of the strip. Thus, as can be seen from Fig. 9(b), when the strip is subjected to longitudinal tension the base 13' of each unit cell portion 1' is deformed resiliently so as to curve outwardly thereof, thereby opening up the aperture 14' . It will be appreciated that similar resilient deformation occurs in the unit cell portion 1 of the strip 10 shown in Fig. 3, when that strip is subjected to an externally applied longitudinal tension, although in this case the re-entrant part 13 of the unit cell portion 1 will merely tend to straighten, rather than bow outwardly like the base parts 13' shown in Fig. 9(b) . The tie strip 10 can be used as follows to secure together laterally a bundle of cable wires 20 shown diagrammatically in cross-section in Figs. 10 and 11. As shown in Fig. 10, a suitable length of tie strip 10 is first pulled from a roll thereof (shown diagrammatically at 200) and looped around the wires 20. The strip is held at points A and B thereon, either manually or by means of a tool. At this stage, the unit cell portions 1 are in a relaxed state as shown in Fig. 3. The unit cell portion held at point A is then pulled in the direction of arrow T, thereby subjecting the unit cell portions of the strip 10 that are located between points A and B to a longitudinal tension. This opens up the apertures (14) in these unit cell portions and moves the point A of the strip to a position A' shown in Fig. 11. The holding point A is then relocated to a point further along the strip towards point B with the aid of an optional holding point C. This process is repeated until the tie strip is tensioned to a desired amount. A unit cell portion 101 at a free end of the tie strip remains in a relaxed state. To latch the tie strip 10 into a closed loop, so as to hold the enclosed wires together, the end unit cell portion 101 is inserted into a selected relaxed (untensioned) unit cell portion 102 in the direction shown by the arrow I in Fig. 11. The grips on the strip 10 at points A and B are then released, and the resilience of the strip material acts to tighten the strip around the wires as the strip tries to return to its relaxed condition. The latch members (11) of the unit cell portion 101 resist withdrawal of that unit cell portion from the unit cell portion 102. With the tie strip thus secured around the wires 20, a residual part 103 of the strip can be cut off at or near the point A' and wound back onto the roll 200. The severed residual part of the strip can be used for another such securing operation, so waste is minimized. It will be appreciated that the tie strip 10' of Fig. 9(a) can be used in a similar manner. The unit cell at a free end of the strip being passed through the selected unit cell when that selected unit cell is in a tensioned (opened-up) condition. Figs. 12, 13 and 14 show possible modifications to the unit cell portion 1' of Fig. 8. The unit cell portion shown in Figs. 12(a) and 12(b) has an oblique rear end surface 131 to aid latching. Fig. 13 shows two unit cell portions, the base 13' of each of which is formed with rearwardly projecting horns 60, to aid latching. Figs. 14(a) and 14(b) show a unit cell portion having serrated surfaces which can facilitate the tensioning process. Similar modifications could be made to the unit cell portion 1 of Figs. 1 to 5. Figs. 15(a) and (b) and 16(a) and (b) show tie strips having resiliently bendable zig-zag spring portions 30 provided separately from portions 31 defining apertures, and from portions 32 defining barb¬ like latch members. The tie strip shown Figs. 15(a) and 15(b) comprises a regular sequence of these portions 30, 31 and 32, while the tie strip shown in Figs. 16(a) and 16 (b) , comprises an irregular sequence of such portions. Figs. 17(a) and (b) and 18(a) and (b) show tie strips having resiliently bendable zig-zag spring portions 30 provided separately from portions 33 defining both apertures and barb-like latch members. Figs. 17(a) and 17(b) show a tie strip comprising a regular sequence of such portions 30 and 33, and Figs. 18(a) and 18(b) show an irregular sequence of such portions. Figs. 19(a) and (b) and 20(a) and (b) show tie strips having portions 31 defining apertures provided separately from portions 34 which define latch members and also provide spring portions. The structure of these portions will be self-evident from the drawings. Figs. 19(a) and 19(b) show a regular sequence of such portions 31 and 34 and Fig. 20(a) and (b) show an irregular sequence of such portions. Tie strips having portions 35, which define apertures and provide spring portions, provided separately from portions 32 defining barb-like latch members, are shown in Figs. 21(a) and (b) and 22(a) and (b) . The structure of these tie strips will be readily apparent from the drawings. The tie strips shown in Figs. 15 to 22 can be used in substantially the same manner as that described above with reference to Figs. 10 and 11.

Claims: CLAIMS ; 1. An integrally formed tie strip (10) having portions formed to define a series of apertures (14) through the strip, at respective locations that are spaced apart in succession therealong, and having portions formed to define a series of laterally projecting latch members (11) , at respective locations that are spaced apart in succession along the strip, for resisting withdrawal from one of the said apertures after having been passed therethrough. 2. A strip as claimed in claim 1, which is made " of a semi-rigid resiliently bendable material, and is provided with a series of spring portions, at respective locations that are spaced apart in succession along the strip, formed by parts (13) of the strip that extend transversely with respect to its longitudinal axis, whereby resilient bending of the said parts when the strip is subjected to an applied longitudinal tension affords resilient longitudinal extension of the strip. 3. A strip as claimed in claim 2, wherein, when the strip is subjected to an applied longitudinal tension, the strip portion formed to define a selected one of the said latch members (11) at one end region of the strip can be passed through a selected one of ■ the said apertures (14) so as to form a closed loop whereafter on relaxation of the applied tension the loop will tend to contract whilst the selected latch member inhibits withdrawal thereof from the selected aperture. 4. A strip as claimed in claim 2 or 3, wherein the said portions (32) defining the latch members are separate from the said portions defining the apertures (31) and from the said spring portions (30) , the said spring portions being separate from the said portions defining the apertures (14) . 5. A strip as claimed in claim 2 or 3, wherein the said portions (33) defining the apertures (14) comprise the respective said portions defining the latch members. 6. A strip as claimed in claim 2 or 3, wherein the said portions (35) defining the apertures (14) comprise the respective said spring portions. 7. A strip as claimed in claim 2 or 3, wherein the said spring portions (34) comprise the respective portions defining the latch members. 8. A strip as claimed in claim 2 or 3 comprising a series of unit cell portions (1) connected one to the next along the strip, each of the said unit cell portions (1) being formed to define at least one of the said latch members (11) and to define one of the said apertures (14) and to provide one of the said spring portions (13) . 9. A strip as claimed in claim 8, wherein each of the said unit cell portions (1) is generally cardioid in form, when the strip is free of longitudinal tension, having at one end thereof a re-entrant part (13) and having at the other end thereof an apical part (15) connected, except at the said one end of the strip, to a central region of the re-entrant part (13) of the next unit cell portion in the series, whereby respective lobe portions (11) of each unit cell portion, which lobe portions (11) are located to opposite sides of the said central region of the unit cell portion, provide respective such latch members. 10. A strip as claimed in claim 8, wherein each of the said unit cell portions (1') has the general form of an isosceles triangle, a mid-portion of each of the sides of which is displaced inwardly of the triangle so as to be concave outwardly thereof when the strip is free of longitudinal tension, the apex (15') of each of the said unit cell portions, except that at the said one end of the strip, being connected to the mid-point of the base (13') of the next unit cell portion of the series, whereby respective portions (11') of the triangle adjacent to the base angles thereof provide respective such latch members that are barb-like in form. 11. A strip as claimed in claim 8, wherein the aperture (14) of the said unit cell portion (1') in a relaxed condition thereof has at least one relatively narrow portion (16') that extends transversely across the strip (10'), in a main plane thereof, so that application of longitudinal tension to the strip causes the aperture to open up longitudinally of the strip so as to facilitate the passage therethrough of another such unit cell portion of the strip.

Inventors: HARSLEY ANDREW JOHN, HARSLEY, ANDREW, JOHN
Applicants: HARSLEY ANDREW JOHN, MILLEPEDE CABLE TIES LIMITED, HARSLEY, ANDREW, JOHN
Application year: 1995
Main classification: B65D63
IPC codes: B65D63, F16L3