I
Fastening or Securing Devices
Technical Field
The present invention relates to fastening or securing devices for example hose clips, hose clamps, securing bands, bundling straps and straps for securing signs.
Background Art
Integrally formed hose clips are well known that include a strap or band, at one end ot which there is a pair ot toothed jaws and at the other end ot which there is a toothed tongue that can be inserted between the jaws to form the strap into a closed loop around an object, for example a hose The tongue can be inserted into the jaws sufficiently to compress the hose and therefore keep it, for example, on a spigot Hose clips of this type are disclosed in UK Patent No 1 ,600,601 Such clips are manufactured by injection moulding.
One disadvantage of the above type of hose clip is that the range of diameters ot hoses that can be clamped by any one clip is limited and it is usually necessary to provide a series ot clip sizes, each size corresponding to a range of hose diameters that it can clamp Since each clip size will need a separate injection-moulding tool, the tooling costs can be high, particularly for clips intended tor relatively large diameter hoses, which in any case are used less frequently than clips toi smallei diametei hoses Also, the cost ot holding a stock ot a large range ot clip sizes is high.
Bundling straps and ties are also known consisting ot a body and an integrally-formed toothed band; the toothed band is passed around the objects being bundled and the end ot the band is inserted into an opening in the body and the band is pulled through the body sufficiently to secure the bundle of objects together One disadvantage ot this arrangement is that, in order to release the bundled objects, the band must be cut. Therefore, the arrangement is not re-useable Also, such straps must be made in a variety of sizes using several injection moulds to secure objects of differing diameters. Alternatively, if the band is of fixed length, it is not possible to use it to secure objects having a perimeter length longer than the length of the band. Such bundling straps can also be used for securing and
closing bags and sacks.
Metallic "Jubilee" hose clips are well-known and have a body permanently fixed to one end of a metal band; the other end can be looped around and secured by a worm gear incorporated in the body. The worm gear engages ridges on the band and can be rotated to tighten the band around an object. The pitch of the worm gear thread and the innate frictional resistance to the gear turning are such that, when the clip is tightened, tension in the band does not cause the release of the clip. Bodi the pitch of the worm gear thread and the resistance to the gear turning make it time consuming and awkward to tighten die clip. In addition, die clip is made of steel and is expensive to make.
Disclosure of Invention
According to die present invention, there is provided a looped securing device comprising: a toothed strap having a first end and a second end: a body secured or securable to the second end of the strap and capable of engaging the first end of die strap and holding it in a closed loop, which body comprises: a pair of jaws having at least one tooth for engaging corresponding teeth at the first end of the strap to retain die first end of the strap and hold d e strap in a closed loop, a rotatable gear for engaging corresponding teeth on the strap which gear. when rotated, feeds the toothed strap through die jaws so that the at least one tooth of the pair of jaws engages with the teeth at d e first end of the strap, the arrangement being such that the inter-engagement of the teeth on the strap with the at least one tooth of the pair of jaws prevents the first end of the strap from being pulled lengthways from between the pair of jaws to open the loop.
The or each tooth of the jaw advantageously has a sloping front face that rides over the teeth of the strap when fed by the gear to tighten the securing device so that the first end of the strap can be advanced lengthways through the jaws to tighten die strap but cannot be pulled lengthways through the jaws to slacken the strap.
The strap is preferably of uniform cross-section and the teeth on the strap preferably extend generally perpendicular to the axis of the strap, correspondingly, the teeth on the jaws extend generally perpendicular to the direction in which the gear feeds die strap between the jaws
The body may be integral with the strap, but will generally not be When it is not integral, the second end of the strap may be secured to the body by the body being formed with a further pair ot jaws for engaging the second end of the strap The further pair of jaws are preferably open at one side to allow the teedi of the strap to be engaged with the further pair of jaws by sliding the second end to the strap sideways through the open side ot the turd er pair ot jaws
Since die strap can be of uniform cross section, it can be formed, e g by extrusion, in long lengths and a strap for a particular application of the desired length can be cut from it. Thus the strap can be any desired length.
Although the body of the device ot the present invention may have to be injection moulded, it can be used in connection with any length ot straps so that it is not necessary to make separate injection moulds tor each diameter ot object to be encircled
Brief Description of Drawings
Figure 1 is a side view of the device of the present invention with the strap being engaged in the body to form a closed loop;
Figure 2 is an axial cross sectional view of the body of Figure 1 ,
Figure 3 is a perspective view showing one side and die underside ot the body and part ot die strap ot the device ot the present invention;
Figure 4 is a similar perspective view of the device of Figure 3 but showing the other side and the top of the body;
Figure 5 is an enlarged isometric view of the gear of the device of Figures 1 to 4;
Figure 6 is an axial cross sectional view of the device of the present invention;
Description of the Preferred Embodiments
Referring firstly to Figure 1 , diere is shown a device of the present invention including body 12 and a toothed band or strap 14. The teeth are provided on the upper and lower flat surfaces of the strap 14 (see Figures 3 and 4); in Figure 1 , the teeth are not shown, for ease of illustration. The strap is formed into a closed loop and the first and second ends 42, 44 are engaged in first and second jaws 22 and 26 of the body. By feeding the first end 42 of the strap through die first pair of jaws using a gear described below, the device can be tightened on the object or objects being clamped (shown generally by the reference number 11 in Figure 1). The object 11 may be a hose pushed onto a spigot, a bundle of objects, e.g. electrical cables or a collection of two or more articles that are to be secured together.
The strap may be formed by extrusion or injection moulding in long lengths, e.g. in excess of 1 metre, and can be cut to any desired length to provide a clamp that can encircle the required object or objects. The teeth 16 of the strap (see Figures 3 and 4) are generally rectangular in profile with vertical front and rear faces, although the tops of the teeth are somewhat chamfered.
The body 12 is shown in Figure 2 and includes the first and second pairs of jaws 22 and 26 respectively having teeth 24 and 28. The teeth of the second pair of jaws each have a profile diat is complimentary to the profile of teeth 16 on die strap 14. i.e. are of rectangular profile. The teeth of the second pair of jaws engage the teedi of the strap and so hold the second end 44 of the strap. Because the teeth of die strap and the teeth of die second pair of jaws have vertical faces, tension in the strap does not tend to force the second pair of jaws open and so, when tension is applied to the strap, the teeth of the second pair of jaws hold the second end of die strap firmly and can do so up to a tension determined by primarily by the strength of the plastic from which the strap and the body are made.
The second pair of jaws 26 is open at one side (the side shown nearest the observer in Figure 3) and is closed at the other side by a wall 34, see in particular Figure 4.
A passage 30 is provided in the body extending betwet n the back of the first jaws 22 and a
rear face 32 of the body (see Fi jure 2).
A bore 29 (see Figures 2 and 6) extends transversely through the body so that the top ot the bore intersects the base of the passage 30. a toothed gear 92 (shown in detail in Figure 5) can be inserted into the bore 29 (see Figures 3 and 4) The gear 92 (see Figure 5) has a toothed shank 94, a hexagonal slotted head 96 and a tail 98 The tip 99 ot the tail 98 of die gear is engaged in a hole 100 in the body and so holds the gear 92 in die bore 29 The tip 99 but can simply be pushed into the hole 100, where it is held by undercut 101 and may be removed from the hole 100 to release die gear from the bore 29 92 (see Figure 4)
[0 In order to secure the device around an object, the second end 44 ot the strap 14 (see Figure 1) is inserted transversely through the open side 37 ot die second pair of jaws in the direction parallel with the teeth 28 of the second jaws, as shown by arrow B 92 in Figure 4 so that die teeth of the strap 14 mesh with the teeth of die second jaws, thereby securing the second end 42 of the strap 14 to the body 12. The strap 14 is then bent around the
15 object being clamped and the first end 42 of the strap is ted into the passage 30 in die back face 32 ot the body 12 in the direction ot arrow C shown in Figure 2 As shown in Figure 6, die teeth of gear 92 mesh with the teedi on the underside of the strap By turning the gear, e.g. using a screwdriver engaged in the slotted head 96, the first end 42 ot the strap can be advanced down passage 30 towards the teedi 24 ot the first pair of μιws 22 0
The teeth 24 ot the first jaws have sloping rear faces 25 As die first end 44 of die strap 14 is moved along the passage 30, it abuts the teeth 24 of the first pair of )aws 22. As die gear 92 is turned further, it urges the strap down the passage 30 and the resulting force exerted by the first end of the strap 14 on die sloping rear face 25 ot die teeth 24 causes 5 the top jaw 33 to flex resihently around the thinned-out region 31 This flexing opens the first jaws and allows the strap to be advanced in the direction of arrow A in Figure 6 In this way, the teeth on the strap can be pushed past successive teeth 24 on die first jaws until the strap is tightened on the object 11
If die circumference of the strap is substantially greater than that of the object 1 1 , the end 42 of strap may be advanced beyond the first pair ot jaws 22 using the gear 92 The initial
tightening can be performed by turning gear 92 and sufficient tension in the strap may be produced in this way. However, additional tension in the strap can be brought about by grasping the first end of the strap, e.g. by a special tool or a pair of pliers, and pulling it in direction A (see Figure 6), causing the strap to be pulled through the first pair of jaws 22 to tighten the strap on the object or objects being encircled.
If required, the gear can be removed from the bore 29 once the strap is tensioned because the first end 42 is held by the teeth 24 of the first pair of jaws.
The body 12 is made of a tough but resilient material, for example "nylon 66" or [ Q fibreglass-filled nylon so that the first pair of jaws 22 can flex to open when the strap is advanced through them. The rear surfaces ot the teeth of the strap and the front surfaces 27 ot the teeth of die first jaws prevent the strap from being pulled back through the jaws (i.e. in die direction opposite to arrow A in Figure 6), e.g. by tension in the strap.
1 The device can be released by levering the first jaws apart, e.g using a pair ot pliers, and so releasing d e tension in die strap. The second end 44 of die strap can then be slid sideways from within the second pair of jaws dirough the open side 37 in die direction opposite to that of arrow B. Once released, the strap can be pulled through die first jaws 22 by pulling on the first end 42 of the strap in the direction of arrow A in Figure 6 to 0 release the strap fully from the body.
The gear 92 may be formed in the same moulding operation as the body 12 in such a way that it can be easily detached from die head and inserted into the bore 29 For example, the gear could be integrally moulded with the body and attached to the body by a dun 5 breakable tie (not shown).
Teeth on the inside of the strap 14 can bite into the object 11 being clamped, in order to avoid this, a resilient pad (not shown) may be placed between die strap and the object
It is conjectured that a reel of strap material and a number of bodies 12 will be provided to a user. In order to form a clip, he will take one of the bodies 12 and cut off a sufficient
length of strap 14 from the reel to encircle the object being clamped. The strap will be secured in a loop using the body 12 and tightened, as described above. In this way the user does not have to keep a range of clips of different sizes in stock and the manufacturer needs only two forming dies to make the device, one for the strap and one for the body/gear.
Pre-sized clamps can be produced by the use of straps of predetermined length.
The device can be used wherever objects have to be secured, clamped, bundled, held or tied togedier. For example, it could be used to close bags, to secure scaffold sheeting onto scaffolding, to bundle pipes or cables together, in packaging, as a hose clip or for securing signs to posts.