This invention relates to a hose fastening, or hose clamp, to a tool, and to a clamping method which is suitable for clamping a hose around a pipe or nipple of a pipe fitting.

BACKGROUND OF THE INVENTION

Hose clamps are used in vast numbers, and by far the most common hose clamp used for general purposes at the time of writing this specification is a clamp made from a band or strap, usually of stainless steel and usually having perforations which function as the female portion of a screw fastener, being engaged by a screw carried by a projecting head.

There are many problems however with such fastenings. Firstly, even if made from stainless steel, corrosion (especially crevice corrosion) can occur and fastenings frequently break at the locality of the perforations, since the band is essentially thin (usually less than 0.5 mm in thickness). Secondly, the hose clamps of the band type are very slow to fit, and it is difficult after having opened up the clamp to a C-shape to reinsert the tail so as to be threadably engaged by a screw. Thirdly, the screw is essentially of relatively large diameter, usually about 8mm, and must be carried in a formed head which can be bulky and inconvenient when in confined spaces.

With the object of overcoming at least some of these difficulties, in this invention use is made of a hose clamp which comprises a wire anchor having a central aperture flanked by two apertures for receiving wire of a wire type clamp, and the anchor is provided with locking means to lock the wire of the clamp near its projecting ends. The apertures may be channels or holes.

With such an arrangement, there is more resistance to corrosion because of the relatively small surface over area ratio of the wire, and secondly wire will embed itself more deeply into an elastomeric surface such as the surface of a rubber hose. That being the case, there is less requirement for periodic tightening of the clamp than with a band-type clamp.

PRIOR ART

Some prior art exists with respect to this specification, and the reader may refer to the Australian Patent Application No 84749/75 in the name of Townsend, wherein a hose clamp comprised a double turn of spring wire with hook end portions. In another application 30864/67 in the name of Gillmaster, there was described a ferrule having two apertures to receive the tails of a double turn of wire, and a central recess to carry the intermediate wire.

However, with both the abovementioned prior art documents, difficulties are encountered. In Gillmaster, it is necessary to thread the wire tails through the apertures and threadably engage the projecting ends with very small diameter nuts. The amount of tension which can be applied to the wire is limited by the thread strength of those very small nuts.

In Townsend, Application No 84749/75, the hose clip was described also having two full turns of wire but the hose clip was suitable for only a very small range of dimension of hose and could not be adapted to hoses of widely different diameters.

BRIEF SUMMARY OF THE INVENTION

With the object of overcoming the abovementioned difficulties, at least to some extent, in an embodiment of this invention there is provided a wire anchor having a central recess to accommodate an intermediate convolution of a two turn wire hose clamp, and this is flanked on both sides by apertures to receive the wire ends, the anchor having locking means constituted by wall deformation of the anchor wherein its side walls are crimped against the wire.

In another aspect of the invention there is provided a tool for effecting the clamping of the wire around a hose, wherein the tool has a pair of tensioning handles and a pair of crimping handles, each having clamping ends of the handles, the clamping ends of the tensioning handles clamping the two ends of the wire and tensioning those ends so as to tighten the loops of the wire around a hose, while the crimping handles crimp the side walls of the wire anchor inwardly against the wire so as to inhibit dislodgment of the wire ends from the wire anchor.

The clamping means for the wire can be of various known types, but are most conveniently pawls, there being two pawls on one handle of the tensioning handles and one pawl on the other, so that pivotal movement of the handles can tension and retain the wire in place while it is crimped and cut.

While the crimping handles can be separated at their actuating ends by hand to crimp the side walls of the anchor so as to retain the wire ends, it is quite often more convenient for them to be moved together, and this involves small extension levers at the lower ends of the crimping handles which are linked together by a pair of links, the levers amplifying the mechanical advantage of the handles. The links can then form their secondary purpose of providing mounting means for one or a pair of wire cutters, each wire cutter having an anvil which will underlie a projecting end of wire while a wire cutting

handle is pivoted with respect to the anvil to effect the necessary cut. Conveniently the anvil can be fast with a link, and can extend the cutting zone a short distance away from the wire anchor so that the cut end will be at a location where the existence of the hose will not interfere with positioning of the anvil.

DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED

EMBODIMENT

An embodiment of the invention is described hereunder in some detail with reference to and is illustrated in the accompanying drawings wherein:

Fig 1 is a partly sectioned elevation of a tool;

Fig 2 is a section taken on line 2-2 of Fig 1 , Fig 2 also identifying the plane 1-1 of Fig 1 which is the plane upon which the Fig 1 section is taken;

Fig 3 is a fragmentary isometric drawing drawn to a larger scale which shows, in particular, the wire cutting facility;

Fig 4A is a section through a wire anchor before crimping;

Fig 4B is a section corresponding to Fig 4a after crimping;

Fig 4C is a top view of the wire anchor after crimping;

Fig 5A is an isometric drawing of a sheet of steel before bending into a ferrule; and

Fig 5B is an isometric drawing of a ferrule when ready for use.

Referring first to Figs 1 and 2, a clamping tool 10 for securing the wire coils 11 of a hose clamp to a ductile wire anchor 12 is provided with a pair of tensioning handles 13a and 13b of which the handle 13a is the major handle and 13b is the minor handle, and a pair of crimping handles which are substantially identical, and designated 14.

The major tensioning handle 13a is provided with an extended projecting flange 17 which crosses a central plane P-P of the crimping handles 14, and terminates in a lug 18 which carries a pivot pin 19 by which the minor handle 13b is pivoted for relative movement. A compression spring 20 separates the handles, so that it is by closure of 13b towards 13a that tensioning occurs in the direction of arrow A in Fig 2. The major handle 13a is provided with two pawls 21 and 22 which pivot about respective pins 23 and 24, and these pawls overlie respective projecting wire ends 25 and 26 of the coils 11 , which in turn overlie the anvil feet 27.

The minor tensioning handle 13b is provided with a pawl 30 which is oriented in the same direction as the pawl 22, and when the handle 13b is

manually actuated to rotate in an anti-clockwise direction as drawn about the pivot pin 19, the teeth of the pawl 30 move the projecting end 26 in a right hand direction shown by the letter A. Each pawl 21 , 22 and 30 is biased by respective spring 31.

In tensioning, several movements of the handle 13b may be required, and the pawl 22 will inhibit return movement of the projecting end 26 of the wire of the loops 11.

The projecting flange 17 is provided with two lugs 33 to which the crimping handles 14 are pivoted about pivot pins 34, this arrangement retaining tensioning handles 13 and crimping handles 14 in a single assembly, which is quite important because the crimping should be effected while the wires are tensioned.

It is most convenient that crimping should be effected by closing the actuating ends of the crimping handles 14 towards one another, since this can frequently be effected satisfactorily with the arrangement shown by a single hand of an operator. In order to prevent "cross over" of the crimping handles 14 it is necessary to utilise respective extension levers 36 pivoted by pins 37 which lie between the anchor engaging end 38 of the crimping handles and their pivot pins 34. These are retained together by means of a pair of transverse links 39 about which the extending levers pivot on the pivot pins 40 (not illustrated in Fig 3). If the crimping handles 14 are required to be moved together in their crimping mode, it is desirable that they should be separated when not in use and that is achieved by a spring 41 extending between the pivots 37.

For simplicity of illustration, neither Fig 1 nor Fig 2 illustrates any wire cutting assembly, but that is illustrated in Fig 3 which is drawn to a larger scale. In Fig 3 the handle 13a is shown to have a hooked lower end 44, and handle 13b also has a hooked lower end, for supporting the two projecting ends 25 and 26 of the wire coils 11 , each hooked end 44 being fast with its respective wire end when the wires are being crimped. The pivot pins 40 extend outwardly from links 39, and pivotally carry respective wire cutting handles 45 (Fig 3) which pivot about pins 40 and co-operate with hooked lower ends 44 to effect cutting of the wire projecting ends 25 and 26 in a guillotine action, but obviously the cutting could be effected with the required modification in a pincers action. While wire cutters are conveniently carried on the tool as illustrated, they can be quite separate.

Figs 4a, 4b and 4c illustrate the uncrimped and crimped stages of the anchor 12. As illustrated, the anchor 12 is in the form of a ferrule of metal which is ductile, and has two upwardly facing channels 48 and one downwardly facing channel 49. If there are two loops of wire coil 11 as shown there will be a requirement for three channels as best seen in Fig 3, the downwardly facing channel carrying the intermediate loop.

After the wires have been tensioned, they will be firmly retained within the upwardly facing channels 48 and the intermediate loop will be within the downwardly facing channel 49. Crimping is effected as best seen in Fig 1 by the anchor engaging ends of the crimping handles 38 (being the ends of extension levers 36) and these have the effect of compressing the central side walls to the shape which is shown in Figs 4b and 4c, in doing so bending the wire projecting ends 25 and 26 and firmly retaining the wires against dislodgment. The side walls 50 will be seen in Fig 4b to be caused to slightly overlap the upper surfaces of the projecting wires 25 and 26, thereby firmly retaining them in position. Attention may also be drawn to the sharp corner 51 in Fig 4a of each of the channels 48, which facilitates this deformation.

It will thus be seen that the method can be summarised as clamping a hose with the clamp shown in Figs 1 and 2, by firstly locating the wire in the channels of the wire anchor 12 as described above, separating pawl 20 from the two pawls 21 and 22, so as to in turn separate the projecting ends 25 and 26 and tighten the coils 11 around a hose, and after the wire is tensioned, crimping the side walls with the crimping handles 14 to distort them as shown in Figs 4b and 4c so as to restrain the wire from dislodgment from the anchor, and finally utilising the cutter assembly by swivelling the cutter handles 46 about their pivot pins 40 to sever the wires 25 and 26 at positions slightly removed from the coils 11.

The anchor 12 can also be produced from sheet metal as shown in Figs 5A and 5B, firstly lancing locking teeth 55 and then guillotining the sheet at 56, before forming to the shape shown in Fig 5B. Altematively, the ferrule apertures may be holes extending through the ferrule.