per WORLD INTELLECTUAL PROPERTY ORGANIZATION International Bureau

INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT

(51) International Patent Classification 4 (11) International Publication Number: WO 89/ 01 A44B 11/08 Al

(43) International Publication Date: 9 March 1989 (09.0

(21) International Application Number: PCT/GB88/00699 (74) Agents: CALDERBANK, T., Roger et al.; Mew Ellis, 2 Cursitor Street, London EC4A 1BQ (GB

(22) International Filing Date: 23 August 1988 (25.08.88)

(81) Designated States: AT (European patent), BE (E

(31) Priority Application Number: 8719973 pean patent), CH (European patent), DE (Euro patent), FR (European patent), GB, GB (Euro

(32) Priority Date: 25 August 1987 (25.08.87) patent), IT (European patent), JP, LU (Europea tent), NL (European patent), SE (European pat

(33) Priority Countr : GB US.

(71) Applicant (for all designated States except US): WEEKS Published

& TAYLOR LIMITED [GB/GB]; 40/44 Folly Lane, With international search report. St. Philips, Bristol BS2 0RH (GB). Before the expiration of the time limit for amendin claims and to be republished in the event of the re

(72) Inventors; and of amendments.

(75) Inventors/Applicants (for US only) : WEEKS, Wilfred, Gwyn [GB/GB]; TAYLOR, Malcom, Arthur [GB/ GB]; Weeks & Taylor Limited, 40/44 Folly Lane, St. Philips, Bristol BS2 0RH (GB).

(54) Title: STRAP FASTENER

(57) Abstract

A self-locking fastener comprises a body (10) and casing (11) around the body (10). Rollers (13, 18) situated in cesses (14, 19) in the body (10) are moved along outwardly inclined slopes (20, 23) opposite when ends (25, 26) of a str (22) are pulled through gaps (16, 17) between the body (10) and the casing (11) thereby to trap the ends of the strap ( against the casing (11). Any attempt to pull the ends of the strap out of the gaps in the opposite direction to their inserti is resisted by movement of the rollers (13, 18) along the slopes (20, 23) to reduce the spacing between the rollers (13, 1 and the adjacent casing (11).

STRAP FASTENER BACKGROUND OF THE INVENTION

The invention relates to a fastener for retaining at least one end of a strap. The fastener has application in e.g. packaging in which a strap or band of suitable material (hereinafter "strap") is placed around a container or package.

It is known to provide self-locking seals which comprise a rectangular planar body having one or more rectangular slots formed transversely therein.

A cylinder is journalled in the slot with its axis parallel to the long edge of the slot, and movable in a direction parallel with the short edge of the slot. A strap can be threaded through the slot o'r slots in such a way that the cylinder is in frictional contact with the strap, and moves to trap the ≤^rap against the edge of the slot when the strap is partially withdrawn from the slot.

This arrangement suffers the disadvantages that the sliding journals are complicated to make, and that excessive force applied to the strap can break the sliding journals, so releasing the strap. Also, the body must be planar and have the slot all the way through, to thread the strap, and this means that the seal body is not sufficiently strong for some applications. SUMMARY OF THE INVENTION

The present invention seeks to provide a fastener with a simple construction which provides secure fastening of

the strap. At its broadest, the present invention proposes that the strap be trapped between the casing of the fastener and a member movable along an inclined surface of a recess in a body in the casing.

Therefore, there is provided a fastener for a strap having a hollow casing with a body therein defining a gap between the body and the casing for receiving the strap, the body having at a recess adjacent the gap, the recess containing a member projecting from the recess and being movable along an inclined wall of the recess, such that movement of the member along the inclined wall is adapted to trap the strap beween the member and the casing. In this way, the fastener provides a self-locking seal for the strap. The strap is inserted into the fastener (in a direction which moves the member down into the recess and permits the end of the strap to pass through the fastener) and then pulled tight. The pull moves the member up the inclined wall giving a locking action.

In practice, the member projects from the recess towards the casing by an amount which varies in dependence on the movement of the member along the inclined wall. It is desirable that a part of the member projects from the recess even when the member is furthest from the casing, so that the member will be contacted by the strap.

The movable member may be a cylinder (preferably with a roughened surface) arranged transverse to the direction of insertion of the strap into the fastener. This provides

a large surface area of contact, in use, with the strap, so increasing the strength of retention of the strap.

There may be one such member and recess in the body so that one end of a strap may be secured. However, it may be desirable to secure the other end of a strap, or an end of another strap to the fastener. Therefore, there is preferably a second gap between the body and the casing- on the opposite side of the body from the first gap there being another recess in the body adjacent the second gap, which another recess contains another member movable along an inclined wall of the another recess. In this way, another part of the strap, or a second strap can be trapped in the second gap between the another member and the casing. This provides a large surface area of contact, in use with the strap, so increasing the strength of the retention of the strap. DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

Fig. 1 is a perspective, exploded view of a fastener according to the present invention;

Fig. 2 is a cross-section through the line II-II in Fig. 1 , but with the fastener assembled. DETAILED DESCRIPTION

A fastener according to the present invention as shown in Fig. 1, comprises a body 10 and a casing 11. The body

is substantially rectangular and along the two longer sides are walls 12 of height greater than the thickness of the body 10. The casing is a hollow cuboid with two open ends, having an internal height substantially equal to that of the walls 12 of the body 10, and a length and breadth substantially equal to the length and breadth of the body 10. The body 10 is positioned inside the casing 11, and because its thickness is less than the internal height of the casing, gaps 16,17 are defined between the body 10 and the casing 11. The body is fastened to the casing by the walls 12 e.g. by means of an interference fit.

Cylindrical rollers 13,18 are situated in respective substantially transverse recesses 14,19 in the body. In Fig. 2, each recess can be seen to be shaped to have an inclined surface 20,23 and a surface 21 , 2k generally perpendicular to the direction of extension of the respective gap 16,17- Also shown are the ends 25,26 of a strap 22 which extend through the gaps 16,17 and which are in frictional contact with the cylindrical rollers 13,18.

The operation of the fastener will now be described. One end 26 of the strap is inserted into the gap 17 from the end remote from the roller 18. To guide the end 26 of the strap 22, and also to identify which end of the gap 17 should receive the end 26 of the strap 22, a projection 15 is provided on the casing 11. The end 26 of the strap 22 is passed along the gap 17, past the roller 18. When the strap 22 is then pulled in the reverse direction, as

indicated by the arrow A, i.e. in the direction of upward inclination of the inclined slope 23, the roller 18 is rolled up the slope 23 by the frictional contact with the strap 22, and towards the casing 11. As it does so, the strap 22 is forced by the roller 18 against the casing 11. Eventually the strap 22 is forced against the casing 11 so hard that frictional forces between the strap 22 and casing 11 prevent further movement of the strap 22 from the fastener. If more force is applied to the strap 22 in the direction of the arrow A, the strap is forced harder against the casing 11 so that the frictional forces preventing the movement of the strap 22 also increase.

It will be apparent that if the strap 22 is pulled in the opposite direction (i.e. the direction of insertion), the roller 18 moves to its lowest point in the recess 14, so that the strap 22 is free to move in this direction.

The second roller 13 functions in an identical way to the first, but in the opposite direction. This is convenient for when the strap 22 is a loop positioned around an article. Thus, the other end 25 of the strap 22 may be inserted into the other gap 16, in the opposite direction of insertion to the direction of insertion of the end 26. The strap 22 is then tightened around the article, and movement of the strap 22 in the direction of arrow B is resisted by the action of the roller 13. An advantage of "S the loop arrangement is that articles of varying size can be strapped using a reel of strap and by using only the

desired length of strap straight from the reel.

In this embodiment, both the strap 22 and rollers 13,18 have roughened surfaces to assist the operation described above.

Although this embodiment uses cylindrical rollers 13.18 as the movable members, it is possible to use e.g. a ball in a recess or even a movable member of non-circular side cross-section to achieve the advantages of the invention. Similarly, a variety of recess shapes may be used, for example a symmetrical recess with two inclined walls which prevents substantial movement of the strap 22 in either direction.