GB2220979A

GB2220979A - Security band-clamp or -tie

Info

Publication number: GB2220979A
Application number: GB8916371A
Authority: GB
Inventors: Reginald Alfred George Smith
Original assignee: R A SMITH PLASTICS Ltd
Current assignee: R A SMITH PLASTICS Ltd
Priority date: 1988-07-18
Filing date: 1989-07-18
Publication date: 1990-01-24
Anticipated expiration: 2009-07-18
Also published as: GB8916371D0; GB2220979B; GB8817060D0

Abstract

The head of a security tie has a slot 26 which houses a tongue 27. The wall of the slot opposite the tongue has a ramp surface 251 for urging a strap against the tongue. A wing 28 is also preferably provided, which enhances engagement of the tongue with the formation 11 provided on the strap portion of the tie. A pair of moulding tools for forming the head portion comprise a first tool having side surfaces for forming an entry portion of the slot, and a second tool having side surfaces forming an exit portion of the slot. Both tools have formations which cooperate to form a tongue within the slot. (Fig 6, not shown). <IMAGE>

Description

SECURITY TIES Security ties are known which consist of a strap with an integral head having a slot through which the tail end of the strap may be passed. Formations on the strap cooperate with a tongue located within the slot to prevent retraction of the strap. Damage caused to the strap is therefore indicative of tampering.

It is possible to achieve an acceptable level of security with such a tie but in general this necessitates a complicated construction.

An object of the present invention is to provide a simple but nevertheless effective construction for a security tie.

This object is achieved by the features of the tie shown in the drawings, in which: Figure 1 is a perspective view of the tie, Figure 2 is a side elevation of the head of the tie, Figure 3 is a top plan view of the head of the tie, viewed in the direction of arrow III in Figure 2, Figure 4 is an underneath plan view of the head of the tie, viewed in the direction of arrow IV, Figure 5 is section through the head of the tie, taken in the plane of symmetry and to an enlarged scale, Figure 6 is a section through the core pins used in the moulding of the head of the tie, Figure 7 is a fragment of the head of the strap.

Referring to the drawing, the tie consists of a strap 1 and an integral head 2, moulded from plastics.

The head has a base 21 and a post 20 formed by upstanding side walls 22 joined by a pair of cross-pieces 24, 25 to define a slot 26 through which the strap may pass. The inner surfaces 221 of the side walls are curved in crosssection and both mouths of the slot are generally semicircular in shape. The base 21 is formed with a second slot 29. A tongue 27 penetrates into the slot 26 and a tongue 29 penetrates into the slot 28, for cooperation with teeth 11 on the strap.

In order to secure an article, such as the mouth of a bag, the strap 1 is passed through the slot 26 and back through the slot 30, being latched by the teeth.

The inner face of cross-piece 24 is planar and is formed with the tongue 27 for cooperation with complementary teeth on the strap. The surface of the cross-piece 25 facing the strap is planar and includes an entry section 251 inclined towards the cross-piece 24 at an angle of 15. to the vertical centre-plane of the slot (i.e. the plane perpendicular to the under surface of the base 21), an intermediate section 25 inclined away from the crosspiece 24 at angle of 15' to the centre-plane, and an exit section inclined away from the cross-piece 24 at an angle of 30' to the centre-plane. The inner surface of the cross-piece 24 has an entry section 241 which, at a distance below (i.e. nearer to the base than) the lower end of ramp section 251, terminates in the root of the outer facing surface 271 of tongue 27.

The inner and outer facing surfaces 271, 272 respectively of the tongue are substantially parallel and project at an angle of substantially 15 to the centre-plane of the slot. The surface 272 of the tongue faces a main section 242 of cross-piece 24 which extends at an angle of substantially 3 to the centre-plane of the slot.

There is a slight clearance between the root of the inner facing surface 272 of the tongue and the lower end of the intermediate section 242 to enable the tongue to be forced back against the intermediate section.

Projecting from the exit section 253 is a resilient wing 28 arranged at an angle of 20 to the centre-plane of the slot. The edge 243 of the wall 24 is formed into a tooth.

As the strap is passed through the slot 26, the ramp section 251 forces the strap to follow a path in which it is pressed against the tongue, which is in turn pressed back by the passing crests of the teeth against the main section 242. When the strap enters its tightened position it interlocks with the tongue, being held against the tongue by the ramp surface thereby ensuring reliable interlocking engagement between the teeth and the tongue. The wing 28 also presses the strap towards the other side of the slot and enhances reliable contact with the tongue.

The enlargement of the mouth of the slot 26 facilitates insertion of the end of the strap. When the strap is in its tightened position, one of the teeth 11 cooperates with the tooth 243 so as to provide additional security.

The widenings given to the mouths of the slot 26 improve the moulding process without detracting from the reliability of the tie.

The tools 3 and 4 for moulding the slot are shown in Figure 6, and interfit to form the surface of the crosspieces and the tongue in a single moulding operation.

Claims

1. A security tie having a head and strap, the head being provided with a slot defined by two opposed surfaces, a tongue projecting from one of said surfaces to interlock with formations on a strap, the other surface having a ramp portion shaped to press the strap against the tongue as it passed through the slot.

2. A security tie as claimed in claim 1, including a wing projecting from said other surface for biasing the strap towards said one surface.

3. A security tie as claimed in claim 2 wherein the mouths of the slot are tapered, and the wing is formed on an outwardly tapering portion of said other surface.

4. Moulding tools for use in forming a slot through the head of a security tie, one tool having side surfaces for forming an entry portion of the slot, the other tool having side surfaces for forming an exit portion of the slot; both tools having portions which cooperate to form a tongue within the slot.