GB2226377A - Fasteners - Google Patents

Abstract

A method of constructing a fastener comprising a lever 11 pivoting on a frame 10 having two side walls 12 and 13, between "release" and "locking" positions, comprising: a) providing a through-bore 17 in one wall 12 of the frame 10, and providing means eg blind-bore 18 for receiving a shaft end in the opposite frame wall 13, the through-bore and the receiving means being substantially in alignment; b) passing a shaft into the through-bore, and across the frame until one end of the shaft engages the receiving means; c) securing the shaft in position relative to the frame; d) mounting the lever on the shaft, before or after its shaft engages the receiving means; and e) providing that the lever is pivotally mounted to the frame. <IMAGE>

Description

FASTENERS Field of the Invention The invention relates to fasteners of the kind comprising a lever pivotally mounted on a frame having a pair of side walls. The lever is moveable between a release position in which the lever extends at an angle to the frame and a locking position in which the lever is disposed substantially flush with the frame in between the side walls of the frame.

Such a fastener will be referred to as a fastener of the kind specified.

An example of a fastener of the kind specified is the buckle shown in United Kingdom patent specification No 2 167 510.

Another fastener of the kind specified is shown in the present applicant previous United Kingdom patent application No 88 26365.2 to which the reader is referred.

The invention is more specifically concerned with a method of constructing a fastener of the kind specified.

Summary of the Invention According to the invention, there is provided a method of constructing a fastener of the kind specified from a lever member and a frame member, the method comprising the steps of: a) Providing a through-bore in one wall of the frame member, and providing means for receiving the end of a shaft in the opposite frame wall, the through-bore and the receiving means being substantially in alignment; b) passing a shaft into the through-bore and across the frame until one end of the shaft engages the receiving means; c) Securing the shaft in position relative to the frame; d) Mounting the lever on the shaft before or after the end of the shaft engages the receiving means; e) providing that the lever is pivotally mounted with respect to the frame.

The receiving means are preferably provided by forming a blind bore in the wall of the frame. The shaft may with advantage be secured to the frame. This is preferably achieved by ultrasonically welding the shaft to either the receiving means or the through-bore or both the receiving means and the through-bore.

When secured to the frame, the shaft may serve to brace the frame, and thus to inhibit any flexing of the frame during the use of the fastener.

The lever preferably snap fits onto the shaft. In this case, the snap fitting portion of the lever may with advantage comprise separate aligned opposite end regions of the lever.

Preferably the end of the shaft engaging the receiving means is so formed as to key into the frame wall when secured thereto.

Brief Description of the Drawings The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a plan view, partly broken away, of the frame of a fastener; Figure 2 is an end view of the frame; Figure 3 is a sectional view along the line C-C of figure 1; Figure 4 is a side view of the frame; Figure 5 shows in more detail the part of the frame labelled X in figure 1; Figure 6 is a plan view, partly broken away, of the lever of the fastener; Figure 7 is a sectional view along the line B-B of figure 6; Figure 8 is a side view of the lever; Figure 7 is a sectional view along the line B-B of figure 6; Figure 8 is a side view of the lever; Figure 9 shows in plan the fastener constructed from the lever and the frame; Figure 10 is a sectional view along the line D-D of figure 9, showing the lever superimposed on the frame;; Figure 11 is a side view of the fastener; Figure 12 shows in more detail the part of the fastener labelled Z in figure 11; and Figure 13 shows a shaft for use in constructing the fastener.

Description of the Preferred Embodiment The fastener shown in the drawings is intended for use in, for example, the transport industry for tightening a strap on the side of a lorry and for holding the strap securely in a tightened condition. The fastener includes a frame 10 and a lever 11 which, in use, engage a strap in the same way as the frame and lever of the fastener disclosed in UK patent application No 88 26365.2.

Referring to figure 1, the frame 10 is of channel form in cross-section having side walls 12 and 13. One end of the frame 10 includes a latching mechanism 14 which, in use, engages corresponding formations 15 (shown in figure 7) on the lever 11 to releaseably hold the lever 11 and hence the fastener, in a locking position.

The latching mechanism 14 and the formations 15 are identical in form and function to the corresponding components of the fastener disclosed in UK patent application No 88 26365.2. The lever 11 may thus be released from its locking position by exerting an inward manual pressure on a pair of disc shaped portions 16 externally projecting beyond the side walls 12 and 13 of the frame 10.

A through-bore 17 is formed in the wall 12 towards the opposite end region of the fastener (figure 3), and is aligned with a blind bore 18 formed in the wall 13. As can be seen from figure 5, the blind bore 18 has a 4 degree taper on each of the walls 12 and 13 a hollow cylindrical protruberance 19 projects inwardly from the periphery of respectively the through-bore 17 and the blind bore 18.

Each protruberance 19 is, in use, held in a part circular recess 20 in a lug 21 on the lever 11 (figures 6, 9 and 12). Each lug 21 includes a second, smaller recess 22 which is adjacent to and concentric with the recess 20.

The lugs 21 are situated in opposite end regions of the lever 11, and in the end of each lug 21 there is defined an opening 23. The opening 23 includes a constriction adjacent the recess 22, which constriction is formed between a pair of opposed lips 24.

The lugs 21, in use, fit over a hollow cylindrical shaft 25 (figure 13), the diameter of which is larger than the width of the constriction between the lips 24.

The size and shape of the lugs 21 relative to the shaft 25 are such that the lever 11 may be pivotally mounted on the shaft 25 in the following way. The openings 23 are so positioned against the shaft 25 that the lips 24 bear against the circumferential surface of the shaft 25.

A force is then applied to the lever 11 in such a direction as to urge the recesses 22 towards the shaft 25. The application of such a force causes the lugs 21 to so deform that the recesses 22 move towards the shaft 21, causing the lips 24 to separate.

Continued application of the force causes the lever to move against the resilience of the lugs 21 until the lips 24 of each lug 21 lie on a diameter of the shaft 25. As the lever 11 continues to move beyond this point, the inherent resil tents of the lugs 21, which urges each pair of lips 24 to move towards one another, tends to pull the shaft into the recesses 22.

The lever 11 is thus snap fitted onto the shaft 25.

The relative shapes and sizes of the recesses 22 are such that, in use, the lugs 21, whilst holding the lever 11 on the shaft 25, allow the lever 11 to pivot relative to the shaft 25.

Referring to figure 13, there are provided on one end of the shaft 25 a series of annular serrations 26. When the fastener is to be constructed, the leading end of the shaft 25, the end bearing the serrations 26, is passed into the through-bore 17 and across the buckle until the leading end engages in the blind bore 18.

The leading end of the shaft 25 is then ultrasonically welded to the blind bore 18, causing the material adjacent the blind bore 18 to flow around, and thus key onto, the serrations 26. Additionally, the other end of the shaft 25 may be ultrasonically welded to the through-bore 17.

The lever 11 is then snap fitted onto the shaft 25, the lugs 21 being so shaped as to hold the shaft 25 whilst enabling the lever 11 to pivot relative to the shaft 25 and the protruberances 19.

Alternatively, each lug 21 of the lever 11 may include a circular through-bore instead of the part circular recess 22. Since there is no gap in the periphery of each through bore, a fastener having such a lever would be constructed in the following way: The lever 11 is positioned within the frame 10 with the through-bores in the lugs 21 aligned with the through bore 17 and the blind-bore 18. The leading edge of the shaft 25 is then passed through the through-bore 17 and across the frame 10, passing through the through-bores in the lugs 21 and into the blind-bore. 18 in the process.

The shaft 25 is then ultrasonically welded to the blind bore 18. and optionally the through-bore 17 in the same way as before.

The shapes and sizes of the through-bores in the lugs 21 are such that the lever 11 is pivotally mounted with respect to the shaft 25 and hence the frame 10.

In this case, each lug 21 may include a slip-way (not shown).

The slip-ways facilitate the location of the lever 11 on the protruberances 19, and hence within the frame 10, prior to the insertion of the shaft 25.

Claims (9)

CLAIMS:

1. A method of constructing a fastener of the kind specified from a lever member and a frame member, the method comprising the steps of: a) providing a through-bore in one wall of the frame member, and providing means for receiving the end of a shaft in the opposite frame wall, the through-bore and the receiving means being substantially in alignment; b) passing a shaft into the through-bore, and across the frame until one end of the shaft engages the receiving means; c) securing the shaft in position relative to the frame; d) mounting the lever on the shaft, before or after the end of the shaft engages the rec eiving means; and e) providing that the lever is pivotally mount ed in respect to the frame.

2. A method according to claim 1 in which the receiving means are provided by forming a blind bore in the wall of the frame.

3. A method according to either of the preceding claims in which the shaft is secured to the frame by being ultrasonically welded to either the receiving or the through bore of both.

4. A method according to any of the preceding claims in which the lever snap fits onto the shaft.

5. A fastener according to claim 4 in which the snap fitting portion of the lever comprises separate aligned opposite end regions of the lever.

6. A fastener constructed by method according to any of the preceding claims.

7. A fastener according to claim 6 in which the end of the shaft engaging the receiving means is so formed as to key into the frame wall when secured thereto.

8. A method substantially as described herein with reference to the accompanying drawings.

9. A buckle as substantially as described herein with reference to, and as illustrated in, the accompanying drawings.