GB2106584A

GB2106584A - Fasteners

Info

Publication number: GB2106584A
Application number: GB08227501A
Authority: GB
Inventors: Douglas James Cunningham
Original assignee: Britax Excelsior Ltd
Current assignee: Britax Excelsior Ltd
Priority date: 1981-09-29
Filing date: 1982-09-27
Publication date: 1983-04-13
Also published as: GB2106584B

Abstract

A fastener has a body 10 with a hook-like formation 14 defining an article-receiving recess. A closure member 24 is pivotally mounted on the body 10 for angular movement between an open position within the recess and a closed position bridging the mouth of the recess. When the closure member 24 is in the closed position it is further moveable relative to the body 10 into a blocking position in which angular movement to the other position is blocked. <IMAGE>

Description

SPECIFICATION Fasteners This invention relates to fasteners and is particu larly, but not exclusively concerned with safety hook fasteners.

Marine safety harnesses and many safety ap pliances in industry require the use of hook fasten ers. Often these fasteners are provided with spring loaded latches to prevent a rope, wire, ring or eye located on the hook from becoming disengaged.

However, it has been found that many such fasten ers can be accidently tripped open in a number of ways, for example by impact between an eye secured on the fastener and the outside of the latch.

It is already known from G.B. Specification No.

1257238 to provide a fastener having provision for mitigating this disadvantage, but fastener disclosed therein requires the provision of both a closure member to close the recess and a separate locking member to prevent accidiental release of the closure member. The present invention is concerned with the provision of a fastener of this type in which the functions of the closure member and the locking member are combined in a single component.

According to the invention a fastener comprises a body defining an article-receiving recess, a closure member pivotally mounted on said body for angular movement between an open position within said recess and a closed position bridging said recess, said pivotal mounting being adapted to permit additional relative movement between the body and the closure member when the latter is in the closed position between a blocking position in which said angular movement is blocked and a release position in which said angular movement is permitted, the closure means being resiliently biased into the closed position and the pivotal mounting thereof being resiliently biased into the blocking position.

Preferably, a single spring is used both to bias the closure member into its closed position and to bias the pivotal mounting into its blocked position.

In one form of the invention the pivotal mounting comprises a pivot pin either secured to the closure member and extending through a slot in the body or secured to the body and extending through a slot in the closure member, the closure member and the body having interengaging formations which block said angular movement when the pivot pin is at one end of the slot but not when the pivot pin is at the other. Preferably, the closure member carries a second pivot pin adapted to engage in an openended slot on the side of the recess opposite to the said pivotal mounting. When the closure member is moved from its blocking position to its release position, it pivots about this second pivot pin as the first mentioned pivot pin moves along the slot.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a side view of a safety hook in accordance with the invention with the closure member in its closed and blocked position, Figure 2 is a sectional view taken on the line 2-2 in Figure 1, Figure 3 is a side view similar to Figure 1 but with the closure member in its closed and released position, Figure 4 is a side view similar to Figures 1 and 3 but with the closure member in its open position, and Figure 5 is a side view of the closure member, taken from the side facing outwardly of the hook.

Referring to the drawings, a safety hook fastener has a body 10 with an aperture 12 to which a safety harness or the like may be permanently connected.

The other end of the body 10 has a hook-like formation 14 with an opening 16 (Figure 4) at one side. Adjacent to the opening 16 the hook formation 14 has an inwardly opening slot 18.

On the opposite side of the opening 16 from the slot 18the body 10 hasa closed slot 20 through which a pivot pin 22 projects. Mounted on the pivot pin 22 is a closure member comprising two side portions 24 and 26 located one on each side of the body 10 and interconnected by a web 28. The closure member 24, 26 also carries a second pivot pin 30 which in the closed position, is received in the slot 18 and a third pivot pin 32 which projects through an opening 34 in the body 10.The edge of the opening 34 further from the pivot pin 20, has a first portion 36 oriented and dimensioned to permit the pin 32 to move along an arc centered on the inner end of the slot 18 and a second portion 38 oriented and dimensioned to permit the pin 32 to move along an arc centered on the end of the slot 20 occupied by the pivot pin 22 when the closure member 24, 26 is in its released position. The shape of the other edges of the opening is not critical.

A recess 40 extending part of the way through the thickness of the body 10 accommodates a coiled lever spring 42 which has one end limb 44 connected to the body 10 and the other end limb 46 connected to the side portion 24 of the closure member so as to bias the latter into its closed and blocked position.

The operation of the safety hook fastener is as follows. Starting from the position shown in Figures 1 and 2 when it is desired to open the hook fastener, the blocking member 24,26 is first pivoted about the pin 30 in the slot 18 so that the pin 22 moves from the left hand end to the right hand end of the slot 20 (as viewed in Figures 1,3 and 4) thereby stressing the spring 42. The closure member is thus in the position shown in Figure 3, with the pin 32 at the junction between the two parts of the slot 34, having moved from the end of the section 36 thereof. The closure member, 24 26 can now pivot about the pivot pin 22 into the open position shown in Figure 4, the pin 32 moving along the second part 38 of the slot 34 and the spring 42 being further stressed. A rope, eye or the like can now be inserted into or removed from the hook. If the closure member is then released, the spring 42 moves it back first to the position shown in Figure 3 and then to the position shown in Figure 1.

Any attempt to open it again, for example by pressure on the outer surface of the part bridging the opening of the opening 16 of the hook (in the vicinity of the web 28) is blocked by engagement of the pin 32 with the side of the first part 36 of the slot 34.

Claims

1. A fastener comprises a body defining an article-receiving recess, a closure member pivotally mounted on said body for angular movement between an open position within said recess and a closed position bridging said recess, said pivotal mounting being adapted to permit additional relative movement between the body and the closure member when the latter is in the closed position between a blocking position in which said angular movement is blocked and a release position in which said angular movement is permitted, the closure means being resiliently biased.

2. A fastener according to claim 1, wherein the pivotal mounting comprises a pivot pin secured to one of the closure members and the body and extending through a slot in the other of the closure member and the body, the closure member and the body having interengaging formations which block said angular movement when the pivot pin is at one end of the slot but not when the pivot pin is at the other end.

3. A fastener according to claim 2, wherein the closure member carries a second pivot pin adapted to engage in an open-ended slot on the side of the recess opposite to the said pivotal mounting, the closure member pivoting about this second pivot pin as the first mentioned pivot pin moves along the slot.

4. A fastener according to claim 2 or 3, wherein the interengaging formations comprise a camming surface on the body and a cam follower on the closure member.

5. A fastener according to any preceding claim, wherein a single spring is used both to bias the closure member into its closed position and to bias the pivotal mounting into its blocked position.

6. A fastener substantially as hereinbeforede- scribed with reference to the accompanying drawings.