GB2373554A

GB2373554A - A release nut

Info

Publication number: GB2373554A
Application number: GB0107387A
Authority: GB
Inventors: John Robert Cottle
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-03-23
Filing date: 2001-03-23
Publication date: 2002-09-25
Also published as: GB0107387D0

Abstract

A release nut (2) comprising a sleeve (4), a plurality of segments (6) positioned inside the sleeve (4) and having a threaded inner surface (8) for enabling the release nut (2) to screw to a threaded anchor member (10), abutment means (12) for preventing the segments (6) from moving radially outwardly thereby to enable the release nut (2) to be tightened on the threaded anchor member (10), recess means (16) for permitting the segments (6) to move radially outwardly thereby to enable the release nut (2) to release from the threaded anchor member (10), and actuator means (18) for causing the sleeve (4) to move longitudinally with respect to the segments from a first position in which the abutment means (12) is operative to a second position in which the recess means (16) is operative.

Description

A RELEASE NUT This invention relates to releaseable fasteners and, more especially, this invention relates to a release nut.

Releaseable fasteners are known and they are typically used in applications such for example as the release of lifeboats, the release of payloads attached to aircraft, the release of emergency ballast on submarines, and the release of emergency access panels. These known releaseable fasteners are not as strong as standard fixings, and they therefore require special interfaces.

Typically, the releaseable fasteners are caused to operate by explosive devices or devices that are complex and costly. In addition, the operation of the releaseable fasteners by explosive devices tends to cause debris to be projected, which can make them dangerous and not renewable.

It is an aim of the present invention to reduce the above mentioned problems.

Accordingly, in one non-limiting embodiment of the present invention there is provided a release nut comprising a sleeve, a plurality of segments positioned inside the sleeve and having a threaded inner surface for enabling the release nut to screw to a threaded anchor member, abutment means for preventing the segments from moving radially outwardly thereby to enable the release nut to be tightened on the threaded anchor member, recess means for permitting the segments to move radially outwardly thereby to enable the release nut to release from the threaded anchor member, and actuator means for causing the sleeve to move longitudinally with respect to the segments from a first position in which the abutment means is operative to a second position in which the recess means is operative.

The release nut of the present invention may be constructed to be substantially as strong as a standard non-release nut. The release nut of the present invention may be of a similar size to the standard nut, thereby allowing direct replacement with no change in interface.

Still further, the release nut can be operated such that debris is not projected, which makes the nut attractive for use in applications where personnel are in close proximity.

The release nut may be manufactured to be reusable. The release nut may be such that a structural load can be

fastened in a manner that will guarantee its integrity.

" The load or structure can then be released or caused to fail by operation of the actuator means.

When the actuator means is operated, the sleeve is caused to move longitudinally with respect to the segments from the first position to the second position. In the second position, the recess means is operative and the segments are able to move radially outwardly. The segments are caused to move radially outwardly due to the angle of the engaging threads on the segments and the threaded anchor member. Force on the segments thus becomes directionalised and the segments are forced radially outwardly, thereby to enable the release nut to release from the threaded anchor member. A load or structure held in position by one or more of the release nuts can thus be released or caused to fail in a quick, simple and relatively safe manner.

The abutment means may comprise engaging abutment formations on the segments and the sleeve. Preferably, the release nut is one in which each one of the segments has two of the engaging abutment formations, and in which the sleeve has two of the engaging abutment formations. The two engaging abutment formations on each one of the segments may be two flanges, and the two engaging abutment formations on the sleeve may be one flange and one shoulder. Other types of engaging abutment formations may be employed.

The recess means preferably comprises grooves on the "'segments and the sleeve. Each one of the segments may have one of the grooves, and the sleeve may have two of the grooves. Other arrangements of the grooves may be employed. The grooves may be of the same or similar cross sectional shape.

Any suitable and appropriate type of actuator means may be employed. Thus, for example, the actuator means may be responsive to a hydraulic actuator, a pneumatic actuator, a pyrotechnic actuator, or a mechanical actuator.

Preferably, the release nut is one in which the actuator means is responsive to a hydraulic actuator or a pneumatic actuator, and in which the sleeve comprises conduit means for receiving fluid from the hydraulic actuator or the pneumatic actuator and for causing the sleeve to move longitudinally with respect to the segments from the first position to the second position.

The threaded anchor member can be vertically mounted, horizontally mounted, or at any suitable and appropriate angle. The release nut will simply be screwed longitidunally along an appropriate threaded portion of the threaded anchor member.

The present invention also extends to the combination of the nut and the threaded anchor member.

The threaded anchor member may be a bolt or any other suitable and appropriate type of quick release fastener.

The nut and the threaded anchor member can be made of "any suitable and appropriate materials. They will usually be made of a metal such for example as stainless steel. Plastics materials may however be employed if suitable and desired.

An embodiment of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 illustrates a release nut on a threaded anchor member, with the release nut being in a fastening non-activated condition; Figure 2 is a view of the release nut and the threaded anchor member similar to Figure 1, but shows the release nut in a released activated condition; Figure 3 is a partial section through the release nut shown in Figures 1 and 2 and illustrates the release operation of the release nut; and Figure 4 is a part sectional view illustrating how the release nut and the threaded anchor member are used to position an object.

Referring to Figures 1-3, there is shown a release nut 2 comprising a sleeve 4 and a plurality of segments 6 positioned inside the sleeve 4 as shown. The segments 6 have a threaded inner surface 8 for enabling the release nut 2 to screw to a threaded anchor member 10.

The release nut 2 includes abutment means 12 for preventing the segments 6 from moving radially outwardly,

thereby to enable the release nut to be tightened on a "threaded portion 14 of the anchor member 10 as shown in Figure 1.

The release nut 2 also comprises recess means 16 for permitting the segments 6 to move radially outwardly, thereby to enable the release nut 2 to release from the threaded anchor member 8 as shown in Figure 2. Actuator means 18 are employed for causing the sleeve 4 to move longitudinally with respect to the segments 6 from a first position as shown in Figure 1 in which the abutment means 12 is operative, to a second position as shown in Figure 2 in which the recess means 16 is operative.

The abutment means 12 comprises engaging abutment formations 20 on the segments and the sleeve. As can be seen from Figures 1 and 2, each one of the segments 6 has two of the engaging abutment formations 20, and the sleeve has two of the engaging abutment formations 20. The engaging abutment formations 20 on the segments are in the form of flanges as shown. The engaging abutment formations 20 on the sleeve are in the form of one flange as shown and one shoulder as shown.

The recess means 16 comprises grooves 22 on the segments 6 and the sleeve 4. As can be seen from the drawings, each one of the segments 6 has one of the grooves 22, and the sleeve has two of the grooves 22. The uppermost groove 22 on the sleeve 4 has two sides as shown.

The lowermost groove 22 on the sleeve 4 has an open lower "side as shown.

The actuator means 18 is responsive to a hydraulic actuator (not shown). The actuator means 18 comprises conduit means in the form of bores 24 for receiving fluid from the hydraulic actuator in the direction of the arrows 26 shown in Figure 2. As can be seen from Figure 3, the fluid that passes through the bores 24 is received in a space 28 between a top part 30 of the sleeve 4 and an adjacent part 32 of the segments 6. The space 28 is sealed by seals 34,36. Thus fluid introduced into the space 28 under pressure causes the sleeve 4 to move upwardly as shown in Figure 3 to the position shown in Figure 2. In the position shown in Figure 2, the recess means 16 is operative and the segments 6 are able to move radially outwardly as indicated by the arrows 38.

Referring now to Figure 4, two of the threaded anchor members 10 are each shown in the form of a bolt having a shank 40 and a head 42. The release nut 2 is shown in a tightened position on the shank 40 of each threaded anchor member 10. The threaded anchor members 10 shown in Figure 4 are shown holding an object 44 to a securing platform 46.

Pressure in the inside 48 of the object 44 is prevented from being lost at the interface of the object 44 with the sealing platform 46 by a seal 50. On appropriate activation of the hydraulic actuator, the release nuts 2 will simply and quickly release in a non-dangerous manner

from the threaded anchor members 10, and the object 44 then "automatically releases from the securing platform 46.

It is to be appreciated that the embodiment of the invention described above with reference to the accompanying drawings has been given by way of example only and that modifications may be effected. Thus, for example, the sleeve 4 and the segments 6 may be of different shapes than shown. The threaded anchor member 10 may be other than a bolt as shown in Figure 4. The release nut 2 can be used in a wide variety of applications including those currently used by non-quick release fasteners.

Claims

CLAIMS 1. A release nut comprising a sleeve, a plurality of segments positioned inside the sleeve and having a threaded inner surface for enabling the release nut to screw to a threaded anchor member, abutment means for preventing the segments from moving radially outwardly thereby to enable the release nut to be tightened on the threaded anchor member, recess means for permitting the segments to move radially outwardly thereby to enable the release nut to release from the threaded anchor member, and actuator means for causing the sleeve to move longitudinally with respect to the segments from a first position in which the abutment means is operative to a second position in which the recess means is operative.
2. A release nut according to claim 1 in which the abutment means comprises engaging abutment formations on the segments and the sleeve.
3. A release nut according to claim 2 in which each one of the segments has two of the engaging abutment formations, and in which the sleeve has two of the engaging abutment formations.
4. A release nut according to claim 3 in which the two engaging abutment formations on each one of the segments are two flanges, and in which the two engaging abutment formations on the sleeve are one flange and one shoulder.
5. A release nut according to any one of the preceding claims in which the recess means comprises grooves on the segments and the sleeve.
6. A release nut according to claim 5 in each one of the segments has one of the grooves, and in which the sleeve has two of the grooves.
7. A release nut according to any one of the preceding claims in which the actuator means is responsive to a hydraulic actuator, a pneumatic actuator, a pyrotechnic actuator, or a mechanical actuator.
8. A release nut according to claim 7 in which the actuator means is responsive to a hydraulic actuator or a pneumatic actuator, and in which the sleeve comprises conduit means for receiving fluid from the hydraulic actuator or the pneumatic actuator and for causing the sleeve to move longitudinally with respect to the segments from the first position to the second position.
9. A release nut substantially as herein described with reference to the accompanying drawings.
10. The combination of the release nut according to any one of the preceding claims and the threaded anchor member.
11. The combination according to claim 10 in which the threaded anchor member is a bolt.