GB2532750A

GB2532750A - Improvements in and relating to hydrostatic release units

Info

Publication number: GB2532750A
Application number: GB1421006.6A
Authority: GB
Inventors: Kearsley Paul
Original assignee: Orolia Ltd
Current assignee: McMurdo Ltd
Priority date: 2014-11-26
Filing date: 2014-11-26
Publication date: 2016-06-01
Anticipated expiration: 2034-11-26
Also published as: GB2532750B; GB201421006D0

Abstract

A hydrostatic release unit (HRU) 16 comprises a first body part and a second body part connected by a connector (7, Fig 3), means for biasing the first body part away from the second body part, means (54, Fig 5) for capturing a first part of the connector with the first body part, means for capturing a second part of the connector with the second body part, and release means to release at least the second part from the second body part upon a hydrostatic activation event.

Description

Improvements in and Relating to Hydrostatic Release Units

Field of the Invention

The present invention relates to hydrostatic release units.

Background to the Invention

A sea water activated Hydrostatic Release Unit (HRU) is used to secure a two-part assembly together that typically retains a radio beacon and/or storage media and/or life-saving/safety equipment. The HRU is retained to both halves of the assembly by a retaining bolt. If the ship/boat or fixed/rotary wing aircraft were to get into difficulty and sink the HRU would activate at a pre-determined depth due to the increase in water pressure by deflecting a pressure sensitive diaphragm that in turn will activate a spring loaded blade to cut the connecting bolt allowing the two halves of an assembly to separate so a radio beacon and/or storage media and/or life-saving/safety equipment can be released and float to the surface.

There is a desire to produce a blade-free HRU.

It is an aim of preferred embodiments of the present invention to provide a blade-free HRU.

Summary of the Invention

According to the present invention in a first aspect, there is provided a hydrostatic release unit (HRU) comprising a first body part and a second body part connected by a connector, means for biasing the first body part away from the second body part, means for capturing a first part of the connector with the first body part, means for capturing a second part of the connector with the second body part, and release means to release at least the second part from the second body part upon a hydrostatic activation event.

Suitably, the connector comprises a bolt including a head and release means comprises an expanded head for being captured by a rotatable fork.

Suitably, the unit comprises a biasing means whereby the rotatable fork is biased to a release configuration. Suitably, the biasing means is a torsion spring.

Suitably, the rotating fork is secured in a locked configuration by a locking mechanism, which locking mechanism is released by the activation event. Suitably, the locking mechanism comprises a pin that engages in a slot or hole in the rotating fork.

Suitably, the torsion spring lies within a chamber of the rotating fork, with the fork to one side of the chamber.

Suitably, the activation event comprises the ingress of water into the HRU. Suitably, the HRU comprises water ingress holes in communication with a water chamber having a diaphragm connected to the pin of the locking mechanism whereby, in use, the ingress of water into the water chamber exerts pressure on the diaphragm to move the pin from a position in which it is engaged in the slot or hole to one in which it is disengaged from the slot or hole, thereby releasing the hook part to rotate to release the second part of the connector.

Suitably, the HRU further comprises a replaceable cover stem projection, which cover stem is configured to secure the HRU to an assembly cover. By being replaceable it means that the HRU can be used with a multiplicity of different emergency assemblies.

Accordingly there is provided a blade-free HRU with a reliable, yet simple release mechanism that can be used with a variety of emergency assemblies. Being blade free improves safety during manufacture and use.

The present invention extends to an emergency assembly including such a HRU.

Brief Description of the Drawings

Figure 1 shows an exploded view of an emergency beacon assembly incorporating a HRU according to the present invention.

Figure 2 shows a cross-sectional view of the emergency beacon of Figure 1 in an assembled configuration.

Figure 3 shows an exploded view of the emergency beacon of Figures 1 and 2 after separation, with the HRU separated.

Figures 4A and 4B show an upper (4A) and lower (4B) perspective view of the HRU shown in Figures 1 -3.

Figure 5 shows an exploded perspective view of the HRU.

Figure 6 shows a cross sectional, side elevation of the HRU shown in Figure 5.

Figures 7A, 7B and 7C show three perspective views of the mechanics to capture and secure the retaining bolt of the HRU shown in the preceding Figures.

Figures 8A and 8B show two cross-sectional views of the HRU shown in the preceding Figures showing how the diaphragm and lock pin react under pressure to activate the unit.

Figures 9A, 9B and 9C show three perspective views of the HRU shown in the preceding Figures illustrating the mechanics to release and free the retaining bolt.

Figures 10A, 10B and 10C show three perspective views of the interchangeable top mounting stem.

Detailed Description of a Preferred Embodiment

Figures 1 -3 of the accompanying drawings show an emergency beacon assembly 100 comprising a base 17, a cover 18, a HRU 16 and a beacon 19. In use the beacon 19 and HRU 16 are held between the base 17 and cover 18. A connector means in the form of a connection bolt 7 (described later in relation to Figure 5) secures the base 17 to the HRU 16. The HRU 16 in turn is secured relative to the cover 18 by a cover stem projection 15 using a spring clip 20. The connecting bolt is factory pre-installed in the HRU 16.

A launch cradle 21 is hingedly attached to the base 17, which cradle 21 is spring biased away from the base 17.

Referring to Figures 4 -6 of the accompanying drawings, the HRU 16 comprises a main housing 1 (second body part) and a base cover 2 (first body part) that are joined by snapping the two together, although any method of joining could be utilised such as ultrasonic welding, screwing or bonding. Between the main housing 1 and base cover 2 are installed a large 0-ring 3, a torsion spring 4 (biasing means), a rotating fork 5 (capturing means) and a small 0-ring 6. Additionally there is a connection bolt 7 with a first end with a first expanded head 56 and a second end with a second expanded head 58.

Before the housing 1 and base 2 are clipped home the rotating fork 5 and the torsion spring 4 need to be installed. The tail ends of the spring 4 locate into location holes (capturing means, not shown) in the main housing 1 and rotating fork 5 (capturing means). A central mandrel on the rotating fork 5 locates into a bearing recess in the main housing 1 to provide the pivot for rotation. The two 0-rings 3 and 6 provide the seal to protect the components from the ingress of moisture and debris once the base 2 is snapped into position.

The rotating fork 5 is rotated within the sealed chamber by the use of a tool engaging into a drive feature 23 that is exposed on the underside of the unit; see Fig 5. Fork part 54 will capture the connection bolt 7 head. On rotation the torsion spring 4 is wound up creating a rotational force that will want to spin the rotating fork 5 back when allowed to do so. On the main housing 1 there is a water chamber 50 on the top side that houses a diaphragm sub assembly 12, a compression spring 11, a diaphragm support ring 14 and 2 0-ring seals 13 and 10. These are assembled into the water chamber and retained in place by the housing cap 9 that clips onto the main housing 1. The diaphragm is held in a downward condition by compression spring 11. Compression spring can be sized to tune or alter the activation pressure of the HRU 16. The upper side of the diaphragm is a sealed atmospheric chamber; the underside is open to the pressure of the sea through an array of slots 52 in the main housing (see Fig 8A).

Fig 6 shows a side sectional view of the fully assembled HRU 16 in the armed position. The arming procedure is depicted by Figures 7A, 7B and 7C of the accompanying drawings. Fig 7A shows the rotating fork 5 in its rest position allowing the retaining bolt 7 and 0-ring 8 to be inserted into the main housing chamber through the aperture in the base 2. The rotating fork 5 is then rotated using a tool engaging into a drive feature 23 that is exposed on the underside of the unit see Fig 4. Fig 7B shows the rotating fork swinging round and about to capture the flanged head of the retaining bolt 7, the torsion spring 4 is also being wound up as the rotating fork 5 is turned. Eventually the fork 5 will engage with the flanged head of the retaining bolt 7 (release means) and cannot be turned any further as shown in Figure 7C. The retaining bolt 7 is now trapped and the 0-ring 8 is sandwiched between a shoulder on the retaining bolt 7 and the base cover 2 creating a seal around the aperture. Simultaneously the lock pin 25 (Fig 8a) on the diaphragm 12 will engage in to a slot on the rotating fork 5 to stop it rotating back with the torsion spring force. The unit is now armed and ready to be installed into a typical radio beacon and/or storage media assembly housing as previously described.

The HRU 16 is installed into a typical radio beacon assembly base 17 by passing the bolt head of retaining bolt 7 through the launch cradle 21 and depressing it against spring pressure 22. The HRU is then held captive by sliding the unit forward so the bolt head slides into a slot in the assembly base 17 trapping the HRU 16 in place see Fig 2, as a result the launch cradle 21 is held down against spring 22. A typical radio beacon and/or storage media 19 is then located on to the launch cradle 21 in a specific polarised position, the assembly cover 18 can then be placed over the radio beacon and/or storage media 19 and HRU 16 ensuring the protruding stem 15 of the HRU passes through the hole in cover 18. The cover 18 is then located on to the assembly base 17; this is then secured in place by fitting a spring clip to the stem 16 that is protruding through the cover. It should be noted that any type of fastening could be devised here such as a screw, nut, circlip or knob.

The assembly base 17 would have been fixed to the marine/aviation craft's deck/superstructure prior to the fitment of HRU 16, a typical radio beacon 19 and assembly cover 18.

If the said ship/boat or fixed/rotary wing aircraft should get into difficult when at sea and start to sink the assembly 100 will sink with it allowing the assembly to flood with water and the HRU 16 will also be subjected to this increasing pressure as the ship/boat or fixed/rotary aircraft sinks deeper. At a pre-determined depth the water pressure will be sufficient to activate the HRU mechanism, this will allow the retaining bolt 7 to separate from the HRU 16, this has the dual effect of firstly allowing the assembly cover to move away from the base assembly 17 along with the HRU 16 that it will still be attached to, and secondly allowing the launch cradle 21 to spring up due to spring force 22 and pushing the life-saving/safety equipment or typical radio beacon and/or storage media 19 away from the base assembly 17 so that it is free to float to the ocean surface where it can start to transmit distress, non-distress and positional signals -see Fig 3.

Referring to Figures 8A and 8B of the accompanying drawings, when the HRU 16 is submerged as it would when the ship/boat or fixed/rotary wing aircraft is sinking, activation of the unit is caused by water entering the chamber underneath the diaphragm through an array of open slots 24 (see Fig 8A). As the unit sinks further the pressure increases in this chamber causing the diaphragm to deflect upwards as shown in Fig 8B causing the lock pin 25 on the diaphragm sub-assembly 12 to withdraw from the slot in the rotating fork 5, this allows it to rotate back due to the torsion spring force.

Figures 9A, 9B and 9C of the accompanying drawings show the sequence that allow the retaining bolt 7 to separate from the main HRU unit 16. The radio beacon and/or storage media and/or life-saving/safety equipment can then be deployed as previously explained.

Figures 10A, 10B and 10C of the accompanying drawings shows the mechanics for an interchangeable cover stem projection 15. This slides on by engaging a set of rails on both the stem base 15 and main housing 1 of the HRU assembly 16. Once the stem 15 has been pushed on far enough the latch 26 will click in place to retain the stem 15 on the HRU assembly 16. The stem 15 cannot be removed easily if at all by hand, but if it does need to be taken off the use of a flat tip screwdriver or blade to prise the latch up while the part is pushed off will facilitate. The idea behind an interchangeable stem is the HRU can be adapted for different housings or alternative fixing methods to the sprung clip.

It should be noted that although described in relation to an emergency beacon assembly, the HRU 16 can be used with a variety of components, such as storage media or life saving/safety equipment.

By using a pin or bolt to connect two parts of the HRU together and disengaging a locking mechanism for the pin upon activation, the release mechanism is simple and blade-free.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS1. A hydrostatic release unit (HRU) comprising a first body part and a second body part connected by a connector, means for biasing the first body part away from the second body part, means for capturing a first part of the connector with the first body part, means for capturing a second part of the connector with the second body part, and release means to release at least the second part from the second body part upon a hydrostatic activation event.
2. A HRU according to claim 1, wherein the connector comprises a bolt including a head and release means comprises an expanded head for being captured by a rotatable fork.
3. A HRU according to claim 2, wherein the unit comprises a biasing means whereby the rotatable fork is biased to a release configuration.
4. A HRU according to claim 3, wherein the biasing means is a torsion spring.
5. A HRU according to claim 2, wherein the rotating fork is secured in a locked configuration by a locking mechanism, which locking mechanism is released by the activation event.
6. A HRU according to claim 5, wherein the locking mechanism comprises a pin that engages in a slot or hole in the rotating fork.
7. A HRU according to claim 4, wherein the torsion spring lies within a chamber of the rotating fork, with the fork to one side of the chamber.
8. A HRU according to any of the preceding claims, wherein the activation event comprises the ingress of water into the HRU.
9. A HRU according to claim 5, wherein the HRU comprises water ingress holes in communication with a water chamber having a diaphragm connected to the pin of the locking mechanism whereby, in use, the ingress of water into the water chamber exerts pressure on the diaphragm to move the pin from a position in which it is engaged in the slot or hole to one in which it is disengaged from the slot or hole, thereby releasing the hook part to rotate to release the second part of the connector.
10. A HRU according to any of the preceding claims wherein the HRU further comprises a replaceable cover stem projection, which cover stem is configured to secure the HRU to an assembly cover.
11. An emergency assembly comprising a cover, a base and a hydrostatic release unit (HRU) according to any preceding claim, whereby the unit is configured whereby activation of the HRU releases the cover of the assembly.
12. A hydrostatic release unit substantially as described herein, with reference to the accompanying drawings.
13. An emergency assembly, substantially as described herein, with reference to the accompanying drawings.Amended claims have been filed as follows:-CLAIMS 1. An emergency beacon assembly comprising a first body part and a second body part connected by a Hydrostatic Release Unit (HRU), with a connector securing the HRU to the second body part, means for biasing the first body part away from the second body part, means for capturing a first part of the connector with the HRU, means for capturing a second part of the connector with the second body part, and release means to release at least the second part of the connector from the first body part upon an ingress of water in to the HRU wherein the connector comprises a bolt including a head and release means comprises an expanded head for being captured by a rotatable fork.2. An emergency beacon according to claim 1, wherein the HRU comprises a biasing means whereby the rotatable fork is biased to a release configuration.3. An emergency beacon according to claim 2, wherein the biasing means is a torsion spring.4. An emergency beacon according to claim 1, wherein the rotating fork is secured in a locked configuration by a locking mechanism, which locking mechanism is released by the ingress of O water.CO 5. An emergency beacon according to claim 4, wherein the locking mechanism comprises a pin that engages in a slot or hole in the rotating fork.6. An emergency beacon according to claim 3, wherein the torsion spring lies within a chamber of the rotating fork, with the fork to one side of the chamber.7. An emergency beacon according to claim 5, wherein the HRU comprises water ingress holes in communication with a water chamber having a diaphragm connected to the pin of the locking mechanism whereby, in use, the ingress of water into the water chamber exerts pressure on the diaphragm to move the pin from a position in which it is engaged in the slot or hole to one in which it is disengaged from the slot or hole, thereby releasing a hook part to rotate to release the second part of the connector.8. An emergency beacon assembly according to any of the preceding claims wherein the HRU further comprises a replaceable cover stem projection, which cover stem is configured to secure the HRU to an assembly cover.9. An emergency assembly, substantially as described herein, with reference to the accompanying drawings.