Water activated inflator for inflatable device and method of air deployment
The present invention relates to a water activated inflator and a method of air deployment of a water activated inflatable device. A gas cylinder opening device for opening a sealing mechanism of the gas cylinder is disposed in the housing movable along a first axis having a first orientation between a cocked position and a fired position. A tension mechanism provides tension acting along the first axis for moving the gas cylinder opening device from the cocked position to the fired position. A plunger is holding the gas cylinder opening mechanism in the cocked position. The plunger is movable along a second axis having a different second orientation between a first position and a second position. A water soluble element is holding the plunger in the first position. A first interacting surface of the gas cylinder opening device is disposed at a predetermined angle to the first axis. A second interacting surface of the plunger is in contact with the first interacting surface at the predetermined angle. The angle is determined such that a component along the second axis of a component of the tension acting onto the second interacting surface is within a predetermined range for ensuring structural integrity of the water soluble element in the cocked position and for ensuring movement of the plunger when at least a portion of the water soluble element is dissolved. Using the water activated inflator in a rescue kit is highly beneficial for air rescue operations over a body of water by providing proper timing of the inflation shortly after impact.
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This application claims the benefit of U.S. Provisional Patent Application No. 60/566,170 filed Apr. 29, 2004.
FIELD OF THE INVENTIONThis invention relates to air deployment of an inflatable device and in particular to a water activated inflator for use in an air deployable device and a method of air deployment using the same.
BACKGROUND OF THE INVENTIONThere is a continuing need for development of methods of accurately dropping inflatable devices from an airplane, for example, life rafts to survivors in a body of water. The most advanced method, presently in use, is dropping an inflatable device in a deployment container using a parachute and timer as disclosed, for example, in U.S. Pat. No. 4,639,229. Use of the parachute substantially ensures correct orientation of the container on impact with the body of water and a predetermined range of speed at impact through aerodynamically braking the descent of the container. After impact the container is partially or completely submerged in the water, bobbing in the water and then floating on the surface until the device is inflated. Using a timer, the inflation is initiated after a preset time interval elapses, predetermined at time of manufacturing the inflatable device based on an expected altitude of an airplane flying above the water surface such that the inflation starts shortly after impact of the container on the body of water. However, the exact timing for initiating the inflation is a major problem of this method of air deployment using a timer. If the inflation is initiated too early, the device is inflated while still in the air resulting in the inflated device being blown away from a target zone in the presence of wind—even at a relatively small wind speed. On the other hand, if the inflation is initiated too late the container is floating on the surface for a considerable amount of time reducing the likelihood of the device being inflated in its proper orientation. In most rescue operations survivors have to be rescued from rough seas. Under such conditions it is likely for a container to be toppled by the rough sea while floating on the surface resulting in the device being inflated upside down rendering it problematic for rescuing survivors. One solution to this problem is the use of a reversible life raft as taught in U.S. Pat. No. 6,375,529. However, use of a reversible life raft requires physical action from survivors—people in distress—in order to set up a canopy for protecting them from the elements. In particular, for rescue operations in cold climates it is essential to provide life rafts with a canopy in order to protect survivors from hypothermia.
Auto-inflation of life vests and other personal floatation devices using water activated inflators is well known in the art. Water activated inflators using a water soluble element for holding a membrane piercing mechanism in a cocked position are disclosed, for example, in U.S. Pat. Nos. 6,589,087; 5,852,986; 5,694,986; 5,370,567; and 5,333,656.
In order to quickly inflate a large floatation device such as a life raft, a large gas flow is needed. Therefore, the inflator has to rapidly open a sealing mechanism of a gas cylinder containing a large volume of gas under high pressure. In order to instantly and reliably create a large opening, it is preferred to provide a significant stroke to a valve—defining the opening—of the sealing mechanism, rather than piercing a sealing membrane. However, for providing a significant stroke a relatively strong force acting along a relatively long distance has to be applied. Timed actuators, explosive actuators, and electronic actuators are typically used to provide the force and distance required in inflating a large inflatable device. As is evident to those of skill in the art, such devices cause serious storage and maintenance problems as well as safety problems during transport in an airplane and, therefore, are not considered useful for air rescue missions. Conversely, none of the passive water activated devices provide for the force and distance of operation required for quickly and reliably inflating a life raft.
It would be advantageous to provide a passive water activated device for supporting inflation of a life raft.
SUMMARY OF THE INVENTIONIt is, therefore, an object of the invention to provide a water activated inflator capable of providing sufficient force acting along a sufficient distance for opening a sealing mechanism of a gas cylinder in order to quickly and reliably inflate a large inflatable device.
It is further an object of the invention to provide a water activated inflator for inflating a large inflatable device that is safe for use in air deployment.
It is yet further an object of the invention to provide a method of air deployment of a large inflatable device using a water activated inflator.
In accordance with the present invention there is provided a water activated inflator comprising:
a housing having a connecting mechanism for mating with a neck of a gas cylinder;
a gas cylinder opening device for opening a sealing mechanism of the gas cylinder, the gas cylinder opening device being disposed in the housing movable along a first axis having a first orientation between a cocked position and a fired position;
a tension mechanism in mechanical communication with the housing and the gas cylinder opening device for providing tension acting along the first axis for moving the gas cylinder opening device from the cocked position to the fired position;
a plunger for holding the gas cylinder opening mechanism in the cocked position, the plunger being disposed in the housing movable along a second axis having a different second orientation between a first position and a second position;
a water soluble element for holding the plunger in the first position through mechanical communication along the second axis with the plunger and the housing;
a conduit for providing water to the water soluble element;
a first interacting element in mechanical communication with the gas cylinder opening device having a first interacting surface, wherein at least a portion of the interacting surface is disposed at a predetermined angle to the first axis; and,
a second interacting element in mechanical communication with the plunger having a second interacting surface for interacting with the first interacting surface at the predetermined angle when the plunger is in the first position for holding the gas cylinder opening mechanism in the cocked position, wherein the predetermined angle is determined such that a component along the second axis of a component of the tension acting onto the second interacting surface is within a predetermined range for ensuring structural integrity of the water soluble element in the cocked position and for ensuring movement of the plunger when at least a portion of the water soluble element is dissolved.
In accordance with the present invention there is further provided a water activated inflatable device comprising:
an inflatable device body;
a gas cylinder in fluid communication with the inflatable device body; and,
a water activated inflator comprising:
a housing having a connecting mechanism mated with a neck of the gas cylinder;
a gas cylinder opening device for opening a sealing mechanism of the gas cylinder, the gas cylinder opening device being disposed in the housing movable along a first axis having a first orientation between a cocked position and a fired position;
a tension mechanism in mechanical communication with the housing and the gas cylinder opening device for providing tension acting along the first axis for moving the gas cylinder opening device from the cocked position to the fired position;
a plunger for holding the gas cylinder opening mechanism in the cocked position, the plunger being disposed in the housing movable along a second axis having a different second orientation between a first position and a second position;
a water soluble element for holding the plunger in the first position through mechanical communication along the second axis with the plunger and the housing;
a conduit for providing water to the water soluble element;
a first interacting element in mechanical communication with the gas cylinder opening device having a first interacting surface, wherein at least a portion of the interacting surface is disposed at a predetermined angle to the first axis; and,
a second interacting element in mechanical communication with the plunger having a second interacting surface for interacting with the first interacting surface at the predetermined angle when the plunger is in the first position for holding the gas cylinder opening mechanism in the cocked position, wherein the predetermined angle is determined such that a component along the second axis of a component of the tension acting onto the second interacting surface is within a predetermined range for ensuring structural integrity of the water soluble element in the cocked position and for ensuring movement of the plunger when at least a portion of the water soluble element is dissolved.
In accordance with an aspect of the present invention there is provided a method of air deployment of a water activated inflatable device comprising:
dropping from an airplane over a body of water a deployment container comprising an inflatable device body, a gas cylinder in fluid communication with the inflatable device body and a water activated inflator mated to a neck of the gas cylinder;
deploying a parachute attached to the deployment container for aerodynamically braking the descent of the container and for ensuring a predetermined orientation of the deployment container at impact on the body of water;
activating the water activated inflator through contact with water after impact of the deployment container on the body of water;
using the water activated inflator opening a sealing mechanism of the gas cylinder; and, inflating the inflatable device.
In accordance with the aspect of the present invention there is further provided a water activated inflatable device for air deployment over a body of water comprising:
an inflatable device body;
a gas cylinder in fluid communication with the inflatable device body;
a water activated inflator mated to a neck of the gas cylinder;
a deployment container containing the inflatable device body, the gas cylinder and the water activated inflator, the deployment container comprising a conduit for enabling provision of water to the water activated inflator after impact of the deployment container on the body of water; and,
a parachute attached to the deployment container for aerodynamically braking the descent of the deployment container and for ensuring a predetermined orientation of the deployment container at impact on the body of water.
Using a water activated inflatable device according to the invention is highly beneficial for air rescue operations over a body of water. The water activated inflator provides proper timing of the inflation shortly after impact independent of the height of the air plane at the time instant the inflatable device is dropped substantially increasing the likelihood of proper placement of the inflatable device in a target zone as well as substantially increasing safety of the rescue personnel in the airplane.
BRIEF DESCRIPTION OF THE FIGURESExemplary embodiments of the invention will now be described in conjunction with the following drawings, in which:
Referring to
The connecting mechanism 104 comprises a tube affixed to the housing as shown in
In operation the inflator 100 is connected via connecting mechanism 104 to the neck of a gas cylinder with the gas cylinder opening device being connected to the sealing mechanism of the gas cylinder. During storage and transport of an inflatable life raft the inflator 100 is in the cocked position with the tension mechanism 110 under compression and held in this position by the plunger 120, as shown in
The water activated inflator 100 according to the invention is highly beneficial for air deployment of a life raft by providing a safe, reliable, compact, light weight and simple apparatus which is very cost effective to manufacture. It allows use of a very simple water soluble element as trigger in a device providing strong force acting along a large distance. Furthermore, the device is easily adaptable to a different stroke by only adjusting the angle α of the interacting surface allowing use of same parts of the inflator for different applications.
Referring to
Referring to
In the following, a method of air deployment of a water activated inflatable device over a body of water according to the invention will be described. Preferably, a water activated water activated inflatable device 300 as described above is employed for executing the method. The water activated water activated inflatable device 300 is dropped from an airplane over a body of water in a target zone where survivors are suspected. After dropping the water activated inflatable device 300 from the airplane pulling action on pull cord 316 pulls the folded parachute 314 from the deployment container 302 for deployment through interaction with the airflow around the falling deployment container 302. Pulling action on pull cord 310 removes the safety pin from the inflator 312. Alternatively, a same pull cord is used for deploying the parachute as well as for removing the safety pin. The water activated inflatable device 300 is deployed in various different ways, for example, by release from a loading bay of a transport plane or helicopter, or from a release mechanism mounted to the outside of an airplane at the fuselage or under a wing. Deployment of the parachute provides aerodynamically braking of the descent of the water activated inflatable device 300 and ensures a predetermined orientation of the deployment container 302 at impact on the body of water. After impact, the deployment container 302 is first immersed in the body of water, then bopping in the water and finally floating on the water surface. After impact water is provided through the conduit 308 to the inflator dissolving a water soluble element of the inflator. After a portion of the water soluble element is dissolved the tension mechanism of the inflator is capable of pushing the plunger and, thus, moving the gas cylinder opening device for providing a sufficient stroke to the sealing mechanism of the gas cylinder. Using the water activated inflator 100 a large opening of the gas cylinder is provided instantly after dissolving a portion of the water soluble element enabling quick inflation of the inflatable device body 304. Preferably, the inflator 312 and conduit 308 are placed such that the water soluble element is exposed to water within a short time interval after impact. The deployment container 302 is opened prior inflation of the inflatable device 304 through the force acting at impact or using an opening mechanism activated by the inflator. Alternatively, the deployment container 302 is opened through expansion of the inflating device 304.
Using a water activated inflatable device according to the invention is highly beneficial for air rescue operations over a body of water. The water activated inflator provides proper timing of the inflation shortly after impact independent of the height of the air plane at the time instant the water activated inflatable device is dropped substantially increasing the likelihood of proper placement of the inflatable device in a target zone as well as substantially increasing safety of the rescue personnel in the airplane. Since most rescue operations have to be executed under severe weather conditions, employment of prior art rescue kits using, for example, timing devices, either puts the lives of the rescue personnel in the airplane at risk by requiring the pilot to fly the airplane at dangerous heights—below or within a cloud cover for example—for dropping the rescue kit at a given height or substantially reducing the likelihood of proper deployment of the rescue kit by dropping it from a height considered safe by the pilot. Employment of the method of air deployment according to the invention overcomes this dilemma by enabling dropping of the rescue kit from an arbitrary safe height for the airplane and still providing proper deployment and inflation of the life raft.
Executing numerous drop tests, it has been found that the method for air deployment according to the invention ensures a nearly 100% success rate for proper deployment and inflation of the inflatable device. The likelihood of inflation of the life raft upside down has been substantially reduced despite the fact that after impact the rescue kit is immersed in water and then bopping prior inflation.
Numerous other embodiments of the invention will be apparent to persons skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims
1. A water activated inflator comprising:
- a housing having a connecting mechanism for mating with a neck of a gas cylinder;
- a gas cylinder opening device for opening a sealing mechanism of the gas cylinder, the gas cylinder opening device being disposed in the housing movable along a first axis having a first orientation between a cocked position and a fired position;
- a tension mechanism in mechanical communication with the housing and the gas cylinder opening device for providing tension acting along the first axis for moving the gas cylinder opening device from the cocked position to the fired position;
- a plunger for holding the gas cylinder opening device in the cocked position, the plunger being disposed in the housing movable along a second axis having a different second orientation between a first position and a second position;
- a water soluble element for holding the plunger in the first position through mechanical communication along the second axis with the plunger and the housing;
- a conduit for providing water to the water soluble element;
- a first interacting element in mechanical communication with the gas cylinder opening device having a first interacting surface, wherein at least a portion of the first interacting surface is disposed at a predetermined angle other than 90 or 180 degrees to the first axis; and,
- a second interacting element in mechanical communication with the plunger having a second interacting surface for interacting with the first interacting surface at the predetermined angle when the plunger is in the first position for holding the gas cylinder opening device in the cocked position, wherein the predetermined angle is determined such that a component along the second axis of a component of the tension acting onto the second interacting surface is within a predetermined range for ensuring structural integrity of the water soluble element in the cocked position and for ensuring movement of the plunger when at least a portion of the water soluble element is dissolved.
2. A water activated inflator as defined in claim 1 wherein the second axis is oriented substantially perpendicular to the first axis.
3. A water activated inflator as defined in claim 2 wherein the first interacting element comprises a frusto cone.
4. A water activated inflator as defined in claim 3 wherein the second interacting element comprises a half sphere.
5. A water activated inflator as defined in claim 4 wherein the tension mechanism comprises a compression spring.
6. A water activated inflator as defined in claim 5 wherein the gas cylinder opening device comprises a cable for being attached to the sealing mechanism of the gas cylinder.
7. A water activated inflator as defined in claim 6 comprising a tube affixed to the housing along the first axis for accommodating the compression spring.
8. A water activated inflator as defined in claim 6 comprising a plug for holding the plunger and the water soluble element in the first position.
9. A water activated inflator as defined in claim 8 wherein the plug is screwed into a threaded bore of the housing along the second axis.
10. A water activated inflator as defined in claim 8 wherein the plug comprises the conduit.
11. A water activated inflator as defined in claim 1 comprising a safety pin in mechanical communication with the plunger and the housing for locking the plunger in the first position.
12. A water activated inflatable device comprising:
- an inflatable device body;
- a gas cylinder in fluid communication with the inflatable device body; and,
- a water activated inflator comprising:
- a housing having a connecting mechanism mated with a neck of the gas cylinder;
- a gas cylinder opening device for opening a sealing mechanism of the gas cylinder, the gas cylinder opening device being disposed in the housing movable along a first axis having a first orientation between a cocked position and a fired position;
- a tension mechanism in mechanical communication with the housing and the gas cylinder opening device for providing tension acting along the first axis for moving the gas cylinder opening device from the cocked position to the fired position;
- a plunger for holding the gas cylinder opening device in the cocked position, the plunger being disposed in the housing movable along a second axis having a different second orientation between a first position and a second position;
- a water soluble element for holding the plunger in the first position through mechanical communication along the second axis with the plunger and the housing;
- a conduit for providing water to the water soluble element;
- a first interacting element in mechanical communication with the gas cylinder opening device having a first interacting surface, wherein at least a portion of the first interacting surface is disposed at a predetermined angle other than 0 or 90 degrees to the first axis; and,
- a second interacting element in mechanical communication with the plunger having a second interacting surface for interacting with the first interacting surface at the predetermined angle when the plunger is in the first position for holding the gas cylinder opening device in the cocked position, wherein the predetermined angle is determined such that a component along the second axis of a component of the tension acting onto the second interacting surface is within a predetermined range for ensuring structural integrity of the water soluble element in the cocked position and for ensuring movement of the plunger when at least a portion of the water soluble element is dissolved.
13. A water activated inflatable device as defined in claim 12 comprising a safety pin in mechanical communication with the plunger and the housing for locking the plunger in the first position.
14. A water activated inflatable device as defined in claim 13 comprising a pull cord affixed to the safety pin at a first end and for being affixed to a vessel carrying the inflatable device at a second end, the pull cord for removing the safety pin after dropping of the inflatable device from the vessel.
15. A method of air deployment of a water activated inflatable device comprising:
- dropping from an airplane over a body of water a deployment container comprising an inflatable device body, a gas cylinder in fluid communication with the inflatable device body and a water activated inflator mated to a neck of the gas cylinder;
- deploying a parachute attached to the deployment container for aerodynamically braking the descent of the deployment container and for ensuring a predetermined orientation of the deployment container at impact on the body of water;
- activating the water activated inflator through contact with water after impact of the deployment container on the body of water;
- using the water activated inflator opening a sealing mechanism of the gas cylinder; and,
- inflating the inflatable device body.
16. A method of air deployment of a water activated inflatable device as defined in claim 15 wherein the parachute is deployed through pull cord action using a pull cord affixed to the airplane after dropping the deployment container from the airplane.
17. A method of air deployment of a water activated inflatable device as defined in claim 16 comprising:
- removing after dropping the deployment container from the airplane through pull cord action using a pull cord affixed to the airplane a safety pin locking the inflator in a cocked position.
18. A method of air deployment of a water activated inflatable device as defined in claim 17 comprising:
- using the water activated inflator releasing an opening mechanism of the deployment container.
19. A water activated inflatable device for air deployment over a body of water comprising:
- an inflatable device body;
- a gas cylinder in fluid communication with the inflatable device body;
- a water activated inflator mated to a neck of the gas cylinder;
- a deployment container containing the inflatable device body, the gas cylinder and the water activated inflator, the deployment container comprising a conduit for enabling provision of water to the water activated inflator after impact of the deployment container on the body of water; and,
- a parachute attached to the deployment container for aerodynamically braking the descent of the deployment container and for ensuring a predetermined orientation of the deployment container at impact on the body of water.
20. A water activated inflatable device for air deployment over a body of water as defined in claim 19 comprising a safety pin for locking the inflator in a cocked position.
21. A water activated inflatable device for air deployment over a body of water as defined in claim 20 comprising a pull cord affixed to the safety pin at a first end and for being affixed at a second end to an airplane carrying the inflatable device, the pull cord for removing the safety pin after dropping of the inflatable device from the airplane.
22. A water activated inflatable device for air deployment over a body of water as defined in claim 21 comprising a pull cord affixed to the parachute at a first end and for being affixed at a second end to an airplane carrying the inflatable device, the pull cord for deploying the parachute after dropping of the inflatable device from the airplane.
23. A water activated inflatable device for air deployment over a body of water as defined in claim 19 wherein the inflator comprises a cable attached to a sealing mechanism of the gas cylinder.
24. A water activated inflatable device for air deployment over a body of water as defined in claim 21 comprising a release mechanism operated by the inflator for opening the deployment container.
25. A water activated inflatable device for air deployment over a body of water as defined in claim 19 wherein components within the deployment container are distributed such that after impact of the deployment container on the body of water a center of gravity of the deployment container and the components is located below a center of buoyancy of a portion of the deployment container immersed in the body of water.
Type: Application
Filed: Apr 27, 2005
Publication Date: Nov 3, 2005
Applicant: Irvin Aerospace Canada Limited (Belleville)
Inventors: Ed Medford (Comox), Ned Miljic (Belleville)
Application Number: 11/115,174