An unmet market exists for a high performance inflator used in life vests and similar marine and rescue applications. Inflators are used in a multitude of operations where the safety of life and equipment is threatened due to sinking in water or bogs. In general, the inflator is attached to personal flotation devices (life vests), rafts, or flotation collars and, when activated, fills the bladders of this equipment with gas thus providing flotation.
At present, inflators are widely used in applications from casual boating to rescue and special force attack situations. The consumer market is vast—some type of life vest is required for every boater, cruise passenger and marine sports enthusiast. The majority of life vests are bulky, static, and contain flotation fillers such that they are inherently buoyant, but an increasing number of upper-end vests in this market use compact CO2 cartridges as an inflation means. These upper-end life vests are filled by manual action or by an automatic action, generally based upon the dissolution of a soluble pellet impeding the penetration action of a plunger that breaks a gas cartridge seal to release inflation gas (CO2). Some upper-end vests actuate after receiving an electrical conductivity signal as the inflator is wetted.
The common use of a soluble pellet as a trigger component has serious flaws. Water must be able to reach and dissolve the pellet but, if water enters at the wrong time, inflation can cause mobility problems and can destroy the usefulness of the vest. The pellet is also a single use product requiring replacement of the entire inflation mechanism after a single use. With a water and humidity sensitive trigger, reliability is also called into question. The pellet is also sensitive to low temperature, where it freezes, thus preventing inflation of the vest when needed.
The use of conductivity is also a problem because wet surfaces and/or unplanned wetting may trigger inflation. While conductivity of water is good at sea, fresh water creates problems due to high resistivity of the water.
A 400 volt high voltage sensor is used in a few applications but the high voltage is difficult to use safely. Accidental water infiltration and shorting of the mechanism is an unconquered problem. Development in this area does indicate a real need for a reliable inflator with advanced features.
At present, inflators tend to be bulky due to use of compressed coil springs. Therefore, there is a need for a better powering of the penetrator motion that is less bulky.
To increase power of the penetrator motion, in most units, a new spring of higher rating is needed. Therefore, there is a need for easily adjustable spring force in inflators.
Too many inflators are subject to inadvertent inflation due to accidental infiltration of water into the mechanism and the resulting dissolution of the penetrator motion blocking pellet causing inappropriate inflation. This needs a cure.
When wet, too many inflators are triggered and inflate even if the wetting is temporary or from a wave, etc. Therefore, there is a need for redundancy with prevention of inadvertent inflation in water triggered inflation.
In drops, in deep diving, and other rescue operations, inflation at or just above the surface may allow the life vest or inflation collar to be blown from the target. Therefore, there is a need for an easily set depth of inflation underwater. Such a settable inflator could prevent loss of life due to narcosis for example.