fs on ebay: buoyco sub pac

http://cgi.ebay.co.uk/ws/eBayISAPI.d...MESE%3AIT&rd=1


Buoyco sub pac
manufactured by North Wales Divers
date: unknown

for info:

http://www.everypatent.com/comp/pat5007364.html

http://www.mavericksdiving.co.uk/equipment/abcbcd/

http://www.freepatentsonline.com/4527582.html

A device for automatically opening a gas supply valve when the device
reaches a predetermined depth, e.g. when diving, has a gas reservoir, a
pressure sensing means providing a control signal when the ambient
pressure exceeds that of the gas reservoir, and a supply valve which is
opened upon receipt of that signal. A preferred embodiment has a
flexible diaphragm exposed at its faces respectively to the ambient
pressure and to the gas reservoir pressure, and arranged to move an
actuator which acts directly or indirectly on the gas supply valve.
Underwater buoyancy apparatus, for use for example by a diver, has a
buoyancy chamber to which as can be supplied to alter buoyancy, and the
device is incorporated between a gas supply and the buoyancy chamber to
give automatic increase of buoyancy when a predetermined depth is
reached.

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"David Parker, of Cornwall's A P Valves, invented the 'Automatic
Mouthpiece' that enabled a diver to breathe air directly from the BCD
bladder, providing access to air from the small inflation cylinder
common to European BCDs. Launched long before octopus rigs, pony
bottles and other alternative air sources became popular, the Auto
Mouthpiece gained widespread acceptance in the UK. Features like rapid
dump valves made an appearance. One design, the Liftstop, had an
automatic braking mechanism to slow a full-blown buoyant ascent in the
last few metres. The next major innovation was connecting the air
supply in a diver's tank directly to the BCD. Direct feeds, as they
are known, were developed by a cave diver and quickly became the norm.
A US manufacturer went further and designed a direct feed that
automatically started to slowly inflate the BC if the diver failed to
breathe regularly or the regulator started to freeflow.


Alternatives to the horsecollar BC were tried. Back-mounted BCDs
provided better underwater stability and less drag. But many divers
were wary of them because they tended to float a diver at the surface
on his face. Scubapro countered this with the Scubapro Stabilizing
Jacket which supported a properly weighted and trimmed diver head-up
at the surface, while holding him horizontal and streamlines while
swimming underwater.


These 'softshell' systems all used flexible air bladders requiring
that the user make adjustments for depth and the changes in buoyancy.
However, some companies were experimenting with hardshell systems.
These used rigid chambers that could be filled with air and water, and
once set for neutral buoyancy were less affected by depth changes -
though suit compression and the reducing weight of the cylinder still
required some occasional compensation. The


British Buoyco Sub Pack


and American Dacor Nautilus are probably the best-known examples.
Possibly launched ahead of their time and hampered by bulk, neither
survived.