Diving snorkel

Claim 2

In a snorkel structure: (a) means forming a main snorkel conduit having an unobstructed, unrestricted opening at the top for conducting ambient air to the snorkel conduit when the top of the snorkel conduit projects above the water surface and which allows water to enter when the top of the snorkel conduit is beneath the water surface; (b) a mouthpiece at the bottom of the snorkel conduit; (c) a bypass conduit having a first opening connected to the main snorkel conduit at a place spaced substantially from and above said mouthpiece along the snorkel conduit and located between the mouthpiece and the top of the snorkel conduit; (d) said bypass conduit having a second opening spaced from said first opening located beneath said first opening automatically to drain excess trapped water from the projecting end of the snorkel upon resurfacing following a dive or other maneuver; (e) a non-return purge valve located at said second opening to block flow of water into said bypass conduit and therethrough to said snorkel conduit; and (f) said purge valve being located distant from said mouthpiece whereby a burst of purge air is applied to the water entrapped in the snorkel conduit to lift it out of the snorkel before air vents through the purge valve.

Claim 3

The snorkel as set forth in claim 1 in which said bypass conduit generally parallels the lower end of said snorkel conduit, there being a common wall between the bypass conduit and said snorkel conduit.

Claim 4

The combination as set forth in claim 1 in which the downward extent between said first and second openings imposes resistance to movement of air to the purge valve sufficient to ensure efficient purging.

Claim 5

In a snorkel structure: (a) means forming a main snorkel conduit having an unobstructed, unrestricted opening at the top for conducting ambient air to the snorkel conduit when the top of the snorkel conduit projects above the water surface and which allows water to enter when the top of the snorkel conduit is beneath the water surface; (b) a mouthpiece at the bottom of the snorkel conduit; (c) said snorkel conduit having a configuration to provide a substantially smooth flow path between said top opening and said mouthpiece which is essentially free of abrupt changes in path direction; (d) a bypass conduit having a first opening connected to said main snorkel conduit at a place located beneath the water surface during normal snorkeling and which is spaced substantially from and above said mouthpiece along the snorkel conduit; (e) said bypass conduit having a second opening spaced from said first opening and located beneath said first opening automatically to drain excess trapped water from the projecting end of the snorkel conduit upon resurfacing following a dive or other maneuver; (f) a non-return purge valve located at said second opening to block flow of water into said bypass conduit and therethrough to said snorkel conduit; (g) said purge valve being located sufficiently distant from said mouthpiece such that the column of water entrapped in the main snorkel conduit is bound by a sharp exhalation effort to move entirely out of the snorkel conduit by the time that the column of water passes the said first opening of the bypass conduit.

Claim 6

In a snorkel structure: (a) means forming a main snorkel conduit having an unobstructed, unrestricted opening at the top for conducting ambient air to the snorkel conduit when the top of the snorkel conduit projects above the water surface and which allows water to enter when the top of the snorkel conduit is beneath the water surface; (b) a mouthpiece at the bottom of the snorkel conduit; (c) said snorkel conduit having a configuration to provide a substantially smooth flow path between said top opening and said mouthpiece which is essentially free of abrupt changes in path direction; (d) a bypass conduit having a first opening connected to said main snorkel conduit at a place located beneath the water surface during normal snorkeling and which is spaced substantially from and above said mouthpiece along the snorkel conduit; (e) said bypass conduit having a second opening spaced from said first opening and located beneath said first opening automatically to drain excess trapped water from the projecting end of the snorkel conduit upon resurfacing following a dive or other maneuver; (f) a non-return purge valve located at said second opening to block flow of water into said bypass conduit and therethrough to said snorkel conduit; (g) said purge valve being located sufficiently distant from said mouthpiece such that the column of water entrapped in the main snorkel conduit is bound by a sharp exhalation effort to move entirely out of the snorkel conduit by the time that the column of water passes the said first opening of the bypass conduit.

Claim 7

The combination as set forth in claim 4 in which said bypass conduit generally parallels said main snorkel conduit and extends downwardly from its said first opening whereby the direction of said bypass conduit offers an impedance to the flow of the water column being purged from the main snorkel conduit.