Abstract: A device is provided for locking a front end of a shaft for a spear gun. The device comprises a bridge-shaped element extending crosswise over a distal end of the gun with a substantially U-shaped nosepiece connected to the distal end and revolving relatively freely about a crosswise axis thereof. The nosepiece includes at least two arms connected respectively to ends of a relatively elastic cable that may be tensioned against a rear end of the shaft, when the shaft is placed on a support surface along the body of the gun. The bridge element is attached to and integrally with the ends of the elastic cable and is placed at a selected distance from the support surface such that the shaft is retained against the surface when the spear is in a stowed or loaded position in the gun.

Abstract: A spear gun for scuba diving that comprises a frame with a body elongated generally in a direction of a longitudinal axis of the gun and a grip at one end of and extending from the elongated body. The grip includes a fixed part attached to and integrally with the body and a movable part adjustably mounted to the fixed part. Also provided is a device for securing the movable part to the fixed part when a desired configuration of the grip has been achieved.

Abstract: A closure device of a second-stage regulator for scuba divers, the regulator comprising a regulator body with an inlet conduit for connection to a first-stage regulator which supplies a breathable gaseous mixture at relatively constant pressure, an outlet conduit for connection to a mouthpiece of the users, and an opening closed by a deformable diaphragm. The device comprises a locking frame connected jointedly to the regulator body to lock the diaphragm in the opening, and a member for fastening the frame to the regulator body.

Abstract: A group for the control of a second-stage regulator for scuba divers. The regulator comprises a regulator body with an inlet conduit for connection to a first-stage regulator which supplies a breathable gaseous mixture at a relatively constant pressure, and an outlet conduit for connection to a mouthpiece of the user. The group comprises a first bushing defining an intermediate chamber with a bottom wall wherein a central hole is formed, a poppet loosely engaged within the hole, the end of the poppet being connected to a lever, a second bushing engaged in the first bushing and defining an inlet chamber, and a third bushing engaged in the second bushing and defining a regulator seat at one of its ends. The head of the poppet engages tightly in the seat and an elastic member is provided coaxial to the poppet in the intermediate chamber for maintaining the head against said regulator seat, the group being removably engaged in the inlet conduit.

Abstract: A second-stage regulator for scuba divers, wherein the user's inhalation effort is lessened considerably by the reduction of the friction between selected components thereof. Coaxially to the regulator poppet, a flexible sleeve is sealingly connected to the poppet and the baffle, so as to avoid blow-by of gaseous mixture through the baffle opening through which there extends the tail of the poppet connected to the lever of the regulator extending in the outlet chamber thereof. The poppet head is placed in ferrule with an at least part-circular profile abutting the inner part of the intermediate chamber to allow the poppet oscillation. The lever end contacting the diaphragm, separating the outlet chamber from the outside, has a generally arched shape with a profile such that the length of the arch between two adjacent contact points measured along the lever is generally equal to the length of the segment between the same adjacent contact points measured along the diaphragm.