A quick connect/disconnect mechanism for a rotary bit having a central mounting hole at a proximal end includes a shaft extending axially and having a proximal end adapted to be releasably secured in a rotary tool and a distal end having a spud extending distally and axially therefrom. A plurality of retainer arms are arrayed about the axis and extending distally, each retainer arm including a catch extending radially outwardly from a distal end thereof. A release sleeve extends about the shaft adjacent to said distal end, the release sleeve having engagement keys to impinge on the proximal ends of the retainer arms, the sleeve being rotatable from a first position in which the engagement keys hold the retainer arms to secure the rotary bit to a second position in which the retainer arms rotate to release the rotary bit.

A fastener including a chisel point that pre-bores a hole in a work piece to prevent damage to the work piece as the fastener advances. The fastener can include a head, a shaft and a chisel brake point formed at an end of the shaft. The chisel brake point can include first and second opposing inclined surfaces disposed at an angle of about 80° to about 150° relative to one another. A thread can begin adjacent the chisel brake point and form an extension of an inclined surface and/or a chisel edge. The chisel brake point can scrape material from a work piece while pre-boring a hole. The material can be transferred to the thread, and subsequently fed up the thread, out of the pre-bored hole. The chisel brake point can also selectively retard advancement of the fastener into the work piece. Methods of installing the fastener also are provided.

A quick connect/disconnect mechanism for a rotary bit having a central mounting hole at a proximal end includes a shaft extending axially and having a proximal end adapted to be releasably secured in a rotary tool and a distal end having a spud extending distally and axially therefrom. A plurality of retainer arms are arrayed about the axis and extending distally, each retainer arm including a catch extending radially outwardly from a distal end thereof. A release sleeve extends about the shaft adjacent to said distal end, the release sleeve having engagement keys to impinge on the proximal ends of the retainer arms, the sleeve being rotatable from a first position in which the engagement keys hold the retainer arms to secure the rotary bit to a second position in which the retainer arms rotate to release the rotary bit.

The problem of penetrating through nets and other objects is solved by cutting the object using various cutter systems, which include, for example a track and a moving carriage containing a cutter, a stationary carriage with a fixed or rotating arm, and/or abrasive cutters. The object is cut by a severing, slicing, or wearing action caused by a moveable blade or abrasive surface. An underwater vehicle incorporating an embodiment of the cutter system can cut a sufficiently large opening in the object to allow the vehicle to pass through.

A quick connect/disconnect mechanism for a rotary bit having a central mounting hole at a proximal end includes a shaft extending axially and having a proximal end adapted to be releasably secured in a rotary tool and a distal end having a spud extending distally and axially therefrom. A collet has a plurality of retainer arms arrayed circularly about the axis and extending distally, each retainer arm including a catch extending radially outwardly from a distal end thereof. A support ring extends about the shaft adjacent to said distal end thereof, the support ring being translatable from a first position in which the retainer arms extend freely distally and are deflectable sufficiently to be inserted through the central mounting hole of a rotary bit; to a second position in which the support ring and collet translate proximally and the spud extends distally to engage the retainer arms so they cannot deflect and release the rotary bit.

The problem of penetrating through nets and other objects is solved by cutting the object using concentric cutters in which a rotatable cutter having floating teeth rotates concentrically about a stationary cutter having fixed teeth. The object is cut by a severing action caused by the floating teeth of the rotatable cutter sliding against the fixed teeth of the stationary cutter. Embodiments of the invention include a UUV system for penetrating through fishing nets and other objects, concentric cutting assemblies for use in the UUV system and other systems, and a method for penetrating through fishing nets and other objects. A UUV system in accordance with an embodiment of the invention has a concentric cutting assembly at the forward end and a propulsor at the aft end. The concentric cutting assembly integrates seamlessly within the UUV housing and is deployed from the forward end of the UUV, enabling the UUV to quickly and efficiently penetrate through objects blocking its path.