Gas canisters and methods for making them

A canister, comprising:

• an elongate body comprising a barrel region defining a first diameter, an enclosed first end, and a neck region extending from the barrel region to an open second end defining an end wall, the elongate body defining a central axis extending between the first end and the second end;
• and
• a cap comprising an annular portion including a closed first end and an open second end, a separable septum formed in the first end of the cap comprising a central region and a relatively-thin perimeter at least partially surrounding the central region, the perimeter region having a thickness thinner than the thickness of the central region for preferentially tearing of the perimeter to at least partially separate the central region from the cap,
• the cap secured to the end wall of the second end of the elongate body, thereby enclosing a cavity,
• the cavity filled with pressurized and/or at least partially liquefied gas.

A gas-actuated tool, comprising:

• a housing comprising a functional portion and an actuator portion including a chamber;
• a canister within the chamber comprising an elongate body comprising an enclosed first end and an open second end, a cap welded to the open second end of the elongate body and including a septum, thereby defining an interior cavity filled with pressurized gas, the septum comprising a central region and a relatively-thin perimeter at least partially surrounding the central region, the perimeter region having a thickness thinner than the thickness of the central region;
• a carriage movable within the housing from the first position, the carriage comprising a pin disposed adjacent the septum, the pin including a blunt, beveled tip;
• and
• an actuator on the actuator portion coupled to the carriage such that initial activation of the actuator causes the carriage to move from the first position to a second position such that the beveled tip of the pin applies localized force to the septum to tear the perimeter region to at least partially separate the central region from the cap, thereby releasing pressurized gas from the canister into one or more passages within the housing.