A powder actuated fastening tool including a charge advance apparatus for advancing a powder charge strip relative to a barrel of the tool, wherein the charge advance apparatus includes a rotatable ratchet having teeth for engaging receptacles formed in the powder charge strip, and a charge advance member coupled to a trigger of the tool, wherein the charge advance member acts on the rotatable ratchet to rotate the ratchet in response to actuation and/or release of the trigger, such that the rotation of the ratchet causes advance of the powder charge strip relative to the barrel.

Various embodiments of the present disclosure provide powered fastener driving tools and clean lubricants for powered fastener driving tools that reduce contaminant, residue, and deposit buildup or accumulation in the powered fastener driving tools, and thus reduce necessary maintenance for such powered fastener driving tools (or increases the time intervals between such necessary maintenance of powered fastener driving tools).

Various embodiments of the present disclosure provide powered fastener driving tools and clean lubricants for powered fastener driving tools that reduce contaminant, residue, and deposit buildup or accumulation in the powered fastener driving tools, and thus reduce necessary maintenance for such powered fastener driving tools (or increases the time intervals between such necessary maintenance of powered fastener driving tools).

A powered nailer includes a power source including a driving element reciprocating within a cylinder between a prefiring position and a fastener driving position, the latter occurring when the driving element engages a bumper disposed at the bottom of the cylinder. A reciprocating valve element defines a combustion chamber in fluid communication with the cylinder, and is configured for receiving a dose of fuel and air prior to a user-generated ignition. A return chamber at least partially surrounds the cylinder and is in fluid communication with the cylinder, being configured for receiving a supply of pressurized air generated by the driving element as it moves from the prefiring position to the fastener driving position, the pressurized air acting on an underside of the driving element for returning it to the pre-firing position.

A powered nailer includes a power source including a driving element reciprocating within a cylinder between a prefiring position and a fastener driving position, the latter occurring when the driving element engages a bumper disposed at the bottom of the cylinder. A reciprocating valve element defines a combustion chamber in fluid communication with the cylinder, and is configured for receiving a dose of fuel and air prior to a user-generated ignition. A return chamber at least partially surrounds the cylinder and is in fluid communication with the cylinder, being configured for receiving a supply of pressurized air generated by the driving element as it moves from the prefiring position to the fastener driving position, the pressurized air acting on an underside of the driving element for returning it to the pre-firing position.

A driver capable of suppressing an increase in a load of a bumper is provided. The driver includes a striking portion provided movably and configured to move to strike a fastener; a bumper configured to be in contact with the striking portion to restrict a range of movement of the striking portion; and a housing configured to support the bumper, the driver further including a load suppressing portion configured to suppress an increase in a load of the bumper based on the load of the bumper detected by a load detection portion or number of operations of the striking portion within a predetermined time.

An exhaust valve comprising an elastomeric flap portion (e.g. of silicone) covering one or more exhaust ports in a normally closed position for a combustion driven fastener hand tool is disclosed. The elastomeric flap portion is much shorter than a comparable steel reed valve, allowing it to be disposed in small spaces. A single flat piece of elastomeric material can be configured held fixed to a housing surface along a line between one or more pairs of ports such that a flap portion of the material extends to each side of the line and covers one of the pairs of ports. The flat piece can be conveniently held in position against the housing surface by a rib or standoff on the interior surface of an exterior housing.

An exhaust valve comprising an elastomeric flap portion (e.g. of silicone) covering one or more exhaust ports in a normally closed position for a combustion driven fastener hand tool is disclosed. The elastomeric flap portion is much shorter than a comparable steel reed valve, allowing it to be disposed in small spaces. A single flat piece of elastomeric material can be configured held fixed to a housing surface along a line between one or more pairs of ports such that a flap portion of the material extends to each side of the line and covers one of the pairs of ports. The flat piece can be conveniently held in position against the housing surface by a rib or standoff on the interior surface of an exterior housing.

The present disclosure provides various embodiments of a combustion-powered-fastener-driving tool that include a lockout device to ensure the tool's valve sleeve doesn't move to an unsealed position and the tool's combustion chamber remains sealed until the piston returns to the pre-firing position. The lockout device is engageable with a lockout device engaging member operably connected to the tool's trigger, which gives the operator direct control over locking the valve sleeve in the unsealed position.

The present disclosure provides various embodiments of a combustion-powered-fastener-driving tool that include a lockout device to ensure the tool's valve sleeve doesn't move to an unsealed position and the tool's combustion chamber remains sealed until the piston returns to the pre-firing position. The lockout device is engageable with a lockout device engaging member operably connected to the tool's trigger, which gives the operator direct control over locking the valve sleeve in the unsealed position.