Fastener driving apparatus

A fastener driving apparatus, comprising:

• a power source;
• a control circuit;
• a motor;
• at least one gas spring, the at least one gas spring including a chamber and a rod disposed within the chamber;
• a drive mechanism, the drive mechanism being capable of selectively engaging and disengaging the at least one gas spring, the at least one gas spring capable of moving to an energized position upon being engaged by the drive mechanism;
• and
• an anvil assembly, the anvil assembly including an anvil,
• wherein the drive mechanism includes a first lifting mechanism and a second lifting mechanism, wherein the first lifting mechanism actuates the at least one gas spring for a portion of an operation cycle, and the second lifting mechanism thereafter actuates the at least one gas spring for a subsequent portion of the operation cycle before the drive mechanism ceases applying a force on the at least one gas spring and the at least one gas spring releases at least a portion of its potential energy and accelerates the anvil to drive a fastener,
• wherein the anvil assembly includes at least two materials including a first material comprising an elastic modulus of at least 28 million psi and a second material having a density of less than 0.15 pounds per cubic inch.

A fastener driving apparatus, comprising:

• a power source;
• a control circuit;
• a motor;
• at least one gas spring, the at least one gas spring including a chamber and a rod disposed within the chamber, wherein the gas spring includes a rod seal, the rod seal being stationary with respect to movement of the rod,
• a seal which acts against the rod, the rod being capable of moving linearly within the chamber and with respect to the seal;
• a drive and lifting mechanism, the drive and lifting mechanism being capable of selectively engaging and disengaging the at least one gas spring, the at least one gas spring being capable of moving to a position of increased potential energy upon being engaged by the drive mechanism, wherein the drive mechanism continues to operate and re-engages the gas spring to relieve force on an anvil prior to stopping of the drive mechanism;
• and
• an anvil assembly, the anvil assembly including the anvil, the anvil assembly being coupled to the gas spring rod,
• wherein the drive and lifting mechanism selectively lifts the at least one gas spring to apply a force on the at least one gas spring to move the rod of the at least one gas spring at least 80% of the stroke of the anvil assembly and thereafter releases from and ceases applying a force on the at least one gas spring, wherein the at least one gas spring releases at least a portion of its potential energy and accelerates the anvil to drive a fastener.