Nailers with jamming-alleviating mechanisms

1. A fastener tool comprising:

a motor;

a drive mechanism connected to the motor and adapted to drive a piston; and

a cylinder filled with compressed gas,

wherein the piston is accommodated in the cylinder and suitable for a reciprocating motion within the cylinder;

wherein the drive mechanism includes a blade fixed to the piston and a gear coupled to the motor, wherein the gear includes a plurality of teeth adapted to engage with a plurality of lugs on the blade such that a rotation of the gear is transformed to a linear movement of the blade,

wherein the drive mechanism further includes a separator which, within a period of a rotation cycle of the gear, is configured to prevent one of the plurality of teeth from unintentionally engaging with a misaligned one of the lugs of the blade by shifting the gear laterally outward from the blade,

wherein the gear is rotatable about a rotational axis, and wherein the separator is configured to shift the gear laterally outward from the blade along the rotational axis.

2. The fastener tool of claim 1 , wherein the plurality of teeth of the gear are spaced apart on a gear body of the gear in a rotational direction by at least a first pitch and a second pitch different from the first pitch respectively, wherein the first pitch is smaller than the second pitch, and wherein one of the plurality of teeth being a first tooth after the second pitch on the rotational direction.

3. The fastener tool of claim 2 , wherein the second pitch corresponds to a range of 180 degrees in the rotational direction.

4. The fastener tool of claim 2 , wherein the separator further comprises a first cam surface formed on the gear body and a second cam surface formed on a wedge that is stationary at least within the period, wherein the gear is urged axially by the first cam surface engaging with the second cam surface within the period so that the first tooth is offset from the blade along the rotational axis.

5. The fastener tool of claim 4 , wherein the wedge is stationary during an entirety of the rotation cycle.

6. The fastener tool of claim 4 , wherein the second cam surface is stationary within the period but is rotatable together with the gear body outside the period.

7. The fastener tool of claim 6 , wherein the separator further comprises a stopper element movable between a first position in which the stopper element does not interfere with a rotation of the second cam surface, and a second position in which the stopper element prevents the second cam surface from rotating.

8. The fastener tool of claim 7 , wherein the stopper element is movable by an electronic device into the second position within the period.

9. The fastener tool of claim 8 , wherein the electronic device is a solenoid.

10. The fastener tool of claim 4 , wherein the gear is configured to be urged outwardly from a central axis of the blade during the period.

11. The fastener tool of claim 2 , further comprising an electronic device adapted to lock the blade.

12. The fastener tool of claim 11 , wherein the electronic device is turned on or off according to an angular position of the gear body.

13. The fastener tool of claim 12 , further comprising an object mounted on the gear body and a sensor adapted to sense a distance from the object to the sensor to determine an angular position of the gear.

14. The fastener tool of claim 12 , wherein the object is a magnet and the sensor is a Hall sensor.

15. The fastener tool of claim 11 , wherein the electronic device is a solenoid connected with a latch, and wherein the latch is adapted to engage with a geometrical feature on the blade to lock the blade.

16. The fastener tool of claim 1 , wherein the period is defined by an angular range within the rotation cycle of the gear.