Drive Mechanism for Launcher

1 . A projectile launcher including:

a base;

a barrel supported on the base;

a magazine supported on the base for rotation relative to the base and the barrel about an axis, the magazine having a plurality of chambers adapted to contain a plurality of projectiles to be launched individually through the barrel; and

a drive mechanism for selectively rotating the magazine relative to the base between a plurality of index positions, in each index position one of the chambers being aligned with the barrel for launching the projectile in the one chamber through the barrel;

the drive mechanism including a drive shaft fixed for rotation with the magazine about the axis, the drive shaft having a plurality of grooves;

the drive mechanism also including a detent in engagement with the drive shaft, the detent being manually movable in a direction parallel to the axis and relative to the drive shaft to rotate the drive shaft and thereby the magazine about the axis.

2 . A launcher as set forth in claim 1 wherein the plurality of grooves includes a plurality of groove sets, each groove set including a rotating groove and a return groove, the number of groove sets on the drive shaft being equal to the number of chambers in the magazine.

3 . A launcher as set forth in claim 3 wherein each rotating groove is helical and each return groove straight.

4 . A launcher as set forth including a manually engageable saddle that is supported for axial sliding movement relative to the drive shaft, the saddle carrying the detent, manual sliding movement of the saddle causing indexing movement of the magazine.

5 . A launcher as set forth in claim 3 wherein at each intersection between a rotating groove and a return groove there is formed an indent for holding the detent and thus resisting relative movement between the detent and the drive shaft and thereby resisting rotation of the magazine.

6 . A drive mechanism for a projectile launcher including a magazine rotatable about an axis between a plurality of index positions, the drive mechanism comprising a drive shaft fixed for rotation with the magazine about the axis, the drive shaft having a plurality of grooves, and a detent member in engagement with the drive shaft, relative axial movement between the detent member and the drive shaft producing rotation of the drive shaft about the axis.

7 . The drive mechanism of claim 6 wherein half of the plurality of grooves are rotating grooves and the other half of the grooves are return grooves.

8 . The drive mechanism of claim 7 wherein the rotating grooves are helical and the return grooves are straight, each rotating groove intersects at its ends with a return groove, and each return groove intersects at its ends with a rotating groove.