Silk screen printing machine having variable printing length

Claim 1

A stencil printing machine comprising: a. a reciprocating frame supporting a stencil; b. a drum mounted on a central shaft to oscillate the former in opposite directions; c. said drum being mechanically coupled to said frame to impart translatory movement thereto in opposite directions corresponding to the direction of the oscillatory movement of the drum; d. a drive motor; e. coupling means for mechanically linking said motor to said drum to turn the latter first in one direction for a printing operation and then in reverse direction to a predetermined starting position so as to cause each printing operation to commence from the same starting position; f. means for adjusting said coupling means to control the oscillatory motion of the drum for different lengths of material to be printed: g. said adjusting means comprising i. a gear ring mounted co-axially with said drum; ii. a pivoted sector member having a toothed arc engaging said gear ring; iii. an arcuate lever having one end pivoted on a shaft, the other end being free; iv. a connecting rod having one end connected to said arcuate lever, the other end being connected to said sector member for oscillating said drum; v. crank means driven by said motor and connected to said Lever shaft to turn the pivoted end of the lever in a hypothetical sector arc of a predetermined angle; vi. said connecting rod being adjustable on said arcuate lever to a position which corresponds to the axis of said sector arc; vii. the length of the arm of said connecting rod in said adjusted position being equal to the length of the radius of said sector arc.