Hydraulically operated drum series printer

Marking apparatus comprising,

• a marking head,
• a wheel rotatably supported by said marking head,
• said wheel having a periphery with a plurality of marking characters positioned thereon,
• a ratchet portion on said wheel,
• a first shaft positioned adjacent said wheel,
• engaging means rotatably positioned on said first shaft for engaging said ratchet portion,
• said first shaft being normally maintained in a first position adjacent to said ratchet portion when said engaging means is disengaged from said ratchet portion,
• pressure means for moving said engaging means into engagement with said ratchet portion,
• said pressure means being operable upon actuation to rotate said engaging means on said first shaft into engagement with said ratchet portion when said first shaft is in said first position,
• actuator means for moving said first shaft in an arcuate path through a preselected angle so that said engaging means moves through a corresponding angle to rotate said wheel in a preselected direction through an angle corresponding to the angle of movement of said engaging means and thereby advance said marking characters on said wheel,
• said actuator means being operable upon acutation to move said first shaft in an arcuate path to a second position so that said engaging means being engaged to said ratchet portion rotates said wheel to advance said wheel one marking character,
• said pressure means being operable upon advancement of said wheel to release said engaging means from engagement with said ratchet portion once said first shaft is moved to said second position, and
• said actuator means being operable following disengagement of said engaging means from said ratchet portion to move said first shaft from said second position back to said first position.

Marking apparatus comprising,

• a marking head,
• a wheel rotatably supported by said marking head,
• said wheel having a periphery with a plurality of marking characters positioned thereon,
• a ratchet portion on said wheel,
• a first shaft positioned adjacent said wheel,
• engaging means rotatably positioned on said first shaft for engaging said ratchet portion,
• pressure means for moving said engaging means into engagement with said ratchet portion,
• actuator means for moving said first shaft in an arcuate path through a preselected angle,
• extensible means associated with said actuator means for limiting rotation of said wheel,
• said extensible means being connected to said first shaft, and
• said actuator means being operable upon actuation to extend said extensible means a preselected length and effect limited arcuate movement of said engaging means so that said wheel is turned through a preselected angle to advance the next adjacent marking character into marking position.

Marking apparatus comprising,

• a marking head,
• a wheel rotatably supported by said marking head,
• said wheel having a periphery with a plurality of marking characters positioned thereon,
• a ratchet portion on said wheel,
• a first shaft positioned adjacent said wheel,
• engaging means rotatably positioned on said first shaft for engaging said ratchet portion,
• pressure means for moving said engaging means into engagement with said ratchet portion,
• a pair of double-acting, air actuated cylinders,
• each of said cylinders having an extensible and retractable rod portion,
• said rod portion being connected to said first shaft,
• said cylinders being pivotally connected to said marking head, and
• said cylinders being operable upon actuation to extend said rod portions a preslected length to move said first shaft downwardly in a limited arcuate path through a preselected angle and thereby limit the swing of said engaging means through an angle to rotate said wheel to move one marking character out of marking position and the next adjacent marking character into marking position.

Marking apparatus comprising,

• a marking head,
• a wheel rotatably supported by said marking head,
• said wheel having a periphery with a plurality of marking characters positioned thereon,
• a ratchet portion on said wheel,
• a first shaft positioned adjacent said wheel,
• engaging means rotatably positioned on said first shaft for engaging said ratchet portion,
• a block member supported by said marking head adjacent to said engaging means,
• at least one chamber extending through said block member,
• said chamber having an inlet and an outlet,
• a plunger longitudinally positioned in said chamber and having an end portion adapted to move between a first position in said chamber and a second position extended from said chamber outlet into contact with said engaging means,
• means for selectively supplying air under pressure to said inlet of said chamber and thereby move said plunger from said first position to said second position to exert a force upon said engaging means to pivot said engaging means on said first shaft into engagement with said ratchet portion of said wheel,
• resilient means for applying a force upon said engaging means to move said plunger from said second position back to said first position when said inlet is vented to permit air to escape from said chamber, and
• actuator means for moving said first shaft in an arcuate path through a preselected angle so that said engaging means moves through a corresponding angle so that said engaging means moves through a corresponding angle to rotate said wheel in a preselected direction through an angle corresponding to the angle of movement of said engaging means and thereby advance said marking characters on said wheel.

Marking apparatus comprising,

• a marking head,
• a plurality of wheels rotatably supported by said marking head,
• said wheels each having a periphery with a plurality of marking characters positioned thereon,
• a ratchet portion on each of said wheels,
• a shaft supported adjacent said wheels,
• engaging means pivotally positioned on said shaft for selectively engaging said ratchet portions of said respective wheels,
• said engaging means each having a first end portion and a second end portion,
• said first end portion being movable upon rotation of said engaging means on said first shaft into and out of engagement with said ratchet portion,
• pressure means for selectively moving preselected ones of said engaging means into engagement with said ratchet portions of said respective wheels,
• said second end portion being positioned in abutting relation with said pressure means,
• resilient means positioned on said first shaft for exerting a force upon said engaging means to normally maintain said engaging means first end portions disengaged from said ratchet portion and said engaging means second end portions abutting said pressure means,
• said pressure means being operable upon actuation to apply a force to said engaging means second end portions and overcome the force of said resilient means to pivot said engaging means on said first shaft and move said engaging means first end portion into engagement with said ratchet portions, and
• actuator means for moving said shaft in an arcuate path through a preselected angle so that said engaging means move through a corresponding angle to rotate said wheels engaged by said respective engaging means in a preselected direction through an angle corresponding to the angle of movement of said engaging means and thereby selectively advance said marking characters on said wheels.

A method for controlling the movement of marking indicia of a marking wheel for a marking apparatus comprising the steps of,

• rotatably supporting a marking wheel having a ratchet portion in a marking head,
• rotatably supporting an engaging means adjacent the marking wheel,
• normally maintaining the engaging means in a first position removed from engagement with the ratchet portion of the marking wheel,
• pivoting the engaging means in the first position into engagement with the ratchet portion of the marking wheel,
• moving the engaging means from the first position in an arcuate path through a preselected angle to a second position,
• turning the marking wheel by movement of the engaging means from the first position to the second position through an angle corresponding to the angle of movement of the engaging means to thereby advance preselected marking indicia on the marking wheel into marking position,
• releasing the engaging means from engagement with the ratchet portion of the marking wheel after the engaging means is moved to the second position, and
• thereafter, moving the engaging device disengaged from the marking wheel from the second position back to the first position.

A method for controlling the movement of the marking indicia of a marking wheel for marking apparatus comprising the steps of,

• rotatably supporting a marking wheel having a ratchet portion in a marking head,
• rotatably supporting an engaging means adjacent the marking wheel,
• pivotally supporting the engaging means about a fulcrum point of the engaging means on a shaft in a position normally disengaged with the ratchet portion,
• applying a force to a first end of the engaging means to pivot the engaging means about the fulcrum point on the shaft and move a second end of the engaging means into engagement with the ratchet portion of the marking wheel,
• maintaining the engaging means in a pivoted position on the shaft and engaged to the ratchet portion of the marking wheel,
• applying a force to the shaft to move the shaft together with the engaging means in an arcuate path through a preselected angle,
• turning the marking wheel by movement of the engaging means to advance the next adjacent marking indicia into marking position,
• thereafter releasing the force applied to the first end of the engaging means,
• applying a force to the second end of the engaging means to pivot the engaging means about the fulcrum point and move the second end portion of the engaging means out of engagement with the ratchet portion of the marking wheel,
• applying a force to the shaft to move the shaft together with the engaging means in an arcuate path and return the engaging means to its normally disengaged position with the ratchet portion, and
• maintaining the marking wheel fixed while returning the engaging means to its normally disengaged position with the ratchet portion.