Parallel input printing mechanism

Claim 2

A print action mechanism for a parallel input printer having at least one font Of type arranged circumferentially at predetermined spaced intervals on a print drum continuously rotated to sequentially advance the type in a succession of corresponding time intervals of a cycle into printing registration at a print station comprising; a. hammer means including a lever formed with a driven arm rotatably mounted for executing a firing stroke by rocking about one rotational axis from a restored position into impact against a type at said print station; b. spring-biased power means including a driving arm rotatably mounted for rocking about a different rotational axis parallel to said one axis and articulated in bearing contact with said driven arm to rock said hammer means when rotated in one rotational direction and to be rocked by said driven arm of said hammer means in the opposite rotational direction, said power means being retainable in a restored position and rockably releasable therefrom under its spring bias to apply torque on said driven arm for rocking said hammer means from its restored position through a firing stroke; c. actuator means engaging said power means to retain same in its restored position and energizable to release said power means at a time of the cycle corresponding to the time a selected type arrives at said print station; and d. restoring cam means shaped to provide at least one cam lobe disposed to bear on said hammer means following impact thereof with a selected type at said print station for positively returning said hammer means and concomitantly therewith said power means to their restored positions, said cam means being continuously rotated and synchronized with said drum to initiate and complete its restoring action on said hammer means and power means during the print cycle interval immediately before the next successive type arrives at said print station.

Claim 3

The invention according to claim 1 wherein said power means driving arm is rotatable from its said restored position through an arc constituting a power stroke, and said driven arm is disposed in abutting relation thereto maintaining contact therewith throughout said power stroke, and including; a. means disposed to limit said power means at a degree of rotation which terminates said power stroke before the hammer means completes its firing stroke, said hammer means completing its firing stroke by its own inertia and separated from said power means.

Claim 4

The invention according to claim 2 wherein said limit means comprises a cam member rotatably settable to adjust the extent of the power stroke of said driving arm.

Claim 5

The invention according to claim 1 wherein the spring biasing said power means is stretched between said power means and an anchor member displaceable about a pivotal axis for adjusting the force of the spring bias on said power means.

Claim 6

The invention according to claim 2 wherein said limit means comprises a cam member rotatably settable to adjust the extent of the power stroke of said driving arm, and wherein the spring biasing said power means is stretched between said power means and an anchor member displaceable about a pivotal axis for adjusting the force of the spring bias on said power means and including; a. a first adjusting member for rotatably setting said cam member; and b. a second adjusting member for selectively displacing said anchor member.

Claim 7

The invention according to claim 5 wherein said first and second adjusting members are keyed together and are actuable unitarily to adjust the extent of said power stroke and the tension of said spring.

Claim 8

The invention according to claim 1 wherein said power means comprises a driving arm rotatable from its said restored position through an arc constituting a power stroke, said hammer means being unrestrainably rotatable and having its said driven arm disposed in abutting coplanar relation to said driving arm and maintaining bearing contact therewith throughout said power stroke and including; a. means disposed to limit said power means aT a degree of rotation which terminates said power stroke before the hammer means completes its firing stroke, said hammer means completing its firing stroke in unrestrained free flight and separated from said power means; and b. said hammer means and said power means are counterrotatable when released from their restored positions, said driven arm of the hammer means lever being formed with an undercut extremity and said driving arm of said power means being formed with a recess accommodating said extremity and shaped to restrain independent rocking of said driven arm when said arms are in their restored positions, said extremity and said recess lying near the center line between the respective rotational axes of said arms when in their restored position.

Claim 9

The invention according to claim 1 wherein the profile of said restoring cam lobe includes a steep rise surface engageable with a cam follower projection formed on said hammer means for returning said hammer means to its restored position, said steep rise surface extending from an initial low concentric surface to a high concentric surface and imparting overthrow momentum to said hammer means while returning same into restored position, the cam follower projection of said hammer means being spaced from said high concentric surface when in its restored position.

Claim 10

The invention according to claim 8 wherein said high concentric surface terminates in an instantaneous drop surface merging into said low concentric surface and is rotated into effective position for engagement by said follower projection at the start of a firing stroke, said high concentric surface limiting rotation of said projection to prevent said hammer means from completing its firing stroke until a predetermined time of a print cycle interval after said hammer means and said power means are initially released by said actuator means.

Claim 11

A print action mechanism for a parallel input printer having a font of type arranged circumferentially at predetermined spaced intervals on a print drum continuously rotated to sequentially advance the type in a succession of corresponding time intervals of a print cycle into printing registration at a print station comprising; a. a print hammer in the form of a lever having an impact arm disposed adjacent said print station and a driven arm integral therewith, said lever being rotatably mounted for rocking about one rotational axis through a firing stroke during which said impact arm is driven from a restored position into impact against a type at said print station; b. a spring-biased power lever rotatably mounted on a different rotational axis parallel to said one axis, said power lever having a power release arm and a driving arm articulated in bearing contact with the driven arm of said hammer lever to rock said driven arm when rotated in one rotational direction and to be rocked by said driven arm in the opposite rotational direction, said power lever being retainable in a restored position and rockably releasable therefrom for rocking in said one rotational direction under its spring bias through a power stroke during which a torque is applied to said driven arm by said driving arm for rocking said print hammer from its restored position through a firing stroke; c. actuator means having an armature engageable with said release arm for retaining said power lever in its restored position and energizable to release said power lever to initiate a power stroke; d. a signal emitter synchronized with said print drum and operatively connected to said actuator means for controlling the energization thereof to release said power lever at a time of the cycle corresponding to the time a selected type arrives at said print station; and e. a rotating restoring cam shaped to provide at least one cam lobe disposed to bear on said print hammer following impact thereof with a selected type at said print station for positively returning said hammer and concomitantly therewith said power Lever to their restored positions, said restoring cam being continuously rotated in synchronism with said drum and timed to initiate and complete the restoration of said hammer lever and said power lever during the print cycle interval immediately before the next successive type arrives at said print station.

Claim 12

A print action mechanism for a parallel input printer having a font of type arranged circumferentially at predetermined spaced intervals on a print drum continuously rotated to sequentially advance the type in a succession of corresponding time intervals of a print cycle into printing registration at a print station comprising; a. a print hammer in the form of a lever having an impact arm disposed adjacent said print station and a driven arm integral therewith, said lever being rotatably mounted for rocking about one rotational axis through a firing stroke during which said impact arm is driven from a restored position into impact against a type at said print station; b. a spring-biased power lever rotatably mounted on a different rotational axis parallel to said one axis, said power lever having a power release arm and a driving arm articulated in bearing contact with the driven arm of said hammer lever to rock said driven arm when rotated in one rotational direction and to be rocked by said driven arm in the opposite rotational direction, said power lever being retainable in a restored position and rockably releasable therefrom for rocking in said one rotational direction under its spring bias through a power stroke during which a torque is applied to said driven arm by said driving arm for rocking said print hammer from its restored position through a firing stroke; c. actuator means having an armature engageable with said release arm for retaining said power lever in its restored position and energizable to release said power lever to initiate a power stroke; d. a signal emitter synchronized with said print drum and operatively connected to said actuator means for controlling the energization thereof to release said power lever at a time of the cycle corresponding to the time a selected type arrives at said print station; and e. a rotating restoring cam shaped to provide at least one cam lobe disposed to bear on said print hammer following impact thereof with a selected type at said print station for positively returning said hammer and concomitantly therewith said power Lever to their restored positions, said restoring cam being continuously rotated in synchronism with said drum and timed to initiate and complete the restoration of said hammer lever and said power lever during the print cycle interval immediately before the next successive type arrives at said print station.

Claim 13

The invention according to claim 10 wherein said print hammer lever is unrestrainably rotatable and said driven arm is disposed in abutting coplanar relation to said driving arm to maintain said bearing contact therewith throughout said power stroke, and including; a. a member disposed to engage the release arm of said power lever to limit its rotation in said one direction at a degree of rotation which terminates its said power stroke before said hammer lever completes its firing stroke, said hammer lever completing its firing stroke by its own inertia in unrestrained free flight and separated from said power lever.

Claim 14

The invention according to claim 11 wherein said member comprises a rotatable cam settable to adjust the extent of said power stroke.

Claim 15

The invention according to claim 10 wherein the spring biasing said power lever is stretched between said power lever and an anchor member pivotally mounted and rotatively displaceable about its pivotal axis for adjusting the force of the spring bias on said power lever.

Claim 16

The invention according to claim 13 including a cam member disposed for engagement by the release arm of said power lever to limit the extent of said power stroke, said member being rotatably settable to adjust the extent of said power stroke and including; a. a first adjusting member for rotatably setting said cam member; and b. a second adjusting member for selectively displacing said anchor member.

Claim 17

The invention according to claim 14 wherein said first and second adjusting members are keyed together and operate unitarily to adjust the extent of said power stroke and the tension of said spring.

Claim 18

The invention according to claim 10 wherein said hammer lever is mounted for unrestrained rotation and has its driven arm disposed in abutting coplanar relation to said driving arm to maintain bearing contact therewith throughout said power stroke, said hammer lever and said power lever being counterrotatable upon release from their restored positions, the driven arm of said hammer lever being formed with an undercut extremity and the driving arm of said power lever being formed with a recess accommodating said extremity and shaped to prevent independent rocking of said driven arm when said arms are in their restored positions, said extremity and said recess being disposed near the center line between the respective rotational axes of said arms when in their restored position, said extremity withdrawing from said recess while rotating away from said center line to enable independent rocking of said driven arm, and including; a. a limit member disposed for engagement by said power lever at a degree of rotation which terminates said power stroke before the hammer lever completes its firing stroke, said hammer lever completing its firing stroke in unrestrained free flight by its own inertia and separated from the driving arm of said power lever.

Claim 19

The invention according to claim 10 wherein the camming surface of said restoring cam lobe has a profile which includes at its maximum radius a high concentric surface, and said driven arm is formed with a cam follower projection disposed for bearing engagement with said camming surface, the synchronous rotation of said restoring cam positioning said high concentric surface for engagement by said follower projection at the start of a firing stroke, said high concentric surface limiting rotation of said driven arm from its restored position to prevent completion of the firing stroke of said hammer lever until a predetermined time in the cycle.

Claim 20

The invention according to claim 17 wherein the profile of said cam lobe includes a steep rise surface preceding Said high concentric surface and following an initial low concentric surface for returning said hammer lever to its restored position, said steep rise surface imparting overthrow momentum to said hammer lever in returning it into its restored position wherein it is spaced from said high concentric surface.

Claim 21

The invention according to claim 18 wherein said high concentric surface is followed by an instantaneous drop surface extending to said low concentric surface, said drop surface enabling unresisted rotation of said driven arm to complete the firing stroke of said hammer lever after said hammer lever and said power lever are initially released by said actuator means.