Sheet sensor for offset printer

Claim 2

A sensor for determining the simultaneous passage of a number of sheets moving between two cylinders of an offset printing machine of the type having a pair of support arms pivotally mounted on respective sidewalls of the machine for rockably supporting one of the cylinders between the sidewalls, the improvement comprising: a support plate having means for removably mounting the same on one of said sidewalls adjacent to the outer end of the corresponding support arm remote from its axis of rocking movement; an L-shaped device pivotally mounted on said plate and having a leg provided with a pair of spaced projections and a leaf spring secured to and spanning the distance between the projections; a stop; means adjustably mounting the stop on said plate; means biasing the leg toward the stop with the stop normally engaging the leaf spring intermediate the ends of the latter; a switch; and means mounting the switch on the device at a location spaced from the pivotal axis thereof, said switch adapted to be engaged by said outer end of the corresponding arm and actuated in response to the pivotal movement of the same through a predetermined distance when said support plate is mounted on said one sidewall and when said one cylinder rocks relative to and away from said other cylinder, said switch adapted to be coupled to an operative component of the machine to cause the latter to be deactuated when said corresponding arm travels through said predetermined distance.

Claim 3

In an offset printer: a pair of spaced sidewalls; a blanket cylinder mounted on the sidewalls and extending therebetween for rotation about a fixed axis relative thereto; a pair of arms, each arm being pivotally mounted intermediate its ends on a respective sidewall; an impression cylinder below the blanket cylinder, the ends of said impression cylinder being rotatably secured to respective arms in spaced relationship to the axis of pivotal movement thereof so that the impression cylinder can pivot downwardly and away from the blanket cylinder when one or more sheets to be printed pass therebetween; a plate; an L-shaped device pivotally mounted on said plate, said device having a leg provided with a pair of spaced projections and a leaf spring secured to and spanning the distance between the projections; a stop; means adjustably mounting the stop on said plate; means biasing the leg toward the stop with the latter engaging the leaf spring intermediate the ends thereof; a switch carried by said device, said plate having means for removably mounting the same on one of the sidewalls with said switch disposed adjacent to the corresponding arm, said switch being actuated in response to the movement of the arm through a predetermined distance as the impression cylinder pivots away from the blanket cylinder; and an operative component of the machine for sustaining the operation thereof, said component having an electrically actuated drive, said switch being coupled to the drive to deactuate the same in response to the movement of said arm through said predetermined distance.

Claim 4

In an offset printer: a pair of spaced sidewalls; a blanket cylinder mounted on the sidewalls and extending therebetween for rotation about a fixed axis relative thereto; a pair of arms, each arm being pivotally mounted intermediate its ends on a respective sidewall; an impression cylinder below the blanket cylinder, the ends of said impression cylinder being rotatably secured to respective arms in spaced relationship to the axis of pivotal movement thereof so that the impression cylinder can pivot downwardly and away from the blanket cylinder when one or more sheets to be printed pass therebetween; a plate; an L-shaped device pivotally mounted on said plate, said device having a leg provided with a pair of spaced projections and a leaf spring secured to and spanning the distance between the projections; a stop; means adjustably mounting the stop on said plate; means biasing the leg toward the stop with the latter engaging the leaf spring intermediate the ends thereof; a switch carried by said device, said plate having means for removably mounting the same on one of the sidewalls with said switch disposed adjacent to the corresponding arm, said switch being actuated in response to the movement of the arm through a predetermined distance as the impression cylinder pivots away from the blanket cylinder; and an operative component of the machine for sustaining the operation thereof, said component having an electrically actuated drive, said switch being coupled to the drive to deactuate the same in response to the movement of said arm through said predetermined distance.