Patent GB-372484-A (GB)
Title: Improvements in or applicable to platen printing presses
IPC: B41F1/28
Filed: 1931-03-18
Abstract: 372,484. Printing-machines. CHARLTON, C. A., CHARLTON, C. C., and CHARLTON, R. A., Franklin Works, Wright Street, Nottingham. March 18, 1931, Nos. 8286 and 9699. [Class 100 (i).] Delivery apparatus.-In a platen printing- machine the oscillating platen is combined with a paper-removing arm which is pivoted on an axle carried by and receiving oscillating. movements from the platen in a plane which is parallel or approximately parallel to the face of the latter. The paper-removing arm may be provided with automatically controlled means for gripping the printed sheets at one extremity of its movement and releasing them at the other extremity, or alternatively is adapted to work in conjunction with an automatically controlled suction arrangement. The paper-removing arm A is secured at one end to an axle B mounted in a bearing B<1> rigidly secured at one side of the oscillating platen C, the axle B being at rightangles to the arm A and its bearing B<1> at rightangles to the plane of the platen C. The bearing B<1> is at one end of a fixed axle E which is parallel to the platen shaft D and carried by a bracket E<1> secured to the lower part of the platen C. A bevel gear-wheel G secured on the axle B meshes with a bevel gear-wheel F loosely mounted on the axle E on the inner side of the bearing B<1>. The rotation of the gear wheel F relative to the axle E is restricted by an arm H secured at one end to the gear and connected at its other end by a link J to an arm J<1> on a rocking-shaft K. When the platen C moves about the shaft D, it carries the bracket E<1> and the paper-removing arm and rotates the axle B about the axle E, causing the gear wheel G to rotate to swing the paper-removing arm A outwards through an angle of 90‹ in a direction approximately at right-angles to the plane of the platen C. In the arrangement shown in the Figure the paper-removing arm A is fitted with a clamping- plate L which is carried by an axle L<1> fitted with a spring L<2> which normally holds the clamping- plate on the face of the arm. In the printing position the arm A is close to the platen C, and the clamping-plate L is opened to receive the edge of the paper by the engagement of an arm L<3>, secured to the plate, with an abutment M fixed on the frame M<1> of the machine. As the paper-removing arm A approaches the side of the platen C ready to remove a sheet of paper, the rocking-shaft K is actuated to cause the arm J<1> to draw back the link J and compress the spring N thereon to transmit a force through the arm H to hold the arm A up to the side of the platen, thus providing a lost motion between the platen C and the arm A, whereby the latter does not move from the platen C until the latter has retired a certain distance, the gear wheel arm H during this time being moved back by the spring N, thus neutralizing the action of the gear wheels F, G until the arm H contacts with a fixed collar N<1> on the link J. The loss in motion between the platen C and the arm A allows the clamping-plate L to be closed by its spring L2 and grip the paper, which is held until the arm A has carried it clear of the platen C, when the clamping-plate L<3> then contacts with another abutment to release the paper. In an alternative arrangement a hollow paper-removing arm is used having a series of small openings adapted to be covered by a paper sheet, so that when the air is withdrawn from its interior the paper is held on its surface. The hollow interior of the arm is connected to an air suction pump, and mechanically-controlled air inlet valves are provided in the connection to control the attachment and release of the paper sheet. The interior of the arm is divided into separate compartments, a main compartment, and smaller compartments which can be cut off from the suction pipe according to the size of the sheet of paper being printed.