Camming platen endorser

In a document processing machine incorporating a rotary impact endorser, the combination comprising:

• a document track bounded by two walls between which documents are driven;
• said walls including openings therethrough;
• a platen and a print head positioned along opposite sides of the document track and including portions which can be extended through the openings in the walls;
• the print head bearing a stamp for use in providing printed endorsements to documents moving along the document track;
• driving means coupled to said print head to rotate the print head between positions in which the stamp is enabled to contact a document in the track and positions in which other parts of the print head remain free of contact with a document in the track;
• a cam coupled to said driving means to be revolved thereby;
• a cam follower roller;
• linkage means providing a coupling between the platen and the cam follower roller;
• and
• biasing means coupled to said linkage to urge the cam follower into contact with the cam and to urge the platen toward the print head;
• means to absorb landing and shear forces imparted through the linkage from said biasing means when the print head engages the platen, said means comprising a blank rubber pad forming a first portion of the face of the stamp;
• said blank rubber pad serving to convert some of the energy absorbed into torque to drive the platen;
• the cam follower roller being positioned by the linkage means to contact the cam during a portion of each revolution of the cam, whereby the platen is moved in and out of contact with a document in the track synchronously with the rotation of the print head to enable the stamp to provide endorsements to documents in the track and to prevent edge impact between the stamp and the platen.