Dating device for printers

Claim 1

A printer, comprising: a printing plate having a plurality of sides forming an aperture extending from a front face of said plate a predetermined distance into said plate to one of said sides which substantially parallel to said front face, and a groove extending along another of said sides; a dating device, detachably connected inside said aperture to said printing plate, including a frame having means which is slidably engaged in said groove to slide backward and forward between said front face and said one side, an axle connected to said frame having a polygonal cross-section with two opposite first edges, type wheels, of an elastically deformable material, each having a polygonal inner cross-section with a plurality of second edges spaced apart by a plurality of sides, said wheels being rotatably mounted on said axle and in which two of said second edges of said wheels rest on said two opposite first edges of said axle, the distance between said two opposite first edges being greater than the distance between any two opposite sides of said polygonal inner crosssection, wherein when said wheels are rotated on said axle said inner cross-section is deformed by one of said two opposite first edges; and a movable hammer, located opposite said front face of said printing plate, for applying a force to said dating device; said dating device further including types on the periphery of said type wheEls, some of said types being in a printing position facing said hammer and projecting ahead of said front face in a direction towards said hammer, and types on said type wheels opposite said types in the printing position being at a predetermined distance from said one side of said printing plate forming said aperture, wherein when said hammer applies a force to said types in the printing position said frame slides in said groove to enable said types opposite those in the printing position to contact said one side of said printing plate.