Marking unit for tennis balls - leaves permanent impression on ball surface using ink, acid or heat

摘要

The printing surface of the unit is contoured to fit the spherical surface of the tennis ball and preferably consists of an electrically heated area (19) to which the required symbols (21) made of thermally conducting and heat resistant material are attached. The unit incorporates a housing (13) containing a hand-operated stamp (14) mounted removably on the ram (15). A stop is incorporated in the design so that the stamp can be depressed downwards far enough to form an impression only on the fibres of the ball. The ram (15) and housing (13) are made from electrically non-conducting and thermally non-conducting material.