Wagner, T.T.WagnerSchweigert, U.U.Schweigert2022-03-082022-03-081993https://publica.fraunhofer.de/handle/publica/302894A device for stringing rackets for ball sports consists of two flat shaped bodies which are arranged above and below the surface of the racket to be strung and which are provided on their surface with a system of longitudinal and transverse grooves. These grooves are shaped so that when the bodies are placed on top of each other, the longitudinal grooves form a row of channels with a constant depth, whereas the transverse grooves form channels which run in a wave-shaped meandering about the system of longitudinal grooves. The two bodies can be each formed from a single piece and they can be modified to the outer contour of the racket shape or they can consist of individual strip-like web inserts arranged adjacently.de608670patent1992-4225472