GB230250A - Improvements in and means for testing balls, particularly those used in games, such as lawn tennis - Google Patents

Abstract

230,250. Stevens, P. H. Feb. 25, 1924. Testing tennis balls.-Comprises a platen carried on a pressure measuring balance and a second platen in axial alignment with the first, means for approaching the platens with the ball between them, and means for indicating the pressure exerted in compressing the ball to a given degree, or to indicate the degree of compression under a predetermined pressure. The ball to be tested is placed on a lower platen H guided in the framework and formed with a screwed shank engaging a screwed socket G rotatable by bevel gear G<2> G<2> from a shaft G4. The platen is raised until the ball engages a second platen F pivoted to a counterweighted lever B pivoted at B<1> to the frame. This lever is loaded with a weight B<3> which may be moved along the beam by fingers K<1> carried by a rack K operated by a pinion rotated by a milled head. The lever B is given a predetermined load and when the lever is raised by upward movement of the platen H, the depression given to the ball is read off on a dial over which moves a pointer carried by a disc moving in one with a wheel G<10> driven by a worm G' on the shaft G<4>. Fractional parts of a revolution of the shaft G<4> are read off on a wheel G<9>. The wheel G<9> and the indicating disc on the shaft G" are held by friction on their shafts and each may be moved relatively to the shaft to effect a zero adjustment.