The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 27, 2017
Filed:
Jan. 29, 2015
James W. Sorenson, Mt. Pleasant, IA (US);
James W. Sorenson, Mt. Pleasant, IA (US);
Other;
Abstract
A tennis serve trainer mechanically encourages and causes the execution of a counter-intuitive hitting-up-on-the-ball service swing. The trainer has a straight shaft and a ball which can slide freely on the shaft between a tennis racquet grip on one end and a cap on the other. The ball is magnetically held against the grip until a threshold swing speed releases the ball. The magnetic force, the distance from the grip to the cap and the weight of the ball are coordinated so that the ball will strike the cap at the apex of the swing. At that moment, the arm is fully extended, the racquet head speed is accelerated to its maximum, the angle of attack is ideal, the ball and the racquet meet at the perfect impact point at the apex of the serve, and a snap in the racquet motion happens automatically at the top of the swing.