Tennis trainer

Claim 2

A tennis trainer comprising a telescoping shaft assembly having a plurality of shafts slidable with respect to each other, a tennis ball and means for mounting said tennis ball to a first one of said shafts, support means, means for mounting a second one of said shafts to said support means, said first shaft being relatively slidable with respect to said second shaft, at least one intermediate shaft fitting within said second shaft and over said first shaft and being relatively slidable with respect to both said first and second shafts, first resilient means located within said second shaft for stopping the sliding movement of the said first shaft and said intermediate shaft and for imparting return movement to said first shaft and said intermediate shaft.

Claim 3

The tennis trainer according to claim 1 wherein said second shaft is nonslidably mounted to said support.

Claim 4

The tennis trainer according to claim 1 wherein said tennis ball is a pressureless hollow interior ball; an opening in said tennis ball, and a fastener having collapsible and expandable arms adapted to be collapsed and slipped through said opening into the interior of said pressureless tennis ball, said fastener expanding inside said pressureless tennis ball to mount said pressureless tennis ball to said first shaft.

Claim 5

The tennis trainer according to claim 3 further comprising a force plate mounted on said first shaft and adjacent said tennis ball for transferring the impact force of the tennis racket to said first shaft.

Claim 6

The tennis trainer according to claim 1 wherein the said first shaft is heavier than said at least one intermediate shaft.

Claim 7

The tennis trainer according to claim 1 wherein said at least one intermediate shaft is provided with internally mounted means for receiving the force of said first shaft and said at least one intermediate shaft when said ball is struck.

Claim 8

The tennis trainer according to claim 6 wherein the force receiving means is a metallic closure.

Claim 9

The tennis trainer according to claim 1 further comprising means for stopping return movement of each of said first and said at least one intermediate shafts as each of said first and at least one intermediate shaft reaches full extension.

Claim 10

The tennis trainer according to claim 1 further comprising a slidable seal between said second shaft and said at least one intermediate shaft, said slidable seal forming a variable volume chamber comprising said seal, one end of said second shaft and the portion of the second shaft located between said one end and said seal, an opening in said second shaft located a selected distance from the location of said seal when said intermediate shaft is fully telescoped in said second shaft to control the speed at which said at least one intermediate shaft telescope and return to the fully extended position.

Claim 11

The tennis trainer according to claim 1 wherein said support means comprises a first collar fixedly mounted to said second shaft, an extensible bar assembly comprising a rotatable sleeve and an extensible rod mounted in said rotatable sleeve, means rotatably coupling said sleeve to said rod, rotation of said sleeve in a first direction extending said rod to permit mounting said assembly in a door frame, rotation in the direction opposite to said first direction reversing the direction of movement of said rod permitting removal of said assembly for said door frame.

Claim 12

The tennis trainer according to claim 10 further comprising cups mounted on the rod and on the sleeve for engaging the door frame upon extension of said rod.

Claim 13

The tennis trainer according to claim 10 wherein said first collar comprises an opening, a plug in said opening in contact with said extensible bar assembly, said plug having a substantially planar face thereon, a second collar, said second shaft being mounted in said second collar, said second collar having an extension secured in said opening and pushing said plug against said extensible bar assembly to permit movement of the shafts in response to applied force in a plane parallel to the face of the plug in excess of the friction force between said plug and said extensible bar assembly.

Claim 14

The tennis trainer according to claim 1 wherein said support means comprises a flange having an extension thereon; means for securing said flange to a support, a collar assembly comprising a first collar surrounding said extension and means for locating said collar assembly on said extension, a second collar mounted on said first collar, said second shaft being mounted in said second collar, and means for permitting said collar assembly to rotate a selected amount on said extension.

Claim 15

The tennis trainer according to claim 13 wherein said means for permitting said first collar to rotate on said extension comprises an opening in said first collar, said means for locating said first collar on said extension comprising an abutment member, said abutment member being releasably secured to said extension, said abutment member passing through said opening and being smaller than said opening whereby the first collar is located on said extension, the limits of rotation of said collar being fixed by the difference in size of said opening and said abutment member.

Claim 16

The tennis trainer according to claim 14 wherein said plate has an opening therein, a chamber in said extension communicating with said opening, said extension further comprising screw means in said extension, said screw means having one end positioned in said chamber, a rubber plug on said one end adapted to contact said support, said screw means having a head located adjacent the opening in said first collar, said abutment member being releasably mountable to said head.

Claim 17

The tennis trainer according to claim 12 wherein said first collar comprises a wall having an upstanding tube mounted thereon, a rubber plug in said tube, said plug having a substantially planar face thereon, said second collar having an extension secured in said upstanding tube and pressing said plug against said wall to permit movement of the shafts in response to applied force in a plane parallel to the face of the plug in excess of the friction force between said plug and said extension.

Claim 18

A tennis trainer comprising a telescoping shaft assembly having first, second and third shafts, said first shaft telescoping into said second shaft and said second shaft telescoping into said third shaft, a tennis ball mounted on said first shaft, resilient means mounted internally of said third shaft for receiving the force of said first and second shafts when the tennis ball is struck and for returning the first and second shafts towards their fully extended positions, and means for supporting said third shaft.

Claim 19

A tennis trainer comprising a telescoping shaft assembly having first, second and third shafts, said first shaft telescoping into said second shaft and said second shaft telescoping into said third shaft, a tennis ball mounted on said first shaft, resilient means mounted internally of said third shaft for receiving the force of said first and second shafts when the tennis ball is struck and for returning the first and second shafts towards their fully extended positions, and means for supporting said third shaft.

Claim 20

The tennis trainer according to claim 17 wherein said second shaft is lighter in weight than said first shaft.

Claim 21

The tennis trainer according to claim 17 further comprising closure means on said second and third shafts for absorbing the force of said first and second shafts respectively when said first and second shafts reach full extension during their return movement.

Claim 22

A tennis trainer kit comprising (a) a telescoping shaft assembly having first, second and third shafts, said first shaft having a tennis ball mounted thereon, said first shaft telescoping into said second shaft and said second shaft telescoping into said third shaft and means in said third shaft for receiving the force of said first and second shafts when the tennis ball is struck and for returning the first and second shafts towards their fully extended positions; (b) a collar assembly having first and second collars fixedly connected to each other, said first collar being mountable on said third shaft, and means for securing said first collar to said third shaft; (c) means for mounting said telescoping shaft assembly to a fixed surface;

Claim 23

A tennis trainer kit comprising (a) a telescoping shaft assembly having first, second and third shafts, said first shaft having a tennis ball mounted thereon, said first shaft telescoping into said second shaft and said second shaft telescoping into said third shaft and means in said third shaft for receiving the force of said first and second shafts when the tennis ball is struck and for returning the first and second shafts towards their fully extended positions; (b) a collar assembly having first and second collars fixedly connected to each other, said first collar being mountable on said third shaft, and means for securing said first collar to said third shaft; (c) means for mounting said telescoping shaft assembly to a fixed surface;

Claim 24

A tennis trainer kit comprising (a) a telescoping shaft assembly having first, second and third shafts, said first shaft having a tennis ball mounted thereon, said first shaft telescoping into said second shaft and said second shaft telescoping into said third shaft and means in said third shaft for receiving the force of said first and second shafts when the tennis ball is struck and for returning the first and second shafts towards their fully extended positions; (b) a collar assembly having first and second collars connected to each other, said first collar being mountable on said third shaft, said second collar having a hole in its wall, and means for securing said first collar to said third shaft; (c) a support plate having an opening therein, an extension fixedly mounted on said support plate having a chamber therein in communication with said opening and a screw hole in communication with said chamber, said second collar fitting over and rotating said extension said second collar having an opening therein; (d) screw means being mountable in said screw hole, and support surface engaging means on said screw means for positioning in said chamber, and (e) abutment means being mountable in the wall of the hole in said second collar for securing to said extension, said abutment means being smaller than the opening in said collar to permit a selected amount of rotation of said second collar with respect to said extension upon assembly.

Claim 25

A tennis trainer kit comprising (a) a telescoping shaft assembly having first, second and third shafts, said first shaft having a tennis ball mounted thereon, said first shaft telescoping into said second shaft and said second shaft telescoping into said third shaft and means in said third shaft for receiving the force of said first and second shafts when the tennis ball is struck and for returning the first and second shafts towards their fully extended positions; (b) a collar assembly having first and second collars connected to each other, said first collar being mountable on said third shaft, said second collar having a hole in its wall, and means for securing said first collar to said third shaft; (c) a support plate having an opening therein, an extension fixedly mounted on said support plate having a chamber therein in communication with said opening and a screw hole in communication with said chamber, said second collar fitting over and rotating said extension said second collar having an opening therein; (d) screw means being mountable in said screw hole, and support surface engaging means on said screw means for positioning in said chamber, and (e) abutment means being mountable in the wall of the hole in said second collar for securing to said extension, said abutment means being smaller than the opening in said collar to permit a selected amount of rotation of said second collar with respect to said extension upon assembly.