US2034444A

US2034444A - Tennis racket with pneumatic tightener

Info

Publication number: US2034444A
Application number: US714694A
Authority: US
Inventors: Rauch Antonin; Smolik Vaclav
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-03-30
Filing date: 1934-03-08
Publication date: 1936-03-17
Anticipated expiration: 1953-03-17

Description

March 1936- A. RAUCH ET AL 2,034,444

TENNIS RACKET WITH PNEUMATIC TIGHTENER Filed March 8, 1954 2 Sheets-Sheet 2 Patented Mar. 17, 1936 TENNIS RACKET WITH PNEUMATIC TIGHTENER Antonin Ranch and Vaclav Smolik, Prague, Czechoslovakia Application March 8, 1934, Serial No. 714,694 In Czechoslovakia March 30, 1932 1 Claim.

This invention relates to a tennis racket with pneumatic tightening of the gut stringing carried out according to the invention in such a manner, that round the fixed, inner frame and handle of the racket, one or preferably two parallel rubber tubes are located, filled with compressed air; these tubes consist either from one single piece, or conveniently of two interconnected air pipes, or tubes, connected or tied together by a ligament. The stringing of the racket is held together and adjusted by the usual means, such as hooks, or the threading through of the racket frame etc., to the outer rim of the racket frame, which consists of several independent segments, movable respectively to each other and to the inner frame, and is tightened or loosened by inflating or deflating the air tubes.

On the accompanying drawings an embodiment of the invention is given by way of example, with the corresponding details and alternative solutions thereof. Fig. 1 shows schematically the elevation of the racket in section along line II in Fig. 2; Fig. 2 is a side-view of the tennis racket with a double rubber tube, Fig. 3 is a longitudinal axial section led through the handle of the racket with the gear, connecting the air pipes and showing the relief valve and the piston, located nearly in its upper position, omitting the frame. Fig. 9 shows a detailed side-view of the racket part of Fig. 3, Figs. 4 to 8 show five different devices for holding the gut stringing on the pneumatically tightened frame, all in cross section.

The tennis racket consists, according to the invention, of a stiff inner frame [6 of the usual oval shape, which is provided below with a forkextension l2, to which a hollow handle I4 is connected. All round the outer circumference of this inner frame In a slot I6 runs, having a rounded canal section (Figs. 4 to '7) or two similar slots running parallel to each other (Figs. 2 and 8), in each of which an elastic air tube l8 of usual circular cross section is placed. On the outer circumference of the stiff frame l8 and beyond the tube 18, or both parallel air tubes I8 is set a number of segment rim-pieces 26 along the tubes, either between both lateral parallel flanges l6 (Figs. 1, 2, 4 and 5) of the inner frame ID or themselves provided with parallel flanges 28', which cover the tube l8 laterally, as well as the stiff inner frame l0.

Therubber tube I8, or each of both tubes l8 lying side by side, is divided on the top, i. e. at the point opposite to the handle l4; each tube consists thus of two branches, the ends of which may be tightened and provided with a ligament 24. The other ends of the tubes are connected together and fitted to a common piping 26, extending between the sideplates I2 of the handle ID and reaching to a connecting pipe 28, fitted to a relief valve 38 (Fig. 3), serving to close the tube in a way as described below.

The connection of the tube 26 with the pipe 28 is eifected by means of a conical screw-socket 32 provided with an outer thread (Fig. 9), on which a tightening nut 34 may be screwed. This nut ensures an absolutely fixed and immovable connection between the tube extension 26 and the valve pipe 28. The valve needle 36 of the relief valve 36 in the pipe 28 extends up to the middle of the hollow part 38 of the handle I l, where a piston 46 is placed; the piston rod 62 of the piston is terminated on its outer free end by a handle 44, which may be fixed in the normal position by means of a bayonet fastening 46. Inside the hollow piston rod 42 of the piston, a spindle 48 (Fig. 3) is provided, the inner end of which is flattened and located in the space above the piston, Whilst its outer end is provided with a button 52, set in a depression 54 of the piston handle. Under the button of this spindle a return safety spring 56 is placed in the said depression for a purpose hereinafter described.

The racket strings 58 of the gut stringing may be fixed to the outer segmental rim parts 26 of the frame in various manners, as may be seen in Figs. 1, 2, 4 to 8. In the alternative arrangements according to Figs. 1, and 2 the gut stringing is threaded through apertures in the movable parts of the rim 28; these strings are suspended on a number of hooks 68 on the part of the frame lying at the top of the handle, whilst the outer free parts of the rim 28 are interrupted at this place to enable the removal of the tubes from inside the frame by loosening the ligaments 24; the ligaments serve besides to pull these tubes back into the frame groove after effecting the repair or exchange thereof.

In the alternative according to Fig. 4, the stringing 58 is led over a small pulley Wheel 62 suspended freely on a wire stirrup 64, adjusted in a transverse slot 66 of the outer rim 28 of the racket frame.

According to Fig. 5, the gut of the racket stringing is directly threaded through a similar transverse slot 66.

In the arrangement shown in Fig. 6, the pulley wheel 62 is placed on a transverse spindle 68, adjusted on both lateral flanges 26 of the corresponding rim 2!) of the frame.

In the alternative mode according to Fig. 7,

both lateral flanges 20 of the rim segments 20 forming the outer frame of the racket are bent inwards; the flattened base 10 of the suspension hook 12 is held in the required position by the ends 20" of these bent flanges.

In the alternative shown in Fig. 8 the hooks M are led through the fixed inner and the movable outer frame; these hooks are held in the central groove running round the circumference of the rim either by means of an eye with a pin or by any other suitable manner.

The arrangement as described above enables us to adjust the required tension of the gut stringing of the racket at any time; the racket stringing remaining elastic, whatever the degree of tightening may be, owing to the elasticity of the inflated rubber tube, which at the end of the game may be eased or deflated by merely pressing the button 52 together with the central inner spindle 48 inside the racket handle, thus opening the relief valve 36, through which the air may be entirely or partly let out of the rubber tube or tubes 18; the tension of the gut being thereby eased. A further advantage of the arrangement is that when the tubes l8 are deflated, the racket may be strung or restrung without special tension or tensioning devices as restringing is carried out preferably when the pressure in the tubes is eased, contrarily to the hitherto current procedure. The rubber tubes may even be completely removed from off the racket when adjusting the gut stringing, in the manner referred to above.

What we claim is:

A tennis racket comprising a handle, a substantially oval frame attached to said handle, a pair of rubber tubes, a connecting tube positioned in said handle, a pump comprising a cylinder, a piston and a piston rod all positioned in said handle, a valve connected to said connecting tube and said pump cylinder and means extending through said piston rod for opening said valve to reduce the pressure in said rubber tubes.

AIEITONI'N RAU H. VACLAV SMOLIK.