US 3904199 A
A sports stroke training device having a post for mounting vertically on a vertical surface. The post is provided with a longitudinal groove for adjustably retaining a pivot shaft. An elongated bar is mounted intermediate its ends on the pivot shaft for pivotal movement thereon. The bar is provided at each of its ends with a flexible guide member which extends perpendicular from the bar in a direction from the post. A correct racket stroke is made when both guide members are hit during the stroke along the longitudinal centerline of the bar.
Description (OCR text may contain errors)
United States Patent 1191 Burchett [4 1 Sept. 9, 1975 1 SPORTS RACKET STROKING TRAINER  Inventor: Paul James Burchett, P.O Box 386,
Corona del Mar, Calif. 92625  Filed: Aug. 13, 1973  AppL No: 387,922
 U.S. Cl. 273/29 A; 273/26 R [51 1 Int. Cl. A63B 69/40 [581 Field of Search 273/26 R, 29 A, 191 R, 273/191 A, 192, 186 R, 186 A, 186 B,186C
 References Cited UNITED STATES PATENTS 720.406 2/1903 Clifford 273/186 R 1,427.538 8/1922 Long 273/186 R 2,985,452 5/1961 Trippct 273/26 R 334L208 9/1967 Marcella i A i 273/191 A 3.48941 1 1/1970 Morelli ct ul. 273/26 R 3,730,531 5/1973 Zega h 273/119 A Primary Exuminer-Richard C. Pinkham Assistant ExaminerT. Brown  ABSTRACT A sports stroke training device having a post for mounting vertically on a vertical surface. The post is provided with a longitudinal groove for adjustably retaining a pivot shaft. An elongated bar is mounted in termediate its ends on the pivot shaft for pivotal movement thereon. The bar is provided at each of its ends with a flexible guide member which extends perpendicular from the bar in a direction from the post. A correct racket stroke is made when both guide members are hit during the stroke along the longitudinal centerline of the bar.
7 Claims, 4 Drawing Figures PATENTEBSEP ems 3 904,199
SPORTS RACKET STROKING TRAINER BACKGROUND OF THE INVENTION This invention relates to training devices for the stroking of sports rackets. This general term is intended to mean tennis, squash, and badminton rackets and the like.
Except for overhead smashes, the main strokes used in tennis and squash can be divided into two categories. Horizontal strokes are within about 10 of being parallel with the ground, and lobs are up approximately 45 from the ground.
Within the applicants experience, there has heretofore been no way to indicate the angle of a racket stroke. Yet the development of a consistent and proper stroking path is a major factor in controlling the flight path of the ballv The purpose of a lob is to force an opponent to retreat from a net position by hitting the ball above his reach. There is an interesting law of physics that states that the trajectory ofa ball, hit with the same force, will travel furthest horizontally if hit at a 45 angle. The distance can best be controlled if the 45 angle is used consistently and the hitting force varied.
Horizontal strokes can vary slightly in order to add top spin or back spin. Top spin" results from the racket travelling upward at about 10 from the horizontal. This causes the ball to have a flat bounce when it lands. "Back spin" is created when the racket is moving downward at about 10, and causes the ball to bounce more nearly vertical. In these strokes, as well as the flat power strokes between, it is important to follow the same path for a length of nearly two feet.
A volley is a horizontal stroke applied to a ball while traveling nearly flat, usually in the area of the net. r
In this case. the racket should be pushed with the shoulder and body along a straight line rather than in an arc.
SUMMARY OF THE INVENTION My invention allows the stroking of a sports racket to be made more consistent, more accurate and better re lated to follow-thru and foot position.
A principal object of the invention is to provide a device that indicates the angle of a racket stroke relative to the ground.
A further object is to allow an angle indicator to be adjustable in angle as well as in height.
An additional object is to provide for placement of the users feet in a specific position relative to the angle indicator.
A still further object is to allow use of the device by left or right handed players.
In the simplest and preferred embodiment. my invention consists of a vertically grooved post, adapted for attachment to a vertical surface such as a wire fence, and a pivoting bar with a guide member extending hori zontally from each end. The bar is adjustable angularly about the pivot, and the pivot slides in the groove of the post for height adjustment. lndicia on the bar adjacent to the pivot are aligned with the post to provide visual reference for the angular settings.
The guide members are about 22 inches apart and extend about It) inches from the bar. A compliant plastic tube such as polyvinyl chloride is used for each guide member.
In use. the bar pivot is located at about the height of the players belt. Two chalk lines are drawn on the ground in line with the two plactic tubes. For ground strokes and lobs, the outside of the forward foot is placed on the front line. For volleys, the fronts of both feet are placed on the back line. In both cases, the imaginary ball is located at a point 8 inches forward of the rear tube. For backhand strokes and left-handed forehand strokes, the pivoting bar is reversed. The same chalk lines are still usable, since the bar pivot is located centrally between the two guide members.
Stroking of the racket is done in line with the pivoting bar. Both guide members must be hit by the racket head for the stroking angle to be correct. The bar is adjusted in the 45 up position for lobs, and between l up and 10 down for various other ground strokes and volleys.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:
FIG. 1 is a persepctive view of the preferred embodiment in operating position for a right-handed backhand lob.
FIG. 2 is a sectional view taken along lines 2 2 in FIG. 1, showing the assembly clamped to a fence.
FIG. 3 is a perspective view of an alternate embodiment in operating position for a right-handed forehand ground stroke.
FIG. 4 is a sectional view taken along lines 4 4 in FIG. 3, showing a practice ball mounted to the target member.
DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, front guide member 1 and rear guide member 2 are attached near the ends of pivoting bar 3, which is rotatable about pivot shaft 4 relative to vertical post 5. Post 5 contains undercut groove 6 to retain enlarged end portion 7 of shaft 4, shown here as a wingnut on a screw. Mounting screws 8 and 9 fasten thru fence 10 into plate 1] on the opposite side. lndicia I2 are aligned with post 5 to provide visual reference for the angular settings used.
An alternate embodiment is shown in FIG. 3, with front guide member 13 and rear guide member 14 being attached to the ends of bar 15 by screws 24. Bar 15 is rotatably connected to post 16 by bolt 17 and held by wingnut 18. The head of bolt 17 is retained within undercut groove 19 which allows sliding of bar 15 in a vertical direction. Compliant target member 20, held by screw 34, extends horizontally from bar I5 intermediate guide members 13 and I4, and can have practice ball 2! attached to the end of member 20 by screw 22. If the racket approaches in the direction of arrow A, target member 20 will be between bolt 17 and rear guide member 14. Indicia 23 are selectively aligned with groove 19 in post 16 for visual reference to the angular settings chosen. Post 16 is attached at each end to fence 25 by bolts 26 in slots 27, with washers 28 and nuts 29 being applied from the opposite side of fence 25.
In the alternate embodiment of FIG. 3, alignment of the compliant portions of guide members 13 and I4 is used differently to indicate the desired path for the swinging of a sports racket. In the preferred embodiment, both guide members are hit by the racket head. In the embodiment of FIG. 3, target member 20 is the only part contacted by the racket head. The correct swing has been achieved when compliant portions 30 and 3t of front guide member 13 and compliant portions 32 and 33 of rear guide member 14 have all been cleared. To allow this to happen. portions 30 and 31 are separated vertically by a distance greater than the width of a sports racket head. Portions 32 and 33 are similarly separated.
This invention is not to be limited by the embodi ments shown and described, which are given by way of example and not of limitation.
1. A sports racket stroke training device adapted for attachment to a vertical support surface comprising:
a post, said post having attachment means for attaching said post substantially vertical on said support surface, said post also having a longitudinally extending groove therein;
a pivot shaft, said pivot shaft being received in said groove of said post, means for releasably holding said pivot shaft in said groove for selectively adjusting said pivot shaft at an infinite number of positions along said groove;
An elongated bar. said bar having means intermediate its ends for connecting said bar to said pivot shaft. said bar therefore being angularly pivotal and slidably adjustable on said post by said pivot shaft;
a pair of substantially elongated flexible guide members, said bar having a guide member attached substantially perpendicular to each of its ,ends, said guide members extending parallel to said pivot shaft and from a common side of said bar such that a racket must be swung past both guide members when stroked substantially along the longitudinal center line of said bar.
2. The sports stroke training device as defined in claim 1, in which said bar contains indicia adjacent said pivotal shaft, said indicia providing visual reference for angular settings of 45, and for said bar relative to said post.
3. The sports stroke training device as defined in claim 1, wherein said guide members are substantially straight such that both guide members are hit by a racket when a correct racket stroke is made.
4. The sports stroke training device as defined in claim 1 wherein said guide members are shaped as a circular hoop having a section removed therefrom to define an opening, said opening being slightly larger than a racket head, said guide members being attached to said bar at a point substantially diametrically opposite said removed section opening of said hoop such that when a correct racket stroke is made the head of a racket will pass through the opening of the hoop without touching and the handle will pass through said removed section opening of said hoop without touching.
5. The sports stroke training device as defined in claim 1, whirein a target memberfils attached intermediate the ends of said bar such that said target will be hit by a racket head when said racket is stroked along the longitudinal center line of said bar.
6. The sports stroke training device as defined in claim 5 wherein said target is a ball, said ball being held on said bar by an elongated shaft which is perpendicularly attached to said bar.
7. The sports stroke training device as defined in claim 6 wherein said ball holding shaft is flexible such that it will bend when said ball is hit.