JPS5913868B2 - Tennis practice throwing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pitching machine for tennis practice.

Conventional tennis ball throwing machines are equipped with a pair of pitching wheels, and the pitching wheels are rotated in opposite directions so that a tennis ball supplied between the wheels is pitched by contact rotation with the pitching wheel. exist.

In the above-mentioned pitching machine, the pitching hole can be changed to a curve or the like by changing the rotational speed of one of the pitching wheels or by tilting the axes of both wheels from a vertical state.

However, during tennis practice, the pitching wheel is kept in an adjusted state, so the trajectory of the pitched ball after adjustment is constant, and the rotation and tilt of the pitching wheel is adjusted each time a different ball trajectory is attempted. Need to adjust.

In view of the above-mentioned points, the present invention aims to provide a pitching machine suitable for tennis practice, which is capable of continuously pitching balls having irregular trajectories.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in the figure, a support frame 1 is formed to be movable by attaching a plurality of wheels 2 to its lower part, and a pitching machine 3 is supported at the upper part of this support frame 1.

The pitching machine 3 consists of a pair of pitching wheels 4, 4,
The pitching wheels 4, 4 are arranged above and below with a spacing slightly smaller than the outer diameter of the ball between the outer peripheries of the wheels, and are driven by a motor 5 provided on the upper part of the support frame 1. It is designed to rotate in the direction of the arrow in the figure.

A chute 6 is provided at the rear between the pitching wheels 4, 4, and when a ball is supplied to the chute 6, the ball is received by the chute 6 and rolls down inside.
It is supplied between a pair of pitching wheels 4.4.

As shown in the figure, the means for supplying the balls to the chute 6 is to drive the belt conveyor 7 to move the endless belt 8 in the direction of the arrow in FIG. Ball storage case 1
A feeding method may be adopted in which the balls placed inside the ball are conveyed upward and dropped into the chute 6 at an inverted portion of the ball receiver 9 at the upper part of the conveyor 1, or the balls may be fed manually. good.

A tapered cylindrical body 11 is provided in front between the pitching wheels 4, 4, with the end opening on the large diameter side facing between the wheels 4. Driving means 20 is provided for moving it in any direction while facing between the wheels 4, 4.

The driving means 20 is composed of a cylindrical body driving motor 21 tilted with respect to the horizontal, and a driving plate 22 attached to the rotating shaft 21' of this motor 21. The ends of the rods 23 are connected, and the rods 23
A central portion of the support frame 1 is slidably supported by a swivel bearing 24 attached to the support frame 1.

A pin 25 having a ball 25' is used to connect the drive plate 22 and the rod 23, as shown in FIGS. 3 and 4.

The pin 25 is provided so that its position can be adjusted by fitting a plate 25' at the end into a radially extending guide groove 26 formed on the drive plate 22', so that it can be fixed at any position. .

As a means of fixing the pin 25, a set screw 2 is attached to the plate 2CI/
7 is screwed in, and the set screw 27 is tightened by operation.

The pitching machine shown in the embodiment has the above structure, and the connection position between the end of the cylinder support rod 23 and the drive plate 22 is adjusted so that the connection position is eccentric by an appropriate dimension with respect to the center of the drive plate 22. After that, when the cylinder drive motor 21 is driven to rotate the drive plate 22, the cylinder 11 moves circularly and freely with the end opening on the large diameter side facing between the wheels 4, 4. It swings back and forth between the pitching wheels 4, 4 around the bearing 24.

Now, in the state shown in Fig. 3, the inclination angle of the motor 21 with respect to the horizontal is α, the eccentricity of the pin is, and the swivel bearing 2 is
4 and the dimensions up to the pin 25, and the swivel bearing 24 and the cylindrical body 11
Assuming that the dimension ratio to the center of is 1=1, the cylinder 11 moves circularly with the pin eccentricity X as the radius, and swings in the longitudinal direction with a dimension of 2·z Slnα around the universal bearing 24.

When the cylinder 11 moves as described above, the wheel drive motor 5 is driven to rotate the pair of pitching wheels 4°4 in the direction of the arrow in FIG. When the ball is delivered, the ball is thrown forward.

A cylindrical body 11 is provided in front between the pair of pitching wheels 4, 4, and since this cylindrical body 11 moves in a circular motion as described above and swings back and forth, the pitched ball is As shown in the figure, the ball collides with the inner periphery of the cylindrical body 11 and is thrown forward from the small-diameter opening of the cylindrical body 11.

As described above, the cylinder 11 moves circularly and swings back and forth, so the collision position between the pitched ball and the inner periphery of the cylinder 11 constantly changes.

Therefore, the trajectory of the pitched ball is not constant, and the ball is pitched in any direction.

In the case of the embodiment, the cylindrical body is moved in a circular motion and swung in the front-rear direction, but it may be made to move only in a circular motion or only in a rocking motion.

Moreover, it may be made to swing around the rod for supporting the cylindrical body.

Furthermore, the structure of the pitching machine is not limited to the illustrated example, and for example, a pitching machine that pitches by rotational movement of an arm may be adopted.

As described above, according to the present invention, a tapered cylindrical body through which the pitched ball passes is provided on the front side of the pitching machine, and a state in which the ball pitched from the pitching machine fits into the opening at the end is prevented. Since the cylindrical body is held and moved in any direction, the pitched ball collides with the periphery of the cylindrical body, and since the collision position changes each time the ball is pitched, the ball does not come out from the end of the cylindrical body. The trajectory of the ball is inconsistent, making it suitable for tennis practice.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view showing an embodiment of a pitching machine according to the present invention, FIG. 2 is a longitudinal sectional side view of the same, and FIG. FIG. 4 is a side view of the same as the above, and FIG. 5 is a longitudinal sectional front view showing the positional relationship between the pitching wheel and the cylindrical body. 3... Throwing machine, 11... Cylindrical body, 20.
... Drive means, 21 ... Motor, 22.
...Drive plate, 24...Swivel bearing.

Claims (1)

[Scope of Claims] 1. A tapered cylindrical body provided so that a ball pitched from a pitching machine passes through the cylindrical body, and a state in which the pitched ball is held in the opening at the end and the cylindrical body is arbitrarily moved. 1. A tennis practice pitching machine, comprising a drive means for moving the ball in a direction, and causing a hole pitched by the pitching machine to collide with the inner periphery of a cylindrical body moved in an arbitrary direction. 2. The drive means includes a drive plate rotationally driven by a motor, an end of a cylinder support rod is connected to an outer peripheral part of the drive plate, and a central part of the rod is slidably supported by a swivel bearing. A tennis practice pitching machine according to claim 1, characterized in that: 3. The tennis practice pitching machine according to claim 2, wherein the drive plate has an axis inclined with respect to the horizontal. 4. Claim 2, characterized in that the end portion of the rond is connected to the drive plate so that its position can be adjusted in the radial direction.
Throwing machine for tennis practice as described in section.