JPH0427875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a batting practice machine for baseball, tennis, etc.

[Background technology]

Conventionally, batting practice machines have been provided that use a pitching arm with an arcuate cross section made of sheet metal or the like to throw the ball, but in this case, the pitching arm is heavy, so a large drive device is required, and the overall size is large. It becomes something like that. In view of this point, the pitching arm is composed of a pair of rotatable legs, a left-handed coil spring and a right-handed coil spring are connected to the ends of the pitching arm, respectively, and the coil springs are supported by respective shafts. We have devised a system that stores elastic force in the coil springs of the pitching arm and rapidly releases the elastic force stored in each of the coil springs, thereby throwing the ball placed on the ball resting part of the pitching arm. However, by making the pitching arm lightweight, it can be driven by a small and small capacity drive device. However, in this case, the force applied to each leg of the pitching arm and each coil spring during the manufacturing process remains as residual stress in the torsional direction, resulting in a difference in the elastic force stored in each coil spring. As a result, the direction in which the ball was thrown was unstable and the ball was thrown off to the left or right.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to provide a drive unit that can be small in size and small in capacity, and to throw the ball straight in a stable direction. Our goal is to provide a batting practice machine that can.

[Disclosure of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7. In FIG. 1, 1 is a main body case, which is divided at the center into a left main body cover 1A and a right main body cover 1B, and is provided with a front cover 1C. The left main body cover 1A and the right main body cover 1B are assembled by using a pair of nuts 41, which are connected together by a connecting piece 44, as shown in FIG.
42 are fitted and fixed into the mounting holes 5 formed at the bottom front ends of the left main body cover 1A and the right main body cover 1B, respectively, and the left main body cover 1A and the right main body cover 1 are fitted and fixed.
The periphery of the opening with B is overlapped and fixed with screws 43. A pair of legs 45, 46 are screwed onto the pair of nuts 41, 42, each having a rubber foot 47 attached to the tip and a thread formed on the peripheral side. The inclination angle of the main body case 1 is adjusted by changing the amount of protrusion from the main body case 1, and the throwing angle of the ball M is adjusted. The main body case 1 has a ball throwing opening 2 on the front surface and a ball supply section 11 on the side surface.
A first ball stocker 9 made of pipe material is connected to this, and a second ball stocker 9 is connected to the first ball stocker 9.
A ball stocker 10 is connected. 12 is a leg, and 13 is a feed cover.

An outline of the internal structure will be explained. A ball feeding port 3 is provided on the side surface of the right main body cover 1B, and a pair of parallel guide rails 4 for receiving balls M fed therefrom are provided on the left main body cover 1A and the right main body cover 1B. Also, a pitching arm 6,
Ball set arm 7 and their drive device 20
are housed together with the frame 8. The pitching arm 6 has a pair of parallel legs 6 made of wire springs.
A, 6B (Fig. 6), each of the leg pieces 6A,
One end of the ball mounting portion 6B is inclined in the rotating direction and connected to the ball mounting portion 6c, which holds the ball M at three points: the parallel portions of the leg pieces 6A and 6B and the connecting portion. A stepped portion 51 for fixing the damper stopper 80 is formed near one end of each of the leg pieces 6A, 6B, and a bent portion 52 for fixing the cam follower shaft 17 on which the cam follower 16 is rotatably mounted is formed near the other end. ing. The cam follower shaft 17 is disposed at the bent portion 52 and is pressed and fixed to the pitching arm 6 by a click spring 53. The damper stopper 80 has a stepped portion 51
and is fixed to the pitching arm 6 by welding and caulking.

The damper stopper 80 serves to stop the rotation of the pitching arm 6 by colliding with the damper 31 when the pitching arm 6 moves while being accelerated to throw the ball M. The damper stopper 80 is a cam follower 16.
and the ball rest 6C. The surface of the damper 31 that collides with the damper stopper 80 is an uneven surface as shown in FIG. 3 to reduce the impact upon collision. The damper 31 is made of a rubber material, and if necessary, by providing a through hole 31a (FIG. 3), it is possible to further soften the impact and reduce the impact noise. Each of the leg pieces 6A, 6
Coil springs 14 and 15 constituting ball throwing springs are integrally connected to the other end of B, respectively. The coil springs 14 and 15 are the leg pieces 6A and 6B.
Similarly, it is made of wire spring and is wound clockwise and counterclockwise, respectively. The pitching arm 6 is supported by a pipe-shaped support shaft 18 that comes into contact with the inner peripheral surface of each coil spring 14, 15.
Both ends are a pair of opposing side walls 33 of the frame 8,
34 are respectively fitted and fixed to burring portions 32 protruding from the inner surface. The frame 8 is formed into a U-shape by a pair of opposing side walls 33, 34 and a connecting piece 35 connecting one end edge of each of the side walls 33, 34. Each free end 1 of the coil spring 14, 15
4A and 15A are engaged and fixed in hemispherical recesses 28 and 29 formed at the edge of the connecting piece 35 of the frame 8, respectively. A plurality of the recesses 28 and 29 are formed symmetrically at positions corresponding to the respective free ends 14A and 15B of the coil springs 14 and 15, and are arranged in parallel in the direction of the support shaft 18.

The drive device 20 for rotating the pitching arm 6 will be explained. The cam 19 that contacts the cam follower 16 has a diameter that gradually increases in the rotational direction,
There is a discontinuous small path along the way. The cam 19 is driven together with the ball set arm 7 by a motor. This drive transmission system will be explained. A geared motor 21 (FIG. 2) with an integrated motor reduction gear is fixed to the frame 8, and a small gear 23 is press-fitted and fixed to the output shaft 21a of the geared motor 21. Further, a large gear 26 having a protrusion 25 for operating the cam 19 and the ball set arm 7 is connected to the camshaft 24 and is rotatably fitted onto the camshaft 24. By installing the camshaft 24 in this way, the large gear 26 meshes with the small gear 23. The ball set arm 7 is used to feed the balls M one by one from the ball supply section 11 (FIG. 1).

Next, the operation of this embodiment will be explained based on FIGS. 3 to 5. As shown in Figure 3, the ball M is
When the ball is sent inside from the ball feeding port 3, it is held by the ball rest 6C at the tip of the pitching arm 6. The cam 19 rotates in the direction of the arrow in FIG. 3 and drives the pitching arm 6 via the cam follower 16 in the direction of winding the coil springs 14 and 15, thereby accumulating elastic force in the coil springs 14 and 15. . Figure 4 shows the pitching arm 6 just before the ball M is thrown out.
Indicates the status of When the cam follower 16 comes off the large radius part of the cam 19, the elastic force stored in the coil springs 14, 15 of the pitching arm 6 is suddenly released, and the pitching arm 6 is ejected while holding the ball M. The pitching arm 6, which has moved while holding the ball M, suddenly stops when it collides with the damper 31, and only the ball M is thrown out with an initial velocity accelerated by the energy of the coil springs 14 and 15.

Here, a pair of leg pieces 6A, 6B of the pitching arm 6
As mentioned above, the coil springs 14 and 15 are made of wire springs, and the force applied to these wire springs during processing steps such as wire drawing and straight line processing remains as residual stress in the torsional direction. , as in the present invention, the pitching arm 6 is made up of a pair of leg pieces 6A and 6B.
In this configuration, when the pitching arm 6 is driven in the direction of winding each coil spring 14, 15, a difference occurs in the elastic force stored in each coil spring 14, 15. Therefore, each coil spring 14, 15
When the elastic force accumulated in Instead of being thrown straight forward, it shifts to the left and right. In this case, by changing the positions at which the free ends 14A, 15B of the coil springs 14, 15 are engaged with the recesses 28, 29, respectively, the locus of motion of the ball mounting portion 6C of the pitching arm 6 can be adjusted and the ball You can throw M straight out. For example, when the ball M is shifted to the right with respect to the main body case 1 and thrown out, this means that the elastic force stored in the coil spring 15 on the right side is smaller than the elastic force stored in the coil spring 14 on the left side. The free end 1 of the coil spring 15 on the right side
5A in the recess 29 toward the center of the connecting piece 35 of the frame 8, that is, by moving the free end 15A in the direction of further winding the right coil spring 15 (the direction shown in FIG. 7). As a result, elastic force is stored in the right side coil spring 15 from the initial state, so the elastic force stored in each coil spring 14, 15 becomes equal, and the ball M can be thrown straight. Alternatively, the left coil spring 1
Even if the position where the free end 14A of 4 is engaged with the recess 28 is shifted toward the left side surface 33 of the frame 8, that is, the free end 14A is moved in the direction in which the coil spring 14 is unwound (the direction shown in FIG. 7). Similarly, ball M can be thrown straight out. If the ball M is thrown out with a deviation to the left with respect to the main body case 1, the free ends 14A and 15A of the coil springs 14 and 15 can be moved in the → direction in FIG. 7, contrary to the above. Ball M can be thrown straight.

〔Effect of the invention〕

As described above, the present invention provides a pitching arm having a ball resting part at one end and a pair of rotatable wire legs, and a left-handed, right-handed pitcher connected to the other end of the pair of legs of the pitcher arm. It includes a wound coil spring, a support shaft that supports the coil spring, a plurality of recesses that engage the free ends of the coil springs, and a drive device that rotates the pitching arm, Since the pitching arm is made of wire, it can be made lightweight and can be driven by a small and small capacity drive unit;
The ball launch acceleration can be increased, and since the free end of each coil spring has multiple recesses to engage with, the position where the free end of each coil spring engages with the recess can be adjusted arbitrarily. By changing the angle, the angle of the ball's throwing direction can be adjusted and the ball can be thrown straight.The ball's throwing direction and flight distance are always stable, making it easy to use, and the freedom of the coil spring. This has the effect that the coil spring can be easily assembled by simply engaging and fixing the end in the recess.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of an embodiment of the present invention, FIG. 2 is a cutaway front view of the same as the above, FIG. 3 is a cutaway side view of the same as the above when the ball is being fed, and FIG. FIG. 5 is a cutaway side view of the above ball immediately after it has been thrown, FIG. 6 is a perspective view of the pitching arm of the above, and FIG. 7 is a state of engagement of the free end of the coil spring. FIG. 6...Pitching arm, 6A, 6B...Leg piece, 6C
...Ball resting part, 14, 15...Coil spring,
14A, 15B...Free end, 18...Support shaft, 2
8, 29... recess, 20... drive device.

Claims (1)

[Scope of Claims] 1. A pitching arm having a ball mounting portion at one end and a pair of rotatable wire legs; a left-handed pitcher and a right-handed pitcher connected to the other end of the pair of legs of the pitching arm; a coil spring; a support shaft that supports the coil spring; a plurality of recesses that each free end of the coil spring engages with; and a drive device that rotates the pitching arm. A batting practice machine. 2. The batting practice machine according to claim 1, characterized in that a plurality of recesses are arranged in parallel in the direction of the support axis.