JPH045182Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ball batting practice device for golf balls, baseballs, etc.

Among sports, golf and baseball are particularly popular compared to other sports. However, both require very wide cases. For this reason, various devices have been devised to allow practicing indoors or in a limited space, but for various reasons none of them have been ideal. First, the automatic pitching machines for batting practice that have been known so far are complex and expensive, making it difficult for ordinary households to afford, and requiring special knowledge to maintain them. Second, in cheaper devices, the ball is suspended on a string. Since the position of the ball cannot be changed, batters quickly get tired of this monotonous batting. Also, after each hit, the ball must be pulled back and prepared for the next hit. Third, golf practice areas, while much smaller than actual golf courses, still require an area as large as a regular tennis court. Therefore, it was impossible to practice golf at home.

U.S. Patent No. 2,818,255 discloses a batting practice device that uses a cylindrical cam to raise and lower a ball. However, since the cam is periodically raised and lowered in the axial direction as the ball revolves around the shaft, the height of the ball can be easily predicted and the batter quickly loses interest.

Therefore, the main object of the present invention is to provide a batting practice device that eliminates or alleviates the above-mentioned drawbacks.

One of the features of the present invention is that there is a mechanism to reduce the rotational speed, causing the ball rotating around the main shaft to perform irregular movements.

Another feature of the invention is that irregular rotation is further enhanced by a moving device that changes the rotation radius of the device that reduces the rotation speed.

The invention will become more clearly understood from the following description with reference to the accompanying drawings.

The present invention is basically a type of batting practice device, in which a ball 63 is attached to a rotor 6 that rotates around a vertical main shaft 21 supported on a tripod stand. The ball 63 is fixed to one end of the shaped arm 61 and the other end of the arm is attached to the rotor 63. rotor 6
is mounted on the main shaft so that it can rotate radially and slide axially. When a ball is hit, it rapidly rotates around its main axis.

In order to vary the height of the ball 63, a cylindrical cam set 3 consisting of a free cam 3 and a fixed cam 4,
4 are available. The fixed cam 4 is attached to the shaft 21 at a constant height, and the free cam 3 is located above the fixed cam 4 and can freely rotate around the shaft 21 and slide up and down in the axial direction. I'm starting to be able to do it. The free cam 3 is attached to the rotor 6 by a screw 64 so that the latter can rotate and slide together. As shown in FIG. 3, the ball is at its highest position when the apex 31 of the free cam 3 and the apex 41 of the fixed cam 4 meet, and these apexes 31 and 41 are on opposite sides of the shaft 21, respectively. Sometimes the ball is at its lowest point. (At this time, these two cams 3 and 4 are complementary in length and short to form one cylinder.) In order to keep these two cams 3 and 4 in constant contact, the upper end is fixed to the shaft 21, and the lower end is a free cam. A spring 5 is provided which presses against the upper edge of 3. Since the above is not a feature of the present invention, it will not be described in further detail.

The two features of this invention are a mechanism that reduces the speed of the ball with each rotation, and a device that makes it impossible to predict the position of the ball by changing the radius of rotation of that mechanism.

As mentioned earlier, if the height of the ball changes periodically due to the cam, a batter standing at a fixed location will know that the ball is at a fixed height when it comes to his position. Since it goes up and down, it is very easy to hit, and it quickly becomes uninteresting. In view of this, the present invention provides a kind of speed reduction mechanism to reduce the rotational speed, so that the ball rotates irregularly and rapidly when held around the axis. This is achieved by a reduction rotor 7 which is attached to the rotor 6 and rotates freely about an axis S extending radially from the rotor. In order to distinguish between the rotation of the center of the deceleration rotor that revolves around the main shaft 7 and the rotation of the deceleration rotor 7 that rotates around the radial axis S, the former will be hereinafter referred to as the "revolution of the deceleration rotor 7", and the latter will be referred to as the "revolution of the deceleration rotor 7". We will refer to this as ``rotation.'' The speed reduction mechanism further includes a blocking rod 42 attached to the main shaft 21 and extending in the radial direction. The shaft S and the arm 61 are preferably placed on opposite sides of the rotor 6.

A plurality of deceleration rotors 7 (four in the embodiment)
It extends from the leg 71 of. As shown in FIGS. 4A and 4B, when the ball 63 is hit and the deceleration rotor 7 rotates around the main shaft 21 from the position shown in FIG. 4A to the position shown in FIG. One of the legs is blocked by the blocking rod 42, and the leg is scooped up, causing it to "rotate" around the axis S. This "scoop" somewhat reduces the speed of the deceleration rotor 7, and therefore the speed of the ball 63. The ball's movement is also unpredictable because the location where the foot is scooped is not constant. In order to ensure that the leg 71 is always scooped up by the rod 42 every time it "revolutions", the length of the leg 71 must be 1.4 times or less the difference in height between the highest level of the axis S and the level of the rod 42. Must not be.

Also, the length of the rod 42 is from the rotor 7 to the shaft 21.
must be longer than the distance to. The irregularity of revolution is further exacerbated by the use of cams. This is because the blocking effect when the leg is scooped when the rotor 6 is at a low level is stronger than that when the rotor 6 is at a high level. Furthermore, in order to strengthen the irregularity of the revolution of the deceleration rotor 7, a double helical guider having two helical grooves 81 and 82 with a right-hand thread and a left-hand thread is provided. A right-handed or left-handed screw here refers to the direction of the helix extending from the base of the guider 8 to the end, and a right-handed screw is a right-handed screw that turns clockwise when viewed from the base of the guider 8. The one that turns is the left-hand screw. According to this definition, the helical groove 81 is a left-hand thread, and the spiral groove 82 is a right-hand thread. In FIG. 1, the guider 8 is fixed to the rotor 6 by bolts 62. The deceleration rotor 7 is stopped on the inside by a guide pin 72, which is inserted into the groove 81 or 82.
It is stopped or guided by the guider 8 and rotates around the guider 8 while moving on its axis. The rotor is held within the length of the groove in the guider 8 by a fastening bush 9 and a nut 82a. As shown in FIG. 6, both ends of the grooves 81 and 82 meet, and when the deceleration rotor rotates clockwise, the guide pin 72 starts from X and enters the left-hand thread groove 82. Therefore, it passes through W and reaches Y, and then passes through W following the right-hand thread groove 81 and reaches X.
Return to This process continues until the ball loses momentum. FIG. 6 is a graph showing the relationship between the radial position of the pin 72 and the rotation angle theta (θ) around the guider. Since the radius of rotation (ie, the distance from deceleration rotor 7 to rotor 6) changes, the horizontal velocity of the ball becomes unpredictable.

This device can be converted into a golf practice device by omitting the guider 8 and deceleration device and by replacing the platform and lowering the ball level. The golf ball can be received on the tee, and since the tee is in a fixed position, there is no need to change its position.

In order to make the guider easier to guide, a banana-shaped sliding piece (glider) 72a is provided, and the contact portion between this glider and the grooves 81, 82 and the rotor 6 is shaped to fit the contour of the latter. In addition, a hole is made in the center of the glider so that the pin 72 can be movably inserted into the groove 81, so that both can be biased.
82.

In order to let the batter know how hard the ball was hit, a rotating display is provided to display how many times the ball has rotated around the main axis after being hit. The rotary display is a projection 31a projecting in the axial direction from the apex 31 of the free cam 3, and the dial is movably mounted on a shaft passing through the fixed cam. The shape and position of the dial 91 are such that when the free cam rotates once, one of the teeth of the dial 91 is
It is struck by the protrusion 31a and thereby moves by a distance corresponding to the distance of two adjacent teeth, and the protrusion passes over it without being stopped by the dial. Therefore, when the rotor makes one revolution, the dial moves by one piece, and the batter can read from the dial how many revolutions the ball has made.

[Brief explanation of the drawing]

FIG. 1 is an exploded view of the device of the present invention. Second
The figure is a perspective view of the device of the invention. Figure 3 shows
It is a perspective view of a cam part. FIG. 4A and FIG. 4B are diagrams explaining the action of the braking mechanism. Fifth
The figure is a side view of a double screw guider that serves as a moving mechanism. FIG. 6 is a diagram showing the relationship between the radial position of the braking device and the angular position around the double screw guider.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A ball hitting practice device consisting of the following parts: one ball, one vertical support shaft, which receives the ball at a horizontal distance from the shaft, and supports the ball along with the ball. a first rotor that rotates and rotates horizontally around an axis; a second rotor that extends from the rotor and is provided on a horizontal axis and rotates around it; a rotor, and a blocking means not coextensive with the center of rotation of the second rotor; a protrusion having a distal extension, the distal extension being such that when the second rotor revolves around the main axis, the protrusion hits the blocking means but does not impede rotation of the second rotor; The portion is capable of passing through the blocking means by rotating about the horizontal axis. (2) The second rotor is comprised of a plurality of protrusions perpendicular to the horizontal axis, and the blocking means is a rod with one end attached to the main shaft and the other end extending horizontally. The training device according to claim 1, wherein the length of the training device is longer than the distance from the main shaft to the second rotor. (3) The training device according to claim 1, which has a means for changing the distance from the main shaft to the second rotor. (4) The means is comprised of a cylindrical guider whose axis coincides with the horizontal axis and has an endless groove, and the second rotor has a protrusion that is fitted into the endless groove. The training device according to claim 3, which is guided by a utility model. (5) The device according to claim 4 of the utility model registration claim, wherein the endless groove is carved in two opposite helical shapes on the guider, and the ends of both helical grooves meet each other. . (6) The device according to claim 1, which has a means for indicating how many times the ball rotates around the main axis when the ball is hit once.