JPH0772791A - Experiment device for gravitation - Google Patents

Abstract

PURPOSE:To provide the experiment device for gravitation which can easily experiment gravitation through button operation and obtain an accurate measured value. CONSTITUTION:This device is equipped with a base which is erected on a table, a stopwatch with a start/stop button 21 and a reset button 22, a ball feeding mechanism 5 which is open slantingly above a start table with a released claw, a sense lever for a falling ball, a ball sensing part which has an opening/closing lid and a lid closing mechanism, a one-system pressing mechanism wherein a lever connecting a start simultaneous mechanism which places the stopwatch in operation by falling the ball by opening the claw and pressing the start/stop button 21 and a stop means which stops the stopwatch associatively with the sense lever to respective systems is formed in a halfway automatic switching system, and a reset mechanism which sets a display to zero with the reset button 22 pressed and supplies the ball to the start table from the ball feed mechanism 5 to open the opening/closing lid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gravitational experimental apparatus mainly used for experimental learning in schools.

[0002]

2. Description of the Related Art As a conventional gravitational experiment device, a steel ball is attracted to an electromagnet, and a stopwatch is started by the operation of a switch that cuts off the current to the electromagnet, and the steel ball is dropped. What stopped the stopwatch to measure the fall time,
Actual fairness 4-5055 related to the applicant's application (and invention)
A gravity experimental apparatus described in Japanese Patent No. 3 is known. In this conventional device, two steel balls held at different heights are dropped at the same time, and the first falling steel ball pushes the lever abutting the start / stop button of the stopwatch. And start the stopwatch,
Then, there was a device in which the lever was pressed by a steel ball that had fallen to stop it and the fall time was measured.

In addition, as a method for measuring a falling object in a non-contact manner, there are a method of emitting an infrared ray or a radio wave and a method of measuring with a stroboscopic photograph. A gravity pendulum is also used for external precision measurement by the above falling body method.

[0004]

By the way, as for this kind of experimental apparatus, the apparatus cannot be made large due to the ease of handling, transportation, storage, etc., and it is necessary to measure an extremely small drop time at a short measuring distance. It will be. However, in this conventional device, for example, in the former one in which the steel ball sucked by the electromagnet is dropped by cutting off the power supply to the electromagnet, the start of the time switch and the steel ball The fall times do not match,
There was a problem that the measurement accuracy deteriorates. Also, in the latter case where the steel balls held at different heights are dropped at the same time, it is difficult to synchronize the simultaneous opening of the steel balls.
Also, the buttons and levers that start and stop the stopwatch take a short time to return, but it takes time, so it is necessary to put two steel balls on the same lever and operate it if the fall distance is short. There has been a problem that the operation of each part has to be performed more swiftly, which makes manufacturing difficult. In addition, the measurement of a falling object in a non-contact state is not general for learning because it requires a lot of labor, cost, and time required for the measurement work.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object of the present invention is to use one spherical body to press the start / stop button of a stopwatch at the time of start. By adopting the automatic switching system at the intermediate point of the mechanism that connects the start and stop buttons and the operating system that presses the stop button at the time of stop, the pressing of the stop mechanism that works in conjunction with the button pressing of the start mechanism and the sensing lever It is to provide a gravity experiment device that can be operated calmly without interfering with each other, operate the stopwatch accurately even in an extremely short time, and perform precise measurement of the fall time.

[0006]

As a means for solving the above-mentioned problems, in the gravity experimental apparatus of the present invention, a base stand erected on a table and an operation of a timepiece fixed to the base are provided. A stopwatch that has a start / stop button that alternately stops and a reset button that resets the clock display to zero, and is installed on the top of the base, and is held on the top by opening and closing the double-sided open-release claw A start table for dropping the ball, a ball feeding mechanism that opens obliquely above it, and a single-body structure that is installed on the back side of the start table and separates the heavy and straight board, and drops the ball at the same time when the clock starts. , A start-simultaneous mechanism, a sensing lever installed on the same vertical line as the opening / closing center point of the start stand to receive and rotate a falling ball, and an opening / closing lid installed in proximity to the sensing lever. Times with the weight of the ball A ball sensing unit having a lid closing mechanism that slides and closes with a lever, and a start simultaneous mechanism that opens the double-sided opening / closing claw to drop the ball and presses the start / stop button to operate a stopwatch. , A stop mechanism that stops the stopwatch by pressing the start / stop button in conjunction with the sensing lever that has received the dropped ball, an operating system that presses the start / stop button of the stopwatch at the start, and a start system at the time of stop A pressing mechanism formed by an automatic switching system at the midpoint of the mechanism that connects the operating system for pressing the stop button to each system, and the reset button of the stopwatch to press the stopwatch display to zero, and the upper part of the base It communicates with the start stand installed in the, and slides the partition of the ball storage part of the ball feeding mechanism that opens to the upper diagonal. Spheres issued is supplied to the starting blocks rolling contact plate above was configured to include a reset mechanism for opening the lid of the sphere sensing unit.

[0007]

In the gravitational experiment device of the present invention, first, the partition of the ball feeding mechanism is slid by the resetting means, the ball is ejected and rolls on the connecting plate, and the start table with the double opening and closing pawls closed. Reach At that time, the display of the stopwatch becomes zero, and the opening / closing lid of the ball sensing unit is opened. Then, by pressing the start lever, the double-sided opening / closing claw is opened to drop the ball, and at the same time, the start / stop button pressing portion presses the start / stop button of the stopwatch to start the timepiece. The ball dropped from the start stand falls on the sensing lever below the same vertical line as the opening / closing center of the start stand, and the start / stop button pressing part of the stop means interlocking with this sensing lever operates the start / stop button. Press to stop the stopwatch. In this case, the pressing of the start / stop button of the stop mechanism is different from the pressing of the start / stop button of the start mechanism by pressing the stop button of the stopwatch by a system automatic switching system, so that a short drop time can be accurately displayed. . Then, for the ball that has dropped, the lever for opening and closing the lid of the ball sensing unit is rotated to close the opening / closing lid above the sensing lever.
By closing the opening / closing lid, malfunction is prevented and the end of the experiment is notified. After that, the display value of the stopwatch is read and recorded, and when the reset lever is pressed to return the display value to zero, the opening / closing lid is opened by the action of the lid opening mechanism. Also, in conjunction with this, the opening and closing claws of the start stand are closed,
At the same time, the ball partitioning plate of the ball feeding mechanism opens, the ball appears, passes through the connecting plate, and rolls into the start table, so that the experiment can be performed again. By repeating this experiment and taking the average value, the time required for the free fall of the sphere by this device can be obtained more accurately.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, the configuration of the embodiment will be described. As shown in FIGS. 1 to 15, the gravity experimental apparatus A of this example is as follows.
A base 1, a stopwatch 2, a starter 3, a ball detector 4, a ball feed mechanism 5, a start simultaneous mechanism 6, a stop mechanism 7, a reset mechanism 8 and an automatic start / stop switching mechanism 9. The main structure.

The base 1 is for vertically arranging the start base 3 and the ball sensing unit 4 and has a vertically long vertical plate 10 as shown in FIG.

The stopwatch 2 has a counting type display section 20 capable of measuring up to 1/100 second, and a push-type start / stop button 2 for alternately operating and stopping the timepiece.
1 and push-type reset button 2 that returns the count display of the clock to zero
2, the counting display section 20 is provided on the front side of the vertical plate 10, and the start / stop button 21 and the reset button 22 are also provided.
Are located substantially in the center of the vertical plate 10 so that and are on the back surface side of the vertical plate 10.

The starting table 3 is provided with a ball 30 for experiment.
Each of them is placed and then dropped. As shown in FIGS. 1 to 5, the vertical plate 10 is horizontally projected on the upper front surface of the vertical plate 10.
A through hole 31 having a depth of 5 m / m, which is slightly larger than the outer diameter of the sphere 30, is formed at the center of the start table 3.
Opening / closing shafts 32, 32 are rotatably installed penetrating the vertical plate 10 on both sides of the through hole 31 and away from the lower edge of the hole. Then, at the tip of the opening / closing shafts 32, 32, the shafts come into contact with the lower edge of the through hole 31 by the pawl closing operation, and by the pawl opening operation, the pawls 33, 3 are completely separated from the hole edge.
3 is fixed. The claw 33 is formed of a brass tube having an inner diameter of 3 m / m so that the ball 30 can be smoothly dropped. Further, a ball feed mechanism 3 having a ball outlet 35 on the surface of the vertical plate 10 obliquely above the start table 3 and a ball storage portion on the back surface thereof.
4 is installed, and the ramp 36 is connected to the start stand 3. As shown in FIG. 2, the ball storage portion 34a makes the ball 30 stand by at the rear position of the ball outlet 35, and the ball storage portion 34b stands by at the upper rear part. By the way, by rotating the L-shaped arm 37a by the reset mechanism 8 and sliding the inner partition plate 37b integrally formed with the ball outlet partition plate, the ball in the ball storage portion a is discharged to the outside,
One sphere 30 is formed so as to be able to move from the sphere storage part b to the sphere storage part b. In this way, the L-shaped arm 37a is restored to its original state at the same time when the discharge and movement of the ball 30 are completed, and the partition plate 37b connected to this is also restored. 37
d is a rod that connects the L-shaped arm 37b.

The ball sensing unit 4 senses passage of a ball 30 falling from the start table at a predetermined position, and as shown in FIGS. A sensing lever 40, which is provided below the same vertical line and moves up and down by contact with a ball 30, is provided. One end of the sensing lever 40 is pivotally supported at the end of a support shaft 41a that penetrates the substrate 10. The reinforcing arm 40b is fixed. Further, an L-shaped arm 41 fixed to the support shaft 41b below the L-shaped arm 41 is rotated by contacting the sensing lever 40 and then contacting the ball 30.
An opening / closing lid 42 which is opened and closed by sliding on the upper opening 40a of the sensing lever 40, and an L-shaped arm 41 fixed to the support shaft 41b and connected to the lower surface of the opening / closing lid at the upper left end.
By opening and closing the lid 42 by rotating
Can be opened and closed. 42 a is a guide rail for opening and closing 42. In this experimental example, the distance between the ball stop position of the start table 3 and the stopwatch operating position of the sensing lever 40 is set to 0.259 m. 4 in the figure
Reference numeral 5 is an inclined cylinder that guides the ball 30 after rotating the arm 41 to the lower basket 44, and 45a is a buffer plate that reduces the momentum of the ball 30.

The simultaneous starter mechanism 6 includes a starter 3
At the same time that the upper sphere 30 is allowed to fall freely and the timepiece 2 is started, the mechanism will be described first. It is installed on the back side of the start stand 3 with a vertical plate 10 in between, and forms an integral structure with the start stand 3 (see FIGS. 3A, 3B, and 5) and is fixed to the substrate 10. Arms 50c, 50c are provided at both ends of a slide base 51, a slide plate 51a, and an attachment arm 51b that are movable up and down, and a shell contacting a rotary tilt plate described later is provided inside the upper end of the slide plate 51a. The small protrusions are attached. On the other hand, substrate 1
Rotating arms 50, 50 are fixed to the end portions of the shafts 32, 32 penetrating 0, one end of which is near the shaft.

The tip ends of the arms 50c, 50c are brought into contact with the rotary arms 50, 50 to hold the holders 50a,
50a is installed, a stopper 50b is provided above the rotary arms 50, 50, and a stopper 50b is provided below the rotary arms 50, 50.
A locking plate 50d for holding 0 is installed, and the opening / closing claws 33,
When the 33 is closed, the arms 50, 50 are held on the locking plate 50d. Further, an inclined plate 53d, which pivotally supports a central portion that moves slightly back and forth, is installed above the slide plate 51a, one end thereof is in contact with the slide plate 51a, and the other end thereof is the locking plate 50.
It is arranged so as to contact the back side of d, and the locking plate 50d
The starter 50e is installed so that the lower end of the standing plate is provided in the middle of the upper surface of the starter 50e, and the start rod 64e is arranged in contact with the starter 50e.

Further, the slide is connected to the main rod 83 and is axially supported by the vertical substrate 10, and the slide 53c is
A weight reducing lever 83a, one end of which is connected to the main rod 83 and pivotally supported by the vertical plate 10, is connected. On the other hand, an arm 53c is connected to the start lever 53, an arm (for weight reduction) 53d is provided on the upper stage thereof, and is connected to the arm 53c by a link 64d. 62 is a pivotal support for the substrate 10.

A start rod 64e is connected to the weight-reducing arm 53d, and the opening / closing claw 33 is opened at the end of the rod 64e. It is in contact with the starter 50e. On the other hand, the lower surface of the start lever 53 is brought into contact with the substrate 10 at one end.
A lever 53a for automatically switching between a start circuit and a stop circuit pivotally supported on the lever 53a is installed. As shown in FIGS. 3A and 4, the vertical groove provided at the tip of the lever 53a is provided with a link 64b with a stopper. Arm 6 which passed and was installed in the lower stage
It is connected to 3b.

The stop mechanism 7 stops the timepiece 2 at the same time when the sensing unit 4 senses it. As shown in FIG. 8, one end of the vertical plate 10 is pivotally supported on the substrate 10 at the rear surface thereof. One end is connected to the lever 40, and a vertical arm 60 that moves up and down and a rear end are pivotally supported by a bearing 62, and a pressing lever 53b that comes into contact with the start / stop button 21 of the timepiece 2 near the rear end are provided. Rotating arms 63a, 63b axially supported by a bearing 62 are arranged in order from the bottom, and one end of the arm 63a is connected to the other end of the arm 60,
Further, the other end of the arm 63a is connected to one end of the arm 63b by a link 64a, and the other end of the arm 63b and the automatic switching lever 53a of the start circuit and the stop circuit pivotally supported at one end are the holders of the link 64b. 64d
It keeps in contact with and operates. In this case, the lever 53a acts as a weight reduction lever. By the way, the vertical movement of the sensing lever 40 is controlled by the pressing lever 53.
At the position of the start / stop button 21b, the amount is reduced to 1/6 according to the required pressing amount of the button.

The reset mechanism 8 resets the stopwatch 2 to zero the count display section 20, and at the same time,
The opening / closing pawls 33, 33 of the start simultaneous mechanism 6 are closed, and the opening / closing lid 42 of the sensing unit 4 is opened to supply one ball 30 from the ball feeding mechanism 5 to the start base 3.
As shown in FIG. 11, a reset lever 80 pivotally supported by the vertical plate 10 and one end of which is pivotally supported by the vertical plate 10, abuts against the lower surface of the central portion of the lever 80, and moves up and down.
And a reset lever 81b, one end of which is pivotally supported by the vertical plate 10 and which abuts the reset button 22 of the stopwatch 2 at a position near the one end. The reset lever 81b is located at the center right position of the lever 81a and the other end of the reset lever 81b. And are connected by a link 82a. In the figure, 81d is a bearing. As described above, by the three levers and the link structure, the pressing amount received by the reset lever 80 from the outside is sequentially reduced by the lever, and the start / stop lever 53b is located at the reset button 22 position of the reset lever 81b.
Similar to the above case, the required pressing amount of the button is reduced.

When the reset lever 80 is pressed,
In order to set the starter at the same time by closing the opening / closing claws 33, 33 of the start stand, a lever increasing arm 81c pivotally supported at the lower stage of the lever 81a is provided, and the other end of the lever 81a and one end of the increasing arm 81c are provided. It is linked by a link. On the other hand, the other end of the increasing lever 81c has the main rod 8
3, a weight reducing arm 83a is arranged at the end of the rod 83 as shown in FIG. 2, the central left side is pivotally supported, and it is connected to the slide plate 53c of the start simultaneous mechanism 6. Further, when the reset lever 80 is pressed, the slide plate of the ball feeding mechanism 5 shown in FIGS. 14 to 15 is provided so that the ball 30 is automatically supplied from the ball storing portion 34a of the ball feeding mechanism 5 to the start table 3. An L-shaped arm 37a to be connected is installed and is connected to the main rod 83 via a link 82d. One end is pivotally supported and the main rod 8
A lever 81d is installed as the movement magnifying mechanism of No. 3, and the other end of the lever is connected to the link 82c. In this case, the link 82c also serves to adjust the movement of the main rod 83.

Below the lever 81d, a shaft 41B fixed to an L-shaped arm for opening / closing the opening / closing lid 42 of the ball sensing portion 4 penetrates the vertical plate 10, and an arm 41e is provided at the tip of the shaft 41B. A link 82e, which is attached to the arm and has a frame at its end and a stopper at its lower end, passes through the frame of the arm 41e and is connected to the other end of a lever 81d located above it. In this case, when the opening / closing lid 42 is closed, the stopper of the link 82e is installed so as to be in contact with the lower surface of the arm 41e, and when the main rod 83 moves upward, the arm 41e rotates and the opening / closing lid is opened. It will be released. In the present embodiment, a basket 44 for accommodating up to three spheres 30 is provided after the opening / closing lid 42 is closed by the ball sensing unit 4, and a basket loading frame 45b installed at a lower left position of the ball sensing unit 4 is provided. I am trying to insert it. Further, the basket 44 is inserted into the upper part of the ball feeding mechanism 34b with three balls 10 put therein, and the projection 44b of the slide plate 44a provided on the lower surface of the basket.
Is formed so as to hit the groove of the insertion path and the front end of the slide bottom plate is opened, and the sphere 30 is sequentially moved to the storage parts b and a (see FIG. 14).

Next, the operation of this embodiment will be described. This gravitational experiment device A has a counting display unit 2 of a stopwatch 2.
0 indicates zero or the measurement time by the previous experiment, and the open / close lid 42 of the ball sensing unit 4 is closed. Therefore, first, when the reset lever 80 of the reset mechanism 8 is pushed, the lever 81a is rotated and the lever 81b is rotated in conjunction with the link 82. The lever 81b causes the stopwatch 2 to rotate.
The reset button 22 of is pressed to set the count display portion 20 of the watch to zero, and the arms 81c and 81d and the links 82b,
The arm 41e of the ball sensing unit 4 is rotated by interlocking with 82e. By the rotation of the arm 41e, the L-shaped arm 41 fixed to the same shaft as this is rotated rearward, and the opening / closing lid 42 connected to this is opened. At the same time, the opening / closing claws 33, 33 of the start base 3 which have been opened so far are linked to the movement reduction arm 83a and the slide arms 50c, 50c of the start simultaneous mechanism b, which are connected to the main rod 83. By the way, the arms 50, 50 fixed to the rotating shafts of the opening / closing claws 33, 33 have holders 50a, 50 at the tips of the vertical arms 50c, 50c at one outer end near the axis.
When a comes into contact with the slide, the slide rotates slightly against the downward movement of the slide, and when the slide reaches a horizontal position, the opening / closing claws 33,
33 is closed, is installed inside the slide plate, is pivotally supported at the center, the upper end contacts the inner surface of the locking plate 50d, and the other end contacts the small protrusion installed on the inner surface of the upper portion of the slide plate 51a. The slanting plate (see FIG. 5) 53d that moves back and forth is pushed by the small protrusions and contacts the upper end of the locking plate 50d.
The arm 50, 50 to the lower surface of the tip of the arm (2 mm
(Weak), and the lower end of the starter 50e that is in contact with the standing plate provided in the middle of the locking plate 50d is also pushed, so that it contacts the start rod 64e that is close to the upper surface of the starter. Then, when the reset is completed, the slide is restored and the holders 50a, 50a are separated from the arms 50, 50 (FIG. 3A). Further, the main rod 83 is interlocked with the rotation of the lever 81a of the reset mechanism 8 to rotate the L-shaped arm 37 of the ball feeding mechanism, and the partition plate 3
7b is slid sideways to bring the ball 30 in the set ball waiting portion 34a to the through passage, and the ball 30 leaving the through passage 35 rolls on the connecting slope 36, enters the start stand hole 31, and is opened and closed by the opening and closing claw. Held in position.

Next, the start mechanism operates the stopwatch 2 and, at the same time, releases the ball 30 set on the start table by freely opening and closing the claws 33, 33, as shown in FIG. As described above, a start lever 53 pivotally supported on the vertical plate 10 and a start / stop automatic switching lever 53a, one end of which is pivotally supported on the vertical plate 10, abuts against the lower surface of the central portion of the lever 53 and moves up and down. , One end is pivotally supported by the vertical plate 10, and a start / stop lever 53b that abuts the start / stop button 21 of the stopwatch 2 at a position near the one end is provided.
Center right position and the start / stop lever 53b
The other end is connected by a link 64c. In the figure, 62 is a bearing.

On the other hand, regarding the free fall of the ball 30, as shown in FIG.
(See (a)) One end is pivotally supported on the upper surface of the central portion of the start lever 53, and the arm 53c is pivotally supported by the vertical plate 10 at a position closer to one end. Arm 53d for reducing movement
The other end of 3c and one end of the arm 53d are connected by a link 64, and the start rod 64e is connected to the other end of the arm 53d.
, And the tip of the rod 64e is in contact with the starter 50e for opening and closing the opening and closing claw.

By depressing the lever 53a with the start lever 53 of the simultaneous start mechanism 6, the lever breaks the contact with the holder 64d above the link 64b and rotates downward to interlock the link 64c and the lever 53b. By pressing the clock button 21 to start the timepiece, the arm 53c, the link 64, the arm 53d, and the start rod 64e that are connected to the lever 53 are interlocked with each other so that the tip of the start rod 64e pushes the starter 50e. The locking plates 50d of the contacting arms 50, 50 are pushed back, and as a result, the arms 50, 50 rotate downward, respectively, and the opening / closing claws 33, 33 fixed to the rotating shafts of the arms 50, 50 also move downward. As it rotates, the opening / closing claws 33, 33 are opened, and the ball 30 instantly falls freely. Next, the ball 30 that has fallen freely from the through hole 31 of the start table 3 comes into contact with the sensing lever 40 of the ball sensing unit 4 installed below it, and by pushing down the lever, the vertical arm 60 connected to it. , Arm 63
a, 63b and links 64a, 64b, 64c and lever 5
Start the stopwatch 2 in conjunction with 3a.
Press the stop button 21 to stop the clock. still,
At this time, the sensing lever 40 receives the energy of the abutting sphere 30 and largely rotates, but the arm 63b and the lever 5 are rotated.
The movements are reduced one after another by the movement reducing action of 3a and 53b, and the movement of the clock button 21 at the final point is detected by the sensing lever 40.
It is one-sixth of that and is designed to match the required pressing amount of the clock button. Therefore, it is possible to ensure a sufficient movement of the sensing lever 40 and to stop the stopwatch 2 instantly without a time lag.

On the other hand, the sphere 30 that freely falls and comes into contact with the sensing lever 40 and then leaves is guided by the inclined sensing lever 40,
Proceed to the vertical hole provided in the ball sensing unit 4, contact one end of the L-shaped arm 41 connected to the lower surface of the opening / closing lid 42 in the middle of the hole, and rotate the arm 41 to open / close the opening / closing lid 42. It will be closed. Thereafter, the ball 30 passes through the inclined cylinder 45 and is stored in the basket 44. The basket 44 can accommodate three balls 30. Further, the sensing lever 40 is automatically restored when the ball 30 is detached, and enters the standby state.

In the next experiment, the basket 44 is loaded into the upper portion of the ball waiting portion 34b of the ball feeding mechanism 4 while the ball is still contained in the basket 44.

Sphere stop position of the starting table 3 and the sensing lever 4
Set the distance h from the 0 clock operating position to 0.259 m,
The average value of three ball drops measured is 0.23 sec. Met. By the way, the formula h = 1/2 gt ^{2 for} the falling body is modified to h = ² h / t ²
The calculated value in which 0.259 m t = 0.23 sec is substituted is g = 9.079.
20 m / s ² is obtained. However, g is a unit used to represent the acceleration of gravity (gal = 1 cm / s ² = 10 ^-2 m / s ² and is represented by the letter g) h = height (m): MKS unit Note that the measured value of gravity Is usually higher as the latitude is higher, and the measured gravity value by JGSN75 in Iwaki City, Fukushima Prefecture is 9.8000 ・ ・ ・ m / s ² and 9.7962 ・ ・ ・ m / in the south of Aizuwakamatsu City. s ² .

As described above, according to this embodiment, since one ball is used to start and stop the timepiece, the start simultaneous mechanism 6 causes the set of the balls 30 to drop, Accurate measurement is possible because there is no time lag due to misalignment between the start and stop of the stopwatch 2. In addition, the start / stop button of the stopwatch 2 can be operated without interfering with each other between the start circuit and the stop circuit by using the lever 53a of the automatic start / stop operation switching mechanism. Is short enough to ignore the air resistance to the falling sphere, so it is possible to perform extremely short-time measurements. For this reason, the device can be made compact and, on the other hand, after the stopwatch 2 is stopped, the opening / closing lid 42 on the upper part of the sensing lever 40 is closed, so that malfunction can be prevented and the end of the experiment can be notified. Further, since the ball 30 is stored in the ball standby portion 34 and the reset lever 80 is operated, the experiment can be performed three times in succession with the same condition, so that anyone can accurately perform the experiment. still,
After the experiment is completed, the balls 30 are stored in the basket 44.
This is to prevent it from being released to the outside and to prevent dirt and iron rust due to hand dust due to repeated use, and changes in the surface condition and diameter of the sphere prevent accurate measurement.

Although the embodiment of the present invention has been described above, the specific structure of the present invention is not limited to this embodiment, and the present invention is applicable even if there are design changes and the like within the scope not departing from the gist of the invention. Included in the invention. For example, as shown in FIG. 16, the shaft-supporting portion 9 of the arm and the link is provided with a shaft portion 90 in which a shaft 90c is erected on a plate 90b having a hole 90a, and an end portion of the arm 91 is bent into a substantially U-shape. And a shaft hole 91b penetrating both of them is opened, and a nut 91c is welded inside the arm 91 side while avoiding the shaft hole 91b to form a through hole 91d in a screw hole portion, and further, a shaft is provided at an end portion of the link 92. The hole 92a is opened. Then, a link 92 is inserted into the U-shaped bent portion of the arm 91 so that both shaft holes 91b and 92 are formed.
After aligning with a, insert the shaft 90c of the shaft portion 90,
The machine screw 93 may be inserted from the hole 90a to fix the screw shaft 90c to the nut 90c.

In the present invention, in order to make each mechanism operate smoothly, each arm or link is made of a 0.5 m thick zinc-plated iron plate, and brass is used for the frictional part associated with the rotation, and vertical substrates are used for the vertical substrate. When an acrylonitrile plate is used and parts are damaged, only the parts can be replaced and repaired, and there is no cost in terms of equipment maintenance. Therefore, there is an advantage that the same performance can be maintained for a long time. .

[0031]

【The invention's effect】

1) As described above, according to the gravity experimental apparatus of the present invention, since the stopwatch is started and stopped with the potential energy of one ball, only one set of the mechanism for dropping the ball by the start means is required. . 2) The start means and the stop means can be operated without interfering with each other by an automatic start / stop switching lever installed in the middle of the circuit. 3) The ball dropping distance was set to 0.259 m, and accordingly, the entire device could be made compact. 4) Each mechanism of this experimental device is made of a thin zinc-plated iron plate and a lightweight plate material, etc., and it can be operated smoothly, and even if the shaft hole is worn, only that part can be replaced and the device can be replaced. The same performance can be maintained forever with no maintenance costs. 5) Restoration of each mechanism of this experimental device is performed by gravity acting on the main rod and one link of the start circuit. No spring is arranged outside the leaf spring built in the stopwatch. . 6) The present experimental device composed of the lightweight material can be operated as lightly as a gaming machine, and members of a good school can accurately and quickly carry out an experiment of gravity as a part of their study. 7) Press the reset button to reset the count display on the clock to zero,
The power is saved by a so-called single-fist 4 operation in which the opening / closing claw of the start base is closed and the opening / closing lid on the upper part of the sensing plate is opened to perform four operations of sending the ball from the ball sending mechanism by pressing the button once. 8) The thin zinc-plated iron plate parts arranged in this experimental device have the effect of suppressing the generation of rust on the iron surface, and the arm,
The strength of the links and rods is maintained by adopting a square shape or a laminating method. 9) Since the balls used in this experiment are stored in a basket, it is possible to obtain effects such as not contaminating the balls.

[Brief description of drawings]

FIG. 1 is a front view showing a gravity experimental apparatus according to an embodiment of the present invention.

FIG. 2 is a rear view showing the gravity experimental apparatus of the embodiment.

FIG. 3A is an explanatory diagram showing positions of a start simultaneous mechanism and a start / stop switching lever at a moment when a falling ball starts. FIG. 3B is an explanatory diagram showing the state of the simultaneous start mechanism at the moment of resetting.

FIG. 4 is an explanatory view showing a start / stop switching mechanism.

FIG. 5 is a side view illustrating a start simultaneous mechanism.

FIG. 6 is an explanatory diagram of a ball sensing unit.

FIG. 7 is an explanatory diagram of an opening / closing lid of the ball sensing unit.

FIG. 8 is an explanatory diagram of a stop mechanism.

FIG. 9 is an explanatory diagram of a ball sensing lever mechanism.

FIG. 10 is an explanatory diagram of a reset mechanism.

FIG. 11 is an explanatory diagram of a reset lever.

FIG. 12 is an explanatory diagram showing a state where a ball is held on a start table.

FIG. 13 is an explanatory diagram of a start lever.

FIG. 14 is an explanatory view showing an arrangement of rear balls in which a basket with balls is loaded in a ball feeding mechanism.

FIG. 15 is a slide plate diagram of the ball feeding mechanism.

FIG. 16 is an explanatory view showing a pivotal support portion of an arm and a link of another embodiment.

[Explanation of symbols]

 A Gravity experimental device 1 Base 2 Stopwatch 3 Start table 4 Ball sensing unit 5 Ball feeding mechanism 6 Start simultaneous mechanism 7 Stop mechanism 8 Reset mechanism 9 Automatic start / stop switching mechanism 20 Counting type display section 21 Start / Stop button 22 Reset button 30 Ball 33 Open / close claw 40 Sensing lever 42 Open / close lid

Claims (2)

[Claims] 1. A base mounted upright on a base, a start / stop button fixed to the base, for alternately operating and stopping the timepiece, and a reset button for resetting the timepiece display to zero. A stop watch having, a start table provided on the upper part of the base for dropping the ball held on the upper part by releasing the double-opening opening and closing claw, a ball feeding mechanism opening diagonally above the start table, and a start A sensing lever that is located on the same vertical line as the opening and closing center point of the platform and that rotates by receiving a falling ball, and a lever that rotates the opening and closing lid that is installed near the upper part of the sensing lever with the weight of the ball. A ball-sensing unit having a lid closing mechanism that slides and closes with a lid, a double-opening opening / closing claw is opened to drop the ball, and the start / stop button is pressed to activate a stopwatch. You A stop mechanism for pressing the start / stop button to stop the stopwatch in conjunction with a sensing lever for receiving a ball, and a one-system pressing mechanism in which the lever connecting to each system is formed in the middle automatic switching system,
A reset mechanism that pushes the reset button of the stopwatch to zero the display of the stopwatch, supplies a ball to the start stand from a ball feed mechanism that communicates with the start stand, and opens the opening / closing lid of the ball sensing unit. An experimental device of gravity characterized by 2. A gravitational force characterized by comprising a one-body structure with the start stand, and at the same time activating the clock when the ball is free-falling (starting) by pressing the start button, that is, a start simultaneous mechanism is provided. Experimental device.