JPS6110167Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a compass or a device equipped with a compass that uses a magnet or a magnetic needle to determine direction.

In general, when the jewel and support shaft of the indicator needle that indicates the direction wear out, the needle moves poorly, making it impossible to indicate the direction accurately. There was a drawback in that it was not possible to distinguish between a defect and a smooth and quick stopping operation of the indicator needle due to the braking action of the brake disc.

The present invention has been made to solve the above-mentioned drawbacks, and is configured so that the brake disc for braking the direction indicator can be lowered to a position lower than the normal braking position. , the braking action of the braking disc on the indicator needle is reduced, making it possible to check for malfunctions due to wear of the indicator needle's stone and support shaft.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a main body installed on a support base 2, 3 is a support shaft vertically disposed in the center of the main body, and 4 is an indicator supported at the tip of this support shaft 3 via a stone 5 so as to be able to swing and rotate. 6 is a magnet attached to the lower surface of the base of the indicator needle 4. 7 is a scale plate provided along the inner circumference of the main body 1; 8 is a glass plate fitted into the glass frame 8';
Reference numeral 9 denotes a collimating cylinder which is pivotally supported by a horizontal shaft 11 on the upper part of a collimating cylinder support frame 10 fixed to the main body 1. Reference numeral 12 denotes a brake disc provided in the center of the main body 1 through which the support shaft 3 is inserted below the indicator needle 4, the position indicated by the dotted line A is the normal braking position, and the solid line position B is the normal braking position according to the present invention. This position is set so that it can be lowered further than position A. Reference numeral 13 denotes a half-moon cam 15 which has one end inserted through the support shaft 3 and abuts against the brake disc 12, and whose other end is rotated by a knob 14 projecting from the main body 1.
This is a brake disc pushing up plate that abuts on the brake disc and rotates in a vertical plane at a fulcrum 16.

Since the present invention has the above-described configuration, in order to indicate a direction using the indicator needle 4 and to know the direction, the knob 1 must be turned.
4, the half-moon cam 15 is rotated to rotate the brake disc push-up plate 13 clockwise about the fulcrum 16, and the clamp device (not shown) is operated with the brake disc 12 in the normal braking position A. If you release the clamp on the indicator needle 4 and allow the indicator needle 4 to swing freely,
The magnet 6 swings and rotates together with the indicator needle 4, and the brake disc 1
2 cuts the magnetic field lines of this magnet 6, so the brake disc 1
An eddy current is generated in the pointer 2, and a braking torque is generated between this eddy current and the magnetic field of the magnet 6 of the pointer 4. In other words, the pointer 4 can be moved smoothly due to the braking action of the braking disk 12 on the pointer 4. Stop immediately and give directions. To determine whether the movement of the indicator needle 4 has deteriorated due to wear of the jewel 5 and support shaft 3, or whether it has stalled due to the braking action of the brake disc 12,
If the indicator needle 4 still moves poorly even after lowering the brake disc 12 to the solid line position by rotating the knob 14 and reducing the braking effect on the indicator needle 4 that has been lowered to this solid line position, the block 5 and the support shaft 3 are removed. It turns out that the cause is wear on the brake disc 1, and if the movement of the indicator needle 4 improves, then the brake disc 1
It can be seen that the cause is the braking action caused by No. 2.

As described above, the present invention has the effect of being able to distinguish between malfunction of the indicator needle due to wear of the jewel and support shaft, and smooth and prompt stopping action of the indicator needle due to the braking action of the braking disc. .

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an embodiment of the present invention. 3...Support shaft, 4...Indicator needle, 5...Gemstone, 6
...Magnet, 12...Brake disc, A...Normal braking position, B...Position set further below the normal braking position A.

Claims (1)

[Scope of utility model registration request] A compass characterized in that a braking disc for braking a pointer indicating a direction can be lowered to a lower position than a normal braking position.