JP7280621B2 - compass - Google Patents

Description

The present invention relates to a compass for drawing arcs, particularly suitable for use when learning.

A conventional compass has a central leg having a needle at its tip, a rotating leg that holds a writing instrument such as a pencil at its tip and rotates it, a mounting body that pivotally supports the rotating leg and the central leg so that they can be opened and closed, and the mounting body. and a slender, substantially cylindrical operating body protruding upward, and a pencil is pressed and held at the tip of the rotating leg by a screw.

Also, a compass has been proposed that includes a pencil holding cylinder that holds a pencil, a ballpoint pen, etc. by tightening a rotating cam (see, for example, Patent Document 1).

However, the compass according to the above-mentioned patent document can hold not only a pencil but also a ballpoint pen. , has the drawback that it is difficult to stably draw an arc.

Japanese Utility Model Laid-Open No. 58-94590

Therefore, there is a demand for a compass that can be firmly tightened and held without shifting the writing instrument against the load applied to the writing instrument in the vertical direction, and that even a child can easily hold the writing instrument.

In view of the above problems, the compass of the present invention includes a central leg having a needle at its tip, a rotating leg that rotates around the central leg, and an operating body that pivotally supports the rotating leg and the central leg so that the rotating leg and the central leg can be freely opened and closed. be prepared,
The rotating leg has a rotating script body and a writing instrument holding mechanism for holding a writing instrument at the tip of the rotating script body,
The writing instrument holding mechanism includes an outer cylindrical body provided at the tip of the rotating script body, and an inner cylindrical body that is inserted into the outer cylindrical body and tightens the writing instrument,
The inner cylindrical body is formed into a substantially cylindrical body having a notch in the form of a longitudinal groove, and has a collar extending from the upper and lower ends of the outer peripheral surface and abutting on the inner peripheral surface of the outer cylindrical body. death,
The collar portion has an outer peripheral surface formed in the same shape that is one size smaller so as to abut on the inner peripheral surface of the outer cylindrical body whose inner diameter continuously decreases.

In addition to the configuration described above, it is preferable that the inner cylindrical body has a projecting piece formed on the outer peripheral surface.

In addition to the structure described above, the outer cylinder is formed in a substantially cylindrical shape with openings at both ends, and is provided so that the central axis direction forms an acute angle with respect to the longitudinal direction of the rotary script body. It is preferable to have an opening on the outer peripheral surface of the body for rotating the projecting piece of the inner cylindrical body.

In addition to the configuration described above, it is preferable that the opening is formed by notching the outer surface of the outer cylindrical body in a substantially rectangular shape.

In addition to the configuration described above, it is preferable that the projecting piece extends in a vertical direction perpendicular to the rotation direction of the inner cylinder on the outer peripheral surface of the inner cylinder.

According to the inventions described in claims 1 to 5, the writing instrument holding mechanism is provided, which can easily hold the writing instrument and can firmly tighten the writing instrument without causing the writing instrument to shift against the load applied to the writing instrument in the vertical direction. It is possible to provide a compass.

It is a front view which shows an example of the compass which concerns on embodiment of this invention. FIG. 2 is an exploded view showing a writing instrument holding mechanism provided at the tip of the rotating leg of FIG. 1; It is an expanded sectional view which shows the structure of a writing instrument holding mechanism. (a) Front enlarged view and cross-sectional view taken along line AA showing the state before the writing instrument is held by the writing instrument holding mechanism, and (b) Front enlarged view showing the state during holding of the writing instrument and line BB. FIG. 4C is a cross-sectional view, (c) an enlarged front view showing a state in which the writing instrument is held, and a cross-sectional view taken along the line CC. FIG. 2 is a front view showing a state in which the central leg and rotating leg of the compass of FIG. 1 are closed, and an enlarged cross-sectional view around the needle and the tip of the writing instrument;

Embodiments of the present invention will now be described in detail with reference to FIGS. 1-5. Note that the writing instrument 50 in this embodiment is a hexagonal pencil having an outer diameter of about 7.5 to 8.0 mm.

The compass of the present invention, as shown in FIG. 1, has a central leg 10 having a needle 12 at its tip, a rotating leg 20 that rotates around the central leg 10, and pivotally supports the rotating leg 20 and the central leg 10 so as to be openable and closable. and an operating body 30 having a shaft portion 31.

The center leg 10 is provided with a rod-shaped central leg 11 which is mainly made of a metallic material such as zinc and manufactured by casting, and a needle mounting portion 40 provided at the tip of the central leg 11. The needle mounting portion 40 has a needle protection portion 41 that protects the needle 12 and a needle protection portion elevating mechanism that allows the needle protection portion 41 to move up and down.

Similar to the central leg 10, the rotary leg 20 has an elongated groove-shaped rotary script body 21 with a hollow inside, which is made mainly of a metal material such as zinc and manufactured by a mold. and a writing instrument retention mechanism for.

The needle attachment portion 40 is formed by integrally forming a tapered cylindrical body, and the central axis direction of the cylindrical body is inclined at an acute angle α with respect to the longitudinal direction of the central base body 11 . be. Further, the tip 12a of the needle 12 protrudes from the tip of the needle mounting portion 40, and both ends are opened to provide a mechanism for lifting and lowering the needle protection portion. It should be noted that this angle α is set so that when the center leg 10 and the rotary leg 20 are spread apart and an arc with a radius of approximately 4 cm to 8 cm is drawn, the needle can pierce the paper surface approximately perpendicularly. About 20 degrees is preferable.

(Writing instrument holding mechanism)
Next, a writing instrument holding mechanism provided at the tip of the rotary script body 21 for holding the writing instrument 50 will be described in detail with reference to FIGS. 1-5. This writing instrument holding mechanism is mainly composed of an outer cylindrical body 70 provided at the tip of the rotary script body 21, and an inner cylindrical body 71 which is inserted into the outer cylindrical body 70 and tightens and holds the writing instrument 50. It is a thing.

As particularly shown in FIGS. 2 and 3, the outer cylindrical body 70 is formed integrally with the outer surface of the rotating leg body 21 in a substantially cylindrical shape with both ends opened, and is centered with respect to the longitudinal direction of the rotating leg body 21 . It is provided so that the axial direction forms an acute angle, and has an opening 70a on its outer peripheral surface for pushing and rotating a projecting piece 71c of the inner cylindrical body 71, which will be described later. The inner diameter of the outer cylindrical body 70 gradually decreases in a counterclockwise direction starting from the side opposite to the position of the rotary script body 21 (left side in FIG. 4), which is the position before the writing instrument 50 is held. It is formed in a spiral shape.

The angle β of the central axis of the outer cylindrical body 70 is, as shown in FIG. The writing utensil can be held at an inclination angle β equal to or less than the inclination angle α with respect to the central axis of the compass as a whole. More specifically, when the inclination angle α of the needle 12 is 20 degrees, the angle β is set so that the tip of the writing instrument 50 is positioned near the tip 12a of the needle 12, so that the tip shape of the writing instrument 50 is It is preferable to set the angle to about 19 degrees in consideration of the thickness of the .

The opening 70a is formed by cutting the outer peripheral surface of the outer cylindrical body 70. The inner cylindrical body 71 is opened by pushing the projecting piece 71c of the inner cylindrical body 71 into the opening 70a within the range of the rotation angle γ. is rotated. One side of the opening portion 70a is provided with a concavely curved side portion 70b so as to facilitate pushing of the projecting piece 71c of the inner cylindrical body 71. As shown in FIG. In order to improve the operability of the rotation operation for tightening or loosening the writing instrument 50, the opening 70a rotates around the central axis of the outer cylindrical body 70 at a rotation angle γ within a range of 0 to 90 degrees. It is formed by notching into a substantially rectangular shape with a width of about 1/4 of the outer peripheral surface of the outer cylindrical body 70 so as to move.

2 and 3, the inner cylindrical body 71 is formed in a substantially cylindrical body having a vertical groove-shaped notch 71a, and extends from the upper end and the lower end of the outer peripheral surface to extend inside the outer cylindrical body 70. It has flanges 71b, 71b that come into contact with the peripheral surface. The inner cylindrical body 71 also has projecting pieces 71c formed on the outer peripheral surface of the inner cylindrical body 71 between the flanges 71b, 71b at the upper and lower ends.

The flanges 71b, 71b have an outer peripheral surface formed in the same shape that is one size smaller so as to abut against the inner peripheral surface of the outer cylindrical body 70, the inner diameter of which continuously decreases in the counterclockwise direction. When viewed from the plane direction shown in FIG. 4(a), the left side located near the projecting piece 71c is the starting point, the maximum thickness is around the starting point, and the thickness is continuously reduced in the counterclockwise direction. is. The flanges 71b, 71b have a spiral shape formed so as to turn counterclockwise and enter in the direction of the central axis.

Further, the flanges 71b, 71b are discontinuous between the cutouts 71a, but have approximately the same thickness. About three-fourths of the outer peripheral surfaces of the portions 71b, 71b are brought into contact with the inner peripheral surface of the outer cylindrical body 70, and are deformed so as to narrow the width w of the notch portion 71a. At this time, since the inner peripheral surface of the inner cylindrical body 71 is deformed so as to have a substantially circular cross section, it is possible to uniformly apply a tightening force to the entire outer peripheral surface of the writing instrument 50 in the circumferential direction.

The protruding piece 71c extends in the form of a vertically long thin plate on the outer peripheral surface of the inner cylindrical body 71 in a vertical direction orthogonal to the rotation direction of the inner cylindrical body 71. It facilitates the turning operation of the. Further, on the outer surface of the inner cylindrical body 71 in the vicinity of the projecting piece 71c, there is a pattern such as an arrow indicating the rotation direction for tightening or loosening the writing instrument 50. As shown in FIG.

Next, by the above-described writing instrument holding mechanism, the state before holding the writing instrument 50, the state during holding (rotation angle γ is 45 degrees), and the holding state (rotation angle γ is 90 degrees) will be described with reference to FIG.

Before the writing instrument 50 is held, as shown in FIG. 4A, the projecting piece 71c is positioned on the left side with the rotation angle γ of 0 degrees. The flanges 71b, 71b and the outer peripheral surface of the outer cylindrical body 70 have the same shape and have the maximum inner diameter. The length of this maximum inner diameter is set to be larger than the outer diameter of the writing instrument 50 so that the writing instrument 50 can be slid appropriately in the vertical and rotational directions by inserting it, and is about 8.1 mm. It is preferable that

As shown in FIG. 4(b), the writing instrument 50 is positioned in the middle of holding the writing instrument 50 on the lower left side by rotating the rotation angle γ of the projecting piece 71c counterclockwise from about 45 to 60 degrees. The inner cylindrical body 71 is deformed so that the width w of the notch 71a is narrowed so that the outer diameter of the writing instrument 50 and the inner diameter of the inner cylindrical body 71 are matched so as to come into contact with the corners of the outer surface of the writing instrument 50. It is what I did. Along with this, the writing instrument 50 begins to be tightened while following the rotation of the inner cylindrical body 71 . In other words, only the inner cylindrical body 71 rotates while the protruding piece 71c is rotated from the left side (see FIG. 4(a)) to the diagonally lower left side (see FIG. 4(b)). In addition, by providing a section in which the writing instrument 50 does not follow and rotate, the rotational movement of the inner cylindrical body 71 is biased, thereby facilitating the rotational movement for tightening the writing instrument 50 . .

In the state where the writing instrument 50 is held, as shown in FIG. 4(c), the projecting piece 71c of the inner cylindrical body 71 is rotated counterclockwise by a rotation angle γ of 90 degrees and positioned downward. . At this time, the flanges 71b, 71b of the inner cylindrical body 71 are further pressed in the direction of the central axis of the inner cylindrical body 71 while being in sliding contact with the inner peripheral surface of the outer cylindrical body 70 as the inner cylindrical body 71 rotates. Along with this, the inner cylindrical body 71 is deformed so that the width w of the notch portion 71a is further narrowed to the minimum inner diameter, and the writing instrument 50 is tightly tightened so as not to move in the vertical direction and the rotational direction. . This minimum inner diameter is about 7.4 mm, and it is preferable to set the diameter to the extent that all the corners of the pencil, which is the writing instrument 50, are evenly pressed.

In addition, the inner cylindrical body 71 can prevent the writing instrument 50 from moving in the vertical direction by the flanges 71b, 71b provided on both the upper and lower sides of the inner cylindrical body 71. It is possible to further improve the force.

Therefore, by the above-described writing instrument holding mechanism of the compass, the writing instrument 50 can be held by tightening the entire writing instrument 50 by the inner peripheral surface of the inner cylindrical body 71, compared to the conventional general screwdriver type that presses and fixes the writing instrument. The tightening force is improved, and the writing instrument 50 can be tightened and loosened by pushing the projecting piece 71c of the inner cylindrical body 71 only in the range of 0 degrees to 90 degrees, so that even a child can easily hold the writing instrument. It is possible.

Although the preferred embodiments of the present invention have been illustrated in the above embodiments, the present invention is not limited to the above embodiments, and improvements and modifications are possible within the scope of the claims. For example, since the writing instrument holding mechanism can evenly tighten the entire outer peripheral surface of the writing instrument 50, a mechanical pencil or the like can be attached as the writing instrument 50 instead of a pencil.

10 central leg, 11 central script body, 12 needles, 12a tip,
20 rotating leg, 21 rotating script body,
30 operating bodies, 31 shafts,
40 Needle attachment part, 41 Needle protection part,
70 outer cylinder, 70a opening, 70b side,
71 inner cylindrical body, 71a notch, 71b flange, 71c projecting piece,
50 writing instrument (pencil), α, β angle, γ rotation angle, w width.

Claims (5)

comprising a central leg having a needle at its tip, a rotating leg that rotates around the central leg, and an operating body that pivotally supports the rotating leg and the central leg so as to be openable and closable,
The rotating leg has a rotating script body and a writing instrument holding mechanism for holding a writing instrument at the tip of the rotating script body,
The writing instrument holding mechanism includes an outer cylindrical body provided at the tip of the rotating script body, and an inner cylindrical body that is inserted into the outer cylindrical body and tightens the writing instrument,
The inner cylindrical body is formed into a substantially cylindrical body having a notch in the form of a longitudinal groove, and has a collar extending from the upper and lower ends of the outer peripheral surface and abutting on the inner peripheral surface of the outer cylindrical body. death,
The compass, wherein the flange has an outer peripheral surface formed in the same shape that is one size smaller so as to come into contact with the inner peripheral surface of the outer cylindrical body, the inner diameter of which continuously decreases.
2. The compass according to claim 1, wherein the inner cylindrical body has projections formed on the outer peripheral surface. The outer cylindrical body is formed in a substantially cylindrical shape with openings at both ends, and is provided so that the central axis direction forms an acute angle with respect to the longitudinal direction of the rotary script body. 3. The compass according to claim 1, further comprising an opening for rotating the projecting piece of the cylindrical body. 4. The compass according to claim 3, wherein the opening is formed by notching an outer surface of the outer cylindrical body in a substantially rectangular shape. 3. The compass according to claim 2, wherein the protruding piece extends on the outer peripheral surface of the inner cylinder in a vertical direction perpendicular to the direction of rotation of the inner cylinder.

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