JP2008036899A - Electric line-drawing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric line-drawing device which is simply operated and is capable of automatically drawing an arc of an arbitrary radius. <P>SOLUTION: The electric line-drawing device has a cylindrical paperweight 10 made of a transparent resin which holds down the surface of paper with the lower end face 11a thereof and a rotary body 20 which is installed on the upper end face 11b thereof, and a rack gear 15 is provided circularly on the inner peripheral surface of the paperweight 10. The rotary body 20 has a straight bridge part 21 stretching over a hollow part H and a central shaft 22 is suspended from the bridge part 21. A push-button switch 23, a battery 24 and a motor 25 are mounted on the bridge part 21 and a spur wheel 26 engaging with the rack gear 15 is fitted to a motor shaft 25a. A screw bar 28 of which one end portion is supported by a screw support 27 so that it can move idly is oriented on the bridge part 21 and a feeding piece 29 having a suspended writing implement 30 is screwed on the screw bar 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric drawing apparatus that can draw an arc having an arbitrary radius by being placed on a paper surface.

  The normal bifurcated compass requires a rotational movement so that the lower end point of the writing axis is properly pressed against the paper surface while positioning the tip of the central axis at the center of the circle on the paper surface. Therefore, it is necessary for the operator to pay attention to the positional deviation of the central axis and the pressure contact degree of the lower end point of the writing axis over the operation of the rotational movement.

For this reason, a line drawing apparatus in which circular motion is automated by motor drive is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-160852.
JP2004-160852 (FIG. 2)

  However, this line drawing device includes a support plate provided on an eccentric shaft that revolves while revolving inside a cylindrical grip portion, and a writing pen that is supported at a position eccentric with respect to the rotation shaft of the support plate. Therefore, the support plate itself generates circular vibration with the radius from the rotation center of the motor to the eccentric shaft as a radius, and the writing pen does not draw an arc with this radius, but goes around the rotation center of the motor. Since a cometary locus is drawn, an arc with an arbitrary radius cannot be drawn.

  Therefore, in view of the above problems, an object of the present invention is to provide an electric drawing device that is easy to operate and can automatically draw an arc having an arbitrary radius.

  The electric drawing apparatus according to the present invention includes a cylindrical base that holds the paper surface at the lower end surface, a rotating body that is installed on the upper end surface side of the cylindrical base and has a central axis that hangs down in the hollow portion of the cylindrical base, and the rotation A motor drive mechanism that rotates the body around the center axis of rotation, a writing axis that has a writing point that hangs down from the rotating body into the hollow portion and touches the paper surface at the lower end, and the writing axis in the radial direction with respect to the center axis And a radius setting mechanism for adjusting the movement.

  For example, after adjusting the radius of the arc to be drawn with the radius setting mechanism, place the cylindrical base in the area to be drawn on the paper, position the cylindrical base so that the lower end of the central axis points to the center of the circle, and drive the motor When the mechanism is activated, the rotating body rotates on the upper end surface side of the cylindrical table, so that the writing point in contact with the paper surface rotates around the central axis at the set radius, so that an arc is drawn on the paper surface. If the weight of the cylindrical table is sufficient, the friction between the paper surface and the cylindrical table is large even if the rotating body rotates, so the cylindrical table slides in the opposite direction due to the dynamic friction between the writing point and the paper surface. There is no need to hold the outer peripheral surface of the cylindrical body by hand. Since the arc drawn by the writing point on the paper surface can be seen from time to time via a hollow part or a cylindrical base made of transparent material, for example, if there is a problem with the position of the center of the circle or the radius setting, draw the arc as soon as possible. Can be canceled.

  In this way, since the arc can be drawn only by positioning the circle center and starting the motor drive mechanism, the operation is simple, and the radius can be adjusted by the radius setting mechanism, so an arc with an arbitrary radius can be automatically selected. Can be drawn to.

  The writing shaft preferably has an urging means for elastically pressing the writing point against the paper surface. While the writing point is drawing an arc, the writing point is always in elastic contact with the paper surface by the urging means, so that a beautiful arc can be drawn without rubbing in the middle of the drawing line.

  Various configurations can be adopted as the motor drive mechanism, but the motor mounted on the rotating body and the battery for supplying power to the rotating body and the inner peripheral surface of the cylindrical base supported by the rotating body and rotated by the driving of the motor It is desirable to have a drive wheel that rotates around. Since the rotating body is heavier than the motor, battery, and driving vehicle, the writing pressure on the paper surface of the writing points increases, and a beautiful arc can be drawn. In addition, since the rotating body rotates when the drive vehicle is in contact with the inner peripheral surface of the cylindrical table, the rotating body can be attached to and detached from the upper end surface side of the cylindrical table, and the configuration of the rotating body and the cylindrical table is simplified. Can be

  The drive vehicle may be a friction vehicle, but in order to improve the accuracy, a rack gear is provided around the inner peripheral surface of the cylindrical base, and the drive vehicle is preferably a gear that meshes with the rack gear.

  When the motor is mounted on the rotating body, it is desirable that the switch for starting the motor is also mounted on the rotating body, but this switch is preferably a push button switch provided at an upper position of the central axis. When the push button switch is pressed with the fingertip, the rotating body begins to rotate, but the pushbutton switch only rotates on the center axis, so when the rotary body is rotated to a predetermined angle while continuing to press with the fingertip, When the is released, the rotation of the rotating body stops, so that an arc of a predetermined angle can be drawn. The radius setting mechanism can be a screw feed mechanism.

  The electric drawing apparatus according to the present invention is easy to operate and can automatically draw an arc having an arbitrary radius.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an external perspective view showing an electric drawing apparatus according to an embodiment of the present invention, FIG. 2 is an assembled perspective view showing the electric drawing apparatus, FIG. 3 is a plan view of the electric drawing apparatus, and FIG. 3 is a cross-sectional view taken along the line aa in FIG. 3, FIG. 4B is a cross-sectional view taken along the line bb in FIG. 3, and FIG. 5 is a section C in FIG. FIG.

  The electric drawing apparatus of this example includes a cylindrical paper weight 10 made of transparent resin that presses the paper surface at the lower end surface 11a, and a rotating body 20 installed on the upper end surface 11b of the cylindrical paper weight 10.

  An annular guide groove 12 is formed on the upper end surface 11 b of the cylindrical paper weight 10, and an angle scale 14 is provided on the inner circumferential annular protrusion 13. A rack gear 15 is provided around the inner peripheral surface on the upper end surface 11b side.

  The rotating body 20 has a straight bridge portion 21 straddling the hollow portion H, and the straight bridge portion 21 is a pair of protrusions 21a that are loosely fitted into the annular guide groove 12 at positions separated by the diameter of the annular guide groove 12. , 21a and a pair of bent portions 21b, 21b covering the outer peripheral surface 11c on the upper end surface 11b side of the cylindrical paper weight 10 are integrally provided. A central shaft 22 is suspended from the center position of the pair of protrusions 21 a and 21 a in the straight bridge portion 21, and the position of the tip 22 a is set at the same level as the lower end surface 11 a of the cylindrical paper weight 10. . The straight bridge portion 21 has a push button switch 23 directly above the central shaft 22, and a motor 25 and a battery 24 for supplying power to the motor 25 are mounted on one side of the straight bridge portion 21 from the push button switch 23. Yes. A spur gear 26 is attached to a motor shaft 25 a depending on the motor 25, and the spur gear 26 meshes with the rack gear 15. A screw rod 28 is supported on the other side of the straight bridge portion 21 from the push button switch 23 so that one end thereof can be idled by a screw receiver 27. A feeder 29 is screwed into the screw rod 28, and a screw A feed mechanism is configured. An adjustment knob 28 a is provided on the free end side of the screw rod 28. The feeder 29 has a hanging writing instrument 30.

  The writing instrument 30 includes an outer cylinder 31 fixed to the feeder 29, an inner cylinder 32 that can be moved up and down by a predetermined stroke within the outer cylinder 31, and a writing core such as a graphite core that can be moved up and down in the inner cylinder 32. And a shaft 33. The writing shaft 33 is fixed by a shaft set screw 32a. The inner cylinder 32 has a stopper pin 32 b that fits into a long hole 31 a formed in the cylinder wall of the outer cylinder 31, and the upper end of the inner cylinder 32 is pushed downward and biased by a coil spring 34 housed in the upper part of the outer cylinder 31. When the cylindrical paper weight 10 is lifted, the writing point 33a of the writing shaft 33 protrudes downward from the lower end surface 11a.

  A diameter scale 21c representing a rotation radius r of the writing shaft 33, which is a distance from the central axis 22 to the writing shaft 33, is provided in the range of the screw rod 28 of the straight bridge portion 21.

  The electric drawing apparatus is used after the adjustment knob 28a is turned as shown by the arrow A in FIG. 3 to move the feeder 29 in the direction of the radial scale 21c as shown by the arrow B and set to the radius r of the arc to be drawn. The cylindrical paper weight 10 is placed in an area to be drawn on the paper surface, and the cylindrical paper weight 10 is positioned so that the tip 22a of the center axis 22 is in the center of the circle. After that, by continuing to push the push button switch 23 with the fingertip, the spur gear 26 is engaged with the rack gear 15 by the driving motor 25 and rotates as indicated by the arrow C in FIG. The writing point 33a in contact with the paper surface rotates around the central axis 22 with the set radius r, so that an arc E with the radius r is drawn on the paper surface. In order to stop the rotational movement of the rotating body 20, it is preferable only to release the fingertip from the push button switch 23.

  Here, when the weight of the cylindrical paper weight 10 is sufficient, the friction between the paper surface and the cylindrical paper weight 10 is large even when the rotating body 20 rotates, so that the cylindrical paper weight 10 has the writing point 33a and the paper surface. Therefore, it is not necessary to hold the outer peripheral surface 11c of the cylindrical paper weight 10 by hand. It is also preferable to attach a non-slip sheet to the lower end surface 11a of the cylindrical paper weight 10. In addition, since the arc drawn by the writing point 33a on the paper surface can be viewed from time to time through the hollow portion H or the transparent cylindrical paper weight 10, if there is any inconvenience in setting the center of the circle or setting the radius You can stop drawing arcs early.

  In this way, since the arc E can be drawn only by the circle center positioning operation and the motor start operation by the push button switch 23, the operation is simple, and the circle radius can be adjusted by the movement operation of the feeder 29. An arc with an arbitrary radius can be automatically drawn.

  Since the writing point 33a of the writing shaft 33 is always in elastic contact with the paper surface by the urging force of the coil spring 34, the writing point 33a draws a beautiful arc E without rubbing in the middle of drawing while the arc E is drawn. be able to.

  The straight bridge portion 21 is equipped with a motor 25 and a battery 24 for rotationally driving the straight bridge portion 21 itself, and has a heavy load. Therefore, the straight bridge portion 21 is engaged with the spur gear 26 and the rack gear 15 to engage with the straight bridge portion 21. Lifting from the upper end surface 11b of the portion 21 hardly occurs, the writing pressure on the paper surface of the writing point 33a increases, and a beautiful arc E can be drawn. In addition, since the straight bridge portion 21 is equipped with the motor 25 and the battery 24, the electric wire drawing device can be simply configured with the cylindrical paper weight 10 and the rotating body 20 and the cost can be reduced. In particular, since the spur gear 26 is used, it has high accuracy and can be engaged and disengaged with the rack gear 15 simply by attaching and detaching the rotating body 20 in the axial direction of the cylindrical paper weight 10.

It is an external appearance perspective view which shows the electric drawing apparatus which concerns on one Example of this invention. It is an assembly perspective view showing the electric drawing apparatus. It is a top view of the electric drawing apparatus. (A) is sectional drawing cut | disconnected along the aa line in FIG. 3, (B) is sectional drawing cut | disconnected along the bb line in FIG. FIG. 5 is an enlarged view of a portion C in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Cylindrical paper weight 11a ... Lower end surface 11b ... Upper end surface 11c ... Outer peripheral surface 12 ... Annular guide groove 13 ... Inner peripheral side annular protrusion 14 ... Angle scale 15 ... Rack gear 20 ... Rotating body 21 ... Straight bridge part 21a ... Projection 21b ... bent portion 21c ... diameter scale 22 ... center shaft 22a ... tip 23 ... button switch 24 ... battery 25 ... motor 25a ... motor shaft 26 ... spur gear 27 ... screw receiver 28 ... screw rod 28a ... adjustment knob 29 ... feed bar DESCRIPTION OF SYMBOLS 30 ... Writing tool 31 ... Outer cylinder 31a ... Long hole 32 ... Inner cylinder 32a ... Shaft set screw 32b ... Stopper pin 33 ... Writing shaft 33a ... Writing point 34 ... Coil spring E ... Arc H ... Hollow part r ... Turning radius

Claims (6)

A cylindrical base that presses the paper surface at the lower end surface, a rotating body that is installed on the upper end surface side of the cylindrical base and has a central axis that hangs down in the hollow portion of the cylindrical base, and the rotational body that rotates about the central axis A motor drive mechanism that rotates as a writing shaft; a writing shaft that has a writing point that hangs down from the rotating body into the hollow portion and touches the paper surface at the lower end; and moves and adjusts the writing shaft in a radial direction with respect to the central axis An electric drawing device comprising a radius setting mechanism. The electric drawing apparatus according to claim 1, wherein the writing axis includes an urging unit that elastically presses the writing point against the paper surface. 3. The electric line drawing device according to claim 1, wherein the motor driving mechanism is a motor mounted on the rotating body, a battery that supplies power to the motor, a battery that is supported by the rotating body, and is rotated by driving of the motor. And an electric drawing device characterized by having a drive wheel that rotates around the inner peripheral surface of the cylindrical base. 4. The electric drawing apparatus according to claim 3, wherein a rack gear is provided around the inner peripheral surface, and the driving wheel is a gear that meshes with the rack gear. 5. The electric line drawing apparatus according to claim 4, wherein the switch for starting the motor is a push button switch provided at an upper position of the central axis. The electric drawing apparatus according to any one of claims 1 to 5, wherein the radius setting mechanism is a screw feed mechanism.

Images