JPH0615758Y2 - Cursive for plotter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a writing body for a plotter, in particular, a writing body using a core that causes wear such as a core for a shear pencil.

(Prior Art) A conventional writing body of a plotter, especially one using a lead core, has a shaft (2) fixed to a head (1) in an upright state, and a taper inner surface at a lower end of an inner hole in the shaft cylinder. Check case with (3a)
(3) is mounted, and the lead fixing chuck (4) having the lead holding portion (4a) at the lower end portion in the chuck case is the lead holding portion (4a).
The ball (5) is interposed between the concave ball seat (4b) on the outer surface of the and the tapered inner surface (3a) of the check case (3), and the rear end step (4c) and the inner hole of the check case (4). It is internally movably up and down while being biased upward by a chuck spring (6) interposed between the step (3b) (the above chuck cases
(3), core fixed chuck (4), ball (5) and chuck spring
The device constituted by (6) is hereinafter referred to as a ball chuck (α). ), And the base (7) is fixed to the lower end of the barrel (2),
Inside the lower end hole of the mouthpiece (7), a tip pipe (9) urged downward by a spring body (8) interposed between the upper end surface and the lower end surface of the chuck case (3) moves vertically. The tip pipe (9) has a structure such that a holding chuck (10) is fitted directly below the ball chuck in the central hole of the upper end surface of the pipe (9).

(Problems to be solved by the invention) As a method of detecting the core breakage of the writing body for a protter having such a structure, there is a method of accumulating the writing distance, etc., but it is extremely difficult, and it depends on a quick eye measurement. In the current situation, however, there are problems that the core is often broken and the writing is not possible, or that the core is wasted by replacing it too early with a sufficient amount of residual core. It is an object of the present invention to provide a cursive body for a plotter which is an improvement of the cursive body for a plotter described above and has a mechanism for accurately detecting a core break without relying on visual measurement.

(Means for Solving the Problems) In order to achieve the above object, the present invention has a ball chuck (α) inside a shaft cylinder (2) fixed to a head (1), and is installed at a position below the ball chuck (α). Is a cursive body for a platter, which is provided with a holding chuck (10) that is movable in the axial direction, and a chuck case (3) for a ball chuck (α).
The distance between the outer surfaces of both balls (5) in the core holding part (4a) when the core fixing chuck (4) of the ball chuck (α) is in the state of holding the core at the upper position continuous with the taper inner surface (3a). Smaller than that of the core fixing chuck (4) having an inner diameter larger than the distance between the outer surfaces of both balls (5) in the core holding portion (4a) when the core fixing chuck (4) is in the state of not holding the core. The moving hole (3c) is provided, and the core holding part (4a) of the fixed core chuck (4) is inserted into the moving hole (3c) in the shaft tube (2) located slightly above the upper end of the ball chuck (α). A writing instrument for a plotter, which is provided with a sensor (11) for detecting the displacement of the upper end of the lead fixing chuck (4).

(Embodiment and Operation) An embodiment and operation of the present invention will be described with reference to the drawings.

In the illustrated embodiment of the present invention, the shaft cylinder (2) is fixed to a three-dimensionally movable head (1), and the shaft cylinder (2) has a tapered inner surface (3a) at the lower end of the inner hole. The chuck case (3) is installed, and the core fixing chuck (4) having the core holding part (4a) at the lower end inside the chuck case (3) is a concave ball seat formed on the outer surface of the core holding part (4a). The ball (5) is interposed between the taper inner surface (3a) of the chuck case (4b) and the rear end step (4
It is internally movably mounted in the vertical direction while being biased upward by a chuck spring (6) interposed between the c) and the inner hole stepped portion (3b) of the chuck case (4), and the barrel (1). A base (7) is screwed onto the lower end of the base, and a spring body (8) is inserted inside the lower end hole of the base (7) between the upper end surface and the lower end surface of the chuck case (3).
The tip pipe (9), which is urged downward by, is fitted so as to be movable in the vertical direction, and the holding chuck (10) is located directly below the ball chuck (α) in the center hole of the upper end surface of the tip pipe (9). The core fixing chuck (4) at an upper position continuous with the taper inner surface (3a) of the chuck case (3) described above.
Is smaller than the distance between the outer surfaces of both balls (5) when the core holding part (4a) of the core is held by the core (a), and the core holding part (4a) is the core.
The ball chuck of the barrel (2) is provided with the moving hole portion (3c) of the core fixing chuck (4) having an inner diameter larger than the distance between the outer surfaces of the balls (5) when the ball is held in (a). (Α) Displacement of the upper end position of the lead fixing chuck (4) caused by moving the lead holding part (4a) of the lead fixing chuck (4) into the moving hole (3c) at a position slightly above the rear end position. It is equipped with a sensor (11) for detecting.

In this cursive writing instrument for plotter, the core (a) is fixed to the core (4).
From the holding chuck (10) to the lower end of the tip pipe (9), the head (1) is lowered to move the tip of the tip and the tip pipe.
Writing is done with the lower end surface of (9) pressed against the paper surface (b) (see FIG. 1), and the tip pipe (9) moves the spring body (8) as the core (a) is worn by the writing. While compressing, it will rise relatively inside the base (7). When the writing is completed and the head (1) rises and the lower end surface of the tip pipe (9) separates from the paper surface (b), the tip pipe (9) descends relatively in the mouthpiece due to the restoring force of the spring body (8). And hold it at that time
The core (a) is pulled out from the ball chuck (α) by the frictional force between (10) and the core (a). That is, the ball chuck (α) has a large resistance to the upward pushing force of the core (a) due to the wedge action of the ball (5) as well known, but the core (a)
It is possible to pull out downwards even with a weak force such as a frictional force between the holding chuck (10) and the core (a). If this process is repeated and wear of the lead (a) progresses, and the rear end of the lead (a) comes off the lead holding part (4a) of the lead fixing chuck (4), the lead holding part (4a) contracts in diameter. Since it is biased upward by the chuck spring (6), it is a moving hole formed continuously with the ball (5) above the taper inner surface (3a) of the chuck case (3).
Immersed in (3c), the upper end of the lead fixing chuck (4) is also displaced upward and detected by the sensor (11) (see FIG. 2),
You will be informed that the core (a) has disappeared. Of course, the core fixing chuck (4) cannot be immersed in the moving hole (3c) because the distance between both ball outer surfaces is larger than the inner diameter of the moving hole (3c) while holding the core. .

(Effects of the Invention) The present invention has the above-described configuration and operation,
Even if you do not rely on visual inspection, the sensor will accurately detect the wear state of the core, so you will not notice the core breakage or waste the core too early because you have too much remaining core. The problems such as the above are solved. It should be noted that in order to increase the displacement of the wick fixing chuck with and without the wick held to the extent that can be detected by the sensor, it is not necessary to provide a moving hole and the angle of the taper inner surface of the chuck case is made shallow. However, if the inner surface of the taper is made shallow, the wedge effect of the ball becomes too large and the pulling out of the core is hindered, resulting in impairing the function of the ball chuck. It is appropriate that the taper inner surface angle for the ball chuck to function properly be about 10 ° with respect to the axis, and at this angle, the displacement amount with and without the core is about 0.3 mm. As a result of research, it has been found that it is extremely difficult for the sensor to detect it.However, the taper inner surface angle can be properly adjusted only by providing a moving hole continuously above the taper inner surface as in the present invention. It is possible to obtain the amount of displacement that can be detected by the sensor while setting the value to any value. Of course, the amount of displacement of the fixed core chuck can be freely set depending on the type and sensitivity of the sensor.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a vertical sectional view when the lead fixing chuck is in a state of holding the core, and FIG. 2 is a vertical sectional view when the lead fixing chuck is in a state of not holding the lead. , Third
The figure is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 4 is the line BB in FIG.
It is a cross-sectional view of a line. (1) …… Head, (2) …… Shaft cylinder, (3) …… Chick case, (3a) …… Tapered inner surface, (3b) …… Inner hole step, (3c) ……
Movable hole, (4) …… Core fixing chuck, (4a) …… Core holding part, (4b) …… Ball seat, (4c) …… Rear end step, (5) ……
Ball, (6) …… Chuck spring, (7) …… Base, (8) ……
Spring body, (9) …… tip pipe, (10) …… holding chuck,
(11) …… Sensor, (α) …… Ball check, (A)…
… Core, (b) …… Space.

Claims (1)

[Scope of utility model registration request] 1. A writing case for a platter, comprising a ball chuck inside a shaft cylinder fixed to a head, and a holding chuck movably in the axial direction provided below the ball chuck. When the core fixing chuck of the ball chuck is at the upper position continuous with the inner surface of the taper, the distance is smaller than the distance between the outer surfaces of both balls in the core holding portion when the core fixing chuck is in the core holding state, and the core fixing chuck is not in the core holding state. In addition to providing a moving hole for the fixed core chuck having an inner diameter larger than the distance between the outer surfaces of both balls in the core holding part, the core holding part of the fixed core chuck moves to the shaft cylinder slightly above the upper end of the ball chuck. A writing instrument for a plotter, which is provided with a sensor for detecting a displacement of an upper end of a fixed core chuck caused by being immersed in the hole.