JPH0341078B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a so-called sharp pencil type writing instrument in which a pencil lead is drawn out from the tip to write, and is particularly applicable to writing heads of automatic drafting machines, X-Y plotters, etc. The present invention relates to a writing instrument suitable for use in.

[Background technology and its problems]

A so-called sharp pencil type writing instrument that uses a pencil lead generally uses a lead chuck for gripping the lead. Because this lead chuck directly grips the lead of the pencil, it is easy for slippage to occur between the lead surface and the collection of the chuck, and the lead may slip when the writing instrument is strongly pressed against a writing surface such as paper. It may get pushed inside the writing instrument. Also, if the length of the lead becomes shorter than the distance between the tip of the writing instrument (the tip from which the lead protrudes) and the gripping position of the lead chuck,
It is no longer possible to hold the lead, and such a shortened lead cannot be used and is uneconomical.In addition, the amount of writing that can be written with one lead is small, and the frequency of replacement of the lead increases.

These drawbacks pose a serious problem particularly when the sharp pencil type writing instrument is used in an automatic writing device such as an automatic drafting machine or an X-Y plotter. In other words, in the above-mentioned automatic writing device, the pen is moved up and down using a solenoid plunger, etc., and when the impact force or pressing force on the pen tip (tip of the lead) is large during this down movement, or when writing In order to increase the speed, when the speed of up/down of the pen is increased or the number of times of up/down per unit time is increased, the lead is pushed in, and so-called lead sinking tends to occur. In addition, if the length of the lead remaining between the lead chuck and the tip of the writing instrument (so-called remaining lead amount) is long, maintenance will become more complicated as the frequency of lead replacement will increase when using a new lead of the same length. In particular, when using a plurality of writing instruments with different lead diameters and lead hardnesses, replacing the lead is troublesome.

In this case, it may be possible to use a longer core, but generally, commercially available cores of a certain length (for example, 6 mm) are available in a variety of core diameters and core hardnesses, and are easy to obtain. It is preferable to use such a core of a certain standard with as little remaining core as possible.

[Purpose of the invention]

In view of the above-mentioned circumstances, the present invention has a strong gripping force for the lead etc. by the lead check, can prevent the lead from sinking in, etc., and has a small amount of lead remaining when writing becomes impossible, making it economical and requiring frequent lead replacement. The purpose is to provide a writing instrument that requires less.

[Means to accomplish the task]

In order to achieve the above object, the present invention includes a support arm that is provided on a drawing head main body that is movable on a drawing surface and that is driven up and down with respect to the drawing head main body, and a support arm that is supported by the support arm and that is supported by the support arm. An outer cylindrical body that causes the tip of the pencil lead to land on the writing surface by the downward movement of the arm, and lifts and separates the tip of the pencil lead from the writing surface by the upward movement of the arm, and is slidably supported by the lower part of the outer cylindrical body. a writing instrument casing, a pressure spring interposed between the outer cylinder and the writing instrument casing and biasing the writing instrument casing in the direction of the writing screen, and slidably supported at a lower part of the writing instrument casing. a first rubber ring provided at the tip of the lead guide cylinder, into which a pencil lead is inserted and which holds the pencil lead by frictional force; A tailstock that comes into contact with the end of the core is provided integrally or separately at the top of the core guide cylinder, moves integrally with the core guide cylinder, and when the tailstock is inserted, the frictional force is reduced. A second rubber ring that holds the core is fixedly supported at the upper part of the writing instrument housing, and has a strong holding force when an upward force is applied to the core that is inserted. When a downward force is applied, the core chuck is held with a weak holding force, and each time it reciprocates in the axial direction, the core chuck lets out the above-mentioned core pusher, and the lead guide cylinder moves in the direction of the writing surface. It is characterized by being provided with a return spring that applies a return force of , and a lead guide stopper that regulates the height position of the lead guide cylinder from the writing surface.

[Effect]

In the present invention, the writing instrument is lowered by the support arm,
When the tip of the lead touches the drawing paper surface, an upward force is applied to the lead chuck via the pencil lead and the tipping rod, so the lead chuck firmly grips the tipping rod, and the writing pressure from the writing pressure spring is increased. Added to pencil lead.
On the other hand, when the writing instrument rises, the return spring applies a downward force to the lead chuck via the lead guide cylinder, the second rubber ring, and the core pusher rod, so the holding force of the lead chuck on the core pusher weakens, and the lead guide The cylinder, the first rubber ring, the second rubber ring, the pencil lead, and the tailstock are fed out in the direction of the paper surface as a unit, and the corestock is pulled out from the lead chuck.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described.
This will be explained with reference to the drawings.

FIG. 1 shows a sectional view of a writing implement used in an automatic writing device such as an automatic drafting machine or an X-Y plotter, as a first embodiment of the present invention.

In FIG. 1, a writing instrument housing 1 having a substantially cylindrical outer shape is slidably supported by an outer cylinder 3 via a spring 2 for applying writing pressure. This outer cylinder body 3
is held by a support arm, etc. of the automatic writing device, and is moved up and down (so-called pen-up,
down drive). Here, the above support arm is
It is provided on the main body of the drawing head that can move on the drawing surface, and is driven up and down with respect to the main body of the drawing head.The outer cylinder 3 is supported by the support arm, and the tip of the core is moved by the downward movement of the support arm. While landing on the writing surface, the tip of the lead is lifted up and separated from the writing surface by the upward movement.

The writing instrument housing 1 is connected to the lower cylinder body 1 by a threaded portion 11.
2 and an upper cylinder 13, a core guide cylinder 4 is supported in the lower cylinder 12 so as to be slidable in the axial direction, and a rubber holding tube 5 is supported in the upper cylinder 13.
is slidably supported, a lead chuck portion 6 is fixedly supported, and a return force is applied to the rubber holding tube body 5 by a spring 7 in the direction of the writing end (downward in the figure). When the lower cylinder body 12 and the upper cylinder body 13 are connected by the threaded part 11, the lower end surface of the rubber holding tube body 5 comes into contact with the upper end surface of the core guide cylinder body 4, and the spring 7 A downward return force is applied to the core guide cylinder 4 via the rubber holding tube 5.

A pencil lead 10 is placed near the tip of the lead guide cylinder 4.
A first rubber ring 8 through which the
A second rubber ring 9 is provided through which the rubber ring 9 is inserted. The core push rod 20 is made of metal, for example, and has a strong holding force by the core chuck portion 6.
The above-mentioned core sinking phenomenon can be prevented. The diameter of this core push rod 20 may be equal to the diameter of the core 10, but it may also be made different; for example, the diameter of the core 10 may be
0.3 mm, and the diameter of the tailstock 20 can also be 0.5 mm.

The reason why the writing instrument housing 1 can be separated into the lower cylinder 12 and the upper cylinder 13 by the threaded part 11 is as follows.
This is to make it easier to guide and insert the pencil lead 10 into the lower cylindrical body 12. These cylindrical bodies 12 and 13 are integrated, and the lead 10 is inserted through the opening at the upper end of the writing instrument housing 1.
Of course, the core push rods 20 may be inserted in this order.

Here, the outer cylinder 3 of such a writing instrument is gripped and fixed by a gripping member 16 of a support arm of the automatic writing device, and this support arm is a conventional X-Y plotter. It may be similar to the support arm of a writing head or drawing head of an automatic drafting machine, etc., and a pen up/down drive mechanism such as a solenoid plunger is attached to a movable base that is controlled to move in the X-Y direction on the writing surface. It is provided through the Further, a lead guide stopper 17 attached to the movable base or the like comes into contact with the flange 4a formed near the tip of the lead guide cylinder 4, and the height position from the writing surface G of the lead guide cylinder 4 is to regulate. Further, a lead wear detection plate 18 is in contact with a flange 12a provided on, for example, the lower cylinder 12 of the writing instrument housing 1, and the amount of movement of this detection plate 18 in the axial direction (vertical direction in the figure) is detected. The amount of wear on the core is detected.

Next, the core chuck portion 6 is for gripping the core push rod 20, and may have the same internal structure as a general core chuck, for example, as shown in FIG. 2. In FIG. 2, the core chuck portion 6 has a collet member 22 in a roughly cylindrical chuck holder 21 with a slightly swollen lower end and a longitudinal groove.
The collet member 22 is urged upward in the figure by a coil spring 23, and the diameter of the bulging portion of the collet member 22 is reduced by a ring 24 fitted into the lower end, so that the core etc. I'm holding it. Regarding the lead gripping action of the lead chuck part 6, when an upward force is applied to the lead etc., a strong holding force is exerted, but when the lead etc. is pulled downward, the holding force is weak and the lead etc. easily pulled downwards.

Here, the core chuck part 6 grips the core pusher 20, and the core feed-out operation (core pusher) is performed when this core pusher 20 is inserted into the second rubber ring 9 in the rubber holding tube 5. The feeding operation of the rod will be explained with reference to FIG. At this time,
When the core chuck portion 6 and the tube body 5 move relative to each other so as to approach each other, for example, when the core chuck portion 6 moves downward in the figure (or the tube body 5 moves upward in the figure), the core push rod 20 has a second rubber ring 9
Since an upward force in the figure is applied due to the sliding friction force, the core rod 20 is firmly held by the core chuck portion 6 and slides downward in the figure within the tube body 5.
On the other hand, when the core chuck part 6 and the tube body 5 move relative to each other so as to be separated from each other, for example, when the core chuck part 6 moves upward in the figure (or the tube body 5 moves downward in the figure), Second rubber ring 9
The holding force by the core chuck portion 6 is smaller than the holding force of the core chuck 20 due to the frictional force of Move to.

In this manner, each time the core chuck portion 6 reciprocates in the axial direction (vertical direction in the figure) with respect to the rubber holding tube 5, the core pusher rod 20 is drawn out from the core chuck portion 6 downward in the figure.

By the way, FIG. 1 shows the pen down state when the amount of feeding out of the lead 10 is a constant value (initial setting value). At this time, the flange 4a near the tip of the lead guide cylinder 4 is supported by the lead guide stopper 17, so that the pencil lead 10 protrudes by the distance P between the tip of the lead guide cylinder 4 and the writing surface G. It turns out. The outer cylindrical body 3 is held at a certain height position from the writing surface G by the gripping member 16 of the support arm described above, for example, at a position where the lower end of the outer cylindrical body 3 is at a height Q. A pressing force is applied to the writing instrument housing 1 through the pen. This pressing force is
It is applied to the lead pusher 20 via the lead chuck part 6, and the lower end of this lead pusher 20 presses the upper end of the pencil lead 10, so the lower end of the lead 10 presses the paper etc. on the writing surface G, causing the so-called Pen pressure can be obtained. At this time, the height R of the upper end surface of the flange 12a of the writing instrument housing 1 is detected by the detection plate 18, and by detecting this height R, the lower end of the lead chuck 6 is substantially detected. The distance S from to the writing surface G is detected. Further, the distance between the lower end of the core chuck portion 6 and the second rubber ring 9 of the rubber holding tube 5 is, for example, D.

When the writing operation is performed and the lead 10 wears out, the writing instrument housing 1, the lead chuck part 6, the lead pusher 20, and the lead 10 are sent downward in the figure by the amount t of lead wear. This is because the pressure spring 2 presses the writing instrument casing 1 downward in the figure against the outer cylinder 3, and eventually the flange of the casing 1 as shown in FIG. The above-mentioned downward feeding operation can be performed until the lower end surface of the portion 12a comes into contact with the upper end surface of the outer cylindrical body 3 and is locked. In this state shown in Figure 3,
The distance between the lower end of the lead chuck part 6 and the second rubber ring 9 changes to D-t, which means that the core pusher 20 firmly held by the lead chuck part 6 moves into the first position during the above-mentioned writing operation. This is because the core fell down by the amount of wear t while sliding inside the rubber ring 9 of No. 2. Then, in the state shown in FIG. 3 or before reaching this state, the detection plate 18 detects the amount of core wear t at a predetermined value (for example, 0.5 to 1.00).
It detects that the writing operation has reached 3 mm), interrupts the writing operation, and forces the pen-up operation. This pen-up operation is an operation for pulling out the lead (tail push rod 20) from the lead chuck portion 6.

Figure 4 shows the pen up state, with a lead of 10
Since the tip of the rubber ring 9 floats away from the writing surface G, the rubber holding tube 5 is pressed downward in the figure against the lead chuck part 6 by the action of the return spring 7, and the distance between the rubber ring 9 and the lower end of the lead chuck part 6 decreases. becomes D. That is, when transitioning from the pen-down state shown in FIG. 3 to the pen-up state shown in FIG. Minute t tailstock 2
0 is pulled out from the core chuck portion 6.

According to the embodiment of the present invention as described above, the lead pusher 20 made of a metal rod or the like is held by the lead chuck part 6, and the pencil lead 10 is pressed by this lead pusher 20, so that the lead holding force is reduced. (Holding force of the core pusher 20) is extremely strong, and even if the tip of the core is strongly pressed against the writing surface G, the core will not be pushed in, allowing not only trouble-free writing but also protection of the core. be able to. Also, use the core push rod 20 to
Since the core is fed, the amount of remaining core can be extremely reduced. These are particularly preferable when applied to automatic writing devices, as they allow smooth writing without the lead digging in even when writing speeds up, and the lead replacement cycle can be extended, making it easier to replace the lead during use. less. For example, in the case of an automatic writing device that automatically exchanges multiple writing instruments with different lead diameters and lead hardnesses, this is extremely advantageous in terms of handling because it can reduce the frequency of replacing the lead of each writing instrument. .

Further, according to the above-described embodiment of the present invention, the feeding operation of the lead 10 is automatically performed in accordance with the landing and floating movements of the lead tip of the writing instrument, so-called pen-down and pen-up movements, so that the tip of the lead is placed on the writing surface.
The forcible feeding operation of the lead 10 is not performed unless the amount of lead wear t when drawing with a single stroke while in pressure contact with the lead 10 exceeds the above-mentioned certain value (for example, about 0.5 to 1 mm). In addition, if the lead wear amount when drawing with one stroke exceeds the above-mentioned certain value, the writing surface G of the writing instrument housing 1
A change in the height position from 1 is detected by a position detecting means, such as a photo interrupter, provided in connection with the detection plate 18, and in response to this detection output, the writing operation is temporarily stopped and a solenoid plunger or the like is activated. By moving the writing instrument up and down by suction driving, the lead 10 is forcibly drawn out. After this lead feeding operation is completed, the temporarily stopped writing operation may be continued. In this case, it should be noted that the detection of lead wear is carried out regularly during the writing operation, and there is no need to interrupt the writing action just to detect this lead wear. Therefore, by driving the writing instrument in the vertical direction using a single solenoid plunger for pen up and down, the tip of the lead 10 for writing lands on the writing surface G, floats, and draws out the lead 10. and are done at the same time,
There is no need to independently provide drive means such as plungers, and the configuration is simplified. In addition, since the wear condition of the lead 10 is detected by the amount of height position movement of the writing instrument housing 1, the amount of lead wear can be checked with a simple structure, and the amount of displacement of the writing instrument housing 1 can be continuously detected even during writing operation. Therefore, there is no need to interrupt the writing operation just to check for lead wear.

Furthermore, when the writing instrument housing 1 reaches a lowered position relative to the outer barrel 3 (for example, see FIG. 3) even if the pen is down at the start of a writing operation, the detection plate 18 detects lead wear. , the pen up and down operations may be repeated several times to perform the lead feeding operation, and when a predetermined amount of lead feeding is reached, the writing operation may be performed. In this case, even if the pen up and down operations are performed a predetermined number of times (for example, about 5 to 6 times), if the predetermined amount of lead feeding is not reached, an alarm may be issued to request replacement of the lead. .

Next, FIG. 5 shows a second embodiment of the present invention, in which a core push rod 20 is inserted near the upper end of the core guide cylinder 4' without using the rubber holding tube 5 of the first embodiment. A second rubber ring 9 is provided. The return spring 7' is adapted to directly press the core guide cylinder 4'. Other configurations are as above
Since this embodiment is the same as the embodiment shown in FIG. The operation and effects of this second embodiment are also similar to those of the first embodiment.

〔Effect of the invention〕

According to the writing head drawing device according to the present invention,
The lead chuck part does not directly hold the pencil lead,
Because it holds a tailstock made of metal,
It has strong holding power and can protect the core. In addition, since the core is fed out with a core pushing rod, the amount of remaining core can be extremely reduced, making it economical, and the frequency of core replacement is low, making it convenient to use. Particularly, when used in an automatic writing device, smooth writing operation can be guaranteed even when the writing speed is increased, and maintenance such as lead replacement is simplified.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a first embodiment of the present invention, FIG. 4 is a schematic cross-sectional view showing the embodiment shown in FIG. 1 in different operating states, and FIG. 5 is a schematic cross-sectional view showing a second embodiment of the present invention. 1... Writing instrument housing, 2... Pressure spring, 3... Outer cylinder, 4, 4'... Lead guide cylinder, 5... Rubber holding tube, 6... Lead chuck part, 7, 7 '...Return spring, 10...Pencil lead, 20...Tip stick.

Claims (1)

[Scope of Claims] 1. A support arm that is provided on a drawing head main body that is movable on a drawing surface and that is driven up and down with respect to the drawing head main body; an outer cylindrical body that allows the tip of the pencil lead to land on the writing surface and floats and separates the tip of the pencil lead from the drawing surface by an upward movement; a writing instrument housing that is slidably supported at a lower portion within the outer cylindrical body; a pressure spring interposed between the outer cylinder and the writing instrument casing and biasing the writing instrument casing in the direction of the writing screen; and a lead guide tube slidably supported at the lower part of the writing instrument casing. a first rubber ring provided at the distal end of the lead guide cylinder, into which a pencil lead is inserted and which holds the pencil lead by frictional force; and an end of the lead guided into the lead guide cylinder. A tailstock that comes into contact with the part, and a tailstock that is provided integrally or separately on the upper part of the core guide cylinder, moves integrally with the core guide cylinder, and the tailstock is inserted, and the tailstock is pushed by frictional force. A second rubber ring is fixedly supported at the upper part of the writing instrument housing, and when an upward force is applied to the corestock to be inserted, the corestock is gripped with a strong holding force, and the lower rubber ring is fixedly supported. When a force is applied, the core chuck is held with a weak holding force, and each time it reciprocates in the axial direction, the core chuck lets out the above-mentioned core pusher, and the lead guide cylinder applies a return force in the direction of the writing surface. A drawing device for a writing head, comprising a return spring and a lead guide stopper for regulating the height position of the lead guide cylinder from the writing surface.