JPH05201191A - Delivery pencil for automatic plotter - Google Patents

Abstract

PURPOSE:To obtain an automatically delivered pencil by bringing the state, in which the gripping force of a chuck does not work lead when lead is delivered. CONSTITUTION:In a delivery pencil for an automatic plotter having a collet type chuck mechanism 16 composed of a chuck external cylinder 17 mounted into a penholder cylinder 10 in a coaxial manner and a chuck 18 capable of being vertically moved in the chuck external cylinder, a lead holder 12 being held by the front end section of an internal cylinder 11 set up into the penholder cylinder 10 in the coaxial manner and capable of being shifted in the axial direction and a lead tank capable of storing a plurality of lead, the rear end section 12b of the lead holder 12 is engaged with an engaging section 20 installed to the chuck 18. Accordingly, lead is pulled out after the chuck is opened, thus preventing the sliding of lead gripping in a chuck section, then improving durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a drawing pencil for an automatic drawing machine and, more particularly, to a drawing pencil for an automatic drawing machine having a structure in which the core is not peeled off in the drawing mechanism of the core. ..

[0002]

2. Description of the Related Art Conventionally, a drawing pencil used in an automatic drawing machine such as an XY plotter is generally held at its core by a chuck built inside a pen shaft and a core holding rubber inside a pen tip. Is configured. Then, in order to automatically extend this lead during drawing, when the draw-out pencil rises, the force of the spring incorporated inside pulls down the lead holding part and moves the lead holder until it hits the stopper. A form is known in which the core holding rubber is sent out together with the core holder by the frictional force. An example thereof is that disclosed in Japanese Utility Model Laid-Open No. 61-40294.

[0003]

In the conventional drawing pencil for an automatic drawing machine as described above, when the lead is drawn out, the lead remains in the state of being held in the lead gripping portion of the chuck. A slip occurs between the chuck and the core gripping portion. Since the core gripping part of the chuck is usually formed with screw thread-shaped irregularities, the core surface is shaved by these irregularities, and this shavings accumulates in the recesses of the core gripping part, weakening the denting of the core. , The core gripping part of the chuck cannot hold the core. Therefore, durability is reduced.

Further, in the above-mentioned conventional drawing pencil for an automatic drawing machine, it is necessary to move to a predetermined position to feed and discharge the lead, and further, a vertical movement by a knock mechanism is required, resulting in time loss. Is significantly larger. Furthermore, the discharged core has no utility value and is wasted.

In order to solve such a problem, the present invention has a structure in which the chucking force of the chuck can be prevented from acting on the lead during the lead-out operation and the spare lead is continuously fed out. It is to provide a drawing pencil for an automatic drawing machine.

[0006]

In order to achieve such an object, the present invention comprises a chuck outer cylinder provided coaxially inside a pen shaft cylinder and a chuck movable up and down inside the outer cylinder. A collet-type chuck mechanism, a core holder that is held by the tip of an inner cylinder coaxially provided in the pen shaft cylinder and is movable in the axial direction, and a core tank that can store a plurality of cores. In the pay-out pencil for an automatic drawing machine, the rear part of the lead holder is configured to be engaged with a locking part provided on the chuck.

[0007]

In the drawing pencil for the automatic drawing machine of the present invention having such a structure, the lead gripping portion of the chuck is opened when the lead is drawn. Therefore, the pulling of the lead in the state of holding the lead by the chuck is eliminated, and since the core powder is not generated in the lead holding portion of the chuck, the lead is not slipped.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the drawing pencil for an automatic drawing machine according to the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged cross-sectional view of a specific example of a drawing pencil for an automatic drawing machine according to the present invention. 2 is a sectional view taken along the line II-II of FIG. Figure 3
FIG. 3 is a sectional view taken along the line III-III in FIG. FIG. 4 is a partial perspective view showing the relationship between the rear end portion of the extension portion of the lead holder and the locking portion provided on the chuck.

In these figures, a core holder 12 is slidably disposed inside an inner cylinder 11 fixed coaxially with the pen shaft cylinder 10 of the feeding pencil. A core holding piece 15 made of a rubber material is fitted to the tip of the core holder 12. The core holding piece 15 has a hole diameter slightly smaller than the diameter of the core 30, and the core 30 to be inserted is frictionally held at a position before the feeding hole 13 provided in the core holder 12. This core holder 12
The step portion 11 'of the inner cylinder 11 supports the outward step portion 12',
The maximum pressing position is regulated, and the cylindrical upper half part is divided into a plurality of parts as shown in FIG. 3 and extended. The divided extended portion 12a of the lead holder 12 is notched so as to intersect with the mounting slit portion 16a of the collet type chuck mechanism 16 which is kept slidable coaxially with the inner cylinder 11. It has been.

The collet type chuck mechanism 16 includes an inner cylinder.
11 is composed of a chuck outer cylinder 17 that is kept substantially fixed, and a chuck 18 having a core insertion hole 18 ′ that is vertically movably inserted coaxially inside the chuck outer cylinder 17. Has been done. The inner circumference of the tip of the outer chuck cylinder 17 of the chuck mechanism 16 is formed into a tapered surface 17 ', and the balls 18b, 18b interposed in the concave curved surface formed on the outer circumference of the tip of the chuck 18 come into contact with the tapered surface 17'. Let me chuck
The chuck 18 is constructed in a well-known structure in which the base end portion and below are divided so that the core gripping portion 18a of the chuck is closed when the chuck 18 is pushed up.

A plurality of extended portions of the lead holder 12
As shown in FIG. 4, a hook 21 is provided at the rear end (upper end) 12b of the 12a, and the hook 21 is engaged with the locking portion 20 provided at the rear of the chuck 18. This locking part 20
Is a plurality of protrusions protruding laterally in a notch 17a (see FIG. 2) formed by dividing the rear end portion (upper end portion) 17 "of the chuck outer cylinder 17 so as to be rotatable by a required angle. The chuck push-up spring 26 is formed between the step portion 17d inside the chuck outer cylinder 17 and the bottom surface of the base of the locking portion 20.
Is intervened. In the figure, reference numeral 17b is a chuck outer cylinder.
A locking portion for fitting and fixing 17 to the inner cylinder 11 and a spring receiving portion for a coil spring 25 for fixing the chuck outer cylinder 17 are shown at 17c. 22 is a lead receiving part, and a lead insertion hole at the bottom
A spiral core tip guide portion 23 is formed in 19 so that it can be introduced when the core 30 becomes shorter. 24 is a lead storage cylinder. 27 is a lead holder pressing spring.

The drawing pencil for an automatic drawing machine of the present invention thus constructed has a lead 30 slightly projected from the feed hole 13 of the lead holder 12 when the pen barrel 10 is lowered for drawing. Is printed on the drawing sheet on the drawing board. When the pen shaft cylinder 10 is lifted after drawing (drawing) a predetermined distance, the lead holder that was pushed up in the drawing state
12 is pushed down by the lead holder push-down spring 26, and the lead 30 is automatically paid out at this time.

Next, the manner in which the lead 30 is fed will be described with reference to the schematic view shown in FIG. These figures show only essential parts for clarity of the operation of the pay-out pencil of the present invention shown in FIGS. 1 to 4, and structural parts not directly involved in the operation are omitted. Also, the chuck outer cylinder 17
And the pen barrel 10 are shown as integrally connected. First, FIG. 5 (a) shows a mode at the time of pen-up, in which the lead holder 12 is projected from the tip of the pen barrel 10 by the lead holder pressing spring 27. In this state, the chuck 18 is pulled down by the hook 21 provided at the rear end portion 12b of the lead holder 12 via the engaging portion 20.

When pen down is started for drawing, the lead holder 12 is first brought into contact with a stopper 35 attached to a pen carriage (not shown) as shown in FIG. 5 (b). In this state, the chuck core gripping portion 18a of the chuck mechanism 16 is not in a state of positively gripping the core 30 (the chuck core gripping portion 18a is in a loose state). As the pen down progresses, the pen holder 12 is lowered to lower the lead holder 12.
Is pushed into the pen barrel 10. Then, the hook 21 located at the rear end 12b of the extension 12a of the lead holder 12 is disengaged from the locking portion 20, and the chuck push-up spring 26
By this, the locking portion 20 is pushed up, and the chuck 18 including the locking portion 20 is pulled up.

As a result, the ball 18b interposed in the concave curved surface portion of the tip of the chuck 18 becomes the tapered surface 1 of the chuck outer cylinder 17.
The chuck core gripping part 1 is wedged between the 7'and the concave curved surface part.
8a is closed and the core 30 is gripped by the chuck core gripping portion 18a. Therefore, the chuck 18 is
The lead 30 is fixed to the drawing holder 40, and the leading end is held by the lead holding piece 15 in the leading end of the lead holder 12, and the lead 30 is slightly projected from the feeding hole 13. It is ready to draw (see Fig. 5 (c)).

After that, in the drawing, the extension of the lead holder 12 is caused by the pressure applied to the pen barrel 10 from the side of the pen holder (not shown).
The engagement force between the rear end portion 12b of the 12a and the locking portion 20 is maintained, the core gripping by the chuck core gripping portion 18a is maintained, the required writing pressure is applied to the core 30, and the amount of wear of the core 30 is adjusted by the pen. The chuck mechanism 16 descends via the barrel 10, the core 30 is pushed out, and drawing is continuously performed. Therefore, the drawing line is not interrupted until the end of the drawing operation (see FIG. 5 (d)).

When the pen-up is completed after the drawing operation is completed in this way, the state returns to the state shown in FIG. 5 (a). At this time, the lead holder 12 pushed up to the state shown in FIG. It is pushed down by the thrust of 27. Along with this, the hook 21 of the rear end portion 12b of the lead holder 12 and the locking portion 20 attached to the chuck 18 are engaged with each other, and the push-up force applied to the chuck 18 is released.
Is lowered by the pulling down force of the hook 21 against the spring force for pushing up the chuck, and the core gripping portion 18a of the chuck 18 is tapered by the taper surface 17 'of the chuck outer cylinder 17 through the balls 18b, 18b.
The core gripping force by the wedge action of and is released and the core spreads.

At this time, the core 30 descends together with the chuck 18 and is automatically paid out. A core storage cylinder 24 is connected to the rear end (upper end) of the chuck 18 via a core receiving part 22, and the bottom of the core receiving part 22 is a spiral core tip guide part.
Since it is provided with 23, when the rear end of the lead 30 used for drawing moves below the lead tip guide portion 23, the following lead 30 is guided to the lead insertion hole 19 and the lead is automatically fed out. It can be done continuously.

Next, FIG. 6 is a schematic view of the operation mode of the automatic drawing machine drawing pencil of the present invention according to another embodiment. In this embodiment, the same parts as those in the previous embodiment are designated by the same reference numerals and detailed description thereof will be omitted. In this embodiment, the rear end portion 17 ″ of the chuck outer cylinder 17 is formed to have a length so as to stay on the front side (upper and lower sides in the drawing) of the locking portion 20, and the locking portion 20 forming base of the chuck 18 is If the chuck outer cylinder 17 is slidable on the inner periphery of the rear end portion 17 "of the chuck outer cylinder 17, the locking portion 20 can be formed into a flange shape without cuts. Then, the extension portion 12a of the lead holder 12 and the rear end 12b
A chuck pushing-up pressure adjusting spring is provided between the holding portion 20 and the locking portion 20, or, for example, a chuck pushing-up spring 28 is interposed in a part of the extension portion 12a of the lead holder 12.

In this way, as shown in FIG. 6 (a), the chuck 18 is lowered by its own weight before drawing, and the core gripping portion 18a of the chuck 18 is open. When the pen down is started, the lead holder 12 comes into contact with the stopper 35 of the pen carriage (not shown) and is pushed against the pen barrel 10 as shown in FIG. 6 (b).
28 is compressed and the chuck 18 is pulled up via the locking portion 20. As a result, the core gripping portion 18a of the chuck 18 is
The lead 30 is held by the lead holder 12 at the tip of the lead holder 12, and the lead 30 is slightly projected from the feeding hole 13 (see FIG. 1). It is ready for drawing (see Fig. 6 (c)). After that, the same effect as that of the above embodiment can be obtained by operating as shown in FIG. 6 (d) like the above embodiment.

[0021]

EFFECT OF THE INVENTION According to the drawing pencil for the automatic drawing machine of the present invention, when the lead is drawn out, the chuck is opened and then the lead is pulled out. Since no core powder is generated, the durability of the chuck is improved. Moreover, if the spare lead is put in the pen shaft, this lead can be continuously fed into the chuck, so that the time relating to the feeding / discharging lead is eliminated and the drawing time can be shortened. In addition, it is economical because the core can be used most effectively.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a specific example of a feeding pencil of the present invention.

FIG. 2 is a sectional plan view taken along the line II-II in FIG.

FIG. 3 is a sectional plan view taken along the line III-III in FIG.

FIG. 4 is a partial perspective view showing the relationship between the rear end portion of the extension portion of the lead holder and the locking portion provided on the chuck.

5A and 5B are schematic views showing an operation mode of a feeding pencil used in the automatic drawing machine of the present invention, in which (a) is a pen-up, (b) is a pen-down start, and (c) is a drawing. ,
(d) shows the time when the drawing is completed.

6A and 6B are schematic views showing the operation modes of another embodiment of the drawing pencil for an automatic drawing machine of the present invention, in which (a) is a pen-up, (b) is a pen-down start, and (c) is a drawing. In the drawing, (d) shows when the drawing is completed.

[Explanation of symbols]

 10 Pen Shaft Cylinder 11 Inner Cylinder 11 ', 12' Stepped Part 12 Core Holder 12a Core Holder Extension 12b Core Holder Extension End 13 End Feeding Hole 15 Core Holding Piece 16 Collet Type Chuck Mechanism 16a Mounting Cut Part 17 Chuck outer cylinder 17 'Tapered surface 18 Chuck 18a Chuck core gripping part 18b Ball 19 Core insertion hole 20 Locking part 21 Hook 22 Core receiving part 23 Core tip guide part 24 Core storage cylinder 26, 28 Chuck push-up spring 27 Core Holder push-down spring 30 Core 35 Stopper 40 Drawing board 41 Drawing paper

Claims (3)

[Claims] 1. A collet type chuck mechanism including a chuck outer cylinder provided coaxially inside the pen barrel and a chuck movable up and down inside the pen barrel, and coaxially provided inside the pen barrel. In a payout pencil for an automatic drawing machine, which is provided with a lead holder that is held by the tip of the inner cylinder and is movable in the axial direction, and a lead tank that can store a plurality of lead,
A feeding pencil for an automatic drawing machine, wherein the rear portion of the lead holder is configured to be engaged with a locking portion provided on the chuck. 2. The drawing pencil for an automatic drawing machine according to claim 1, wherein the locking portion is configured to be engaged with a hook formed at a rear end portion of the lead holder. 3. The engagement between the locking portion and the rear end portion of the lead holder is such that the chuck push-up spring is interposed at the rear end portion of the lead holder, and the locking portion and the lead are formed in a brim shape. The automatic drawing machine pencil according to claim 1, wherein the rear end of the holder is brought into contact with the drawing end pencil.