JPH05131794A - Extension pencil for automatic plotter - Google Patents

Abstract

PURPOSE:To provide extension pencil whose lead is extended automatically by making holding force of a chuck unworkable on the lead at extending the lead. CONSTITUTION:A slide ring 23 is fixed to an end part of a lead receiving side of a lead holding tool 16 in an extension pencil. A rear part of a lead holder 12 is extended and an inner periphery of a tip 12a of an extension 12a of the holder 12 is contacted to the peripheral face of the slide ring 23. The friction force of the slide ring 23 and the extension 12a of the lead holder is larger than a thrust of a chuck closing spring 19 of a piece of chuck 18 of the lead holding tool 16. A thrust of a lead holder press-down spring is made to be larger, or a lead holding force of a lead holding piece 15 to be provided at the lead holder 12 is made to be larger than the thrust of the chuck closing spring 19. Thus, the lead is pulled out after the chuck is opened, so that the lead holding at the chuck does not slip, thereby 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 used in an automatic drawing machine, and relates to a drawing pencil used in an automatic drawing machine having a structure that does not cause core peeling in a core drawing mechanism section. Regarding

[0002]

2. Description of the Related Art In a drawing pencil used in a conventional automatic drawing machine such as an XY plotter, the lead is generally held by a chuck built inside the pen shaft and a lead holding rubber in the tip of the pen. Is configured. When the lead-out pencil is raised, the lead-holding piece is pulled down by the force of the spring incorporated inside when the lead-up pencil is raised. At this time, the lead is held by the friction force of the lead-holding rubber. It is supposed to be sent out with. As an example, the actual exploitation Sho 61-40294
There is one disclosed in the publication, or one shown in FIG.

FIG. 5 shows a well-known collet chuck composed of a chuck outer cylinder 2 provided on the inner shaft center of a hollow pen shaft body 1 and a chuck piece 3 movable inside thereof. The lead-out pencil includes a lead holder 4 and a lead holder 6 which is axially movable at a tip end of an inner cylinder 5 coaxially attached to the end of the pen shaft 1. In this pay-out pencil, a pencil lead 30 (hereinafter simply referred to as a lead) is passed through a through hole 7 provided at the center of the upper portion of the pen shaft 1 so that a lead holding rubber piece 8 provided at an inner leading end of the lead holder 6 serves to remove the tip. It is held and inserted so as to slightly project from the tip of the lead holder 6. In the figure, reference numeral 9,
9'and 9 "are both coil springs. 4a is a core gripping part of the collet chuck type core holder 4.

[0004] Further, some of the feeding pencils used in conventional automatic drawing machines such as XY plotters have a lead tank containing a plurality of spare lead cores. For example, if the lead is worn out during drawing and the upper end of the lead comes off the chuck when drawing is not possible, making it impossible to draw. The core is configured to be discharged. As a procedure of supplying and discharging the spare lead, first, when the lead is consumed and drawing cannot be performed, the pen carriage automatically moves to a predetermined position (lead discharging position). Next, the chuck is opened by the knock mechanism, and the spare lead is put into the chuck.
At this time, the lower end surface of the spare core is in contact with the upper end surface of the core which has been consumed and shortened. Then, the pencil is lowered until it comes into contact with a stopper provided at a predetermined position, and the lead is discharged.

[0005]

In all of the above-mentioned conventional drawing pencils for automatic drawing machines, when the lead is drawn out, the lead 30 remains in the state of being held in the lead gripping portion 4a of the chuck. Since there is, the core 30 and the core gripping part 4a of the chuck
There is a slip between and. Since the core gripping portion 4a of the chuck is normally formed with screw thread-shaped irregularities, the surface of the core 30 is scraped by the projections and depressions, and the shavings cause the scraping powder to fall into the core gripping portion 4a.
Are accumulated in the concave portions of the core 30, and the grip of the core 30 is weakened, and the core gripping portion 4a of the chuck cannot hold the core 30. Therefore, durability is reduced.

Further, in the conventional drawing pencil for the automatic drawing machine as described above, it is necessary to move to a predetermined position for feeding and discharging the lead as described above, and further the vertical movement by the knock mechanism is also performed. Since it is necessary, the time loss is extremely large. Furthermore, the discharged core has no utility value and is wasted.

In the present invention, in order to solve such a problem, the gripping 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. An object is to provide a feeding pencil used in an automatic drawing machine.

[0008]

SUMMARY OF THE INVENTION In order to achieve such an object, the present invention relates to a drawing pencil used in an automatic drawing machine, and a slide ring for facilitating lead reception at a lead receiving side end of a lead gripping tool. The core holder is divided into a plurality of rear portions from the protruding locking portion and extended so as to surround the outer circumference of the slide ring, and the rear end of the core holder is externally arranged so as to generate an appropriate contact pressure with the peripheral surface of the slide ring. The thrust force B of the push-down spring of the lead holder and the frictional force C between the slide ring peripheral surface and the extension portion of the lead holder are configured so that the force relationship is C <B. It is a feature.

[0009]

Since the feeding pencil of the present invention has such a structure, when the lead is fed, the chuck piece is pulled down through the slide ring by the pushing-down spring thrust of the lead holder. The chuck opens and only the lead is pulled out as it is. Therefore, since the core is pulled out after the chuck is opened, the chuck does not pull the core in a gripped state, and no core powder is generated at this portion, so that the core does not slip.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a feeding pencil used in an automatic drawing machine of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged cross-sectional view of the feeding pencil of the present invention. 2 is a sectional view taken along the line II-II of FIG. FIG. 3 is a diagram showing an aspect in drawing.

In these figures, a lead holder 12 is slidably arranged in an inner cylinder 11 coaxially fixed to the pen shaft body 10 inside the pen shaft body 10 of the feeding pencil. A core holding piece 15 formed of a rubber material is fitted to the tip of the holder 12. This core holding piece 15 has a core 30
The diameter of the core 30 is slightly smaller than the diameter of the core, and the core 30 to be inserted is frictionally held at a position before the feeding hole 13 provided in the core holder 12. In this lead holder 12, a downward step 12 'is supported by an upward step 11' of the inner cylinder 11 so that the maximum pressing position is regulated, and the tubular upper half is As shown in FIG. 2, it is divided into a plurality of parts and extended. In addition, the above core holder
The 12 extended portions 12a are cut out so as to intersect with the attachment slit portions 16a of the lead holder 16 which is kept in a fixed state coaxially with the inner cylinder 11.

The core holder 16 is a chuck having a sheath cylinder 17 which is kept substantially fixed to the inner cylinder 11, and a core insertion hole vertically movably inserted coaxially inside the sheath cylinder 17. A chuck closing operation spring for operating the piece 18 and the chuck 18a provided at the tip of the chuck piece 18 in the closing direction.
19 and a receiving piece 20 for the chuck closing operation spring 19. The inner circumference of the tip portion of the sheath cylinder 17 of the lead holder 16 is formed into a tapered surface 17 ', and balls 18b, 18 intervening in a concave curved surface portion formed on the outer circumference of the tip portion of the chuck piece 18 are provided.
When b is brought into contact with tapered surface 17 'and chuck piece 18 is pulled up, chuck 18a is closed,
The chuck closing operation spring is provided between the step portion 17 ″ formed in the middle of the inner circumference in the upper half inner space of the 17 and the outer step portion 20 ′ of the receiving piece 20.
19 are intervening. It should be noted that the chuck piece 18 has a well-known structure in which the base end portion and below are divided, and the base end portion is the receiving piece 20.
It is fitted and connected with.

Further, at the upper end of the chuck portion piece 18 of the lead holder 16, a lead receiving portion having a shape such that a succeeding lead is easily introduced into the insertion hole 23 "of the lead 30 through the receiving piece 20. A slide ring 23 having 23 'is fixedly connected, and a rear end portion (upper end portion) 12a' of the extended portion 12a of the lead holder 12 is divided by a spring ring 22 into the slide ring 23. Is pressed from the periphery so that a required frictional force C is generated on the outer peripheral surface of the core ring 12. The frictional force C between the outer peripheral surface of the slide ring 23 and the divided extension portion 12a of the core holder 12.
The sliding resistance due to is the thrust A of the chuck closing operation spring 19.
It is related to become larger. Reference numeral 10a in the drawing is an auxiliary pen shaft body.

Further, a wick holder pressing spring 26 is arranged between the inner end surface of the tip portion of the wick holder 12 and the lower end of the stopper piece 25 fitted to the tip of the sheath cylinder 17 of the wick holder 16, and The thrust B of the holder pressing spring 26 is the slide ring.
It is related so as to be larger than the frictional force C between 23 and the extension 12a of the lead holder.

The drawing pencil of the present invention thus constructed is slightly projected from the drawing hole 13 of the lead holder 12 when the pen shaft body 10 is lowered for drawing, as shown in FIG. The drawing paper 41 on the drawing board 40 is drawn by the core 30 that is installed. When the pen shaft body 10 is lifted by drawing (drawing) a predetermined distance, the lead holder 12 pushed up in the drawing state is pushed down by the lead holder pressing spring 26, and at this time, the lead 30 is automatically fed out.

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 and 2, and structural parts not directly involved in the operation are omitted. Further, the sheath cylinder 17 and the pen shaft body 10 are shown integrally connected. First, FIG. 4 (a) shows a mode at the time of pen-up, in which the lead holder 12 is moved by the lead holder pressing spring 26.
It is projected from the tip of 10.

Next, when pen down is started for drawing, as shown in FIG. 4 (b), the lead holder 12 first comes into contact with a stopper 35 attached to a pen carriage (not shown). In this state, the chuck 18a of the lead holder 16 is
Part is not in a state of positively gripping the core 30 (chuck 18
a is loose. ). As the pen down progresses,
As the pen shaft body 10 descends, the lead holder 12 is pushed into the pen shaft body 10. Then, the slide ring 23 pressed from the surroundings by the spring ring 22 through the rear end portion 12a 'of the core holder 12 causes friction between the slide ring 23 and the rear end portion 12a' of the extension portion 12a of the core holder by the spring ring 22. The chuck piece 18 of the lead holder 16 is pulled up by force.

As a result, the ball 18b interposed in the concave curved surface portion of the tip of the chuck piece 18 acts as a wedge between the tapered surface 17 'of the sheath cylinder 17 and the concave curved surface portion to close the chuck 18a portion. ,
The core 30 is gripped by the chuck 18a portion. Therefore, since the chuck piece 18 is fixed to the sheath cylinder 17, the core holder 12 is pushed up by overcoming the frictional force between the rear end 12a 'of the extension 12a of the core holder and the slide ring 23. As a result, the core holding piece at the tip of the core holder 12
The core 30 whose tip is held by 15 is pushed out from the feeding hole 13 at the tip of the core holder 12 by the distance the core holder 12 is pushed up from the time when it is gripped and fixed by the chuck 18a, and at the same time the core 30 is drawn. The paper 41 comes into contact with the paper 41 and is in a drawing state (see FIG. 4C).

During the subsequent drawing, the core gripping by the chuck 18a part via the extension part 12a of the core holder 12 and the slide ring 23 is maintained by the pressure applied from the pen holder side (not shown) to the pen shaft body 10, and the required brush is drawn. Pressure is applied to the lead 30, the lead holder 16 is lowered through the pen shaft body 10 by the amount of wear of the lead 30, the lead 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. 4 (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. 4 (a). At this time, the lead holder 12 pushed up to the state shown in FIG. When it is moved downward by the thrust of 26, the core 30 frictionally held in the hole of the core holding piece 15
And the tip of the slide ring 23 and the extension 12a of the lead holder 12a '
The chucking piece 18 is pulled downward by the frictional force C of the. Then, the chuck 18a located under the chuck piece 18 is moved to the ball 18b by the tapered surface 17 'of the sheath cylinder 17.
The closed state is released via, in other words chuck 18
a opens. As it is, the chuck piece 18 moves downward,
When the end of the chuck portion piece 18 comes into contact with the inner end surface 25 ′ of the stopper piece 25 fixed to the lower end portion of the sheath cylinder 17 and stops, thereafter, the outwardly facing step portion 12 ′ of the lead holder 12 of the inner cylinder 11 is stopped. Only the core 30 is pulled out until it comes into contact with the step 11 'and stops.

Therefore, the core receiving portion 23 ′ of the slide ring 23
If a preliminary core is inserted in the core, if the core 30 to be fed out becomes shorter, the spare core will be inserted from the core receiving portion 23 'through the insertion hole of the core, and the core will be connected and fed out as it is. You can draw without any operation.

In the present invention, the slide ring 23 can be formed integrally with the receiving piece 20. Also,
Even if the chuck closing operation spring 19 is omitted as necessary, the same effect as described above can be obtained. Furthermore, the spring ring 22 can be omitted if the tip portion 12a 'of the extension portion 12a of the core holder 12 is formed so as to be kept in close contact with the outer peripheral surface of the slide ring 23.

[0023]

As described above, according to the present invention, when the lead is unrolled, the chuck is opened and then the lead is pulled out. Therefore, slippage at the lead gripping portion of the chuck, which is a conventional problem, is eliminated, and the lead is removed. Since no dust 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. Moreover,
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 feeding pencil of the present invention.

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

FIG. 3 is a diagram showing an aspect in drawing.

FIG. 4 is a schematic diagram 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.

FIG. 5 is an enlarged sectional view showing an example of a conventional drawing pencil.

[Explanation of symbols]

10 Pen Shaft 11 Inner Cylinder 11 ', 12', 17 "Stepped Part 12 Core Holder 12a Core Holder Extension 13 Feeding Hole 15 Core Holding Piece 16 Core Holding 16a Attachment Split Part 17 Sheath Cylinder 17 'Tapered Surface 18 Chuck part piece 18a Chuck 18b Ball 19 Chuck closing operation spring 20 Receiving piece 22 Spring ring 23 Slide ring 23 'Core receiving part 25 Stopping piece 26 Core holder pressing spring 30 Core 35 Stopper 40 Drawing plate 41 Drawing paper A Chuck closing operation spring Thrust B Thrust force of push-down spring of core holder C Friction force between slide ring peripheral surface and extension of core holder D Core holding force of core holding piece in core holder

Claims (4)

[Claims] 1. In a feeding pencil used in an automatic drawing machine, a slide ring for facilitating lead reception is provided at a lead receiving side end of a lead gripping tool, and a lead holder is divided into a plurality of rear portions from its projecting locking portion. Is extended so as to surround the outer circumference of the slide ring, and the rear end of the slide ring is externally fitted to the slide ring peripheral surface so as to generate an appropriate contact pressure. A drawing pencil used in an automatic drawing machine, characterized in that a force relationship between a surface and a frictional force C between the extension of the lead holder is C <B. 2. In a feeding pencil used in an automatic drawing machine, a slide ring for facilitating lead reception is provided at a lead receiving side end of a lead gripping tool, and a lead holder is divided into a plurality of rear portions from a projecting locking portion thereof. Is extended so as to surround the outer circumference of the slide ring, and the rear end of the slide ring is externally fitted to the slide ring peripheral surface so as to generate an appropriate contact pressure. The relationship between the thrust B of the push-down spring of the lead holder, the frictional force C between the slide ring peripheral surface and the extension of the lead holder, and the lead holding force D of the lead holding piece provided in the tip of the lead holder is as follows. A pay-out pencil used in an automatic drawing machine, characterized in that A <C <B and A <D. 3. The frictional force due to the contact between the peripheral surface of the slide ring and the extension of the lead holder is obtained by pinching the tip of the extension of the lead holder with a spring ring. A feeding pencil used in the automatic drawing machine according to Item 1 or 2. 4. The frictional force due to the contact between the slide ring peripheral surface and the extension of the core holder is configured to be brought into close contact with the slide ring peripheral surface by molding the tip of the extension of the core holder. A feeding pencil used in the automatic drawing machine according to claim 1.