JPH0114459Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to a lead up-down mechanism in the drawing head of a drafting machine that supplies a consumable writing instrument lead, such as a graphite lead, to the paper surface in a lead holder. It is.

(Prior Art) The present applicant previously disclosed in Japanese Patent Application No. 54-44551 that a predetermined pressure is applied and a lead is moved forward while being held in a lead holder configured to hold a long lead. A lead chuck mechanism is provided that releases the holding of the lead when wear of the lead is detected, and when the lead chuck mechanism is released, the lead holder is moved against the pressing force while leaving the lead in the head body. We have proposed a drawing head for a drafting machine that is equipped with a lead feeding mechanism for raising the lead by a predetermined pitch and changing the clamping position of the lead by the chuck. In this drawing machine, the clutch device that clamps or releases the lead holder in the up-down mechanism that raises and lowers the lead holder toward the drawing stop state and the drawing state position is inside a member whose inner surface is formed into a tapered surface with an upward slope. A plurality of balls pressed by a spring are housed inside, and these are fitted around the outer periphery of the lead holder to form a clutch that can clamp the lead holder.

(Problem to be solved by the invention) The above is when supplying the core toward the paper surface.
That is, when the lead holder is released by the clutch, the ball is biased by the spring when it faces toward the tapered surface, and is not energized when it faces toward the lead holder, so that the ball does not have the effect of limiting the descent of the lead holder. This has the drawback that the lead drops rapidly and hits the cutting surface, causing the lead to break.

Therefore, the object of the present invention is to develop a lead up-down mechanism in the drawing head of a drafting machine that prevents the lead from breaking when feeding the lead toward the paper surface.

(Means for Solving the Problems) In order to achieve the above objects, the present invention provides a core up-down mechanism in the drawing head of a drafting machine having the following configuration.

That is, a lead holder with a lead chuck,
A lead pressing mechanism that applies a predetermined pressure to the lead in the lead holder, a lead feeding mechanism that changes the clamping position of the lead holder by the chuck, and a lead holder that raises and lowers the lead holder toward the drawing stop state and the drawing state position. In a device equipped with an up-down mechanism, the clutch device for clamping or freeing the lead holder in the up-down mechanism includes a plurality of balls pressed by a spring inside a member formed into a tapered surface with an upwardly inclined inner surface. The stopper surface of the member that restricts the descent of the ball in the clutch device is formed into a downwardly inclined surface facing toward the lead holder side. This is the core up-down mechanism at the drawing head of a drafting machine.

(Function) According to the present invention, in the clutch device for clamping or freeing the lead holder in the up-down mechanism, the stopper surface of the member that restricts the descent of the ball is formed into a diagonally downwardly inclined surface toward the lead holder side. Therefore, the ball comes into contact with the slide holder surface due to the pressing force of the spring, and the descending speed of the slide holder, that is, the lead holder, is limited. Therefore, when feeding the lead toward the paper surface, the lead holder gradually moves. The core will not be fed unless it descends and suddenly moves toward the paper surface.

(Example) The embodiments shown in the drawings will be described below.

The ones shown are a lead chuck mechanism A installed inside the lead holder, a lead pressure mechanism B that applies a predetermined pressure to the lead holder to apply core pressure, and a lead holding mechanism provided to hold the long lead at the upper end of the lead. Mechanism C, holding mechanism D for the lower end of the lead, lead up/down mechanism E for raising and lowering the lead for drawing, lead feeding mechanism F for changing the lead clamping device when the lead wears out, lead chuck release mechanism G, and lead breakage detection mechanism. Although it consists of H,
The present invention relates to an improvement of the lead up-down mechanism for raising and lowering the lead for drawing in the drawing head of the drawing machine as described above.

The proposed device includes at least a lead holder equipped with a lead chuck, a lead pressure mechanism that applies a predetermined pressure to the lead in the lead holder, a lead feeding mechanism for changing the clamping position by the lead holder chuck, and a lead holder. It is applied to devices equipped with an up-down mechanism that raises and lowers the device toward the drawing stop state and the drawing state.

Now, for convenience of explanation, the core chuck mechanism A will be explained first.

That is, the base 2 of the plotter head body 1
A slide holder 7 is fitted into the lead holder guide cylinder 3 erected therein so as to be able to move up and down, and the lead holder 4 is held in the slide holder 7 .

A lead chuck 5 for clamping the lead a is fitted in the center of the lead holder 4 in the axial direction as shown in FIG.

In FIG. 6, a core insertion hole 5a is provided at the center of the main body of the core chuck 5, and the outer peripheral surface of the lower end thereof is formed into a large diameter cylindrical part, and several holes extend in the axial direction from the lower end to the upper middle part of the main body. A slit is formed and a tightening collet 5b is constructed at the lower end.

The inner surface of the lead holder 4 corresponding to the collet 5b is formed into a tapered guide surface 4d that widens downward, and a recess 5c into which the ball 6 is fitted is provided in the center of the collet 5b.

A lifting spring 11 is interposed between the large-diameter portion 5d at the top of the main body of the lead chuck 5 and the upper step 4b of the lead holder 4, and holds the lead chuck 5.

A stopper 4c for the ball 6 is formed on the inner surface of the lower end of the lead holder 4.

The configuration for holding the lead holder 4 with the slide holder 7 described above is as follows.

That is, the third split 9 that tightens the lower end of the lead holder 4 is inserted from below the slide holder 7,
When this is inserted until it hits the collar 10 that abuts the link 7a fixed to the inner surface of the upper end of the slide holder 7, the third division 9 is narrowed to securely hold the lower end of the lead holder 4.
The upper part of the lead holder 4 is fixed to the ring 7a by pushing in the third part 9.

Next, a core pressing mechanism B that applies a predetermined pressure to the core holder to apply core pressure, and a core upper end holding mechanism C that is provided to hold a long core will be explained.

Reference numeral 13 denotes a core pressure spring receiver that stands upright from a holder 14 fixed at the position of the main body of the plotter head, the base of which is screwed through a connecting tube 13b, and the protective pipe 12 passing through the center.

This protective pipe 12 is press-fitted into a cap 13a which is screwed into the core pressure spring receiver 13, and the core pressure spring 15 wound around this is attached to the lower end of the cap 13a and the slide holder 7 described above.
The cylinder body 8 of the upper guide cylinder 8 moves up and down in unison with the
A is interposed between the upper end and the upper end with a washer interposed therebetween.

The cylindrical body 8a is housed in the inner space of the core pressure spring receiver 13, and is adapted to move up and down using this as a guide.

As described above, the core pressure spring 15 is supported by the holder 14 via the core pressure spring receiver 13, so the upper guide cylinder 8 is pressed by the core pressure spring 15, and a predetermined pressure is applied to the slide holder 7, so that the core pressure spring 15 is supported by the holder 14 via the core pressure spring receiver 13. Core pressure is applied to the core held by the chuck of the holder 4.

Since the protective pipe 12 is provided, the core is supported by this, and the longer the protective pipe is, the longer the core can be held.

The lower end of the protection pipe 12 has an engaging portion 12a. An internal vibrator 16 into which the end of the core is press-fitted is held by a chuck 17 that slides inside the protective pipe 12.

The lower end of the chuck 17 constitutes a vertically split pawl, and is tightened with a ring 17a fitted onto this pawl.

The lower end of the chuck 17 also constitutes a member for pressing a slider, which will be described later, and a cap 18 is screwed onto the upper end of the chuck 17.

The cap 18 engages with the above-mentioned engaging portion 12a, so that when the protective pipe 12 is pulled out from the cap 13a, the chuck 17 can be pulled out together with the protective pipe 12.

The inner pipe 16 held by the chuck 17 is inserted into the core chuck mechanism, thereby making the length of the remaining core as short as possible.

That is, when the inner pipe 16 of the chuck 17 is inserted into the core chuck and the detection mechanism described later is activated, the shorter the distance between the lower end of the inner pipe 16 and the core tip holder mounting tube 20 described later, the less core there is. .

Next, the holding mechanism D at the lower end of the core will be explained.
As described above, the lead holder guide tube 3 guides the slide holder 7 in its elevation and descent, and its lower end is fixed to the base 2. The spring receiver 19 is screwed into the lower end concave hole 3a of the lead holder guide cylinder 3, and the inner hole 19 of the spring receiver 19
The tip holder attachment tube 20 that slides inside a is received at the lower end of the spring receiver 19 by a protruding collar 19b.
The spring 21 in the inner hole 20b of the protruding collar 1
It is now accepted at 9b.

Also, a rubber gasket 23 is held in the saucer of the inverted bottle-shaped nib holder 22 provided at the center of the nib holder mounting tube 20, and the inner diameter of the center hole of the rubber gasket is slightly smaller than the outer diameter of the lead a. The upper end of the center hole of the rubber packing 23 is formed into a funnel shape to facilitate insertion of the core into the center hole from above.

Since there is a clearance between the upper end of the spring receiver 19 and the upper end of the lead tip holder mounting cylinder 20, when the lead is fed out, the frictional holding force of the rubber packing 23 is initially applied against the force of the spring 21 by this clearance. The tip holder mounting tube 20 descends together with a, and its descending stop position is regulated by the protruding collar 19b.

At this stop position, a certain gap is formed between the tip holder 22 of the tip holder mounting tube 20 and the paper surface, and from the position where the tip holder mounting tube 20 stops, the lead a is further affected by the frictional holding force of the rubber packing 23. Push the lead tip holder 22 further by the gap above.
protrude from

The length of the lead protruding from the lead tip holder 22 is such that the lead does not break.

Once the lead protrudes from the lead tip holder 22, it rises while maintaining its protruding length due to the frictional holding force of the rubber packing 23, but the lead tip holder attachment tube 20 also rises together with the lead within the range of the clearance.
When there is no lead, the lead tip holder mounting tube 20 is automatically lifted by the spring 21.

Also, in the inner space of the core holder guide cylinder 3 between the spring receiver 19 and the slide holder 7, there is a core receiver 24 supported from above and below by springs 23, 23a.
is vertically slidable inside, and a core insertion tube 24a is formed at the center of the core receiver 24.

The entrance of the core insertion tube 24a is formed in a funnel shape to facilitate insertion of the core a.

The upper end of the spring 23 is in contact with the lower end of the slide holder 7, and the lower end of the spring 23a is in contact with the upper end of the spring receiver 19.

With the core support 24 as described above, the lower end of the core is supported and the core can be prevented from being broken. The core receiver 24 descends while being located in the center of the space, thereby preventing buckling of the core between the lower end of the core chuck 5 of the core chuck mechanism and the rubber packing 23 and completely holding the lower end of the core. can.

Note that the lead holder guide tube 3 is fitted into the base 2 of the plotter head main body 1 from above,
As shown in FIG. 1, since it can be fixed to the base 2 with a set screw 2a, it can be disassembled from the base 2 in combination with the structure in which the spring receiver 19 is screwed into the lead holder guide cylinder 3.

Next, the lead up/down mechanism E for raising and lowering the lead for drawing will be explained.

That is, 25 is a clutch body which is fitted on the outer periphery of the lead holder guide cylinder 3 and is slidable up and down, and above which is a taper formed in a mortar-shaped part 25a with a tapered surface whose inner surface is inclined upward. ring 26
is placed inside and fixed with a lid member 27 screwed onto the mortar-shaped portion 25a.

A ball 28 is interposed between the taper ring 26 and the outer periphery of the slide holder 7, and is pressed downward by a spring 29 via its seat plate 30.

The ball 28 is restricted from descending by the upper end surface of the lead holder guide cylinder 3.

Reference numeral 31 is a core up/down solenoid supported by the plotter head body 1 via a bracket 32, and its suction disc 33 is drawn down by a coil, and is connected to an operating shaft 33a integrated with the suction disc 33. The tip of the fixed lever 34 engages with the engagement groove 25c of the clutch body 25, thereby raising and lowering the clutch body 25.

An up spring 36 is interposed between the lower end of the lever 34 and a cap 35 attached to the base 2, and urges the lever 34 upward.

Therefore, when the solenoid 31 is de-energized, the spring 36 causes the lever 34 to rise, thereby raising the clutch body.

A spring 69 is provided between the attachment collar of the lead holder guide tube 3 to the plotter head body and the lower end of the clutch body 25 to support the up spring.

Above the solenoid 31 is a stopper 38 supported by the plotter head body 1 via a bracket 37, which limits the upper limit of movement of the suction disc 33.

The core up-down mechanism E is configured as described above, so when the solenoid 31 is turned ON, the taper ring 26 is lowered together with the clutch body 25 from the actuating shaft 33a via the lever 34, but the ball 28 is placed above the core holder guide cylinder 3. Since the downward movement of the ball 28 is restricted at the position where it hits the end face, and the inner surface of the tapered ring 26 is formed into an upwardly inclined tapered surface, the degree of contact of the ball 28 with the slide holder 7 is relaxed, and the ball 28 is not in contact with the slide holder 7. The lock is released, and as a result, the slide holder 7 becomes free and can be freely lowered by the core pressure spring 15.

Next, when the solenoid 31 is turned OFF, the lever 34 is raised by the lifting spring 36, and the clutch body 25 is raised via the lever 34.

Then, since the ball 28 is pressed downward by the spring 29, it slides on the tapered surface of the tapered ring 26 as the clutch body 25 rises, and as a result, the contact with the slide holder 7 becomes stronger, so the slide holder 7 and the taper ring 26 are fixed, and the lead holder 4 is raised via the slide holder 7.

Next, to explain the core feeding mechanism F, a core feeding rotary solenoid 40 is attached to the plotter head main body 1 via a bracket 39, and the tip of an arm 42 shown in FIG. A roller 43 is rotatably supported, and engages from below with a large-diameter collar 8b of an upper guide tube 8 that moves up and down together with the slide holder 7.

The upper guide tube 8 is integrated with the slide holder 7 via an intermediate connecting body 52, and as shown in FIGS. 3 and 4, a sensor shielding plate 68 is attached to this intermediate connecting body 52. A sensor 67 consisting of a light projecting element and a light receiving element is fixed to the plotter head body 1.

Therefore, the core holder 4 is lowered by the core pressure spring 15 via the slide holder 7, and when the slide holder 7 descends in the core holder guide tube 3 as the core a wears out, the rotary solenoid 40
is OFF, the arm 42 descends in a free state while engaging with the large-diameter collar 8b of the upper guide tube 8 that descends together with the slide holder 7.

When the sensor shielding plate 68 is inserted between the light emitting element and the light receiving element of the sensor 67 and detects that the core has been consumed by a certain amount, a signal is sent to the rotary solenoid 40 electrically connected to this. When turned on, the arm 42 is swung upward, and the large-diameter collar 8b that engages with the roller 43 raises the upper guide cylinder 8 until it hits the holder 14.

Next, the chuck release mechanism G will be explained.

Reference numeral 50 denotes a chuck release operating rod, whose middle part is pivotally supported by the intermediate connecting body 52, is inserted into the inner chamber from the lower side of the intermediate connecting body, and its tip engages with the concave groove 51a of the hollow collar 51. are doing.

A spring 47 is installed inside the intermediate connecting body 52 between the collar 51 and the slider 44, and there is also a spring 47a between the ring 7a of the slide holder 7 and the collar 51.

Further, in the center of the collar 51, there is a core insertion hole 51b.

Since the chuck release mechanism G is constructed as described above, when the chuck release operation lever 50 is pressed down, the core chuck 5 is pressed down, and this collet 5b resists the force of the spring 11 and releases the taper guide surface of the lead holder 4. As the ball 6 moves in the direction of enlargement of the ball 4d, the ball 6 descends while being fitted into the recess 5c, releasing the pressure on the collet 5b and the core chuck 5 becomes free.

Next, the core breakage detection mechanism H will be explained.

A slider 44 having an insertion hole 44a is housed in the intermediate connector 52 that connects the upper guide tube 8 and the slide holder 7, and a sensor shielding plate 46 is swingably attached to a bracket 45 attached to the slider 44. A vertical slit groove 52a is provided in the intermediate connector 52 so that the sensor shielding plate 46 can be moved up and down without being obstructed.

Also, corresponding to the sensor shielding plate 46, the bracket 4
A sensor 49 consisting of a light emitting element and a light receiving element is fixed to the plotter head main body 1 via a light emitting element and a light receiving element.

As mentioned above, 49 is a sensor consisting of a light emitting element and a light receiving element, and the other arm 46b of the sensor shielding plate 46 is heavier than the other arm 46a. The tip of the arm 46a is energized so that it is always in contact with the internal pipe 16 or the core inserted into the arm 44a.

The arm 46b blocks light from the light emitting element of the sensor 49.

Since the core breakage detection mechanism H is configured as described above, if there is no core, the arm 46 of the sensor blocking plate 46
Since there is nothing to support the sensor shield plate 46, the sensor shield plate 46 swings counterclockwise in FIG. 1, and the arm 46b blocks the light from the light emitting element.

Accordingly, a signal is sent from the sensor 49 to an alarm device (not shown) to issue an alarm or to disable the drafting machine.

If there is a lead but there is not enough remaining lead to use it, the inner pipe 16 is inserted into the lead insertion hole 44a of the slider 44, and the chuck 17 presses down on the slider 44, so the slider 44 descends against the spring 47. Accordingly, the sensor shielding plate 46 also lowers, and one arm 46b
It is possible to block the light from the light projecting element and also to issue a signal to an alarm system or to disable the drafting machine.

From the above, a single detection device consisting of the sensor shielding plate 46 can detect both the case where there is no lead and the case where there is a lead but it cannot be used because there is too little remaining lead.

Note that when the above-mentioned detection device is in operation, the interior pipe 16 is inserted into the core insertion hole 5 of the core chuck 5.
Since the distance between the lower end of the internal pipe 16 and the tip holder mounting tube 20 is short, the length of the remaining core is shortened.

Therefore, the longer the inner pipe 16 is, the shorter the length of the remaining core can be.

Now, when inserting the lead into the printing head, first insert the lead from above the protective pipe 12 with the internal pipe 16 clamped to the chuck 17, but the solenoid 31 is normally turned OFF when printing is stopped. Therefore, the locking clutch 25 is locked and the lead holder 4 is raised together with the slide holder 7.

Therefore, the solenoid 31 is turned on to lower the lead holder 4 together with the slide holder 7 so that the lead can land on the drawing board surface when the lead is down.

If the lead holder 4 is raised and the lead is inserted until it protrudes below the lead tip holder 22, depending on the amount of protrusion, when the lead holder 4 is lowered, the lead will be on the drawing surface. This is because if the lead holder 4 is hit, it is possible that the lead holder 4 will still fall, and in that case, the lead will break.

Therefore, the core a is protected by the pipe 12 and the slider 44.
The core insertion hole 44a of the collar 51, the core insertion hole 51b of the collar 51
Insert it into the core chuck 5 through the wick.

Then, due to the friction between the lead chuck 5 and the lead a, the lead chuck 5 descends a little and changes its relative position with the lead holder 4, so the ball 6 is pushed to the large diameter part of the lead holder taper guide surface 4d and the ball 6 When the pressure on the tightening collet 5b is released, the core chuck 5 becomes free.

Therefore, the lead a can be inserted until it protrudes from the lead holder 22 of the lead holder attachment tube 20 and comes into contact with the drawing surface.

At this time, the lead tip holder mounting tube 20 is lowered somewhat. After inserting core a, solenoid 3
1 is turned OFF and the lead holder 4 is raised together with the slide holder 7.

Then, the spring 21 causes the lead tip holder mounting cylinder 20 to rise, and the lead also moves to its rubber gasket 23.
It rises with the holding force of .

As the core chuck 5 rises, the spring 11
The lead chuck 5 rises due to friction with the lead a and changes its position relative to the lead holder 4, so the lead chuck 5 operates in the opposite manner to the previous one and becomes locked.

Next, turn on the solenoid 40.

At this time, the once locked lead holder 4 is further pulled up together with the slide holder 7 by the arm 42 via the intermediate connector 52, so the locked state is released and the lead is subsequently held in the lead tip holder 22 by friction. Because the core chuck 5
The lead holder 4 rises with the lead free and the lead remaining, and the position where the lead chuck 5 clamps the lead is changed.

Next, the solenoid 31 is turned ON again for drawing.

Then, the locking clutch 25 will be unlocked, so the core holder 4 and the slide holder 7 will become free and the core pressure spring 1 will be released.
At 5, you can descend freely.

At this time, since the lead tip holder mounting tube 20 is initially stopped by the spring 21, the lead a held by the rubber gasket 23 is also stopped, and the lead chuck 5 is also prevented from moving by friction with the lead a and the spring 11. .

Although the movement of the lead chuck 5 is prevented in this way, the lead holder 4 descends together with the slide holder 7, so that the tightening collector is tightened via the ball 6 at the small diameter portion of the tapered guide surface 4d of the lead holder 4. 5b, the core chuck 5 is locked.

When the lead holder 4 continues to descend, the lead holder mounting cylinder 24 moves downward against the spring 21 due to the friction between the lead a and the rubber packing 23, and the lead holder mounting cylinder 20 hits the protruding collar 19b and descends. stops, and the lead a comes into contact with the drawing surface and stops.

In this case, the lead holder 4 continues to descend, so that the lead chuck completely clamps the lead.

In this way, writing pressure is applied to the lead by the core pressure spring 15 to draw a picture, but in this drawing state, the lead remains locked by the lead chuck mechanism.

Next, when raising the core to stop drawing, turn off the solenoid 31.

Then, the locking clutch will be locked, and the lead holder 4 will rise together with the slide holder 7.

At this time, as the lead holder 4 rises, the lead holder mounting cylinder 20 also rises by its spring 21, so the lead chuck 5 also rises together with the lead a held by the rubber gasket 23 of the lead holder 22, and the lead chuck 5 and the lead holder 4 Therefore, the core chuck mechanism remains in the locked state in the drawing state.

In this way, the lead tip holder mounting tube 20 abuts against the upper end of the inner space of the spring receiver 19 and stops, thereby moving the lead away from the drawing surface.

Next, to explain the case of feeding out the lead, regardless of whether the solenoid 31 is ON or OFF, when the lead wears out, the sensor shielding plate 68 and the sensor 67
Based on the detection means consisting of, a signal is sent to the core feeding rotary solenoid 40, which is turned ON and the arm 42 causes the large diameter flange 8b of the upper guide tube 8 to rise until it abuts against the holder 14.

In this case, since the core holder 4 is actively raised via the intermediate connector 52, the ball 2
8 upward against the force of spring 29 to release the locking clutch.

The lead holder 4 is therefore subsequently raised by the arm 42.

At this time, as the lead holder 4 rises, the lead tip holder mounting cylinder 20 also rises by the spring 21, so the relative relationship between the lead chuck 5 and the lead holder 4 remains unchanged, and the lead chuck mechanism continues to maintain the locked state. Holder 4 and slide holder 7
rises with

Next, when the lead tip holder mounting cylinder 20 hits the upper end of the inner space of the spring receiver 19 and stops, the lead chuck 5 also stops, and only the lead holder 4 rises together with the slide holder 7, so the lead chuck 5 and the lead holder 4 The interrelationship with the core changes, and the core is no longer locked by the core chuck mechanism.

Since the lead chuck 5 is supported by the lead holder 4 by the spring 11, it then rises together with the lead holder 4.

As a result, the clamping position of the core chuck with respect to the core a is changed.

And a certain period of time rubber rotary solenoid 40
is turned OFF, and the arm 42 stops rotating and becomes free.

Next, since the pressure of the core pressure spring 15 is applied to the lead chuck 5, the lead holder 4 is lowered, but since the lead tip holder mounting cylinder 20 is at the rising stop position by its spring 21, the lead chuck 5 is not connected to the lead. It is in a stopped state due to the friction of and spring 11,
Therefore, the relative position between the lead chuck 5 and the lead holder 4 changes, and the chuck mechanism becomes locked.

Even when the chuck mechanism is locked in this way, the lead holder 4 still descends together with the slide holder 7, so the lead tip holder mounting cylinder 20 also descends against the force of the spring 21 due to the friction between the lead a and the rubber packing 23. do.

When the tip holder mounting tube 20 stops descending,
The tip of the lead comes into contact with the drawing surface and stops, but at this point the lead is completely clamped by the chuck mechanism and the drawing state can be continued.

After repeating the above operations, when the tip of the chuck 17 that clamps the interior pipe 16 hits the entrance of the core insertion hole 44a of the slider 44, the slider 44 is pressed down against the spring 47, and the sensor shielding plate 46 is lowered.

In this case, one arm 46a of the sensor shielding plate 46 descends while contacting the interior pipe 16, and the other arm 46b blocks the light from the light emitting element and sends a signal to the control device to issue an alarm. or make the drawing machine inoperable.

Therefore, in order to replace a new lead, the remaining lead must first be removed, but in that case, hold the operating rod 50 and press down on the lead chuck 5 with its collar 51 to release the lead chuck mechanism. The protective pipe 12 is pulled upward from the core pressure spring receiver 13 with the remaining core free.

Then, the cap 18 of the chuck 17 engages with the stopper 12a of the protection pipe 12, and the interior pipe 16 with the remaining core attached is removed together with the protection pipe 12.

In that case, since the chuck mechanism is free, there is no need to worry about this, and the tip holder mounting tube 2
The remaining core can be removed from the rubber packing 23 of 0.

Then, the remaining core is removed from the removed interior pipe 16, a new core is pushed into the interior pipe 16, and it is attached to the printing head together with the protection pipe 12 again.

The above-mentioned drawing head is attached to an automatic drafting machine consisting of X and Y rails, but the one shown in the figure has three of the above-mentioned drawing heads attached.

As shown in FIG. 5, the combination of printing heads can be set arbitrarily using the switching handle 53.

For example, if 54 rows of signs indicate that each head uses the same type of core, turning the switching handle 53 in this direction will automatically use each head in succession. I can do it.

If the sign in column 55 indicates that each head uses a different type of core,
By turning the switching handle 53 toward this point, each head will be used according to its purpose.

In addition, if the sign in column 56 indicates that two heads use the same type of core and the other one uses a different type of core, turning the switching handle 53 will heads can be used automatically and consecutively.

57 is a set/out switch lever for each head.

Note that a roller 60 sliding in the slit groove 59 of the bracket 58 shown in FIGS. 3 and 5 guides the intermediate connecting body 52, and 61 shown in FIG. 1 represents a noise killer. .

The present invention relates to an improvement of the core up-down mechanism in the drawing head of a drawing machine as described above.

That is, when the solenoid 31 is turned on, the clutch body 2 is moved from the operating shaft 33a via the lever 34.
5, the tapered ring 26 descends, and the ball 2
8 is restricted from descending at the position where it hits the upper end surface of the lead holder guide cylinder 3, and since the inner surface of the tapered ring 26 is formed into an upwardly inclined tapered surface, the degree of contact of the ball 28 with the slide holder 7 is limited. is relaxed, and the so-called locking clutch is released, whereby the core holder 4 becomes free together with the slide holder 7, and freely descends by the core pressure spring 15.

In this case, if the upper end surface of the lead holder guide cylinder 3 is formed into a downwardly inclined surface facing toward the slide holder that supports the lead holder as shown in FIG. As a result, the descending speed of the slide holder 7 is limited, and even if the core pressure spring 15 is acting, the slide holder 7 will not descend suddenly. Because it does not drop suddenly, breakage of the core is prevented.

If the upper end surface of the lead holder guide tube 3 is horizontal as shown in FIG. 7, the balls 28 will not be biased toward the slide holder, but will tend to bias toward the tapered surface of the tapered ring. Therefore, the downward movement of the slide holder is not restricted by the ball 28.

Therefore, the lead drops rapidly and hits the cutting surface, causing the lead to break.

(Effect of the invention) According to the present invention, when the lead is fed toward the surface of the paper, when the clutch of the slide holder holding the lead holder in the up-down mechanism is free, the slide holder is pressed by the ball and lowered. This can be done gradually to prevent the core from being fed suddenly toward the paper surface, thereby preventing the core from being broken. As described above, in the present invention, breakage of the lead is prevented, so drawing operations can be carried out smoothly.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of a printing head to which the present device is applied, and Fig. 2 is a cutaway side view of the main parts thereof, Fig. 2 is a cutaway plan view of the same, Fig. 3 is a partially cutaway front view of the same, and Fig. 3 is a partially cutaway front view of the same.
Fig. 4 is a cutaway right side view of the same as above, Fig. 5 is a partially cutaway plan view of the same as above, Fig. 6 is an enlarged sectional view of the main part, and Figs. 7 and 8 are comparative operation explanatory views of the proposed device. be. 3... Core holder guide cylinder, 25... Clutch body, 26... Taper ring, 28... Ball, 29... Spring.

Claims (1)

[Scope of utility model registration request] A lead holder equipped with a lead chuck, a lead pressure mechanism that applies a predetermined pressure to the lead in the lead holder, a lead feeding mechanism that changes the clamping position by the lead holder chuck, and a lead holder that sets the lead holder to a printing halt state. In a device equipped with an up-down mechanism for raising and lowering it toward the drawing state position,
The clutch device for clamping or freeing the lead holder in the up-down mechanism is a member whose inner surface is formed into an upwardly sloping tapered surface with a plurality of balls pressed by springs inside, and these balls are placed up and down on the outer periphery of the lead holder. The stopper surface of the member that limits the descent of the ball in the clutch device faces the lead holder side, and the lead at the drawing line head of the drawing machine is formed into an obliquely downwardly inclined surface. Up-down mechanism.