JPH0328237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a fabric material feeding device for an industrial sewing machine.

<Prior art and its problems> In general, industrial sewing machines need to sew the fabric material of clothing finely or roughly, but automatic mechanical means to deal with this are as follows: Conventionally, a motor with a variable speed transmission has been used, and the speed at which the fabric material is fed into the sewing machine is changed by rotating the motor at variable speeds.

Therefore, it is not possible to easily and accurately obtain various minute objects as the feeding speed changes.
It is necessary to introduce a special product that is extremely expensive as a motor, and there is also the problem that it is easy to cause troubles in its operation.

<Means for Solving the Problems> The present invention is intended to improve such problems, and for this purpose, the present invention has a structure that includes an installation frame on the work floor, and a frame that is mounted and fixed on the top plate of the installation frame. A sewing machine, a material presser mechanism which is also installed on the top plate and which can be moved up and down in order to press or release the material to be sewn by the sewing machine against the top plate; A slide follower is assembled and connected to the presser mechanism from below the top plate, and the slide follower is connected linearly so as to be able to slide integrally with the presser mechanism in order to feed the workpiece to the sewing operation position. The slide driven body is equipped with a drive mechanism also installed below the top plate for reciprocating motion, and a sliding plate that slides along the guide rail of the installation frame, and a sliding plate that is fixed and mounted on the sliding plate. It is made up of a pair of moving and reciprocating air cylinders and engaging elements each held at the lower end of a piston rod that hangs down from both cylinders, and the two piston rods are connected to each other by a corresponding electromagnetic control valve. The drive mechanism for the slide driven body is configured to be able to be selectively moved up and down, and the drive mechanism for the slide driven body is provided by a pair of rotational drive shafts for forward and backward movement of the slide driven body parallel to the guide rail, and a pair of rotational drive shafts for driving both rotational drive shafts. It is also formed from a transmission motor and a transmission timing belt that rotates both rotary drive shafts in the same direction at a constant speed, and the outer circumferential surface of the forward rotary drive shaft has several types of spiral concave grooves with different leads. While the spiral is carved in a continuous form facing in one direction, the outer circumferential surface of the reciprocating rotary drive shaft is provided with one type of helical concave groove with an even lead, and the helix forms a spiral concave groove on the forward rotary drive shaft. The groove is carved in a form that continues in the opposite direction to that of the groove and has a longer lead than the lead of the spiral groove, and when the forward piston rod is lowered, the engager is inserted into the spiral groove of the forward rotation drive shaft. When engaged with the rotary drive shaft, as the rotational drive shaft rotates at a constant speed,
The slide driven body and the material holding mechanism automatically move forward in a continuously variable manner to feed the material to the sewing position of the sewing machine, and the above-mentioned backward movement piston rod is also lowered to return the engager. When engaged with the spiral concave groove of the rotary drive shaft, the slide follower and the material holding mechanism automatically move back in a fast return manner as the rotary drive shaft rotates at a constant speed. This feature is characterized in that the relationship is set so that the material is on standby at the material feeding preparation position.

<Example> Hereinafter, the specific configuration of the present invention will be described in detail based on the illustrated example. This frame includes a sewing machine 10 that sews fabric material M (for example, fabric that forms pockets of clothes), a fabric material presser mechanism D that presses the material M onto the top plate 11 of the installation frame F, and a fabric material presser D that presses the material M onto the top plate 11 of the installation frame F. A slide driven body A that moves the entire presser mechanism D forward in order to feed and pass through a sewing needle (not shown) of the sewing machine 10, and a drive that moves the slide driven body A reciprocating linearly in the front and back direction. A mechanism B and a cutting mechanism C that cuts the material M after sewing to a certain size are incorporated.

First, the sewing machine 10 is attached to the top plate 11 of the installation frame F.
Needless to say, the sewing needle is mounted and fixed on the top, and is equipped with a sewing needle that is linearly moved up and down at a constant speed using the motor 12 as a driving source. Since the sewing machine 10 itself including the sewing needle is well known, the position where the needle acts on sewing the fabric material M will only be indicated by the reference numeral Y-Y in the figure, and detailed explanation of its structure and operation will be given. Although omitted, the material M is fed forward and passed over the top plate 11 by the sewing needle as indicated by the arrow P in Figs. 1, 4, and 5, and is subjected to the required sewing action in the transition process. become.

After the sewing operation is completed, the material is cut into a certain size by the cutting mechanism C. As shown in Figures 6 and 7, the cutting mechanism C consists of a pantograph mechanism that is moved up and down by an air cylinder (not shown), and is installed inside the installation frame F at a position directly below the material M. has been done. Reference numeral 13 denotes a cutter that is removably installed on the elevating tool rest 14 that forms part of the power graph mechanism, and includes a presser plate and a presser ruler in the presser mechanism D that presses the material M onto the top plate 11 from above. In combination with this, the material M is cut from below the top plate 11 in a fixed state.

Next, the material holding mechanism D as a whole, including the dough holding plate 15, its swing arm 16, cylinder mounting support 17, etc., faces onto the top plate 11 of the installation frame F, and is located inside the framework of the installation frame F. By assembling and connecting with the slide driven body A installed in
It is designed to be able to linearly reciprocate in the above-mentioned front-back direction integrally with the main body.

As is clear from FIGS. 2 and 3, the fabric presser plate 15 and the swing arm 16 of the presser mechanism D are arranged in pairs on the left and right, and are kept at a constant interval so as not to interfere with the sewing action of the material M by the sewing needle. In a parallel state, all of them extend long and parallel in the front-rear direction, and are connected and fixed in a continuous state via a plurality of rivets, screws 20, etc. so that they can operate integrally with each other.

In that case, the swinging arm 16 extends the upright piece of the L-shaped dough holding plate 15 forward, so to speak, and at the midway point of the extension, a horizontal pivot pin 24 is attached to the corresponding pair of left and right cylinder mounting columns 17. It is installed so that it can see-saw.

The cylinder mounting support 17 has an inverted L-shape as shown in FIG.
Similarly, an air cylinder 22 for raising and lowering the dough pressing plate 15 is fixedly installed on the flat upper part.

That is, in FIGS. 1 and 4, the front end of the swing arm 16 is raised, and the material M is moved onto the top plate by the dough presser plate 15 that has been lowered around the pivot pin 21.
1, but when the front end of the swinging arm 16 is lowered from this state by the piston rod of the cylinder 22, the fabric presser moves as shown by the chain line in FIG. 1 and in FIG. 5. Board 1
5, conversely, the top plate 1 is centered around the pivot pin 21.
1 to release the pressing force of the material M, thereby making it possible to bite into the material M next time.

Between the fabric presser plates 15 facing each other,
A pair of inverted T-shaped fabric presser foot rulers 23 located at the front and rear of the sewing machine 10 across the sewing operation position Y-Y are also faced from above, and the pair of presser foot rulers 23 are always kept parallel to the top plate 11. Although it is designed to be raised and lowered at the same time, the raising and lowering mechanism constructed on the top plate 11 is not shown.

As described above, when the material M is cut by the cutter 13, the material M is pressed from above by the dough presser plate 15 and the presser ruler 23 and is in a fixed state.

The connecting spacer stand 18 functions as a spacer to connect and integrate the cylinder mounting column 17 of the material holding mechanism D and the slide plate 19 of the slide follower A, and is generally made of H-shaped steel.

The cylinder mounting column 17, the swinging arm 16, the dough presser plate 15, and the presser ruler 23 are supported by the spacer base 18 so as to face the material M through the opening gap (not shown) in the top plate 11.
As is clear from FIG. 2, the sewing machine 10 in the installation frame F is located at a biased position toward the sewing operation position Y-Y, whereas the slide plate 19 of the slide follower A is At a mid-height position inside the frame F,
Moreover, it extends horizontally in the left-right direction so as to cross the frame F, and from this point on, the pair of left and right end support legs 24 and the intermediate support leg 25 interposed between them are integrally suspended. There is. however,
A plurality of the support legs 24, 25 as a whole
Of course, it is also possible to connect them individually.

Reference numeral 26 denotes a pair of front and rear support bars that are fixed horizontally at a mid-height position within the installation frame F, and 27 is a plurality of support bars (total 3 in the figure) that are also installed in a horizontally fixed state along the front and rear direction of the frame F. This is a slide guide rail, and both ends thereof are supported by support bars 26. The support leg 2 of the slide plate 19 in the slide driven body A is
4 and 25 are slidably passed through the guide rail 27, and are linearly reciprocated in the front-rear direction by a drive mechanism B, which will be described below.

Therefore, as long as the slide plate 19 can be guided linearly, a guide rail 27 with a round shaft as shown in the figure is used.
Instead of penetrating the support legs 24 and 25 of the slide board 19, the support legs 24 and 25 and the guide rail 27 may be fitted into a so-called concave-convex fit, or the support legs 24 and 25 may be inserted only onto the guide rail 27. It may also be a form in which it is simply placed.

The drive mechanism B of the slide driven body A includes a pair of left and right rotary drive shafts 2 that function for forward and backward movement of the slide plate 19 in the driven body A.
8, 29, a drive motor 30 that rotates both drive shafts 28, 29, and also both drive shafts 28, 29.
29 and a transmission timing belt 31 that rotates each other in synchronization with each other, and the drive shafts 28, 2
The rotary motion of the slide plate 9 is converted into the linear motion of the slide plate 19.

That is, the pair of rotary drive shafts 28 and 29 extend in parallel with the guide rail 27 in the front-rear direction of the installation frame F, and both of their front and rear ends are connected to the installation frame F. It is rotatably supported by the support bar 26 via a bearing 32, and similarly, the intermediate portions are loosely penetrated by the intermediate support legs 25 of the slide board 19.

Further, a timing pulley 33 is fixed to the front end of both drive shafts 28 and 29, and this pulley 33 and the output pulley 3 of the motor 30 are connected to each other.
Timing belt 31 suspended between 4 and 4.
As a result, both drive shafts 28 and 29 are rotated together at a constant speed in the same direction.

In that case, referring to each of the drive shafts 28 and 29, first, the slide plate 19 is moved forward in the direction of the arrow P in order to feed the fabric material M to the sewing action position Y-Y of the sewing machine 10. Rotation drive shaft 2
As extracted in FIG.
is carved in a continuous form toward one direction f of the spiral, and the leads L1, L2, L
The speed of the linear sliding movement of the slide board 19 is changed according to the difference in length between the sewing machines 3 and 3, so that the fabric material M can be sewn roughly or finely.

In this regard, the figure shows three types of spiral grooves 35 that correspond to changes in length of the leads L1, L2, and L3, but the number of spiral grooves 35 can be further increased or decreased depending on how the fabric material M is sewn. can. In addition, although the engraving depth H is set to be the same between several types of spiral grooves 35, the engraving depth H is also varied between the several types, so that the depth can be changed. SaH and lead L1,L
It may be possible to obtain even more various speed change motions of the slide plate 19 by changing both L2 and L3. The opening shape of the spiral groove 35 is also not limited to the arcuate concave shape in cross section as shown in the figure.

On the other hand, in order to feed the next dough material M forward, a spiral concave groove 36 as shown in FIG. However, the lead L of the spiral concave groove 36 is connected to the forward rotational drive shaft 28.
The length of the drive shaft 29 is set to be longer than that of the drive shaft 29, and the drive shaft 29 is carved as a uniform type that does not change in length or shortness over the entire length of the drive shaft 29. Further, the directionality of the spiral is set to be continuous so that the direction of the spiral is oriented in the direction r opposite to that of the forward rotary drive shaft 28 for the backward movement of the slide plate 19, so that the slide plate 19 can be quickly returned. It is designed to be able to move backwards at high speed as if it were to be moved backwards.

Reference numerals 37 and 38 are air cylinders for forward and backward motion corresponding to the above-mentioned two rotary drive shafts 28 and 29, and as is clear from FIGS. 2, 11, and 13,
They are fixedly installed on the slide board 19 in a pair of left and right parallel configurations. Piston rods 39 and 40 are suspended from the air cylinders 37 and 38 toward the drive shafts 28 and 29, respectively, and are raised and lowered by electromagnetic control valves 41 and 42 connected to the air cylinders 37 and 38, respectively. It's becoming controlled.

Reference numerals 43 and 44 refer to ball holding cases which are screwed onto the hanging ends of the piston rods 39 and 40, respectively, and are assembled in an upright U-shape in cross section, and a ball-shaped case is held in the case so as to be able to roll freely. The engaging members 45 and 46 are configured to engage with the spiral grooves 35 and 36 of the drive shafts 28 and 29, respectively, on the arcuate surfaces exposed from the cases 43 and 44, respectively. 47 and 48 are the engaging elements 4
5, 46, and is enclosed in each case 43, 44, thereby smoothly damping the engagement action with the spiral grooves 35, 36. There is.

The forward rotational drive shaft 28 and the backward rotational drive shaft 29 are connected to corresponding engagers 45, which are attached and held on the slide plate 19 side of the slide driven body A.
46 and are controlled to selectively engage with each other.

In other words, when the forward movement engager 45 is engaged with the spiral concave groove 35 of the forward rotation drive shaft 28 and the slide plate 19 is moving linearly forward as shown in FIGS. The engagement element 46 is in a state of being disengaged from the reciprocating rotary drive shaft 29, and conversely, as shown in FIGS. 12 and 13, the rotary drive shaft 2
When the backward movement engager 46 is engaged with the spiral concave groove 36 of No. 9 and the slide plate 19 is moving backward in a quick return manner as described above, the forward movement engager 45 is engaged with the rotational drive shaft 28 of the slide plate 19. This switching operation is performed from the control valves 41, 42 to the air cylinders 37, 38.
This can be done by controlling the air supply and discharge to and from the air.

<Function> According to the above configuration, the motor 30 rotates the forward and backward rotation drive shafts 28 and 29 in the same direction at a constant speed via the timing belt 31, and By engaging the corresponding engager 45 with the helical groove 35 of the rotary drive shaft 28, the engager 45 rolls within several different types of helical grooves 35 of the leads L1, L2, L3, Therefore, the slide driven body A including the slide plate 19 can be linearly moved along the guide rail 27 in a continuously variable speed forward direction in the direction of the arrow P, and accordingly, the material holding mechanism D can also be moved integrally in the same direction. Due to the linear movement, the material M on the top plate 11 can be fed into the sewing position Y-Y of the sewing machine 10, and the sewing needle can roughly or finely sew the material M into the desired state. This is possible.

After the sewing operation is completed, the material M is cut into a predetermined size by the cutter 13 of the cutting mechanism C, as described above, and the slide driven body A
As soon as the forward movement end point is reached, the corresponding engager 46 is selectively engaged with the spiral groove 36 of the backward rotation drive shaft 29.

Then, the double-acting engager 46 will be connected to the lead L.
Rolling in the uniform spiral concave groove 36, the slide plate 19 also moves linearly backwards along the guide rail 27, and the material holding mechanism D also moves integrally with the slide plate 19 along the guide rail 27. Since it moves linearly on 11, it continues to quickly return to the preparation position for feeding the material M and wait there.

At the end position of the backward movement, the fabric presser plate 15 of the presser mechanism D is floated from the top plate 11 as shown in FIG. 5, and during the forward movement, as is clear from FIG. Of course, the fabric presser plate 15 of the presser mechanism D descends to press down the fabric material M, and the interlocking operation between the material presser mechanism D and the slide follower A is the movement of the fabric material M by the cutter 13. The overall position, including the cutting action of M, is detected by sensors (not shown) and is automatically and electrically operated.

<Effects of the Invention> As described above, in the fabric material feeding device for an industrial sewing machine according to the present invention, due to its structure, it is installed and fixed on the installation frame F on the work floor and the top plate 11 of the installation frame F. sewing machine 10 and its sewing machine 1
In order to press or release the fabric material M to be sewn by the top plate 11 against the top plate 11, there is also a material presser mechanism D which is also installed on the top plate 11 and can be moved up and down, and the material pressed against the top plate 11. In order to send M to the sewing action position Y-Y of the sewing machine 10, the presser mechanism D
the top plate 11 so that it can slide integrally with the
The slide driven body A is assembled and connected to the presser mechanism D from below, and the drive mechanism B is also installed below the top plate 11 in order to linearly reciprocate the slide driven body A. A slide plate 19 that slides the slide follower A along the guide rail 27 of the installation frame F, and air cylinders 37, 3 for forward and backward movements that are mounted and fixed on the slide plate 19.
8 and engagers 45 and 46 held at the lower ends of piston rods 39 and 40 that hang down from both cylinders 37 and 38, respectively. Type control valve 41, 4
2, the drive mechanism B of the slide driven body A is provided with rotary drive shafts 28 and 29 for forward and backward movement of the slide driven body parallel to the guide rail 27. and a driving motor 31 for both rotational drive shafts 28 and 29.
and a transmission timing belt 3 that similarly rotates both rotary drive shafts 28 and 29 in the same direction at a constant speed.
1, and several types of spiral grooves 3 with different leads L1, L2, and L3 are formed on the outer peripheral surface of the forward rotation drive shaft 28.
5 is engraved so that its spiral continues in one direction f, while a lead L
One type of helical concave groove 36 having an equal shape is formed so that the helical direction continues in the direction r opposite to that of the helical concave groove 35 on the forward rotary drive shaft 28,
And the leads L1, L2, L3 of the spiral groove 35
engraved as a longer lead L, and lowered the reciprocating piston rod 37,
When the engaging element 45 is engaged with the spiral concave groove 35 of the forward rotary drive shaft 28, the rotary drive shaft 28
As the material rotates at a constant speed, the slide follower A and the material holding mechanism D automatically move forward in a continuously variable manner to feed the material M to the sewing position Y-Y of the sewing machine 10, When the double-acting piston rod 40 is similarly lowered and its engager 46 is engaged with the spiral concave groove 36 of the double-acting rotary drive shaft 29, as the rotary drive shaft 29 rotates at a constant speed, the slide driven The relationship between the body A and the material holding mechanism D is set so that they automatically return quickly and wait at the feeding preparation position for the material M, which solves the problem of the prior art described at the beginning. It has the effect of reliably solving the problem.

That is, if the forward rotary drive shaft 28 in the drive mechanism B of the slide driven body A is rotationally driven by the common motor 30, the spiral concave groove 35 carved on the outer peripheral surface of the rotary drive shaft 28 will be rotated. By means of the leads L1, L2, and L3, the slide follower A and the material holding mechanism D integrated therewith automatically move linearly in a continuously variable speed to press the fabric material M into the sewing machine 10.
Since the sewing machine is fed to the sewing action position Y-Y, there is no need to use the drive motor 30 as an expensive special product with a transmission to rotate it at variable speeds, and there is no need to worry about any operational troubles. .

Moreover, since the spiral groove 35 of the forward rotation drive shaft 28 is carved in several types with different leads L1, L2, and L3 and in a continuous form facing one direction f, the fabric material M is transferred to the sewing machine 10. Therefore, during the sewing operation, it is possible to sew coarsely or finely in a continuously variable speed, and it is possible to easily and quickly respond to changes in the sewing condition.

On the other hand, the spiral groove 36 of the double-acting rotary drive shaft 29
Although the spiral has a continuous form in the direction r opposite to that of the spiral concave groove 35 on the forward rotary drive shaft 28, the lead L is of one type and is uniform. Compared to the leads L1, L2, and L3 of the spiral concave groove 35, it is carved to be particularly long, so when the lead is driven to rotate, the slide follower A and the material holding mechanism D move linearly in a fast return manner. The return movement after the sewing operation described above can be performed quickly, and the work efficiency can be significantly improved.

In addition, the above-mentioned double rotation drive shaft 2 for forward movement and backward movement
8 and 29 are transmission-connected via a timing belt 31, and if both are rotated in the same direction by a common motor 30, the slide driven body A and the material holding mechanism D can be removed. Since it is possible to obtain a step-shifting forward movement and a fast-returning backward movement, the drive mechanism B can be significantly simplified and rationalized, and the lower part of the top plate 11 in the installation frame F can be saved. It can be incorporated in terms of space.

Furthermore, on the slide plate 19 of the slide driven body A, there are both air cylinders 37 for forward movement and backward movement,
38, its piston rods 39, 40, and engagers 45, 46 are installed in parallel, and corresponding forward and backward rotation drive shafts 28, 29 are supported at the lower position thereof. The slide driven body A and both rotary drive shafts 28, 29 are selectively engaged with each other during forward movement or backward movement via engaging elements 45, 46, and the switching control is performed. is an electromagnetic control valve 41,
42, it has the effect of greatly increasing automation as a fabric material feeding device for industrial sewing machines.

[Brief explanation of drawings]

FIG. 1 is an overall schematic side view of the dough material feeding device according to the present invention, FIG. 2 is a front view thereof, FIG.
The figures are schematic side views showing the states of the slide driven body reaching the forward movement end point and backward movement end point, respectively. Fig. 6 is a side view extracting the cutting mechanism. Fig. 7 is also a front view, and Fig. 8 and 9 The figure is a side view extracting and showing the rotary drive shafts for forward movement and backward movement, and FIG. 10 is a side view of the slide driven body in the forward movement state, broken along the line Figure 11 is an enlarged sectional view taken along the line XI-XI in Figure 10;
3 is a partially cutaway side view and an enlarged cross-sectional view, respectively, showing the sliding driven body in a backward motion state corresponding to FIGS. 10 and 11. FIG. A... Slide driven body, B... Drive mechanism, C... Cutting mechanism, D... Material holding mechanism, F... Installation frame, M
...Fabric material, L, L1, L2, L3...Lead, 1
0... Sewing machine, 19... Slide board, 27... Slide guide rail, 28, 29... Rotation drive shaft, 30...
Motor, 31...Timing belt, 35, 36
...Spiral groove, 37, 38...Air cylinder, 3
9, 40... Piston rod, 43, 44... Ball holding case, 45, 46... Engagement element, 47, 48...
Spring.

Claims (1)

[Claims] 1. An installation frame F on a work floor, and a sewing machine 1 mounted and fixed on a top plate 11 of the installation frame F.
0 and the fabric material M to be sewn by the sewing machine 10 is pressed against or released from the top plate 11. In order to feed the pressed material M to the sewing position Y-Y of the sewing machine 10, it is assembled and connected to the presser mechanism D from below the top plate 11 so that it can slide integrally with the presser mechanism D. The slide driven body A is provided with a drive mechanism B also installed below the top plate 11 in order to linearly reciprocate the slide driven body A, and the slide driven body A is guided by the installation frame F. A slide plate 19 that slides along the rail 27, and air cylinders 37, 3 for forward movement and return movement that are mounted and fixed on the slide plate 19.
8 and engagers 45 and 46 held at the lower ends of piston rods 39 and 40 that hang down from both cylinders 37 and 38, respectively. Type control valve 41, 4
2, the drive mechanism B of the slide driven body A is provided with rotary drive shafts 28 and 29 for forward and backward movement of the slide driven body parallel to the guide rail 27. and a driving motor 30 for both rotational drive shafts 28 and 29.
and a transmission timing belt 3 that similarly rotates both rotary drive shafts 28 and 29 in the same direction at a constant speed.
1, and several types of spiral grooves 3 with different leads L1, L2, and L3 are formed on the outer peripheral surface of the forward rotation drive shaft 28.
5 is engraved so that its spiral continues in one direction f, while a lead L
One type of helical concave groove 36 having a uniform shape is formed so that the helical direction continues in the direction r opposite to that of the helical concave groove 35 on the forward rotary drive shaft 28,
And the leads L1, L2, L3 of the spiral groove 35
engraved as a longer lead L, and lowered the reciprocating piston rod 37,
When the engaging element 45 is engaged with the spiral concave groove 35 of the forward rotary drive shaft 28, the rotary drive shaft 28
As the material rotates at a constant speed, the slide follower A and the material holding mechanism D automatically move forward in a continuously variable manner to feed the material M to the sewing position Y-Y of the sewing machine 10, When the double-acting piston rod 40 is similarly lowered and its engager 46 is engaged with the spiral concave groove 36 of the double-acting rotary drive shaft 29, as the rotary drive shaft 29 rotates at a constant speed, the slide driven Fabric material feed of an industrial sewing machine, characterized in that the body A and the material presser mechanism D are set in a relationship such that they automatically return quickly and stand by at a position in preparation for feeding the subsequent material M. Device. 2. Both the engaging elements 45, 46 are in the form of freely rolling balls and are held at the lower ends of the piston rods 39, 40, respectively, and the spiral grooves 35, 36 are formed in the engaging elements 45, 46.
Spring 47, 48 which should buffer the engagement action with
A fabric material feeding device for an industrial sewing machine according to claim 1, characterized in that a back pressure is applied to each of the fabric material feeding devices of an industrial sewing machine according to claim 1. 3 Spiral concave groove 35 in forward rotary drive shaft 28
A fabric material feeding device for an industrial sewing machine according to claim 1, characterized in that the engraving depth H is varied depending on several types of leads L1, L2, and L3. .