EP1371770A2 - Buttonhole sewing machine - Google Patents

Abstract

The buttonhole sewing machine has a buttonhole cutter (16) with a cutting blade (26) working with a cutter block. A cutter drive (19) moves the cutting blade and cutting block in relation to each other, with a variable cutting force. It uses a number of linear drives, switched in parallel to each other, and operated selectively by pneumatic forces. The linear drive is a multi-chamber cylinder, with a piston in each chamber, mounted at a common piston rod.

Description

The invention relates to a buttonhole sewing machine according to the preamble of claim 1.

From DE 33 15 521 C2 (corresponding to US 4,552,080 A) is such Buttonhole sewing machine known. Here, the drive of the cutting block takes place by means of a pneumatically actuated piston-cylinder drive, the one with different pressure to produce different Cutting forces can be acted upon. Furthermore, the cutting speed be varied. A disadvantage of this known embodiment is that it's very hard to generate well-defined cutting forces.

The invention is therefore the object of the known buttonhole sewing machine so educate, that the cutting force in a simple way is adjustable in exactly reproducible form.

This object is achieved by the features in the characterizing part of claim 1 solved. Because several parallel, pneumatically actuated linear actuators are provided, the optionally acted upon by the same pressure, the cutting force set in several, each exactly reproducible levels or to be selected. This allows a very accurate adaptation to different Cutting conditions are determined by the hardness of the material, the type of fabric, but the number of fabric layers to be cut, but also influenced by the shape and / or size of the cut to be performed become.

In an embodiment according to claims 2 and 3, the linear drives used as active drives for generating the cutting force.

In the advantageous embodiment according to claims 4 and 5 are the linear drives used passively, d. H. the force limiter formed by them forms depending on the loading of the linear actuators one more or less resilient abutment for the cutting force generating Piston-cylinder drive. The piston-cylinder drive always generates at least the maximum possible cutting force, then by the Force limiter optionally a part is compensated.

The actuation of the linear actuators takes place via multi-way valves, which can be controlled from a central control unit.

The dependent claims give advantageous developments again.

Fig. 1

eine Knopfloch-Nähmaschine in Seitenansicht,

Fig. 2

einen horizontalen Teil-Schnitt durch die Nähmaschine entsprechend der Schnittlinie II-II in Fig. 1 in gegenüber Fig. 1 vergrößertem Maßstab,

Fig. 3

eine Ansicht auf ein Messer entsprechend dem Sichtpfeil III in Fig. 1,

Fig. 4

einen Amboss in Seitenansicht in gegenüber Fig. 1 vergrößerter Darstellung,

Fig. 5

einen vertikalen Querschnitt durch den Amboss entsprechend der Schnittlinie V-V in Fig. 4,

Fig. 6

eine Draufsicht auf den Amboss entsprechend dem Sichtpfeil VI in Fig. 5,

Fig. 7

einen perspektivisch dargestellten Teil der Knopfloch-Nähmaschine einschließlich der schaltungsmäßigen Verknüpfung der verschiedenen Antriebe mit einer Steuereinheit und einer BedienEinheit,

Fig. 8

eine Draufsicht auf ein in einer Nähgutklammer gehaltenes Nähgutteil mit einem Augen-Knopfloch,

Fig. 9

eine Draufsicht auf ein in einer Nähgutklammer gehaltenes Nähgutteil mit einem einfachen Knopfloch,

Fig. 10

eine Draufsicht auf eine abgewandelte Ausführungsform eines Messers in einer Darstellung entsprechend Fig. 3,

Fig.11

eine Draufsicht auf einen dem Messer nach Fig. 10 angepassten Amboss in einer Darstellung gemäß Fig. 6,

Fig. 12

eine schematische Darstellung eines Schneid-Antriebs für die Knopfloch-Schneid-Vorrichtung einschließlich der schaltungsmäßigen Verknüpfung mit der Steuer-Einheit und

Fig. 13

eine schematische Darstellung einer weiteren Ausführungsform des Schneid-Antriebs der Knopfloch-Schneid-Vorrichtung einschließlich der schaltungsmäßigen Verknüpfung mit der SteuerEinheit.

An embodiment of the invention will be explained in more detail with reference to the drawing. It shows

Fig. 1

a buttonhole sewing machine in side view,

Fig. 2

2 is a horizontal partial section through the sewing machine according to the section line II-II in Fig. 1 in comparison with FIG. 1 enlarged scale,

Fig. 3

a view of a knife according to the viewing arrow III in Fig. 1,

Fig. 4

an anvil in side view in relation to FIG. 1 enlarged view,

Fig. 5

a vertical cross section through the anvil according to the section line VV in Fig. 4,

Fig. 6

a plan view of the anvil corresponding to the viewing arrow VI in Fig. 5,

Fig. 7

a perspective view of part of the buttonhole sewing machine including the circuit-wise connection of the various drives with a control unit and an operating unit,

Fig. 8

a plan view of a held in a fabric clamp workpiece with an eye buttonhole,

Fig. 9

a top view of a workpiece held in a Nähgutklammer Nähgutteil with a simple buttonhole,

Fig. 10

3 a top view of a modified embodiment of a knife in a representation corresponding to FIG. 3,

Figure 11

8 is a plan view of the knife according to FIG. 10 adapted anvil in a representation according to FIG. 6,

Fig. 12

a schematic representation of a cutting drive for the buttonhole cutting device including the circuit connection with the control unit and

Fig. 13

a schematic representation of another embodiment of the cutting drive of the buttonhole cutting device including the circuit connection with the control unit.

As can be seen in FIG. 1, a buttonhole sewing machine is C-shaped, d. H. it has an upper arm 1, a lower, housing-like design Base plate 2 and a connecting both, approximately vertical Stand 3 on. In the arm 1, an arm shaft 4 is mounted in a conventional manner, which is drivable by a drive motor 5 indicated only in Fig. 7. From the arm shaft 4, the drive of a vertical in the usual way sliding needle bar 6 with a needle 7 and a vibratory drive derived for this purpose.

On the base plate 2, an x-y table 8 is arranged, in which it is so one in two horizontal coordinate directions, namely the x-direction and the y-direction, sliding cross slide is. The x-y table 8 is formed in a conventional manner, as for example from DE 198 07 771 A1 (corresponding to US-PS 6,095,066) is known. The drive of the x-y table 8 takes place by means of only indicated in Fig. 7 Drives, namely an x-drive 9 and a y-drive 10, in which it is about positionable electric motors, so usually preferred Stepper motors, but also controllable DC motors is.

On the x-y table 8, a two-part support plate 11a, 11b is arranged. One of the two partial support plates 11a or 11b can on the x-y table. 8 slidably supported in the x direction, while the other part support plate 11b or 11a immovable, so firmly on the x-y table. 8 is arranged, which is not shown in detail.

On each partial support plate 11a and 11b is a Nähgutklammer 12a or 12b attached, each one on the respective part support plate 11a or 11b mounted partial support plate 13a and 13b, which in each case one clamping plate 14a or 14b is assigned. The clamping plates 14a, 14b are attached to double-armed bearing levers 15a, 15b.

Details of the construction and the drive of the Nähgutklammern 12a, 12b result from DE 102 16 809 A, to which reference is made.

As seen in the y-direction behind the needle bar 6 is a buttonhole cutting device 16, which consists essentially of an upper drivable cutting part 17 and a lower anvil 18. The upper cutting part 17 has a cutting drive 19 which will be described in more detail below, one end of which is fastened in the base plate 2 by means of a joint 20. The other upper end of the drive 19 is connected to a two-armed lever 21 by means of a joint 22, which in turn is articulated by means of a further joint 21 a to a drive rod 23 which is guided vertically displaceably in at least one arranged on the arm 1 guide bearing 24 , At the lower end of the drive rod 23, a knife head 25 is mounted, on the underside of a knife 26 shown in FIG. 3 is mounted replaceably. As can be seen in FIG. 3, the knife 26 has a straight cutting part 27 and an eye cutting part 28. The straight cutting part 27 has a length L ₂₇ , while the entire knife 26, consisting of the straight cutting part 27 and the eye cutting part 28 has a length L ₂₆ .

The anvil 18 has a base body 29 which in the base plate 2 is fixed. On the base body 29, a carrier 30 is arranged, which is displaceable in the x direction. He is by means of strips 31, 32 on the Main body 29 held, wherein the strips 31, 32 by means of screws 33rd are attached to the base body 29. In the main body 29 is an adjustment drive 34 integrated, which is a two-sided, pneumatic acted piston-cylinder drive is. Its cylinder 35 is by a running in the x-direction bore in the base body 29th formed, which is closed at its ends by means of lids 36. In the cylinder 35, a piston 37 is slidably disposed on the end faces thereof in each case a line 38, 39 opens into the cylinder 35, each for Compressed air supply and used for ventilation. The carrier 30 is by means of a bolt 31 a connected to the piston 37, so depending on the application of the piston 37 with compressed air via line 38 or 39 from Piston 37 shifted in x-direction. The two displacement movements are limited by adjustable end-stops 40, 41, which by in Base 29 arranged adjusting screws are formed.

On the carrier 30 are a first cutting block 42 and a second Cutting block 43 by means of screws 44, so interchangeable attached. As is apparent from the overall view of Fig. 3 and Fig. 6, comes when the first cutting block 42 is located below the blade 26, ie cooperates with this, the entire knife 26, so the rectilinear Cutting edge part 27 and the eye cutting part 28 with the cutting block 42 engaged. In contrast, when the second cutting block 43 under the Knife 26 is located, then only the straight cutting part 27 comes with this in engagement; the eye cutting part 28 does not cut. The second Cutting block 43 has in the eye-cutting part associated Area a recess 43 a.

The application of the adjustment drive 34 and thus the shift the carrier 30 in one of the two end positions, in which either the first cutting block 42 under the knife 26 or the second cutting block 43 is located under the knife 26, carried by a not shown Compressed air source via an electromagnetically actuated multi-way valve 45th

The sewing machine is provided with a control unit 46 via which the x-drive 9, the y-drive 10, the multi-way valve 45 for the adjustment drive 34, the drive motor 5 of the arm shaft 4, not shown Clamping drives for the material clamps 12a, 12b and the cutting drive 19 are controlled. The control unit 46 has a memory part 47 on. Furthermore, the one operating unit 48 is an input keyboard 49 and a display 50 provided.

The procedure results from FIGS. 8 and 9. After sewing an eyelet-buttonhole seam 51 in a fabric part 52, the fabric part 52 is transported into the cutting device 16 by means of the xy table 8 in the y-direction. The first cutting block 42 is located under the knife 26. The cutting drive 19 is actuated. The entire knife 26 comes into cutting action with the first cutting block 42 forming a mating surface, so that the straight cutting part 27 and the eye cutting part 28 intersect an eye buttonhole 53 having the length L ₂₆ .

If, by contrast, according to FIG. 9, a simple buttonhole, that is to say a buttonhole without an eye and with any end bartacks, has been sewn, then the second cutting block 43 is under the bite by appropriate loading of the adjustment drive 34 Knife 26 brought. The fabric part 52 with the buttonhole seam 54 is moved over the second cutting block 43. By operating the cutting drive 19, only the straight cutting part 27 of the knife 26 comes into cutting contact with the cutting block 43. Only a straight buttonhole 55 with the length L _{27 is} cut.

An alternative results from Figures 10 and 11. Here, the Knife 26 'has a middle rectilinear cutting part 27 and at the both ends each have an eye-cutting portion 28 and 28 '. The Cutting blocks 42 ', 43' are formed so that the first cutting block 42 'only with the straight edge part 27 and the eye-cutting part 28 comes in cutting connection, while the second Cutting block 43 'is formed so that it only with the rectilinear Cutting edge part 27 and the eye-cutting part 28 'in cutting connection comes. This embodiment thus allows the generation of in their Location different eye button holes.

The cutting drive 19 in the embodiment of FIG. 12 is in Essentially formed by a multi-chamber cylinder 56, which means of the joint 20 is fixed in the base plate 2. There is a piston rod in it 57 arranged, the outer end via the joint 22 with the Lever 21 is connected. In the cylinder 56 are a total of four chambers 58th to 61 separated by partitions 62, 63, 64 from each other, each sealed by the piston rod 57 to be penetrated. The chambers 58 to 61 are thus - based on the length of the cylinder 56 - in a row arranged. In each chamber, a piston 65, 66, 67, 68 is arranged, the is fixedly connected to the piston rod 57 and opposite the cylinder 56th is sealed. The chambers 58, 59, 60, 61 with the piston 65 to 68 form so four spatially arranged one behind the other, active linear actuators. The piston 65 in the first chamber 58 can be acted on two sides, via lines 69, 70, d. H. this is the piston rod depending on admission in Ausschub direction 71 or in insertion direction 72 acted upon.

The three further chambers 59, 60, 61 are by means of a common line 73 only acted upon in such a way that on the piston rod 57 a Force in Ausschubrichtung 71 is exercised. The three lines 69, 70, 73 are by means of three multi-way valves 74, 75, 76 acted upon by the control unit 46 can be controlled by means of the control unit 48.

All pistons 65 to 68 and, accordingly, the chambers 58 to 61 have the same diameter; the pressure of them over the valves 74 bis 76 supplied compressed air is the same, so that depending on the application of each acted upon piston 65 to 68 the same force on the piston rod 57 is exercised. A total of four stages, on the piston rod 57 in Ausschubl direction 71 exerted pushing force and thus one on the knife 26 and 26 'exerted cutting force is thus in a gradation 25%, 50%, 75% or 100% of the maximum possible pushing force exercised. This is done as follows:

Upon loading only the piston 65 via the line 70 and the valve 75, the piston rod 57 in the extension direction 71 with 25% of maximum possible Ausschubkraft applied.

When the pistons 66, 67, 68 and with simultaneous application of pressure of the piston 65 via the line 69 and the valve 74 is the Piston rod 57 with 50% of the maximum possible extension force in the extension direction 71 charged. This results from the fact that by admission the piston 65 via the line 69 a counterforce on the Piston rod 57 is exerted in the insertion direction 72, resulting in a partial compensation the on the piston 66, 67, 68 in the extension direction 71st acting forces leads.

If only the piston 66, 67, 68 acted on the line 73 and the valve 76 be, then the piston rod 57 is a force in the extension direction 71 amounting to 75% of the total possible pushing force exercised.

When the piston 65 via the line 70 and the multi-way valve 75 is applied is and at the same time the piston 66 to 68 via the line 73rd and the valve 76 are acted upon, then act on the piston rod 57 100% of the total possible pushing force.

To retract the piston rod 57, d. H. for lifting the knife 26, 26 'from the anvil 18 after performing a cutting operation only the piston 65 via the line 69 and the valve 74 is applied, while the other two lines 70, 73 are vented.

In the alternative embodiment of the cutting drive 19 'according to FIG. 13 is a double-sided pneumatically actuated piston-cylinder drive 77 provided, the cylinder 78 on the one hand and the piston rod 79th on the other hand are integrated into a toggle mechanism 80. This Knee lever mechanism 80 is on the one hand by means of the joint 22 with the Swivel lever 21 connected and on the other hand by means of the hinge 20 a force limiter 81 supported. The cylinder 78 is via a multi-way valve 82 and two lines 83, 84 connected on both sides of the Open piston 85 of the drive 77 in the cylinder 78. Depending on the admission of the piston 85 via one of the lines 83 or 84 is the Swivel lever 21 pivoted so that the cutting drive 19 ' a cutting movement of the knife 26 or 26 'executes or the knife 26, 26 'returns to its upper rest position. When applying the Piston 85 via line 83 takes the toggle mechanism 80th its stretched position, whereby a cutting movement is performed, while upon loading the line 84, the knife 26, 26 'back in its upper resting position is lifted.

A limitation of the pivoting lever 21 and thus the knife 26th or 26 'applied force is effected by the force limiter 81. This has a four-tier abutment 86, which by means of a stationary Part 87 stationary, d. H. immovable, supported in the base plate 2. The stationary part 87 of the abutment 86 carries a resilient part 88, on which the toggle mechanism 80 is supported by means of the joint 20. The fixed part 87 is constructed like a frame and has one above the other four pneumatically actuated diaphragm cylinders 90, 91, 92, 93 as passive linear drives on. The resilient part 88 of the abutment 86 also has one above the other shelves 94, respectively an intermediate floor 94 is disposed above an intermediate floor 89.

The diaphragm cylinders 90 to 93 are thus each on an intermediate floor 89 and disposed below a false floor 94. Everyone Membrane cylinder 90 to 93 has below its membrane 95, ie in its interior, an inner stop 96 on. On the membrane is 95 in each case an outer stop 97 attached. The respective outer stop 97 can therefore be moved vertically by means of the respective membrane 95 become.

In a depressurized state, the membranes 95 are in contact with the inner stops 96, while in an application of compressed air the outer stops 97 with a rim 97a on a diaphragm cylinder cover 91a get to the plant. The design is such that each diaphragm cylinder only a small stroke of, for example, one to two millimeters.

The membrane cylinders 91, 92, 93 are via lines 98, 99, 100 via Multi-way valves 101, 102, 103 supplied with compressed air. The diaphragm cylinder 90 is connected to the line 83, the drive 77th applied.

Depending on whether an action on the drive 77 in the cutting direction only the always simultaneously acted membrane cylinder 90 or nor one or two or three diaphragm cylinder 91 to 93 applied be on the toggle mechanism 80 via the joint 20 a Abutment force of 25%, 50%, 75% or 100% of the maximum possible Abutment force exercised. In turn, this will be on the Swing lever 21 exerted force applied.

The magnitude of the forces exerted can be predetermined by a pressure regulator 104 be, which is also controlled via the control unit 48. A similar pressure regulator can of course also in the embodiment are provided in FIG. 12. Incidentally, also done in the embodiment of FIG. 13, the control of the valves 82, 101, 102, 103 via the operating unit 48.

The purpose of the force grading is to adapt the cutting device 16 to different cutting conditions by the Hardness of the material to be sewn, the type of material to be sewn, the number of pieces to be cut Sewing material layers, but also by the shape and / or size of the executed Cut are affected. In summary, with the adaptation the cutting force a flexible, the cutting conditions customizable Cutting device 16 created in the knife 26, 26 'and Anvil 18 protected against unnecessary wear due to excessive cutting forces are, whereby the operational readiness is considerably increased.

Claims (7)

Buttonhole sewing machine, with an upwardly and downwardly drivable needle (7), with at least one sewing material clip (12a, 12b) which can be displaced in a y-direction, with a buttonhole cutting device (16), the arranged in the y-direction behind the needle (7), a knife (26, 26 '), at least one with the knife (26, 26 ') cooperating cutting block (42, 43), and a cutting drive (19, 19 ') for moving the blade (26, 26') and the cutting block (42, 43) relative to each other with variable cutting force, characterized, that the cutting drive (19, 19 ') comprises a plurality of linear drives, the are connected in parallel with each other and optionally be acted upon pneumatically. Buttonhole sewing machine according to claim 1, characterized in that the linear drives are designed as multi-chambered cylinders (56) in each chamber (58 to 61) a piston (65 to 68) is arranged, which on a common piston rod ( 57) are mounted. Buttonhole sewing machine according to claim 2, characterized in that at least one chamber (58) is provided with a double-sided acted upon piston (65), and
in that three chambers (59 to 61) are provided with pistons (66 to 68) which can be acted upon jointly on one side in the same direction of movement. Buttonhole sewing machine according to claim 1, characterized in that the cutting drive (19 ') has a piston-cylinder drive (77), which is supported against the power limiters (81) designed as linear drives. Buttonhole sewing machine according to claim 4, characterized in that the force limiter (81) has a plurality of diaphragm cylinders (90 to 93) as Linear drives has. Buttonhole sewing machine according to claim 1, characterized in that the linear actuators via multi-way valves (74 to 76, 82, 101 to 103) can be acted upon, which can be actuated by a central control unit (48). Buttonhole sewing machine according to claim 1, characterized in that the linear drives are combined to form a structural unit.

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