EP2105526B1 - Sewing machine - Google Patents

Description

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

Such a sewing machine is known by public prior use. Other sewing machines are known from the DE 198 20 646 A1 , of the DE 689 09 031 T2 and DE 10 2006 011 495 A1 ,

According to the JP 07 231991 A For example, a sewing machine having a presser foot has a fan adjusting lever for releasing the presser foot and a lift height adjusting lever for setting a feed stroke of the presser foot, and the fan adjusting lever and the lift height adjusting lever can be moved by a common drive.

The JP 06 238078 A shows a sewing machine with a presser foot, which is driven so that no excessively high pressure from the presser foot is applied to the fabric.

From the US 4,915,044 A a Nähfußmechanik is known, which ensures a concern of a presser foot on a sewing material during a Armwellenumdrehung over a large angular range.

According to the FR 2 495 651 is a presser foot in a rest position adjustable by fine thread screws.

Object of the present invention is to reduce the effort in the construction of the fan device and the lifting height adjustment.

The object is achieved by a sewing machine with the features specified in claim 1.

In the case of the previously known sewing machines, insofar as these have their own adjusting shafts for the fan device on the one hand and the lifting height adjusting device on the other hand, independent drives for the fan device on the one hand and for the lifting height adjusting device on the other hand are provided. According to the invention it has been recognized that these two devices can also be driven together. Mechanically, the coupling of the two devices to the common drive can be realized with relatively little effort. Since a drive can be saved, the overall construction is cheaper and more compact. The presser foot can be designed as a hold-down, as it is known for embroidery machines. The presser foot can be configured in two parts with a presser foot and a transport foot. The fan device and / or the lifting height adjustment device are designed so that their respective assigned Adjusting shaft about its rotational position about an adjusting shaft longitudinal axis specifies the desired control value for the fan height and / or the lifting height. This manipulated variable input via the rotational position of the adjusting shaft can be realized for example by an eccentric arrangement of the adjusting.

The common drive can be designed as a stepping motor drive. As a result, different fan heights and / or different stroke settings for the transport stroke with fine gradation can be specified. This can be used to adapt to the respective sewing environment. When sewing thick fabrics, a high fan height can be preset. When sewing various layers of multi-layered sewing material, an enlarged transport stroke with fine adjustment of the lifting height can be specified for bridging the sewing material stages.

Cams according to claim 3 ensure a cost-effective implementation of the mechanical coupling of the fan device on the one hand and the lifting height adjustment on the other hand to the motor shaft of the drive. The cam discs may have a cam disk section which extends coaxially about a bearing shaft of the cam disk and a cam disk section which runs helically around this bearing shaft and which adjoins the coaxially extending cam disk section. As long as a bearing section to be controlled with the cam abuts the cam disk via the coaxially extending cam section, this remains ineffective. Instead of such cams and segmented gears can be used, which are rotated to each other mounted on a drive motor shaft, that only one of the gear segments with a portion to be controlled is engaged. Also in this embodiment with segmented gears, the maximum rotation of the drive motor shaft for generating the maximum control on the one hand the fan device and on the other hand the lifting height adjustment be kept low and, for example, less than 360 °. A backlash of components that come together interacting with each other in the common drive, can be ensured by a spring preload. Another variant instead of two cams can be realized by a lever mechanism. This is designed so that a mounted on the motor shaft of the drive motor lever in a first pivoting direction, for example in a clockwise direction, with the fan device for releasing the presser foot and in a second pivoting direction, for example, counterclockwise, with the lifting height adjustment for actuation respectively one of these two institutions cooperates. Another variant instead of the two cams can be realized by two transmission gear, which can be separated from each other by a pneumatically, mechanically or electrically actuated clutch. The transmission gear can be realized as a pair of gears, toothed / V-belt, coupling gear or as a cam gear. In this variant, a twist angle of the drive motor can also be greater than 360 °. This can be used to provide a larger ratio, so that the torque to be transmitted from the drive motor shaft is reduced.

An arrangement according to claim 4 ensures a functional separation of the operation of the fan device on the one hand and the operation of Transporthubverstellung the other. The fan device then operates independently of the Hubhöhen adjustment, so that these facilities can not interfere with each other.

A design and arrangement of the cams according to claim 5 is particularly preferred in relation to a functional separation of the operation of the fan device from the operation of the lifting height adjustment device via the common drive. Starting from a zero position, both functions can be achieved by a rotation of the motor shaft of the stepping motor with an absolutely small angle of rotation.

Adjusting shafts according to claims 6 and 7 have proven to be safe and robust adjustment of the fan device on the one hand and the lifting height adjustment on the other hand. Alternatively, variants without such adjustment can be realized. By way of example, the ventilating device can be designed so that a lever which causes the sewing foot to air is connected directly to a drive shaft of the common drive.

Cams according to claim 8 reduce the cost again.

A maximum adjustment path according to claim 9 reduces the requirements for the common drive.

A bearing according to claim 10 ensures a safe guidance of the motor shaft, so that the requirements for a drive-side mounting of the motor shaft are reduced accordingly.

The advantages of the common drive variants according to claims 11 to 13 correspond to those which have already been explained above in connection with the common drive according to the invention.

Fig. 1

schematisch ein zum Teil gebrochen dargestelltes Gehäuse einer Nähmaschine in einer Vorderansicht;

Fig. 2

perspektivisch eine Baugruppe mechanischer Komponenten der Nähmaschine mit einer Lüftereinrichtung zum Lüften ei- nes Nähfußes der Nähmaschine und einer Hubhöhen- Verstelleinrichtung zur Vorgabe eines Transporthubes des Nähfußes mit einem gemeinsamen Antrieb in einer Nullstel- lung;

Fig. 3

in einer zu Fig. 2 ähnlichen Darstellung die Baugruppe mit der Hubhöhen-Verstelleinrichtung in der Stellung,, maximaler Hub";

Fig. 4

in einer zu Fig. 2 ähnlichen Stellung die Baugruppe mit der Lüftereinrichtung in der Stellung "gelüfteter Nähfuß";

Fig. 5

ein Diagramm, welches eine Lüfterhöhe sowie einen Trans- porthub in Abhängigkeit einer Drehstellung des gemeinsamen Antriebs für die Lüftereinrichtung und die Hubhöhen- Verstelleinrichtung zeigt;

Fig. 6

in einer zu Fig. 2 ähnlichen Darstellung eine Baugruppe me- chanischer Komponenten der Nähmaschine mit einer Lüfter- einrichtung zum Lüften eines Nähfußes der Nähmaschine und einer Hubhöhen-Verstelleinrichtung zur Vorgabe eines Transporthubes des Nähfußes mit einer weiteren Ausführung eines gemeinsamen Antriebs in einer Nullstellung;

Fig. 7

in einer zu Fig. 2 ähnlichen Darstellung eine Baugruppe me- chanischer Komponenten der Nähmaschine mit einer Lüfter- einrichtung zum Lüften eines Nähfußes der Nähmaschine und einer Hubhöhen-Verstelleinrichtung zur Vorgabe eines Transporthubes des Nähfußes mit einer weiteren Ausführung eines gemeinsamen Antriebs in einer Nullstellung; und

Fig. 8

in einer zu Fig. 2 ähnlichen Darstellung eine Baugruppe me- chanischer Komponenten der Nähmaschine mit einer Lüfter- einrichtung zum Lüften eines Nähfußes der Nähmaschine und einer Hubhöhen-Verstelleinrichtung zur Vorgabe eines Transporthubes des Nähfußes mit einer weiteren Ausführung eines gemeinsamen Antriebs in einer Nullstellung.

An embodiment of the invention will be explained in more detail with reference to the drawing. In this show:

Fig. 1

schematically a partially broken housing of a sewing machine in a front view;

Fig. 2

perspective view of an assembly of mechanical components of the sewing machine with a fan device for releasing a sewing foot of the sewing machine and a Hubhöhen- adjusting device for specifying a transport stroke of the presser foot with a common drive in a neutral position;

Fig. 3

in one too Fig. 2 similar representation of the assembly with the lifting height adjustment in the position "maximum stroke";

Fig. 4

in one too Fig. 2 similar position, the assembly with the fan device in the position "aired presser foot";

Fig. 5

a diagram showing a fan height and a transport hub in response to a rotational position of the common drive for the fan device and the Hubhöhen- adjustment;

Fig. 6

in one too Fig. 2 a representation similar assembly of mechanical components of the sewing machine with a fan device for ventilating a sewing foot of the sewing machine and a lifting height adjustment device for specifying a Transport stroke of the presser foot with a further embodiment of a common drive in a neutral position;

Fig. 7

in one too Fig. 2 a representation of an assembly of mechanical components of the sewing machine with a fan device for releasing a sewing foot of the sewing machine and a lifting height adjustment device for specifying a transport stroke of the presser foot with a further embodiment of a common drive in a zero position; and

Fig. 8

in one too Fig. 2 similar representation of an assembly of mechanical components of the sewing machine with a fan device for releasing a sewing foot of the sewing machine and a lifting height adjustment for specifying a transport stroke of the presser foot with a further embodiment of a common drive in a zero position.

A sewing machine, of which in the Fig. 1 a housing 1 is shown, has a stand 2, an arm 3 and a head 4, so that together with a in the Fig. 1 not shown base plate results in a total C-shaped structure of the sewing machine. An arm shaft 5, which is driven via a main drive, not shown in the figure, drives a needle bar 6 with a sewing needle 7 fixed thereto upwards and downwards. The needle 7 passes through a stitch hole 8 in a needle plate 9, which forms part of a support plate, not shown, which in turn represents the top of the base plate of the sewing machine.

The sewing machine has to hold down and to transport sewing material during sewing a sewing foot 10, which is divided a presser foot 11 and a transport foot 12. The presser foot 11 serves to hold down the material during sewing. The transport foot 12 serves for transporting the material along a sewing direction parallel to the longitudinal extension of the needle plate 9.

To ventilate the presser foot 10 is a generally designated 13 fan device. This has a fan shaft 14, with the Nähfußseitig a first fan shaft rotary lever 15 is rotatably connected. The first fan shaft rotary lever 15 is in turn articulated via a not visible in the drawing in detail connection on the one hand to a Transportfußstange 16 and on the other hand to a presser foot rod 17 of the presser foot 10. At the first fan shaft rotary lever 15 opposite free end of the fan shaft 14, a second fan shaft rotary lever 18 is rotatably disposed. About a bias spring, not shown in the drawing, a contact pin 19 of the second fan shaft rotary lever 18 is pressed against a fan shaft cam 20.

Fig. 2 shows a neutral position of the fan device 13, in which the fan shaft cam 20 is oriented so that the contact pin 19 occupies a minimum distance from a motor shaft 21 of a stepping motor 22. The fan shaft cam 20 is rotatably connected to the motor shaft 21. A fan shaft control cam wall 23 of the fan shaft cam 20 against which the abutment pin 19 abuts extends helically about a longitudinal axis of the motor shaft 21.

Spaced to the fan shaft cam 20, a lifting height adjusting cam 24 is non-rotatably arranged with the motor shaft 21 continues. The cams 20, 24 each have one to the motor shaft 21 coaxial cam portion and a thereto subsequent steadily spiraling cam portion on.

About grub screws or setscrews 25, which are shown in the drawing in an exploded view, there is a rotationally fixed fixing the cams 20, 24 on the motor shaft 21. Corresponding grub screws 25 are used for rotationally mounting the various other wave components in the Fig. 2 to 4 shown assembly. The two cams 20, 24 are identically shaped components.

The Hubhöhen-Verstelleinrichtungs cam 24 is opposite to the fan shaft cam 20 mounted on the motor shaft 21. This opposite orientation is such that the spiral shape of a lift height adjuster cam wall 26 opens opposite to the fan shaft cam wall 23. In addition, the two cams 20, 24 are oriented oppositely oriented on the motor shaft 21 plugged that the free ends of the two cams 20, 24 are arranged offset by 180 ° in the circumferential direction about the motor shaft 21 to each other.

At the lift height Verstellinrichtungs cam 24 is biased by a bias spring not shown in the drawing, a contact pin 27 a Hubhöhen-Verstellinrichtungs rotary lever 28 is applied.

The Hubhöhen-Verstelleinrichtungs rotary lever 28 is rotatably connected to a Hubgetriebewelle 29 of a generally designated 30 Hubhöhen adjustment. The Hubgetriebewelle 29 is connected via a screw jack 31 with a lifting shaft 32 of the lifting height adjustment device 30 in operative connection. Together with a Hubexzenter 33, which on the Arm shaft 5 is arranged, the lifting gear 31 influences a lifting height of a transport stroke of the transport foot 12 and the presser foot eleventh

In the neutral position Fig. 2 is the contact pin 27 of the lifting height adjustment device 30 to the Hubhöhen-Verstelleinrichtungs control cam wall 26 that he occupies the motor shaft 21 a minimum distance. In this neutral position, the presser foot 10 is not released and the transport stroke of the transport foot 12 is 0.

The arm shaft 5, the fan shaft 14, the motor shaft 21, the Hubgetriebewelle 29 and the lift shaft 32 are all parallel to each other.

In the position "maximum stroke" Fig. 3 the stepper motor 22 has the motor shaft 21 starting from the neutral position Fig. 2 180 ° according to a directional arrow 34 in the Fig. 3 twisted. In the perspective view Fig. 3 have the two cams 20, 24, starting from the neutral position Fig. 2 So rotated by 180 ° clockwise. Since the contact pin 19 of the fan shaft rotary lever 18 rests on the motor shaft 21 coaxial portion 35 of the fan shaft cam 20, the position of the second fan shaft rotary lever 18 has not changed with respect to the neutral position. The presser foot 10 therefore does not remain ventilated.

In the position "maximum stroke" is the contact pin 27 of the lifting height adjustment device 30 there with the Hubhöhen-Verstelleinrichtungs control cam wall 26 in Appendix, where this has the greatest distance from the motor shaft 21. The lift height adjuster lever 28 is in the down position Fig. 3 So pivoted maximum counterclockwise, so that the Hubgetriebewelle 29 corresponding to the Turned clockwise from the Neutralstellüng out. The screw jack 31 causes in this position the Hubgetriebewelle 29 maximizing the transport stroke of the transport foot 12 and the presser foot eleventh

Fig. 4 shows the assembly in a position "aired presser foot", in which the stepper motor 22, the motor shaft 21, starting from the neutral position to Fig. 2 180 ° corresponding to a directional arrow 36 in the Fig. 4 has twisted. In the perspective view Fig. 4 is the motor shaft 21, starting from the neutral position, to the position to Fig. 4 So rotated by 180 ° counterclockwise. The contact pin 27 of the lifting height adjustment device 30 runs at this adjustment on the coaxial to the motor shaft portion 37 of the Hubhöhen-Verstelleinrichtungs cam 24 so that the contact pin 27 in the position "aired presser foot" after Fig. 4 its position compared to the neutral position after Fig. 2 did not change. In the position "lifted presser foot" after Fig. 4 So it stays with the transport stroke 0. In the position after Fig. 4 is the fan shaft pin 19 there on the fan shaft cam wall 23 where it has the maximum distance from the motor shaft 21.

In the position "ventilated presser foot" the second fan shaft rotary lever 18 and the fan shaft 14 are pivoted clockwise. The first fan shaft pivoting lever 15 pivots correspondingly. The latter displaces both the transporting foot rod 16 and the presser foot rod 17 upwards via its linkage, so that the sewing foot 10 is released.

Fig. 5 shows in a diagram once again the rotation angle n _{MW of} the motor shaft 21 dependent conditions in the ventilation and in the Hubhöhenverstellung. The in the Fig. 5 horizontal axis shows the angle of rotation the motor shaft 21 in degrees, starting from the neutral position at 0 °. In the Fig. 5 pulled through the dependence of the rotation angle n _{LW of} the fan shaft 14 from the rotation angle of the motor shaft 21 is shown. At negative angles of rotation, ie in the range of rotation of the motor shaft 21 between the positions after the Fig. 2 and 3 , the fan shaft 14 is not rotated at all, so that the presser foot 10 remains unventilated. At positive angles of rotation of the motor shaft 21, ie in the range of rotation of the motor shaft 21 between the positions after the Fig. 2 and 4 , the rotational angle of the fan shaft 14 depends linearly on the rotational angle of the motor shaft 21. At a rotational angle of the motor shaft 21 of 150 °, the fan shaft 14 is pivoted absolutely by about 52 °.

Dashed is in the Fig. 5 the dependence of the rotation angle n _{HW of} the Hubgetriebewelle 29 shown by the rotation angle of the motor shaft 21. With positive angles of rotation of the motor shaft 21, the Hubgetriebewelle 29 remains in the neutral position, so it is not pivoted. At negative angles of rotation of the motor shaft 21, the rotational or pivoting angle of the Hubgetriebewelle 29 depends linearly on the rotation angle of the motor shaft 21. At a rotation angle of the motor shaft 21 of -150 ° results in a pivot angle of the Hubgetriebewelle 29 of about 55 °.

At a given angle of rotation of the motor shaft 21 so at most one of the two cams 20, 24 for the displacement of the fan device 13 or the lifting height adjustment device 30 is active.

Due to the fact that in situations where a Nähfußlüften takes place, the transport stroke is always equal to zero, jamming of the presser foot 10 during ventilation is reliably prevented.

Between the two cams 20, 24 is a radial bearing 38 (see. Fig. 1 ), which supports the motor shaft 21 relative to the housing 1. The radial bearing 38 is designed as a ball bearing. A bearing shell of the radial bearing 38 is not shown in the drawing.

Based on Fig. 6 to 8 Three further embodiments of mechanical couplings of the stepping motor 22 to the fan device 13 on the one hand and to the lifting height adjusting device 30 on the other hand will be described below. Components which correspond to those described above with reference to Fig. 1 to 5 already described, bear the same reference numbers and will not be discussed again in detail.

In the execution after Fig. 6 a power transmission from the stepper motor 22 to the fan shaft 14 on the one hand and on the Hubgetriebewelle 29 on the other hand via tooth segments. Rotationally fixed to the motor shaft 21 of the stepping motor 22, two toothed segments 39, 40 axially spaced apart plugged. The first stepper motor toothed segment 39 meshes with a fan shaft toothed segment 41, which in turn is non-rotatably mounted on the fan shaft 14. The second stepper motor gear segment 40 meshes with a Hubgetriebewellen-toothed segment 42 which is non-rotatably mounted on the Hubgetriebewelle 29.

Fig. 6 shows the assembly in a zero position in which the presser foot 10 is not released and the transport stroke of the transport foot 12 is zero. If in the Fig. 6 the motor shaft 21 is rotated counterclockwise (direction arrow 43), the fan device 13 is activated and the presser foot 10 is released. During this rotation, the gear segment pair 40, 42 remains ineffective, so that the lifting height adjustment device 30 is not activated and the transport stroke of the transport foot 12 with the sewing foot 10 lifted

Zero remains. Upon rotation of the motor shaft 21 of the stepping motor 22, starting from the neutral position to Fig. 6 , Clockwise direction (direction arrow 44) via the intermeshing tooth segments 40, 42, a rotation of the Hubgetriebewelle 29 and a corresponding specification of a non-zero transport stroke of the transport foot 12. In this clockwise rotation in turn remains the pair of toothed segments 39, 41st ineffective, so that the presser foot 10 is not released when the transport stroke is set.

The toothed segment 39 has a peripheral section equipped with teeth, which covers approximately ¼ of the entire circumference around the motor shaft 21, ie 90 °. When toothed segment 40, the teeth extend over a comparable peripheral portion of 90 °. In the toothed segments 41, 42, the teeth extend over a peripheral portion of about 60 °.

About the peripheral portions of the toothed segments 39 to 42, carry the teeth, as well as over the radius of these toothed segments bearing peripheral portions and the tooth widths can be a ratio between a rotation of the motor shaft 21 and the respective driven shaft 14 and 29 pretend.

An initial engagement of the tooth segments with each other is ensured via a configuration, not shown in the drawing of a stop and a biasing spring.

In the execution after Fig. 7 the motor shaft 21 is connected to the fan shaft 14 on the one hand and with the Hubgetriebewelle 29 on the other hand via a lever mechanism. The motor shaft 21 carries axially spaced two levers 45, 46. The levers 45, 46 are non-rotatably mounted on the motor shaft 21. About a contact pin 47 of the stepper motor lever 45 cooperates with a fan shaft lever 48 which is rotatably mounted on the fan shaft 14. About a contact pin 49 of the further stepper motor lever 46 cooperates with a Hubgetriebewellen lever 50. The latter is in turn rotationally fixed to the Hubgetriebewelle 29 plugged.

Shown in the Fig. 7 in turn, the neutral position of the assembly in which the presser foot 10 is not released and the transport stroke of the transport foot 12 is zero. Upon rotation of the motor shaft 21 in the counterclockwise direction (direction arrow 43) is, according to what the above to the modules after the Fig. 2 to 4 or after Fig. 6 has been explained, the fan device 13 is activated. Upon rotation of the motor shaft 21 in a clockwise direction (direction arrow 44), the lifting height adjusting device 30 is activated accordingly.

As far as the levers 48, 50 in the operation of the stepping motor 22 with the contact pins 47, 49 are disengaged, these levers 48, 50 remain in a neutral position, being secured by a stop, not shown, and a biasing spring, not shown.

The contact pins 47, 49 may be made of a damping material, so that the noise in the operation of the lever mechanism after Fig. 7 is minimized.

About the relative lengths of the levers 45, 46, 48, 50 to each other, the drive ratio of the motor shaft 21 on the fan shaft 14 on the one hand and on the Hubgetriebewelle 29 on the other hand can be specified.

In the execution after Fig. 8 there is a drive connection of the motor shaft 21 with the fan shaft 14 on the one hand and with the Hubgetriebewelle 29 on the other hand via couplings. The stepper motor shaft 21 contributes to the embodiment Fig. 8 Two axially spaced and slipped onto the motor shaft 21 clutches 51, 52. With the clutches 51, 52 respectively connected to motor shaft gears 53, 54. About an endless drive belt 55 is the first motor shaft gear 53 as a driven gear with a Fan shaft gear 56 in drive connection. The fan shaft gear 56 is rotatably mounted on the fan shaft 14. With the second motor shaft gear 54 as output gear is about a further endless drive belt 57, a Hubgetriebewellen gear 58 in drive connection, which is non-rotatably mounted on the Hubgetriebewelle 29.

Shown in the Fig. 8 the assembly in the neutral position in which the presser foot 10 is not released and in which the transport stroke of the transport foot 12 is zero.

The two clutches 51, 52 provided a drive connection between the motor shaft 21 and the driven gears 53, 54 only in each case in one direction of rotation of the motor shaft 21. In the respective opposite direction, a freewheel of the clutches 51, 52 ensures that there is no operative connection between the motor shaft 21 and the driven gears 53, 54.

The clutch 51 provides a frictional connection between the motor shaft 21 and the output gear 53 when the motor shaft 21 is rotated in the counterclockwise direction (direction arrow 43). In this case, drives the motor shaft 21, the fan shaft 14, but not the Hubgetriebewelle 29 at. The clutch 52 then establishes a frictional connection between the motor shaft 21 and the output gear 54 when the motor shaft 21 is rotated in the counterclockwise direction (directional arrow 44). In this case, the motor shaft 21 drives the Hubgetriebewelle 29, but not the fan shaft 14 at.

The function of the drive connection according to Fig. 8 Thus corresponds to that of the drive connections, the above with reference to the embodiments of the Fig. 1 to 7 was explained.

Shown are the gears 53, 54, 56, 58, each with the same number of teeth and the same diameter. By means of a variation of the numbers of teeth and the diameter of the gears, it is possible to adapt a ratio of the drive on the one hand to the fan device 13 and on the other hand to the height adjustment device 30 to default values.

Claims (13)

1. Sewing machine

   - having at least one sewing foot (10) for holding down, during the sewing, material to be sewn,

   - having a raising device (13) for raising the sewing foot (10),

   - having a lifting height adjustment device (30), embodied separately from the raising device for setting a transport lift of the sewing foot (10),

   - having a common drive (22) for the raising device (13) and the lifting height adjustment device (30), characterised in that

   - the raising device (13) on the one hand and the lifting height adjustment device (30) on the other hand each exhibit their own adjustment shaft (14, 29) for setting a raising height on the one hand and a lifting height on the other hand and

   - the raising device (13) and/or the lifting height adjustment device (30) are designed such that the corresponding adjustment shaft (14, 29) allocated to them in each case sets, via its rotation position around a longitudinal axis of the adjustment shaft, the desired adjustment value for the raising height and/or the lifting height.
2. Sewing machine according to claim 1, characterised in that the drive (22) is formed by a stepper motor.
3. Sewing machine according to claims 1 or 2, characterised in that there are mounted on a motor shaft (21) of the drive (22) two cam discs (20, 24),

   - the one of the two cam discs, the raising shaft cam disc (20), being mechanically connected with the raising device (13) and

   - the other of the two cam discs, the lifting height adjustment device cam disc (24), being mechanically connected with the lifting height adjustment device (30).
4. Sewing machine according to claim 3, characterised in that the cam discs (20, 24) are formed and oriented on the motor shaft (21) such that for a given rotation angle of the motor shaft (21) no more than one of the two cam discs (20, 24) is active for shifting the raising device (13) or for shifting the lifting height adjustment device (30).
5. Sewing machine according to claim 4, characterised in that the cam discs (20, 24) are formed and oriented on the motor shaft (21) such that in a first direction of rotation of the drive (22) one of the two cam discs (20, 24) and in the second direction of rotation of the drive (22) the other of the two cam discs (20, 24) is active.
6. Sewing machine according to one of the claims 3 to 5, characterised in that the raising device (13) exhibits an adjustment shaft (14), which is swingable around its longitudinal axis through the shifting of the active raising shaft cam disc (20).
7. Sewing machine according to one of the claims 3 to 6, characterised in that the lifting height adjustment device (30) exhibits an adjustment shaft (29), which is swingable around its longitudinal axis through the shifting of the active lifting height adjustment device cam disc (24).
8. Sewing machine according to one of the claims 3 to 7, characterised in that the two cam discs (20, 24) exhibit the same exterior shape.
9. Sewing machine according to one of the claims 3 to 8, characterised by a maximum adjustment range of the motor shaft of less than 360°.
10. Sewing machine according to one of the claims 3 to 9, characterised in that between the two cam discs (20, 24) there is arranged a radial bearing for the motor shaft (21).
11. Sewing machine according to one of the claims 1 to 2, characterised in that on the motor shaft (21) of the drive (22) there are arranged two tooth segments (39, 40),

    - the one of the two tooth segments, the raising shaft tooth segment (39), being mechanically connected with the raising device (13) and

    - the other of the two tooth segments, the lifting height adjustment tooth segment (40), being mechanically connected with the lifting height adjustment device (30).
12. Sewing machine according to one of the claims 1 to 2, characterised in that on the motor shaft (21) of the drive (22) there are arranged two levers (45, 46),

    - the one of the two levers, the raising shaft lever (45), being mechanically connected with the raising device (13) and

    - the other of the two levers, the lifting height adjustment device lever (46), being mechanically connected with the lifting height adjustment device (30).
13. Sewing machine according to one of the claims 1 to 2, characterised in that on the motor shaft (21) of the drive (23) there are arranged two clutches (51, 52),

    - the one of the two clutches, the raising shaft clutch (51), being mechanically connected with the raising device (13) and

    - the other of the two clutches, the lifting height adjustment clutch (52), being mechanically connected with the lifting height adjustment device (30).

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