Industrial sewing machine

Abstract

The invention relates to an industrial sewing machine (17) comprising at least one unit (18) connected to a control cylinder (1). The control cylinder (1) is hydraulically coupled to an actuator cylinder (3), and a cam drive (6) driven by an electric stepper motor (5) engages with the piston rod (4) of said actuation cylinder.

Description

[0001] industrial sewing machine

[0002] Technical area

[0003] The invention relates to an industrial sewing machine with at least one device connected to an actuating cylinder.

[0004] State of the art

[0005] To adapt to different sewing conditions, certain components of industrial sewing machines, such as presser feet, thread cutters, fabric edge guides, and differential feeders, can be adjusted or set. To eliminate the need to perform these adjustments manually, controllable actuators are increasingly being used. These actuators, increasingly pneumatic, offer the advantage of being smaller and offer sufficient travel ranges compared to electromagnetic actuators. However, in addition to the fact that compressed air must be provided at great expense, these pneumatic actuators have the disadvantage that the travel range is predetermined by the piston stop, and intermediate positions cannot be controlled.

[0006] Description of the invention

[0007] The invention is therefore based on the object of creating a simple control system for adjustable devices on industrial sewing machines, allowing these devices to be sensitively adapted to different sewing conditions. Starting with an industrial sewing machine of the type described above, the invention achieves this object by hydraulically coupling the actuating cylinder to an actuating cylinder, whose piston rod is actuated by a cam drive driven by an electric stepper motor.

[0008] By providing an actuating cylinder hydraulically coupled to the actuating cylinder, a slip-free transmission of the piston stroke is achieved between the actuating cylinder and the actuating cylinder, so that any intermediate position of the actuating cylinder's piston rod can be controlled with a corresponding travel of the actuating cylinder. Due to the hydraulic coupling of the actuating cylinder and the actuating cylinder, which requires only a hydraulic line between the pressure chambers of the actuating cylinder and the actuating cylinder, the actuating cylinder with its cam drive can be installed independently of the actuating cylinder's arrangement on the industrial sewing machine, which depends on the device to be controlled, but also separately, thus creating space-saving installation conditions for the actuating cylinder.In addition, a travel ratio between the actuating cylinder and the positioning cylinder can be provided by mutual coordination of the pressure chamber volumes.

[0009] Since a cam drive is provided for adjusting the piston rod of the actuating cylinder, and this cam drive is connected to an electric stepper motor, the cam can be rotated according to the desired cam stroke by controlling the electric stepper motor. This allows for precise adjustment of the actuating cylinder and thus adjustment of the respective device of the industrial sewing machine in both adjustment directions, independent of predefined end stops. It is only necessary to ensure that the cam drive interacts with the piston rod of the actuating cylinder without play.

[0010] Particularly simple construction conditions arise when the

[0011] The piston rod of the actuating cylinder is hinged to an actuating lever, which rests on the cam of the cam drive between its bearing axis and the pivot axis on the piston rod. The actuating lever, which can be pivoted using the cam, results in a travel ratio that makes the cam stroke independent of the required travel of the actuating cylinder or the actuating cylinder.

[0012] In industrial sewing machines, individual work steps must be synchronized, which requires synchronous control of the devices provided for them. To enable simple conditions for such synchronous, coordinated control of the actuating cylinders of these devices, a cam drive can be provided for actuating multiple devices, each with an actuating cylinder hydraulically coupled to an actuating cylinder. This cam drive has a cam on a common camshaft for each actuating cylinder. The common camshaft for the different cams ensures a simple, interdependent control of the actuating cylinders for the individual devices.

[0013] Brief description of the invention

[0014] The drawing shows an example of the subject matter of the invention.

[0015] Fig. 1 shows a device according to the invention for controlling an actuating cylinder in a schematic plan view,

[0016] Fig. 2 is a section along the line ll-ll of Fig. 1,

[0017] Fig. 3 shows a device according to the invention for controlling several actuating cylinders in a schematic plan view,

[0018] Fig. 4 a section along the line IV-IV of Fig. 3 and

[0019] Fig. 5 shows an industrial sewing machine according to the invention in a schematic block diagram.

[0020] 1 and 2, a device for controlling an actuating cylinder 1, with the aid of which a device of an industrial sewing machine is adjusted, comprises an actuating cylinder 3 which is coupled to the actuating cylinder 1 by a hydraulic line 2 and whose piston rod 4 is connected to a cam drive 6 driven by an electric stepping motor 5. The stepping motor 5 is flanged to a frame 7, in which the camshaft 8 driven by the stepping motor 5 is mounted between two end walls 9. Between these end walls 9 there is also an actuating lever 10 which can be pivoted about a bearing axis 11 and which is connected at its free end by means of a linkage axis 12 to the piston rod 4 of the actuating cylinder 3 which is mounted on an axis 13 so as to be pivotable between two arms 14 of the frame 7.Between the bearing axis 11 and the pivot axis 12, the actuating lever 10 is supported by a roller as a cam follower 15 on the cam 16 of the cam drive 6 and is held in play-free contact with the cam 16 by a restoring torque. This restoring torque can be provided by a restoring spring acting on the actuating lever 10 or the piston of the actuating cylinder 3, or by a restoring force transmitted from the device to be adjusted or from the actuating cylinder to the actuating cylinder 3 via the hydraulic line 2.

[0021] If the cam 16 is rotated by the electric servomotor 5, the actuating lever 10 is pivoted by the cam 16 in accordance with the cam stroke associated with the respective rotation step, with the result that the piston of the actuating cylinder 3 is displaced and hydraulic fluid is displaced from the pressure chamber of the actuating cylinder through the hydraulic line 2 into the pressure chamber of the actuating cylinder 1, which results in an adjustment of the piston of the actuating cylinder 1 and thus a corresponding actuation of the device of the industrial sewing machine connected to the actuating cylinder.Although only one hydraulic line is required when the actuating cylinder 1 and the actuating cylinder 3 are designed as cylinders that can be actuated from one side, the actuating cylinder 1 and the actuating cylinder 3 can also be designed as double-acting cylinders, the pressure chambers of which on both sides of the piston are each connected to one another by a hydraulic line to form a hydraulic circuit.

[0022] According to Figs. 3 and 4, a device is provided for controlling a plurality of actuating cylinders 1a, 1b, 1c, each of which is hydraulically actuated by an actuating cylinder 3a, 3b, 3c. A common cam drive 6 is assigned to the actuating cylinders 3a, 3b, 3c, which, however, provides a separate cam 16a, 16b, 16c for each actuating cylinder on a common camshaft 8. The basic construction, determined by a cam 16a, 16b, 16c each, for actuating the individual actuating cylinders 3a, 3b, 3c by the actuating levers 10a, 10b, 10c acting on the piston rods 4a, 4b, 4c, corresponds in each case to the construction of the cam drive 6 according to Figs. 1 and 2. With the aid of the electric stepper motor 5, which is connected to the camshaft 8, the cams 16a, 16b, 16c and thus the actuating cylinders 1a, 1b, 1c are inevitably driven in a mutually dependent manner.

[0023] Fig. 5 shows an industrial sewing machine 17 with devices 18 that can be adjusted according to the invention. Although only the presser foot 19 and a fabric edge guide 20 with the associated adjusting cylinders 1 are visible, other devices can also be controlled according to the invention, namely, according to the exemplary embodiment, a thread cutter and a differential feeder. The adjusting cylinders 1 of these devices are connected to the actuating linkage 21 of the thread cutter and to the adjusting lever 22 for the differential feeder.

[0024] The actuating cylinders 1 of the various devices 18 are controlled by a control unit 23, which, depending on the requirements, comprises control devices according to Figs. 1 and 2 and / or according to Figs. 3 and 4. Thus, for example, no adjustment is required between the setting of the fabric edge guide 20 and the other setting parameters of the industrial sewing machine 17, so that a control device according to Figs. 1 and 2 is to be provided to control the fabric edge guide 20. The same applies to the contact pressure of the presser foot 19, by whose actuating cylinder 1 the pretension of the compression spring acting on the presser foot 19 should be preset independently of other setting parameters.

[0025] However, if a mutually dependent adjustment of different devices 18 is required, a control device according to Figs. 3 and 4 is preferably used, wherein for each device 18 a separate cam 16 is provided for actuating the hydraulic actuators assigned to the individual devices 18, each comprising an actuating cylinder 3 and a setting cylinder 1.

Claims

7 Patent claims 1. Industrial sewing machine (17) with at least one device (18) connected to an actuating cylinder (1), characterized in that the actuating cylinder (1) is hydraulically coupled to an actuating cylinder (3), on whose piston rod (4) a cam drive (6) driven by an electric stepper motor (5) acts.

2. Industrial sewing machine (17) according to claim 1 , characterized in that the piston rod (4) of the actuating cylinder (3) is articulated to an actuating lever (10) which is supported between its bearing axis (11 ) and the pivot axis (12) on the piston rod (4) on the cam (16) of the cam drive (6).

3. Industrial sewing machine (17) according to claim 1 or 2, characterized in that a cam drive (6) is provided for actuating several devices (18) by means of a hydraulically coupled actuating cylinder (1a, 1b, 1c) for each actuating cylinder (3a, 3b, 3c). (3a, 3b, 3c) has a cam (16a, 16b, 16c) on a common camshaft (8).

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