Classifications

• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B27/00—Work-feeding means
  • D05B27/10—Work-feeding means with rotary circular feed members
  • D05B27/14—Work-feeding means with rotary circular feed members rotating discontinuously
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B27/00—Work-feeding means
  • D05B27/10—Work-feeding means with rotary circular feed members
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B27/00—Work-feeding means
  • D05B27/02—Work-feeding means with feed dogs having horizontal and vertical movements
  • D05B27/04—Work-feeding means with feed dogs having horizontal and vertical movements arranged above the workpieces
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B29/00—Pressers; Presser feet
  • D05B29/06—Presser feet
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B73/00—Casings
  • D05B73/04—Lower casings
  • D05B73/12—Slides; Needle plates
• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
  • D05D2207/00—Use of special elements
  • D05D2207/02—Pneumatic or hydraulic devices

Definitions

• the invention relates to a sewing machine with a rotationally driven upper feed means according to the preamble of claim 1.
• the drive of an upper, rotatingly driven feed means which is arranged to support the feed of the sewing material, takes place either from the main shaft of the sewing machine or from a separate drive motor.
• the upper feed means is driven by the main shaft of the sewing machine or by a gear connected to it in
• the drive shaft If the drive shaft is connected, then its drive direction must be reversed by a suitable measure in order to carry out a reverse thrust, or the feed means must be released from the drive.
• DE-PS 3008 135 discloses an upper feed means driven by a stepping mechanism, in which a reversing gear with a clutch (radial toothing) is part of the drive connection for generating forward and backward feed movement of the feed means.
• a drive device for a caster in which a rocker arm with freewheel drives a first gear located on a bearing piece, which is connected to a second tooth connected to the caster. ad is engaged, the bearing piece being pivoted on a roller foot carrier.
• a gear wheel of a rear opener which gear wheel is connected to a shift sleeve, meshes with the first gear wheel.
• a Bowden cable is connected to the stitch control lever, which first pushes the switching bushing and thus the gear wheel of the backstop via a driver when switching from forward to reverse stitch (reverse sewing). disengages and then pivots the bearing piece so that the first gear is disengaged from the gear arranged on the roller foot.
• the caster foot drive is thus interrupted by removing the driven gear wheel.
• the drive direction of the motor must be reversible for the reverse stitch so that the roller presser can be driven synchronously with the reverse feed, or the feed means must be able to be released from the drive.
• the invention is based on the object of creating a sewing machine with a rotatingly driven upper feed means which allows the feed means to be left freely rotatable on the sewing material with the same contact pressure and in both directions of rotation when its drive is interrupted, the space requirement and the inertia of the Setup should be low, shifting should be soft and shift rate should be high.
• the transmission of an axially acting force is made possible in an advantageous manner both when the feed means is engaged and when it is disengaged, so that the feed means can also be disengaged state can rest with a predeterminable pressure on this.
• the embodiment according to claim 2 offers the further advantage of being able to lift the feed means from the sewn material only by axially displacing the driven part instead of displacing the entire drive device.
• the measure described in claim 3 also advantageously achieves a defined assignment of the axes of the driven and driven parts.
• the arrangement of the pressure medium channel for applying pressure to the pressure medium piston within the drive shaft is advantageous because it saves space and also reduces weight (claim 7).
• FIG. 1 shows the drive device for a sewing machine according to the invention equipped with a roller foot, partially in section;
• Fig. 2 shows a section II II through the clutch
• FIG. 3 shows a partial side view of the drive device according to FIG. 1;
• Fig. 4 shows the arrangement of the roller foot.
• the drive unit shown in Fig. 1 essentially consists of a drive shaft 1, a spherical bearing 2 that can be rigidly fastened to the sewing machine head and in which the drive shaft is mounted, two drive bushings 3 (one-way clutches) provided with a freewheel, on which the links 4 act are arranged on a swing arm 6 located on the sliding shaft 5 of the sewing machine, as well as a clutch with a wrap spring 7 arranged on the drive shaft 1 on the roller foot side.
• the drive part 8 of the clutch is one with the
• the central element of the clutch is the wrap spring 7, which is bent at its ends to form end pieces 10, 10a that are approximately parallel to the axis and one end of which is attached to the end piece 10 on a first disc 11 provided with a slot 14, which is fixed in the drive part 8 by means of a threaded pin 12 (Fig.
• a second disc 13 which is provided with a slot 14 and which is freely rotatably arranged in the driven part.
• the elongated holes 14 of the two discs 11, 13 are advantageously provided with a chamfer on both sides.
• the outer diameter of the wrap spring 7 is slightly larger than the inner diameter of the one surrounding it
• the output-side end of the wrap spring 7 can be twisted relative to the drive-side end. This is a through the
• Flat piston rod 15 which is wound helically on the output side and is axially displaceable.
• the F'ikoltu . rod 15 is firmly connected to a piston 16, which is guided in a form-fitting manner in the drive part 8 and which can be pressurized with compressed air via a channel 17 in the drive shaft 1, whereby the axial displacement of the flat piston rod 15 is accomplished.
• the compressed air is applied via a controllable valve located outside of the device, via the supply line 18 and the annular groove 20 located in the stationary extension piece 12. Sealing rings 21 in the extension piece 19 ensure defined pressure conditions.
• the driven part 9 carries a slotted ball head 22, which engages in an indicated caster foot unit 23 of known construction, which transmits the rotational movement of the driven part to the caster foot 24 via a spiroid gear, with a ring gear connected to the caster foot being driven by a ring gear driven by the ball head 22 and eccentrically meshing pinion is driven.
• the switching clutch makes it possible to switch off the roller presser drive even during sewing operations, without the roller presser having to be lifted off the material to be sewn.
• the drive shaft 1 and thus also the drive part 8 of the clutch are driven intermittently as a result of the movement of the swing arm 6 connected to the sliding shaft and the link 4 by the two drive bushes 3 arranged in opposite directions and each provided with a one-way clutch.
• Both drive bushings drive when turning clockwise, while they run free when turning counterclockwise, so that the drive shaft is constantly given rotary impulses in one direction, which in the coupled state is force-fitting via the wrap spring 7 on the driven part 9 the slotted ball head 22 and thus be transferred to the indicated roller foot unit 23 with the roller foot 24.
• the caster foot drive is interrupted when the non-positive connection between the wrap spring 7 and the driven part 9 of the clutch is released.
• the roller foot unit 23 is arranged on the presser bar 25, which is pressed at its end facing away from the sewing material by means of a leaf spring against the sewing material and can be lifted off the sewing material together with this if necessary.
• the caster foot unit 23 presses on the drive device and pushes it with the drive bushings 3 upwards.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Sewing Machines And Sewing (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6387489

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Citations (4)

Family Cites Families (2)

• 1989
  • 1989-08-21 DE DE3927493A patent/DE3927493C1/de not_active Expired - Lifetime
• 1990
  • 1990-08-20 WO PCT/EP1990/001367 patent/WO1991002836A1/de not_active Ceased
  • 1990-08-20 JP JP2511996A patent/JPH07504576A/ja active Pending
  • 1990-08-20 KR KR1019920700376A patent/KR920703907A/ko not_active Withdrawn

Patent Citations (4)

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