Classifications

• • 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
  • D05B29/08—Presser feet comprising relatively-movable parts

Definitions

• the invention relates to a sewing machine according to the preamble of claim 1.
• Such a sewing machine is the subject of the earlier patent application P 37 24788.3-26. It contains an arrangement for delaying the sequence of movements of the upper feed foot in the area of its contact position on the sewing material, in the case of a sewing machine in which only the upper feed foot lifts off the sewing material in sewing operation, while the presser foot is only relieved during the feed movement of the sewing material.
• the movement of the upper transport foot on the material to be sewn has an oblique course both in the area where the material is placed on the sewing material and in the lifting area.
• a phase shift between the lifting and the sliding movement of the upper feed foot allows a certain correction in the course of its touchdown area, but this further worsens the inclination of the curve during backward transport.
• the invention is therefore based on the object of correcting the oblique course of the placement movement of the upper feed foot on the sewing material present in the older arrangement in such a way that this movement sequence is essentially perpendicular.
• the measure according to the invention now results in a vertical course of the lifting movement of the upper transport foot.
• Fig. 1 is a side view of a sewing machine with a
• FIG. 2 shows a diagrammatic representation of the drive parts for the top transport device and their adjustment
• Fig. 3 is an enlarged view of the transmission elements for the upper feed foot, partially cut and
• Fig. 4 is a side view of the parts shown in Fig. 3, partially in section.
• FIG. 1 shows a side view of a sewing machine, in the housing of which a cloth presser rod 2 carrying a presser foot 1 and a needle bar 4 mounted in a needle bar holder 3 are accommodated, the thread-guiding needle 5 of which cooperates with a gripper (not shown).
• the sewing machine has an upper transport foot 6 which interacts with a lower fabric pusher, not shown.
• a main shaft 7 (FIG. 2), which is driven in a known manner, is furthermore mounted in the housing of the sewing machine, said main shaft being driven by a crank 8 and a handlebar 9 drives the needle bar 4.
• the handlebar 9 is mounted on a pin 10 fastened in the crank 8.
• an intermediate member 11 which is connected to a pin 12 rotatably mounted in the housing axially to the main shaft 7, on which an eccentric 13 is fastened.
• the lever arm 15b of the angle lever 15 (FIG. 1) is connected via a link 16 to a pin 17 which is carried by a crank 18. This is mounted on a pin 19 which is attached to a support element 20.
• the support element 20 is fastened on a rod 21 which is part of a support system 23.
• a coupling 28 is pivotally mounted on the pin 17, the other end of which is connected in an articulated manner via a pin 29 a to a carrier 29 for the upper feed foot 6.
• the support element 20 also carries a pin 30 on which a telescopic rod 31 is mounted, which is also connected to the carrier 29 via a pivot pin 32.
• the parts 18, 28 and 29 form a four-bar mechanism 33 for delaying the lifting movement of the upper feed foot 6 in its mounting position. Together with parts 14 to 17 and 19, they also form a handlebar system S1 for lifting the upper feed foot 6.
• the upper drive foot 6 is driven by a stitch actuator 40 (FIG. 2) which is connected to an eccentric 41 fastened to the main shaft 7.
• the stitch actuator 40 has an actuating shaft 42 mounted in the housing, which is firmly connected to a bracket 43, between the arms of which another bracket 44 passes through
• Pin 45 is rotatably mounted.
• the arms of the bracket 44 connect a bolt 46 to which an eccentric rod 47 is articulated.
• the Eccentric 41 which is enclosed by the eccentric rod 47, gives the bolt 46 oscillatory movements around the pin 45.
• a link 49 engaging on one end on the bolt 46 is articulated on the other end on a lever arm 51 which is fastened to one end of an oscillating shaft 52 mounted in the housing parallel to the main shaft 7.
• a lever arm 53 is connected to the other end of the oscillating shaft 52 and engages on an oscillating lever 55 via a link 54.
• This is fastened on an oscillating shaft 56 (FIG. 1) mounted in the shoulder of the housing, which carries a further oscillating lever 57 which is connected via a connecting link 58 to a pin 59 which is fastened to the coupling 28 between its end points.
• the parts 52 to 58 form a handlebar system S2 for pushing the upper feed foot 6.
• a lever arm 60 is fastened on the adjusting shaft 42 (FIG. 2) of the stitch actuator 40 and is connected via a link 61 to a crank 63 fastened on an adjusting shaft 62.
• a control crank 64 is clamped on the control shaft 62 mounted in the housing and is connected via an intermediate member 65 and a further control crank 66 to an intermediate shaft 67 mounted in the housing.
• a lever 68 is attached to this.
• the lever 68 is connected via a ball pull rod 69 to one end of a rocking lever 70 which is pivotable about an axis 71 fixed to the housing.
• the still free end of the rocker arm 70 has a spherical projection 72 and projects into a positioning curve 73 of a lockable adjusting wheel 74, which is arranged on an axis 75 fixed to the housing.
• the steep curve 73 in the setting wheel 74 runs so helically to its axis 75 that it allows stitch lengths of, for example, 1 to 6 mm to be set on the upper feed foot 6.
• a spring 76 surrounding the intermediate shaft 67 and fastened at one end in the housing keeps the shoulder 72 of the rocking lever 70 in constant contact with one of the side walls of the steep curve 73.
• the adjusting shaft 62 is connected to the lower slider, not shown, in a known manner, so that at one Adjustment of the adjusting wheel 74, both the upper feed foot 6 and the lower fabric slide can be adjusted synchronously with one another.
• the telescopic rod 31 arranged between the support element 20 (FIGS. 3 and 4) and the carrier 29 for the upper transport foot 6 is divided into an upper fork 80 and a lower fork 81.
• the lower fork 81 is connected to a bolt piece 82 and the upper fork 80 to a socket piece 83, which are pushed into one another and held together by a screw 84 screwed into the bolt piece 82.
• a screw 84 screwed into the bolt piece 82.
• the pretensioning of the plate spring assembly 86 can be changed by means of a nut 87, which is screwed onto the threaded socket piece 83.
• the feed size of the upper feed foot 6 (FIGS. 1 and 2) is set by turning the setting wheel 74, as a result of which the positioning curve 73 rotates the intermediate shaft 67 accordingly via the rocker arm 70.
• the intermediate shaft 67 adjusts the actuating shaft 62 via the intermediate member 65 and the actuating shaft 42 via the link 61 and the lever arm 60. This arrangement ensures that when the adjusting wheel 74 is adjusted, the feed adjustment of the upper feed foot 6 is synchronized with the feed adjustment of the lower fabric slide the actuating shaft 62 is changed.
• the telescopic rod 31 shortens during the work process while increasing the spring tension of the plate spring assembly 86 and returns to its original length when the load is released. After the upper feed foot 6 has been placed on the material to be sewn, the plate spring assembly 86 thus absorbs both its remaining stroke and the stroke movement of the lower fabric slide above the needle plate.
• the upper feed foot 6 swings out on an inclined circular path K around the pivot pin 32 as the center point. Due to the articulation of the connecting link 58 between the articulation points of the coupling 28, when the lifting movement is transmitted through the coupling 28, a horizontally directed compensating component is transmitted to the upper transport foot 6 by the rightward movement of the pin 17 in its rightward oscillation around the pin 19 left movement of the pin 29a and thus the otherwise obliquely upward circular movement of the upper transport foot 6 around the pin 32 is superimposed on a movement component directed to the left. By a suitable choice of the articulation point of the connecting link 58 on the coupling 28, an extensive correction of the lifting movement of the upper feed foot 6 can be achieved, so that both its placement movement on the sewing material and its lifting movement run in the vertical direction.

Landscapes

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

Applications Claiming Priority (2)

Publications (1)

Family

ID=6372935

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (2)

• 1989
  • 1989-12-06 WO PCT/EP1989/001492 patent/WO1990008849A1/de not_active Application Discontinuation
  • 1989-12-06 EP EP90900106A patent/EP0454687A1/de not_active Ceased
  • 1989-12-06 JP JP2500563A patent/JPH04503015A/ja active Pending
  • 1989-12-06 KR KR1019900702157A patent/KR910700374A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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