US3808995A - Sewing machine with differential feed - Google Patents

Sewing machine with differential feed Download PDF

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Publication number
US3808995A
US3808995A US00313515A US31351572A US3808995A US 3808995 A US3808995 A US 3808995A US 00313515 A US00313515 A US 00313515A US 31351572 A US31351572 A US 31351572A US 3808995 A US3808995 A US 3808995A
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United States
Prior art keywords
impulse
feed
counter
emitter
sewing machine
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Expired - Lifetime
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US00313515A
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English (en)
Inventor
W Baus
R Dobner
E Willenbacher
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Pfaff Industriemaschinen GmbH
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Pfaff Industriemaschinen GmbH
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Application filed by Pfaff Industriemaschinen GmbH filed Critical Pfaff Industriemaschinen GmbH
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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
    • D05B27/08—Work-feeding means with feed dogs having horizontal and vertical movements with differential feed motions
    • 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
    • D05D2207/05—Magnetic devices
    • D05D2207/06—Permanent magnets

Definitions

  • the invention relates to sewing machines of the type equipped with differential feed means for maintaining the surplus width on cut blanks of clothing and for simultaneously fixing of the maintained width by means of a seam, where the difference between the amount of feed of the feed dogs is controlled by a rotating program carrier.
  • a machine of this type serves, for example, for fitting in the surplus width of sleeve blanks in order to produce automatically the differences required in the gathering of the arm joint in the individual circumferential sections of the sleeve.
  • the program carrier consists of a cam disk which, in order to effect its controlled rotary movement, is coupled to the arm shaft of the machine by Way of a reduction gear.
  • a complete rotation of the program carrier is attained upon termination of a predetermined number of stitches.
  • the seam program stored on the cam disk can only be carried out with a stitch length setting coordinated to this seam length.
  • the feed elements influence the feed of the materials differently for different kinds of materials and depend also on the instant feeding speed as to their reaction to the transporting conditions.
  • the gathering of the feeding elements is strongly influenced by the characteristics of the material to be sewn and varies especially in cases of deflections between the direction of feed and the direction of the threads of the textile material.
  • the amounts of differences thus developing between the desired value and the actual value of the feed path per stitch add themselves so strongly for a number of stitches required of the gathering program provided on the program carrier that even sewing results are out of the question.
  • the measuring wheel is arranged in the proximity of the material feed dog in order to scan the material directly.
  • the measuring'wheel measures, for example, the consumption of a non-stretchable material band that has to be sewn along.
  • an adaptable impulse counter is provided between the impulse emitter and the stepping motor, which further switches the stepping motor when it is set back by way of an onward switching impulse.
  • a particularly fine grading step of the seam length adjustment is obtained in that the machine is provided with switching means where the impulse emitter releases the opening of the counting operation of the impulse counter, as well as that of a second impulse counter by way of a bi-stable storage unit whose received counts are connected to a second impulse emitter which produces impulses of very high constant frequency and the second impulse counter when set back to its initial position upon reaching a predetermined counter position closes by way of the storage unit the counting functions of both impulse counters.
  • FIG. 1 is a schematic illustration of one embodiment of a sewing machine with its prime mover
  • FIG. 2 is a graphic illustration of the feed mechanism of the sewing machine
  • FIG. 3 is a side view of the stitch forming toolsof the sewing machine
  • 9 FIG. 4 is a simplified circuit of the electrical controls.
  • FIG. 1 shows the housing 1 of a sewing machine which is driven by the drive motor 3 by way of a V-belt 2, the number of rotations of which can be controlled by a foot pedal 4 by way of an actuating lever 5 of motor 3.
  • the sewing machine has, a main feed dog 6 (FIG. 2) and a lower auxiliary feed dog 7, each of which is carried by a support 8 and 9, respectively.
  • These supports present bifurcated ends 10, 11 into which extend eccentrics l3, 14 mounted on a shaft 12.
  • Shaft 12 is driven in a conventional manner, not illustrated, in order to impart lifting movements to feed dogs 6 and 7.
  • a bifurcated lever 22 is rigidly connected with the shaft 20 and has linked to it the support 8 which is connected with the main feed dog 6.
  • a bifurcated lever 23 is rigidly connected with shaft 21 and the support 9 housing 1.
  • the free end of the eccentric bar 18 is linked to a bolt 24 which is connected rigidly with a guide member 25 and rotatably with a guide element 26.
  • the guide element 26 is linked by means of a stud 27 to a lever arm 28 which is secured by means of its hub to the shaft 20, while the guide member 25 is rotatably linked by means of a stud 29 to a lever 30 that is secured to a setting shaft 31.
  • the free end of the eccentric bar 19 is linked to a rod 32, which is rigidly connected with a guide element 33 and is rotatably connected with a guide member 34.
  • Guide member 34 is linked by means of a stud 35 to a lever 36 which has a hub secured to a rod 21, while the guide element 33 is turnably connected by means of a pin 37 with a lever 38 that is secured to a setting shaft 39.
  • levers 30 and 38 as well as guide elements or members 25, 26, 33 and 34 are of the same effective length.
  • a lever arm 40 is mounted on setting shaft 31 which is connected to an arm of a lever 42 by way of a link bar 41.
  • the other arm of the lever 42 mounted on shaft 43 which is journalled in the housing of the sewing machine presents a spherical head which is guided in a slot 45 of a setting disk 46 that is likewise rotatably mountedin housing 1.
  • the slot 45 extends spirally to the axis of rotation of the setting disk 46 in such a manner that the main material feed dog 6 may be set for file of a program support that is in the form of a control disk 55.
  • the control disk is seated on the drive shaft 56' (FIG.
  • a lever 58 is clamped on the setting shaft 39 and connected by a link bar 59 to a leverarm 60 which is secured to a setting shaft 61 journalled in housing 1.
  • a bridge 62 is mounted on setting shaft 61 between the arms of which a further bridge member 63 is rotatably journalled by means of studs 64.
  • the arms of the bridge member 63 are connected by a bolt 65 to which an ec- --arm 73 is connected with the other end of the rocking shaft 72 which is connected by way of a link member 74 to'an arm of a double armed lever 75 journalled likewise in housing 1.
  • the other arm of lever 75 engages an arm 76 (H6.
  • auxiliary feed dog 77 which is in the form of a double armed lever.
  • the auxiliary feed dog 77 is supported by a guide bar 78 which is linked to support member 79 that is secured to the lower end of a presser foot bar 80 of known form of construction.
  • the presser foot bar is guided in a bearing sleeve 81 journalled in housing 1.
  • a presser foot 82 is secured to the support member 79 which is equipped with a sole'83 that cooperates with the feed dogs 6 and 7 thathasrecesses 84 for the passage of toes of the auxiliary feed dog 77 that engage the material being sewn.
  • a bar 86 is disposed in the hollow presser foot bar 80 andis provided at its lower end with a roller 88 that is guided in a bifurcated part 87 of the upper feed dog 77 and which is moved axially up and down in a known. manner for effecting the thrust movements of the auxiliary upper feed dog 77.
  • a crank 89 secured to arm shaft 67 (FIG. 2) is in op- 1 erative connection by way of a link bar 90 with a needle bar 93 equipped with a needle 91 and journalled in a guide member 92.
  • the needle 91 (FIG. 3) here works in a known manner with a looper (not illustrated) driven below the stitch plate 94 through a stitch hole 95.
  • a looper (not illustrated) driven below the stitch plate 94 through a stitch hole 95.
  • One each slot 96 and 97 are provided in the stitch plate 94 ahead of and behind the stitch hole for the passage of the feed dogs 6 and 7.
  • the feed dogs 6, 7 and 77 are arranged in a manner that the main feed dog 6 can make contact with the sole 83 of the feed dog 82 behind the stitch hole 95 As seen in the direction of sewing and thetwo feed dogs 7 and 77 ahead of the stitch hole 95. V
  • the control of the step motor 57 is by way of a control circuit with a pulse emitter, known per se, in the form of a pole wheel 98.
  • a support 99 is secured to the bearing sleeve 81 for the presser foot bar 80 which carries a downwardly extending stud 101 on a lateral chuck 100.
  • a sleeve 102 is slidably mounted which is pressed by a spring 103 provided between it and chuck againsta safety disk 104 fastened to the lower end of stud 101.
  • Sleeve 102 is provided with an arm 105' which has rotatably secured to it a bearing member 106 in which the pole wheel 98 is rotatably mounted.
  • the pole wheel 98 which is symbolically illustrated in FIG. 4 is provided in a known manner with a pair of Hall generators that have coordinated therewith a number of permanent magnets. As the pole wheel 98 rotates the two Hall generators are penetrated by varying magnetic fields and generate alternating potentials whose frequency isproportional to the speed of rotation of the pole wheel 98. The alternating potential is fed to an impulse dressing stage 108 which is arranged in a manner that an impulse appears at the output of the impulse dressing stage for each millimeter of the length of the path covered by the pole wheel 98.
  • This impulse is conducted to the setting entrance of a bistable storage unit 109 whose output A is connected by way of a reversing element 110 with the closing entrance of an impulse counter 111 and whose output is connected with the closing as well as also with the back setting entrance of a second impulse counter 112.
  • the outlet of the counter 111 is connected by way of a reversing element 113 with the resetting entrance of the counter 111 as well as also with a switching amplifier 114 for the stepping motor 57.
  • an impulse emitter 115 is connected which constantly emits impulses of a very high frequency, for example, 33 kc.
  • the output of the impulse counter 1 12 is connected by way of a reversing element 1 16 and or-member 117 to the resetting entrance of the storage unit 109.
  • a second entrance of the or-member 117 is connected with the output? of a bi-stable storage element 118 whose setting entrance is connected by way of a switch 119 connected with the foot pedal actuating plate 4 for the drive motor 3, to the plus pole of a source of potential.
  • the resetting entrance of the storage element 1 18 is connected by means of a reversing element 120 with a slot initiator 121 which cooperates with a flag 122 secured to the control disk 55 (FIG. 1) and rotating therewith.
  • the counter 111 is adjustable by means of a preselecting keyboard 125 (FIG. 1) which is provided in a control box 126 mounted in the operating range of the seamstress on the sewing machine which accommodates the entire switching means.
  • the counter 112 on the other hand is set to a fixed counting value.
  • the setting shaft 31 when turning carries along the lever 30 and thus sets the stud 29 serving as the axis of rotation for the link or guide member 25 in relation to the stud 27.
  • the link member 25 therefore executes a pure rotary movement about the stud 29, whereas the link member 26 executes besides this rotary movement also a relative movement about the shaft 20.
  • This relative movement is transmitted by the lever 28 as a rocking movement onto the lever 22,
  • the magnitude of the feed movement depends on the position of the setting screw 46 and thus on the magnitude of the setting difi'erence between the studs 27 and 29.
  • the turning of the setting shaft 31 simultaneously effects a rotating of the setting shaft 39 by way of the lever arm 47, links 49 and 50 and lever arm 48.
  • the lever 38 that is fixedly connected with the latter thereby moves the link 33 so that the stud 37 is displaced relative to the stud 35.
  • the link 34 efiects for reasons stated in connection with the function of parts 24 to 30 besides a rotary movement about the stud 37 a relative movement about the shaft 21.
  • This movement effects a rocking movement of the shaft 21 which imparts feed movements to the auxiliary feed dog 7 by way of lever 23 and support 9.
  • lever 58 effects during the turning of the setting shaft 39 a rotating of the setting shaft 61 by way of the link 59 and lever arm 60.
  • the strut 62 which is securely fastened thereto turns the strut 63 so that the studs 64 serving as the axis of rotation for the strut 63 are displaced relative to the stud 70.
  • the link 69 also effects a relative movement about the rocking shaft 72 and thus causes the same to effect a rocking movement by way of lever arm 71.
  • These rocking movements are transferred by the rocking shaft 72 by way of lever arm 73, link 74 and lever 75 (FIG. 3) to the upper auxiliary material feed dog 77 as feed movements.
  • the setting disk 46 thus adjusts the stitch length of the main feed dog 6 as well as also that of the two auxiliary feed dogs 7 and 77 that engage the work blank in the manner of tongs. To the amount of feed of the two auxiliary feed dogs 7 and 77 that supply the material to the stitch forming location there is in addition superimposed an amount of feed which depends on the profile of the cam disk 55.
  • the material is displaced by the two auxiliary feed dogs 7 and 77 by a larger amount than by the main feed dog 6 from which the required gathering results or the adherence to the surplus width in a manner known per se.
  • the step motor 57 and therefore also the control disk 55 are in their starting position in which the flag 122 extends into the slot initiator.
  • the two bi-stable storage units 109 and 118 are set back.
  • the impulse emitter swings steadily and imparts impulses to the counting receipts of the two impulse counters 111 and 112. However these impulses are not counted because a locking signal is present from the storing unit 109 at the locking entrances of the counters 111 and 112. Both counters 111 and 112 are positioned at zero.
  • the seamstresss By the seamstresss moving the foot pedal plate 4 backwards theswitch 1 19 is closed and the storage unit 118 is set so that the relay 123 drops and the rest contacts 124 in the circuit of the motor remain closed. Simultaneously the storage unit 109 is freed which previously was continuously set back by way of the or member 117 through the storage unit 118. Now the seamstress can start the sewing operation by stepping on the foot pedal plate 4 in which connection she can control the sewing speed in a known manner by; means of the foot pedal 4.
  • the pole wheel 98 is turned by the moving material being sewn.
  • the alternating potential produced by the two Hall generators is supplied to the impulse preparation stage 108 and is utilized there in a manner that for each millimeter of material fed an impulse appears in its output.
  • This impulse sets the storage unit 109.
  • the latches at the counters 111 and 112 are released so that the impulses supplied by the impulse emitter 115 are now counted simultaneously in both counters 111 and 112.
  • the counter 112 is set to a constant numerical value, for example, 7, then the seventh arriving impulse of the impulse emitter 115 produces at its exit a zero signal which is inverted at the reversing stage 116 and sets back the bi-stable storage unit 109 by way of the or-element 117. As a result, both counters 111 and 112 are closed and counter 112 is simultaneously returned to zero. The counter position 7 is maintained in counter 1 11.
  • the next impulse at the impulse maker 108 releases v in the same manner by way of storage unit 109 the freeing of both impulse counters 111 and 1 12, the counting of seven impulses into both counters and the return of the storage unit 109, whereupon the counter position of the impulse counter 11 1 stands at 14.
  • next impulses of the path are again multiplied by seven count the counter 1 1 1 up to preselection and release further steps of the stepping motor 57.
  • This motor rotates dependent on the number of the arising impulses and the preselected choice set up in the control box 126.
  • the control disk 55 rocks the double-lever 53 which acts on the two links 49 and 50 by way of the transfer bar 52.
  • the rotational position of the setting shaft 39 is thereby changed as a result of which also the magnitude of the feed device of the two auxiliary feed dogs 7 and 77 which effect a common feed movement changes with respect to the feed movement of the main feed dog.
  • the formation of the contour of the control disk 55 is determined by the differential displacement of the auxiliary feed dogs 7 and 77 during a complete course of a scam in relation to the main feed dog 6, while the angular rotation of the control disk 55 corresponds exactly to the advance of the material being sewn.
  • the different seam lengths caused by the different sizes of sleeves can be so set by adjustment of the preselecting keyboard 125 on the control. box 126 that the controldisk 55 effects a complete turn corresponding to the lengths of seams now changed for performing the entire seam course.
  • the gathering program stored on the cam disk can be adapted to the most variegated lengths of seams which are: smaller than a predetermined maximum seal length to be made.
  • this maximum adjustable seam length in the preselection 100 at the preselecting keyboard 125 amounts, for example, to 68 millimeters, then a desired seam length L can be produced by setting to the preselection x L X 100/680.
  • control disk 55 At the end of the seam the control disk 55 has rotated through 360 and the flat rotating with it enters the slot initiator 121. This initiator setsback the storage unit 118 by way of the reversing element 120. Thereby the storage element or memory 109 is closed and the further impulses from the pole wheel 98 are faded out; the cam disk 55 remains in this end position. ln addition the relay 123 opens the rest contacts 124 which renders the drive motor 3 devoid of current. The sewing machine stops and indicates to the seamstress the end of the operation.
  • Sewing machine having differential feed means for maintaining surplus width of garment blanks and simultaneously fixing by a scam the surplus width maintained, where the difference of the amount of feed of the feed dogs is controlled by a rotating program carrier comprising a measuring wheel which scans the actual amount of material feed at the stitch forming location of .the machine, said measuring wheel having at least one impulse emitter controlling a stepping motor, said program carrier being driven by said stepping motor.
  • Sewing machine in accordance with claim 1 including an adjustable impulse counter between said impulse emitter and said stepping motor, said impulse counter being adapted to be set back, thereby imparting a forward switching impulse to said stepping motor.
  • Sewing machine in accordance with claim 2 including a bi-stable storage unit, a second impulse emitter and a second impulse counter, said first impulse emitter being operative to release the counting functions of said first and said second impulse counters by way of said bi-stable storage unit, the counted inputs of said first and said second impulse emitters being connected with said second impulse emitter which is oper-v ative' to produce impulses of very high constant frequency, and said second impulse counter being operative upon resetting to its starting position after having attained a predetermined position of count to stop the counting functions of both impulse counters by way of said storage unit.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US00313515A 1971-12-10 1972-12-08 Sewing machine with differential feed Expired - Lifetime US3808995A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2161295A DE2161295C2 (de) 1971-12-10 1971-12-10 Nähmaschine mit Differential vorschub

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US3808995A true US3808995A (en) 1974-05-07

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US (1) US3808995A (it)
JP (1) JPS536891B2 (it)
DE (1) DE2161295C2 (it)
IT (1) IT975834B (it)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0003492A1 (fr) * 1977-12-21 1979-08-22 Reece Machinery Company (France) S.A. Perfectionnements aux machines servant à fabriquer des ouvertures passepoilées dans une pièce de tissu ou analogue
US4214543A (en) * 1979-07-05 1980-07-29 The Singer Company Electronically controlled top feed arrangement for a sewing machine
EP0068625A1 (en) * 1981-06-29 1983-01-05 G.M. Pfaff Aktiengesellschaft Control system for providing stitch length control of a sewing machine
DE3614104A1 (de) * 1985-04-25 1986-10-30 Brother Kogyo K.K., Nagoya, Aichi Naehmaschine
WO2003053659A1 (en) * 2001-12-12 2003-07-03 Fra-Ser S.P.A. Apparatus for hot applying strips or films on textile or non textile supports
CN104233644A (zh) * 2014-09-02 2014-12-24 蔡金财 上下差动送料的缝纫机

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55126770U (it) * 1979-03-05 1980-09-08
SE8004226L (sv) * 1980-06-05 1981-12-06 Husqvarna Ab Metanordning
DE3632757A1 (de) * 1986-09-26 1988-04-07 Pfaff Ind Masch Naehmaschine mit einer vorschubvorrichtung
DE10260451B3 (de) * 2002-12-21 2004-05-19 Beisler Gmbh Verfahren zur Herstellung von Hosenbund-Teilen und Nähanlage zur Durchführung des Verfahrens

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3174449A (en) * 1962-04-02 1965-03-23 Necchi Spa Differential feed device for a sewing machine
US3368507A (en) * 1964-10-31 1968-02-13 Pfaff Ag G M Feeding mechanism for sewing machines
US3611817A (en) * 1969-05-26 1971-10-12 Union Special Machine Co Differential feed mechanism for a sewing machine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3174449A (en) * 1962-04-02 1965-03-23 Necchi Spa Differential feed device for a sewing machine
US3368507A (en) * 1964-10-31 1968-02-13 Pfaff Ag G M Feeding mechanism for sewing machines
US3611817A (en) * 1969-05-26 1971-10-12 Union Special Machine Co Differential feed mechanism for a sewing machine

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0003492A1 (fr) * 1977-12-21 1979-08-22 Reece Machinery Company (France) S.A. Perfectionnements aux machines servant à fabriquer des ouvertures passepoilées dans une pièce de tissu ou analogue
US4214543A (en) * 1979-07-05 1980-07-29 The Singer Company Electronically controlled top feed arrangement for a sewing machine
US4404919A (en) * 1980-11-26 1983-09-20 Microdynamics, Inc. Control system for providing stitch length control of a sewing machine
EP0068625A1 (en) * 1981-06-29 1983-01-05 G.M. Pfaff Aktiengesellschaft Control system for providing stitch length control of a sewing machine
DE3614104A1 (de) * 1985-04-25 1986-10-30 Brother Kogyo K.K., Nagoya, Aichi Naehmaschine
WO2003053659A1 (en) * 2001-12-12 2003-07-03 Fra-Ser S.P.A. Apparatus for hot applying strips or films on textile or non textile supports
US20050126460A1 (en) * 2001-12-12 2005-06-16 Luciano Salotto Apparatus for hot applying strips or films on textile or non textile supports
US7412996B2 (en) * 2001-12-12 2008-08-19 Fra-Ser S.P.A. Apparatus for hot applying strips or films on textile or non textile supports
CN104233644A (zh) * 2014-09-02 2014-12-24 蔡金财 上下差动送料的缝纫机
CN104233644B (zh) * 2014-09-02 2016-05-11 宁波三合鑫自动化有限公司 上下差动送料的缝纫机

Also Published As

Publication number Publication date
DE2161295A1 (it) 1973-03-29
DE2161295C2 (de) 1973-10-18
JPS536891B2 (it) 1978-03-13
IT975834B (it) 1974-08-10
DE2161295B1 (de) 1973-03-29
JPS4876641A (it) 1973-10-15

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