EP0420856A1 - Thread-cutting device for sewing machines. - Google Patents
Thread-cutting device for sewing machines.Info
- Publication number
- EP0420856A1 EP0420856A1 EP89905094A EP89905094A EP0420856A1 EP 0420856 A1 EP0420856 A1 EP 0420856A1 EP 89905094 A EP89905094 A EP 89905094A EP 89905094 A EP89905094 A EP 89905094A EP 0420856 A1 EP0420856 A1 EP 0420856A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- thread
- gear element
- needle
- cutting device
- tension
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- D—TEXTILES; PAPER
- D05—SEWING; EMBROIDERING; TUFTING
- D05B—SEWING
- D05B47/00—Needle-thread tensioning devices; Applications of tensometers
-
- D—TEXTILES; PAPER
- D05—SEWING; EMBROIDERING; TUFTING
- D05B—SEWING
- D05B65/00—Devices for severing the needle or lower thread
Definitions
- the invention relates to a thread cutting device according to the preamble of claim 1.
- a thread cutting device By a sewing machine design, which was taken into account in the formation of the preamble of claim 1, a thread cutting device has become known in which an axially displaceable gear element in one direction of movement detects the needle and the looper thread and pulls them out in its other direction of movement and the cutting knife feeds.
- Trigger mechanism for thread tension is attached to the gear element, a control cam which actuates the trigger mechanism.
- the invention has for its object to form the trigger mechanism for the thread tension in a thread cutting device according to the preamble of claim 1 so that the thread tension is only opened during the tightening of the needle thread.
- the thread tension now remains closed during the penetration of the thread catcher into the needle thread loop, so that the stability of the loop is retained when it is caught by the thread catcher.
- the thread tension is only opened at the beginning of the pulling of the needle thread and only closes when no further thread menr is pulled.
- Claim 2 contains a structurally simple design of the one-way clutch.
- the measure according to claim 3 ensures a jerk-free opening of the thread tension and its immediate closing after sufficient tightening of the needle thread.
- FIG. 1 A section of a sewing machine with the control of the cutting device and the thread tension, partially cut, the thread tension itself is shown graphically in Fig la;
- FIG. 2 shows a plan view of a part of the drive of the thread cutting and tension release device shown in FIG. 1;
- FIG. 3 to 5 different positions of the control cam and the one-way clutch for controlling the thread tension.
- the base plate (1) is shown, under which the horizontal
- Gripper drive shaft (2) is mounted. This is driven by a lower main shaft (4) via a transmission gear (3). At the front end of the
- Gripper drive shaft (2) the gripper (5) is attached. It works together with the needle (6) which can be moved up and down and which is fastened in a needle bar (6a) which is only indicated.
- Thread cutting device (7) arranged, the structure and operation of which is described in DE-PS 11 25 742.
- the thread cutting device (7) has a thread catcher (8) which is arranged coaxially to the gripper (5) and which interacts with a cutting knife (9) attached to the underside of the base plate (1).
- the fade catcher (8) is fastened to a support arm (10) which is connected to a ring (11) which loosely surrounds the gripper drive shaft (2). This is secured in the axial direction and rotatably mounted in an annular path (12) which is attached below the base plate (1).
- a link (13) is articulated on the support arm (10) and is connected to an arm of an angle lever (14) which is supported by a bearing block (15) fixed to the housing.
- the other arm of the angle lever (14) is connected via a rod (16) to a drive device (17) for the thread catcher (8).
- Parallel to the main shaft (4) (see also FIG. 2) is a gear element designed as an axially displaceable shaft (21) mounted in a carrier (22) fastened below the base plate (1).
- a control lever (24) provided with a roller pin (23) and a release lever (25) are fastened to the gear element (21).
- a pawl (28) equipped with a locking lug (26) and a stop (27) is loosely mounted on a bushing (30) fastened in a side wall (29) of the carrier (22) and is detached from the side wall (29) of the carrier ( 22) and an end flange (30a) of the bushing (30) against axial displacement.
- the spring (31) acts as a compression spring and shifts the gear element (21) into its right end position shown in FIG. 1, in which the roller bolt (23) faces the control groove (19) when the sewing machine is in the needle down position.
- An electromagnet (32) is fastened in the carrier (22), the armature (33) of which is connected to an arm (35) of a switch lever (36) via an eyelet (34). This is mounted in the carrier (22) and is turned upwards by a torsion spring (37) until a bent attachment (38) is placed against the locking lug (26) of the pawl (28) or - when the pawl is pivoted off - an end piece (39) pivoted to an adjustable threaded pin (40) fixed in the carrier (22).
- the thread tension (42) (Fig. La) for the needle thread consists of a sleeve (43) fastened in the machine housing with a longitudinally slotted threaded bolt (44) on which two tension disks (45, 46) are arranged, which are secured by a knurled nut (47).
- adjustable tension spring (48) are compressed to exert a braking force on the needle thread.
- a release pin (49) is arranged in the sleeve (43) so as to be longitudinally displaceable, by means of which the tension disk (45) can be lifted from the tension disk (46) against the action of the tension spring (48) in order to open the thread tension (42).
- a control cam (50) is attached to the gear element (21) (FIGS. 1 and 2), the surface of which is designed as a cam curve which is wedge-shaped at one end has rising curve section (51) and at the other end a rectilinear and then radially falling curve section (52).
- a one-way clutch (53) cooperates with the control cam (50) and is arranged on a lever arm (54) mounted on the carrier (22).
- the one-way clutch (53) consists of a segment-like lever (55), which is rotatably mounted on the lever arm (54) and interacts with the control cam (50), as well as a stop (57), which acts under the action of a torsion spring ( 58) against a pin (59) fastened in the lever arm (54).
- the lever arm (54) is actuated by a torsion spring (60) until a lateral contact surface (54a) or the one-way clutch (53) abuts the control cam (50). twisted.
- the torque emanating from the torsion spring (60) considerably exceeds the torque emanating from the torsion spring (58).
- the lever arm (54) is connected via a rod (61) to an angle lever (62) mounted on the machine housing.
- a push rod (63) is articulated on this and carries at its front end a release element (65) provided with an inclined surface (64) (FIG. 1 a).
- the device works as follows: At the end of the seam, the sewing machine is stopped for a short time as a starting position for thread cutting by a needle positioning device.
- the control groove (19) in the control cam (18) assumes such a position that the roller pin (23) on the control lever (24) can be moved into the control groove (19) by a simple pivoting movement.
- the control cam (50) and the one-way clutch (53) are in the position shown in Fig. 3, in which the thread tension (42) is closed.
- the switch lever (36) is pulled down by the armature (33) of the electromagnet (32) and presses the roller pin (23) into the control groove (19) via the release lever (25) and the control lever (24).
- the spring (31) pivots the pawl (28), the locking lug (26) of which lies over the shoulder (38) on the switch lever (36) and thus secures the position of the roller bolt (23) pushed into the control groove (19).
- the cam groove (19) running in the axial direction displaces the gear element (21) from its rest position via the control lever (24) according to a first section of the cam groove ( 19) to the left.
- the gear element (21) moves the thread catcher (8) via the angle lever (14) and the handlebar (13) into the needle thread loop which is gripped and widened by the gripper (5) and thereby detects the leg of the needle thread loop leading to the material to be sewn and the thread Looper thread.
- the gear element (21) is moved to the right as a result of the curve of the control groove (19) (FIG. 5).
- the wedge-shaped curve section (51) of the control cam (50) pushes against the lever (55) of the one-way clutch (53) and pivots thereby the lever arm (54), which via the rod (61) opens the angle lever (62) and the push rod (63) the thread tension (42) for the needle thread, by the trigger pin (49) through the inclined surface (64) of the trigger element ( 65) axially displaced, thereby lifting the tension disk (45) against the action of the tension spring (48) from the tension disk (46).
- the thread catcher (8) pulls thread from the hook and needle thread supply through the rightward movement of the gear element (21) until shortly before the end of this movement, the cutting knife (9) attached to the underside of the base plate (1) cuts off both threads.
Abstract
Dans les machines à coudre actuelles de ce type, le tendeur se détend dans les deux sens de déplacement de l'engrenage (21) axialement mobile, ce qui fait que le tendeur de fil s'ouvre également lors de la saisie du fil de l'aiguille. Selon l'invention, le mouvement de l'engrenage (21) est transmis par un embrayage unidirectionnel (53), de sorte que le tendeur de fil ne s'ouvre que lorsque le fil de l'aiguille est tiré.In current sewing machines of this type, the tensioner expands in both directions of movement of the axially movable gear (21), so that the thread tensioner also opens when gripping the thread of the thread. 'needle. According to the invention, the movement of the gear (21) is transmitted by a one-way clutch (53), so that the thread tensioner does not open until the needle thread is pulled.
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3819135 | 1988-06-06 | ||
DE3819135A DE3819135C1 (en) | 1988-06-06 | 1988-06-06 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0420856A1 true EP0420856A1 (en) | 1991-04-10 |
EP0420856B1 EP0420856B1 (en) | 1992-12-02 |
Family
ID=6355922
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP89905094A Expired - Lifetime EP0420856B1 (en) | 1988-06-06 | 1989-04-26 | Thread-cutting device for sewing machines |
Country Status (8)
Country | Link |
---|---|
US (1) | US5113774A (en) |
EP (1) | EP0420856B1 (en) |
JP (1) | JPH03504809A (en) |
KR (1) | KR960015663B1 (en) |
BR (1) | BR8907056A (en) |
DE (1) | DE3819135C1 (en) |
ES (1) | ES2013511A6 (en) |
WO (1) | WO1989012129A1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07100093B2 (en) * | 1989-10-31 | 1995-11-01 | ブラザー工業株式会社 | Sewing machine with thread trimming mechanism |
DE4118008A1 (en) * | 1990-11-30 | 1992-06-11 | Pfaff Ag G M | METHOD AND DEVICE FOR SHORTENING THE NEEDLE THREAD AT THE START OF SEWING IN DOUBLE-LOCK STITCH SEWING MACHINES |
US5289791A (en) * | 1993-03-31 | 1994-03-01 | General Motors Corporation | Sewing machine with thread wiper and auxiliary cutter |
CN1036017C (en) * | 1993-09-18 | 1997-10-01 | 高林股份有限公司 | Thread-cutting apparatus for multi-needle sewing machine |
CN1036214C (en) * | 1994-04-08 | 1997-10-22 | 高林股份有限公司 | Device for severing lower thread of multi-needle sewing machine |
JP4074533B2 (en) * | 2003-03-06 | 2008-04-09 | セイコーエプソン株式会社 | Electro-optical device and electronic apparatus |
CN108914413B (en) * | 2018-09-10 | 2021-01-05 | 拓卡奔马机电科技有限公司 | Sewing machine |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1125742B (en) * | 1961-08-11 | 1962-03-15 | Pfaff Ag G M | Thread trimmer on sewing machines |
US3141432A (en) * | 1962-04-26 | 1964-07-21 | Pfaff Ag G M | Thread-trimming mechanism for sewing machines |
US3386402A (en) * | 1966-07-05 | 1968-06-04 | Singer Co | Thread trimming mechanism for sewing machines |
DE2325564C2 (en) * | 1973-05-19 | 1974-09-05 | Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern | Chain stitch sewing machine with a device for thread cutting a |
DE7912758U1 (en) * | 1979-05-03 | 1979-07-26 | Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern | THREAD CUTTING DEVICE ON SEWING MACHINES |
US4365568A (en) * | 1980-05-15 | 1982-12-28 | The Singer Company | Underbed thread trimmer and controlled single-operation cam mechanism therefor |
DE3124795C1 (en) * | 1981-06-24 | 1982-11-04 | Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern | Thread cutting device for zigzag sewing machines |
DE3244996C2 (en) * | 1982-12-04 | 1985-04-04 | Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern | Thread cutting device on sewing machines |
US4611547A (en) * | 1984-06-13 | 1986-09-16 | Janome Sewing Machine Co., Ltd. | Upper thread tension device of a sewing machine |
DE3529369C1 (en) * | 1985-08-16 | 1986-11-27 | Pfaff Industriemaschinen Gmbh, 6750 Kaiserslautern | Sewing machine with a device for tensioning the needle thread |
-
1988
- 1988-06-06 DE DE3819135A patent/DE3819135C1/de not_active Expired
-
1989
- 1989-04-26 US US07/499,265 patent/US5113774A/en not_active Expired - Fee Related
- 1989-04-26 EP EP89905094A patent/EP0420856B1/en not_active Expired - Lifetime
- 1989-04-26 JP JP1504505A patent/JPH03504809A/en active Granted
- 1989-04-26 BR BR898907056A patent/BR8907056A/en unknown
- 1989-04-26 KR KR1019890702434A patent/KR960015663B1/en not_active IP Right Cessation
- 1989-04-26 WO PCT/EP1989/000452 patent/WO1989012129A1/en active IP Right Grant
- 1989-06-05 ES ES8901949A patent/ES2013511A6/en not_active Expired - Fee Related
Non-Patent Citations (1)
Title |
---|
See references of WO8912129A1 * |
Also Published As
Publication number | Publication date |
---|---|
ES2013511A6 (en) | 1990-05-01 |
JPH03504809A (en) | 1991-10-24 |
DE3819135C1 (en) | 1989-07-13 |
BR8907056A (en) | 1991-01-02 |
KR900700679A (en) | 1990-08-16 |
JPH0528640B2 (en) | 1993-04-26 |
EP0420856B1 (en) | 1992-12-02 |
US5113774A (en) | 1992-05-19 |
WO1989012129A1 (en) | 1989-12-14 |
KR960015663B1 (en) | 1996-11-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE3028729C2 (en) | ||
DE2632362C2 (en) | Thread cutting device on sewing machines | |
EP0357902B1 (en) | Device for tensioning and sealing a plastic tying strap | |
EP0420856B1 (en) | Thread-cutting device for sewing machines | |
CH438114A (en) | Device for joining two yarn threads | |
CH381149A (en) | Wire tensioning and locking device | |
DE2155068C2 (en) | Sewing machine with two drum-shaped fabric supports that can be moved relative to the sewing device | |
DE2239199B2 (en) | Device for tying packages with a weldable plastic band | |
DE3402022A1 (en) | DEVICE FOR FEEDING ADHESIVE TAPES ON MACHINES IN THE TOBACCO PROCESSING INDUSTRY | |
DE1489112A1 (en) | Device for applying a tape system to an object | |
DE2157100C3 (en) | Machine for sewing net webs together | |
CH392345A (en) | Method and device for fixing the thread end on textile bobbins | |
DE954208C (en) | Thread tensioning device for sewing machines | |
DE4032130C2 (en) | Needle thread guide device for a sewing machine | |
DE1785553C3 (en) | Automatic winding device for automatic weaving machines, in particular colored weaving machines | |
DE3744401A1 (en) | DEVICE FOR CUTTING AND POSITIONING A THREADED CHAIN | |
CH693383A5 (en) | Device for cutting a suture in a sewing machine and use of the device to pull the upper thread down. | |
DE3032908A1 (en) | DEVICE FOR REMOVING A KNOT FROM THE KNOT HOOK ON AGRICULTURAL MACHINERY, IN PARTICULAR BALERS | |
DE262452C (en) | ||
DE1302190B (en) | MACHINE FOR ATTACHING SUSPENSION LOOPS TO THICK PIECES OF WORK, FOR EXAMPLE MEATS | |
DE135945C (en) | ||
DE1560411C3 (en) | Spooling device for automatic loom | |
DE76758C (en) | Device for automatic thread tensioning for embroidery machines from HEILMANN's system | |
DE377730C (en) | Dishwasher | |
DE1485276C (en) | Sewing machine with a device for pulling out the needle and looper thread before cutting |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19891206 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): CH IT LI NL |
|
17Q | First examination report despatched |
Effective date: 19920428 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): CH IT LI NL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19921202 |
|
ITF | It: translation for a ep patent filed |
Owner name: JACOBACCI CASETTA & PERANI S.P.A. |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Effective date: 19930430 Ref country code: LI Effective date: 19930430 |
|
NLV1 | Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20050426 |