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US2902960A - Thread tension releasing devices for sewing machines - Google Patents

Thread tension releasing devices for sewing machines Download PDF

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Publication number
US2902960A
US2902960A US715378A US71537858A US2902960A US 2902960 A US2902960 A US 2902960A US 715378 A US715378 A US 715378A US 71537858 A US71537858 A US 71537858A US 2902960 A US2902960 A US 2902960A
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US
United States
Prior art keywords
thread
tension
needle
work
sewing machine
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.)
Expired - Lifetime
Application number
US715378A
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English (en)
Inventor
Stanley J Ketterer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Singer Co
Original Assignee
Singer Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Singer Co filed Critical Singer Co
Priority to US715378A priority Critical patent/US2902960A/en
Priority to DES61733A priority patent/DE1119635B/de
Application granted granted Critical
Publication of US2902960A publication Critical patent/US2902960A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B47/00—Needle-thread tensioning devices; Applications of tensometers

Definitions

  • This invention relates to sewing machines, and more particularly, to a releasing mechanism for the needle threadtensiondevice of a lock stitch sewing machine.
  • Fig. 1 represents a side elevational view of a sewing machine having the tension'release mechanism of this invention :applied :thereto
  • Fig, j 2' represents an end elevational view of the sewing machine of Fig. 1 with the end cover plate removed to expose the mechanism therein, and illustrating the position of the parts at the completion of a cycle of stitching-operation
  • Fig. 2A r'epresentsatopplan view of the thread trim- -ming mechanism within the bed of the machine including the needle and bobbin thread thereon in the position the parts illustrated in Fig. 2,
  • Fig. "3 ' is a perspective view of the guide block for the jc lamp lifting slide rod, illustrating the tension releasing track formed thereon.
  • '-Figs.-4,”5 and 6 represent enlarged cross sectional views of the thread tension and tension release devices in the bracket arm head of the sewing machine taken substantially along line xx in Fig. 1 showing in Fig. 4, the first release of the tensionyin Fig. 5, the reestablishment 6f the-tension; and in Fig. 6, the final released the ten- Figs. 4A and 48 represent, respectively, a top plan slew of the thread trimming mechanism and an end elewational view of the'thread wiper in the position these par-tswilLoccuply when the tension release mechanism :is in the position illustrated in 'Fig. 4,
  • Figs. SA and 5B are views similar to Figs. 4A and4B -but with the parts illustrated in the positions occupied when thetension'releasemechanism is in the position illustrated in Fig. 5 and ice Figs. 6A and 6B are views similar to Figs. 4A and 4B but with the parts illustrated in the positions occupied when the tension release mechanism is in the position illustrated in Fig. 6.
  • the sewing machine illustrated in Figs. .1 and 2 to which this invention is applied is of the type described in detail in the co-pending'US.
  • patent application of Hale et 211. Serial No. 537,704, filed September 30, 1955, now Patent No. 2,822,771, granted February 11, 1958, to which reference may be had fora complete description thereof.
  • the sewing machine comprises a frame including a standard 11, a work supporting bed 12 and a bracket arm 13 overhanging the bed.
  • the drive of the sewing machine occurs through a stop motion mechanism 14 which renders the operation of the machine cyclic and, therefore, especially suitable for tacking, ornamenting, or article attaching.
  • the sewing machine is fitted with a work clamp including a frame 15 to which is affixed a lower jaw plate '16 opposed by a pair of upper jaw members 17 carried in the frame 15 and biased downwardly by leaf springs 18. So that the work clamp may be opened to remove and replace Work between cycles of sewing operation, each of the upper jaw members is provided with a pin 19 which pins overlie a bracket 20 fast at the lower extremity of a slide rod 21 journaled vertically in the bracket-arm -13 of the sewing machine. Clamped to the slide rod within the bracket arm is a guide block, indicated generally as 22,'the guide block being preferably formedwitha splitclamp 23 for this purpose.
  • The'guide block extends into a vertical channel 24 formed in the bracket arm and serves in one capacity as a means for preventing turning of the slide rod 21.
  • the guide block as best illustrated in Fig. 3 is slotted, as 25, to accommodate'a link 26 which is pivoted to the guide block'by a pin 27 and is pivotally connected in turn to the freeextremity of a rock-arm 28 fast on one extremity of a rock shaft 29 journaled along the bracket arm.
  • a rock arm 30 fast on the opposite extremity of the rock arm is connected by means of a'pivoted link 31 to a clamp lifting lever 32 fulcrumed at 33 on the machine standard.
  • a chain 34 connected to the lever 32 may be directed to -a treadle, knee shifter, or the like to facilitate opening of the clamp by the machine operator.
  • the work supporting bed 12 of the sewing machine is fitted with a throat plate 40 provided with a needle aperture 41 as isconventional in sewing machines.
  • a thread trimming mechanism carried'by the throat plate is of the type which is substantially similar in construction and manner of operation to that disclosed in the United States Horton Patent No. 807,67 6, December 19, 1906 towhich reference may be had.
  • Pivotally mounted beneath the throatplate on an axle '42 journaled between the throat plate and a bracket 43 are a pair of thread engaging and cutting fingers 44 and 45 which are secured in fixedrelation to each other.
  • the finger 44 is disposed between the .finger 45 and the throat plate and extends to a position in advance ofthe free extremity of thefinger 45.
  • the finger 44 is formed with a sharpened edge 46 extending substantially circumferentially with respect to the axle 42 and is thus adapted to sever a thread loop which is drawn along the finger 44.
  • The'finger 45 is formed with a sharpened edge 47 extending substantially radially with respect to'the mile 42 and-disposed tocooperate with a ledger blade '48 fixed beneath the throat plate to sever thread therebe tween.
  • Fixed on the axle 42 is a gear segment 49 meshing with a rack 50 .carriedby a slide rod 51 arranged lengthwise in the sewing machine bed.
  • a block 52' is pivoted to theslide rod within the standard .11 is embraced by th e the machine standard.
  • the lever 53 is actuated to op- 3 erate the thread trimming mechanism by means of a link 55 pivoted at one extremity to the lever 53 and at the other extremity to the clamp lifting lever 32.
  • the sewing machine is fitted with a thread Wiper which serves to engage and carry the needle thread out of the work after the thread has been cut at the completion of each cycle of machine operation.
  • the thread wiper comprises a wire thread engaging member 60 extending from one arm 61 of a bell crank lever fulcrumed at62 to a support block 63 fixed to depend from the bracket. arm 13 of the sewing machine.
  • the other arm 64 of the bell crank overlies the clamp lifting slide rod bracket 20 so that the thread engaging wire member 60 will'be moved beneath and across the path of the sewing needle when the work clamp is opened.
  • the bracket arm 13 of the sewing machine is fitted with a pair of thread guides 70,
  • the tension device shown in greater detail in Figs. 4, and 6, comprises a base member 73 fixed by means of a set screw 74 in a bore 75 in the bracket arm.
  • a stud 76 which extends outwardly from the base member 73 is formed with a transverse slot 77 and is externally threaded at its free extremity. Disposed loosely on the stud are a pair of friction disks 78 between which the needle thread is directed.
  • a coil spring '79 on the stud bears against a'pressure plate 80 which is seated against the outer friction disk and has a diameter bar 81 extending into the slot '77 of the stud.
  • a nut 82 on the threaded extremity of the stud serves to adjust the spring tension acting to bias the friction disks against the base member.
  • the tension base member 73 is counterbored, as at 83, to accommodate a check spring 84 which is anchored to the stud 76 and extends outwardly through a radial slot 85 in the base member.
  • the stud 76 has a bore 86 in which is accommodated a tension release pin 87 which contacts the diameter bar 81 of the pressure plate 80.
  • a plunger 88'disposed in a bore 89 in the bracket arm engages the tension release pin at one extremity and at the other extremity bears against the guide block 22.
  • the guide block is formed with two notches 9t ⁇ , 91 and with a land 92 therebetween, all in the path of engagement of the plunger 88 with the guide block so that when the work clamp is closed, as illustrated in Figs. 1 and 2, the plunger will seat in the notch 90 permitting the tension coil spring to bias the friction disks 78 together.
  • opening ofthe work clamp is initiated, and as illustrated in Fig.
  • Fig. 2A which illustrates the position of the parts of the trimming mechanism at the completion of a sewing cycle
  • the thread engaging fingers 44 and 45 will have been shifted across the needle aperture by mechanism in the sewing machine not shown in the present drawings but described in the above referred to Horton patent. This initial movement of the thread engaging fingers will occur during the last stitch of each cycle, the finger 44 moving across the needle aperture before needle penetration and thus engaging only the bobbin thread B, 'and the finger 45 moving across the needle aperture after needle penetration andengaging only the needle thread N.
  • Figs. 4, 5 and 6 illustrate the thread tension device and tension releasing mechanism in three successive stages during the opening of the work clamp.
  • Figs. 4A and 4B 4 illustrate the thread trimming mechanism and the thread wiper, respectively, in the positions occupied when the tension release mechanism is in the stage illustrated in Fig. 4.
  • Figs. 5A and 5B correspond in timed relation with Fig. 5 and Figs. 6A and 6B with Fig.6. ..1 M
  • Figs. 4, 4A and 4B illustrate that, when the thread tension device is first released, the threads B and N are not yet severed by the trimming mechanism and the thread wiper 60 has not yet come in contact with the needle thread.
  • the purpose, therefore, of the initialrelease of the thread tension is to provide for relaxation of the check spring 84.
  • the check spring will thus relax from its stressed stitch setting position by drawing an additional amount of thread through the tension disks from the guides 70 and 71 and thence from the thread supply. Since this relaxation of the check spring occurs before the threads are severed, all possibility of the check spring drawing the severed needle thread back through the eye of the needle is obviated.
  • the threads B and N are severed before or during reestablishment of the needle thread tension device.
  • the needle thread cutting edge 45 and ledger blade 48 will operate to sever the thread in complete independence upon the tension existing in the thread.
  • the purpose of the reestablishment of the tension is to prevent the thread wiper from drawing thread from the supply.
  • reestablishment of the tension coincides with the initial engagement of the thread wiper 60 with the needle thread.
  • the tension device'thus influences the thread wiper to draw the severed end of needle thread out the work.
  • the parts will be disposed as illustrated in Figs. 6,'6A and 6B with the threads B and N severed, the severed end of the needle thread wiped out of the work and carried to one side by the thread wiper, and the thread tensioning device opened to release the tension on the needle thread so that the sewing machine may if needed'be rethreaded.
  • the thread tension releasing mechanism of this invention provides a'novel and-highly exacting control for the length of needle thread for the beginning of each new stitching cycle. Relaxing of the thread tension check spring is accomplished so that the movement of thread necessary for such relaxation must 'come from the thread supply and cannot act abnormally to shorten the thread length from the eye of the needle.
  • This tension releasing mechanism cooperates with the thread Wiper to insure that the needle thread end will be wiped from the preceding tack thus to prevent'the thread end from remaining in the work where it'would be in danger of being pulled out to an abnormally long length when the operator removes the work from the sewing machine.
  • a sewing machine having a work support, an endwise reciprocating threaded needle carried at one side of said work support, thread trimming mechanism effective to sever the needle thread at the opposite-side of said work support closely, adjacent aiwork fabric being stitched thereby, a thread wiper disposed to act upon the needle thread between the needle and the work fabric, mechanism for actuating in sequence the thread trimming mechanism and the thread wiper,'a thread tensioning device arranged to provide frictional resistance to' vmovement of said needle thread toward said needle, a check spring operative on said needle thread between said tensioning device and said needle, a tension releasing member shiftably supported with respect to said sewing machine and efiective when shifted in one direction to render said thread tensioning device inefiective, cam means disposed to act upon said tension releasing member, said cam means being operatively associated with said mechanism for activating said thread trimming mechanism and said thread wiper, said cam means formed to efiect two successive movements of said tension releasing member in a direction to release said thread tensioning
  • a cyclically operated sewing machine having a work clamp, means for raising and lowering said work clamp, a thread trimming mechanism, a needle thread wiper, mechanism eifective upon operation of said means for raising said work clamp for operating in sequence said thread trimming mechanism and said thread wiper,
  • tension releasing means including a cam member carried for movement with said Work clamp raising and lowering means, said cam means being formed to provide for two successive releases of said thread tensioning device upon raising of said work clamp, a first of said tension releases occurring before operation of said thread trimming mechanism to relax said check spring, and a second of said tension releases occurring after operation of said thread wiper to insure that the thread will be wiped from the Work fabric rather than from the thread supply.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US715378A 1958-02-14 1958-02-14 Thread tension releasing devices for sewing machines Expired - Lifetime US2902960A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US715378A US2902960A (en) 1958-02-14 1958-02-14 Thread tension releasing devices for sewing machines
DES61733A DE1119635B (de) 1958-02-14 1959-02-11 Nadelfadenspanneinrichtung fuer Doppelsteppstich-Naehmaschinen

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US715378A US2902960A (en) 1958-02-14 1958-02-14 Thread tension releasing devices for sewing machines

Publications (1)

Publication Number Publication Date
US2902960A true US2902960A (en) 1959-09-08

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Family Applications (1)

Application Number Title Priority Date Filing Date
US715378A Expired - Lifetime US2902960A (en) 1958-02-14 1958-02-14 Thread tension releasing devices for sewing machines

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US (1) US2902960A (de)
DE (1) DE1119635B (de)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3081722A (en) * 1959-08-28 1963-03-19 Peloggio Achille Thread-cutting device in linking machines
US3191562A (en) * 1962-04-16 1965-06-29 American Safety Table Co Thread trimming device
US3463105A (en) * 1966-11-12 1969-08-26 Tokyo Juki Industrial Co Ltd Thread cutting mechanism in a sewing machine
US3498243A (en) * 1967-01-16 1970-03-03 Tokyo Juki Industrial Co Ltd Wiper mechanism in sewing machine
US3584589A (en) * 1970-01-27 1971-06-15 Clinton Ind Thread trimmer
US3601074A (en) * 1970-02-27 1971-08-24 Union Special Maschinenfab Thread wiper for sewing machines including a thread-separating arrangement
US3895591A (en) * 1974-10-17 1975-07-22 Singer Co Thread cutting device
US4123986A (en) * 1976-05-07 1978-11-07 Durkoppwerke Gmbh Thread-cutter device for double lock stitch sewing machine
US4364319A (en) * 1978-04-08 1982-12-21 Durkoppwerke Gmbh Controlled thread clamp device for needle threads
US4450781A (en) * 1982-04-01 1984-05-29 Usm Corporation Thread wiping mechanism

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US670078A (en) * 1897-06-12 1901-03-19 George Humphrey Tension device for straw-sewing machines.
US2165016A (en) * 1938-04-26 1939-07-04 Singer Mfg Co Tension-releaser for sewing machines
US2230896A (en) * 1936-04-20 1941-02-04 Henry Beulah Louise Seam and method of forming seams
US2822771A (en) * 1955-09-30 1958-02-11 Singer Mfg Co Sewing machines
US2833237A (en) * 1954-08-16 1958-05-06 Pfaff Ag G M Thread tension release and presser bar lifter

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE693262C (de) * 1939-03-23 1940-07-05 Singer Mfg Co vorrichtung
DE901860C (de) * 1940-05-25 1954-01-14 Singer Mfg Co Verfahren zum Befestigen eines Gegenstandes an einem Arbeitsstueck und Naehmaschine zur Durchfuehrung des Verfahrens

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US670078A (en) * 1897-06-12 1901-03-19 George Humphrey Tension device for straw-sewing machines.
US2230896A (en) * 1936-04-20 1941-02-04 Henry Beulah Louise Seam and method of forming seams
US2165016A (en) * 1938-04-26 1939-07-04 Singer Mfg Co Tension-releaser for sewing machines
US2833237A (en) * 1954-08-16 1958-05-06 Pfaff Ag G M Thread tension release and presser bar lifter
US2822771A (en) * 1955-09-30 1958-02-11 Singer Mfg Co Sewing machines

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3081722A (en) * 1959-08-28 1963-03-19 Peloggio Achille Thread-cutting device in linking machines
US3191562A (en) * 1962-04-16 1965-06-29 American Safety Table Co Thread trimming device
US3463105A (en) * 1966-11-12 1969-08-26 Tokyo Juki Industrial Co Ltd Thread cutting mechanism in a sewing machine
US3498243A (en) * 1967-01-16 1970-03-03 Tokyo Juki Industrial Co Ltd Wiper mechanism in sewing machine
US3584589A (en) * 1970-01-27 1971-06-15 Clinton Ind Thread trimmer
US3601074A (en) * 1970-02-27 1971-08-24 Union Special Maschinenfab Thread wiper for sewing machines including a thread-separating arrangement
US3895591A (en) * 1974-10-17 1975-07-22 Singer Co Thread cutting device
US4123986A (en) * 1976-05-07 1978-11-07 Durkoppwerke Gmbh Thread-cutter device for double lock stitch sewing machine
US4364319A (en) * 1978-04-08 1982-12-21 Durkoppwerke Gmbh Controlled thread clamp device for needle threads
US4450781A (en) * 1982-04-01 1984-05-29 Usm Corporation Thread wiping mechanism

Also Published As

Publication number Publication date
DE1119635B (de) 1961-12-14

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