US3176641A - Electrically controlled sewing machines - Google Patents

Electrically controlled sewing machines Download PDF

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Publication number
US3176641A
US3176641A US228123A US22812362A US3176641A US 3176641 A US3176641 A US 3176641A US 228123 A US228123 A US 228123A US 22812362 A US22812362 A US 22812362A US 3176641 A US3176641 A US 3176641A
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United States
Prior art keywords
brake
needle
shaft
rotation
clutch
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
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US228123A
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English (en)
Inventor
Palmer George William
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.)
Lights London Ltd
Original Assignee
Lights London Ltd
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Filing date
Publication date
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Publication of US3176641A publication Critical patent/US3176641A/en
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    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B69/00—Driving-gear; Control devices
    • D05B69/22—Devices for stopping drive when sewing tools have reached a predetermined position

Definitions

  • This invention relates to electrically driven sewing machines.
  • This invention relates to electrically driven sewing machines.
  • the machine operator desires to remove a workpiece from the machine and declutches the drive to the needle for this purpose it may well happen that the needle sops whilst it is in engagement with the workpiece. This in turn means that the needle has to be brought manually into a position outside the workpiece before removal of the workpiece can take place.
  • an electrically driven sewing machine comprises an electric motor having a first shaft, driving wheel means freely rotatably mounted on the first shaft, a sewing needle drive including a second shaft, driven wheel means mounted on the second shaft for co-operation by means of an endless band with the driving wheel means, electromagnetic clutch means including a driving member mounted on the first shaft for rotation therewith and a driven member mounted for rotation with the driving wheel means, elec-- tromagnetic brake means including a first element mounted on the second shaft for rotation therewith and a second element for attracting and thereby arresting the first element upon energization of the brake means, cam means provided on the second shaft and adapted during rotation thereof to actuate contact means electrically connected with the brake means and switching means adapted to switch a source of electrical power from the clutch to the brake means thereby to-elfect energization of the brake means upon actuation of the contact means and consequent arresting of the second shaft.
  • FIGURE 4 is a front elevation of an upper part of the machine of FIGURES lto 3, the casing of the machine being partly broken away to illustrate details of the interior thereof; 7
  • FIGURE shows a detail of the machine
  • FIGURE 6 shows in diagrammatic form an electrical circuit of the machine.
  • an electrically'driven sewing machine is provided with an induction motor 2 the shaft 3 of which, otherwise herein called the first shaft, is arranged horizontally below a table 4 of the machine to extend in a direction from front to rear of the table.
  • a head casting 5 of the sewing machine which is mounted on the upper side of the table 4 also extends from front to rear of the table so that a needle drive shaft 6, otherwise referred to herein as the second shaft, in the machine head is disposed parallel with the first or motor shaft.
  • the drive from the second shaft 6 to the needle for vertical reciprocation of the latter is largely of conventional known form and includes a collar 7 in which a vertical post 8 which at its lower end carries a needle 9 is mounted for vertical reciprocation by means of a link 10 and eccentric 11 of known form, the
  • FIGURE 1 is a side elevation of an electrically driven sewing machine according to the invention
  • FIGURE 2 is a fragmentary side elevation, partly in section of the machine of FIGURE 1 drawn to a larger scale than that figure;
  • FIGURE 3 is a sectional side elevation drawn to a larger scale than FIGURE 1 of a rear part of the machine;
  • a presser foot 12 is arranged for movement parallel with the direction of movement of the sewing needle 9. To this end the foot 12 is carried on a vertical rod 13 which is slidable in collars 14 and 15. On the rod 13 is secured a member 16 which has a laterally projecting abutment piece 17, the latter co-operating with a cam portion 18 of a lever 19 which is pivoted at 20 for movement in a vertical plane. It will be seen that on upward and outward rotation of lever 19the cam portion 18 co-operates with the abutment piece 17 to effect lifting of the foot 12.
  • a member 21 the function of which is hereinafter described.
  • a helical spring 22 is provided which biasses the rod 13 downwardly.
  • a driving wheel 25 in the form of a pulley is freely rotatably mounted on the first shaft by means of a ball race 26 and co-operates by means of an endless belt 27 with a driven pulley 28 keyed to the second shaft 6 and forming part of a fly wheel 29.
  • On the rear face of the driving wheel remote from the motor is secured as by screws 36 to rotate with the pulley a plate 31 of an electromagnetic clutch 32.
  • the plate 31 is formed with a rearwardly projecting central boss 33 the outer surface of which is formed with splines 34 extending longitudinally of the motor shaft 3.
  • a driven plate member 35 of the clutch provided on its rear face with a suitable friction lining.
  • the plate member 35 can thus move axially relative to the wheel 25 but is retatable with that wheel.
  • the clutch includes a driving plate member 36 which is secured to the first shaft 3 as by screw 37 and which has a suitable friction lining on its forward face.
  • an energizing clutch coil 38 which is disposed in a housing 39 arranged concentrically with the first shaft 2 and carried on a bracketed secured to the casing of the motor 2.
  • the housing 39 includes inner and outer cylindrical walls 42 and 43 concentric with shaft 2 and closed at rear ends thereof by radial wall 44 which is secured to a plate 45 in turn secured to bracket 49.
  • the periphery of the driving plate 7 the wall 43 whilst a rearwardly projecting annular wall 46 of the member 36 closely overlies the forwardend of inner wall 42.
  • the annular gap between the walls 42 and 43 is substantially closed by driving plate men her 36.
  • a brake plate which is keyed to the driven pulley so as to be capable of limited axial movement relative thereto.
  • a boss 51 formed on its outer surface with axially extending splines with which the brake plate 5 co-operates.
  • annular brake housing 52 disposed concentrically with the second shaft 6 and secured to a plate 53 in turn secured to a bracket 54 carried on the head casting 5.
  • a brake energizing coil 55 which, when energized, magnetises a front plate 56 of the housing adjacent the brake plate 5% causing the latter to be attracted to the housing and thereby stopping the second shaft.
  • the forward and rear surfaces of the housing front plate 56 and brake plate 50 respectively are suitably friction lined.
  • a cam 60 On an end of the second shaft 6 projecting rearwardly of bracket 54 is provided a cam 60 which is secured to the shaft for rotation therewith.
  • a cam follower 61 Engaging the cam and mounted on the rear face ofthe bracket 54 is a cam follower 61 which is pivoted at 62 .andbiassed by spring 63 (see FIGURE 5) towards the cam.
  • the follower carries one contact 64 of a pair of contacts, the other contact 65 of the pair being mounted on an insulated support 66 carried on the rear face of the bracket54.
  • the action of the'cam follower biassing spring is to bias towards closure the pair of contacts whilst urging the follower into contact with the cam and rotation of the cam causes the follower to be-rnoved, once per revolution,
  • a field winding 79 of the induction motor 2 is supplied from an alternating current supply 71 by way of a double pole mains switch 72.
  • the alternating current supply is a 250 volts S0 1 V movement of a contact arm 76 of the microswitch 74 upon raising or lowering of the presser foot 12.
  • the arm 76 is biassed into engagement with afirst contact 77 of the microswitch and when the presser foot is lowered the element 75 moves the arm 76 into contact with a second contact 78 of the microswitch whereupon the output of the rectifier energizes the clutch coil 38.
  • the presser foot does not have to be fully raised to eiiect actuation of the microswitch 74. Because of this, and as hereinafter described, the machine is particularly suited for use with the device described in co-pending application No. 170,622.
  • the contacts 82 .and 83am actuated to close by movement of the element by the lever 19 to a position slightly above that at which the element 75 permits the contact arm of the microswitch 74 to engage contact 77. If the lever 19 is moved so that the element 75 passes the position at which the contacts 82 and 33 close, these contacts immediately re-open. In use the lever 19 is moved so that the element 75 momentarily closes the contacts of microswitch 84 and when this happens the clutch coil 38 is energized in series with resistor 81 and drives the machine until the cam 60 once again closes contacts 64 and 65 to energize the brake coil and bring the machine needle to its uppermost position.
  • the resistor 81 is adjusted so that if the clutch'coil is still energized when contacts 64 and 65 close, the clutch will slip as a result of the load imposed on the needle drive by the brake. It will be noted that the resistor 81 is mounted on the side of the head of the machine.
  • the foot is raised to its uppermost position by lever 19 and the switch 72 is closed- A workpiece is then inserted below the presser foot and the foot is lowered whereupon contact arm 76 closes with contact 78 and the clutch coil 38 is energized to initiate sewing.
  • the lever 19 is moved to raise the presser foot 12 and at the same time effect closure of contact arm 76 with contact 77.
  • the clutch is de-energized and the rive to the needlecontinues to move under its own inertia until the cam 60 reaches the position at which it closes contacts 64 and 65 and thereby energizes the brake coil 55 to stop the needle drive with the needle in its uppermost position.
  • the invention is particularly suitable for use with the device described in co-pending application No. 170,622.
  • the presser foot of the machine is provided with a downwardly extending projection which engages with the sewing track of the device.
  • the presser foot is lowered on to the top of the device so that the projection on the lower side of the presser foot contacts the top sheet of the device.
  • the clutch winding is not, however, energized until the projection on the presser foot is lowered into the sewing track of the device. 7
  • the machine commences sewing.
  • the presser foot is automatically raised on the ramps provided at the end of the track and the raising of the presser foot effects automatic stopping of the machine with the needle in its predetermined position, suitably its uppermost position. If the needle does not stop in its predetermined position, it is brought to this position by movement of lever 19 to effect momentary actuation of microswitch 84.
  • electromagnetic clutch means operatively associated with the driving shaft and the driving wheel and comprising (1) a coupling element movable between a clutch engaged position at which the coupling element constrains the driving wheel to rotate with the driving shaft and a clutch disengaged position at which the coupling element permits the driving wheel to rotate relative to the driving shaft, and
  • first electromagnet means energizable to hold the coupling element in one of its said positions
  • (D) needle actuating means comprising (1) a rotatable driven shaft and (2) means for translating rotation of the driven shaft into up and down motion of the needle;
  • electromagnetic brake means operatively associated with the driven wheel and comprising (1) a brake element movable between a brake disengaged position and a braking position, at the latter of which said brake element is engaged with the driven wheel and with a fixed part on the sewing machine to restrain the driven wheel against rotation, and
  • said switch means comprises a double-throw switch having a movable contactor connectable with a current source, and having a pair of terminals that are alternatively connectable with said contactor, depending upon the position of the latter, and which are respectively connected with the first and second electromagnet means, so that said switch efiects energization of one of said electromagnet means concomitantly with de-energ'ization of the other.
  • said switch means also comprises a single-pole single-throw switch connected between the second electromagnet means and that terminal of the doublethrow switch with which the second electromagnet means is connected, so that the second electromagnet means cannot be energized unless the single-throw switch is closed;
  • the cam means comprises an actuator for said single-pole single-throw switch whereby the latter is closed only when the driven wheel is in its said predetermined rotational position.
  • said switch means comprises a double-throw switch having a movable contactor connectable with a current source and having a pair of terminals that are alternatively engageable by said contactor, depending upon the position of the latter,
  • (C) impedance means connected in series circuit with said other switch and the first electromagnet means so that the first electromagnet means exerts a less than normal clutching force with said other switch closed, permitting continued rotation of the driving wheel after the driven wheel is restrained by the braking element.
  • said impedance means comprises a variable resistor connected between the second mentioned terminal of the double-throw switch and said other switch.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US228123A 1961-10-19 1962-10-03 Electrically controlled sewing machines Expired - Lifetime US3176641A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB37572/61A GB947200A (en) 1961-10-19 1961-10-19 Improvements in electrically driven sewing machines

Publications (1)

Publication Number Publication Date
US3176641A true US3176641A (en) 1965-04-06

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Family Applications (1)

Application Number Title Priority Date Filing Date
US228123A Expired - Lifetime US3176641A (en) 1961-10-19 1962-10-03 Electrically controlled sewing machines

Country Status (6)

Country Link
US (1) US3176641A (de)
AT (1) AT264274B (de)
CH (1) CH398278A (de)
DK (1) DK104157C (de)
ES (1) ES281157A1 (de)
GB (1) GB947200A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3598071A (en) * 1969-03-29 1971-08-10 Pfaff Ag G M Electrically driven sewing machine with means for stopping the machine in a predetermined position of the needle bar
US4269132A (en) * 1978-01-13 1981-05-26 Hsu Yung San Position indicating unit for sewing machines
US4687461A (en) * 1985-05-10 1987-08-18 Frankl & Kirchner Gmbh & Co Kg Multiple rotary drive system for a textile-working machine

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2692667A (en) * 1950-08-16 1954-10-26 Hansen Glove Corp Sewing machine needle control mechanism
US2876407A (en) * 1953-08-03 1959-03-03 Pfaff Ag G M Arrangements for stopping electrically operated sewing or other machines
US2942564A (en) * 1952-01-30 1960-06-28 Singer Mfg Co Needle positioning devices for sewing machines
US2962992A (en) * 1958-10-01 1960-12-06 Singer Mfg Co Control for electric sewing machines

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2692667A (en) * 1950-08-16 1954-10-26 Hansen Glove Corp Sewing machine needle control mechanism
US2942564A (en) * 1952-01-30 1960-06-28 Singer Mfg Co Needle positioning devices for sewing machines
US2876407A (en) * 1953-08-03 1959-03-03 Pfaff Ag G M Arrangements for stopping electrically operated sewing or other machines
US2962992A (en) * 1958-10-01 1960-12-06 Singer Mfg Co Control for electric sewing machines

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3598071A (en) * 1969-03-29 1971-08-10 Pfaff Ag G M Electrically driven sewing machine with means for stopping the machine in a predetermined position of the needle bar
US4269132A (en) * 1978-01-13 1981-05-26 Hsu Yung San Position indicating unit for sewing machines
US4687461A (en) * 1985-05-10 1987-08-18 Frankl & Kirchner Gmbh & Co Kg Multiple rotary drive system for a textile-working machine

Also Published As

Publication number Publication date
ES281157A1 (es) 1963-03-01
DK104157C (da) 1966-04-12
AT264274B (de) 1968-08-26
CH398278A (de) 1965-08-31
GB947200A (en) 1964-01-22

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