US3698334A - Position signaling devices for sewing machine driving unit - Google Patents

Position signaling devices for sewing machine driving unit Download PDF

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Publication number
US3698334A
US3698334A US151664A US3698334DA US3698334A US 3698334 A US3698334 A US 3698334A US 151664 A US151664 A US 151664A US 3698334D A US3698334D A US 3698334DA US 3698334 A US3698334 A US 3698334A
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US
United States
Prior art keywords
sewing machine
drive shaft
signaling device
main drive
arm
Prior art date
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Expired - Lifetime
Application number
US151664A
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English (en)
Inventor
Johann O Kleinschmidt
Heinz E Walter
Helmar H Holl
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.)
SSMC Inc
Original Assignee
Singer Co
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Filing date
Publication date
Application filed by Singer Co filed Critical Singer Co
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Publication of US3698334A publication Critical patent/US3698334A/en
Assigned to SSMC INC., A CORP. OF DE reassignment SSMC INC., A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SINGER COMPANY, THE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • D05B69/24—Applications of devices for indicating or ascertaining sewing-tool position

Definitions

  • ABSTRACT A direct drive unit for a sewing machine applied on the sewing machine frame co-axially of the sewing machine main shaft including a device for producing signals responsive to discrete positions of the sewing machine main shaft.
  • the position signaling device is capable of indicating a plurality of different angular positions of the sewing machine main shaft, which positions may be selected simply by turning frictionally restrained arms accessibly located on the free extremity of the drive unit into the angular positions for which signals are desired.
  • Prior position signaling devices have not been entirely satisfactory in that they have been complicated and expensive, have provided only very limited ranges of adjustment, and have required the use of tools and in many cases calibration equipment in order to effect a change or adjustment of the discrete main shaft position to be signaled.
  • the object of this invention is attained by a signaling device located at the free extremity of a direct driving unit carried co-axially of a sewing machine main shaft and comprising an element carried for rotation with the main shaft and capable, upon traversing a discrete angular position, of generating a signal.
  • a frictional coupling secures the rotating element relatively to the main shaft so that the angular position of the rotating element which bears a direct relationship to the angular main shaft position to be signaled, may be changed simply be physically repositioning the rotating element angularly about the main shaft axis.
  • FIG. 1 is a front elevational view of a sewing machine showing a direct driving unit thereon having this invention applied thereto,
  • FIG. 2 is an enlarged horizontal cross-sectional view of the sewing machine driving unit taken substantially along line 2--2 of FIG. 1,
  • FIG. 3 is an exploded perspective view of the posi tion signaling device of this invention.
  • FIG. 4 is an end elevational view of the free extremity of the driving unit with the end cover plate removed to expose the position signaling device
  • FIG. 5 is an enlarged cross-sectional view taken substantially along line 5--5 of FIG. 4 showing the frictional connection between the rotating arms of the position signaling device and the motor shaft.
  • FIG. 1 illustrates a conventional sewing machine including a frame with a work supporting bed 11, a standard 12 rising from the bed and abracket arm 13 extending from the standard and overhanging the bed.
  • the sewing machine is illustrated as supported on a power table 14.
  • Thesewing machine is equipped with stitch forming instrumentalities of which the needle 15 is illustrated in FIG. 1, which stitch forming instrumentalities are actuated from a main shaft 16 journaled in the bracket arm 13 of the sewing machine frame.
  • the operative connections between the main shaft and the needle and other stitch forming instrumentalities may take any conventional form.
  • a sewing machine direct driv- 0 ing unit is carried on the the power table, and the wiring harness may include control conduits as well as conductors for a supply to the driving unit.
  • the sewing machine frame at the juncture of the bracket arm 12 and standard 13 is formed with a seat 30 for supporting the driving unit 20.
  • the sewing machine main shaft 16 carries a coupling member 32 which is secured to the sewing machine main shaft by a set screw 34 and by a headed screw 35.
  • the free extremity of the coupling member 32 is formed of a plurality of spaced axially extending fingers 36 by which a driving connection with an electric motor is made, as will be described hereinbelow.
  • a supporting casing 41 Secured on the seat 30 on the sewing machine frame by cap screws 42 is a supporting casing 41 having a bell-shaped outer flange 44 formed with a motor accommodating seat 45 and with clearance holes 46 for fastening screws 47 by which an electric motor may be fastened thereto.
  • the handwheel is. formed with a continuous rim 53 which is disposed within a circular cavity 54 inside the supporting casing '41. As shown in FIG. 1, the supporting casing 41 is cut away as at 55 at the top portion thereof to expose a segment of the handwheel rim for ready access by the sewing machine operator.
  • an electric motor secured on the motor seat 45 of the supporting casing is an electric motor, indicated generally at 70, and including a cylindrical housing 71 fitted at each end with circular end plates 72 each secured by bolts 73 to provide a substantially airtight compartment 74.
  • a motor shaft 75 is journaled in bearings 76 in the end plates 72.
  • An armature in the form of a disc 77 is made fast on the motor shaft within the airtight compartment and rotates therein relatively to a plurality of permanent magnets 78 supported on the end plates 72.
  • Brushes 79 are also supported within theairtight motor compartment to contact electric windings which may be printed or otherwise provided on the armature disc to provide a low inertia electric motor of the type which is disclosed and described in greater detail in US. Pat. No. 2,970,238, Jan. 31, 1961 of R. L. Swiggett to which reference may be had.
  • a brake disc with a surface 91 of high friction material is secured to power the motor shaft 75.
  • a brake shoe 93 which is preferably constructed as an ele'ctro-magnet which when energized will be drawn into braking engagement with the friction surface 91 on the brake disc 90.
  • Coil springs 94 on the guide pins 92 serve to urge the brake shoe 93 out of braking engagement when the electro-magnet is deenergized.
  • the electric motor shaft 75 carries a coupling member 100 which is preferably shaped in a fashion similar to that of the coupling member 32 on the sewing machine main shaft 16.
  • the coupling member 100 thus includes axial fingers 101 which are arranged in interdigitated relation with the fingers 36 of the coupling member 32 to define a driving connection between the motor shaft and the sewing machine main shaft.
  • the interdigitated fingers 36 and 101 occupy only a fraction of the circumference of the coupling members.
  • a disc 102 of heat insulating material such as rubber or the like is interposed between the coupling members 32 and 100 and is formed with radial teeth 103 which extend between the interdigitated fingers 36 and 101 and fill the circumferential space therebetween.
  • a base member 107 preferably formed of synthetic plastic material is secured to the free extremity of the direct drive unit by the bolts 73 which hold the electric motor housing together.
  • the base member accommodates a group of locating and signaling devices of which the position signaling device of this invention is included.
  • Reception sockets 108 formed on the base member 107 snugly accommodate securing pins 109 carried by a cover member 110.
  • the cover member extends in overlapping relation with an annular flange 111 on the base member 107 and defines an enclosed compartment 112 within which the free extremity 113 of the electric motor shaft 75 extends. Because of the interconnected coupling members 32 and 100, the motor shaft 75 is secured for movement in synchronism with the main drive shaft 16 of the sewing machine. Therefore, any signal which is responsive to a discrete angular position of the motor shaft 75 will also bear the same relationship to the position of the sewing machine drive shaft and to the stitch forming instrumentalities driven thereby, as for instance, the position of the needle 15.
  • annular tachometer rotor 120 Secured to the main drive shaft within the compartment 112 is an annular tachometer rotor 120, preferably comprising opposed ferrous plates 121 each formed with inturned fingers 122 which are interdigitated.
  • the plates 121 are disposed one at each side of an annular block 123 which is permanently magnetized.
  • the plates and permanent magnet block may be assembled as a unit on a hub member 125 secured, as by a set screw 126, to the motor shaft 75.
  • bracket 128 Secured, as by screws 127, to the base member 107 and motor end plate 72 is a bracket 128 which carries a coil 129 responsive to the passage adjacent thereto of the fingers 122 of the tachometer rotor and provides recurring signals in an electric circuit 130 of which the frequency of the signals is a measure of the speed of rotation of the motor shaft 75.
  • each of the coils 140, 140' are wound on a ferrous core having a ferrous yoke 142, 142' secured to one end and extending about the coil terminating in spaced relationship to the opposite end of the core to concentrate the magnetic field existing adjacent to the coils.
  • the cores 141, 141' are disposed each closely adjacent to the path of motion of one of a pair of permanent magnets 150, 150' each secured as by an adhesive or by a force-fit into a reception opening in one of the rotating arms 151, 151' carried on the hub member of the tachometer rotor.
  • the travel of each of the permanent magnets 150, 150' past the respective electric coils 140 changes the magnetic flux concentration adjacent to the coil and gives rise to a signal in the form of a voltage pulse in the coil and in the circuits 143, 143' leading from the coils 140, 140.
  • the hub member 125 is formed with a radial flange 152 from which a hub extension 153 of reduced diameter extends.
  • Each of the rotating arms 151, 151' is formed with a circular aperture 154, 154' loosely embracing the hub extension 153 so that the rotating arms 151, 151' may be turned freely on the hub extension.
  • a dished spring washer 155 preferably formed with spaced radial spring fingers 156 for increased flexibility, is carried on the hub extension 153 and is maintained in compression urging the rotating arms 151, 151' against the radial hub flange 152 by a split retaining ring 157 which is seated in an annular groove 158 cut in the free extremity of the hub extension 153.
  • the restraining torque which must be exceeded before either of the rotating arms 151, 151' can be shifted angularly relatively to the motor shaft 75 is a function of the normal force exerted by the dished washer 155 urging the rotating arms against the radial hub flange 152. If the restraining torque is higher than the maximum torque which is developed during acceleration of the driving unit by the inertia of the rotating arms, the rotating arms will not shift angular position during operation of the driving unit.
  • the dished washer is designed so as to be compressed by the split retaining ring 157 to such a degree that the force exerted and the restraining torque which is developed in response thereto is sufficient to prevent accidental shift of angular position of the arms 151, 151 but not sufficient to interfere with convenient adjustability of the angular position of the rotating arms by a sewing machine operator while the drive is in stopped condition.
  • the end cover member 110 may be removed and one or both of the rotating arms may be manually shifted relatively to the motor shaft 75.
  • Such selection of the angular position of the rotating arms, and of the members 150, carried thereby, which move relatively to the coils 140, 140' during the machine operation, may be accomplished easily and readily with the sewing machine arm shaft 16 being held in desired angular position by manipulation of the handwheel 52 while the rotating arms 151, 151' are shifted.
  • a position-signaling device for the actuating mechanism of a sewing machine having a frame and a main drive shaft journaled in said frame, said positionsignaling device comprising a stationary signal generating member secured in a fixed position relatively to said sewing machine frame, a movable member adapted to render said signal generating member effective in response to passage of said movable member closely adjacent thereto, means supporting said movable member for rotation in a path traversing closely adjacent to said stationary signal generating member, and a friction coupling drivingly interconnecting said movable member with said sewing machine main drive shaft, said friction coupling being such as to require for slippage of said movable member relatively to said sewing machine main drive shaft a torque which is greater than the maximum torque generated by the inertia of said movable arm during acceleration of said sewing machine main drive shaft.
  • a position-signaling device as set forth in claim 1 in which a hub member drivingly interconnected with said sewing machine drive shaft has journaled on it a rotatable arm which carries said movable member for rotation, in which said friction coupling comprises a flange on said hub member against which one side of the rotatable arm abuts, spring means engaging the opposite side of the rotatable arm, and means on said hub member for maintaining said spring means under sufficient tension as to require for slippage of said rotatable arm relatively to said sewing machine main drive shaft a torque which is greater than the maximum torque generated by the inertia of said rotatable arm during acceleration of said sewing machine main drive shaft.
  • a position-signaling device as set forth in claim 1 in which said signal generating means comprises an electrical coil and in which said movable member includes a permanent magnet arranged to induce a voltage signal in said coil upon passage of said member closely adjacent thereto.
  • a position-signaling device for a sewing machine having a frame, a main drive shaft journaled in said frame, and a direct driving unit secured to said sewing machine frame and including an electric motor with a mote r shaft interconnect'e d at one end with said sewing mac ine main drive s a said position-signaling device comprising an arm loosely journaled in an accessible position on the free extremity of said electric motor shaft, signal generating means supported in fixed position relatively to said sewing machine frame adjacent to the path of rotation of said arm for providing a pulse responsive to each movement of said arm through a discrete angular segment of said path of rotation, and a friction coupling between said motor shaft and said arm permitting manual rotary adjustment of said arm on said shaft.
  • a position-signaling device as set forth in claim 4 in which said electric motor shaft of said direct driving unit is supported in substantial axial alignment with said sewing machine drive shaft, in which a handwheel accessible to an operator of the sewing machine is fast on said sewing machine main drive shaft between the sewing machine frame and the electric motor of the direct driving unit, and in which a removable cover is provided for the position-signaling device at the free extremity of the electric motor shaft.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US151664A 1971-06-10 1971-06-10 Position signaling devices for sewing machine driving unit Expired - Lifetime US3698334A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US15166471A 1971-06-10 1971-06-10

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US3698334A true US3698334A (en) 1972-10-17

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US151664A Expired - Lifetime US3698334A (en) 1971-06-10 1971-06-10 Position signaling devices for sewing machine driving unit

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US (1) US3698334A (it)
DE (1) DE2227116A1 (it)
FR (1) FR2141315A5 (it)
GB (1) GB1393294A (it)
IT (1) IT955935B (it)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3821937A (en) * 1972-12-18 1974-07-02 Singer Co Cooling of low-inertia motor driven direct drive sewing machine
US4147118A (en) * 1977-11-14 1979-04-03 The Singer Company Combined electronic and mechanical pattern control for a sewing machine
US20110094426A1 (en) * 2007-11-09 2011-04-28 Vsm Group Ab Thread cut with variable thread consumption in a sewing machine
US20110113999A1 (en) * 2009-06-01 2011-05-19 Kerstin Widell Texture hoop fixture
US20110146551A1 (en) * 2008-06-26 2011-06-23 Vsm Group Ab Mechanically operated presser foot lift arrangement and a sewing machine comprising the arrangement
US9631304B2 (en) 2013-03-15 2017-04-25 Singer Sourcing Limited Llc Variable timing system of a sewing machine and method for selectively adjusting a timing of such a system

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2470087B1 (fr) * 1979-11-20 1986-02-21 Ivan Sarl Ensemble orientable de distribution-comptage pour liquides, gaz et pulverulents
DE19949020C1 (de) * 1999-10-11 2001-04-05 Viking Sewing Machines Ab Husk Nähmaschine mit einem ein Lüfterrad und einen Drehzahlgeber aufweisenden Elektromotor
WO2009029019A1 (en) 2007-08-30 2009-03-05 Vsm Group Ab Positioning of stitch data objects
WO2009085005A1 (en) 2007-12-27 2009-07-09 Vsm Group Ab Sewing machine having a camera for forming images of a sewing area
CN102277696B (zh) 2010-06-09 2015-03-11 Vsm集团股份公司 送料器移动补偿
US8960112B2 (en) 2013-02-01 2015-02-24 Vsm Group Ab Stitching system and method for stitch stop embellishments

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3821937A (en) * 1972-12-18 1974-07-02 Singer Co Cooling of low-inertia motor driven direct drive sewing machine
US4147118A (en) * 1977-11-14 1979-04-03 The Singer Company Combined electronic and mechanical pattern control for a sewing machine
US20110094426A1 (en) * 2007-11-09 2011-04-28 Vsm Group Ab Thread cut with variable thread consumption in a sewing machine
US8925473B2 (en) 2007-11-09 2015-01-06 Vsm Group Ab Thread cut with variable thread consumption in a sewing machine
US20110146551A1 (en) * 2008-06-26 2011-06-23 Vsm Group Ab Mechanically operated presser foot lift arrangement and a sewing machine comprising the arrangement
US8763543B2 (en) 2008-06-26 2014-07-01 Vsm Group Ab Mechanically operated presser foot lift arrangement and a sewing machine comprising the arrangement
US20110113999A1 (en) * 2009-06-01 2011-05-19 Kerstin Widell Texture hoop fixture
US8833281B2 (en) 2009-06-01 2014-09-16 Vsm Group Ab Texture hoop fixture
US9631304B2 (en) 2013-03-15 2017-04-25 Singer Sourcing Limited Llc Variable timing system of a sewing machine and method for selectively adjusting a timing of such a system

Also Published As

Publication number Publication date
FR2141315A5 (it) 1973-01-19
GB1393294A (en) 1975-05-07
IT955935B (it) 1973-09-29
DE2227116A1 (de) 1972-12-28

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Date Code Title Description
AS Assignment

Owner name: SSMC INC., A CORP. OF DE, CONNECTICUT

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:SINGER COMPANY, THE;REEL/FRAME:005041/0077

Effective date: 19881202