US3303802A - Solenoid bobbin winders - Google Patents

Description

Feb. 14, 1967 J. w. cRAwFoRD SOLENOID BOBBIN WINDERS 2 Sheets-Sheet l Filed Feb. 19, 1964 INVENTOR WITNESS United States Patent O 3,393,802 SOLEND B01531151 WENDERS John W. Crawford, Neptune, NJ., assigner to r111e Singer Company, New York, N.Y., a corporation of New Jersey Filed Feb. 19, 1964, Ser. No. 345,892 3 Claims. (Cl. 2112-184) This invention relates to lock stitch sewing machines of the type including mechanism for winding thread on the bobbin in place in the loop taker, and more particularly, to a novel and improved means for operating the bobbin winding mechanism.

It is an object of this invention to provide a solenoid carried by the sewing machine and operatively connected so as to effect shift of the bobbin winding mechanism into operative position.

In the operation of a mechanism for winding thread on a bobbin in place in the sewing machine loop taker during normal interrelated movements of the needle and loop taker as are required for the formation of stitches, a problem exists in -providing a means for preventing or deerring overwinding of the bobbin, which overwinding can occasion jamming of the loop taker and breakage of parts. Heretofore, it has been known to use switching mechanism responsive to the sensing of fully wound condition of the bobbin for terminating the winding operation. This approach to the problem, however, requires that delicate switching components be provided and that a highly critical arrangement of these switching components be maintained. It has also been known heretofore to provide a means responsive to the sensing of fully wound condition of the bobbin for overloading the sewing machine drive motor to deter overwinding of the bobbin, but this approach to the problem raises the possibility of damage to the relatively costly sewing machine drive motor. l

lt is another object of the present invention to provide a novel means for actuating a bobbin winding mechanism in place in a sewing machine loop taker which will function to signal the onset of bobbin overwinding without switching components or the like and without imposing an overload condition on the sewing machine drive motor.

In accordance with this invention, the shift of the bobbin winding mechanism of the sewing machine into operative bobbin winding position is accomplished by an alternating current operated solenoid which may be energized by the same power supply as is used to drive the conventional sewing machine drive motor.

The solenoid is arranged such that its armature seats or bottoms in the operative bobbin winding position of the bobbin winding mechanism when the bobbin is not fully wound, By arranging the device for sensing the fully wound condition of the bobbin so as to effect a shift of the solenoid armature slightly out of seated or bottomed position, the hum incident to the alternating current actuated solenoid operation is materially increased, thus providing an audible signal useful to deter overwinding of the bobbin.

It lis also an object of this invention to provide a novel control circuit for the solenoid which will simultaneously actuate the bobbin winding mechanism solenoid and the sewing machine drive motor in complete independence from the conventional sewing machine drive motor control. This novel control circuit arrangement is advantageous in that it provides for the termination of the drive to the sewing machine mechanism upon termination of the bobbin winding operation and thus obviates sudden unexpected initiation of stitch forming operations. Moreover, this novel control arrangement is also advantageous in that it provides for preselection of the operating con- Patented Feb. 14, 1967 dition of the sewing machine drive motor to an optimum value for bobbin winding during the bobbin winding operation.

With the above and additional objects and advantages in View as will hereinafter appear, this invention comprises the devices, combinations, and arrangements of parts hereinafter described and illustrated in the accompanying drawings in which:

FIG. l represents a vertical cross sectional view of a sewing machine having this invention applied thereto,

FIG. 2 represents an enlarged vertical cross sectional view of the loop taker of the sewing machine of FIG. l together with the bobbin winding mechanism actuating solenoid with the solenoid turned bodily at right angles to the position shown in FIG. 1 more clearly to illustrate the relationship of parts and with the parts illustrated in the bobbin winding position and the bobbin not fully wound,

FIG. 3 represents a vertical cross sectional View of the loop taker and solenoid similar to that of FIG. 2 but with the parts illustrated in the bobbin winding position with the bobbin fully wound, and

FIG. 4 is a wiring diagram illustrating the control circuit for the bobbin winding mechanism solenoid and for the sewing machine drive motor.

Referring to the drawings, this invention is illustrated as applied to a sewing machine of the type including a provision for winding replenishment thread on the bobbin in place in the loop taker such as is disclosed in the United States patent of S. l. Ketterer, No. 3,115,855, December 31, 1963, to which reference may be had. The sewing machine includes a frame having a bed 11, a standard 12 rising from the bed, and a bracket arm 13 extending from the standard and overhanging the bed. Journaled in the bracket arm is a main drive shaft 14 to which is secured a handwheel 15 and a worm wheel 16 which meshes with a worm 17 fast on the drive shaft of an electric motor 18 which may be housed within the standard as illustrated in FIG. 1. A crank 19 carried on the main drive shaft serves by way of a drive link 20 to reciprocate a needle bar 21 which is journaled for endwise movement in the bracket arm and carries at its lower extremity a needle 22. The crank 19 also serves to impart oscillatory motion to a needle thread take up member 23. Iournaled in the bed 11 in a position to c0- operate with the needle in the formation of stitches is a loop taker indicated generally as 24. The loop taker is fast on a hollow loop taker shaft which is drivingly connected by miter gears 2e to a bed shaft 27 connected in turn by miter gears 28 and 29 and a vertical shaft 30 in the standard to the main drive shaft 14. It will be understood that the main drive shaft 14 and the gear drive 26, 28 and 29 constitute an actuating mechanism for imparting interrelated motion to the needle and loop taker as is required for the formation of lock stitches.

Referring particularly to FiGS. 2 and 3, the loop taker 24 is formed with a cup-shaped body portion 4@ of which the rim is formed with an annular bearing rib 42 ernbraced by an annular raceway 43 formed in a bobbin case 44 which is constrained from rotation with the loop taker body portion as is well known in sewing machine art. Resting upon an annular shoulder 45 formed Ion the bobbin case is Ithe upper flange 45 of a thread carrying bobbin 47 which is formed with a lower antge 48 having an annular groove 49 formed therein, in which groove a driving abutment 50 is formed. The bobbin 47 is constrained against the bobbin case shoulder 45 by a springloaded lever 51 which is carried on the bobbin case 44 and is formed with a spherical protuberance 52 seated in a depression 53 in the upper ange 46 on the bobbin.

For winding replenishment thread on the bobbin in place in the loop taker while the needle 4and loop taker partake of normal interrelated motions as are required f-or the formation `of lock stitches, a bobbin winding member 60 is provided within the cup-shaped body portion of the loop taker and beneath the bobbin. The bobbin winding member 60 is fast on a rod 61 which is slidable endwise in the hollow loop taker shaft 25. A bracket 62 which is fast on the rod 61 beneath the loop taker shaft is formed with an upturned lug 63 which enters an aperture 64 in that miter gear of the miter gear set 26 which is fast on the loop taker shaft, so that the bobbin winding member 60 is constrained to rotate with the loop taker. The bobbin winding member 60 is formed with an upwardly extending flange 65 which serves to embrace the lower flange i8 of the bobbin when the bobbin winding member and the rod 6,1 are shifted upwardly as illustrated in FIGS. 2 and 3. In addition, the bobbin winding member 60' includes a driving lug 66 which enters the annular groove 49 in the lower flange 48 of the bobbin when the bobbin winding member 60 is raised, and thereby assumes a bobbin driving relationship with the abutment formed with the annular groove 49. As explained more completely in the above referenced United States Patent No. 3,115,855 to which reference may be had, the bobbin winding member 60, when raised into the position illustrated in FIGS. 2 or 3, serves to effect winding of replenishment thread on the bobbin by virtue of the ange 65 on the bobbin winding member which deflects thread being manipulated by the loop taker into the space between the bobbin flanges, and by virtue of the driving relationship between the driving lug 66 and the abutment 50 which serve to rotate the bobbin with the loop taker, thus to wind on the bobbin a thread extending from the needle 22. When the tbobbin winding member is lowered into the position illustrated in FIG. l in which the flange of the bobbin winding member is completely beneath the lower flange 48 of the bobbin. needle thread loops seized and manipulated between loop taker beak 41 are free to pass beneath and about the bobbin, thus to concatenate with thread wound on the bobbin tto form lock stitches.

For effecting elevation of the bobbin winding member 60 into operative bobbin winding position, a solenoid indicated generally at 70 is employed in this invention. The solenoid includes a core '71 which may be of conventional laminated construction and is secured as by fastenings 72 to a casing '73. An Ioutturned lug 74 on the solenoid casing is slotted as at 75 to accommodate a fastening screw 76 by which the solenoid core may be secured to the sewing machine bed 11 with provision for limited adjustment `of the position of the solenoid in a direction axially of the loop taker. Articulated relatively to the armature core as by a pivot pin 77 passing through one pole 78 tof the solenoid core is an armature 7) which is thus shiftably supported for movement into and out of engagement with the other pole 80 of the armature core 71. A solenoid coil 81 wound on the core 71 when energized serves to draw the armature 79 into seated or bottomed relation against the pole 80 of the armature core. A shading coil 82 may be provided on the pole 80 of the armature core to provide for a continuity of magnetic flux when the solenoid coil is energized by an alternating current so as to minimize the vibration of the armature relatively to the solenoid core when the armature is seated or bottomed against the pole 80 of the solenoid core.

The solenoid 70, which is thus adapted for alternating current operation, is formed with an extended armature extremity which is apertured as at 91 to embrace the lower extremity of the bobbin winding member rod 61 and is preferably constrained relatively to the rod 6-1 ybetween spaced nuts 92 threaded thereon. The `armature extension 90 may also be slightly crowned as at 93 so that the pivotal motion of the armature will not conflict with the translatory endwise sliding movement of the rod 61. The solenoid fastening screw 76 in the slotted lug 74 4- of the solenoid casing may be used to secure the solenoid to the sewing machine bed in a selected position in which the solenoid armature 79 will occupy a seated or bottomed position against the solenoid core pole 80 when the solenoid is energized and the bobbin winding member is raised into operative bobbin winding lengagement with the bobbin as illustrated in FIG. 2 and the bobbin is not fully wound with thread. In this position of the parts, as the bobbin thread repleni'shing process begins and while the bobbin is less than fully wound, the solenoid 70 will operate with a minimum of vibration or hum.

Pivoted on a pin set into the bobbin case 44 is a bobbin thread sensing member 101 having a thread engaging shoe 102 extending between the anges 46 and 48 of the bobbin. The bobbin thread sensing member 101 also is formed with an inclined cam surface 103 disposed for engagement with the upturned flange 65 of the bobbin winding member when the bobbin thread sensing member is forced outward by engagement of the thread engaging shoe 102 with thread that is being wound on the bobbin. As illustrated in FIG. 3, the cam surface 103 is positioned relatively to the thread engaging shoe 102 so as to engage and depress the ange 65 of the bobbin winding member as the thread approaches the fully wound condition on the bobbin 47. The rod 61 associated with the bobbin Winding member will, in being depressed with t-he bobbin winding member 60, force the solenoid armature 79 slightly out of seat or bottomed relation against the `armature core pole 80 as illustrated in FIG. 3 of the drawing in which condition the inuence of the shading coil 82 of the solenoid will be materially decreased resulting in a noticeable increase in the vibration and hum developed by the alternating current actuation of the solenoid. This hum is of such a noticeable nature as to serve as a persistent audible signal to the sewing machine operator that the -bobbin is in fully wound condition. Furthermore, it is pointed out that the inuence of the Ibobbin thread sensing member in camming the bobbin winding member 60, the rod 61, and the solenoid armature 79 downwardly in response to the fully wound condition of the bobbin does not materially inuence the driving force required of the sewing machine actuating mechanism and therefore, does not impose any appreciable overload condition upon the sewing machine drive motor 18.

Referring to FIG. 1, the wiring in the electrical circuit for both the sewing machine drive motor 18 and for the solenoid 70 is associated in the sewing machine with a three pin receptical which is adapted, as is conventional in the sewing art, to accommodate a plug 111 to which is directed conductors 112 and 113 to a source of power supply indicated at 114 and also a conductor 115 to a foot controller 116. Referring to the circuit diagram illustrated in FIG. 4, the foot cont-roller 116, which is of the type including an on-oif switch and a rheostat for controlling the sewing machine drive `motor speed at the will of the sewing machine operator is connected by a conductor 119 to the conductor 112 and is wired in series with the sewing machine drive motor 18 by the conductors 118 and 119 within the sewing machine. Indicated at 120 is a double circuit push button switch which is preferably spring loaded into the normally open position and must be held closed by the Operator of the sewing machine. The switch 120 is connected by the conductor 121 to the conductor 112 and controls simultaneously two circuits across the conductors 112 and 113 from the power source. The sewing machine drive motor 18 is connected into one of the circuits controlled by the switch 120 by a conductor 122 in which circuit a motor speed controlling resistor 123 may be included so as to provide for a preselected motor speed when 'the switch 120 is closed and the foot controller 116 is not operated. The other circuit controlled by the switch 120 serves by way of conductors 124 and 125 to connect the solenoid coil 81 across the conductors 112 from the power source 113. With this arrangement closure of the push button switch 120 by the sewing machine operator serves to energize simultanously the sewing machine drive motor 1S and the solenoid 70 which initiates a bobbin winding operation. When an audible signal is provided to the sewing machine yoperator by virtue of the hum produced -by the solenoid when the fully wound condition of the bobbin is sensed, release or" the push button switch 120 by the operator will serve to terminate the bobbin winding operation and to deenergize the sewing machine drive motor so that the sewing machine will not suddenly revert to normal sewing operation. Thereafter, the motor 18 may be energized to control the sewing machine during sewing by the use of the foot controller 116.

Having set forth the nature of this invention, what is claimed herein is:

1. In a lock stitch sewing machine having a frame, a thread carrying needle endwise reciprocable in said frame, a circularly moving loop taker journaled in said frame, a thread carrying bobbin journaled within said loop taker, act-uating mechanism in said frame operatively connecting said needle and said loop taker for interrelated movements as are required for the formation of lock stitches, a bobbin Winding member carried within said loop taker, and means shiftably supporting said bobbin winding member for movement axially of said loop taker into and out of operative engagement with said bobbin, means for at Will shifting said bobbin winding member axially of said loop taker into operative engagement with said bobbin comprising a solenoid including a core provided with a solenoid coil, an armature shiftably supported relatively to said core, means operatively connecting said armature to said bobbin winding member, and means securing said solenoid core to said sewing machine frame with said solenoid armature in seated relation against said solenoid core in the operative engaged position of said bobbin winding member with said bobbin.

2. In a lock stitch sewing machine having a trame, a thread carrying needle endwise reciprocable in said frame, a circularly moving loop taker iournaled in said frame, a thread carrying bobbin journaled within said loop taker, actuating mechanism in said frame operatively `connecting said needle and said loop taker for interrelated movements as are required for the formation of lock stitches, a vbobbin Winding member carried within said loop taker, and means shiftably supporting said bobbin winding member for movement axially of said loop taker into and out of operative engagement with said bobbin, the combination of means for shifting said bobbin winding member axially of said loop taker into operative engagement with said bobbin comprising la solenoid including a core provided with a solenoid coil, an armature shiftably supported relatively to said core, means operatively connecting said armature to said bobbin Winding member, and means securing said solenoid core to said sewing machine frame with said solenoid armature in seated relation against said solenoid core in the operative engaged position of said bobbin winding member with said bobbin, a bobbin thread sensing member shiftably supported in said loop taker in position for movement under the inliuence of a predetermined quantity of thread Wound on said bobbin, and means operatively connecting said bobbin thread sensing member with said solenoid armature for eiecting a shift of said solenoid armature out of said seated relation against said solenoid core upon movement of said bobbin thread sensing member in response to said predetermined quantity of thread Wound on said bobbin.

3. In a lock stitch sewing machine having a frame, a thread carrying needle endwise reciprocable in said frame, a circularly moving loop taker journaled in said frame, a thread carrying bobbin journaled within said loop taker, actuating mechanism in said frame operatively connecting said needle and said loop taker for interrelated movements as are required for the formation of lock stitches, an electric motor drivingly connected to said actuating mechanism, a bobbin winding member carried within said loop taker and means shiftably supporting said bobbin winding member for movement axially of said loop taker into and out of operative engagement with said bobbin, means for at will shifting said bobbin Winding member axially of said loop taker into operative engagement with said bobbin comprising a solenoid carried by said sewing machine frame and including a core provided with a solenoid coil, an armature shiftably supported relatively to said core, means operatively connecting said armature to said bobbin winding member, and a control circuit for said electric motor and said solenoid coil from a common source of electrical supply comprising a ti-rst switch means operatively connecting only said electric motor to said source of supply, and a second switch means operatively connecting both said electric motor and said solenoid coil simultaneously to said source of supply.

References Cited by the Examiner UNITED STATES PATENTS 1,029,335 6/1912 Baker 112-186 1,794,255 2/1931 Stephenson 112--181 2,255,152 9/ 1941 Colegrove 242-22 3,156,429 11/1964 Jones 242-865 3,138,127 6/1964 Ketterer 112-184 3,154,035 10/1964 Edwards et al i12-184 JORDAN FRANKLIN, Primary Examiner.

H. H. HUNTER, Assistant Examiner.

Claims (1)

1. IN A LOCK STITCH SEWING MACHINE HAVING A FRAME, A THREAD CARRYING NEEDLE ENDWISE RECIPROCABLE IN SAID FRAME, A CIRCULARLY MOVING LOOP TAKER JOURNALED IN SAID FRAME, A THREAD CARRYING BOBBIN JOURNALED WITHIN SAID LOOP TAKER, ACTUATING MECHANISM IN SAID FRAME OPERATIVELY CONNECTING SAID NEEDLE AND SAID LOOP TAKER FOR INTERRELATED MOVEMENTS AS ARE REQUIRED FOR THE FORMATION OF LOCK STITCHES, A BOBBIN WINDING MEMBER CARRIED WITHIN SAID LOOP TAKER, AND MEANS SHIFTABLY SUPPORTING SAID BOBBIN WINDING MEMBER FOR MOVEMENT AXIALLY OF SAID LOOP TAKER INTO AND OUT OF OPERATIVE ENGAGEMENT WITH SAID BOBBIN, MEANS AND OUT OF OPERATIVE ENGAGEMENT WITH SAID BOBBIN, AXIALLY OF SAID LOOP TAKER INTO OPERATIVE ENGAGEMENT WITH SAID BOBBIN COMPRISING A SOLENOID INCLUDING A CORE PROVIDED WITH A SOLENOID COIL, AN ARMATURE SHIFTABLY SUPPORTED RELATIVELY TO SAID CORE, MEANS OPERATIVELY CONNECTING SAID ARMATURE TO SAID BOBBIN WINDING MEMBER, AND MEANS SECURING SAID SOLENOID CORE TO SAID SEWING MACHINE FRAME WITH SAID SOLENOID ARMATURE IN SEATED RELATION AGAINST SAID SOLENOID CORE IN THE OPERATIVE ENGAGED POSITION OF SAID BOBBIN WINDING MEMBER WITH SAID BOBBIN.

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