US3376838A

US3376838A - Bobbin changer for sewing machines

Info

Publication number: US3376838A
Application number: US524222A
Authority: US
Inventors: Fred J Schiffmacher; Walter A Roman
Original assignee: Ivanhoe Research Corp
Current assignee: Ivanhoe Research Corp
Priority date: 1966-02-01
Filing date: 1966-02-01
Publication date: 1968-04-09
Anticipated expiration: 1985-04-09
Also published as: DE1760106A1

Description

April 9, 1968 F. J. SCHIFFMACHER E AL 5,

I BOBBIN CHANGER FOR SEWING MACHINES Filed Feb. 1, 1966 5 Sheets-Sheei 1 INVE TORS.

FRED J. SCHIFFMACHER BY WALTER A. ROMAN A TTORNEYS.

April 9, 1968 F. J. SCHIFFMACHER ET'AL 3,376,838

BOBBIN CHANGER FOR SEWING MACHINES Filed Feb. 1, 1966 I 5 Sheets-Sheet 7i INVENTORS.

. FRED a. SCHIFFMACHER BY WALTER A. ROMAN WWFZM United States Patent BOBBlN CHANGER FOR SEWING MACHINES Fred J. Schiifmacher, New Canaan, and Walter A.

Roman, Nor-walk, Conrn, assignors, by mesne assignments, to Ivanhoe Research Corporation, New

York, N.Y., a corporation of Delaware Filed Feb. 1, 1966, Ser. No. 524,222 8 Claims. (Cl. 112-186) ABSTRACT OF THE DISCLOSURE A bobbin changer for sewing machines including a carrier for carrying an assembly of bobbin and case from a magazine to the holder with transfer means for moving the assembly from the carrier into the holder, the transfer means also removing the assembly from the holder when the bobbin has been depleted. An opening in the carrier for reception of the bobbin assembly into the carrier is positioned adjacent to and aligned with the magazine to receive a bobbin assembly therein and in a second position of the carrier this opening is adjacent to and aligned with the holder for transferring the bobbin assembly into the holder. The transfer means includes a movable hook to push the bobbin assembly from the carrier into the holder, this hook being engageable with the pivoted latching element on the bobbin case for releasing the assembly from the holder to remove the deplete-d assembly, with the operations carried out in sequence providing a quick automatic replacement of the depleted bobbin assembly.

The invention relates to a bobbin changer for sewing machines.

In the operation of sewing machines for factory production work two different procedures. have been followed for the removal and replacement of used bobbins. In the case of work entailing fairly long sewing operations, the operator tends to rewinding of a spare bobbin while performing the sewing operation; but where the sewing operations are of brief duration a supply of rewound or new bobbin spools will generally be kept at hand for replacement of the used bobbins as needed. In either case the bobbin changing procedure is a rather fussy, timeconsuming operation involving as it does the several steps of (1) Unlatching and pulling out the bobbin assembly from the basket of the bobbin holder;

(2) Removing the used bobbin spool from its case;

( 3) Placing the new or rewound spool in the empty case from step 2; and

(4) Placing the new bobbin assembly from step 3 into the basket of the holder and pressing it in to latch it in place.

These several steps all must be performed while the machine is stopped and thus add to the idle time during which the investment in the machine is earning no return. Also, the performance of these steps adds to the strain on the operator, dissipating energy which otherwise would be available for productive effort.

It has been an object of our invention to provide a bobbin changing system and machine which simplifies the procedure and makes it possible to change bobbins by the actuation of an automatic changer mechanism. Our bobbin changer does not operate according to the manual procedures heretofore followed, but performs the several steps in a different'manner and sequence as will be explained.

Summary Our invention is applicable to any conventional form of sewing machine which includes a bobbin holder. The

3,376,838 Patented Apr. 9, 1968 bobbin 'holder generally comprises a rotary hook within which is rotatably mounted a basket which receives the bobbin assembly comprised of the bobbin spool and the case for such spool. A latch on the case holds it in place in the basket of the bobbin holder. As applied to such a machine our bobbin changer comprises (a) a magazine holding in axial alignment a number of bobbin assemblies each comprising a bobbin and a bobbin case, the bobbin being assembled into the case,

(b) a bobbin carrier movable between a position in which it is aligned with the magazine to receive a bobbin assembly from the magazine and another position in which the carrier is aligned with the bobbin holder,

(c) transfer means for moving the bobbin assembly from the carrier to the bobbin holder and for removing the bobbin assembly from the holder when the bobbin is substantially empty, and

(d) means for activating the transfer means and bobbin carrier sequentially for removal of a bobbin assembly from the holder, moving of a new bobbin assembly from the magazine to align it with the holder and for transfer of the new bobbin assembly to the holder.

The transfer means (c) for moving the bobbin from the carrier to the bobbin holder and for removing the bob-bin from the holder includes a movable hook which is arranged to push the bobbin from the carrier into the bobbin holder, and the hook also is arranged to grasp the bobbin as the hook retracts for removing the bobbin from the holder.

The bobbin carrier receives the bobbin assembly from the magazine in one side of the carrier and the transfer means moves the bobbin assembly to the bobbin holder from the same side of the carrier. The carrier when aligned with the bobbin holder is positioned directly adjacent the holder.

Other features will appear as the description proceeds.

Description We shall now describe the best mode contemplated by us for carrying out our invention, referring to the accompanying drawings in which:

FIG. 1 is a perspective view showing the general arrangement of our bobbin changer mechanism,

FIGS. 2, 3 and 4 are detail operational views showing essential portions of the principal elements of the mechanism,

FIG. 2 showing the carrier aligned with the empty bobbin holder preparatory to loading a new bobbin into the holder,

FIG. 3 showing the transfer means at the end of its loading movement, and

FIG. 4 showing the movable hook of the transfer means retracted for engagement with the pivoted latching element of the bobbin case for releasing the bobbin assembly from the holder and ready to pull the assembly away from the holder as the pivoting arm of the transfer means retracts.

FIG. 5 is a circuit diagram for the electrical controls to activate the several operating components of the bobbin changer mechanism.

FIG. 6 is a schematic representation of the timing for sequential operation of the several operating components.

Referring to FIG. 1, in which the bobbin holder of a conventional sewing machine is indicated at H, our bobbin changer comprises (a) magazine means M for holding in alignment a number of bobbin assemblies 1 each comprising a bobbin and a bobbin case 2, the bobbin being assembled into the case,

(b) a bobbin carrier C movable between a first position, FIGS. 1 and 4, in which the carrier is aligned with the magazine M to receive a bobbin assembly from the magazine and a second position, FIGS. 2 and 3, in which the carrier is aligned with the bobbin holder H,

() transfer means T for moving the bobbin assembly from the carrier to the bobbin holder and for removing the bobbin assembly from the holder when the bobbin in substantially empty, and

(d) means 3, 4 for activating the transfer means T and bobbin carrier C sequentially for removal of a bobbin assembly from the holder, moving of a new bobbin assembly from the magazine M to align it with the holder H and for transfer of the new bobbin assembly to the holder.

The transfer means T for moving the bobbin from the carrier to the bobbin holder and for removing the bobbin from the holder includes a pivoting arm 5 (pivoted as at 6 to the frame 7 of the machine) and a solenoid-actuated hook 8 recipro-cably mounted on arm 5, the pivoting arm arranged to push the bobbin from the carrier into the bobbin holder, FIG. 3, and the solenoid-actuated hook 8 arranged to grasp the bobbin, FIG. 4, as the pivoting arm 5 retracts for removing the bobbin from the holder.

As applied in the use of bobbin assemblies in which the bobbin case 2 includes a pivoted latching element 9, FIG. 4, for releasing the bobbin assembly from the bobbin holder, the solenoid-actuated book 8 is arranged to engage the pivoting latching element 9 of the bobbin case for releasing the bobbin assembly from the holder and pulling the assembly away from the holder as the pivoting arm 5 retracts.

In our preferred construction, the activating means includes a sensor element 10 engageable by a bobbin assembly 1 received by the bobbin carrier C from the magazine, this sensor element being interlocked with an electrical control circuit, FIG. 5, forming part of the activating means to prevent activation of the carrier until the sensor element is engaged by a bobbin assembly in the manner shown in FIG. 4. (In FIGS. 2 and 3 the sensor finds no bobbin assembly engaging it.)

We have found it particularly advantageous to construct the bobbin changer in the manner shown wherein the bobbin carrier C receives the bobbin assembly from the magazine M in one side of the carrier and the transfer means T moves the bobbin assembly to the bobbin holder H from the same side of the carrier. For best operating results it is also quite essential that when the carrier is aligned with the bobbin holder, the carrier be positioned directly adjacent the holder in the manner clearly shown in FIGS. 2 and 3.

In the preferred construction illustrated, the magazine M comprises a tubular container 11 whose axis is normal to the path of movement of the carrier C, and such magazine includes spring means for urging the bobbin assemblies aligned within the magazine toward the carrier. We have used a flat coil spring of the constant rewind tension type known as a Hunter spring, the coiled portion of which is shown at 12 and the unwound portion of which is shown at 13. The unwound portion is anchored to the base 14 by which the magazine is mounted on the frame 7 of the machine. The carrier includes an opening 15, FIG. 4, through which the bobbin assemblies pass for reception into the carrier and a barrier strip 16 extending lengthwise beyond such opening so that when the carrier moves into its second position, FIGS. 2 and 3, in alignment with the bobbin holder, the discharge end of the magazine is covered by the barrier strip to hold the bobbin assemblies within the magazine until released one by one each time the empty carrier returns to its first position, FIGS. 1 and 4.

The carrier C as shown, besides having an opening at one side to receive a bobbin assembly, also has an opening 17 at the other side to allow entry of the hook 8 of the transfer means T for moving the bobbin assembly from the carrier to the bobbin holder. Opening 17 not only extends through the other side of the holder but also through the end thereof as can be seen in FIG. 1, thus allowing the hook 8 to pass through the side and end of the holder in reaching the position shown in FIG. 3.

Activating means 3 and 4 may include fluid-actuated pistons operating within cylinders 18 and 19, cylinder 18 being pivoted at its base as at 20 to a clevis 21 mounted on a bracket 22 secured to the frame 7 of the machine. Piston rod 23 extending from the end of the cylinder is pivoted as at 24 to the pivoting arm 5 of transfer means T. Cylinder 19 is fixed to the frame 7 of the machine and its piston rod terminates in a clevis 25 secured to the carrier C. Carrier C may have a flanged base engaging a guide track 26 along which the carrier travels in its movements between the magazine and the holder.

As an aid in removing the used bobbin assemblies from the holder H, one or more suitable air jets may be employed, these being arranged in the manner shown at 27, 28 and connected to a suitable source of compressed air (not shown).

In practice the circumference of the bobbin case must be properly aligned with the basket of the holder. The basket is indexed in a predetermined position opposite the sewing machine needle N as by means of a projection on the arm 29, FIG. 2, suitably mounted above the holder, such projection engaging the basket adjacent the opening for the needle. The bobbin case in turn is indexed relative to the basket and this may be accomplished by having a projection on the bobbin case (or of the latching mechanism thereof) engage a groove in the magazine M and a similar groove in the carrier C, the projection of the bobbin case being slideably engaged in these grooves. Thus when the transfer mechanism is actuated, hook 8 will deliver the bobbin assembly to the holder in proper alignment with the indexed position of the basket of the holder.

FIG. 5 illustrates one suitable electric circuit for operating the valves of cylinders 18 and 19 and the solenoid of the transfer means T. Conventional symbols are used. Switch 1 controls the solenoid for the valve of cylinder 19 for actuation of the carrier C as it moves from the magazine to the holder and back again. Switch 2 controls the operation of the solenoid of a valve for the cylinder 18 which controls the pivoting movements of the transfer means T toward and away from the bobbin holder. Switch 3 controls the solenoid for actuation of the reciprocating hook 8 as it extends to pass around the end of the bobbin latch and then retracts to engage such latch in the manner shown in FIG. 4. Limit switch 1 is actuated by the sensor element 10 so as to prevent operation of the carrier from its FIG. 1 position until the carrier has received a bobbin assembly from the magazine.

FIG. 6 explains the sequence of operation according to which the cycle begins at the point that a used bobbin is to be removed from the holder: The book 8 extends; pivoting arm 5 moves toward the holder and at the limit of such movement hook 8 retracts to engage the bobbin latch 9 in the manner shown in FIG. 4; arm 5 swings away, removing the bobbin from the holder; once removed, the bobin drops through the opening 30 in the frame of the machine; the carrier moves opposite the holder; arm 5 pivots toward the holder to deliver the new bobbin into the holder; and finally arm 5 swings away and carrier C moves opposite the magazine at which point barrier 16 opens the end of the magazine permitting another new bobbin to pass into the holder. The switches may be controlled in any known manner as by means of a suitable clock mechanism (not shown). The clock mechanism may be operated according to a predetermined setting of the cycle which may be initiated by a manual switch or by a switch controlled by a counted mechanism in turn actuated by the operation of the sewing machine. An electric motor M is shown in this example for driving the clock mechanism.

A control relay CR-l has its winding connected in parallel with the solenoid for the valve of cylinder 19. This control relay includes a pair of normally open contacts which are in shunt with the limit switch 1. They become closed upon energization of the relay winding and serve to continue the movement of the carrier C over to the holder H even though the limit switch 1 may have become opened after the carrier C begins its movement.

The terms and expressions which we have employed are used in a descriptive and not a limiting sense, and we have no intention of excluding equivalents of the invention described and claimed.

We claim;

1. In a sewing machine including a bobbin holder, 6. bobbin changer comprising (a) magazine means for holding in alignment a number of bobbin assemblies each comprising a bobbin and a bobbin case, the bobbin being assembled into the case,

(b) a bobbin carrier slidable between a first position in which the carrier is aligned with the magazine to receive a bobbin assembly from the magazine and a second position in which the carrier is aligned with the bobbin holder,

(0) transfer means for moving the bobbin assembly from the carrier to the bobbin holder and for removing the bobbin assembly from the holder when the bobbin is substantially empty, and

(d) means for activating the transfer means and bobbin carrier sequentially for removal of a bobbin assembly from the holder, moving of a new bobbin as; sembly from the magazine to align it with the holder and for transfer of the new bobbin assembly to the holder.

2. In a sewing machine including a bobbin holder for holding a bobbin assembly in position near the sewing machine needle, an automatic bobbin changer comprising (a) magazine means for holding in alignment a number of bobbin assemblies, each assembly comprising a bobbin and a bobbin case, the bobbin being assembled into the case,

(b) a bobbin carrier for carrying a bobbin assembly from the magazine to said holder, said carrier having an opening therein adapted to receive the bobbin assembly enclosed within the carrier,

(c) said carrier being movable between a first position in which said opening is adjacent to and aligned with the magazine to receive a bobbin assembly from the magazine and a second position in which said opening is adjacent to and aligned with the bobbin holder in readiness for transferring the bobbin assembly from said opening into the holder,

(d) means for automatically moving said carrier from said first position to said second position and for returning said carrier back to said first position,

(e) transfer means for moving the bobbin assembly from said opening in the carrier into the bobbin holder and thereafter for removing the bobbin assembly from the holder when the bobbin is substantially empty,

(f) said carrier receiving the bobbin assembly from said magazine into said opening on one side of said carrier, and said transfer means moving the bobbin assembly from said opening on the same side of the carrier, and

(g) means for activating said transfer means to move the bobbin assembly from said opening into the holder when said carrier is in said second position and to remove the bobbin assembly from the holder when said carrier is in said first position.

3. In a sewing machine including a bobbin holder for holding a bobbin assembly in position near the sewing machine needle, an automatic bobbin changer as claimed in claim 2, wherein each bobbin assembly comprises a bobbin and a bobbin case, the bobbin being assembled into the case, and the case having a pivoted latching element for holding the assembly in the holder and for re leasing the assembly from the holder, and in which said transfer means (e) includes a movable hook, said activating means (g) moving said hook to push the bobbin assembly from said opening in the carrier into the holder when said carrier is in said second position, said hook being engageable with said pivoted latching element of the bobbin assembly to be removed from the holder, and said activating means engaging said movable hook with said pivoted latching element and retracting said book for releasing the assembly from the holder and pulling the assembly away from the holder to remove the assembly from the holder when said carrier is in said first position.

4. In a sewing machine including a bobbin holder for holding a bobbin assembly in position near the sewing machine needle, an automatic bobbin changer as claimed in claim 2, in which said carrier is movable along a track from said first position to said second position, said carrier in said second position being located between said holder and said transfer means, said opening in said carrier extending through said carrier to the opposite side thereof, and said transfer means entering said opening on the opposite side from said holder for pushing the bobbin assembly from said carrier into the holder.

5. In a sewing machine including a bobbin holder adapted to hold a bobbin assembly comprising a bobbin and a bobbin case, the bobbin being assembled in the case when said case is held in the holder, an automatic bobbin changer for removing from the holder an assembly having a depleted bobbin and for leading into the holder another bobbin assembly, said automatic bobbin changer comprising (a) transfer means engageable with a depleted assembly in the holder for removing the assembly from the holder,

(b) means for operating the transfer means to move the transfer means from an initial position to engage the depleted assembly and remove the assembly from the holder,

(c) magazine means for holding a number of bobbin assemblies,

(d) a carrier comprising an enclosure with an opening therein for receiving the bobbin assembly therein, said carrier movable bet-ween a first position in which the carrier is aligned with the magazine to receive a bobbin assembly from the magazine and a second position in which the carrier is aligned with the holder for loading the assembly into the holder,

(e) means for moving the carrier from said first position to said second position and for returning said carrier to said first position,

(f) timer means for controlling said operating means and said moving means to actuate said moving means to move said carrier to said second position after the depleted assembly has been removed from the holder, and

(g) said timer means thereafter actuating said operating means causing said transfer means to load the bobbin assembly from said carrier into the holder while said carrier is in its second position and then to move said transfer means back to its initial position and to return said carrier to its first position.

6. In a sewing machine machine including a bobbin holder, a bobbin changer comprising (a) a magazine means for holding in alignment a number of bobbin assemblies each comprising a bobbin and a bobbin case, the bobbin being assembled into the case,

(b) a bobbin carrier movable between a first position 7 in which the carrier is aligned with the magazine to receive a bobbin assembly from the magazine and a second position in which the carrier is aligned with the bobbin holder,

(c) transfer means for moving the bobbin assembly from the carrier to the bobbin holder and for rernoving the bobbin assembly from the holder when the bobbin is substantially empty, and

(d) means for activating the transfer means and bobbin carrier sequentially for removal of a bobbin assembly from the holder, moving of a new bobbin assembly from the magazine to align it with the holder and for transfer of the new bobbin assembly to the holder,

(e) said magazine comprising a tubular container whose axis is normal to the path of movement of the carrier, and in which such magazine includes spring means for urging the bobbin assemblies aligned within the magazine toward the carrier, and

(f) said carrier (b) includes an opening through which the bobbin assemblies pass for reception into the carrier and a barrier strip extending lengthwise beyond such opening so that when the carrier moves into its second position in alignment with the bobbin holder the discharge end of the magazine is covered by the barrier strip to hold the bobbin assemblies (3 within the magazine until released one by one each time the empty carrier returns to its first position.

7. In a sewing machine according to claim 1, the construction in which the carrier (b) comprises a member having an opening at one side to receive a bobbin assembly and having an opening at the other side to allow entry of the transfer means for moving the bobbin assembly from the carrier to the bobbin holder.

8. In a sewing machine according to claim 1, the construction in which the carrier (b) comprises a member having an opening at one side to receive a bobbin assembly and an opening extending through the other side and the end of said member to allow entry of the transfer means for moving the bobbin assembly from the carrier to the bobbin holder.

References Cited UNITED STATES PATENTS 975,155 11/1910 Pepperling 112186 2,298,871 IO/1942 Cumfer 112186 2,438,459 3/1948 Sebel 112-186 2,507,470 5/1950 Hirsch 112181 2,690,725 10/1954 Schumann 112186 2,733,676 2/1956 Schumann 112180 2,808,795 10/1957 Wortham 112-186 X HERBERT F. ROSS, Primary Examiner.