US1438548A - Thread-cutting mechanism for sewing machines - Google Patents

Description

F. W. OSTROM AND I. F. WEBB.

THREAD CUTTING MECHANI8M FOR SEWING MACHINES. APPLICATION FILED FEB. 1a. 1918.

' l,%38,54:8. Patented Dec. 12, 1922.

2 SHEETS-SHEE] I.

2 67 f f Z7- 6 dam INVENTOR I I 3 b I 57544311050? BY O m YTTORNEY F. W. OSTROM AND I. F. WEBB.

THREAD CUTTING MECHANISM FOR SEWING MACHINES APPLICATION FILED FEB-16,1918.

1 %38,5%8, Patented Dec. 12 1922 2 SHEETS-SHEET 2.

ATTORNEV Patented Dec. 12, 1922.

STATES FREELAND W. OSTROM, OF NEWARK, AND IRVING F. WEBB, 0F ELIZABETH, NEW

JERSEY, ASSIGNORS TO THE SINGER MANUFACTURING COMPANY, A CORPO- RATION OF NEW JERSEY.

THREAD-CUTTING MECHANISM FOR SEWING MACHINES.

Application filed February 16, 1918. Serial No. 217,471.

To all'whomit may concern:

'13s it known that we, FREELAND W. Os- TROM5 and IRVING F. WEBB, citizens of the United States, residing, respectively, at Newark, in the county of Essex and State of New Jersey, and Elizabeth, in the county of Union and State of New Jersey, have invented certain newv and useful Improvements in Thread-Cutting Mechanisms for A further object of this invention is to provide a continuously operated threadcutter adapted to sever the thread, extending from a sewed article, at the work side of the cloth-plate.

The invention has for a still further object to provide a continuously operated thread-cutter with means, to positively direct the thread extending from a sewed article into the path of operation of said thread-cutter.

Other objects of this invention will be apparent from the following description and claims.

In its preferred embodiment, the present improvement comprises a thread-cutting mechanism substantially as disclosed in the U. S. patent to Albert Rontke, No. 1,156,821, October 12,1915 but having continuously operated connections with the actuating mechanism of the sewing machine. The cloth-plate of the sewing machine is provided with an opening through which the thread-cutter is projected in its operating movements. Bridging said opening and extendin in the direction of feed are raised workirecting members adapted to divert the stitched article out of the path of movement of the thread-cutter, but permitting a spring-pressed, chain-directing member pivotally supported by the resser-foot to direct the thread extending from said article into the path of movement of the cutter, which severs the thread at the work sideof the cloth-plate as in the Rontke construction referred to.

The present improvement is particularly adapted for use in connection with filled sack-sewing machines, but it is apparent that its use is not limited to that class of machines inasmuch as the thread will be positively directed into the path of movement of the cutter regardless of the plane in which the sewing machine cloth-plate may lie.

In the accompanying drawings, Fig. 1 is a front side elevation of a filled-sack sewing machine of earlier construction, partly broken ofl:' and embodying the present improvement. Fig. 2 is an end elevation, partly in section, of a portion of the sewing machine, illustrating the effective position of the thread-cutter mechanism and in dotted lines the position of the ch,ain-directing member during the passage of the sack thereunder. Fig. 3 is a rear side elevation, partly in section of a portion of the sewing machine and showing the actuating means for the thread-cutter blades. Fig. 4 is a perspective view of a portion of the sewing machine cloth-plate and including the material-diverting bridge. perspective view of the chain-directing member. Fig. 6 is a fragmentary view illustrating a portion of the autom'atic seamcontrolling mechanism for the sewing machine as viewed in the direction indicated by the arrow A in Fig. 1.

The filledsack sewing machine illustrated comprises a base 1 from which rise the vertical standards 2 and 3 supporting the table 4. Mounted upon the table 4 is a bracket 5, carrying the overhanging sewing machine head 6, having stitch-forming mechanism of wellknown construction and including a needle 7. The cloth-plate '8' of the sewing machine is provided with a throat-plate 9 having a feed-slot 1-0 traversed by thefeeddog 11, secured upon a feedbar 12, pivoted to the feed-rocker 13, actuated to impart feeding movements tothe feed-dog by means of a pitman 14 from an eccentric on the Fig. 5 is a messes ing wires 26 and 27, the thread-cutter becomes effective to sever the chain as heretofore described. After the stitched sack rides past the end of the'trip-bars 49, the latter assume their raised position under the reverse action of the belt-shifting weight 63 thereby stopping the operation of the sewin machine.

I-Iaving thus set forth the nature of the invention, what we claim herein is 1. In a filled sack sewing machine, the combination with a cloth-plate, stitchforming mechanism includin a reciprocating needle, and feeding mec ianism including a feed-dog with actuating means for said mechanisms, of a thread-cutter operatively connected with said actuating means, and a cutter-guard projecting outwardly from said cloth-plate substantially in the direction of reciprocation of the needle to direct the sack mouth outside the field of cuttenactuation rearward of the point of seam-formation.

2. In a filled sack sewing apparatus, in combination, stitch-forming mechanism, means for conveying a filled sack past said stitch-forming mechanism, automatic controlling means for determining the period of operation of said stitch-forming mechanism, a thread-cutter having a path of operation intersecting the plane of the sack mouth at the point of seam-formation, means for continuously operating said thread-cutter during the period of operation of said stitch-forming mechanism, and means for diverting the stitched sack mouth out of the path of operation of said thread-cutter.

3. In a filled sack sewing machine, in combination, stitch-forming and feeding mechanisms, a cloth-plate, a thread-cutter having a path of operation substantially at right angles to the line of seam-formation and its effective cutting position on the, work-side of the cloth-plate, means for continuously operating said thread-cutter, and means 'for diverting the filled sack mouth out of the path of operation of said threadcutter and permitting the latter to sever the sewing-thread extending from the stitched sack.

4. A sewing machine including in combination, stitch-forming and feeding mechanisms, a cloth-plate, an opening in said cloth-plate in the rear of the stitch-forming mechanism, a thread-cutter comprising a pair of movable cutting blades having an operative path of movement through said opening intersecting the plane of the article being stitched at the point of seam-formation, means for continuously operating said thread-cutter, and means for directing a stitched article out of the path of movement of said thread-cutter.

5. In a filled sack sewing machine, the combination with a cloth-plate, stitchforming and feeding mechanism, and means for actuating said-mechanism, of a threadcutter having a path of operation substantially at right angles to the line of seamformation, means for operating said threadcutter, and. a yieldingly mounted threadchain positioning member having a threadengaging portion located at the rear of the rearward limit of feed-movement of the feeding mechanism for positioning a thread chain below the plane of said cloth-plate to be engaged and severed by said thread cutter. v

6. In a filled sack sewing machine, the combination with a cloth-plate, stitch forming and fabric feeding mcchanism,and actuating means for the latter, of a threadcutter having a cutting portion operative above the plane of said cloth-plate and operatively connected with said actuating means, and a thread-chain positioning memher for positioning a thread-chain below the plane of said cloth-plate to be engaged and severed above the latter by said threadcutter.

7. In a filled sack sewing machine, the combination with a stitch-forming mechanism, a fabric feeding mechanism, a presser-foot, and actuating means for. said mechanisms, of a thread-cuttter operatively connected with said actuating means. a thread-chain positioning member provided with a thread-chain guiding surface and hinged to said Presser-foot, and means for directing a filled sack outside the field of cutter-actuation, said chain-guiding surface, directing means and thread-cutter being located at the rear of the rearward limit of feed-movement of the feeding mechanism.

8. In a sewing machine, the combination with stitch-forming and feeding mechanism, of a thread-chain positioning member having movements inva direction substantially transverse to the plane of the fabric being stitched, a thread-cutter, and means for actuating the thread-cutter to sever a chain of thread. said thread-cutter actuating means including devices for imparting to the thread-cutter movements in a direction opposed to said movements of the thread-chain positioning member to tighten said chain during the severing of the same.

In testimony whereof, we have signed our names to this specification.

FREELANI) W. OSTROM. IRVING F. WEBB.

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