US1177138A - Seam-trimmer for sewing-machines. - Google Patents

Description

J. C. HINGE. SEAM TRIMMER FOR SEWING MACHINES.

APPLICATION FILED APR. 9. 1914.

Patented Mar. 28, 1916.

2 SHEETMS-SHEET I.

WITNESSES.

A TTORA/EY J. C. RINGE.

SEAM TRIMMER FOR SEWING MACHINES.

APPLICATION FILED APR. 9, 1914.

Patented Mar. 28, 1916;

' 2 SHSHEET 2. J .3. V v

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JOHN G. RINGE, 0F BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE SINGER MANUFAC- TUBING COMPANY, A CORPORATION OF NEW JERSEY.

- SEAM-TRIMMER FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented Mar. 25, 1916..

To all whom it may concern:

Be it known that 1, JOHN C. RINGE, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Seam- Trimmers for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawmgs.

This invention relates to improvements in seam trimmers for sewing machines and has for its object to provide atrimming mechanism adapted to pierce and sever the fabric and to discontinue such severing operation at any point in the line of scam formation at the will of the operator during the stitching operation.

In the accompanying drawings, which form a part of the specification, Figure 1 is a front side elevation, partly in section, of one form of commercial sewing machine fitted with the present invention. Fig. 2, a rear side elevation of Fig. 1; Fig. 3 a perspective of the trimmer-blade and its actuating mechanism detached from the sewing machine; Fig. 4, a plan of the mechanism for controlling the lateral movements of the needle. Fig. 5 a detail of certain elements shown in the previous figure, later to be referred to. Fig. 6, a plan of the throator needle-plate, together with the ledger trimmer-blade. Fig. 7, a sectional view of certain elements shown in Fig.3, later to be referred to. Fig. 8, upper and under side views, left to right respectively, of the clothpresser-foot. Fig. 9 an enlarged side elevation of the trimmer-blade shown in Figs. 1 and 3. Fig. 10, a view illustrating the trimming and zigzag sewing operations as when joining the free edge of a fabric to the trimmed edge of an under ply.

The present construction preferably includes a stitch-forming mechanism capable of effecting both zigzag and straight-away stitching, but it is to be understood thatit is not limited in its applicability, as the trimmer mechanism is mounted independently of the actuating mechanism of the sewing machine exceptthat it is operatively connected with the mainor needle-bar driving shaft.

Referring to the figures, 1 represents the sewing machine bed-plate upon which is mounted the bracket-arm comprising the arm standard 2 and arm- bracket 3, 4 the main or needle-bar driving shaft carrying the band wheel 5 and operatively connected wlth the needle-carrying-bar 6 by the link 7 8 denotes the needle, 9 the cloth-pressercarrying bar, 10 the needle-thread take-up and 11 the thread tension.

12 represents the lower main or loop-taker drivmg shaft mounted in the tubular feedlift rock-shaft 18, as in earlier constructions, and provided at its rear end with a pulley 13 connected by suitable belt 14 with a pulley 15 secured on the main-shaft 1, the pulleys 13 and 15 being of the ratio of one to two, thus giving to the shaft 12 two r0- tations to the one rotation of the shaft 4. To the forward end of the loop-taker drivmg shaft is suitably secured a beveled gear 16 which'meshes with a like gear 17 (shown in dotted lines only, Fig. 1) fast on the looptaker shaft (not shown), common to the present form of stitch-forming mechanism, said loop-taker shaft being provided with one form of commonly employed loop-taker (not shown).

The herein employed cloth-feeding mechanism is substantially the same as is represented by U. S. Patent No. 1,020,089, dated March 12, 1912 to C. F. Gray, and as it has no particular bearing on the present construction it is deemed suflicient to designate the parts illustrated by the numeral 18.

19 represents a rock-shaft journaled in a suitable bearing formed in the bracket-arm and at its inner end carrying a crank-arm 20, its opposite end being provided with a rigidly secured indexing lever 21 whose free end is provided with an indexing blade 22.

23 denotes an indexing bracket having a hollow hub 24 secured by screw 25 upon a suitable hub 26 (shown in dotted lines only, Fig. 4) formed integral with the bracketarm, the upper end of said bracket being provided with an index 27, and slot 28, and through the latter and through a suitable opening formed in the upper end of the lever 21 extends a securing bolt comprising a threaded portion 29 and a head or disk portion 30, said threaded portion being provided with a nut 31, which latter, in connection with said disk portion, acts to secure the index blade 22 against accidental movement.

-32 represents a link pivoted at 33 to the crank-shaft 20, its opposite end being journaled on the stud-bolt 34 secured in the needle vibrating connection 35-, the latter being fulcrumed on a stud 36 secured in the needle-bar carrying frame 37 the opposite end of said connection being forked to receive the cam 38 carried by the cam-shaft 39, the latter operatively connected with the main-shaft 4 by spiral gear 40 carried by said main-shaft meshing with a like gear 41 carried by said cam-shaft, the ratio of said gears being as one to two, thus giving to the cam-shaft one rotation to two rotations of said main-shaft.

The cam 38 imparts to the connection 35, under all conditions of stitch-formation, vibratory movements and the crank 20 and link 32 are of substantially the same length. It therefore results that the rock-shaft 19 and crank-arm 20 constitute the fulcrum support for the swinging link 32, and that the axis of the pivotal point 33 may be shifted, through the manipulation of the index lever 21, from a position intersecting an imaginary line drawn through the axes of the shaft 39, bolt 34 and stud 36 to a position above such line a distance sufficient to effect the desired amplitude of vibration of the needle.

It is to be understood that when the axis of the pivotal point 33 intersects said imaginary line the connection 35 is given vibratory movements only on the pivot 36, and that at such time the needle occupies its zero or straight line stitching position, but when the pivotal point 33 is moved upward, as shown in dotted lines, Fig. 5, said connections, through the angle given said link with respect to said imaginary line, is caused to transmit lateral movements to the needle in a direction to the left of its zero or straight line stitching position.

Referring now to the features in construction more directly connected with the invention, 42 represents a bracket secured by suitable screws (not shown) to the arm standard 3 and provided with a hub 43 into which is journaled by screw 44 a short shaft 45 carrying a segment or rock-lever 46 provided with an under-cut guide-slot 47, said rock-lever being operatively connected with the main-shaft 4 by an eccentric 48 and eccentric strap connection 49.

50 denotes a cutter carrying rock bar provided at its forward or free end with an ad justably secured trimmer-blade 51 provided with a piercing element 51, its opposite end being operatively connected by the rock'lever connection 52 and ball joint connections, as 53, with said rock-lever, the fulcrum for the cutter carrying rock bar comprising a pin 54 provided with an eccentric 54, said pin being mounted in suitable bearings formed in the bracket 55 suitably secured to the under side of the bed-plate, the axial adjustment of .the pin effecting movements of the trimmer-blade across the line of seam formation, the screw 56 acting to secure said pin against accidental movement.

57 represents a trimmer-blade adjusting rock-shaft whose forward end is journaled in a bracket 58 secured by screws, as 59, to

the head 60 of the arm bracket, its opposite crank-shaft carrying a crank-arm 68 piv- I oted to one end of a link 69 whose opposite end is pivotally connected with a ball joint stud 70 threaded into a slide block 71 tracking the groove 47 formed in the rocklever 46.

72 denotes a spring-pressed plunger mounted in the bracket 42 and coacting with notches as 73 (one only of which is shown) to hold the crank-shaft 66 against oscillatory movements, the spring 74 acting in opposition to the spring-pressed plunger to yieldingly hold the head 75 of the crankshaft 66 against the face of the bracket 42.

76 represents the needle or throat-plate provided with the usual needle opening 77 and feed-dog openings, as 78, 79 denotes the trimmer-ledger blade secured by screw 80 to said throat-plate, its extended portion 81 provided with the cutting edge 82 constructed to yield slightly to the action of the trimmer-blade 51, normally located in the opening 83 in said throat-plate.

84 represents a cloth-presser pivotally secured by pin 85 to the cloth-presser bracket 86, which latter is secured by screw 87 to the spring depressed cloth-presser carrying bar 9, the cloth-presser being provided with a fabric guiding wall 88 and an adjustably secured edge guide 89, later to be referred to.

In the present embodiment of the invention the cutting edges of the trimming members are preferably arranged to trim the fabric in line with the zero or right hand line of stitches.

To effect a product represented by Fig. 10, the fabric 90 is passed beneath the presser-foot to the action of the trimming and stitch-forming mechanisms as shown in the figure, the fabric 91 being passed from the supply over the inclined or turned-up portion 92 of the cloth-presser 84, through the opening 88 and beneath the rear end portion of the presser foot with its free edge 93 in guiding relationship with the edge-- guide 89, the trimmer-blade 51 and said edge-guide acting to guide the free edges 93 and 94 within the field of the lateral movements of the needle 8, thus causing the edges to be bound by the successive overedge stitches, the receiving end 92 of said cloth-presser acting to guide the fabric 91 out of the field of action of the fabric,

piercing element carried by the trimmerblade.

When it is desired to continue the stitching and suspend the trimming operation, the operator through the manipulation of the hand lever 62 rocks the shaft 57 in the direction indicated by the arrow which, through the connections previously pointed out, rocks the crank-arm 68 in a like direction a distance sufficient to cause the springpressed plunger 72 to register with one of the notches 73 or in position to cause the axis 95 of the upper of the ball joint connections 53 to intersect the axis of the short shaft carrying the rock-lever 46, such adjustment of the axis 95 acting to suspend the rocking movements of the bar and owing to the guide slot 47 being inclined with respect to the vertical arrangement of the connection 52 the trimmer-blade piercing element is carried below the plane of the throat-plate, or out of accidental engagement with the fabric. a Having thus set forth the nature of the invention what I claim herein is 1. In a sewing and fabric trimming machine of the character described, the combination with a stitch-forming and clothfeeding mechanism including a needle-plate, a needle and a needle-carrying bar, of a trimming mechanism including a ledger trimmer-blade carried by said needle-plate and a coacting trimmer-blade, the cutting edge of the latter overhanging the needleplate and provided with a piercing element arranged to pierce a fabric in a direction opposite to that of the fabric piercing movements of said needle.

2. In a sewing and fabric trimming machine of the character described, the combination with a stitch-forming and clothfeeding mechanism including a cloth-presser provided with an edge-guide and a guiding-wall, a needle-plate and a needle, of a trimming mechanism including a ledger trimmer-blade carried by said needle-plate and a coacting trimmer-blade, the cutting edge of the latter overhanging the needleplate and provided with a piercing element arranged to pierce a fabric in a direction opposite to that of the fabric piercing movement of said needle, said edge-guide and guiding wall acting to direct an overlying fabric to the action of the needle outside the field of action of said trimming mechanism.

3. In a sewing and fabric trimming ma- A chine of the character described, the combination with a stitch-forming and clothfeeding mechanism including a cloth-Presser provided with an edge-guide, an inclined receiving end and an opening for the passage of a fabric, a needle-plate and a needlecarrying bar provided with a needle having lateral movements efiecting an overedge seam, of a trimming mechanism including a ledger trimmer-blade carried by said needleplate and a coacting trimmer-blade, the cutting edge of the latter overhanging the needle-plate and provided with a piercing element arranged to pierce a fabric in a direction opposite to that of the fabric piercing movements of said needle, said edge-guide acting to guide the free edge of an overlying fabric through said opening in the presser-foot substantially in line with that portion of the overedge stitches anchored in an underlying fabric, which latter is passed beneath said inclined receiving end of the Presser-foot in its travel to the action of the needle and trimming elements.

4. In a sewing and fabric trimming machine of the character described, the combination with a stitch-forming and clothfeeding machanism including a needle-bar actuating shaft journaled in the sewing machine bracket-arm, a needle-plate, a needle and a needle-Carr ing bar, of a trimming mechanism inclu ing a ledger trimmerblade carried by said needle-plate and a coacting triimner-blade, the cutting edge of the latter overhanging the needle-plate and provided with a piercing element arranged to pierce a fabric in a direction opposite to that of the fabric piercing movements of said needle, and connections including a segment lever for operatively connecting said trimmer-blade with said needle-bar actuating shaft.

5. In a sewing and fabric trimming machine of the character described, the combination with a stitch-forming and clothfeeding mechanism including a needle-bar actuating shaft journaled in the sewing machine bracket-arm, a needle-plate, a needle and a needle-carrying bar, of a trimming mechanism including a ledger trimmer-blade carried by said needle-plate and a coacting trimmer-blade, the cutting edge of the latter overhanging the needle-plate and provided with a piercing element arranged to pierce a fabric in a direction opposite to that of the fabric piercing movements of said needle, and connections for operatively connecting said trimmer-blade with said needle-bar actuating shaft, said connections including a rocking cutter-carrying bar, a segment lever, an eccentric carried by said needle-bar actuating shaft operatively connected with said segment lever, and operative connections between the latter and said cutter-carrying bar.

6. In a sewing and fabric trimming machine. of the character described, the com-' bination with a stitch-forming and clothfeeding mechanism including a needle-bar actuating shaft journaled in the sewing machine bracket-arm, a needle-plate, a needle and a needle-carrying bar, of a trimmingmechanism including a ledger trimmer-blade carried by said needle-plate and a coacting trimmer-blade, the cutting edge of the latter overhanging the needle-plate and provided With a piercing element arranged to pierce a fabric in a direction opposite to that of the fabric piercing movements of said needle, and connections including a segment lever for operatively connecting said trimmer-blade With said needle-bar actuating shaft and manually controlled means operating on said segment lever to suspend 15 the trimming action of said trimmer-blade.

In testimony whereof, I have signed my name to this specification, in the presence of tWo subscribing Witnesses.

JOHN C. HINGE.

Witnesses:

N. H. HOYT, 4 STANLEY N. SMITH.

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