US1433705A - Trimming mechanism for sewing machines - Google Patents

Description

A. H. DE VOE. TRIMMING MECHANISM FOR SEWING MACHINES.

m APPLICATION FILED MAR- 3, 1920. 1,433, (Q50 Pamm/ed (M. 311, 11922.

3 SHEETS-SHEE1 l.

/ IIIII WI'II'NIES s: NVENTOR W 1 ATTORNEY A. H. DE VOE. TRIMMING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAR. 3, 1920. A Lw fiiwn Emma 0%31 1922 3 SHEETSSHEET 2- III I IILI-N WWNEESS t5! INVENTOR A. H. DE VOE. v TRIMMING MECHANISM FOR SEWING MACHINES.

I APPLICATION FILED MAR- 3, I920. L4I3$fi5 Patented Oct 311, 1922' 3 SHEETS-SHEET 3.

2 INVENTOR ,JMQ g MJW 4 BY z" 19 I ATTORNEY Patented Get. 31, 1%22.

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ALBERT H. DE VOE, OF WESTFIELD, NIIEW JERSEY, ASSIGNOR TO THE SINGER MANU- FACTUPJIINTG COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

TBIMMING MECHANISM FOR. SEWING MACHINES.

Application filed March 3; 1920. Serial No. 363,044.

To all whom it may concern:

Be it known that T, ALBERT H. DE Von, a citizen of the United States, residing at Westfield, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Trimming Mechanisms for Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to trimming mechanisms for sewing machines and has for an object to provide such a mechanism capable of operating at a high rate of speed with a minimum of friction, noise and vibration.

A. further object is to provide a trimming mechanism capable of being thrown into and out of action during the running of the machine and which is devoid of latches, locks &c.

A still further object is to provide a trimming mechanism ofthe above character adjustable relative to the line of scam formation Whereb the fabric may be trimmed at various distances from the seam.

The objects of the invention are attained in the present mechanism which preferably comprises an upper trimmer-blade carried by the lower end of a vertically reciprocating trimmer-bar guided in the machine head and which is actuated from and constantly connected with a rotary trimmeractuating shaft carried by and extending lengthwise of the machine arm and driven from the main-shaft of the machine. The upper. trimmer-blade cooperates with a stationary trimmer or ledger-blade carried by the throat plate of the machine and which is adjustable transverse to the line of scam formation for varying the working position of the trimmer-blades with respect to the seam.

Operative movements of the trimmerblade may be effected or discontinued by means of a hand-lever conveniently located adjacent the machine head and which determines the position of the fulcrum of a connection between the cutter-bar and the trimmer-actuating shaft, the position of said fulcrum determining the action or inaction of the trimmer as will later be explained.

The invention is illustrated in its preferred form in the accompanying drawings, in which Fig. 1 is a rear elevation partly in section of a sewing machine embodying the present invention. Fig. 2 is an end view partly in section of the machine shown in Fig. 1. Fig. 3 is a detail side elevation of the trimming mechanism looking in a direction opposite to that of Fig. 2. Fig. 4 is a sectional view taken on the line 4-4 of Fig. 2. Fig. 5 is a detail plan view of the throat-plate of the machine and the ledger-blade carried thereby showing in dotted lines the lateral adjustment of the throat-plate and ledgerblade, andFig. 6 is an enlarged detail sectional view on the line 6-6 of Fig. 5 showing in full and dotted lines two operative positions of the trimmer-blades.

Referring more particularly to the drawings, the trimming mechanism is shown embodied in a sewing machine constructed with a base 1 formed integral with the standard 2 which carries the overhanging arm 3 terminating in the head 4:. The main-shaft 5 is supported in bearings carried by the base 1 and is provided with a hand-wheel and pulley 6 and a crank 7 which actuates, through suitable -mechanism, the needle-bar 9 carrying the needle 10. This needle-bar actuating mechanism comprises a pitman 8 connected at its lower end to the crank 7 and at its upper end to an arm 8 fixed upon a needle-operating shaft 8 journaled in the overhanging arm 3 and having fixed upon its forward end a. crankarm 8 connected by a link 8 to a.collar on the needle-bar 9. Cooperating with the needle 10 in the formation of stitches is the looper 11 actuated from the main-shaft 5 through suitable mechanism 12.

.Feeding mechanism 13 is also actuated from the main-shaft 5 and acts to feed the material between successive stitches.

Cooperating with the feeding mechanism is the resser-foot 14: secured upon the lower end of the spring-depressed presserbar 15 adapted to be moved vertically in bearings 16 formed in the head 4. Slidably mounted within the head 4: is the trimmerbar 17 carrying at its lower end the flexible trimmer-blade 18 constructed with a pierc- I ing point 19 and a cutting edge'20.

- motion 1 shaft 5 for operating mechanism supple- The trimmer-bar 17 is provided with integrally formed lugs 21 and 21' apertured to embrace and slide upon the presser-bar 15 whereby the trimmer-bar is guided in its reciprocating movements. The trimmerbar is prevented from turning about the presser-bar 15 by the walls 22 of a cut 23 in the machine head through which the trimmer-bar passes. (See Fig. 4).

The main-shaft 5 isformed, adjacent the crank 7, with a second crank 24'oblique to the axis of said main-shaft and about this crank is fitted a sleeve 25 connected by a pitman 26 to a like sleeve 27 surrounding a like crank 28 on the supplemental or trimmer-shaft 29 journaled substantially parparallel with the needle-operating shaft in bearings 30 carried by the rear side of the arm 3, whereby through the elements 24, 25, 26,27 and 28, the shaft 29 is given rotary in synchronism with the mainmental to the stitch-forming mechanism such as, for example, the trimmer mechanism described.

Upon the forward end of the shaft 29 is secured an eccentric element 31 surrounded by a strap 32 having an arm 33, to which is pivoted at 34 one end of a connecting element in the form of a trimmer actuating lever 35, the opposite end of which is pivoted at 36 to an car 37 projecting from the jug 21 on the trimmer-bar 17.

Thelever 35 is provided with a cam-slot 38 into which projects a roller 39 carried by the upper end of an arm 40 fixed upon one end of a short rock-shaft 41 journaled within the machine head and upon the opposite end of which is secured a hand-lever 42 for manually adjusting the roller 39 in the slot 38 to render the trimming mechanism either effective or ineffective.

en the arm 40 is in the position shown in Figs. 2 and 3, the roller 39 constitutes a fulcrum for the lever 35 by means of which the lever gives to the trimmer-bar. oppositely directed reciprocatory movements with respect to the arm 33 actuated from the eccentric 31 but when, by manipulation of the hand-lever 42, the arm 40 is moved tothe position shown in dotted lines, Fig. 3, with its roller 39 in the ineffective portion 38" of. the slot 38 and adjacent the pivot 36, the roller 39 acts upon the wall 38 of the cam-slot 38 causing the trimmer-bar to be raised and the trimmer-blade to be retracted from operative position and the lever 35 then oscillates idly about the pivot 36, no movement being given to the trimmer-barl A retaining spring 43, secured upon the overhanging arm 3, acts upon the lug 44 on the hub of the hand-lever 42 to maintain the arm 40 and roller 39 in either of the two positions just described.

Cooperating with the flexible trimmerblade 18 is a trimmer or ledger-blade 45 carried by the throat-plate 46 supported by standards 47 and 47 rising from the base 1 and upon a projection 48 of this throatplate is pivotally secured a trimmer-guard 50'. A coil spring 51 seated within a cavity in the throat-plate bears against the rearward end of the trimmer-guard and acts to hold the forward end 50 against the trimmer-blade 18, whereby the. trimmings are prevented from being carried beneath the throat-plate. The trimmer-guard being spring-pressed against the trimmer-blade yields therewith in its lateral adjustments now to be described.

For the purpose of regulating the working position of the trimmer with respect to the seam, the throat-plate 46 is pivoted near one end upon a screw 52 threaded into an extension of the standard 47 and is at its opposite end provided with spaced walls 53 and 53 upon which acts a cam 54 fitted about the shank of a screw 55 passing through a. slot 56 in the throat-plate 46 and threaded into the standard 47. By manually adjustin the cam 54 from the position shown in .full lines, Fig. 5, to that shown in dotted lines, the cam acts upon the wall 53 and moves the throat-plate and the ledger-blade carried thereby laterally of the line of scam formation and changes the working position of the trimmer, it being understood that the trimmer-blade is thereby flexed out of its normal position and moves with the ledger-blade 45.

The piercing point of the trimmer-blade 18 is preferably bevelled at 19, which acts to deflect the trimmer-blade and prevent it from striking upon the upper surface of the ledger blade when it is lowered to working position. I

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing-machine constructed with a base, a standard and an overhanging arm, in combination, a main-shaft journaled in said base, a trimmer-shaft carried by said overhanging arm and actuated by and in synchronism with said main-shaft, a trimming mechanism comprising a stationary trimmer-blade, a movable trimmer-blade and a movable trimmer-bar to which said movable trimmer-blade is secured and manually controlled means connecting said trimmerbar with said trimmer-shaft whereby said trimmer-shaft may be caused to actuate said trimmer-bar.

2. In a sewing machine provided with a mainshaft, a trimming mechanism comprising a rotary trimmer-shaft actuated from said main-shaft, an eccentric element on said trimmer-shaft, a trimmer-bar, a trimmer-blade carried thereby, a constantly moving connection between said trimmer-bar and azar/ca said eccentric, and means whereby said connection may be caused to actuate said trimmer-bar.

3. In a sewing machine provided with a main-shaft, a trimmer-shaft actuated thereby, a trimmer-bar, a lever connected thereto and actuated from said trimmer-shaft. a fulcrum for said lever, and means for shifting said fulcrum whereby the position of said fulcrum determines the action or inaction of said trimmer-bar.

4C. In a sewing machine provided with a main-shaft, a trimmer-shaft actuated thereby, a trimmer bar, a slotted trimmer-actuating lever pivoted thereto and actuated from said trimmer-shaft, a fulcrum for said lever located, during the trimming operation, within said slot and intermediate the ends of said lever, and means for shifting said fulcrurn to an inefiective point in said slot thereby discontinuing the trimming opera- 5. A trimming mechanism for sewing machines comprising a stationary trimmerblade, a movable trimmer-blade, a movable trimmer-bar to which said movable blade is secured, a trimmer-actuating shaft, a slotted trimmer-actuating lever pivoted to 'said trimmer-bar and actuated by said trimmershaft, a rock shaft, an arm carried thereby, a roller carried by said arm and constituting a fulcrum for said trimmer-actuating lever, and means including a manually operable lever fixed to said rock-shaft for adjusting said fulcrum in said slot to determine the action or inaction of said trimming mechanism.

6. In a sewingvmachine constructed with a base, a standard, an overhanging arm and a head, in combination, a main-shaft journaled within said base, a trimming mechanism comprising a rotary trimmer-shaft actuated by said main-shaft, a stationary trimtrier-blade, a movable trimmer-blade cooperating therewith, a movable trimmer-bar to which said movable trimmer-blade is secured, means for actuating said trimmer-bar from said trimmer-shaft including a slotted lever, a fulcrum therefor, means for adjusting said fulcrum to determine the action or inaction of said trimmer-bar, said lastmentioned means including a manually operable lever located adjacent the machine head, and means for maintaining said lever in adjusted positions.

7. ltn a sewing machine constructed with a base, a standard, an overhanging arm and a hollow head, in combination, a main-shaft jOhlltHfit-litld within said base, a trimming mechanism comprising a rotary trimmer-actuating shaft carried by said overhanging arm in rear thereof and actuated by said main-shaft, a stationary trimmer-blade, a movable trimmer-blade cooperating therewith, a reciprocating trimmer-bar supported within said hollow head and to which the movable trimmer-blade is secured and means for actuating said trimmer-bar including an eccentric carried by said trimmer-shaft and a lever connected to said trimmer-bar and operatively connected with said eccentric on said trimmer-shaft.

8. In a sewing machine provided with a main-shaft, a trimmer-shaft actuated thereby, a trimmer-bar, a trimmer-blade carried by said trimmer-bar, a lever connected to said trimmer-bar and actuated from said trimmer-shaft, a movable fulcrum for said lever, and means for shifting said fulcrum to discontinue the movement of the trimmerbar and simultaneously therewith to retract the trimmer-blade to an inoperative position.

9. In a. sewing machine constructed with a base, a standard, an overhanging arm and a head, in combination, a throat-plate pivoted at one end to said base and provided at its opposite end with spaced walls, a normally stationary trimmer-blade carried by said throat-plate, a trimmer-bar slidingly mounted in said head, a flexible trimmer-blade carried by said trimmer-bar and cooperating with said stationary trimmer-blade, and a manually adjustable cam fitted within said spaced walls and acting thereupon to turn said throat-plate about its pivot to change the working position of said trimmer-blades.

10. In a sewin machine provided with a base, a late pivotally secured thereto, a trimmer-b ade secured to said plate, and means for adjusting said plate about its pivot to change the working position of said trimmer-blade.

11. In a sewing machine constructed with a base, a throat-plate pivotally secured thereto and provided with spaced walls, a trimmer-blade carried by said throat-plate, and manually operable means acting against said walls for turning said throat-plate about its ivot to change the working position of sand trimmer-blade.

12. In a sewing machine constructed with a base, a standard, an overhanging arm and a head, in combination, a throat-plate pivoted to said base, a normally stationary trimmer-blade carried by said throat-plate, a trimmer-bar slidingly mounted in said head, a flexible trimmer-blade carried by said trimmer-bar and cooperating with said stationary trimmer-blade, a spring-pressed trimmer-guard pivotally attached to said throat-plate and bearing against said flexible trimmer-blade at the side opposite said stationary trimmer-blade, and means for turning said throat-plate about its pivot to change the working position of said trimmer-blades and trimmer-guard.

13. In a sewing machine, in combination, a

' frame including a base, a standard, an overhanging arm and a head, stitch-forming mechanism incorporated in said frame and including a reciprocating needle and a needle-operating shaft carried by said overhanging arm, a main-shaft journaled in said base, a driving connection between said main and needle-operating shafts, a rotary trimmer-shaft carried by the overhanging arm in substantial parallelism with the needle-operating shaft, means actuated by the main-shaft for rotating the trimmershaft, and a trimmer carried by the head and actuated by said trimmer-shaft, said trimmer including a blade operating on the work adjacent the line of seam formation.

14. A sewing machine having, in combination, a frame including a base, astandard and an overhanging arm, a lower mainshaft journaled in said base and formed adjacent-the standard with a pair of cranks one of which is inclined to the axis of said shaft, upper shafts carried in substantial parallelism by the overhanging arm, a crank on one of said upper shafts, an inclined crank on the other of-said upper shafts, a sleeve on each of'said inclined cranks, a single pitman connection between said sleeves, and an additional pitman connection between the other crank on the main-shaft and the crank on said one of the upper shafts, sewing mechanism including a needle actuated by one of said upper shafts, and mechanism supplemental to the sewing mechanism and connected. to be operated by the other of said upper shafts.

In testimony whereof, I have signed my name to this specification.

ALBERT H. DE VOE.

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