US1779996A - Sewing machine - Google Patents

Description

GI'E. WARREN SEWING MACHINE Filed De'c.

3 Sheets-Sheet l Oct. 28, 1930. 5. E. WARREN 1,779,996

SEWING MACHINE Filed Dec. 14, 1922 3 Sheets-Sheet 2 Oct. 28, 1930. G] E. WARREN SEWING MACHINE Filed Dec. 14. 1922 3 Sheets-Sheet 3 Patented Oct. 28, 1930 UNITED S ATES.

PATENT OFFEC a GEORGE E. WARREN, OF SWAM?SCOTT, MASSACHUSE'I' 'rs,- AssIe1'\ToR r0 UNIVTED SHOE MACHINERY coaronerrcn, or rnrnnsou, NEW JERSEY, A CORPORATION. or NEW JERSEY snwnve MACHINE I" Application-filed December 14, 1922. Serial No. 606,918.

The present invention relates to hook needle lockstitch' sewing machines and is intended primarily as an improvement in lockstitch sewing machines of the so-called McKay type, although the invention is not limited to use in machines of this type) In McKay sewing 'machines in which the shoe is supported by ahorn which'ext'ends inside of the shoe it has'been found to be impracticable to use a threadarm :or thread measuring device to supply thread for one side of the needle loop as the needle retractsthrough the work. Consequently, heretofore it has beenthe practice in this type of lockstitchmachines, where a take-up has been employed to set thestit'ch, to use an extreme, ly large needle as compared to thesize of the thread so as to permit the thread to reeve through the hook of the needle. 7

In machines of this type in which a takeup is not-employed, to setthe stitchit has heretofore beenthe practice to utilize the shuttle to set thestitch the threadfor the Work side of the needle loop, as the needle retracts through. the work, being supplied from the preceding-needle loop which is sub sequently drawn down into its final position in the seam bythe action of the shuttle. In these machines the stitch is set against a thread lockand where the shuttle has been utilized to set the stitch it has been the prac tice to open the thread lock' during the passage of the needle loop over'the shuttle so'as to permit the shuttle, after setting the st1tch,'

to draw thread from the supply for use in; making the 'neXt stitch. The use of-a large needle is objectionable for obviousreasons and whenthe shuttleis utilized both to pull I oifithread from the supply and to set the i 1 stitch the position of the lockeof'the stltch in the work is irregular and also there is liability of injury to thethread by the action thereon of the thread look as it isv opened while the thread is under the stitch setting strain tending to pull the thread through the: lock. it To eliminate the objectionablefeatures of h prior hook'needle lockstitch' machines which are notprovided with-a thread arm or equivalent thread measuring device and to provide is eliminated a machine of this class which will operate to sew a seam of stitches which are disposed ac curately and uniformly in the work andwithout liability of breakage or injury to the thread the present inventioncontemplates the provision ina machine of this class of thread handling devices constructed and arranged to cooperate in such a manner as to permit the stitch to be set by the needle. 'By utilizing the needle to set the stitch the thread lock can be opened and closed at points, in the cycle where there is substantially no strain upon the thread tending ,to pull it through the lock so that any liability of injury to the thread and also an accurate and uniform manipulation of the thread is insured so that the locks of the stitches are uniform 1y located with relation to the surface of the work. 7 j I 7 Toper'mit' the stitch to beset by the nee-1 dle it'is necessary to provide means otherthanthe needle for shortening the preceding loop after it has been passed about the shuttle and, accordingly, a machine embodying the present invention will comprise a takeup which acts to pull the needle loop-from the shuttle partially back through the work. A

stant the lengthof loop left 'on the needle sideof theiwork by the take-up and in the preferred embodiment of the invention here inafter described this result is secured varying the operation of the take up. During each cycle of they machine the required;

amount of thread may be drawn :fromthe supply by suitable means, but it is pre ferredto utilize the shuttle to perform this function, it being understood that the term shuttle as here used and as hereafter used in theclaims is intended to include a hook or other loop taking device, by which gthei locking thread is passed through the loops of needle thread.

The. several features of the present invention will be clearly understood from an inspection of the accon anying drawin s, illustrating the preferref embodiment 0 the invention, in connection with the following description.

Referring to the drawings Fig. 1 is a view in side elevation of a lockstitch McKay shoe sewing machine embodying the present in vention; Fig. 2 is a detail View showing in front elevation and partially in section certain parts of the machine and illustrating particularly the mechanism connected with the Presser foot for varying the operation of the take-up Fig. 3 is adetailsectional plan View of the, take-up mechanism Fig. 4 is a View in side elevation, partly in section, of the mechanism illustrated in Fig. 3 and Figs. 5, 6 and 7 are diagrammatic views illustrating the operation of the thread handling de vices of the machine in forming and setting a stitch.

The machine illustrated in the drawings is the same in the general construction and arrangement of its parts as the lockstitch Mc- Kay shoe sewing machine illustrated in the patent to Goddard and Jerram, No. 1,353,827, dated September 28, 1920. Reference to this patent may be had for a full disclosure of details of constructions not illustrated in the drawings of thepresent application.

Referring to Figs. 1 and 2 the straight hook needle of the machine is indicated at 9, the shuttle at 10, the resser foot at 11, the feed point at 12, the s we supporting horn at 13, and the whirl which lays the thread in the book of the needle at 141. The needle,.presser foot and feed point are actuated from a horizontal cam shaft driven through bevelled gears 15 and 16 from a vertical shaft 17, and the shuttle and whirl are driven through connections from the vertical shaft 17, as in the machine of the Goddard and Jerram patent.

The thread lock against which the stitch is set comprises a spring pressed plunger 18 mounted upon a lever 19 and a fixed clamping plate 20 mounted in a bracket 21 of the machine frame. The lever 19 carrying the plunger 18 is actuated from a cam groove in the .barrel member 22 on the vertical shaft 17, the construction being such that the lever is actuated to open and close the thread lock during each cycle of operations of the machin f To permit the needle to set the stitch, the illustrated machine is provided with a take-up mechanism which draws back through the work a portion of the needle loop which has been passed aroundthe shuttle, leaving just enough thread in the loop projecting above the work to supply the needle with thread until it reaches the end of its retracting stroke. This take-up mechanism comprises two take-up levers s3 and 24 provided respectively with a thread guiding roll 25 and with thread guiding rolls 26 and 27. These levers are acted upon by cam grooves in the barrel member 22 and the construction is such that during each cycle of operations of the machine the forward ends of the levers are caused to approach and separate. T he thread passes from the supply through the thread look, around a guide roll29 mounted on the bracket 21 and then around the rolls on the take-u levers and to the work. As the front ends 0 the levers approach each other thread is given up to the retracting needle and to the shuttle and as the front ends of the levers separate, the thread lock being closed at this time, thread from the needle loop which has been passed about the shuttle is drawn back through the work.

To compensate for diiierent thicknesses of work, means are provided for varying the action of the take-up as the work varies in thickness. This means comprises a guide roll 30 at the upper end of a bar 31 arranged to slide vertically in the bracket 21. The roll 30 is so positioned in the machine that as the take-up lever 2i approaches its lower limit the thread extending between the rolls 26 and 27 is engaged by the roll 30 and deflected up wardly between the rolls. The lower end of the bar 31 is connected to the presscr foot bar of the machine through a lever 33, a connect ing rod 34 and a lever 35, so that as the work varies in thickness the position of the roll 30 is correspondingly changed andthereby an amount of thread pulled back through the Work by the take-up varying with the thickness of the work.

The operation of the thread handling devices of the machine has already been indicated but may be briefly stated follows: At the end of the take-up action of the takeup the parts are in the position illustrated in Fig. 5, the take-up levers being separated, the thread lock'being closed and the needle being just about to enter the work on its downward stroke. As will be obvious from the figure, the needle loop which has been passed around the shuttle has been p ulled back through the work until just enough thread remains in the loop on the needle side of the work to furnish one side of the next needle loop during the rctracting stroke of the needle. This length of loop remaining above the work at the end of the take-up action is constant for all thicknesses of work, the variation in the action of the take-up mechanism to produce this insult being effected by a variation in. the thickness of the work'as has been described. After the needle passes through the work the thread is laidin its hook and the needle retracts to the limit of its'upw'ard stroke. Duringthis action of the needle the thread lock remains closed and as the needle reaches the limit of its upward stroke, as indicated in Fig. 6, a stitch setting strain is exerted on the thread so that the stitch is set by the needle against the thread lock, the shuttle thread being pulled into the Work by the needle thread a predetermined and exact distance. The thread lock is now opened, the needle loop is taken by the shuttle, and as it passes over the shuttle, thread. for the next stitch is pulled from the supply. After the loop passes over the top of the shuttle the thread lock is closed and the take-up levers are actuated to shorten the loop, the parts then being again in the position indicated in Fig. 5. e

The nature and scope of the present invention having been indicated and the preferred embodiment of the invention having been specifically described, what is claimed is 1. A lockstitchsewing machine having, in combination, stitch forming and setting devices including a. hook needle acting during its retracting stroke to set the stitch, a shuttle, atake-up, a thread lock against which the stitch isset, means for actuating the parts, and means controlled by the thickness of the workfor determining the position of the lock of the stitch in the work;

2. A lockstitch sewing machine having, in combination, stitch forming and setting'devices including a hook needle acting during its retracting stroke to set the stitch, a shuttle, a take-up, a thread lock against which the stitch is set, means for, actuating the parts, and means for varying the action of the takeup, to compensate for different thicknesses of work. I r v V 3. A lockstitch sewing machine having, in

combination, stitch forming and setting devices including a hook needle acting duringits retracting stroke to set the stitch,. a shuttle acting to pull 0E thread for the next stitch, a take-up, a thread lock against which the stitch is set, and means for varying the action of the take-up to compensate for difl'erw cut thicknesses of work.

, combinatlon,

4. A lockstitch sewing machine having, in i stitch forming and setting devices including a hook needle acting during its retracting stroke to set the stitch, a shuttle acting to pull off thread for the next stitch, a take-up, a thread lock against which the stitch is set, and means for actuating the parts.

7. A lockstitch sewing machine having, in combination, stitch forming and settingdevices includinga hook needle acting at the limit of its'retracting stroke to set the stitch, a shuttle, a take-up, a thread lock against which the stitch is set, and means for actuating the parts.

8. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle acting during its retracting stroke to draw thread fromrthe preceding needle loop, a shuttle, take-up mechanism other than the needle or shuttle acting to pull the loop of needle thread from the shuttle part way down to the work, and means for ad usting the take-up, mechanism to vary its taking up action to leave substantially the same amount of thread projecting from Work of different thicknesses.

GEORGE E. WARREN.

vices including ahook needle acting during 7 its retracting stroke to set the stitch, ashuttle, a take-up, a thread lock against which the stitch is set, means for actuating the parts, and means controlled bythe thickness of the work for maintaining constant the length of the loop left on the needle side of'the work by the take-up. p

5. A lockstitch sewing machine having, in combination, stitch forming devices including a hook needle acting during its retracting stroke to draw thread from the preceding needle loop, a shuttle acting to pull off thread for the next stitch, a take-up acting to pull the needle loop from the shuttle partially back a ainst which the stitch is set. i 6. A lockstitch sewing machine having, in combin'atiom'stitch forming and setting dethrough the work, and a thread lock

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