US2099574A

US2099574A - Slip stitch sewing machine

Info

Publication number: US2099574A
Application number: US17160A
Authority: US
Inventors: Rosenman Herman; Roseman Leo
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-04-19
Filing date: 1935-04-19
Publication date: 1937-11-16
Anticipated expiration: 1954-11-16
Also published as: DE654361C; GB470708A

Description

Nov. 16, 1937. H. ROSENMAN ET AL 2,099,574

SLIP STITCH SEWING MACHINE Filed April 19, 1935 7 Sheets-Sheet l g mvg s r Y 7mm Nqv. 16, 1937. H. ROSENMAN ET AL SLIP STITCH SEWING MACHINE Filed April 19, 1955 7 Sheets-Sheet 3 INVEN Rs W TTbRNEY Gar mevrt' v H. ROSENMAN ET AL- SLIP STITCH SEWING MACHINE 7 SheetsSheet 4 Filed April 19, 1955' 2. INVENT 5 M ATTORNEY Nov.. 16, 1937. H. ROSENMAN ET AL SLIP STITCH'SEWING MACHINE Filed April 19, 1955 7 Sheets-Sheet 5 V INVENTO l fiTTORNEY' 6 5 05 1 7 0 0 m w oi M; i- WW w LE T A J i Nov. 16, 1937. I H.ROSENMANQET AL 4 SLIP STITCH SEWING MACHINE Filed April 19, 1935' 7 Shee ts-Sheet 6 iNvENT M BY 4 W ATTORNEY 7 Sheets-Sheet 7 Filed April 19, 1955 4 INVE OR M z 7ATTbRNEY Patented Nov. 16, 1937 PATENT OFFICE sur s'rrrcn sswmc. MACHINE Herman Rosenman and Leo Roseman,

Newark, N. J.

Application April 19, 1935, Serial No. 17,160

30 Claims.

This invention relates to a sewing machine especially for skipping or slipping of stitches in a line of stitches according to a method described and claimed in the application of Herman -Rosenman filed February 19, 1935, Serial No.

While our machine. is useful for many purposes, it is particularly desirable for stitching together two or more plies or thicknesses of material with continuous lines of stitches where-- in at predetermined intervals stitches are skipped or slipped to form gaps between two adjacent plies to receive fastener elements such as hooks or eyes for example to form fastener tape or to receive clasps of clasp steels or the like at the edges of corsets.

Our invention contemplates a machine wherein a needle forms a loop in the thread which is picked up by a loop taker and interlocked with another thread, for example, from a bobbin mechanism, for completing a stitch during normal operation of the machine, although the invention is susceptible to use with other types of sewing machines, including multiple needle ma- 3 chines.

It has been proposed to skip stitches in a line of stitches formed by a sewing machine, either by interrupting the reciprocation of the needle bar so that the needle is prevented from penem crating the work, or by throwing the needle bar out of cooperation with the loop taker of the bobbin mechanism, or by throwing the loop taker out of cooperating relation with the needle, so that the loop taker cannot pick up the loop which is formed by theneedle during normal operation in making a stitch. All of these machines involve complex mechanisms and opera- -tions and require modification of the usual stitch forming mechanism for accomplishing the skipping of stitches, and furthermore in these In other cases, stitches are skipped underma chines no provision is made to take up or compensate for the surplus thread which results from the skipped stitches, so that the thread tangles.

erly located, and the operation is tedious and slow.

Prime objects of our invention are to provide a sewing machine-embodying novel and improved features of construction whereby one or more 5 stitches can be slipped or skipped automatically by manipulation or control of the thread independently of the normal stitch forming mechanism of the sewing machine instead of modifying or manipulating the loop taker oi the bobbin mechanism or the needle bar; and to provide such a machine whereby the skipped or slipped stitches shall be located accurately and automatically by the machine and the operation of forming a line of stitches including skipped or slipped stitches shall be rapid and require a minimum of manual effort and attention. Our invention is particularly directed to means for pulling of the thread so as to prevent the formation of a loop in the thread and thereby prevent cooperation of the loop taker with the needle thread to prevent the formation of a stitch or stitches.

In normal, operation, the loop of course requires a predetermined quantity of thread, and the loop is formed normally during withdrawal of the needle from the work but before the needle is disengaged from the work. In accordance with our invention novel and improved means is provided to exert tension on the needlethread during withdrawal of the needle from the work and at the same time withdraw from the work in timed relation to the movement of the needle a predetermined or measured quantity of thread which is necessarily present to permit formation of a loop to cooperate with the loop taker, so as to' ensure that enough thread shall be Withdrawn to prevent formation of the loop and at the same time the thread shall not be broken by excess tension.

Further objects are to provide in a machine of the character described novel, improved and simple means for controlling or withdrawing the thread automatically in a. regular cycle in timed relation to the movement of the needle and independently of or without afi'ecting the normal operation of the stitch forming mechanism or the work feed mechanism of the machine; and thus to provide sucha machine which shall be capable of forming a line of stitches in the usual way, in combination with novel and improved mechanism for-gripping the thread at a certain time above the eye of the needle while the needle is in approximately its uppermost position and preferably while the thread is taut between the point of gripping and the point of interlockin of the thread in vthe work on the last previously formed stitch, then manipulating the thread in timed relation to the movement of the needle to prevent formation of a stitch, and thereafter releasing the grip on the thread whereby it shall be possible to form a line of stitching having skipped stitches spaced along the line accurately at desired intervals.

Further objects are to provide such a machine which shall include novel and improved means for timing the spacing of the skipped or slipped stitches so that said skipped stitches may be located at predetermined intervals; and thus to provide means preferably actuated approximately synchronously with the "drive shaft and needle bar of the machine for pulling or manipulating the thread, in combination'with means operable in timed relation with but at slower speed than said drive shaft and needle bar to control the gripping of the thread by the pulling or manipulating means.

Another object is to provide a machine of the character described which shall include novel and improved means for moving or controlling the surplus thread that is present due to skipping of a stitch, so that said surplus thread shall be prevented from becoming entangled with the needle and thereby obviate breaking of the thread during formation of subsequent stitches.

In many cases, it is desirable that a skipped stitch be located a certain distance from the edge of a piece of work at the beginning of the stitching 'operatlon, and therefore another object o! my invention is to provide novel and improved indicator means for pre-setting the machine so that the first skipped stitch in a piece of work shall be located at the desired distance from the edge of the work at the beginning of the stitching operation, or to indicate the number of stitches that have been made after a slip stitch.

It is often necessary that the slipped stitches be exactly spaced in the work, especially in making a fastener strip where the gaps resulting from the slipped stitches are intended to receive fastener elements to cooperate with complemental fastener elements on another fastener strip; and therefore our invention contemplates mechanism for slipping or skipping stitches including a reciprocating feed dog, in combination with auxiliary positive work advancing means ahead of the feed dog, for example continuously rotating feed rollers to grip the work between them, for

preventing underfeeding or overfeeding of the work by the feed dog.

In applying strips to the edge of a garment and skipping or slipping stitches to leave gaps for fastener elements, as hereinabove described, it is desirable in many instances that the slip stitches be located in certain relations to the garment, for example that the last slipped stitch be spaced a certain distance from the end of the garment, and the operator can see that with continued feeding of the work with normal or usual feed of the work, the last slipped stitch will not be properly located. Therefore, another object is to provide such auxiliary work advancing means in combination with the usual feed dog work feed mechanism whereby the feed of the strips and garment may be modified at the will of the operator for various purposes, for example, to cause the last slipped stitch to be located at least approximately at the desired point.

A further object is to provide novel and improved means in a machine of the character described for throwing the thread gripping or controlling mechanism out of or into. operation at will, so that it shall be possible to form a continuous line of stitches without skipping stitches whenever desired.

Other objects are to provide means which can be applied to many known types of sewing machines for controlling or manipulating the thread without modification of the usual stitch forming mechanisms or work feed mechanisms, and to obtain other advantages and results as will be brought out by the following description.

Referring to the accompanying drawings, in which corresponding and like parts are designated by the same reference characters,

Figure 1 is a topplan view of a sewing machine embodying my invention.

Figure 2 is a front elevation thereof.

Figure 3 is an end elevation of the machine showing the thread gripping mechanism in the position which it takes at the beginning and the end of the thread control movement.

Figure 4 is a similar view showing the thread gripping mechanism in the position which it takes just prior to the pulling of the thread to skip a stitch.

Figure 5 is a detached top plan view of the thread gripper.

Figure 6 is a fragmentary top plan view of the cam mechanism for controlling the gripping of the thread showing the cam in the position assumed just prior to the thread gripping operation.

I Figure '7 is a schematic perspective view of the thread gripping mechanism with the parts in the positions assumed just prior to gripping of the thread.

Figure 8 is a view similar to Figure 6 showing the position of the cam during gripping of the thread.

Figure 9 is a view similar to Figure '7 showing the position of the parts just prior to the beginning of the thread pulling operation.

Figure 10 is a view similar to Figure 8 showing the position of the cam at the end of the thread pulling operation.

Figure 11 is a similar view showing the position of the cam just after release of the thread by the gripper.

Figure 12 is an enlarged transverse vertical sectional view through a portion of the needle and work illustrating the position of the needle at the beginning of the formation of a stitch as shown in Figure 3.

Figure 13 is a similar view showing the needle in the limit of its penetration of the work and just prior to the beginning of the formation of the thread loop.

.Figure 14 is a similar view showing the risin of the needle and the normal formation of the loop in the needle thread.

Figure 15 is a like view showing the rising of the needle and the pulling of the thread to prevent the formation of a loop.

' Figure 16 is a similar view showing the three 8. completely pulled from the work.

Figures 17, 18, l9-and 20 are fragmentary schematic side views'of the parts for throwing the tlgjread gripping mechanism into and out of opera on.

Figure 21 is a top plan view of a machine showing a modification of the invention.

Figure 22 is a front elevation thereof.

Figures 23 and 24 are end elevations corresponding to Figures 3 and 4.

Figure 25 is a detached perspective view of one of the parts of the thread gripper.

Figure 26 is a schematic perspective view of the thread gripping mechanism shown in Figures 21 to 24 inclusive illustrating the parts in the positions assumed just prior to gripping of the thread.

Figure 27 is a similar view showing the parts in the positions assumed just prior to pulling the thread.

Figure 28 is a fragmentary schematic perspective view showing the operation of the means for throwing the thread gripping mechanism into and out of operation.

Figure 29 is a top plan view of the indicator for presetting the machine to locate the first skipped stitch a predetermined distance from the edge of the work at the beginning of the stitching operation, or for indicating the number of normal stitches that have been formed after a slip stitch.

Figure 30 is an enlarged longitudinal vertical sectional view through work having a line of stitches therein and illustrating the skipped stitch.

'Figure 31 is a fragmentary perspective view of two superposed plies of material stitched together with a line of stitches in accordance with the invention.

Figure 32 is a rear perspective view showing the plies of material folded backwardly upon each other.

Figure 33 is a front perspective view corresponding to Figure 32.

Figure 34 is an enlarged transverse vertical sectional view through the plies shown in Figures 32 and 33 with a fastener strip inserted therebetween and a fastener projecting through the gap formed by the skipped stitch.

Figure 35 is a top plan view of a modified form of thread gripper especially designed for use with two needle machines.

Figure 36 is a perspective view of two superposed strips of fabric for a fastener tape having two lines of stitches formed with a two needle machine and having corresponding slipped stitches to form a gap for a fastener element, and

Figure 3'7 is a similar view showing a line of stitches formed with an'oscillatory or so-called zig-zag machine and having a slipped stitch.

For the purpose of illustrating the princ ples of our invention we have shown it schematically in connection with a known type of sewing machine which includes the usual frame 6 having the usual stitch forming mechanism including a needle bar A reciprocable therein by known mechanism (not shown). The needle bar carries the usual needle 3, and the machine also includes a take-up lever l which is utilized for supplying and taking up the thread in cooperation with the loop taker. The needle has the usual eye 6 and the longitudinal groove i at one side in which the thread is seated as the needle penetrates and is removed from the work which is designated W.

Cooperating with'the needle bar is thebobbin mechanism 5 of known type which includes a loop taker hook 8 to pick up the loop formed in the needle thread during-the normal operation of the machine in the formation of a stitch.

The machine also includes suitable known work feed mechanism which includes the reciprocating feed dog R for advancing the work beneath the needle in steps each equal'to the length of one stitch, and a presser foot P of known structure. is included to hold the work against the feed dog. For the sake of simplicity these parts are only schematically and fragmentarily illustrated.

As usual, the thread T is threaded from a supply spool or the like through the tension device 5, the eye of the take-up lever 4 and the eye of the needle 6, and during normal operation of the machine'the needle reciprocates and on its descent penetrates the work to carry the thread through the work as shown in Figure 13 of the drawings. As the needle rises, normally the thread at one side of the needle frlctionally engages the work while the thread at the other side of the needle is in the groove I, so .that as the needle rises a loop L in the thread is formed below the work, as shown in Figure 14, andthis loop is picked up by the loop taker 8, carried around and interlocked with the bobbin thread to form a stitch S indicated in Figure 30. After the needle leaves the work, the work feed mechanism R moves the work forwardly a distance equal to the length of one stitch, preparatory to the next work penetrating movement of the needle for the next stitch. When the needle is in its uppermost position, the thread between the take up lever and the point in the work where the threads are interlocked to form .the last previously formed stitch,

is substantially taut, and there is suflicient thread present to form a loop for the next stitch.

As above indicated, when it is desired to slip a stitch, we propose to manipulate or control the thread T so as to prevent the formation of the loop L; and when it is desired to slip a stitch Now specifically describing the thread gripping and pulling mechanism, said mechanism includes a gripper G which comprises two gripping jaws i0 and ill one of which is fixedly connected to a horizontal tubular shaft it? which is mounted on a bearing bracket it secured on the goose-neck of the machine. The other jaw ii is mounted on the end of a rod it which is slidable longitudinally of the tubular shaft 93 with one end projecting from the tubular shaft and in abutting relation to an adjustable screw i5 mounted in one end of a lever 96 which is pivotally mounted at i "i in the bracket 93 and connected to one end of a follower lever to which carries a roller is that follows a cam 20. The two jaws i0 and ii are in juxtaposed relation and receive the thread '1 between them, and the jaws are normally influenced together by tension spring 2! connected to a pin 22 which is fixed in the jaw ii and slidable through the jaw it transversely of the latter.

The pin 22 causes the jaws to swingtogether about the axis of the shaft it. As shown; the jaws are mounted for oscillation in a vertical plane which is approximately the plane of the portion of the thread between the take up lever t and the needle.

The jaws are oscillated and in timed relation with the drive shaft D of the machine and the needle bar by a cam 23 which is mounted on the drive shaft (see Figure 7). The cam 23 cooperates with the follower roller 32 which is connected to a lever 3i pivotally connected at one end at 33 on the machine and connected at its other end by a link 34 to a crank arm 35 on the tubular shaft l2. The roller 32 is caused to follow the cam 23 by a spring 36.

its lowermost work penetrating position shown in Figure 13. As the needle rises the cam 23 actuates the gripper upwardly into the position shown in Figures 3 and 7. The gripper jaws I0 and II as so controlled by means about to be described that during the withdrawal of the needle from the work the gripper pulls out an amount'of thread that is present for forming a loop so as to prevent formation of a loop as shown in Figure 15. During the movement of the needle to the point which locates the thread above the loop taker 8, the movement of the gripper is in advance of the movement of the needle to ensure pulling out of the thread that is present for normal formation of the loop, and during the remainder of the upward movement of the needle the gripper preferably moves at a speed to prevent the thread beneath the gripper becoming entangled with the point of the needle and this obviates breaking of the thread during formation of subsequent stitches.

The gripper jaws I0 and II are actuated toward and from each other to grip and release the thread by the cam 20 which actuates the follower lever I8, lever I6 and rod I4. This cam 20 is mounted on a vertical countershaft 24 journaled in suitable bearings 25 connected to the gooseneck of the machine and is driven by worm and worm gear drive 26 from the drive shaft D of the machine at a reduced speed. The speed ratio between the shaft D and 24 may be as desired, for example so that the shaft 24 will make one revolution for a given number of stitches. One stitch is made during each revolution of the shaft D as usual, and as shown the speed ratio is twelve to one; in other words the cam 20 will make one revolution while the drive shaft D is making twelve revolutions which during normal operation of the machine will result in the formation of twelve continuous stitches for each revolution of the cam 20. In the present instance it is desired that one stitch shall be slipped in each series of twelve stitches, in other words, that eleven continuous stitches shall be formed and then one stitch shall be slipped. For this purpose the cam 20 has a concentric dwell 21 with which the follower roller I9 contacts during the formation of eleven stitches, and a cam recess 28 which the follower roller engages during the interval required for formation of one stitch by the stitch forming mechanism.

The spring 2| normally holds the follower roller i4 in contact with the cam 20 and when the gripper is in its approximatey upper position the gripping jaws are separated so as to release the thread as shown in Figure 7, the follower roller and cam being in the relative positions shown in Figure 6. As the follower roller 20 enters the cam recess 28., the jaws are drawn together to grip the thread approximately simultaneously with the beginning of a downward movement of the gripper jaws, and the gripping relation to the thread is maintained throughout the work penetrating movement of the ,needle approximately synchronously with the movement of the thread. As the needle begins to rise, the cam 23 and connected parts swing the gripper Jaws upwardly slightly in advance of the normal movement of the thread so as to pull the thread out of the work to prevent the formation of a loop as shown in Figure 15. The gripper need move in advance of the thread only during the movement of the needle to the point which locates the thread above the loop taker so as to ensure pulling out of the thread that is present for normal formation of the loop, and during the remainder of upward movement of the lever the gripper preferably moves at a speed to take up the thread beneath the gri per so as to prevent the thread from becoming entangled with the needle. Approximately as the gripper jaws reach their upper position the follower roller is forced out of the cam recess as shown by Figures 10 and 11 so as to release the thread, and thereafter the machine will continue to make stitches because while the gripper jaws may be continuously oscillated they cannot grip the thread and therefore cannot pull out the thread to prevent formation of stitches. With this construction it will be observed that in operation of the machine, eleven continuous stitches will be formed followed by skipping of one stitch, after which eleven more stitches will be formed and so on.

Obviously by modifying the cams 20 and 29-I33 two or more stitches might be skipped in succession, and byvarying the timed relation between the stitch forming mechanism and the thread gripping mechanism, the intervals at which the skipped stitches will be formed may be .varled.

It is desirable to prevent oscillation of the gripper during the normal formation of stitches both to prevent unnecessary wear on the thread gripping mechanism and to avoid unnecessary noise. For this purpose, the cam 20 may have a. concentric cam surface 29 engaged by aroller 30 mounted on the lever 3I to hold the follower roller 32 out of contact with the cam 23 as shown in Figure '7 except during the operation of skipping a stitch. To permit operation of the gripper for skipping the stitch, the cam surface may be interrupted by a recess I33 in proper relation to the cam recess 28 to permit the roller 30 to drop and thereby enable the follower roller 32 to follow the cam 23 as shown in Figure 9.

It will readily appear to those skilled in the art that the cam 23 and follower roller 32 might P be eliminated, and the cam notch I33 modified to actuate the lever 3i and shaft I2 through roller 30 instead of using the notch I33 simply as a clearance for the roller 30 to permit the roller 32 to follow the cam 23.

It will be understood that during the pulling of the thread the work feed R. will have moved the work forwardly in the normal way a distance equal to the length of one stitch and the needle will have penetrated the work so as to leave a hole 0 in the work as shown in Figure 30. Preferably the jaws will be released from the thread slightly before they reach their uppermost position of Figures 3 and '7 and will be held released from the thread by the cam dwell 21 a sufficient time to permit the take up lever 4 to adjust the thread for the next stitch.

It will be observed that the thread is maintained substantially taut between the needle and the gripper throughout the reciprocation of the needle from the beginning of its descent as shown in Figures 3 and 7 to its lowermost work penetrating position shown in Figures 4 and 13, and then through its upward movement back to its uppermost position; and due to the constant grip on the thread during the movement of the gripper there is; ensured the exact and measured amount of t d between the point of gripping and the lnterloc oi the thread. in the .last previously formed stitch, by reason ofwhich formation of the loop may be positively prevented and breaking of the thread is obviated. Preferably the grip by the jaws on the thread is frlctionally yielding so that the thread may be pulled through the operation of the -stitch forming and 'work feed mechanism of the machine.

Where it is desired to throw the thread grip- .ping and pull mechanism out of operation, for

example to form a continuous line 01 stitches without skipping stitches, we may utilize a control device including a lever pivotally mounted intermediate its ends at 4! on the machine and which may be manually operated. Oneend of the lever has a pin and slot connection 42 with a eontrolslide 43 mounted in the top of the machine to cooperate with an extension 44 on the lever 3|. The slide 43 moves transversely of the extension 44 and has a lug 45 at its extremity and an inclined or ,wedging surface 46 adjacent said lug. When the gripper has been moved to its upper position as shown in Figures 3 and 7 the slide may be pushed beneath the extension 44 as shown in Figure 18, and upon continuation of this movement of the slide the wedge or inclined portion 46 will engage the extension to'swing the gripper furtherupwardly to clear the follower roller 22 from the cam 23 as shown in Figures 19 and 28 and thereby completely disconnect the gripper from the driving mechanism. Therefore, it will be observed that with the parts in the positions shown in Figures 19 and 20, the gripper cannot operate, and in order to permit operation of the gripper the slide '43 must be disengaged from the extension 44 as shown inFigure 18. Due to the lug 45 operation of the gripper cannot be started until it reaches its upper position because as shown-in Figure any attempt to disengage the slide 43 from'the extension 44 while the gripper is below its uppermost position is prevented by engagement of the lug 45 with the extension.

It will alsobe observed that when the gripper is in its intermediate or lower positions as shown in Figures 4 and 9 the slide cannot be slid under the extension 44 as shown in Figures 9 and 17 and therefore the operation of the gripper cannot be stopped until it has reached its uppermost position as shown in Figures 7 and 18.

From the foregoing, it will appearthat the thread gripping and pulling mechanism may be thrown into and out of operation at will by operation of the lever 40, and when out of operation it will always be located at its uppermost position as shown in Figures 3 and '7. While the thread gripping'mechanism is out of operationthe stitch forming and work feed mechanism will make a continuous line of stitches, while when the control slide 43 is disengaged from the extension 44, a stitch will be skipped at predetermined intervals, in the present instance every out of operative relation to the cam 20 when oscillation'of the thread gripper" is stopped by the control slide 43 and for this purpose, the V lever 40 may have a lug 450 to engage the 101- lower lever It so as to swing the latter to slidethe gripper jaw l I away from the jaw l0 simultaneously with the movement oifthev control slide 43 beneath the extension 44. Obviously, the lever 40 will be so mounted asto overcome the resist ance of the spring 2|. As shown, thelever 4|! and slide 43 are mounted on a plate secured to the top of the goose-neck of the machine, and

the follower lever l8 projects through a slot"- in said plate.

While the form of the gripper jaws I0 and, II may be considerablyvaried, a satisfactory structure is shown in the drawings, particularly Fig-' ures 4 and 5 wherein one of the gripper jaws has a spring wire loop 62 through which the thread is passed and which holds the thread in approximately proper relation to the gripping surface of the jaws, and the other jaw has a guide plate 53 formed with a slot 54 to receive the thread and hold it in exactly the proper relation to the gripping surfaces.' The movable jaw may move relatively to the guide plate 53.

In some cases it may be desirable toform a groove I96 in one of the gripping jaws of a' depth less than the diameter of the thread to ensure that the thread shall always be gripped between the same portions of the gripping surner as shown in Figures 1 and '7,'namely' by the spring 2|. In operation, when the gripper is in approximately its uppermost position, the

gripping jaws are brought into engagement with the wedge GI and are separated by the wedge so as to release the thread as shown in Figure 26, the upward movement of the gripper under the influence of the cam 23 forcing the jaws illand II over the wedge so that the jaws are spread 'apart; and when the cam 23 permits the gripper to move downwardly under the influence of the spring 36, the jaws are slipped oil. the wedge and moved together by the spring 2i to grip the thread as shown in Figure 27.

For controllingthe oscillation of the jaws so as to skip a stitch'at proper intervals, we utilize a cam 63 having a surface similar to the cam surface 29 and mounted on the countershaft 24 and formed with.- a cam .notch 64 to cooperate with a roller 65 corresponding to the roller 30 of Figure '7. One revolution of the cam 63 corresponds to twelve stitches and while the roller 65 5" is in engagement with the fiat cam dwell 66, the gripper jaws are, held in their uppermost position, separated by the wedge 6i. When the cam has been rotated to the point where the roller 65 may drop into the notch 34', thegripper jawsareswung downwardly under the influence of;

the spring 36 'under control of the cam 23, and

are then raised. by the cam 23 to move the roller out of the notch so as to be again engaged by the. dwell 66. The speed and character of Figures 1 to 11 inclusive, the cam 88 and wedge 8| in effect taking the place of the cam 20, the follower roller l8 and the levers l8 and l8.

To illustrate the character of the skipped or slipped stitch formed by the machine, we have shown in Figure 30 complete stitches S and a slipped or skipped stitch K. It will be noted that between the two stitches S the needle thread T and bobbin thread T-T haye not been interlocked as they are at -U when the stitches areformed.-

Furthermore to illustrate one possible use of the machine we have shown in Figures 81 to 34 inclusive work of one type that can be performed with the machine. In Figure 31 are shown two plies of

material

10 and 1| stitched together adjacent their edges by a line of stitches 12 including a skipped' stitch 18. In Figure 32 the two plies are shown as folded backwardly upon each other after stitching, and Figure 33 illustrates the two folded plies with a gap 14 therebetween left by the skipped stitch 18. In Figure 34 the two plies of material are shown as having between them a fastener strip 18 which has a fastener such as a wire eye 18 projecting through the gap 14. The structure shown constitutes one type of garment fastener and may be embodied directly in the edge of a garment or may be composed of strips of material which may be secured to the edges of a garment.

In making such fastener tape, it is highly desirable that the gaps 14 be accurately spaced, and our machine makes this possible automatically. The usual feed dog work feed mechanism is not sufficiently reliable to produce the necessary accuracy and to ensure that the work shall be fed uniformly and accurately, we utilize an auxiliary feed mechanism to cooperate with the usual feed dog illustrated in Figure 3. This auxiliary feed mechanism includes two serrated feed rollers8|l and 8| between which the material to be operated upon is gripped, one roller being mounted in the frame of the machine on shaft 88 and the other mounted on a shaft 84 in a frame 840 pivoted at 84| so that roller 8| may be influenced toward roller 88 by a spring 842. The rollers are geared together to rotate at the same peripheral speeds by intermeshing pinions 82, one on each of the

roller shafts

83 and 84, and-one of the shafts, in the present instance the shaft 83, is driven by a helical gear connection 85 with a jack shaft 88 which has a helical gear connection 81 with the counter-shaft 24. The rollers 80 and 8| more firmly grip the work than do the presser foot and feed dog, and feed the work accurately in timed relation to the stitch forming mechanism. The feed dog is normally adjusted to feed a length of work slightly greater than the length supplied by the feed rollers for each stitch to ensure that the full amount of work shall be brought to the needle, and the pressure of the feed dog on the work'is such that it may slip beneath the work after it has fed the exact amount controlled by the feed rollers. With this construction, the work is positively gripped between the feed rollers 88 and 8| and the rollers are constantly rotated at a uniform speed in timed relation to the drive shaft D and the needle, so that the work may be fed with extreme accuracy and the skip stitches 18may be accurately spaced in the work and overfeed of the work is prevented. Underfeed also is prevented by the adjustment of the dog R to feed more than desired, and the preventing of excess feed by the rollers 80, 8| which hold back the work to the feed desired,the dog slipping slightly over the work to compensate therefor;

In many cases it is desirable to locate the first skipped stitch a predetermined distance from the edge of the work at the beginning of the stitching operation and to indicate the number of stitches that have been made after 'a skipped stitch when the machine is stopped; and to accomplish this result we have shown an indicator disc 81 mounted on the countershaft 24 and having a series of graduations 88 corresponding in number to the number of stitches to be made in the work per inch. As shown, there are twelve graduations corresponding to twelve stitches per inch, and for convenience the zero graduations correspond to a skipped stitch. The disc 81 cooperates with a pointer 88 mounted in convenient relation on the machine, and the parts are so related that when the follower roller l8 engages the cam recess 28 for skipping a stitch the zero graduation on the indicator stitch is in juxtaposition to the pointer 88. Therefore should it be desired to form six stitches inwardly from the edge of the work at the beginning of the stitching operation before skipping a stitch the drive shaft D will be rotated until the graduation 6" on the disc 81 is juxtaposed to the pointer 89. Then upon operation of the machine six stitches will be formed followed by a skipped stitch, and then continued operation of the machine will result in the formation of eleven continuous stitches followed by a skipped stitch, and so on. To assist the operator in beginning operation upon the next piece of work without unnecessary stopping of the machine, we mount on the disc a visible indicator Hill which may be a set screw adjustable circumferentially of the disc, and this visible indicator will be set in juxtaposition to the graduation on the disc which is in juxtaposition to the pointer at the beginning of the stitching operation, in the foregoing example, the graduation 8. Then when the end of one piece of work has passed the needle the operator will watch until the visible indicator i110 reaches the pointer 88 whereupon the machine will be stopped. Then the next piece of work may be inserted into the machine and operation resumed with the assurance that the first skipped stitch on the second piece of work will be spaced the same distance from the edge as was the skipped stitch in the first piece of work. This feature is particularly important where a long piece of facing strip to receive fasteners is to be stitched to a plurality of gar ments in succession.

In such cases the facing strip is fed through the feed rollers 80, 8|, but the garments are laid on top of the strip and do not pass through the feed rollers; and in some cases it is desirable to slightly modify the feed of the tape and the garments especially where it is necessary that the last slipped stitch shall be spaced approximately a certain distance from the end of the garment at the completion of the stitching operation. In normal operation this distance may vary for different reasons, particularly because of slight The sewing machine has the usual mechanism slip stitches is not changed. Howeven'the last generally designated A-A in Figure 2 such as shown in United States Patent No. 718,988 dated .feed, the last slipped stitch will be too far from the garment end, the feed mechanism will be adjusted to increase the length of stroke of the feed dog. Except for our feed rollers this would ordinarily increase the length of stitches by increasing the length of the steps of feeding of the work, but in the present case the tape is held back by the feed rollers and the material is substantially non-stretchable so that the length of the stitches is not increased. However, the feed dog does exert greater tension on the tape than during normal .feeding and takes up any slight slack there may be between the feed dog and the rollers, and the garment follows the tape between the feed dog and the presser foot a distance greater than the length of a normal stitch. The pressure of the presser foot on the work is less than the pressure exerted on the work by the feed rollers 80 and 8|, and the tape is held by the feed rollers while the garment is not so held, so that the tape is under tension and the garment is not under tension. Therefore, at the end of the feeding movement when the feed dog retracts from and releases the tape and before the needle penetrates the garment and tape, the ape slightly retracts sliding beneath the garment. and the garment remains at the point to which it was fed. This results in there being slightly more of the garment than of the tape traversed by the stitch; in other words, the garment is slightly taken up or puckered and accordingly the length of stitches remaining the same, the last slip stitch will be located closer to the end of the garment. Should the operator discover that the last slip stitch with normal feed will be too close to the end of thegarment, the garment may be held back manuallyagainst the influence of the feed dog. Ordinarily this would result in changing the length of the stitches and distance between the slip stitches,

but with our machine, due to normal tendency of the feed dog to overfeed, the backward tension or pull on the garment is compensated for by the overfeed, and as the tape is not retarded the length of stitches or spac ng between the sl p stitch will be located farther from the garment end.

Obviously, these adjustments of the feed may be used .in connection with other machines for skipping or slipping stitches in different ways,

and are not limited to our particular form of thread manipulating mechanism.

While we have so far described the invention in connection with a single needlemachine. it may be used with a multiple needle machine. For example. another needle may be placed in the place provided in the needle bar A alongside the needle 3, and threaded as s the needle 3. Then the gripper may be modified as shown in Fi ure .35 by forming the thread guide plate 90 with a hole 92 to receive both threads, or two holes close together each to receive one thread so that both threads may be located between the gripping surfaces 9| and 95. If' desired the claim is:

nally of the jaw in either direction to move the threads from between the

gripping surfaces

94, 95 when it is not desired to slip stitches. With this construction two parallel lines of stitches It'll may be formed as indicated in Figure 36 and both threads may be caused .to slip stitches I02 at the same time and in juxtaposition.

This is important in securingfasteners with long shanks in the gapslbetween the plies of material beneath the slip stitches with the inner row of stitches adjacent the base of the fastener, to prevent the material being slid backwardly along the shanks so as to expose the latter.

A similar effect can be obtained with a socalled zig-zag stitching machine having an oscillatory needle which may be periodically oscillated to form transverse stitches I03 at opposite sides of a slipped stitch I04 as shown in Figure 3'7. The transverse stitches I 03 serve the same function as the two lines of stitches of IM in preventing the fabric strips from sliding along the shanks of fasteners that are disposed beneath the slipped stitches.

It will be observed that in all forms of the invention the characteristic features are the sk pping stitches by pulling of the thread instead of by modifying or manipulating the stitch forming mechanism or the bobbin mechanism, and the means for controlling the skipping of the stitches is substantially independent of the stitch forming mechanism and work feeding mechanism. Moreover, the mechanism is simple and reliable in.

roller 32 since undue wear of these parts would materially affect the accuracy of the o erat on of the gripper jaws, it being understood that a very delicate relationship must obtain between the movement of the gripping jaws and the thread and needle to ensure pulling out of the thread loop and at the same time obviate breaking of the thread.

Furthermore, due to the independent relation of our thread manipulating mechanism to the stitchforming and work feed 'mechanism of the sewing machine, the machine may be operated at substantially its usual high speed; our invention does not hinder, impede or slow the speed of stitching as would be the case were the operation of the needle bar or bobbin mechanism modified to slip stitches.

Having thus described our invention, what we 1. In a machine of the character described the combination with work feed mechanism and stitch forming mechanism including a reciprocating needle and a loop taker operable n tim d relation for forcing a thread through a p ece of work forming a loop in the thread at one side of the work and interlocking another thread through said loop to normally form a line of needle to exert tension on the thread as the needle rises from work penetrating position to prevent formation of loops.

2. The machine set forth in claim 1 wherein the means for operating the gripping means to grip the thread and said means for actuating the gripping means in timed relation to movement of the needle, actuate the thread gripping means as the needle rises from the work to maintain the thread substantially taut between said gripping means and the point of interlocking of the threads in the last previously formed stitch.

3.1n a machine of the character described the combination with work feed mechanism and stitch forming mechanism including a reciprocating needle and a loop taker operable in timed relation for forcing a thread through a piece of work, forming a loop in said thread at one side of the work and interlocking another thread through said loop, of a gripper for gripping the needle thread above the needle, means operable at slower speed but in timed relation with said needle for automatically actuating said gripper at intervals to grip said thread while the needle is above the work and maintain said grip during movement of the needle into and out of the work, and means operable approximately synchronoifsly with said needle during a portion of each of the descending and ascending movements of the needle but at slightly greater speed during the first portion of the movement of the needle from the limit of its work penetrating position to actuate said gripper to exert tension, on the needle thread and prevent formation of a loop.

4. The machine set forth in claim 3 wherein the means for automatically actuating the gripper at intervals actuates said gripper to grip said thread when the needle is at approximately its uppermost position and also actuates said gripper to release said thread while the needle is at approximately its uppermost position.

5. In a machine of the character described the combination with work feed mechanism and stitch forming mechanism including a reciprocating needle and a loop taker operable in timed relation for forcing a thread through a piece of work, forming a loop in said thread at one side of the work and interlocking another thread through said loop, and a drive shaft and operative connections between it and said stitch forming mechanism, of a gripper to grip the needle thread above the needle, a cam shaft geared for reduced speed to said drive shaft, a cam on said cam shaft and operatively connected to said gripper for actuating said gripper at intervals to grip said thread while the needle is at approximately its uppermost position, and to release said thread while the needleis in said position, and a cam on said drive shaft operatively connected to said gripper for moving the gripper approximately synchronously with said needle during a portion of the descending and ascending movements of the needle but at a greater speed than the needle during the first portion of its movement from the limit of its work penetrating position to exert tension on the needle thread and prevent formation of loops.

6. In a machine of the character described the combination with work feed mechanism and stitch forming mechanism including a reciprocating needle and a loop taker operable in timed relation for forcing a thread through a piece of work, forming a loop in said thread at one side of the work and interlocking another thread through said loop, o'fa gripper including two opposed jaws normally yieldingly influenced toward each other to grip, the needle thread above the needle, means for moving said gr pp r approximately synchronously with said needle during a portion of each of the descending and ascending movements of the needle but at slightly greater speed during the first portion of the movement pf the needle from the limit of its work penetrating position, means for starting and stopping said movement of said gripper while the needle is at approximately its uppermost position, and stationa means to be engaged by and separate said jaws to release the thread when the needle is at approximately its uppermost position and to release said jaws and to grip said thread as the needle begins its descent from said uppermost position, whereby said gripper will pull said thread as the needle rises from its work penetrating position to prevent formation of a loop.

'7. The machine set forth in claim 1 wherein said gripping means includes two relatively movable opposed jaws and spring means for normally yieldingly drawing them together to, grip the thread, and said means for actuating the gripping means to grip the thread relatively moves saidjaws to separate them and permits the spring means to move them toward each other.

8. The machine set forth in claim 1 wherein said gripping means includes two relatively movable opposed jaws and spring means for normally yieldingly drawing them together to grip the thread, and a horizontal shaft connected at one end to both said jaws to oscillate the jaws in a vertical plane with the needle thread between them, said means for actuating the gripping means to grip the thread relatively moves said jaws to separate them and permits the spring means to move them toward each other, and the means for actuating the gripping means in timed relation to movement of the needle thread by the needle oscillates said shaft.

9. The machine set forth in claiml wherein said gripping means includes two relatively movable opposed jaws, said means for actuating the gripping means to grip the thread includes a cam operatively connected to one of the jaws to control movement of the latter toward and from the other jaw, and a horizontal shaft connected at one end to both said jaws to oscillate the jaws in a vertical plane with the needle thread between them, and said means for actuating the gripping means to exert tension on the thread includes a cam rotatable in timed relation to the movement of the needle, and an operative connection between said cam and said shaft to oscillate said gripping means.

10. The machine set forth in claim 1 with the addition of a common means independent of the stitch forming mechanism for controlling starting and stopping of the means for actuating the gripping means to grip the thread and the means for actuating the gripping means to exert tension on the thread.

11. The machine set forth in claim 5 with the addition of means for connecting and disconnecting said gripper from said two cams independently of the operation of said stitch forming mechanism.

12. The machine set forth in claim 8 with the addition of means for controlling starting and stopping of the means for moving the gripper with the needle independently of. the stitch forming mechanism.

13. Th' machine set forth in claim 1 with the position.

14. The machine set forth in claim 3 with the I addition of means for controlling starting and stopping of the means for actuating the gripping means to grip the thread and the means for actuating the gripping means to exert tension on the thread independently of the operation of said stitch forming mechanism and only while the needle is at approximately its uppermost addition of means for controlling starting and stopping of the means for actuating the gripper to grip the thread and the means for actuating saidgripper to exert tension on the thread independently of the operation of said stitch formtng mechanism and only while the needle is at approximately its uppermost position.

I 15. The machine set forth in claim 5 with the addition of a control slide to separably engage the operative connection between said cam on they drive shaft and said gripper when the needle 8 at approximately its uppermost position to disconnect and hold disconnected said operative con-- nection from said cam to stop movement of said gripper independently of said stitch forming mechanism.

16; The machine setforth in claim 5 with the addition of a control slide to separably engage the operative connection between said cam on the drive shaft and said gripper when the needle is at approximately its uppermost position to disconnect and hold disconnected said operative connection from said cam to stop movement of said. gripper independently of said stitch forming mechanism, and means for disconnecting and holding disconnected from said cam on the cam shaft the operative connection between said cam and said gripper substantially simultaneously with disconnection of said cam on the drive shaft from said gripper.

17. The machine set forth in claim .5 with the addition of means including a stationary pointer and an indicator disk on said cam shaft to cooperate with said pointer for presetting the machine to form a predetermined number of stitches prior to operating said thread manipulating means to prevent formation of a loop and slip a stitch.

18. In a machine of the character describedthe combination with work feed mechanism and stitch forming mechanism including a reciprocating needle and a loop taker operable in timed re-- lation for forcing a thread through a piece of work, forming a loop in said thread at one side of the work and interlocking another thread through said loop, and a drive shaft and operative connections between it and said stitch forming mechanism, of a gripper to grip the needle thread above the needle including a pair of opposed relatively movable jaws and a horizontal shaft connected to one end of each jaw for oscillating the jaws in a vertical plane with the needle thread between them, a cam shaft geared for reduced speed to said drive shaft, a cam on said cam shaft and an operative connection between said cam and one of said gripper jaws to control movement of said jaws toward and from the other at inter-- vals to grip and release the needle thread when the needle is approximately in its uppermost position, a cam on said drive shaft, and an operative connection between said cam and said gripper shaft to control oscillation of thelatter to swing said gripper approximately synchronously with said needle during a portion of each of the descending and ascending movements of the needle but at a greater speed than the needle during the first portion of its movement from the limit of its work penetrating position to exert tension on the needle thread and prevent formation of loops.

19. The machine set forth in claim 5 with the addition of means for preventing said operative connection between said cam on the driveshaft and said gripper from engagement with said cam except at intervals corresponding. to the intervals at which the gripper grips said thread.

20. In a machine of the character described the combination with work feed mechanism and stitch forming mechanism including a reciprocating needle and a loop taker operable in timed relation for forcing a thread through a piece of work, forming a loop in said thread at one side of the work and interlocking another thread through said loop and a drive shaft and operative connections between it and said stitch forming mechanism, of a gripper to grip the needle thread above the needle including a pair of opposed relatively movable jaws and a horizontal shaft connected to one end of each jaw for oscillating the .jaws in a vertical plane with the needle thread between them, means operable in timed relation to the needle for controlling actuation of said movable jaw toward and from the other jaw at intervals to grip and release said needle thread above the needle when the needle is in approximately its uppermost position, a cam on said drive shaft, a follower lever pivoted at one end one, fixed support and connected at its other end to said gripper shaft so as to rotate said gripper shaft in one direction upon movement of said follower lever by said cam to swing said gripper, and a spring for rotating said gripper shaft in the other direction.

21. The machine set forth in claim 1 wherein the means for actuating the gripping means to grip the thread is constructed'to actuate the gripping means into gripping relation to the thread only while the needle is at approximately its uppermost position and also is constructed to actuate the gripping means to release the thread when the needle is in said position.

22. The machine set forth in claim 1 with the addition of a positive auxiliary work advancing device ahead of said work feed mechanism operable in timed relation to said stitch forming mechanism to supply the work to the work feed mechanism at a predetermined rate and wherein said work feed mechanism is adjusted to slightly overfeed but move relatively to the work without feeding after the amount supplied by the auxiliary device has been fed, so as to ensure accurate spacing of the skipped stitches.

23. The machine set forth in claim 3 with the addition of a positive auxiliary work advancing deviceahead of said work feed mechanism operable in timed relation to said stitch forming mechanism to supply the work to the work feed mechanism at a predetermined rate, and wherein said work feed mechanism is adjusted to slightly overfeed but move relatively to the work without feeding after the amount supplied by the auxiliary device has been fed. so as to ensure accurate spacing of the skipped stitches.

25. The machine set forth in claim 6 with the addition of a positive auxiliary work advancing device ahead of said work feed mechanism operable in timed relation to said stitch forming mechanism to supply the work to the feed dog at a predetermined rate, and wherein said work feed mechanism is adjusted to slightly overfeed but move relatively to the work without feedin after the amount supplied by the auxiliary device has been fed, so as to ensure accurate spacing of the skipped stitches.

26. In a machine of the character described the combination with work feed mechanism and stitch forming mechanism including a reciproeating needle and a loop taker operable in timed relation for forcing a thread through a piece of work, forming a loop in the thread at one side of the work and interlocking another thread through said loop to normally-form a line of stitches, of means for gripping said thread at intervals, and means operating in timed relation to the gripping of said thread and the movement of the needle and said loop taker for moving said gripping means while the thread is gripped and in the same direction as the movement of said needle and exerting tension on the thread as the needle rises from work penetrating position and prior to the reaching of loop-taking relation between the loop taker and the needle thread to prevent interlocking of said threads.

27. The machine set forth in claim 26 wherein said gripping means and the means for moving said gripping means and exerting tension on the thread, are operated to maintain the grip on the thread as the needle rises and keep the thread substantially taut between the point of gripping and the needle to prevent entanglement of the surplus thread with the needle.

28. Thecombination with a sewing machine comprising work feeding mechanism, stitch forming mechanism including a needle and needle thread for forming a line of stitches, and means for causing slipping of stitches at intervals, of

means to grip the needle thread, and means for controlling. actuation of said gripping means automatically into gripping relation to said needle thread at intervals, and means to move said gripping means while the thread is so gripped to carry to a point above the needle the surplus thread'which is present as the result of the slipped stitches.

29. The combination with a sewing machine comprising work feeding mechanism, stitch forming mechanism. including a needle and needle thread for forming a line of stitches, and means for causing slipping of stitches at intervals, of means to grip the needle thread, and means for controlling actuation of said gripping means auto- 'matically into gripping relation to saidneedle thread at-intervals and to move to a point above the needle the surplus thread which is present as the result of the slipped stitches, said gripping means including -two relatively movable opposed Jaws to grip theneedle thread between them and pivotally mounted at one end to move together in approximately the plane of move-' ment of the needle.

30. In a machine of the character described the combination with work feed mechanism and stitch'forming mechanism including a reciprocating needle and a loop taker operable in timed relation for forcing a thread through a piece of work, forming a loop in the thread at one side of the work and interlocking another thread through said loop to normally form a line of stitches, of means operable in timed relation to the movement of the needle thread by said needle to automatically manipulate said thread at intervals during normal operation of the stitch forming mechanism and work feedmechanism in forming a stitch to prevent interlocking of said threads; 8, positive auxiliary work advancing device ahead of said' work feed mechanism operable in timed relation to said stitch forming mechanism to supply the work to the work feed mechanism at a predetermined rate, and said work feed mechanism being adjusted to slightly overfeed but move relatively to the work without feeding after the amount supplied by the auxiliary device has been fed, so as to ensure accurate spacing of the skipped stitches.

HERMAN ROSENMAN. LEO ROSEMAN.