US2381817A - Sewing apparatus - Google Patents

Description

Aug, 7,1945. P. GARDNER Erm.

SEWING APPARATUS Filed Sept. 15, 1941 2 Sheets-Sheet 1 W um. 1 L@ Q MMA NM ma IW Wu .K

Aug. 7, 1945. P. GARDNER x-:TAL n 2,381,817

SEWING APPARATUS Filed Sept. 15, 1941 2 Sheets-Sheet 2 W Z y VZ?. 5

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ze? I Patented Aug. 7, 1945 2,381,817 SEWING APPARATUS Percy Gardner, Glen Ridge, N. I.. and Balph Kagan, Brooklyn, N. Y.. auignors to Lever Bias Machine Corporation, New York, N. Y., a corporation of New York Application September 13, 1941, Serial No. 410,682

(Cl. Ilz-235) 7 Claims.

This invention relates to new and4v useful improvements in sewing apparatus and has particular reference to apparatus for sewing sheet material into tubular form preparatory to its being cut into bias sheets and then later cut into strips of bias-cut material for use in many trades and fashions. l

Although it was in connection with the preparation of bias-,cut material that this invention was developed, it is to be clearly understood, and it will become clearly apparent from a study of the matter to follow, that the use of thisinvention is notlimited to such a line of manufacture but can be l employed in almost any instance where material is to be fed past a sewing point and fastened there together.

The main object of the invention is to produce a simple, efficient and compact apparatus in and by which material can be sewedl or fastened together at much greater speed, more securely, and with a minimum of eifort on the part of the operator. e

A further object is to provide a sewingA apparatus in which the usual lower feed or clamping dog is entirely eliminated thus presenting a machine which will operate as emciently with much less complicated structure and number of parts, thereby reducing the cost of building.

Further and more specific objects, features, and advantages will more clearly appear from a consideration of the specification to follow, especiallywhen taken in connection with the annexed drawings which form part of the specitlcation and which illustrate a present preferred form which the invention may assume.

'I'he invention briefly and generally stated,

with respect to one aspect thereof, has to do with a presser foot which is provided with means which, at all times during the operation of the machine on the material, will alone contact the goods with varying pressure to maintain it in position to be sewed or fastened together.

A further feature of the invention has to do with the combination of the improved presser i'oot and a pull-away mechanism which exerts on the goods, during the operation of moving it past the fastening or sewing point, a steady pull to tend to move it at a constant speed through the machine and which constitutes the only means i'or pulling the material through the machine A further feature of the combination with the i new presser foot andthe pull away mechanism is a tensioning or compensating device disposed l stantly moved up and between the fastening or sewing point and the pull away mechanism so as to permit the pull away mechanism to continue its action while, at the instant of fastening or stitching of the materiel. the material is being firmly gripped and hc.d by the presser foot, thereby preventing tearing of the goods while allowing continuous operation of all the active elements of the machine.

More particularly the novel form of presser foot concerns an ordinary presser foot to the bottom of which is attached a plate or plates which, by some form of resilient means, is pressed constantly down against the goods beneath with a varying degree of pressure dependent upon the position of the presser foot which is vbeing condown by suitable means to be later described.

The apparatus as a combination may then be considered as comprising a pull-away mechanism, a tensioning or compensating device, a presser foot with vresiliently operated pressure plates, and a base plate over which the material moves and against which itis at all times pressed by the foot. The general operation may well be brietly described as follows:

Assuming that the needle is up and the presser foot is'also up at the top of its operative stroke, the pull-away mechanism is pulling the material through the device but the pressure plates are pressing against the goods, but not with enough pressure to stop the pull-away mechanism from causingl a movement of goods past the sewing point. The compensating. device is pressing against the -goods to keep a part of "it off the straight line from the sewing pointto the pullaway mechanism so as to hold a certain length of it in reserve for purposes which will become clear as the detailed description is later set forth. Now as the needle descends, .the presser foot also is timed to descend and thus presses the pressure plates much more firmly against the goods so that, as the needle passes through the material, the pressure on the goods is suillcient to hold it momentarily so that the stitch can be made and the needle withdrawn without tearing the goods.

Aline of the material to change allowing enough oi the tensioned goods to pass while the rest of the goods is being temporarily held at the sewing point. As soon asv the needle withdraws from the goods, then the presser foot rises somewhat and the pressure of the pressure plates is somewhat relieved so that the pull of the pull away device is again effective to allow tlze goods to pass through the sewing point again, although the pressure plates never, during the operation on the goods, entirely lose pressure contact with the gooc s, degree of pressure varies periodically during the operation.

In the impro'ved form of the machine, below the base plate over which the material passes, there is only the usual shuttle holding the lower thread to cooperate with that held by the needle. There is no lower clamping of feed dog. This novel construction thus reduces the l complexity of the mechanism and materially reduces the number of the parts required for effective oper-ation.

A present preferred form which the invention may assume is illustrated in the drawings, of which- Fig. 1 is a somewhat schematic side elevation of a portion of the apparatus showing the longitudinal relation of the pull-away mechanism, the compensating device, and the new form of presser foot together with several guide devices which are employed to guide the material effectively to the sewing or fastening point;

Fig. 2 is a side elevation of a portionof the new and improved presser foot showing the needle in the uppermost position;

Fig, 3 is a similar view in end elevation of the presser foot;

Fig. 4 is a vertical cross section taken on the line 4--4 of Fig. 3;

Fig. 5 is a horizontal cross section taken on the `line 5-5 of Fig. 2;

Fig. 6 is a horizontal cross section taken on the line 6-6 of Fig. 3;

Fig. 7 is an inverted plan view of the pressure plate shown in Fig. 6;

Fig, 8 is a vertical cross section taken on the line 8-8 of Fig. 5, showing the parts in the position of minimum pressure;

- Fig. 9 is a similar view showing the parts in the position of maximum pressure;

Fig. 10 is a side elevation of a portion of a modified form of presser foot with a single pressure plate attached;

Fig. 11 is a plan view of the parts shown in Fig. 10; and

Fig. 12 is a cross section through a still further modified form rof presser foot.

The form of the invention shown in the drawings is one which has been developed through trial and tests as the present form preferred to achieve the results intended. Figure 1 somewhat .diagrammatically shows. the .general layout of the various elements of the improved machine and is somewhat similar to a lay-out shown in our copending application Serial Number 384,224, entitled Apparatus for forming tubular material, filed March 19, 1941. The vfigure shows the material A being unwound from a roll (not shown) in flat sheet form over guiding rollers 20 on a suitable support 2| and then through guide members 22 and 23 over the bed 24 of a sewing device, which, however, maybe a fastening device other than a sewing machine. The sewed or fastened material now in tubular form passes from the bed 24 to a pull away device indicated generally by the although, as above described, the.

' tened together and the form shown is the form preferred, namely, a sewing device, although it y is to be understood that the action later described number 25 which is generally and basicallysimilar to the one shown in the above-mentioned application. 'I'he pull'away device 25 is designed to exert on the material a steady even pull and constitutes the only means in the entire apparatus is such that other means of fastening the material than sewing maybe employed. The sewing device comprises a sewing head 28, provided with a vertically reciprocable presser foot rod 29 on which is a stud 30 engaged by the end of an arm 3i, said arm 3| being adapted in any suitable manner (not shown) to be oscillated by a suitable means during theA operation of the machine so as to raise and lower the rod 29. A spring 32 connected to the rod 23 tends to move it downwardly at all times. The head also supports the usual reciprocable needle 33 driven in the usual manner to move to and from the material.

On the lower end of the rod 29 lis a presser foot having a main body portion 34. Since this' main body portion 34 is fastened to the lower end of the rod 29 it rapidly rises and falls with said rod vand therefore its distance from the goods varies during the operation of sewing the material. Disposed below this main body portion 34 is a pressure means which, regardless ofthe position of the portion 34, will always maintain at least a certain minimum contact pressure with the material. This variable contact pressure is greatest at the time the needle is passing through the goods and least when the needle is at the highest point of its stroke. although it is always sufficient to maintain control of the material and prevent it from moving under the foot unless pulled by the pull-away device. In other words,` the material under the foot is at all times under the control of the foot. When the sewing is actually taking place, the foot holds the goods so firmly that the pull-away device itself could not move it but when the sewing is not actually taking place then the presser foot device still holds the goods but with lesser pressure so that the pull-away device can pull the goods past the sewing point.

The `preferred form of the means above mentioned which has been adopted is an auxiliary plate -35 which is disposed directly beneath the main body portion 34 and lies on the goods. This auxiliary plate may also be of one or two pieces as shown in Figures l1 and 6 respectively. The contact means is preferably not directly connected to the main body portion 34Abut is provided with pins 36 which extend up through holes 3l in the portion 34. Springs 38 surround the pins 36 between the portion 34 and plate 35 and tend to push the lower plate away from the main body portion 34 at alltimes. In the modified form ofthe plates shown in Fig. 12, the push away force is provided by weights 39 on the tops of the pins 36 instead of the springs 38. The two forms of plates employed are merely indicative of the fact that the kind of'plates used is dependent upon the kind of sewing or fastening which is being done as well as the kind of stitch and also on the kind of material being treated.

.A general description of the operation will turn i the attention particularly to Figures 2 and 4, the

the needle is at the top of its stroke, and the other of which shows the parts in position when the needle'is at the bottom of the stroke. When the needle is as shown in Fig. 2, the main body portion 34 is moved up against the action oi.' the spring 32 by means of the cam-operated arm Il and is at its highest point or distance away from the lower plate' il which is stili being pressed against the goods by means of the springs 8l. It willbe clear that in this position the springs Il are not under much compression and therefore are pressing the plate ll as lightly as possible upon the goods but sumciently to maintain control on the goods. At this point, then, in the operation, the pull-away device 2l is able to advance the kgoods past the sewing or fastening Point.

As the needle 4starts down on its travel to the goods the main body portion u also starts down and therefore slowly increases the compression of thesprings 3l and approaches the plate 35. The

portion v3l is allowed to do this by the lowering of arm 3| andthe downward pressure of the spring I2. As the needle starts throughthe'goods the portion 84 'is all the way down and pressing fiat on top of the lower plate 3l and the spring l2 is exerting its full pressure to hold the two 'plates together. This pressure is suillcient upon the goods to overcome the pulling tendency of the j pull-away means 2i and the goods consequently f .stands still for an instant. If this were not al- .lowed for, the goods between the sewing point 1 and the pull-away device would be subjected to an abnormalstrain. but this is where the compensating device comes into play.' As the goods at the sewing point stops moving for van instant, the pull on the -material causes the compensating device 20 to start being pulled down so'that the off-side relation of the goods along the sewing line vis changed toward a directline relation and the compensating device thus gives the pull-away device a little of the material which it has thus far been holding Aoff-side. This allows the goods =between the vsewingpoint and the pull-away to move while at the same` time vthe goods right at the `sewing point are beelng held for an instant stationary. Therefore undue and abnormal strains on the goods lare avoided. As soon as the needle 'startsupagain the rod 2l also starts up` slowly" releasing the compression on the springs i Il so that,r as the needle comes out of the goods,

the compressionl has -been reduced a suillcient j amount 'so-'that the contactpressure of the plate Aall von thejgoc'da-while holding the goods under r.:;{cnntrol,will 'permit the pull-away device -to advance them forward a lpredetermined distance.v

This. 'ycleof 'operations :is ofcourse repeated at high speed and the goods 'hasv been delivered to 'the sewingpoint' smoothly and under perfect con.. trol andeven vtension and has been drawn away l Vi'ro'msaid pointy' under equally smooth and even' tension.v

It may be notedv thai'nounng `has been sala thus :far ofa feed dogbelowthe-bed '24 for the vsimple reason that in this machine thereis no -such device. 'The only element, below the bed 24 is thev usualshuttle containing the usual lower thread to cooperate with the one carried in the usual manner by the' needle. As far as we know, -this'is the rst device" in which'material can be fastened .or sewed together at high speed andv under perfect :controlg as demonstrated many times in actual practice, without the use of a lower dog'wliichnot only does not'feed the material but also does noteven momentarily clampsewing point for minutes at a time. While the invention has been described in detail herein asto a preferred form, it is to be clearly understood that many changes and moditlcations may be made in the construction without departing from the spirit and scope of the invention set forth, and it is not intended therefore to limit the invention to the particular form shown but only in so far as it may be limited by the scope of any one or more of the appended claims.

We claim:

1. lIn a sewing machine having a sewing point and a reciprocatory needle at the sewing point and without a lower feed dog, the combination of means spaced apart from the sewing point and providing a continuous pull on the material tend 40 material.

2. In a sewing machine havinga sewing point f' and a reciprocatory needlev at the sewing point and without a lower feed dog, the combination of means spaced apart from the sewing point and providing a continuous pull on the material tending to pull it past the sewing point, means to reciprocate saidv needle in synchronism with the speed of the pulling'means, a presser foot adjacent the needle and having a main body portion, means to reciprocate the main body portion toward and away from the material being sewn in cyclical relation to the movement of the needle. aV plate disposed below and supported from the main body portion of the presser foot and engaging the material at all times, and means for causing the plate tov press upon the material with a pressure varying in accordance with the position of the main body portion with respect to the material.

v means spaced apart from the sewing point and providing a continuous pull on thematerlaltenli-vv v ing to pull it past the sewing point, means to re'- ciprocate said needle in synchronism with thev speed of the pulling means, a presser foot adiacent the needle and having a main body'portion, means to reciprocate the' main body portion toward and away from the 4material being sewn in cyclical relation to the movement of theneedie, a plate disposed below and supported from the main body portion of the presser foot and engaging the lmaterial at all times, and resilient means disposed in association with the main body portion and the lower plate and tending always to move the plate away from the main body portion and to press it against the material, said speed of the pulling means,`a presser foot adjacent the needle and having a main body portion, means to reciprocate the main body portion toward and away from the material being sewn in cyclical relation to the movement of the needle, means on the presser foot and engaging the material at all times with a varying pressure depending upon the position of the main body portion of the presser foot with respect to the material, and resilient means between the sewing point and the pulling means and engaging the sewn seam to divert the seam at the engaged point from the direct line fromy the sewing point to the pulling means.

5. In a sewing machine having a sewing point and a reciprocatory needle at the sewing point and without a lower feed dog, the combination of means spaced apart from the sewing point and providing a continuous pull on the material tending to pull it past the sewing point, means to reciprocate said needle in synchronism with the speed of the pulling means, a presser foot adjacent the needle and having a main body portion, means to reciprocate the main body portion toward and away from the material being sewn in cyclical relation to the movement of the needle, a plate disposed below and supported from the main body portion of the presser foot and engaging the material at all times, and means for causing the plate to press upon the 'material with a varying pressure in accordance with the position of the main body portion with respect to the material, and resilient means between the sewing point and the pulling means and engaging the sewn seam to divert the seam at the engaged point from the direct line from the sewing point.

to the pulling means.

6. In a sewing machine having a sewing point and reclprocatory needle at the. sewing point and without a lower feed dog, thev combination of means spaced apart from the sewing point and providing a continuous pull on the material' tending to pull it past the sewing point, means to reciprocate said needle in synchronism with the speed of the pulling means, a presser foot adjacent the needle and having a main body portion, means to reciprocate the main body portion toward and away from the material being sewn in cyclical relation to the movement of the needle, a plate disposed 4below and supported from the main `body portion of the presser foot and engaging the material at all times, and resilient means disposed in association with the main body portion and the lower plaie and tending always to move the plate away from the main body portion and to press it against the material, said pressure varying in accordance with the position of the main body portion with respect to the material, and resilient means between the sewing point and the pulling means and engaging the seam to divert the seam at the engaged point from the di- Vrect line from the sewing point to the pulling means.

'1. In a sewing machine having a sewing point and a reciprocatory needle at the sewing point and without a lower feed dog, the combination of means spaced apart from the sewing point and providing a continuous pull on the material tending to pull it past the sewing point, means to reciprocate said needle in synchronism with the speed of the pulling means, a presser foot adiacent the needle and having a main body portion, means to reciprocate the main body portion toward and away from the material being sewn in cyclical relation to the movement of the needle, means on the presser foot and engaging the materialat all times with a varying pressure depending upon the position of the main body portion of the presser foot with respect to the material, and yielding means between the sewing point and the pulling means and engaging the material to divert the material from the direct line from the sewing point to the pullinggmeans.

PERCY GARDNER. RALPH KAGAN.

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