US2308910A - Sewing machine - Google Patents

Description

V. BGTTGER SEWING MACHINE Jan. 19, 1943.

Filed July 18, 1939 2 Sheets-Sheet 1 Fig. 1

VE TOR 'TORN v. BGTTGER SEWING MACHINE Jan. 19, 1943.

Filed July 18, 1939 2 Sheets-Sheet 2 Fig.3

aws x R n 9 O .MN w I T 1H. m am 9 v T .m N T u A I m n E m m 2 M '1 \\\4 5 Z W t 3 aw 5 U M 2 a g II I I v z m .w Ch 6 Patented Jan. 19, 1943 SEWING MACHINE Very Biittger, Stollberg i. E., Germany; vested in the Alien Property Custodian Application July 18, 1939, Serial No. 285,127

Germany July 19, 1938' 3 Claims.

This invention relates to a whipstitch sewing machine equipped with feed cylinders and a yieldable guide member for the material.

In the known kinds of whipstitch machines the material (hereinafter the word material will be used to refer to any cloth, fabric, or the like being stitched) is, as a rule, guided and fed by two vertical cylinders which at the point where they perform this function have fluted edges and are yieldably pressed together. The material is thus vertically guided and sewn, and the seam is formed at the point of contact of the two cylinders and preferably in such manner that the point at which the needle pierces the material lies slightly, approximately 1 mm., in front of the theoretical touching point of the two cylinders, the material being guided so that it projects somewhat beyond the top edge of the feed cylinders.

A single thread seam is formed by a threadcarrying needle and looper members which lift the loop away from the edge of the seam and place it before the needle prior to the next piercing operation of the latter. In case of two or three thread seams one or more loopers are provided which pass their loops through the loop of the needle and at the next stitch offer a looper thread to the needle.

The feed cylinders carry out a step-by=step rotary motion and stand still while the needle pierces the material. During the time required by the needle to withdraw from the material prior to performing the next stitch the cylinders are turned so that the needle can pierce the material advanced the length of a stitch.

The known types of whipstitch sewing machines fitted with feed cylinders are used particularly for sewing together stockings made on Cotton machines, though they have also been successfully employed for sewing gloves made from fabric or leather cuttings. The position of the piercing point of the needle in such machines has been particularly mentioned above for the reason that it is an important part of the invention.

It is an object of this invention to provide a guide member arranged to press the material into engagement with the peripheral surface of one of the cylinders in front of the point of contact of the two cylinders, and to arrange the needle to reciprocate and pierce the material in front of the said point of contact and near the place where the material is pressed against the said peripheral surface.

In the known machines of this class in which the needle pierces the material at the point of contact of the feed cylinders the latter not only advance the material but also hold it while the seam is being formed to prevent it from being drawn out upwardly during the piercing operation of the needle and the tightening of the loops. If the material were not held in position, it would gradually travel higher and higher, thereby preventing the production of a narrow overcast seam.

According to the invention, the function of the feed cylinders is restricted to advancing the material in horizontal direction, which is held during the formation of the seam by a new guide member arranged in front of the point of contact oi. the cylinders and so constructed that pulling up and tearing of the material are prevented. The feed cylinders cannot prevent this, as they must be fluted in the direction of the pull of the work, i. e.. of their axes, to enable them to perform their main function of horizontally feeding the material. Furthermore, when the needle is arranged in the usual manner above the point of contact of the feed. cylinders, it moves on or shortly before a plane passing through the two cylinder axes and thus reciprocates above the center of the two cylinder surfaces. If the feed cylinders are arranged so as to be supported by shafts coming from. below, their surfaces will be unobstructed and the needle as well as the looper members moving above the cylinders will not be impeded. It has been found, however, that sewing, particularly in case of stockings, can be considerably facilitated by employing suspended cylinders affording a free space underneath, whereas in the known constructions the cylinder shafts are in the way of the reciprocating needle. The provision of a guide member according to the invention permits to and fro motion of the needle above the cylinders on a straight line lying in front of the plane passing through the two cylinder axes to such an extent that the reciprocating needle as well as the bar carrying it are not impeded by the shafts of the two cylinders.

The use of suspended cylinders insures therefore greater security in forming the seam.

The guide member according to the invention can be made in various ways, one form thereof being illustrated by way of example in the accompanying drawings, in which Figure l is a view of a whipstitch sewing machine fitted with suspended cylinders, seen obliquely from above and from the side;

Fig. 2 is a plan view, with parts removed, of the machine shown in Fig. 1;

Fig. 3 is a side view of the guide shown in Figs. 1 and 2: and

Figs. 4 and 5 are perspective and sectional views. respectively, on an enlarged scale. of the adjustable connection for the guide of Figs. 1 to 8.

Before the features of the invention are explained in detail. the machine shown in Fig. 1 will be described. a machine equipped with suspended cylinders being chosen because such a machine brings out all the advantages afforded by the invention. whereas a machine with vertical cylinders supported from below shows only some of them.

The machine shown in Fig. 1 comprises a casing I of which only the front portion is indicated and which contains all the driving parts for the sewing elements and the cylinders. The feed cylinders l and 2 are suspended. the cylinder i being in the rear and the cylinder 2 in front. and are, respectively, mounted upon the rigid shafts I, 52 which secure them in fixed positions with respect to each other and are arranged in the upper portion of the casing 9. The shaft ii is gradually rotated by means of a friction-pawl gear partly visible at 52 in Fig. 1, the upper portion 80 of the casing 0 being cut open for this purpose. The rotation of the shaft II and cylinder I is transmitted to the cylinder 2 and shaft l2 by a toothedwheel ll secured to the upper end of the shaft Ii and engaging a toothed wheel I on the shaft 82. The shaft 52 is mounted in a bearing 51 which may be adjustably positioned in the casing I. thereby permitting shaft '2 to be moved relatively to the shaft II and the clearance between the cylinders l and 2 varied accordingly. A spring. not shown, keeps the bearing ll tensioned to bring the cylinder I into contact with the cylinder 2, and the material 32 passing between the cylinders i. 2 is thus securely conveyed in horizontal direction. The sewing members comprise the needle 2 and the loopers I, O. The machine shown serves for producing a three thread seam.

Figs. 2 and 3 show one form of a guide member according to the invention. The two feed cylinders I. 2 contact on the connecting plane .e--:: of their vertical central axes m. m at y (hereinafter referred to as the point of contact of the cylinders"). The reciprocating needle 8 pierces the material at z, and just below the point z a small guide plate 4c presses the material 58 into engagement with the fluted feed ed e of the front cylinder 2. thereby causing the cylinder to feed the material to the point where the needle pierces the material. This preliminary feed at this point is effective only at the beginning of the seam, and as soon as sewing has proceeded far enough to bring the first part of the material II to the point of contact 11 of the cylinders, feeding is performed by both cylinders I. 2.

Yleldable pressing engagement of the guide plate 4c with the material can be effected in various ways. In the construction shown an arm Ii firmly connected with the plate to and disposed below the rear cylinder i is articulated to a member l2 pivotally mounted on the machine casing and acted upon by a spiral spring I! which presses the guide plate 4c against the front cylinder 2 by means of the members II. II. The members Ii and i2 have a common joint II which is secured in a rigid position by the bolt ll. By loosening the nut II. the position of thearm ll relativelytothatofthearm l2 canbeadjustedinaplanetransversetothe axis of the bolt Ii. After each adjustment. the nut H is. of course. tightened again to press the parts of the joint firmly together. The split or her! in the end of the arm ii adjacent the common joint renders the bifurcated end of the arm yleldable so that the parts thereof at each side of the end of the arm II will yield sufllciently under the pressure exerted by the tightening of the nut II to cause the end of the arm l2 to beflrmlygrippedandthepartsheldinthead justed position. Instead of having the guide plate to act against the front cylinder 2 it may be arranged so as to act against the rear cylinder I, though the first alternative is preferable as it insures the introduction of the material toward the operator and therefore greater convenience.

I claim:

1. A whipstitch sewing machine which comprises at least two feed cylinders each of which is mounted upon a vertically disposed shaft. the two cylinders being in operative contact where the material to be stitched is fed therebetween. a sewing needle for piercing the material located to one side of the contact point. loopers arranged to cooperate with the needle in forming a seam. a guide member mounted for pressing the material against one of the cylinders near the place where the needle pierces the material, resilient mans for forcing the guide member yieldingly against the material pressing it against the cylinder.

2. A whipstitch sewing machine which com prises two vertically disposed feed cylinders the fluted feed surfaces of which are in operative contact at one point with the material to be stitched. a sewing needle mounted to pierce the material to one side of the point of contact. a guide member arranged near the needle and pressing the material into engagement with one of the cylinders, and resilient means yieldingly.

forcing the guide member against the material. the needle being arranged to stitch the material while it is pressed by the guide member against the cylinder and before it reaches the contact point.

3. A whipstitch sewing machine which comprises two feed cylinders the exterior surfaces of which are disposed in upright positions, the two cylinders being arranged to have an operative point of contact where material to be stitched is fed between the cylinders. means on at least one of the said cylinders to grip the material causing it to be drawn between the eviinders. a guide member located ahead of the point of contact of the cylinders for pressing the material against one of the cylinders, resilient means for pressing the guide member yieldingly against the material. and a sewing needle arranged in front of the contact point and to pierce the material where it is pressed 'against one of the cylinders by the guide member.

VERY BO'I'I'GER.

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