US3310014A - Sewing machine - Google Patents

Description

, 1967 A. G. TUCCI SEWING MACHINE March 21 2 Sheets-Sheet 1 Filed March 9, 1964 INVENTOR ATTORN EY March 21, 1967 A. G. TUCCI SEWING MACHINE 2 Sheets-Sheet 2 Filed March 9, 1964 INVENTOR Anthony G. Tucci United States Patent 0 3,310,014 SEWING MACHINE Anthony G. Tucci, 96-02 103rd Ave., Ozone Park, N.Y. 11417 Filed Mar. 9, 1964, Ser. No. 350,224 4 Claims. ((11. 112-212) This invention relates to an improved type of sewing machine. In particular, this invention relates to a sewing machine having a belt feed and especially adapted for continuous sewing of seams of indefinite length or of a series of workpieces in continuous production of garments and the like.

Many varieties and modifications of sewing machines have been suggested for various purposes, including special machines for sewing particular kinds of seams, offarrn machines for making tubular pieces such as sleeves and the like and a host of double-needle and curved-needle machines, each designed for a particular specialized purpose.

In all of the above machines, there has necessarily been provided some means for transporting the workpiece through the sewing area at controlled speed. It is important that the speed of the workpiece be kept uniform, because otherwise the stitch length is not constant, the stitches being longer when the workpiece is moving rapidly and shorter when the workpiece is moving more slowly. The usual form of controlled-speed advancing mechanism is a serrated mover which operates through the sole plate adjacent the point where the needle passes through the workpiece and through the sole plate. By means of a complicated system of cams, or of levers and cranks, the mover is caused to rise up through the sole plate, contact the workpiece, and advance it by the desired length of one stitch during the interval when the needle is up and away from the workpiece, and to recede below the sole plate and leave the workpiece stationary during the interval when the needle is down and projecting through the workpiece in the process of form-ing a stitch. This intermittent motion has been deemed necessary because it was thought that, were the workpiece to advance while the needle is projecting through it, it would exert a transverse pressure on the needle which would either distort the material or break the needle.

In the attempt to overcome certain di sadvantages of the conventional sewing machine with the four-motion feed dog or mover, a number of alternative feed means have been proposed. To overcome the undesirable repeated pounding of the fabric by the four-motion feed, it has been proposed to substitute therefor an intermittently-moving chain belt having serrated links, which links remain in continuous contact with the workpiece, but move forward only during that part of the cycle when the needle is not projecting through the workpiece. In another type of machine that has been proposed, the fourmotion feed has been omitted and replaced by a pair of belts which remain in contact with the workpiece and carry it forward under the presser foot, the belts being in edge-to-edge contact with each other throughout most of their run, and being transversely displaced in the sewing zone to provide a space between them for the passage of the needle. The intermittent character of the advancement in this type of device can be provided for either by driving the belts intermittently, or by driving the belts continuously using a drive with sufficient flexibility so that the resistance of the needle while it projects through the workpiece is sufficient to momentarily halt the advance.

In any sewing operation, aside from some purely decorative stitching operations, there are involved at least two layers of cloth, one atop the other. In all of the above types of sewing machine, the advance has operated to adice vance the bottom layer only, and there has been a definite tendency for the upper layer or layers to lag behind the bottom one, particularly at the point where the work is forced to enter the constricted zone under the curved presser foot. Manual control by the operator, assisted to some extent by the frictional engagement between the layers, has been depended upon to keep the upper layer or layers from lagging behind the bottom one and thus distorting the finished product. The degree of effectiveness of such manual control depended naturally, upon the skill of the operator.

In certain other types of machine, particularly those designed for sewing through multiple layers of heavy material such as denim, canvas and the like, this disadvantage has been partially overcome by providing gripping means in the form of mating rollers or the like, to grasp that portion of the work that has already been sewn, and exert a tension on it in order to assist the advance of the remainder of the piece through the sewing zone. This is a useful expedient as regards the type of operation to which it is adaptable. It is obviously unsuitable, however, for short workpieces or those made of material that will not withstand the tension without being distorted or torn.

Still another arrangement that has been proposed for certain specialized machines is to support the workpiece (for example the top of a bag or the like) vertically between a pair of facing belts, in such a way the portion to be sewn projects above the top edges of the belts where it can be sewn by a horizontal needle. Arrangements of this type, however, are suitable only for such specialpurpose machines, and cannot be readily adapted to the conventional general-purpose type of machine used in most sewing operations.

An object of this invention therefore, is to provide an improved sewing machine.

Another object is to provide a sewing machine having a novel and improved work-advancing mechanism.

Still another object is to provide a sewing machine having an advance mechanism which overcomes the tendency for one or more layers of material to lag behind the driven layer.

A further object is to provide such a machine, which is useful as applied to short workpieces and to materials that cannot be tensioned.

Yet another object is to provide a sewing machine which does not depend on the skill of the operator to ensure that all layers of the work being sewn advance at an identical rate.

An additional and important object is to provide an advance mechanism to accomplish the above objects, which can readily be incorporated into new and existing sewing machines of conventional general-purpose design. Other objects and advantages will become apparent from the following more complete description and claims.

A feature of the present invention is the use of a belt to advance the workpiece through the sewing zone.

Another feature is the use of bearing means such as a presser foot to urge the belt toward the underlying supporting surface.

Another and particularly desirable feature is the provision of control means for lifting the bearing means and the belt simultaneously away from the supporting surface.

A feature of an especially preferred embodiment of this invention is the use of a pair of belts arranged to advance in parallel fashion, one on either side of the needle.

In one particularly desirable aspect, this invention contemplates a sewing machine comprising in combination a supporting surface, said surface being perforated by a needle hole, a needle perforated near the pointed end thereof, reciprocating means for causing said pointed end to pass intermittently through said needle hole, said reciprocating means being located at a generally fixed point relative to said supporting surface and connected to said needle near the end opposite the pointed end thereof, thread-supply means for supplying thread to said perforation in said needle, thread-catching means for catching thread from said needle and forming a stitch thereof, said thread-catching means being located adjacent said needle hole and on the side of said surface opposite said reciproeating means, an endless belt located entirely on one side of said surface, a portion of said belt being positioned to traverse a portion of said surface adjacent said needle hole, bearing means for urging said belt toward said surface, drive means for causing longitudinal motion of said belt and control means for lifting said bearing means and said traversing portion of said belt simultaneously away from said surface.

Referring now to the figures:

FIGURE 1 is a perspective view of a sewing machine according to the present invention.

FIGURE 2 is a perspective view similar to FIGURE 1, showing another and preferred embodiment of the sewing machine of this invention.

FIGURE 3 is a perspective view of the machine of FIGURE 2, showing the bearing means and the belt in the raised position.

As shown in the drawings, the sewing machine of the present invention is conventional in many respects, differing from the conventional sewing machine primarily in the provision of advancing means in the form of an endless belt 17 located so that a portion of its traverses the table at a point close to the needle hole, that is to say in the zone where the actual sewing takes place. The belt is supported by rollers 12, 13, 14-, 15 and the machine is also provided with a fifth roller 16, which compresses belt 17 against roller 12. At least one of rolls 12 and 16 is a drive roll, actuated by any suitable power takeoff such as a flexible cable 22 connected to the motor of the sewing machine. The function of the drive roll is to drive the belt in the direction indicated 'by the arrow. All five rollers, as well as presser foot 18, are mounted on a common vertical bar 11. Bar 11 corresponds to the vertical bar on which the presser foot is mounted in the conventional sewing machine, but differs in that it is extended upwardly through the top of the sewing head and terminates in a spider which supports rollers 12, 13 and 16. At its lower end, in addition to the presser foot, bar 11 is connected to a spider which forms the mounting means for rolls 14 and 15. Bar 11, with the presser foot, spiders and rollers, can be raised as a unit, by operation of control lever 21. When the assembly is in the lower position illusrtated in FIG. 1, belt 17 is held in contact with the underlying surface by presser foot 18, and as it travels, it advances through the sewing zone any workpiece that happens to be there.

The conventional four-motion feed dog (not shown) may be used, if desired, together with belt 17. The use of both types of advance simultaneously is sometimes advantageous, for particular purposes, as for example for shirring, which is readily accomplished by adjusting the belt to run faster than the four-motion advance, so that the 'belt advances the upper layer of fabric faster than the four-motion advance (operating upwardly from below) advances the lower layer. For ordinary sewing, however, the conventional four-motion feed may be dispensed with and removed altogether. The belt is in frictional engagement with the upper fabric layer, and the upper layer is in frictional engagement with the upper surface of the lower fabric layer, whereas the bottom of the lower layer is in contact only with the smooth and essentially frictionless surface of the table, so that in the normal case, both layers go through the sewing zone together at the same speed.

The needle is held in a conventional needle mount 19,

reciprocated toward and away from the needle hole by a conventional reciprocating mechanism (not shown). Thread is supplied to the needle by a conventional thread supply as indicated generally at 20. Stitches are formed from this thread and if desired other thread supplied from a conventional bobbin, through the agency of a conventional thread catching means such as a chain-stitch hook or a lock-stitch hook and bobbin, located under the table adjacent, the needle hole. The thread-catching means is not shown in the figures.

To equalize the forces advancing the workpiece through the sewing zone, it is particularly advantageous to use the type of apparatus illustrated in FIG. 2, which is provided with two belts, rather than the single belt illustrated in FIG. 1, for example. In the conventional sewing machine, the serrated feed dog contacts the underside of the workpiece only on one side of the needle (usually the right side, as seen by the operator). It is then up to the operator to push the left side of the workpiece through the sewing region with his fingers at substantially the same speed as the same is being advanced from the right by the feed dog. Failure of the operator to match the speed of the feed dog results in a seam which is not straight, but curved to the left or the right, depending on whether the operators manual advance is faster or slower than that of the feed dog. This is, of course desirable and necessary in some operations, where the seam is required to be curved. Where a straight seam is required, however, it can be achieved more easily and accurately by using the apparatus of FIG. 2, which is provided with two belts, one on either side of the needle. Both belts are stretched over the same set of rollers, and share a common drive, so that they travel at the same speed, and advance both sides of the workpiece at the same rate, thus assuring a straight seam. Should it be desired to sew a curved seam, it is a simple matter to slip off one of the belts (ordinarily the lefthand one) and operate the machine in the same manner as a conventional sewing machine. In the apparatus as shown in FIG. 2, it Will be observed that the belts run parallel and slightly spaced apart throughout their respective lengths. It is important that the belts be parallel at least fro-m the point at which they first contact the workpiece until after the workpiece is sewn; otherwise, there is a tendency for the work to be slewed from side to side as the belts converge or diverge, thereby produc ing a crooked seam. The unique construction of the sewing machine of this invention, particularly the use of an assembly in which the belt or belts are entirely on one side of the sewing table, and mounted on a common bar with the presser foot, provides certain distinct advantages. The spatial relationships between the belt or belts and the presser foot are undisturbed by variations in the thickness of the workpiece, and are not altered by raising 0r lowering of the presser foot. Rather, the belts and the presser foot are mounted on a common mount, and operated by a common control, so that the whole assembly of presser foot, rolls and belts can be manipulated by a single operation of one control, resulting in appreciable saving in time and motion.

In sewing operations generally, it is important that the material surrounding the point where the needle is to penetrate be well supported from the side opposite the needle. If this is not done, there is a tendency for the needle to push the material ahead of it rather than penetrating. This results in the material being stuffed, to some degree, into the hole provided in the backing surface for penetration of the needle, and tremendously increases the friction on the system, resulting in frequent breakage of needles and overheating so severe that the needle becomes hot enough to burn up the thread. In the conventional sewing machine, this support is provided by the flat sole plate which underlies a considerable area surrounding the needle hole, and the presser foot which ensures good contact of the surrounding material with the sole plate. In some of the machines that have been proposed as improvements over the conventional machine, the construction has been such that adequate support was not provided for the material in the material in the area surrounding the needle hole. In the apparatus according to the present invention, adequate support is assured by a substantial flat area (the sole plate) surrounding the needle hole, said fiat area being firm and solid, and uninterrupted by channels, belts or the like. Moreover, a substantial area of the workpiece in the neighborhood of the needle hole is in frictional engagement with the belt above it, which militates against any tendency for material of the workpiece to be drawn sideways and stuffed by the needle into the needle hole.

Conventional attachments, such as hemmers, folders and the like may be used in conjunction with the sewing machine of this invention in substantially the same manner as with conventional sewing machines.

Surprisingly, it has been found that it is not necessary to provide for intermittent motion of the belt, synchronized with the movement of the needle. Provided the stitches are kept small, there is sufiicient flexibility provided by the needle, which can flex slightly, and by the fabric, which can undergo momentary minute distortions without damage, so that the belt and the workpiece with it can be allowed to continue traveling forward, even during that part of the cycle when the needle is projecting through the workpiece and into the needle hole. The size of the stitch is a function of the relationship between linear belt speed and needle speed in terms of cycles per second. The belt can be successfully permitted to travel continuously when this relationship is such as to produce a stitch as long as inch or, in some cases, even longer.

While this invention has been described in terms of certain preferred embodiments and illustrated by way of certain drawings, these are illustrative only, as many alternatives and equivalents will readily occur to those skilled in the art, without departing from the spirit and scope of the invention. The invention is therefore not to be construed as limited, except as set forth in the appended claims.

What is claimed is:

1. A sewing machine comprising in combination a presser foot, a supporting surface, said surface being perforated by a needle hole, an endless belt located entirely on one side of said surface, a portion of said belt being positioned to traverse a portion of said surface adjacent said needle hole, said presser foot urging said 6 belt toward said surface, drive means for causing longitudinal motion of said belt, and control means for lifting said presser foot and said traversing portion of said belt simultaneously away from said surface.

2. A sewing machine comprising in combination a presser foot, a supporting surface, said surface being perforated by a needle hole, a pair of endless belts located entirely on one side of said surface, said belts being positioned to traverse said surface in spaced parallel paths one on each side of said needle hole, said presser foot for urging said belts toward said surface, drive means for causing longitudinal motion of said belts, and control means for lifting said presser foot and said belts simultaneously away from said surface.

3. A sewing machine comprising in combination a presser foot, a supporting surface, said surface being perforated by a needle hole, an endless belt positioned to traverse a portion of said surface adjacent said needle hole, said presser foot urging said belt toward said surface, drive means for causing longitudinal motion of said belt, and control means for lifting said presser foot and said belt simultaneously away from said surface.

4. A sewing machine comprising in combination a supporting surface, said surface being perforated by a needle hole, an endless belt positioned to traverse a portion of said surface adjacent said needle hole, drive means for causing longitudinal motion of said belt, a mounting bar, a presser foot mounted on said mounting bar urging isaid belt toward said surface, a plurality of rollers mounted on said mounting bar, said belt being stretched over said rollers, and control means for moving said mounting bar away from said surface, thereby simultaneously moving said presser foot, said rollers and said belt away from said surface.

References Cited by the Examiner UNITED STATES PATENTS 2,106,517 1/1938 Christensen et al. 112-212 2,106,536 1/1938 Rubel et al 112212 2,241,230 5/1941 Wilmoth 112-212 2,809,599 10/1957 tBeeren 1122 2,885,979 5/1959 Perkins 112-2 3,219,002 11/1965 Levy 112-214 X FOREIGN PATENTS 1,068,536 11/1959 Germany.

JORDAN FRANKLIN, Primary Examiner.

RICHARD J. SCANLAN, JR., Examiner.

Claims (1)

1. A SEWING MACHINE COMPRISING IN COMBINATION A PRESSER FOOT, A SUPPORTING SURFACE, SAID SURFACE BEING PERFORATED BY A NEEDLE HOLE, AN ENDLESS BELT LOCATED ENTIRELY ON ONE SIDE OF SAID SURFACE, A PORTION OF SAID BELT BEING POSITIONED TO TRAVERSE A PORTION OF SAID SURFACE ADJACENT SAID NEEDLE HOLE, SAID PRESSER FOOT URGING SAID BELT TOWARD SAID SURFACE, DRIVE MEANS FOR CAUSING LONGITUDINAL MOTION OF SAID BELT, AND CONTROL MEANS FOR LIFTING SAID PRESSER FOOT AND SAID TRAVERSING PORTION OF SAID BELT SIMULTANEOUSLY AWAY FROM SAID SURFACE.

Images