Abstract: A separate pair of tensioning elements for the needle thread and for the looper thread in sewing machines adapted to form seams of stitches on a succession of workpieces which are advanced in the direction of sewing by a main transport device and an auxiliary transport device disposed in spaced relation to the latter. A sensing device and control device is operatively associated with the tensioning elements and tension is caused to be applied by each pair of elements on their respective thread when a workpiece is present in the main transport device. Upon advance of the workpiece to a point where its advance is effected solely by the auxiliary transport device, the tension imposed by one of each pair of elements is automatically released.

Abstract: The tension of the sewing machine's upper thread is varied automatically, in a variety of ways not requiring conscious participation on the part of the user of the machine. When one of a set of selectable stitch-patterns is selected by the user, an appropriate thread-tension value is automatically established, although the user retains the ability to adjust the automatically established tension value if he wishes. When the user swings the presser-foot lever of the machine up, to raise the cloth presser foot up from the cloth, e.g., for basting work, the thread tension is automatically lowered to a predetermined value suitable for basting, although still adjustable by the user if he thinks necessary. Where a stitch-pattern is implemented using an addressable ROM, tension command data for each stitch of the stitch-pattern may be stored in the ROM, for variation of thread tension from constituent stitch of the pattern to the next.

Abstract: Disclosed is a lightweight, inexpensive toy electric sewing machine made primarily of molded plastic components which are easily assembled with minimum of tools.

Abstract: Thread control device for stitching machines comprising a mechanism for applying torque to a feed roller around which the needle thread is fed to provide proper thread feed when a small number of threads are used and to provide control of seam variation. The device further has a thread break monitoring device signaling the program control in case of thread breakage to stop the device.

Abstract: An improved weft control device for shuttleless looms in which weft is drawn between a pair of friction plates mounted on individual post elements in a manner whereby their free ends are disposed in contiguous relation. The device provides a control lever fixed to the lower end of each post element which are operatively connected one to the other. One of the control levers is of greater length than the other and defines an indicating arm that is disposed in operative association with a band of indicating indicia provided on a support member for the post elements. By manually moving the indicating arm in one direction or the other to a pre-selected graduation of the indicating indicia, the post elements will rotate simultaneously and in opposite directions and the force with which one friction plate engages the other can be increased or decreased as desired.

Abstract: A thread tensioning device for a sewing machine, which is capable of automatically imparting, without any manual operation, a thread passing therethrough a suitable tension for the ordinary sewing, in accordance with the kind of thread as well as the thickness thereof. The device includes a pair of plate members closely confronted to each other for forming a narrow gap therebetween, being constantly urged by spring force acting at a concentrated point on one of the two members, and either one is provided with, on the inside surface thereof, a plurality of grooves formed perpendicularly to the direction of the thread running, each groove having a sharpened edge between the side surface of the groove facing the thread advancing direction and the thread engaging surface of the plate member for imparting a resistance independent of the spring force to the thread according to the surface condition thereof peculiar to each kind of threads.

Abstract: A modular upper thread tension device utilizing an end of a tension beam to press together at least a pair of opposed thread engaging discs, and a raised helix form track on an end cam to provide a variable pivot point for the beam, all the components of the tension device being arranged to provide a compact form of construction. The entire tension assembly is supported on a sheet metal bracket which is attachable to the sewing machine frame with the thread engaging discs thereof lying beneath a slot in a top cover. A bell crank is fulcrummed on a pin attached to the support bracket, and has one leg thereof pivotably attached to a first end of the tension beam, which is arranged to lie as an extension to that leg. A mandrel is supported, by lugs of the support bracket, parallel to the tension beam, and has one end thereof extending through the second leg of the bell crank.

Abstract: A thread cutting device applicable to sewing machines includes elements connected to a support plate to be installed in the sewing machine at the position therein where the common sliding elements are to be located. The support plate has a screw which acts on a bridge element when the bridge element is pressed against the lower face of a panel of the machine. One of the elements of the thread cutting device has a generally Y-shaped configuration and is provided with an alternating lineal movement, either by means of manual, electro-pneumatic or electromagnetic operation, in directions parallel to that of the sewing of the machine. Such shaped element angularly operates a movable knife against a fixed knife in synchronized cooperation with a thread collecting hook which also has an angular displacement. The arrangement further includes a thread withdrawing device and a thread tension opening device.

Abstract: A tufting machine wherein the needle bar is reciprocated by a number of like, mounting assemblies which are positioned along the length of the machine, with each assembly comprising a number of linkage arms which are pivotally interconnected to thereby minimize friction and power consumption. Also, the reciprocation of the needle bar, which is guided by the assemblies, results in a pause at the bottom of the needle movement to facilitate pick-up of the yarn loops by the loopers, and the needles have a component of movement in the direction of movement of the backing fabric at the bottom of their stroke, whereby the needles function to deposit the yarn loops on fixedly mounted loopers. The machine further includes a yarn tension control arrangement which is readily adjustable during operation of the machine.

Abstract: A method and apparatus for forming a continuous chain of stitches between pieces of material on a double needle sewing machine which includes a sensing device for detecting the presence of material in the sewing area and connected to the sensing device elements are provided for releasing the tension on one of the needle threads upon indication of absence of material in the sewing area. Additionally an auxiliary feed device functioning in cooperation with the machine's feed dog and needle plate is effective in simultaneously advancing the untensioned needle thread with the single chain of stitches being formed.

Abstract: A mechanism for selecting the tension setting of a needle thread tension device for sewing machines. A slot is formed in the face of the sewing machine arm top cover through which extends an operator influenced tension selecting knob. The tension device for influencing the needle thread tension is connected to the tension selecting knob by a leaf spring and lever fulcrummed to the arm top cover. Movement of the tension selecting knob along the slot in the arm top cover varies the force exerted on the needle thread by the tension discs contained within the tension device.

Abstract: A sewing machine is disclosed which includes at least one regulatable operating instrumentality, such as, for example, an adjustable needle thread tensioner. Means are provided for generating signals indicative of different parameters which affect the ultimate overall stitch, such as, for example, fabric thickness at the seam, thread type, and pattern type. A central processor is provided with an algorithm for controlling the thread tension so as to maintain uniform stitch quality as a function of the different parameters.

Abstract: A threading device facilitating threading of a pretension device located on the rear surface of the bracket arm of a sewing machine. The threading device has a segment projecting beyond a rear corner of the arm to facilitate introduction of thread by an operator seated in front of the machine. An ear and fin member guide the thread from the point of thread introduction into engagement with the pretension device, and preclude the thread from becoming unthreaded.

Abstract: A thread-tensioning device of a sewing machine comprises thread-squeezing plates between which the thread passes. A shaft applying pressure to the plates is subjected to the action of a transmission lever which is acted upon by a spring-urged ball which is moved by a control button along an arcuate path from adjacent the pivoting axis of the lever to near an end of the lever. The angle of the lever can be set to enable progressive setting of the thread tension for a constant spring pressure, or with variation of the spring pressure.

Abstract: This disclosure relates to thread tensioning apparatus for sewing machines of the type disclosed in U.S. Pat. No. 3,667,414, issued June 6, 1972, and in particular has for its purpose a simplification of such a mechanism by providing a novel tension transmission means including a leaf spring for transmitting spring pressure to the thread tensioning discs of said mechanism, an adjustable abutment means positioned against one side of said spring means provides for presetting the initial minimum tension on the leaf and a slidable fulcrum member bearing against the other side of said spring member is adjustable for varying the pressure exerted on the discs. The relationship of fulcrum positions, which may be adjusted by means of a dial or the like, with respect to resulting tension applied to the thread may be caused to occur in an advantageous non-linear manner by choice if the proper contour of the leaf spring.

Abstract: An air passage is formed in the weft yarn grasping means to permit the passage of air therethrough upon weft yarn releasing action of the grasping means, so that any yarn waste and miscellanea gathering in the grasping means are removed by the passing air.

Abstract: Thread tension discs for sewing machine thread tension devices which urge thread in toward the center of the device. Complimental indentations in the surface of the discs at the point of entry of thread into the device so change the angle of the edge of the discs at the point of entry that the thread has a tendency to work its way into as opposed to out of the device.

Abstract: A thread tensioning device for a sewing machine including a pair of elongated plate members closely confronted with each other by a spring member, disposed in the path of a thread, for forming a substantially wedge-shaped and extremely narrow gap therebetween which extends along the thread path, whereby the device can impart a thread passing through the narrow gap between the two plate members a certain tension suitable for the sewing without any manual operation, because the resistance acting on the passing thread is automatically determined in response to the size thereof.

Abstract: A thread tensioner for a sewing machine has smooth flat, parallel plastic surfaces between which the thread is passed and which can be urged together with variable tension by a cam acting through a spring. One of the surfaces is a part of an inner wall of a box-like housing. The other surface is carried by a hollow block slidable in the housing and containing the spring, and into which the cam projects.

Abstract: The sewing machine includes a reciprocating needle bar with a thread-engaging needle which cooperates with a rotatable looper carrying the looper thread which is driven by a rotatable looper drive shaft. The construction includes a thread knife and a thread clamp mounted adjacent the looper and a catcher mounted on a catcher shaft for rotation therewith selectively in the same direction of movement as the looper toward engagement with the knife and in an opposite return direction. The construction includes an improved control member for operating the catcher which is freely rotatable on the looper shaft and is axially displaceable therealong between an operative position and an inoperative position spaced axially from the operative position. A coupler is provided between the control member and the looper shaft which includes a driver having a rod portion which extends in a groove of the control member. A biasing spring biases the control member into an operative position.

Abstract: A tension disc assembly for tension devices, used for controlling thread on sewing machines, which is formed with a relatively large supporting frame into which a hardened tension disc is secured. The supporting frame allows the use of a standard-sized tension disc while serving as a guide for threading single and multi thread tension devices.

Abstract: A thread feeder for sewing machines is disclosed which feeds the thread from one of the bobbins to an automatic threading machine. It includes a movable table over the sewing machine, bobbins mounted thereon, thread tension regulators for adjusting tension to the thread from the bobbin, and feed rollers for feeding the thread from the thread tension regulator to the automatic threading device on a sewing machine. By such an arrangement, threads of different color or material can be fed conveniently one after another in a desired order.

Abstract: An improved thread-tensioning mechanism for the stop motion means of a multi-needle machine of a well known type wherein each needle thread, in extending from its supply spool to its needle, normally travels through a thread-tensioning section at a speed and tension which varies in proportion to its rate of variable usage within a given operating or usage range. Its tension variations are sensed by a sag sensor that shuts down the machine when the tension falls below said given range. In our improved thread-tensioning mechanism, a group of independently rotatable idler wheels is provided, one for each needle thread of a corresponding group of individual threads. The periphery of each idler wheel gravitationally engages and presses its needle thread against the periphery of a rotating shaft common to all wheels. Through this engagement, each wheel is rotated by and at the varying speed of its thread.

Abstract: An automatic threading device for sewing machines is disclosed which can thread the needle thereon automatically. It carries with a stream of air the thread from a thread feeder through the thread take-up at standstill, guides it to the front of the needle hole, and passes it through the needle by means of a threading tool.

Abstract: A device for automatic tension release in an upper thread tension adjusting assembly which includes a drive shaft, actuating the detachment of the tension disks of said adjusting device, characterized in that said drive member is built in the thread tension adjusting device and is made by an electromagnet placed in a circular crown arranged between the tension disks and the adjusting knob.

Abstract: A tensioner unit in a thread supply path for a domestic sewing machine which by its structural arrangement and location on an upper face of a machine provides a feed path across the frontal face of the machine for full visibility and accessibility of the thread without obstructing the view of the work area. The feed path through the tensioner unit is also arranged to provide a wrap of thread through the unit about a vertical axis in excess of 180 degrees to provide stable frictional engagement of the thread in the tensioner unit.

Abstract: Pretension threading device which includes two thread deflecting means supported on opposite sides of a pretension, and arranged to deflect thread caught and drawn into the thread deflecting means into wrap around the pretension. One thread deflecting means extends to beyond the pretension in a direction away from a thread supply tapering to a point beyond the pretension spaced from the adjacent sewing machine housing. The other thread deflecting means lies in covering relationship to the pretension, terminating at the pretension and tapering beyond the pretension device in a direction away from the thread supply to the adjacent sewing machine housing.

Abstract: This disclosure relates to threading apparatus for sewing machines and in particular to a movable thread engaging means disposed in proximity to a disc-type tension device which thread engaging means is operative during movement of the tension discs towards one another for guiding the thread between and in operative relationship with the tension discs so as to ensure that the thread will be properly threaded through the tension device.