Abstract: In a fabric feeding mechanism of a sewing machine there are provided a pair of elastic members each connected between two pivot axes at both ends of each of a pair of link elements. The elastic members have their pitches slightly different from those of the corresponding link elements and elastically displaceable in the longitudinal direction of the latter, so that backlash which may be caused at the pivot axes by abrasion resulting from repeated use of the sewing machine will be absorbed to thereby maintain a predetermined feed referenced point thereof.

Abstract: A force transfer assembly connects the output centerpoint of a Cardan gear mechanism to a work performing assembly. The motion of the output centerpoint moving in a first and second plane is translated by the force transfer assembly such that the work performing assembly moves in first, second and third planes. The force transfer assembly preferably includes a rotatable spherical element carried by the output lever of the Cardan gear mechanism, with a slider pin journalled in the spherical element and connected to the work performing assembly.

Abstract: A Cardan gear assembly wherein rotary input motion of the main shaft is converted to elliptical output at the Cardan gear output centerpoint. The Cardan gear output centerpoint is connected via a ball and a pin slideable therethrough to a support having a work performing instrumentality arranged at its distal end. During operation, the elliptical output motion of the Cardan gear output centerpoint is transmuted into three dimensional, elliptical like motion at the tip of the work performing instrumentality.

Abstract: A sewing machine motor is provided with an elongate pin which is affixed in the end portions of the arms of sheet metal motor end brackets, and which is pivotally mounted in frame affixed resilient end blocks to enable the motor to be adjusted about the axis of the pin for the purpose of altering tension in a belt driven by the motor.

Abstract: In a micro-computer controlled sewing machine a conversion switch is provided which can be switched between a first position and a second position. A manually operable controller, such as a foot pedal, is connected to the conversion switch. The circuit means connects the conversion switch to the micro-computer in the electronic sewing machine. When the conversion switch is in its first position, the operable machine controller will control the rotation speed of the sewing machine. When the conversion is in the second position, the manually operable controller will control the needle swing amplitude.

Abstract: A sewing needle in which an elongated locator portion is provided extending transversely from the shank and of a length to extend from a retaining means fixing the sewing needle to the needle bar, sufficiently and in a direction to permit its use as an accessory driving stud.

Abstract: An electric motor is supported at one end on a molded plastic electrically non-conducting housing which is slidably mounted on the metallic frame of a sewing machine at the base and which is biased toward the base of a compression spring to set tension in a belt through which the motor drives a pulley on the arm shaft of the sewing machine.

Abstract: A sewing machine device comprises a base, a platform elevated above the base, and a stitching head assembly suspended from the platform. The stitching head assembly includes a frame, a needle bar mounted for reciprocal movement, a clamp eye having an opening through which the needle passes and mounted for vertical reciprocal movement relative to the frame, and a thread take-up member mounted on the frame for relative movement towards and away from the needle eye. A stitching drive mechanism is mounted on a platform and imparts reciprocating motion to the needle bar, clamp eye, and thread take up. This mechanism includes a main shaft providing rotary drive motion and a drive head for transforming the rotary motion to reciprocating motion. A rotary sewing hook is mounted on a hook shaft journalled in the frame. A suspending bar is pivotally attached to the platform and journals the hook shaft a predetermined distance below the platform.

Abstract: A speed-control circuit for a motor of the sewing machine is disclosed. The circuit includes a controller, thyristors for controlling the rotation of the motor in dependence upon the operation of the controller, operational amplifiers activated in dependence upon the operation of the controller to produce a speed designating voltage, a frequency - voltage converter which receives a frequency representing the speed of rotation of the main shaft of the sewing machine, a comparator for comparing that speed designating voltage with the voltage of the frequency-voltage converter to detect a motor drive phase, and a light emitting diode and a phototransistor activated by the motor drive phase and operative for controlling the ignition phase of those thyristors.

Abstract: A clutch element fastened to the end of a sewing machine main shaft by a shouldered screw is slidable thereon to a first position wherein axially extending clutch fingers thereof extend through guide notches in an interlock element fixed to the main shaft by the shouldered screw, into axially aligned recesses in a belt driven handwheel so as to drive the sewing machine main shaft. In a second position of the clutch element, the axially extending fingers thereof are withdrawn from the recesses in the handwheel so that the sewing machine main shaft is not driven. Detent means are provided to maintain the clutch element in a selected position.

Abstract: A basting stitch mechanism in which a latch is carried on the side of the needle bar carrier and is fashioned with a front portion extending in front of the needle bar terminating in a wedge, which wedge fits into a notch in a driving stud hinge pin extending about the needle bar and slidable thereon. The latch wedge connection to the driving stud eliminates the requirement for establishing a clearance between the needle bar carrier and the driving stud carrying the driving stud hinge pin. An extension spring connected between the sewing machine frame and a rear portion of the latch operates to increase the latching force as the needle bar is moved downwardly. By proper design of the wedge on the latch and the notch on the driving stud hinge pin, separation of the driving stud hinge pin from the latch may take place at some force designed to avoid breakage of the sewing needle.

Abstract: An automatic sewing machine is provided with a workpiece feeding device for imparting a continuous motion to the workpiece during the sewing cycle and with a sewing head having a needle bar which is oscillatorily driven by an arm shaft via a crank gear. In order to reduce the needle deflection due to the continuous workpiece feed motion in a simple way, in addition to the crank gear for driving the needle bar, there is interposed a double crank gear between the arm shaft and the crank gear which reduces the angle of rotation while the needle penetrates the workpiece.

Abstract: A sewing machine is described comprising a mechanism arranged to convert movement signals generated by a decoder unit into movements of a feed dog for the fabric with the main characteristic of the machine being that said mechanism comprises a plurality of levers; a selector unit which is controlled by the decoder unit and selects one of said levers, to place this latter in a working position; a member angularly coupled to a control shaft for the dog and angularly positionable in a predetermined angular position by the selected lever; and a dragging element controlled by said decoder unit and arranged to move the member from its predetermined angular position towards an angular reference position.

Abstract: A handwheel clutch for a sewing machine having a bistable tiltable element for engaging or disengaging the clutch thereby coupling or decoupling the handwheel from the arm shaft.

Abstract: An electromechanical actuator is formed in flat and thickness reduced configuration having a stator, a movable portion to drive or control a needle positioning mechanism and a work feed regulating mechanism or the like in response to electrical signals. Said stator portion includes a pair of parallel spaced yokes to define a single air gap therebetween, and a plate-like permanent magnet secured to an inner wall of at least one of said yokes, the magnet being magnetized so that oppositely directed flux fields are established within the air gap. Said movable portion includes planar armatures disposed in said flux fields to pivotally move with the fulcrums placed at the opposed peripheral portion, and exciting windings each carried by said armatures.

Abstract: In a sewing machine having an upper presser (6), a work feed (8) disposed below and aligned with the upper presser (6), and a work support (9) about the feed mechanism (8), the feed mechanism (8) and the work support (9) are movable in unison to a raised position adjacent the upper presser and into a lowered position in which the feed mechanism is spaced further from the upper presser, the feed mechanism and the work support being resiliently loaded upwardly. In another aspect, a drive for a thread take-up element includes a rotary axially-acting cam (15,23), and a cam follower (24) coupled to the thread take-up element (25,29).

Abstract: In a sewing machine a workpiece feeding device having a lower feeding member intermittently and reversably driven and an upper feeding member in a steady contact with the workpiece and drivingly connected to the lower feeding member by means of connecting elements including one-way coupling means and a device arranged between the latter and the upper feeding member for interrupting or reversing the upper feed motion simultaneously when reversing the lower feeding member; different embodiments are described.

Abstract: A pneumatic needle positioner for positioning a needle of sewing and stitching machines in a predetermined position in the sewing or stitching cycle is provided by utilizing a handwheel sensing device in cooperation with a pneumatically powered positioning motor engageably disposed relative to a drive V-belt which engages the V-belt with a V-belt pulley of the pneumatic needle positioning motor at the end of the sewing cycle, by the actuation of a biasing piston having a roller to tension the V-belt toward the pulley disposed on the pneumatically powered positioning motor. Preferably the biasing piston and roller for the pneumatically powered positioning motor is disposed slightly above or below an axially adjacent position to the air motor pulley to provide a sinesoidal shaped bias against the pnematically powered positioning motor pulley to more effectively cooperate with the positioning device to achieve a more reliable and accurate positioning of the needle.

Abstract: A reversible mechanism including a driven member with a rim having drive surfaces on its opposite sides. An elongate driving member is flexibly engageable with either of these surfaces at a predetermined position. The mechanism is useful in conjunction with a manually operated motor for controlled winding or unwinding of strands or yarns. It is also adaptable for reversal of movement by providing an extremity or extremities on the rim which, upon movement to the predetermined position, allow the driving member to disengage from one surface of the rim and to engage the other surface.

Abstract: An automatic sewing machine provided with a memory for storing stitch instructions directing a relative position between a vertically reciprocated needle and a work piece and a speed control means for controlling the machine's drive motor at a suitable speed for each particular sewing operation carried out according to the stitch instructions. To determine the maximum permissible speed suitable to the variation of the relative position for each stitch, all of the stitch instructions in the memory are checked by a central processing unit before starting each sewing operation. The unit provides a control signal concerning the maximum permissible speed to a speed control means so that the driving speed of the drive motor is limited to no more than the maximum permissible speed.

Abstract: An automatic sewing machine having an improved drive speed control system. Many stitch instructions each indicating the relative position between a vertically reciprocated needle and a workpiece are stored in a memory in a predetermined sequence. The large number of stitch instructions are divided into a plurality of groups consisting of a predetermined number of consecutive stitch instructions. For each group, a maximum permissible speed is determined in accordance with the variations of the relative position between the needle and the workpiece directed by the instructions of the group. This maximum permissible speed causes formation of an exact stitch pattern in the workpiece according to the stitch instructions in each of the groups. A speed control device controls the speed of the drive motor in accordance with the various maximum permissible speeds. This causes sewing to be performed in a highly effective and exact manner.

Abstract: The output centerpoint of a Cardan gear mechanism is connected via a ball and a pin slideable therethrough to a lever which in turn carries a looper. Because the major axis of the lever and the axis swept out by the output centerpoint are skewed the lever is reciprocated back and forth along its own major axis while being rotated therearound. This results in the looper being swept back and forth along part of a generally helical-like path.

Abstract: A fabric workpiece fed along the worktable of a sewing machine by the intermittent movement of the fabric-advance dogs operating through openings in the worktable, is also engaged by an intermittently rotated feed wheel above the worktable. The stepwise rotary movement, whose stepping angle can be varied in a stepless manner, is imparted to the wheel by the output element of a planetary-gear transmission, one input of which is connected to a stepless transmission while the other input is connected to a crank drive with a steplessly variable output-oscillation angle establishing a dwell period.

Abstract: A Cardan gear assembly having an output centerpoint means which moves along an elliptical path. A force transfer means connects the output centerpoint to a means operative to carry a work performing means. The major axis swept out by the means operative being skewed with respect to the major axis of the ellipse which is swept out by the output centerpoint. As a result, the work performing means will be swept along a curve which is of a portion of a helix as well as part elliptical. This curve takes the form of a partial helix wherein the outgoing path is different from the return path.

Abstract: A sewing machine motor is provided with stamped out sheet metal end brackets including arms with disc like end portions which are mounted for pivotal movement in slots in a frame to permit the motor to be adjusted as required to alter tension in a belt driven by the motor.

Abstract: A Cardan gear assembly wherein rotary input of the main shaft is converted to elliptical output at the output centerpoint. A force transfer means connects the output centerpoint to a means supporting a work performing instrumentality. Thus during operation the work performing instrumentality is driven through an elliptical like curve.

Abstract: A thread-tension regulating device for multi-thread sewing machines comprises a speed change mechanism and a thread-tension regulating mechanism. The speed change mechanism has an infinite speed variator and pulleys for operating the variator. The thread-tension regulating mechanism comprises a cam shaft rotated by the speed change mechanism, cams fixed onto the cam shaft, operating rods reciprocated by the cams, pairs of tension discs mounted on the corresponding operating rods, and biasing elements for periodically imparting tension to threads which pass between the paired tension discs according to the reciprocating movement of the operating rods. By selecting the shape, dimension and angular phase differences of the cams, a biasing force between the paired tension discs, and the rotational speed of the cam shaft as given by the speed change mechanism, a variety of patterns can be formed on cloth by the multi-thread sewing machine.

Abstract: An input gear and a hook driving gear in mesh with the input gear in the gear train for the hook of a sewing machine are rendered self-adjusting by having the input gear drive the hook driving gear through a key which is movable in one direction on an input shaft and with respect to which the input gear is movable in a direction perpendicular to said one direction, and by having the hook driving gear drive the hook through shaft affixed collar permitting movement of the hook driving gear transversely relative to a bushing upon which such gear is rotatably mounted.

Abstract: A low speed adaptor for use in a sewing machine driven by a main motor, particularly to one which employs a main transmission belt and an auxiliary transmission belt to change the speed of the sewing machine from high to low. This main transmission belt passes over the belt pulley of the main motor, then over the transmission belt pulley of the adaptor, and then over the belt pulley of the sewing machine; while, the auxiliary transmission belt passes over the belt pulley of the auxiliary motor and over the belt pulley of the adaptor body. The adaptor comprises an electromagnetic clutch and brake device capable of selectively switching the drive of the sewing machine from the main motor operating at high speed to the auxiliary motor operating at low speed.

Abstract: A motor controller for an electric sewing machine mounted in a removable portion of the housing of the machine. The controller is actuatable by a pneumatic switch which successively closes a plurality of contacts as the air pressure to the switch is increased to enable the speed of the motor to be increased smoothly and gradually without sparking at the contacts.

Abstract: A reverse treadling inhibiting device having an electric motor connected to a sewing machine arm shaft through a one-way clutch and inhibiting the reverse treadling of the sewing machine by utilizing the one-way clutch connection to the electric motor to add inertia and resistance to reverse treadling of the sewing machine.

Abstract: A module including a frame which supports a motor, reduction gearing and a belt driving pulley is mounted in a sewing machine for position adjusting movements in one direction effective to set tension in a shaft timing belt, and position adjusting movements in another direction effective to set tension in a hook shaft timing belt.

Abstract: A sewing machine work feed mechanism with guide means for tilt free motion of the feed dog in a linear path, the feed mechanism utilizing a fabricated sheet metal feed bar, centrally pivoted, and of a length from the pivot to one end of at least 10 times the maximum feed stroke.

Abstract: Disclosed is an improvement in a sewing machine supplied with stepping motors for the generation of setting movements of the stitch forming elements. A mechanical stop is provided in order to permit the stepping motors to be calibrated against the stop and thus provide precise settings of the stitch forming elements. Protection against jamming is provided by the use of elastic members between the coupling arm and linkages such that the elastic members absorb external forces against which the stepping motor is to be protected in order to keep the calibration intact. Additionally disclosed is an apparatus for setting the stepping motor either in whole steps or in arbitrary intermediate steps which are actually between two discrete stable positions.

Abstract: A mechanism for coupling and uncoupling a driven rotatable drive wheel from a rotatable shaft, particularly, the arm shaft of a sewing machine from its associated drive wheel in order to spool up the lower thread, comprises a rotatable shaft which has an annular collar portion which is frictionally engageable by a drive wheel which is freely rotatable on the shaft. The drive wheel is continuously driven from a drive, such as a belt, and it may be urged into engagement with the collar by means of a nut which is threaded onto the end of the shaft. The arrangement includes a stop disc which has a cam surface which is engageable with a stop defined on the nut end face in a recess thereof. The cam surface and the stop define a cam structure which permits rotation of the nut so as to permit frictional engagement of the drive wheel with the shaft collar for driving the shaft and the disengagement thereof by rotation of the nut in a reverse direction.

Abstract: A sewing machine has a main drive shaft to which is drivingly coupled the output member of a coupling motor unit, the latter including an electric motor having a constantly rotating output shaft, a braking structure, and electrically controlled electromagnets for causing the output member to engage and become disengaged from the output shaft and the braking structure to increase and decrease the rpm of the main drive shaft of the machine. An rpm regulator has first and second inputs for receipt of a desired-rpm command signal and an actual-rpm feedback signal. The actual-rpm feedback signal is generated using a pole wheel rotating synchronously with the sewing-machine drive shaft and a plurality of pick-up transducers spaced along the pole-wheel periphery. During pole-wheel rotation, an A.C. voltage is induced in each such pick-up transducer. The spacing of the transducers relative to the spacing of the poles of the pole wheel is such that these induced voltages are phase-shifted relative to one another.

Abstract: A circuit which limits the maximum permissible speed of a sewing machine motor when specific stitch patterns are selected. Electronic signals from a means for sensing the selected stitch pattern are analyzed by the circuit to control the operation of a relay which connects a resistance in series with the sewing machine motor to reduce the maximum speed at which the drive motor may be operated.

Abstract: A thread winding mechanism including a thread winding shaft and a clutch member for disconnecting a torque transmission between a main shaft of a sewing machine and a drive pulley. Once the bobbin is manually inserted into the thread winding shaft the clutch member is automatically actuated to disconnect the main shaft from the drive pulley for preparation of the thread winding operation.

Abstract: The invention relates to a feed drive for work holders of sewing assemblies, by which, during the formation of the initial stitches of a seam taking place at a low speed, the control cam plate moving the work holder is driven at a reduced speed, and, during the formation of the main part of the seam taking place at a high sewing speed, the control cam plate is driven intermittently in a manner such that at every lowermost position of the needle, the work holder is temporarily stopped. The feed drive comprises a planetary gearing having two inputs, of which the first input can receive a constant rotary motion, and the second input can receive, at the start of the seam formation, a continuous rotary motion which is subtractively superimposed upon the rotary motion at the first input, and, during the ordinary sewing operation, an oscillatory motion whose frequency is equal to the frequency of the needle bar motion.

Abstract: This disclosure relates to hook drive mechanisms for sewing machines and in particular to a hook drive mechanism wherein the hook member is freely supported by a bearing means in a hook support plate carried by the bed portion of the frame and is driven by a likewise freely supported drive member. The support plate with the hook member is supported for relative adjustment with the needle for adjusting the hook point-to-needle relationship. The hook member is readily removable in that it is freely supported in the aforementioned bearing means and is otherwise only restrained by a movable restraining means carried by a hook member cover plate which when removed from restraining relationship permits the bobbin and the hook member to be easily lifted out from the machine. Further, means are carried on the hook support plate for adjusting and maintaining tension on a timing belt drive means for the hook mechanism.

Abstract: This disclosure relates to a direct drive feed mechanism for sewing machines which is driven by an electronically controlled reversible electric motor and includes a linearly operable feed dog mechanism which is compact in structure and modular in nature. More particularly, the disclosure of this invention relates to a novel four motion feed mechanism for a sewing machine wherein reciprocating feed motion of the feed dog is initiated by a reversible electric motor which in turn is controlled by electronic logic means. Because of the novel structure of this invention, the feed of the fabric by the machine can be readily controlled so as to be capable of producing a plurality of programmed feed patterns.

Abstract: A drive motor drives a reciprocating sewing needle. A static memory has lateral-control-signal outputs at which it furnishes signals indicating how much the needle should be laterally shifted for each stitch in a selected pattern, and feed-control-signal outputs at which it furnishes signals indicating how much a work feeding device should feed the work for each stitch of the pattern. An addressing circuit response to a pattern selector applies to the static memory a repeated sequence of address signals, causing the memory to produce repeated sequences of lateral-control and feed-control signals at its outputs. The first address signal in any of the repeated sequences of address signals causes the static memory to produce at its output a first lateral-control signal constituting a maximum-speed-establishment signal, and a first feed-control signal constituting a maximum-permissible-speed signal. A latch receives the feed-control signals but does not in general register them, except when activated.

Abstract: A sewing machine motor speed regulating system which provides two speed ranges which, in turn, have independently controllable maximum attainable speed adjust. This is accomplished by selectively exciting one of two variable trim resistors serially inserted in the silicon controlled rectifier gate/controller circuit.

Abstract: The device is incorporated in a sewing machine having an arm enclosing and rotatably mounting an arm shaft connected to the sewing mechanism, a drive wheel rotatably mounted on the arm shaft and driven in any suitable manner, and a thread winder including a wheel selectively engageable with the drive wheel. A clutch ring surrounds the arm shaft and is pivotal on a pin extending diametrically of the arm shaft, the clutch ring having a trapezoidal engaging cam engageable in trapezoidal recesses in the drive wheel. A flat spring biases the clutch ring normally to couple the drive wheel to the arm shaft. When the thread winder is moved into a position adjacent a fixed stop, a release stirrup engages the clutch ring and pivots it to a position disconnecting the drive wheel from the arm shaft. Another spring biases the release stirrup away from the clutch ring.

Abstract: The control device controls the sewing speed of a sewing needle automatically in a manner such that the temperature of the sewing needle, subjected to the influence of heat generated by friction with the material being sewn, does not exceed an adjustable predetermined value. Respective measuring members determine the temperature of the sewing needle and the temperature of a reference needle mounted at a location spaced from the sewing needle, and are connected to the input of a differential comparator circuit providing the differential voltage of the measuring members. A signal generator is operatively associated with the sewing needle and produces output pulses responsive to reciprocation of the sewing needle, to control connection of the output of the differential comparator circuit to the input of the sewing machine motor control. The reference needle is substantially identical with the sewing needle.

Abstract: In a stitching machine having a main shaft, a stitching needle and a looper and means for driving the shuttle so that the looper effects thread loop seizing and dropping movements and needle evading movements, the improvement in which the means for driving the looper comprises a crank rigidly connected to the main shaft, a slide mounted on the crank for driving by the crank, the slide having a free end which is formed with an outer spherical surface and an inner spherical surface which is offset relative to the outer spherical surface, a guide cylinder having a segment shaped cut out, the outer spherical surface being received in and guided by the guide cylinder, a ball having a bore and being rotatably mounted in the inner spherical surface, a looper shaft for mounting the shuttle, a transmission lever having one end rigidly connected to the looper shaft and the other end in engagement with the bore in the ball.

Abstract: In apparatus for imparting a swinging motion to a driven shaft from a drive shaft through a pair of eccentric discs or crank pins mounted on the drive shaft and link mechanisms, the link mechanisms comprise a pair of flexible links. Each link has a loop at one end thereof which encircles the eccentric disc or crank pin. The other ends of the links are connected to the driven shaft such that the other ends are wrapped about the driven shaft in the opposite direction and over an angle larger than the swinging angle of the driven shaft.

Abstract: An apparatus for selectively delivering incremental linear motion to a reciprocably mounted tool of a machine, for example, the shifting needle bar of a carpet tufting machine, includes means for intermittently delivering rotary power to a set of oppositely rotatable shafts each having coupling means which, during each dwell period of power delivery, are coupled to driven shafts which are linked to rotate together in the same direction; program controlled latch means are provided for selectively operating one or the other of the coupling means to provide control of the direction and duration of the transmission of motion from the power source.

Abstract: A system is disclosed for a sewing machine in which preselected stitch patterns may be formed automatically. Information related to the positional coordination of the needle penetration for each stitch of each pattern is stored in the sewing machine. Logic means are used to select and release said stitch information in timed relation with the operation of the sewing machine. The selected information is converted to positional analog signals which control closed-loop servo means including a moving-coil linear actuator which directly controls the position of conventional stitch-forming instrumentalities of the sewing machine to reproduce a pattern of stitches corresponding to the selected stitch information.

Abstract: This disclosure relates to the combination of a sewing machine and a work table wherein the sewing machine is supported in the work table for movement between a sewing position and a tilted position, a drive motor supported remote from the driven mechanism of the machine and an idler pulley supported intermediate the drive motor and the machine with the idler pulley drivingly connecting the machine with the drive motor by means of drive belts, and the idler pulley being supported for movement with the sewing machine during tilting thereof in a manner whereby the tension in the drive belts is relieved during tilting of the sewing machine and tension is restored during return movement of the sewing machine to the sewing position.