Abstract: A proximity sensor or switch having a sensing coil, an oscillator connected to the coil, a comparator connected to the oscillator, a reference voltage module connected to the comparator, and an output driver connected to the comparator. The voltage module may incorporate a resistor having an end connected to a high side of a power source, and a digital potentiometer having a first end connected to another end of the resistor and to the comparator, and having a second end connected to a ground side of the power source. The digital potentiometer may have a resistance that is varied with a signal. A variation of the resistance for the digital potentiometer may result in a change of a voltage from the reference voltage module which further changes a switching distance of the proximity switch to a predetermined value.

Abstract: A sewing machine includes a thread tension mechanism, a thread feed sensor, a sewing portion, a processor, and a memory. By executing instructions stored in the memory, the processor causes a first tension to act on an upper thread by the thread tension mechanism to be in a first state, in a state in which a sewing is stopped. The processor causes a second tension that is smaller than the first tension to act on the upper thread, by causing the thread tension mechanism to be in a second state, when the movement of the upper thread is detected by the thread feed sensor. The processor causes a third tension that is equal to or greater than the second tension to act on the upper thread by causing the thread tension mechanism to be in a third state, in a state in which the sewing is performed.

Abstract: A bobbin thread winder of a sewing machine including a bobbin winder spindle holding a bobbin and a driving mechanism to apply a drive force to the bobbin winder spindle, comprises a time measuring unit to measure an bobbin-thread winding execution time with respect to the bobbin, and a bobbin-thread winding amount calculating unit which calculates a winding amount of the bobbin based on the bobbin-thread winding execution time with respect to the bobbin measured by the time measuring unit. In the bobbin thread winder, since the bobbin-thread winding execution time was measured by the time measuring unit, and the bobbin winding amount of the bobbin is calculated based on the bobbin-thread winding execution time by the bobbin-thread winding amount calculating unit, it is possible to detect the bobbin winding amount of the bobbin accurately regardless of the type and thickness of the bobbin thread.

Abstract: A stitched sensor including a plurality of threads stitched to a textile in a stitch geometry is described. The plurality of threads includes a conductive thread, and the stitch geometry is configured such that an electrical property of the stitched sensor changes based on at least one of stretching, relaxation, or bending of the textile. Methods for forming a stitched sensor are also described.

Abstract: The present invention relates to an airbag cushion and an airbag system including the same, and particularly to an airbag cushion, including: at least one fabric; and seam parts connecting the fabric, wherein deviation of upper seam thread length per a unit length of the fabric between the first seam part sewed in forward direction and the second seam part sewed in reverse direction in the seam parts is 15% or less, a method of preparing the same, and an airbag system including the same. The airbag cushion of the present invention is superior in working stability and unfolding performance because of the optimized properties of the seam parts, provides superior shape stability and air-tight effect at the same time, and can protect a passenger by minimizing the shock given to the passenger.

Abstract: A pressure-sensing hose assembly and method of its use are disclosed. In an example aspect, the pressure sensing hose assembly includes a hose assembly including a hose having first and second conductive layers and a circuit electrically connected to the first and second conductive layers of the hose assembly. The circuit generates an electrical response across the first and second conductive layers of the hose assembly. The pressure-sensing hose assembly further includes a computing system configured to receive the electrical response and estimate a pressure within the hose assembly based on the electrical response.

Abstract: A bobbin includes a bobbin main body including flanges at both ends of a bobbin winder spindle for winding the bobbin thread and an outer flange attached to one of the flanges (a second flange) of the bobbin main body. A gap in which a thread end of the bobbin thread is housed is provided between the outer flange and the flange of the bobbin main body.

Abstract: A lower thread ending region detection apparatus prevents problems associated with false stitchings occurring from inability to detect lower thread's exhaustion during sewing operation. The lower thread ending region detection apparatus comprises: light control unit, which contacts a part of lower thread wound on a thread bobbin and activates or inactivates at least one of the functions of emitting light, reflecting light, passing light and blocking light, due to the effect of the physical movement force generated depending on whether the lower thread of the ending region is unwound; light receiving unit, which receives the light transferred out by the light control unit and outputs a detection signal; and control and notification unit, which analyzes the detection signal output from the light receiving unit to determine whether the lower thread has reached the ending region and outputs the result to the user.

Abstract: Systems, methods, and apparatus for embroidery thread color management are disclosed. An example method comprises determining a first set of thread colors to be used in an embroidery design, determining a second set of thread colors assigned to a first embroidery machine, determining a third set of thread colors assigned to a second embroidery machine, determining a first difference of the number of thread colors in the first set of thread colors that are not in the second set of thread colors, determining a second difference of the number of thread colors in the first set of thread colors that are not in the third set of thread colors, and assigning the embroidery design to a queue for the first embroidery machine when the first difference is smaller than the second difference.

Abstract: Techniques for controlling sewing machine stitch length based on thread usage are provided. The techniques include a sewing machine computer storing a stitch length setting and using a thread movement sensor to sense the movement of thread as the thread is drawn from a spool due to the user moving an object relative to a sewing machine needle and thereby drawing thread from the needle and the spool. The techniques also include a sewing machine computer receiving information from the thread movement sensor and determining a length of thread drawn from the spool after formation of a previous stitch, comparing the length of thread with the stitch length setting, and operating a sewing machine motor to create a stitch when the length of thread drawn from the spool after formation of the previous stitch corresponds to the stitch length setting.

Abstract: The present invention relates to a lower thread ending region detection apparatus (LTERDA) that prevents problems associated with poor quality and re-work resulting from false stitchings due to being unable to detect the exhaustion of the lower thread during the sewing operation.

Abstract: The present invention relates to a lower thread supply device for a sewing machine, comprising: a housing (100) which is fixed to a main body of a sewing machine, has a cylindrical shape in which a front side and a back side are opened along a central axis, and has a (a housing cut out portion) (110) formed by cutting the outer circumferential surface of one side; a rotation plate (200) which is connected to a power shaft of a sewing machine, has a disk shape, has a power transmission protrusion (210) formed on the front surface of the disk, and is provided at the back inner lateral side of the housing (100) to rotate; a hook body (300) which is rotatably provided inside the housing (100), has a cylindrical shape with an opened front side, a protrusion receiving part (320) formed at the back outer portion to receive the torque of the rotation plate (200) by being engaged with the power transmission protrusion (210), a bobbin mounting post (330) formed at the back inner portion, and a hook (310) that passes th

Abstract: A bobbin thread monitor includes a rotatable thread pulley together with a rotation sensing counter and numeric count display. During bobbin loading, the thread supply is looped about the pulley in a first direction resulting in rotation of the thread pulley in a corresponding first direction. The rotation of the thread pulley in the first direction produces an accumulated account within the rotation sensing and display apparatus. During sewing operations, the thread supply is looped about the thread pulley in a second opposite direction loop resulting in opposite direction rotation of the thread pulley during the sewing process. The opposite direction rotation of the thread pulley during the sewing process produces a downcount of the number accumulated during the bobbin loading process. This down count is indicative of bobbin supply remaining and may be used to activate additional alarm apparatus.

Abstract: A sewing machine includes a plurality of needle bars to a lower end of each of which a needle can be attached, a display portion that is configured to display various information, a first display control portion that causes the display portion to display replacement information, the replacement information being information pertaining to a replacement needle bar that corresponds to a thread spool for which replacement is necessary and that is at least one of the plurality of the needle bars, a specifying portion that specifies a replacement-completed needle bar during a period in which the replacement information is being displayed on the display portion, the replacement-completed needle bar being a needle bar that corresponds to a thread spool that has been placed after replacement, and a second display control portion that causes the display portion to display a result that has been specified by the specifying portion.

Abstract: Systems, methods, and apparatus for embroidery thread color management are disclosed. An example method comprises determining a first set of thread colors to be used in an embroidery design, determining a second set of thread colors assigned to a first embroidery machine, determining a third set of thread colors assigned to a second embroidery machine, determining a first difference of the number of thread colors in the first set of thread colors that are not in the second set of thread colors, determining a second difference of the number of thread colors in the first set of thread colors that are not in the third set of thread colors, and assigning the embroidery design to a queue for the first embroidery machine when the first difference is smaller than the second difference.

Abstract: A sewing machine includes a sewing machine motor that vertically drives a sewing needle via a main shaft; a sewing speed commander that produces a command sewing speed determined by rotational speed of the sewing machine motor; a stitch-pitch specifier that specifies a stitch pitch to be applied to manually fed sewing operation; a consumed thread amount detector that detects a consumed needle-thread amount in each ongoing sewing cycle; a sewing speed controller that controls sewing speed at the command sewing speed when the command sewing speed is equal to or less than a predetermined reference sewing speed, and that controls sewing speed at a target sewing speed calculated based on the consumed needle-thread amount and the stitch pitch when the command sewing speed is greater than the reference sewing speed.

Abstract: The present invention relates to a device and a method for monitoring a thread wound on a bobbin during operation in a sewing machine that reduces the expenditure on apparatus and production technology with increased monitoring reliability wherein at least three different marking states are provided in the area of the bobbin (3) and are coupled to an optical device (8) in such a manner that movement of the bobbin (3) produces a change in marking which can be detected in the optical device (8) which can be evaluated in a logic unit connected to the optical device (8), that the marking (10) in the area of the bobbin (3) comprises more than two states, wherein at least one state is defined by at least one true color (g, r, b) or a mixture of the primary colors.

Abstract: The present invention relates to an apparatus and a method for detecting the ending-point of a bobbin thread for a sewing machine using a bar code, which is capable of alerting a sewing operator of his/her desiring bobbin thread remains when they are left enough to finish sewing under operation. The present invention of the apparatus for detecting the ending-point of a bobbin thread for a sewing machine using a bar code so as to sense the ending-point of a bobbin thread during a sewing operation, comprises a bobbin to wind a bobbin thread therearound and at least one bar code to indicate a position in the surface of a bobbin, of which the bar code is printed on one or both side(s).

Abstract: An electronic sewing machine includes a sewing machine motor that vertically drives a sewing needle via a rotation of a main shaft; a stitch-pitch setting unit that sets a stitch-pitch in sewing manually fed workpiece cloth; a consumed thread amount detection unit that detects consumed thread amount of at least either of a needle thread or a bobbin thread consumed in each ongoing sewing cycle; a consumed thread amount calculation unit that calculates consumed thread amount based on an output from the consumed thread amount detection unit; and a speed control unit that controls rotational speed of the sewing machine motor based on calculated result of the consumed thread amount calculation unit so that an amount of manual cloth feed equals the stitch-pitch set by the stitch-pitch setting unit.

Abstract: Disclosed herein is a bottom thread supply device for sewing machines. The bottom thread supply device of the present invention includes a light source (500) and a light receiving sensor (110). When the light source (500) radiates light onto a bobbin (300), around which a bottom thread is wound, if there is no remaining thread, the light receiving sensor (110), which is disposed in a central portion of a rotary hook (100), detects the light, thus generating a signal to let a user know that there is no remaining thread. As such, when there is no remaining thread, the present invention automatically lets the user know this thanks to the operation of the light receiving sensor, thus preventing unproductive or defective sewing, thereby increasing productivity and preventing economic loss.

Abstract: A method and apparatus for detecting longitudinal thread motion in a quilting/sewing machine for controlling the actuation of a fixedly located stitch head. A preferred detector comprises an optical sensor which directly senses the longitudinal movement of a thread as it moves along a guide path from a supply source toward a stitch head needle.

Abstract: The present invention relates to a device and a method for monitoring a thread wound on a bobbin during operation in a sewing machine. In order to further develop a method and a device of the type specified initially whilst reducing the expenditure on apparatus and production technology with increased monitoring reliability it is suggested for a device for monitoring a thread wound on a bobbin (3) during operation in a sewing machine (1), wherein at least two different marking states are provided in the area of the bobbin (3) and are coupled to an optical device (8) in such a manner that movement of the bobbin (3) produces a change in marking which can be detected in the optical device (8) which can be evaluated in a logic unit connected to the optical device (8), that the marking (10) in the area of the bobbin (3) comprises more than two states, wherein at least one state is defined by at least one color (g, r, b) or a mixture of the primary colors.

Abstract: Support section for contacting and movably supporting a string-shaped material is provided between a material holder and a guide member, and it supports the material, paid out from the holder, in a slackened condition while it applies a tensile force, corresponding to a state of the contact, to a portion of the material to be directed to the guide member. The consumed amount and the paid-out amount of the material can be controlled to agree with each other, which can prevent any excessive tensile force from being applied to the portion to be supplied to a sewing position and which can reduce the tensile force acting on the material and yet keep the tensile force generally constant. As a result, the string-shaped material can be sewn accurately in an aesthetically pleasing manner.

Abstract: A monitoring device (15) for monitoring the needle thread (9) on a sewing machine (1) is provided which includes a regulator spring (25) with at least one cam switch (39) being connected thereto in a rotational manner. In case of changing thread tension and/or thread consumption the cam switch (39) and/or the detection zones (41) embodied thereat passes through a sensor (45) with two sensor areas (a, b). Here, not only the presence and absence of the cam switch (39) can be detected but also a direction of motion and the speed of motion. From these measurements conclusions can be drawn on various parameters of the needle thread (9).

Abstract: A stitching apparatus with thread tension control is provided. Tension in a thread is monitored during stitching apparatus operations, and remedial action is taken in response to the detection of an anomaly in the thread tension profile. The remedial action can include altering a feed rate of the thread in order to adjust the thread tension, and/or repeating a previous operation. Anomaly detection can be performed with respect to stitching or sewing operations, and also with respect to trim operations performed in connection with moving between elements and/or thread color changes.

Abstract: A method and apparatus for producing uniform stitches in a stack of fabric layers while allowing a user to manually guide the stack across a planar surface beneath a stitch head. Stitch head actuation is controlled as a function of the rate of thread payout.

Abstract: To determine the thread supply on a lower-thread bobbin (17), holes (19) are arranged in the shape of a spiral in a flange (21) of the bobbin. Light from a light source (35), which is directed towards the flange (21), is reflected only by those holes (19), behind which there is no longer any thread, so that the light beams (36) reach the rear flange (22) and can be reflected therefrom and received by the light receiver (39).

Abstract: A sewing apparatus such as a sewing machine includes a sewing mechanism in which a needle thread is used, a cassette mount to which a thread cassette, while in a closed state, holding the needle thread used in the sewing mechanism is detachably attached, a determining unit determining a type of the thread cassette attached to the cassette mount, and a control device controlling the sewing mechanism according to the type of the thread cassette determined by the determining unit.

Abstract: The present disclosure relates to a control device to control a sewing machine which executes a sewing operation using a bobbin thread wound on a bobbin and a needle thread by the drive of the sewing machine motor. The control device includes a sewing restarting unit that restarts the sewing operation after stopping the sewing machine motor in response to a detection of bobbin thread scarcity by a bobbin thread remaining amount detection unit. A permitted sewing amount is preset for the sewing operation restarted after stopping the sewing machine motor and when an actual amount of sewing performed after the stop of the sewing machine motor reaches the permitted sewing amount, information is given by the control device.

Abstract: A stitching apparatus is disclosed which has at least one active thread feeder and is operable to adjust stitching operation based on the condition of a thread being stitched. The active thread feeder is operable to feed thread from a spool to a needle assembly, where the thread is stitched into fabric. The stitching apparatus includes at least one thread sensor. The thread sensor outputs information related to thread tension, which is received at a control which includes a first controller, and the first controller is used for controlling the thread. The control can calculate a thread feed length, and activate the active thread feeder to feed the appropriate amount of thread to the needle assembly. The control can use information from the thread sensor to adjust thread tension by adjusting the active thread feeder. The control can also detect a break in the thread, or a break in an underthread which is located in a lower arm assembly and is used to lock stitches.

Abstract: From a light source (51), light beams (57) are directed tangentially through the hook body (17), the hook base (27), and the bobbin case (28), onto a light receiver (53). Using the time (t) or the position of angular rotation of the hook body (17) at the impingement of the first light beam (57), the diameter of the bobbin packing on the lower thread bobbin (29) can be calculated.

Abstract: A sewing machine includes a sewing bed on which cloth to be sewn is placed, a pillar extending upward from the bed, a sewing arm extending horizontally from the pillar so as to be located over the bed, a high brightness LED lamp including a lens, a lamp cover provided to cover and support the LED lamp and made from a material which can transmit light emitted by the LED lamp, and a supporting member provided on the arm for supporting the lamp cover further supporting the LED lamp.

Abstract: A stitching apparatus is disclosed which has at least one active thread feeder and is operable to adjust stitching operation based on the condition of a thread being stitched. The active thread feeder is operable to feed thread from a spool to a needle assembly, where the thread is stitched into fabric. The stitching apparatus includes at least one thread sensor. The thread sensor outputs information related to thread tension, which is received at a control which includes a first controller, and the first controller is used for controlling the thread. The control can calculate a thread feed length, and activate the active thread feeder to feed the appropriate amount of thread to the needle assembly. The control can use information from the thread sensor to adjust thread tension by adjusting the active thread feeder. The control can also detect a break in the thread, or a break in an underthread which is located in a lower arm assembly and is used to lock stitches.

Abstract: Monitoring of the rotation speed and stationary state of the lower thread bobbin in a sewing machine is performed using a light emitter and two reflected light receivers. The light rays reflected at the surface of the front flange of the bobbin are incident in a sequence which differs in time on the reflected light receivers. These data are evaluated by a computer, which can be the computer of the sewing machine, and are used to stop the machine or the sewing process before the thread end leaves the stitch plate of the sewing machine. It can also be determined from the observed direction of rotation of the bobbin whether the bobbin is correctly placed in the bobbin housing. From the relationship of kind of stitch, stitch speed, and bobbin rotation speed, the bobbin thread supply can also be calculated.

Abstract: A stitch balancing thread tension 11 of a sewing machine 1 includes a rotary disk 17 having a surface extending perpendicular to an axial direction of a shaft 16 on which the rotary disk 17 is mounted. The thread breakage detection device includes a permanent magnet member 21 attached to the surface of the rotary disk 17, a hole element 22 that detects a magnetic field generated at the permanent magnet member 21 and outputs detection signals, and a detection unit that detects the thread breakage based on the detection signals from the hole element 22. Because the thread breakage detection device is integrally formed to the stitch balancing thread tension 11, the thread breakage detection device can be provided to the sewing machine 1 without increasing a number of components and the size of the sewing machine 1.

Abstract: A thread winder unit, which is capable of winding thread of spools set on spool bars, is removably attached to a machine body. The sewing machine includes a feed motor for feeding the thread during sewing, an upper thread state detecting sensor disposed between the feed motor and the thread winder unit for detecting tensed thread, and a CPU for controlling thread winding operations based on a signal from the upper thread state detecting sensor. The sewing machine intermittently drives the feed motor in a reverse direction to that in the sewing to feed the thread toward the thread winder unit, every time the upper thread state detecting sensor detects the tensed thread, and the thread winder unit winds the fed thread around the spool. The CPU, recognizing the thread wound by a given amount, stops winding.

Abstract: From a light source (51), light beams (57) are directed tangentially through the hook body (17), the hook base (27), and the bobbin case (28), onto a light receiver (53). Using the time (t) or the position of angular rotation of the hook body (17) at the impingement of the first light beam (57), the diameter of the bobbin packing on the lower thread bobbin (29) can be calculated.

Abstract: A sewing machine capable of preventing formation of no first stitch (skipping stitch), which is readily caused immediately after the sewing machine starts to operate, is obtained. This sewing machine comprises a first detector detecting that a thread engaging part of a balance is located in the vicinity of a forward movement starting point leftward beyond a thread receiving opening of a thread guide plate and an indicator operating on the basis of a detection signal received from the first detector. Thus, the operator can recognize that the thread engaging part of the balance is located in the vicinity of the forward movement starting point leftward beyond the thread receiving opening of the thread guide plate through the indicator.

Abstract: A stitch balancing thread tension 11 of a sewing machine 1 includes a rotary disk 17 having a surface extending perpendicular to an axial direction of a shaft 16 on which the rotary disk 17 is mounted. The thread breakage detection device includes a permanent magnet member 21 attached to the surface of the rotary disk 17, a hole element 22 that detects a magnetic field generated at the permanent magnet member 21 and outputs detection signals, and a detection unit that detects the thread breakage based on the detection signals from the hole element 22. Because the thread breakage detection device is integrally formed to the stitch balancing thread tension 11, the thread breakage detection device can be provided to the sewing machine 1 without increasing a number of components and the size of the sewing machine 1.

Abstract: A sewing machine capable of preventing formation of no first stitch (skipping stitch), which is readily caused immediately after the sewing machine starts to operate, is obtained. This sewing machine comprises a first detector detecting that a thread engaging part of a balance is located in the vicinity of a forward movement starting point leftward beyond a thread receiving opening of a thread guide plate and an indicator operating on the basis of a detection signal received from the first detector. Thus, the operator can recognize that the thread engaging part of the balance is located in the vicinity of the forward movement starting point leftward beyond the thread receiving opening of the thread guide plate through the indicator.

Abstract: A method for transferring an embroidery frame backward in case of thread breakage, includes the steps of: a) detecting the thread breakage to generate a thread breakage signal if the thread breakage occurs at a needle contained in needle holders; b) generating the control signal to control an embroidery-frame driver in response to the thread breakage signal; and c) transferring the embroidery frame backward in response to the control signal.

Abstract: An operation data processing device that summarizes trouble situations that occur during sewing operations. A log data storing device generates and stores log data based on an operation state of pattern sewing machines. A trouble summarizing device summarizes trouble information that occurs during operations. The trouble information is then summarized in association with a stitch number based on the stored log data. A displaying device visualizes the trouble information in a manner that allows a user to easily determine a trouble location and frequency for a given sewing pattern.

Abstract: An apparatus for automatically changing a bobbin case on a quilting machine having a hook drive operatively supporting the bobbin case during a stitching operation. The apparatus includes a staging station adapted to support at least one bobbin case normally having a full spool of thread, and a carriage movable between the staging station and the hook drive. A finger is movably mounted on the carriage, and the finger moves a release lever on the bobbin to an unlock position and clamps the release lever at the unlock position. A method of using the above apparatus in an automatic bobbin changing operation is also provided. A controller determines the need for a bobbin change, for example, by counting stitches and calculating the thread remaining on the bobbin. The bobbin change can be carried out between patterns or during a pattern by cutting the bobbin thread or both the top and bottom threads. The sewing of tacking stitches may also be done in sequence with the thread cutting and bobbin changes.

Abstract: Method for transmitting thread-specific data in re-reeling operations for the manufacture of two-thread lock stitch seams which have to be documented comprising the following steps: the bobbin taking over the thread, in particular the under-thread bobbin (10) is provided with a definite bobbin identification, in a reeling station (28), in which thread material for the under-thread is reeled from a thread stock (30) onto the under-thread bobbin (10), the bobbin identification is detected and is stored in a data storage medium (24) together with a first data record characterizing the thread material and the reeling operation, after inserting the under-thread bobbin (10) into a sewing machine (18) the bobbin identification is detected, from the bobbin identification the first data record stored therewith is determined and is assigned to a second data record concerning the sewing operation and/or the sewn product, whereupon the data set so formed is stored.

Abstract: A sewing machine includes a sewing machine motor, a main shaft driven by the sewing machine motor, a sewing needle driven by the main shaft, a shuttle for capturing a thread loop in cooperation with the sewing needle, the shuttle having a hook shaft, a shuttle driving motor for driving the hook shaft of the shuttle independent of the sewing machine motor, a drive control device for controlling the sewing machine motor and shuttle driving motor so that the shuttle is rotated in synchronism with the main shaft, a thread jamming detecting device for detecting a thread jamming in the shuttle, and a releasing device for controlling the shuttle driving motor so that the shuttle is released from the thread jamming, when the thread jamming is detected by the thread jamming detecting device.

Abstract: An apparatus for monitoring consumption of a supply of thread includes entry keys for allowing a user to input an initial supply of thread, and a minimum allowable supply of thread, and a detector for providing signals indicative of the rate of thread consumption. The apparatus also includes a control circuit for receiving the initial supply, the minimum allowable supply, and the signal indicative of the rate of thread consumption. The control circuit then calculates a consumed amount of thread and an actual supply of thread remaining, and produces a display signal indicative of the actual supply and/or the consumed amount, and an alarm when the actual supply of thread is equal to or less than the minimum allowable supply. The apparatus further includes a display panel for displaying the actual supply and the consumed amount upon receipt of the display signal from the control circuit.

Abstract: A computerized stitching apparatus that automatically controls thread tension is disclosed. In one embodiment, at least two factors are used to determine the desired thread consumption for the next stitch. A thread length encoder is used to determine the amount of thread actually consumed for a particular stitch. The operator must enter a desired thread length ratio or an equivalent factor related to desired thread length used for a particular stitch into the operator input device. Another factor such as speed, stitch length, fabric thickness, or stitch angle change is used with at least the operator's input to determine the desired thread consumption. The tension of the thread is adjusted by the stitch control system which will affect the actual thread consumed for the particular stitch.

Abstract: In an under thread detection device for a sewing machine, a probe arm is located outside a rotary bobbin case, and is adapted to be accessible to a bobbin through a space provided at the rotary bobbin case when the rotary bobbin case ceases its rotary movement. An urging member provides an urging force in such a direction as to urge the probe arm toward a stem of the bobbin. A wire transmits the urging force of the urging member to the probe arm. A stroke detection device measures a stroke displacement of the wire. A detection control device calculates a residual amount of an under thread wound on the bobbin on the basis the stroke displacement measured by the stroke detection device. A display device exhibits the residual amount of the under thread wound on the bobbin on the basis of the calculation performed by the detection control device.

Abstract: A thread consumption detecting apparatus includes an axial supporting shaft, a detector lever, a torsional spring, a proximity sensor, and a central processing unit (CPU). The detector lever includes an intermediate portion, a loop-shaped thread-contact end, and a base end. The intermediate portion is fitted idly around the supporting shaft so that the detector lever can swing. The thread-contact end is disposed so as to pass a thread outside the loop-shaped portion. The base end is detected by the proximity sensor. A swinging stroke of the detector lever is disposed so as to interfere with a thread-transfer-route variation range resulting from a fluctuation in tension of the thread. The torsional spring urges the detector lever in one swinging direction. The proximity sensor detects the base end on approach when the detector lever is swung by the tension of the thread. The CPU judges whether the thread is consumed or not in accordance with a signal output from the proximity sensor.

Abstract: A bobbin thread winding apparatus which can reliably twine a bobbin thread around the bobbin within the bobbin case. With the reliable twining of the thread, the thread is not cut and also will never be forced out of the bobbin case, thereby forming a good seam. Since the thread is not wound around a shaft other than the bobbin shaft, no manual operation is required for resetting the thread to the clamping mechanism, improving the reliability of the bobbin thread winding apparatus. The bobbin thread winding apparatus can accurately detect an effective thread winding amount of the bobbin thread irrespective of the yarn count of the thread used, and does not apply an excessive load to the thread winding mechanism, causing any adverse effect on the stitching quality. The bobbin thread winding apparatus allows a lower thread to be drawn out of the thread supply source and is then securely twisted around the bobbin shaft without a thread draw-out mechanism.