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: 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: 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: 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 method and device for regulating the transport of material in a sewing or embroidery machine (1) that uses information from a position or movement sensor (33) located underneath the throat plate (21). The controls for the sewing machine (1) calculate deviations of the actual feeding increments of the article to be sewn from the corresponding target values from the periodically read sensor signals. With this information, the feeding increments are regulated in such a way that the deviations are cancelled out by averaging.

Abstract: Identification elements for identifying the size, shape, and kind of embroidery frame (37) are installed on the embroidery frame (37) for a sewing or embroidery machine with an embroidery module (33). Furthermore, at least one reference cam (44) is provided on the embroidery frame (37), and by means thereof the precise position of the embroidery frame (37) relative to the embroidery module (33), and thus also relative to the needle (27), can be derived. By a comparison of the actual position of the embroidery frame (37) with the desired position, a fault can be detected and a new positioning of the embroidery frame (37) can be performed in the case, for example, that switching steps of the drive element in the embroidery module (33) have been lost.

Abstract: A device for detachable fastening of an embroidery frame (27) with one or more embroidering fields on an embroidery frame support (25) of a program-controlled sewing or embroidering machine. On the embroidery frame (27), two sliding interlocks (61) are fastened which guarantee a play-free latching in the x and y direction and which, for sliding the embroidery frame (27) in relation to the embroidery frame support (25), move a latching element temporarily out of a latching slot (51). The latching element is configured as a pivotable lever with a downward-projecting detent.

Abstract: A device for detachable fastening of an embroidery frame (27) with one or more embroidering fields on an embroidery frame support (25) of a program-controlled sewing or embroidering machine. On the embroidery frame (27), two sliding interlocks (61) are fastened which guarantee a play-free latching in the x and y direction and which, for sliding the embroidery frame (27) in relation to the embroidery frame support (25), move a latching element temporarily out of a latching slot (51). The latching element is configured as a pivotable lever with a downward-projecting detent.

Abstract: A device to introduce the upper thread into the eye of the needle (7) of a sewing machine which includes two guide clips (49, 51) having two inlet sections (53, 55) ending in a narrow point. The two guide clips (49, 51) are generally identical and can spread evenly when encountering the needle. The grasping hook (57) that lies in a plane in the center of the two guide clips (49, 51) is always guided exactly centered into the eye (25) of the needle (7). In addition, the two guide clips (49, 51) are mounted for tilting movement about a horizontal axis (B).

Abstract: The electric motor and the needle locating device of a sewing machine are adjusted by a pivotable treadle controlling a radiation directing member which is located in the path of radiation issuing from one end of one or more first optical fibers the other end or ends of which receive radiation from a suitable source, and the member controls the amount of radiation entering the adjacent end or ends of one or more second optical fibers which convey the radiation to an optical detector. The latter selects the speed of the motor in dependency on the amount of radiation which is transmitted into the second optical fiber or fibers and selects the position of the needle when the motor is off. The radiation directing member can constitute a glass plate which is rotatable or performs translatory movements between the first and second optical fibers and includes portions of different radiation transmissivity or reflectivity.

Abstract: Elementary patterns are sewn in a sewing machine wherein the work can be fed by increments T. The making of a pattern involves repeatedly moving the work in and counter to the feed direction between starting the final needle penetration points which are spaced apart a distance nT wherein n is a whole number exceeding one. This results in the making of several continuous thread legs each having a length nT which can exceed, at least slightly, the maximum bight range of the needle and each extending all the way between the starting and final penetration points. In order to form a second elementary pattern which intersects the first pattern, the work is fed to move the needle to an intermediate penetration point, for example, midway between the starting and final penetration points, and the work is then fed to position the needle at the starting penetration point of the second pattern.

Abstract: A row of at least two coherent cruciform elementary patterns of stitches is formed in a zig-zag sewing machine by first making a first series of at least two zig-zag stitches and by thereupon making a second series of at least two zig-zag stitches which are mirror images of the stitches of the first series and each of which crosses a different stitch of the first series of stitches. The needle is caused to penetrate into the work in the middle of the first or last stitch of the first series of stitches prior to making the second series of stitches. Each stitch of the first and second series of stitches includes at least one uninterrupted length of thread. Only one crossing point of the stitches which form the first and second series is located at a needle perforation point. The first row of at least two cruciform elementary patterns can be followed by any desired number of additional rows in any desired orientation to form ornamental or other arrays of rows of cruciform patterns.

Abstract: A sewing machine wherein the fabric supporting arm or bed carries a fabric guide which is movable to any one of a number of positions at different distances from the needle. The fabric guide carries a tape measure or the arm or bed carries a ruler. The tape measure or the ruler has an eyelet for temporary attachment of the tape measure or of the ruler to the needle. The fabric guide is movable along the tape measure or ruler to a position at a desired distance from the needle. The eyelet is then detached from the needle and the tape measure or the ruler is retracted, either by hand or by a spring, to be out of the way during sewing. At such time, one edge of the fabric abuts a stop of the fabric guide while the needle makes a row of stitches at the selected distance from the edge.

Abstract: Apparatus for guiding and braking elastic or nonelastic bands during sewing to pieces of fabric has an elongated flat housing of rectangular cross-sectional outline with a transversely extending channel for a band. The housing is separably affixed to the table of a household sewing machine and contains a reciprocable slide which can alter the effective width of the channel. The slide is installed at one side of the channel, and the housing supports an adjustable fabric guide at the other side of the channel. A plate-like biasing member is installed in the channel at a level above the band, and the biasing member can be moved up or down by a screw having a knurled head so as to select the force with which the underside of the biasing member bears against the upper side of the band.

Abstract: The upper side of the sole plate in a sewing machine presser foot is formed with a transversely extending channel for the median portion of a guide which steers the needle during making of a row of stitches adjacent the edge of a marginal portion of a piece of fabric. To this end, the guide has two end portions which extend laterally beyond the respective sides of the sole plate and have downwardly bent tips one of which slides along the edge of a piece of fabric when the sewing machine is in use. The guide can be moved longitudinally to place its end portions at selected distances from the respective sides of the sole plate. A male detent member on the sole plate normally engages a selected graduation of a notched scale on the central portion of the guide to maintain the guide in a selected position. The tips of end portions of the guide are located at a level slightly above that of the underside of the sole plate.

Abstract: The takeup limb of each needle thread loop in a central bobbin hook type sewing machine is engaged by a kidney-shaped cam on the shuttle hook driver and by a projection on the housing for the hook while the takeup lever of the machine reduces the size of the loop. This ensures that the takeup limb is held and the loop is guided substantially during the entire interval of reduction of the size of the loop. The cam has a lobe with a groove for the takeup limb, and the projection of the housing engages the loop prior, during and subsequent to withdrawal of the takeup limb from the groove of the lobe.

Abstract: An elongated workpiece is transported forwardly and backwards in a sewing or stitching machine by looping it upstream and downstream of the sewing or stitching station, by maintaining both loops under tension, by increasing the size of the downstream loop simultaneously with a reduction of the size of the upstream loop, and vice versa.

Abstract: The winder shaft for a sewing machine, fashioned as a support for a thread bobbin, is positioned directly on the shaft of a low-voltage motor, independent of the drive motor for the sewing mechanism of the sewing machine. An on/off switch for this motor is operable by means of a three-armed switching lever, with the first arm being adapted to scan the package of wound thread forming on the bobbin. A trigger cam disposed on the third arm slides, during this operation, over a first surface of a spring-biased dual ramp. Once the thread bobbin is full, the trigger cam surpasses the apex of the dual ramp, and the switching lever flips into a disconnect position and cuts off the motor by way of a switching cam disposed on the second arm. All of the elements of the spooling device are mounted to a common support so that the spooling device, which is independent of the drive mechanism of the sewing machine, can be attached as a composite unit at any desired location on the sewing machine.

Abstract: An alternating presser foot with a vertically movable sole portion, fixed in the feeding direction of a feed dog, and a clamping pressure foot adapted to be placed on sewing material relative to the movable sole portion by means of a drive lever which cooperates with a needle bar for movement along with the sewing material in the feeding direction of the feed dog. For transmission of motion from the drive lever to said clamping pressure foot, an angle lever is provided, one arm of which, extends approximately vertically, defining a guide cam cooperating with a follower of the drive lever, while the other arm thereof extends approximately horizontally defining a pressure element for stressing said clamping pressure foot in order to place it in engagement with the sewing material.