Abstract: A device for aligning and cutting lengths of terrycloth along the woof thread comprises two aligning ledges capable of movement relative to one another that can be lowered into the pileless rows of the length of material. The aligning ledges are connected each with one of two diagonally opposite joints of a parallelogram frame. On the two intervening joints is mounted a cutting device that operates transverse to the direction of feed of the length of material with a cutting plane that is always located exactly in the middle between the two aligning ledges.
Abstract: A sewing machine is equipped with a needle thread tensioning device which has two gripping discs mounted on a pin. The gripping discs are connected via a spring mechanism with two adjusting members on the same axis capable of movement relative to one another, of which at least one is mounted on a threaded section of the pin. In addition, the tensioning device has a mechanism for occasional suspension of the effect of the spring. With the tensioning device, in spite of the common mounting of both the adjusting members on the same pin, two tensions of varying degrees, a main tension and an auxiliary tension, can be adjusted and transmitted to the needle thread independently of one another and quickly switched one for the other. For this purpose, the two adjusting members are designed as inner and outer parts and separated from one another by a stationary support placed between the inner and the outer part.
Abstract: An arrangement for monitoring the shuttle thread reserve in a sewing machine with a lockstitch revolving shuttle and with a light-emitting diode, which sends a beam of light through openings in the bobbin housing and in the bobbin to a photodetector which triggers a switching pulse for an actuating device. To obtain maximum utilization of the residual thread, the photodetector is used at the same time as a pulse generator for a counter which controls the actuating device. The counter can be connected to a switch-off device of a drive motor for the sewing machine.
Abstract: A lockstitch sewing machine includes a rotary hook. For the rotation secure retention of the bobbin housing of the hook, two cams are arranged in the central region of the loop cast-off side, which receive a spring rod between them. A shoulder formed at the bobbin housing is associated with the cam or with the spring rod. Through the special position of the cams, the movement resistances during the guiding of the needle thread loop around the bobbin housing is reduced to a minimum.
Abstract: A skin holding device on an apparatus for letting out skins is driven by drive devices to follow the treatment and feed tools acting on the skin, so that the skin zone received in the skin holding device is moved synchronously with the skin zone gripped by the treatment and feed tools. In this way a skin, when being let out, can neither be distorted nor can it deviate from its initial angular alignment.
Abstract: A sewing machine with a sensing device positioned ahead of a stitch-forming point, senses changes in the thickness of a material being fed by the sewing machine. In order to determine the difference in thickness, the sensing device has a pickup foot capable of vertical movement with a sensing surface that lies on the material adjacent the point the stitch is formed. A sensing lever is movably mounted on the pick-up foot with a sensing arm that lies on the material ahead of the sensing surface, a measuring member detects the relative movement between the pickup foot and the sensing lever.
Abstract: Sewing machine with a control for the movement of a workholder. For the formation of edge parallel seams when sewing on labels with seam sections extending parallel to the movement axes of a cross slide system carrying the work holder, there are arranged at uniform distance from the stitch hole four transmitted light sensors, of which always only the one which can recognize the crosswise extending following edge of a seam section is switchable into readiness for operation. After a signal has been given by a sensor, the respective drive motor of the cross slide system is controlled by means of a microcomputer in such a way that the respective seam section ends exactly in the intended corner. Because of the work related feed control, a sewing program is not needed. Besides, the control automatically adapts itself to different label dimensions.
Abstract: A guide device for the workpieces on a sewing machine comprises driven guide wheels arranged one above and one below the workpiece, and revolving in a plane extending crosswise to a sewing direction for the workpieces. The guide wheels are each mounted on a low-mass rocker which are, in turn, mounted on a support. Due to the low-mass construction of the rockers, they form together with the respective guide wheels, vibratory systems uncoupled from the respective supports, whereby a uniform frictional contact between the guide wheels and the workpieces is achieved.
Abstract: A housing for a sewing machine which has a base portion, an upright portion extending upwardly from the base portion and an arm portion extending outwardly from the upright portion and overlying the base portion comprises a housing construction extending over said portions having flat outer surfaces, and means defined on said surfaces for affixing attachment units.
May 8, 1986
Date of Patent:
July 7, 1987
Pfaff Industriemaschinen GmbH
Horst Diener, Ernst Albrecht, Erich Willenbacher
Abstract: A sewing machine with a needle bar mounted in a rocker, has a step motor drive for the oscillation of the rocker. A memory is used in which are contained selected digital data for influencing the step motor and a control unit is inserted between the memory and the step motor for selection and conversion of the digital data into stepping pulses for the step motor. A pulse generator operating synchronously with a main shaft of the sewing machine is used for triggering the transmission of stepping pulses to the step motor. To improve the drive transmission and to avoid reactions on the step motor, the step motor is connected to a lever arm of the rocker via an eccentric transmission.
Abstract: A lockstitch sewing machine includes a rotary hook, with a bobbin housing and a cam is provided for the rotation-secure retention of the bobbin housing and it is arranged a small distance behind the stitch hole in the direction of hook rotation. A holding finger for holding the bobbin housing against rotation with the hook body projects from the bobbin housing, as well as a supporting finger arranged substantially 90.degree. before the stitch hole. A shoulder projecting from the bobbin housing is associated with the supporting finger.
Abstract: A device for forming a doubly turned hem on lengths of fabric with a folding sleeve, in the inner space of which a flexible sheet is provided as auxiliary folding device, which presses the fabric against the guiding surface of the folding sleeve and, as the start of fabric is pushed through the folding sleeve, constantly follows its cross-sectional shape. The effective area of the auxiliary folding device can have a fur-like surface, the pile of which is aligned in the direction of advance of the material to be sewn. In order to open a gap for the unimpeded introduction of the edge of the fabric, a shaped metal plate, by means of which the auxiliary folding device is coiled, is movable between the guiding surface of the folding sleeve and the auxiliary folding device.
Abstract: A sewing machine having a reciprocating needle bar and a presser foor which is movable upwardly and downwardly to engage material and move it over a sewing station includes a presser foot measuring device. A system for measuring the pressing force of the presser foot of sewing machines comprises a lever type force absorption element which is elastically deformable by the pressing force of the presser foot and which is provided with an electric sensor responding to the deformation. Connected with the sensor is a circuit which contains a digital display on which the pressing force is indicated in newtons.
Abstract: Method and apparatus for determining and regulating the amount of advance of a plurality of workpiece plies at a sewing machine which is affected by scanning the individual plies while recording the stitches being formed between two separate feed points and actuating top and bottom feed devices to achieve a desirable feed of each ply. Signs present or to be applied at any desired point of the workpiece plies are scanned at two successive points, and pulses generated by a pulse generator connected with the main shaft of the machine are summed during this period of time. The pulse sum is compared with a number of pulses which depends on the mutual spacing of the scanning points and on the adjusted stitch length. For two work plies the pulse sums formed between the recognition of the signs are compared directly. As signs to be scanned are used either imprinted marks, the jags of a pinked workpiece edge, or the bright, dark structure of a surface section of the workpiece.
July 11, 1986
Date of Patent:
April 21, 1987
Pfaff Industriemaschinen GmbH
Fritz Jehle, Erich Willenbacher, Oskar Braun, Dietmar Becker
Abstract: A thread clamp for sewing machines comprises a helical spring as a clamping element which is disposed in a bore extending crosswise to the feed direction of the work in a guide piece placed on the stitch plate. To obtain a very short closing path, the helical spring has in the region of the respective thread pull-off path windings whose mutual distance is greater than in the other regions. The helical spring is compressible by a setting drive for the fixed clamping of the threads.
Abstract: A braking device for strip material particularly for a sewing machine which sews a garment requiring ruffling comprises a fixed guide over which the strip material such as tape is fed. A resilient member overlies the fixed guide and it is engaged by a multi-step cam plate mounted for rotation about an axis so that a plurality of flat sides thereof may be selectively engaged against the resilient member to force it against the material passing on the guide so as to apply a selected braking force thereto. The resilient member advantageously comprises a leaf spring and the multi-step cam plate includes a plurality of engagements surfaces arranged at different distances from the central axis of its rotation which may be positioned by a hand knob control to bear against the resilient member and effect the varying braking of the tape being fed.
Abstract: An edge guiding device is provided for sewing work with several edges extending at angles to each other, and on which parallel seams are to be formed, e.g., collars. The device has an edge ruler which is formed by a central section and two sections controllable independently of the central section, each with a guide face. During the formation of seams which begin or end at inside corners of the collar or work, the edge ruler is moved synchronously with the work displacement. Thereby, e.g., one-piece collars plus collarbands can be securely guided from the start during the formation of the seam sections beginning or ending at the inside corners of the collars. For guiding at a long side of the collar, which is usually curved, the outer sections of the edge ruler are pulled back and only the central section with its arched guide face is used for guiding the work.
Abstract: An apparatus for securing and releasing an embroidery frame to a clamping rail comprises a connecting piece guide with a bore therethrough and a rod extending through the bore and extending along the clamping rail and guided in the bore for movement in the connecting piece guide bore. The rod carries a pressure piece which is movable with the rod. The clamping rail has a plurality of spaced apart embroidery frame pin receiving openings and embroidery frames are secured by inserting the pins of the frame into the openings. Each pin has a side with a cutout and each pin receiving opening has a fixed spacer plate adjacent the opening which carries a resilient holder which may be engaged in a cutout of the embroidery frame pin when it is inserted into the associated opening.
June 2, 1986
Date of Patent:
February 24, 1987
Pfaff Industriemaschinen GmbH
Gottfried Schmidt, Edgar Busch, Lothar Schilling
Abstract: In a sewing machine with a device for setting the feed movement of a cloth feed by a revolving stitch regulator adjustable relative to the main shaft and comprising an eccentric which is connected to the cloth feed via a transmission and whose setting element is, after locking engagement with the housing of the sewing machine by a fixing element adjustable in stepwise setting amounts by rotation of the main shaft, and which is equipped with a display device for indicating the adjustment amount of the setting element, a pulse generator is coupled with the main shaft of the sewing machine for the visible display of the feed amount during operation of the machine. The pulse generator cooperates with markings which deliver pulses corresponding to the stepwise amounts and can be switched on via a switch actuable upon locking engagement of the setting element. The pulse generator is connected to a display unit via a pulse evaluating device.
Abstract: A sewing machine includes a housing with a base portion having a covering base plate and an upright standard adjacent one end of the base portion extending above the base plate and an arm portion extending out of the standard and overlying the base plate. A feed drive in the housing includes a ratchet wheel driven by the feed drive located on the arm portion which cooperates with a shuttle carried in the base portion. The feed drive includes a variable drive including an eccentric which may be shifted so as to vary the driving speed of the shuttle. The construction includes a setting device for setting the speed of the shuttle, an actuating device connected to the setting device and the variable drive so that the drive of the shuttle may be varied.