Abstract: A sewing machine has an electronic control for the production of at least one stitch pattern consisting of a plurality of different single stitches, with a read-and-write memory RAM for storing in memory at least the single stitches of the stitch pattern and with a feed mechanism whose feed adjustment occurs by a step motor controlled in accordance with the stored data of the read-and-write memory within the inactive phase of the feed mechanism. To carry out a feed variation exceeding the maximum number of steps of the step motor between two predetermined sewing stitches, the control unit contains a comparator which compares the magnitude of the displacement amount of the step motor before the next displacing movement is carried out with a given maximum displacement amount, in order to prevent a stitch formation between the point of insertion of the previous stitch and the desired point of insertion of the next following stitch when the maximum displacement amount is exceded.

Abstract: The lateral displacement or oscillation of a sewing machine needle bar is controlled by a permanently installed servomotor-driven cam operated in coordination with a second similarly installed servomotor-driven cam controlling the displacement of the fabric feed dog. Manipulation of the faces on the two cams, in a synchronized manner, allows numerous stitch patterns to be achieved according to the amplitude and direction of displacement of the needle bar and feed dog pursuant to the positioning of the faces on the two cams by their respective servomotors.

Abstract: A drive and control device for sewing machines, automatic sewing installations, and the like, with a recognition unit which responds for the purpose of end recognition when the sewing tools have approached a predetermined spacing from the desired seam end. The drive and control device also includes a preselection stitch counting unit, which can be triggered by means of the recognition unit, for the presetting of a predetermined number of remaining stitches still to be executed subsequently to the end recognition, and a correction unit for the performance of a stitch correction in dependence on the respective needle position at the instant of end recognition. The correction unit serves for automatically varying the length of at least one of the remaining stitches.

Abstract: A sewing machine for automatically making edge-parallel seams comprises a scanning device for recognizing the geometric form of the workpiece edge and a pressure piston lowerable laterally of the stitch formation point. For straight workpiece edges extending at an angle to each other, the pressure piston, having been lowered onto the workpiece with the sewing machine stopped, is rotated around the needle which is inserted in the workpiece, the workpiece being taken along accordingly. For a convexly arcuate edge pattern, first the lateral distance of the pressure piston from the needle is readjusted in such a way that it corresponds to the radius of the edge arc (e.g. scallop). Thereafter, with the sewing machine continuing to run, the pressure piston is lowered, whereupon the feed dog of the sewing machine rotates the workpiece around the pressure piston.

Abstract: In a sewing machine having a feed adjusting device which is operated by means of a drive pulse motor, a feed adjusting member is pivoted relative to an attaching member such that the feed adjusting member is turned about an axis of an output shaft of the pulse motor by rotating a fine feed-adjusting member, an eccentric part of which is mounted in a groove formed in the feed adjusting member so that a fine adjustment of the feed pitch may be provided.

Abstract: In a sewing machine, particularly an industrial sewing machine, with a needle which can be driven up and down by means of a needle bar, a feed dog for the forward transfer of the workpiece in co-ordination with the needle movement, an actual feed rate sensing device which supplies a corresponding electric signal and at least one sensor for detecting a workpiece edge, for the purpose of increasing the accuracy of the positioning of the corner stitch of a seam portion with acceptable constructional expenditure, a device is provided for displacing the longitudinal axis of the needle parallel to the sewing direction as a function of the actual feed rate sensing device on the one hand and the detection of a workpiece edge by the sensor on the other.

Abstract: An overlock sewing machine having a dial and a conversion means for converting the rotary motion of the dial into a linear motion which are associated with a cutter blade holder such that the adjustment of the distance between a stationary claw and a movable claw adjusts the looping width in correspondence with the linear movement of the cutter blade holder perpendicular to the direction of feed of the cloth caused by rotation of the dial. The movable claw, carried by a movable member, can move between an operative position in which the movable claw is positioned next to the side of the stationary claw and an inoperative position spaced away from the side of the stationary claw. The position at which the cutter blade holder is supported on the machine body is offset from the position at which the upper and lower cutting blades make contact.

Abstract: A connecting link for setting stitch width or length is fashioned as a flat metal piece and is retained on the bearing side in a molded-on synthetic resin bearing head. The bearing head is suspended by means of two trunnions on a bearing bracket and on an index lever attached to the bearing bracket. The sliding block is constituted by a sliding sleeve made of a synthetic resin, encompassing the connecting link and articulated by way of two trunnions to the linkage leading to the needle bar frame.

Abstract: A feed drive for a stitch group sewing machine includes a cam plate serving to drive a cloth clamp and it is connected with a separate motor. In order to keep the stitch length constant at varying length of the stitch group, the motor speed is controllable by a control device as a function of the rotational speed of the sewing machine, of the transmission ratio of a gearing between cam plate and cloth clamp which determines the length of the stitch group, and of the adjusted stitch length. The stitch group to be sewn can be divided into two sections with a stitch length variable independently of each other, in that a path-dependent switch operable after a partial revolution of the cam plate corresponding to the length of the first section alternately connects one of two potentiometers which determine the stitch length, with the motor control circuit.

Abstract: A stitch shortening device for a blind stitch sewing machine. A multiple cam is provided for reciprocating the feed drive lever. An adjustment wheel with peripheral teeth regulates the drive position of the multiple cam for lengthening or shortening the stitch by adjusting the feed drive. A pneumatic motor drives a toothed wheel meshing with the peripheral teeth of the adjusting wheel. When the pneumatic power is applied, the motor rotates the adjusting wheel in the direction of rotation of the sewing machine shaft but at a greater speed to maintain the adjusting wheel in large stitch drive position. When the operator activates a switch to cut off the pneumatic drive, the toothed wheel is idled and the adjusting wheel is moved into short stitch drive position. Applying the pneumatic power again moves the adjusting wheel into large stitch drive position again.

Abstract: There is disclosed a method of finishing lengthwise both ends of a towel fabric by sewing after automatically forming a three-ply part on each and, and an apparatus for practicing this method.At each end of the towel fabric, a first part and a second part to wrap up the first part are folded automatically in turn so as to form a three-ply part including the above two parts and a ground fabric part.Selvages extending outwardly slightly farther than crosswise both ends of the first and the second parts are formed on both ends of the ground fabric part of the three-ply part. The three-ply part thus provided with selvages is stitched from one selvage side to the other with sewing thread so that automatic folding and sewing of the three-ply part can be performed without causing the crosswise end of the first and the second folded parts to jut out from crosswise both ends of the towel fabric.

Abstract: An adaptive semi-automatic sewing system (10) comprises a sewing machine (12), a drive unit (42) including a variable speed direct drive motor and encoder for counting stitches sewn and for sensing the rotation of the motor, at least one material edge sensor (40) mounted ahead of the needle (22) of the sewing machine, and a microprocessor controller (51) coupled to the sewing machine controls. Accurate control of seam lengths and end points is achieved by initiating countdown of a variable number of final stitches responsive to detection of the material edge by the sensors (40). The amount of stitch completion at the time of detection of the material edge is monitored and a stitch length variance mechanism (17) is actuated at a selected angle of motor rotation taking into account the time delay of the stitch length variance mechanism and the feed characteristics of sewing machine (12) to precisely control the length of the last stitch sewn to improve the accuracy of the seam end point.

Abstract: A photoelectric device on the head of a sewing machine detects the trailing edge of a fabric workpiece and initiates a count of pulses representing increments of the steps of displacement of the workpiece in stitch formations. Each step is subdivided into a plurality of segments which are represented by respective multiplicities of increments so that from a count of increments after detection of the reference point to a particular angular orientation of the arm shaft, a stitch combination can be drawn from a memory which will include stitches of an original length and stitches of a length reduced from the original by a fixed amount so that in the number of stitches of the selected combination the row will be completed to a certain distance from the reference edge.

Abstract: A sewing machine which is operable in either a cam controlled feeding mode or a manually controlled feeding mode is provided with a spring which is moved into loading engagement with a feed regulating control lever by mode selecting mechanism when the selecting mechanism is disposed for manual control, and is moved away from the feed regulating control lever when the selecting mechanism is disposed for cam controlled feeding.

Abstract: A sewing machine with at least one feed means, the feed amount of which is variable by means of a positioning device acting on at least one positioning gearing; with a system for approaching a predeterminable end point of a seam in spaced relation to the edge of a workpiece; with a sensor disposed before the needle which during passage of the edge triggers the process for the positioning of the needle in the end point; with a pulse generator coupled with the main shaft of the sewing machine for the delivery of counting pulses for a pulse counter and a microcomputer which interrupts the action of the feed means as a function of the pulses emanating from the sensor and from the pulse generator in the end point.

Abstract: Vibrational movements of a spring biased lever, which is selectively positionable by a stitch length control lever and controls the operation of feed regulating mechanism in a sewing machine accordingly, are dampened by the operation of a plunger that is carried by said control lever and has a camming surface thereon to engage and lift the spring biased lever when the control lever is moved.

Abstract: A semi-automatic split needle bar sewing machine (10) includes a sewing machine (12) which is driven by a motor (26) that drives a left needle (22) and a right needle (23). A presser foot (24) is operated by presser lift actuator (30). The needles (22) and (23) can activate in unison or independently by use of fall out actuators (41) and (43), respectively. A control chassis (50) includes a microprocessor controller (51) that is programmable through an input panel (44). An edge detector (40) detects the edge of the material to provide feedback for the microprocessor controller (51). The microprocessor controller (51) is operable to sew a decorative pattern with mitered corners by sensing the pivot point of the mitered corner and automatically disengaging one of the needles (22) or (23).

Abstract: A feeding module in the base on an electronic mechanical sewing machine is driven by an input shaft having two cam surfaces, one of which is arranged to drive a guide element in an oscillating movement. A block journalled on a shaft secured to a slide is displaceable in the guide by a mechanical or computer controlled electrical setting device. The slide is journalled in the feeder and displaceable perpendicularly to the working surface of the feeder. Upon a displacement of the slide the block will move into a corresponding position in the guide thereby effecting an adjustment of the feeding. The other cam surface is arranged to act upon a link connected to the transferring device to the feeder and is coordinated with the cam surfaces to guide the feeder in rectangular movements.

Abstract: The present invention includes a sewing machine (12) with a variable top feed mechanism (25) that feeds the top layer of material for a sleeve at a variable rate to change the fullness thereof. The machine (12) is driven by a motor (42) which is controlled by a controller (51). A program is taught to the controller (51) for storage therein. The controller (51) then controls both the motor (42) and a controller (45) for the top feed mechanism to regulate the number of stitches and the relative rates of speed for the top and bottom materials fed by the machine. The program initially is taught to the machine and can be utilized for any type of material or size by inputting the correct sizes and types of material on a control panel (44). The machine (12) therefore semi-automatically sews sleeves onto armholes with the correct fullness sewn therein.

Abstract: A hand operable chain stitch sewing machine is provided with a top work feeding arrangement wherein a feed dog is moved away from a stop to engage and move a work piece under a sewing needle. The stop is adjustable and may be positioned with an operator's control to predetermine stitch length.

Abstract: A sewing machine for sewing shaped seams comprises equipment for exactly positioning an end stitch. By means of two edge sensing sensors provided one after the other in the feed direction, a pulse generator coupled to the main shaft, and a microprocessor, the difference between the desired feed length of the workpiece and the actual feed length thereof is determined. A microprocessor controls a step motor for adjusting a stitch setting device, the adjustment being a function of the difference between the desired and actual feed lengths of the workpiece and of the angular position of the main shaft at the instant of response of the second sensor. In this way, the length in excess of the last stitch which, without a correction, would extend beyond the predetermined end point, is uniformly distributed among the last stitches of the seam, while at the same time taking into account slippage between the feed dog and the workpiece.

Abstract: Railway sewing apparatus is disclosed for sewing and piecing together the free ends of two separate sheets of fabric which includes a frame 10 on which a horizontally extending rail A is carried. A sewing unit B is carried for horizontal movement back and forth across the rail and a sewing machine 50 is carried by the sewing unit. A D.C. drive motor 76 and rack and pinion gear drive 18, 82 impart a drive motion for driving the sewing unit B across rail A when energized. Means for driving the sewing machine 50 at a constant sewing speed is provided by a separate A.C. motor 44. An electrical control circuit 100 provides a variable output responsive to the position of the sewing unit on the rail energizing the drive motor as sensed by cams 36, 38 and switches 92, 94.

Abstract: An apparatus for adjusting stitch length in a sewing machine by means of a selectively adjustable eccentric possessing a self-locking device. The apparatus includes a support collar fixed on the machine's main shaft with an eccentric support mounted on the support collar which is operatively connected to a connecting rod for actuating the machine's feed dog. The eccentric support includes a central opening within which the adjustable eccentric is operatively disposed and which forms an integral part of a support ring rotatably mounted on the machine's main shaft. A manually operable push button serves to hold the support ring stationary and to release the self-locking device. The machine includes the conventional hand wheel fixed on one end of the machine's main shaft and, while the pushbutton is held in a depressed condition, the self-locking device remains in a released state thus enabling the selective rotation of the machine's main shaft by the hand wheel.

Abstract: During stitching a pattern, there is often issued a designation to change the pattern under forming to the other. In such a case total load on a fabric feed control motor and a needle amplitude control motor is temporarily increased. A microcomputer which controls driving of these motors, discriminates the new designation and rotating phase of the sewing machine and drives the fabric feed control motor by means of specific data by mean value of the maximum and the minimum fabric feed control data, instead of the fabric feed control data which is first read out next to said designation.

Abstract: A sewing machine work feed regulating arrangement is disclosed including a manual control dial for setting the magnitude and direction of work feed and a pattern cam for automatically influencing feed magnitude and direction. Control cam means associated with the manual control dial and effective during a small angular dwell segment thereof influences separate follower means positively to effect either engagement or disengagement of the pattern cam control of the work feed.

Abstract: A control assembly for varying the transmission ratio between a sewing machine driving shaft eccentric for feed dog transverse movement, and thus the feed and stitch widths, of a sewing machine which includes an oscillating lever mounted for oscillation adjacent to the feed dog and connected to it to move it backwardly and forwardly and an eccentric drive acting on the feed dog to move it upwardly and downwardly. The control assembly includes a push rod having one end connected to the oscillating lever to oscillate it and an opposite end having a pin thereon which is confined for movement in an oblong slot of a link which is articulated at its opposite end to one arm of a double armed lever, the other arm of which is engaged by the driving shaft eccentric to oscillate it. The pin carries a sliding block which is engaged in a sliding block guide and they are both made of a plastic having a sliding surface at their engagement surfaces.

Abstract: A blind stitch sewing machine comprises in the transmission between its main drive shaft and the fabric feeder an arrangement for stitch shortening and tacking. This arrangement comprises a coupling device with two arms which are guided for movement in longitudinal direction relative to each other and coupled by a coupling spring. One of the arms, which is fixed to the fabric feeder for movement therewith is provided with a recess into which a solenoid operated bolt is engageable when the fabric feeder reaches its forward end position to thereby stop the one arm and the fabric feeder connected thereto, while the main drive shaft and the remainder of the transmission remain in operation. Thereby feed of the fabric is substantially stopped and the seam tacked. Subsequently thereto the bolt is withdrawn from the recess and the coupling spring will again couple the one arm to the drive.

Abstract: An adaptive semiautomatic sewing system (10) comprises a sewing machine (12), a drive unit (42) including a variable speed motor and encoder for counting stitches sewn and for sensing the rotation of the motor, at least one material edge sensor (40) mounted ahead of the needle (22) of the sewing machine, and a microprocessor controller (51) coupled to the sewing machine controls. The system (10) has manual, teach and auto modes of operation. In the teach mode, control parameters for each seam are stored as the operator sews the initial piece. Accurate control of seam lengths and end points is achieved by initiating countdown of a variable number of final stitches responsive to detection of the material edges by the sensors (40). In dependence upon the amount of the stitch which has been sewn upon edge detection, the reverse lever (17) is moved against stop member (13) in order to reduce the length of the last stitch sewn in order to improve the accuracy of the seam end point.

Abstract: A feed regulator clamp in the shape of a bell crank having the pivot rod thereof retained in a slot in a sewing machine bed by a flat spring which also may serve to urge the clamp into clamping engagement with a feed regulator. A first arm of the bell crank comprising the clamp is for engagement with the feed regulator and a second arm of the bell crank is for engagement with a cam controlling the engagement of the first arm with the feed regulator. The flat spring which retains the clamp to the sewing machine bed urges the first arm into engagement with the feed regulator whenever permitted by the cam which is circular in cross-section except for a flat spot which, when aligned with the second arm, will permit the first arm to come into clamping engagement with the feed regulator.

Abstract: A machine for sewing together two workpiece parts having edges of equal or unequal length by using a bead seam, especially for joining together the edge of a vamp and the shorter edge of a plug of a true moccasin shoe, so that the length of the plug matches that of the longer edge of the vamp, in only one operation. The bead seam forming device essentially consists of an auxiliary folding and ruffling finger acting in front of the needle of the sewing machine and in synchronous driving connection with the needle; several machines are described which are provided with different bead seam forming devices.

Abstract: An arrangement for indicating to an operator whether a selected stitch length is within, below or above a preferred range for a selected pattern in a multiple pattern sewing machine includes a slide contact board and a group of slide contacts connected to a stitch length selection lever. The different patterns are grouped in accordance with preferred stitch length ranges, each group having associated therewith one of the slide contacts on the lever. The slide contact board is arranged to define the preferred ranges so that for each of the pattern groups, a circuit is completed to energize a low LED if the selected stitch length is below the preferred range; to energize an in-range LED if the selected stitch length is within the preferred range; and to energize the high LED if the selected stitch length is above the preferred range.

Abstract: This invention relates to a feed mechanism for a blindstitch sewing machine including a stitch shortening and tacking mechanism. Elliptical feeding movement is imparted to the feed dog by a fulcrumed lever driven off an eccentric on the main shaft of the machine. An operator controlled eccentric actuator is operatively connected to mechanism which changes the fulcrumed position of the feed lever to vary the elliptical path of the feed dog whereby effecting the advancement of the workpiece during the sewing operation without effecting needle reciprocation. An auxiliary thread tensioning assembly is provided to control the amount of thread utilized during the stitch tacking operation.

Abstract: Sewing machines comprising automatic guide apparatus for the piece, have a presser foot adapted to bear against the piece during operation so as to turn the piece, this bearing of the presser foot being controlled by a detector. A device for regulating the stitch length and a device for regulating the speed of operation of the machine are provided, and the control device for stitch length and the control device for the speed of driving of the piece are actuated by application of the guiding presser foot so as to increase the stitch length and reduce the speed as long as the presser foot is applied, that is, so long as the machine is stitching around a curve.

Abstract: An actuating mechanism is proposed for the hook and feed dog in a portable sewing machine of the type employed for sewing bags of jute, paper, and the like. In the proposed mechanism, a single cam determines both the compound movement of the hook, which is spring loaded against the cam and provided with at least one ball for reducing the frictional resistance, and of the feed dog by means of a connecting rod journalled at one end to a vertically adjustable support such as to allow the length of the seam stitch to be varied.

Abstract: A device for the automatic guiding of a workpiece on a sewing machine to produce a curved edge parallel seam operates in conjunction with a sewing machine having a reciprocating needle and a presser foot engageable with the workpiece and a feed member engageable with the workpiece to move it relative to the needle. The sewing machine also includes a guide roll disposed in spaced relationship to the needle for guiding the edge of the workpiece and a scanner for scanning the workpiece edge for sensing its position. In accordance with the position sensed, a plunger is mounted above the workpiece and is movable into the engagement with the workpiece to hold the workpiece at a selected point so as to turn the workpiece during the feeding movement of the workpiece by this feed member.

Abstract: An apparatus is disclosed which is to be connected to a domestic sewing machine for converting it into one capable of sewing heavier materials and sewing materials having edgewise designs so that the designs are maintained in alignment. The converted machine can also be capable of having an adjustable amount of hook throw. This apparatus includes a member which pivotally connects a needle bar and a feed foot to the sewing machine. The apparatus also includes a member which pivots the connecting member back and forth in a feed direction and a reverse feed direction. So that the workpiece being sewn by the machine will not slip during pivoting in the reverse feed direction, the apparatus also includes a clamp element for retaining the workpiece against a workpiece supporting surface during this time. Additionally the apparatus includes a mechanism which lowers and raises a feed dog when the connecting member has been pivoted to the substantial extremes of the feed direction and reverse-feed direction.

Abstract: A sewing machine which utilizes a pulse motor to vary feed rate in steps is equipped with a microcomputer that causes the pulse motor to operate in a repeated sequence in which two adjacent feed rates are alternated. By operating the computer in accordance with a manually-operable control, an overall feed rate can be produced which is intermediate the two adjacent feed rates.

Abstract: The stitch-forming instrumentalities of a sewing machine are subject to small mechanical operational errors due to play in the motion-transmitting connections. The invention overcomes this problem by providing two springs which are respectively connected to a transmission element coupled to a driven mechanism of the machine, and to a drive. The two springs counterbalance one another with respect to the drive.

Abstract: An arrangement for obtaining pattern feed elongation in an electronically controlled sewing machine by utilizing a potentiometer for feed length variation, which potentiometer at a certain point switches in a feed multiplication and reduces its effectiveness so as to obtain a uniform change in feed from 0 to the maximum multiplication desired. Two embodiments are disclosed, one of which utilizes a comparator to eliminate a switch.