Abstract: A work advancing mechanism for a sewing machine which includes a driven circulatory belt for positively advancing the work beneath the presser foot of the machine. The belt is entrained about and driven by a wheel assembly having an adjustable operative circumference for modulating the lineal advancement rate of the belt.

Abstract: The invention is concerned with the technical field of machines for attaching knit or woven fabric hems to generally knit wearing apparel, and in particular, relates to a machine designed to perform such operations by precision-stitch sewing. To retain a constant match of the loops forming a lower flap in a folded hem with the loops in the upper flap while sewing the hem onto wearing apparel, the machine comprises a sewing assembly with which a hem entraining assembly and feeding assembly for a garment to be sewn are arranged to cooperate, and is characterized in that said entraining assembly includes a pair of entraining members defining a hem passageway therebetween and being kinematically connected to attain substantially equal and oppositely directed peripheral velocities.

Abstract: The lifting device (19) of the presser foot (21) of a sewing machine is operable through the use of an operating axle (18) and a toggle lever (20). The operating axle (18) is connected to a slide (15) capable of engaging and disengaging a coupling mechanism (10). The coupling mechanism (10) is arranged between the lifting device (6) of the feed dog (3) and the oscillating drive means (7) of the lifting device. During the lifting of the presser foot (21) by means of the toggle lever (20), the coupling pin (12) of the coupling mechanism (10) is simultaneously placed out of engagement with the driven oscillating lever (8) by means of the slide (15). Thus the drive of the lifting device (6) is interrupted, and a spring (13) pulls the feed dog (3) into its lowered position. Thus the manipulation of the sewing material is made possible without the feed dog presenting an obstacle.

Abstract: A sewing machine is equipped with an automatic control assembly for the needle bight and/or the feed dog. The control assembly comprises a control cam block having a plurality of juxtaposed cam track portions to be operatively connected, through a contact mechanism, to the sewing machine needle or to a device for setting the feed dog. The contact mechanism comprises a contact finger which can be set by a handwheel, and a cam track connected to the handwheel, against one of the various cam track portions. The handwheel is mounted on a shaft carrying the control cam block, while the cam track connected to the handwheel forms a ring surrounding the control cam block. The contact finger directly engages the cam track, so that a control assembly of small overall length and having a small number of parts is obtained.

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

Abstract: An adaptor for sewing machines permits a fabric to be fed past the stitch forming area in a choice of two perpendicular directions. The adaptor includes feed dog means and a support plate for said feed dog means. A first connector assembly produces horizontal backward and forward reciprocating movements of the feed dog and support plate and a second connector arm assembly produces a horizontal sideways reciprocating movements of the feed dog and support plate. A rocker rod assembly mounted below the feed dog and support plate includes a pair of axially aligned rocker rods, one of the rocker rods being a powered rod and the other being a driven rod. The driven rod is operatively connected to the first connector arm assembly and the powered rod is operatively connected to the second connector arm assembly by way of a freely rotatable sleeve mounted on the powered rod.

Abstract: A thread tightening device for a sewing machine of the type having a main shaft, a vertically reciprocable needle bar with a needle carrying an upper thread, a loop taker and a drive shaft for driving the loop taker and a feed dog; the thread tightening device includes a group of pattern cams operatively connected to the main shaft, pattern selecting device and an arrangement for controlling the vertical movement of the feed dog. This arrangement comprises a control cam and a rotatable shaft, the control cam being slidably axially mounted on the rotatable shaft but not turnable with respect to the shaft. The thread tightening device also includes an element arranged for vertical reciprocating movement in a timed relation with the feed dog, which element engages a lower thread during the stitching operation of the sewing machine.

Abstract: A sewing machine with a feed dog vertically displaceable between an upper operative position and a lower inoperative position has a control element connected with a control shaft of a control motor and turnable by the latter within a predetermined range in two opposite directions, a cam element displaceable from an inoperative position to an operative position by the control element during turning of the latter in one of the directions, a cam follower normally engaging the cam element and displaceable from an inoperative position to a set position by the cam element during displacement of the latter from its inoperative position to its operative position and being further displaceable to an operative position by the control element during turning of the latter in the other of the directions, and a transmitting element operatively connected with the cam follower and the feed dog and operated by the cam follower during displacement of the latter from its set position to its operative position so as to displace

Abstract: A stitch-length correcting sewing machine and a stitch-length measuring presser foot assembly used therein are disclosed. The sewing machine and presser foot assembly enables stitches of a predetermined length to be sewn, without the necessity of stitching a trial stitch on a piece of fabric and adjusting the sewing machine to compensate for variations in fabric type and thickness. The presser foot assembly utilizes a presser foot which is detachably securable to a presser bar. A movable presser frame slides on the presser foot as fabric is fed. A potentiometer is fixed to the presser foot and responds to sliding of the presser frame so as to enable distance moved by the presser frame to be ascertained by detecting the resistance of the potentiometer. The presser foot assembly can be used as a fabric sensor responsive to fabric motion in an electronic sewing machine.

Abstract: A thread tightening device for a sewing machine of the type having a main shaft, a vertically reciprocable needle bar with a needle carrying an upper thread, a loop taker and a drive shaft for driving the loop taker and a feed dog, the thread tightening device includes a group of pattern cams operatively connected to the main shaft, pattern selecting device and an arrangement for controlling the vertical movement of the feed dog. This arrangement comprises a control cam and a rotatable shaft, the control cam being slidably axially mounted on the rotatable shaft but not turnable with respect to the shaft. The thread tightening device also includes an element arranged for vertical reciprocating movement in a timed relation with the feed dog, which element engages a lower thread during the stitching operation of the sewing machine.

Abstract: This disclosure relates to a four motion feed mechanism for sewing machines that is adapted to advance a work piece past the stitch forming point of the machine. Orbital movement is imparted to the feed dog by a drive mechanism including first and second linkage assemblies driven off a common eccentric arranged on the sewing machine bed shaft. A feed lift regulatory assembly is operatively connected to one of the linkage assemblies and is provided to selectively modify the amplitude of lift that is imparted to the feed dog of the machine.

Abstract: The invention relates to a sewing machine and more particularly relates to a device for directly driving the fabric feeding shaft of the sewing machine independently of the upper main shaft and the lower loop taker drive shaft so as to secure a correct movement of the feeding shaft in a timed relation with the upper main shaft and the lower loop taker drive shaft for the purpose of avoiding the breakage of the needle and the formation of loosened stitches.

Abstract: An upper layer feed mechanism in a sewing machine is disclosed herein. The upper layer feed mechanism comprises a first interlocking arm secured at one end to a horizontal feed shaft, an upper layer feed shaft rotatably supported on the machine frame of a sewing machine and having a second interlocking arm, a connector rod connecting between the first and second interlocking arms, an adjusting mechanism adjusting the connection between the second interlocking arm and connector rod, a support arm rotatably supported at one end on the machine frame, an upper layer feed arm rotatably supported at one end on the support arm and having an upper layer feed dog at the other end, a connection mechanism transmitting the rocking movement of the upper feed shaft to the support arm, a resilient means normally urging the upper layer feed dog downwardly and a means urging the upper layer feed dog upwardly against the resiliency of the resilient means.

Abstract: A sewing machine including stitch forming device, electrically driven means for driving the needle and the feed dog, a static memory to control the electrically driven means and a pattern selecting arrangement. The electrically driven means comprise a pulse motor for controlling a horizontal feeding amount of the feed dog and a clutch solenoid operatively connected to a shaft of the pulse motor. The device is provided with a feed control arrangement having an operating member to actuate the position of the feed dog. The clutch solenoid is operatively connected to the operating member and is energized in response to a stitch signal from the static memory to define the position of the feed dog in accordance with a selected pattern.

Abstract: A sewing machine provided with a set of pattern generating cams is also provided with a user-operated multi-setting pattern selector dial. When the selector dial is turned to a particular setting, to thereby cause the pattern generating cams to generate the corresponding pattern, a first mechanism automatically selects a respective feed pitch (amount of cloth feed per needle penetration), appropriate for the type of pattern selected. Accordingly, the user is not troubled to determine, by trial or error or otherwise, what feed pitch values would be clearly unsuitable for the selected pattern, and is instead automatically presented with a standard feed pitch value appropriate for the selected pattern.

Abstract: Digital control signals can be accepted and translated directly into low inertia, high torque intermittent rotary motion by this fast time response apparatus which comprises a low mass, rotatably mounted driving member, a source of driving torque such as a torque motor, a low rotary inertia torsion member which interconnects the driving member with the torque member to thereby apply torque to rotate the driving member, reciprocatably operated escapement means for controlling the rotation of the driving member, and a two-ended toggle linkage connected at one end in an operating relationship with the escapement means, and at the other end to a mechanism which supplies a reciprocating driving force. The toggle linkage has a normally flexible knee joint which can be selectively locked by electromechanical means to which the digital signals are supplied.

Abstract: In preparing for the sewing of fancy or complicated stitch patterns, on a sewing machine provided with a feed dog able to feed sewn material both forwards and backwards and also provided with a transversely shiftable needle for implementation of zig-zag effects, the sewing machine is operated as if to sew the stitch pattern desired, but without any cloth actually present beneath the machine's needle. The movement of the machine's feed dog and the transverse or zig-zag shifting of the machine's needle are both detected by transducers which generate corresponding electrical signals. These signals are processed and converted into a form suitable for application to the x- and y-inputs of an x-y recorder, which then generates a display of what the thusly simulated stitching pattern will look like when actually stitched on cloth. The transverse shifting of the machine's needle is readily detected and unproblematic because of its definiteness.

Abstract: A sewing machine is disclosed wherein positioning of the work feeding regulator is controlled by a digital actuator responsive to digital signals applied thereto. The positioning of the work feeding regulator is thereby adjustable in discrete increments. A manual override and feed balance mechanism is provided for effecting continuous positioning of the work feeding regulator.

Abstract: A sewing machine work feeding mechanism of the drop feed variety having a feed dog adjustably supported at one end of an elongated feed bar. The pivot end of the feed bar is supported between a pair of pintles by a trunnion pin. The trunnion pin is journalled in a threaded pivot pin which is supported within the feed bar by a threaded sleeve which is free to rotate within the pivoted end of the feed bar. The inclination of the feed dog with respect to the throat plate may be adjusted by turning the threaded sleeve against the threaded pivot pin, thereby changing the height of the feed bar with respect to the plane of the support pintles. The feed dog is attached to the feed bar by a feed dog carrier and a threaded stud which permits the height of the feed dog carrier to be adjusted relative to the feed bar, thereby allowing independent adjustment of the height of the feed dog above the throat plate.