Abstract: A needle guide integrated in a thread cutter of a sewing machine installed with a hook operating about a horizontal axis and a feeding mechanism generating a relative movement as a feed motion between a workpiece and stitch former. The needle guiding element is incorporated with the thread catcher receiving member and alternately moved into operation by the thread cutter actuator. Adjustors are provided to position the needle guide with respect to the needle.

Abstract: A cutting device for a sewing machine is provided with a cutting instrument associated to a cutting zone. The cutting instrument is formed with a blade movable towards the cutting zone. Furthermore, a protective guard is provided with a blade cover surrounding the blade, movable from an inoperative position spaced apart from the cutting zone to a position in front of the cutting zone. The blade and the blade cover are drivable in such a manner that the blade is only movable towards the cutting zone after the blade cover has been moved in front of the cutting zone. In order to reliably position the blade cover in front of the cutting zone prior to the movement of the blade to the cutting zone for performing the cutting operation, a mechanical locking mechanism is provided for the blade, which is only released when the blade cover is positioned in front of the cutting zone. The blade cover is non-positively connected to its drive in order to prevent injuries by the blade cover.

Abstract: A thread cutting device for a lockstitch sewing machine having a rotary hook rotating in a horizontal plane, comprises a thread catcher which is pivotable in a horizontal plane and designed with a catch shoulder for needle and bobbin threads. The catcher cooperates with a stationary cutting tool as well as with a leaf spring which serves as a clamp for the end portion of the bobbin thread. The thread catcher is designed with a retaining shoulder by which the needle thread loop, upon being passed around the bobbin case, is caught and then released before being cut. The temporarily retained thread length substantially corresponds to the thread length which is pulled out sidewards while the thread catcher moves into its cutting position. Since no needle thread is thereby pulled off the thread supply by the thread catcher, only a minimum force is needed for moving the catcher.

Abstract: A thread cutting device for a double lockstitch sewing machine is provided with a rotatably driven hook including a hook beak for seizing a needle thread loop. In order to assure a safe pickup, the thread catcher performs an operating movement in a tilt direction oppositely directed with respect to the direction of rotation of the hook. Furthermore, the thread catcher is operable if the hook point has passed the stitch hole for a range of about 90.degree. considered in the direction of rotation of the hook.

Abstract: A sewing machine has a bobbin mechanism, a sewing needle mechanism, and a mechanism capturing and severing bobbin thread comprising a stationary blade, a picker having at least one hook for capturing a bobbin thread and wherein the picker is movable towards the blade to sever the bobbin thread. At least one notch is disposed on the picker for capturing at least one needle thread and is cooperative with the blade for severing the needle thread upon movement of the picker towards the blade.

Abstract: A manual thread cutter for a sewing machine is disclosed in which a cutting blade is supported on a canted surface merging toward the corner of the hollow interior of a face plate covering the head end of the sewing machine. A slot extends continuously through adjacent walls of the face plate approximately medially of the canted surface so that sewing thread may be drawn through the slot to the cutting edge of the cutting blade. A platform extends from one of the adjacent walls coextensive with the bottom surface of the slot so that thread may be pivoted about the platform and drawn into the slot to impinge upon the cutting edge of the cutting blade.

Abstract: A thread catcher of a cutting device in sewing machines is actuated by an air cylinder whose piston has two portions of unequal diameter. The small cylinder space accommodating the smaller-diameter piston portion is permanently pressurized while the larger cylinder space is alternately pressurized and vented. The larger cylinder space portion on its end closer to the smaller piston portion is permanently vented through a conduit. Both this conduit and the conduit for supplying the larger cylinder space include a throttle. The obtained effect is that the first step of motion of the thread catcher is quick and exact in duration, while the second step of motion is slower but performed with a greater force, so that thin threads are prevented from tearing prematurely and thick threads are cut reliably.

Abstract: A thread gripper and cutting device for a sewing machine is inserted in a cover plate (1) forming the working surface (A) of the sewing machine. Thus the thread gripper and cutting device is inserted in one of the corner points of the diagonal of an imagining square (y), with the point of needle penetration (x) lying in the other corner point thereof. A first clamping disk (8) is integrally joined via a marginal web (4c) with the shank portion (4a) of a retaining bush (4). The clamping disk (8), which is rounded on all sides, projects only a little beyond the working surface (A) and is slightly inclined with respect to the latter. The corresponding end face (12) of a second clamping disk (11) is urged, by means of a spring (14), against the inner face (9) of the clamping disk (8). This second clamping disk is seated on a pin (13) guided in the shank portion (4a). The lead-in slot (15) for the threads (F) lies at the highest point of the clamping plane formed by the clamping surfaces (9, 12).

Abstract: A thread cutter for a zig-zag sewing machine which has a needle which swings transversely to the material feed direction to form a zig-zag seam of predetermined width while the needle is reciprocated to pierce material to be sewn in cooperation with a revolving looper as the material being sewn is moved transverse to the swing direction and includes a cutting knife which cooperates with a movable catcher which is moved in time relationship to the rotation of the looper. The catcher is a plate-like member having an end terminating in the tip and a lateral edge on each side of the tip with one lateral edge having a first barb for engaging one leg of the needle thread loop and an opposite lateral edge having a second barb for engaging another leg of the needle thread loop, the one leading directly to the needle.

Abstract: A thread trimming device comprises a first ratchet disposed on a first shaft having a first partial gear, a first cam surface, a first radial projection, and blank surfaces on its periphery. A second ratchet disposed on a second shaft has a second partial gear, a second radial projection, and a second cam surface on its periphery. A stationary blade is secured to a framework. A pivotably movable blade is connected to the second shaft. A solenoid moves the second ratchet along the second shaft such that, upon actuation of the solenoid, the toothed portion of the first and second partial gears are engaged with each other to rotate the movable blade to an operable position relative to the stationary blade. Thereafter the first cam surface comes into contact with the second partial gear to slowly rotate the movable blade to cooperate with the stationary blade to perform the thread trimming operation.

Abstract: A thread cutter assembly in a sewing machine having a thread cutting cam which is driven by an opener shaft operated in response to the rotation of the rotary shaft of a rotary hook assembly. A movable edge is coupled to a cam follower engageable with the thread cutting cam. The engagement and disengagement of the cam follower and the thread cutting cam are controlled by a control mechanism to carry out a thread cutting operation.

Abstract: A solenoid operated sewing machine thread trimmer with a compression spring influenced armature, a spring offsetting permanent magnet, and solenoid coil means with energizing circuits alternately offsetting the permanent magnet freeing the compression spring to shift the armature in one direction or augmenting the permanent magnet to return the armature.

Abstract: An omni-directional thread cutter in a sewing machine including an annular groove formed in the cylindrical surface of the presser bar. The lower surface of the groove forms an acute angle with the cylindrical surface thereby forming a sharp cutting edge.

Abstract: This invention relates to a needle guard which is adapted to position the needle relative the lower stitch forming mechanism and further serves to minimize skipped stitches during the sewing operation. The needle guard is positioned beneath the work supporting surface of the machine and during the sewing operation is disposed proximate the needle path. Upon completion of the sewing operation the needle guard is retracted from the path of the needle. Adjustable means are provided so as to accomodate the needle guard to needles of various sizes and to permit positioning of the needle guiding surface with respect to the path of the needle.

Abstract: Apparatus for simultaneously cutting both needle threads and both bobbin threads for a twin needle tacker or the like; the apparatus being mounted to the bottom of the throat plate and being removable with the throat plate as a single unit.

Abstract: A thread-cutting device for sewing machines including a housing mounting a reciprocating thread guiding needle which cooperates with a revolving looper comprises a thread catcher adjacent the looper which is movable to engage the thread and to advance the thread past a fixed knife. The catcher is mounted so that it may move relative to the looper and the fixed knife to urge thread held by the catcher into cutting engagement with the knife. Double action fluid pressure operated piston and cylinder is connected to the catcher so as to move it relative to the knife and to the looper. A member is connected to the mechanism between the fluid pressure cylinder operator and the thread catcher and a spring has one end connected to the member and an opposite end mounted on the housing in such a manner that the force of the spring may be adjusted. A fluid pressure operated control has a movable control piston rod which is engageable with the member in an engagement portion thereof such as an opening therethrough.

Abstract: A picking arm for an underbed thread trimmer which engages the bobbin thread and one limb of the needle thread and holds them so that a thread catching arm may engage the bobbin and needle threads and draw them into severing relation with a cutting edge of a thread cutting blade. After the threads have been cut, the picking arm returns to a rest position with the end of the bobbin thread retained in a channel contained in its thread engaging extremity. The bobbin thread is held in a position where it will be available for concatenation with a needle thread for the production of lockstitches.

Abstract: Thread cutting device for lockstitch sewing machines equipped with vertical axis looptaker and provided with a thread catching member displacing around an axis parallel to the looptaker axis along a path passing over the looptaker, wherein the thread catching member is formed by a plate ending with a pointed portion having a notching extending upwardly for the needle thread catching and a small foil bent at a right angle relative to the pointed portion, the small foil being so shaped as to be provided with a bobbin thread catching zone and a bobbin and needle thread cutting zone, the cutting zone being closer to the sewn fabric than the needle thread catching zone and than the notching for the needle thread catching.

Abstract: Herein disclosed is a below the throat plate thread trimmer which is moved in a path from the right side of the rotary hook assembly, up and over it and then downwardly to the left of it. The path being in the nature of a compound angle whereby elements of the thread cutter portion pass into the needle thread loop at a most advantageous angle. After securing and separating the bobbin thread and respective legs of the needle thread loop, the thread trimmer is moved to position directly below the needle hole. While in this position the bobbin thread and one leg of the needle thread loop are cut.

Abstract: An underbed thread trimmer mechanism for severing the needle and bobbin threads upon completion of a sewing operation. Operation of the thread trimmer may be selectively initiated by operator command. A plurality of cams and members cooperate to transfer power from a loop taker shaft to a thread handling disc-like member situated in close proximity to the sewing machine loop taker. A thread cutting knife is disposed in covering relation to the thread handling member and cooperates with the thread handling member to trap the needle and bobbin threads and direct them to a knife surface of the thread cutting knife where they are severed. The mechanism that drives the thread trimmer resets itself at the completion of the thread cutting cycle.

Abstract: A sewing machine having a shuttle device rotatable in a horizontal plane. A shuttle opener is swingably provided at one side of the shuttle device and a shuttle retainer is provided at the other side for restraining the shuttle device against rotation. A thread catcher arm of the thread cutting mechanism is provided for swinging movement in a horizontal plane between an advanced position and a retracted position. A rotary solenoid provides the swinging movement of the catcher arm into the advanced position and a cam mechanism is provided for effecting the return movement of the catcher arm during which the thread cutting is performed.

Abstract: A driving mechanism for actuating an underbed thread trimmer in a post-type sewing machine. The unit is selectively controlled by a solenoid and actuated by two cams located on the hook shaft of the feeding post. Rotary motion of the shaft and cams is converted into translational motion for the trimmer by a pivoting swivel lever and cam follower combination.

Abstract: A thread-cutting device for a cyclically operated double lock stitch sewing machine forming part of an automatic sewing system serves to cut the needle and bobbin or looper threads, respectively, at the underside of the throat or stitch plate of the sewing machine in close proximity to the needle hole in the throat or stitch plate. For cutting of the threads, a cutting edge is moved with respect to a stationary cutting blade into a cutting position for simultaneously cutting of the two threads. The carrier for the movable cutting tool moves the stationary cutting blade into its effective cutting position and further carries thread control fingers which assist in preparing the threads for the cutting operation. The cutting mechanism is actuated by the control means for the cyclically operated double lock stitch sewing machine.

Abstract: A sewing machine thread trimming mechanism for severing both the needle thread and bobbin thread close to the workpiece at the end of a stitching operation and for providing a sufficient length of bobbin thread after trimming so that stitching on a succeeding seam may proceed. The thread trimming mechanism includes a trimming device having two pivotly connected moveable blades which are swingably mounted beneath the sewing machine throat plate. One of the blades is mounted for movement into the needle thread and bobbin thread path whereby engaging and carrying the same into severing engagement with the second moveable blade. The second moveable blade is eccentrically pivoted relative the first blade and is provided with a floating fulcrum which controls the movement of the second blade so as to produce a true scissor like action between the two blades.