Abstract: A brushless direct current motor is provided with a rotor having a rare earth magnet within a nonferrous cylinder and a pair of coil windings which are air wound. To effect rotation of the rotor, current through the coils is controlled to rotate the resultant magnetic flux generated by the currents through the coils so that the rotor attempts to align itself magnetically with the resultant flux from the coils. Both coils are simultaneously energized and the polarity of current flow through the coils is reversed in such a manner that there is a current reversal through only one of the coils whenever the current is switched. Coil switching is directed by a triggering magnet fixed on the rotor shaft, which magnet operates Hall effect switches. The Hall effect switches in turn operate power switches to apply the correct voltage and polarity simultaneously to both windings.

Abstract: A tension device for sewing machines is disclosed having thread tensioning discs and a linear actuator for applying a compressive force between the discs. The invention is characterized in that for any given tension setting of the device, the applied compressive force, or tension, remains constant regardless of any variations in the spacing of the discs due to variations in the thread thickness, up to the range of travel of the linear actuator.

Abstract: A Hall effect switch device converted to a latching relay by having a reversible bias magnet attached thereto adjacent the Hall sensor so as to operate the switch circuit in one polarity of the bias magnet, and release the switch circuit in the other polarity of the bias magnet.

Abstract: A single air gap permanent magnet electric motor is provided with field magnets formed as thick annular segments concentric with the axis of rotation of a solid non-magnetic cylindrical armature. The field magnets are magnetized radially to the axis and have oppositely polarized pole faces facing the axis. The ratio of the thickness to the inner diameter of the annular segments is maintained within a defined range to provide for a high magnetic flux density across the single air gap.

Abstract: An electric motor, such as a rare-earth permanent magnet single airgap direct current motor is provided with generally longitudinally extensive heat transfer or cooling means comprising heat receptor elements adjacent but minimally spaced apart from and parallel the armature. These heat transfer elements are then cooled, as by being thermally connected with external heat discharging or dissipating structure to transfer the heat away from the motor. In one embodiment or modification the heat transfer elements project inwardly from a heat conductive end cap provided on its outer surface with heat radiating fins. In another embodiment or modification the heat transfer elements are hollow and a coolant, such as air, is circulated therethrough. The heat receptor elements may be provided with fins to increase their surface area, with the fins preferably facing the armature structure. The receptor elements are also preferably substantially coextensive with the active portion or windings of the armature.

Abstract: A sewing machine, wherein a stitch controlling instrumentality is positioned during operation of the machine by a motor acting through connecting linkages, is provided with a ring magnet that is connected to said linkages for angular displacement thereby about its axis and with a linear output Hall effect sensor that is disposed within the ring magnet to produce an output voltage proportional to displacement of the stitch forming instrumentality.

Abstract: A pump is disclosed having a housing with a recess therein, an elastomeric diaphragm stretched across said recess forming a pump cavity in which the medium being pumped is circulated, and inlet and outlet valves. An electronically controlled linear actuator is attached to the diaphragm within the pump cavity thereby allowing compactness in the construction of the pump and improved heat dissipation from the linear actuator. The pump fits within the frame of a sewing machine and creates an air vacuum for assisting in needle threading.

Abstract: A fixed speed sewing machine is disclosed having only start and stop control capability for the actual running of the machine. An arrangement is provided for controlling the acceleration of the sewing machine drive motor so that it is gradual, rather than abrupt.

Abstract: A pump for needle threading is disclosed having a housing with a recess therein, an elastomeric diaphragm stretched across said recess forming a pump cavity in which the medium being pumped is circulated, and inlet and outlet valves. An electronically controlled linear actuator is attached to the diaphragm within the pump cavity thereby allowing compactness in the construction of the pump and improved heat dissipation from the linear actuator.

Abstract: A circuit which limits the maximum permissible speed of a sewing machine motor when specific stitch patterns are selected. Electronic signals from a means for sensing the selected stitch pattern are analyzed by the circuit to control the operation of a relay which connects a resistance in series with the sewing machine motor to reduce the maximum speed at which the drive motor may be operated.

Abstract: A mechanism for detecting the depletion of bobbin thread in a sewing machine. A bobbin is formed with a polygonal core having a plurality of light reflecting surfaces contained thereon. A light source transmits a beam of light toward the polygonal core of the bobbin and the light reflected therefrom is intercepted by a photodetector. The polygonal reflecting surfaces contained on the bobbin core do not begin to reflect light until a sufficient quantity of bobbin thread has been consumed in the sewing process to expose a part of the reflective surface portion of the bobbin core. The rotation of the bobbin thereafter results in flashes of light being received by the photodetector. An electronic circuit analyzes the output of the photodetector and distinguishes between the flashes and steady ambient light to signal the impending depletion of bobbin thread.

Abstract: An operator manipulating means for a programable electronically controlled sewing machine. The operator manipulating means provides an array of switch points, each related in a row, to discrete needle positions attainable by the electronically controlled sewing machine; and in a column, to the least feed increment attainable thereby. The switch array is fabricated using a pair of printed circuits, one of which must be flexible and each having spaced, parallel conductors, and arranged with respect to each other so that the conductors of one are substantially perpendicular to the conductors of the other and are in facing relationship. The printed circuits are separated in a first embodiment by a pair of insulating sheets, each having an array of apertures in spaced registry with each other and aligned in rows and columns with the conductors on the printed circuits. The pair of insulating sheets are separated by a flexible conducting sheets which may be used as a common conductor.

Abstract: A controller to permit a sewing machine operator to control a sewing machine drive motor from control members located in close proximity to the needle bar. Means are provided to permit the operator to select the sewing speed and the needle stop position prior to commencing the sewing process. The operator may thereafter control the sewing process by light finger pressure applied to the control members without attention being distracted from the work feeding area. The operator may suspend the sewing process by removing pressure from the control members. The sewing machine will thereafter stop with the needle bar in the selected position. A reset circuit is provided to prevent the operator from unintentionally actuating the sewing machine drive motor.

Abstract: This disclosure relates to electric motor/actuators and in particular to an electric motor/actuator for driving a sewing machine and operating sewing machine controls regulating, for instance, the position coordinates of the resulting stitches formed by the sewing machine. The electric motor includes multiple non-magnetic armatures having commutated windings rotatable in a single air gap formed between opposing permanent magnets having their opposed polarized poles facing said armatures and wherein individual ones of said armatures are capable of different output functions free of significant interaction with others of said armatures.

Abstract: This disclosure relates to a direct drive feed mechanism for sewing machines which is driven by an electronically controlled reversible electric motor and includes a linearly operable feed dog mechanism which is compact in structure and modular in nature. More particularly, the disclosure of this invention relates to a novel four motion feed mechanism for a sewing machine wherein reciprocating feed motion of the feed dog is initiated by a reversible electric motor which in turn is controlled by electronic logic means. Because of the novel structure of this invention, the feed of the fabric by the machine can be readily controlled so as to be capable of producing a plurality of programmed feed patterns.

Abstract: A position sensing device is disclosed including an assembly of a Hall effect generator element shiftably supported relatively to a permanently magnetizable element. Each such Hall effect generator element being randomly chosen from an inventory of parts having wide tolerance limits of Hall effect output under like magnetic flux influence; and each magnetizable element from an inventory having a widely varying magnetic capability after exposure to like magnetizing influence. The magnetization of the magnetizable element of each such assembly being imparted thereto under control of the Hall effect output of the specific Hall effect generator in the assembly with the result that every position sensing device so assembled can be made to produce substantially identical Hall effect output in each relative position of said elements.

Abstract: The present disclosure relates to zig-zag sewing machines including means for controlling the bight stops in order to produce ornamental patterns. In particular, the disclosure relates to electronically controlled sewing machines having storage means for storing stitch information and wherein logic means are used to select and release stitch information in timed relation with the operation of the sewing machine. The disclosure of the invention has particular application in those sewing situations wherein it is desired to use more than one needle in a single needle holder of the needle bar which therefore necessitates a limitation on the magnitude of the jogging or swinging of the needle bar in order to accommodate the multiple needles in the aperture of the needle plate. In accordance with the disclosure of the present invention, whenever more than one needle is used switch means responsive to the presence of more than one needle automatically puts the machine into a multiple needle mode of operation.

Abstract: There is disclosed a sewing machine having a needle bar gate vibrating mechanism whereby the sewing machine is adapted to produce zigzag stitches. The needle bar gate vibrating motion is obtained through the use of two spaced apart circular magnets mounted on a rotating shaft of the sewing machine and having disposed between them a pair of bar magnets operatively connected to the needle bar gate, the polarization of the magnets being such that one of the circular magnets exerts attractive force on the bar magnets while the other circular magnet exerts repulsive forces. As the shaft rotates these forces reverse, resulting in the imparting of vibratory motion to the needle bar gate.

Abstract: The present disclosure relates to zig-zag sewing machines including means for controlling the bight stops in order to produce ornamental patterns. In particular, the disclosure relates to electronically controlled sewing machines having storage means for storing stitch information and wherein logic means are used to select and release stitch information in timed relation with the operation of the sewing machine. The disclosure of the invention has particular application in those sewing situations wherein it is desired to use more than one needle in a single needle holder of the needle bar which therefore necessitates a limitation on the magnitude of the jogging or swinging of the needle bar in order to accommodate the multiple needles in the aperture of the needle plate. In accordance with the disclosure of the present invention, whenever more than one needle is used switch means responsive to the presence of more than one needle automatically puts the machine into a multiple needle mode of operation.

Abstract: This disclosure relates to means for preventing the reciprocating needle of a sewing machine from operating in a zig-zag mode when a straight stitch throat plate means is positioned on the work bed surface. A latching means is provided for selective interconnection between the zig-zag jogging mechanism and the needle mechanism with said latching means being responsive to movement of the presser mechanism for unlatching the latching means. A locking mechanism is also provided to lock the latching mechanism in an unlatched position.