Patents by Inventor Kurt Bolldorf
Kurt Bolldorf has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 4444133Abstract: A multi-head embroidering machine comprises a work carrier to which movements relative to the embroidering heads and corresponding to the embroidery pattern are imparted by a coordinate control device. The work carrier is provided with guide rails which can be engaged directly, through a clutch mechanism, to the output sides of the coordinate control device. Each clutch mechanism comprises at least one guide roller which is connected to the output side of the coordinate control device, and a back-up roller which is mounted on a coupling lever, with the two rollers engaging the respective guide rail of the work carrier from opposite sides. This makes it possible to exchange a work carrier for a new one in standby position outside the embroidering machine, in a simple way and within a shortest time.Type: GrantFiled: May 2, 1983Date of Patent: April 24, 1984Assignee: Pfaff Industriemaschinen GmbHInventors: Kurt Bolldorf, Gottfried Schmidt
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Patent number: 4369721Abstract: A thread changer for an embroidering machine, having a plurality of needles for different threads, comprises, a driving shaft, a plurality of thread levers loosely mounted on the driving shaft, a coupling element for each thread lever connected to the driving shaft and rotatable therewith, and a clutch member connected between the drive shaft and the thread levers for coupling a selected one of the thread levers to the drive shaft to move the selected thread lever into association with a selected one of the needles.Type: GrantFiled: September 10, 1980Date of Patent: January 25, 1983Assignee: Pfaff Industriemaschinen GmbHInventors: Kurt Bolldorf, Ernst Bruckner
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Patent number: 4362114Abstract: A table top for an embroidering machine having a plurality of embroidering units with stitch plates which are arranged in a plane on an associated embroidering frame, comprises a step bearing adapted to be secured in position adjacent the frame. A bearing strap is pivotally mounted in the step bearing for rotation about a horizontal axis and it carries a table top which may be pivoted therewith between a horizontal position aligned adjacent the plane of the stitch plates to a substantially vertical position below the stitch plates. The pivot for the strap is located in a horizontal plane below the assemblies of the embroidering units. The position of the table may be finally adjusted by means of an adjusting screw. Construction includes a control shaft for actuating the embroidering units which are located beneath the units and extend over the entire length of the table top and is displaceable for controlling the embroidering machines.Type: GrantFiled: September 10, 1980Date of Patent: December 7, 1982Assignee: Pfaff Industriemaschinen GmbHInventor: Kurt Bolldorf
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Patent number: 4289086Abstract: A needle bar coupling in an embroidering machine which has a plurality of needle bars driven by separate cranks operated by a drive shaft, comprises a crank which is connected to the needle bar and to the drive shaft to move the needle bar upon rotation of the shaft. For this purpose a coupling or collar is engaged on the shaft and it carries the crank. A pawl is pivoted on the crank and it includes a tooth portion which engages in a groove of the coupling so that the coupling drives the crank when the shaft is rotated. In order to disengage the crank and the needle bar drive a contact member is provided adjacent the pawl which is shifted to engage the pawl and dislodge the tooth of the pawl from the coupling.Type: GrantFiled: September 19, 1980Date of Patent: September 15, 1981Assignee: Pfaff Industriemaschinen GmbHInventors: Kurt Bolldorf, Ernst Bruckner
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Patent number: 4285289Abstract: An embroidering machine comprises a plurality of embroidering head each equipped with a plurality of needles formed into a group each with its thread. A needle bar is engageable with one needle at a time in the group to bring the needle from a rest position thereof into an operating position. A presser foot mechanism with a presser foot attached cyclically moves the presser foot upwardly and downwardly from an upper dead center position to a lower dead center position. The presser foot is provided with a hole for the passage of the one needle. Thread cutting and holding devices are provided for cutting the thread of the one needle to form a thread end portion and hold the thread end portion. Upon the termination of an embroidering operation with the one needle, the presser foot mechanism is operable to move the presser foot substantially transversely to a longitudinal axis of the needles and, after the thread is cut, to lift the presser foot upwardly beyond its upper dead center position.Type: GrantFiled: September 11, 1980Date of Patent: August 25, 1981Assignee: Pfaff Industriemaschinen GmbHInventors: Kurt Bolldorf, Gottfried Schmidt
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Patent number: 4276838Abstract: In a machine for embroidering a workpiece of the type having a needle magazine, a plurality of needles movably mounted to the needle magazine to define a needle groove, each needle of the needle group equipped with a different thread, and a mechanism for selectively imparting axial reciprocatory movement to the needles of the needle group to perform a thread change, an improved arrangement is disclosed in which the reciprocating mechanism includes a single elongated needle bar associated with the group. The needle magazine is movable relative to the needle bar to selectively align each needle with the needle bar. A disengaging coupling permits a selected needle of the needle group to be coupled to the needle bar. A locking mechanism is provided for detachably locking each of the needles to the needle magazine.Type: GrantFiled: July 3, 1980Date of Patent: July 7, 1981Assignee: Pfaff Industriemaschinen GmbHInventor: Kurt Bolldorf
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Patent number: 4134346Abstract: A sewing machine for sewing buttonholes in a workpiece comprises a stationary lower part and an arm having one end pivotally mounted on the lower part and having an opposite end which carries a rotary hook which cooperates with a reciprocating needle carried in the lower part. The arm is pivotal relative to the base part to move the arm from a fixable sewing position with said hook spaced by a predetermined distance from the needle at a stitch-forming area to a rest position in which it is spaced away from the stitch-forming area. A thread-monitoring device is located adjacent the needle for monitoring the thread and detecting any breakage thereof. The machine includes a buttonhole cutting mechanism which is connected to the drive means so as to periodically cut the workpiece. A clamp is carried by the upper arm and it has a lower portion which rests on a resilient support which is biased upwardly by a spring.Type: GrantFiled: October 27, 1977Date of Patent: January 16, 1979Assignee: Firma Pfaff Industriemaschinen GmbHInventors: Kurt Bolldorf, Walter Hager, Gunter Tolle
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Patent number: 3991691Abstract: Stepping mechanisms are used to move an embroidering frame in both the vertical and horizontal directions on a machine frame. Each stepping mechanism includes a hydraulic cylinder-piston rod assembly, a multi-way valve for directing the flow of hydraulic fluid to the assembly, and an electric stepping motor connected to the valve for regulating the flow to the assembly. To effect movement a signal is transmitted to the stepping motor which positions the valve to operate the hydraulic cylinder-piston rod assembly. The piston rod is in direct contact with the frame and its movement provides the desired movement of the embroidering frame. The piston rod is connected to the stepping motor for closing the valve when the desired position of the embroidering frame has been reached.Type: GrantFiled: November 5, 1975Date of Patent: November 16, 1976Assignee: Pfaff Industriemaschinen GmbHInventor: Kurt Bolldorf