Abstract An apparatus for automatically guiding sheet material substantially in its own plane and relative to an operating zone by numerical control. The work, for instance a flexible fabric to be stitched in a sewing machine along a predetermined path, is moved in precise directional increments the X and Y components of which are imparted between tool strokes or needle insertions by coacting motive means in a non-rectilinear coordinate system. Low inertia is attained by a movable work supporting or clamping structure wherein a pivotal Y-arm carries a motor for moving an X-arm about its pivot, and the pivotal X-arm carries a motor for moving the work clamp and work radially relative to the X-arm pivot. A pulse generator coupled to the machine embodying the invention, illustratively a sewing machine devoid of conventional work feeding means such as a dog, provides multiple pulsing per revolution of a main crankshaft, and a pulse counting means signals each motor to yield an intermittent feed each controlled step of which is accelerated-decelerated between selective, variable dwells.
Inventors
👤 H Schaefer
👤 R Williams
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-25 16:38
CPC Classifications
D; D05; D05B; D05B23/00; D05B33/00
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
160 words
In an automatic work guidance mechanism for a sewing machine having a rotary crankshaft and a needle cyclically operated thereby, the mechanism having a member engaging the work for movement parallel and normal to its own plane relative to the needle, a pulse generating synchronizer energized by the crankshaft, and means responsive to the synchronizer pulses for providing stepping motor driving pulses, means mounting the member for movement in substantially incremental X and Y directions parallel to the work plane comprising: a coordinate arm only pivotable about an axis normal to the work plane; a first stepping motor operatively connected to the pivotable arm by a rack and pinion for swinging the arm; a second stepping motor operatively connected to the arm by a rack and pinion and to the member for radially shifting the member relative to the pivotal axis of the swinging arm; and means interconnecting the stepping motors and the driving pulse means for driving the motors.
Claim 2
Dependent Claim
160 words
In an automatic work guidance mechanism for a sewing machine having a rotary crankshaft and a needle cyclically operated thereby, the mechanism having a member engaging the work for movement parallel and normal to its own plane relative to the needle, a pulse generating synchronizer energized by the crankshaft, and means responsive to the synchronizer pulses for providing stepping motor driving pulses, means mounting the member for movement in substantially incremental X and Y directions parallel to the work plane comprising: a coordinate arm only pivotable about an axis normal to the work plane; a first stepping motor operatively connected to the pivotable arm by a rack and pinion for swinging the arm; a second stepping motor operatively connected to the arm by a rack and pinion and to the member for radially shifting the member relative to the pivotal axis of the swinging arm; and means interconnecting the stepping motors and the driving pulse means for driving the motors.
Claim 3
Dependent Claim
21 words
A mechanism as in claim 19 additionally comprising a second arm supporting the first stepping motor for swinging the pivotable arm.