Material thickness sensing device for sewing machines
AssigneePfaff Industriemaschinen GmbH
InventorOskar Braun
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Abstract
A sewing machine with a sensing device positioned ahead of a stitch-forming point, senses changes in the thickness of a material being fed by the sewing machine. In order to determine the difference in thickness, the sensing device has a pickup foot capable of vertical movement with a sensing surface that lies on the material adjacent the point the stitch is formed. A sensing lever is movably mounted on the pick-up foot with a sensing arm that lies on the material ahead of the sensing surface, a measuring member detects the relative movement between the pickup foot and the sensing lever.
Claims6
A sewing machine thickness sensing device for sensing the thickness of material being sewn at a stitching point, comprising a pickup foot having a material engaging sensing surface, means mounting said pickup foot for vertical movement with its sensing surface lying on the material adjacent the point at which the stitch is formed, a sensing lever movably mounted on said pickup foot with a sensing arm portion lying on the material ahead of said sensing surface, and a measuring member connected to said sensing lever and movable in response to the movement of said sensing arm portion on the material to indicate changes of thickness of the material by detecting the relative movement between said pickup foot and said sensing lever.
Dependencies are inferred from the claim text.