Sewing machine presser bar mechanism
AssigneeThe Singer Company
InventorsEarl F. Dunn, Henry Erskine, Edward Hooper
Life of this patent
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Abstract
A low inertia presser bar system for a sewing machine has a short hollow presser bar including a light internal compression spring with an abutment member on top engaged in a depression in the underside of an arm of a fulcrumed bell-crank lever. An upper presser bar having a heavy spring is linked to the upper side of the same arm of the lever. A stop member is threaded into the head of the sewing machine to engage the other arm of the bell-crank lever to oppose and thereby limit the force of the upper spring and isolate the lower spring and presser bar until the lower spring is compressed solid.
Claims10
A presser mechanism for a sewing machine having a frame including a head overlying a work support, said mechanism comprising a presser bar having a presser foot on one end slidably journaled for endwise movement in said head, a force transfer member mounted in said head, first resilient means acting between said presser bar and said force transfer member for normally urging said presser bar toward the work support and said member away from the work support, a second resilient means acting between said head and said force transfer member for urging said member toward the work support with a force greater than that of said first resilient means, a stop acting of said force transfer member in opposition to the urging of the second resilient means for limiting the extent to which said member is urged toward the work surface thereby to isolate the presser bar and first resilient means from the second resilient means until a predetermined force on said first resilient means is exceeded, and means for adjusting said stop to change the predetermined force.
Dependencies are inferred from the claim text.