Motor isolator pulley
AssigneeThe Singer Company
InventorsAnthony D. Spasiano, Vaclav Jelinek
Life of this patent
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Abstract
A coupling in the drive train between a sewing machine motor and mechanism for driving the sewing instrumentalities of the machine is provided with resilient bumpers. The coupling is further provided with tangs which interface with the bumpers in a manner that is effective to render the spring rate of the coupling variable and reduce both vibrational effects and impact forces in the machine.
Claims6
A drive coupling including a rotatable cup with inwardly projecting fixed portions, a rotatable hub including stiff fixed tangs which project into the cup where they extend between the inwardly projecting fixed portions of the cup, and a plurality of identical non-metallic resiliently compressible bumpers which extend between said fixed hub tangs and inwardly projecting cup portions, and which constitute the only drive connection between the hub and cup for the transmission of torque therebetween, the tangs being formed with raised portions which alone engage the bumpers whenever less than a predetermined driving torque is applied to the coupling, and with other portions which engage the bumpers when said predetermined torque is exceeded to thereupon significantly increase the area of engagement between the tangs and bumpers and change the spring constant of the bumpers.
Dependencies are inferred from the claim text.