Sew length control and measuring apparatus
AssigneeLevi Strauss & Co.
InventorHubert Blessing
Life of this patent
Estimating the term…
Abstract
The lengths of at least a pair of limp workpieces fed through a work station are controlled by pressing each of the workpieces into engagement with a separate toothed wheel and by controlling the rotational velocity of one of the toothed wheels as a function of the rotational velocity of the other toothed wheel. In one preferred embodiment the contorl of the rotational velocities of the two wheels is accomplished by means of a differential gear and a motor which operates under the control of rates of feed sensors which monitor the rates of feed of the two workpieces.
Claims10
In combination with a sewing machine of the type having reciprocating feed dog means for drawing one or multiple limp workpieces through the sewing machine, apparatus for controlling the lengths of the workpieces as they are drawn through the sewing machine, the controlling apparatus comprising a pair of wheels, means for separately, rotatably supporting the wheels and for biasing each of them into rolling engagement with a separate one of the workpieces, means for intercoupling the wheels to control the rotational velocity of one of the wheels as a proportion of the rotational velocity of the other wheel, and wherein the controlling apparatus is attached to the sewing machine ahead of the feed dog means taken in the direction of travel of the workpieces through the sewing machine.
Apparatus for controlling the lengths of one or multiple limp workpieces as they are drawn through a work station, the controlling apparatus comprising a pair of wheels, means for separately, rotatably supporting the wheels and for biasing each of them into rolling engagement with a separate one of the workpieces, and means for intercoupling the wheels to control the rotational velocity of one of the wheels as a proportion of the rotational velocity of the other wheel, the wheel intercoupling means including a motor, a differential gear having two inputs and an output and wherein one of the wheels is connected to drive one of the inputs of the differential gear, the motor is connected to control the other input to the differential gear, and the other wheel is connected to the differential gear output.
Dependencies are inferred from the claim text.