The speed control is brutally simple: a carbon-pile rheostat in series with the 120 VAC 1 A sewing machine motor.
Cutex Foot Control Pedal w/ 3 Uneven Prong #6811 6812 for Kenmore Sewing Machine
Kenmore Sewing Machine Foot Controls for sale
Kenmore Sewing Machine Foot Controls for sale
Speed Control Foot Pedal 3 Round Unevenly Spacing Pins Fits Many Kenmore Sewing Machines 148.12071,1
Disassembly of Kenmore Sewing Machine Foot Pedals
Kenmore Sewing Machine Feet and Adapters version 2
Kenmore Sewing Machine Foot Controls for sale
Kenmore 385.19233 Sewing Machine Parts
Old Kenmore Sewing Machine Foot Control Repair – The Smell of Molten Projects in the Morning
IF OLD SEWING PEDALS COULD TALK PART 4: Kenmore's Foot Controllers Were a Sears Servicer's Dream!!