Mechanical brake for tap changers

Claim 1

Mechanical brake for the driving device of a tap changer, comprising a rotatable control disc and a brake mechanism; said control disc having a periphery comprising at least two parts of different radial lengths; said brake mechanism comprising a rotatable brake disc, a pair of brake shoes straddling said brake disc at one end thereof and being interconnected at the other end thereof for relative movement with respect to each other, and an operating rod; each brake shoe of said pair having a roller mOunted thereon between the said ends of said brake shoe; one end of said operating rod positioned between and abutting said rollers for longitudinal movement substantially tangentially with respect to said brake disc; said one end of said operating rod having a first section of a predetermined width, and second and third sections on opposite sides of said first section having a width greater than the width of said first section; said operating rod is in a first position when said first section is between said rollers enabling said braking shoes to contact said braking disc and in a second position when said second or third sections are between said rollers separating said braking shoes away from and out of contact with said brake disc; said operating rod having an end opposite said one end and said opposite end of said operating rod being connected to one end of a control arm; said control arm being pivotable and having a control roller journalled thereon and in abutment with said periphery of said control disc, whereby as said control roller moves over the different radial lengths of said periphery said control arm pivots and thereby longitudinally moves said operating rod between said first and second positions; and a means for driving said control disc and brake disc in unison.