Non-homogeneous cam, and operating mechanism and electrical switching apparatus including the same

An operating mechanism for opening and closing separable contacts, said operating mechanism comprising:

• a coupling mechanism comprising a non-homogeneous cam comprising:
• an eccentric disk comprising:
• two side surfaces having an opening extending therethrough, and
• a cam surface disposed between the two side surfaces,
• wherein the cam surface is defined by a first radius extending from a point within the opening to a number of first portions of the cam surface and by a plurality of second radii extending from the point within the opening to a plurality of second portions of the cam surface;
• wherein the first radius is greater than each of the second radii,
• wherein the cam surface comprises a first cam surface generally having the first radius and a second cam surface having a plurality of the plurality of second radii,
• wherein the first cam surface and the second cam surface define an angle of less than 90 degrees,
• wherein the eccentric disk is generally made of a first material having a first strength, and
• wherein a portion of the eccentric disk between the first cam surface and the second cam surface is made of a different second material having a second strength greater than the first strength.

An electrical switching apparatus comprising:

• separable contacts;
• and
• an operating mechanism structured to open and close said separable contacts, said operating mechanism comprising:
• a crank shaft,
• a pole shaft, and
• a coupling mechanism coupling the crank shaft to the pole shaft, said coupling mechanism comprising:
• a non-homogeneous closing cam fixed on the crank shaft, said closing cam comprising:
• an eccentric disk comprising:
• two side surfaces having an opening extending therethrough, and
• a cam surface disposed between the two side surfaces,
• wherein the cam surface is defined by a first radius extending from a point within the opening to a number of first portions of the cam surface and by a plurality of second radii extending from the point within the opening to a plurality of second portions of the cam surface;
• wherein the first radius is greater than each of the second radii,
• wherein the cam surface comprises a first cam surface generally having the first radius and a second cam surface having a plurality of the plurality of second radii,
• wherein the first cam surface and the second cam surface define an angle of less than 90 degrees,
• wherein the eccentric disk is generally made of a first material having a first strength, and
• wherein a portion of the eccentric disk between the first cam surface and the second cam surface is made of a different second material having a second strength greater than the first strength.