Multi-circuit panelboard for circuit breakers

Claim 1

A PANELBOARD COMPRISING A METAL BASE MEMBER, A PLURALITY OF INTERMEDIATE INSULATING BLOCKS HAVING INTERLOCKING PORTIONS FOR ALINING SAID BLOCKS IN A UNIT AND EACH HAVING ON OPPOSITE SIDES THEREOF SPACED APART PROJECTIONS, SAID BASE MEMBER HAVING SPACED APART TABS OVERLYING SAID INTERMEDIATE BLOCK PROJECTIONS TO HOLD SAID BLOCKS AGAINST SAID BASE, AND GROUND AND TERMINAL BLOCKS SECURED TO SAID BASE AND HOLDING SAID INTERMEDIATE BLOCKS IN POSITION ON SAID BASE THEREBETWEEN, SAID TABS HAVING A SPACING THEREBETWEEN SOMEWHAT GREATER THAN THE SPACING BETWEEN SAID INTERMEDIATE BLOCK PROJECTIONS TO AFFORD INTERLEAVING OF THE LATTER SPACES BETWEEN SAID TABS TO PERMIT INSERTION OR WITHDRAWAL FROM SAID BASE OF AN INTERMEDIATE BLOCK WHEN ONE OR THE OTHER OF SAID GROUND AND TERMINAL BLOCKS ARE REMOVED FROM SAID BASE.