Switchboard drawout apparatus with interlocked joint clamping and racking mechanisms

Drawout apparatus for racking an electrical device into and out of a compartment in an electrical enclosure, wherein the device and enclosure are respectively equipped with plural associated stab and receiver primary terminal connectors, said drawout apparatus comprising, in combination:

• A. a carriage mounting the device;
• B. means mounted by the enclosure and supporting said carriage for movement between a disengaged position and an engaged position through an intermediate test position;
• C. a racking mechanism mechanically assisting movement of said carriage and device between said test and engaged positions, said racking mechanism including a racking lead screw rotatably mounted by said carriage and having a head accessible at the front of said carriage to facilitate manual rotation pursuant to operating said racking mechanism to effect movement of said carriage and device between said test and engaged positions;
• D. a joint clamping mechanism mounted by said carriage, said clamping mechanism having joint clamped and unclamped conditions, with said clamping mechanism in said unclamped position, contact elements of associated stab and receiver connectors readily move into and out of lapped relation as said carriage and device are moved into and out of said engaged position, with said clamping mechanism in its clamped condition and the device and carriage in its engaged position, the lapped contact elements of associated stab and receiver connectors are clamped by said clamping mechanism in secure electrical interconnection, said clamping mechanism including a clamping lead screw rotatably mounted by said carriage and having a head accessible at the front of said carriage to facilitate manual rotation pursuant to operating said joint clamping mechanism to its clamped and unclamped conditions;
• and
• E. an access control assembly mounted by said carriage for movement between a first position affording access to said racking lead screw head while denying access to said clamping lead screw head and a second position affording access to said clamping lead screw head and denying access to said racking lead screw head, said assembly mechanically interlocked with the position of said carriage and the condition of said clamping mechanism such as to regulate movement of said access control assembly between said first and second positions.