Control key for extension adapter

A control key extension having engagement means for an operating key of the type having an elongate flattened bitted shaft having bits extending therefrom in a major plane of the shaft and having a proximal end and a distal end, an operating lever being provided at the proximal end, the extension comprising:

• a bitted shaft extending portion having one end adapted to engage the distal end of the operating key to locate a major plane of the extending portion in the major plane of the operating key to extend it at the distal end of the key, and having at least one bit projecting therefrom to lie in the major plane of the key when the one end of the extending portion engages the distal end of the key;
• a lever end having engagement means for engaging the key operating lever;
• and
• an elongate thin web connecting the extending portion and the lever end, the web having a first surface adapted to fit face to face with the flattened bitted shaft of the key and a second surface parallel to the first surface and its plane parallel with the major plane of the extending portion, the web having a longitudinally extending rib upstanding from the first surface, the rib being contoured for registration with a corresponding longitudinal groove of the key shaft.

In combination, a control key extension and an operating key, the operating key comprising:

• an elongate flattened bitted shaft having bits extending therefrom in a major plane of the shaft, a proximal end and a distal end and an operating lever provided at the proximal end, the extension comprising;
• a bitted shaft extending portion having one end adapted to engage the distal end of the operating key to locate a major plane of the extending portion in the major plane of the operating key to extend it at the distal end of the key, and having at least one bit projecting therefrom to lie in the major plane of the key when said one end of the extending portion engages the distal end of the key;
• a lever end having engagement means engaged with the key operating lever;
• and
• an elongate thin web connecting the extending portion and the lever end, the web having a first surface fitting face to face with the flatted bitted shaft of the key and a second surface parallel to the first surface and its plane parallel with the major plane of the extending portion, the web having a longitudinally extending rib upstanding from the first surface, the rib being contoured for registration with a corresponding longitudinal groove of the key shaft.