Adjustable clamping arrangement for magnetic mounting plate

An arrangement for mounting a drill press on a manhole cover comprising:

• an adjustable plate having an arcuate periphery defined by an arcuate rim projecting below the plate and being substantially concentric with an axis of the arcuate periphery;
• wherein the plate mounts the drill press on a manhole cover;
• an electromagnetic fixing the drill press to the plate;
• a plurality of brackets located in spaced relation on the arcuate rim of the plate and an L-shaped clamp slidably disposed in a slot in each bracket;
• the L-shaped clamp having a first arm extending in the direction of the axis and a second arm extending radially inward toward the axis with the first arm being slidably mounted in the bracket;
• the bracket having a first screw for engaging the first arm to an axial position, the first arm in the bracket holding the second arm in clamping position with respect to the manhole cover;
• a second screw threaded through the manhole cover in alignment with the second arm for clamping the plate to the manhole cover, and
• an enlargement disposed on the first arm of the L-shaped clamp, which enlargement has a dimension larger than the slot in the bracket through which the first arm is received, wherein the L-shaped clamp is loosely retained in the slot in the bracket by the arrangement and second arm until the first screw is tightened.