Patent ID: 7845119

Claim:
An access unit for location in an opening in an upper floor, the access unit comprising: a support frame having a generally 0 -shaped configuration with an open central region, the support frame including U-shaped first and second members with an open end of each U-shaped member facing one another, each of the first and the second members comprises a base frame of fixed width defining one end of the open central region, and a pair of spaced apart side arms extending parallel to one another from opposite ends of the base frame; the pair of side arms of the first member being telescopically received within the pair of side arms of the second member to facilitate adjustment of a length of the open central region; and the open central region, defined by the base frame and the pair of spaced apart side arms of the first member and the base frame and the pair of spaced apart side arms of the second member, being completely unobstructed and open without anything being located between the base frames for the first and the second members so as to allow unhindered passage of a person through the open central region, and the telescopic adjustment of the pair of spaced apart side arms facilitates desired spacing of the base frame of the first member from the base frame of the second member over a range of distances; and each of the spaced apart side arms of the second member having a clamp for temporary securing of the side arms of the first member to the side arms of the second member at a pre-determined relationship and maintaining the desired spacing of the base frame of the first member from the base frame of the second member; only the second member having a pair of spaced apart vertically adjustable props which are pivotably attached adjacent the base frame of the second member for supporting the second member at a desired level; the first member having a flame arranged for overlying a support surface, at the first location, so that the flange at least partially overlaps a surface of the first location and solely vertically supports the first member at the first location; and the pair of spaced apart adjustable props of the second member facilitate positioning of the second member at substantially a same level as the first member, supported by the flange, so as to position the support frame of the access unit within a stairwell in a substantially horizontal orientation.