GSA Courthouse Management Group
Mechanical Lift Analysis Supplement
CHARACTERISTICS OF THE BASIC DESIGN
The design concept of the Spiralift consists of mechanical engagement between a heavy
gauge coiled steel strap which is slipped within grooves of a flat spring forming a ribbed
spiral column. The electrical worm-drive motor extends the spring vertically to allow
insertion of the strap into a groove on the surface of the spring. This design is referred to as a
tubular thrust screw. (See photographs and diagrams at the end of this section.)
These design characteristics minimize the compressed depth of the system by limiting the
height to the compressed spring and the recoiled steel strap in the collapsed configuration.
(The height of the Spiralift unit at a resting position is 9 in. and the thickness of the
platform will be approximately 2 in., which makes the depth required at a recessed pit section
containing the drive mechanism approximately 11 in. if the top of the platform is to be
flush with the courtroom well finished floor level.)
Limit switches govern the suspended height and the brake can be released allowing manual
lowering of the platform should there be a loss of electrical power. Control of the up and
down movement is by push buttons.
The smaller single unit Spiralift platform design operates in combination with heavy gauge
tubular steel scissors guide elements which help to provide stability.
ADAPTATION FOR ACCESSIBLE NEEDS
A custom design variation of the standard 6 in. unit includes an offset location for the
Spiralift operating mechanism, allowing the cantilevered platform to rest at a lower position.
(The only requirements for a recessed slab relate to the platform thickness and/or the
dimensions of the tubular members of the scissor guides.)
Paco Corporation was developing a version of the 6 in. Spiralift , to be sold in Europe for
accommodation of the physically disabled within the requirements of the newly enacted
accessible standards similar to those of ADA and UFAS in the United States.
FEASIBILITY FOR THE COURTROOM ENVIRONMENT
A discussion was held with the design and engineering staff at Paco headquarters to
determine whether it would be feasible to adapt a version of the 6 in. Spiralift for use in the
witness box and Judge's bench in compliance with the new design criteria as indicated in the
Mechanical Lift Analysis.
It was determined that a system design, using the Spiralift, can easily accommodate the
recommended standard clear platform area dimensions of 3 ft by 5 ft.
HDR Architecture, Inc.