The Morgan House Lift
Handi-Lift, Inc. designed a vertical platform wheelchair lift for an open staircase, enabling accessibility from the atrium level into the original Morgan mansion on the Madison Avenue side of the new building. The lifting mast was concealed within a wooden enclosure at the side of the stair, with the opposite side against the architectural metal curtain wall. The mast was tied back to the stair stringer by hidden brackets that supplied rigidity to the lower- and upper-landing doors and support for the stair handrail. The call station at the lower landing was integrated into the end of the staircase railing and forms the lower newell post. The doors and enclosure walls of the wheelchair lift are all false, save the wood-encased mast. The wheelchair lift platform itself was also fitted with glass walls. All the glass was "bare edge" and connected with patch hardware maintaining the architect's vision of clear sight lines and reveals.
The lower door interlock was located in the floor with its deadbolt operating vertically to engage a strike plate located in the kickplate on the bottom of the door. The pivot point on the lower door engages a Tomax power-door operator in the floor. The operator is covered by a removable wooden panel that matches the flooring.
The lower platform is structural and difficult to modify, so the design evolved into two platforms. The top platform is thinner, creating a step down on the sides. This allows the glass support shoe to be beneath the finished floor, creating the appearance of floating glass panels. The car-operating station was custom fabricated in a rectangular stainless steel tube that also fastened to the lower platform and is centered on the side wall. The glass panels come to within one-quarter-inch of the stainless pedestal, again giving the illusion of no supporting hardware.
The vertical platform wheelchair lift is a hydraulic drive system, allowing Handi-Lift, Inc. to place a manual lowering valve on the top of the machine mast. The electrical disconnect is also located on top of the mast. This allowed the carpenter to build a cover on the top of the mast, rather than having a visible access door on the side. The car top cover and side panels are removable to allow maintenance and service for then wheelchair lift.
The system operates via a self-contained hydraulic motor pump and valve assembly. The valve opens automatically on pressure of the pump running and lowers by gravity when the down valve is actuated. The unit is held in place by a check valve.
The controls are dedicated micro-processor-based and operate at 24 VDC power. The in-floor Tormax power-door operator is a self-contained hydraulic door operator powered by 230 -volt three-phase AC. The operator meets all requirements for ADA compliance. The interlocks are a commercial grade Folder-Adams deadbolt type 401 and monitor door closed as well as secondary door locked.
Equipment Description
Vertical Lift at Morgan House
SW-72 Vertical platform lift by Garaventa
500-pound capacity with a factor of 5 for safety
ADA-compliant platform
1.5hp drive motor
Speed 20 fpm
Hydraulic/chain drive
Microprocessor-based control logic
Broken-chain safety with electrical cut-out protection
Keyed-call station operation with constant pressure
Platform keyless operation
Power operated lower landing door
The McKim Lift
This wheelchair lift travels from the open area of the atrium to the entryway into the McKim building. The design challenge was much different: This unit was to be nestled into a corner of an existing stair and platform that was all sawn limestone. The architect did not want the stair to be semi-enclosed as the other one was, the design was for a glass railing going up the stair on top of the stringer which also goes around the entire upper landing platform, so it was not an option to have a full-height lower door and enclosure, even if it were glass.
The design was to have the wheelchair lift against the wall where the stair stringer met the upper platform wall and to have a low wall opposite the stringer wall. This would have the wheelchair lift recessed into the space bounded by the stringer, upper landing and the short wall opposite the stringer. The car would carry a lower gate and side walls of glass that would be 42-inch tall, conforming to code. The upper landing would have a 42-inch high glass door integrated into the "bare edge" glass railings and the same "floating glass" design for the step down of the platform to accommodate the glass shoe support. The three interior walls of the shaftway are clad with the same sawn limestone as the stairs and walls in the area. A frame was constructed to hang on the lower side of the platform to allow a slab of the limestone to be attached under the wheelchair lift. By having a deep pit, the stone "skirt" could be under the car when it descended and visible when the car ascended.
Everything at the lower landing is finished in the matching limestone. At the upper landing, the platform glass door and glass side walls blend with the upper landing glass railings.
The hydraulic system is based on a CEMCOlift residential elevator power unit, using a direct acting self-supporting cylinder. The controls are of programmable-logic type by CEMCOlift and were modified to accommodate semi-automatic operation and constant pressure with anti-creep. The interlocks are a commercial grade Folger-Adams deadbolt type 401 and monitor door closed as well as secondary door locked. This allows one to look through the lift and does not interfere with the openness and sight lines. The architect's intent was to have the lift always parked at the upper landing to always maintain the invisibility of the lift, but have it available for immediate use.
With the constraints of no visible hardware and a solid stone skirt on the front of the platform, servicing the unit became an issue. The stone skirt could be removed, but would require at least two mechanics with rigging since the skirt was slightly more than the travel and equal to the platform width and one-inch thick. There was also the issue of possible damage to the stone work and the other finishes in the lobby in a main traffic area of the atrium. The solution was to have a manhole in the platform floor, interlocked with the final safeties. The platform was then covered with a removable finished wood floor. Now the mechanic can lift off the finished floor, open the manhole and have access to the cylinder, limits, selector and guide rail system.
With not having the luxury of a place to hide the lift mast it was decided to go with a direct acting hydraulic unit so HandiLift turned to Frank Giampa at CEMCOlift to design and supply a direct-acting hydraulic cylinder, pump unit and controller. The controller for the lift was a modified CEMCO residential elevator unit. The anti-creep feature was retained, since the lift would always be parked at the upper landing. The logic in the controller was modified to allow only slow speed constant pressure with leveling. The cylinder was fabricated with a flat one-inch-thick plate 24-inch square with triangular gussets on the bottom so as to be self supporting. The machine room was remote and located to the side and below in the basement.
The architect's design was to not have any visible hardware on the stone walls of the enclosure. Handi-Lift needed a way to guide the platform as well as to stop the lift from trying to rotate, so it proposed two small slots in the stone to allow guide rails behind the stone, with guide shoes on the platform. The idea was rejected. The architect did agree to allow the stone to be moved out 6 to 8 inches, thereby creating a cavity behind the stone which allowed us to install rail brackets and 8-pound rails. An angle iron frame was constructed to allow a pair of swivel guide shoes to be mounted beneath the platform to guide the car and stop any attempt at rotation. As an additional means of stabilization, a pair of roller guides were installed on the two platform sides that were 90 degrees from the rail wall. These roller guides were adjusted to just clear the wall as the lift ran. If the lift were to be loaded off center or the guide shoes lost adjustment then the roller guides would maintain proper running clearance.
Equipment Description:
Lift at McKim Building
Custom hydraulic vertical platform lift
500-pound capacity with a factor of 5 for safety
ADA-compliant Platform
1.5 drive motor
Speed 20fpm
Microprocessor-based control logic
Keyed-call station operation with constant pressure
Platform keyless operation
Complete custom design and fabrication
