Sometimes, a business needs to raise or lower materials in situations that don’t require a rider, and for such times, vertical reciprocating conveyors — such as those manufactured for decades by Gillespie Corp. — can be the perfect choice. In other situations, there may be a need to move both goods and personnel. Traditionally, a freight elevator with fully enclosed cab and hoistway has been the answer. But, what do you do when you need the functionality of a freight elevator, but without the accompanying costs or extensive building modifications?
Gillespie, of Ware, Massachusetts, has developed a low-cost alternative to freight elevators that will still allow riders, so when a client of Mobility Elevator Co. needed such a solution, Mobility turned to Gillespie. The answer? A Gillespie Type B Material Lift, which offers a limited pit depth and can be used by authorized riders. The Type B lift is covered by its own section under ASME A17.1.
Mobility Elevator’s customer, Spectrum Chemical of New Brunswick, New Jersey, wanted a low-cost lift to move material but that also could be used by plant personnel. In many instances, this would be accomplished with the installation of a standard freight elevator. This wasn’t a good option for Spectrum, however, because of the cost of building a hoistway. Compounding that problem was the fact that structural issues meant a variance would have been necessary to build a standard pit.
Gillespie has designed and manufactured numerous shallow-pit freight and passenger elevators around the country, but Spectrum did not want to go to the expense of a full-blown freight elevator.
Gillespie reviewed the constraints and determined a lift could be designed that would meet the requirements of a Type B material lift per A17.1, Section 7.4. These requirements include a maximum speed of 30 fpm, access and usage restricted to authorized personnel, and penetration of only one floor. Once it was confirmed that this lift would meet the proper requirements, the shallow pit (5-1/4 in.) became the next issue to be addressed. The A17.1 code permits the Type B material lift to accommodate shallow pits through the use of a nonremovable device that satisfies the bottom-car clearance requirement, so a solution was readily available. Gillespie engineer Yakov Mikhlin went to work designing the elevator.
The lift provided has a 5-ft., 4-in. by 5-ft., 4-in. platform. The travel is 20 ft., the capacity is 3000 lb., and it operates at a speed of 30 fpm. The pit depth is 5-1/4 in. The car is guided by two 15-lb./ft. T-rails connected to W-beams for stability. The unit has 13 ft., 4-1/2 in. of overhead, and the car is lifted by an overhead drum machine with a 5.4-hp motor. As stated earlier, the shallow pit depth meant non-removable devices were required to satisfy the bottom car clearance. When deployed, the devices stop the car 60 in. above the pit floor.
Although not required per code, the customer requested and the lift was provided with a Gillespie collapsible car gate. All the structural steel on the lift was powder coated blue, as were both the upper and lower landing wire-mesh enclosures, which were supplied by WireCrafters.
The lower landing enclosure is 19-ft., 3-in. high, while the upper landing enclosure is 8-ft., 5-in. high. Each enclosure has a 5-ft., 2-in. by 7-ft. double swing gate so that larger materials can be loaded onto the platform with a forklift. The gates are fitted with interlocks to ensure they can only be opened at the floor at which the car stops.
The nonremovable devices are mounted to the guide rails and use linear actuators to deploy and retract. There are two microswitches that monitor the position of the devices. One switch prevents the car from running unless the nonremovable devices are fully retracted, while the other switch prevents access to the shaft unless the nonremovable devices are fully deployed.
Control stations are located at the lower and upper landings, and the lower landing control station also has a key switch to control the non-removable devices. Additionally, there is a car-operating panel in the car that allows control by authorized riders. The lift has upper and lower normal and final limit switches.
To operate the lift, it is first called to the specific landing. Once it reaches the landing, the retiring cam extends and releases the interlock so the wire-mesh door is unlocked. From here, the lift can be loaded with material. The lift can then be either called or sent to the other landing. When the lift is called to another level, the retiring cam retracts, locking the wire-mesh door, and the lift begins traveling in the shaft.
As demonstrated by the Spectrum project for Mobility Elevator, the Type B material lift by Gillespie provides a practical, flexible and less-expensive alternative to the traditional freight elevator. The suppliers list was made up of:
• Elevator designer and manufacturer: Gillespie Corp.
• Installer: Mobility Elevator & Lift Co.
• Fixtures: Innovations Industries Inc.
• Machine: SEW-Eurodrive
• Wire-mesh enclosure and gates: WireCrafters
John Linsley is engineering manager for Gillespie Corp. He has 28 years’ experience in the vertical-transportation industry.
Demetri Kachulis is a project engineer for Gillespie. He has three years’ experience in the industry.