Opinion ID: 1377
Heading Depth: 3
Heading Rank: 1

Heading: The Scissor Lift

Text: In 1999, JLG manufactured a scissor lift and later sold it to United Rentals. As 1 James Magoffe and the representatives of Anthony Magoffe and Camerino Ramirez brought the complaint. For the sake of simplicity, we collectively refer to them as “Appellants” unless named individually. 2 United Rentals settled the lawsuit and is not a party to this appeal. -2- described by the district court, a scissor lift is “a portable elevator on wheels with a retractable work platform.” (Appellants’ Appx. at 370.) This particular lift, a JLG Model 500 RTS, moves on four wheels with rubber tires and is capable of extending its work platform 50 feet above the ground. It has two control stations—a “ground control station” located on the lift’s base and a “platform control console” located on the work platform.3 Most field operations are performed from the platform control console, which is connected to the lift’s base by two electrical control cables. It houses numerous operating controls, including four leveling jack toggle switches each corresponding to one of the four hydraulic leveling jacks located at each corner of the lift’s base. In addition, a platform lift switch raises and lowers the work platform and the PQ controller, a joystick-style device, controls drive direction and steer angle when the lift is being moved horizontally. The platform control console also contains three interrelated speed switches: (1) a drive speed switch (allowing either fast or slow drive speed),4 (2) an engine speed switch (allowing either high or low engine speed), and (3) a pump speed switch (allowing high or low flow of hydraulic oil).5 The operation of the lift at high speed is attended by noticeably higher engine noise. The lift is designed with several safety mechanisms. The lift cut out switch 3 The ground control station is not relevant to this appeal. 4 At oral argument, JLG indicated fast speed allowed the lift to be driven at two miles per hour while slow speed limited the drive speed to one-half mile per hour. 5 Because the drive speed, engine speed, and pump speed are regulated together by the Drive Speed Cut Out Switch (DSCOS), they are collectively referred to as the “highspeed functions.” -3- prohibits the work platform from being raised higher than 22 feet unless the lift is leveled and stabilized with the four leveling jacks.6 The lift also includes a Tilt Alarm Warning Horn to alert the operator if the lift is not level (if the base is sloped more than two degrees in any direction). Another safety device, the Drive Speed Cut Out Switch (DSCOS), is closed only when the work platform is stowed (not raised over 6 inches). When the work platform is extended above 6 inches, the DSCOS no longer permits the unit’s high-speed functions to operate. The DSCOS has another critical function. At the same time it disables the highspeed functions, it disables the leveling jacks by opening a switch.7 The open switch prevents electrical power from reaching the leveling jacks, effectively making them inoperable; a user cannot extend or retract the leveling jacks until the work platform is lowered to 6 inches or less. In summary, when the work platform is stowed the leveling jacks can be extended or retracted. If the jacks are retracted, the unit can be driven — at the faster speed when the work platform is stowed and at the lower speed if the work platform is raised more than 6 inches (but less than 22 feet). The work platform cannot be raised above 22 feet 6 From the work platform (in a fully lowered position), the operator uses toggle switches to manipulate the leveling jacks until the lift’s base is level, which can be determined from a level bubble located on the lift’s base and visible from the work platform. 7 Industry design standards for scissor lifts with leveling jacks require the manufacturer to integrate an interlock device (cut out switch) to prevent a user from inadvertently retracting the leveling jacks once they are set. The DSCOS satisfied the industry design standard. -4- unless the leveling jacks are extended, the jacks are bearing weight, and the unit is level (and, of course, the lift cannot then be moved horizontally). Once deployed the jacks cannot be moved until the work platform is returned to the stowed position. The leveling jacks can only be moved by an operator in the work platform.8