A Through W: A Glossary of Glass Lifting and Handling Terms

By Jordan Scott

Lifting equipment has become an increasingly important tool for glazing contractors as glass becomes heavier and jobsites become more complex. There are several considerations when purchasing or using the equipment. Here is a glossary of important terms as defined by the experts:

Actuator – This is a mechanical device used to manipulate a load without manual effort. Rick Bigbee, vice president of sales at Bailey Crane & Aerials in Muskego, Wis., says it’s important for glaziers to know if their machine has the ability to move up, down, left and right 180 degrees. It’s important for overhead placement and picking glass up off of a flat surface.

Annually – This is how often a glass lifter should be serviced, according to Rick Carlei, director at Quattrolifts, who says lifters should be serviced and load-tested at least once a year. A load test involves lifting the maximum weight that the equipment is supposed to be able to lift. Carlei explains that a stress test should also be performed. This involves applying twice the lifting capacity to ensure that nothing will fail. However, daily checks should still be performed to ensure the equipment is functional.

Boom – A boom is the part of a lifter that moves toward and away from the machine  with a load. Some booms can extend as far out as 9 feet, says Jerry Nudi, principal at Ergo Robotic Solutions.

Counter balance – This is weight placed toward the back of the machine to keep it in balance so it doesn’t tip over when lifting heavy glass, adds Nudi.

Deflection – If vacuum cups are placed too far from the edge of the glass, deflection, a “bending” of the glass, can occur. Nudi says a certain amount of deflection is expected but too much can stress the glass and cause it damage. He explains that greater amounts of deflection are more likely when installing a skylight or table that will lay flat.

Extension bars – Nudi describes these as bars that hold the vacuum cups on the glass  manipulator. They typically are moveable so the cup array can be changed and made smaller or larger. They are adjustable to accommodate everything from lifting a 2- by 4-foot window or a 10- by 15-foot window.

Fine proportion control – A responsive control allowing the machine to move quickly if the controlling person moves quickly. If the controls are moved slowly the machine will move slowly in proportion to the controller’s movement.

Fin lifter – Glass lifting and handling companies have created fin lifters to solve a problem in the industry. Fins are often long and thin, according to Nudi, meaning that they require a long and thin vacuum assembly to hold and lift them into place. Fins also often are made of several layers of laminated glass, which makes them heavier.

Ground condition – Carlei says it’s important to ensure that the condition of the floor or ground at a jobsite is level to avoid making the machine unstable.

Height-to-center of glass – An important measurement to know. It tells how high the center of the glass is from the ground where the machine is located. Nudi says the center of glass height is used most often because lifters pick up the glass where the center of weight is located, which is most often the center of glass.

Inside-out set – This is a situation where the glass handler is inside a building and has to mount a window on the outside of a building, according to Nudi. This often requires tilting the glass, driving the handler forward, then re-tilting the glass and pulling it plumb against the window.

Jumbo glass – Glass will continue to become larger and heavier, and some companies will need to purchase larger handling machinery. Carlei says many glass companies are still installing manually. The larger glass sizes are pushing them to purchase automated machines.

Load chart – This is a chart on a lifting or handling machine that indicts how many pounds can be lifted within the machine’s range of motion. It will indicate the maximum weight as the arm gets higher and farther out from the machine.

Micromotion – Nudi says micromotion is a tiny movement of the machine useful for precision. The setting cuts down the power of the movement so the machine can move slower.

Nominal diameter – This is the approximate diameter of a vacuum cup, measured to the outermost sealing edge and rounded. Bryan Wood, president of Wood’s PowrGrip in Laurel, Mont., explains that the actual diameter may change slightly when the vacuum cup is attached to glass, but the nominal diameter provides what it calls a consistent and convenient way to identify the size of the cup.

Non-marking tires – Steven Brooks, national sales director for SmartLift US in Frankfort, Ill., explains that these are white tires that prevent all types of floors from becoming marked up when working indoors.

Overhead system – Gary Bond, head engineer at Wood’s Powr-Grip, defines these types of systems as a permanent apparatus used to suspend a “below-the-hook” lifter over a work area. Examples include a bridge or jib crane.

Pedestrians – While glass lifters improve the safety conditions of glazing installers, they can present a hazard to people around the jobsite at level and on the ground. Carlei says it’s important to make sure the machine and area are safe before operating the equipment.

Puncture-proof tires – These tires are injected with foam so that if a lifter runs over a nail that tire won’t go flat, making the machine inoperable. Brooks says companies can choose this option for most machines.

Quick connect – This is a type of fitting that can be connected or disconnected rapidly without the aid of tools. Barry Wood, vice president of marketing and commercial development at Wood’s PowrGrip, says his company uses this for some of its below-the-hook vacuum lifters when they need to connect to a compressed air source or to allow the removal of a pad arm or pad frame section.

Ramp – A ramp allows companies to get a lifter in and out of a trailer or sprinter van, says Brooks. It’s important for companies to know that they can transport these machines to and from the jobsite themselves.

Redundant vacuum – Many glass lifters have a redundant vacuum pump in case the primary one stops working. This prevents glass from falling, breaking or potentially harming someone.

Renting – Renting is an option for glazing contractors. Bigbee says a company should purchase a machine that does 80% of their work. “If they only need to use a specific lifter once or twice a year then they should look for a rental alternative,” he says, adding that it doesn’t make sense to spend twice as much on a machine to lift heavier glass if they would only use it 20% of the time.

Safety – Using a glass lifter helps to prevent injuries, says Carlei. These machines prevent glaziers from having to lift heavy lites of glass or, sometimes, from having to work at a height where falling is possible. Not having to lift glass reduces strain overtime and reduces the risk of an accident.

Serviceability – It’s important for companies to know if parts for their equipment can be accessed locally or if they need to be imported, says Bigbee. He adds that the person who does forklift maintenance for a company should be able to handle the maintenance and annual inspections  needed for glass lifters as well.

Skyhooks – Skyhooks are underhook devices used to lift windows and keep them balanced. They generally have moveable counterbalances and keep them balanced when lifting heavy glass. This prevents glaziers from having to reach out a window with handheld cups to pull the glass toward the opening, which puts them at risk.

Temperature considerations – When operating a lifter in below-freezing temperatures, Carlei says it’s important to dehumidify the vacuum system so it can operate properly.

The floor – Keep the floor in mind. Some floors can’t withstand the weight of a glass lifter and glass. Carlei says it’s important to determine a floor’s load capacity before bringing a lifter inside. He points out that this is especially important in older buildings.

Transportation – Bigbee says a company being able to transport a machine themselves is important. He explains that most lifters can be accommodated with a single- or dual-axis trailer.

Upright horizontal or vertical – Bond defines the upright horizontal orientation as being in a vertical plane with the long dimension of the glass running horizontally. The upright vertical is the opposite, with the glass being oriented in a vertical plane with the long dimension running vertically.

Vacuum cup assembly – Vacuum cup assemblies take the vacuum cup to the next level, according to Nudi. He says this equipment has everything needed to be hooked up to a machine, including the nuts, bolts, springs and cups. These assemblies also can include an offset that gives an assembly depth to prevent it from hitting a mullion or other obstacle.

Weight rating – A weight rating informs the user how much the equipment can lift. Nudi says that many people pay attention to the total maximum rating, but that will change depending upon how far out the boom is from the machine.

Wireless remote control – While many modern glass lifters come with wireless remote controls to move the machine and the glass, it can be better to use the hard-wired controls because they give the operator a better sense of a machine’s movement.

To view the laid-in version of this article in our digital edition, CLICK HERE.