Lifting curved or bent materials presents unique challenges because most standard vacuum pads and pad frames are nearly flat, so as to attach quickly and easily on flat surfaces. Vacuum pads designed for curved surfaces employ several special features to enable them to attach easily. Often, standard vacuum pads can be replaced with pads designed for curved surfaces and used on standard multipurpose and production line lifters. Because load capacity may be affected, consult your Authorized Wood’s Powr-Grip Dealer or Technical Sales Representative prior to exchanging vacuum pads.

In some instances, simply adding concave vacuum pads on standard vacuum lifters allows attachment to a curved load. Other applications may require special options or a custom lifter design, in order to accommodate more radical curves or bends. Pad mounting options, such as spring-shaft pad mounts and rotating pad mounts, can be incorporated along with concave vacuum pads for less radical situations. However, for materials with a large arc, a custom lifter may be preferable.

Custom vacuum lifters with specially shaped pad frames can be designed for nearly any concave or convex curve. These designs range from simple to complex and are available with manual or powered load movements and either AC or DC power systems. As mentioned in the previous article, concave vacuum cups require longer pumping cycles, so DC-powered lifters can incur increased battery discharge. Some designs incorporate adjustable frame curvature to accommodate a variety of material radiuses (see photo at left).

Wood’s Powr-Grip has compiled a Vacuum Lifter Selection Worksheet in order to help consumers identify specifically which type of vacuum lifter is the best choice for their application. For additional information contact an Authorized Wood’s Powr-Grip Dealer or factory Technical Sales Representative.

Joe Landsverk is the Marketing Director of Wood’s Powr-Grip. With more than 20 years service, he oversees and coordinates the company's day-to-day marketing and advertising activities.