Ergonomic materials handling equipment protects one of your facility's most important assets – the health and safety of workers. Without equipment such as lift tables and overhead positioners, people often have to bend and stretch unnecessarily to maneuver bulky, heavy loads into position. In addition, ergonomic handling equipment minimizes excessive and repetitive movements that can cause musculoskeletal disorders and result in chronic pain.

The bottom line is good ergonomics is good for the safety and morale of your people. Good ergonomics also improves productivity while reducing absenteeism and costly worker compensation claims.

Lift tables and overhead positioners, two of the most widely used ergonomic tools, work two different sides of the ergonomic street, so to speak. Lift tables raise and lower loads to a desired working height generally in a stationary location. Overhead positioners are typically used to move loads from one location to another. Both are available in a wide range of capacities and configurations for a variety of ergonomic applications on the plant or warehouse floor.

Lift tables usually position loads weighing between 10 and 5,000 pounds; however, the largest models can handle loads of 70 tons. Typical lift table travel distance from the floor to the maximum height is 36 inches. Other standard travel distances are 24, 30, and 48 inches. The average lift table costs $2,000 and up, depending on the size and model.

There are several common uses for lift tables. They are perhaps best known for positioning items at the proper height at workstations. Lift tables also help feed materials to production machinery. Large paper rolls, metal coils, and steel beams are handled by lift tables. Warehouse workers often manually load pallets on lift tables.

To meet this range of applications, lift tables come in different designs. Vertical positioners, pallet positioners, stackers, tilters and upenders are the most widely used. Many operate manually while some are electrically powered.

Vertical positioners typically have a scissor lift and are very common in manufacturing. Some designs include a turntable that allows the load to be rotated. Pallet positioners are ideal for loading and unloading individual pallets. They eliminate the need for workers to bend by raising or lowering the load as items are placed on or removed from the pallet.

Stackers resemble mini forklift masts. They are used most often to stack shelves. In addition, they can be utilized in situations that are difficult for traditional forklift trucks to access easily. Tilters are lift tables that have a wire basket attached as part of the table. As inventory is removed, these items can be adjusted so that a worker does not have to lean over to retrieve product at the bottom of the container. Upenders reposition a load at a 90 degree angle.

Movement and positioning of lift tables is under hydraulic, pneumatic or mechanical control.

Hydraulic is the most popular, versatile and cost effective. These lift tables are, however, the least clean of the three due to their use of hydraulic fluid that may weep.

Pneumatic lift tables rely on compressed air to expand and contract cylinders or bags. These lift tables are the cleanest of the three and are ideal in dust free clean room applications. A downside to utilizing these devices is less lift precision due to the pneumatics.

Mechanical lift tables move loads with a screw linear actuator, which is comprised of a working ball and screw that lifts and lowers the table. Although typically the most expensive of the three, the mechanics of mechanical lift tables provide the highest degree of precision. In robotic and exact machining applications, for instance, these types provide the necessary lifting and positioning accuracy.

Overhead positioning equipment typically consists of a lifting device that is tethered to an overhead rail, workstation crane or other device that allows the operator to move the load from one location to another.

Just as with lift tables, there are several different designs of overhead positioners. For instance, vacuum lifters move loads in horizontal and vertical directions. Tilters angle the item to a new orientation, making it easier for workers to access a specific area. Rotators lift the item and then rotate it as required. Some are powered while others are manual.

Loads are lifted by pneumatic, vacuum, or mechanical means.

Pneumatic lifters are the most widely used. These devices use compressed air to first secure an item and then hold on to it during movement. Pneumatic positioners are extremely quiet, and are capable of lifting items ranging from 2,000 to 100,000 pounds.

Vacuum actuated devices, the next most widely used type of overhead positioning equipment, are ideal for quick pick and place operations. However, these lifters are not capable of moving especially heavy loads, generally operating in the 10 to 500 range.

Mechanical overhead positioners are the most basic of the three. One design uses a hook on a chain while another utilizes a grab mechanism to secure the load. While generally used for the simplest overhead positioning applications, mechanical positioners have the greatest weight lifting capabilities of the three types.

Due to the simplicity of design and ease of use, ergonomic overhead positioning devices can easily be adapted to complicated operational parameters required in highly automated facilities. The devices also help to free up valuable floor space in congested work areas, improving productivity and worker safety.

In short, ergonomic lifting equipment is a smart investment for facilities that are conscious of cost and worker safety.

Click this icon to read more about ergonomics.

Click this icon for more ergonomic information.

Other Helpful Ergonomic Web Sites:

www.ergonext.com
www.osha.gov
www.mhia.org/psc/psc_councils_ergonomic.cfm