The efficient supply of compressed air and electricity to tools on assembly lines is not as easy as one might think. While small products can be assembled with tool movements limited to an area of 2 to 3 square feet, larger products, such as appliances, cars and earth moving-equipment, require workers to move around the product during assembly. In some cases, the worker is also required to walk alongside the product as it moves down the assembly line.

Tools connected to fixed power sources also require a central shelf or tray for storage, forcing workers to move back to the shelf to exchange tools, or to change or replace bits or sockets. If the associated hoses and electrical cords lie on the floor, this presents a hazard that can affect worker safety and workplace efficiency.

Tool rails with moving trolleys parallel to the assembly line can increase efficiency dramatically, and this is the approach taken by K¿bohrer Gel¿efahrzeug AG (Laupheim, Germany) for its Snowcat assembly line. The firm installed a W4-airsolutions tool rail with two independent trolleys from Wampfler AG (Weil am Rhein, Germany) on each of the four, 86-foot-long assembly lines for Snowcat cabs.

The tool rail and air supply line are combined in a single aluminum extrusion. The integrated air pipe can be fed at one or both ends of the system and 0.5-inch ball valves for tapping the air are pre-installed at 6-foot intervals. The ball valve outlets are connected to the trolleys with a polyurethane hose. The hose is enclosed in a plastic chain within the aluminum profile. This arrangement allows for very short hoses that yield high efficiency, because air pressure decreases as hose length increases. The trolley also picks up electrical power from bus bars in the tool rail.

Each tool trolley is equipped with a tool carrier for storing tools right on the assembly line. The tool control unit is attached to the carrier frame. Compressed air and electric power are delivered to the tools via a 0.5-inch diameter hose and five-conductor 14 AWG cable, respectively.

Tools are suspended from a spring balancer connected to the trolley. The trolley can be easily shifted to an exact location along a workstation up to 60 feet long, giving workers mobility along the assembly line. Furthermore, the mobile trolleys can accommodate more than one tool, so operators can exchange tools very quickly.

For more information on tool rails and trolleys, call 800-326-2899 or visit www.wampfler.com.