Rail Systems

The Ultimate Vacuum Gripper System

Rail system modules include all the features of an EDCO Vacuum Gripper with a positive or limited purge. In addition, they include a pilot-operated cartridge valve for vacuum on/off control. The modules mount to the side of a lightweight 1-1/2" X 3" rail profile. Air supply plumbing is completely eliminated by utilizing the rail as a manifold to distribute compressed air to each module.

Simple System Zoning

One of the most important features of the rail system is the ease and ability of zoning. Zoning groups several modules to a pair of 3-way solenoid pilot valves. One solenoid pilot valve controls the vacuum-on and the second controls the positive purge for each zone. Zones can include one to several modules and a system can have one to several zones. Systems should be configured with the smallest number of zones that provide the degree of control required for the application. If the requirements of the application change over time, the rail system can easily be reconfigured by adjusting the number of modules per zone and/or the number of zones per system.

Zones with small numbers of modules provide the most system control, however, they also require the largest number of solenoid pilot valves. Application example: picking and placing various sizes of cases onto a single mixed pallet load.

Systems with all modules controlled as a single zone are the simplest and require only two solenoid pilot valves. These systems are limited to basically on/off operation for all of the modules. Application example: picking and placing identical cases onto a single pallet load.

Positive Pressure Purge: PP

Air pressure supplied to the venturi is diverted to the vacuum port by blocking the venturi exhaust with a piston operated by a pilot pressure signal. Tool separation movement must begin immediately (no dwell) when purge signal is initiated to prevent exceesive positive pressure inside vacuum cups due to forces pressing the tool onto the work surface. Vacuum switches should not be used due to their limited over-pressure capability.

Limited Pressure Purge: LP

Limited Purge is similar to Positive Purge except it is modified to limit the pressure applied to the vacuum cup. Purge air flow is not as robust as with the PP option but the pressure is limited so a vacuum switch can be used for part presence detection.

Cleaning Operation

Some systems may not require the quick-release provided by the PP or LP options. For these systems, the purge pilot ports can be plugged and not used. However, it would be worthwhile to connect all the purge ports to one pilot valve to provide a brief reverse-flow cleaning action to blow out any ingest debris from the vacuum cups every few cycles depending on the application environment. This brief cleaning operation won't add to total cycle time and should be performed during the return-home period while vacuum cups are open to atmosphere.

Rugged Shear Key Mount

Two-point mount with shear keys eliminates the possibility of pumps shifting out of position during operation. Work loads are efficiently and directly transferred to the mounting profile so that mounting screws carry only tensile loads.