The FRL systems are mounted between the compressor and the pneumatic equipment (typically closer to the pneumatic equipment) so compressed air will flow through them. A filter removes particles from the airflow, and a built-in regulator ensures airflow remains at optimum, preset levels. The FRL systems are also equipped with a fill and drain that enable users to add lubricant, reducing wear to downstream pneumatic equipment.

Each basic model is designed for different applications. The New Deal FRL systems are all-metal aluminum composite units with semimodular construction, making them rugged and easy to install for most compressor applications, such as for power tools and automotive uses. These units also serve outdoor applications such as oil refining and natural-gas transmission.

The BIT FRL systems are miniature, measuring 40 by 40 millimeters and 102, 122, or 156 millimeters tall. Their compact size enables the units to serve in the tight spaces found in packaging and material-handling equipment. The components can be used to perform a single function or grouped to perform two or three functions together.

The Skillair FRL systems consist of three modules. Their bowls are made of Zytel and their bodies of Rynite, both DuPont technopolymers that enable the systems to resist the harsh industrial solvents used in chemical processing, process control, and conveying applications. Another technopolymer, Grillamid, made by EMI Chemie, is used for the Skillair filter bowls. All three FRL systems are equipped with a lockable three-position adjustment knob to prevent tampering.

At the heart of the actuator is a patented roller-screw actuator mechanism that Exlar researchers developed to convert electric motor power to linear motion. Planetary rollers attached to the actuator's extending rod follow threads machined on the inner surface of the actuator's hollow armature shaft. Linear motion is precisely synchronized with the armature rotation. An integral three-phase dc brushless servomotor enables the actuator to be installed in a conventional closed-loop servo system where electronic control of position and velocity is provided.

By using rollers instead of balls such as those in ball screws, the Exlar design allows a large contact area between all the rolling elements. This ensures a long life for the actuator, even at high loads and high speeds. All rolling members are rigidly supported by bearings, making the actuator capable of operating at armature speeds of 3,000 rpm. In addition, the critical elements of the GS actuators are sealed within the actuator's extruded aluminum casing, protecting them from the particles and corrosives found in most industrial environments.

In a dual-stage function, the batch controller monitors the amount of fluid passing through its flow sensor. As the flow total approaches the final batch quantity selected, the flow rate is throttled back to a fraction of its peak fill rate. The controller continues to monitor the reduced flow rate until the final batch quantity is obtained. This process eliminates overrun because less fluid is flowing when the valve is finally shut off. A truck manufacturer installed a Flowstar 2003 and a Hoffer Mini-Flowmeter outside a paint booth that sprays truck chassis. The controller is preset to deliver exactly 31.5 ounces of spray solvent for each chassis, which is within the 32-ounce limit set by the Environmental Protection Agency. The batch controller also totals the amount of solvent passing through the Mini-Flowmeter for verification purposes.

The Flowstar 2003 is designed to accept up to four flowmeter inputs, and it can communicate along RS232, RS422, or RS485 protocols. A liquid crystal display indicates the fluid flow for operators in either English or metric units.

The clutch is installed between the power take-off of the engine, the transmission, or the multipump gear box and a hydraulic pump or motor. Like previously developed Horton clutches, a series of dry multiple-friction disks transmits torque to the driven components, but their configuration has been altered to reduce the PTO clutchÕs width from 11.8 inches to approximately 7.3 inches. This allows the clutch to fit with the pump flange.
The main casing and flanges of the new clutch are made of anodized aluminum, replacing the nickel-plated cast iron of its predecessors; the shafts are made of an aircraft-grade steel alloy. These new materials cut the weight of the PTO clutch nearly in half, from 80 pounds to 42.5 pounds.

Because the clutch is designed to be engaged by either hydraulic or pneumatic pressure, its clutch disks had to be protected against oil seepage. This was accomplished by equipping the unit with Buna A seals, along with special coatings to the piston chamber.

The Horton Global 500 clutch has a rated torque capacity of 500 foot-pounds with maximum input capacity of 286 horsepower at 3,000 rpm. The other model, the Horton Global 250 clutch, has a torque capacity of 250 foot-pounds with a maximum input power rated at 150 horsepower. Both clutches are equipped with a manual engagement system. Municipal authorities, railway maintenance crews, highway commissions, and parks and recreation personnel are currently beta-testing the clutch on their emergency and sanitation vehicles.

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© 1996 by The American Society of Mechanical Engineers