EARLE EG-2B Lock Bar Operators
Wherever, whenever Heavy Duty Connectors are required to support shear loads between two structures yet have the ability to be withdrawn to permit the structures to move, EARLE Lock Bar Operators have proved their value time and time again. This weatherproof, self-contained operator requires minimal maintenance and provides repeatable, trouble-free service.
Standard units are available in strokes up to 18 inches and may be adapted to accommodate even longer strokes. The operators are assembled from standard parts, stocked by Steward, and are readily available for new installations as well as replacement purposes.
Linear movement is achieved through an Acme lead screw and a driven, captive nut. Both members are packed with lubricant and totally enclosed, well protected and not exposed to contamination of foreign materials in the environment.
Repeated, accurate travel is controlled by enclosed, protected limit switches that are tripped by the lock bar. The units are completely shop assembled, adjusted and tested so that field installation time is minimized. A safety interlock is provided to prevent accidental starting of the motor while the unit is being operated with the emergency hand drive.
The lock bar operator includes a motor and brake, reduction gearing and limit switches in one weatherproof, self-contained assembly.
Gearing consists of double reduction generated helical gears of heat treated alloy steel. Anti-friction bearings are used throughout. The unit is provided with a removable hand crank for manual operation and a removable protective cover for the shaft end. Total ratio equals 19.4:1 and the operation of the lock bar takes approximately six (6) seconds to complete its 9" stroke. The operator is designed to deliver a thrust of 8,800 lbs. to the lock bars at 50% of the stall torque of the motor.
A superior quality high starting torque, induction type "D" flange motor is used. This 1.5 horsepower, 1800 RPM, 3 phase, 60 hertz, 240/480 volt, NEMA design D, frame B145TDZ, TENV Motor has a 15-minute duty rating and is equipped with a 3 ft.-lb. marine duty brake with manual release and safety interlock switch. It is a totally enclosed, non-ventilated, ball bearing motor designed especially for outdoor applications subject to adverse weather conditions.
Travel by the lock bar in each direction is governed by a two pole, snap-action limit switch. These provide two normally open and two normally closed contacts for each length of travel. A safety interlock switch is included, which when properly wired into the motor controller circuits, interrupts power to the lock bar motor. This prevents accidental operation of the lock bar and possible injury to personnel when the hand crank is used.
All parts of the operator are designed in accordance with ASSHTO Standard Specifications for movable Highway Bridges 1988, Paragraph 2.5.22 and AREA Specifications for Movable Railway Bridges 1989, Chapter 15, Paragraph 6.5.12.
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Note: Above Mounting dimensions are for 9" stroke. Longer strokes have longer mounting bases.
Now available in model EG-2B low profile with an overall height of just 13 inches for direct mounting on the lower flange of the bascule girder. Call for details.
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