EARLE^® GEAR

In 1986, Steward Machine Co. bought the assets of Earle® Gear and Machine Co., Philadelphia, Pennsylvania. The same reliable Earle® Gear Speed Reducers and Lock Bar Operators are now being manufactured by Steward Machine Co. in Birmingham, Alabama, utilizing Earle® concepts and engineering data.

Earle® Speed Reducers are specially designed and manufactured to meet the demands of low-speed, high-torque applications. They have been used successfully for more than 90 years to operate movable bridges, in heavy lifting and hoisting machinery, and other custom drives. In addition to conforming to appropriate American Gear Manufacturers Associate standards, Earle® units also incorporate the benefits gained by such long experience. They have been designed with reserve strength and dependability to safely control massive inertial loads.

Earle® pioneered the development and use of Differential Speed Reducers in movable bridge operating machinery systems, and Earle® reducers continue to occupy a position of leadership in that field. The differential reducer incorporated a balanced, three-pinion, bevel gear assembly which ensures load sharing between the two output shafts.

Earle® Speed Reducers are compact, self-contained, fully enclosed units of high mechanical efficiency. Quiet in operation, they provide for automatic lubrication of gears and bearings. The large variety of sizes and capacities available is listed and illustrated on the following pages. In addition, we specialize in designing and manufacturing custom gear reducers and mechanical drives for unusual applications.

The Cushionloks® system consists of a rectangular bar that fits through a guide on one leaf tip and into a receiver on the other. This allows shear load transfer from one leaf to the other, so the leaf tips deflect uniformly during the passage of vehicular traffic.

Stiff disc springs support the wear shoes in the guide and receiver housings and ensure firm, continuous contact between the bar and shoes. Shock loads to the bar are reduced, zero clearance exists between the bar and shoes, and uncontrolled bounce of the leaf tips is eliminated.

The first Cushionloks® were installed and put into operation in February 1995 on the Bellaire Causeway Bascule Bridge, Pinellas County, Florida. Since then, many have been installed on bridges with varying sizes and traffic loading. Lock bar sizes range from 4 x 6 inches to 7 x 10 inches for shear load transfers from 25,000 lbs to 120,000 lbs. per lock bar. In all installations, the maintenance savings have been significant because bar and shoe wear has been reduced and emergency maintenance has been minimal. The leaf tips continue to deflect uniformly and without pounding or noise during the passage of heavy traffic.

Several improvements have been incorporated into the current production of the Cushionloks® guide. The most significant is the addition of screw adjustable spring settings.   Now all preload is set by simply tightening a threaded cartridge.  This way, preload can be added or subtracted anytime without removing the lock bar or shoes or dissembling the spring stacks.

Standard Models:

• EG-2B9 to 14 inch
• EG-316 to 26 inch
• EG-4XL15 and 20 inch

Wherever heavy-duty connectors are required to support shear loads between two structures yet can 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 28 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.

Benefits:

• Steel housings
• Two-piece, split construction
• ASTM B-22 bronze bearing
• AASHTO and AREMA load ratings
• Two-way thrust capacity
• Sub-drilled or blank mounting holes
• Brass, laminated liners
• Double spiral lubrication grooves
• Giant button-head lube fitting
• 1/2 inch nominal, full size, stainless steel shim packs

Specifications

Housings:

Housings are ASTM A38 plate steel. Two-piece split construction with accurate cap and base registration. Caps are secured by threaded studs with double hex nuts. The cap is equipped with a button head lubrication fitting threaded directly into bushing. Base bolt holes are blank to permit field drilling and reaming (AASHTO 6.7.7.1.1).

Bushings:

Double flanged, split-type bronze bushings conforming to ASTM B22 UNS ALLOY C91100. Counter sunk flange screws are used to secure the bushings in the housing and prevent rotation. Bushing bores have ¼” wide x ⅛” deep double spiral grooves for grease distribution (AASHTO 6.7.7.1.2)

Liners:

Each pillow block is furnished with ¼” thick brass liners consisting of one solid piece of 0.125” thick and one piece 0.126” thick in 0.003” laminations (AASHTO 6.7.7.1.3).