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Crane Definitions

 

abnormal operating conditions

braking, mechanical


abnormal operating conditions: environmental conditions that are unfavorable, harmful, or detrimental to or for the operation of a crane, such as excessively high or low ambient temperatures, exposure to adverse weather, corrosive fumes, dust-laden or moisture-laden atmospheres, and hazardous locations.

administrative or regulatory authority: governmental agency or, in the absence of governmental jurisdiction, the employer.

appointed: assigned specific responsibilities by the employer or the employer's representative. authorized: appointed by a duly constituted administrative or regulatory authority.

auxiliary hoist: supplemental hoisting unit usually of lower load rating and higher speed than the main hoist.

boom (of gantry cranes): an extension of the trolley runway that may be raised or retracted to obtain clearance for gantry travel.

boom (of overhead cranes): a horizontal member mounted on the trolley to permit hoisting and lowering the load at a point other than directly under the hoist drum or trolley.

brake: a device, other than a motor, used for retarding or stopping motion by friction or power means.

brake, holding: a friction brake for a hoist that is automatically applied and prevents motion when power to the brake is off.

brake, mechanical load: an automatic type of friction brake used for controlling loads in a lowering direction. This unidirectional device requires torque from the motor to lower a load but does not impose any additional load on the motor when lifting a load.

braking means: a method or device used for stopping/ holding motion by friction or power.

braking, control: a method of controlling speed by removing energy from the moving body or by imparting energy in the opposite direction.

braking, counter torque (plugging): a method of controlling speed by reversing the motor line voltage polarity or phase sequence to develop torque in the direction opposite the rotation of the motor.

braking, dynamic: a method of controlling speed by using the motor as a generator, with the energy being dissipated in resistors.

braking, eddy current: a method of controlling or reducing speed by means of an electrical induction load brake.

braking, emergency: a method of decelerating a drive when power is not available. The braking effort may be established as a result of action by the operator, or automatically when power to the drive is interrupted.

braking, hydraulic: a method of controlling or reducing speed by means of displacement of a liquid.

braking, mechanical: a method of controlling or reducing speed by friction.