Quantcast Normal Terminal Stopping Devices - mo1180121

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Also determine if swivel-type or roller-type guide shoes are free to move as intended. Inspect the
counterweight suspension fastenings.
4.2.6 Suspension And Fastenings
Examine the condition of the fastenings at the car and machine or counterweight ends to
determine if they have been properly made up. The A17.1 Code requires that cars and
counterweights, except for dumbwaiters having direct-plunger hydraulic or rack and pinion or
screw-type driving machines, shall be suspended by one or more iron or steel wire hoisting
ropes or chains secured to the car or counterweight or rope hitch by babbitted sockets, rope
clamps, or equally substantial fastenings. Chains where used shall be roller, block, or
multiple-link silent type. Wire ropes shall not be lengthened or repaired by splicing. The
winding drum ends of car and counterweight ropes or chains shall be secured inside the drum,
and there shall be not less than one turn of the rope or chain on the drum when the car or
counterweight has reached the extreme limit of its over travel.
4.2.7 Normal Terminal Stopping Devices
Run the car to the top of its travel at slow speed to examine the normal terminal stopping
device. on traction dumbwaiters and on most winding drum type installations, this device usually
consists of a switch or switches installed in a hoistway actuated by cams on the car. In some
cases, however, normal terminal stopping devices of a traction dumbwaiter may be located in the
machine room or overhead machinery space and be mechanically connected to and driven by the
car. Where the normal terminal stopping device of traction dumbwaiters is so located and the
required broken-drive device is located on top of the car, manually open it with the car at rest.
The opening of this switch should prevent the car from starting. In the case of some winding
drum machine installations, the device is part of an automatic stop-motion switch mounted on
and operated directly by the driving machine. Determine that stopping switches and cams are in
correct alignment and are securely fastened in place. Also determine the condition of the limit
switch rollers, as reduction of the effective roller diameter due to either wear or loss of the tires
may interfere with or prevent proper operation of the switch. Excessively worn car guide shoes
and worn limit switch rollers, combined, may cause cars to overrun their terminals. If the
equipment is in proper condition and sufficient overhead clearance exists, make a test of top
normal terminal stopping devices with an empty car at rated speed. Repeat operation with
bottom normal terminal stopping devices. On each of these stops, the car should stop at or near
the terminal landing.
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