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8.1 Rails and Guides
Guide Rails
Cars and counterweights are guided up and down the hoistway on rails of either Tee or round cross section.
Assembly of the Tee-shaped rails to the hoist-way wall is shown in Figure 8.1-1. The two'piece bracket permits both vertical and horizontal adjustment of rail position. The tie.plate prevents horizontal motion of the rail with respect to the bracket. The rail is held firmly against the bracket by a clip-and-spring combination. However, clip design permits the rai I to move vertically with respect to the bracket as the building settles.
To prevent rust formation that would inhibit this sliding action, the mating surfaces of the spring and the rail are coated with grease or heavy oil during installation.
FORGED RAIL CLIP
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TIE.PLATE
5/8 SQUARE HEAD BOLTS CAN BE USED. "STOP" ON CLIP
'''''''' "AO ''OM '""'~
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STEEL SPRING
GUIDE RAIL
.~fj;j
~ RAIL BRACKETS
AFTER RAI LS ARE SET, BEND THE ENDS OF THE TIE.PLATE AROUND THE BRACKET TO HOLD RAIL IN PLACE
MM.139
Figure 8.1-1. Tee Rail Assembly
8.1.1
Rails and Guides
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FISHPLATE
RAIL JOINT, •
Figure 8.1-2. ree Rail Fishplate
Tee rail sections are approximately 10 feet long.
Side-to-side motion of mating rail sections is prevented by the tongue- and- groove design of the end surfaces. (See Figure 8.1-2.) The mating rail sections are secured by fish plates which also prevent front-to-back motion of the rails.
1/2 x 3" SLOTS
"U" TYPE COUNTERWEIGHT SUPPORT BRACKET
65EW2 BOLT 1/2. 13 FIN NUT 1/2 SAE WASHER
1/2 SPRING LOCK.WASHER
ROUND RAIL BRACKET
SUPPORT ANGLE
Figure 8.1-3. Round Rail Assembly
8.t-2 MM.139
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Assembly of the round rails to the hoistway wall is shown in Figure 8.'-3. In this example, a U-shaped bracket, bolted to the hoistway wall, supports both counterweight rails. Each rail is mounted to an arm of the "U" by a two-piece bracket which permits both lateral and vertical adjustment.,.
SPLICE PIN
If? --""\,\
I~ 9\
:~~!
I ~I
~II
I I
( I
~-'
FISHPLATE 2" X 2" x 1/4"
ANGLE
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MM.139
Maintenance
Figure 8.1-4. Round Rail Fishplate
Mating round rail sections are joined by splice pins as shown in Figure 8.'-4. The joints are further secured by an angle fish plate bolted in place.
Clean car and counterweight rails annually.
One man operates the car from the top inspection buttons. The second man satu rates a cloth with Otis Elevator Co. cleaning compound NO.2 and holds it against the rail as it is moved up. Dry off the rails. Do not lubricate rails.
8.1.3
Rails and Guides
Roller Guides
Roller guides are guide shoes that ride on the
"T" or round guide rails to keep the car or counterweight aligned and plumb with the hoist-way. More importantly, they maintain the position of the car safety (and, where used, counterweight safety) such that the safety jaws will engage the guide rails when tripped.
Roller guides are located at four positions on the car frame: two at the top on opposite ends of the crosshead, and two at the bottom on opposite ends of the safety-plank channels.
(See Figure 8.1-5.) The top roller guides differ from the bottom roller guides only by the addi-tion of guard plates.
A similar arrangement is used for the counter-weight.
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ROLLER
GUIDE
ROLLERJ
GUIDE
SAFETY
PLANK
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Figure 8.1.5. Location of Roller Guides
8.1-4 MM.139
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SIDE ROLLER
STOP SPRING
ADJUSTMENT
SPRING ADJUSTING NUT
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MM.139
Figure 8.1-6. Roller Guide Assembly
A typical roller guide comprises three rubber-tired rollers mounted on a stand: two side rollers for front and rear alignment and one for side-to-side or postwise alignment. (See Figure 8.1-6.)
Each roller rides on a bearing and is mounted on one end of a lever. The other end of the lever is attached to a compression spring wh ich maintains the roller in constant contact with the rail blade. Each roller arm has two adjustments:
one for spring tension, which determines the amount of pressure the roller has on the rail blade; and a stop, which limits tlie maximum displacement of the roller.
8.1-5
Rails and Guides
Several variations of the typical roller gu ide are in current use.
o A springless guide for hydraulic applications uses rollers mounted on eccentric shafts.
The eccentric permits adjustment of roller position with respect to the rail blade.
A three-roller version is supplied for "T"
rail applications, a two-roller version for round rails.
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Maintenance
o Some smaller roller guides utilize a single tension spring for the two side rollers.
There is no spring adjustment for these side rollers, but there are stop adjustments.
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..8.1.6
A properly lubricated roller guide should give long, trouble-free service. No adjustment or maintenance is required unless a noisy ride or excessive sway is noticed when riding the car.
A noisy ride is symptomatic of excessive spring pressure, a defective rubber tire, or lack of lubrication.
To locate the defective roller guide, turn each guide by hand. If the roller cannot be easily rotated, the fault is either excessive pressure or lack of lubrication. Lubricate the pin and bushing area with Otis Oil NO.2. If necessary, add grease to the Alemite fitting. If the roller still appears stiff, ease up on spring tension.
Replace entire roller if rubber tire exhibits flat or worn spots. The tires are of a special rubber, selected after extensive tests of many compounds, and are vulcanized directly to the metal. wheel.
Tires will give long service if the roller is properly lubricated and spring pressure correctly set.
A scraping sound heard when the car is loaded to one side, or excessive sway during full-speed
runs, are symptomatic of incorrect spring pressure or incorrect adjustment of the stop.
To locate the source of the scraping, ride the top of the car with a 600-lb weight in the back of the cab. If scraping sound does not occur, repeat test with the weight in the front, then on the left, and finally on the right side. Run at full speed, listening for the noise. If heard, take up on the mechanical stop as shown in
Figure 8.1-6 .
MM-139
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MM-139
IF GAP IS ALWAYS GREATER THAN l/l6-INCH, INCREASE NUMBER OF ACTIVE TURNS
Figure B.I-7. Setting of Spring-Adjusting Block
The same test can be made to locate the source of excessive sway. If the space between the roller arm and the stop (Figure 8.1-7) is always more than 1/16 inch, increase the number of active turns set by the spring-adjusting block.
Back off if the roller arm touches the stop.
If any springs are readjusted, do not forget'to reset the stop nut.
For roller guides that don~t have spring-adjusting blocks, the spring compression is either increased or decreased, as needed, by turning in or backing off the spring-adjusting nut or stud. (See Figure 8.1-8) A good starting point is to pry the car until the slot in the guide stand rests solidly against the rail blade. Set the spring compression finger-tight, then release the pry and advance the adjusting nut two turns for 7 7/8 inch rollers, or one turn for 3 3/4 inch rollers. The stops are set to prevent the guide stand from rubbing against the rail blade when the test run is made with the eccentric or unbalancing weights placed at each of the four platform positions shown earlier.
It js permissible if the roller arm touches the stop occasionally during the test run.
8.1-7