Installation and Service Instructions - Type CB | ||||||||||
| General Description The type CB brakes have an AC solenoid for operation. When the brake solenoid is energized, the lining will clear the wheel, and when de-energized, the linings are pressed against the wheel by means of a compression spring. These brakes are designed with power failure protection; that is, in the event of a power failure, the brake automatically spring-sets. |
Mounting If the brake was shipped with the wheel clamped between shoes, remove wheel from shoes by pushing down solenoid lever at point 'A'. With wheel mounted on shaft, install brake as follows: 1. Brake must be mounted on a flat surface parallel to shaft. Distance from center line of shaft to bottom of base of brake should agree with 'G' dimension within limits of +.03, -0 inch. Center line X-X should pass midway between mounting holes within .03 inches.
2. Release brake by pushing down solenoid lever at point 'A'. Place brake in position over mounting holes, then release solenoid lever to clamp lining on wheel. Insert shims under base if required, then bolt brake to base. 3. The brake should be mounted in the horizontal mounting position for maximum solenoid life. Adjustment The solenoid plunger (2) has two lines scribed around its surface. The upper line is an indication of normal travel and the lower line is for readjustment (see Table 2). For normal travel, the upper scribed line should line up with the top of the solenoid frame (1). The brake is set for normal travel at the factory; however, if the adjustment is off, then bring into adjustment by moving adjustment nut (15). Turning this nut in will decrease amount of travel and turning nut out will increase amount of travel. Nut (12) is used to lock this adjustment in place. Adjustment in stop bolt (18) is used to obtain equal lining opening at both sides of wheel. When the brake is energized the shoe arm linkage is pulled towards the solenoid; therefore, the adjustment bolt is required to equalize this movement between shoe arms. | |||||||||
 Figure 1 Operation | ||||||||||
| Caution The power supply must be disconnected before any adjustments or servicing work is performed on the brake. |
Operataion (See Fig. 1) 1. When brake is de-energized, the compression spring (6) exerts pressure on the brake wheel as follows:
The solenoid plunger (2) pulls into the stationary portion of solenoid (1) moving lever arm (4) down. The lever acting about pivot pin (8) forces the inner and outer shoe arms apart by moving the tie rod to the right through tie rod pin (9). | |||||||||
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Turning bolt in allows more clearance at the inner shoe and backing bolt out allows more clearance at the outer shoe. Stop bolt (18) has a lock nut for maintaining its position. Either using a feeler gauge or rotating the wheel by hand can insure that there is clearance between the wheel and lining.
Due to variation in the lining thickness, there may be occasions, at initial installation, when the normal travel setting will not give complete clearance between the lining and the wheel. If this should happen, temporarily in-crease the solenoid plunger travel beyond the normal travel line. Once the lining has worn in, reset the plunger to the normal travel line. Torque Adjustment Brake is adjusted at our factory for the torque rating as given on the nameplate. With brake de-energized and solenoid plunger adjusted for normal travel, the compressed length of spring should be per value in Table 1. Table 1
Readjustment for Lining Wear The brake solenoid has sufficient power to operate when the solenoid plunger travel is beyond the readjust line; however, to obtain maximum brake life, the travel should be maintained within the limits scribed on the plunger (Table 2). |
When lining wear results in travel beyond the readjust line, bring the travel into normal adjustment as described under Adjustment section. Table 2  Normal Travel Maximum Travel Re-adjust
CB Torque Ratings
CB brakes are single phase AC brakes available in the following voltages:
Relining Shoe Arms To reline the shoe arms, relieve the spring pressure by backing off spring nut (5). Back off nut (15) and remove roll pins that retain base pins (16). Remove base pins and swing shoe arms away from wheel. The drive rivets holding the lining are easily removed with a drift. After replacing the lining, reassemble brake and readjust per Adjustment Section. Drive rivets are reusable. Shoes with bonded linings will have to be re-bonded or drilled for rivet type linings. |
Coil Connection All CB brake coils are single phase, single voltage coils. Knockouts are located on each side of the conduit box for attaching the conduit for the power leads. Power leads are connected to screw terminals on the coil. Removing Coil and Plunger Guides Caution The power supply must be disconnected before removing coil. Disconnect power leads from the coil. To remove coil and plunger guides, disconnect link (3) from solenoid plunger (2). Remove plunger from solenoid frame. The plunger guides are held in place by screw (21) located in the bottom of the solenoid frame. Remove this screw and the plunger guides can be pulled out of the solenoid frame. With the guides removed, the coil slides out of the frame. The same coil is used for either continuous or intermittent duty. It is necessary to specify the torque rating so that the spring can be properly adjusted. If the torque ratings of the type CB-AC brake are exceeded and only AC voltage is available, a type TM-DC brake can be supplied with a rectifier (i.e., type TMR-twin magnet rectified). | ||||||||||||||||||||||||||||