R&M Materials Handling WIRE ROPE HOISTS Service - Manual (Page 69)

R&M Materials Handling, Inc.
4501 Gateway Boulevard
Springfield, Ohio 45502
P.: (937) 328-5100
FAX: (937) 325-5319
69/130
R&M Materials Handling, Inc. reserves the right to alter or amend the above information without notice.
!
The drum brake must always be kept clean. The braking torque reduces strongly if any
grease or oil penetrates to the friction surfaces.
5.26.1 Holding Brake
The holding brake acts as a second brake and mechanically locks the drum when the hoisting or lowering
motion has stopped. When the operator starts hoisting or lowering, the holding brake will be released and
driving upwards or downwards is possible. However, in case the main brake has slipped during standstill,
the cam (2) may be locked against the brake rim (1) and the electromagnet (3) is not able to release the
cam. In this case it is necessary to drive the hoist in upwards direction prior to powering, in order to
release the drum brake.
!
Do not drive the hoist in the upper stop limit switch when handling heavy loads. Stop lifting
as soon as the hoist enters the upper slow down limit.
#
In case the holding brake locks frequently, it may indicate wear of the main brake.
1 24 25
c_db02a
1.Brake rim
2.Cam
3.Electromagnet
16.Solenoid
24. Disc springs
25. Screw
5.26.2 Service
• Check that the drum brake and surrounding surfaces are free from oil, grease, excessive dust and/or
other substances that may reduce the effectiveness of the friction material of the drum brake.
• Check that the solenoid works properly and the cam closes against the brake rim.
• Manually activate the holding brake limit switch when operating in down direction and verify that
hoisting is stopped in the down direction. Up direction should continue to operate.