Hoist brakes are an essential safety feature of overhead cranes.

1. K.J.SOMAIYA COLLEGE OF ENGINEERING
(An Autonomous College Affiliated to University of Mumbai)
UMEL502 – THEORY OF MACHINES II
Experiment 2 – Analysis of Brake.
HOIST BRAKES.
AMAN NILESH HINDOCHA.
A4 BATCH.
T.Y.MECH A.
1825005.

2. • INTRODUCTION :-
• Hoist brakes are an essential safety feature of overhead cranes.
• Designed to hold a load when the hoist motor is not running, these
brakes reduce the risk of falling loads that could result in injury and
property damage.
• Hoist Brakes consist of shoe or disc brakes on the high speed side of
the motor.

3. • HOIST BRAKE :-

4. • COMPONENTS :-
• Each brake has multiple springs
rated for 10+ million cycles.
• The brake operation is very basic –
the only moving part is the armature.
• No linkages. No moving parts to
wear and replace due to actuation.
• Hoist brakes have a boosted coil
with more springs which allows
higher brake torque and hence
increased effectiveness.

5. • WORKING :-
• The general principle of operation is that when hoist lowering is
selected, the holdingbrake will be released (electrically released,
spring applied) and the load wants to fall.
• During the hoisting mode the load brake is unlocked and
freewheeling.
• The purpose of a “load brake in a hoist application is to keep the
suspended load from falling without power to the hoist and
independent of the motor brake.”

6. • REQUIREMENTS :-
• Holding brakes on hoists shall have ample thermal capacity
for the frequency of operation required by the service.
• Holding brakes on hoists shall be applied automatically when
power is removed.
•Where necessary holding brakes shall be provided with
adjustment means to compensate for wear.
• The wearing surface of all holding-brake drums or discs shall
be smooth.

8. • ADVANTAGES :-
•Hold a load when the hoist motor is not running
•Reduce the risk of falling loads that could result in injury
and property damage
•To provide fail-safe performance. They set and hold the
load without external power, such as during a power
failure
•Each independent hoisting unit of a crane is equipped with
at least two hoist brakes