Designed primarily for mining, steel and
other heavy industries, the Bibbigard Series
300 Plate Controlled Release Backstop
provides the same high safety attributes as
the basic Series 300 unit, but additionally
incorporates a ‘Plate’ brake to provide
SAFE, CONTROLLED RELEASE of excessive
conveyor belt tension resulting from
trapped tail ends or similar staked (holdfast)
conditions.
In these units the catcher rings (1, 2) are
bolted to a pressure plate assembly (3,4,5)
which forms part of the controlled release
mechanism. The brake lining (6) is a
continuous ring of friction material located
between a clamp ring (7) and the pressure
plate assembly. A series of M24 socket head
cap screws (8) pass through the clamp ring
(7) and are threaded into the adaptor plate
(10) to provide the brake tightening and
release operation. The bearing (4) of the
pressure plate assembly is located between
the adaptor plate (10) and the pressure
plate (3).
1. The brake is fully applied at all times
while the conveyor is operating
normally.
2. ln the event of a staked, or hold-fast,
condition arising in the conveyor belt,
switch off the conveyor drive and
establish the reason in accordance with
the appropriate Code of Practice. Do
not attempt to clear the obstruction at
this time.
3. Remove cover (9) from Backstop Unit
to gain access to the M24 brake
adjustment screws (8).
4. Gradually slacken off the screws (8) a
maximum of a quarter turn at a time,
in diametrically opposite order, to
release the brake. This permits the
‘locked’ Backstop and drive shaft to
rotate slowly, allowing the stored
energy in the belt to be dissipated
safely under control. At the same time,
the conveyor can be let down, still
under control, as far as is required.
5. The obstruction may now be safely
cleared.
6. Before re-starting the conveyor, retighten
the brake adjustment screws
(8) in diametrically opposite order, to
the tightening torque recommended
by Bibby Transmissions, thereby reactivating
the plate brake mechanism.
7. Re-fit cover (9) and re-start the drive.
included in the maximum torque ratings.
PCR sizes can be supplied with a higher
maximum torque rating as a special unit.
