2
Boston Gear • 800-825-6544
P-3002-BG
The drive pawl is held in its engaged position by
the combined compression of the drive and reset
springs. (See Figure 1) The combined compression
of these two springs determines the maximum
torque which is transmitted without overload. With
the clutch in its engaged position, the rotor and the
housing are held together and the entire unit rotates
with the drive shaft at the same speed.
When an overload occurs, the rotor rotates from its
normal position within the housing. At this instant,
the combined compression of the drive and reset
springs is overcome. The drive pawl is forced out of
its engaged position from the rotor and as it pivots
up, the reset pawl applied pressure to the top of the
drive pawl holding it in contact with the rotor.
After one revolution, the drive pawl will automatically
re-engage. For a manual reset clutch the drive pawl
is forced out of its engaged position from the rotor
and as it pivots up, the reset pawl lifts and locks the
drive pawl out of contact with the rotor. See Section
B2 for resetting instructions.
The automatic limit switch actuating mechanism
assembly consists of five basic components: the
actuating plate, the cam plate, the liftout buttons,
the return pins and return springs. Upon overload,
the rotation of the rotor causes the cam plate, which
is keyed to the rotor, to exert a force on the liftout
buttons forcing them to move the actuating plate
axially away from the clutch housing. (See Figure
3) When the clutch is re-engaged, the actuating
mechanism will automatically return to its original
position by the force of the return springs on the
return pins.
Contents
I. Introduction
A. Operating Principle ............................. 2
B. Resetting Instructions ......................... 3
C. Torque Adjustment ............................. 3
Il. Mounting Sprockets or Sheaves to Clutch
A. Type “T” Housing ................................ 4
B. Type “B” Housing ............................... 5
Ill. Locating and Mounting Clutch and
Couplings to Shaft
A. Location ............................................ 6
B. Mounting the Basic Clutch .................. 6
C. Mounting Type “C” Flexible
Coupling ............................................. 7
D. Mounting Type “N” Index and Type
“R” Rigid Coupling .............................. 8
IV. Limit Switches
....................................... 9
V. General Maintenance
A. Lubrication .......................................... 9
B. Annual Inspection ............................... 9
Vl. Repair Instructions
A. General Disassembly .......................... 9
B. Basic Unit Assembly ........................ 10
C. Torque Verification ............................ 12
D. Final Assembly .................................. 12
E. Limit Switch Actuating Plate
Assembly .......................................... 12
Vll. Trouble Shooting
................................. 13
Exploded View Drawing .......................... 14
Catalog Numbers .................................. 15
Reset Spring
Reset Spring Screw
(Stamped 9)
Reset Paw
l
Housing
(Stamped 22)
Drive Spring Screw
(Stamped 8)
Drive Spring
Rotor
(Stamped 26)
Drive Paw
l
I. Introduction
A. Operating Principle
The ORC Series, Model F Overload Release Clutch
consists of three basic components: the rotor, the
housing assembly and the limit switch actuating
mechanism assembly. The clutch rotor is keyed
and secured to a shaft with a locking collar
(Models FJ or FG), or with a setscrew (Model FR).
The housing assembly includes a drive pawl and a
reset pawl which pivot within the clutch housing.
Figure 1