Specifications

Limit Switch Pin
Standard
Limit
Switch
Pin
Limit
Switch
Start
Jog
Stop
To Motor
ORC
Overload
Clutch
Limit Switch Actuating Mechanism
Limit
Switch
Optional
Limit
Switch
Actuating
Mechanism
ORC
Overload
Clutch
Start
Jog
Stop
To Motor
ORC SERIES, MODEL S CLUTCHES
ORC Series, Model S
8
BOSTON GEAR
BOSTON GEAR
®
FIGURE 15 – LIMIT SWITCH LAYOUT
IV. LIMIT SWITCHES
The ORC Series, Model S Overload Release Clutch is
available with two types of limit switch actuators, a limit
switch pin (LSAP) and a limit switch actuating mechanism
(LSAM).
A. Limit Switch Pin
A Limit Switch Pin is furnished as a standard item to
activate a limit switch that triggers the electrical controls.
The Limit Switch Pin protrudes radially from the clutch
housing and its travel is controlled by the drive pawl
motion upon disengagement. The Limit Switch Pin can
be used if the housing continues to rotate when an
overload occurs and the rotor stops, i.e, the housing is
the driver and the rotor is the driven. Housing RPM has
to be considered to determine the time for the Limit
Switch Pin to revolve around before contacting the limit
switch. See Figure 15 for Limit Switch Pin Travel.
The standard Limit Switch Pin extension is 1 inch from
the outside diameter of the clutch housing. It can also
be made flush with the surface of the housing in an
engaged position.
B. Limit Switch Actuating Mechanism
A Limit Switch Actuating Mechanism provides instant
operation of a limit switch to immediately shut down the
drive or actuate an alarm should an overload occur.
The mechanism is entirely contained in the clutch cover
and is actuated by the motion of the drive pawl. When
an overload occurs, the drive pawl motion releases the
actuating plate and it trips a limit switch. The total travel
of the plate is 5/16 of an inch (see Figure 15).
The actuating plate must be reset by manually pushing
it back into position. The clutch must be engaged when
resetting the plate or the plate will not reset when the
clutch is disengaged.
A limit switch should be able to operate within the plate
travel of 5/16 of an inch. The switch should be wired in
parallel with a jog circuit so that the drive can then be
indexed to the start/run circuit.
V. GENERAL MAINTENANCE
A. Lubrication
The Overload Release Clutch is prelubricated at the
factory and is also equipped with a grease pack fitting.
For optimum performance and wear resistance it is
suggested that the clutch be lubricated with a Bentone
type, NLGI grade 0 grease. The lubrication schedule
should be in accordance with good operating practices
for the equipment on which the clutch is mounted. The
clutch is also supplied with a grease relief fitting. When
there is enough grease in the clutch any excess grease
will be extruded through the relief fitting.
B. Annual Inspection
The Overload Release Clutch is constructed of heavy
duty materials. Under reasonably clean conditions the
unit will operate with a minimum of maintenance. A
scheduled annual inspection of bearings, pawls, rotor,
springs, tripping mechanism, and other internal
components is suggested. However, the actual
frequency should be in accordance with good operating
practices for the equipment on which the clutch is
installed.
Limit Switch Pin Travel
Size Travel
1 .13"
2 .13"
3 .13"
4 .13"
5 .13"
6 .25"