TM 9-4940-444-14 & P
MICRO SWITCH
DESCRIPTION
TYPICAL SIMPLIFIED DIAGRAMS
The Micro-Switch is a precision snap action switch.
TABLE AND SPINNER CONTROL CIRCUIT
The particular style which we use is a side mounting
ON TABLAST
design, enclosing in a die cast housing for protection
of the switch mechanism. Further protection to the
mechanism is provided by the "Q" type plunger which
permits an overtravel of 7/32" on the plunger without
damage. Further overtraveling of the plunger is
prevented by a stop ring on the plunger.
HOW USED
The Micro-Switch is used to protect the motor and
driven equipment from damage due to jamming of the
Table Drive, on the #2 Table, and of the Table and
Spinner Drive on the #3 Table, and of the Mill Drive
on Tumblasts. The Micro-Switch is also used as a
door safety switch on Tumblasts to prevent operation
of the wheel when door is open and to further prevent
Operating Force .................................. 9 to 13 oz.
the mill running in reverse when door is closed. The
Release Force ..................................... 4 oz., min.
Switch is factory mounted on a suitable bracket so
Pretravel ....................................... 0.020 in., max.
that the actuator plunger is 1/16" from the bearing
Overtravel........................................ 7/32 in., min.
pedestals (in case of the #3 Table) and 1/16" from the
Movement Differential .................. 0.002 in., max.
Table speed reducer, in the case of the #2 Table. A
Net Weight ....................................0.52 lbs., max.
similar distance is held between the actuator plunger
and the mill reducer base plate on Tumblasts. When
Application
used as a door safety switch on Tumblasts, the
switch is operated by a suitable cam on door shaft. A
1.
#2 Multi-Table
closer setting than approximately 1/16" will result in
2.
#3 Multi-Table
undue tripping of the drive and over a 1/16" setting
3.
Tumblasts
fails to provide the proper protection.
4.
Special Applications
Jamming of the drive mechanism usually results in
excessive pull which causes deflection of the drive
components. It is this deflection which causes the
micro-switch to trip, thus removing the equipment
from service.
See typical diagrams for more information.
HOW TO SPECIFY
AWECo. Part 76168 - Micro Switch: Metal clad, with
M.S. 1 - MILL MICRO SWITCH
normally open and normally closed (three point)
M.S.2 - DOOR MICRO SWITCH
contacts, catalog BZE-2RQ.
SD1942
71
