Sheffer LA SERIES - Manual (Page 2)

C20-
L SERIES - Basic Actuator
The actuator is operated through the action of a hardened
cam which is similar to a cushion piston. When the cylinder
is cushioned, the cam also performs the function of the
cushion piston. The cam contacts the actuator plunger
approximately
3 / 16 inch from the end of stroke and moves
the plunger and stem assembly about 1 / 16 inch. The action
compresses the spring which returns the plunger and stem
assembly when the stroke is reversed and cam disengagement
takes place. A lighter force spring is employed for pneumatic
cylinders and a heavier one for hydraulic. Shown in this
Accesories Brochure on Page AC-2 is an illustration of an
actuator in the head end of a cylinder. The hardened cam has
not yet engaged the plunger. Operation of an actuator in the
cap end of a cylinder is similar except the cam is an extension
of the piston rod as is employed in a cushioned rear cylinder.
The
L Series actuator is available for applications which
require the mounting of a limit switch or signal device other
than those described below. The customer-supplied device
can be mounted by utilizing the
5 / 8 -l8 UNF-2 threaded
extension. A locking nut is provided. 180°F continuous
temperature rating.
LB and LD SERIES – Actuator with Switch and
Junction Box
The actuator is supplied with a limit switch enclosed by a
junction box. The box is gasket sealed, making it dust proof
and water tight. The cover is easily removed and removal
provides easy access to the switch for removal or adjustment.
Two
1 / 2 inch threaded ports, one on each side, provide for
conduit connection. The box is retained by a lock nut and
can be rotated up to 360° after installation.
The
LB Series has a SPDT limit switch with an electrical
rating of 15 amps at 125, 250 or 480 volts AC. It can be
wired either normally open or normally closed.
The
LD Series is similar to the LB series except the limit
switch is DPDT 180°F continuous temperature rating.
LS SERIES - Actuator with Sealed Switch
The actuator is supplied with an adapter and a DPDT sealed
switch. The switch is sealed to dust and moisture. It has six
72 inch long leads of No. 20 wire and has an electrical rating
of 5 amps, 125 volts with a 180°F continuous temperature
rating. Each wire is marked with circuit identification and
wire gauge number.
The DPDT switch is housed in a one inch diameter enclosure
and can be removed without disturbing the built-in actuator.
Adjustment is easily accomplished by rotating the switch
housing.
LX
SERIES
The actuator is supplied with an installed mounting adapter
and an explosion proof SPDT enclosed switch. The enclosed
switch is UL approved for hazardous locations Class 1,
Groups C and D and also Class 11, Groups E and G.
The switch is rated at 15 amps, 125, 250 or 480 volts AC:
1 / 8
HP-125 volts AC, 1 / 4 HP-250 volts AC. The switch is also
rated at 1 / 2 amp at 125 volts DC and 1 / 4 amp at 250 volts DC.
LA SERIES
The actuator is supplied with an adapter bracket and a
mini air valve which serves as an air limit switch. The
valve functions as a normally open or a normally closed
2-way and as a normally open or a normally closed 3-way.
The valve is flow rated at 24 CFM with 100 psi inlet pressure.
Ports are
1 / 8 inch NPT. Switch is rated for 200 psi.
The use of air limit switches offers the all-air control
advantages of better reliability, more convenience, and
less expense. Air limit switches replace both the electrical
switches and solenoids.
• AVAILABLE ON SHEFFER
SQUARE HEAD CYLINDERS –
150 PSI PNEUMATIC TO 3000
PSI HYDRAULIC
• OFFERED FOR EITHER OR
BOTH ENDS OF CYLINDER
• SEVERAL SWITCH SERIES
AVAILABLE, OR ACTUATOR
ONLY, TO OPERATE YOUR
OWN SIGNAL DEVICE
LIMIT SWITCH ACTUATORS - OPERATION
Mechanical
1 AC-1