Sheffer LA User Manual

ACCESSORIES

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

/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

/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

AC-1

L SERIES

LB SERIES

LS SERIES

ITEM QUANTITY

NUMBER DESCRIPTION NUMBER REQUIRED

78 LIMIT SW. MTG. SCREW * 2

85 HOUSING SEAL * 1

87 ACTUATOR ASSEMBLY * 1

88 ADAPTER 698-54316 1

94 ADJUSTING SCREW * 1

95 BOX SEAL * 1

96 PLUG * 1

97 GROUND SCREW * 1

128 JAM NUT 698-30058 1

Parts List

ITEM QUANTITY

NUMBER DESCRIPTION NUMBER REQUIRED

74 PLUNGER * 1

76 JUNCTION BOX ASSEMBLY * 1

76A JUNCTION BOX COVER * 1

76B JUNCTION BOX * 1

76C GASKET * 1

76D COVER SCREW * 2

76E COVER SCREW * 2

77 LIMIT SWITCH * 1

77A SWITCH 698-30002 1

*Model number and serial number are required when ordering this part.

HARDENED CAM (CUSHION PISTON ON CUSHIONED FRONT CYLINDERS)

LIMIT SWITCH ACTUATORS - PARTS LIST

Mechanical

128

76B

128

76C

76D

76A

77A

76E

AC-2

L SERIES

LB AND LD SERIES

LS SERIES

/8"-18UNF-2

/16 MN.

/32 MAX.

.050 TRAVEL

/16"

SOME BORE & ROD

COMBINATIONS

REQUIRE WELDED

BOSS – SEE CHART

/2"

/8"

/16"

DIA.

/8"

/16"

/2 CONDUIT

CONNECTION

SOME BORE & ROD

COMBINATIONS

REQUIRE WELDED

BOSS – SEE CHART

SOME BORE & ROD

COMBINATIONS

REQUIRE WELDED

BOSS – SEE CHART

LIMIT SWITCH ACTUATORS

Mechanical

AC-3

LA SERIES

ILLUSTRATION A

Switches are also available installed in the cap face as shown by Illustration A.

GENERAL NOTES:

When using limit switch operators for pneumatic service, assure that the system air is clean and dry. While operators are designed to be resistant to dirt and moisture, as with any fine machinery, lack of reasonable care can result in malfunction.

We will be pleased to quote you on either pneumatic or hydraulic cylinders with operators and custom mounting brackets for your selection of air valve or other signal device. Contact our distributor with your specific requirements.

33/4

13/4

57/16

21/4

/16

211/16

15/8

35/8

NPT

SOME BORE & ROD

COMBINATIONS

REQUIRE WELDED

BOSS – SEE CHART

SOME BORE & ROD

COMBINATIONS

REQUIRE WELDED

BOSS – SEE CHART

LIMIT SWITCH ACTUATORS

Mechanical

LX SERIES

AC-4

A SERIES

ROD HEAD CAP

BORE DIA. A C B C

/2†

/4†

/2†

/4†

/16†

/2†

/16†

/2†

13/8

/16†

/2†

/16†

/2†

/16†

/2†

13/8

/16†

/2†

13/4

/16†

/2†

/2 —

13/8

/2 —

13/4

/2 —

/8 —

/2 —

13/8

/8 —

/2 —

13/4

/2 —

21/2

/16

/2 —

/8 —

/2 —

13/8

/8 —

/2 —

13/4

/8 —

/2 —

/8 —

/2 —

21/2

/16

/2 —

31/2

/2 —

13/8

/8 —

/16 —

13/4

/16 —

21/2

/16 —

31/2

/16

/16 —

13/8

/8 —

/16 —

13/4

/16 —

21/2

/16 —

31/2

/16 —

41/2

/16

/16 —

/16

/16 —

13/8

/8 —

/16 —

13/4

/16 —

21/2

/16 —

31/2

/16 —

41/2

/16 —

51/2

/16

/16 —

13/4

/8 —

21/2

/8 —

31/2

/8 —

/4 —

/8 —

41/2

/16 —

/8 —

/16 —

/8 —

51/2

/16 —

/8 —

12 ALL

/8 —

14 ALL 1 — 1 —

* Not available with cushions. †Because of possible interference, not recommended for RF, RFX, RX and

BX mounts. Always check dimensions for possible interference.

MH SERIES

ROD HEAD CAP

BORE DIA. A C B C

/16†

/4†

/16†

/4†

/16†

/2†

/16†

/2†

13/8

/16†

/2†

/16†

/2†

/16†

/2†

13/8

/16†

/2†

13/4

/16†

/2†

/8 —

13/8

/8 —

13/4

/8 —

13/8

/8 —

13/4

/8 —

2 1/2

/8 —

13/8

/8 —

13/4

/4 —

/8 —

/4 —

/8 —

21/2

/4 —

/8 —

/32

/8 —

31/2

/32

/8 —

13/8

/4 —

13/4

/4 —

21/2

/4 —

/32 —

/4 —

31/2

/32 —

/4 —

/32

/4 —

13/8

/4 —

13/4

/4 —

21/2

/4 —

/32 —

/4 —

31/2

/32 —

/4 —

/32 —

/4 —

41/2

/32 —

/4 —

/32

/4 —

13/8

/4 —

13/4

/4 —

21/2

/4 —

/32 —

/4 —

31/2

/32 —

/4 —

/32 —

/4 —

41/2

/32 —

/4 —

/32 —

/4 —

51/2

/32 —

/4 —

†Because of possible interference, not recommended for RF, RFX, RX and

BX mounts. Always check dimensions for possible interference.

11/2

31/4

21/2

31/4

LIMIT SWITCH ACTUATORS - DIMENSIONS

Mechanical

AC-5

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