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Machine Screw Actuators (Imperial)

Duff-Norton offers a complete line of both standard and custom engineered machine screw actuators for applications up to 350 tons.

Machine screw actuators offer positive mechanical action, precise positioning, and uniform lifting speeds. Standard configurations include upright or inverted units with translating or rotating lifting screws, and top plate, threaded, or clevis ends.

  • Precise Positioning - can be controlled accurately for positioning within thousandths of one inch
  • Self Locking – models featuring higher gear ratios are inherently load holding as long as the actuator is not subject to vibration
  • Uniform Lifting Speeds – since many actuators feature the same gear ratios different capacities can be used in the same application to lift unevenly distributed loads with uniform speeds
  • Quick, Sure Operation – All actuators are designed and built to be positive acting, for accurate response to motive power
         
Machine Screw Actuator Performance Specifications (Imperial)
Performance Table Instructions
When reviewing any Duff-Norton Actuator Performance Specifications Table, as part of the process of selecting the best-suited actuator for your application, there are several important worm-gear ratios to consider.

Standard Ratio – is frequently chosen when higher speeds and efficiency ratings are desired.
Optional Ratio(s) – is frequently chosen when the application requires higher lifting capacities, lower speeds, or to ease the use of a handwheel.
Numeric Ratio – is frequently chosen for applications requiring fine adjustments, higher lifting capacities, lower speeds, the easy use of a handwheel, self locking applications, and also offers the benefit of an even number of worm input turns per inch of stroke.

 

Capacity (Tons)

 1/4

 1/2

1

2

3

5

10

15

Max. Speed Cface Driven (in/min)** 

 

72.0

72.0

108.0

108.0

108.0

Max. Speed Red. Driven (in/min)** 

 

14.4

21.9

21.9

21.9

21.9

Dimensional Information Shown on Page(s): 

 

18

19

20

21-23

24

25

26

27

Lifting Screw

Diameter (in)

 1/2

 5/8

 3/4

1

1

1 1/2

2

2 1/4

Pitch (Std.&Opt.)

0.250

0.125

0.200

0.250

0.250

0.375

0.500

0.500

Pitch (Numeric)

0.250

0.250

0.250

Type

ACME

ACME

ACME

ACME

ACME

ACME

ACME

ACME

Worm Gear Ratios

Std.

5:1

5:1

5:1

6:1

6:1

6:1

8:1

8:1

Optional No. 1

20:1

24:1

24:1

24:1

24:1

24:1

Optional No. 2

12:1

12:1

12:1

Numeric Ratio

20:1

25:1

25:1

25:1

25:1

25:1

Turns of Worm for 1" Stroke

Std.

20

40

25

24

24

16

16

16

Optional No. 1

100

96

96

64

48

48

Optional No. 2

48

48

32

Numeric Ratio

100

100

100

100

100

100

Worm Torque at No Load (in-lb)

Std.

2

2