RATIO CLAMP
 



Clamping device Ratio-Clamp® hydraulic clamp from Hänchen

The Hänchen hydraulic Ratio-Clamp® is a positive rod clamping safety device. The Ratio-Clamp® is unlocked by hydraulic pressure. In the event of an electrical / hydraulic power loss, the potential energy of the internal Bellville washers load a conical piston, driving it over the friction fingers resulting in securing the load. “ a true self contained safety clamp”.

Boasting a retention force of up to 450 kN, the clamp hydraulic holds the piston rod in whatever position it is in at that particular moment. Without having to generate extra power (no extra energy) and for an unlimited period of time. The clamping device Ratio-Clamp® is approved by the German Technical Inspection Agency (TÜV). Special development of Custom solutions (larger rod diameters, intermediate sizes, greater clamping forces…) pose no problem for the Hänchen specialists. 

Hänchen is particularly proud of its RC-H model. Following a request from the Health and Safety Centre of the Employers' Liability Association (BGZ iron and metal section III, Düsseldorf), Hänchen developed the new safety clamping hydraulic Ratio-Clamp® under extreme conditions for use with hydraulic presses and injection moulding machines.

The possibilities for your application:

Rod-Ų from 16-140 mm,
Release pressures from 35-105 bar
  Grabs and clamps for all it's worth...
At the very latest when a power failure (intentional or not) or a malfunction occurs and the safety of man and machine needs to be ensured, Ratio-Clamp® from Hänchen comes into its own.

It grabs and fixes the piston rod in place wherever it is at that particular moment. Without having to rustle up some extra power (no extra energy) and for as long as it takes to rectify the breakdown. Ratio Clamp® is approved by the German Technical Inspection Agency (TÜV). Neither does the development of specific solutions (larger rod diameters, intermediate sizes, greater clamping forces…) pose a problem to the Hänchen specialists.
 
The program - user oriented
Hänchen has designed its tried-and-tested Ratio-Clamp® to users, who have until now had to undertake clamping with their own designs or customized solutions. As Ratio Clamp® and the clamping, flange and intermediate flange components are available individually, The installation dimensions and technical data can be accepted quickly without any fuss by the designer from the Hänchen electronic -catalogue "E-Kat". A multifaceted catalogue range of clamping unit products with a clamping force of between 10 and 450 kN and for rod diameters of 16 to 140 mm covers further application areas without customized designs. Ratio Clamp® enables safeguards to be established for employees and systems where control breakdowns and malfunctions in production occur, similar to that found in foundries, in mould building and press construction. Hänchen Ratio Clamp® works particularly effectively in:
  • Plastic injection-molding machines
  • Metal pressure die-casting machines
  • Aluminium smelting furnaces
  • Aircraft towing tractors
  • Shock absorber and tire testing systems
  • Electrical discharge machines
  • Assembly facilities of various kinds
  • Machine tools
  • Ship propulsion drives
  • Honing machines
  • Welding robots
  • Presses

and much more.

 
Operating principle - a patented matter 

The patented operating principle serves to ensure that man and machine are safeguarded. As long as the release pressure is applied, each rod can be moved freely in both directions. The force accumulated in the springs is released and forces the rod to be clamped whenever the release pressure is no longer applied. This occurs either due to an intended reduction in pressure or where the hydraulic system suffers a loss of pressure through an emergency switch off, power loss or damage to the system. The clamp will remain in position for an unlimited period of time and without any additional power being supplied to it until the clamp is opened by the release pressure and the piston rod can freely move again. 
Clamping force

The clamping force is dependent on the available release pressure. The percentages relate to the respective minimum release pressures as printed in the table (on the reverse side of the brochure), the clamping force percentages relate to the maximum axial loads which are also given in the table. 
Clamping Indicator switch

In order to display whether the clamping unit is locked or not it is advisable to install an inductive proximity sensor. The proximity sensor operates without making contact and is thus free of wear-and-tear. The user can also obtain details on the various designs, matching plugs and the required installation dimensions in the Hänchen electronic -catalogue "E-Kat". . 
A true fit: mounting kits and flanges

Various fastening parts can be mounted to a standard Ratio Clamp®. Or you may receive them already mounted on a Hänchen cylinder. The mounting dimensions, which are made up of the various types of cylinders, are all available in the "E-Kat". In the event that you should wish to mount the Ratio-Clamp® to an existing cylinder, we will require the exact dimensions of any other make of cylinder. 

Where to next? The control block

When using a safety clamp on hydraulic cylinders the use of Hänchen control blocks has proven to be practical. They provide a safeguard after the subsequent operational sequence and also reduce the switching technology expenditure for the user to a minimum. Naturally, the control blocks are also available in the Hänchen electronic -catalogue.
Ratio Clamp® RC-H model - The new safety model

The Ratio Clamp® RC-H model especially is available for utilisation, for example on hydraulic presses and on injection-moulding machines.

This clamping unit complies with the regulations as posted by the "Berufsgenossenschaft lichen Zentrale für Sicherheit und Gesundheit - BGZ" (German Trade Association Headquarters for Safety and Health) and the "Fachausschuss Eisen und Metall III "(Technical Committee for Iron and Metal III) in Düsseldorf.
  • The clamping forces correspond to at least 2x the load's weight to be held by the force.
  • The locked state is queried by an inductive proximity sensor and displayed. The sensor operates without making contact and is thus practically free of wear-and-tear. 
  • The proximity sensor is equipped with an additional diagnosis output to enable it to monitor its own functions. 
  • The clamping unit is intended to be used to lock during a machine downtime.

Federal German law (BG) requires that the user ensures that the Ratio-Clamp® RC-H clamping unit model is installed in compliance with the requirements prEN 693 or DIN EN 201 and that control technology measures are taken, which will prevent the clamping unit from releasing prematurely (before the load is supported on the pressure column) and which implement a solution through which the holding force can be inspected when in installed status. This is the somewhat down-to-earth requirement. Next to the providing the user with the catalogue range of products we at Hänchen are only too glad to offer our know how and experience with regard to clamping units in their planning and configuration
Technical data

Rod 
Ų
mm

Release- 
pressure, 
minimum 
bar

RC model
Max. axial 
load
in KN

RC-H model
Max. axial 
load
in KN

16

60

10

5

16

50

8

 

18

55

12.5

6.25

18

35

8

 

20

55

14

7

20

40

9

 

22

70

17

8.5

22

45

12

 

25

70

20

10

25

50

15

 

28

90

31.5

15.75

28

65

25

 

30

105

40

20

30

75

30

 

32

60

40

20

32

45

30

 

36

75

45

22.5

36

50

32

 

40

80

50

25

40

55

38

 

45

70

65

32.5

45

50

45

 

50

90

80

40

50

60

55

 

56

75

90

45

56

50

60

 

60

75

100

50

60

55

70

 

63

85

100

50

63

55

60

 

70

80

140

70

70

55

100

 

80

90

180

90

80

65

130

 

90

65

200

100

100

75

250

125

110

65

300

150

120

70

330

165

125

75

350

175

140

65

450

225

 
  • The Ratio Clamp® enables each
    rod with a hard surface (e.g.
    chrome plated = 48 HRC) to be
    locked using the f7 (Rz < 6.3 µm)
    fit.
  • Maximum rod speed, 0.5 m/s.
  • Maximum permissible release
    pressure, 160 bar.
  • Operating temperature, -25°
    …+70 °C.
  • Media: mineral hydraulic fluid
      with a viscosity of 22 to 68 cST
      at +40 °C.

Rod 
Ų
inches

Release- 
pressure, 
minim. 
psi

Type RC
max. allowable 
thrust
lbf

Type RC-H
max. allowable 
thrust
lbf

0.628

870

2,248

1,124

0.628

725

1,798

 

0.707

797

2,810

1,405

0.707

507

1,798

 

0.785

797

3,147

1,574

0.785

580

2,023

 

0.864

1,015

3,821

1,911

0.864

652

2,697

 

0.982

1,015

4,496

2,248

0.982

725

3,372

 

1.1

1,305

7,081

3,541

1.1

942

5,620

 

1.179

1,522

8,992

4,496

1.179

1,087

6,744

 

1.258

870

8,992

4,496

1.258

652

6,744

 

1.415

1,087

10,116

5,058

1.415

725

7,193

 

1.573

1,160

11,240

5,620

1.573

797

8,542

 

1.77

1,015

14,612

7,307

1.77

725

10,116

 

1.967

1,305

17,984

8,993

1.967

870

12,364

 

2.203

1,087

20,232

10,117

2.203

725

13,488

 

2.36

1,087

22,480

11,241

2.36

797

15,736

 

2.478

1,232

22,480

11,241

2.478

797

13,488

 

2.754

1,160

31,473

15,737

2.754

797

22,480

 

3.148

1,305

40,465

20,234

3.148

942

29,225

 

3.541

965

44,961

22,782

3.935

1,087

56,202

28,102

4.329

965

67,442

33,703

4.724

1,015

74,186

37,095

4.921

1,087

78683

39,343

5.512

942

10,1164

50,584
  • Any shaft with the appropriate 
    surface (e.g. chrome-plated,
    = 48 HRC), with the fit f7 (Ra < 
    32 µin) can be locked with the 
    Ratio Clamp®.
  • Maximum shaft speed, 1,64 ft/s
  • Maximum allowable releasing 
    pressure 2320 psi.
  • Operating temperature, -13° F 
    to +158° F.
  • Media mineral oils with a 
    viscosity from 22 to 68 cST at 
    +104° F.