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Hydro-Mechanical Turn Clamp


Area of application

The hydro-mechanical turn-clamp unit type DE8V is designed for medium-sized and large presses exerting a force of ca. 500 tons and upwards. It is particularly suitable for top die clamping and for internal die clamping with multiple action presses.

The clamp unit is installed rigidly on the ram ledge. Alternatively, installation in the surface of the ram or bed is possible.

Its use requires dies that have lock plates or clamping edges with a U-recess.

Mode of operation

After a 90° rotation of the tie rod into the clamping position, a hydraulically actuated mechanically locking toggle mechanism transmits its clamping force to the tie rod.

Whereas the clamping force is developed mechanically, the rotary movement of the tie rod is produced hydraulically. The tie rod pinion rotates over a toothed rod unit, after a maximum 90° rotary movement, the tie rod reaches the clamping position. In this position, an edge control bore releases the hydraulic pressure to the clamping cylinder which actuates the toggle mechanism.

In the clamping position, automatic mechanical locking is carried out, and this can only be released by means of hydraulic pressure when unclamping.

Movement sequence for securing the slide:

Distinguishing features

The clamp unit is fitted with the well-proven Optima toggle mechanism. In this system, the clamping force required is transmitted by mechanical components which are actuated by low hydraulic pressure during the clamping or release process. By so doing, the clamping force is independent of the compressibility of the pressure medium, operating temperatures and line losses.

The clamping force is continuously and directly monitored by the patented Optima "Aktivator". For this to function, there must not be any hydraulic pressure on the clamp unit. In this type of control, the clamp units are connected to the machine control system via electrical switches (precision limit switches) and in the event of irregularities, bring the machine to a standstill. In this clamping system, the tie rod projects from the surface of the ram or bed when unciamped. Due to the standard fitting with a pre-clamping block, die thickness tolerances up to ±0.5 mm are permitted.

Electrical control of the following functions (switches):



  • Mechanical self-locking
  • Maximum safety due to continuous monitoring of clamping force by means of the "Aktivator"
  • Central control
  • Hydraulic pressure only necessary during the clamping or release process
  • High mechanical load capacity.


The clamp unit has a forged and gunmetal finish tie rod. The individual components of the toggle mechanism are made of hardened steels.

The clamp unit is secured by four bolts, of strength class 10.9 (not included). The thread dimension depends on the type (see technical drawing).

Technical data

Type DESV 100 DESV 200
Nominal clamping force kN 100 200
Set pressure bar 100 100
Max. load capacity kN 125 250
Max. operating pressure (min. set pressure + 20 bar) bar 140 140
Release stroke mm (ca.) 3.5 3.5
Die thickness tolerance mm ± 0.5 ±0.5
Oil volume required (each process) clamping cm3 76 144
Oil volume required (each process) release cm3 76 144
Delivery rate per unit* l/min. 1.0-1.5 1.5-2.0
Weight kg (ca.) 48 68
Hydraulic connections see drawing
Max. operating temperature °C 70 70
Pressure medium Hydraulic oil DIN 51524 - HLP
(ISO DIN 51519)
Viscosity 25 - 60 cST/40°C
Filter 20 - 25 µm

*If a pump with a higher delivery rate than necessary is used, the oil flow must be reduced by means of flow regulating valves or oneway restrictors.

Precision position switches

Switching function: single-pole change-over
snap-action contact
Supply voltage: 250 V AC
Switching capability: 2A/230 V AC
5A/24 V DC
Contacts: screw connection
Cable lead-in: armoured cable 9

For a water- and oil-tight installation, we
recommend cable screw joints, in conjunction
with a protective sleeve.

Hydraulic Circuit DiagramHydraulic Circuit Drawing
Dimensional diagrams
Type FSP


a1) b
c d e f g h i
DESV 100 100 125 390 ±0.5 3.5 80 30 32 36 130 91 119
DESV 200 200 250 485 ±0.5 3.5 98 45 32 42 155 100 162
Dimensional diagrams
m n o
p r
s t u w x y z Weight
112 125 92 75 38 50 50 M8 92 108 40 20 162 48
114 150 107 90 49 70 60 M8 125 100 50 32 166 68