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Symmetric Quickcoupler SQ

Symmetric Quickcoupler SQ

by Lehnhoff for Excavators from 8 to 43 t

With the fully automatic Lehnhoff SQ system, you can change all hydraulic attachments without leaving the cab. The combination of symmetrical quickcoupler and integrated, patented Lehnhoff valve technology gives you investment security and the following advantages:

  • Greater economic efficiency through savings in excavators, personnel and time
  • Protection of the machine, attachments and hydraulic hoses
  • More efficient work - tool change even with short work cycles
  • More safety and comfort for the driver

Lehnhoff SQ: One Standard - many possibilities

Lehnhoff SQ quickcouplers are based on the S standard and, thanks to their design, are compact, comparatively light and very robust. The standardised interface with 2 coupling shafts enables the attachment to be rotated by 180°, i.e. a bucket can be used as a backhoe or shovel bucket.

S-Standard +

Lehnhoff SQ complements the symmetrical concept of the S-standard with an ingenious feature: a symmetrically constructed valve block allows attachments such as a tilting bucket or a crusher bucket to be operated hydraulically in shovel mode. A built-in protection prevents misdirected engagement with attachments that are not intended for reverse mode.

Lehnhoff SQ: The technical highlights


  • Fully symmetrical valve block arrangement enables the use of hydraulic attachments rotated by 180°, e.g. tilting buckets, sorting buckets, crusher buckets (where appropriate)
  • precise hydraulic connection through patented valve clamping technology
  • Lehnhoff short-stroke valves with minimal pressure loss and low heating with the greatest oil flow
  • The block depressurisation unit integrated in the valve block enables particularly low installation effort
  • Particularly maintenance-friendly valve technology (seals can be changed on site in 2 minutes)
  • Emergency unlocking and locking - partially possible with a socket wrench (SQ70)

Internal block depressurisation unit

  • During the unlocking process, the working line and rotary gripper line in the S block and A block are depressurized
  • Increases the service life of the valves
  • Integrated in the valve block, no need for costly and time-consuming installation on the excavator
  • Installation effort corresponds to that of a conventional hydraulic quick coupler

SQ - valve blocks

S-Block: Valve block in the quick coupler

  • with 5 symmetr. arranged short stroke valves
  • including leakage oil line
  • integrated hydraulic bracing support for fixed hydraulic connections
  • optionally with power feed-through

A-Block: Valve block in the attachement

  • Number of valves matched to the respective attachment
  • Unused valve positions are given a so-called dummy insert
  • Short stroke valves are flush with the block surface - > very easy to maintain
    • Working group valves

    • Gripper turning circle valves

    • Oil leakage valves

    • Valve dummy

    • Optional
      current feedthrough

SQ-Adapters - suitable for attachments of all types and brands

No matter which attachment of which brand you want to connect to your excavator: Lehnhoff offers adapted SQ adapters for all attachments. Thanks to the defined S standard, all SQ adaptations of a class fit all quickcouplers that use the S standard.

Adapter frame for e.g. bucket conversion

Screw-on adapter with valve block and drilling pattern suitable for e.g. hydraulic hammer / sorting grab / shear etc.

Grab adapter for hanging grab with valve block and universal joint suitable for the respective type

Screw-on adapter with valve block and multi-hole pattern, suitable for the most common types of attachments -> available immediately!

Technical Data SQ

Fully hydraulic quickcoupler SQ
  SQ 60 SQH 60 SQ 70 SQH 70 SQ 80 SQH 80
Excavator 8 - 18 t 8 - 18 t 15 - 28 t 15 - 28 t 25 - 43 t 25 - 43 t
Coupling shaft Ø (mm) 60 60 70 70 80 80
Distance of axles (mm) 480 480 600 600 670 670
Width (mm) 340 340 450 450 590 590
Weight ca. (kg) 170 170 280 280 430 430
Operating pressure locking (bar) 50 50 180 180 50 50
Operating pressure unlocking (bar) 210 210 280 280 210 210
Valve configuration 3x KV1
2x KV3
- 2x KV1
2x KV4
1x KV3
- 2x KV1
2x KV4
1x KV3
© 2021 Lehnhoff Hartstahl GmbH

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