Hydraulic locking cylinder with throttled supply of fluid during unlocking stage

US5097748A · kind A · utility

Assignee

• Pacoma Hydraulik GmbH · DE

Inventors

• Georg Koch · Unterschleißheim, DE
• Wolfgang Traupe · Treffurt, DE
• Frank van de Poel · Rottenburg am Neckar, DE
• Kurt Schaible · Aidlingen, DE
• Holger Seel · Aidlingen, DE

Key dates

• Filing date: Dec 20, 1990
• Grant date: Mar 24, 1992
• Expiry date: Dec 20, 2010

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F15B15/261
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A hydraulic cylinder that locks into position has a housing (1) with at least one pressure connection (7) and a piston (3) and rod (6) that travel tight in an out of the housing. The locking mechanism comprises a piston (11) that rests against a spring (35) and a barrier mechanism (23) with a cage of balls (25) that roll radially into a locking position in a locking groove (26) and back into an unlocking position in an unlocking groove (22). The primary piston communicates with a hollow space (18) and acts on a primary participating surface (19) and the locking piston communicates with an unlocking space (13) and acts on an unlocking surface (14) by way of the pressure connection. There is a variable choke (17), which disengages after a while, beween the pressure connection and the primary space (18) in the primary piston (3). The unlocking space in the locking piston (11) can be supplied with fluid without being choked by way of the pressure connection, so that, once fluid has been supplied from the pressure connection, no pressure can build up in the primary space until the locking piston has left its locking position.