Automatic lifting apparatus

US5028037A · kind A · utility

Inventor

• John Wang · Chiayi, TW

Key dates

• Filing date: May 12, 1989
• Grant date: Jul 2, 1991
• Expiry date: May 12, 2009

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16F9/06
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

An automatic raising apparatus includes a hollow cylinder having a partition member separating said cylinder into a first chamber and a second chamber. A floating piston is mounted in said second chamber defining a third chamber. A sleeve member is mounted slidably and coaxially in said cylinder and has a first end connected with an article to be raised or lowered and an open second end extending through the partition member into the second chamber. The sleeve member has an axial bore which is opened toward the second chamber, and a radial hole formed thereon communicating the bore and the first chamber. A yieldably resilient member is mounted or contained in the third chamber biasing the floating piston to cause the sleeve member to move outward relative to cylinder. Fluid fills the first and second chambers and the bore of the sleeve member. A piston member is annularly fixed to the sleeve member in the first chamber and is sealed and slidably engaged with an inner surface of the cylinder in the first chamber. A stop valve device is provided for being manually closed and opened to alternately to stop and permit fluid flow between the first chamber and the second chamber. Whereby,…