Rotary door closer with fluid check

Abstract

Abstract 1,227,248. Door closing device. OY WARTSILLA AB. 20 Aug., 1968 [21 Aug., 1967], No. 39682/68. Heading E2M. [Also in Division F2] A fluid-braked door closing device has a piston 2 screw-threadedly engaged by a cylinder 1, the piston having a fluid chamber 4 which communicates with the cylinder via a non-return valve 8 and a return duct provided with an adjustable throttling means 13 which may be operated from outside the device. There is also a constant throttling means provided by an annular gap 10 between the piston and cylinder and an opening 11 in the piston wall. Movement of a door attached to the arm 7 causes rotation and thus axial displacement of the piston so that fluid flows from the chamber 4 to chamber 5 via valve 8. When the door is released, a spring 9 urges the cylinder I back to its initial position relative to the piston 2, fluid returning to the chamber 4 via ducts 12 and 11. The screw 13 may be made of a material having a greater coefficient of expansion than that of the piston so that the throttling effect and thus the closing speed of the door remains substantially unchanged with changes in temperature.

Inventors

• 👤 Toimi Rassa

Bibliographic Details