Totally enclosed door check

• US 3,979,790 A
• Filed: 10/06/1975
• Issued: 09/14/1976
• Est. Priority Date: 10/06/1975
• Status: Expired due to Term

• Current Assignee: Mark IV Transportation Products Corp.
• Original Assignee: Vapor Corporated
• Inventors: Chiarappa, Ralph F.
• Primary Examiner(s): Schroeder, Werner H.
• Assistant Examiner(s): Berman, Conrad L.
• Application Number:
  US05/619,725
• Time in Patent Office: 344 Days
• Field of Search: 16/51, 16/66, 16/84, 188/313, 188/318
• US Class Current: 16/84
• CPC Class Codes: E05F 3/04 with liquid piston brakes rotary type E05F3/14
• CPC Class Codes: E05F 3/12 Special devices controlling the circulation of the liquid, e.g. valve arrangement E05F3/223 takes precedence; valves per se F16K
• CPC Class Codes: E05Y 2201/20 Brakes; Disengaging means, e.g. clutches; Holders, e.g. locks; Stops; Accessories therefore
• CPC Class Codes: E05Y 2201/254 Fluid or viscous friction
• CPC Class Codes: E05Y 2900/132 Doors

Abstract

A check assembly using compressible fluid for linearly dampening the closing movement of a door includes a cylindrical, hollow housing having a cavity defined therein with first and second ends. Slidably mounted within the cavity and attached to the door is a piston of substantially the same cross-sectional area as the cavity. The piston has flap-type, relief check valves allowing free passage of compressible fluid through the piston only during motion of the piston in the door opening mode. The check assembly further includes longitudinal grooves fabricated circumferentially around the cavity and of a dimension such that the seal of the piston against the cavity wall is broken at different points during movement of the piston allowing compressible fluid to flow from one side of the piston to the other. Finally, the check assembly includes a fluid bypass continuously communicating compressible fluid from one end of the cavity to the other thereby defining a closed loop system. The bypass includes a variable orifice comprising an orifice and a needle valve such that the rate of fluid flow through the bypass may be adjusted to allow the same assembly to be used with doors of different weights and to compensate for linkage wear.

Claims

1. In combination with a door movable to open and closed positions

a check assembly comprising a housing having a cavity therein closed at the ends thereof and containing compressible fluid,

a movable member mounted within said cavity having a cross-section substantially identical to the cross-section of said cavity,

means connecting said member to said door such that movement of said door moves said member within said cavity,

said member movable in a first direction upon opening of said door and in a second direction upon closing said door,

means connected to said door for returning said door to a predetermined position upon said door being opened,

means for resisting movement of said member in said second direction,

a bypass member placing said ends in fluid communication thereby providing compressible fluid to either of said ends from the other end as required by the movement of said member, and

variable orifice means in said bypass member for controlling the flow rate of said fluid in said bypass member and thereby controlling a vacuum behind said member during movement in said second direction.

2. The check assembly of claim 1, said check assembly being a closed system.

3. A method of linearly dampening the closing motion of a door, said door being attached to a dampening assembly comprising a housing having a central chamber therein closed at first and second ends, compressible fluid in the chamber, and a piston slidably mounted in said chamber movable between said ends, said piston being attached to said door, the steps comprising

continuously communicating said fluid from a first portion of said chamber between said first end and said piston to a second portion of said chamber between said second end and said piston such that as said piston moves from said first end toward said second end, fluid in said second portion may flow to said first portion of the chamber as said door opens,

continuously communicating said fluid from said second portion of said chamber such that as said door closes moving said piston from said second end toward said first end, said fluid in said first portion of the chamber flows to said second portion of the chamber, and

controlling the rate of flow of said fluid from said first portion of said chamber to said second portion of the chamber during closing of said door to maintain linear dampening of said door at a desired rate by controlling the magnitude of a vacuum in said second portion of said chamber created by the movement of said second piston.

4. An apparatus using compressible fluid for checking the motion of an element comprising

a hollow housing having a cavity therein containing a quantity of compressible fluid,

a movable element having first and second sides slidably mounted within said cavity and attached to said element so as to move within said cavity and against said fluid as said element moves,

a passage placing said sides of said element in continuous fluid communication and variable orifice means in said passage for controlling the flow rate of said fluid in said passage whereby as said element moves in a given direction, fluid in front of said element in the direction of movement continuously flows to the other side of said member such that said orifice means controls the magnitude of a vacuum on said other side of said element created by the movement of said element thereby controlling the compression of said fluid in front of said element and the resistance to the movement of said element.

5. The apparatus of claim 4 further including at least one groove within said cavity parallel to the direction of travel of said element having a larger transverse dimension than said element.

6. The apparatus of claim 4, said apparatus being a closed system.

7. The apparatus of claim 4, said member including means for resisting movement of said member in only one direction.