GB2349173A

GB2349173A - Door closer

Info

Publication number: GB2349173A
Application number: GB0009692A
Authority: GB
Inventors: Rex H Lasson; Daniel R Mclaughlin
Original assignee: Schlage Lock Co LLC
Current assignee: Schlage Lock Co LLC
Priority date: 1999-04-21
Filing date: 2000-04-20
Publication date: 2000-10-25
Anticipated expiration: 2020-04-20
Also published as: CA2305994A1; GB0009692D0; GB2349173B

Abstract

A door closer has a low melting point e.g. plastics, plug (48) in an aperture in the top of the closer body. In the event of a fire, as the door heats up, the closer body also heats up. When the temperature of the closer reaches approximately 250{ F (120{ C), the hydraulic fluid within the closer will begin to emerge from the plastics plug area and spills over and collects in the top of the closer body casting which forms an open-surfaced, fluid-retaining reservoir. The contained fluid smokes and evaporates from the heat. No fluid escapes down to the door and the floor. This reduces the chance of causing a fire on the non-fire side of the door and frame.

Description

DOOR CLOSER This invention relates generally to door closers and more particularly to door closers using hydraulic fluid.

Fire doors are designed to protect against passage of fire from one room to another in a building. In the U. S., the National Fire Protection Association promulgates construction and installation standards for fire doors and windows as a publication, NFPA 80. Listed fire doors are classified in twelve categories, and protection of an opening depends upon the use of a listed fire door, a listed frame, listed door hardware, and a listed door control device as specified under each door type. Fire classifications for buildings are specified in model building codes, government regulations, and state and local building codes. Fire door classifications are expressed in hourly ratings according to the Standard for Fire Tests of Door Assemblies-UL 10B, ANSI. A2.2, ASTM E-152, CSFM 43.7, CAN4-S104 (ULC-S104), UBC 43-2-1991, and NFPA 252.

The classifications are determined by exposing the doors to fire testing under standard conditions, and hourly ratings indicate the duration of exposure which the door can withstand, such as 4,3,2,1/2,1,3/4 hours, and 30 or 20 minutes. It is permissible to test a fire door with special hardware and installation. This is usually done by door manufacturers who wish to establish a fire rated door, frame, door control, and hardware combination which can be specified in a building contract. It should be noted that, although there are several. very similar fire door assembly tests in use throughout the world, there is no single international fire test standard.

Generally, fire doors must be maintained closed and latched or must automatically close and latch under a broad range of fire exposure conditions in order to properly serve their fire protective function. Thus, the door control device must assure that the door closes after it has been opened, and the latch must maintain the door latched. Typically, most fire door tests are performed without a door control device, or, if included, the door control is mounted on the fire side of the door. However, fire test standards are changing to require that the door closer be mounted on the non-fire side of the door during testing.

Most currently used door control devices employ hydraulic damping technology to control opening and closing speed of the door. The hydraulic fluid is commonly a petroleum based oil which is relatively inexpensive, plentiful, non-corrosive, and compatible with a wide range of metals and other materials. However, petroleum oils have an auto-ignition temperature ranging between approximately 500 and 750 degrees Fahrenheit (260-400 C) and may contribute to the spread of the fire, if exposed to high temperatures, even when the door control device is mounted on the non-fire side of the door.

Within a few minutes after a fire begins, assuming it is adjacent to a fire door, the temperature of the door control device on the non-fire side of the door begins to increase by conduction through the door. This causes the hydraulic fluid to expand, to leak around the seals of the door control device, and to run down the door.

Approximately 10 to 15 minutes after the fire starts, the temperature on the non-fire side of the door is high enough to cause auto-ignition of the leaking fluid. Even though the door and frame assembly may have a fire rating of 2 hours, or more, the fire has transferred through the door in less than 15 minutes.

According to the present invention, there is provided a door closer comprising a door closer body having an open surfaced fluid retaining reservoir in a top portion thereof and a plug aperture in the top portion, a plug within the plug aperture and hydraulic fluid within the door closer body, an inner end of the plug aperture being in fluid communication with the hydraulic fluid.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Fig. 1 is a perspective view of a door closer; Fig. 2 is a side view of the door closer shown in Fig.

1; Fig. 3 is a top view of the door closer shown in Fig.

1 ; and Fig. 4 is a partial cross-section of a central boss showing a plug and plug aperture.

Figures 1 to 3 show a door closer 10 having a cylindrical door closer body 20 containing an operating fluid, typically an hydraulic fluid. The door closer 10 shown in the figures is an LCN (a division of Schlage Lock Company) concealed overhead 2010 door closer. Other door closers can be used with the present invention, such as the door closers shown in U. S. Patent Nos. 4,080,687, 4,130,913,4,263,694 and 4,979,261, the disclosures of which are hereby incorporated by reference.

The top of the door closer 10 includes a central casting boss 45 with an aperture 49 extending therethrough into fluid communication with the hydraulic fluid within the door closer body 20. A plastics, preferably nylon, plug 48 is inserted into th--aperture 49 (See FIG 4). The plastics plug 48, preferably, has a melting point between 200 F and 300 F (93 C-148 C). Normally, the plug 48 is press fit into aperture 49. Other materials having similar low melting temperatures, such as solder, can be used.

The top of the door closer body 20 is formed into an open surfaced fluid retaining reservoir 40 defined by longitudinally extending sides 42 and connecting ends 44, which extend from one side 42 to the other side 42. The sides 42 and ends 44 extend above the central portion 41 of the door closer body 20.

Although the preferred embodiment shows the meltable plug 48 and aperture 49 within the central casting boss 45, the plug 48 and aperture 49 could be in other locations in the top of the door closer body 20.

When the door closer body 20 heated, such as by a fire on the other side of the dror, plug 48 melts allowing the hydraulic fluid, which is increasing in pressure because of the heat of the fire, to seep out of aperture 49, spilling over boss 45 and collecting in the open surfaced fluid retaining reservoir 40. The collected hydraulic fluid smokes and evaporates from the extreme heat. This reduces the likelihood of the hydraulic fluid to escape down to the door and floor, which reduces the chance of causing a fire on the non-fire side of the door and frame.

Claims

1. A door closer comprising a door closer body having an open surfaced fluid retaining reservoir in a top portion thereof and a plug aperture in the top portion, a plug within the plug aperture and hydraulic fluid within the door closer body, an inner end of the plug aperture being in fluid communication with the hydraulic fluid.

2. A door closer according to claim 1, wherein the plug is a meltable material.

3. A door closer according to claim 2, wherein the meltable material melts between 200 F and 300 F (93 C to 148 C).

4. A door closer according to claim 2 or 3, wherein the meltable material is nylon.

5. A door closer according to any one of the preceding claims, wherein the open surfaced fluid reservoir is formed by two longitudinally extending sides extending above a central portion of the door closer body and two ends extending above a central portion of the door closer body and extending from one longitudinally extending side to the other longitudinally extending side.

6. A door closer according to any one of the preceding claims, wherein the door closer body has a circular boss extending above the fluid reservoir, the plug aperture being within positioned within the circular boss.

7. A door closer substantially as hereinbefore described, with reference to the accompanying drawings.