Today, most commercial buildings have automatic door closers to keep building doors closed. Fire safety is the biggest reason for having door closers because they prevent the spread of fire and help protect building occupants. Door closers typically have a significant counter force when a door is being opened. For the elderly or infirm, this force can often prevent them from opening a door. This can be dangerous at worst and inconvenient at best.
Many areas prohibit propping open a door to defeat the door closer. As a result, door holders have been developed that counter the door closer. These door holders are designed to hold a door open, but in an emergency such as a fire, they are designed to release the door so that the door closer can close it. Door holders are an improvement over constantly having to fight a door closer. However, they do not allow privacy because the door is held open continuously.
Some devices have been developed to try to solve this problem. U.S. Pat. No. 4,979,261 teaches a variable position door closer. This device uses a rack and gears to move the door closer in a linear path as the door is opened or closed. This movement reduces the force needed to open and close the door. This makes operation of the door closer easier for the elderly and infirm. Another answer to the problem uses powered door openers to counter the force of the door closer. A user simply presses a button and the motor driven door opener does the work. Although these devices are convenient, they are costly and sometimes require reconstruction around the door. Thus, they tend to be used in high traffic areas of a building. They are too expensive to put on all the patients' doors in a rest home, for example. An example of this type of system is found in U.S. Pat. No. 5,375,374. The above mentioned solutions work; but at high cost and inconvenience. The problem with these solutions is that they are too limited. Although they solve the problem of overcoming the force of a door closer, they do so in an expensive and excessive manner.
USPTO Backgrounds
USPTO Backgrounds