Door damper

From DDL Wiki

Revision as of 14:04, 17 September 2012

Executive Summary

A door damper is a standard piece of industrial hardware that is used on thousands of doors across America. Our team is analyzing competitor door dampers to determine the function, strengths, and weaknesses.

The competitor's damper was dissected in order to gain a better understanding of it functionality and the parts that are used. Following dissection, DFM, FMEA, and DFE analysis was performed. DFM analysis revealed that while the parts are mass produced, they are neither standardized nor easy to assemble. FMEA revealed that failures of the product are highly unlikely and unlikely to harm the user. Instead, failure modes focused around the door damper becoming unable to fulfill its purpose. DFE analysis revealed that while there was little carbon dioxide cost associated with the manufacture of the device, the hydraulic fluid used could be toxic and a hazard if disposed of improperly. The lack of proper instruction or disposal advice implies that proper disposal is unlikely if possible.

We have determined that there are several possible areas of improvement. These believe that these areas focus around on the elimination of the petroleum-based damping fluid, standardization of parts, and possible additional features.

Primary Stakeholders and Product Needs

Consumers are building owners who must absorb cost of original door damper, instillation, as well as maintenance costs and replacement. Also must consider installers (construction workers), maintenance workers, and building planers.

Product Function and Evaluation

The door damper has two main roles. First, the damper closes the door automatically. Secondly, the damper ensures that the door moves at a safe and controlled rate.

Self closing functionality is achieved with the use of a spring. The spring is compressed when the door is open. It then expands and forces the door into a closed position.

Speed is controlled by moving a piston through a viscous fluid. Speed can be controlled by opening additional channels to allow the fluid less head loss.

Motion is controlled and transmitted through the use of a two bar linkage, a rack, and a pinion. This provides both mechanical advantage for the spring, as well as allowing the use of a linear spring to cause rotational motion of the door.

Steps for use

• Install door closer to door and frame
• Adjust to desired angle and closing speed
• Push/pull door open
• Allow door to close behind you

User Study

Industrial door closers are standard in their function. They can be adjusted for the angle to which the door is allowed to open, as well as the speed at which the door closes. They allow the door to open easily in a single direction and then damp the motion as the door closes in the opposite direction. The motion is usually stopped fully by the frame of the door.

Observations

• Shorter amount of time to push open a door than to pull (also easier when carrying things)
• Dampers protect walls from damage due to doors slamming
• If not damped enough the door can hit a person when closing
• Some people will fling door open as far as possible, so as not have to push door again as they walk through
• Greater effort is needed to open doors with dampers than without (adds resistance)
• Sometimes the door will be pushed open into a person on the other side

List of Parts

Design For Manufacturing and Assembly

DFM &DFA

Failure Mode and Effect Analysis

Design for Environment

Team Members

References