Examples 41-50

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This rental truck has a door latch which will not allow the loading ramp to slide out while the the latch is in the closed position.  

trucklatch1 trucklatch2


Mr Coffee mr coffee2

This automatic coffee pot is equipped with a “pause and serve” feature.  The lid of the pot presses up on the button (shown at right above), releasing a valve which allows the coffee to pour into the pot. If you remove the pot before brewing is finished, the valve closes so coffee is not spilled. (A friend who owns one of these reports that the valve leaks like a sieve. A good try none the less.)


bathroom door 1 Bathroom door 2

I have never hung my coat in a bathroom stall and then walked out without it.  But apparently someone has, because this stall door in the Dallas Galleria is designed so you cannot unlatch the door without moving your coat.


jetway You would like to move the jetway up to the plane quickly so travel weary passengers can get off. Your plane is worth millions of dollars, Great care should be taken. Quickness and care don’t always go together so well.  The solution: build a switch into the jetway which stops it an inch away from the plane’s fuselage.


wheelchair wheelchair2

Correspondence from www.saferwheelchairs.com reports that the U.S. Consumer Product Safety Commission has recorded 167 deaths due to wheelchair related accidents from 1997-1999. Of these, 105 were wheelchairs rolling away from the person for one reason or another.

The response? A mistake-proofing device that locks the wheelchair when no one is sitting in it.  An unlocking lever on the handle allows the wheelchair to be moved when empty.


syrup syrup2
Hungry Jack syrup has a small window near the bottom of the container that changes from black to clear when heated revealing the word HOT. This signals that the syrup is warm and ready to serve.


washing machine

Substantial damage is caused when washing machine hoses burst while homeowners are away.

The Saf-T-Smart valve kit detects when the washing machine is operating and opens the valves allowing water to flow freely. When the washing machine is off, the valves are closed, reducing pressure on the hoses and avoiding serious water damage (and returning to a flooded house).


Garage door Well Designed garage door openers have two safety features that prevent people or pets from being crushed by a closing door: (1) a contact safety reverse feature, which opens the door if it hits a person or object, and (2) an infrared beam across the doorway that causes the door to reverse automatically if a person or pet who passes through the beam.




This treadmill has a clip that attaches to the user’s clothes.  If the user falls off the back of the machine, a safety peg is pulled from the machine turning the motor off
























Estes’ rocket launcher system has two mistake-proofing devices:

1. A safety key must be inserted in control box inorder to launch the rocket.  The key is attached to a plastic cap that is supposed to be put on the end of the launch pad guide rod.  Thus locking out a launch while people are nearby. It’s weakness is that there is no mechanism for enforcing the devices use.

2. A light is provided on the control box that lights when the circuit to the rocket motor is properly attached. When the saftey key is in and the light is on, pushing the button should result in successful launch.

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Examples 1-10

Examples 11-20

Examples 21-30

Examples 31-40

Examples 41-50

Examples 51-60

Examples 61-70