⛔★ Help me design a simple time delay (not electrical)

[myeng]

Hey everyone I'm trying to design a simple time delayed device. Device could me mechanical but it doesn't really have to be as long as it does what I want.

Just need something that is relatively small could be wide and tall just not thicker then 1 inch.

The device should have a arm/button that you can push down (1 inch travel at least), when you push the arm/button down it should stay down for about 2 minutes and then come out and have enough push power to push up something thats about 1/2LB. The arm/button that does the pushing/work can come out slow or fast

[JAlberts]

One type of mechanical timer you are describing that can be constructed is a hydraulic timer consisting of a spring loaded piston, with a small flow metering hole,inside a cylinder (the reverse of shock absorbers used in industry to dampenimpacts) but this type of device will require careful sealing of the piston shaft and can be prone to leakage of the hydraulic fluid due to wearing of that seal. As long as appropriate materials are used for the units construction the fluid can be water; but, a more viscous fluid is better forlong delay periods and more accurate performance. Generally the spring on such a device is located outside of the cylinder between the cylinder end and the fitting at the end of the cylinder rod; but, for a more compact design the spring can be located inside the cylinder under the piston.
Time delay electric timers use a pneumatic version of this design but the load to close the contact at the end of the stroke; and, therefore, the spring load and piston pressure are lower than you want for your device.

[Hudson]

Some towel dispensers use a suction cup as a timer to keep towels from being dispensed too rapidly. Also look at timers that interupt the flight of rubber band powered model airplanes.

[myeng]

Both of you guys are briliant, this is why I LOVE forums. Best I could come up with to be honest was memory foam in like a balloon with a one way check valve. Now my device needs to be dare I say, stupid cheap so the suction cup idea is fitting. I'm going to try a few and see if this can do the job :-)