mhoulroyd
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Last week I was visiting a customer in Boston. They had an exciting new product they were about to launch. The young engineers were brillant and there was no doubt in my mind their product would take off successfully. While they demonstrate the product, they show how the consumer would easily place the device back into a recharging station. I sat there in disbelief, I asked them to show me again how their customers would dock their device. To my horror, they were placing this heavy device directly onto the spring pins without providing support. The spring pin pistons could be driven hard back into the barrel if the consumer was not careful. i pointed out to them that spring pins, regardless of who manufactures them, are not intended to perform as shock absorbers. i explained and demonstrated the construction of a spring pin and together we're going to redesign their docking station so their customer doesn't call up complaining about the product no longer working after two docking cycles.
1. In the illustration below - A typical spring pin is constructed of a barrel, spring and piston.
2. Every spring pin has an initial preload force, intended to keep the piston from reducing height and setting after being initially depressed.
3. You do NOT want to engage and hold your height at preload distance (if the initial force is under 0,5N) the contact resistance will typically be over 20milliOhm.
4. You WANT to begin to engage your application at a depressed height that will result in a minimum of 0,5N force, this will result in a contact resistance 20milliOhm or less.
5. The distance from the starting height described in step 4 to the full stroke distance of the spring loaded contact is known as the "Working Travel"
6. Operating within the "Working Travel" distance will bring about the best interconnect results.
To prevent the piston from being driven back into the shell, which can result in many bad things such as:
a. Bent piston, which will bind and stick within the shell.
b. Reduced spring loaded contact height due to spring going coil on coil and taking a set.
c. Piston shear from repeated unprotected lateral force engagement.
To prevent these bad things from happening, a savvy designer will incorporate molded bosses and standoff hardware to prevent the mating object
from driving the piston back hard into the barrel. Spring loaded contacts are the hottest, most popular method companies are developing
modular design applications. If I can help you with a spring pin connector application, please contact me, I'll be happy to assist you.
Kind Regards, Marty
**broken link removed**
**broken link removed**
1. In the illustration below - A typical spring pin is constructed of a barrel, spring and piston.
2. Every spring pin has an initial preload force, intended to keep the piston from reducing height and setting after being initially depressed.
3. You do NOT want to engage and hold your height at preload distance (if the initial force is under 0,5N) the contact resistance will typically be over 20milliOhm.
4. You WANT to begin to engage your application at a depressed height that will result in a minimum of 0,5N force, this will result in a contact resistance 20milliOhm or less.
5. The distance from the starting height described in step 4 to the full stroke distance of the spring loaded contact is known as the "Working Travel"
6. Operating within the "Working Travel" distance will bring about the best interconnect results.
To prevent the piston from being driven back into the shell, which can result in many bad things such as:
a. Bent piston, which will bind and stick within the shell.
b. Reduced spring loaded contact height due to spring going coil on coil and taking a set.
c. Piston shear from repeated unprotected lateral force engagement.
To prevent these bad things from happening, a savvy designer will incorporate molded bosses and standoff hardware to prevent the mating object
from driving the piston back hard into the barrel. Spring loaded contacts are the hottest, most popular method companies are developing
modular design applications. If I can help you with a spring pin connector application, please contact me, I'll be happy to assist you.
Kind Regards, Marty
**broken link removed**
**broken link removed**