How Secure is an Automatic Hair Comb in Your Pocket?

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SUMMARY

The discussion centers on the security of an out-the-front (OTF) automatic hair comb, which utilizes a magnetic force of 1 lb, 12 oz to keep the comb blade securely in place. The user has conducted various tests, including jumping and shaking, to assess the likelihood of accidental ejection while the comb is carried in a pocket. The user seeks mathematical formulas or insights to determine the conditions under which the comb might eject unintentionally, noting that an acceleration of 28 gees is required to trigger the mechanism.

PREREQUISITES
  • Understanding of magnetic force and its applications
  • Basic knowledge of physics, particularly forces and acceleration
  • Familiarity with out-the-front (OTF) comb mechanisms
  • Experience with safety testing methodologies
NEXT STEPS
  • Research the physics of magnetic force and its implications for safety devices
  • Learn about the mechanics of automatic knife and comb mechanisms
  • Investigate safety testing standards for pocket tools and knives
  • Explore mathematical models for calculating force and acceleration in mechanical devices
USEFUL FOR

This discussion is beneficial for product designers, safety engineers, and consumers interested in the reliability and safety of automatic pocket tools, particularly those involving magnetic mechanisms.

goldliger
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Hey guys!

I've got an OTF comb (a.k.a. "out the front," where the plastic hair comb "blade" ejects straight out from the handle) that is held in the closed position with 1 lb, 12 ounces of magnetic force. I.e, upon measuring it takes 1 lb, 12 oz. of finger pressure against the comb switch to eject the comb *automatically*. The plastic comb "blade" itself weighs 1 oz.

Basically, I'm wondering how one would go about determining whether this is a reasonably secure configuration -- and by "secure" I mean - what would it take to have the comb eject from the handle accidentally while being carried in the pocket) considering the plastic comb "blade" will be carried in the pocket and generally tip pointed down (within the handle, of course). I've done rudimentary testing such as jumping up and down, stomping, shaking my pockets, etc, with this automatic comb in my pocket - pretty much everything short of jumping off a 100 foot cliff with rock slab at the bottom...

Any ideas, mathematical formulas, etc, are most welcome, and thanks for your time!
 
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Since it takes 16+12= 28oz of force to eject the 1oz blade it would require an acceleration of 28 gees (28 times gravity). This is the impact acceleration required to set off an airbag...
 
goldliger said:
Hey guys!

I've got an OTF comb (a.k.a. "out the front," where the plastic hair comb "blade" ejects straight out from the handle) that is held in the closed position with 1 lb, 12 ounces of magnetic force. I.e, upon measuring it takes 1 lb, 12 oz. of finger pressure against the comb switch to eject the comb *automatically*. The plastic comb "blade" itself weighs 1 oz.

Basically, I'm wondering how one would go about determining whether this is a reasonably secure configuration -- and by "secure" I mean - what would it take to have the comb eject from the handle accidentally while being carried in the pocket) considering the plastic comb "blade" will be carried in the pocket and generally tip pointed down (within the handle, of course). I've done rudimentary testing such as jumping up and down, stomping, shaking my pockets, etc, with this automatic comb in my pocket - pretty much everything short of jumping off a 100 foot cliff with rock slab at the bottom...

Any ideas, mathematical formulas, etc, are most welcome, and thanks for your time!
This is reposting a locked thread, and very dishonest. Thread is closed. Check your messages.
 

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