Safety sensor

inwo

Joined Nov 7, 2013
2,419
I use light curtain machine sensors for safety and missing parts detection on punch presses.

The other day I was looking at a spare machine that may be put in service soon.

For the light curtain circuit, it had a vertical 2' fluorescent light, in a box on one side. The box cover had a row of ~7/8" holes ~2" apart.

2' away was a similar box with holes and detectors in series.
I don't recall the type of detectors used.

At first look I thought it was just for illumination.

I haven't seen the press run.
It was fairly new compared to the 40 year old ones I'm used to.
Lights show signs of being in service for a long time.

I can only assume it worked for the intended purpose.
If I work on the press, It's gone!:eek:

ps.

All the curtains I've seen, are not truly curtains, but closely spaced beams. Sometimes criss-crossed. sp.?
 

Thread Starter

Dritech

Joined Sep 21, 2011
901
Thanks for the reply. If I use a fluorescent light I afraid it will be affected by ambient light.

Is there another way of making such sensor?
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
I have installed a few industrial made light curtains and they had a batch of IR emitters with receivers on the opposite side.
They have a synchronized sequencing pattern that ripples down the curtain in order to help make them fool proof or any ambient detection.
Max.
 

inwo

Joined Nov 7, 2013
2,419
Any other solution would include optics and I'm no help there.:(

If it is for safety, use a commercial product.
The liability is huge.
I even worry implementing the commercial product.

I get them on Ebay for pennies on the dollar.

Even have 1 listed. Well half of one.:D barbjb
 
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