the application has an uncontrolled roller conveyor that delivers packages that are in random order sizes and shape. They then arrive to 3 sequential conveyors all about 6 feet in length. I need to create a 10" gap between each box at the end of the 3rd conveyor. Presently there is 1 photo eye and a single encoder that can be used to determine speed control.

Are their any package spacing gurus out there that can give me a hand? Thanks in advance!!

 

if you make the last conveyor run faster then the conveyor feeding it, you will always have a gap between boxes.

Bob Peterson

 

If each of the 3 conveyors are controlled separately, it might be worthwhile to speed eachone up just a hair to create the spacing regadless of the source spacing. or put in a higher speed small conveyor before the 3 to create the distance

Cheers from: Jeremy Pollard, CET The Crazy Canuckian!
Integration and Automation Training, Consulting, and Software
http://www.tsuonline.com

 

You will need a (2) sensor, (2) valve arrangement. The first valve will act as a gate, the second as a clamp. The box stops at the gate, the second sensor detects the next box and clamps it. After a short time the gate opens for the first box and then closes off the trailing edge of the first sensor. The timers that you create will create the gap between the boxes.

I am working on a project right now that does the same thing.

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This is simply a system of two linear equations, one to calculate when the spot you want will arrive and the second to determine the time you have to get the box there from where you detect it. You would have to hold up the boxes to achive this and control the belt velocity. Obviously, if the boxes don't arrive at the rate they are placed on average, all bets are off. But if you need at least 10" it can be done with angles and the belt speed differential. The trick is to get a little tipping action to delay the box "grabbing" the second belt even if they are back to back.

Regards

cww

 

With a project like this, the value of having cases reliably delivered to the end of conveyor 3 with the required 10" spacing must be measured against the cost involved. With that in mind, I would have conveyor 2 run faster than 1 to pull a gap between cases. A sensor at the discharge of 2 works in combination with a sensor 10" upstream on conveyor 3. Conveyors 2 and 3 must run the same speed. Some additional things to keep in mind...What happens to cases at the discharge end of conveyor 3? Do they fall on the floor or is there a stop? If the case stops then the conveyor needs to stop. If conveyor 3 stops then conveyors 2 and 1 may need to stop. Notice that the cases move in one direction while the control (interlocking) moves the opposite direction. Don't forget the case that is less than 10" long or an employee adding or deleting a case. I hope this helps.
Regards [email protected]