Conveyor rollers that get past the customer

[carnut2]

This week has been a full moon of oddities. Several times in one day we have had customers get one or two rollers between their wheels. One can pull the car if you leave extra room but two will lock up the conveyor trap door on the exit and I feel it could break the chain. Is it better to stop the customer at the tunnel entry and have them back up over the roller to start fresh? I tried that yesterday and that big King cab truck gave my roller a good twist.

 

[robert roman]

Conveyor issues are difficult to analyze online because of the many factors that can be involved.

In my mind, a conveyor roller is like an upside down dollie. However, instead of carrying an object, the dollie part is attached to chain and the roller pushes or pulls the tire.

Regardless, conveyor rollers are not meant to be driven over. Even if you don’t break the chain, this practice can stretch the chain.

If you are getting two rollers up, the clevis may be hanging up or something else is wrong.

If two rollers jam the exit end trap door, the plate or hinge may be misaligned, bent or loose bolts.

Since the conveyor is at the heart of your automated carwash system, I wouldn’t hesitate to bring in a qualified technician.

After all, if you can’t count on your conveyor, what can you count on?

 

[chadrpalmer]

Have you figured out why it happened? Is it still happening? Is it consistently happening or randomly? Slow day today likely with the weather as it is, good chance to figure it out and correct it...If I can be of any help, feel free to give me a call, I am not super smart, but been at this a while, and would be glad to try and look at it with you after hrs. (913) 636-8843

 

[Washmee]

Regardless, conveyor rollers are not meant to be driven over. Even if you don’t break the chain, this practice can stretch the chain.

Conveyor chain cannot be "Stretched". The joints may wear over time which will cause the chain to lengthen, but to claim that it can be "stretched" by driving over rollers is a "Stretch". You could just have the customer apply their brake while the conveyor is running to allow the extra roller to pass under the tire. Are you rear wheel push or front wheel pull? What controls when the rollers come up and how many come up?

 

[robert roman]

Well, Mr. Shaw, you can nitpick all you want but back in 1969 the owner of the wash I worked at described a slackened chain as “stretched” (lengthened). In the 1990’s, I knew many owners, myself included, who would commonly describe a slackened chain as stretched.

Semantics aside, I believe it is a stretch that a conveyor manufacturer would agree with your advice to have customers just apply brakes while the conveyor is running to allow extra rollers to pass under the tire as a standard operating procedure.

 

[Earl Weiss]

We have had cars follow to closely and drive in ahead of a safety roller. So, it is common to tell them to hold the brakes so that roller passes under the front tire when that happens.

Now to the OP. I am guessing they are rear wheel push with one or more safety rollers. (carnut2 please advise if I get this right.) For whatever reason when their is excessive resistance -Foot on brake, not being in neutral - low tire, misalignment, tire pressed against rail, and the first and / or second roller passes under the back tire which is then picked up by a safety roller. Now when the car exits the driver pulls out over the middle roller.

Here are the choices:
1. Do nothing, spit happens, set the torque on the conveyor high enough to pull the roller under a tire if the brakes are on but not so high as to break a chain if it jams.
2. Stop the conveyor and have the customer pull ahead over the middle roller(s) and hope the same issue doesn't repeat itself.
3. Walk to the exit end and try to direct the customer when to exit. Hold your hand up like a policeman to keep them from pulling out too early and wait for the middle rollers to drop before motioning them forward.

And finaly, while yes it is common vernacular to say a chain "Stretches" when it wears, this is caused by friction of touching surfaces and any addittional wear from the small percentage that drive over the rollers would be negligible.

I have spoken.

 

[carnut2]

Conveyor chain cannot be "Stretched". The joints may wear over time which will cause the chain to lengthen, but to claim that it can be "stretched" by driving over rollers is a "Stretch". You could just have the customer apply their brake while the conveyor is running to allow the extra roller to pass under the tire. Are you rear wheel push or front wheel pull? What controls when the rollers come up and how many come up?

Its a rear wheel push conveyor. The number of rollers and spacing are controlled by my WBC board.

I think the big training comes from having the attendant explain what they are going to do and the bumpride it is going to create to get the car back on track, especially for the occasional customer that gets two rollers trapped between their front and rear wheel.

Thanks for the feedback!

 

[Earl Weiss]

Conveyor chain cannot be "Stretched". The joints may wear over time which will cause the chain to lengthen, but to claim that it can be "stretched" by driving over rollers is a "Stretch".

FWIW checked out "Stretch" on Dictionary.com and some of the definitions fit!

 

[Washmee]

It's far safer to have a customer hold their foot on the brake to allow a roller to pass under the tire. Asking the customer to put their car in gear and try to hop over the roller can result in disaster. They could easily jump their vehicle out of the track or surge forward and damage another vehicle ahead or behind them.

 

[Washmee]

Its a rear wheel push conveyor. The number of rollers and spacing are controlled by my WBC board.

I think the big training comes from having the attendant explain what they are going to do and the bumpride it is going to create to get the car back on track, especially for the occasional customer that gets two rollers trapped between their front and rear wheel.

Thanks for the feedback!

Is there a limit switch or electric eye that senses the roller position so the controller knows when to bring up the roller?

 

[JustaGuy]

Is there a limit switch or electric eye that senses the roller position so the controller knows when to bring up the roller?

Yes, you can position a switch (I've seen both limit and eyes used, though I like the eye approach best) such that it detects rollers as they pass so your controller can know when to bring up a roller. It depends on the controller though, some can use that kind of switch and others can't.

 

[AppleExpress]

ok, so this has been a big problem for me. I recently (august) took over managing a 90' express tunnel system. It is a front wheel pull, using a log chain and roller assembly. I am constantly having issues with f-150"s and closely styled trucks jamming the rollers at the exit. it seems that as the roller pushes the vehicle over the exit door for the rollers, the weight keeps the door from rising enough for the first roller to drop down. its a constant battle because not all trucks do it, depends on how "loose" neutral is for that truck. some just keep rolling others stop dead.

i have replaced the rear door and pin as the old ones were bent slightly. i am using a thicker pin now as well, and while the problem has decreased, as there is no longer a "gully" for the vehicle to sit in, im still having problems with it. any suggestions?

 

[Earl Weiss]

I am constantly having issues with f-150"s and closely styled trucks jamming the rollers at the exit. it seems that as the roller pushes the vehicle over the exit door for the rollers, the weight keeps the door from rising enough for the first roller to drop down.

HAve you tried a "Roll Off Plate".

I have them at all locations and we are rear wheel push. Reduces strain on conveyor by having vehicles roll off past the door.

 

[Washmee]

ok, so this has been a big problem for me. I recently (august) took over managing a 90' express tunnel system. It is a front wheel pull, using a log chain and roller assembly. I am constantly having issues with f-150"s and closely styled trucks jamming the rollers at the exit. it seems that as the roller pushes the vehicle over the exit door for the rollers, the weight keeps the door from rising enough for the first roller to drop down. its a constant battle because not all trucks do it, depends on how "loose" neutral is for that truck. some just keep rolling others stop dead.

i have replaced the rear door and pin as the old ones were bent slightly. i am using a thicker pin now as well, and while the problem has decreased, as there is no longer a "gully" for the vehicle to sit in, im still having problems with it. any suggestions?

Does the trap door have a steel roller on it? Also, on a front wheel pull system its common to bring up an additional roller behind the rear wheel to help push the vehicle off the conveyor after the roller on the front tire drops into the exit trap door.

 

[AppleExpress]

Earl- no i have not tried a "roll off plate" i will look into that, thank you.
Washmee- Yes the trap door does have a steel roller, which i replaced at the time of the new door as the old one had worn. i do launch additional rollers on the rear tires as well, but because of the wheel bases, those rollers come up about a foot behind the trucks rear wheel, and the jamming is happening before those rear rollers make it to the tire.

Currently im running a 3'6" configuration, with 2 rollers coming up for the front wheel and 2 coming up as backup for the rear wheel. Im thinking about dropping to a single roller for the front wheel as i have noticed the jamming is happening more on the second roller for the front wheel, but occasionally does occur with the first roller.

 

[Washmee]

Are you saying that the second roller is getting stuck after the front tire is past the trap door? Or is the truck not rolling past the trap door and just sitting there?

 

[AppleExpress]

its staying on top of the door. Most times the front roller will drop, but then the truck rocks back onto the door, and the second roller jams. however today, i had a silverado get stuck... it didnt roll over the trap door and just sat in place so the door wouldnt raise, causing the first roller to jam.

 

[Washmee]

I think Earls suggestion of the roll off plate should fix your problem. Make sure that there isn't some type of issue with the structure of the conveyor sagging somewhere causing this problem.

 

[carnut2]

It's far safer to have a customer hold their foot on the brake to allow a roller to pass under the tire. Asking the customer to put their car in gear and try to hop over the roller can result in disaster. They could easily jump their vehicle out of the track or surge forward and damage another vehicle ahead or behind them.

Ah I think ou are right about that. I asked an older customer to back over the roller and I think she bvery nearly gunned it off the track and over me two feet away. In the future, the direction will be explain what will happen and then hold the brake while the roller passes under.

 

[carnut2]

Are you saying that the second roller is getting stuck after the front tire is past the trap door? Or is the truck not rolling past the trap door and just sitting there?

In the cases I am talking about I have customers with two rollers between their front and back tire so when the roller behind the front tried to push them over the exit trap door and return the roller it cant because the second roller IN FRONT of the rear wheel does not give it enough play. The car is reasting on the trap door with the front roller unable to dissappear and the rear wheel preventing the car from moving forward.

I think it is inexperienced customers and not consciensciojus enougfh attendants to stop the problem at the front of the tunnel/