L-shaped 6-bar linkage motion

[fast4door]

I'm trying to open an access panel, but the packaging is very tight. I need to move sideways about 2 inches, then upward about 18 inches. The initial motion has to be very horizontal so that tends to rule out 4 bar linkages like on bus luggage doors. Also, I can't go sideways more than 6 inches or I crash into something else. Last but not least, the door can't really rotate much as it travels upward because it would hit yet another obstruction.

At this point I'm likely going to use a linear bearing that pops outward, but that requires quite a bit of trickery to make sure it won't go up before it's completed the outward motion.

Has anyone seen a 6-bar linkage that would do the L-shaped motion that I described?

 

[zekeman]

"Has anyone seen a 6-bar linkage that would do the L-shaped motion that I described? "

No,

 

[FeX32]

Nothing exact. You could try to think of a possible way to modify a straight line mechanism (3-4 known to man). One is

http://en.wikipedia.org/wiki/Hoekens_linkage

Fe (IronX32)

 

[rb1957]

instead of a linkage, could you use a track to guide the movement ?

 

[MotionGirl]

I would assume you know how to design a 6-bar mechanism with a traslating link? Because there is a method to do that. You first of all need to find a 4-bar with a coupler curve - or with part of a coupler curve that delivers your horizontal followed by vertical motion - I'd look for a 4-bar with a symetric coupler curve first as they are the easiest to understand and search for. Once you have your 4-bar coupler curve, then stick on another dyad to give you a link that translates and attach your 'thing' to that. THe main issues I think is the 'aspect ratio' of your coupler curve.

 

[fast4door]

FEX32, the Hoekens would be the bomb, but the links are on the wrong side of the L.

rb1957, we looked at bendy tracks from a supplier (like a garage door), but they're several hundred dollars each.

MotionGirl, I wish I understood what you're talking about because it sounds promising, but you're speaking French to me. I'm not familiar with the terminology you used.

It's crunch time and I have to make a decision, so I'm planning to use a linear bearing with a toggle mechanism. The toggle will kick out the bottom of the linear bearing rod (top one will have to be hinged), then the door will travel upwards assisted by a gas strut. The trick will be to have a catch that prevents the upward motion from beginning until the toggle is fully extended. On the way down the toggle will keep the panel from swinging inward until the linear bearing un-straightens it.

Thanks everyone for your feedback. This was my first time posting and you've been very helpful.

 

[ornerynorsk]

You never mentioned if there were a reason why it couldn't detach and simply be removed?

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[fast4door]

It's an access panel for an agricultural unit. It needs to move to access the air cleaner. The whole panel will weigh about 50 pounds and it's big and bulky.