Supporting heavy hinged lids.

Greetings and salutations...

On 11 Apr 2005 16:02:15 -0700, [email protected] (Schmuck)
wrote:

>Hi all,
>
>I am looking for a way to hinge a heavy chest lid such that it will
>remain open at a 60 degree angle.
>
>The lid will be heavy as it will contain quite a bit of electronics:
>This is a "stealth" home theatre installation. I'm thinking up to 30kg
>(it probably won't be this much, but I like to over engineer) with a
>depth of 45 - 60cm, depending on whether I I hinge the entire lid or
>only 2/3 of it.
>
>Any suggestions on how to support this. I've been wondering if I could
>somehow adapt gas lifts from the rear hatch of a car?
>
>Thanks for any ideas
>
>Matt

I am a little fuzzy on what you are trying to do here...are
you trying to support a flat screen TV, so that it will rise out of
a storage area? or is this like the old, 8-Track tape drives, where
the electronics tilt up so you can get to the players, tuner, etc?
Also...how quickly does this need to raise and lower? And
the other poster's questions about stability, vibration etc, are
well put too..and of interest.
In any case, what you MIGHT want to consider doing is a
straight-up lift of the top of a box. There are commercial units
to do that, but, with some work, it would be easy enough to get
some acme-threaded rods (four...one for each corner), hook them
together with a chain, driven manually or (preferably) with an
electric motor, and have them raise the electronics up to visiblity.
The one problem with a tilting lid is that stuff is going to
get set on it...and it will have to be moved when the electronics
are used...with a straight rise, and smooth action, stuff on top
of the container can stay there.
Regards
dave Mundt

On 11 Apr 2005 16:02:15 -0700, [email protected] (Schmuck)
wrote:

>I am looking for a way to hinge a heavy chest lid such that it will
>remain open at a 60 degree angle.

A toggle latch. Look at a big mechanic's toolbox - there's a two-part
hinged strut at the side of the lid, with a stop between the two
struts. When you lift the lid there's an over-centre action and they
lock. To close it you lift the lid and pull the strut forwards to
unlock them

You can make this or buy it.

>Any suggestions on how to support this. I've been wondering if I could
>somehow adapt gas lifts from the rear hatch of a car?

Terrible idea. You really can't "adapt" gas struts. You have to get
the maker's application note and follow the design guidance for how to
choose the correct open and shut lengths, and force, for the situation
you have. A mis-sized gas strut is either inadequate to hold it or
prone to making the lid fly open - it's very hard to take an arbitrary
ready-made strut and find how to attach it to a box so that it's
balanced.

Secondly, gas struts wear out. Ones from scrapyards are usually
half-dead anyway.

Does this lid with a 100+ lb load need to remain at a solid, fixed position for
an extended period of time? Will there be any vibration produced by the
aforementioned equipment? If so, I would think something like gas shocks or
springs could help counterbalance the weight, but you should include a positive
support of some sort to hold everything steady in the open position.
--
JeffB
remove no.spam. to email

Schmuck wrote:

> Hi all,
>
> I am looking for a way to hinge a heavy chest lid such that it will
> remain open at a 60 degree angle.
>
> The lid will be heavy as it will contain quite a bit of electronics:
> This is a "stealth" home theatre installation. I'm thinking up to 30kg
> (it probably won't be this much, but I like to over engineer) with a
> depth of 45 - 60cm, depending on whether I I hinge the entire lid or
> only 2/3 of it.
>
> Any suggestions on how to support this. I've been wondering if I could
> somehow adapt gas lifts from the rear hatch of a car?
>
> Thanks for any ideas
>
> Matt