Talk:butterfly door

2016 deletion discussion

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butterfly door

The Lamborghini Murciélago with butterfly doors.

The definition given looks to me like the definition of a revolving door. "Butterfly door" a.k.a. "scissor door" is used of a certain type of car doors, see Butterfly door or this result of Google image search [1]. --Hekaheka (talk) 17:48, 8 January 2016 (UTC)

Sigh. This is an example of why some entries really need a picture and a WP link. If the contributor had tried to provide them and failed, he might not have added he entry. If he had succeeded, there might not have been a need for an RfV. DCDuring TALK 00:37, 9 January 2016 (UTC)

There seem to be numerous kinds of "butterfly doors" united mostly be some fancied resemblance to a butterfly's wings.

1. The sportscar doors
2. boiler firebox doors. See this image. (stationary and locomotive; coal- or other solid-fuel-fired only?)
3. an architectural door pivoting on a vertical center pivot. See here.
4. a center-pivoting valve "door". See this image for an automotive application, but there are many kinds of applications.

Only for the last of these is the pressure-differential explanation relevant. Also there are butterfly doors that have offset pivots, which weakens the association with the image of bilaterally symmetrical butterfly wings. DCDuring TALK 01:37, 9 January 2016 (UTC)

Of those the sportscar doors seem to have a well-defined meaning, at least among the sportscar enthusiasts. Almost every picture found in the Google pic search for "butterfly doors" is of the automotive type. I added a definition for them. Here's another example of a door that may be called "butterfly door" [2]. I'm not proposing that we add a definition for it. --Hekaheka (talk) 02:22, 9 January 2016 (UTC)

We have an entry for butterfly valve that covers the last. The "boiler firebox door" sense is attestable. The center-pivoting architectural door sense is hard to find in use. DCDuring TALK 02:57, 9 January 2016 (UTC)

The "door" component of a butterfly valve is usually called a disk/disc, so the challenged definition seems unlikely to be attestable. DCDuring TALK 03:24, 9 January 2016 (UTC)

Cited on citations page. SpinningSpark 16:27, 10 January 2016 (UTC)

The cites look good. I didn't think to look at patents. Now all we have to do is improve the wording and/or get a good image for that type of butterfly door. DCDuring TALK 23:26, 10 January 2016 (UTC)

File:Henry Pratt Butterfly Valves.jpg -SpinningSpark 01:42, 11 January 2016 (UTC)

These pictures are all of butterfly valves. Each one seems to me to have too many extraneous features to clearly illustrate the "door" element. I have selected a silly gif schematic to illustrate butterfly door because I thought butterfly valve is a better home for the images such as those above. A gallery of such images might lead a user by induction to the common element of the images, but that seems like a modest benefit for the visual complexity involved.

• Another kind of butterfly door is one with two center-hinged leaves that open to the same side of the opening. An example is a top-opening freezer cabinet, but there is similar geometry in many architectural and mechanical applications.

It is interesting that the butterfly metaphor is exploited in two? distinct ways (hinge geometry, physical appearance) and that these prototypical instances of butterfly door are the metaphorical source for the challenged sense in which there is no center hinge of two independent leaves but rather a center pivot of a rigid disk. DCDuring TALK 13:35, 11 January 2016 (UTC)

I think virtually every application of this kind of butterfly door is going to be in some kind of valve or other. An image of the door by itself would be useless for understanding how it operates. SpinningSpark 18:23, 11 January 2016 (UTC)

The patent etc citations you provided did not seem to me to refer to typical valves. None of the illustrations seem to show such uses of butterfly doors. I didn't find anything in the patent drawings either. No presentation using available images seems very good, IMO. But perhaps we could improve the wording, add usage contexts etc. DCDuring TALK 19:26, 11 January 2016 (UTC)

@DCDuring I really have no idea how you came to that conclusion. If you look at figure 9 of the first patent, for instance, ("Door for changing over air passage") it shows precisely that kind of door viewed from above. SpinningSpark 18:28, 16 January 2016 (UTC)

I looked at the patents and tried to find a usage image that made it clear what component was called a butterfly door and how it was hinged or pivoted. I still would like to see an image of a door that has labeled a butterfly door of the type that corresponds to the challenged definition.

To clarify the images below: Are those doors ever configured as revolving doors? Do the closed doors swing open when pushed? If they do, do the doors swing both ways? DCDuring TALK 19:45, 16 January 2016 (UTC)

• 
  one open and two closed butterfly doors
• 
  one open and one closed butterfly door with a standard door that is open
• 
  two closed butterfly doors
• 
  a single butterfly door, closed
• 
  a butterfly door next to a standard door, both closed
• 
  an open butterfly door next to a closed butterfly door

The central pivot type of butterfly door, is a door, not valve. Though it's action is the same as a butterfly valve. See

• https://www.flickr.com/photos/steve-brandon/239867248
• http://www.montrealgazette.com/squeaky+wheels+expensive+butterfly+m%C3%A9tro+doors+hard+open+reader+says/7462725/story.html
• http://blog.fagstein.com/2009/09/18/el-e-va-tion/
• http://www.cbc.ca/archives/entry/montreal-metro-the-heavy-door-phenomenon
• https://www.reddit.com/r/montreal/comments/2h4txe/deepest_metro_station_least_used_metro_station/

-- 70.51.44.60 15:06, 12 January 2016 (UTC)

The National Fire Protection Association uses this butterfly door (see this 1995 report [3]) [double-panel center pivot door] -- 70.51.200.135 04:35, 30 January 2016 (UTC)

This reminds me of words like blackbird, which can refer to birds from any of a large number of species of only distantly related dogs. "Butterfly doors" seem to differ greatly in use and configuration. DCDuring TALK 13:32, 30 January 2016 (UTC)