Talk:Combination lock

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Actually, it IS a permutation lock...

A "combination" lock is, mathematically, a "permutation lock with repitition". I noticed the article states it's not a permutation, but rather a sequence. This assumes unique elements of the permutation...but there are also permutations with repitition.

Hands on throat (talk) 22:05, 10 February 2009 (UTC)[reply]


The article isn't about math, where this distinction would be important. I removed it's mention in the article as off-topic. If they were called "numbers locks", or "secret locks", or something that didn't happen to be a math term, no one here would be complaining. You would just think of it as "what it's called", which is actually the case. "Combination Lock" is simply "what it's called". It isn't a reference to the specific math term, just a reference to the more general meaning of "combination" (as in "Combination Pizza Hut and Taco Bell" (!) :-) ). It is way off topic to add discussion of the math term to the article UNLESS it can be verified (and cited) that historically the name was actually meant to refer to the mathematical meaning of the word. And, even then, the focus should not be on the arcane details of math.
108.7.11.138 (talk) 21:25, 30 December 2011 (UTC)[reply]
There are also plenty of locks where combination is what's used by the mechanism, not permutation. Andy Dingley (talk) 21:32, 30 December 2011 (UTC)[reply]

Hmm. What about Al-Jazari?

The article Al-Jazari states the following:

"Al-Jazari described fifty mechanical devices in six different categories, including water clocks (one of his famous clocks was reconstructed successfully at the London Science Museum in 1976), combination locks, hand washing device, machines for raising water, double acting pumps with suction pipes and the use of a crank shaft in a machine, accurate calibration of orifices, lamination of timber to reduce warping, static balancing of wheels, use of paper models to establish a design, casting of metals in closed mould boxes with green sand, and more." - emphasis added by me.

I have no idea about the veracity of the above, but if it is accurate the current article on combination lock should reflect that. I make it Al-Jazari predates Cardano by a few centuries. -- Cimon Avaro; on a pogostick. 21:22, 4 April 2007 (UTC)[reply]

Joseph Loch

A Google search indicates that Joseph Loch filed a patent for a "permutation-lock" in 1878, not 1862 as cited in the text. In addition, there is no evidence I could find of a patent infringement dispute. Shalom (HelloPeace) 20:07, 14 February 2008 (UTC)[reply]

should we add...

What to do if you lose your combination?

It's here

Electronic combination locks

The paragraph on electronic combination locks says that with these types of locks "[i]t is much easier to determine the lock sequence by viewing several successful accesses, since the arrangement of numbers is fixed."

That's not always true, though. A number of electronic combination locks scramble the digits on the keypad after each use to avoid this problem. One example of such a lock is the Miwa TKU-002, but I'm sure there are others. Should this section be reworded to make it clear that this vulnerability doesn't exist with all electronic combination locks? Chukhung (talk) 01:54, 9 July 2008 (UTC)[reply]

Master single dial combination locks

About the number of combinations to try that can be reduced to 100: Actually, these days it's now down to 64. 66.114.93.6 (talk) 11:43, 18 May 2012 (UTC)[reply]

Advantages

What are the uses of the combination lock? 42.201.206.192 (talk) 10:24, 4 December 2012 (UTC)[reply]

  1. Setting school homework questions
  2. Locking stuff up. Sometimes they're just a "better" lock than a keyed lock.
  3. Locking stuff up where there's no key to get lost. A lost key makes a lock insecure, as you don't know who might have that key. Maybe it was stolen, not lost?
  4. Locking stuff up where it would be awkward to distribute keys to many people, especially where they're far apart. You can tell a combination by phone or email.
  5. Locking stuff up cheaply. It's cheaper to make a cheap combination lock than a cheap keyed lock.
  6. Locking up keys. Many elderly people have a key to their house on the outside, in a small box locked with a combination lock. Visiting carers can know this combination.
  7. Avoiding the need to change keys. If keys need to be changed frequently, it's easier to change a combination than to cut a new key. This is especially so if many people need the key or combination.
  8. Having the key distributed across several people. It's often easier to give two people half of a combination each than it is to give each of them half a key.
  9. Remember that for a large installation over a long time, the cost of keys exceeds the cost of the locks.
Andy Dingley (talk) 11:49, 4 December 2012 (UTC)[reply]
Several of those points are not valid.
  1. WTF?
  2. Not a valid point, unless you explain why exactly.
  3. Valid.
  4. Not valid. If they're too far to get a key, they're also too fat to use the lock. Also, a key can easily be transported by mail.
  5. Oh really? Do you work for a company that makes locks? I don't know about where you live, but around here combination locks are super rare (other than the really lame 3-wheel ones), where as keyed locks are cheaply available at every hardware store.
  6. This point is just ridiculous. Why buy an extra lockable box, an extra combination lock, if it's much cheaper and easier to go to a locksmith and get another spare key made?
  7. Valid.
  8. This would be a major disadvantage, as it would require those several people to all be present each time the lock needs to be opened. Each keyed lock comes with several keys and it's cheap to get more made by a locksmith.
  9. Do you run a "large installation"? Why do you assume that you would need that many keys? Keyed locks usually come with a total of 3 keys, which in 99+% of the cases is more than enough. Sure, eventually a lot of keys would be lost to fired, or quit employees, but who's to say you wouldn't end up having to "brute force" their locks open, if they refused to tell you the combination?
GMRE (talk) 20:59, 6 September 2014 (UTC)[reply]

A possible additional picture

File:Rare combination lock with 4 dials.PNG

I have a rare 4 dial lock. GMRE (talk) 16:36, 21 October 2014 (UTC)[reply]

Congratulations, you have a cheaply mass-made 4 dial combination padlock. What makes you think it's rare? Andy Dingley (talk) 17:46, 21 October 2014 (UTC)[reply]
It's rare thanks to key locks out numbering combination locks by like 100 to 1 and 3 dial combination locks outnumbering the rest of combination locks by 100 to 1. And it's rare, because the specific lock I have doesn't have normal dials, like the 3 dial locks that are shown on the pictures currently in the article. My lock dials are turnable knobs, like the 1 dial ones that are common in US. Have you ever seen a lock with 4 of those? GMRE (talk) 15:31, 22 October 2014 (UTC)[reply]
Here's a rare 4 dial combination lock (or at least a collectible one): http://www.swiss-banking-antiques.com/e/shadow-boxes/combination/lock.html
The picture is just a cheaply made pressed steel padlock. They're made in all sorts of ways. America likes single dial combination locks, Europe favours separate barrels. Barrels are favoured to dials because they're smaller for the same number of differs, but that's not enough to make a dial lock from "uncommon" to "rare". Andy Dingley (talk) 16:16, 22 October 2014 (UTC)[reply]
Nah. What you got there is the other 4 dial combination lock. But in any case, wikipedia could have had a picture of this design, but now it won't. GMRE (talk) 17:04, 22 October 2014 (UTC)[reply]

Merge proposal

I have suggested merging Rotary combination lock into Combination lock as it is fairly short and I cannot see it being expanded in the future. Willh26 (talk) 21:13, 18 March 2016 (UTC)[reply]

Oppose. I can see your point, but there's enough material to cover both (potentially as large articles).
Many combination locks are cheap crap. Yet we still ought to cover them. The high end locks though are pretty much all of one specific type, the single-dial rotary sequentially-dialled combination lock. That specific type, among a multiplicity of types, has enough notability to stand alone. Andy Dingley (talk) 23:06, 18 March 2016 (UTC)[reply]
Closing, given opposition and no support (and stale discussion). Klbrain (talk) 12:28, 20 January 2018 (UTC)[reply]

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