Co.Design

How Do You Reinvent Something as Common as the Padlock?

Talking with Master Lock's Lea Plato, lead designer of the ingenious Speed Dial combination lock.

Introduced in 2009, Master Lock's Speed Dial is the first "directional" combination lock. It replaces a series of numbers with a sequence of up-down and left-right movements (like a video-game cheat). We talked to Lea Plato, one of the designers who worked on the lock, about how the lock came to be and why it's easier to use than what we're all used to.

Co.Design: The Speed Dial lock does away with numerical combinations and replaces them with left-to-right and up-and-down movements. What inspired the change?

Lea Plato: The combination lock for lockers has been around for so long, so Master Lock is trying to push different ideas. The Speed Dial is a very different and unexpected design. That's what attracted us to the idea.

The face of the lock?just four arrows?is clean and straightforward. How did that design come about?

We were trying to play off of simplicity. We wanted the appearance of the lock to match that simplicity. It's really basic?up, down, left, and right?and easy to remember. So nothing too fancy.

The center button has a nice accent ring around it to show that this is what you push on to make the movements. And the arrows are really simple triangles to suggest which direction you should be moving it in. A lot of the design of the actual body of the lock is driven by the interior mechanism. But we also wanted to give it a nice round shape so it fits well in your hand and it's easy to move that button up and down.

Another thing we focused on is how everyone could use it. A lot of the numbers are too small for people to see. If you're visually impaired, you don't have to see anything to be able to open this lock. Or if your dexterity isn't very good, the lock is still easy to use. We wanted the lock to be something that everyone can use without making it look like it was designed for just one person in particular.

Did those sorts of "universal design" considerations limit what you could do with the lock?

They weren't really constraints, but we did always have in the backs of our minds that we wanted all different types of people to be able to use the lock. We didn't want to limit the customer anymore. But I wouldn't say it limited the design; instead, it accentuated certain features of the design.


What was the design process for the Speed Dial?

We started by identifying what the user wants and needs. In this case, they want a lock that's easy to use and has a combination that's easy to remember. Once we identified the customer, then we brainstormed and made sketches. That's where the product really developed.

A lot of the ideas we worked with were about how the user could possibly interact with the lock. So, how could someone use directional movement, and how could that be different? There were a lot of different styles for the shape. Some were more suggestive of direction, others were a little more harsh. Some ended up hindering use, which we found when we created prototypes. The ones that weren't as easy to use ultimately didn't look as nice because they were frillier and not quite as functional. We played with some square and diamond shapes?they don't fit quite as well in the person's hand and don't feel as nice to use.

In the end, it's really the directional movement (rather than a dial with numbers) that makes the lock unique. But that movement is also familiar: Up, down, left, right?just like a video game, right?

Definitely. And that helped validate our exploration of the design?that people can remember these codes. The whole video-gaming thing is fun, and it's never been used before in a lock. I've talked to a lot of gamers, and they just absolutely love that left-right movement.

Electronics in general hint a lot at directional movement. We use that kind of movement all the time in all different things, whether it's volume control or play and fast forward. Even way back, the VCR used directional symbols to show what you wanted to do. I think being around technology everywhere?and it hinting at directional movement?played a part in the actual function of the lock. You just remember directional movement more easily. It's more intuitive than numbers or alpha-numeric code.

What do people think of the lock?

People seem to enjoy it. I've gotten a lot of comments from people who said they didn't think the combination lock could ever change?until this one.

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5 Comments

  • Guest

    They should make a sensor type lock. It'll be round like most of the locker locks, but will be unlocked by something on your wrist(not too bulky of course).

    Life would be so much easier without turning that dial, because I sometimes need two hands to carry my textbooks(they're heavy)! 

  • Bronco

    I wonder, with only four directions to choose from will the combinations be too easy to guess or will the code become longer then 3 digits, and harder to remember.
    How many direction will the code have to be in order to offer the same number of possibilities as the traditional numeric lock?

  • Guest

    40^3=64,000 64,000root4= 15.9  So about 16 movements will offer the same level of protection

    40 numbers on standard dial
    3 numbers for combination
    64000 possibilities
    4 movements (up, down, left right) 

  • Reed

    I think a lot of combos will be the 'Contra' code from old konami video games. Up-Up-Down-Down-Left-Right-Left-Right.

  • Don Jarrell

    I'll be very interested to see the numbers and demographics on *sales* of this lock when it is available side-by-side with the traditional combination lock. This article seems to report only the perspective of the "designers", and some non-predicate feedback - which is nice to know, but not the complete product management story.