Let’s get this out of the way: yes, the Accent Vibrato appeared before the Gibson Maestro Vibrola and yes, they are mechanically identical. But no, Gibson did not plagarize the Accent. And that’s because Rickenbacker didn’t invent it either. Both companies licensed the design from the actual inventor, Paul D. Butts.

You’ve seen the “Ac’cent by paul” plates on Accent equipped guitars from 1960-1963 guitars? Now you know who Paul was.

There are four basic components to the Accent. Per the patent:
(1) a tailpiece which fastens to a musical instrument on one end and a spring on the other end;
(2) a spring in the shape of a curved plate with ends bent to form attachment clips;
(3) a string engaging saddle which engages both the spring and the strings of a musical instrument, and;
(4) a handle with mechanism attaching it to the string engaging saddle.
The above parts are held together and fastened to a musical instrument by various means. The assembled parts form a mechanical tremolo device
Let’s make that visual:

At the top we have the “string engaging saddle” with the handle attached. Bottom left is the tailpiece, and bottom right the spring. Both the “string engaging saddle” and tailpiece have a folded over lip that allows them to engage with the “attachment clips” on the spring. It all just interlocks and then is held in place by string tension.

The little rubber pads you see on the spring rest on the guitar’s face and provide cushioning. With all the components together it looks like this from the side:

So how does it work? We’ll go back to the patent:
The string engaging saddle floats in a centered position under the opposing forces of the instrument's strings on one hand, and the spring on the other hand. The device produces a tremolo effect when a musician playing the instrument moves the string engaging saddle back and forth across it's centered position by means of the attached handle. The above movement alternately loosens and tightens the tension of the strings, thereby lowering or raising the pitch of the sound produced by the strings.
Ok, I realize that’s kinda technical and dry, so we’ll put it into plain language. I know the “spring” here probably doesn’t fit your mental picture of a spring, but it is, all right? You can make it compress or decompress by respectively pulling up or pushing down on the handle, and when you let go, it returns to its original shape. That’s a spring, baby. Pulling the arm up raises the string tension, raising pitch, and pushing it down lowers string tension, lowering pitch. Letting it go returns pitch to where it started. And presto, vibrato!
Is it a “good” vibrato (unit)? I mean, there are worse, but not especially, no. There’s not a lot of upwards or downwards play, which limits the range of your bending—no dive-bombs here!—and overuse will mess up your tuning. But for a light shimmer or warble every now and again? It’s fine. It’s certainly better than the Kauffman Vibrola it replaced!
So you can see from above Butts filed the patent in September of 1960, but he’d already begun shopping the design around. Looking to replace the woefully outdated Kauffman, Rickenbacker jumped on the simple but relatively effective design and it began appearing on vibrato-equipped Capris in mid 1960.

In order to improve tuning stability, Accent equipped guitars were equipped with roller bridges to remove friction points, just as Kauffman equipped guitars had been.

As already noted, from launch to mid 1963 the tailpiece had a plaque affixed that read “Ac’cent by paul” and “PAT APPL. FOR”. The chrome plating over the brass plaque can be prone to wearing.

The larger F-bodies got their own version of the Accent, with a longer tailpiece with music note cutouts.

While Butts’ patent was granted in September of 1962, the “Ac’cent by paul” with “PAT. APPL. FOR” plaque lasted until mid to late 1963 when it disappeared. The apostrophe/accent in the “Ac’cent” name would remain on the pricelist, however, through 1969.

Until the end of the mid 1960s, vibrato equipped guitars would outsell their non-vibrato equipped brothers. All of the 6-string Rose Morris models, for example, came equipped only with the Accent.

But as the 1960s wound down, so did sales of the Accent. The design was old—and it was crude when it was new—and guitar technology was passing it by. I have no idea whether the timing of the license period (or what the period even was!) played a role in the decision to discontinue, but demand was speaking for itself and by 1970 the Accent was no more.
That’s not to say a few thusly equipped models didn’t trickle out of the factory the first few years of the 1970s—you could custom order it as long as they had stock—but very few people did. And thus endeth the Accent’s story.
Well, its first chapter anyway. We fast forward to 1986 and the launch of the vintage reissue models. Specifically a guitar designed to look just like this one:

The Accent (minus its apostrophe/accent) was back. And has been ever since, appearing on multiple reissue models of classic 1960s guitars like Lennon’s above and the Rose Morris models. In the mid 1990s to early 2000s it could even be added to (almost) any 6-string model by clicking the “Vintage reissue vibrato (VB)” box on the custom order form. Today it is only available on the 325C64 or from the Boutique (and not always there).
There are even aftermarket versions on the market today, most notably Winfield Vintage’s. You wanna know if the Accent on your guitar is factory or aftermarket? Look at the side view of the “string engaging saddle”. Here’s the Winfield piece:

Notice how you can see inside? Now look at the factory version:

You can’t. The ends are closed off. There are other differences, but that’s the easy one to spot.
That’s it. All you ever wanted to know about the Accent. Want to learn more about…everything else? Check out the rickenbacker101 site map and see what’s already been covered! Have a suggestion about what we should tackle next? Drop it in the comments and we’ll add it to the queue!