Browning Automatic Transmission
The Browning Automatic Transmission is a bicycle transmission that is far superior to current designs. The product sports an automatic shifting design in that the bicycle computer will automagically determine what gear to be in based on spoke and hub magnet counts. In addition to that, the shifting mechanism is a radical improvement over the standard derauiller design. For those who like control, the system can be shifted into a fully manual mode.
Products:
There is currently a 4-speed version of the bicycle slated for
market release to multiple vendors as well as a 12-speed number
in the works.
Company
Browning Automatic Bicycles is a company owned in part by the former owners of
Browning Automatic Rifles (or just
Browning) for short. The
company owns several sub-orginizations:
- Browning Component
- which is responsible for the machine shop as well as the distribution/manufacture of the transmission.
- Browning Research
- Which is in the business of general R&D with the Automatic Transmission still as their main project
Some info on the bike
The major ideas Browning Research
developed include a
replacement for the
age-old derailleur system used to
change gears since the
1800s. The
gearset actually changes into an effective
spiral allowing the chain to
ride up the
gearset. It shifts
wonderfully under load and is
beautiful to watch. The
Browning crew have termed the
thingie a
selectorBasically, the selector works by tripping a one-time cam so that springs pull the
guide either left or right. The selector guides a small metal tab that is attached to the gearset either direction, spiralling the gears in that direction. As the tab hits the guide, it pushes the selector back to the middle as it shifts. The 4-speed bike transmission is good for approximately 50,000 shifts before depleting the battery (a simple 9-volt cell).
The bike computer uses hysteresis to keep from dithering from gear to gear; it also has a system whereby you can tell it to change gears in automatic mode and it will remember to change to selected gear under similar conditions if possible.
Facts:
- The browning computer uses an 8051-based controller (Phillips is the current manufacturer used)
- Browning Automatic Rifles made a 10-speed bicycle before the Browning family left the company; that bicycle was used as a testbed for the first gearset designs.
- The first design of the shifting mechanism had no smarts; in fact it was purely mechanical
- The bicycle prototypes proved to be a major advantage during Olympic Racing trials; professional bikers shaved seconds off currently held world records.
The bike was unfortunately banned from the Olympics under a technicality; which is just as well, the US would have won hands down had it been introduced
They have the following patents (all viewable from Delphion)
- US5073152
- US5261858
- US5152720
- US5356349
Oddly enough, they managed to get away with patenting hysteresis, so don't do it or get sued