Zeroshift

Zeroshift or seamless-shift gearbox is a type of automotive transmission which allows for changing gear without interruption of torque to the driving roadwheels. The Zeroshift principle was invented by Bill Martin, the company Zeroshift Ltd is based in Milton Keynes, England.
The Zeroshift gear system has demonstrated superior performance over the manual transmission, which must disengage the engine from the driving wheels to prevent drivetrain wear. An automatic transmission can waste power due to its torque converter if unlocked, and usually provides inferior performance compared to a manual.
Currently the Zeroshift transmission is under development, and a volume production non-exclusive licence has been sold to an undisclosed global transmission manufacturer. The Zeroshift principle has been demonstrated on a number of the company’s development vehicles. It is expected that the Zeroshift transmission may be a replacement for current semi-automatic transmission.
Method of operation
The Zeroshift transmission is mechanically similar to a manual transmission with all parts other than the synchros being the same. The Zeroshift gearbox is operated by "bullets" which engage and disengage the gears. Each set of gears has two bullets: a drive bullet and an overdrive bullet.
;Change Sequence
#Bullets engage 1st gear
#Bullets requested to engage 2nd gear, only the overrun bullet is free to move to engage 2nd gear
#2nd bullet engages dog on 2nd gear cog in position, 1st gear bullet is held engaging drive in 1st gear under load due to retention angle on the 1st gear dog
#2nd gear picks up drive
#2nd gear overruns first gear
#1st gear bullet disengages dog and moves to 2nd gear.

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