Manumatic

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Transmission types
Manual

Non-synchronous
Automatic

Semi-automatic
Continuously variable
Bicycle gearing
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Manumatic is a portmanteau word, combining the words manual and automatic, that applies to a class of automotive transmissions.

[edit] Early manumatic transmissions

The "Manumatic" (copyrighted by Borg and Beck) transmission was offered on several smaller British cars in the period 1957-59. The system was based upon a dual clutch arrangement where the regular clutch was activated by a vacuum mechanism controlled by an electric control box and a second, centrifugal clutch which was co-located in the clutch housing. An electric switch on the gear shift activated the electric control box which in turn activated the vacuum mechanism (consisting of a vacuum tank and a vacuum cylinder). There were only two pedals on the floor - the brake and the gas. To start off, you grabbed the gearshift lever, depressing the button and activating the gearchange lever switch, which in turn activated the control box which then activated the vacuum cylinder to disengage the clutch. You then put the gearshift lever in the usual place for first gear (or reverse if that is the direction you wanted to go). When you let go of the shift lever button, the vacuum mechanism would re-engage the clutch. However, the car did not move as the centrifugal clutch was not yet engaged. Applying gas increased the speed of the engine and caused the centrifugal clutch to slowly engage and away you went, at least until you needed to change gears again. When you touched the gearshift lever, intending to shift into second gear, the vacuum mechanism again disengaged the clutch. Once the transmission was in second, you could let go of the gear shift and vacuum mechanism would release the clutch.... but again you would need to apply power until the centrifugal clutch engaged. You did this through all forward gears. An advantage of the centrifugal clutch is that the engine had to be spinning faster than the transmission in order for the centrifugal clutch to engage, eliminating rough engagements. Needless to say, this was a rather complicated mechanism, requiring special parts to keep serviced. It didn't prove very popular and many cars were converted back to normal manual shift at first trade in to improve resale values. However, it did allow “one foot” driving in smaller engined cars not suited to the heavy, relatively inefficient (by today's standards) fully automatic transmissions of the day, as fitted to the larger English cars such as Jaguar, Humber Snipe, Austin Westminster and Ford Zephyr, as an option. This was a boon to the less than wealthy disabled and war injured whose only previous option had been retrofitted cable hand clutch operation (like a motorcycle), notoriously unreliable and difficult to use and master. The 'Manumatic' transmission was only used briefly in England for a few years at the end of the fifties (Austin A50, Morris Oxford, Hillman Minx, Standard Ten 'Standrive', Ford 100E, and possibly others). In the Rootes cars (Hillman and Singer) it was replaced by the 'Easidrive' fully automatic transmission in 1960, and two pedal control options were abandoned for the new range of one litre cars introduced in 1959 (Triumph Herald, Ford Anglia 105E, Austin A40).

[edit] Recent manumatic transmissions

Chrysler Corporation made some luxury cars with a manumatic transmission where the transmission is an automatic with some elements of a manual (e.g. a gear can be manually selected instead of having the computer control all shifts). This type of transmission was introduced in the beginning of the 21st century. Different car manufacturers have been using a variety of labels for their manumatic transmissions, such as Tiptronic, Touchshift, Sporttronic, Sensodrive, Allshift, Speedshift, Multitronic (MMT) and others.

Manumatic is sometimes used to describe an electro-hydraulic manual transmission that is designed to behave somewhat like an automatic transmission, with electronics in the shift system depressing the clutch when necessary. Mercedes-Benz has a version called Sequentronic, and BMW has SSG (Sports Sequential Gearbox) and SMG (as used in the BMW M3). Implementations of this manual masquerading as an automatic have the unpleasant characteristics of hard shifting when changing gears, and difficulty operating the vehicle in reverse. These effects are seen due to operational differences between torque converter (used by automatic transmissions) and clutch (used with manual transmissions) that many drivers are not fully aware of. These are also referred to as clutchless manuals.

[edit] See also