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On Off Machine Lockout System Dead Key

IP.com Disclosure Number: IPCOM000052933D
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 3 page(s) / 83K

Publishing Venue

IBM

Related People

Kindler, T: AUTHOR [+4]

Abstract

With a certain type of keyboard, it is desirable upon the turning off o the typewriter to establish certain mechanical lockouts to prevent accidental jamming of the keyboard. It is also desirable to be able to effect dead key operation and clearing of jammed keyboards by the operator. Clearance of jammed keyboards is essential to reduce service calls if the keyboard is inadvertently locked up during a time period when the machine is on.

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On Off Machine Lockout System Dead Key

With a certain type of keyboard, it is desirable upon the turning off o the typewriter to establish certain mechanical lockouts to prevent accidental jamming of the keyboard. It is also desirable to be able to effect dead key operation and clearing of jammed keyboards by the operator. Clearance of jammed keyboards is essential to reduce service calls if the keyboard is inadvertently locked up during a time period when the machine is on.

In turning the machine on, as shown in Fig. 1, by rocking the on/off button 10 clockwise, the on/off lever drives the on/off link 14 which is connected to a toggle switch, supplying electric power to the machine. In turning the machine on, the on/off lever 12 also interacts with a lug 16 on the lockout interposer 18, pulling it forward and withdrawing interposer 18 from the ball or compensator tube 20. In turning the machine off, a spring 22 pulls the lockout interposer 18 into the ball tube 20 until the lockout interposer 18 grounds out against the interposer fulcrum rod 24. In doing so, this prevents entry of any or all character interposers and locks out all character keylevers. The lockout interposer further moves a lug 26 under the carriage return and backspace keylevers 28, 30, preventing their depression and locking out these functions. The keyboard correction function (not shown) is dependent on the depression of the backspace keylever and is, therefore, also locked out. Locking out these functions prevents excessive motor loads during initial machine turn on. With the lockout interposer 18 in this position, an adjustment lug (Fig. 2) has been advanced toward the filter shaft 34 for setting the character interposer to filter shaft clearance.

The interposer restore function is accomplished when turning the machine from on to off. The on/off lever 12 has a cam surface 36 which remains in contact with the outer on/off bellcran...