1.  Field of the Invention
The present invention relates to a lock mechanism for equipment of data processing technology comprising a microswitch and a key-operable pivoted lever lock whose pivoted lever is displaceable into a locking position and into an unlocking position against the force of an over deadcenter spring secured to the pivot lever and comprises both a locking element for a locking device of a first part to be locked and an actuation element assigned to the microswitch, which actuation element presses against a contact element of the microswitch in the locking position of the pivoted lever. 
2.  Description of the Prior Art
Equipment such as, for example, personal computers that should only be accessible to authorized persons are frequently utilized in data processing technology.  To this end, for example, these equipment are equipped with a key-operable lock or, respectively, are made lockable.  The lock either interrupts the power supply, suppresses access to the control panel, for example the keyboard, with a mechanical cover lying thereabove, or carries out both operations simultaneously. 
Locks that effect both a quasi-electrical and a mechanical locking or known per se.  Such locks are employed in automotive engineering as what are referred to as ignition locks, whereby the microswitch controls the central locking of the doors of a vehicle.  Such locks, however, are expensive and waste space for equipment of data processing technology and, in particular, for personal computers.  Most cost-effective lock mechanisms have therefore become known in data processing technology that likewise enable an electrical and a mechanical locking.  These lock mechanisms employ a simple pivoted lever lock as employed, for example, as a cassette lock, as well as in combination with a microswitch.  The microswitch is thereby directly or indirectly actuated by the pivoted lever, whereby the pivoted lever also serves as a mechanical lock element for, for example, a cover over a keyboard, or for the housing of a computer.  Since intermediate positions are possible given these simple pivoted lever locks, regardless of whether they comprise a latching at the detent that marks the final positions are not, and overdead center spring that pulls the pivoted lever into the respective end position is additionally installed at the pivoted lever. 
What is disadvantageous in the case of such lock mechanisms is that they comprise only one mechanical interlock device.  In personal computers, for example, this one interlock device is frequently not adequate in order to sufficiently protect the device against access by unauthorized persons because, for example, mechanical access to the mass memory device such as diskettes and/or cassette tape drives are always still possible.  The user must therefore exercise care that he removes the diskettes or magnetic tape cassettes inserted into these memory drives as soon as he leaves the equipment, in order to prevent a possible misuse.  A lock mechanism that comprises yet a second mechanical interlock device, in addition to the two interlock types that were heretofore simultaneously executed, namely electrical, on the one hand, and mechanical, on the other hand, is therefore advantageous, the mentioned equipment components being mechanically locked with a second cover on the basis of this second mechanical interlock device.  Diskettes or, respectively, tape cassettes can then be left in the drive units.  At the same time, the drive units are also protected against disassembly. 
One solution of this problem, for example, is in providing a pivoted lever lock of the type initially mentioned with a second pivoted lever, that directly arrests a second lockable part via an additional lock bolt.  The lock bolt can be loaded in the locking position by a spring, so that the second pivoted lever only has to pull the lock bolt into the unlocked position as needed.  This lock mechanism therefore requires a great number of individual component parts.