7 slides through cutout 10 in wall 2 as shown in fig4 latch key 7 also slides through groove 11 of mounting plate 12 which is affixed to wall 2 by screws 13 latch key 7 is shown in the open position resting in safety catch 15 in order to move dead bolt 4 to the locked position it is necessary to lift latch key 7 out of safety catch 15 then slide latch key 7 to the locked position then drop latch key 7 into safety catch 14 safety catch 14 ensures that dead bolt 4 will not be accidentally brushed open the basic principal of operation of universal dead bolt 1 relies on the center mounted sleeves 5 and 5 39 an approximate ratio of three to one between the dead bolt 4 length and the length of groove 11 and sleeve 5 39 ensures a powerful dead bolt across door 3 the center mounted sleeves 5 and 5 39 remove any reliance on surface mounted screws 13 for strength only sleeves 5 and 5 39 and their respective mounting supports door jam 6 and door 3 receive pressure during an attempted forced entry mounting plate 12 merely serves to hold latch key 7 in either the open or locked position fig2 a 2f shows all the parts of the preferred embodiment of the universal dead bolt assembly 1 shown in fig1 the installation procedure is as follows first mounting holes for sleeves 5 and 5 39 are drilled into door 3 and door jam 6 respectively next a cutout 10 is chiseled into wall 2 in order to allow latch key 7 to slide about two inches in the preferred embodiment cutout 10 must also be large enough to allow the mounting of nuts 8 and.