Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
255 words
A lock cylinder comprising a housing having a recess therein, a key plug supported in said recess for rotation relative to said housing and having a keyway therein, a roll-back supported externally of said housing for rotation relative thereto, drive means for connecting said roll-back to said key plug for rotation therewith, a stop lug in said housing rearwith of said key plug, a control member in said housing rearward of said key plug and rotable with said key plug and said roll-back, said control member being movable relative to said key plug and said housing between a first position wherein said control member is in general alignment with said stop lug and a second position out of alignment therewith, means for biasing said control member toward said key plug and to said first position, said control member in said first position being engagable with said stop member to limit angular movement of said key plug and said roll-back in one and an opposite direction, said key plug said control member and said roll-back being freely rotable in one and an opposite direction when said control member is in said second position, an operating key insertable in said keyway for rotating said key plug with said control member in said first position, and an emergency key insertable in said keyway and engagable with said control member to bias said control member to and retain said control member in said second position and for rotating said key plug with said control member in said second position.
Claim 2
Dependent Claim
255 words
A lock cylinder comprising a housing having a recess therein, a key plug supported in said recess for rotation relative to said housing and having a keyway therein, a roll-back supported externally of said housing for rotation relative thereto, drive means for connecting said roll-back to said key plug for rotation therewith, a stop lug in said housing rearwith of said key plug, a control member in said housing rearward of said key plug and rotable with said key plug and said roll-back, said control member being movable relative to said key plug and said housing between a first position wherein said control member is in general alignment with said stop lug and a second position out of alignment therewith, means for biasing said control member toward said key plug and to said first position, said control member in said first position being engagable with said stop member to limit angular movement of said key plug and said roll-back in one and an opposite direction, said key plug said control member and said roll-back being freely rotable in one and an opposite direction when said control member is in said second position, an operating key insertable in said keyway for rotating said key plug with said control member in said first position, and an emergency key insertable in said keyway and engagable with said control member to bias said control member to and retain said control member in said second position and for rotating said key plug with said control member in said second position.
Claim 3
Dependent Claim
255 words
A lock cylinder comprising a housing having a recess therein, a key plug supported in said recess for rotation relative to said housing and having a keyway therein, a roll-back supported externally of said housing for rotation relative thereto, drive means for connecting said roll-back to said key plug for rotation therewith, a stop lug in said housing rearwith of said key plug, a control member in said housing rearward of said key plug and rotable with said key plug and said roll-back, said control member being movable relative to said key plug and said housing between a first position wherein said control member is in general alignment with said stop lug and a second position out of alignment therewith, means for biasing said control member toward said key plug and to said first position, said control member in said first position being engagable with said stop member to limit angular movement of said key plug and said roll-back in one and an opposite direction, said key plug said control member and said roll-back being freely rotable in one and an opposite direction when said control member is in said second position, an operating key insertable in said keyway for rotating said key plug with said control member in said first position, and an emergency key insertable in said keyway and engagable with said control member to bias said control member to and retain said control member in said second position and for rotating said key plug with said control member in said second position.
Claim 4
Dependent Claim
255 words
A lock cylinder comprising a housing having a recess therein, a key plug supported in said recess for rotation relative to said housing and having a keyway therein, a roll-back supported externally of said housing for rotation relative thereto, drive means for connecting said roll-back to said key plug for rotation therewith, a stop lug in said housing rearwith of said key plug, a control member in said housing rearward of said key plug and rotable with said key plug and said roll-back, said control member being movable relative to said key plug and said housing between a first position wherein said control member is in general alignment with said stop lug and a second position out of alignment therewith, means for biasing said control member toward said key plug and to said first position, said control member in said first position being engagable with said stop member to limit angular movement of said key plug and said roll-back in one and an opposite direction, said key plug said control member and said roll-back being freely rotable in one and an opposite direction when said control member is in said second position, an operating key insertable in said keyway for rotating said key plug with said control member in said first position, and an emergency key insertable in said keyway and engagable with said control member to bias said control member to and retain said control member in said second position and for rotating said key plug with said control member in said second position.
Claim 5
Dependent Claim
31 words
A lock cylinder as set forth in claim 1 wherein said control member is axially movable relative to said key plug and in general radial alignment therewith in said first position.
Claim 6
Dependent Claim
56 words
A lock cylinder as set forth in claim 1 including means for arresting further movement of said control member when said control member attains said second position, said control member, said key plug and said roll-back being freely rotable in said one and said opposite direction only when said control member is in said second position.
Claim 7
Dependent Claim
69 words
A lock cylinder as set forth in claim 1 including a removable core slidably received in said recess and adapted for releasable locking engagement with said housing, said key plug comprising a part of said core, and a change key insertable in said keyway for rotating said key plug in one and an opposite direction respectively to lock said core in said housing and to release said core therefrom.
Claim 8
Dependent Claim
31 words
A lock cylinder as set forth in claim 4 wherein said control member is axially movable relative to said key plug and in general radial alignment therewith in said first position.
Claim 9
Dependent Claim
37 words
A lock core as set forth in claim 4 wherein said recess has a generally figure-8 cross sectional configuration and said core has a generally figure-8 cross sectional configuration complementing the cross sectional configuration of said recess.
Claim 10
Dependent Claim
44 words
A lock core as set forth in claim 4 wherein said recess is defined by a pair of parallel intersecting particylindrical bores, said stop lug is received in one of said bores and said control member is recEived in the other of said bores.
Claim 11
Dependent Claim
35 words
A lock core as set forth in claim 4 wherein said biasing means cooperates with said stop lug to retain said control member in assembled relation with said housing when said core is removed therefrom.
Claim 12
Dependent Claim
25 words
A lock core as set forth in claim 1 wherein said biasing means comprises a spring washer connected to said control member for rotation therewith.
Claim 13
Dependent Claim
81 words
A lock cylinder as set forth in claim 1 wherein said drive means comprises a drive member journaled on said housing for coaxial rotation with said key plug and having a pair of axially parallel drive pins extending into said recess and said key plug has a pair of axially extending openings therein respectively receiving said drive pins, said control member supported for axial movement on said pins and relative to said drive member and for rotation with said drive member.