# US 4,393,790 A · Safe door assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,393,790 A - Document ID: US4393790A - Status: Granted - Kind: A - Application number: 06/272,323 - Filed: 1981-06-10 - Granted: 1983-07-19 - Earliest claimed: 1981-06-10 - Inventors: William H. Bagwell - Web page: https://patentgrep.com/patent/US4393790A ## CPC - E05B 15/1614: {of hard materials, to prevent drilling (E05B67/04, E05B67/38 take precedence)} - E05B 17/0062: {with destructive disengagement} - E05B 65/0075: {for safes, strongrooms, vaults, fire-resisting cabinets or the like (safes, closures and fastenings therefor E05G)} - Y10T 70/20: Attack-actuated defeating mechanisms - Y10T 70/5274: Combination operable only - Y10T 70/7949: Yielding or frangible connections - E05B: LOCKS; ACCESSORIES THEREFOR; HANDCUFFS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A safe door assembly comprising a door casing, a door, a plurality of locking bolts operated by a combination lock so as to be selectively extended outwardly from or retracted inwardly into said door to lock or unlock, respectively, the door to the casing; the casing including a seat to accomodate a shoulder on a door and a recess to receive each of the outwardly extending locking bolts, the door having a combination lock with a retractable tongue directly connected to one locking bolt and also connected via a sliding link bar and lever means to the remaining locking bolts in such a fashion that all bolts extend and retract simultaneously; a pivotable relocking bar spring biased to pivot into a position which prevents movement of the sliding link bar and thereby prevents retraction of the locking bolts when the combination lock is displaced inwardly from its normal position; the assembly also comprising a hardened steel barrier protecting the outer extremities of said locking bolts from access by a drill, a hook means of attachment of one locking bolt to the tongue of the combination lock, and weakened handle support bolts which will shear in the shank portion when subjected to the normal torque or unloosening the bolt from its lock nut. The safe door assembly of this invention provides an improved protection against unauthorized tampering. ## Claims ### Claim 1 In a safe door assembly comprising a door casing, a door, a plurality of locking bolts operated by a combination lock so as to be selectively extended outwardly from or retracted inwardly into said door to lock or unlock, respectively, said door to said casing; said casing including a seat to accommodate a shoulder on said door and recess to receive each of said outwardly extended locking bolts; said door also including a combination lock with a retractable tongue operatively connected to a sliding link bar with lever means to simultaneously extend or retract said locking bolts; the improvement comprising a pivotable relocking bar spring biased to pivot into a position whereby a portion of said bar mates with a corresponding portion in said link bar to prevent said link bar from sliding, said relocking bar positioned to mate with said link bar when said combination lock is disposed inwardly from its normal position; a hardened steel barrier separating the mechanism of said combination lock from the outside wall of said door; and a plurality of bolts through the outer wall of said door and through said hardened steel barrier fastened with lock nuts and supporting a handle for moving said door away from said casing, said bolts being weakened in their shank portions to shear off the head of the bolt if subjected to the torque normally required for unloosening said bolt from its lock nut. ### Claim 2 (depends on 1) The assembly of claim 1 which additionally comprises a hardened steel barrier spaced outwardly from said recess. ### Claim 3 (depends on 1) The assembly of claim 1 wherein said door and said casing are circular. ### Claim 4 (depends on 1) The assembly of claim 1 wherein said casing is positioned in the floor of a room and said door rests thereon by gravity. ### Claim 5 (depends on 1) The assembly of claim 1 which comprises at least three locking bolts. ### Claim 6 (depends on 1) The assembly of claim 1 wherein said tongue is directly linked to one of said locking bolts by a hook means and also directly connected to said link bar by a pin means. ### Claim 7 In a safe door assembly comprising a door casing, a door, a plurality of locking bolts reciprocally movable outwardly to mate with a recess in the door casing, a combination lock operatively connected with said locking bolts to selectively permit or prevent movement of said bolts, respectively, to lock or unlock said door; the improvement comprising a hardened steel barrier spaced apart from and around the outer end of said locking bolts, and a plurality of bolts through the outer wall of said door and through a hardened steel plate interiorly adjacent said outer wall are fastened with lock nuts and support a handle for moving said door away from said casing, said bolts being weakened in their shank portions to cause shearing of the bolt when subjected to the torque normally required for unloosening said bolt from its nut. ### Claim 8 (depends on 7) The assembly of claim 7 wherein said door and door casing are circular in shape and said barrier is a ring. ### Claim 9 (depends on 7) The assembly of claim 7 wherein one of said locking bolts is connected to a retractable tongue of said combination lock by a hook means, and the other locking bolts are connected to said tongue by lever means which cause all of said locking bolts to move simultaneously. ### Claim 10 (depends on 9) The assembly of claim 9 wherein said lever means comprises a slidable link bar having a pin connection to said tonque and pivotable arms connecting said link bar to said other locking bolts. ### Claim 11 (depends on 10) The assembly of claim 10 which additionally comprises a pivotable relocking bar spring biased to pivot into a position where a portion of said bar mates with a corresponding portion of said link bar whereby the link bar is prevented from sliding, said spring bias being positioned to release said relocking bar to mate with said link bar when said combination lock is displaced inwardly from its normal position. ### Claim 12 In a safe door assembly comprising a door casing, a door, a plurality of locking bolts reciprocally movable outwardly to mate with a recess in said door casing, and a combination lock operatively connected with said locking bolts to selectively cause outward or inward movement of said bolts, respectively, to lock or unlock said door; the improvement which comprises a reciprocable tongue attached to said combination lock said tongue moving linearly outwardly and inwardly, respectively, to lock and to unlock said safe, said tongue having a transverse slot at the outer end thereof to fit with a hook-shaped end of one of said locking bolts; said tongue also having a pin extending laterally therefrom to fit into a corresponding hole in a slidable link bar to which are connected lever means to cause all other locking bolts to move simultaneously with the movement of said locking bolts with the hook-shaped end; and two bolts through the outer wall of said door and through a hardened steel plate interiorly adjacent said outer wall fastened at the inside of said plate with lock nuts and supporting a handle for moving said door away from said casing, said bolts having a head with a weakened shank portion immediately adjacent said head to cause shearing of the bolt when subjected to a torque normally required to unloosen said bolt from said lock nut; said bolts also having adjacent said weakened shank portion a shoulder portion of larger diameter than all other shank portions of said bolt and of appropriate size to fit into a counterbore in said outer wall. ### Claim 13 (depends on 12) The assembly of claim 12 wherein a hardened steel barrier is spaced outwardly from the outer extremities of said locking bolts and positioned to prevent access thereto by a drill. ### Claim 14 (depends on 12) The assembly of claim 12 wherein said door and door casing are circular in shape. ### Claim 15 (depends on 12) The assembly of claim 12 which comprises a pivotable relocking bar spring biased to pivot into a position whereby said relocking bar mates with a corresponding portion of said slidable link bar to prevent it from sliding when said combination lock is displaced inwardly from its normal position. ### Claim 16 In a safe door assembly comprising a door casing, a door, a plurality of locking bolts reciprocally movable outwardly to mate with a recess in said door casing, and a combination lock operatively connected with said locking bolts to selectively cause outward or inward movement of said bolts, respectively, to lock or unlock said door; the improvement which comprises a handle for moving said door away from said casing, and a plurality of bolt and lock nut combinations passing through a bore in the outer wall of said door and through a hardened steel plate interiorly adjacent said outer wall to support said handle and said hardened steel plate, the head of each bolt being on the outside of said door and the corresponding lock nut being on the inside of said door, each of said bolts being weakened in a shank portion adjacent said head to the extent that application of the normal torque to unloosen said bolt from said lock nut will cause shearing of the bolt at said weakened portion, said bore including a counterbore to accommodate an enlarged shoulder portion on said bolt adjacent said weakened portion. ### Claim 17 (depends on 16) The assembly of claim 16 wherein said weakening is the result of reducing the diameter of said shank portion over a short length of said shank portion. ### Claim 18 (depends on 16) The assembly of claim 16 wherein a hardened steel barrier is spaced outwardly form the outer extremities of said locking bolts and positioned to prevent access thereto by a drill. ### Claim 19 (depends on 16) The assembly of claim 16 wherein said door and door casing are circular. ### Claim 20 (depends on 16) The assembly of claim 16 comprising two of said bolt end lock nut combinations. ### Claim 21 (depends on 16) The assembly of claim 16 wherein said combination lock included a reciprocable tongue capable of linear movement outwardly or inwardly, respectibely to lock or unlock said door, said tongue being connected by a hook attachment to a first locking bolt and being connected by a pin attachment to a slidable link bar which in turn is connected by lever means to the other locking bolts so as to move outwardly and inwardly with said first locking bolt. ### Claim 22 (depends on 21) The assembly of claim 21 comprising a pivotable relocking bar spring biased to pivot into a position where a portion of said bar mates with a corresponding portion of said slidable link bar whereby said link bar is prevented from sliding, said spring bias being positioned to release said relocking bar to mate with said link bar when said combination lock is displaced inwardly from its normal position. ### Claim 23 (depends on 7) The assembly of claim 7 which comprises at least three locking bolts. ### Claim 24 (depends on 12) The assembly of claim 12 which comprises at least three locking bolts. ### Claim 25 (depends on 13) The assembly of claim 13 wherein said barrier is a ring.