| 摘要 |
<p>955,828. Barrel locks; change-key locks. AMERICAN HARDWARE CORPORATION. May 26, 1960 [May 27, 1959], No. 18679/60. Heading E2A. A barrel lock comprises a key plug 10 and a housing 5 therefor, a tumbler bore in the key plug 10 communicating with a key-way 15 and alignable with a tumbler bore 16 in the housing, tumbler elements 17, 18, 19 and 20 in the bores, first and second keys 25, 27 bitted for co-operation with the tumbler elements, which include a temporary tumbler element 23 sized to permit operation of the key plug 10 by the first and second keys, and a recess 24 provided in the key plug for reception of the temporary element 23 when the key plug is operated initially by the second key 27, the remaining tumbler elements in the bores being such as to prevent subsequent operation of the key plug 10 by the first key 25. As shown, a master key may also be used to operate the key plug 10 after the temporary element 23 has been moved into the recess 24 by operation of the key plug by key 27. A temporary element 23 may be associated with any one or more of the pin bores of the lock. In another arrangement Figs. 14 and 15, the key plug comprises a master ring 32 which is rotatable in a housing portion 30, and a key barrel 33. The housing, master ring and key barrel are provided with pin tumbler holes forming pin bores 34 for tumbler elements 36, 37, 38, 39 and a temporary pin 43 which is displaceable into a pocket 44 in the master ring 32 by a master key 45 to prevent subsequent operation of the lock by a temporary master key. Specification 955,829 is referred to.</p> |
