US1819059A - Safety key for locks - Google Patents

Description

Aug. 18, 1931. E. SCHMID SAFETY KEY FOR LOCKS Filed June 15, 1929 Patented Aug. 18, 1931 UNHTED STATES ERNEST SGHMID, OF GLADSTONE, OREGON V SAFETY KEY non LOCKS 1 Application filed. June 15,

This invention relates to keys and more particularly to keys to be left in the keyhole after the usual key has thrown the bolt, to protect the lock against an unauthorized per- '5 son unlocking or withdrawing the bolt to unlocked position.

The object of the present invention is to provide a safeguard for looks which may be operated from only one side and which will insure the door remaining locked to all but the proper person.

A further object is the provision of means which may be left in the keyhole to prevent the insertion of a key which would ordinarily operate the look.

A still further object is the provision of means which will automatically take a position to prevent a duplicate key from being used.

A still further object is to provide a key capable of being automatically retained in a keyhole and requires but the ordinary motions used in ordinarily opening or locking a lock to actuate same.

The invention is illustrated in the accom panying drawings in which Figure 1 is a front view of the key showing the sections secured together to insert in a lock.

Figure 2 is a section on line 2-2 on Fig. 1.

Figure 3 is a broken elevation, partly in section, of the improved key.

The key is illustrated in the drawings as of conventional shape having a handle section 4 and a bit section 5. The two sections when fitted together form an ordinary locking key which is no more inconvenient to carry or use than such a key. The bit section 5 is hollow Z6 and includes a somewhat elongated portion 12 of uniform diameter throughout and a somewhat enlarged portion 5 of less length than and of a diameter somewhat greater than that of the portion 12.

The bolt 13 is fitted within the hollow bit 5, this bolt having an enlarged portion 13 fitted within the portion 5 of the hollow bit, such portion 13 of the bolt being formed with a longitudinally ranging bore 6 inter- 50 nally threaded at 7 to cooperate with a stud 8,

1929. Serial m. 371,250.

threaded at 9, projecting from the handle section 4.

The bit section 5 has a bit 10 having a centrally located groovelll cut therein. From the bolt 13 extends a locking pin 14, the latter being semicircularin cross section and is adapted to fit in the groove 11, the flat surface of the pin coming flush with the surface of the bit so as not to interfere with the insertion and removal of the key in the keyhole A spring 15 secured to the shank 12 of the bit section at 16 and to the bolt 13 at 17 tends to force the pin away from the groove 11, to extend at an angle with the bit. This provides a means for locking the key in the keyhole so that it cannot be pushed from the keyhole by the insertion of any instrument in said hole.

In operation, the usual key is inserted in the key hole to throw the lock bolt in locked position, then the key is withdrawn and therqw improved key with the handle section and bit section tightly screwed together to bring the pin. 14 in the groove 11, is inserted in the key hole of the lock, with the lower edges of the bit in engagement with the walls X X 3 of the lock frame. Then by unscrewing the handle section to free the bolt 13 so that the spring 15 will turn the pin 14 from the groove 11, as shown in Fig. 2, and by continuing to unscrew the handle section, it cang be separated and withdrawn from the bit section, with the latter remaining locked within the lock frame. In this operation, it is to be understood that the bit 10 engages the walls X X of the key opening and is thereby prevented from turning when screwing or unscrewing the handle section to engage or disengage it from the bit section. When the pin 14 is swung away from the bit by the spring 15, it prevents the bit being with- 7 drawn from the lock, and at the same time locks the bit in the frame and prevents the insertion of another key and thus prevents an unauthorized person tampering with the lock.

-To remove the bit section of the key to unlock the lock, it is only necessary to insert the stud 8 of the handle section into the bore. 6 of the bit section and screw the two sections together. This causes a bind-m0 ing action between the handle section and the bolt 13, and the latter is thus turned with the handle section, and the pin 14: is returned to the groove 11,whereupon the key as a whole can be withdrawn from the lock and the usual key inserted to unlock the lock. Of course, in screwing the sections together to remove the key, the bit 10 is prevented from turning by engaging the walls of the key opening as previously described.

What I claim is A key comprising a handle section and a bit section, said bit section including a hollow shank open at one end and closed at the opposite end and formed with an ofiset bit, the interior of the hollow shank at the open end being enlarged diametrically to provide an abrupt shoulder interiorly of the hollow shank,a bolt mounted for movement Within the hollow shank and formed with parts of different diameters to accurately fit the similar parts of the hollow shank, the bolt having a shouldered portion to bear on the shouldered portion within the shank, a pin carried by and projecting at right angles from the bolt and extended through a slot in the hollow shank, the bit carried by the hollow shank being formed with a groove to house the pin in one position vof the bolt relative to the hollow shank, one end of the bolt being formed with a threaded socket, the opposite end of the bolt being of reduced diameter, and a spring encircling the portion of reduced diameter of the bolt and terminally secured to the bolt and to the closed end of the hollow shank, the handle section having a threaded projection to cooperate with the threaded socket in the bolt.

ERNEST SCHMID.

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