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Publication numberUS1295351 A
Publication typeGrant
Publication dateFeb 25, 1919
Filing dateAug 23, 1918
Priority dateAug 23, 1918
Publication numberUS 1295351 A, US 1295351A, US-A-1295351, US1295351 A, US1295351A
InventorsLyttleton F Morgan
Original AssigneeLyttleton F Morgan
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1295351 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)


KEY.- a APPLICATION nuan- Aua.2"3'. ms.

1,295,351. PatentedFeb. 25, 1919.




Specification of Letters Patent.

Patented Feb. 25, 1919.

Application filed. August 23, 1918. Serial No. 251,087.

T 0 all whom it may concern:

Be it known thatLLY'rTLEroN F. MORGAN, a citizen of the United States, residing at 2228 Amsterdam Ave., in the county of New York and State of New York, have invented new and useful Improvements in Keys, of which the following is a specification.

This invention consists in an improvement in keys of the well known" Yale type, that is, keys cut and stamped of sheet metal and with their blades corrugated on both sides and bitted on one edge.

It frequently happens that keys of this kind break off in the lock, causing much inconvenience and expense. As now constructed, the weakest part of the key is in the blade at the deepest bit, and when a key is broken in the lock, part of the blade remains in and can only be extracted with great difliculty.

I overcome this objection by locating the weakest part of the key, that is, the place where it has the least cross sectional area, in the head or in that portion of the key which does not enter the look. I do this by providing the blade with an enlargement and uniting this enlargement to the bow by a reduced portion or neck of less cross sectional area than any part of the blade. Thus, if too much force is used in attempting to turn the key in the lock, it will break at that reduced portion or neck and the key can nevertheless be withdrawn by taking hold of the enlargement and, if desired or necessary, can continue to be used, the enlargement serving as the handle or grip.

I am aware that it is not new to provide a weak spot in some kinds of machinery so that the break will be definitely located in the event of too much strain, but I believe I am the first to apply the idea to a key and that the improved construction described and claimed is novel; its utility is obvious.

The invention is, of course, adapted to any style of flat sheet metal key having a bitted blade. Its essential feature is the provision of two by a neck which constitutes the weakest part of the key. Preferably the first grip is a relatively small enlargement of the blade and the outer one is the usual apertured bow. The enlargement may also have an aperture in it so that the key can be carried 01% a ring even after the how has been broken ov handles or grips connected The invention is illustrated in the accompanying drawing.

Figure 1 is an elevation of a key embodying my improvement.

Fig. 2 is an elevation of equipped with a slightly modified the improvement, and

Fig. 3 is an edge view of the blank of Fig. 2.

1 represents the corrugated shank or blade of the key and 2 the bow or handle. 3 is the enlargement at the end of the blade, or, as it may be called, the emergency grip; in Fig. 1, it is provided with the hole 4 to slip on a key ring or attach a tag. 5 is the reduced portion or neck which connects the grips 2 and 3 and which is the weakest point of the key. It must be of less cross sectional area than the blade at the point of the deepest bit 6. In Fig. 1 the neck is of the same thickness as the rest of the key while in Fig. 2 it is shown as of reduced thickness.

It will be obvious that the invention is independent of the particular shape and form of the blade and handle; that illustrated is by way of example merely. Any kind of flat key can be provided with the improvement.

Having thus described my what I claim is:

1. A fiat key comprising a bitted blade having a widened portion at its base, a bow or grip, and a neck between said widened portion and said bow, the amount of metal in said neck being less than at any part of the blade.

2. A fiat key comprising a blade provided with bits in its edge, a head or emergency grip on said blade, and a bow united to said head by a neck the cross sectional area of which is less than that of the blade at the deepest bit.

3. In a sheet metal key, the combination with the blade and bow, of an enlargement forming an emergency grip at the base of the bladeand a reduced neck uniting said bow to said enlargement, the dimensions of said neck being such that the key will break there if too much force is used.

In testimony whereof I have hereunto set my hand.

a key blank form of invention,


copies at this patent may be obtained tor five cents each, by aagreaging the "commissioner of Iii-tents,

. Washington, D. G,"

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5697239 *Jul 19, 1996Dec 16, 1997Master Lock CompanyPin tumbler cylinder lock with shearable assembly pins and method and apparatus of manufacture
US5735153 *Apr 14, 1997Apr 7, 1998Master Lock CompanyPin tumbler cylinder luck with shearable assembly pins and method and apparatus of manufacture
US6023954 *Dec 6, 1996Feb 15, 2000Medeco Security Locks, Inc.Keys for cylinder locks
US6263713Mar 3, 1999Jul 24, 2001Master Lock CompanyShearable lock assembly and method of manufacture
US6546768 *Aug 30, 1999Apr 15, 2003Daimlerchrysler AgIgnition lock system for motor vehicles
WO1995005919A1 *Aug 22, 1994Mar 2, 1995Master Lock CompanyPin tumbler cylinder lock with shearable assembly pins and method and apparatus of manufacture
WO2010004235A1 *Jul 7, 2008Jan 14, 2010Talaris Holdings LimitedKey, lock assembly and method of actuating a lock
U.S. Classification70/406, 70/422, 70/461
Cooperative ClassificationE05B19/0029