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Publication numberUS3499304 A
Publication typeGrant
Publication dateMar 10, 1970
Filing dateApr 19, 1967
Priority dateApr 21, 1966
Also published asDE1553482A1, DE1553482C3
Publication numberUS 3499304 A, US 3499304A, US-A-3499304, US3499304 A, US3499304A
InventorsNaujoks Manfred
Original AssigneeSchulte C E Gmbh
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Flat keys for cylinder locks
US 3499304 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

4 Marh 10,1970 M.NAUJOKS 3,499304.


INVENTOR United States Patent Ofice' 3,499,304 Patented Mar. 10, 1970 3,499,304 FLAT KEYS FOR CYLINDER LOCKS Manfred N aujoks, Velbert, Rhineland, Germany, assignor to C. Ed., Schulte G.m.b.H., Velbert, Rhineland, Ger- Filed Apr. 19, 1967, Ser. No. 632,085 Claims priority, appliscation Ggrmany, Apr. 21, 1966,

ch 38, Int. Cl. E051) 19/04, 19/16 US. Cl. 70-406 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The invention relates to a flat key for cylinder locks of closing mechanisms with variations in profile. In known fiat keys parallel ribs are provided along the side faces of the keys and are fully or partially omitted as required in order to vary the profile. The master key of the set has no ribs at all and can thus easily be counterfeited by rubhing down the ribs. Moreover the ribs must have an adequate width sogiven the standardised height of the keyonly a small number of them can be arranged on each face. The number of variations which can be used in practice depends on the number of ribs.

Some known flat keys for cylinder locks of closing mechanims with variations in profile are provided with grooves on each face. With this construction the master key contains most grooves and each of the subordinate keys contains less. This makes it considerably more difficult to counterfeit the master key, since it already contains the most grooves. The side faces of the key cannot readily be rubbed down to the bottom of the grooves, particularly if the grooves extend substantially as far as the plane of the key, since in this case they would be coplanar with the bottoms of the grooves on the other side. Here again the number of variations in profile depends on the number of grooves.

In both constructions gaps have to be left between the projections or between the grooves, and these gaps still further diminish the side surfaces available for the provision of projections or grooves. A flat key for cylinder locks is therefore already known, wherein the projections are shaped like saw teeth.

SUMMARY OF THE INVENTION The invention aims to provide a fiat key for cylinder locks of closing mechanisms with variations in profile in which such drawbacks are avoided. This is achieved, according to the invention, substantially in that the keys have ribs which are known per se and omitted from the master 'key and grooves which are also known per se and present in their full complement in the master key, and that the projections and grooves which are present and omitted where necessary, are arranged in alternating sequence. This is a simple way of providing fiat keys of this type, admitting of a particularly large number of variations in profile. The alternating sequence of projections known per se and grooves known per se makes full use of the parts of the lateral surfaces between two projections or grooves for theprovision of additional grooves or projections.

It is an advantage for projections on one side of the key to be opposite grooves on the other side. This is a simple method of giving the key an adequate wall thickness over its whole width in spite of the provision of grooves.

It is particularly advantageous for the depth of the grooves to extend at least almost as far as the center plane of the key. By this simple step the bottoms of the grooves on one side are made substantially coplanar with the bottoms of the grooves on the other side of the key, and it is impossible to counterfeit a master key by abrading the parts between the grooves.

An example of the invention is illustrated in the drawings, in which:

FIG. 1 shows a key cross section with all the possible ribs and grooves for the variations in profile,

FIGS. 2 and 3 show two examples of derived variations in profile, and

FIG. 4 shows a cross section through the associated master key.

The key 10 according to the invention as illustrated in the drawings has a guiding portion 11 at the back containing a guide groove 12. The portion 11 with the groove 12 is identical in all keys in a series. In order to produce additional series of keys more than one guiding groove 12 may be provided in the portion 11, and the groove 12 may be located in a different position and/or on the other side of the key.

The remainder of the side faces of the key 10 each have three grooves 13, 14, 15 and 16, 17, 18 and three ribs 19, 20, 21 and 22, 23, 24, the grooves 13-18 alternating with the ribs 19-24. This is a simple way of ensuring that the key has a particularly large number of different cross sectional shapes.

For the variations in profile the grooves 13-1-8 and/or ribs 19-24 may be omitted where required, in part or wholly. Of the large number of possible key cross sections two examples are illustrated in FIGS. 2 and 3. In the section shown in FIG. 2, for example, the grooves 13, 14 and 16 and the ribs 21, 23 and 24 are provided, Whereas in FIG. 3 the key section is provided with the grooves 13, 14 an 17 and the ribs 21, 22 and 24.

In the master key illustrated in FIG. 4 all the grooves 13-18 are present and all the ribs 19-24 omitted. The key 10 will thus fit into all the locks in that series.

As will be seen particularly from the figures illustrated, the projections 19-24 on one side of the key 10 are opposite the grooves 13-18 on the other side. By this simple method the key 10 is given an adequate wall thickness over its whole width in spite of the grooves 13-18. The method further enables the grooves 13-18 to be taken relatively deep into the key 10 and to extend :at least nearly as far as the center plane of the key. This is an easy way of preventing the master key from being counterfeited by abrading the parts of the cross section between the grooves.

As already mentioned, the embodiment illustrated is only an example of the invention. The invention is not restricted to it and many other constructions and applications are possible. For example, the key section shown in FIG. 1 could be used in mirror image to produce a further series of keys.

I claim:

1. A set of cylinder lock keys consisting of a master key, and at least one other key operative in conjunction With a lock, each of said keys comprising a strip-shaped body portion having opposite marginal zones, said master key being free from projections and comprising only grooves in each of said marginal zones with the grooves in one of said marginal zones being oifset relative to the grooves in the other of said marginal zones, and said I other key being provided in at least one of the marginal 3 zones thereof with at least one projection and in said marginal zones with a number of grooves which is smaller than the number of grooves in the marginal zones of said master key.

2. A set of keys as defined in claim 1, wherein said master key comprises three of said' grooves in each of said opposite marginal zones of said body portion thereof.

3. A set of keys as defined in claim 1, said body portions being flat and said marginal zones having respective edge faces provided with said grooves.

4. A set of keys as defined in claim 1, said strip-shaped body portions being longitudinally bisected by a center line, and at least some of grooves in the opposite marginal zones extending at least substantially to said center line.

4 References Cited UNITED STATES PATENTS 608,069 7/1898 Noack 70375 r 1,782,464 11/1930 Falk 70406 FOREIGN PATENTS 355,710 8/1961 Switzerland.

1,186,776 2/1965 Germany.

10 MARVIN A. CHAMPION, Primary Examiner R. L. WOLFE, Assistant Examiner

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US608069 *Jul 3, 1897Jul 26, 1898 Cylinder-lock
US1782464 *May 18, 1928Nov 25, 1930Morris FalkMaster key for cylinder locks
CH355710A * Title not available
DE1186776B *Feb 7, 1964Feb 4, 1965Voss Kg JGruppenschluessel
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3691508 *Jun 30, 1970Sep 12, 1972Polaroid CorpNovel plug and socket assemblies for flash cubes
US3902342 *Jul 2, 1973Sep 2, 1975Pitney Bowes IncKey
US4168617 *Jun 27, 1978Sep 25, 1979Evva-Werk Spezialerzeugung Von Zylinder- Und Sicherheitsschlossern Gesellschaft Mbh & Co. KommanditgesellschaftLock system
US4368629 *Jun 26, 1979Jan 18, 1983Evva Werk Spezialerzeugung von Zylinderschlo/ssern Gesellschaft MbH & Co. KommanditgesellschaftLock system
US4825672 *Feb 4, 1988May 2, 1989Jacob RabinowKey for flat tumblers
US5088306 *Oct 31, 1989Feb 18, 1992Medeco Security Locks, Inc.Cylinder lock with changeable keyway
US5182929 *Jun 5, 1989Feb 2, 1993Fort Lock CorporationMethod of providing a universal keyway lock and plug therefor
US5287712 *Jul 10, 1992Feb 22, 1994Emhart, Inc.Locking arrangement consisting of key and lock cylinder
US6023954 *Dec 6, 1996Feb 15, 2000Medeco Security Locks, Inc.Keys for cylinder locks
US6615628 *Jul 20, 2001Sep 9, 2003Chi-Wen LouPicklock-proof key slot for a lock device and a key thereof
US7412860Mar 30, 2007Aug 19, 2008Medeco Security Locks, Inc.Key blank and key
US7552608Jun 18, 2008Jun 30, 2009Medeco Security Locks, Inc.Lock, key blank, and key of a hierarchical lock system
US7788956Aug 7, 2009Sep 7, 2010Medeco Security Locks, Inc.Lock, key blank, and key of a hierarchical lock system
EP0261298A2 *Jan 28, 1987Mar 30, 1988EVVA - Werk Spezialerzeugung von Zylinder-und Sicherheitsschlössern Gesellschaft m.b.H. & Co. KommanditgesellschaftFlat key profile for a cylinder lock key
U.S. Classification70/406
International ClassificationE05B19/06, E05B35/00, E05B19/00, E05B35/10
Cooperative ClassificationE05B27/0053, E05B19/0029
European ClassificationE05B27/00M