NZ328154A - Cylinder lock-key combination with groove(s) in cylinder housing coacting with key spine profile to prevent turning of key with wrong profile - Google Patents

Description

New Zealand No. 328154 International No. PCT/ TO BE ENTERED AFTER ACCEPTANCE AND PUBLICATION Priority dates: 20.12.1996; Complete Specification Filed: 23.06.1997 Classification:^) E05B35/00; E05B63/00 Publication date: 24 September 1998 Journal No.: 1432 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention: Cylinder lock Name, address and nationality of applicant(s) as in international application form: Assa AB, a Swedish company of Box 371, S-631 05 Eskilstuna, Sweden 3281 No: Date: NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION CYLINDER LOCK We, ASSA AB a Swedish company of Box 371, S-631 05 Eskilstuna, Sweden do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by -vhich it is to be performed to be particularly described in and by the following statement -1- (followed by la) 2 3 JUN 199^ < v.; v 32 815 4 CYLINDER LOCK FIELD OF INVENTION The present invention relates generally to cylinder lock-key combinations and more specifically to cylinder locks of the kind defined in the preamble of Claim 1.

The invention also relates to a key for such a combination.

BACKGROUND OF THE INVENTION There are at present used in respect of known cylinder locks keys that have a profiled pattern on one or both side surfaces 15 of the key bit. The purpose of these profiled patterns is to allow only keys that have profiled surfaces which coact with the configuration of the key slot provided in the cylinder plug to be inserted into the lock. Thus', a key that has the wrong profile will not function with a lock that has a different 20 profile, even though the keys should have the correct code.

A development of this principle is disclosed in U.S. Patent 3,287,945 (Yulkowski). According to this publication, the key must also include an elongated axial groove in the spine of the 25 key bit. If this groove is not present, insertion of the key is blocked by a protective element in the key slot that projects out from a longitudinal groove in the cylinder housing.

Turning of a wrong key is prevented in this further develop-30 ment, by a protective element wherein projections are disposed at regular intervals therealong. The element is disposed longitudinally in a groove in the cylinder housing and the projections extend radially inwards of the cylinder plug. In order for the key to be turned past the protective element, the 35 key must include notches which are positioned to coincide with the projections on the protective element when the key is turned. This mutual registration of the projections and the notches allows the key to pass the protective element, whereas 2 2 815 the protective element will prevent turning of a key that has no such notch or when the notches are wrongly positioned on the spine of the key bit.

The same principle is illustrated in U.S. Patent 2,803,959 (Schlage), even though the projections from the cylinder housing are arranged in another way.

The drawback with both of the solutions is that the cylinder 1C plug must include a groove that coincides with the projection. This thus prevents the use of a standard cylinder plug. Furthermore, it is necessary to position the projections so that they will not coincide in the longitudinal direction of the lock with those tumbler channels that extend between the 15 cylinder plug and the cylinder housing. If the key should include a notch that is coincidental with a tumbler, there is a risk that the tumbler in the cylinder housing will "sink down" into the notch and therewith make further turning of the key impossible. Even if turning of the key is not prevented, 20 the notch will nevertheless subject the tumbler to significant wear, therewith rendering the lock unusable after being in use for some time.

This limitation with regard to the configuration of the plug 25 makes manufacture of this type of lock more expensive than locks that can use standard cylinder plugs. Furthermore, the position of the projections in the cylinder housing greatly limits the number of possible projection combinations, and consequently this principle is of small value with respect to 30 its use as an additional code.

Furthermore, the illustrated solutions result in frail constructions which will give or break when the key is subjected to heavy pulling forces, for instance if an attempt is made to 35 open a heavy or sluggish door by simply pulling on the key.

OBJECT OF THE INVENTION 328154 The object of the present invention is to avoid the aforesaid drawbacks associated with known locks and to provide a lock-key combination that will enable the use of a code disposed on the spine of the key bit.

A further object of the invention is to provide a lock-key combination in which the key will withstand greater pulling forces, or tension forces, than in the case of known locks, and in which wear on the key is reduced.

SUMMARY OF THE INVENTION The aforesaid objects are achieved with a construction in which the latching elements are disposed outwardly of the plug 15 radius. This construction enables the use of a standard cylinder plug and is more robust than earlier lock constructions .

Thus, there is provided a cylinder lock-key combination in 20 which the cylinder lock includes a lock cylinder having a cylinder housing and a cylinder plug which is accommodated in an opening in the cylinder housing and which includes a key slot for receiving a key bit, wherein the combination is characterized in that the opening in the cylinder housing 25 includes at least one groove which, when the key is inserted to an operative position in the cylinder lock, coacts with a profile on the spine of the key bit in manner to prevent turning of a key that has the wrong profile.

A key for this combination is also provided. The key is characterized in that the spine surface of the key bit carries a profile in the longitudinal direction of the key, said profile coacting with at least one groove in a cylinder housing opening when turning the key.

The invention is particularly useful in cylinder locks of the kind that have no through-penetrating tumbler channels between cylinder plug and cylinder housing. Positioning and distribu- 32 815 4 tion of the projections can be varied greatly in locks of this kind, because the positions of the tumblers need not be taken into account when configuring the spine code.

The position in which the key is removed from the lock is defined with great precision in accordance with the invention, so that other mechanisms are protected against increased wear should the user of the key turn the key in conjunction with withdrawing the key from the lock.

Other preferred features of the invention will be evident from the dependent Claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawings, in which Figs, la, lb illustrate an inventive cylinder lock housing; Figs. 2a, 2b illustrate a cylinder lock plug; Figs. 3a, 3b illustrate an inventive key for use with the 25 cylinder lock housing in Fig. 1; Figs. 4a, 4b show the key inserted into the cylinder; and Figs. 5a, 5b show the key inserted and turned through about 45° 30 from its insertion position.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS A preferred embodiment of a cylinder lock and associated key 35 according to the invention will now be described.

Fig. 1 illustrates a cylinder lock housing 10 which is intended to be fitted to a door or sorae like element and which includes 3 a conventional/ generally cylindrical outer shape. The cylinder lock housing can thus be interchanged with present-day known cylinder lock housings.

Drilled in the housing 10 is an opening 12 which accommodates a cylinder lock plug 20 shown in Fig. 2. The illustrated housing is intended for a lock of the kind marketed under the trademark ASSADESMO, and the principle of this type of lock is described, for instance, in Swedish Patent Specifications SE-B-10 469 565 and SE-B-469 566 in the name of ASSA AB, to which the reader is referred for further information. Two grooves 14a, 14b extend typically in the longitudinal direction of the walls of the opening. A side bar engages in a respective groove in the locked state of the lock. A groove 15 extends symmetrically 15 with respect to the two grooves 14a, 14b, said groove 15 being slightly wider than the grooves 14a, 14b. The wider groove 15 is intended to receive a part of the spine of an inserted key 30. This key will be described in more detail hereinafter with reference to Fig. 3.

In addition to the aforementioned longitudinally extending grooves, the housing also includes a plurality of circumferentially grooves 16a-e, as evident from Fig. lb. The shape, depth and width of these grooves can vary, although a common feature of the grooves is that they all extend fully 25 around the inner surface of the hole 12 in a plane that'extends transversely to the longitudinal direction of the housing, i.e. transversely to the key insertion direction.

The internal diameter of the hole 12 in other respects is 30 adapted for insertion of the cylinder plug 20 shown in Fig. 2. The design of the cylinder plug 20 is typical for this type of lock and includes an abutment or collar 22 which functions to position the plug correctly in the housing 10. The plug also includes the two grooves 24 that accommodate respective side 35 bars, although only one of these grooves is shown in the Figure. The plug also includes a key insertion slot 26, the position of which is evident from Fig. 2b. The width of the key • « 328154 slot coincides essentially with the width of the groove 15 in the housing 10.

The ability to use known cylinder plugs represents a cost 5 saving in the manufacture of the inventive lock.

Fig. 3a illustrates a key 30 whose main parts are comprised of a grip 31 and a key bit 32. The sides of the key bit 32 have code grooves which when inserting the key coact with known 10 tumblers in the cylinder plug 20; c.f. the aforesaid patent specifications to ASSA AB, for instance. Fig. 3b is a cross-sectional view of the key bit. It will be seen from this Figure that the spine surface 33 of the bit is rounded to conform to the radius of the hole 12 in the housing. The greatest height 15 of the key bit 32 corresponds generally to the combined length of the key slot 2 6 in the core 20 and the depth of the groove 15 in the housing 10, therewith enabling the key to be inserted into the key slot when the position of the plug in the housing 10 is such that the slot will be in register with the key slot 20 15.

Seen in side view, the spine surface 33 has a toothed profile that includes projections 34a-e and interspersed straight parts 35. As will best be seen from Fig. 4, the shape and positions 25 of respective projections 34a-e correspond to respective grooves 16a-e in the housing. Since the illustrated type of lock has no top and bottom tumblers, etc., there is no need for a straight partition line between plug and housing. The positions of the projections can therefore be varied freely 30 along substantially the whole of the spine surface 33, therewith permitting a wide variation of spine codes.

It will be understood that the total height or vertical extension of the key will be greater than the total height or 35 vertical extension of a key for a conventional lock, and that a key blank having a higher key-bit part must be used. The spine surface is machined to provide the straight parts between the projections. In view of the heat that is generated when • , 32815 4 machining the blank and by rotating tools, and with view to obtaining a smoother shape, inclined transition surfaces between the projections 34 and the intermediate parts 35 are preferred, such as at the projection 34d. This does not prevent 5 the use of right angles, however.

If a key of standard height is inserted into the key slot, the groove 15, which is used in the key insertion and key withdrawal position when using an inventive key, will prevent the 10 tumblers from taking their correct code position, since a key of standard height will "slip down" in the groove 15 to some extent.

In order to obtain a correct key insertion position in the 15 lock, the key also includes a stop shoulder or an abutment 36 which stops further insertion of the key when the shoulder is in abutment with the end surface of the plug.

The manner in which the inventive lock and key combination 2 0 works will now be described with reference to Figs. 4 and 5. Fig. 4 shows the key 30 inserted in the plug 20 but not rotated therein. It will also be seen from the Figure that the spine profile of the key is coincidental with the peripherally extending grooves in the housing when the key is inserted to a 25 position in which the shoulder jd is in abutment with the end surface of the cylinder plug. Because the projections 34 are able to move in the groove 16, turning of the key is not blocked and the key will function in the same way as in a conventional lock.

On the other hand, if the key has an incorrect spine profile, i.e. a profile that does not harmonize with the groove 16, turning of the key from the position shown in Fig. 4 is prevented and the lock cannot be released, even though the key 35 in general may have the correct code grooves or code surfaces.

In the position shown in Fig. 5, with the key turned through about 45°, the projections 34a-e will engage corresponding 3281s t 8 grooves 16a-e. This means that axial movement of the key is blocked and that the key is able to take-up relatively large axial forces without damaging the key or the lock. This is an advantage, because the key will then also function as a 5 "handle" for opening the door in which the lock is mounted.

The person skilled in this art will realize that the illustrated embodiment can be varied and modified within the scope of the following Claims without departing from the inventive 10 concept. For instance, the invention is not limited to locks that lack through-penetrating tumbler channels between the cylinder plugs and cylinder housings, but can also be applied with locks that include such channels. However, in this latter type of lock the grooves are limited to positions between the 15 tumbler channels.

In the case of the preferred embodiment, the grooves 16a-e extend fully around the inner periphery, i.e. enable the key to be turned through 360°. However, locks in which the grooves 20 extend only partially around the cylinder plug accommodating hole are also conceivable. This is particularly preferred when the lock includes through-penetrating tumbler channels between the cylinder plugs and cylinder housings, since turning of the key can therewith be restricted.

The illustrated embodiment includes a housing having two sidebar accommodating grooves 14a, 14b. It will be understood, however, that the invention can also be applied with locks that have only one side bar or which have no side bars at all. The 30 number of grooves 16 may, of course, vary in accordance with the number of profile shapes used. 328154

Claims (9)

WHAT WE CLAIM IS:

1. A cylinder lock-key combination in which the cylinder lock includes a lock cylinder having a cylinder housing and a 5 cylinder plug . which is accommodated in an opening in the cylinder housing • and which includes a key slot for receiving a key bit of a key characterized in that the opening in the cylinder housing includes at least one groove which, when the key is inserted to an 10 operative position in the cylinder lock, coacts with a profile on the spine of the key bit in manner to prevent turning of a key that has the wrong profile. 15 2. A combination according to Claim 1, characterized in that the transition surface between the cylinder housing and the cylinder plug lacks through-penetrating tumbler channels.

2 0

3. A combination according to Claim 1 or 2, characterized in that the profile extends along essentially the full length of the spine of the key bit.

4. A combination according to any one of Claims 1-3, charac-25 terized by a key insertion groove that extends in the opening in the cylinder housing in the longitudinal direction of said hcusing.

5. A combination according to any one of Claims 1-4, charac-30 terized in that said at least one groove extends circumferentially.

6. A combination according to any one of Claims 1-5, characterized in that it includes at least one side bar which, in a 35 locked state, engages a respective groove in the opening in the cylinder housing. 10

7. A key belonging to the combination according to any one of Claims 1-6, characterized in that the spine surface . . of the

8. A cylinder lock-key combination substantially as herein described with reference to the accompanying drawings.

9. A key as claimed in claim 7 substantially as herein described with reference to the accompanying drawings. key bit has . profile in an opening . has in the longitudinal direction of the key a that coacts with at least one groove Lng . in the cylinder housing. ASSA AB By its Attorney DON HOPKINS & ASSOCIATES Per: