The invention relates to a disc tumbler lock assembly device for machining tumbler discs packed in a cylinder so as to correspond to the key for that lock.

BACKGROUND OF THE INVENTION

A disc ^'" 'tumbler.. ^' cylinder ^' lock is a structure having a fixed outer cylinder and, therein, a rotating inner cylinder., ,-■ inside _; which there are a number of tumbler discs. The tumbler discs are rotatable through a rotating movement of the key for the lock so that a locking bar controlled in the radial direction of the lock by the tumbler discs so as to lock the inner cylinder to the outer cylinder is, in the position of the tumbler discs as determined by the key, able to move radially ^' to a position that releases the inner cylinder. Traditionally, the disc tumbler cylinder lock has been assembled from different tumbler discs which have been packed in the inner cylinder as a combination that corresponds to the key. The structure is slow and difficult to assemble, and it requires a great number of different tumbler discs of which the required discs are then selected in a correct order.

A solution to this problem has been sought by the method according to Finnish patent FI-66965. In the method,, the inner cylinder is loaded with identical tumbler discs, that is to say, having no peripheral notches machined for the locking bar. The key is then inserted in its place and used to turn the tumbler discs to the opening position that corresponds to the key. A groove can then be machined in the pack of turn- bier discs at the position of the locking bar so as to correspond to the shape of the locking bar.

The disclosed method is theoretically functional as such, but is not feasible on the basis of the teachings of the publication. If the tumbler discs in the cylinder are just turned to a specific position by a key, it does not yet allow the machining of a groove for a locking bar. The tolerances of the inner cylin- der, tumbler discs and the key together result in the tumbler discs turned to a correct position not remaining in their place to a sufficient degree during ma- Chining, and they cannot be effectively held -in their place even by rotating the key when machining the groove .

OBJECTIVE OF THE INVENTION

The objective of- the invention is to remedy the above- mentioned defects of the prior art. Specifically, the objective of the invention is to disclose a new assem ^¬ bly device allowing efficient and accurate assembly of locks.

SUMMARY OF THE INVENTION

The disc tumbler lock assembly device according to the invention is designed for machining tumbler discs packed in an inner cylinder so as to correspond to the key for that lock. In other words, the assembly device is designed for machining in the tumbler discs a groove for a locking bar to allow the locking between the inner cylinder and outer cylinder to be released. According to the invention, the assembly device includes a holder having at least one support hole in which an inner cylinder provided with tumbler discs can be positioned. The support hole is tight-fitting with the inner cylinder, yet allowing the inner cylin- der to be turned in the hole. Substantially over the entire length of the support hole there is a machining groove in the direction of the support hole opening to the outer surface of the holder therefrom, thus form- ing for a suitable machining edge an open and free access to the inner cylinder placed in the support hole and to the tumbler discs therein. Further, the assembly device includes a locking cap for locking the inner cylinder in its place in the holder. In connection with the locking cap, i.e. in the locking cap itself or in a part provided in immediate proximity thereto, there is a locking hole that corresponds to the cross- sectional profile of the key as accurately as possible so that the key inserted through the locking cap reli- ably remains in its place in a rotationally stiff manner. In addition, the assembly device includes, at the end of the holder opposite to the locking cap, a turning element for turning the pack of tumbler discs in the inner cylinder relative to the immovable key and a tightening element for tightening the cylinder and the turned tumbler discs tightly in their place. This way, as the tumbler discs, the key and the inner cylinder are pressed tightly together as an unmovable assembly, a groove for a locking bar can be machined on the out- er periphery of the tumbler discs along the machining groove of the holder. The machine tool and the machining edge used may be any suitable means and method known per se, such as different milling cutters or cutting beams.

In one embodiment of the invention, the holder is a cylindrical object and includes a number of support holes which are parallel and symmetrically provided around the central axis of the holder. This way, it is possible to simultaneously mount in the holder a number of inner cylinders and corresponding keys so as to complete a number of locks at the same time. It is to be noted that the locking holes that correspond to the profile of the key in the locking cap need not be similar. Thus, it is possible that the holder includes for instance five support holes and the locking cap has. five corresponding locking holes. All five locking holes may be different and correspond to each one specific cross-sectional profile of a key type. One device can thus be used to assemble five different locks. It is certainly possible that all locking holes are similar, so that a number of locks that belong for example to the same system can be produced at ^" the same time The purpose of the locking cap is firstly to lock the key in its place in a rotationally stiff manner and secondly to press the inner cylinder with tumbler discs in its place in the holder. Since the inner cylinders may have minor differences in tolerances, it is preferred that the locking cap includes a flexible structure around the locking hole for arranging a flexible pressure locking to the inner cylinder provided with tumbler discs in the longitudinal direction thereof. Thus, as compared to a rigid locking cap, each inner cylinder can be provided with a reliable and uniform locking. The flexible structure is suitably provided in the locking cap by openings made around the locking hole so that the locking hole is supported to the locking cap by means of narrow strips only. By selecting suitable widths for the strips, the locking can be provided with the desired flexibility.

In one embodiment of the invention, the turning element includes a turning shaft that extends into the support hole for turning the inner cylinder placed in the support hole accompanied by the tumbler discs against the key locked in its place.

The turning element suitably includes, for each sup- port hole of the holder, a specific turning shaft and a common turning wheel in power transmission communication with each turning shaft for turning all cylinders at the same time. Thus, by turning one turning wheel once in a specific direction, all inner cylin- ders and the tumbler discs therein can be turned to the positions determined by the corresponding keys.

The tightening element suitably includes a threaded shaft provided centrally relative to the holder so as to extend therethrough. This way, the holder and the structures at the ends thereof, including the locking cap, can be rotationally pressed in their place as a tight structure that holds the inner cylinders with tumbler discs in their place.

In a preferred embodiment of the invention, the turning element and the tightening element are arranged to be operated by a common turning wheel and a common shaft. In this case, the shaft can be moved in the longitudinal direction thereof relative to the holder so that, in the longitudinal direction of the shaft, in a first position when the shaft is rotated the turning element operates by turning the inner cylinders to the desired position and in a second position the tightening element operates by tightening the structure so as to be ready for machining. Of course, when operated in the opposite direction, in the second position of the shaft the tightened structure can be opened and then in the first position of the shaft the inner cylinders can be turned to the initial position β where the keys can be drawn out from the key cylinders .

Preferably, guide grooves are provided in connection with the outer periphery of the holder of the assembly device. Correspondingly, the machine tool for machining the tumbler discs has guide bars that correspond to the guide grooves. This way, the assembly device can be supported to the guide bars of the machine tool with precision and pushed along the guide bars so that the edge of the machine tool machines a groove for a locking bar in the tumbler discs through the machining groove of the holder. The guide grooves provided in connection with the holder may reside in the holder itself or in plate-shaped end pieces installed at the ends of the holder or both. It is essential that the entire tight assembly of pieces can be moved precisely as required by the machining operation of the machine tool being used so that the desired accurate groove can be machined in the tumbler discs.

ADVANTAGES PROVIDED BY THE INVENTION

The disc tumbler lock assembly device according to the invention has considerable advantages over the prior art. The new features of the invention and the compact size of the device allow the production of tumbler discs regardless of place. The device allows very accurate and exact machining of grooves in tumbler discs. Furthermore, a number of assembly operations can be made at the same time by one device. The device is also readily- adaptable to any key profile. The holder part used in the device forms a good support for the inner cylinders with tumbler discs, so it can be used as a storage and transportation support for the parts of the lock and as a sales package therefor. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below in detail with reference to the accompanying drawings, in which

Fig. 1 is a schematic sectional view of one device ac- cording to the invention,

Fig. 2 is a more detailed exploded view of one device according to the invention and

Fig. 3 shows the device of Fig. 2 mounted on a machine tool.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a sectional view of one assembly device according to the invention, wherein the central body of the device is formed by a cylindrical holder 4 hav- ing ^' a number of support holes 5 symmetrically around the central axis thereof. The support holes can be provided with inner cylinders 1 of a disc tumbler cylinder lock loaded with similar tumbler discs 2 with no grooves. The inner cylinders can be locked in their place by a locking cap 7 placed thereon. The locking cap has a locking hole 8 aligned with each support hole 5, the shape of the opening accurately corresponding to the cross-sectional profile of the key to be inserted therein.

The other end of the holder 4, i.e. the opposite end relative to the locking cap 7, has a structure that jointly constitutes a turning element 9 and a tightening element 10 of the device. It includes a central turning shaft 14 that extends into the holder 4 and has a turning wheel 13 at the outer end thereof for turning the turning shaft. A central gear 18 is arranged around the turning shaft in power transmission communication with a turning gear 19 provided for each support hole, by the turning of which the corresponding inner cylinder 1 can be turned. In addition, the central gear can be coupled to the turning shaft when a coupling element 20 provided on the turning shaft is transferred to the level of the central gear in the longitudinal direction of the turning shaft. Thus, by drawing the turning wheel 13 outwards in Fig. 1 and by bringing the coupling element 20 to the level of the central gear 18, the turning of the turning wheel 13 will turn the inner cylinders 1 and the tumbler discs 2 therein. Before turning, keys have been inserted through locking holes 8 centrally into the tumbler discs so that they limit the turning of the ^: tumbler discs and define for them specific rotating angles.

Fig. 2 illustrates in more detail one assembly device according to the invention. The holder 4 that constitutes the central body of the device is a cylindrical object. A central hole 21 extends therethrough. The holder has, symmetrically around the hole 21, five support holes 5. The support holes are so dimensioned that they close-fittingly accommodate the inner cylinders 1 ^' of the disc tumbler cylinder lock loaded with tumbler discs. The holder 4 has, at each support hole 5, a machining groove 6 that opens perpendicularly, i.e. in the radial direction, therefrom to the outer cover of the holder and extends over the entire axial length of the holder. Further, midway between each machining groove 6 on the surface of the holder there are. guide grooves 15 in the direction of the machining groove 6.

The inner cylinders 1 can be placed in the support holes of the holder 4 from one end of the holder only, and this end can be closed by a plate-shaped abutment piece 22 and the locking cap 7 positioned thereon. Both of the abutment piece and the locking cap have a machining groove 6 and a guide groove 15 that corre- spond to the shapes of the holder. Further, between the abutment piece 22 and the locking cap 7, suitable adjustment and abutment pieces 23 can be used, by which the pressure between different parts can be bal- anced and increased as required.

The locking cap 7 has, in positions that correspond to the support holes 5 of the holder, five corresponding locking holes 8, of which each can be provided with a key 3 so that it extends into the corresponding inner cylinder 1. The locking hole 8 accurately corresponds in shape to the cross sectional profile of each key being used so that the key is not able to turn in the locking hole but lies in its place therein in a rota- tionally stiff manner. The locking holes 8 that lock the key in a rotationally stiff manner may as well be provided in the adjustment and abutment piece 23 or in the abutment piece 22 or also in a number of them at the same time. Further, around each locking hole 8 of the locking cap 7, there is formed a flexible structure 11, i.e. curved openings that surround the locking hole, so that between them there are only narrow strips supporting the locking holes 8. This way, flexibility is provided around the locking holes of the locking cap 7 to balance the pressure of the locking cap toward the inner cylinders.

The other end of the holder 4 includes a turning element 9 and a tightening element 10 provided as one structure in the following way. A disc—shaped turning wheel 13 is rigidly fitted with a shaft 14 supported to this turning tightener body 24 rotationally and slidingly in the longitudinal direction of the shaft. The outer end of the shaft is threaded. Thus, the shaft 14 inserted through the hole 21 of the holder 4 can be threaded to the corresponding threads of the central holes in the abutment piece 22 and the locking cap 7. Thus, by pressing the holder 4 between the body 24 and the locking cap 7, the inner cylinders 1 can be locked in their place in the support holes 5 of the holder 4.

Before tightening the package together as mentioned above, the same shaft 14 is used to turn the inner cylinders 1 accompanied by the packs of tumbler discs therein to the position of machining the grooves for locking bars as follows. As illustrated in connection with Fig. 1, for each support hole of the holder there is a corresponding turning shaft 12 with the outer end extending to the end of the inner cylinder placed in the support hole 5. Further, the turning shaft has a turning gear 19 that contacts the central gear 18 around the shaft 14. When positioning the shaft in the longitudinal direction thereof in a specific position relative to the. central gear, a coupling element 20 arranged therein is provided to the level of the central gear. In this case, the turning of the turning wheel 13 turns the shaft 14 accompanied by the central gear 18, the turning gear 19, the turning shaft 12 and the inner cylinder 1 in contact thereto with the tum- bier discs. Thus, by turning the turning wheel 13, the tumbler discs can be turned as required by the key 3 inserted and locked in its place therein.

Orice the assembly device according to Fig. 2 has been loaded with inner cylinders 1 and corresponding keys 3 and turned and locked to the position of machining the grooves for locking bars, the whole - device can be transferred to a machine tool 16 according to Fig. 3. The machine tool 16 includes a motor 25, a gearbox 26 and a machining edge 27. Over the machining edge there are two parallel guide bars 17, and centrally there- above there is a third guide bar 28. In the triangle constituted by these three parallel guide bars, i.e. between the guide bars, the assembly device can be inserted, having the guide grooves 15 that correspond in 5 shape to the guide bars 17 and 28 on the outer surface thereof. The guide grooves 15 and guide bars 17 and 28 are dimensioned accurately relative to each other so that the assembly device settles tightly on the guide bars and slides along the guide bars with precision. 0

The assembly device being positioned on the guide bars 17,28, the machining edge 27 is placed so as to extend to the tumbler discs to be machined■ through the machining groove 6 of the holder when the · assembly de- 5 vice is pushed along the guide bars. The tumbler discs can thus be accurately provided with a correctly shaped groove for a locking bar in a correct position. As the assembly device is symmetrical relative to the ■ ^: central axis thereof, it can be installed on the guide0 bars of the machine tool 16 sequentially in all five different positions, and thus all five different inner cylinders with the tumbler discs can be machined one after the other. 5 The depth of the groove to be made in the- tumbler discs can be adjusted by raising or lowering, relative to the machining edge 27, the support structure 29 which supports the guide bars 17 and 28. This way, the distance of the whole assembly device from the machin-0 ing edge can be suitably varied and the groove created in the tumbler discs made suitably deep.

The assembly device illustrated in the drawings can be readily used also for keyless production of tumbler5 discs. In this case, the tumbler discs are positioned in the inner cylinder so that the limiter of the turn- bier disc is arranged in the groove of the inner cylinder 1. The tumbler disc is thus not able to turn relative to the inner cylinder. The turning of the turning wheel 13 turns the shaft 14 accompanied by the central gear 18 and the turning gear 19. With the turning gear 19, the turning shaft 12 is turned as well as the inner cylinder 1 in contact thereto with the pack of tumbler discs therein. For example the turning gear 19 or other suitable part may be provided with a scale, by means of which the desired turning angle can be determined accurately, which allows accurate machining of the groove for a locking bar in the desired position of the pack of tumbler discs to produce the desired tumbler discs.

The invention has been described above by way of examples with reference to the accompanying drawings; however, different embodiments of the invention are possible within the scope defined by the claims.