Cylinder lock

Abstract: Lock cylinder for fastening in a lock, which lock cylinder can be released only by means of an associated key and an auxiliary tool which controls an arresting member into a release position. The arresting member (33) can be displaced by turning the cylinder core (24) into its locking position and is blocked in the key removal position by the cylinder core (24) against return displacement into the release position. Assembly and disassembly thus require the use of the correct key.

Description: The invention relates to a cylinder lock. A cylinder lock is known from DE-PS 597 570, in which two pegs extending parallel to the longitudinal axis of the lock cylinder project from one lock cylinder and, while passing through corresponding holes in lock case base and lock case cover of a mortise lock, engage in aligned holes in the opposing lock cylinder. One of the two pegs is provided with a recess into which a spring-loaded arresting member springs when the lock cylinders are assembled. The arresting member is arranged in the housing of the lock cylinder which housing has an inclined channel, the orifice of which terminates at the end face of the cylinder core. The orifice extends in an arrangement which is offset in the angle of rotation to the longitudinal plane of the key channel. It is therefore necessary, in order to release this fastening, to displace the cylinder core by means of the associated key by a certain angle of rotation so that the channel orifice is aligned with the key channel. The locking member can then be disengaged by means of a pin-shaped auxiliary tool which penetrates both the lock slot in the edge region and the inclined channel. Such a design is complicated in construction. Furthermore, disassembly necessitates a rotational angle position which is to be maintained accurately so that the auxiliary tool can be inserted into the channel. A relatively large space for installation is therefore required, so that such designs are found only with round cylinders. Finally, it should also be mentioned that the lock cylinder fastening can be implemented without using the associated key. A lock cylinder which can be released from the lock by contemporaneous use of a key and an auxiliary tool is also known from GB-A- 384 524. It is an object of the invention to design a lock cylinder of this type which is simple to produce and in which assembly and disassembly of the lock cylinder require the use of the associated key and the security against break-ins is increased. The invention provides a lock cylinder for fastening in a lock, which lock cylinder can be released from the lock only by contemperaneous use of an associated key and an auxiliary tool which controls an arresting member into a release position, the arresting member being moveable between an arresting position and at least one release position after rotation of the cylinder core from the key removal position, characterised in that the arresting member is non-spring loaded in the direction of displacement and is blocked in the key removal position by the cylinder core alone against return displacement into the release position. As a result of such a design, an improved lock cylinder is provided. Installation, which can be effected simply and easily, requires the key belonging to the lock cylinder. The cylinder core has to be turned with the key so that the locking member enters its release position. In this position, it is possible to insert the lock cylinder, for example, into a bushing. After the lock cylinder has been inserted and rotated, the locking member enters the locking position due to rotation of the cylinder core. This is also the key removal position in which the cylinder core blocks the arresting member against return displacement into the release position. Even if the auxialliary tool should be introduced in this position, it is not possible to displace the arresting member with it. Disassembly of the lock cylinder therefore requires the use of the associated key in order to rotate the cylinder core. The arresting member can then be moved back by means of the auxilliary tool, into the release position which is not now protected. The lock cylinder can subsequently be disassembled. The components required can be physically small in design and can be produced economically. They can be used in oval cylinders without adversely affecting the tumblers. As assembly of the lock cylinder requires the use of the corresponding key, the lock cylinder cannot be inserted in an unauthorised or unintentional manner. This results in increased security against break-ins. Although the arresting member is accessible to a certain extent, it is particularly effectively protected against return displacement into the release position. Release of the lock cylinder also requires the predetermined handling sequence. The cylinder core should initially be rotated by means of the corresponding key. The arresting member can then be displaced into the release position by means of the auxiliary tool. Reverse handling is unsuccessful. The arresting member is displace from its release position into the arresting position by means of a corresponding control flank of the cylinder core. If two control flanks arranged in the form of a roof are provided on the cylinder core, the lock cylinder can be installed or removed in two rotational positions of the cylinder core. In the prior art, there is only a single rotational position of the cylinder core during removal of the lock cylinder. The above-mentioned compact design is substantially due to the fact that the arresting member is designed as a slider which can be displaced on the rear face of the lock cylinder housing transversely to the axis of the cylinder core and catches in the locking position. As a result, the arresting member is prevented from unintentionally entering the release position but rather remains in the locking position during the closing turn after the lock cylinder has been installed. Even vigorous knocks are incapable of bringing the arresting member out of its locking position. In this engaged locking position, the arresting member slider engages behind a step of the pin projecting into the lock cylinder housing. As this pin is a rigid component of a lock housing, even relatively great extraction forces are unable to bring the lock cylinder out of its inserted position. Disassembly requires the insertion of the auxiliary tool into the inlet opening of the lock cylinder housing extending adjacent to the cylinder core. If the lock cylinder housing has an oval shape, the auxiliary tool inlet opening is preferably located on the curvature of the lock cylinder housing remote from the cylinder core. As a result, the inlet opening is designed as a free space in the housing of the lock cylinder, on the external wall side, and intersects an arresting member control nose equipped with a ramp. However, this arresting member control nose falls obliquely in the direction of the key-insertion end of the lock cylinder housing. The auxiliary tool inserted through the inlet opening therefore reaches the arresting member control nose in a reliable manner. However, displacement of the arresting member demands rotation of the cylinder core so that the arresting member can be brought via its control nose into the release position. In the process, the arresting member releases the pin. The outer end of the control nose also extends inside the inlet opening and therefore does not prevent the removal displacement of the lock cylinder. The arresting member control nose also fulfils a double function: on the one hand it serves for the return displacement of the arresting member by means of the auxiliary tool. On the other hand, the control nose represents an additional limit which complicates any attempt to remove the lock cylinder and consequently also contributes to the security against break-in of the lock cylinder. An embodiment of the invention will now be described with reference to two locks of different designs, with reference to the accompanying drawings of which Figure 1 is a side elevation of a cental lock with lock cylinder inserted; Figure 2 is a front view of Figure 1; Figure 3 is an elevation of the associated key; Figure 4 is an elevation of the auxiliary tool constructed in the form of a key; Figure 5 is an enlarged view of the shank of the auxiliary tool; Figure 6 is a section along line VI-VI in Figure 5; Figure 7 shows the central lock without inserted lock cylinder (roughly doubled in size); Figure 8 is a front elevation of Figure 7; Figure 9 shows, partially in elevation and partially in a longitudinal section, the associated lock cylinder in the key removal position; Figure 10 is a front elevation of Figure 9; Figure 11 is a section along line XI-XI in Figure 9; Figure 12 is a view corresponding to Figure 7, but during insertion of the lock cylinder; Figure 13 is a section along line XIII-XIII in Figure 12; Figure 14 is a section along line XIV-XIV in Figure 12; Figure 15 is a longitudinal section corresponding to Figure 12, but in the lock removal position; Figure 16 is a section along line XVI-XVI in Figure 15; Figure 17 is a view corresponding to Figure 12, but with the auxiliary tool inserted and the arresting member brought out of action for disassembly of the lock cylinder; Figure 18 is a section along line XVIII-XVIII in Figure 16, Figure 19 is a perspective view of the arresting member; Figure 20 is an espagnolette receiving the lock cylinder, partially in elevation and partially in longitudinal section, but with the lock cylinder not inserted; Figure 21 is a rotated view of Figure 20; and Figure 22 shows, partially in elevation and partially in longitudinal section, an enlarged view of the espagnolette with the lock cylinder inserted. According to Figures 1 to 19, a lock cylinder 1 is or will be allocated to a central lock 2. Such locks are used, in particular, in office furniture, for example in desks. The central lock 2 has a tubular lock housing 3 which is oval in outline and projects integrally from a fastening plate 4 of the same material. This elongated fastening plate 4 has, in its edge region, holes 5 for the passage of fastening screws (not shown) which connect the central lock 2 to the corresponding piece of furniture. A coupling peg 7 is rotatably mounted in the tube base 6 projecting from the fastening plate 4. The coupling peg 7 is provided with a larger diameter head 8 forming an eccentrically located coupling slot 9. The end of the coupling peg 7 carries a transverse peg 10 penetrating an arc-shaped slot 11 of a lock member 12 which is rotatable, to a limited extent, on the coupling peg 7. A bearing collar 13 which projects beyond the tube base 6 and is formed integrally therewith forms two stop shoulders 14 which are arranged with rotational angle spacing and co-operate with an axially directed stop 15 of the lock member 12. This enables the lock member 12 equipped with a locking peg 16 to be rotatable through 180° relative to the bearing collar 13. Furthermore, the peg/slot engagement 10, 11 allows the coupling peg 7 also to rotate through 180° relative to the lock member 12. The coupling peg 7 is mounted concentrically to the curve of the oval lock housing 3 on the narrow edge side. From the tube base 6 located on the remote side of the coupling peg 7, a pin 17 projects, which is arranged parallel to the longitudinal direction of the tubular lock housing 3 and has, in its region facing the coupling peg 7, a transverse recess 18 which forms a step 18′ extending at right angles to the longitudinal direction of the lock housing 3. The pin 17 is located firmly in the tube base 6 and is able to absorb harmlessly relatively large axial forces. The arc region adjacent to the pin 17 of the tubular lock housing 3 has at its crest line a transverse recess 19 adjacent to the tube base 6. The lock cylinder 1 has an outline which is adapted to the shaping of the tubular lock housing 3. The lock cylinder housing S therefore also has an oval outline which is characterised in that two arc regions 20, 21 extending over 180° are joined together by portions 22, 23 extending rectilinearly and in parallel. The centre of the arc region 20 is aligned with the axis passing through the cylinder core 24. In the cylinder core 24 a key channel 25 runs which extends in the longitudinal direction and one narrow side of which is open toward the external wall side of the cylinder core. The shank 26 of a key 27 designed as a flat key can be inserted into the key channel 25. The handle 28 thereof lies in a plane with the key shank 26. On the narrow edge remote from the back 26′, the key shank 26 is equipped with notch-like lock indentations 29 which serve to locate pin tumblers (not shown). The pin tumblers comprise, in known manner, core pins and housing pins. The housing pins are loaded by pin springs. The pin tumblers are located by the inserted key 27 such that the separating lines between the core pins and housing pins lies at the level of the turning joint of the cylinder core such that the cylinder core can be turned by means of the key 27. As shown in Figure 3, the key handle 8 projects further over the key shank 26 in the direction of the lock indentations 29. The cylinder core which can be rotated in a core bore 30 of the lock cylinder housing S projects beyond the rear face 31 of the lock cylinder housing S and is equipped with a web-like coupling projection 32 there. This is offset from the longitudinal axis of the cylinder core. The corresponding offset corresponds to that of the coupling slot 9 of the coupling peg 7 so that when the two are in alignment, the lock cylinder 1 can be inserted into the tubular lock housing 3. An arresting member 33 is located on the rear face 31 of the lock cylinder housing S. It is designed as a slider which can be displaced transversely to the axis of the cylinder core 24. Its outline corresponds to that of the lock cylinder housing S. A slot 35 which is open at the edge is worked from one arc-shaped edge region 34 and allows the arresting member 33 to be placed onto a portion 24′ of the cylinder core 24 the cross section of which is reduced by an annular groove. From the rear face 31 of the lock cylinder housing S, a longitudinal groove 31′ projects which opens into the cylinder core bore 30 and extends to the crest of the arc region 21. A mating web 36 of the slider-like arresting member 33 engages in the longitudinal groove 31′ the free end of which arresting member serves as arresting member control nose 37 and is equipped with a ramp 38. This ramp extends obliquely down in the direction of the rear face of the longitudinal groove 31′ of the lock cylinder housing S. The ramp 38 has an inclination of about 30°. The edge 39 of the arresting member control nose 37 is rounded according to the arc region 21 of the lock cylinder housing S. The edge 39, as well as the edge region 34, can be brought into alignment with the edge regions 20, 21 of the lock cylinder housing S if the arresting member 33 is suitably displaced. The edge region 40 adjacent to the edge 39 is also rounded and is adapted to the arc 21. However, the edge region 40 is arranged at a smaller distance from the edge region 34 so that the slider-like arresting member 33 can be displaced in the transverse direction to the cylinder core 24, the edge regions 34, 40 invariably remaining within the cuter contour of the lock cylinder housing S apart from the arresting member control nose 37. The web 36 extending to the cylinder core bore 30 co-operates with two control flanks 41 of the cylinder core 24 arranged in the manner of a roof. The control flanks 41 enclose an angle of about 90°. The roof-like ridge 41′ extends substantially in the turning joint of the cylinder core and lies in the longitudinal centre plane of the key channel 24. This means that, in the key removal position, the roof-like ridge 41′ strikes the web 36 of the arresting member 33 and holds the arresting member in a position in which its control nose 37 projects beyond the arc region 21 of the lock cylinder housing S, cf. Figures 9 to 11. A blind bore 42 is worked from the rear face 31 of the lock cylinder housing S. It extends to the side of the longitudinal groove 31′ and is arranged so that it can receive the pin 17 of the lock housing 3. A blind bore 43 is also located on the other side of the longitudinal groove 31′ in opposition to the blind bore 42. The blind bore 43 is used for arranging a compression spring 41 and a catching pin 45, the rounded head 45′ of which catches in the key removal position of the cylinder core 24, that is in the locking position, with the arresting member 33. For this purpose, the arresting member 33 forms a trough-like groove 46 at the level of the catching pin 45 such that an indentation 47 projects from the trough base. It is designed as a continuous hole and receives the rounded head 45′ in a catching manner in the locking position, cf. in particular Figure 18. The lock cylinder housing S is also equipped in its arc region 21 with an auxiliary tool inlet opening 48. This is an arc-shaped edge recess which extends over the length of the lock cylinder housing S. The arc region is about 90°. This inlet opening 48 can receive the mating shank 49 of an auxiliary tool 50. The auxiliary tool 50 is key-shaped and has a handle 51 attached to the shank 49. When viewed in a transverse direction, the shank 49 extends in the form of an arc and runs over an arc region adapted to that of the auxiliary tool inlet opening 48. If the lock cylinder 1 is to be inserted into the tubular lock housing 3 of the central lock 2, the associated key 27 should be inserted into the key channel 25 of the cylinder core 24 and the cylinder core 24 should be rotated through about 45° into the position according to Figures 12 and 13. The roof-like ridge 41′ of the control flanks 41 which are arranged in the form of a roof consequently removes itself from its position supporting the locking member 33. After suitable rotation, the arresting member 33 can therefore be brought out of its catch so that the web 37 is placed onto one of the two control flanks 41. In the process, the edge 39 of the arresting member control nose 37 extends in alignment with the arc region 21 of the lock cylinder housing S. An arresting flank 53 formed by a corner recess 52 of the arresting member 33 also leaves the peripheral region of the blind bore 42. When the coupling slot 9 and coupling projection 32 are aligned, the lock cylinder 1 can be inserted completely into the lock housing 3, as illustrated in Figures 12 to 14. If the key 27 is then rotated back into the key removal position according to Figure 15, the arresting member 33 is displaced via the corresponding control flank 41, its arresting flank 53 projecting into the pin recess 18 and therefore extending before its step 18′. In the process, the arresting member control nose 37 has entered the transverse recess 19 of the lock housing 3. In this locking position, the catching pin 45 engages with the arresting member 33 and prevents unintentional displacement thereof during the normal locking process. Suitable furniture can therefore be equipped with the central locks. The lock cylinder 1 is then installed, for example, on delivery. Different lock systems can be provided on the lock cylinders themselves. Plate tumblers could also be used instead of pin tumblers. Although the auxiliary tool inlet opening 48 allows access to the arresting member control nose 37 after insertion of the lock cylinder 1, the arresting member 33 cannot be shifted back as it rests with its web 36 on the roof-like ridge 41′ of the cylinder core 24. Disassembly of the lock cylinder 1 therefore requires the associated key 27. After insertion thereof into the key channel 25 of the cylinder core 24, the cylinder core 24 should be rotated through about 45°. The arresting member 33 does not yet enter the release position. This can only be effected by means of the auxiliary tool 50, the shank 49 of which strikes the ramp 38 of the arresting member control nose 37 while passing through the auxiliary tool inlet opening 48 and therefore displaces the arresting member 33 from its catching position into the release position according to Figure 17. In this release position of the arresting member 33, the arresting flank 53 disengages from the pin 17. The outline of the arresting member 33 also lies inside that of the lock cylinder housing S so that the lock cylinder 1 can be removed from the lock housing 3 of the central lock 2 by means of the key 27 or its handle 28. The sequence necessarily has to be observed during disassembly of the lock cylinder 1. If, for example, the auxiliary tool 50 is inserted first of all, the key 27 cannot be introduced as the handle 51 of the auxiliary tool 50 obstructs the insertion path of the handle 28 of the key 27. The lock cylinder 1 can also be allocated to an espagnolette 54 without any modification, as can be seen from Figures 20 to 22. The lock cover 56 closing a lock case 55 is equipped with a bearing bush 57 which supports a tubular lock housing 58. In contrast to the first embodiment, this lock has a circular configuration. Only the receiving opening 59 corresponds to the outline of the lock cylinder housing S of the lock cylinder 1. The lock housing 58 is equipped with a radially directed projection 60. This enables the lock housing 58 to be allocated a turning knob by means of which the bar 61 of the espagnolette 54 can be moved to and fro over the lock housing 58 at the same time as a rotation of a corresponding turning rod which passes through the espagnolette 54 but is not illustrated. In this version, the lock housing 58 also carries a pin 17 with recess 18. Furthermore, a coupling peg 7 with coupling slot 9 is mounted in the lock housing 58. With this design, it is possible to allocate the lock cylinder 1 to the lock housing 58 of the espagnolette 54 in the manner described above such that, after removal of the key 27, the locking position shown in Figure 22 is achieved, in which the arresting member 33 is displaced from the roof-like ridge 41′ such that the arresting member control nose 37 dips into a transverse recess 61 in the lock housing 58. As the arresting member 33 with its arresting flank 53 engages in the recess 18 at the same time, it is not possible to remove the lock cylinder 1 unless the prescribed measures are taken. Different furniture can therefore be equipped with corresponding lock cylinders at a later stage.

Claims: Lock cylinder for fastening in a lock, which lock cylinder (1) can be released from the lock only by contemporaneous use of an associated key and an auxiliary tool which controls an arresting member (33) into a release position, the arresting member (33) being moveable between an arresting position and at least one release position after rotation of the cylinder core (24) from the key removable position, characterised in that the arresting member (33) is non-spring loaded in the direction of displacement and is blocked in the key removal position by the cylinder core (24) alone against return displacement into the release position. Lock cylinder according to Claim 1, characterised in that the cylinder core (24) has a control flank (41) for displacing the arresting member (33) into the locking position. Lock cylinder according to Claim 1 or Claim 2, characterised in that it comprises two control flanks (41) which are arranged in the form of a roof. Lock cylinder according to any of Claims 1 to 3, characterised in that the arresting member (33) is designed as a slider which can be displaced transversely to the axis of the cylinder core (24) on the rear face (31) of the lock cylinder housing (S) and catches in the locking position. Lock cylinder according to any of Claims 1 to 4, characterised in that the arresting member slider (33) locks on a step (18') of a pin (17) projecting into the lock cylinder housing (S). Lock cylinder according to any of Claims 1 to 5, characterised in that an auxiliary tool inlet opening (48) of the lock cylinder housing (S) is provided adjacent to the cylinder core (24). Lock cylinder according to any of Claims 1 to 6, characterised in that the inlet opening (48) is designed as a free space of the lock cylinder housing (S) on the external wall side and intersects an arresting member control nose (37) equipped with a ramp (38).

Inventors: HAUSER HERBERT PHILIPP, RADDATZ MANFRED, HAUSER, HERBERT PHILIPP, RADDATZ, MANFRED
Applicants: DOM SICHERHEITSTECHNIK, DOM-SICHERHEITSTECHNIK GMBH & CO. KG
Application year: 1991
Main classification: E05B9
IPC codes: E05B9