The invention relates to a cylinder lock intended to be operated by a key. With locks of this type, in particular locks of the wafer tumbler lock type as described for instance in US 2008/0178647 A1 , the object arises to secure the rotor of the lock containing the tumblers against rotation when no key or a non-fitting key is inserted into the lock.

US 2017/0234035 A1 shows to block a rotation of the rotor before all tumblers are moved into their respective unlocked position for a pin tumbler lock by means of a separate transversal locking function. However, the size of the lock is increased by this measure, and construction space at the location of the lock is, as a rule, limited.

It is an object of the invention to provide a versatile and compact cylinder lock in which the rotor is additionally secured against rotation to increase inviolability of the lock. This object is achieved with a cylinder lock comprising the features of claim 1. The cylinder lock, intended to be operated by a key, comprises a rotor mounted rotatably in a housing and a plurality of spring-loaded tumblers arranged movably in the rotor and in the housing, the tumblers being moveable along a locking direction between a locked position in which they prevent a rotation of the rotor and an unlocked position in which they allow the rotation of the rotor. Each tumbler is pretensioned towards its locked position by a spring element arranged alongside the respective tumbler with regard to the locking direction. Each of the spring elements is arranged in a receptacle formed in the rotor. Further, a sidebar is provided on the rotor, the sidebar being arranged for motion between a locked position in which it prevents the rotation of the rotor and an unlocked position in which it allows the rotation of the rotor, the sidebar being arranged along the locking direction of the tumblers beyond a radially inner end of all receptacles of the spring elements. As the sidebar is arranged on the rotor in a position where it does not interfere with the arrangement of the spring elements pretensioning the tumblers, the inventive design may be used with a wide variety of different tumblers.

In particular, the cylinder lock has two receptacles placed on either side of each tumbler alongside the respective tumbler. These receptacles are arranged in the same plane as the respective tumbler, this plane extending perpendicular to a rotational axis of the rotor. The rotational axis of the rotor coincides with a longitudinal direction of the rotor.

Further, the cylinder lock according to the invention can be manufactured with only a small number of parts, thereby reducing material and assembly costs.

The invention can be used in any cylinder lock, but most preferred the cylinder lock is a wafer tumbler lock.

Preferably, the sidebar extends in its locked position partly inside the rotor and partly inside the housing, analogous to the tumblers.

T o improve on the space requirement, an outer surface of the sidebar may have the same curvature or as an outer surface of the rotor adjacent the sidebar.

The sidebar should be pretensioned towards its unlocked position, i.e. in the direction towards the rotor.

It is possible to use a single spring acting on the sidebar, in particular a coil spring, to generate the entire pretensioning force. Advantageously, the spring is accommodated in a close-fitting bore in the housing extending perpendicularly to the locking direction of the tumblers. Due to the location of the sidebar below the radially inner end of the receptacles of the spring elements, the bore does not extend in a radial direction of the rotor, but is offset from the center and, accordingly, from the rotation axis of the rotor.

In a preferred embodiment, a ball is arranged between the sidebar and the spring, the spring acting only on the ball, and, in turn, the ball transferring the pretensioning force to the sidebar. This arrangement allows for an improved force transmission between the linearly acting spring and the curved outer surface of the sidebar, in particular when the outer surface of the sidebar is adapted to the curvature of the outer surface of the rotor. The whole sidebar group may consist only of one single sidebar, one single spring and one single ball.

In a first preferred embodiment, the sidebar is arranged for linear displacement between its locked and its unlocked position. Preferably, the direction of displacement of the sidebar is perpendicular to the locking direction of the tumblers. Also, the direction of displacement of the sidebar can be perpendicular to the rotational axis of the rotor.

In a second preferred embodiment, the sidebar is arranged for rotation between its locked and its unlocked position.

In this case, the rotor may comprise a bearing in which an axle of the sidebar, preferably in form of two end side stub shafts, is mounted, to decrease the construction space needed by the sidebar. It is possible, with the same technical effect, to design the sidebar for a rotational motion or for a pivoting or a swiveling motion about the axle.

In the unlocked position, the sidebar should be completely accommodated in the rotor so that the rotor can rotate without being held back by the housing.

Each of the tumblers preferably comprises an engagement structure that interacts with the sidebar in the unlocked position of the sidebar to allow the sidebar to move into its unlocked position.

For instance, the engagement structure may be a notch on a side face of each of the tumblers that is engaged by the sidebar. As long as the respective tumbler is not in its unlocked position, the sidebar is held in its locked position by the shape of the outer surface of the tumbler adjacent to the notch.

Further details of the invention are described in the following on the basis of two preferred embodiments, with reference to the attached drawings in which:

Figure 1 shows a cylinder lock according to a first embodiment of the invention in an unlocked state in a schematic sectional view;

Figure 2 shows an enlarged detail of Figure 1 ; Figure 3 shows a cylinder lock according to a second embodiment of the invention in a schematic sectional view with the sidebar in its locked position;

Figure 4 shows the cylinder lock of Figure 3 with the sidebar in its unlocked position; and

Figure 5 shows a schematic perspective view of the rotor and the sidebar of the cylinder lock of Figure 3.

Figures 1 and 2 show a cylinder lock 10 according to a first embodiment.

As is known from conventional cylinder locks, in particular wafer tumbler locks, a rotor 12 is arranged in space 13 manufactured in a housing 14 so that it can rotate about a central rotation axis. The rotational axis coincides with a longitudinal direction A of the cylinder lock 10 and of the rotor 12.

The rotor 12 has several slots 16 arranged along its longitudinal direction A that each extend perpendicularly to the longitudinal direction A (indicated in figure 5). Into each of the slots 16, a single tumbler 18 is inserted so that the respective tumbler 18 is movable along a locking direction L. The locking direction L coincides with the radial direction of the rotor 12.

Each of the tumblers 18 can move along the locking direction L in an unlocked position (shown in figure 1 ) and locked position (shown in figure 3). In the locked position, the respective tumbler 18 extends partly in the rotor 12 and partly in the housing 14 so that a rotation of the rotor 12 about its rotational axis is blocked. To this effect, the housing 14 has appropriately sized slots 19 positioned correspondingly to the slots 16 in the rotor 12, to accommodate the part of the tumbler 18 that projects beyond the rotor 12. The slots 19 are part of the space 13.

In the example shown, the tumblers 18 are thin, flat and plate-like elements with a through-hole 20 in their large surfaces through which a key is pushed when the cylinder lock 10 is to be locked and unlocked (not shown).

Alongside each of the tumblers 18 in the cutting plane shown in the figures (corresponding to the plane defined by the respective tumbler 18), a spring element 22 acting on the respective tumbler 18 is arranged in a receptacle 24 formed in the rotor 12. The receptacle 24 can be positioned on either side of the tumbler 18. It is equally possible to provide receptacles 24 on both sides of the tumbler 18 as is shown in the second embodiment (see for instance figure 3).

The receptacles 24 extend along the locking direction L parallel to the diameter of the rotor 12. Each of the receptacles 24 has a radially outer end 26 constituting an opening in an outer surface 28 of the rotor 12. Also, each receptacle 24 has a radially inner end 30 that is closed and lies inside the rotor 12. Usually, all of the receptacles 24 have the same length so that the radially inner ends 30 of the receptacles 24 defines a plane E through the rotor 12 parallel to the longitudinal direction A and perpendicular to the locking direction L. The spring element 22 usually is a coil spring.

The spring element 22 pretensions the tumbler 18 into its locked position so that the cylinder lock 10 is locked when no key is inserted.

By insertion of the correct key through the through-holes 20 in the tumblers 18, each of the tumblers 18 is moved from its locked position into its unlocked position against the pretensioning force of the spring element 22.

As long as one or more of the tumblers 18 are still in their locked position, the rotor 12 is prevented from rotating by the respective tumbler(s) 18 that come(s) into engagement with the edges of their slots 19 in the housing 14.

As a further measure of keeping the rotor 12 from turning before all of the tumblers 18 are correctly moved into their unlocked position by a fitting key, a sidebar 34 is provided on the rotor 12.

The sidebar 34 is a single elongated component that extends along the longitudinal direction A of the rotor 12 along all of the slots 16 accommodating the tumblers 18.

Regarded along the locking direction L, the sidebar 34 is arranged beyond the plane E on the side of the rotor 12 facing away from the radially outer ends 26 of the receptacles 24. Because of this design, the sidebar 34 does not interfere with any of the receptacles 24 on either side of the tumblers 18. Is it to be mentioned that regarded along the locking direction L and with reference to the plane E, the opening of the radially outer end 26 of the receptacle 24 is arranged on the opposite side of the sidebar 34. In the first embodiment, shown in figures 1 and 2, the sidebar 34 is arranged for linear displacement between its locked and its unlocked position.

Perpendicular to the extension of the sidebar 34, a bore 36 is provided in the housing 14, extending parallel to the plane E and perpendicular to the longitudinal direction A. A spring 38 is positioned inside the bore 36, pretensioning the sidebar 34 towards the rotor 12 and its unlocked position.

Between the sidebar 34 and the spring 38, a ball 40 is arranged, the spring 38 acting on the ball 40 and the ball 40, in turn, acting on an outer surface 42 of the sidebar 34.

In this example, the outer surface 42 of the sidebar 34 is adapted in its curvature to the curvature of the adjacent part of the outer surface 28 of the rotor 12, i.e. forming a part of the circular circumference of the rotor 12 (see Figs. 1 and 2).

Each of the tumblers 18 is provided with an engagement structure 44, with which the sidebar 34 can interact in its unlocked position. In this example, the engagement structure 44 is realized by a notch 46 in a side face of each of the tumblers 18 facing the sidebar 34. The sidebar is provided with a nose 48 having a shape corresponding to the notch 46. The nose 48 is arranged on an outer surface of the sidebar 34 that faces the tumblers 18.

As long as at least one of the tumblers 18 is in its locked position, the nose 48 of the sidebar 34 lies against the flat side 50 of this tumbler 18 adjacent to the notch 46. Consequently, the sidebar 34 is hindered from moving into its unlocked position. As in this position a part of the sidebar 34 still extends into the bore 36 in the housing 14, the rotor 12 cannot rotate.

Only when all of the tumblers 18 are in their unlocked position is the spring 38 able to push the sidebar 34 all the way into its unlocked position where the nose 48 engages the notches 46 of all of the tumblers 18. In this unlocked position, the sidebar 34 is accommodated entirely inside the rotor 12, its outer surface 42 forming part of the outer surface 28 of the rotor 12, allowing the rotor 12 to turn about its rotation axis A. This situation is shown in figures 1 and 2.

The notch 46 has chamfered edges 52, corresponding to chamfered edges 54 of the nose 48 of the sidebar 34. When the cylinder lock 10 is to be locked, the rotor 12 is turned back by the key and the key is removed. The tumblers 18 are moved back into their locked position by the spring elements 22. Due to the interaction of the chamfered edges 52, 54 of the notch 46 and the nose 48, the sidebar 34 is pushed back into its locked position and slides out of the notches 46 so that it lies again against the flat side 50, keeping the sidebar 34 in its locked position against the pretensioning force of the spring 38.

In this example, the bore 36 extends through the housing 14 all the way to an outer surface of the housing 14. This allows an easy mounting of the sidebar 34. First, the sidebar 34 is positioned in the rotor 12. Then the ball 40 and the spring 38 are fitted into the bore 36, and the spring 38 is compressed. Finally, the edges of the opening of the bore 36 in the outer surface of the housing 14 are permanently deformed radially inwards, for example by crimping, to secure the spring 38 inside the housing 14 (not shown).

Figure 3 to 5 show a second embodiment of the cylinder lock 100. Components that are identical to those of the first embodiment or are only slightly altered keep their already introduced reference numbers to increase legibility.

The only difference between the cylinder lock 100 of the second embodiment and that of the first embodiment is the design of the sidebar 134.

In this example, the sidebar 134 is configured for rotational motion from its locked position into its unlocked position and back.

To this effect, the sidebar 134 has at its longitudinal ends stub shafts 160, 162 by which an axle of the sidebar 134 is accommodated in bearings 164, 166 manufactured in the rotor 1 12.

As figures 3 and 4 show, an engagement structure 144 is provided on the tumblers 18. In this example, the engagement structure 144 comprises a notch 146 in each of the tumblers 18, analogous to the engagement structure of the first embodiment. Also, a correspondingly shaped nose 148 extending along the sidebar 134 is provided.

As in the first embodiment, in its locked position, the sidebar 134 extends partly in the rotor 1 12 and partly in the housing 1 14 so that the rotor 1 12 cannot rotate. In its unlocked position, the sidebar 134 is completely accommodated inside the rotor 1 12, and the rotor 1 12 is free to turn about the rotation axis A.

In the housing 1 14 a shoulder 168 is provided that is manufactured at the opening of the bore 36 into the space 13 inside the rotor 1 12. The sidebar 134 has a protrusion 170 that in the locked position engages the shoulder 168. The shoulder 168 is oriented such that the rotor 1 12 is hindered from rotating in opening direction of the cylinder lock 100.

The pretensioning force acting on the sidebar 134 towards its unlocked position can be provided as shown in first embodiment by a combination of a spring and a ball arranged in the bore 36 of the housing 1 14. In this case, the ball 40 acts on the sidebar 134 slightly off-axis so that the ball 40 applies a rotational force to the sidebar 134 (not shown).

The operation principle of the cylinder lock 100 is the same as described for the first embodiment. As long as even one of the tumblers 18 is not in its unlocked position, the sidebar 134 cannot engage the engagement structure 144 on all of the tumblers 18 and the sidebar 134 is held back in its locked position. Only when all tumblers 18 are in their unlocked position is the nose 148 on the sidebar 134 pushed into engagement with all of the notches 146 by the pretensioning force generated by the spring 38 and the ball 40. Only then, the sidebar 134 is able to rotate into its unlocked position.

When the cylinder lock 100 is to be locked again and the key removed from the tumblers 18, the tumblers 18 are moved back into their locked position by the force of the spring elements 22. Due to the chamfered sides of the notches 146, the nose 148 of the sidebar 134 is pushed out of the notches 146, and the sidebar 134 is turned back into its locked position, again preventing a rotation of the rotor 1 12.

An embodiment in which two or more tumblers 18 are inserted into each slot 16 is also possible and compatible with a sidebar 34, 134 as described above.