AU699150B2 - Lock cylinder for a safety lock - Google Patents

Description

I -rm 1 ;-i-i--~irr~rrri~ WO 97/07309 PCT/CH96/00272 Lock cylinder for a safety lock The invention relates to a lock cylinder for a safety lock, with a cylinder housing and with at least one cylinder plug which is rotatably mounted in a continuous housing orifice and which is inserted into the housing orifice from the rear side of the latter, the said plug having a thickening at its rear end, with tumblers which are arranged in order by means of an insertable key capable of being introduced into a keyway, and with guide means for coupling the cylinder plug to a driver, the said guide means being arranged on the rear side of the cylinder plug.

A lock cylinder of this type is known in the prior art from CH-A-674,542. In this, the door-outside cylinder plug has a thickening on its rear side, thus making it appreciably more difficult to pull out the cylinder plug. In such an attempt to pull it out, a self-tapping steel screw is screwed into the dooroutside cylinder plug and very high tensile forces are exerted on the cylinder plug by means of a pulling-off device attached to this screw.

The inventor made it his object to provide a lock cylinder of the type mentioned, the tensile strength of which can be determined individually and can therefore conform to different safety requirements.

The lock cylinder is also intended, in particular, to satisfy more stringent safety requirements as regards tensile strength.

In a generic lock cylinder, the object is achieved in that an extension is arranged on the rear side of the thickening, the said extension having the guide means. In a lock cylinder according to the invention, the coupling part is guided essentially in the extension on the rear side of the thickening. The ,uide slots for the coupling can therefore be worked into this extension. This avoids the guide slot weakening the thickening of the cylinder plug, as has been the case hitherto. The cylinder plug can thus be w* Th WO 97/07309 -2 PCT/CH96/00272 made substantially more robust, and consequently just as high tensile safety as hitherto can be achieved with a shorter thickening. It is essential, moreover, that the extension can have a smaller diameter than the thickening. This makes it possible for the driver, into which the extension engages, to be capable of being designed with a substantially more stable wall.

According to a development of the invention, the thickening is embedded into the cylinder housing and/or into a lengthening piece of the cylinder housing. Due to this measure, the thickening can be made not only substantially more robust, but at the same time also longer, thereby even further increasing safety against the door-outside cylinder plug being pulled off. The range for individual adaptation to different safety requirements is consequently additionally made wider.

Since, in the lock cylinder according to the invention, the door-outside cylinder plug is anchored in the cylinder housing extremely safely as regards being pulled out, correspondingly very high forces for breaking the lock cylinder can be exerted in the region of the four-end screw bore by means of a pulling-off device. In order to prevent such a break, according to a development of the invention a connecting web is provided, which is thickened in the region of the fourend screw bore, this thickening being made wider than a recess for the passage of the driver. The thickening of the web may advantageously be produced by means of an attached tubular piece. Further advantageous features are the subject of dependent patent claims.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings in which: Figure 1 shows diagrammatically a partially cutaway cylinder according to the invention, Figure 2 shows a part section through the lock cylinder according to Figure 1, I I rl-*90% ~RT WO 97/07309 3 PCT/CH96/00272 1W: Figure 2a shows a section along the line IIa- IIa of Figure 2, Figure 3 shows a view of the lock cylinder according to Figure 1, Figure 4 shows a view of the rear side of a cylinder half, Figure 5 shows diagrammatically a partially cutaway part view of a lock cylinder according to a variant, Figures 6 and 7 show diagrammatically an illustration of the method of pulling or breaking the plug, Figure 8 shows a view of a connecting web, Figure 9 shows a section through the connecting web along the line IX-IX of Figure 8, and Figure 10 shows a further view of the connecting web.

The lock cylinder 1 shown in Figures 1 to 4 is a so-called double lock cylinder and has two housing parts 2 and 3 which are fixedly connected to one another by means of a separately produced connecting web 20. The housing parts 2 and 3 each possess a continuous cylindrical housing orifice 11, in which a cylinder plug 4 is mounted in each case. At least one door-outside cylinder plug 4 is inserted into the housing orifice 11 from the rear side of the housing part 2 and possesses a flange-like thickening 13 which engages, at least in regions, into a corresponding widening 12 of the orifice 11. The thickening 13 is provided particularly in the case of the door-outside cylinder plug 4, since this is particularly exposed to an attempt to break in by force. The other cylinder plug can be designed conventionally and be inserted correspondingly from the front into the corresponding housing orifice 1.

An extension 14, in which a guide slot 25 is worked, is integrally formed on the rear side of the thickening 13. A coupling part 24 known per se is guided in this slot 25 so as to be longitudinally *r rici

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9- -LI L-L LIP I~Fti-~- t WO 97/07309 4 PCT/CH96/00272 displaceable. This coupling part 24 serves in a way known per se for coupling the cylinder plugs to a driver 15, on which a cam 16 is integrally formed for actuating a lock bolt. This driver 15 is provided with S a recess 26, into which the extension 14 engages.

To actuate the lock cylinder 1, an insertable key, not shown here, is inserted into a keyway 5 and the coupling part 24 is displaced to the right out of the position shown in Figure 2, after which the cylinder plug 4 is coupled to the driver 15. The tumblers, not shown here, are arranged in order by means of the insertable key, so that the cylinder plug 4 and consequently the driver 5 can be rotated.

iii To guide the cylinder plug 4 in the housing part 2, the said plug has, on its end face, two blind bores 7 arranged at a distance from one another and a radial slot 8. Inserted into the slot 8 is a crescentshaped catch 9 which is held by hardened steel pins 6, inserted into the bores 7, in a position in which the said catch engages into a peripheral groove 10 in the inner face of the housing orifice 11. The catch 9 is guided in the groove 10 so as to be slidably displaceable and, when the cylinder plug 4 is rotated, is displaced in this groove 10 in the circumferential direction. The catch 9, together with the thickening 13, secures the exact axial positioning of the cylinder plug 4 in the orifice 11. When the cylinder plug 4 is mounted in the housing part 2, the catch 9 is sunk completely in the slot 8 and therefore does not project on the outside of the cylinder plug 4. When the steel pins 6 are inserted into the bores 7, the catch 9 is displaced outwards and, finally, engages into the groove 10, as indicated in Figure 3. The steel pins 6 fix the catch 9 and at the same time constitute protection against drilling open. The catch 9 is preferably likewise produced from hard material and Sconstitutes further protection against drilling open the cylinder plug 4.

WO 97/07309 5 PCT/CH96/00272 The two housing parts 2 and 3 are fixedly connected to one another by means of the connecting web shown in more detail in Figures 8, 9 and 10. To receive the web 20, the housing parts 2 and 3 each have a recess 21, into which an arm 31 engages in each case.

Worked into each of the arms 31 is a transverse bore 32, into which is inserted in each case a pin 22 which engages into a bore 35 of the housing part 2 or 3 and connects the web 20 fixedly to the housing parts 2 and 3. The web 20 possesses centrally a thickening 33 which is preferably formed by an attached tubular piece.

Worked in from above on this thickening 33 is a recess which, when the lock cylinder 1 is actuated, allows the driver cam 16 to pass through. The thickening 33 is substantially wider than the recess 30. The thickening 33 is therefore comparatively wide and engages at each of the two ends into a step 23 of a cylinder pocket 19.

Peripheral shoulders 36 of the thickening 33 bear in each case against an inner face of the housing part 2 or 3. The thickening 33 is preferably produced by means of a tubular piece which is pushed onto the arms 31 and fixed by means of crosspins 37. This tubular piece stabilizes the arms 31, particularly in the region of the four-end screw bore 29, and effectively prevents the web from breaking as a result of material fatigue in the event of an attempt to bend it in the region of the four-end screw bore 29. The lock cylinder 1 according to the invention ensures that the cylinder plug 4 cannot be pulled out, even with high tensile forces, and, moreover, it is scarcely possible to break it in the region of the four-end screw bore 29. Figure 6 illustrates diagrammatically an attempt to pull the plug out by means of a steel screw 27. This steel screw 27 is screwed into the cylinder plug 4, and a very high tensile force is exerted on the cylinder plug 4 in the direction of the arrow 20 by means of a pulling-off device not shown here. The cylinder plug 4 is prevented from being pulled out of the housing part 2 particularly by means of the thickening 13 which bears WO 97/07309 -6- PCT/CH96/00272 with a shoulder 17 against the rear side of the housing part 2. Figure 7 illustrates a break in the region of the four-end screw bore 29 as a result of such an attempt to pull the plug out. In such an attempt, bending forces are exerted on the web 20, with the aim of achieving a fatigue fracture. In the lock cylinder according to the invention, the web is stabilized by the thickening 33 which engages round and, in particular, bending forces are absorbed by the thickening 33.

Figure 5 shows a variant of the lock cylinder 1 according to the invention. In this, a lengthening piece 34 is attached to the rear side of the housing part 2 which has a cylindrical passage 38, into which the cylinder plug 4 engages with its thickening 13. The lengthening piece 34 lengthens the housing part 2 in a way known per se. A version with a plurality of lengthening pieces 34 which are placed against one another is also conceivable. Finally, the thickening 13 may at the same time engage into a corresponding widening of the housing part 2. In this version too, an extension 14, into which a guide slot 25 for the coupling part 24 is worked, is integrally formed on the rear side of the thickening 13. Here too, the slot thus constitutes a guide means for the coupling part 24.

Despite the considerable advantages of the lock cylinder according to the invention, it is clear that it can be produced with relatively few simple and robust components, so as to provide, according to the invention, a lock cylinder which not only pre-eminently takes into account safety requirements, including simple assembly, but, on account of its simple and robust practicability, is beneficial in terms of cost and, operationally, extremely reliable.

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Claims (11)

1. Double lock cylinder for a safety lock, with a door-outside cylinder housing and with at least one cylinder plug which is rotatably mounted in a continuous housing orifice of this cylinder housing and which is inserted into the housing orifice from the rear side, the said plug having a thickening integrally formed at its rear end, with tumblers which are arranged in order by means of an insertable key capable of being introduced into a keyway, and with an extension integrally formed on the rear side of the cylinder plug and having guide means for coupling the cylinder plug to a driver, characterised in that, on the rear side of the thickening, a guide slot extending in the longitudinal direction of the cylinder plug is worked as a guide means into the extension, and the extension has a smaller outside diameter than the thickening, and in that the thickening engages into a corresponding widening of a housing part.

2. Lock cylinder according to claim 1, characterised in that the thickening engages into a passage of a housing lengthening piece.

3. Lock cylinder according to one of claims 1 to 2, characterised in that the extension S engages into a corresponding recess of a driver. 20

4. Lock cylinder according to one of claims 1 to 3, characterised in that the cylinder plug has, at its front end, a radial slot, in which is inserted a catch which is in engagement with a housing part.

Lock cylinder according to claim 4, characterised in that the catch is a crescent-shaped 25 disc which is held in the interlocked position by hardened pins inserted into the cylinder plug on the end face.

6. Lock cylinder according to claim 5, characterised in that it is a double lock cylinder and has two housing halves which are connected to one another by means of a connecting 3 eb. ~pS~t^ r P:\WPDOCS\AMD\SPEC\673842.KEL 30/9/98 -8-

7. Lock cylinder according to claim 6, characterised in that the connecting web is thickened in the region of the four-end screw bore and has, on each of the two sides of a radial recess for a driver cam, a peripheral shoulder bearing against a housing part in each case.

8. Lock cylinder according to claim 7, characterised in that the shoulder is formed by a peripheral thickening.

9. Lock cylinder according to claim 7 or 8, characterised in that the thickening is formed by an attached tubular piece.

Lock cylinder according to one of claims 1 to 9, characterised in that at least one lengthening piece is arranged on the rear side of a housing part, the said lengthening piece having an orifice, into which the thickening engages.

11. Double lock cylinder, substantially as herein described with reference to the drawings. DATED this 30th day of September, 1998 c t tC t .t 20 ERNST KELLER By His Patent Attorneys DAVIES COLLISON CAVE StC i d c c CaC CCI WO 97/07309 9 PCT/CH96/00272 Abstract A safety lock comprises a lock cylinder with a cylinder housing 3) and with at least one cylinder plug which is rotatably mounted in a continuous housing orifice (11) and which is inserted into the housing orifice from the rear side, the said plug having a thickening (13) at its rear end. There are tumblers which are arranged in order by means of an insertable key capable of being introduced into a keyway. An extension (14) is arranged on the rear side of the thickening the said extension having the guide means for coupling the cylinder plug to a driver (Figure 1) L 'I