Padlock for securing a switch

Abstract

A lockout padlock for securing a switch of an industrial plant comprises a lock housing composed of plastic, a hoop, a lock cylinder that has a cylinder housing and a rotatable cylinder core, and a key, with the cylinder core being rotatable between a locked position in which the hoop is locked or lockable to the lock housing and an unlocked position. The lock cylinder has a plurality of tumblers, with each tumbler being movable between a respective release position and a respective blocking position. The plurality of tumblers comprise a plurality of pin tumblers that are spring-loaded in the direction of their respective blocking positions. The plurality of tumblers furthermore comprise a plurality of supplementary tumblers that are not spring-loaded and that are freely movably supported between their respective release positions and their respective blocking positions.

Claims

1. A lockout padlock configured for securing a switch of an industrial plant, the lockout padlock comprising: a lock housing composed of plastic; a hoop displaceably held at the lock housing; a lock cylinder arranged in the lock housing and comprising a cylinder housing and a cylinder core rotatable about a cylinder axis in the cylinder housing; and a key, wherein the cylinder core is rotatable by means of the key between a locked position in which the hoop is locked or lockable to the lock housing and an unlocked position in which the hoop is released for an opening movement relative to the lock housing, wherein the lock cylinder comprises a plurality of tumblers, with each tumbler being movable relative to the cylinder housing between a respective release position in which the tumbler releases the cylinder core for a rotation into its unlocked position and a respective blocking position in which the tumbler blocks the cylinder core in its locked position relative to the cylinder housing, wherein the plurality of tumblers comprise a plurality of pin tumblers that are spring-loaded in the direction of their respective blocking positions, wherein the plurality of tumblers furthermore comprise a plurality of supplementary tumblers that are not spring-loaded and are freely movably supported between their respective release position and their respective blocking position, and wherein the plurality of pin tumblers and the plurality of supplementary tumblers are configured to have different kinematic behaviors so that unintentional movement of the plurality of pin tumblers and the plurality of supplementary tumblers to the respective release positions, caused by vibration of the lockout padlock by the industrial plant, is prevented.

2. A lockout padlock in accordance with claim 1, wherein the supplementary tumblers are cylindrical or substantially cylindrical.

3. A lockout padlock in accordance with claim 1, wherein the supplementary tumblers are formed in one part.

4. A lockout padlock in accordance with claim 1, wherein the supplementary tumblers are formed as shorter than the pin tumblers along their respective directions of movement.

5. A lockout padlock in accordance with claim 1, wherein the supplementary tumblers are supported in the cylinder core and engage in their respective blocking positions into a blocking recess at an inner periphery of the cylinder housing.

6. A lockout padlock in accordance with claim 5, wherein the blocking recess extends at the inner periphery of the cylinder housing along a peripheral angle in a direction of rotation of the cylinder core, said peripheral angle substantially corresponding to the width of the respective supplementary tumbler, with the blocking recess being bounded in the direction of rotation of the cylinder core by at least one guide chamfer.

7. A lockout padlock in accordance with claim 1, wherein the supplementary tumblers are movable within a respective plane that is perpendicular to the cylinder axis.

8. A lockout padlock in accordance with claim 1, wherein the supplementary tumblers are arranged behind one another along the cylinder axis.

9. A lockout padlock in accordance with claim 1, wherein the hoop extends within a plane of extent, with the direction in which the supplementary tumblers are movable extending at an angle different from zero to the plane of extent of the hoop.

10. A lockout padlock in accordance with claim 1, wherein the direction of movement of the pin tumblers and the direction of movement of the supplementary tumblers extend in parallel with one another or at an angle different from zero.

11. A lockout padlock in accordance with claim 1, wherein the pin tumblers have a respective housing pin and a respective core pin, with the housing pin being substantially supported in the cylinder housing and the core pin being substantially supported in the cylinder core.

12. A lockout padlock in accordance with claim 1, wherein the key has a shaft whose cross-section has a longitudinal shape having two broad sides and two narrow sides, with a plurality of primary coding sections being provided at each broad side that are associated with the pin tumblers, and with a plurality of secondary coding sections being provided at each broad side and/or at each narrow side that are associated with the supplementary tumblers.

13. A lockout padlock in accordance with claim 1, wherein the cylinder housing has a hollow cylinder section and a web section extending radially from the hollow cylinder section, with the cylinder core having a keyway that has an elongate cross-sectional shape having a long side and a short side, with the long side extending perpendicular to the radial direction of extent of the web section.

Description

(1) The invention will be explained in the following only by way of example with reference to the drawings. Elements which are the same or of the same kind are marked by the same reference numerals therein.

(2) FIG. 1 shows a lockout padlock in an exploded view;

(3) FIG. 2 shows a lockout padlock in an longitudinal sectional view;

(4) FIG. 3 shows a lock cylinder in a longitudinal sectional view;

(5) FIG. 4 shows a front view of the cylinder housing of the lock cylinder in accordance with FIG. 3;

(6) FIG. 5 shows a further lock cylinder in a cross-sectional view;

(7) FIG. 6 shows a lockout padlock in a cross-sectional view;

(8) FIG. 7 shows a key in a plan view; and

(9) FIG. 8 shows a further key in a plan view.

(10) The padlock shown in FIG. 1 has a lock body 11 and a hoop 13. The hoop 13 has a U shape with one shorter limb 13′ and one longer limb 13″. An inwardly directed locking cutout 15 is formed at both limbs 13′, 13″ of the hoop 13. Furthermore, a ring groove 17 with an abutment head 19 adjacent to it is provided at the free end of the longer limb 13″.

(11) The lock body 11 has a lock housing that has an outer housing 21 and an inner housing 23. The outer housing 21 and the inner housing 23 comprise plastic. The inner housing 23 can be pushed into the outer housing 21 and can be fixed to the outer housing 21 by means of a securing screw 25. The outer housing 21 and the inner housing 23 accommodate a lock cylinder 27 and a locking mechanism 29 via which the lock cylinder 27 cooperates with the hoop 13.

(12) The lock cylinder 27 has a cylinder core 31 having a keyway 33. The cylinder core 31 is rotatably mounted within a hollow cylinder section 32 of a cylinder housing 35 with respect to a cylinder axis A (FIG. 2), wherein a rotary actuation should only be possible when an associated key 55 (FIG. 2) is introduced into the keyway 33. The cylinder housing 35 furthermore has a web section 36 radially extending from the hollow cylinder section 32 laterally for the pin tumblers explained in the following. The cylinder core 31 has a drive prolongation 37 at the rear side.

(13) The locking mechanism 29 comprises an entrainer 39 and two locking balls 41. The entrainer 39 has a substantially hollow cylindrical shape with an engagement nose 43 at the inner side which enables a rotationally fixed coupling to the drive prolongation 37 of the lock cylinder 27. The entrainer 39 has two receiving cutouts 45 at its outer side which can partly accept the locking balls 41 on an unlocking actuation of the lock cylinder 27 and thus of the entrainer 39. At the periphery, in each case adjacent to the receiving cutouts 45, the entrainer 39 forms locking sections 47 by which the locking balls 41 can be held in locking engagement with the locking cutouts 15 of the hoop 13.

(14) As regards the mutual fastening of the outer housing 21 and the inner housing 23, FIG. 2 additionally shows that the fastening screw 25 can cooperate with a nut 49 rotationally fixedly inserted into the inner housing 23. The fastening screw 25 is inserted into a hoop receiving passage 51 of the outer housing 21 which is closed by the hoop 13 when the hoop 13 is locked to the lock body 11—as shown in FIG. 2. The nut 49 is covered by means of a cover 53. Provided that the lock cylinder 27 has been brought into the open position and the shorter limb 13′ of the hoop 13 has been removed from the hoop receiving passage 51, the securing screw 25 can again be released from the nut 49 to remove the inner housing 23 from the outer housing 21.

(15) The padlock shown in FIGS. 1 and 2 selectively allows the locking of the hoop 13 to the lock body 11 in its closed position (locked position of the cylinder core 31) or the release of the shorter limb 13′ of the hoop 13 from the lock body 11 (unlocked position of the cylinder core 31) by a corresponding actuation of the lock cylinder 27, for example to be able to introduce the hoop 13 into an eyelet of a switch or to remove it therefrom in its open position. The padlock shown is in particular suitable for use as a lockout padlock.

(16) FIG. 2 shows a state of the padlock in which the hoop 13 is locked and is thus secured against removal from the lock body 11. The locking sections 47 of the entrainer 39 hold the locking balls 41 in locking engagement with the locking cutouts 15 of the hoop 13 for this purpose. To unlock the padlock, a rotational unlocking actuation by means of an associated key 55 is required. The drive prolongation 37 of the cylinder core 31 and the entrainer 39 are hereby rotated by 90° so that a respective receiving cutout 45 of the entrainer 39 is rotated into the region of the locking balls 41. The locking balls 41 can thus move back out of the locking cutouts 15 of the hoop 13. The hoop 13 can now be pulled out of the lock body 11 axially until the abutment head 19 of the longer hoop limb 13″ abuts the respective locking ball 41. The shorter limb 13′ of the hoop 13 now already projects out of the lock body 11. The hoop 13 can now be rotated about the longitudinal axis of the longer hoop limb 13″. A repeated locking of the hoop 13 to the lock body 11 takes place in the reverse order.

(17) FIG. 3 shows a possible embodiment of the lock cylinder 27 of the lockout padlock in accordance with FIGS. 1 and 2 in a longitudinal section, with the associated key 55 being introduced into the keyway 33 of the cylinder core 31. The lock cylinder 27 has a plurality of pin tumblers 61 that are arranged behind one another along the cylinder axis A and that block the cylinder core 31 against a rotational movement relative to the cylinder housing 35 in their respective blocking positions. The pin tumblers 61 are movable in a vertical direction with respect to the representation in accordance with FIG. 3. The pin tumblers 61 each have a housing pin 63 and a core pin 65 and they are spring-loaded in the direction of their blocking positions by means of a respective compression spring 67. The pin tumblers 61 are moved against the respective spring load out of their blocking positions into release positions shown in FIG. 3 by means of the key 55 introduced into the keyway 33.

(18) The lock cylinder 27 furthermore has a plurality of pin tumblers 71 that are arranged behind one another along the cylinder axis A and that likewise block the cylinder core 31 against a rotational movement relative to the cylinder housing 35 in their respective blocking positions. The supplementary tumblers 71—unlike the pin tumblers 61—are not spring-loaded, but are rather freely movably supported in the cylinder core 31 between their release positions and their blocking positions. In the embodiment shown, the supplementary tumblers 71 are likewise movable in a vertical direction with respect to the representation in accordance with FIG. 3. The supplementary tumblers 71 are formed in one part and are relatively short in comparison with the pin tumblers 61. The supplementary tumblers 71 are substantially cylindrical, with both ends having a frustoconical shape, however.

(19) In their blocking positions, the supplementary tumblers 71 engage into a blocking recess 73 at an inner periphery of the hollow cylinder section 32 of the cylinder housing 35. As can be seen from the front view of the cylinder housing 35 in accordance with FIG. 4, the blocking recess 73 is formed by a continuous groove that extends along the cylinder axis A at the inner periphery of the hollow cylinder section 32. In the direction of rotation of the cylinder core 31, the blocking recess 73 extends along a peripheral angle 75 at the inner periphery of the cylinder housing 35, said peripheral angle 75 substantially corresponding to the respective supplementary tumbler 71, with the blocking recess 73 being bounded at both sides by a respective guide chamfer 77 in the direction of rotation of the cylinder core 31.

(20) Since the supplementary tumblers 71 are freely movable supported in the cylinder core 31, that is are inserted in a substantially loose manner, the supplementary tumblers 71 can be moved relatively simply between their release positions and their blocking positions in comparison with the pin tumblers 61. A movement of the respective supplementary tumbler 71 can thus already be caused—apart from the use of the key 55—by gravity or by vibrations that are introduced onto the lockout padlock from the outside and that can be effected, for instance, by vibrations or shocks of the fastening environment of the lockout padlock. The extent to which such outside effects actually result in a movement of the supplementary tumblers 71 depends on the strength and on the frequency of the introduced mechanical vibrations and on the alignment of the lockout padlock relative to the direction of gravity. Since the freely movably and relatively light supplementary tumblers 71 do not necessarily react uniformly in this respect, the supplementary tumblers 71 can adopt slightly different positions, as is shown in FIG. 3.

(21) A lockout padlock provided with a lock cylinder 27 (FIGS. 1 and 2) in accordance with FIG. 3 is thus characterized by particularly high security against an unintentional opening, in particular with respect to mechanical vibrations that are introduced from the outside and that could arise in the fastening environment of the lockout padlock due to machine parts that have not been stopped, for instance, and that could be transmitted to the padlock hung at a switch (the key 55 is admittedly not introduced into the lock cylinder 27 in such a scenario, but is removed again). The supplementary tumblers 71, in contrast, can namely already be moved by relatively weak vibrations between their respective blocking positions and release positions due to their free movability, whereby the supplementary tumblers 71 start to move or to “jump” between their respective blocking positions and release positions in accordance with a non-uniform pattern (earlier than the spring-loaded pin tumblers 61) when vibrations occur. The risk is hereby reduced that all the tumblers 61, 71 are simultaneously accelerated and moved by an outer effect such that the separation surface between the cylinder housing 35 and the cylinder core 31 is no longer temporarily blocked.

(22) FIG. 5 shows in a cross-sectional view (sectional plane extends perpendicular to the cylinder axis A) that the supplementary tumblers 71 can (alternatively or additionally) also be freely movably supported in a horizontal direction (with respect to the representation in accordance with FIG. 5), that is in a direction perpendicular to the direction of movability of the pin tumblers 61. Different relative angles than the shown 90° angle are also possible.

(23) FIG. 6 shows in a cross-sectional view (sectional plane extends perpendicular to the cylinder axis A) an embodiment of a lockout padlock (such as, for example, a lockout padlock in accordance with FIGS. 1 and 2). In this embodiment, the hoop 13 extends within a plane of extent B that is spanned by the two limbs 13′, 13″ of the hoop 13. The fastening screw 25 arranged in the axial prolongation is shown in the right region in FIG. 6 instead of the limb 13″. The direction E in which the supplementary tumblers 71 are movable is furthermore shown in FIG. 6. This direction E extends at an angle different from zero to the plane of extent B of the hoop 13. An angle of approximately 20°, 25″, or 30° can be provided, for example. It can hereby be achieved that vibrations that are transmitted onto the hoop 13 and thus onto the lock cylinder 27 from the outside generally extend in a different direction than the direction E of the movability of the supplementary tumblers 71.

(24) FIG. 7 shows a key 55 that has a key shaft 81 whose cross-section has a longitudinal shape having two broad sides 83 and two narrow sides 85. In the plan view in accordance with FIG. 7, only one of the two broad sides 83 is visible, with the other broad side 83 being of identical design. The two broad sides 83 can be profiled in a typical manner, that is can be provided with webs and grooves that extend in the longitudinal direction of the key shaft 81. A plurality of secondary coding sections 87 can be provided at each broad side 83 in the form of recesses that are associated with the pin tumblers 61 of the lock cylinder 27. A plurality of primary coding sections 89 can furthermore be provided at each broad side 83 in the form of recesses that are associated with the supplementary tumblers 71 of the lock cylinder 27. In their respective release positions the pin tumblers 61 engage into the primary coding sections 87 and the supplementary tumblers 71 engage into the secondary coding sections 89.

(25) FIG. 8 shows a similar key 55 whose key shaft 81 has two broad sides 83 and two narrow sides 85. A plurality of primary coding sections 87 are in turn arranged at each broad side 83 in the form of recesses for the pin tumblers 61. A plurality of secondary coding sections 89 are furthermore arranged at each narrow side 85 in the form of lateral notches for the supplementary tumblers 71.

(26) In the respective key 55 in accordance with FIGS. 7 and 8, the primary coding sections 87 and the secondary coding sections 89 are arranged at the key shaft 81 in a rotationally symmetrical manner (with respect to a rotation of the key shaft 81 by 180° about its longitudinal axis). The keyway 33 of the associated lock cylinder 27 can have, corresponding to the cross-sectional shape of the key 55, an elongate cross-sectional shape having a long side and a short side, with the long side in particular being able to extend perpendicular to the radial direction of extent of the web section 36 of the cylinder housing 35 in accordance with FIG. 4.

REFERENCE NUMERAL LIST

(27) 11 lock body 13 hoop 13′ limb 13″ limb 15 locking cutout 17 ring groove 19 abutment head 21 outer housing 23 inner housing 25 securing screw 27 lock cylinder 29 locking mechanism 31 cylinder core 32 hollow cylindrical section 33 keyway 35 cylinder housing 36 web section 37 drive prolongation 39 entrainer 41 locking ball 43 engagement nose 45 receiving cutout 47 locking section 49 nut 51 hoop receiving passage 53 cover 55 key 61 pin tumbler 63 housing pin 65 core pin 67 compression spring 71 supplementary tumbler 73 blocking recess 75 peripheral angle 77 guide chamfer 81 key shaft 83 broad side of the key shaft 85 narrow side of the key shaft 87 primary coding section 89 secondary coding section A cylinder axis B plane of extent B of the hoop E direction of movability of the supplementary tumblers