Safety switch

Abstract

A safety switch (2) with a latching unit (12), by means of which an associated actuator (3) is held in a latched position. The latching unit (12) has an opening (9) and a blocking element. In a latched position, the blocking element projects into the opening (9) and rear-engages an actuator head (8) of the actuator (3), which is in the latched position. The blocking element is held in the latched position by means of a positioning element with a setting force. When the actuator head (8) is inserted into or removed from the opening (9), the actuator head (8) pivots the blocking element out against the setting force.

Claims

1. Safety switch (2) with a latching unit (12), by means of which an associated actuator (3) is held in a latched position, characterized in that the latching unit (12) has an opening (9) and a blocking element, wherein in the latched position, the blocking element projects into the opening (9) and an actuator head (8) rear-engages the actuator (3) that is in the latched position; that the blocking element is held in the latched position by means of a positioning element with a setting force; and that, when the actuator head (8) is inserted into or removed from the opening (9), the actuator head (8) pivots the blocking element out against the setting force wherein the latched position of the actuator (3) is monitored by recording signals from a transponder (11) in the actuator (3) with a reader unit of the safety switch (2), when the actuator (3) is moved into the latched position in the safety switch (2) wherein the positioning element is formed by a rocker (14), wherein the latching unit (12) is associated with a locking unit (18) by means of which the blocking element is held in the latched position, and wherein the locking unit (18) has a hinged armature solenoid (19) that has an electromagnet (20) and an armature (21) that can be pivoted using the electromagnet (20), wherein the armature (21) is brought into a locked position in which the armature (21) blocks the rocker (14).

2. Safety switch (2) according to claim 1, characterized in that the blocking element is formed by a latch (13).

3. Safety switch (2) according to claim 2, characterized in that the latch (13), with a lower end, is engaged with the positioning element, and that in the latched position, the upper end of the latch (13) projects into the opening (9), wherein the upper end has a circular edge (13a) that is adapted to the contour of the opening (9).

4. Safety switch (2) according to claim 1, characterized in that the latch (14) has a bar-shaped rocker element (15), wherein at a first longitudinal end of the rocker element (15) a swivel bearing (16) is provided, and wherein, on the underside of the rocker element (15), a spring (17) that generates the setting force for the blocking element is arranged.

5. Safety switch (2) according to claim 4, characterized in that the spring (17) abuts a central region of the rocker element (15) on the latter's underside, and that in this region a lower end of the latch (13) lies on the upper side of the rocker element (15).

6. Safety switch (2) according to claim 4, characterized in that the setting force is adjusted by pre-tensioning the spring (17).

7. Safety switch (2) according to claim 1, characterized in that the geometry of the opening (9) is adapted to the shape of the actuator head (8), wherein the actuator head (8) is ball-shaped or has an ovate or polygonal cross-section.

8. Safety switch (2) according to claim 1, characterized in that the rocker (14) has a detent (15a) at a second free end, wherein the armature (21) is engaged with this detent (15a) in the locked position.

9. Safety switch (2) according to claim 1, characterized in that the armature (21) is pivotable about a swivel axis, wherein a pivoting arm (21a) forms a lever that is brought into engagement with the rocker (14), and wherein a second pivoting arm forms a counterweight by means of which improved shock stability is achieved.

10. Safety switch arrangement (1) according to claim 1, characterized in that the actuator (3) has a base body (6) that is connected to the actuator head (8) by means of a connecting element (7), wherein the cross-sectional surface of the connecting element (7) is smaller than the cross-sectional surface of the actuator head (8).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained below based on the drawings. The following is shown in:

(2) FIG. 1 Exemplary embodiment of the safety switch arrangement in accordance with the invention with a safety switch and an actuator.

(3) FIG. 2A One state of the latching unit and locking unit of the safety switch arrangement from FIG. 1, upon insertion of the actuator into a latched position.

(4) FIG. 2B Another state of the latching unit and locking unit of the safety switch arrangement from FIG. 1, upon insertion of the actuator into a latched position.

(5) FIG. 2C A further state of the latching unit and locking unit of the safety switch arrangement from FIG. 1, upon insertion of the actuator into a latched position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) FIG. 1 shows schematically an exemplary embodiment of a safety switch arrangement 1 with a safety switch 2 and actuator 3.

(7) This safety switch arrangement 1 can be used, for example, to secure a protected door that serves as access to a hazard area. The actuator 3 can be arranged at the safety door; the safety switch 2 can be arranged on a frame surrounding the door opening that is closed off by means of the safety door.

(8) The components of the safety switch 2 are integrated into a housing 4 from which a cable connector 5 protrudes for connection to external units.

(9) As is evident from FIG. 1, the actuator 3 has a core body 6 in which a connecting element 7 is mounted. The connecting element 7 is formed by an elongated body, the cross-section of which is at least approximately constant over its entire length.

(10) The connecting element 7 is mounted in the core body 6 with its first free end such that the longitudinal axis of the connecting element 7 is oriented perpendicular to the surface of the core body 6. At the other end of the connecting element 7, an actuator head 8 is mounted. In the present case, the actuator head 8 is sphere-shaped. In principle, the actuator head 8 can also be formed by another body with rotational symmetry. In principle, the actuator head 8 can also have an oval or polygonal cross-section. In any case the actuator head 8 has a larger cross-sectional area than the connecting element 7, such that the actuator head 8 projects across its entire cross-sectional plane beyond the connecting element 7.

(11) In general, the connecting element 7 is made of a material that ensures high rigidity of the connecting element 7 in the axial direction and which maintains the connecting element 7 in its base position shown in FIG. 1, especially when the effects of gravity are present.

(12) On a sidewall of the safety switch 2, an opening 9 is provided into which a cavity in the safety switch 2 opens out into which cavity the actuator head 8 can be inserted such that the actuator 3 is then in its latched position.

(13) The opening 9 is circular in form. A reading coil 10 is provided in the edge region of the sidewall that delimits the opening 9. The reading coil 10 is mounted on a separate circuit board (not shown) and forms a reader unit, specifically an RFID reader unit. Corresponding to this, a transponder 11 is mounted in the actuator head 8. In general, the transponder 11 can also be provided in the base body 6 of the actuator 3.

(14) By means of the reading coil 10, signals from the transponder 11 can be detected in the actuator head 8 when the actuator 3 is moved into the latched position in the safety switch 2, by which means it can be verified that the actuator 3 is actually in the latched position.

(15) For secure latching and locking of the actuator 3 in its latched position, the safety switch 2 has a latching unit 12. The latching unit 12 has a blocking element in the form of a latch 13 that can, with its upper end, be moved into the region of the opening 9.

(16) The latch 13 is composed of a planar component that is closed-off at its upper end by a circular-shaped edge 13a. At the lower edge, a convex support element 13b is provided which forms a mechanical coupling to a positioning element. The latch 13 is displaceably mounted in the axial direction, i.e., in the vertical direction. Preferably, guide elements (not shown) are additionally provided.

(17) The positioning element is realized in the form of a rocker 14 that has a bar-shaped rocker element 15. A swivel bearing 16 is provided at a first longitudinal end of the rocker element 15 such that the rocker element 15 is pivotable about a swivel axis extending through the swivel bearing 16. A detent 15a is provided at the second longitudinal end of the rocker element 15.

(18) The rocker 14 formed in this manner is associated with a spring 17, the longitudinal axis of which extends in the vertical direction and the lower end of which is mounted on a stationary support. The upper end of the spring 17 abuts a central region of the rocker element 15 on the underside of the latter. The support element 13b of the latch 13 abuts the rocker element 15 on the latter's upper side in the same region. As evident in FIG. 1, the support element 13b is arranged along the longitudinal axis of the spring 17. The spring force of the spring 17 effects a setting force that is transmitted from the rocker element 15 to the latch 13 such that the latch 13 is pushed upwards and with its upper edge 13a projects into the opening 9. This position shown in FIG. 1 is the locked and latched position of the latch 13.

(19) The setting force can be adjusted by appropriately pre-tensioning the spring 17.

(20) This latching unit 12 is associated with a locking unit 18 by means of which the latch 13 can be locked in place.

(21) The locking unit 18 has a hinged armature solenoid 19 that has an electromagnet 20 and an armature 21. The armature 21 is realized in the form of a lever that forms a pivoting arm 21a which is pivoted about a swivel bearing 22. The arrangement can be expanded by a second pivoting arm 21b that forms a counterweight to the lever, thereby resulting in improved shock stability of the hinged armature solenoid 19. The hinged armature solenoid 19 furthermore has a spring element 24 mounted on a guide segment 23 of the electromagnet 20. As a result, the armature 21 is pivoted out when current is supplied to the electromagnet 20. Locking of the latching unit 12 is effected insofar as the armature 21 is pivoted out such that it clicks into the detent 15a of the rocker element 15. In general, the hinged armature solenoid 19 can be shaped differently in various embodiments and works according to the normally de-energized circuit (i.e., open circuit) principle or normally energized circuit principle. It can also be implemented as a bistable magnet.

(22) The functioning of the latching and locking of the safety switch arrangement 1 is explained based on FIGS. 2A to 2C.

(23) In the starting position, for example, with an open protective door, the actuator 3 lies at a distance from the protective door. When the protective door is closed, the actuator 3 is moved into a latching unit 12 inside the safety switch 2.

(24) To this end, the actuator 3 with the actuator head 8 is moved against the opening 9 in the safety switch 2, wherein in this starting position the latch 13 is in the latched position and projects into the opening 9.

(25) When the actuator head 8 is inserted into the opening 9 of the safety switch 2, the latch 13 is pushed down and out of the latched position due to the pressing force of the actuator head 8 since the diameter of the actuator head 8 is adapted to the inner diameter of the opening 9 and fills it virtually completely. This situation is depicted in FIG. 2A. The actuator head 8 lies in the opening 9, and the latch 13 is pushed down and out of the latched position against the spring force of the spring 17 such that the upper circular curved edge 13a lies in the edge region of the opening 9. Here it is advantageous for the curvature radius of the upper edge 13a of the latch 13 to correspond to the radius of the opening 9 such that the edge contour of the latch 13 corresponds approximately or exactly to the edge contour of the opening 9. In general, the opening can also have a non-circular contour, wherein also the edge 13a is then adapted to this contour.

(26) The actuator 3 is then pushed farther into a latched position such that the actuator head 8 lies completely in the cavity adjacent to the opening 9. Then, as shown in FIG. 2B, the connecting element 7 lies in the region of the opening 9. Since the diameter of the connecting element 7 is smaller than the diameter of the actuator head 8, the latch 13 is pushed up and into the latched position (FIG. 2B) by the spring force from the spring 17 and secures and locks the actuator head 8 in the latched position. The locked and latched position of the actuator 3 is monitored by reading the signals from the transponder 11 in the reader unit. In the locked and latched position, the latch 13 rear-engages the actuator head 8, thereby holding the actuator 3 in the latched position.

(27) In the situation shown in FIG. 2B, the locking has not yet been activated, i.e., the armature 21 of the hinged armature solenoid 19 is not engaged with the detent 15a of the rocker element 15 of the rocker 14. Therefore, it is still possible to unlatch the actuator 3, i.e., the actuator 3 can be pulled out of the locked and latched position when exposed to forces, wherein then, when the actuator head 8 passes through the opening 9 of the safety switch 2, the latch 13 is pushed down and out of the latched position against the spring force.

(28) Finally, FIG. 2C shows the situation when the actuator 3 is inserted into the latched position and locking is activated. In the latched position, the latch 13 in the latched position rear-engages the actuator head 8 and holds the actuator 3 in the latched position.

(29) The locking is activated such that the armature 21 is pivoted out by means of the electromagnet 20 and engages in the detent 15a of the rocker 14. The rocker 14 is therefore secured in place. Due to the secured rocker 14, the actuator 3 can no longer move out of the latched position since the rocker 14 secures the latch 13 from moving out of the latched position. Therefore, the actuator 3 can only be released again when locking is deactivated, i.e., when the armature 21 is no longer engaged in the detent 15a.

(30) When the safety switch arrangement 1 according to the invention is used to secure a protective door serving as access to a hazard area, the safety switch 2 can, when the actuator 3 is latched and locked, emit a switching signal that can be used to release a hazardous system within the hazard area for operation.

LIST OF REFERENCE NUMERALS

(31) (1) Safety switch arrangement (2) Safety switch (3) Actuator (4) Housing (5) Cable connection (6) Core body (7) Connecting element (8) Actuator head (9) Opening (10) Reading coil (11) Transponder (12) Latching unit (13) Latch (13a) Edge (13b) Support element (14) Rocker (15) Rocker element (15a) Detent (16) Swivel bearing (17) Spring (18) Locking unit (19) Hinged armature solenoid (20) Electromagnet (21) Armature (21a) Pivoting arm (21b) Second pivoting arm/counterweight (22) Swivel bearing (23) Guide segment (24) Spring element