Interlocking device

Abstract

An interlocking device for locking a movable safety guard has a locking unit, an electric mover, an additional release unit, a sensor device and an evaluation unit. The locking unit is movable between a locking position for interlocking the movable safety guard and a release position for releasing the movable safety guard and the mover is configured to move the locking unit between the locking position and the release position. The additional release unit is movable from a neutral position into an additional release position to move the locking unit from the locking position into the release position. The sensor device is configured to detect a position of the locking unit and a position of the additional release unit. The evaluation unit is configured to output a locking signal, a normal release signal, and an additional release signal.

Claims

1. An interlocking device for locking a movable safety guard, having a locking unit, an electric mover, an additional release unit, a sensor device and an evaluation unit, the locking unit being movable between a locking position for interlocking the movable safety guard and a release position for releasing the movable safety guard, the mover being configured to move the locking unit between the locking position and the release position, the additional release unit being movable from a neutral position into an additional release position to move the locking unit from the locking position into the release position, the sensor device being configured to detect a position of the locking unit and a position of the additional release unit, the evaluation unit being configured to output a locking signal when the locking unit is in the locking position, a normal release signal when the locking unit has been moved into the release positon by the electric mover, an additional release signal when the locking unit has been moved into the release position by the additional release unit.

2. The interlocking device according to claim 1, the sensor device being configured to be actuated by the locking unit in dependence of the position of the locking unit.

3. The interlocking device of claim 1, the sensor device being configured to be actuated by the additional release unit in dependence of the position of the additional release unit.

4. The interlocking device of claim 3, the sensor device comprising an auxiliary sensor being configured to be actuated by the locking unit and by the additional release unit.

5. The interlocking device of claim 4, the additional release unit comprising an auxiliary sensor actuator configured to actuate the auxiliary sensor, the locking unit comprising a further sensor actuator configured to actuate the auxiliary sensor.

6. The interlocking device of claim 5, the further sensor actuator and the auxiliary sensor actuator being positioned about each other along a line of movement of the locking unit.

7. The interlocking device of claim 4, the evaluation unit being configured to determine whether the auxiliary sensor has been actuated by the additional release unit or by the locking unit by evaluating an actuation of a main sensor of the sensor device.

8. The interlocking device of claim 1, the additional release unit being configured to engage with the locking unit to move the locking unit from the locking position into the release position.

9. The interlocking device of claim 8, the additional release unit being configured to engage with a coupling element positioned between the mover and a locking element of the locking unit.

10. The interlocking device of claim 1, the additional release unit having a mechanical stop on which the locking unit abuts in the locking position.

11. The interlocking device of claim 1, the additional release unit comprising an auxiliary coupler, the auxiliary coupler comprising a guiding section, the guiding section enclosing a coupling element of the locking unit at least on three sides, thus guiding the coupling element when being moved from the locking position to the release position by the mover.

12. The interlocking device of claim 1, the locking unit being independently movable with respect to the additional release unit when the additional release unit is in the neutral position.

13. The interlocking device of claim 1, comprising a mechanical biasing element that keeps the additional release unit in the neutral position when the mover moves the locking unit from the locking position into the release position.

14. The interlocking device of claim 1, the additional release unit being mechanically movable from the neutral position into the additional release position.

15. The interlocking device of claim 14, the additional release unit being manually movable from the neutral position into the additional release position.

16. Method for determining a position of a locking unit of an interlocking device for a movable safety guard, the locking unit being movable by an electric mover of the interlocking device between a locking position for interlocking the movable safety guard and a release position for releasing the movable safety guard, the locking unit being additionally movable from the locking position into the release position by a movable additional release unit, wherein the method comprises: reading out a main sensor of the interlocking device which is configured to be actuated in dependence of the position of the locking unit and reading out an auxiliary sensor of the interlocking device which is configured to be actuated in dependence of a position of the additional release unit, outputting a locking signal when the locking unit is in the locking position, outputting a normal release signal when the locking unit has been moved into the release positon by the electric mover, outputting an additional release signal when the locking unit has been moved into the release position by the additional release unit.

17. Method of claim 16, the auxiliary sensor being actuatable by the additional release unit and by the locking unit, wherein the method comprises determining whether the auxiliary sensor is actuated by the additional release unit or by the locking unit in dependence of an actuation of the main sensor.

Description

(1) In the following, the invention will be explained in detail by means of exemplary embodiments and with references to figures showing schematically

(2) FIG. 1 a perspective view of an interlocking device for a safety guard;

(3) FIG. 2 a perspective view of a locking mechanism of the interlocking device;

(4) FIG. 3 a perspective close-up view of the locking mechanism in a locking unit of the interlocking device in a release position;

(5) FIG. 4 a further perspective close-up view of the locking mechanism with the locking unit in the release position;

(6) FIG. 5 a perspective close-up view of the locking mechanism with the locking unit in a locking position; and

(7) FIG. 6 a perspective close-up view of the locking mechanism with the locking unit in the release position and an additional release unit in a release position.

(8) FIG. 1 shows a perspective view of an interlocking system 1 for a safety guard (not shown). The interlocking system 1 comprises an interlocking device 10 forming a stationary part of the interlocking system 1 and being attachable to a stationary part of a machine comprising the safety guard. The interlocking system 1 further comprises a movable part 20 attachable to the safety guard itself. The movable part 20 comprises a holding element 21. The holding element 21 may be fastened to the safety guard by two fastening elements 22, which may be configured as screws, for example. The movable part 20 comprises an actuator 23, configured as a tongue, which is attached to the holding element 21 and comprises an opening 24.

(9) The interlocking device 10 comprises a locking unit 100 with a locking element 120 (i.e. a latch). The locking unit 100 is surrounded by a housing 12 of the interlocking device 10 with the locking element 120 extending through an opening of the housing 12. The locking element 120 is linearly movable back and forth through the opening of the housing 12 along a line of movement. Along a line or direction of movement 2, a closing direction is orientated from inside the housing 12 towards the outside of the housing 12 and a release direction is orientated from outside the housing 12 towards the inside of the housing 12. The locking element 120 has a generally cylindrical shape with an axis of the cylinder orientated along the line of movement 2. In particular, the locking element 120 is configured as a locking pin.

(10) When the guard is closed, the opening 24 of the actuator 23 of the movable element 20 is positioned, especially centered, around the axis of the locking element 120 and the locking element 120 may be inserted into the opening 24 or removed from the opening 24 by moving it along the line of movement 2. In particular, the locking element 120 may be inserted into the opening 24 by moving the locking element 120 out of the housing 12 and the locking element 120 may be removed from the opening 24 by retracting the locking element 120 into the housing 12. When the locking element 120 is positioned inside the opening 24, the position of the movable part 20 is laterally fixed with respect to the interlocking device 10 and the guard is locked. When the locking element 120 is retracted into the housing 12 and not positioned inside the opening 24, the guard is released and may be moved laterally with respect to the stationary part 10.

(11) The locking unit 100 may comprise a termination element (not shown) that is positioned above the opening in the housing 21 so that a gap is formed between the housing 21 and the termination element. When the guard is closed, the actuator 23 may move into the gap. The termination element may be configured to inhibit a movement of the actuator 23 along the axis of the locking element 120 thus preventing the actuator 23 being axially removed axially from the locking element 120. When being in the locking position, the locking element may engage with the termination element.

(12) The interlocking device 10 further comprises a mounting plate 14 which is part of the housing 12. The stationary part 10 can be fastened to a frame of the safety guard. The housing 12 and the locking unit 100 are placed on one side of the mounting plate 14. On an opposing second side of the mounting plate 14, an emergency release element 202 of an additional release unit 200 of the interlocking device 10 is attached to the interlocking device 10. The emergency release element 202 is manually actuatable and comprises a push button 201, in particular as an emergency push button. When the interlocking device 10 is mounted to the frame of the safety guard, the emergency release element 202 extends into a safety area closed off by the safety guard and thus is accessible from inside the safety area.

(13) The interlocking device 10 comprises a further release element 204, which may be actuated manually by using a tool, particularly by using a screwdriver. To this end, the further release element 204 comprises a tool receiving section 203 in which the tool may be applied. The further release element 204 is only accessible from outside the safety area.

(14) FIG. 2 shows a perspective view of a locking mechanism of the interlocking device 10. The locking mechanism comprises an electric mover 130 configured to move the locking element 120 along the line of movement 2. The electric mover 130 is configured as a solenoid comprising a slug 132 surrounded by an electromagnetic coil (not shown). The electric mover 130 could also be configured as an electric motor or a threaded piston. Along the line of movement 2, the slug 132 is rigidly or fixedly connected via a coupling element 110 to the locking element 120. The slug 132 and the coupling element 110 are configured to synchronously move with the locking element 120 along the line of movement 2.

(15) The emergency release element 202, as well as the further release element 204 act upon an auxiliary coupler 210 of the additional release unit 200. When actuating the emergency release element 202 or the further release element 204, the emergency release element 202 or the further release element 204 cause the auxiliary coupler 210 to move in a release direction orientated towards the electric mover 130. The emergency release element 202 and the further release element 204 of the additional release unit 200 each form an additional mover of the additional release unit 200.

(16) The emergency release element 202 comprises a shaft 205 that couples the push button 201 of the emergency release element 202 to the auxiliary coupler 210. The shaft 205 is movable perpendicularly to the line of movement 2. On a first end of the shaft 205, the push button 201 of the emergency release element 202 is located. On its second end, the shaft 205 has a skewed end surface 206 (see also FIG. 3). When moving towards the auxiliary coupler 210 in the direction perpendicular to the line of movement 2 of the locking element 120, the end surface of the shaft 205 slides over a slide face 211 (FIG. 3) of the auxiliary coupler 210 and pushes the auxiliary coupler 210 in the release direction. The slide face of the auxiliary coupler 210 is orientated essentially parallel to the skewed end surface 206 of the shaft 205.

(17) The further release element 204 comprises two rotating elements 205, each of which has cylindrical shape. An axis of each rotating element 205 is aligned perpendicular to the line of movement 2. Each rotating element 205 comprises at one end a protruding section having a flat surface that extends over the auxiliary coupler 210 of the additional release unit 200. Upon rotating one of the rotating elements 205, the flat surface of the protruding section engages a corresponding flat surface of the auxiliary coupler 210 and pushes the auxiliary coupler 210 towards the release direction. The auxiliary coupler 210 is generally positioned about the coupling element 110 of the locking unit 100 in the locking direction.

(18) The interlocking device 10 further comprises a sensor device with a main sensor 30 and an auxiliary sensor 32. The main sensor 30 and the auxiliary sensor 32 are each configured as a light-barrier. They comprise an opening, which is configured as a slit. The opening extends along the line of movement 2. The sensors 30, 32 are configured to detect an object inserted into the openings. To this end, the sensors 30, 32 are configured to emit a light beam from one side of the opening towards the other side of the opening. The light beam has an angle with the line of movement 2 and is in particular orientated perpendicular to the line of movement 2. The sensors 30, 32 are further configured to detect an interruption of their light beam by the object inserted into the opening of the respective sensor 30, 32.

(19) FIG. 3 shows a perspective close-up view of the locking mechanism of the interlocking device 10. In particular, FIG. 3 shows the shaft 205 with the skewed end surface 206 and the slide surface 211 of the auxiliary coupler 210.

(20) The coupling element 110 of the locking unit 100 comprises a sensor actuator 111 and a further sensor actuator 112. The sensor actuators 111, 112 of the locking unit 110 are formed platelike, whereby their extension along the line of movement 2 is larger than perpendicular to the line of movement and in the direction of the light beams of the sensors 30, 32. As the sensor actuator 111 and the further sensor actuator 112 are attached to the coupling element 110, they move together with the coupling element 110 along the line of movement 2. The sensor actuator 111 is configured to actuate the main sensor 30 by moving into the slit of the main sensor 30 and thus blocking the light beam of the main sensor 30 and the further sensor actuator 112 is configured to actuate the auxiliary sensor 32 by moving into the slit of the auxiliary sensor 32 and blocking the light beam of the auxiliary sensor 32.

(21) The auxiliary coupler 210 of the additional release unit 200 comprises an auxiliary sensor actuator 212, which has the same platelike shape as described with respect to the sensor actuators 111, 112 of the coupling element 110 of the locking unit 100. The auxiliary sensor actuator 212 is located about the further sensor actuator 112 and configured to actuate the auxiliary sensor 32 by moving into the slit of the auxiliary sensor 32.

(22) According to alternative embodiments of the interlocking device 10, the sensor actuator 111 and/or the further sensor actuator 112 may be attached to any other movable part of the locking unit 100. In particular, they may be attached to the locking element 120 or to the electric mover 130. Analogously, the auxiliary sensor actuator 212 may be attached to any other movable part of the additional release unit 200. The auxiliary sensor actuator 212 may in particular be attached to the emergency release element 202 and/or the further release element 204.

(23) FIG. 3 shows the locking unit 100 in a release position, in which the locking element 112 is retracted into the housing 12 of the interlocking device 10. In the release position, the sensor actuator 111 actuates the main sensor 30 by blocking its light beam. The further sensor actuator 112 is located outside the slit of the auxiliary sensor 32, so that the auxiliary sensor 32 is not being actuated and its light beam is not being blocked. FIG. 3 further shows the additional release unit 200 in a neutral position, in which the further sensor actuator 112 is located outside the auxiliary sensor 32 and does not actuate the auxiliary sensor 32.

(24) As can be seen from FIG. 3, only the main sensor 30 is actuated, when the locking unit 100 is positioned in the release position and the additional release unit 200 is positioned in the neutral position. Therefore, a main sensor signal of the main sensor 30 represents a logical one, while an auxiliary sensor signal of the auxiliary sensor 32 represents a logical zero.

(25) The interlocking device 10 comprises a biasing element 220, which is configured as a spring. The biasing element 220 is placed between the auxiliary coupler 210 of the additional release unit 200 and a carrier 222 of the interlocking device 10. A position of the carrier 222 is fixed with respect to the mounting plate 14 and the housing 12 of the interlocking device 10. The carrier 222 comprises a guiding element 223, which is configured to guide the auxiliary coupler 210 of the additional release unit 200 along the line of movement 2. The guiding element 223 is placed inside the spring of the biasing element 220, thus also guiding the biasing element 220. The guiding element 223 has essentially cylindrical shape with an axis of the cylinder orientated along the line of movement 2.

(26) The guiding element 223 is configured as a hollow cylinder with a through-hole centered on its axis. The coupling element 110 of the additional release unit 200 has a guiding pin 224 with essentially cylindrical shape. The guiding pin 224 is aligned in parallel to the guiding element 223 of the carrier 222 and extends into the hole of the guiding element 223, thus being guided by the guiding element 223 along the line of movement 2. In alternative embodiments of the interlocking device 10, the guiding element 223 may be configured as a full cylinder and/or the auxiliary coupler 210 of the additional release unit 200 may comprise an opening, through which the guiding element 223 extends along the line of movement 2.

(27) FIG. 4 shows a further perspective close-up view of the locking mechanism of the interlocking device 10 with the locking unit 100 positioned in the release position and the additional release unit 200 positioned in the neutral position. The auxiliary coupler 210 of the additional release unit 200 comprises a guiding section 214. The guiding section 214 comprises three side faces of the auxiliary coupler 210 that are orientated parallel to the line of movement 2. The side faces enclose the coupling element 110 on three sides and thus guide the coupling element 110 along the line of movement 2.

(28) The auxiliary coupler 210 further comprises a mechanical stop 216. The mechanical stop 216 is formed by at least one flat side surface of the auxiliary coupler 210 that faces in the opening direction and extends perpendicular to the line of movement 2. In the locking direction, the mechanical stop 216 is positioned about a corresponding limiting element 114 of the coupling element 110. The limiting element 114 is configured as a protrusion of the coupling element 110 in a transverse direction forming a flat surface that is orientated perpendicular to the line of movement 2. When the coupling element 110 is moved into the locking direction, it abuts with the limiting element 114 on the mechanical stop 216, as soon as the coupling element 110 reaches the locking position. Therefore, the mechanical stop 216 engages with the coupling element 110 when the coupling element 110 is positioned in the locking position.

(29) FIG. 5 shows a perspective close-up view of the locking mechanism of the interlocking device 10 with the locking unit 100 positioned in a locking position and the additional release unit 200 positioned in the neutral position. In the locking position, the locking unit 100 has been moved in the locking direction towards the outside of the housing 12 of the interlocking device 10.

(30) In the locking position, the sensor actuator 111 is placed outside the slit of the main sensor 30 and the further sensor actuator 112 is located inside the slit of the auxiliary sensor 32, so that the auxiliary sensor 32, but not the main sensor 30 is being actuated by the locking unit 100. The main sensor signal then represents a logical zero and the auxiliary sensor signal represents a logical one.

(31) When the locking unit 100 is placed in the locking position and the additional release unit 200 is moved from the neutral position in the opening direction, the additional release unit 200 engages with the locking unit 100 via the mechanical stop 216. Therefore, the additional release unit 200 pushes the locking unit 100 in the release direction and towards the release position of the locking unit 100. When the locking unit 100 reaches the release position, the additional release unit 200 simultaneously reaches an additional release position.

(32) FIG. 6 shows a perspective close-up view of the locking mechanism of the interlocking device 10 with the locking unit 100 positioned in the release position and the additional release unit 200 positioned in the additional release position. The sensor actuator 111 of the locking element 110 actuates the main sensor 30 and the auxiliary sensor actuator 212 of the additional release unit 200 actuates the auxiliary sensor 32. The main sensor signal, as well as the auxiliary sensor signal then represents a logical one.

(33) An evaluation unit of the interlocking device 10 is connected to the main sensor 30 and the auxiliary sensor 32 and receives the main sensor signal and the auxiliary sensor signal. The evaluation unit is connected to a control unit of the machine secured by the interlocking system 1 and transmits a status signal representing a state of the interlocking device 10 to the control unit. If the main sensor signal represents a logical one and the auxiliary sensor signal represents a logical zero, the evaluation unit outputs a normal release signal as the status signal. If the main sensor signal represents a logical zero and the auxiliary sensor signal represents a logical one, the evaluation unit outputs a locking signal as the status signal. If both the main sensor signal and the auxiliary sensor signal represent a logical one, the evaluation unit outputs an additional release signal as the status signal. The evaluation unit may be a logic module, for example a microcontroller, microprocessor or FPGA.

LIST OF REFERENCE SIGNS

(34) 1 interlocking system

(35) 2 line of movement

(36) 10 interlocking device

(37) 12 housing

(38) 14 mounting plate

(39) 15 mounting elements

(40) 20 movable part

(41) 21 holding element

(42) 22 fastening elements

(43) 23 actuator

(44) 24 opening

(45) 30 main sensor

(46) 32 auxiliary sensor

(47) 100 locking unit

(48) 110 coupling element

(49) 111 sensor activator

(50) 112 further sensor activator

(51) 114 limiting element

(52) 120 locking element

(53) 130 electric mover

(54) 132 slug

(55) 200 additional release unit

(56) 201 push button

(57) 202 emergency release element

(58) 203 tool receiving section

(59) 204 further release element

(60) 205 shaft

(61) 206 end surface

(62) 210 auxiliary coupler

(63) 211 slide surface

(64) 212 auxiliary sensor activator

(65) 214 guiding section

(66) 216 mechanical stop

(67) 220 biasing element

(68) 222 carrier

(69) 223 guiding element