EP2047494B1 - Safety switching device for interlocking a protection device - Google Patents

Description

The invention relates to a safety switching device for locking a protective device, such as a protective door of a motor or an industrial robot or drgl.

A particular problem with safety switching devices occurs when particularly high, acting on the operating bar tensile forces occur that lead to the destruction of the lock, whereby the protection device is disabled. Which may mean that with the drive head disengaged, removed or destroyed (by shearing off or even disassembling the drive head), it is possible for the safety switching device to change to a normally safe switching state, i. The contact is switched as if the protective device (protective door) was closed and locked. This means that the protected system (motor or machine) can be operated with the safety guard open.

A safety switching device for locking a protective device is in the document DE 31 12 097 A1 shown in which a plunger protrudes when inserted actuator in a window-like recess of the actuating element. In this case, a pivotable by the actuating element between a first and a second position locking disc is provided, which has a slot-like opening with different widths at the end, through which the plunger end can pass through depending on the pivot position in the recess of the actuating element.

From the publication DE 34 30 090 A1 is known in principle, the safety switching device DE 31 12 097 A1 in addition to be provided with a force acting on the plunger electromagnetic locking.

In addition, a key switch is known ( DE 10 2005 050 313 A1 ) with an operable by a bolt-like, a window having key control disk. The control disk has an interior in which engages one end of a locking bolt. In the inserted position of the key, the locking pin end does not reach into the window of the key.

From the publication DE 92 12 093 U1 discloses a safety switching device for the locking of a protective device, comprising a housing, a housing formed in the lock shaft for the insertion of an actuating element for the switching device, and wherein the actuating element of a windowed latch consists and the window is closed in the direction of actuation of lying with a cross bar, one of a feed in locking position and back in the release position perpendicular to the direction of the locking bar longitudinally movable locking pin and a full insertion of the bolt to an activation (by means of energized holding magnet) of the feed of the locking pin comes and in the Einführendlage of the bolt, the locking pin end enters the window and the withdrawal of the bolt locks, and upon deactivation of the feed (holding magnet is de-energized) the locking pin end leaves the window. A comparable facility is in the DE 4328297 C1 described.

However, the known devices show the problem mentioned in the introduction that they are not sufficiently secured against the application of high tensile forces on the actuating bolt. It is therefore an object of the invention to make a reinforcement of the device.

The object is achieved according to the invention by the features of patent claim 1. The dependent claims point to advantageous and expedient embodiments of the invention.

With the device according to the invention results in a much higher level of security against unusually strong forces or loads.

The essence of the invention is the special use and the design of the control disk. This is actuated by the bolt and is pivotable about a perpendicular to the actuating direction of the bolt and senkecht arranged for movement of the locking pin axis between a first (release) and a second position (locking). The control disk has an interior in which the locking pin end ends. The control disk has a cut formed on the circumference, the position in relation to the locking shaft is such that the crosspiece of the bolt engages in the recess and it comes with a complete insertion of the bolt to a rotation in the second position (locking) of the control disk and in the insertion end position of the bolt and upon activation of the advance of the locking bolt ("locking the locking means") the locking pin end enters the window and locks the pulling out of the bolt, or when deactivating the feed, the locking bolt end leaves the window. Regardless of the position occupied by the control disk, the locking pin end is located in the interior of the control disk.

The special design of the device prevents the pulling out of the bolt even with extreme traction. The bolt is blocked by the locking pin located in the control disk, preferably made of steel. In a proven training can the switching device is also secured with acting on the bolt tensile forces of up to 2400 N, which corresponds to an exceeding of about 30% of the regulation DIN EN 1088 or DIN EN 954.

The subject matter of the application includes the following preferred embodiments, which may be used individually or in combination with each other.

Parallel to the axis of rotation of the control disk, a pin is guided through an opening in the control disk, which is adjacent in position to the locking pin end on the side of the insertion shaft. The pin is tight - approximately at the height of the axis of rotation of the control disc - passed the locking pin. When the feed is activated, the locking pin is in the locked position. In this situation, pulling the bolt loads the locking bolt in bending. The pin is an additional abutment that intercepts the bending load of the locking pin.

On the control disk locking grooves may be present, which cooperate with spring-loaded detent pin in the two end positions of the control disk, and thus produce an increased, but surmountable resistance to the actuation of the control disk when pulling or inserting the bolt.

In the interior of the control disk, a stop is formed, on which the locking pin is held in activated feed in abutment.

The feed (locking of the locking pin) can be applied by the force of a tensioned spring or by an electromagnet. In the former case, the relaxed spring is tensioned by a current-supplied electromagnet. The release of the lock is generated by the energization of the electromagnet. In the second case, the electromagnet is energized to activate the feed (so-called working current principle) and the feed is deactivated by switching off the energization. The release of the lock is generated by the force of the electromagnet in the home position moving return spring when de-energized electromagnet.

The invention can be used independently of the locking principle used. For description, however, the working current principle is to be addressed, in which an electromagnet in the energized state, the locking pin moves to a first position, wherein the locking pin protrudes into the locking shaft and locks the bolt mechanically.

When de-energized electromagnet, the lock is passivated, wherein the locking pin moves out of the locking shaft and thereby releases the latch by the force of a return spring moves the locking pin against the locking direction to a second position. The bolt takes during his door movement with the control disk. The bolt is guided in the recess of the control disk. The locking pin then remains inevitably in its release or unlocking position.

The device further comprises a housing in which mechanical switching contacts, for example, pairs or individual contacts of openers and / or closers can be arranged. Accordingly, an indication and / or monitoring of the switching and operating state of the switching device (open, closed, locked, malfunction) can take place via the contacts. In the housing, a longitudinally displaceable dome tappet be mounted for direct mechanical actuation of the switch contacts, wherein the dome ram of the tumbler of the locking pin, a return spring and a drive head located in the mechanical control disc is movable in two end positions, wherein the drive head, locking pin and contact apparatus arranged one behind the other in the axial direction are.

In addition, further monitoring functions may be present, for example in such a way that the feed of the locking bolt is released only after a presettable delay time in order to release the switching device. As a result, the immediate removal of the bolt from the locking shaft after release of the safety switching device is not possible. Only after the delay time has elapsed is the latch released.

The housing of the switching device may be formed of a rigid housing body and a rotatably formed on the housing body drive head. In the drive head in such an embodiment, the control disk together with their storage and locking means (see below) housed. The drive head is rotatably mounted against the basic housing coaxial with the locking pin (preferably by 360 °). As a result, the device can be used in many ways, because the drive head can be positioned in four rotated by 90 ° positions.

The rotatable mounting of the drive head can be additionally secured with non-removable pins against removal. The pins can be made of metal or plastic, and are driven firmly into the housing body, so that the drive head is anchored. This safety measure prevents the removal of the drive head after loosening the (four) screws to change the approach direction, whereby the device is a manipulation possibility is prevented, which would otherwise be present with removable drive head.

The safety switching device is arranged primarily on a solid body (for example, on a post, box, or grid, or on a wall) of a system, with plant usually a protected area or a sensitive machine (eg a robot) is to be understood ; The actuating element of the safety switching device is arranged on an additional element of the system, wherein the additional element is a movable part, usually a protective door leading to the plant.

In the drive head, a device may be provided which cooperates with arranged at the front end of the bolt insertion bevels, whereby a release or blocking of the insertion of the bolt takes place. The locking device is used to protect against manipulation or misuse of an inadmissible bolt. Such locking devices are known, for example, those in DE 4238016 A1 is described.

• Fig. 1 Schnitt durch den Antriebskopf, Riegel in Verriegeltstellung,
• Fig. 2 Schnitt durch den Antriebskopf; Riegel in der Stellung frei und TÜR geschlossen,
• Fig. 3 Schnitt durch den Antriebskopf; Riegel in der Stellung frei und TÜR offen,
• Fig. 4 Schnitt durch den Antriebskopf in gegenüber den Figuren 1 bis 3 um 90° gedrehten Schnittebene,
• Fig. 5A und 5B: Steuerscheibe perspektivisch und im Schnitt, und
• Fig. 6 der Riegel

In the following the device according to the invention for the locking in an exemplary embodiment will be explained in more detail with the aid of the drawing.

• Fig. 1 Section through the drive head, bolt in locked position,
• Fig. 2 Section through the drive head; Latch in the position free and DOOR closed,
• Fig. 3 Section through the drive head; Latch in the position free and DOOR open,
• Fig. 4 Section through the drive head in relation to the FIGS. 1 to 3 cutting plane rotated by 90 °,
• Figs. 5A and 5B : Control disc in perspective and in section, and
• Fig. 6 the latch

The Fig. 1 shows a section through the arranged at the upper end of the housing 105 of the device according to the invention drive head 110 in the position of the captured latch 32. The actuating latch is for example attached to a protective door (or other locking device) of a motor or an industrial robot. The bolt 32 is inserted to the right, the control disk 10 is in the rotated to the right end position. The bolt end 21 is in its extreme extended position in the cavity 14 of the control disk. The removal of the bolt 32 is not possible through the window 36 located, preferably made of steel locking pin 20, because of its excellent stability.

The locking pin is a locking force (solenoid) and a restoring force (spring) to the hub W (see Fig. 2 ) emotional. Here, the locking pin may be formed as an elongated design of the armature of an electromagnet. In the first - in Fig. 1 shown position predominates the locking force of the restoring force (solenoid energized) and the bolt 20 has moved into the locked position. The locking pin 20 has penetrated into the plane of the insertion shaft 30 and extends with its end 21 in a window 36 of the bolt 32. Thus, the bolt 32 is no longer extend out of the drive head 110. In this locking position contacts that mediate the door lock and the door position, closed and signal via appropriate control and display means the dangerous state of the machine or system. A restoring force (return spring, not shown) conveys the bolt to a retracted position (solenoid de-energized).

On average, the control disk 10 is also recognizable, which further in Figs. 5A and 5B will be described. In the control disk, a cavity 14 is formed, in which the locking pin comes to rest in both end positions. In Fig. 1 the bolt is in the locked position; the locking pin protrudes into the window 36 of the bolt and the crosspiece 34 (see Fig. 5 ) of the bolt abuts against the locking pin.

The Fig. 2 shows (again in section) the unlocking state of the device. The restoring force comes into play and moves the locking pin 20 against the locking direction. The bolt end 21 moves out of the window 36 of the bolt and releases it. The system is now in a safe state with the door closed.

Parallel to the axis of rotation 11 'of the control disk 10, a pin 50 is guided through an opening (groove 18) in the control disk, which is in its position adjacent the locking pin end 21 on the side of the insertion shaft 30 (see Fig. 1 to 3 ). The pin passes close to the locking pin so that the locking pin slides along the pin. If the bolt is pulled in locking position of the locking pin, although the locking pin is loaded on bending, but the pin is an abutment that intercepts the load on the locking pin.

In Fig. 2 the bolt end 21 is retracted, the bolt 32 is still inserted and the control disk 10 is rotated to the right. The bolt 32 can now slide over the bolt end and be moved out (to the left); In this case, the transverse web 34 comes against the edge 13 "of the control disk 10 and there is a left-hand rotation of the control disk .. The swivel angle in the embodiment is about 90 ° Fig. 3 shown position. By turning to the left is by means of cam (there the locking edge 16) on the control disk, the bolt 20 inevitably still moved a small way further down, which is sufficient to actuate and open an electrical contact. A protective door is now also under 'mediation' the electrical contact open.

A (possible) movement in the locked position of the retracted locking bolt is prevented by the locking edge 16 (on the control disk), since the locking edge 16 is seated in front of the shoulder 22 formed on the bolt end 21.

Furthermore, an encoded barrier is used in the described arrangement, as for example in the DE 4238016 A1 is shown. In accordance with this prior art, in the present embodiment two locking carriages 90 (FIG. Fig. 4 ), which prevent a movement of the control disk as a barrier. The locking slides 90 are actuated by ramps 33 'formed on the latch, which act as coding elements. The locking slides slide with spring force actuation behind the locking edge 13 "'of the control disk 10 and can only be moved to the side by pushing the bolt in. Snaping behind the locking edge 13"' inevitably produces a mechanical reclosing lock. The introduction of a bolt without proper coding is limited. With a bar without coding or with a mis-coded bar, the lock is not actuated. In the present device, the control disk is in the in Fig. 3 shown locked position in the drive head.

For signaling, (existing) door position contacts can now be opened and signal the opened and thus safe state of the relevant safety area.

In the situation after Fig. 3 the device is ready to be switched on. The bolt is still pulled down by the restoring force of the locking spring. The locking slide 90 are moved towards each other by spring force. Upon insertion of the latch, the bevels 33 'formed on the tabs 33 of the latch move the locking carriages 90 to the side and terminate the blockage at the edge 13 "'.

The front edge of the crossbar 34 meets the edge 13 'in the incision and moves the control disc (clockwise according to FIG) in the second position. When the electromagnet is energized, the locking force applied by the electromagnet moves the bolt into the locking position.

In Fig. 4 is the cut in one opposite the FIGS. 1 to 3 rotated through 90 ° by the housing 105 of a device and arranged on the housing drive head 110. The drive head is rotatably mounted on the base housing. Recognizable is in the axes 11 'mounted control disc 10. At this locking grooves 19 are present (see also Fig. 5A ), which cooperate with acted upon by springs 82 locking pin 80 in the two end positions of the control disk and produce noticeable locking positions. It is thus achieved that an increased, but surmountable resistance to the operation of the control disk is present, which complicates the pulling or insertion of the bolt. As a result, the control disc is still under bias with an unlocked, but closed guard door, so that the protective door does not jump open immediately even with small forces.

The bearing of the drive head is secured against removal with non-removable pins 108. The pins are driven firmly into the housing body, so that the drive head is anchored.

The FIGS. 5A, 5B and 5C show the control disc in perspective and in section. The control disk is rotatably mounted axially in the bearings 11 (see also Fig. 4 ). The axis 11 'intersects the longitudinal axis of the locking pin at right angles. On the circumference of the control disk an actuating cut 12 is formed for the bolt. In the two end positions (right, left rotated) of the control disk of the operating recess 12 is aligned with the insertion shaft 30. When inserting the bolt (control disk in the left position in accordance with Fig. 3 ), the crossbar 34 of the bolt comes into contact with the inner edge 13 'in the recess of the control disk. To pull the bolt (control disk in position right according to Fig. 2 ) abuts the cross bar 34 of the bolt of the inner edge 13 "in the operating recess 12.

Also present on the circumference of the control disk is a locking edge 13 "', which has already been mentioned, which cooperates with the lock present in the drive head 110 of the device according to the invention limited to the disk carrying the bearing 11 for the axis of rotation, into which the bolt protrudes (in each of its end positions) .The stroke of the bolt is indicated by W in Fig. 2 located. The size W of the lifting movement corresponds approximately to the height of Riegeleinführschachts. The cavity 14 is open up to the operating recess 12. During the longitudinal displacement of the bolt, the switching device from its open state to the closed state, so that when the door is closed, the protected system can be put into operation.

The Fig. 6 shows a flat-plate element on a mounting flange 33 "formed, double-tongued latch 32. At the front ends of the tongues 33 bevels 33 'formed.The tongues 33 and a transverse web 34 surround a window 36, in which the locking pin engages in the locking position that the bevels 33 'of the present embodiment are formed on the outside of the tongues, whereas the bevels in the prior art (FIG. DE 4238016 A1 ) are formed on the inside of the tongues. The formation of the slopes corresponds to the formation of the locking heads (locking slide). The locking slides are linearly movable in grooves against each other and engage locking edges or locking grooves of a locking or control means, in the present embodiment, the bevels 33 'move away the locking slide from each other during insertion of the bolt and move the spring heads when removed to move towards each other.

In the DE 4238016 A1 lies an inverse principle. The bevels move the bolt heads towards each other when the bolt is inserted, and when the bolt is removed, the bolt heads are moved apart by spring force.

Two trained in the drive head locking slide 90 engage - in the sectional drawing of Fig. 3 viewed from behind (behind the plane of the drawing) and from the front (in front of the plane of the drawing) - behind the edge 13 "', only with the insertion of a suitable bolt (see Fig. 6 ) is a functional actuation.

reference numeral

10

control disc

11 11 '

Bearing and swivel axis

12

operation incision

13 '13' '13' ''

edge

14

cavity

15

Stop for bolts

16

Locking edge for 22

18

groove

19

locking grooves

20

bolt

21

pintail

22

Shoulder at the bolt

30

Insert shaft bolt shaft

32

Latch (actuator)

33

Tongues of the bolt

33 '

slope

33 ''

mounting tab

34

crosspiece

36

window

50

pen

80

locking pin

82

compression spring

90

two locking carriages

100

Safety breaker

105

casing

108

pencils

110

powerhead

Claims (12)

1. Safety switching device to lock a protective device, comprising :

   - a housing (105),

   - a bolt shaft (30) in the housing (105) to insert an actuating element for the switching device,

   - and wherein the actuating element consists of a window (36) bolt (32), and the window (36) is locked with a frontal crosspiece (34) in the actuating direction,

   - a longitudinally moveable locking pin (20) that is moved into the locking position and back into the release position perpendicular in the direction of the actuation of the bolt (32) by a feed,

   - a control disc (10) rotating between a first and second position, actuated by the bolt (32) that can pivot perpendicularly in the direction of the actuation of the bolt and perpendicular to the movement of the locking pin's (20) axis rotation

   - wherein the control disc (10) has a cavity (14) in which the end of the locking pin end (21) terminates, and

   - the control disc (10) with a groove on the perimeter (12), the position of which relative to the bolt shaft (30) is such that the crosspiece (34) of the bolt (32) fits into the groove (12) and when the bolt (32) is fully inserted can rotate into the second position of the control disc (10) and into the insertion end position of the bolt (32) and when the locking pin feed (20) is activated, the locking pin end (21) enters the window (36) to prevent the withdrawal of the bolt and, when the feed is deactivated, the locking pin end (21) exits the window.
2. Safety switching device in accordance with claim 1, characterised in that a pin (50) is inserted parallel to the rotation axis (11) of the control disc through an opening (18) in the control disc (10), that in its position to the locking pin end (20) is adjacent to the site of the insertion shaft (30).
3. Safety switching device in accordance with claim 1 or 2, characterised that an end-stop (15) is located in the cavity (14) of the control disc (10) to which the locking pin (21) is attached when the feed is activated in the system.
4. Safety switching device in accordance with one of the preceding claims characterized that locking grooves (19) are located on the control disc (10) that use spring-loaded detent pins (80) in the two end positions of the control disc to generate a surmountable resistance.
5. The safety switching device, in accordance with one of the preceding claims characterised that the feed is applied using the power of a tensioned spring, and the relaxed spring is placed under tension by an energised electromagnet.
6. The safety switching device, in accordance with one of the claims 1 to 3, characterized that the feed is applied by an electromagnet which is energised to activate, and the feed is deactivated when the power source is switched off
7. Safety switching device in accordance with one of the preceding claims, characterised in that the locking pin (20) is moved into the lock position (LP) and the release position (RP) and wherein the switching contacts are activated that serve to display and/or monitor the operational function of the switching device.
8. Safety switching device in accordance with one of the preceding claims, characterised that the locking pin feed (20) is only withdrawn after a pre-set time delay to release the switching device.
9. Safety switching device in accordance with one of the preceding claims, characterised that the housing (105) consists of a rigid housing body and a rotating drive head (110) on the housing body, wherein the control disc (10) and its storage are housed in the drive head, and the drive head is positioned against the base housing coaxial to the locking pin (20) such that it can be rotated.
10. The safety switching device, in accordance with the preceding claim, characterised that the mounting of the drive head (110) takes place in the housing body with secured pins (108) to prevent withdrawal (108).
11. The safety switching device in accordance with one of the preceding claims, characterised that the switching device can be mounted to a fixed base body of a system and the actuation element (32) can be mounted on an auxiliary element of the system.
12. The safety switching device in accordance with claim 1, characterised that a device contained in the drive head (110) operates with lead-in chamfers (33, 33') at the front end of the bolt (32) that together regulate the release or locking of the bolt insertion.

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