Safety Gate Monitoring Module

Abstract

To provide a safety gate monitoring module (16) having longer life expectancy and / or improved reliability to monitor a state of a safety gate (14).SOLUTION: A safety gate monitoring module is provided with an actuator insertion port (38) to receive an actuator (36), and is configured to generate a safety gate signal upon insertion of the actuator (36) into the actuator insertion port (38), wherein the actuator insertion port (38) is provided with a guard lock device (44) configured to hold the actuator (36) in the actuator insertion port (38) in an operation state, and the guard lock device (44) is provided with a bolt (50) having a bearing element insertion port (58), and a bearing element (54) rotatably attached in the bearing element insertion port (58) and placed on a free end (62) of the bolt (50), and the bearing element (54) at the free end is configured to engage with the actuator (36) in the operation state.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a safety gate monitoring module for monitoring the state of a safety gate.

[0002] The present invention relates to a safety gate monitoring module having a safety gate as access to a safety area, a safety gate monitoring module of the above-described type, an actuator, and a control unit configured to read a safety gate signal and control a machine or system arranged in the safety area according to the safety gate signal.

Background Art

[0003] Safety gate monitoring modules of the above-described type are often also referred to as safety switches. Exemplary safety gate monitoring modules, i.e., safety switches, of the type mentioned at the beginning are known from the following Patent Document 1, the following Patent Document 2, the following Patent Document 3, and the following Patent Document 4.

[0004] Safety gate monitoring modules of the type under discussion are used for safety gates, safety flaps, etc. The terms "safety gate monitoring module" and "safety gate" are used in this specification, but the safety gate monitoring module according to the present invention can be used for any type of separating protective device. Therefore, the term "safety gate" in the sense of the present invention must be interpreted broadly. Therefore, only the term "safety gate" is used hereinafter instead of the general term "separating protective device", but this is not intended to limit the scope of protection.

[0005] The safety gates that can be used by the safety gate monitoring module usually function, for example, as access to a safety area where an automatically operating machine or system is located. The machine or system can be, for example, a robot, a machine tool with a high-speed rotating spindle, a transportation or conveying system, a press, or any other machine or system whose operation poses a danger to humans in the above-mentioned safety area or the working area of the machine. The safety gate monitoring module may function as a signaling device, with the help of which the control unit can detect the closed state of the safety gate. The control unit is configured to read the safety gate signal generated by the safety gate monitoring module and to control the machine according to the safety gate signal. For example, the machine can only be operated when the safety gate signal is present. In other words, the control unit is configured to enable the operation of the machine or system only when it receives the safety gate signal from the safety gate monitoring module (i.e., when the safety gate is closed). On the other hand, if (assuming it is possible) the safety gate is open during operation, the control unit must put the machine or system in a safe state, for example, by turning off the power supply to the machine or system.

[0006] For example, there are still many machines and systems that, because they are still gradually stopping, still pose a danger for a certain period even after being turned off. For such applications, a safety gate monitoring module is required to prevent the safety gate from opening until the machine or system reaches its safe state. This function is called the guard lock function.

[0007] Conventionally, this type of safety gate monitoring module has what is called an actuator and an actuator insertion port that functions as its counterpart. The actuator insertion port is part of the basic unit, where additional electronic components are usually housed, and from where a connection cable for connecting the safety gate monitoring module to the control unit usually starts. Therefore, the basic unit with the actuator insertion port is preferably arranged on the fixed part of the safety gate (for example, on the door frame), while the actuator is preferably arranged on the movable part of the safety gate (for example, on the door leaf of the movable door). This has the advantage that the part of the safety gate monitoring module arranged on the movable part of the safety gate does not need to be powered. This is generally because only the basic unit of the safety gate monitoring module needs to be powered.

[0008] When the safety gate is closed, the actuator engages with the actuator insertion port, which is detected with the help of one or more sensors. In the case of a safety gate monitoring module with a guard lock system, the actuator is also locked or closed within the actuator insertion port against storage. The "guard lock system" is equipped with a locking device for locking the actuator within the actuator insertion port.

[0009] In the latter case, the safety gate monitoring module performs two functions. That is, one is the detection function, with the help of which the closed position of the safety gate is detected. The other is the guard lock function, by which the safety gate is prevented from opening as long as the actuator is locked within the actuator insertion port. The actuator can be released, for example, by an electric motor actuator, which is started by the control unit as soon as the machine or system being monitored estimates its safe state.

[0010] This type of safety gate monitoring module is sold by the applicant under the name PSENmlock. This safety gate monitoring module is very versatile. The actuator of the safety gate monitoring module may be substantially rod-shaped or pin-shaped, and the actuator insertion opening that operates in conjunction with it has a through slot, a U-shaped opening, or a blind hole or through hole into which the rod-shaped or pin-shaped actuator engages.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0012] When the opening and closing process of the safety gate is repeated, after being used as intended, it has become clear that this leads to material wear at the actuator and the guard lock device or the actuator insertion opening. Due to this wear, for a safety gate monitoring module having a specified number of times for the opening and closing process, the required service life may not be achievable. Furthermore, this may pose a safety risk. This is because the guard lock function can no longer be guaranteed with sufficient reliability.

[0013] Therefore, an object of the present invention is to provide a safety gate monitoring module having a longer service life and / or improved reliability.

Means for Solving the Problems

[0014] The object of the above invention is to monitor the state of a safety gate based on a safety gate monitoring module of the type described at the beginning. For this purpose, the safety gate monitoring module includes an actuator insertion port for receiving an actuator, and is configured to generate a safety gate signal when the actuator is inserted into the actuator insertion port. The actuator insertion port is provided with a guard lock device configured to firmly hold the actuator within the actuator insertion port in an operating state. The guard lock device includes a bolt having a bearing element insertion port and a bearing element rotatably mounted within the bearing element insertion port and disposed at the free end of the bolt. This end is achieved by the fact that it is configured to engage the actuator in the operating state.

[0015] The guard lock device according to the present invention particularly includes a bearing element rotatably attached to the bolt, and the bearing element is arranged in such a way that it can come into contact with the actuator.

[0016] Unlike conventional guard lock devices in which the bolt slides on the actuator, according to the present invention, the bearing element attached to the bolt can roll on the actuator. Therefore, according to the present invention, it is preferably possible to reduce the friction and / or wear in the frictional contact between the guard lock device and the actuator, and thus it is also possible to minimize the opening and closing force in the safety gate monitoring module.

[0017] When the actuator is inserted into the actuator insertion port, the bearing element can contact the actuator to simplify the insertion of the actuator into the actuator insertion port and / or to reduce the friction and / or wear between the guard lock device and the actuator. During the insertion of the actuator into the actuator insertion port, if the bearing element rolls on the actuator instead of sliding on it, the frictional contact features rolling friction instead of sliding friction. Therefore, the friction in the frictional contact can be reduced. The same applies to the opening process of the safety gate. During the opening process, the actuator is pulled out from the actuator insertion port.

[0018] Therefore, a solution for reducing the wear between the guard lock device and the actuator and improving the reliability of the guard lock device is provided in a simple design and an economical way.

[0019] Moreover, the present invention preferably enables a more free and thus simpler bolt configuration. In particular, the shape of the bolt can be configured to be more independent of the actuator. At the same time, the bearing element can be treated independently of the rest of the bolt, for example with respect to surface finishing, to improve the characteristics of the frictional contact. This can have the effect of simplifying the manufacture of the guard lock device and the actuator.

[0020] Moreover, the present invention enables the bearing element to be replaced independently of the rest of the bolt. In the guard lock device according to the present invention, even if it is inevitable that the wear is reduced compared with the conventional guard lock device, the bearing element may still wear due to continuous use. In this case, it is possible to selectively replace only the bearing element and continue to use the other parts of the bolt. Therefore, the components of the guard lock device can be used continuously.

[0021] In order to adjust the characteristics of the frictional contact (for example, the coefficient of friction between the two parties of the frictional contact) as needed, in normal procedures, in particular, the materials of the two parties of the frictional contact are harmonized with each other. Furthermore, the present invention enables the guard lock device to comprise different materials. Thereby, the materials of the two parties of the frictional contact can be better harmonized with each other.

[0022] According to the present invention, the bearing element may comprise a material different from that of the bolt. Therefore, by the selected combination of materials of the bearing element and the actuator, it is possible to define the characteristics of the frictional contact, and at the same time, the selection of the material of the bolt can be made more independent from the material of the actuator.

[0023] Therefore, the object of the present invention described above is fully achieved.

[0024] According to a preferred aspect of the invention, the bolt is provided with loss prevention means configured to hold the rotatably mounted bearing element moored to the bolt.

[0025] By the loss prevention means, the bearing element is permanently held in the desired position and / or alignment in the bolt. In this way, the reliability of the safety gate monitoring module can be improved.

[0026] According to another aspect of the invention, the loss prevention means is formed by a cross-section fastener of the bearing element insertion opening.

[0027] Therefore, according to this aspect of the invention, the bearing element insertion opening is tightened to hold the bearing element in the desired position and / or alignment in the bolt. The cross-section fastener can act as a latch element for the bearing element. This enables simple and economical manufacture of the guard lock device.

[0028] According to another aspect of the invention, the diameter of the cross-section fastener is smaller than the diameter of the bearing element.

[0029] This ensures that the rotatably mounted bearing element cannot be released from the bearing element insertion opening. Thus, the bearing element is firmly held in the desired position and / or alignment in the bolt.

[0030] According to a preferred aspect of the invention, the bearing element is a ball.

[0031] Due to its symmetry, the ball has the advantage that it can be used as a bearing element that moves in multiple directions. Thus, while the actuator can be inserted into the actuator insertion opening from any direction, the ball functions as a bearing element to reduce the friction and wear described above.

[0032] However, the bearing element may also have any other suitable shape (e.g., cylindrical shape), which is particularly suitable for rotation or rolling in the actuator.

[0033] According to one aspect of the invention, the bearing element insertion opening comprises a conical shape, a spherical-cup-shaped or a cylindrical first part and a cylindrical second part.

[0034] In particular, the first part may be in contact with at least a part of the bearing element and / or may act as an insertion opening for the bearing insert. In particular, the second part may be in contact with at least a part of the bearing element and / or may act as a casing or housing (especially to counter the ingress of foreign objects).

[0035] According to one aspect of the invention, more than half of the bearing element is disposed within the bearing element insertion opening.

[0036] This means in particular more than half of the volume of the bearing element. Thus, most of the bearing element is protected within the bearing element insertion opening. The other part of the bearing element (i.e., less than half of the (volume) of the bearing element) is arranged outside the bearing element insertion opening and can come into contact with the actuator.

[0037] According to another aspect of the invention, the bolt is pre-loaded by a spring device.

[0038] The spring device is configured to operate the guard lock device such that the guard lock device firmly holds the actuator within the actuator insertion opening. The spring device preferably engages from the free end on the opposite side of the bolt and can push the bearing element into engagement with the actuator. During insertion of the bolt into the actuator and withdrawal of the bolt from the actuator, the bolt can generate a resistance force against the spring force.

[0039] According to a preferred aspect of the invention, the bolt comprises a body and a bearing shell inserted therein and forming at least part of the bearing element insertion opening.

[0040] Thus, the bolt is preferably configured in at least two or three parts. The bearing shell as a separate component inserted into the bolt enables easy protection of the bolt.

[0041] The bearing element is rotatably arranged within the (inserted) bearing shell. The bearing shell may be configured to receive the bearing element in such a way that the bearing element can roll on the bearing shell. Thus, advantageously, it is possible to reduce the requirements for the configuration of the bolt and the bearing element insertion opening, and it is possible to simplify the production of the bolt. In addition, the frictional contact can be lubricated.

[0042] The bearing element insertion opening is preferably designed in a conical shape on the side opposite to the bearing element.

[0043] Thus, preferably, for example, by forming a hole in the bolt, relatively easy production of the bearing element insertion port becomes possible. When the bolt includes a bearing shell, it is preferably possible to drill only one hole for inserting the bearing shell.

[0044] According to one aspect of the invention, the body of the bolt comprises a first material, and the bearing shell comprises a second material different from the first material.

[0045] Preferably according to this aspect of the invention, it becomes possible for the inserted bearing shell to comprise a material different from that of the bolt. In this way, the characteristics of the frictional contact between the bearing element and the bearing shell can be selectively adjusted independently of the material of the bolt (particularly with regard to reducing friction and wear).

[0046] According to another aspect of the invention, the bolt comprises a sleeve, the sleeve being fixed to the body of the bolt and forming at least part of the bearing element insertion port.

[0047] Therefore, according to this aspect of the invention, the bearing element insertion port is configured to be made up of at least two parts, and at least part of the bearing element insertion port is formed by the body of the bolt and the sleeve fixed thereto. Thus, preferably, it becomes possible to reduce the requirements for the body of the bolt with respect to production, and therefore, economical and easy production of the bolt becomes possible.

[0048] According to another aspect of the invention, the sleeve forms at least part of the anti-loss means. In this case, the sleeve preferably forms part of the cross-sectional clamping body of the bearing element insertion port. Therefore, the sleeve can act as a latching element for the bearing element.

[0049] In this way, regarding the manufacture of the bearing element insertion opening, the requirements for the bolt body can be preferably further reduced, and the production of the bolt can be simplified. Moreover, the bearing element can preferably be pre-mounted more easily, and therefore the sleeve can be used, for example, as a loss prevention means for the assembly process.

[0050] The sleeve can be fixed to the bolt body removably or non-removably. In particular, the sleeve can be fixed to the body by, for example, screws, rivets or pins, by force-fitting and form-fitting. It is likewise or additionally possible to connect the sleeve to the body materially (in particular, by adhesive bonding, brazing and / or welding). For example, it is also possible to shrink-fit the sleeve onto the body. A sleeve fixed removably to the body can have a suitable effect because the bearing element can be easily replaced (for example, after a certain number of opening and closing processes of the actuator and / or after exceeding a predetermined wear limit).

[0051] According to one aspect of the invention, the bolt comprises a number of bearing balls (bearing spheres) that can be arranged in the bearing element insertion opening.

[0052] The bearing element and the bearing balls can be configured to be in contact with each other and roll on each other. The bearing balls may preferably be made of a material different from that of the bolt. Thereby, the characteristics of the frictional contact between the bearing element and the bearing balls can be selectively adjusted more easily, in particular independently of the bolt (in particular with regard to the reduction of friction and wear).

[0053] The bearing balls preferably each have a diameter smaller than that of the bearing element. More preferably, the bearing balls each have the same diameter.

[0054] As a material, the actuator preferably comprises at least in part a chromium-nickel-molybdenum-stainless steel alloy (especially in the contact area with the guard lock device in the operating state of the guard lock device), and / or the bearing element comprises rolling bearing steel, and / or the bolt comprises free-cutting steel or case-hardening steel.

[0055] As already mentioned at the beginning, a further aspect of the invention relates to a safety gate monitoring system comprising a safety gate of the above-described kind (having a safety gate monitoring module according to the invention), an actuator, and a control unit.

[0056] The first part of the safety gate where the basic unit is arranged is preferably the fixed part of the safety gate (e.g., the door frame or door case). Equally, the second part of the safety gate where the actuator is arranged is preferably the movable door element (e.g., the door leaf). Arranging the basic unit on the fixed part of the safety gate has the advantage that the power supply to the part of the safety gate monitoring module attached to the movable part of the safety gate can be dispensed with. This is because usually only the basic unit of the safety gate monitoring module requires power supply.

[0057] The actuator preferably comprises an insertion opening configured to receive the guard lock device in the operating state. More preferably, the insertion opening of the actuator is configured to contact the bearing element. Therefore, the insertion opening of the actuator preferably has an engagement shape corresponding to the shape of the bearing element (especially a conical spherical cup shape or a cylindrical engagement shape).

[0058] It is obvious that the above-described features and the features described below can be used not only in the specific combinations specified without departing from the scope of the present invention, but also in other combinations or alone.

Brief Description of the Drawings

[0059]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11A

Figure 11B

Figure 11C

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0060] Exemplary embodiments of the present invention (hereinafter simply referred to as "embodiments") are shown in the figures and will be described in more detail in the following description.

[0061] FIG. 1 schematically shows a safety gate monitoring system according to one embodiment of the present invention. In the figure, the entire safety gate monitoring system is indicated by reference numeral 10.

[0062] Here, the safety gate monitoring system 10 includes a robot 12, and its working area is protected with the help of a safety gate 14. A safety gate monitoring module 16 is arranged on the safety gate 14.

[0063] The safety gate monitoring module 16 includes a gate portion 17 arranged on a movable gate element (the door of the gate) of the safety gate 14 and a frame portion 18 arranged on a fixed second portion 20 of the safety gate 14. In the illustrated embodiment, the fixed second portion 20 of the safety gate 14 is the gate frame or the gate framework. In other embodiments, this fixed second portion 20 of the safety gate 14 may also be the second gate door of the safety gate made up of two parts.

[0064] The frame portion 18 of the safety gate monitoring module 16 is connected to the safety switching device 26 via two lines 22, 24. The safety switching device 26 is, for example, a PNOZ (registered trademark) series safety switching device sold by the applicant of the present application. This is a multi-channel redundant safety switching device configured to evaluate the output signal of a signaling device such as the safety gate monitoring module 16 and, accordingly, turn off the electrical load. In this case, the electrical load is the robot 12. Therefore, the safety switching device 26 activates contactors 28, 30, and their make contacts are arranged at the connection between the power source 32 and the robot 12.

[0065] As an alternative to the safety switching device 26, the safety gate monitoring module 16 could also be connected to a programmable safety controller such as that sold by the applicant under the name PSS (registered trademark). Thus, the safety switching device 26 is generally the control unit 26 of the safety gate monitoring system 10, although it is not thereby limited to a particular embodiment.

[0066] Multiple embodiments of the safety gate monitoring module 16 according to the present invention will be described below. Here, identical or equivalent components are denoted by the same reference numerals.

[0067] FIG. 2 shows a perspective view of the safety gate monitoring module 16 having a basic unit 34 and an actuator 36 that interacts with the basic unit 34. The basic unit 34 preferably comprises one or more sensors and / or further electronic components and is therefore preferably connected to a power source. Furthermore, the basic unit 34 is preferably connected to the control unit 26 via lines having multi-channel redundancy such as lines 22, 24 here. The basic unit 34 preferably forms the above-described frame portion 18 of the safety gate monitoring module 16.

[0068] Although it might be similarly considered to use the basic unit 34 as the door part 17 of the safety gate monitoring module 16, this is not very preferable. In such a case, it would be necessary to route the wiring, which is normally fixed to the control unit 26, and the power source to the movable part of the safety gate 14, and this is usually more complex than connecting the lines 22, 24 and the power source to the fixed part 20 of the safety gate 14.

[0069] The actuator 36 operates as a partner of the basic unit 34 and serves to start the basic unit 34. For this purpose, the basic unit 34 is provided with a corresponding actuator insertion port 38 into which the actuator 36 can be inserted.

[0070] One function of the basic unit 34 is to detect whether the actuator 36 is inserted into the actuator insertion port 38. For this purpose, the actuator 36 preferably comprises an RFID chip that can be read by a detector arranged in the actuator insertion port 38. The basic unit 34 is configured to generate a safety gate signal when the actuator 36 is inserted into the actuator insertion port 38. This safety gate signal is preferably generated as an electrical signal. This may be a digital, pulse, encoded and / or other (preferably electrical) signal.

[0071] By evaluating the safety gate signal in the control unit 26, the safety gate monitoring system 10 can always clearly determine whether the safety gate 14 is closed or not. Depending on this, the robot 12 can be controlled in such a way that it can only be operated when the safety gate 14 is closed.

[0072] Figures 2, 3A - 3B, and 4 show the actuator element 40 inserted into the actuator insertion port 38 with the safety gate 14 in the closed state. In the embodiments shown in Figures 2 - 4, the actuator 36 includes a substantially rod / pin-shaped actuator element 40 that can be inserted into the actuator insertion port 38. On its end face inserted into the actuator insertion port 38, the actuator element 40 has a through hole 42 (see Figures 3B and 4) designed as a positioning hole, and in the operating state of the guard lock function, the guard lock device 44 engages with the through hole 42 to hold the actuator 36 in the actuator insertion port 38.

[0073] The basic unit 34 further includes one or more optical monitoring indicators 46 that display the state of the safety gate monitoring module 16. Additionally, the basic unit 34 includes an operator control device 48 (see Figure 2), whereby the user can change the state of the safety gate monitoring module 16. For example, the operator control device 48 is designed for manual deactivation of the guard lock function of the safety gate monitoring module 16 as an "emergency unlock function" by unlocking the guard lock device 44.

[0074] The guard lock device 44 includes a bolt 50, a spring element 52, and a locking device 53. The bolt 50 includes a bearing element 54 rotatably attached thereto, is pre-loaded by the spring element 52, and is configured to engage with the through hole 42 in the actuator 36. When the actuator 36 is inserted into and withdrawn from the actuator insertion port 38, due to the pre-load of the spring, the bolt 50 retreats downward, opposite to the spring force generated by the spring element 52. The locking device 53 is configured to lock the bolt 50 in the operating state of the guard lock device 44, and as a result, the actuator 36 is firmly held within the actuator insertion port 38.

[0075] The locking of the bolt 50 may be effected automatically as a result of a signal (for example, from the control unit 26 or the safety gate monitoring module 16), or manually by the operator control device 48.

[0076] If the safety gate 14 is to be opened again, first the actuator 36 must be withdrawn from the actuator insertion opening 38 again. For this purpose, the locking device 53 automatically releases the bolt 50 again as a result of a corresponding signal, or as a result of manual unlocking by the operator control device 48.

[0077] FIG. 5 shows, in cross-section, a first embodiment of a bolt 50 forming part of the guard locking device 44. The bolt 50 comprises a bearing element 54 rotatably mounted thereon, which is designed here as a sphere (ball) 56. The ball 56 is rotatably arranged in a bearing element insertion opening 58 formed in the bolt 50, and the bearing element insertion opening 58 is formed in the body 60 of the bolt 50. In this case, more than half of the volume of the ball is arranged within the bearing element insertion opening 58.

[0078] The ball 56 used as the bearing element 54 is arranged at the free end 62 of the bolt 50, and thus when the bolt 50 is inserted into the actuator element 40, the ball 56 can contact and roll on the actuator element 40. The ball 56 can likewise roll on the actuator element 40 when the bolt is withdrawn from the actuator 36.

[0079] The bearing element insertion opening 58 shown in FIG. 5 comprises a first part 64 and a second part 66. The first part 64 has a conical shape, but in principle it may also be cylindrical, spherical cup-shaped, etc.

[0080] In the embodiment shown in FIG. 5, the ball 56 can roll within this first portion 64 at the bearing element insertion port 58. The second portion 66 is cylindrical, but may also be cuboidal or the like. In the embodiment shown in FIG. 5, the ball 56 is held in place by the second portion 66, and in this case, the second portion 66 also functions as a housing at the same time.

[0081] The bolt 50 is at least partially configured as a cylindrical object. In this case, a cylindrical object refers to an object whose cross-sectional area is constant along the longitudinal axis. In particular, the bolt may be a cylinder (such as shown in FIG. 5 for example), but may also be a cubical object or a prism.

[0082] The bolt 50 further includes loss prevention means 78 for holding the ball 56 on the bolt 50. For this purpose, the bearing element insertion port 58 is provided with a cross-sectional clamping body 80 at the free end 62 of the bolt 50, which acts as a latch element and thus as loss prevention means 78 for the ball 56. The cross-sectional clamping body 80 is made smaller than the diameter of the ball 56.

[0083] The cross-sectional clamping body 80 may be produced, for example, by an imprinting process.

[0084] FIG. 6 shows the imprinting process for the bolt 50 shown in FIG. 5. For example, the bolt 50 is designed as an upside-down part, and the bearing element insertion port 58 is manufactured by forming a hole. After the ball 56 is inserted into the bearing element insertion port 58 of the bolt 50, the cross-section of the bearing element insertion port 58 is clamped by an imprinting punch 82 and a counter punch 84. The arrow in FIG. 6 indicates the direction in which the imprinting punch 82 is pressed against the counter punch 84. Here, it should be noted that the imprinting process must maintain or not impair the rotatability of the attached ball 56.

[0085] FIG. 7 shows a second embodiment of bolt 50, where, unlike the bolt 50 shown in FIG. 5, the bearing element 54 is a rotatably mounted cylinder 68 (or "barrel", "needle", etc.). Similar to ball 56, cylinder 68 can roll on actuator 36. However, when the bearing element 54 is implemented as a barrel or cylinder, it will be understood that the actuator 36 can only be inserted into the actuator insertion port 38 from one direction and not from the other direction. Such an embodiment could be used, for example, in the case of a sliding door.

[0086] In the case of the bearing element insertion port 58 shown in FIG. 7, the first portion 64 has an engaging shape that corresponds to the cylinder 68 and holds the cylinder in place. The second portion 66 is cube-shaped.

[0087] FIGS. 8 and 9 show two further embodiments of bolt 50, where a bearing shell 70 is inserted into the body 60 of bolt 50 to form part of the bearing element insertion port 58.

[0088] In FIG. 8, the first portion 64 of the bearing element insertion port 58 is integrated into the second portion 66, or both the first portion 64 and the second portion 66 are cylindrical and have the same diameter. In FIG. 9, the first portion 64 is conical and the second portion 66 is cylindrical. The first portion 64 designed to be conical can be provided by a conventional hole. The bearing shell 70 in the embodiments shown in FIGS. 8 and 9 has engaging shapes corresponding to the first portion 64 and the second portion 66 respectively.

[0089] In the embodiment shown in FIGS. 8 and 9, the bearing shell 70 is inserted into the bearing element insertion port 58 of the bolt 50 from the free end 62. The bearing shell 70 and the main body 60 can preferably be produced separately, enabling easier production. The material of the main body 60 may be, for example, relatively suitable free-cutting steel, while the material of the bearing shell 70 may be optimized with respect to wear characteristics.

[0090] FIG. 10 shows another embodiment of the bolt 50. Here, similar to the embodiment shown in FIG. 5, the bearing element insertion port 58 is formed directly in the main body 60 of the bolt 50. However, in principle, a bearing shell 70 could also be provided here as described above.

[0091] A number of bearing balls 74, on which the ball 56 can roll, are arranged in the bearing element insertion port 58. The bearing balls 74 are arranged in the bearing element insertion port 58 between the ball 56 and the main body 60 of the bolt 50.

[0092] The bearing balls 74 have a diameter smaller than that of the ball 56. As a result, the ball 56 can roll simultaneously on a number of bearing balls 74 while having a number of contact points 76. In addition, the bearing balls 74 generally conform to the contour of the bearing element insertion port 58 (especially to the first part 64) and can disperse themselves within the bearing element insertion port 58. Here, the first part 64 of the bearing element insertion port 58 is configured in a spherical cup shape.

[0093] FIG. 11A shows another embodiment of the bolt 50. Different from the embodiments shown in FIGS. 5 - 10, here the bolt 50 is provided with an additional sleeve 86, in which loss prevention means 78 for the ball 56 are formed. The sleeve 86 is arranged on the main body 60 of the bolt 50 and forms part of the bearing element insertion port 58.

[0094] Unlike the embodiment of the bolt 50 shown in FIGS. 5 to 10, the cross-sectional fastener 80 in FIG. 11A is formed not on the main body 60 but on the sleeve 86. The ball 56 and the bearing shell 70 are inserted into the sleeve 86. Therefore, the sleeve 86 forms a housing for a part of the ball 56 and the bearing shell 70. However, when the bolt 50 is designed with such a sleeve 86, it will be understood that the bearing shell 70, which is here designed as a separate component, does not necessarily have to be provided. Even when the bolt 50 is designed with the sleeve 86, instead, the bearing element insertion port 58 may be directly integrated into the main body 60 of the bolt 50, for example, in the same manner as in the case of the bolt 50 shown in FIG. 5.

[0095] FIGS. 11B and 11C schematically show the assembly process of the bolt 50 shown in FIG. 11A. Starting from the state shown in FIG. 11B, first the ball 56 and then the bearing shell 70 are inserted into the sleeve 86 (FIG. 11C). Next, the main body 60 of the bolt 50 is inserted into the sleeve 86, or the sleeve 86 having the ball 56 and the bearing shell 70 is arranged on the main body 60 of the bolt 50 (FIG. 11A). The sleeve 86 makes it possible to omit the stamping process shown in FIG. 6 as a manufacturing step, and therefore, the stamping punch 82 (and the counter punch 84) is not required as a separate tool for manufacturing, which has the effect of simplifying the assembly.

[0096] The sleeve 86 may be connected to the main body 60 of the bolt 50 removably or non-removably. FIGS. 12 to 15 show various embodiments in this regard. For example, the sleeve 86 may be screwed to the main body 60 of the bolt 50 (FIG. 12), or welded or brazed thereto (FIG. 13), or fixed to the main body 60 by pins (FIG. 14) or stamping (FIG. 15).

[0097] FIG. 12 shows a body 60 having a male screw 88 and a sleeve 86 having a corresponding female screw 90, the female screw 90 being formed on a part of the inner surface of the sleeve 86. Thus, the body 60 of the bolt 50 and the sleeve 86 are removably screwed together. For example, after a certain number of opening and closing processes of the guard lock device 44, the sleeve 86 may be unscrewed from the body 60 in order to replace the ball 56.

[0098] FIG. 13 shows a bolt 50 having a sleeve 86, the sleeve 86 being fixed to the body 60 by a number of weld seams 92. In this embodiment, the weld seams 92 are uniformly distributed around the body 60 and the sleeve 86.

[0099] FIG. 14 shows a bolt 50 having a sleeve 86 and a pin 94, the pin 94 being disposed in a through hole 96 in the body 60 and the sleeve 86 of the bolt 50 and fixing the body 60 to the sleeve 86. The central axes of the through holes 96 in the body 60 and the sleeve 86 are aligned with each other and extend substantially perpendicular to the longitudinal axis of the bolt 50.

[0100] FIG. 15 shows a bolt 50 having a sleeve 86, the sleeve 86 being fixed to the body 60 by a stamped feature 98. The stamped feature 98 is plastically formed on the body 60 by a pressing portion of the sleeve 86, whereby the sleeve 86 is connected to the body 60 by a press fit and a form fit. For example, the stamped feature 98 can be introduced by a centre punch.

[0101] In the embodiment shown in FIG. 15, the body 60 includes two recesses 100 (or sockets) into which a portion of the sleeve 86 is pressed. Similarly, the body 60 of the bolt 50 may have one or more recesses 100 in the form of a pointed tip, may extend continuously around the outer circumference, or may extend over a portion of the outer circumference. It is equally conceivable that the body 60 does not have a pre-provided recess 100, and as a result, a portion of the sleeve 86 is plastically pressed into the material of the body 60 by stamping.

[0102] It is self-evident that the embodiments shown in the figures are merely illustrative of the advantages of the safety gate monitoring module according to the present invention, which is intended to illustrate the advantages of the safety gate monitoring module according to the present invention. Various modifications can be made to these embodiments without departing from the scope of the present invention.

Description of Reference Numerals

[0103] 10 Safety gate monitoring system 12 Robot 14 Safety gate 16 Safety gate monitoring module 17 Gate portion 18 Frame portion 20 Fixed portion 22, 24 Line 26 Control unit 28, 30 Contactor 32 Power source 34 Basic unit 36 Actuator 38 Actuator insertion port 40 Actuator element 42 Through hole 44 Guard lock device 46 Monitoring indicator 48 Operator control device 50 Bolt 52 Spring device 54 Bearing element 56 Ball 58 Bearing element insertion port 60 Body 62 Free end 64 First part 66 Second part 68 Cylinder, barrel 70 Bearing shell 74 Bearing ball 76 Contact point 78 Loss prevention means 80 Cross-section tightening body 82 Marking punch 84 Counter punch 86 Sleeve 88 Male thread 90 Female thread 92 Welding line 94 Pin 96 Through hole 98 Marked feature 100 Recess

Claims

1. A safety gate monitoring module (16) for monitoring a status of a safety gate (14), comprising: the safety gate monitoring module (16) comprises an actuator receptacle (38) for receiving an actuator (36) and is configured to generate a safety gate signal when the actuator (36) is inserted into the actuator receptacle (38); the actuator receptacle (38) includes a guard locking device (44) configured to retain the actuator (36) within the actuator receptacle (38) in an operational condition; The guard locking device (44) includes a bolt (50) having a bearing element socket (58) and a bearing element (54) rotatably mounted within the bearing element socket (58) and disposed at a free end (62) of the bolt (50), the free end being configured to engage the actuator (36) in the operating condition, the safety gate monitoring module (16).

2. 2. The safety gate monitoring module (16) of claim 1, wherein the bolt (50) is provided with a loss prevention means (78) configured to retain the rotatably mounted bearing element (54) captive to the bolt (50).

3. 3. The safety gate monitoring module (16) according to claim 2, wherein the loss prevention means (78) is formed by a cross-sectional tightening body (80) of the bearing element socket (58).

4. 4. The safety gate monitoring module (16) of claim 3, wherein the diameter of the cross-sectional clamping body (80) is smaller than the diameter of the bearing element (54).

5. 2. The safety gate monitor module (16) of claim 1, wherein the bearing elements (54) are balls (56).

6. 2. The safety gate monitoring module (16) of claim 1, wherein the bearing element receptacle (58) comprises a conical, spherical cup-shaped or cylindrical first portion (64) and a cylindrical second portion (66).

7. 2. The safety gate monitoring module (16) of claim 1, wherein more than half of the bearing element (54) is disposed within the bearing element receptacle (58).

8. 2. The safety gate monitoring module (16) of claim 1, wherein the bolt (50) is preloaded by a spring device (52).

9. 2. The safety gate monitoring module (16) of claim 1, wherein the bolt (50) comprises a body (60) and a bearing shell (70) inserted therein and forming at least a portion of the bearing element socket (58).

10. 10. The safety gate monitoring module (16) of claim 9, wherein the body (60) of the bolt (50) comprises a first material and the bearing shell (70) comprises a second material different from the first material.

11. 2. The safety gate monitoring module (16) of claim 1, wherein the bolt (50) includes a sleeve (86) secured to a body (60) of the bolt (50) and forming at least a portion of the bearing element socket (58).

12. 3. The safety gate monitoring module (16) of claim 2, wherein the bolt (50) includes a sleeve (86) fixed to a body (60) of the bolt (50) and forming at least a portion of the bearing element socket (58), and wherein the sleeve (86) forms at least a portion of the loss prevention means (78).

13. 12. The safety gate monitor module (16) of claim 11, wherein the sleeve (86) is screwed, riveted, pinned, and / or physically connected to the body (60).

14. 2. The safety gate monitoring module (16) of claim 1, wherein the bolt (50) includes a plurality of bearing balls (74) disposed in the bearing element socket (58).

15. A safety gate (14) as access to the safety area; a safety gate monitoring module (16) according to any one of claims 1 to 14 for monitoring a state of the safety gate (14); An actuator (36); a control unit (26) configured to read the safety gate signal and to control a machine or system (12) located in the safety area according to the safety gate signal.

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