PLACEMENT HEAD WITH TWO ROTOR ARRANGEMENTS WITH INDIVIDUALLY ACTUATABLE HANDLING DEVICES

Abstract

A placement head for automatically placing electronic components on a component carrier. The placement head has a chassis; a first rotor assembly that is mounted so that it is rotatable relative to the chassis about a first axis of rotation and that has a first quantity of first handling devices; and a second rotor assembly that is mounted so that it is rotatable relative to the chassis about a second axis of rotation and that has a second quantity of second handling devices. Each handling device includes a sleeve to which a component holding device for temporarily picking up a component can be attached, and a drive device with a linear drive for moving the sleeve along its longitudinal axis, and a rotary drive for rotating the sleeve about its longitudinal axis. Furthermore, a placement machine with such a placement head and a method for automatic assembly of a component carrier using such a placement head.

Claims

1. A placement head for automatically placing electronic components on a component carrier, the placement head comprising: a chassis; a first rotor assembly that is mounted so that it is rotatable relative to the chassis about a first axis of rotation and that has a first quantity of first handling devices; and a second rotor assembly that is mounted so that it is rotatable relative to the chassis about a second axis of rotation and that has a second quantity of second handling devices; wherein each handling device comprises: a sleeve, on which a component holding device for temporarily picking up a component can be mounted, and a drive device comprising: (i) a linear drive for moving the sleeve along its longitudinal axis and (ii) a rotary drive for rotating the sleeve about its longitudinal axis.

2. The placement head according to claim 1, wherein the first axis of rotation and the second axis of rotation are parallel to each other.

3. The placement head according to claim 2, wherein the first axis of rotation and the second axis of rotation are on a common axis of rotation.

4. The placement head according to claim 2, wherein the first axis of rotation is offset in relation to the second axis of rotation.

5. The placement head according to claim 1, further comprising: a first motor for rotating the first rotor assembly; and a second motor for rotating the second rotor assembly; wherein the two motors can be controlled independently of each other, so that the first rotor assembly can be rotated independently of the second rotor assembly.

6. The placement head according to claim 5, wherein the first motor is configured to rotate the first rotor assembly continuously or at least quasi-continuously; and/or wherein the second motor is configured to rotate the second rotor assembly continuously or at least quasi-continuously.

7. The placement head according to claim 1, wherein a first quantity of the first handling devices is the same as a second quantity of the second handling devices.

8. The placement head according to claim 1, wherein: the first handling devices are arranged on a first circumference at a first radial distance from the first axis of rotation, wherein the circumferential distance along the first circumference between two adjacent first handling devices is different from an additional circumferential distance along the first circumference between two adjacent additional first handling devices; and/or the second handling devices are arranged on a second circumference at a second radial distance from the second axis of rotation, wherein the circumferential distance along the second circumference between two adjacent second handling devices is different from an additional circumferential distance along the second circumference between two adjacent additional second handling devices.

9. The placement head according to claim 1, further comprising a camera that is attached to the chassis and that is configured to detect picked-up components.

10. The placement head according to claim 9, wherein the camera is movably attached to the chassis.

11. The placement head according to claim 10, further comprising an additional camera that is attached to the chassis and that is configured to detect additional picked-up components.

12. The placement head according to claim 9, further comprising a data processing unit that is connected downstream of the camera or the additional camera, and that is configured to perform an evaluation of the image taken of each individual component.

13. The placement head according to claim 1, further comprising: for each first handling device and/or each second handling device, a component sensor that detects the presence of a component and/or the relative position between a picked-up component and the relevant sleeve that picks it up.

14. A placement machine for automatically placing electronic components on a component carrier, the placement machine comprising: a frame base structure; a positioning system with a stationary component and a movable component, wherein the stationary component is attached to the frame base structure; and a placement head according to claim 1, wherein the chassis of the placement head is attached to the movable component of the positioning system.

15. The placement machine according to claim 11, further comprising: a component feeding system comprising: a first component feeding device by means of which electronic components are supplied at a first collection position, and a second component feeding device by means of which electronic components are supplied at a second collection position, wherein the two collection positions are spaced from each other such that the placement head can simultaneously collect a first electronic component from the first collection position and a second electronic component from the second collection position.

16. A method for automatically placing electronic components on a component carrier by means of a placement machine according to claim 14, wherein the method comprises: picking up a first electronic component from a first collection position with a first component holding device that is attached to a first sleeve of the first rotor assembly of the placement head; picking up a second electronic component from a second collection position with a second component holding device that is attached to a second sleeve of the second rotor assembly of the placement head; transporting the two picked-up electronic components into a placement area in which a component carrier that is to be assembled is located; placing the transported first electronic component at a first installation position on the component carrier; and placing the transported second electronic component at a second installation position on the component carrier.

17. The method according to claim 16, wherein the first electronic component and the second electronic component are picked up simultaneously; and/or wherein the transported first electronic component and the transported second electronic component are placed simultaneously.

18. The method according to claim 17, further comprising: picking up an additional first electronic component from an additional first collection position with an additional first component holding device that is attached to an additional first sleeve of the first rotor assembly; picking up an additional second electronic component from an additional second collection position with an additional second component holding device that is attached to an additional second sleeve of the second rotor assembly; transporting, together with the two picked-up electronic components, the two picked-up additional electronic components into the placement area; placing the transported additional first electronic component at an additional first installation position on the component carrier; and placing the transported additional second electronic component at an additional second installation position on the component carrier; wherein the additional first electronic component and/or the additional second electronic component is picked up at the same time as the first electronic component and the second electronic component are picked up; and/or wherein the placement of the transported additional first electronic component and/or the placement of the transported additional second electronic component occurs simultaneously with the placement of the transported first electronic component and the transported second electronic component.

19. The method according to claim 16, wherein the sleeve and/or a component holding device attached to the sleeve is/are formed by at least one handling device eccentric to an axis of rotation of the rotary drive of the at least one handling device, wherein the method further comprises: actuating the rotary drive of the at least one handling device in such a way that the spacing is changed between (i) a tip of the component holding device and (ii) a tip of another component holding device, which is assigned to another handling device of the first rotor assembly or the second rotor assembly.

20. A method for automatically placing electronic components on a component carrier by means of a placement machine according to claim 14, wherein the method comprises: picking up an electronic component from a collection position with a first component holding device and with a second component holding device; transporting the picked-up electronic component into a placement area in which a component carrier that is to be assembled is located; and placing the transported electronic component at an installation position on the component carrier.

21. The method according to claim 19, wherein both component holding devices are each assigned to a sleeve of the first rotor assembly or wherein both component holding devices are each assigned to a sleeve of the second rotor assembly.

22. The method according to claim 19, wherein one of the two component holding devices is assigned to a sleeve of the first rotor assembly and wherein the other of the two component holding devices is assigned to a sleeve of the second rotor assembly.

23. A method for automatically placing electronic components on a component carrier by means of a placement head according to claim 1, wherein the method comprises: picking up a first electronic component from a first collection position with a first component holding device that is attached to a first sleeve of the first rotor assembly of the placement head; picking up a second electronic component from a second collection position with a second component holding device that is attached to a second sleeve of the second rotor assembly of the placement head; transporting the two picked-up electronic components into a placement area in which a component carrier that is to be assembled is located; placing the transported first electronic component at a first installation position on the component carrier; and placing the transported second electronic component at a second installation position on the component carrier.

24. A method for automatically placing electronic components on a component carrier by means of a placement head according to claim 1, wherein the method comprises picking up an electronic component from a collection position with a first component holding device and with a second component holding device; transporting the picked-up electronic component into a placement area in which a component carrier that is to be assembled is located; and placing the transported electronic component at an installation position on the component carrier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0082] FIG. 1 shows a schematic perspective illustration of a placement machine according to one embodiment of the invention.

[0083] FIG. 2 shows a perspective view of the basic structure of a placement head according to one embodiment of the invention in.

[0084] FIG. 3 shows a top view of the placement head.

[0085] FIG. 4 shows a perspective view of the handling device.

[0086] FIG. 5a and FIG. 5b illustrate the geometries of two different placement heads in relation to a predetermined spacing between two component feeding devices of a component feeding system.

[0087] FIG. 6 shows a placement head with two cameras for measuring the physical position and the angular position of picked-up components.

DETAILED DESCRIPTION

[0088] It should be noted that, in the following detailed description, features or components of different embodiments that are identical or at least functionally identical to the corresponding features or components of another embodiment are provided with the same reference numerals or with reference numerals that are identical in the last two digits of the reference symbols of corresponding identical or at least functionally identical features or components. To avoid unnecessary repetitions, features or components that have already been explained on the basis of a previously described embodiment are no longer explained in detail at subsequent points.

[0089] Furthermore, it is noted that the following described embodiments only represent a limited selection of possible variations of embodiments of the invention. In particular, it is possible to combine the features of individual embodiments in a suitable manner, such that a multitude of different embodiments can be viewed as obviously disclosed for the person skilled in the art with the embodiments explicitly described here.

[0090] FIG. 1 shows a placement machine 100 that has a frame base structure 102 on which two parallel linear guides 103 are attached. The two linear guides 103 carry a transverse support arm 104. The transverse support arm 104 itself has a linear guide 105 on which a carrier element 106 is displaceably mounted. The two linear guides 103 run along a y-direction, the linear guide 105 runs along an x-direction. A placement head 130 is arranged on the carrier element 106. The linear guides 103, transverse support arm 104, linear guide 105 and carrier element 106 constitute a positioning system for the placement machine 100, with the linear guides 103 forming a stationary component of the positioning system and the carrier element 106 forming a movable component of the positioning system.

[0091] In accordance with embodiments of the invention, the placement head 130 has two rotor assemblies that are arranged concentrically to one another and that can be rotated relative to a chassis 132 of the placement head 130 about a common axis of rotation that is oriented along a z-direction. The z-direction is indicated in FIG. 1 with a straight double arrow. The rotary movement is indicated in FIG. 1 with a curved double arrow. Each of the two rotor assemblies has a plurality of handling devices that are arranged on a circumference at a certain radial distance from the axis of rotation. With each handling device, a component can be taken up, held while the placement head 130 is moving, and placed on a component carrier.

[0092] The radial distance of the handling devices of the one (inner) rotor assembly is smaller than the radial distance of the handling devices of the other (outer) rotor assembly. These characteristic structural properties of the placement head 130 are not shown in FIG. 1 for reasons of clarity. Only two component holding devices 134 designed as suction nozzles are visible, which are devices detachably attached in a known manner to the sleeves of two handling devices of the outer rotor assembly.

[0093] The placement machine 100 also comprises a component feeding system 110, shown schematically, that comprises at least two component feeding devices 112. The component feeding devices 112 provide electronic components (not shown) at a plurality of collection positions 112a for a so-called “Collect & Place” placement process. In this case, components of the same or different types can be supplied by means of different component feeding devices 112.

[0094] The placement machine 100 also comprises a conveyor belt 115 with which a component carrier 190 can be introduced into a placement area of the placement machine 100. The component holding devices 134 can be positioned parallel to the xy-plane within the entire placement area by a suitable translational movement of the placement head 130 and by a suitable rotational movement of the outer rotor assembly.

[0095] Furthermore, the placement machine 100 has a master data processing device 101. A processing program can be run on this for the placement machine 100 to place electronic components 195 on the component carriers 190, so that all components of the placement machine 100 work in a precisely coordinated manner and thus contribute to the error-free and rapid placement of components 195 on component carriers 190.

[0096] A so-called circuit board camera 120, which is provided for detecting at least one marking 192 placed on the component carrier 190, is additionally secured to the carrier element 106. In this manner, the exact position of the component carrier 190 introduced into the placement area can be determined by measuring the position of the at least one marking 192 within the field of view of the circuit board camera 120.

[0097] It should be pointed out that the components 195 can also be detected by a stationary camera (not shown) on their way to the component carrier 190. Such a stationary camera is arranged in a stationary manner in relation to the frame base structure 102 and is attached directly or indirectly to the frame base structure 102.

[0098] FIG. 2 shows a perspective view of the basic structure of the placement head 130 according to one embodiment of the invention. The placement head has two rotor assemblies, a first rotor assembly 240 and a second rotor assembly 250. The two rotor assemblies 240, 250 are arranged concentrically to each other and are rotatable about an axis of rotation (not shown).

[0099] A plurality of first handling devices is attached to a first cylindrical body of the first rotor assembly 240 and are designated by reference numerals 242a, 242b, 242c, 242d, 242e, 242f, 242g and 242h. The handling devices 242a-h are located on a first circumference 244, which is shown with dashed lines in FIG. 2. Correspondingly, multiple second handling devices are attached to a second cylindrical body of the second rotor assembly 250 and are designated by reference numerals 252a, 252b, 252c, 252d, 252e, 252f, 252g and 252h. The handling devices 242a-h are located on a second circumference 254, which is also shown with dashed lines in FIG. 2.

[0100] All of the handling devices 242a-h and 252a-h have, in particular, a sleeve (not shown in greater detail in FIG. 2 for reasons of clarity) and a drive device (also not shown in detail). The sleeve is configured in a known manner such that a component holding device designed as a suction nozzle can be detachably attached for temporarily picking up a component. The drive device has (i) a linear drive for moving the sleeve along its longitudinal axis and (ii) a rotary drive for rotating the sleeve about its longitudinal axis. The drive device is therefore able to displace the suction nozzle both along its longitudinal axis or in a z-direction and to rotate it about its longitudinal axis. These two movements are required in a known manner in order to take up an electronic component and later to place it in the correct position on a component carrier that is to be assembled. The construction of the handling devices is explained in greater detail below with reference to FIG. 4.

[0101] FIG. 3 shows a top view of the placement head 130.The common axis of rotation 336 is labelled with reference numeral 336. In this FIG. 3, the two concentrically arranged rotor assemblies 240, 250 can be seen particularly well, together with their handling devices 242a-h and 252a-h. The “radial distance” between (i) the first circumference 244 of the outer first rotor assembly 240 and (ii) the second circumference 254 of the inner second rotor assembly 250 is designated by “c” in FIG. 3.

[0102] Due to the concentric arrangement of the two rotor assemblies 240, 250 with the many handling devices, the placement head 130 can clearly also be called a “double turret placement head”. The English term “turret” translates as “Werkzeugrevolver” [revolver head] in German.

[0103] The first rotor assembly 240 and the second rotor assembly 250, which are driven by a first motor 341 and a second motor 351, respectively, can be rotated about the axis of rotation 336 as desired and independently of each other. Taking into consideration (i) the so-called XY positioning of the entire placement head 130 within the coordinate system of a placement machine and (ii) the rotational position or angular position of the two rotor assemblies 240, 250, at least two of the handling devices can be positioned so that their distance a is precisely as great as the distance between the collection positions of two adjacent component feeding devices of a component feeding system. In FIG. 3, these are (i) a handling device 242b or 242g of the first handling devices 242a-h and (ii) a handling device 242g or 252g of the second handling devices 252a-h. Such positioning that has been adapted to the spatial structure of the component feeding system advantageously makes it possible to take up two components simultaneously. Naturally, this also applies in the event that distance a corresponds to a multiple of the distance between two adjacent collection positions.

[0104] In addition, if distance b between two handling devices of one and the same rotor assembly, in FIG. 3 where the distance between the second handling device 252b and the second handling device 252g corresponds to a multiple of the distance between two adjacent collection positions, then four components can be simultaneously taken up from a corresponding component feeding system. As a result, the process of taking up a plurality of components can be accelerated in comparison to picking up the components sequentially, so that the placement rate of the placement head is correspondingly increased.

[0105] Correspondingly, the same also applies to the process of placing the components on a component carrier. However, it should be noted that the placement positions of the various components are typically not on a uniform grid. This spacing of the placement positions, which is typically different for each placement operation, can at least be produced for two components by appropriately setting the relative angle of rotation between the two rotor assemblies. As a result, at least two components can be placed simultaneously with the described placement head 130, which leads to an additional acceleration in placement processes compared to a sequential placement of components.

[0106] FIG. 4 shows a perspective view of a (first) handling device 442. The second handling devices 252a-h shown in the two previous FIGS. 2 and 3 are constructed in the exact same way.

[0107] The handling device 442 comprises a drive device consisting of a linear drive 445 and a rotary drive 446. The rotary drive 446 can be displaced along a z-direction by means of the linear drive 445 on a linear guide 442-1. The rotary drive 446 is coupled to a sleeve 447 that is rotated about its longitudinal axis when the rotary drive 446 is actuated. The longitudinal axis of the sleeve 447 also runs along the z-direction.

[0108] A component holding device designed as a suction gripper can be attached to the front end of the sleeve 447 in a known manner. This is identified with reference numeral 448 in FIG. 4. A component can then be held on the front side of the suction gripper 448, likewise in a known manner, by means of a pneumatic vacuum. To generate this vacuum, a vacuum generation unit (not shown) is provided, which transfers the generated negative pressure to a suction channel of the suction gripper via a pneumatic hose 442-2. The vacuum generation unit can be a central unit in a known manner, which “distributes” the negative pressure to the individual suction grippers of the various handling devices through suitable pneumatic switch valves.

[0109] The handling device 442 further comprises two encoders. A first encoder detects the current z-position of the sleeve 447 or the attached suction gripper 448. This encoder is identified with reference numeral 442-3 in FIG. 4. The second encoder detects the current angle of rotation of the sleeve or of a component taken up by the suction gripper 448.

[0110] According to the embodiment depicted here, the handling device 442 further comprises a component sensor 449. Provided that the linear drive 445 is in its upper position, the linear drive 445 can be set in such a way that a component that has been picked up is within the detection range of the component sensor 449.

[0111] According to the embodiment depicted here, the component sensor 449 and a downstream evaluation unit (not shown) are configured to detect (i) the presence of a component and/or (ii) the relative position between a picked-up component and the sleeve picking it up. The component sensor is a light barrier with (i) a light-emitting diode or a laser diode and (i) a photodiode. When a component is detected, it is located between the diode and the photodiode.

[0112] FIGS. 5a and 5b illustrate the geometries of two different placement heads in relation to the spatial and physical configuration of a component feeding system 510. As is evident from these two figures, the component feeding system 510 has a plurality of component feeding devices 551 that are arranged directly next to each other. According to the embodiment depicted here, all component feeding devices have a width a, which is shown on the left with a double arrow in FIG. 5b. The component collection positions are each indicated by a cross in both FIGS. 5a and 5b, and are labelled with reference numeral 553. The component collection positions 553 are each located in the middle of a component feeding device 551. Therefore, the distance between two adjacent component collection positions 553 is also the above-mentioned width a.

[0113] A double turret placement head that has 2×12 handling devices is illustrated in FIG. 5a. Twelve first handling devices 542, which are assigned to an outer first rotor assembly, lie on a first circumference 244, which is spaced from the common axis of rotation 336 by a first radial distance R1. Twelve second handling devices 552, which are assigned to an inner second rotor assembly, lie on a second circumference 254, which is spaced from the common axis of rotation 336 by a second radial distance R2.

[0114] As can be seen in FIG. 5a, both the first handling devices 542 as well as the second handling devices 552 are not arranged equidistantly from each other on their respective circumferences 244 and 254. Specifically, along the perimeter of the relevant circumference, some pairs of handling devices that are adjacent to each other are spaced at a comparatively small distance and other pairs of handling devices that are adjacent to each other are spaced at a comparatively large distance. According to the embodiment depicted here, the short distances and long distances alternate along the direction of the perimeter. This applies for both rotor assemblies.

[0115] Radial distances R1 and R2 as well as the different perimeter distances between two adjacent handling devices on the two circumferences 244 and 254 are selected so that four components can be removed from the component feed system 510 simultaneously when the physical position of the placement head and angular position of the two rotor assemblies are suitably configured. This is evident in FIG. 5a by the fact that the four handling devices in question “cover” the four corresponding collection positions.

[0116] A double turret placement head that has 2×10 handling devices is illustrated In FIG. 5b. The first handling devices are also identified here with reference numeral 542 and the second handling devices are identified with reference numeral 552.

[0117] The distribution of the handling devices along the perimeter is also not completely equidistant with the placement head according to FIG. 5b. However, together with the two radial distances R1 and R2, the distribution is such that four handling devices can simultaneously take up components again.

[0118] FIG. 6 shows a perspective view of the placement head 130 with two cameras for measuring the physical position and the angular position of picked-up components. A first camera 662 is configured and arranged to detect components that are each held by a first handling device 542 from below. A second camera 664 is configured and arranged to detect components that are each held by a second handling device 552 from below.

[0119] When the two rotor assemblies rotate, the components held by all handling devices are moved one after another through the detection area of the first camera 662 and the detection area of the second camera 664. This detection of the held components takes place as already previously described while the components are being transported from the component feeding system to the placement area. As soon as the placement head 130 has reached the placement area, the two cameras 662 and 664 are folded away by means of a swivelling mechanism (not shown) so that all components are moved downwards spatially unimpeded by the camera through actuation of the linear drive 445 depicted in FIG. 4 and thus can be placed on the component carrier that is to be assembled. The two cameras 662 and 664 are also in the “folded away” position when components are being picked up so that components can be picked up unhindered in the area of the component feeding system 510.

[0120] It should be noted that, deviating from the illustration in FIG. 6, at least one of the two cameras 662, 664 or a holder of at least one of the two cameras 662, 664, can be attached to or integrated into a supporting bearing of the inner rotor assembly.

[0121] Further information on features and/or advantages of possible embodiments of the invention are described below:

[0122] For optically sharp detection of the components, a height sensor (e.g., a light barrier or a so-called light curtain, not shown), can initially be used to detect component position. Based on this information, the component or the surface of the component that is relevant for detection can be brought into the camera's focus through proper actuation of the linear drive.

[0123] Depending on the specific application and, in particular, on the optical properties (of the surfaces) of the components, different illumination light with different spectral properties can be used for component detection. The light colours of blue, blue and red or also white have proven to be suitable for the reliable optical detection of components.

[0124] Two or more image recordings of a component can also be taken during placement operations using different illumination settings. This can take place in a short period of time during which the component in question is at a fixed position within the camera's detection range, because the rotor assembly in question is at rest during this period of time. Alternatively, the two images can also be moved through the camera's detection area while the component is moving. The two image recordings can be evaluated together, for example, to detect component tilting reliably. The camera can also be a so-called Multi-Field Of View (MFOV) camera. In this case, a large camera image can be generated by joining together (“stitching”) various smaller individual recordings, wherein the individual recordings show (usually overlapping) sections of the component. Such “stitching” can be used in an advantageous manner, particularly for large components.

[0125] The image recordings can be synchronized with the rotational movement of the rotor assembly in question. This can be done, for example, via a synchronization light flash, which is emitted by a light transmitter located in or on the camera in the case of a stationary camera, and received by an appropriate light receiver on the moving part of the placement head.

[0126] Cleaning the camera regularly can also help with capturing high-quality images. Such cleaning can be performed by means of a cleaning nozzle, blown air pulses from an empty suction nozzle and/or a special cleaning tool picked up by a handling device.

[0127] It is noted that the term “have or comprising” does not exclude other elements and that the word “one or a” does not exclude a plurality. Elements, which are described in connection with different exemplified embodiments, can also be combined. It should also be noted that reference numerals in the claims should not be construed as limiting the scope of the claims.

REFERENCE NUMERALS

[0128] 100 Placement machine

[0129] 101 Master data processing device

[0130] 102 Frame base structure

[0131] 103 Linear guides

[0132] 104 Transverse support arm

[0133] 105 Linear guide

[0134] 106 Carrier element

[0135] 110 Component feeding system

[0136] 112 Component feeding devices

[0137] 112a Collection positions

[0138] 115 Conveyor belt

[0139] 120 Circuit board camera

[0140] 130 Placement head

[0141] 132 Chassis

[0142] 134 Component holding device/Suction nozzle

[0143] 190 Component carrier

[0144] 192 Marking

[0145] 195 Component

[0146] 240 First rotor assembly

[0147] 242a-h First handling devices

[0148] 244 First circumference

[0149] 250 Second rotor assembly

[0150] 252a-h Second handling devices

[0151] 254 Second circumference

[0152] 336 (Common) axis of rotation

[0153] 341 First motor

[0154] 351 Second motor

[0155] 442 First handling device

[0156] 445 Linear drive

[0157] 446 Rotary drive

[0158] 447 Sleeve

[0159] 448 Component holding device/Suction gripper

[0160] 449 Component sensor

[0161] 442-1 Linear guide

[0162] 442-2 Pneumatic hose

[0163] 442-3 Optical encoder

[0164] 510 Component feeding system

[0165] 551 Component feeding device

[0166] 553 Component collection position

[0167] 542 First handling device

[0168] 552 Second handling device

[0169] 662 First camera

[0170] 664 Second camera

[0171] a Spacing between the first handling device and the second handling device/ [0172] Wide component feeding device/Spacing between adjacent collection positions

[0173] b Spacing between two second handling devices

[0174] c Radial distance between the first circumference and the second circumference

[0175] R1 First radial distance

[0176] R2 Second radial distance