Patent Document

BACKGROUND OF THE INVENTION 
     The invention relates to an out-processing facility for individual goods, comprising: 
     a storage or support area with a plurality of storage or support passages for items to be out-processed extending parallel to one another therein, whereby only items of the same type are located in each passage; 
     a loading area at one end of the storage passages with means for in-loading new items into the storage passages provided therefor; and 
     an out-processing area at the other end of the storage passages with removal devices for computer-controlled transfer of individual items out of the storage passages onto downstream conveyor devices. 
     Warehouse order-processing technology is gaining importance in all fields of commerce and in particular in the wholesale foods industry. However, warehousing in its narrower sense (i.e., static storage of individual goods) is becoming less significant while the dynamic processes and especially turn-around handling of goods is gaining importance. The goal of modern warehousing is therefore to keep the retention time of the individual goods in the warehouse to a minimum and thus to keep to a minimum the amount of capital tied up in warehousing. 
     Known out-processing facilities are multi-story racks that have storage passages for the individual goods and that are arranged adjacent to and above one another. The floors of the passages are provided with roller conveyors made of freely rotatable rollers and are slightly inclined so that goods warehoused at the one end of the passage, the so-called stocking or loading side, move along the roller conveyors to the other end of the passage, the removal or order processing side. Placing the individual goods into position on the stocking side is generally done manually in that the individual goods are removed from a pallet and placed into the assigned passage. Order-processing at the removal side of the racks is also frequently performed manually. 
     However, also known are computer-controlled drivable removal devices in the form of conveyor devices that can be driven in a passage arranged on the order-processing side of the rack and that, corresponding to the order, take the individual goods maintained instock in the individual passages and assemble the order. The conveyor devices used for this can be driven over corresponding guides in two coordinates so that each conveyor device can access individually each of the passages arranged adjacent to and above one another. 
     The object of the invention is to provide an out-processing facility with which high turn-around rates can be achieved and which is also suitable for simultaneous processing of goods that are very different in terms of weight and size. 
     SUMMARY OF THE INVENTION 
     For achieving this object in an out-processing facility of the type described in the foregoing, it is proposed that every passage comprise a roller conveyor, the rollers or cylinders of which can be set in motion via a common drive means, and that each passage be provided with a discrete removal apparatus that is actuatable independent of the other removal apparatus. 
     Such an out-processing facility makes it possible to achieve a higher turn-around rate than is the case in conventional systems because each individual passage is provided with a discrete removal apparatus that is actuatable independent of the other removal apparatus in the out-processing facility. This means that the inventive out-processing facility makes possible a turn-around rate at which it would even be possible, at full capacity, to remove items from all of the passages and assemble an order simultaneously. The items can even also be very different individual goods in terms of their weight and size. The use of a roller conveyor for each passage, the rollers or cylinders of which can be set in motion via a common drive means, ensures that light and heavy, large and small individual goods and containers are transported and stocked in the passages with the same degree of assurance. Even individual goods that are critical in conventional warehouse engineering, such as, for instance, full plastic crates of beverages, can be processed with no problem using the driven roller conveyor. 
     In accordance with one preferred embodiment of the out-processing facility, the common drive means is a continuous drive belt, and the drive belt has a first and a second group of longitudinal segments, whereby the longitudinal segments of each group alternate, the longitudinal segments of the first group exert a friction and/or positive driving torque on the rollers or cylinders, and the longitudinal segments of the second group exert no driving torque or comparatively less driving torque on the rollers or cylinders. Such a drive belt with longitudinal segments that work at different strengths leads to reduced conveyor pressure on the roller conveyor so that above all only limited pressure is exerted on the individual goods arranged at the first position on the removal-side end of the passage. This is advantageous precisely in the case of goods or containers that are sensitive to shock or pressure. It is furthermore advantageous that the removal apparatus of the out-processing area can be operated with limited drive power due to the limited dynamic pressure. 
     The drive belt preferably comprises a continuous base body, which has the same thickness over its entire length, and drive segments that are affixed by segment to the base body and that form the longitudinal segments of the first group. For achieving a slip-free form-fit, it is furthermore advantageous when the drive segments have teeth on their exterior side and the teeth thus formed engage with corresponding opposing teeth on the circumference of the rollers or cylinders of the roller conveyor. 
     For achieving sufficient constructive freedom in the design of the drive and reversing devices for the drive means of the roller conveyor, it is furthermore suggested that the drive belt be reversed via reversing rollers that are situated in or below the loading area and/or the out-processing area. 
     For achieving limited drive slip while maintaining a cost-effective design of the roller conveyor, it is furthermore suggested that the drive belt be conducted between the rollers or cylinders and a pressure counter bearing, and that the pressure counter bearing be a longitudinally extending profile that is connected to a roller conveyor profile on which the individual rollers or cylinders are borne. 
     One preferred embodiment of the out-processing facility is characterized in that a transport conveyor that is preferably continuously driven extends along the removal apparatus and transverse to the passages for the items removed using the removal apparatus, and in that components of each removal apparatus are an actuatable retaining element projecting into the conveyor path of the roller conveyor and a horizontal conveyor that is arranged after the retaining element in the direction of *p+11Xconveyance and whose conveyor speed is greater than the conveyor speed of the roller conveyor. Preferably the conveyor speed of the horizontal conveyor is at least 25% greater than the conveyor speed of the roller conveyor. This achieves assured and problem-free separation of the first items to be removed from the items arranged thereafter and being conveyed by means of the drive device of the roller conveyor. 
     For achieving a constructively simple design of the out-processing area, it is furthermore suggested that a plurality of horizontal conveyors be driven via a common drive shaft that extends transversely to the passages. Furthermore suggested is a controlled switchable coupling for time-delimited initiation of an unblocking motion by the retaining element that releases the conveyor path from the rotational movement of the common drive shaft, whereby the coupling of each removal apparatus can be triggered separately from the other couplings. In contrast to the unblocking motion, it is not necessary to use the motor drives present for the subsequent re-blocking motion of the retaining element. Rather, it is sufficient when the retaining element is provided with restoring means that act upon the retaining element with a restoring force in the direction of its blocking motion, whereby the restoring force is less than the weight of the items/containers stored in the passage. This restoring force can be produced, for instance, by the weight or force of a suitable restoring spring. 
     In terms of the coupling, this is preferably a magnetic coupling annularly enclosing the common drive shaft, the output member of which is a cam that pivots against the restoring element when the magnetic coupling is triggered. 
     With the goal of a compact design for the out-processing area, it is suggested that the horizontal comprises a first, non-rotating belt pulley that is coaxially connected to the drive shaft, at least one additional belt pulley that runs therewith, and a continuous belt conducted via the belt pulleys, whereby the driven belt pulley defines the forward end and the belt pulley that runs therewith defines the rear end of the horizontal conveyor. 
     One embodiment of the loading area of the inventive out-processing facility is characterized by a transport conveyor for new items to be in-loaded that extends transversely to the passages and constitutes individual transport cylinders, whereby transverse conveyors that are separately actuatable for each said passage are arranged between the transport cylinders in the direction of that passage. The transverse conveyor preferably comprises belt pulleys over which is conducted a continuous drive belt on the exterior side of which are attached catch elements, which, when they are located on the carrying run of the drive belt, project beyond the conveyor surface of the transport cylinders. Transport means of the transverse conveyor are therefore not the belts themselves, but rather the catch elements attached thereto. Their interval on the drive belt is preferably greater than the length of the carrying run. This ensures that the catch elements do not impede the movement of the individual goods along the transport cylinders that comprise the transport conveyor. 
     In one additional embodiment of the out-processing facility it is suggested that the drive of a plurality of transverse conveyors occurs via a common main drive shaft and that each transverse conveyor has a discrete coupling for initiating its movement from the rotational movement of the main drive shaft, whereby the coupling of each transverse conveyor can be triggered separately from the other couplings. A magnetic coupling is preferably employed in this case, as well. For the purpose of structural simplification, it is finally suggested that the movement of the common drive means of the roller conveyor also be initiated by the rotational movement of the main drive shaft, preferably via a reverse gear and a coupling, preferably magnetic, that can be triggered individually for each roller conveyor. In this manner the number of drive components, such as electromotors, is reduced to a minimum. Compared to a separate electrical drive, current consumption by the electrical magnetic couplings is very low; they are only triggered for short periods, in contrast to the main drive shaft, which can be operated continuously. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following explains an inventive out-processing facility using an exemplary embodiment and with reference to the drawings. 
     In the drawings: 
     FIG. 1 is a perspective illustration of a section of an out-processing facility comprising a loading area, a storage area, and an order-processing area; 
     FIG. 2 is an enlarged top view of a part of an out-processing facility, whereby for reasons of simplification the storage area is shown much abbreviated; 
     FIG. 3 is a detailed drawing of a storage or support passage corresponding approximately to FIG. 2 with associated loading area and an associated removal apparatus; 
     FIG. 4 is a cross-section in accordance with the line IV—IV in FIG. 3; 
     FIG. 5 is an enlargement of detail V in FIG. 4; 
     FIG. 6 is a partial cross-section along the line VI—VI in FIG. 3; 
     FIG. 7 are details of the removal of items on the out-processing side of the out-processing facility in six steps; and 
     FIG. 8 are details of loading the passage in the loading area of the out-processing facility in six steps. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     The out-processing facility for individual goods, including full cases of beverages and containers for grocery items that have a high turn-around rate in commercial trade, essentially comprises a storage area  1 , a loading area  2  upstream of the storage area  1 , and an out-processing area  3  downstream of the storage area  1 . New individual goods that are to be in-loaded are in-loaded in the loading area  2  in the correct storage site inside the storage area  1 . In the out-processing area  3 , the individual goods corresponding to the order are removed, computer-controlled, from the storage area  1  and conveyed to a location at which the orders are then assembled and if needed packed in larger packages. Provided for removing the individual goods from the storage area  1  are removal apparatus  4  that place items removed individually from the storage area  1  onto a downstream transport conveyor  5  along which the items are then further transported. 
     The items are also supplied to the loading area  2  by means of a continuously-driven transport conveyor  6 , which, like the transport conveyor  5  of the out-processing area  3 , comprises a plurality of driven transport cylinders  6   a  upon which the transported individual goods roll. 
     The storage area  1  constitutes a plurality of support passages  7  that are arranged horizontally at uniform height and parallel to one another. The passages  7  comprise roller conveyors  8  made of rollers or cylinders that are borne in profiles on either side. Limits  9  separate the individual passages  7  from one another so that goods cannot inadvertently travel into adjacent passages. In the framework of the embodiments explained in more detail in the following, the function of the limits  9 , that is, lateral guidance of the goods, can also be realized by flanges on the rollers or cylinders. 
     Only items or goods of the same type are located in each passage  7  in the out-processing facility. It is therefore possible to store four different types of items in the storage area  1  illustrated in FIG. 1, which comprises a total of four passages. Items of the same type are arranged one behind the other in each passage  7 , whereby they move up to the end of the passage  7  facing the out-processing area  3  as a result of the drive of the roller conveyor, described in greater detail in the following, and the forward-most item is held there at a retaining element. 
     The total of four passages  7  illustrated in FIG. 1 together form a module  10 . A plurality of such modules can be arranged adjacent to one another so that, depending on physical parameters, up to 100 passages can be arranged adjacent to one another and with common devices in the loading area  2  and the out-processing area  3 . In addition, the illustrated out-processing area can be arranged in several layers in order to increase space utilization. 
     The transport conveyor  6  is common to all passages  7 , which is why even items of different types can be conveyed using the transport conveyor  6 . In order to categorize each of these items into the correct passage  7 , each passage has a discrete transverse conveyor  11  with a direction of conveyance  12  in the direction of the passage. Each transverse conveyor  11  is controlled fully automatically as a function of the group of items supplied via the transport conveyor  6 . These can be identified, for instance, using a barcode located on the individual goods. 
     From the basic illustration of FIG. 1, it cannot be seen that a second out-processing area can be disposed on the other side of the transport conveyor  6  that faces away from the passages  7  so that outlet processing areas on both sides can be loaded via the transport conveyor  6 . Naturally in this case the transverse conveyors  11  should be able to transport in both directions. 
     In the out-processing area  3 , the items are removed individually from the passages  7  by means of the removal apparatus  4  and are transferred to the common transport conveyor  5 , which extends transverse to the passages. Each individual passage  7  is allocated a discrete removal apparatus  4 , which is why items can be removed from several passages  7  at once and transferred to the transport conveyor  5 , which is designed to be wide enough for this purpose. 
     Details and the functioning of the roller conveyors  8  of the storage area are described in the following using FIGS. 2 through 6. 
     The cylinders  15  of each roller conveyor can be caused to rotate via a drive means that is common to all of the cylinders in the roller conveyor. This common drive means is a continuous drive belt  16  that is guided via reversing rollers  17 ,  18 . The reversing roller  17  is located below the out-processing area  3 , and the reversing roller  18  is located below the loading area  2  of the out-processing facility. Provided in addition are suitable tension rollers  19  that produce the tensioning pressure on the drive belt that is required for properly transporting the drive belt  16 . This tension can also be produced directly via the reversing roller  17  and  18 , however. 
     FIGS. 5 and 6 illustrate how the drive belt  16  effects the drive of the individual cylinders  15  in the roller conveyor. The drive belt  16  comprises a continuous base body  20 , which has the same thickness across its entire length and drive segments  21  in the form of toothed bands affixed by segment to the base body  20 . However, the drive segments  21  cover only a portion of the length of the drive belt  16  so that there are additional segments between each drive segment  21  that do not have any teeth. Both groups, that is, the segments of the drive belt  16  provided with the drive segments  21  and the segments of the drive belt comprising only the base body  20 , alternate, whereby the intervals between successive drive segments  21  are preferably the same. 
     The ends of the cylinders  15  are provided with opposing teeth  22  that engage with the teeth of the drive segments  21 . In this manner a cylinder  15  is only driven if one of the drive segments  21  is directly beneath it. In contrast, a cylinder  15  is not driven if directly beneath it there is only the base body  20  of the drive belt  16 . 
     To ensure that the drive belt  16  in the region of its drive segments  21  engages securely with the opposing teeth  22  of the cylinders  15 , the resultant reaction force must be absorbed. A pressure counter bearing  23  is used for this; it extends across the entire length of the roller conveyor  8  in the form of a continuous surface. The upper or carrying run of the drive belt  16  is thus pulled between the pressure counter bearing  23  and the individual cylinders  15 . The interval is designed such that the drive segments  21  of the drive belt  16  can be pulled through this gap with no play so that the teeth and opposing teeth  22  truly engage. The pressure counter bearing is formed by the flat top side of a profile  24  that is inserted in a roller conveyor profile  25 . An exterior leg  26  of the roller conveyor profile  25  supports the individual rollers or cylinders  15 . The rollers or cylinders  15  are provided with short spindles  27  that are attached to the exterior leg  26  of the roller conveyor profile  25  via clips  28  that can be clipped on. The clips  28  make it possible to exchange individual cylinders for other cylinders rapidly and easily. During return transport, the bottom run of the drive belt  16  runs inside the roller conveyor profile  25 , preferably on. the smooth upper side  29  of the profile  24 , as seen in FIG.  6 . 
     Details and functioning of the removal apparatus  4  are explained in the following using FIG.  7 . 
     Each removal apparatus  4  comprises a horizontal conveyor  30  and a retaining element  31 . The horizontal conveyor  30 , the conveying level of which is the same as the conveying level of the roller conveyor  8 , comprises two belt pulleys  32 ,  33  that guide a wide belt  34 . Each horizontal conveyor  30  comprises a total of three of these belts  34 . The belt pulley  32 , which is farther away from the roller conveyor  8 , is driven and for this purpose is seated directly on a drive shaft  35 . The drive shaft  35  is continuously driven and simultaneously drives the horizontal conveyors  30  of a plurality of passages. All of the horizontal conveyors  30  therefore run continuously. In contrast to the belt pulley  32 , the other belt pulley  33  of the horizontal conveyor  30  is not driven. The belt pulley  33  is located in the closest possible proximity to the roller conveyor  8 . In the exemplary embodiment it is located between the belt pulley  33  and a smaller, free-running roller  36  adjacent to the next cylinder  15  of the roller conveyor. 
     Another component of the retaining element  31  of the removal apparatus  4  is furthermore a lever  37 , at the end of which is located the blocking member of the retaining element. The lever  37  is borne on a horizontal axis  38 . The retaining element  31  can be pivoted back and forth about the axis  38  between two positions. In the first position, illustrated at the top of FIG. 7, the blocking member of the retaining element  31  projects into the conveyance path for the items  39 . In its other position, the retaining element  31  drops to the conveying level or below. The second and third stages illustrated in FIG. 7 show the retaining element  31  in this position. 
     Provided in order to move the retaining element  31  out of its blocking position into its unblocking position is a cam  40  that is borne on an axis that is coaxial with the drive shaft  35 . The cam  40  has a surface  41  that runs along a roller  42 , whereby the roller  42  is located on the lever  37 . In the exemplary embodiment, the lever  37  is a two-armed lever, whereby the blocking member is located at the end of one arm of the blocking member, while the roller  42  is borne on the length of the other arm. 
     If the cam  40  is rotated approximately  900 , as can be seen in the second stage of FIG. 7 compared to the first stage in the figure, the interaction of the surface  41  with the roller  42  causes the lever  37  to move, the retaining element  31  dropping below the conveying level of the roller conveyor. At this point in time, the first item  39  is no longer retained by the retaining element  31  and therefore rolls, driven by the roller conveyor, onto the horizontal conveyor  30 . As soon as the bottom side of the first item  39  comes into contact with the belt  34  of the horizontal conveyor  30 , the item  39  immediately assumes the speed of the horizontal conveyor  30 . Depending on the weight of the item, this speed is at least 25% higher than the speed of the roller conveyor  8 . Due to this higher speed on the horizontal conveyor  30 , the first item  39  is separated from the subsequent item  39   a.  FIG. 7 illustrates this with the different speeds V 2  and V 1 , V 2  being greater than V 1 . 
     In the third stage in accordance with FIG. 7, the item  39 , conveyed with its weight virtually exclusively by the horizontal conveyor  30 , via the speed thereof, rolls over the retaining element  31 . At this point in time, the cam  40  has dropped again due to a time control. In addition, the retaining element  31  remains in its lowered position, since its restoring force is less than the weight of the item  39 . The aforesaid restoring force is produced by a counterweight  43  that is suspended on the second arm of the lever  37 . The lever  37  of the retaining element cannot pivot upward again due to the counterweight  43  until the bottom side of the item  39  has passed over the retaining element  31 , as illustrated in the fourth stage of FIG.  7 . The conveyor is immediately blocked again so that the subsequent item  39   a  is stopped at the retaining element  31 . Then the next removal procedure can be initiated, whereby the method repeats. The item  39  conveyed off by the horizontal conveyor  30  travels onto the transport cylinders  6   a  of the continuously driven transport conveyor  5 . 
     The cam  40  is driven by the continuous rotation of the drive shaft  35 . Seated on the drive shaft  35  is an electrical magnetic coupling  44 , the drive member of which is the cam  40 . Thus it is only during the time-delimited excitation of the magnetic coupling  44  that the cam  40  is actuated and the retaining element  31  thus unblocks. The drive force to be applied for this is relatively low, which is why a small magnetic coupling on the drive shaft  35  is sufficient for driving the cam  40 . A tension spring  45  draws the cam  40  back to its rest position. 
     The detail and functioning of the transverse conveyor  11  in the loading area  2  of the out-processing area are explained in the following using FIG.  8 . Located in front of each passage is a discrete transverse conveyor  11 . The transverse conveyor  11  works, as was explained in the foregoing for the out-processing area, using a continuous belt  46  that is conducted over belt pulleys  47 ,  48 . Belt  46  and belt pulleys  47 ,  48  are provided with mutually engaging teeth for preventing slip. A chain can also be employed instead of the belt  46 , and pinions instead of the belt pulleys  47 ,  48 . 
     The upper or carrying run  49  of the belt  46  is located somewhat lower than the top side of the transport cylinders  6   a.  Belt  46  and belt pulleys  47 ,  48  are relatively narrow so that they fit between two successive transport cylinders  6   a  in the transport conveyor  6 . Arranged on the exterior side of each continuous belt  46  are catch elements  50  that can circulate together with the belt  46 . When they are on the carrying run of the drive belt  46 , the catch elements  50  project higher than the conveying surface  51  of the transport conveyor  6 . 
     As can be seen in the uppermost illustration in FIG. 8, the interval between catch elements  50  is somewhat greater than the length of the carrying run  49 . In this manner, neither of the two catch elements  50  projects over the conveying surface  51 , and thus into the conveying path of the transport conveyor, in the uppermost stage illustrated in FIG.  8 . It is not until the transverse conveyor  11  has been turned on that the exterior of the two catch elements  50  moves up and grips the item  52  so that it is pushed along the transport rollers  6   a  into the passage  7 . A total of two catch elements  50  are provided In the exemplary embodiment, but their number can also be lower or higher, depending on the width of the transport conveyor  6 . 
     The transport belts  46  of the transverse conveyor  11  are also driven using magnetic couplings  53 . The magnetic couplings  53  are seated on a main drive shaft  54  that is common to all of the transverse conveyors  11  and that can be controlled separately for each passage. When current is flowing, the magnetic couplings  53  produce a momentary connection between the belt pulley  48  and the main drive shaft  54 , the drive belt  46  thus being caused to operate for as long as current flows in the magnetic coupling  53 . 
     As can be seen in particular from FIG. 2, the main drive shaft  54  causes not only all of the transverse conveyors  11  to move, but it also drives the roller conveyor  8 . An additional shaft  55  extends parallel to the main drive shaft  54 , whereby the additional shaft  55  is driven by means of a reversing gear  56  by the main drive shaft  54 . The reversing gear  56  comprises two opposing toothed wheels that are seated on the main drive shaft  54  or shaft  55  secure against torque. The reversing roller  18  is seated on the shaft  55  via an additional magnetic coupling  57  and is the drive roller for the drive belt  16 . Thus, while the shaft  55  runs continuously driven by the main drive shaft, torque is only transferred to the reversing roller  18  when the magnetic coupling  57  is actuated. In this manner it is possible, controlled by the magnetic coupling  57 , to drive the roller conveyor  8  only as needed. This is the case when new items are to be in-loaded into the passages in the loading area  2 , or when an item is to be removed from this passage in the out-processing area. Otherwise the roller conveyor for this passage can rest due to the non-actuation of the magnetic coupling  57 , so that the item there is not subjected to unnecessary friction. 
     Finally, as can be seen from FIG. 2, each transverse conveyor  11  comprises a plurality of transport belts  46 , four transport belts each in the exemplary embodiment. This achieves better and quieter transverse transport of the items  52  into the passages. The transport cylinders  6   a  of the transport conveyor  6  stand still during this transverse transport. 
     It is obvious that the out-processing facility described is program-controlled. Despite its complexity, the expense for the controls is relatively low since the great majority of processes can be controlled by turning on and off the magnetic couplings  44 ,  53 ,  57 , which require practically no maintenance. 
     “The specification incorporates by reference the disclosure of European priority document PCT/EP99/08823 of Nov. 17, 1999. 
     The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims.” 
     Legend 
       1  Storage area 
       2  Loading area 
       3  Out-processing area 
       4  Removal apparatus 
       5  Transport conveyor 
       6  Transport conveyor 
       6   a  Transport cylinder 
       7  Storage passage 
       8  Roller conveyor 
       9  Limit, flange 
       10  Module 
       11  Transverse conveyor 
       12  Direction of conveyance 
       15  Cylinder 
       16  Drive belt 
       17  Reversing roller 
       18  Reversing roller 
       19  Tension roller 
       20  Base body 
       21  Drive segment 
       22  Opposing teeth 
       23  Pressure Counter Bearing 
       24  Profile 
       25  Roller conveyor profile 
       26  Leg 
       27  Spindle 
       28  Clip 
       29  Carrying run 
       30  Horizontal conveyor 
       31  Retaining element 
       32  Belt pulley 
       33  Belt pulley 
       34  Belt 
       35  Drive shaft 
       36  Roller 
       37  Lever 
       38  Axis 
       39  Item to be removed 
       39   a  Subsequent item 
       40  Cam 
       41  Cam surface 
       42  Roller 
       43  Counterweight 
       44  Magnetic coupling 
       45  Tension spring 
       46  Transport belt 
       50  Catch element 
       47  Belt pulley 
       48  Belt pulley 
       49  Carrying run 
       51  Conveyor surface 
       52  Item 
       53  Magnetic coupling 
       54  Main drive shaft 
       55  Shaft 
       56  Reversing gear 
       57  Magnetic coupling

Technology Category: 7