Robotic end effector quick change mechanism with switchable magnetic coupler with moment support

A robotic end effector quick change coupling apparatus employs a drive motor assembly having a center drive interface. A coupling component having a magnetic element extends from the drive motor assembly concentric with the center drive interface. An end effector tool has a drive connection adapted to removably receive the center drive interface. A mating coupling component having a mating magnetic element extends from the end effector tool concentric with the drive connection. The magnetic element and mating magnetic element are separably engaged by mutual magnetic attraction to couple the end effector to the drive motor assembly.

BACKGROUND INFORMATION

Field

Embodiments of the disclosure relate generally to the coupling of robotic end effectors and more particularly to a system employing concentric magnetic engagement of an end effector tool on a drive motor assembly with a center drive interface.

Background

Robotic manipulators are employed in many phases of modern manufacturing. Different end effectors are typically attached to arms on the manipulator to accomplish different tasks using the same generalized robot system. Existing solutions for quick change tool heads or end effectors require additional actuators to mechanically lock end effector in place. Typical locking system operate using pneumatics or electrical devices. These create additional volume and mass at the end of the manipulator arm and/or the end effector and require additional controls to engage or disengage the end effector from the manipulator arm.

It is therefore desirable to provide a method and system to allow attachment and replacement of end effectors on robotic manipulators with reduced complexity, minimal three and without the need for additional actuators. It is also desirable to reduce cost through automation.

SUMMARY

Embodiments disclosed herein provide a robotic end effector quick change coupling apparatus employing a robotic manipulator having a coupling component having a magnetic element and an aperture with a contact wall. An end effector tool has a mating coupling component having a mating magnetic element and an extending protrusion having a mating contact wall closely received within the aperture. The magnetic element and mating magnetic element are separably engaged by mutual magnetic attraction to couple the end effector to the drive motor assembly, whereby the robotic manipulator engages or disengages the end effector and the contact wall and mating contact wall provide resistance to moments exerted on the end effector.

The embodiments allow a method for coupling a robotic end effector wherein a robotic manipulator is aligned with an end effector. An extending protrusion on the end effector is closely received in an aperture in the robotic manipulator having a contact wall engaging a mating contact wall on the protrusion to provide resistance to moments exerted on the end effector. A magnetic element incorporated in a coupling component extending from the drive motor assembly concentric with the center drive interface and a mating magnetic element incorporated in a mating coupling component extending from the end effector tool are then separably engaged by magnetic attraction.

DETAILED DESCRIPTION

Embodiments disclosed herein provide a system that incorporates magnetic coupling of an end effector to a drive motor assembly attached to a robot manipulator. By magnetically attaching the end effector, easy engagement and disengagement from the drive motor assembly may be accomplished. Mating antirotational features in the end effector and drive motor assembly prevent rotation of the end effector during operation of the motor.

Referring to the drawings,FIGS. 1A-1Cshow a first embodiment of the robotic end effector quick change coupling apparatus. A drive motor assembly10, which may be attached to a robot manipulator, has a center drive interface12. As seen inFIG. 1A, a coupling component, a first flange14for the first embodiment, extends from the drive motor assembly10concentric with the center drive interface12. The first flange14of the coupling component supports a magnetic element16which may take various forms as will be described subsequently. An aperture18in the first flange14allows engagement of the center drive interface12. As seen inFIG. 1B, an end effector20has a drive connection22adapted to removably receive the center drive interface12. The end effector20may include such elements as a hole maker, a hole filler, inspector/scanner end effectors and painter end effectors. A mating coupling component, a second flange24for the first embodiment, extends from the end effector tool20concentric with the drive connection22. The second flange24supports a mating magnetic element26. The magnetic element16and mating magnetic element26separably engage by mutual magnetic attraction to connect the end effector tool20to the drive motor assembly10. A mating aperture28in the second flange24allows engagement of the center drive interface12and drive connection22contact of the flange14and mating second flange24mutually engages the center drive interface12and drive connection22.

Returning toFIG. 1A, an antirotation mechanism has a first portion associated with the coupling component and a second portion associated with the mating coupling component. For the exemplary embodiment, the first portion employs hex surfaces30surrounding the aperture18as a relief in the first flange14while the second portion employs a hexagonal shoulder32(seen inFIG. 1B), the relief and shoulder constituting mating hex features. When the flange14and second flange24are engaged by the magnetic element16and mating magnetic element26the hex features interlock preventing relative rotation between the end effector20and the drive motor assembly10.

As seen inFIG. 1C, with the end effector20engaged to the drive motor assembly10, the robotic manipulator37(shown inFIG. 1E) may position and operate the end effector20for manufacturing operations. A tool holder34may be employed to hold the end effector20for pickup by or disengagement from the drive motor assembly10. For the embodiment shown, the tool holder34incorporates a relief36sized to closely receive the profile of the end effector20as seen inFIG. 1D. The drive motor assembly10may then be withdrawn by robotic manipulator37along a connection axis38through the center drive interface12to break the magnetic engagement between the magnetic element16and mating magnetic element26thereby freeing the end effector20from the drive motor assembly as seen inFIG. 1E.

As previously discussed, the magnetic element16and mating magnetic element26may take several forms. In the first embodiment, the magnetic element16may be a ring magnet in the flange14as shown inFIG. 1A. The mating magnetic element26may then be a magnetically attractive metal ring or a second ring magnet of opposite polarity in the second flange24as seen inFIG. 1B. As an alternative, the magnetic element16may be a plurality of magnets17concentrically spaced on the flange as seen inFIG. 1F. To enhance the magnetic field produced the magnets17may have the magnetic poles aligned with common polarity as indicated by the “N” designation on the magnets17. With a plurality of magnets in the first flange14, the mating magnetic element26may again be a ring of magnetically attractive metal as shown inFIG. 1Bor, as seen inFIG. 1G, may be a mating plurality of either ferromagnetic coupons or magnets, oriented with opposite polarity to the magnets17as indicated by the “S” designation, as mating magnetic elements27, in embodiments where it is advantageous that flange24is made from a non-magnetic material such as aluminum.

An enhanced second embodiment is shown inFIGS. 2A and 28. As seen inFIG. 2A, the magnets17may be held in a pattern on a face39of a rotatable sleeve40which concentrically surrounds the center drive interface12. As seen inFIG. 2B, the mating magnetic elements27are positioned in a mating pattern in a non-magnetic mating face25on the second flange24on the end effector20such that with the rotatable sleeve40at a first rotational position the magnets17and mating magnetic elements27are aligned (as shown by phantom lines31) for maximum magnetic attraction as seen inFIG. 2Cand when the drive motor assembly10and end effector20are engaged along the connection axis38by the robotic manipulator, the magnets17and mating magnetic elements27are magnetically engaged. The magnetic elements27may be magnets or ferromagnetic coupons as previously described. If the magnetic elements27are optionally magnets, then the face39would be fabricated from non-magnetic material. As in the first embodiment, contact of the face39and mating face25on flange24mutually engages the center drive interface12and drive connection22. By rotating the rotatable sleeve40to a second position with the magnets17and mating magnetic elements27no longer aligned (as indicated by the phantom lines31) as seen inFIG. 2D, the magnetic attraction is minimal and little or no force is required for the robotic manipulator37to separate the end effector and drive motor assembly.

As seen inFIG. 2E, a paddle42may extend from the tool holder34and lateral motion of the drive motor assembly10along a lateral axis45perpendicular to the connection axis38by the robotic manipulator engages a lever44extending from the rotatable sleeve40to rotate the sleeve40. Engagement of the paddle42by the lever44in a first direction along the lateral axis45induces rotation of the rotatable sleeve40for alignment of the magnets17and mating magnets27for activating magnetic engagement. While engagement of the paddle42in a second direction along the lateral axis45induces rotation of the rotatable sleeve40to misalign the pattern of magnets17and magnetic elements27to deactivate the magnetic engagement.

The second embodiment may alternatively employ magnetically attractive metal inserts46as seen inFIGS. 2A, 2C and 2Dwhich are fixed in the flange14and align with the magnets17in the first rotational position of the rotatable sleeve40. When aligned, the metal inserts46will have an induced magnetic field from the magnets17. When not aligned with the rotatable sleeve40in the second rotational position, the metal inserts46will not have any magnetic field. By positioning the mating magnetic elements27′ in the flange24on the end effector20for alignment with the metal inserts46as seen inFIG. 2F, magnetic attraction between the metal inserts and the mating magnetic elements27′ will be present when the magnets17are aligned with the metal inserts46in the first rotational position of the rotatable sleeve40to provide magnetic engagement between the drive motor assembly and end effector20. However, when the rotatable sleeve40is rotated to the second rotational position no magnetic field will be present in the metal inserts46and therefore no magnetic attraction with the mating magnetic elements27′ will be present.

Shaping of the interconnecting first and second flanges14,24and antirotation mechanism such as hex shoulder32and relief30on the end effector20and drive motor assembly10may be altered to accommodate specific geometry or operational needs.FIGS. 3A-3Cdemonstrate an alternative embodiment in which flange50on the drive motor assembly10and mating flange52on the end effector20are modified elliptical shapes. Antirotation shoulder54extending from the flange50(seen inFIG. 3A) is a concentric modified elliptical shape which is received in relief56in mating flange52(seen inFIG. 3B). Shaping of the shoulder54and relief56prevent rotation when engaged. Flange50supports a plurality of magnets58which are placed in alignment for magnetic engagement with mating magnetic elements60supported by the mating flange52when the flange50and mating flange52are appropriately aligned for engagement of the antirotation shoulder54and relief56. Engagement and disengagement of the drive motor assembly10and end effector20may be accomplished as previously described with respect to the first embodiment with use of a tool holder34for the end effector20using the robotic manipulator37to engage or withdraw the drive motor assembly10along connection axis38for engagement/disengagement of the magnets58and mating magnetic elements60.

Magnetic interengagement of the end effector20and drive motor assembly10may also be accomplished in a three point connection as shown for the embodiment inFIGS. 4A-4C. This configuration allows implementation of a torque transducer62in a floating drive train engaged by a gear64as seen inFIG. 4A. The torque transducer62is concentric with the center drive interface12extending through the center aperture18in flange14as in the first embodiment. Interengagement between the end effector20and the drive motor assembly10is accomplished at a first point between the center drive interface12and drive connection22accessed through mating aperture28in flange24. The second point of engagement is10between gear64extending from the torque transducer62and mating teeth64in the end effector20. The third point of engagement is provided with a plurality of antirotation protrusions66extending from the periphery of flange14to be received in a plurality of mating slots68in the periphery25of mating flange24. While multiple protrusions66and slots68are shown in the exemplary embodiment a single protrusion and mating slot or alternatively cylindrical pins to mating holes or slots may be employed. Contact of the flange14and mating flange24mutually engages the center drive interface12and drive connection22and engages the protrusions66in slots68as the antirotation mechanism. As in prior embodiments, the magnetic element16and mating magnetic element26separably engage flange14and mating flange24to secure the end effector20to the drive motor assembly10with magnetic engagement as seen inFIG. 4C.

A fifth embodiment is shown inFIGS. 5A-5Dwhich improves resistance to moments exerted between the end effector20and the drive motor assembly10. As seen inFIG. 5A, a coupling component, a first flange14as in the first embodiment, extends from the drive motor assembly10concentric with a center drive interface comparable a to the center drive interface12ofFIG. 1Abut not visible due to the length of the coupling component as will be described subsequently. The first flange14of the coupling component supports a magnetic element which consists of a plurality of magnets16. An aperture18in the first flange14has an inner cylindrical portion70and an outer cylindrical portion72of greater diameter providing a shoulder relief. As seen inFIG. 5B, an end effector20has a drive connection22adapted to removably receive the center drive interface12. A mating coupling component, a second flange24for the fifth embodiment, extends from the end effector tool20with a protrusion74concentric with the drive connection22. The protrusion74has a first outer cylindrical portion76and a second inner cylindrical portion78of greater diameter to provide a shoulder. The protrusion74is separably received within the aperture18and a contact wall80of the cylindrical inner portion70receives a mating contact wall82of the first outer cylindrical portion76of the protrusion while the shoulder created by the second inner cylindrical portion78is received within the should relief provided by the outer cylindrical portion72of the aperture. The second flange24supports a mating magnetic element26which may be a feromagnetic metal face of the flange. The magnetic element16and mating magnetic element26separably engage by mutual magnetic attraction to connect the end effector tool20to the drive motor assembly10. A mating aperture28in the protrusion74allows engagement of the center drive interface12and drive connection22contact of the flange14and mating second flange24mutually engages the center drive interface12and drive connection22. Close engagement of the protrusion74within the aperture18resists lateral moments which may be incurred between the drive motor assembly10and end effector20during use. This moment resistance allows reduction of the magnetic force required between the magnetic element such as magnets16and the mating magnetic element26to effectively connect the end effector to the motor drive assembly. For the embodiment shown the first outer cylindrical portion76and second inner cylindrical portion78of the protrusion74are chamfered to assist in alignment for engagement within the inner cylindrical portion70and outer cylindrical portion72of the aperture18in the drive motor assembly.

Returning toFIG. 5A, an antirotation mechanism for the exemplary fifth embodiment is provided by a first portion comprising two cylindrical pins84extending from the second flange24while the second portion comprises two bores86in the first flange14. When the flange14and second flange24are engaged by the magnetic element16and mating magnetic element26the pins84are engaged in the bores86preventing relative rotation between the end effector20and the drive motor assembly10. For the embodiment shown, pins84are diametrically opposed on the second flange24and the bores86are diametrically opposed on the first flange14at a common radius with the pins. While a pair of pins and bores is shown for the exemplary embodiment, a single pin and bore or three or more pins and bores may be employed.

As seen inFIG. 5C, with the end effector20engaged to the drive motor assembly10, the robotic manipulator37(shown inFIG. 1E) may position and operate the end effector20for manufacturing operations. A tool holder34may be employed to hold the end effector20for pickup by or disengagement from the drive motor assembly10. For the embodiment shown, the tool holder34incorporates a relief36sized to closely receive the profile of the end effector20as seen inFIG. 5D. The drive motor assembly10may then be withdrawn by robotic manipulator37along a connection axis38through the center drive interface12to break the magnetic engagement between the magnetic element16and mating magnetic element26thereby freeing the end effector20from the drive motor assembly as as previously described with respect toFIG. 1E.

A method for coupling a robotic end effector employing the embodiments disclosed is accomplished as shown inFIG. 6with reference to exemplary embodiments ofFIGS. 5A-5D. A robotic manipulator having a drive motor assembly10including a center drive interface12is aligned with a drive connection on an end effector20, step602. A coupling component, such as flange14, having a aperture18and a magnet element, such as a plurality of magnets16, and extending from the drive motor assembly10concentric with the center drive interface12is engaged with a mating coupling component, such as second flange24, having a protrusion74and a mating magnetic element26and extending from the end effector20concentric with the drive connection22, by inserting the protrusion74into the aperture18, step603and then engaging the magnetic element and mating magnetic element, step604. The magnetic element and mating magnetic element are separably engaged by mutual magnetic attraction. The end effector tool may be secured in a tool holder34, step606, and the robotic manipulator37may withdraw the drive motor assembly10to separate the magnetic element and mating magnetic element to break the mutual magnetic attraction and remove the end effector20from the drive motor assembly10, step608. A contact wall in the aperture and a mating contact wall on the protrusion provide resistance to any moments between the end effector and drive motor assembly, step610, thereby reducing the required magnetic three necessary to effectively engage the end effector tool to the drive motor assembly.

Embodiments of the disclosure may be employed in the context of an aircraft manufacturing and service method700(method700) as shown inFIG. 7and an aircraft800as shown inFIG. 8. During pre-production, the exemplary method700may include specification and design704of the aircraft800and material procurement706. During production, component and subassembly manufacturing708and system integration710of the aircraft800takes place. Thereafter, the aircraft800may go through certification and delivery712in order to be placed in service714. While in service by a customer, the aircraft800is scheduled for routine maintenance and service716(which may also include modification, reconfiguration, refurbishment, and so on).

As shown inFIG. 8, the aircraft800produced by the exemplary method700may include an airframe818with a plurality of systems820and an interior822. Examples of high-level systems820include one or more of a propulsion system824, an electrical system826, a hydraulic system828, an environmental system830, and flight control system832. Any number of other systems may also be included. Although an aerospace example is shown, the embodiments of the disclosure may be applied to other industries. The embodiments disclosed herein may be used on steps or elements708,710,714,716,818and822, of the method and aircraft as disclosed inFIGS. 7 and 8

Apparatus and methods embodied herein and previously described may be employed during any one or more of the stages of the production and service method700. For example, components or subassemblies corresponding to production process708may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft800is in service. In addition, one or more apparatus embodiments as described herein, method embodiments described herein, or a combination thereof may be utilized during the production stages708and710, for example, by substantially expediting assembly of or reducing the cost of an aircraft800. Similarly, one or more of apparatus embodiments, method embodiments, or a combination thereof may be utilized while the aircraft800is in service, for example and without limitation, to maintenance and service716.

Having now described various embodiments of the disclosure in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present disclosure as defined in the following claims.