ROBOTIC GRIPPER APPARATUS

Various aspects of robotic grippers are disclosed herein. In one aspect, a robotic gripper may include three gripper fingers arranged on a mechanical end effector, the three gripper fingers configured to translate radially when actuated to contact and align with a gripper interface located on a part to enable manipulation of the part. In various embodiments, each gripper finger may include an elongated portion configured to contact an outer surface of the gripper interface when the gripper fingers are actuated. Each gripper finger may further include a hook portion configured to contact an inner surface of the gripper interface opposing the outer surface. In various embodiments, the hook portion may include a receptacle positioned to align with a complementary protrusion on the gripper interface.

BACKGROUND

Field

The present disclosure relates generally to automated movement of parts, and more particularly, to robotic grippers for fixtureless movement of parts.

Introduction

Conventional manufacturers of diverse or heavy equipment may employ hard automation techniques or robots for moving or manipulating different parts, such as in automotive, aircraft or spacecraft manufacturing facilities, and similar factories using heavy machinery or parts with multiple geometries. To lift or otherwise manipulate heavy equipment or bulky parts that may be unwieldy to handle, it is not uncommon for manufacturers to build tooling specific to the parts that allow the robots to handle the parts. These fixtures may enable the manufacturer to manipulate the product and perform processing operations on it. However, a major disadvantage of this approach is that the fixtures are limited to specific products or product lines. When the products change, it is typically an expensive capital investment to retool the fixtures to accommodate the new parts.

Furthermore, to move heavy parts or awkward parts with uneven weight distributions, manufacturers may in some cases have to use multiple points of contact, which in turn may require additional grip points on a single part, in addition to the increased inefficiency of dedicating multiple robots to a single task. Conventional automated robotic grip mechanisms may also inadvertently damage the part if the grip mechanism contacts the part surface, such as when a part unintentionally moves or slips relative to the robotic arm.

SUMMARY

Several aspects of robotic grippers are disclosed in various embodiments described herein.

In one aspect of the disclosure, a robotic gripper includes three gripper fingers arranged on a mechanical end effector. The three gripper fingers are configured to translate radially when actuated to contact and align with a gripper interface located on a part to enable manipulation of the part. Each gripper finger includes an elongated portion configured to contact an outer surface of the gripper interface when the gripper fingers are actuated, and a hook portion configured to contact an inner surface of the gripper interface opposing the outer surface. The hook portion includes a receptacle positioned to align with a complementary protrusion on the gripper interface.

In another aspect of the disclosure, a robotic gripper includes three gripper fingers arranged on a mechanical end effector and configured to translate radially outward when actuated to engage a gripper interface located on a part to enable manipulation of the part. Each gripper finger includes an elongated portion arranged on the end effector and configured to contact an outer surface of the gripper interface when the gripper fingers are actuated, and a hook portion configured to contact an inner surface of the gripper interface opposing the outer surface to securely engage the gripper interface.

In still another aspect of the disclosure, a robotic gripper includes three gripper fingers arranged on a mechanical end effector and configured when actuated to translate radially outward to contact and engage a gripper interface located on a part to enable manipulation of the part. Each gripper finger includes a base portion arranged along a surface of the end effector and configured to contact an outer surface of the gripper interface during the engagement, and a hook portion configured to contact an inner surface of the gripper interface opposing the outer surface, the hook portion further including a first feature positioned to align with a second feature on the gripper interface, the second feature being complementary to the first feature.

It will be understood that other aspects of robotic grippers will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only several embodiments by way of illustration. As will be realized by those skilled in the art, the disclosed grippers are capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the current disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended to provide a description of various exemplary embodiments of the concepts disclosed herein and is not intended to represent the only embodiments in which the disclosure may be practiced. The terms “example” and “exemplary” used in this disclosure mean “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments presented in this disclosure. The detailed description includes specific details for the purpose of providing a thorough and complete disclosure that fully conveys the scope of the concepts to those skilled in the art. However, the disclosure may be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form, or omitted entirely, in order to avoid obscuring the various concepts presented throughout this disclosure.

The present disclosure is generally directed to various embodiments of a robotic gripper. The robotic gripper may generally be characterized by a master side. The master side may include the robot, the robotic arm, the end effector coupled to the arm, and the robotic gripper. Various aspects may further include a tool side. The tool side may include a gripper interface that can be machined or 3-D printed into the part that is to be manipulated. The parts to be moved, shifted, or otherwise manipulated can be any custom or standard part.

The robots used for the robotic grippers may be independent, movable robots, or they may be robotic arms secured to a fixed region, depending on the application. Also, as noted, requiring multiple tooling to accommodate different parts typically results in large capital expenditures. The grippers may be designed for use in fixtureless assemblies. Fixtureless assembly eliminates the need for different tools and fixtures to accommodate different part models or geometries. With fixtureless assembly, for example, a part may be in the process of being repositioned by one manipulator while being polished or welded by another manipulator. Here, the fixtures may be replaced by sensor-guided robots, which can result in substantially lower costs.

In various embodiments of the disclosure, the robotic gripper may use three generally concentric gripper fingers that expand outward to provide a “wedge shaped” geometry. The three gripper fingers may expand to an amount that is consistent with the interface. The robotic gripper, unlike conventional approaches, can be made capable of efficiently holding large parts, while concurrently resisting adhesive joining forces that otherwise may cause the robotic gripper to stick to the part.

In various embodiments of the disclosure, the part to be manipulated can be equipped with a gripper interface. The gripper interface may be 3-D printed on the part, or it may in some embodiments be machined onto the part. Unlike conventional interfaces, the gripper interface as disclosed herein is typically compact. As described in greater detail below, the gripper interface may be printed or formed on an appropriate surface of a part such as an aircraft or automobile component. Because only one gripper interface is typically integrated into a part, the gripper interface introduces a small footprint. Further, using a three-finger gripper, each of the fingers in some embodiments can be independently positioned at different ratios relative to the gripper interface to optimally couple to the gripper interface. Depending on factors like the size and geometry of the gripper interface formed on a part and the achievable angle between the interface and the robotic gripper, the three fingers can be independently positioned to extend by different amounts in order to grasp the interface strongly while optimizing the footprint of the gripper and the gripper interface. That is to say, each of the three grippers may be strategically positioned to couple to the interface using an optimal ratio given the relative dimensions of the members and other criteria, and the relative positioning of the part to the floor and the robotic gripper. This feature stands in contrast to conventional robotic grippers, in which each of the fingers may not be independent and are therefore required to move together uniformly with the same position ratio. These conventional grippers lack flexibility and often cannot form an optimal grip with the interface.

The gripper interface may also, in some embodiments, take advantage of certain hollow portions of a steel surface of a part to enable the robotic gripper to engage with the part by latching onto both an inner surface and an outer surface of the gripper interface. The result is a robotic gripper that can move or manipulate a part for any reason directly without requiring fixtures, including, for example, assembling vehicle structures for automobiles, transporting the part to another region of the facility, or stabilizing the part while it is being polished, mechanically modified, or otherwise processed, etc.

FIG. 1is a perspective view of a robotic gripper according to an embodiment. The robotic gripper100may include a sensor (not shown in this embodiment) for identifying a coordinate-based position of a gripper interface. In general, the robotic gripper100disclosed inFIG. 1may include three gripper fingers102a-carranged in a generally concentric configuration relative to one another on an end effector110. The end effector110may be an end-portion of a robotic arm and its accompanying features. The end effector110may be coupled to an arm of a robot or a stationary automated system. Each of the gripper fingers102a-cin the embodiment shown may include an elongated portion112and a hook portion118.

In various embodiments, the configuration of the robotic gripper100is such that the end effector110may be coupled to a robotic arm of a robot. Using the sensor, the end effector110—and hence the robotic gripper100—may approach the gripper interface as described in figures to follow. The three hook portions118may be configured to enter an aperture made available for the hook portions118, such as a gripper entry area842(FIG. 8), to enable the gripper to securely connect to inner and outer surfaces of the gripper interface840(FIG. 8) to guarantee a snug fit regardless of the radius of the gripper entry area842.

Each gripper finger102a-cmay include an elongated portion112that may be arranged on a guide (FIG. 3) on the surface of the end effector110. In various embodiments, the elongated portion112may be formed over an end effector aperture120. In these embodiments, the end effector apertures (one for each elongated portion112) may be configured to guide the elongated portion112as the gripper finger is translated radially outward from its open position.

In other embodiments described below, the gripper finger is arranged over another guide or structure that may fasten to each of the elongated portions112via fastener116. Two fasteners116may be included on a single gripper finger102a, borc. In various embodiments, the fasteners116may be used by a servo motor or by a pneumatic actuation mechanism to radially translate the elongated portions112and hook portions118of each gripper finger102a-cin an outward position to enable the hook portion118and its associated receptacle114to lock with a gripper interface (below). In some embodiments, the gripper fingers (see gripper finger102c) may be guided by an end effector aperture120, which may have edges (obscured from view) along which the gripper finger102ccan be guided as it moves during its outward translation. The other edges may be associated with similar end effector apertures120. As noted above, in some aspects of the disclosure, each of gripper fingers102a-care designed to independently move, free from the movements of each other. This accords flexibility in enabling the gripper to handle a variety of different interfaces with different geometries. This also allows the gripper, if necessary, to handle a part differently depending on the geometry of the part, its weight, and its position relative to the factory floor, among other benefits.

In additional embodiments as will be seen, the end effector aperture120includes a guide mechanism that includes fasteners for the gripper fingers102a-c(and specifically elongated portions112) and that includes an interface with the internal pneumatic activation device that enables movement of the gripper fingers from the unlocked position shown inFIG. 1to a locked position. Further, in various embodiments, each hook portion118includes a flange126. The flange126may be an orthogonal outcropping on each side of the hook portion118. Each of the flanges126on the different hook portions118(six flanges126here in total) may further include a front edge128at the top of each flange126. The front edge128, which is generally facing in a radial outward direction toward an edge of the end effector110, may include an inclined wall130between the front edge128and the elongated portion surface132. In various embodiments, the inclined wall130may be present to align with a complementary feature on a gripper interface of a part when the gripper pneumatically locks onto the part.

In sum, each gripper finger102a-cin this embodiment includes a receptacle114facing radially outward (for subsequent alignment with a complementary member), an opposing pair of flanges126in a generally transverse direction to the elongated portion112, for each flange126of the pair on the hook portion118, a front edge128also facing outward and an inclined wall130between each flange126and a surface of the elongated portion112. In various embodiments, each of the three elongated portions112may also include a pair of opposing side members112athat are coupled to the respective hook portion118for the particular finger gripper102a,102bor102c. The elongated portion surface132may extend to include these side members112a, enabling the inclined wall130at the front edge128of each flange126to be coupled to the elongated portion surface132via this extension of the elongated portion112(i.e., the side members112aincluded in this embodiment as part of the elongated portion112).

In various embodiments, each hook portion118may include a flange126that includes a front edge128on each side of the receptacle114. The receptacle114may be positioned, during outward translation, to align with a complementary protrusion on the gripper interface as described in subsequent embodiments. It should be noted that inFIG. 1, the gripper fingers102a-care effectively in the “unlocked” position as identified by the sensor in the sense that the fingers are not secured to another part, and therefore any outward radial movement of the type described has yet to occur. Rather, the geometry of the three hook portions118is contoured so that the portions118fit snugly in the middle region of the end effector110, which conserves room and ensures that that gripper can fit within smaller spaces.

Referring still toFIG. 1, the end effector110may include another advantageous feature for eliminating or minimizing damage to the parts during the movement. As can be seen at the edges of the end effector110between different ones of the gripper fingers,102a-c, three support structures106may be positioned. The geometry of the support structure106may vary based on different robotic grippers. Each support structure is selected so that it is sturdy enough to endure a force caused by a collision, whether or not intentional. Each support structure106includes a dedicated contact region108. The first movement in the part gripping process, addressed in more detail below, is the approach of the part by the end effector of the robotic arm, and then contact. The portion of the end detector110that houses the equipment ofFIG. 1uses a sensor as noted to approach a gripper interface built into the part (described below). The result of this initial action is that some portion of the gripper interface comes into contact with the gripper interface. The three support structures106, which may be concentrically arranged around the end effector110gripper surface, come into contact with the part primarily via the contact region108on the upper surface of each support structure. Two of three support mounts119can be seen in this embodiment, with the third obscured from view. In various embodiments, the support mounts119may be a block of rubber or another material that can be used to provide support for either the end effector110or the part in the event of an unintended collision. The support mount119may also be fastened securely to each side of the end effector and, in some cases depending on the material from which they are made, they may also provide a stabilizing effect to the robotic gripper.

Atop the contact region include dome-like protrusions104. In the embodiment ofFIG. 1, there is one such protrusion104for each contact region108. In various embodiments, the function of each protrusion104is to prevent excessive motion of the part during assembly after the corresponding gripper102a, b, or c is released and just prior to extraction of the robotic gripper100along the z-axis (perpendicular to the end effector surface in this example. The protrusions104work by providing a protruding male feature on the surface of the robotic gripper100, such that, as shown below, a matching or complementary female feature may be built into the part on the gripper interface. Under normal operation, these respective protrusions104and female features have no contact. However, if deflections from ongoing assembly operations on the part in question after robotic gripper100release cause excessive deflection of the part that exceed a nominal amount, at least one of the protrusions104can enter a complementary feature constructed into the gripper interface. Thus protrusion104can inhibit excessive deflection and can allow the angled gripper fingers102a-cto be extracted without snagging on the part or the gripper interface.

FIGS. 2A, 2B and 2Care top200a, perspective200b, and side200cviews of exemplary gripper fingers200a-c, respectively, with a complementary portion of an effector interface as described below. Referring first to gripper finger200a, the elongated portion212is easily visible, as is the elongated portion surface232and the receptacle214used to align with a complementary protrusion (not shown) on the gripper interface during locking. Hook portion218is illustrated as well with flanges226on each side, and front edges228extending at least partially along the flanges226. Fastener openings216amay allow an aligning set of fasteners, e.g., from the end effector aperture of another structure below the gripper finger200ato lock into place and move the gripper finger200ausing the fastener openings216a.

Various geometrical settings are displayed that may be pertinent to rotational stability, stiffness, and other requirements of the gripper fingers200a-c. For example, the front edges228may form straight lines on either side of the receptacle214and, when measured around the rear of the hook portion218the lines may form an angle of B degrees, as shown inFIG. 2A. In like manner, referring toFIGS. 2A and 2B, the mouth224of the receptacle214forms either a width or an angle of A, depending on the shape of the receptacle214, for example.

The perspective view of the gripper finger200bofFIG. 2Balso includes some additional views of the hook portion218not directly available from the top view. The inclined wall230at flange226meeting the front edge228and an elongated portion surface232shows that the inclined wall230may form an angle with the elongated portion surface232of less than 90°. In addition, an inner portion of the receptacle214including an inner wall226of the receptacle214is viewable inFIG. 2Bas well.

An exemplary perspective view of gripper finger200binFIG. 2Bshows many of the same features, including that the receptacle214may include a mouth224, with the dimensional width A of the mouth shown inFIG. 2AandFIG. 2C. Similarly, the gripper finger200cinFIG. 2Cshows a side view of the gripper finger ofFIGS. 2A and 2B. A noteworthy point that may be underscored inFIGS. 2B and 2Cis that the hook portion218can either be a separate member that is adhered to the elongated portion212using some adhesive or fastening mechanism, or in some embodiments hook portion218can be integrally formed with, and in effect can be the same part as, the elongated portion212. By way of example, if the gripper fingers200a-care additively manufactured, e.g., using a laser or electron beam powder-bed fusion process or some similar technique, it may be more sensible to form the elongated and hook portion as one geometrically integral member in order to maximize the forces that it could withstand, although this is not required.

The view of the gripper finger200cinFIG. 2Calso includes a side view of the inclined wall230and the front edge228. As shown inFIG. 2C, the inclined wall230may form an angle C° with the elongated portion surface232. The side view of gripper finger200calso shows the side of the fastener openings216a, albeit not necessarily to scale.

As described below, the inclined wall230and its analogous portions on various parts of the different gripper fingers can be used to assist with the alignment of the gripper and also to provide an optimized set of properties using appropriately calculated dimension/angles A, B° and C°. By way of example, in the embodiments ofFIGS. 1 and 2, rotational stiffness about a z axis orthogonal from the perspective of a part to an approaching gripper may be provided by varying the feature dimension A (width of the aperture) and angles B° and C° to provide the gripper fingers200a-cwith three exemplary resistive functions. As another example, the overturning stiffness about hypothetical x and y axes perpendicular to z and generally parallel to the face of the robotic gripper, generally refers to the resistance of the part held by the gripper to rotating about one of the x or y axes. As an example, the cartesian graph on the right ofFIG. 12shows x, y and z axes relative to the part approach1265. This overturning stiffness can generally be optimized (that is, made as high as possible without reducing other critical parameters faced by the engineer) by adjusting feature angles B° and C°, or the angle around a posterior of the receptacle (FIG. 2B) as delimited by the front edges228, and the angle between the inclined wall230and elongated portion surface232(FIG. 2C). In one embodiment, stiffness may ideally be limited to about 0.02° for optimal quality control. It should also be noted that tight tolerances of dimension A and angle B helps provide higher repeatability along with higher rotational stiffness. Tight tolerance of C also provides axial stiffness and overturning stiffness, as well as reliable contact of the support structures106and contact regions108(FIG. 1).

The above factors may be taken into account during the assembly of the CAD model in the case where the robotic gripper100is 3-D printed. The gripper fingers200a-calso may be designed in some embodiments to provide repeatable positioning of the part being gripped. Repeatability and ability to position features on demand can, over the long haul, lengthen the life of the gripper. Repeatability also allows for a more accurate prediction of where the part will be located in space relative to coordinates. This knowledge may allow for smaller variation ranges, which allows the engineer to create a smaller scan patch size for measuring metrology features.

In addition to the above factors, one significant benefit of many of the embodiments herein is their ability to tolerate print (or other part) inaccuracies in embodiments including 3-D printed parts for assembly. With the use of the three concentric fingers that expand outward to form the generally-wedge shaped geometry, a “slop-free” engagement can be realized with a gripper interface, since the manufacturer in these cases need not rely on ultra-high precision fits, or perform conventional methods by contacting a wall using a pin/hole fit (neither of which are achievable options when the part is in the as-printed condition). Thus, the system herein is able to absorb print inaccuracies which may range on the order of several millimeters, for example. Another key benefit of the gripper herein over conventional grippers is strength. Given the mass of some of these parts, it is not surprising that strength (or lack thereof) may act as a key constraint to conventional grippers. For example, in contrast to many conventional gripper systems, the gripper systems herein rely on a single contact point to carry, lift, move and otherwise manipulate large assemblies.

The contact point may be otherwise vulnerable to deflection as a result of adhesive joining forces between the gripper and the interface. The three grippers102a-care formed from durable materials such as metal alloys for top performance. The three grippers complement each other to avoid stability problems, and can provide significant lift strengths so often needed for gripping heavy parts and the multiple applications of robotic grippers. In addition, in some embodiments, the gripper systems described herein have a “push back” mechanism on retraction, meaning that the large joining strengths can be resisted immediately upon retraction of the gripper. That is to say, when the lock is released, the end effector can be configured to push the gripper fingers away from the part to ensure that the part does not inadvertently adhere to the robotic gripper.

Other key benefits of the grippers described herein include vision friendly lead-ins, with several millimeters of clearance in some cases. Thus, using sensors and imagers in some embodiments, the gripper can be carefully and accurately maneuvered to reach its target.

FIG. 3is a view of a top surface of an exemplary end effector300. For clarity in this embodiment, certain structures including the gripper fingers have been omitted from view. End effector300includes three gripper finger guides380strategically placed in radial regions starting from the center of the end effector300to a region close to the perimeter of the end effector300. In various embodiments, the gripper finger guides380are sized to fit into the radial apertures underneath (see end effector aperture120,FIG. 1). Each gripper finger guide380is designed to hold one gripper finger (not present in the figure) in place on top of it. In some embodiments, the gripper fingers are configured to receive pneumatic pressure to enable them to slide radially along a gripper finger base381when actuated by a controller. The gripper finger base381is securely positioned under the guide and is immobile. Each of the gripper finger guides380are configured to attach to one of the three elongated portions112(FIG. 1). Each gripper finger guide380includes two gripper finger engagement features382. The gripper finger engagement features382can be fastened to each respective elongated portion112via fastener116(FIG. 1) so that, in these embodiments, the gripper fingers102a-c(FIG. 1) are designed to translate radially outward with the gripper finger guides380when pneumatic actuation occurs.

In various embodiments, each gripper finger guide380may further include one or more rails or edges383on the sides of each gripper finger guide380to enable the gripper finger guide380to more easily maintain restricted motion along the axial direction during locking and unlocking. In various embodiments, the two gripper finger engagement features382on each gripper finger guide380may be aligned with the two fasteners116so that they may connect to the two fasteners on each of the gripper fingers102a-c. In some embodiments, the two gripper finger engagement features382on each gripper finger guide380may also be coupled to motor or actuator circuits that may be present in the end effector aperture120regions (FIG. 1). With an appropriate servomotor or other actuator circuit present in the end effector aperture120regions to move the gripper finger engagement features382, the actuators may easily move the respective gripper fingers102a-cvia the fasteners116to which the gripper finger engagement features382are coupled. This configuration may allow for controlled movement (e.g., outward radial translation) by using pneumatic pressure to translate the gripper fingers102a-coutward to enter into the locked mode, and to retract the gripper fingers102a-cwhen moving to the unlocked mode. Further, the gripper finger guides380may be used to keep the elongated portions112moving in the correct direction (via the fasteners116) depending on whether locking or unlocking is desired. It will be appreciated that the pneumatic pressure mechanism may be replaced by another method of power in some embodiments. Further, the gripper finger guides380in some embodiments may themselves be part of the gripper fingers102a-c. For example, in these embodiments, the gripper finger guides380may be built into the elongated portions112of the corresponding gripper fingers102a-c. In some arrangements, the gripper finger bases381may be used to assist the pneumatic actuators in providing the correct amount of force for the gripper fingers102a-c. In other cases, the gripper finger bases381may not be required, or they may be present but only for support purposes.

FIG. 3also shows a middle surface cover309that may be used as a supporting surface to place the hook portions118of the respective gripper fingers102a-c. Thus, for example, a hook portion118of a gripper finger102amay extend from a region near a middle edge of the end effector300and up onto the middle surface cover309, where it meets the other hook portions118. When the device is unlocked, e.g., the hook portions118are seated partly or completely on the middle surface cover309, the hook portions118may be contoured (see, e.g.,FIG. 1) so that they take up very little room on the robotic gripper100, thereby minimizing the size of the gripper. In various embodiments, the middle surface cover309may also be used to provide support for the actuators.

FIG. 3also shows the respective support structures306and the cross-hatched contact regions. The contact regions can be used to make contact with the part during the initial approach by the part to the gripper interface located on the part. In various embodiments, the contact regions308can just be designed high enough relative to the other structures on the end effector that the contact regions308are likely to contact the part before other features. The contact regions308may be flat so as to minimize any sharp edges affecting the part or the gripper interface. As noted above, a principle surface of the crossed-hatch areas in accordance with this embodiment is to provide a predictable and repeatable surface upon which the relevant portions of the gripper interface or the part may rest when the robotic gripper approaches the gripper interface to effect the gripping function, as described below. These predictable regions also help ensure proper engagement of the gripper fingers102a-c, in part because the flat repetitive contact regions308add stability to the end effector300as the gripper fingers102a-care actuated from their unlocked position.

Thus, in the exemplary embodiment ofFIG. 3, the gripper finger guide380is placed in a secure region above the end effector aperture (such as, for example, atop the gripper finger base381) and the gripper finger's elongated version 112, located in turn on each respective gripper finger guide380, can be translated radially outward and returned using the power provided to the elongated portions112by the gripper finger engagement features382, each of which may be further attached to the respective fastener116on one side and to the actuators/motors on the other side. For example, the elongated portion212inFIGS. 2A and 2Bincludes fastener openings216awhich serve as the basis for each fastener116(two on each gripper finger102a-c). In various embodiments, the central member382aof the gripper finger engagement feature382may act as the fastening element in the middle of fastener116(FIG. 2). That is, the central member382amay protrude through the openings216a(FIG. 2) and may be secured after passing therethrough (via adhesive, treads, or otherwise) to form each of fasteners116inFIG. 1. The gripper finger guide380, the gripper finger engagement features382, or either one of those, may be powered to provide pneumatic or other electrical power to the gripper fingers102a-cto allow the gripper fingers to translate in either direction as necessary. Other embodiments are possible.FIG. 3also shows the protrusion304atop the contact region308of the support structure, discussed further with reference toFIG. 4.

FIG. 4is a side view of an exemplary end effector, such as the end effector300ofFIG. 3. The end effector400includes a clearer view of end effector aperture420, over which the gripper finger guide380is placed in the embodiment ofFIG. 3. In some embodiments as noted, a base of the gripper fingers102a-cmay be placed directly in a slot within the end effector aperture420or in additional embodiments, the gripper finger base381(FIG. 3) may instead be secured over the end effector apertures420(3 such apertures in total). In some arrangements, the gripper finger guide380may be inserted at a top of the aperture (with or without the gripper finger base381, and in some cases, using a rail or metallic edge383on each side of the guide as described inFIG. 3. As described, the gripper finger guides380may be used to contact the corresponding gripper fingers102a-c(FIG. 1) to guide the gripper fingers102a-cradially inward or outward during movement.

The end effector apertures may provide area for the mechanical structures and/or pipes or lines necessary to provide electrical, mechanical or pneumatic power to the gripper fingers102a-cand the end effector400.FIG. 4also includes the support mounts419, which may be made of rubber or a softer material to avoid scratching or damaging parts while the end effector400is moved. In other embodiments, the sides of the end effector may include one or more flexible hoses (not shown), tubes, or wires, near the perimeter of the end effector400to carry pneumatic fluids or electric power, for example, to the robotic gripper as needed.

As noted with reference toFIG. 1, each of the support structures406may include a protrusion404stemming from the contact region408of the support structure406. The protrusion, also shown as protrusion304inFIG. 3, may be a dome-like protrusion that can be used to inhibit excess motion, for example, in the event that during the retraction process when the grippers102a-care returning inward to the middle region of the end effector400and the part suddenly moves excessively (e.g., beyond a threshold movement or rotation) relative to the robotic gripper100, one of the protrusions404closest the part or gripper interface can act as an “anti-snag” feature.FIG. 4shows a side view of this feature, whileFIGS. 3 and 1show a top view. As noted, the anti-snag feature of this protrusion404is designed to prevent motion of the part during assembly of the part and after the gripper is released but prior to the extraction of the gripper along the z axis (orthogonal to the plane of the end effector facing the gripper interface). The anti-snag feature functions by providing the male protrusion404in three different places, one on each of the contact regions408of the support structures406, together with a matching female complementary feature1144(see, e.g.,FIG. 11) on the gripper interface1100. While during normal operation these complementary features do not ordinarily come into contact, in an assembly deflection exceeding a nominal amount following retraction of the gripper fingers102a-cas described, the anti-snag feature (protrusion404) brought inward closest to the part as a result of the movement may temporarily engage the complementary (female) feature on the gripper interface. Once the two are mated, further deflection is prevented, and the gripper fingers102a-ccan thereupon continue to be retracted with little or no chance of snagging on or causing damage to the gripper interface. In some embodiments discussed above, the gripper fingers can accelerate suddenly to move quickly away from the gripper interface to avoid adhering to the gripper interface. In other embodiments, this can also be done by forcefully causing the end effector to move away as a unit from the gripper interface.

In addition to showing the side view of the end effector, including the body410,FIG. 4also shows two of the support mounts419. In addition to providing further structural integrity, the support mounts may also be used to buffer any inadvertent collisions between the end effector and the part or another object. Further, the height D of one of the protrusions404is shown. Typically, a tight tolerance of dimension D helps ensure that the anti-snag nature of the protrusion404will function consistently and predictably.

One advantage of using a pneumatically actuated, centric style, three gripper finger robotic gripper as described above is that these features may permit precise outer diameter and inner diameter gripping of work pieces. In various embodiments, the gripper may be combined with a sensor, which may also include a controller or may rely on a separate controller, to indicate when the gripper is locked and unlocked, along with other possible functions.

To meet a larger clearance requirement, a manufacturer may desire to increase the length of the overall travel of gripper fingers beyond what COTS elements can provide. Accordingly, in various embodiments, to increase overall gripper finger travel, washers may be placed between the coupler and the piston head of the gripper100. These washers can effectively increase the distance the piston can travel.

FIG. 5is an interior perspective view of an exemplary end effector500with gripper mechanism facing down, i.e., into the page. The interior area of the end effector body510can be used to provide sufficient room to house the various mechanical elements that may be needed to assist in the pneumatic activation of the gripper fingers or the presence of any electronics, tubes, etc. In some embodiments, heavy duty threads may be included to facilitate attachment to the robot side, e.g., in features to contact to robot side513. In other embodiments, the interior may remain hollow to minimize mass.

FIG. 6is a perspective view of the exemplary end effector600with the top side facing the robot. This portion of the end effector, with the upper region toward the robotic arm, appears to be similar to the end effector representation500inFIG. 5. Here, however, a heavy duty central cover623is mounted, via threads or otherwise, in the central region. The heavy duty contact threads513remain on the outer perimeter, as do various apertures that may be used for a combination of connection purposes and for routing one or more wires or fluids originating from the robotic arm. The support mounts119, this time in an inverted position, are also in view.

FIG. 7is a perspective view of an exemplary robotic gripper shown without the gripper fingers and certain structures associated with the same. The embodiment ofFIG. 7, for example, shows middle surface support309A, which may be the structural foundation that resides under the middle surface cover309inFIG. 3. Further shown are three gripper finger guides780, which may be used to house the gripper fingers102a-cin a manner discussed earlier with reference toFIG. 3. In the embodiment shown, two of the three gripper finger guides780include a pair of gripper finger engagement features782. The third gripper finger guide780just shows the openings where the gripper finger engagement features782would reside. The gripper finger engagement features782may protrude up through the opening in the gripper finger openings216ashown inFIGS. 2A and 2B. As noted, a third gripper finger guide780toward the perspective rear ofFIG. 7is shown without the protrusions. Each of the gripper finger guides780may be mounted along the edges780aof the metal apertures and may be translated inward and outward in various ways, including via the embodiments discussed above. The gripper fingers102a-cmay be mounted on the gripper finger guide780, with the gripper finger engagement features used for attaching to the fasteners on the gripper fingers. In addition, a mount area for the support structure121appears on each side of the triangular-shaped gripper. The mount area for the support structure121further includes an internal aperture, which may in various embodiments be used for routing wires or fluid into or out of the end effector, e.g., to provide force for the actuation or electrical power for a controller, sensor or similar device.

FIG. 8is a perspective view of an exemplary part800within which a gripper interface840is embedded. The part800may be any portion of the structure that can practically be accessed, taking into account the mass distribution and relative size of the part800, for example. The representation ofFIG. 8shows the outer surface841of the gripper interface840. The “outer surface” means that the gripper interface840is seen from the perspective of an individual looking at the outside of the part840. The gripper interface840may include three complementary features844that respectively correspond to the three protrusions404(FIG. 4) on the robotic gripper and that were discussed earlier with respect to inadvertent movement of the robotic gripper100. As described, the complementary features844can advantageously inhibit the part from excess motion if it moves in an amount that exceeds a threshold just after the gripper fingers102a-care retracted. The part800may also include contoured walls. The contoured walls844and the gripper interface840in general are designed to match the features of the gripper finger geometry described above.

In various embodiments, the gripper interface840may be a 3-D printed member843. In some cases, the part has been built using machining, additive manufacturing (AM), or some combination thereof. The gripper interface840may also be constructed into the part800using machining, casting, tooling, extruding, incorporation of COTS parts, or any available manufacturing technique. Building the gripper interface840using 3-D printing (additive manufacturing) has a number of advantages. First, being geometry agnostic, a 3-D printer can render just about any necessary custom design to match the characteristics of the robotic gripper. Second, given that strength of the interface is important, a manufacturer can use the strongest possible materials conducive to use in 3-D printing, such as various alloys or compounds that exhibit great strength. While material selection is possible using machining or COTS parts, the selection of possibilities is likely not as diverse. A variety of different AM techniques have been used to 3-D print components composed of various types of materials. Numerous available techniques exist, and more are being developed. For example, Directed Energy Deposition (DED) AM systems use directed energy sourced from laser or electron beams to melt metal. These systems utilize both powder and wire feeds. The wire feed systems advantageously have higher deposition rates than other prominent AM techniques. Single Pass Jetting (SPJ) combines two powder spreaders and a single print unit to spread metal powder and to print a structure in a single pass with apparently no wasted motion. As another illustration, electron beam additive manufacturing processes use an electron beam to deposit metal via wire feedstock or sintering on a powder bed in a vacuum chamber. Atomic Diffusion Additive Manufacturing (ADAM) is still another recently developed technology in which components are printed, layer-by-layer, using a metal powder in a plastic binder. After printing, plastic binders are removed and the entire part is sintered at once. Another of several such AM techniques, as noted, is DMD or direct material deposition. More common types of AM may include powder bed surface or PBF-based printing in which layers of powder are deposited on substrate in a powder bed. Between each deposition cycle, a laser or energy beam source may scan the desired cross-section of the build piece to melt, and then solidify, the appropriate area. The 3-D printing can result in a versatile build of a gripper interface840that falls well within the required tolerances of a gripper. Still other printing types, such as fused deposition modeling (FDM), may also be used to manufacture the print interface.

One advantage of the robotic gripper disclosed herein is that, unlike many conventional systems which need to access the part at multiple points (potentially due to a relative weakness in the gripper or the interfaces when compared with the part), the gripper/interface system described herein may be manufactured in a manner such that only one gripper is necessary to move, carry or manipulate the part. Among efficiency benefits and lower power costs, this also means that more robots can simultaneously work on the part as necessary. Thus, as the part is held and slowly rotated by the robotic gripper, processes like polishing, drilling, sanding and/or other tasks can be performed in parallel since the single-point contact provides room for these multiple assembly operations. In cases where extremely strong, dedicated or precise gripper interfaces are necessary, the gripper interface can be tooled as noted above, although most forms of PBF printing can rival the strengths of existing tooling techniques simply by using the correct alloys.

FIG. 9is a perspective view of an exemplary gripper interface900showing an inner surface thereof. For simplicity, the part that would ordinarily be surrounding the 3-D printed device is omitted. Unlike the gripper interface840inFIG. 8, the inner surface940of the gripper interface900inFIG. 9is shown. Inner surface940is the region of the internal surface that is interior to the part. The gripper interface900inFIG. 9may initially be a CAD model representation of the interface, until the CAD model is printed using a suitable 3-D printer. The body955of the gripper interface900is generally circular in nature, and includes three inner mounting recesses953that can be mounted or adhered to the part (not shown) to provide a strong grip. The interior portion of the gripper interface900includes three complementary protrusions950, meaning that they are complementary relative to the receptacles114within which the protrusions950are positioned to adhere upon being locked. Thus, as shown below, when the gripper fingers102a-care being translated outward to be actuated, the receptacles114in the hook portions118can come into alignment with the corresponding complementary protrusions950on the gripper interface900.

FIG. 9further shows a number of inner surfaces. The inclined walls of that are part of the hook portions118may be configured to align with these inner surfaces to ensure that a snug fit is obtained when the gripper fingers are locked. Thus, in addition to the alignment of the complementary protrusions950into the respective receptacles114of the hook portions118, the inclined walls (130and230ofFIGS. 1 and 2) associated with the robotic gripper (e.g.,FIGS. 1 and 2) are made flush against the inner surface portions940to enhance the overall strength of the grip and to reduce the chances of the grip slipping.

The gripper interface900ofFIG. 9also includes outer surface958directly under each of the complementary protrusions950, but the outer surface958is more or less obscured from view by the complementary protrusions950. In these embodiments, however, the three receptacles114(one associated with each of the hook portions118of gripper fingers102a-c) include the part of the elongated portion112surface directly within the receptacles114that can be designed to firmly grip and support each corresponding outer surface958when the receptacle114is locked in place. Locking includes when the gripper fingers102a-calign with the complementary protrusions950. That is to say, the outer surface958may contact the outer surface of each of the gripper fingers (i.e., that part of the elongated portion surface132within the receptacles114) once the sensor determines that gripper fingers102a-care aligned.

FIG. 10Ais a top view of an inner surface1040of an exemplary gripper interface1000a.FIG. 10Ais another view of the body1053of the gripper interface, and may be 3-D printed to fit with the corresponding gripper apparatus. Like that ofFIG. 9,FIG. 10Ashows a view of the gripper interface1000athat is interior to the part. The hook portions118may be configured to first enter the “hook portions entry area”556(e.g., a large aperture in the gripper interface1000a) before the gripper fingers102a-care actuated, to ensure that the gripper fingers102a-cfit. The gripper fingers102a-cmay then be translated outward once they are actuated, e.g., using the robotic controller or the instructions from the controller(s) that is programmed to manipulate the effector end, often using input from one or more sensors.

Once the hook portions are inside the gripper interface1000a, the elongated portions112of the robotic gripper100may be configured to translate radially outward until they securely contact an outer surface of the gripper interface (e.g.,FIG. 9, 958). Meanwhile, when the grippers102a-capproach the complementary protrusions1050using the radially-actuated gripper fingers102a-c, the receptacles114between the respective flanges126of the corresponding hook portions118may then be configured to contact an inner surface1040of the gripper interface1000a, such that the elongated portion surface132of the elongated portion112within the respective hook portions118may be positioned to align flush with a complementary protrusion1050on the gripper interface1000a. Once the inner walls226(FIG. 2) of the receptacles114have become flush (e.g., as flush as possible, without needing a completely flush fit for all parts of the receptacles114and inner wall) with the complementary protrusion walls907in the select places and the receptacles214are evenly aligned with the complementary protrusions, the gripper fingers102a-cmay be locked and the connected part is ready for manipulation. This procedure is shown in more details inFIGS. 12-14.

FIG. 10Bis a side view of an exemplary gripper interface1000b. Each of the complementary protrusions1050can be seen. The angle C that forms the angle between the inclined wall230and the elongated portion surface232is also visible is also shown, with two other similar angles in other parts of the gripper interface1000b. Orifices1052, which are also shown from another perspective inFIG. 10A, are visible in the cross-section. In some embodiments, the orifices can be used for passageways for electrical wiring.FIG. 10Aalso shows a portion of inner surface1040, in which the inclined wall230(FIG. 2) may be aligned against when in the locked position, as described above.

FIG. 11Ais a top view of an outer surface of an exemplary gripper interface1100ofFIG. 10A, with the outer surface1141now visible. Three slight protrusions represent complementary protrusions1050aofFIG. 1A—that is, the complementary protrusions on the opposite side fromFIG. 9. During actuation, the elongated portion112of the gripper contacts the outer surface, while the hook portion118is in contact with the inner surface (not shown). The body1153of griper interface1100also includes three female complementary features1144, each of which may be complementary to one of the dome-like protrusions discussed, for example, with respect toFIG. 4. In other words, the complementary features1144highlight the anti-snag features located on the gripper interface1100.FIG. 11Bis a side view1100B of the same gripper interface, and shows the body1153along with the inner surface1141(this time below the representation of the gripper interface1100ofFIG. 11Aand therefore not visible inFIG. 11A, a cross-hatched area which represents the gripper entry area1142shown inFIG. 11Aand which allows the hook portions to move inside the gripper interface1100prior to actuation, and a side view of the complementary feature1144. In some embodiments like inFIG. 11B, the top portion of the complementary feature1144is wider in nature and is therefore has a greater cross-sectional area, making it more likely that the corresponding protrusion404(e.g.,FIG. 4) will successfully latch onto the complementary feature1144when an abrupt shift in the part occurs upon retraction of the gripper fingers.

FIG. 12is a perspective view of an example robotic gripper approaching a gripper interface for making contact. The two parts shown in the embodiment ofFIG. 12are the perspective view of the gripper interface1200a, and the robotic gripper1200bitself. The figure provides an illustration of an initial approach to, and contact with, the gripper interface1200a. For simplicity and ease of explanation, the part itself (which would be an extension of the gripper interface1220a) is omitted from the figure.

Addressing the gripper interface1220afirst, it can be seen that the inner surface1240is coincident with the side opposite the part, and as such the relevant surfaces therein are called inner surfaces1240. As can be conspicuously seen, the main portions of the inner surface reside each of two sides of a complementary protrusion1250. As in previous embodiments, the complementary protrusion1250is an outcropping structure that enables the hook portion1218, after being inserted into the recess in the middle of the gripper, to expand radially along its guides and align its corresponding receptacle1214with the complementary protrusion. It will be appreciated in these embodiments that the complementary protrusion need not necessarily be the same size as the receptacle, as long as there is an ability for the two structures to properly align and have at least part of their respective vertical walls become flush. This feature is described in greater detail below.

FIG. 12also shows the robotic gripper1200b, which is similar to the embodiment shown inFIG. 1. For example,FIG. 12includes three support mounts1219for protecting other obstacles in the way of the gripper, for example. In addition,FIG. 12shows two of the three end effector apertures1220. As noted with respect to previous embodiments, the apertures may include guides near the elongated portions1212to allow the elongated portions to translate in a straight fashion radially outward. In some embodiments, the guide that performs that task may be the edges of the end effector aperture1220itself wherein the edges meet the base of the elongated portions. In still other embodiments, the end effector apertures1220include a guide (obscured from view in this embodiment). As shown inFIG. 7, for example, the guide may cover the top area of the end effector aperture1220, and it may be used as a seating mechanism for the elongated portion, which resides over a guide. The guide may further include gripper finger engagement features (FIG. 7) which allow the gripper fingers1202to fasten to the engagement feature via fasteners1216. It should be understood that a variety of additional and different embodiments may be possible for the construction of the gripper fingers, with each embodiment accomplishing the same goal of allowing the gripper finger1202at issue to be actuated in a radially outward direction when the need arises. What is shown have been just a few of the relevant embodiments that are capable of accomplishing this task.

FIG. 12includes three gripper fingers1202, just like inFIG. 1, with each gripper finger1202including an elongated portion1212and a hook portion1218securely coupled or integrally formed together. The gripper fingers1202in this embodiment are in a closed position, meaning that the robotic gripper1200bis locked. As shown in part inFIGS. 5 and 6, the end effector1210on which the robotic gripper1200bis mounted is coupled to further members, which are ultimately coupled to a robotic arm or other maneuvering device. A controller may be included within the robotic arm, the gripper, externally, or in more than one such location to control movement of the gripper1200b, approach to a specified gripper interface1200a, actuation, retraction, etc. Because the gripper fingers1202bare closed in this case, the gripper1200bis in the ideal condition to pass the hook portions1218through the gripper entry area1242in the center of the gripper interface1200a. Right now, the arrow identified as1265is identified as “part approach” meaning that the robotic arm and end effector1210at this point are approaching the gripper interface1200adesignated by the control in order to grip the part (not shown) associated with that gripper interface1200a. It is also noted that the hook portions1218ofFIG. 12are likewise similar to the embodiment ofFIG. 1. That is, the hook portion includes the receptacle1214at its center with a pair of flanges1226on each side, and inclined walls1216along with front edges1228on each of the flanges in order to securely align with the appropriate inner surfaces1240and complementary protrusions1250in the gripper interface1200a.FIG. 12also shows each of the three contact regions1208at the top of support structure1206, structures that will be used in the upcoming figure.

After the robotic gripper has initiated its approach to the gripper interface, it can move on to the next sequence in the part gripping process, which is the actual contact. After the approach of the robotic gripper as described above with reference toFIG. 12, the first part in the sequence concludes with the robotic gripper coming into contact using the contact region1208of the support structures1206.

FIG. 13is a perspective view of an example robotic gripper contacting the gripper interface (collectively1300) via contact regions1208of support structures1206, both obscured from view by the presence of the perspective gripper interface1300a. ThusFIG. 13shows gripper interface1300balong with robotic gripper1300a, similar to the configuration ofFIG. 12but in this event the approach described inFIG. 12has ended in mild contact between the contact regions1208of support structures1206of the robotic gripper1300a(again obscured from view inFIG. 13by the gripper interface1300b). The generally even, level nature of contact regions1208enables the gripper1300ato rest firmly and comfortably while the controller reorients itself as necessary and prepares to execute the next steps in the sequence with minimal chance of the gripper slipping or causing damage to the gripper interface1300aor the part (not shown). For this process to be successful, the master side should approach the part with some minimal accuracy. The numerical dimensions can vary in nature and may depend on the implementation, the mass of the devices involved, their speed ranges, and other factors.

Thus, as described in the box labeled1367, the robotic gripper1300ahas positioned itself, while locked, via a correct orientation through the gripper interface1300b. As can be seen inFIG. 13, the hook portions1318including their flanges and front ends may be adjusted to align optimally with the gripper interface. For example, the sensor embedded in the robotic gripper1300amay determine that the robotic gripper1300aneeds to reorient itself in order to line up the receptacle and complementary protrusion, as well as the inclined and inner walls. In various embodiments, the robotic gripper1300acan use the contact regions1308as a resting place to engage in small rotational movements, if the sensor of the robotic gripper1300determines that such reorientation is necessary to help align the complementary parts in the final steps. InFIG. 13, it is assumed that the robotic gripper1300ahas used its sensor (not shown) to align the locked hook portion1318, including the receptacles1314, front edges1328and flanges associated with each hook portion1318, with the complementary structures that reside on the gripper interface1300b, including for example the complementary protrusions1350and the inner surfaces1340adjacent the complementary protrusions1350. It is noteworthy that, having aligned itself appropriately during the contact stage (which may optionally be performed after the initial contact has been made, or on the initial approach to contact), the unlocked nature of the gripper fingers1302(such that the hook portions1318are bunched together in the middle region at their closest distance, e.g., as adjudged by the sensor) means that when necessary, the hook portions1318may be able to seamlessly pass through the entry area of the robotic gripper1300bwithout obstacles in the way.

FIG. 14is a perspective, top down view of an example robotic gripper/gripper interface1400engaging from an unlocked position to a locked position on the gripper interface. For example, with reference to the gripper/gripper interface1400on the left side of the drawing, a top view is shown where the complementary protrusions1450are disengaged from the respective gripper fingers1402ainFIG. 13. As shown in the box below the robotic gripper/interface1400, the system on the left remains for the moment in the unlocked stated1472. Thus, as noted above, the sensor may determine that the hook portions are resting in their respective default positions in the middle area1469of the end effector, as far as possible away from the edge of the end effector. Also, as discussed with reference toFIG. 13, the robotic gripper inFIG. 14has aligned itself, its receptacles, inclined walls, etc., with the corresponding complementary protrusions1450and inner surfaces1440of the gripper interface. Again, while it is assumed in most cases that the gripper interface is located in the middle of the part at some suitable point that is strong enough to be manipulated by the robotic gripper at that single point as in embodiments described herein, the remaining portions of the part have been omitted for simplicity.

While the box1472indicates that the configuration of the robotic gripper and gripper interface1400is initially unlocked and contact is made between the contact regions1408and the gripper interface, the gripper fingers1402acan be actuated. Reference is now made to the three arrows pointing radially outward from the middle area1469of the end effector, labeled with the corresponding 1 symbol. In these embodiments, the controller has activated the pneumatic pressure system (or other form of power used by the gripper) to actuate the gripper fingers1402a. When so actuated, the gripper fingers begin to translate outward, optionally in unison, in a radial direction Ω. Thus the elongated portions move along the guides (obscured from view) and concurrently, the hook portion1418attached to each elongated portion1412of a corresponding gripper finger1418moves along with it, as the pneumatic actuation (1470) moves the three gripper fingers outward from their unlocked position (1470.1).

Referring now to the right side of the drawing, the outward translation of the gripper fingers continues until, as noted in1486, the receptacle inner wall (e.g.,FIG. 2)226is flush with the complementary protrusion wall907(e.g.,FIG. 9). In some embodiments, only opposing portions of the walls need be flush for alignment; that is, the walls of the inner wall need not be in contact with all points of the receptacle inner walls of the gripper fingers1402a, as is the case inFIG. 14. In addition, the respective front edges1428of the flanges on each side of the hook portion become flush with the upper edge of the inner surface1440, and the inclined walls of the flanges/hook portions (obscured from view) become aligned with the inner surfaces1440of the grip interface. Once alignment is achieved as confirmed by the sensor, the sensor determines that the robotic gripper is locked in1474to the gripper interface. If, for example, an error occurs such that the robotic gripper for some reason did not achieve precise alignment, the sensor can sensor can inform the controller of the error, and the gripper fingers can unlock until they are appropriately aligned and readjusted.

Thus, stating the above set of events in another way, the first primary movement of the robotic gripper involves the movement of the robotic gripper such that the contact regions (obscured) on the side of the robotic gripper come into actual contact with the gripper interface. The second primary movement involves the application of pneumatic pressure to actuate the robotic gripper, which in turn moves the three gripper fingers1402a-cfrom a retracted (unlocked) to an extended (locked) state. As the gripper fingers1402a-ctranslate radially outward from the retracted to the extended position, the planes with angles B and C come into alignment with the complementary features on the gripper interface. Once the gripper fingers1402a-ccome into contact with the gripper interface at their appropriate points of alignment as described above, the inner surfaces of the gripper interface and the inclined wall and front edge of the robotic gripper can nest together.

FIG. 15Ais a perspective view of an exemplary robotic gripper1500a, including six hook portions1518.1. In some embodiments, the end effector1510may include a central contact region1508for use when the robotic gripper closes in on the gripper engagement interface1500b(seeFIG. 15B). In the embodiment shown, three elongated portions1512are used and positioned similarly to those of earlier embodiments. The elongated portions1512likewise include fasteners, or optionally gripper engagement fingers1516, to enable the pneumatic pressure system to apply a force to the fingers to translate them radially outward. In the embodiments shown, the hook portion includes six much smaller prong-like portions1518that initially extend vertically, but that curve at its upper part as if to include a miniature receptacle. As shown by the coordinate axis1523, in some embodiments such as in this example, the end effector surface is angled 45° from the horizontal (where the horizontal is shown in perspective in the figure).

The embodiments ofFIG. 15Amay include a six prong, 45° ramp with a center boss that includes the split finger design to facilitate bolt clearance, as well as to provide six points of contact to sustain heavy loads. One benefit of these multiple points of contact is that they can reduce the force at each contact point, resulting in smaller deformations when the gripper is used, particularly on a heavier part.

FIG. 15Bis a side perspective view of an example gripper engagement interface1500bfor the robotic gripper ofFIG. 15A. In lieu of previous embodiments, the side cross-sectional view of the gripper engagement interface1500bofFIG. 15Bincludes a central receptacle1542, which may be of a size sufficient to both allow the contact region1508on the robotic gripper1500a(FIG. 15A) to insert itself in the central receptacle1542but may also be small enough to enable the gripper to align itself with the hook portion receptacles1518.2in which the hooks are seated. In some embodiments, the alignment is performed near the surface, and the contact region1508need not protrude into the central receptacle1542. When the hook portions1518.1are ready for insertion into one or all of the hook portion receptacles1518.2, the gripper fingers1502may be actuated as much as necessary to enable the hook portions to slide down to the bottom of the receptacles1518.2, as physically permitted by the volume and geometry of the receptacles1518.2. Thereupon, in these embodiments, the sensor can detect that the hooks are at the bottom and can then cause the gripper fingers1502to extend outward such that the receptacles are either seated into similarly shaped geometrical voids, or until they are securely gripping the side of the receptacles1518.2in a manner sufficient to provide an adequate locking force. Other embodiments can be contemplated using the principles of these smaller prongs. For example, in some embodiments, four prongs may be more appropriate per gripper finger to increase lock strength.

FIG. 16is a perspective view of another exemplary robotic gripper1600. Gripper1600includes two regions that include a guide member1681. One purpose of the guide member1681may be to enable a user to quickly switch the configuration of the end effector1610, especially when using multiple configurations. In addition to the guide members, the main member in this embodiment includes a base portion1612and two dual gripper fingers1690formed with the base portion1612. Within a recess of each of the gripper fingers1690facing radially outward is a rubber insert1691, one corresponding to each gripper finger1690. Thus the gripper fingers in this embodiment include shallow ramp rubber pads. Dual gripper fingers1690may be used for bold clearance, with a shallow ramp tuned for an increased radial force, and a minimal required z (vertical) locking force. As noted above, the recesses of the gripper fingers may include adhesive backed rubber inserts for increased z rotation resistance and grip.

FIG. 17Ais a perspective view of an exemplary robotic gripper secured to a gripper interface1700a. The gripper interface1740includes three receptacles1791, with one of the receptacles1791being used in this embodiment. The base portion may be guided using the dual gripper fingers onto the gripper interface1740. The rubber fingers may provide a secure grip to reduce the instance of the radial force while maintaining a gentle grip. In some embodiments, the robotic gripper can use two or three sets of dual gripper fingers along with the gripper interface1740.FIG. 17Aalso shows the inner surface1729of the receptacle1791within which one of the gripper fingers can be seated.

FIG. 17Bis a transparent, perspective view of a portion of the engagement of the example robotic gripper with the gripper interface1700b. The robotic gripper in various embodiments can include a longer finger or prong, such as the prong1790displayed on the robotic gripper of this embodiment. A similar or identical gripper interface is used inFIG. 17Bas the gripper interface1740inFIG. 17A. The elongated portion1712of the finger gripper in this embodiment includes an opening through which the prongs1790and part of the elongated portion1712can pass. This opening can act as a fastener to stabilize or move the elongated portion1712and its prongs when the latter two elements are seated properly in the receptacle1791. The robotic gripper includes a 45° ramp-angled entry, with up to six points or possible prongs to fill the three recesses of the gripper interface1740. The gripper interface1740also provides an angled entry for misalignment or print tolerances.

FIG. 18Ais a perspective view of a portion of another example robotic gripper1800a.

The gripper1800aof this embodiment may include a radial pin lock, such as realized by fasteners1816, and a gripper finger1802that includes a base portion1812and two compliance features1805in a horizontal direction relative to the base portion. Key features in this embodiment include a press fit long nose spring plumbers installed on the gripper fingers1802(only one of which is shown). Further, in this embodiment, the spring plungers may get compressed as the gripper finger1802moves out until bottoming out occurs.FIG. 18Bis a top transparent view of the example robotic gripper engaged with a gripper interface. In the case ofFIG. 18B, the robotic gripper includes a gripper interface1800band the dual pronged portion seated within the interface are represented by locking features1807.

FIG. 19Ais a side perspective view of an example robotic gripper portion1900a. In the robotic gripper portion1900ashown, one gripper finger1902is attached to an elongated portion1912having a fastener1916, and two hook portions1918(one of which is referenced). Each of the hook portions1918further includes a compliance feature1905, which protrudes from the vertical wall1985. End effector1910is also shown at the rear of the component inFIG. 19A. In the exemplary view ofFIG. 19B, a side transparent view of the example robotic gripper portion1900aengaged with a gripper interface1940is shown. In this case, the elongated portion1912is seated generally evenly with the end effector, and the hook portion1918with the compliance features1905are in the upward position in a separate compartment of the gripper interface1940. In various embodiments, a shallow ramp set screw is provided along with an angled entry based on the gripper interface1940. Key features in these embodiments include the shallow ramp, and the angled entry as described. Further, in this embodiment, the compliance feature1905includes a set screw which can be moved in and out to change the locking configuration as needed.

FIG. 20Ais a perspective view of another example robotic gripper portion2000a, including a gripper finger with a similar elongated portion2012, a pair of circular openings2015which may be used with standard fasteners as described in other embodiments herein, a receptacle2014and a hook portion2018. Unlike the immediately preceding embodiment, the hook portion2018as shown is part of a single body for apparent added support. The gripper finger2002also includes a 45° ramp, a bayonet mount pin and compression spring. The gripper finger is also mounted close to the end effector2010. The embodiment inFIG. 20Bincludes a transparent illustration of the gripper interface2000b. The figure also shows a pair of cylindrical-like compliance features2005, with one such feature protruding outward further than the other.

FIG. 20Bis a transparent perspective view of the example robotic gripper finger2002engaged with a gripper interface2000b. The gripper interface is also designated by reference numeral2040. The gripper finger2002ofFIG. 20Bincludes a base portion2012as well as a hook portion2018that is almost as long as the base portion2012. The hook portion2018includes an inclined or curved wall2030at its lower part, and compliance features2005on its upper part. The compliance feature2005with the longer outward protrusion is seen closer to the viewer's perspective in this view. In some embodiments, two or three gripper fingers1940can be used with an end effector where necessary.

FIG. 21Ais a top view of another example robotic gripper portion2100a. The gripper finger2102in this embodiment includes elongated portion2112and compliance feature2104embedded within the hook portion2118.FIG. 21Bis a side perspective view of the example robotic gripper portion2100bengaged with a gripper interface2140. The gripper finger2102in the embodiment ofFIG. 21Bcan be seen at a slight angle relative to that ofFIG. 21A. Otherwise the gripper finger2102ofFIG. 21Bincludes a receptacle2114defined in part by the inclined wall2130, and the generally vertical hook portion2118. The gripper finger2102can be inserted into the gripper interface2140from directly underneath, with the elongated portion2112protruding out of the interface as inFIG. 21A. The compliance feature2104of the embodiments inFIGS. 21A and 21Binclude a single point engineered spring. As shown more clearly inFIG. 21B, the compliance feature2104has a generally cylindrical-type shape with a reduced cylinder radius closer to the outer end.

FIGS. 22A and 22Binclude a side perspective view of another example robotic gripper portion2200a, which includes gripper finger2202coupled to an end effector2210. Each of the gripper fingers2202inFIGS. 22A and 22Bincludes a base portion2212and a hook portion2218(2220inFIG. 22B), which together define receptacle2214. The hook portion2218is largely rectangular but with a flexure2204at one of its ends. A small portion of a gripper interface2040is shown inFIG. 22B. One advantage of this embodiment is the ease with which the hook portion2218can be inserted into the relatively thick gripper interface2240, as shown inFIG. 22B. The gripper finger2202of this embodiment includes a 45° ramp, a compression tab, and a cutout for a locking nub.

FIG. 23Ais a side view of another example gripper finger2300a. The gripper finger2300aincludes elongated portion2312, hook portion2318, and an inclined wall2330that converts into a vertical wall as the hook portion2318extends down to the elongated portion2312, thereby forming a receptacle2314.FIG. 23Bis a perspective view of a gripper interface2300bfor use with the example gripper finger. Included in an exemplary space for the gripper finger2300ais a complementary recess2305. In this figure, the gripper interface2300bis also pointing downward such that outer surfaces2341correspond to the external side of the part (not shown). The tool side is also identified as2305. This embodiment includes a straight 45° ramp with a taper (e.g., the inclined wall2330). The gripper interface2300bincludes three angled planes at 120 degree increments, which advantageously can provide both axial and rotational constraints. Thus, locking security is provided in both of these directional components.

FIG. 24Ais a perspective view of another example gripper finger2400a. The gripper finger2400aincludes elongated portion2412, two receptacles2493and two fastener openings2416which may accept fasteners, and hook portion2418. The hook portion includes a front edge2428with inclined walls2430. This embodiment differs substantially from earlier embodiments in that it includes a thin vertical wall2430awhich partitions the two receptacles2494and which can act to fit into the vertical wall insertion point ofFIG. 24B. The vertical wall2430asegments the hook portion2418into two symmetrical portions. The embodiment may include a vee 45° ramp with a taper.

FIG. 24Bis a perspective view of a gripper interface for use with the example gripper finger. Like in the previous embodiments, the outer surface2341and tool side2405are on the top in the figure. It is easy to see how the gripper finger2400ais inserted into the complementary recess2405and the vertical wall insertion point2424(where the protrusion with the vertical wall2431is inserted). The gripper interface provides six angled planes with three recesses2405at 120 degree increments. As such, these embodiments provide both axial and rotational constraints. Another advantage of these embodiments is that the relatively small diameter of the gripper interface2400breduces the footprint on the part in which it is used.

FIG. 25Ais a perspective view of another example gripper finger. The gripper finger2500ais similar to the one shown inFIG. 1with some key exceptions. A base portion2512is provided, and in these embodiments the base portion2512is significantly shorter. Two fastener openings2516are present, through which fasteners can be positioned. The hook portion2518is similar to the embodiments fromFIG. 1and earlier figures, with the hook portion slightly wider. A pair of flanges2526and2528extend out in opposite directions, which produce inclined walls2530that are angled relative to the base portion2512. A receptacle2514is also included. Referring now toFIG. 25B, which is a perspective view of a gripper interface2500bfor use with the example gripper finger2500a, various advantages of the design as viewed from tool side2509(outer surface2541) are apparent. The six corners in the interior, as shown include six angled planes of three complementary recesses2505at 120° increments, which as in the above embodiments, provide both axial and rotational locking constraints. Further, the larger gripping diameter of the gripper finger2500amay advantageously reduce the loads into both the gripper finger and the gripper interface2500b. It should be borne in mind, however, that the larger gripping diameter may increase the part footprint. The gripper interface2500bfurther includes three complementary protrusions2550for engaging with the gripper fingers2500a. Complementary recesses2505are also shown for engaging with front edge2528of the gripper finger2500a.

FIG. 26Ais a perspective view of another example gripper finger2600a. The gripper finger2600aincludes, in addition to the elongated portion2612, two receptacles2616which may accept fasteners, a hook portion2618, and a vertical wall2630athat in turn creates two side walls2630b, one of which is visible. The gripper fingers2600amay fit into a gripper interface similar toFIG. 26B, which shows a perspective view of a gripper interface2600bfor use with the example gripper finger2600a. As before, three gripper fingers2600bcan be fit, with each area including a complementary recess2605. The outer surface2541(and the tool side2605) are shown on the upper part of the gripper interface2600b. As in prior embodiments, the gripper interface includes six angled planes at 120° increments for providing both axial and rotation locking. As another benefit of these embodiments, the sharper plane angle may create an increased clamping force. In addition, the small diameter of the gripper interface2600bcan reduce the part footprint.

FIG. 27Ais a perspective view of another example gripper finger2700a. The elongated portion2712includes a fastener opening2716and an open fastener opening2717for facilitating different connection options. The longer hook portion2718includes a slightly curved vertical wall with an additional angled inclined wall2730closer to the two prongs2733. The elongated portion is otherwise flat and includes elongated portion surface2732.

FIG. 27Bis a perspective view of a gripper interface2700bfor use with the example gripper finger. Viewing the component from the tool side2745of the outer surface2741, the three gripper finger receptacles2708include a complementary recess2705to fit the pronged portion2733of the hook portion. Three circular openings2716are included for additional engagement with complementary parts. This embodiment includes three angled planes at 120° increments for providing axial and rotational constraints, and a small diameter of the gripper interface. Another benefit of this embodiment is that the top slot can provide rotation resistance because of the snug fit of the prongs2733into the complementary recess2705.

FIG. 28Ais a perspective view of another example gripper finger. The gripper finger2800aprovides an elongated portion2812with two fastener openings, as well as a hook portion2818. Uniquely, the gripper finger2800aincludes a ball connector2819.FIG. 28Bis a perspective view of a gripper interface2800bcross-section for use with the example gripper finger. At least one ball-connector based gripper finger2800acan be inserted into the right complementary recess2805. The gripper interface2800balso shows an additional recess2805afor potential use by another gripper finger or ball connector element similar to element2819. The ball will beneficially contact an incline plane, in turn providing a locking force in added directions simultaneously.

FIG. 29Ais a perspective view of another exemplary gripper finger2900a. The gripper finger2900aalso includes a ball connector, but which is located in the center between the fastener openings.FIG. 29Bis a perspective view of a gripper interface cross section2900bfor use with the example gripper finger2900a. A portion of surface2941is visible. The complementary recess2905can be used to secure the ball connector2919of the hook portion2919in a similar manner asFIG. 28B.

FIG. 30Ais a perspective view of another exemplary gripper finger3000a. The gripper finger3000aincludes, in addition to the elongated portion3012a hook portion3018in the form of a ball connector3019. In the embodiment ofFIG. 30A, however, at the posterior of the ball connector3019is a fin3099.FIG. 30Bis a perspective view of a gripper interface for use with the example gripper finger3000aand similar in most respects to the gripper interface ofFIG. 29B. The fin3099can beneficially be used to add additional resistance to unwanted rotation. A complementary recess3005can stabilize the ball connector3018and fin, except that the fin may enable a smaller footprint for the locking mechanism and thus a smaller gripper interface3000bfor the part.

FIG. 31Ais a perspective view of another exemplary gripper finger3100a, which is similar in most respects to the gripper finger shown inFIG. 2. The gripper finger3100aincludes a hook portion3118having flanges3126and a receptacle3114. The flange3126on each side includes a front edge3128. The receptacle includes mouth3124. An elongated portion3012is coupled to the hook portion3118. On the elongated portion surface3232, two fastener openings3116are positioned to receive fasteners for securing the gripper finger3100ato the remaining equipment. A major difference from the gripper inFIG. 2lies in the gripper interface3100bused to house the gripper fingers.FIG. 31Bis a perspective view of a gripper interface looking towards the outside from inside the part including the gripper interface for use with the example gripper finger3100a(FIG. 31A). Gripper interface3100bincludes inner surface3141and gripper entry area3126to enable the gripper100(FIG. 1) to engage the gripper interface3100b. Also, six surface apertures3177are distributed on the inner surface3141. This embodiment includes six angled planes at 120° increments to provide both axial and rotational constraints. Further, while this embodiment maintains a smaller radial gripping diameter, it compensates for this smaller diameter by increasing the polar separation between the ramps. In addition, the smaller diameter minimizes the part footprint.

FIG. 32is another perspective view of an inner surface of the gripper interface3200blooking towards the outside from inside the part including the gripper interface for securing a gripper finger configuration ofFIG. 31A. Six angled planes3240at 120° increments can provide both axial and rotational constraints. While this gripper interface3200bmaintains a small radial gripping diameter, as in the previous embodiment, it increases the polar separation between the ramps. In addition, like the above embodiment, the smaller diameter minimizes the part footprint. The center nub and upper cross member have been removed from the illustration to enable the user to appreciate the impact of the current design on deflection resistance. A flat inner surface3241runs around a circumference of the gripper interface3200bon the inner side of the body3253.

FIG. 33is a perspective view of a gripper interface3300alooking towards the outside from inside the part including the gripper interface with angled planes3370a-f.FIG. 33uses the same gripper fingers as that ofFIG. 31A. The gripper interface3100aincludes surface apertures3391, a gripper entry area3326, and a generally flat inner surface3341. Key benefits of this embodiment include six angled planes at 120° increments that, as usual, provide both axial and rotation constraints. Also, similar to the embodiments inFIG. 32, the design maintains a small radial gripping diameter but increases the polar separation between the ramps. The small diameter also minimizes the part footprint. A small clearance, on the order of a few millimeters in this example, further provides for a more robust locking engagement.

FIG. 34is a perspective view of a robotic gripper system manipulating a part using a robotic arm. In various embodiments including in the robotic gripper3400shown, the part3443can be lifted, carried or otherwise manipulated whether or not other robots are performing tasks on that part. Part3443includes a single gripper interface3401that advantageously minimizes the overall area that the part3443must devote to such an interface. Also, using composite material along with different features as described above, both the gripper interface3401and the robotic gripper itself can be made to withstand objects of essentially arbitrary complexity and weight using that single gripper interface3401with one end effector3410. Power can be provided to the locking mechanism from a pneumatic actuator3457. The robotic arm3494, depending on the application, can either be a mobile automated constructor as is often the case, or it can have its own base, for example, where it is at a station for other robots to perform contemporaneous processing activities with the part3443.

FIG. 35is a perspective view of a robotic gripper system3500manipulating a part3444using a robotic arm3595. Like previous embodiments, the part3444has a single gripper interface3501. In this case, certain additional robotic arms are performing additional processing tasks on the same part3444. Thus, in some embodiments, the robotic arm3595and associated end effector3510may be used to stabilize the weight of the part or otherwise hold the part, while other robots perform different tasks on the part such as polishing, sanding, printing, milling, etc. The part3444only needs to include the single gripper interface3501.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these exemplary embodiments presented throughout this disclosure will be readily apparent to those skilled in the art. Thus, the claims are not intended to be limited to the exemplary embodiments presented throughout the disclosure, but are to be accorded the full scope consistent with the language claims. All structural and functional equivalents to the elements of the exemplary embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. § 112(f), or analogous law in applicable jurisdictions, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”