Gripper for T-profiles

Abstract

The invention relates to a gripping device for gripping a T-profile-shaped launch adapter ring. It comprises a gripping device body and at least one U-shaped rotary clamp with four contact points, each arm having two contact points and a rotating base body extending between them. The inner surface of each arm forms a contact point, and each arm contains an undercut element forming a further contact point. The rotary clamp is rotatable, and the undercut element is oriented in the direction of rotation. The rotating base body has an axis of rotation that is substantially orthogonal to the gripping device body. The invention includes at least a fifth contact point and is characterized in that the rotary clamp is rotatably connected to the gripping device body via the axis of rotation, and the fifth contact point is attached to the gripping device body.When the clamp is closed, the undercut elements engage behind the head of the T-profile-shaped launch adapter ring, and the fifth contact point rests against the launch adapter ring, thus preventing the gripper body from rotating around at least one axis. The gripper also has a sixth contact point, which, in the closed clamp state, rests behind the head of the T-profile-shaped launch adapter ring.

Description

[0001] The description relates to a gripping device and a method for gripping a T-profile-shaped launch adapter ring.

[0002] It is known from the prior art that launch adapter rings (LARs) are used as mounting elements for satellites to attach them to the rocket structure; they can also be referred to as "Marman rings" or "payload attach fittings (PAFs)." Generally, an LAR consists of a ring-shaped T- or L-profile. These elements no longer serve a function after the rocket launch, once the satellite separates from the rocket and remains in orbit. Repairing satellites in orbit requires a robotic arm capable of grasping the satellite at the appropriate point. The most suitable point for grasping is the LAR, as it offers high mechanical stability and is present on most satellites.

[0003] Because existing LAR grippers feature complex mechanisms with numerous rotary bearings and / or linear guides for gripper finger support, they exhibit high mechanical complexity and thus an increased risk of failure under space conditions. This high mechanical precision can lead to jamming, especially across a wide temperature range. Furthermore, the gripping process must be divided into a "soft grasp" and a "rigid grasp" to quickly and efficiently capture the LAR and establish a secure connection with the gripper. The requirement to provide high transmissible force in a closed configuration also presents a challenge and determines the speed at which, in particular, heavy satellites can be moved.

[0004] Technical background information on the present invention can be found in the following publications: DE 10 2013 021 674 A1 EP 3 892 550 B1 EP 3 693 281 B1 EP 3 137 379 B1 US 2018 / 0 257 242 A1 US 7 370 896 B2

[0005] The object of the invention is to provide a gripping device and a method for gripping a T-profile-shaped launch adapter ring, which has low mechanical complexity and at the same time enables high force transmission.

[0006] The problem is solved according to the invention by claims 1 and 7.

[0007] The gripping device according to the invention for gripping a T-profile-shaped launch adapter ring comprises a gripping device body. It is preferred that the gripping device body has at least two opposite sides, each with a surface. One surface preferably has a mounting unit for attaching it to a robot arm, while the other surface preferably has components of the gripping device. It is further preferred that the gripping device body is made of a material that is particularly resistant to cold welding.

[0008] The gripping device according to the invention for gripping a T-profile-shaped launch adapter ring further comprises at least one rotary clamp with four contact points. A rotary clamp is designed such that the movement for opening or closing the rotary clamp is orthogonal to the direction of force transmission.

[0009] The rotary clamp according to the invention further comprises a U-shape, wherein the U-shape has two arms, each with two contact points, and a rotating base body extending between them. A U-shape according to the invention particularly has two arms and a rotating base body. The dimensions of the U-shape are preferably adapted to the standardization of the LAR ring. A U-shape can be a U-shape whose arms are either parallel, converging, or diverging. Thus, a triangular, rectangular, polygonal, or round shape with at least one open side can also be a U-shape. A contact point according to the invention is a point, an edge, or a surface that establishes contact between the LAR ring and the gripping device.

[0010] The arms according to the invention each have an inner surface, which is the inner surface of the U-shaped rotary clamp. The inner surfaces each have a contact point which restricts the degree of freedom of the LAR in one direction.

[0011] The arms of the rotary clamp according to the invention each have an undercut element, which forms a contact point. An undercut element is a component shaped so that it projects beyond another component, thus preventing direct access. Preferably, the undercut element is designed as the base of an L-shape, such that when the rotary clamp rotates into the closed position, the top of the T-shaped LAR ring projects beyond the base of the L-shaped undercut element. An L-shaped undercut element consists of two legs, each connected at one end at an angle of 90° or 85°–95°. In an alternative embodiment, the undercut element can also be designed as a rod with a notch or groove.

[0012] The rotary clamp according to the invention is rotatable in one direction of rotation, and the undercut element is oriented tangentially in the direction of rotation. The tangential direction of rotation is the direction in which a tangent to a circle that would result at the end of the arm of the rotary clamp during rotation extends, in the direction of rotation for closing the rotary clamp.

[0013] The rotation axis of the rotary clamp according to the invention is essentially orthogonal to the gripping device body and the rotation base body. Essentially orthogonal preferably means 90°, or between 85° and 95°, wherein the rotation base body has an axis of rotation that runs essentially orthogonal to the gripping device body. It is preferred that the axis of rotation is essentially orthogonal to the surface of the gripping device body with the other components of the gripping device. It is further preferred that the axis of rotation is essentially orthogonal to the outer surface of the U-shaped rotation base body. The outer surface of the U-shaped rotation base body is the surface that lies on the outside of the U-shaped rotation base body.

[0014] The gripping device according to the invention further comprises a fifth contact point. The fifth contact point preferably designates a contact point between the LAR and the gripping device, thus further restricting the degrees of freedom between the LAR and the gripping device. In a preferred embodiment, a fifth contact point could be configured as a rod and / or a further undercut element.

[0015] The gripping device according to the invention is designed such that the rotary clamp is rotatably connected to the gripping device body through the axis of rotation in both directions. Rotatable here means that it can rotate either infinitely or finitely in a plane. A preferably finite rotation could be defined by a stop or by a gear mechanism, which is preferably used to drive the rotary clamp.

[0016] The gripping device according to the invention is designed such that the fifth contact point is attached to the gripping device body at a distance from the rotating clamp. The distance between the rotating clamp and the fifth contact point preferably extends along a surface. This distance is preferably located on the side of the gripping device body with the surface that preferably contains components of the gripping device. The distance can preferably extend along the x-axis, the y-axis, the z-axis, or a combination of these axes, as long as the fifth contact point or the base of the further undercut element lies on the same surface as the base of the axis of rotation between the gripping device body and the rotating clamp. The base of the further undercut element is, for example, the end of the longer leg of an L-shaped undercut element or an end of the rod or the rod with the notch or groove.The starting point of the rotation axis is, for example, the end of the rotation axis which is attached to the gripping device body or the rotation clamp.

[0017] The gripping device according to the invention is designed such that, in the closed clamping state, the undercut elements grip under the head of the T-profile-shaped launch adapter ring.

[0018] The gripping device according to the invention is designed such that the fifth contact point rests against the T-profile-shaped launch adapter ring when the clamp is closed, thus preventing the gripping device body from rotating about at least one axis. The fifth contact point is preferably designed to compensate for the torque exerted by the rotary clamp on the LAR (Launch Adapter Ring). Preferably, the rotary clamp exerts a torque on the LAR such that the contact points of the rotary clamp are continuously in contact with the LAR when closed. This torque must be compensated, particularly in microgravity, so that the LAR does not continuously rotate or rotate away from the contact points of the rotary clamp. This function is preferably fulfilled by the fifth contact point, which is preferably located on the outer edge of the top of the T-profile. It is further preferred that the fifth contact point rests against one of the long surfaces of the T-profile body.

[0019] The gripping device according to the invention further comprises a sixth contact point, wherein the sixth contact point rests behind the head of the T-profile-shaped launch adapter ring in the closed clamping state. Preferably, the sixth contact point is designed as an undercut element. In a further preferred embodiment, the fifth and sixth contact points are designed like an arm of one of the rotary clamps.

[0020] A preferred gripping device in the closed state, which restricts fewer than six degrees of freedom, is in the soft-grasp state. The six degrees of freedom consist of three translational and three rotational degrees of freedom. In weightlessness, it is preferred to align bodies relative to each other with as little torque as possible. The lower the torque, the longer it must be applied for the desired bodies to reach their target configuration. For this reason, gripping bodies preferably occurs in two stages. The first stage is called soft-grasp, in which fewer than six degrees of freedom are restricted quickly, preferably within a few seconds. In the second stage, preferably called rigid-grasp, the remaining degrees of freedom are restricted slowly, preferably over several seconds or minutes.

[0021] A preferred gripping device body further comprises a central part, wherein the central part of the gripping device body has a push pin that is movable orthogonally to the gripping device body, and wherein the push pin bears against the head of the T-profile-shaped launch adapter ring in the closed gripping device state. The central part of the gripping device body is preferably the area, or a portion thereof, of the gripping device body between the rotary clamp and the fifth contact point. The orthogonally movable push pin thus moves orthogonally to the surface of the gripping device body. A preferred push pin is preferably cylindrical. A cylinder has a lateral surface and a base. The base can have a variety of geometric shapes, for example, circular, square, cuboid, triangular, elliptical, or polygonal.The orthogonally movable thrust bolt preferably restricts the last remaining degree(s) of freedom, allowing the gripping device to switch from soft-grasp to rigid-grasp mode with the aid of the thrust bolt. In rigid-grasp mode, after the thrust bolt is fully extended, a base surface of the cylinder rests against the outer T-shaped roof surface of the LAR.

[0022] A preferred gripping device further comprises a fifth contact point, which is designed as a second rotary clamp. This rotary clamp is rotatably connected to the gripping device body by a second axis of rotation, the direction of rotation of the second rotary clamp being opposite to the direction of rotation of the first rotary clamp. Designing the fifth contact point as a second rotary clamp has the advantage that the force distribution during soft-grasp contact on the LAR is more symmetrical and that no additional torque needs to be absorbed when the fifth contact point strikes the LAR, which is designed as an undercut element.

[0023] A preferred gripping device further comprises a rotary spring per rotary clamp, which exerts a torque on the rotary clamp such that the contact points of the rotary clamp are moved or pressed against the LAR. A preferred rotary spring could be designed as a coil spring, which is located on or in the gripping device body and the axis of rotation of the rotary clamp.

[0024] A preferred gripping device further comprises a guide pin for each rotary clamp, which is attached to the rotating base body of the rotary clamp orthogonally to the axis of rotation. A guide pin is preferably cylindrical and attached orthogonally to and / or to the axis of rotation of the rotary clamp. The pin preferably limits the rotation of the rotary clamp.

[0025] A preferred gripping device further comprises a groove for each rotary clamp in the sleeve of the push bolt. A preferred groove in the sleeve of the push bolt is preferably designed such that the guide pin of the rotary clamp can be guided within it.

[0026] A preferred rotary spring is further designed such that the restoring force of the rotary springs rotates the rotary clamps into the closed state of the gripping device.

[0027] A preferred gripping device is further designed such that the guide pins of the rotary clamps are guided in the grooves of the push bolt.

[0028] A preferred gripping device is further designed such that the groove has a profile which, depending on the movement state of the push bolt, adjusts the restoring force of the rotary springs via the guide pins in such a way as to prevent the rotary clamps from closing. The profile is defined by a maximum and minimum stop. The maximum stop defines the maximum opening distance of the clamp, and the minimum stop defines the minimum closing distance. Between the stops, the profile can have a function-defined curve. This function can be, for example, linear, quadratic, polynomial, exponential, or logarithmic. The function determines how quickly the clamp closes, depending on the extension state of the push bolt.

[0029] A preferred gripping device is further designed such that the rotary clamps are fully open when the push bolt is fully retracted.

[0030] A preferred gripping device is further configured such that the rotary clamps are fully closed, so that they rest against the LAR, with the push bolt only partially extended. In a preferred embodiment, the rotary clamps can rest fully against the LAR by the torque of the rotary springs, while the push bolt is not yet resting against the LAR. In this preferred scenario, the gripping device is in the soft-grasp state.

[0031] A preferred gripping device is further designed such that the rotary clamps are fully closed when the thrust bolt is not fully retracted.

[0032] A preferred gripping device is further configured such that the rotary clamps and the push bolt are actuated separately. This preferred separate actuation of the rotary clamps and the push bolt allows for greater control and, in particular, dynamic torque control during the rigid-grasp process. Separate actuation could be achieved by using separate motors for each rotary clamp and one motor for each push bolt.

[0033] A preferred gripping device is further designed such that all rotary clamps and the push bolt are mechanically coupled, so that they can be moved together with only one motor.

[0034] A preferred gripping device is further configured such that all rotary clamps are mechanically coupled, allowing them to be moved together by a single motor. This mechanical coupling minimizes the number of motors required and enables a more cost-effective and compact design. The coupling of the rotary clamps can preferably be achieved by a set of gears, a transmission, belts, or rollers.

[0035] The inventive method for gripping a T-profile-shaped launch adapter ring using a gripping device comprises the following process steps: a. Closing the at least one rotary clamp around the head of the T-profile-shaped launch adapter ring. Preferably, closing the rotary clamps does not restrict all degrees of freedom of the LAR. It is further preferred that five degrees of freedom are restricted by closing the rotary clamps, so that the gripping device is in the soft-grasp state. b. Extension of the movable pushrod, so that force is slowly built up between the gripping device and the launch adapter ring, causing the gripping device and launch adapter ring to slowly align with each other. In weightlessness, it is preferable to align bodies with each other using as little torque as possible. The lower the torque, the longer it must be applied for the desired bodies to reach their target configuration. By extending the pushrod, the gripping device achieves rigid-grasp. Preferably, the remaining degrees of freedom are restricted slowly, preferably over several seconds or minutes.

[0036] Preferred embodiments of the invention are explained below with reference to figures.

[0037] They show: a. Fig. Figure 1 shows a T-profile-shaped launch adapter ring. b. Fig. Figure 2 shows a preferred embodiment of the gripping device for a T-profile-shaped launch adapter ring. c. Fig. Figures 3a-3d show a preferred sequence for gripping a T-profile-shaped launch adapter ring. d. Fig. Figure 4 shows another preferred embodiment of the gripping device.

[0038] The LAR 100 according to Fig. Figure 1 shows a circularly curved T-beam, as well as its cross-section 101.

[0039] The gripping device 200 according to Fig. Figure 2 shows a gripping device body 201 with two opposing surfaces, the outer surface having a mounting unit 202 for attaching it to a robot arm, and the other surface preferably having components of the gripping device 203, 220, 240. A mounting unit 202 can preferably also be designed as a projection for a motor shaft to control components of the gripping device, such as the push bolt and / or the rotary clamps.

[0040] One in Fig. The component of the gripping device 200 shown in the invention is the rotary clamp 203. The rotary clamp 203 is designed so that the movement to open or close the rotary clamp is carried out with a small force transmission to the LAR 230. The rotary clamp 203 according to the invention further comprises a U-shape, wherein the U-shape has two arms 205, each with two contact points 206, 207, and a rotating base body 204 extending between them. The arms according to the invention each have an inner surface 209, which are the inner surfaces of the U-shaped rotary clamp. The inner surfaces each have a contact point 207, which restricts the degree of freedom of the LAR 230 in one direction.

[0041] The in Fig. The arms 205 of the rotary clamp 203 shown in the two illustrations of the invention each have an undercut element 211, which each forms a contact point 206. An undercut element 211 is a component that is shaped so that it projects beyond another component, making it inaccessible. Preferably, the undercut element 211 is designed as the base of an L-shape, such that when the rotary clamp rotates into the closed position, the top of the T-shaped LAR ring 230 projects beyond the base of the L-shaped undercut element 211.

[0042] One in Fig. 2 shown in the invention, the rotary clamp 203 is rotatable in a rotation direction 212 and the undercut element 211 is oriented tangentially in the rotation direction 299.

[0043] One in Fig. 2 The rotation axis 208 of the rotary clamp shown in the invention is essentially orthogonal to the gripping device body 201 and the rotation base body 204.

[0044] One in Fig. 2 The preferred gripping device shown further has a fifth contact point, which is designed as a second rotary clamp 220, wherein the rotary clamp 220 is rotatably connected to the gripping device body 201 by a second axis of rotation, wherein the direction of rotation 212a of the second rotary clamp 220 is opposite to the direction of rotation 212 of the first rotary clamp.

[0045] One in Fig. The preferred gripping device 200 shown in Figure 2 is designed such that the second rotary clamp 220 is rotatably mounted on the gripping device body 201 at a distance from the first rotary clamp 203. The distance between the rotary clamp 203 and the rotary clamp 220 preferably extends along a surface. This distance is preferably a distance along the surface of the gripping device, with the surface preferably comprising components 203, 220, and 240 of the gripping device 200.

[0046] One in Fig. The preferred gripping device body shown in Figure 2 further comprises a central part 241, wherein the central part 241 of the gripping device body has a push pin 240 that is movable orthogonally to the gripping device body, and wherein the push pin 240 bears against the head of the T-profile-shaped launch adapter ring 230 in the closed gripping device state. The central part 241 of the gripping device body is preferably the, or a part of, the surface of the gripping device body 201 between the rotary clamp 203 and the rotary clamp 220. The orthogonally movable push pin 240 thus moves orthogonally to the surface of the gripping device body 201, which preferably comprises components 203, 220, and 240 of the gripping device 200.

[0047] One in Fig. Figure 3a shows the gripping device 200 in its free, open state, so that LAR 230 and gripping device 200 are completely separated from each other. Additionally, the push bolt 240 is fully retracted and the rotary clamps 203 and 220 are fully open.

[0048] One in Fig. Figure 3b shows the gripping device 200 in the open position, such that LAR 230 and gripping device 200 are oriented relative to each other in such a way that, should the gripping device now close, the LAR would be enclosed by the gripping device. The push bolt 240 is fully retracted and the rotary clamps 203 and 220 are fully open.

[0049] One in Fig. The gripping device 200 shown in Figure 3c is depicted in the closed soft-grasp state, so that LAR 230 and gripping device 200 are in the soft-grasp position. The push bolt 240 is partially extended, and the rotary clamps 203 and 220 are fully closed and rest against LAR 230.

[0050] One in Fig. The gripping device 200, shown in 3D, is depicted in the closed rigid-grasp state, so that LAR 230 and gripping device 200 are in the rigid grasp position. The push bolt 240 is fully extended and rests against LAR 230, and the rotary clamps 203 and 220 are fully closed and rest against LAR 230.

[0051] One in Fig. Figure 4, a preferred embodiment shown on the right, depicts gripping device 400 in a top view. The gripping device body is hidden. Two rotary clamps 460, 470, each with a rotary spring 461, 471 and a guide pin 463, 473, are shown. Furthermore, on the left side of Fig. Four pushrods 450 with two grooves 462, 472 are shown. The guide pins 463, 473 sit in the grooves of the pushrods 462, 472. The rotation springs 461, 471 apply a torque to the rotation clamps 460, 470 clockwise and counterclockwise (towards the closed rotation clamp state). Any resulting rotation is prevented by the contact of the guide pins 463, 473 in the profile of the grooves 462, 472. On the left side of Fig.Figure 4 shows a side view of the push bolt 450 with groove 462. Each of the grooves 462, 472 has a maximum stop 462a and a minimum stop 462b, as well as a groove profile 462c defined by a function. Depending on the extension of the push bolt, the point at which the guide pins 463, 473 are blocked by the stops or the groove profile changes. This also changes the opening position of the rotary clamps 460, 470. The groove profile 462c thus defines the rate at which the rotary clamps open or close, depending on the extension of the push bolt 450. In the open position, the pin rests against the maximum stop 462a. In the soft-grasp position, the pin is close to the minimum stop 462b. In the rigid-grasp state, the thrust bolt 450 continues to move until it rests on the LAR.In this process, pins 463 and 673 lift off the groove, allowing the push bolt to continue moving while the rotary clamps are already in contact with the LAR.

Claims

[1] A gripping device (200, 220, 240, 400) for gripping a T-profile-shaped launch adapter ring, wherein the gripping device (200, 220, 240, 400) comprises: a. A gripping device body (201), b. A rotary clamp (220, 460, 470) with four contact points (206, 207), i. wherein the rotary clamp (220, 460, 470) has a U-shape, wherein the U-shape has two arms (205) each with two contact points (206, 207) and a rotational base body extending between them, 1. wherein the inner surface of the arms (205) each form a contact point (206, 207), 2. wherein the arms (205) each have an undercut element (211) which each forms a contact point (206, 207), 3. wherein the rotary clamp (220, 460, 470) is rotatable in a direction of rotation and the undercut element (211) is aligned in the direction of rotation, 4. wherein the base body of rotation has an axis of rotation (208) which is substantially orthogonal to the gripping device body (201), c. A fifth contact point d. characterized by , that the rotary clamp (220, 460, 470) is rotatably connected to the gripping device body (201) via the axis of rotation (208), e. wherein the fifth contact point is spaced apart from the rotary clamp (220, 460, 470) and attached to the gripping device body (201), f. wherein, in the closed clamping state, the undercut elements (211) engage behind the head of the T-profile-shaped launch adapter ring, g. wherein the fifth contact point rests on the T-profile-shaped launch adapter ring in the closed clamp state and thus prevents the gripping device body (201) from rotating away about at least one axis h. a sixth contact point, i. wherein the sixth contact point is located behind the head of the T-profile-shaped launch adapter ring in the closed terminal state. [2] A gripping device (200, 220, 240, 400) according to any of the preceding claims, characterized by , that the gripping device body (201) has a central part (241), wherein the central part (241) of the gripping device body (201) has a push pin (240, 450) that is orthogonally movable to the gripping device body (201), wherein the push pin (240, 450) rests against the head of the T-profile-shaped launch adapter ring in the closed gripping device state. [3] A gripping device (200, 220, 240, 400) according to one of the preceding claims characterized by, that the fifth contact point is formed by a second rotary clamp (220), wherein the rotary clamp (220, 460, 470) is rotatably connected to the gripping device body (201) by a second axis of rotation, wherein the direction of rotation of the second rotary clamp (220) is opposite to the direction of rotation of the first rotary clamp (203). [4] A gripping device (200, 220, 240, 400) according to any of the preceding claims, wherein the gripping device (200, 220, 240, 400) further comprises: a. One rotation spring (461, 471) per rotation clamp (220, 460, 470) b. A guide pin (463, 473) per rotary clamp (220, 460, 470), which is attached to the rotation base body of the rotary clamp (220, 460, 470) orthogonally to the axis of rotation (208), c. a groove (462, 472) per rotary clamp (220, 460, 470) in the sleeve of the thrust bolt (240, 450), d. characterized by, that the restoring force of the rotary springs (461, 471) rotates the rotary clamps (220, 460, 470) into the closed state of the gripping device (200, 220, 240, 400), e. wherein the guide pins (463, 473) of the rotary clamps (220, 460, 470) are guided in the grooves (462, 472) of the push bolt (240, 450), f. wherein the groove (462, 472) has a profile which, depending on the movement state of the push bolt (240, 450), adjusts the restoring force of the rotation springs (461, 471) by the guide pins (463, 473) so that it prevents the closing of the rotation clamps (220, 460, 470). g. wherein the rotary clamps (220, 460, 470) are fully open in the open gripping device state with the push bolt (240, 450) fully retracted, h. wherein the rotary clamps (220, 460, 470) are fully closed in the soft-grasp state, and the push bolt (240, 450) is not yet fully extended. i. wherein the rotary clamps (220, 460, 470) and the thrust bolt (240, 450) are fully closed or extended in the rigid-grasp state, so that they rest against the LAR. [5] A gripping device (200, 220, 240, 400) according to one of claims 1, and / or 2, and / or 3, characterized by , that the rotary clamps (220, 460, 470) and the push bolt (240, 450) are actuated separately. [6] A gripping device (200, 220, 240, 400) according to any of the preceding claims, characterized by , that all rotary clamps (220, 460, 470) are mechanically coupled, so that they can be rotated together with only one motor. [7] Method for gripping a T-profile-shaped launch adapter ring using a device according to claims 3-6, comprising the following method steps: a. Closing the at least one rotary clamp (220, 460, 470) around the head of the T-profile-shaped launch adapter ring, b. Extension of the movable push bolt so that force is slowly built up between gripping device (200, 220, 240, 400) and launch adapter ring, so that gripping device (200, 220, 240, 400) and launch adapter ring slowly align themselves with each other.

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