Device for separating two rocket stages

Abstract

The invention relates to a device for separating a first rocket stage from a second rocket stage, comprising a bolt assembly (A) which can be connected to the first rocket stage and a receiving assembly (B) which can be connected to the second rocket stage, wherein the bolt assembly (A) comprises a bolt (1) having a neck (13) and having a free end (15) which adjoins the neck and which is expanded in a mushroom shape, and in a connected state a transition region (14) between the neck (13) and the expanded end (15) is clampingly received and secured by a plurality of blocking elements (10) in the receiving assembly (B), and in a disconnected state the blocking elements (10) are in a position shifted radially outward with respect to the bolt (1), whereby the end (15) expanded in a mushroom shape is released and the bolt assembly (A) can be removed from the receiving assembly (B). It is disadvantageous here that the force transmission is not optimal and therefore very large separating devices must be used. The aim of developing a device for separating a first rocket stage from a second rocket stage such that high force transmission occurs and at the same time rapid detachability is ensured is achieved in that each blocking element (10) has two end faces (10b) between which a circumferential surface (16) having a convex barrel shape lies and the transition region (14) of the bolt (1) has, for each blocking element (10), a contact surface (1b) which is complementary to said convex barrel shape.

Description

[0001] Device for separating two rocket stages

[0002] The invention relates to a device for separating a first rocket stage from a second rocket stage according to the preamble of claim 1.

[0003] In multi-stage rockets, such as those used for space exploration and launching satellites into space, the first stage, which typically has several high-powered engines and large fuel tanks, must separate after reaching a certain altitude, i.e., when its fuel is exhausted. This allows the rocket to continue its flight with the remaining second stage, which has less powerful engines. The separated stage then falls back to Earth.

[0004] For this to work, it is crucial to completely and safely separate the first rocket stage from the second stage at a specific point in time. This requires special separation devices that, on the one hand, guarantee a secure connection between the two rocket stages during launch and during the operation of the first stage, and on the other hand, allow the connection to be separated quickly and completely under load so that the first rocket stage detaches entirely from the second stage.

[0005] For this purpose, it is common practice in the state of the art to use so-called quick-change modules, such as those sold by the Tooling Tech Group under the brand name “Segen”.

[0006] Such quick-change systems feature a bolt assembly connectable to the first rocket stage and a receiver assembly connectable to the second rocket stage. The bolt assembly comprises a bolt with a neck and a mushroom-shaped, flared free end. In a connected state, the transition area between the neck and the flared end is clamped and secured by multiple locking elements in the receiver assembly. In a separated state, the locking elements are displaced radially outward with respect to the bolt, releasing the mushroom-shaped flared end and allowing the bolt assembly to be detached from the receiver assembly, thus enabling the first rocket stage to be detached from the second rocket stage. Spherical locking elements are the industry standard and are referred to as "ball locks." These spherical locking elements interact either at a point or along a line with the complementary contact surfaces.Furthermore, the lengths of the line contacts are relatively short.

[0007] A disadvantage of these known devices is that the force transmission is not optimal, and therefore very large separating devices must be used, which increase the weight of the rocket and worsen the aerodynamics, as these are located in the area of ​​the outside of the connection between the two rocket stages.

[0008] The task is therefore to further develop a device for separating a first from a second rocket stage in such a way that a high force transmission takes place and at the same time rapid detachability is ensured.

[0009] This problem is solved by the features specified in claim 1. Advantageous embodiments can be found in the dependent claims.

[0010] According to the invention, each of the locking elements has two end faces, between which lies a circumferential surface with a convex barrel shape, and the transition area of ​​the bolt to each locking element has a contact surface complementary to this convex barrel shape. The barrel shape can also be described as a barrel shape. The essential point is that the locking elements are bulbous and outwardly directed.

[0011] The use of barrel-shaped locking elements allows the innermost interaction between the locking elements and the bolts to be implemented as a surface area. The resulting interaction area permits significantly higher clamping forces than would be possible with conventional spherical locking elements, since the local maximum curvatures of barrel-shaped elements are considerably greater than those of spheres.

[0012] The use of barrel-shaped locking elements also allows for line contact between the locking elements and the piston, enabling the piston to be designed as a purely rotationally symmetrical component. This allows for a smaller installation volume and lower weight than would be possible with other locking element shapes. Preferably, the locking elements are mounted in openings of an anchor element of the receiving assembly (B).

[0013] Preferably, in each locking element, the bulbous barrel shape of the circumferential surface is extended over an angular range of the end faces on each of its two end faces, forming finger elements projecting beyond the respective end faces.

[0014] The finger-shaped protrusions on the end faces of the barrel-shaped locking elements prevent them from falling through the anchor element when open. These finger-shaped protrusions are complex to manufacture. They allow for maximizing the interaction line lengths between the locking elements, the anchor element, and the piston, as well as the interaction area between the locking elements and the bolt. The combination of the barrel shape of the locking elements and the finger-shaped protrusions maximizes force transmission while minimizing the overall size and weight.

[0015] Preferably, the angle range of the end faces is between 5 and 180 degrees, ideally between 60 and 120 degrees.

[0016] Preferably, the bolt has a polygonal element which, in the connected state, engages in a corresponding anti-rotation element of the receiving assembly.

[0017] The polygonal element in conjunction with the anti-rotation element of the receiving assembly allows the nut to be tightened without additional forces and stresses arising from the rotation of the bolt relative to the anchor element.

[0018] Preferably, the anti-rotation element is positively connected to the anchor element.

[0019] Preferably, the receiving assembly comprises a housing in which a cup-shaped piston is slidably mounted. In the connected state, the piston presses the locking elements against the transition area with a section of smaller inner diameter. In the disconnected state, it is displaced within the housing relative to the connected state and receives the outwardly pressed locking elements in a second section of larger inner diameter, thereby releasing the end of the bolt. Preferably, the piston is slidably sealed against the housing and is supported by an inner bottom surface against a lower surface of the anchor element via a helical spring. The transition of the piston from the connected to the disconnected state is effected by applying pressure to the space between the housing and the piston, thereby compressing the helical spring.

[0020] Preferably, the pressure is exerted via a connection piece located in the housing by a pneumatic or hydraulic pump.

[0021] Preferably, the anchor element has an annular damping element for damping the impact of the free end of the piston during the transition from the connected to the separated state.

[0022] Preferably, the anchor element is screwed into the housing.

[0023] An embodiment of the invention is explained in more detail below with reference to the accompanying drawings. These show:

[0024] Fig. 1 A perspective view of a bolt assembly A separated from the receiving assembly B.

[0025] Fig. 2 An exploded view according to Fig. 1;

[0026] Fig. 3 A perspective view of the locking element shown in Fig. 2 (a) and this locking element in longitudinal section (b) and in cross section (c);

[0027] Fig. 4 A cross-sectional view of the bolt assembly (a) locked to the receiving assembly and the bolt assembly (b) unlocked;

[0028] Fig. 5 A representation of the locking mechanism of the locking elements with the complementary contact surfaces, partially shown in section;

[0029] Fig. 6 A representation according to Fig. 5 with fully drawn locking elements and without housing and damping element.

[0030] Figure 1 shows a perspective view of a bolt assembly A separated from the receiving assembly B. The connection between receiving assembly B and bolt assembly A to the rocket stages is not shown. Receiving assembly B can, for example, be connected to the first (lower) rocket stage, and bolt assembly A to the second (upper) rocket stage. It should be noted that, as a rule, several combinations of bolt assembly A and receiving assembly B are used around the circumference of the rocket stages, e.g., two, four, or more combinations of these two assemblies. During the separation of the two rocket stages, it is important that all combinations of bolt assembly A and receiving assembly B are separated from each other at precisely the same time. However, this will not be described in detail below, as this description only refers to a single unit consisting of a bolt assembly A and a receiving assembly B.

[0031] The receiving assembly B has a housing 4, which is essentially cylindrical. At the lower end of the housing 4 is a connection 5 for a pneumatic or hydraulic pressure supply, which is not shown in detail. It should be noted that either hydraulic or pneumatic pressure can be introduced into the housing 4 via this hydraulic pressure supply, preferably intermittently. The generation of this pressure is not described in detail below.

[0032] At the upper end of the housing 4 is an anchor element 11 screwed into the housing 4. The inner surface of this anchor element is octagonal and incorporates an anti-rotation element 12, the inner surface of which is also octagonal. Screws 6 are located to the left and right outside the top of the housing 4. These screws are shown schematically in Fig. 1, i.e., without threads.

[0033] Above the receiving assembly B is the bolt assembly A, which has a bolt 1 with a polygonal element 1a. As can be seen in Fig. 2, the bolt 1 has a neck 13, with contact surfaces 1b arranged on the mushroom-shaped widened free end 15 of the bolt 1. In the illustrated embodiment, there are eight contact surfaces 1b, evenly spaced around the circumference of the mushroom-shaped widened end 15 of the bolt 1, and on the mushroom-shaped widening, so that the contact surfaces 1b point upwards, i.e., away from the receiving assembly B. A washer 2 and a nut 3 are also attached to the bolt 1. The entire assembly is shown in exploded view in Fig. 2. The receiving assembly B with the housing 4 and the screws 6, as well as the connection piece 5 for the pneumatic or hydraulic pressure supply, is also shown here.Also shown is the previously described anchor element 11 with the anti-rotation element 12, which has an internal octagonal shape, allowing the anti-rotation element 12 to be positively engaged in the anchor element 11. The locking elements 10 are shown partially installed and partially removed in an exploded view. They form the connection between the receiving assembly B and the bolt assembly A. When installed, these locking elements 10 rest against the contact surfaces 1b. Therefore, the number of locking elements 10 must be equal to the number of contact surfaces 1b.

[0034] Between the housing 4 and the anchor element 11 is a piston 7, the outer surface of which, starting from the housing 4, is initially cylindrical, then continuously widens, and subsequently becomes cylindrical again with a larger outer diameter. The piston 7 is sealed against the housing 4 by an O-ring 7b. The piston 7 accommodates a helical spring 8, which acts between the inner base of the piston 7 and the anchor element 11.

[0035] The design of the locking elements 10 is shown in Fig. 3. Here, illustration (a) shows the locking element 10 in perspective view, illustration (b) the locking element 10 in longitudinal section and illustration (c) the locking element 10 in cross section.

[0036] The locking element 10 is designed such that it has two end faces 10b, between which lies a circumferential surface 16 with a convex barrel shape, which could also be described as a barrel shape or bulge. This is best seen in Fig. 3(a). All figures in Fig. 3 show that, in a preferred, but not essential, embodiment of each locking element 10, the convex barrel shape, which can also be described as a bulge, of the circumferential surface 16 extends over an angular range of the two end faces 10b, forming finger elements 10a projecting beyond the respective end faces 10b. These finger elements 10a serve to fasten the locking elements 10.The indicated radius R4 is the radius of the barrel-shaped circumferential surfaces 16 of the locking elements 10, and the indicated radius R5 is the radius describing the body diameter of the locking elements 10, where radius R5 is smaller than radius R4. The axis of radius R4 is perpendicular to the axis of radius R5, and these two axes do not intersect. The finger elements 10a on the end faces 10b of the barrel-shaped locking elements 10 prevent the locking elements 10 from falling through the anchor element 11 in the open state. These finger elements 10a are complex to manufacture and allow for maximizing the interaction line lengths between the locking elements 10, the anchor element 11, and the piston 7, as well as the interaction area between the locking elements 10 and the bolt 1.The combination of the barrel shape of the locking elements 10 with the projecting finger elements 10a allows the power transmission to be maximized while minimizing the construction volume and weight.

[0037] Figure 4 shows a cross-sectional view of the bolt assembly A locked to the receiving assembly B in subfigure (a) and the bolt assembly A unlocked in subfigure (b). First, the locked state in subfigure (a) is described. The housing 4 of the receiving assembly B is shown, containing the piston 7 and a damping element 9, which dampens the impact of the piston 7 when the device is opened. The piston 7 is sealed against the housing 4 by an O-ring 7c. Above the O-ring 7c, the piston 7 has an internal recess 7b that extends along its entire circumference and forms a kind of internal groove, widening the inside of the piston 7 at this point so that, in the unlocked state, the locking elements 10 can be received in this area.A coil spring 8 acts between the lower inner side of the piston 7 and the anchor element 11, the force of which pushes the anchor element 11 away from the underside of the piston 7, thus maintaining a maximum distance between the underside of the piston 7 and the anchor element 11.

[0038] On the side of bolt assembly A, the bolt 1 is shown with the mushroom-shaped extension at its lower end 15 and the contact surfaces 1b located thereon. Also shown is the polygonal element 1a on the bolt 1, which engages in the internal octagon of the anti-rotation element 11. Furthermore, the washer 2 and the nut 3 are again located on the side of the bolt 1 in contact with the flange 19, which remains loosely connected to the bolt 1 and the nut 3 after the separation mechanism is opened, and to the underlying flange 20, which is firmly connected to the housing 4 by the screws 6. Between the receiving assembly B and the bolt assembly A are the locking elements 10, described in detail with reference to Fig. 3, such that they bear on one side against the contact surfaces 1b of the mushroom-shaped extension at the end 15 of the bolt 1 and on the other side against the upper inner side of the piston 7.In this way, a stable connection between bolt assembly A and receiving assembly B, mediated by the locking elements 10, is ensured in the state shown in part 4(a). The first angle 17 between the bearing surface of the anchor element 11 and the sliding surface on which the locking elements 10 can move to release the mechanism is shown, as is the second angle 18 between the sliding surface of the anchor element 11 and the barrel-shaped interaction surfaces Id of the bolt 1. The first angle 17 is chosen to provide an optimal ratio between size, weight, and the clamping force to be absorbed, and the second angle 18 is chosen to be as small as possible to minimize the radial force on the piston 7. However, this second angle 18 is large enough to prevent the locking element 10 from self-locking when the mechanism is opened.The polygonal element la on bolt 1 in conjunction with the anti-rotation element 12 allows the nut 3 to be tightened without additional forces or stresses arising from the rotation of the bolt 1 relative to the anchor element 11.

[0039] The prominent finger elements 10a allow for maximizing the interaction line lengths between the locking elements 10, the anchor element 11, and the piston 7, as well as the interaction area between the locking elements 10 and the bolt 1. The combination of the barrel shape of the locking elements 10 and the finger elements 10a allows for maximizing force transmission while simultaneously minimizing the overall volume and weight.

[0040] The separated representation of mounting assembly B and piston assembly A is shown in subfigure (b) of Fig. 4. The spring 8, which would otherwise be shown compressed, has been omitted. It can be seen that the piston base (shown below) is now spaced apart from the base of the housing 4. This space was created by pressurizing the connecting piece 5 with either pneumatic or hydraulic pressure, so that the pressure inside the housing 4 between the inside of the housing and the outside of the piston 7 became high enough to compress the spring 8. This is possible thanks to the O-rings 7c, without any compressed air or hydraulic fluid escaping between the housing 4 and the piston 7.

[0041] In illustration b (Fig. 4), it can be seen that the locking elements 10 are no longer pressed against the narrowest uppermost point of the piston 7, but, due to the upward movement of the piston 7, can move outwards towards the bolt element A into the recess 7b on the inside of the piston 7. The inner diameter of the circle formed by the locking elements 10 thus increases beyond the outer diameter of the mushroom-shaped extension at the end 15 of the piston 1, so that this mushroom-shaped extension can slide upwards through the locking elements 10 and out of the entire receiving assembly. In subfigure (b) of Figure 4, the flange 19 is no longer shown, as it is pulled upwards together with the piston 1, the washer 2, and the nut 3.This pulling action is supported by the acceleration effect of the onset thrust of the engine of the second rocket stage, on which the bolt assembly (A) is located.

[0042] The precise geometry of the individual radii of the components used is shown in Fig. 5, which depicts the locking mechanism of the locking elements 10 with the complementary contact surfaces 1b. Also shown here is the bolt 1 with the polygonal element 1a mounted on it, as well as the complementary contact surfaces 1b at the mushroom-shaped extended end 15 of the bolt 1, which interact with the locking elements 10. The end faces 10b and the finger elements 10a are also shown. The anchor element 11, the damping element 9, the housing 4, the piston 7 with the O-ring 7c, and the coil spring 8 are also depicted. The position shown corresponds to the locked state between the receiving assembly B and the bolt assembly A. The radius RI shown is the radius of the inner cylindrical surface of the piston 7, which forms line contact with the locking element 10.The second radius, R2, is the radius of the inner cylindrical surface of the anchor element 11, which forms a line contact with the locking element 10. The third radius, R3, is the radius of the barrel-shaped interaction surfaces 1b of the bolt 1, which form a large surface contact with the locking elements 10. The fourth radius, R4, is the radius of the barrel-shaped outer surfaces of the locking elements 10. The fifth radius, R5, is the body diameter of the locking elements 10, whereby the fifth radius, R5, should be smaller than the fourth radius, R4, as already described. The remaining radii, R1, R2, R3, and R4, should be equal or approximately equal.The use of barrel-shaped locking elements 10, provided that the radius R5 is smaller than the radius R4, allows for line contact between the locking elements 10 and the piston 7, enabling the piston 7 to be designed as a purely rotationally symmetric component. This results in a lower overall weight than would be possible with other shapes of the locking elements 10.

[0043] Finally, Fig. 6 shows a representation according to Fig. 5 with the locking elements 10 fully drawn and without the housing 4. Also shown here are the coil spring 8, the seal 7c, the recess 7b within the housing 7, the anchor element 11, the anti-rotation element 12, and the piston 1 with the additional polygonal element 1a. For a more detailed description of the shape of the locking elements 10, please refer to the description of Fig. 3.

Claims

Claims 1. Device for separating a first rocket stage from a second rocket stage, comprising a bolt assembly (A) connectable to the first rocket stage and a receiving assembly (B) connectable to the second rocket stage, wherein the bolt assembly (A) has a bolt (1) with a neck (13) and a mushroom-shaped extended free end (15) adjoining it, and a transition area (14) between the neck (13) and the extended end (15) is clamped and secured in a connected state by a plurality of locking elements (10) in the receiving assembly (B), and the locking elements (10) are radially displaced outwards with respect to the bolt (1) in a separated state, thereby releasing the mushroom-shaped extended end (15) and allowing the bolt assembly (A) to be pulled away from the receiving assembly (B), characterized in that each locking element (10) has two end faces (10b),between which lies a circumferential surface (16) with a convex barrel shape and the transition area (14) of the bolt (1) to each locking element (10) has a complementary contact surface (1b) to this convex barrel shape.

2. Device according to claim 1, characterized in that the locking elements (10) are mounted in openings of an anchor element (11) of the receiving assembly (B).

3. Device according to claim 2, characterized in that, in each locking element (10), the bulbous barrel shape of the circumferential surface (16) extends over an angular range of the end faces (10b) on each of its two end faces (10b), forming finger elements (10a) projecting beyond the respective end faces (10b).

4. Device according to claim 3, characterized in that the angular range is between 5 and 180 degrees, preferably between 60 and 120 degrees.

5. Device according to one of the preceding claims, characterized in that the bolt (1) has a polygonal element (1a) which is connected condition engages in a corresponding antirotation element (12) of the receiving assembly (A).

6. Device according to claim 5, characterized in that the anti-rotation element (12) is positively connected to the anchor element (11).

7. Device according to one of claims 2 to 6, characterized in that the receiving assembly (B) has a housing (4) in which a pot-shaped piston (7) is slidably mounted, wherein the piston (7) in the connected state presses the locking elements (10) against the transition area (14) with a region of smaller inner diameter and in the separated state is displaced within the housing (4) relative to the connected state and receives the locking elements (10) pressed outwards in a second region of larger inner diameter, thereby releasing the end (15) of the bolt (1).

8. Device according to claim 7, characterized in that the piston (7) is displaceably sealing relative to the housing (4) and is supported with an inner bottom side against a bottom of the anchor element (11) via a helical spring (8), wherein the transition of the piston (7) from the connected to the separated state is effected by applying pressure to the space between the housing (4) and the piston (7) and thereby compressing the helical spring (8).

9. Device according to claim 8, characterized in that the pressure is exerted by a pneumatic or hydraulic pump via a connecting piece (5) located in the housing (4).

10. Device according to one of claims 7 to 9, characterized in that the anchor element (11) has an annular damping element (9) for damping the impact of the free end of the piston (7) during the transition from the connected to the separated state.

11. Device according to one of claims 7 to 10, characterized in that the anchor element (11) is screwed into the housing (4).

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