A spherical joint with a wide range of motion

Abstract

The invention relates to a spherical joint having a wide range of motion. In particular, the invention relates to a spherical joint comprising a socket formed of segmented parts, wherein the segments are configured to be separated into discrete portions and to be moved independently of one another by the component attached to the ball, thereby enabling an increased range of motion.

Description

[0001] A SPHERICAL JOINT WITH A WIDE RANGE OF MOTION

[0002] Technical Field

[0003] The invention relates to a spherical joint with a wide range of motion.

[0004] The invention particularly relates to a spherical joint comprised of segmented parts, with a socket in which the segments can be moved independently of each other by the component attached to the ball, in order to achieve an extremely wide range of motion.

[0005] State of the Art

[0006] Spherical joints (also known as ball joints or ball-and-socket joints) are a fundamental component of mechanical systems, acting as a connecting element that enables multidirectional movement. These connectors are formed by seating a ball in a suitable socket and, by design, allow limited rotational movement within the mechanism in which they are mounted. Motion in a Cartesian coordinate system can be described by translation along three axes and rotation about three axes. However, due to the structural characteristics of spherical joints, the relative motion between the connected links is limited to rotation about three axes. Although this constraint provides certain advantages, it also results in workspace limitations dictated by design requirements.

[0007] Spherical joints are used in systems requiring high flexibility and a wide range of motion. Some technical fields in which such joints are employed are described below.

[0008] They are commonly used in vehicle suspension systems to connect control arms to steering knuckles, thereby enabling steering and suspension motion. This usage enables vehicle suspension systems to achieve desired functional characteristics. In steering systems, spherical joints permit controlled rotational movement of vehicle wheels.

[0009] In industrial automation and robotics, spherical joints are used, particularly in robot arms, to provide multi-axis degrees of freedom between connected links. For example, in welding robots, spherical joints may be used to enable the robot to reach different welding points and to accommodate various configurations. This illustrates the role of spherical joints in manufacturing processes. Spherical joints also play an important role in biomedical applications. They are commonly employed, particularly in the design of prosthetic links, to replicate the natural motion of human joints. Prosthetic knee joints provide flexion and rotation similar to a natural knee, enhancing the user's mobility in daily activities. Such applications may contribute to the functionality and comfort of prostheses.

[0010] In addition, in various industrial machines, spherical joints act as pivot points between moving parts. Such use increases the degrees of freedom of the machines, contributing to their functionality.

[0011] In the furniture industry, spherical joints are used to provide adjustable motion for movable elements. In office chairs, the adjustability of the arms and backrests is enabled by spherical joints, allowing the components to be positioned as required. This contributes to ergonomic design.

[0012] A review of the technical literature reveals that spherical joints have advantages as well as certain limitations. Structurally, their movement is limited to rotation about three axes, which may be insufficient for certain applications. For example, in advanced robotic systems or mechanisms requiring complex motion, the limited range of motion of spherical joints may restrict performance. Another example is snake-like robotic arms.

[0013] Snake-like robotic arms can be designed with connected links using spherical joints. The existing spherical joints employed in these systems, due to their mechanical structure, limit the bending of connected links at large angles. This restricts the robot's mobility and may limit sharp maneuvers, particularly in confined spaces. For example, to achieve a 90-degree bending motion, approximately nine links may need to be connected sequentially in a snake-like robotic arm. This approach significantly increases the robot's production cost and makes it challenging for the design to meet the compactness and efficiency requirements. The robot's limited agility negatively affects its performance in challenging operating environments or in applications requiring complex maneuvers, thus restricting its operational scope. In this context, the insufficient bending capability of existing spherical joints represents a technical limitation in systems where flexible movement is critical, such as serpentine robots. Such systems require innovative solutions with an increased range of motion and enhanced bending capability.

[0014] In conclusion, spherical joints represent a mechanical solution used to accommodate versatile motion requirements in various technical fields. This solution is applied in a wide range of applications, including vehicle suspension systems, robotic arms, prosthetic limbs, and adjustable furniture components, particularly in systems requiring motion flexibility and controlled movement. However, with evolving technologies and increasing demands, the need for innovative solutions that address the limitations of spherical joints remains.

[0015] As a result of the search conducted with respect to the subject matter, the application numbered CN213731837U has been identified. The application CN213731837U relates to a ball-and-socket joint having a wide range of motion, in which the socket is designed as a single-piece structure. It is observed that an extended range of motion is achieved by means of a sliding block movable within a sliding groove formed in the socket. The application CN213731837U specifies that the maximum angle through which the joint elements can move relative to each other from one end position to the other is 120 degrees, and no approach is disclosed for achieving a wider range of motion.

[0016] As a result, in view of the aforementioned drawbacks and the insufficiency of existing solutions, a need has arisen for an improvement in the relevant technical field.

[0017] Object of the Invention

[0018] The invention has been developed in view of the existing state of the art and is intended to overcome the aforementioned drawbacks.

[0019] The invention provides an innovative approach to spherical joint design that overcomes the limitations of existing techniques. In particular, the invention is intended to increase mobility in mechanical systems employing spherical joints and to enable the links to achieve a wider angular range of motion.

[0020] In the state of the art, existing spherical joint designs are generally limited to a maximum joint angle of approximately 120 degrees due to inherent structural constraints. This limitation constitutes a significant drawback, particularly in robotic applications and systems that require high mobility in confined spaces. In existing technologies, attempts to increase the range of motion have typically been addressed by increasing the number of interconnected links. However, this approach leads to increased production costs and reduced maneuverability of robotic systems. The spherical joint structure according to the present invention overcomes these technical limitations by enabling an angular range of motion of up to 250 degrees. This novel design allows links connected via the spherical joint to achieve a substantially wider range of motion, thereby significantly enhancing the mobility of robots and other mechanical systems. An angular range of 250 degrees enables the development of more agile and efficient systems capable of performing sharp maneuvers, particularly in narrow and challenging environments. Furthermore, this solution not only improves system performance but also provides additional advantages, including reduced manufacturing costs and minimized design complexity.

[0021] In order to achieve the objects described above, the present invention is a spherical joint in order to enable a wide range of motion, comprising a spine in the form of a shaft, a truncated sphere, a socket base, having a contact surface compatible with the spherical outer surface of the truncated sphere and being integrated as a single piece with the spine, a truncated sphere shaft mounted inside the truncated sphere,

[0022] • a ball set mounted on the shoulders (flange) of the spine,

[0023] • a socket segment shaft guide positioned around the spine to accommodate the ball set without protrusion from the top or bottom, by means of a central hole, and constrained against radial movement (right-left, inward-outward),

[0024] • a semi-circular socket segment shaft guide cover, configured to completely cover the top and bottom of the socket segment shaft guide and to be integrated therewith, so as to prevent axial (up-down) movement of the socket segment shaft guide,

[0025] • at least two movable segments arranged around the socket base so as to allow movement of the truncated sphere over a wide range, comprising the following: o a socket segment having a spherical inner surface compatible with the spherical surface of the truncated sphere and being movable in the axial direction (upward or downward) in response to the movement of the truncated sphere, o a tenon rail and socket segment shaft integrated with the socket segment, o a tenon connected to a tenon rail, which is movable along a tenon rail channel (mortise) on the socket base, o a linear bearing connected to the socket segment shaft guide, configured to limit the socket segment shaft to move only in the axial direction (upward or downward), o a tension spring connected at one end to a metric hook integrated with the socket segment shaft guide and the socket segment shaft guide cover, and at the other end to another metric hook mounted on a balance restoring auxiliary integrated with the socket segment shaft, the tension spring being configured to return the socket segment that has moved downward to its initial position.

[0026] The structural and characteristic features of the invention and the advantages thereof will be more clearly understood by means of the figures given below and the detailed description written with reference to these figures; therefore, the assessment should be made taking said figures and the detailed description into account.

[0027] Figures to Help Understand the Invention

[0028] Figure 1 is an isometric view of the spherical joint of the invention.

[0029] Figure 2 is a front view showing the positions of the elements in the spherical joint of the invention when the truncated sphere moves through a wide angular range.

[0030] Figure 3 is an isometric view showing the positions of the elements in the spherical joint of the invention when the truncated sphere moves through a wide angular range.

[0031] Figure 4 is a front view of the internal details of the spherical joint of the invention.

[0032] Figure 5 is a detailed view of the spine and the ball set.

[0033] Description of Piece References

[0034] 1 Spine

[0035] 2 Ball set

[0036] 3 Socket base

[0037] 4 Socket segment shaft guide

[0038] 5 Socket segment shaft guide cover

[0039] 6 Socket segment shaft

[0040] 7 Socket segment

[0041] 8 Tenon rail

[0042] 9 Tenon

[0043] 10 Balance restoring auxiliary

[0044] 1 1 Metric hook

[0045] 12 Tension spring

[0046] 13 Linear bearing

[0047] 14 Truncated sphere

[0048] 15 T runcated sphere shaft 16 T runcated sphere cover

[0049] A Spherical joint

[0050] B Movable segment

[0051] Detailed Description of the Invention

[0052] In this detailed description, preferred embodiments of the spherical joint (A), which is the subject of the invention, are described solely for the purpose of better understanding the invention.

[0053] The spherical joint (A), which is the subject of the invention, presents an innovative structure for spherical joint design, enabling the development of mechanical systems with a wide an angular range of motion. The invention has been specifically developed to enable an angular range of motion of up to 250 degrees in robotic arms and similar mechanical components.

[0054] In the invention, a spine (1 ) in the form of a shaft and a socket base (3) are integrally formed as a single-piece link. The socket base (3) has a contact surface compatible with the spherical outer surface of a truncated sphere (14), said contact surface being configured to mechanically control the movement of the truncated sphere (14). The inner portion of the truncated sphere (14) is formed by material removal so as to enable mounting of a truncated sphere shaft (15), and the volume formed by said material removal is closed by a truncated sphere cover (16).

[0055] The spine (1 ) is provided with a shoulder (flange), on which a ball set (2) is positioned. A socket segment shaft guide (4) is positioned such that, by means of a central hole thereof, the ball set (2) is received on the spine (1 ) without protruding from the upper or lower sides of the socket segment shaft guide (4). This structure prevents radial movement of the socket segment shaft guide (4). In order to prevent axial movement of the socket segment shaft guide (4), a semi-circular socket segment shaft guide cover (5) is designed to completely cover the upper and lower portions of the socket segment shaft guide (4) and to be integrable with the socket segment shaft guide (4). In this manner, the socket segment shaft guide (4) and the socket segment shaft guide cover (5) are free to rotate about the axis of the spine (1 ), and the joint formed by this assembly has one (1 ) degree of freedom. A socket segment (7) having a spherical inner surface compatible with the spherical surface of the truncated sphere (14) is integrated with a tenon rail (8) and socket segment shaft (6). The tenon rail (8) operates in an assembled manner with a tenon (9) that is movable along a tenon channel (mortise) on the socket base (3). The socket segment shaft (6) is restricted to move only in the axial direction by a linear bearing (13) interfitted with the socket segment shaft guide (4). The truncated sphere shaft (15) moves the socket segment (7) and its connected elements downward in the axial direction guided by the linear bearing (13). Upon removal of the driving force, the system returns to its starting position. This return movement is effected by a tension spring (12). The tension spring (12) is connected at one end to a metric hook (11 ) integrated with the socket segment shaft guide (4) and the socket segment shaft guide cover (5), and at the other end to another metric hook (11 ) integrated with the socket segment shaft (6) and a balance restoring auxiliary (10).

[0056] The structure comprising the socket segment shafts (6), socket segment (7), tenon rail (8), tenon (9), balance restoring auxiliary (10), metric hook (1 1 ), tension spring (12), and linear bearing (13) described above is defined as the movable segment (B), and at least two, preferably eight, of these movable segments (B) are arranged around the socket base (3).

[0057] The invention relates to a spherical joint (A), which overcomes the limitations of the prior art by providing a wider range of motion and enhanced mechanical flexibility. All elements of the invention have been optimized to improve system performance and to enable the reliable execution of complex mechanical movements

Claims

CLAIMS1. A spherical joint (A) in order to enable a wide range of motion, comprising:• a spine (1 ) in the form of a shaft,• a truncated sphere (14),• a socket base (3), having a contact surface compatible with the spherical outer surface of the truncated sphere (14) and being integrated as a single piece with the spine (1 ),• a truncated sphere shaft (15) mounted inside the truncated sphere (14) characterized by comprising:• a ball set (2) mounted on the shoulders (flange) of the spine (1 ),• a socket segment shaft guide (4) positioned around the spine (1 ) to accommodate the ball set (2) without protrusion from the top or bottom, by means of a central hole, and constrained against radial movement (right-left, inwardoutward),• a semi-circular socket segment shaft guide cover (5), configured to completely cover the top and bottom of the socket segment shaft guide (4) and to be integrated therewith, so as to prevent axial (up-down) movement of the socket segment shaft guide (4),• at least two movable segments (B) arranged around the socket base (3) so as to allow movement of the truncated sphere (14) over a wide range, comprising the following: o a socket segment (7) having a spherical inner surface compatible with the spherical surface of the truncated sphere (14) and being movable in the axial direction (upward or downward) in response to the movement of the truncated sphere (14), o a tenon rail (8) and socket segment shaft (6) integrated with the socket segment (7), o a tenon (9) connected to a tenon rail (8), which is movable along a tenon rail channel (mortise) on the socket base (3), o a linear bearing (13) connected to the socket segment shaft guide (4), configured to limit the socket segment shaft (6) to move only in the axial direction (upward or downward),o a tension spring (12) connected at one end to a metric hook (11 ) integrated with the socket segment shaft guide (4) and the socket segment shaft guide cover (5), and at the other end to another metric hook (11 ) mounted on a balance restoring auxiliary (10) integrated with the socket segment shaft (6), the tension spring (12) being configured to return the socket segment (7) that has moved downward to its initial position.

2. The spherical joint (A) according to claim 1 , characterized by comprising eight movable segments (B).

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