Utility Arm Joint Clamping via Spherical Pressure Wedges
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Solution Overview
Problem
Existing utility arm designs are inefficient due to axial nature of pivoting joint clamp contact, prone to slip and wear, lack of explicit tension range, and uneven torque distribution across joints, leading to tilting or failure under load.
Innovation Solution
A utility arm design featuring a central bolt with upper and lower pressure wedges and split pistons with roller bearings, allowing for variable and repeatable clamping force through compression springs and frustoconical surfaces, reducing wear and enabling adjustable torque resistance across joints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If axial clamp contact is used in pivoting joint, then the structure is simple, but the joint is inefficient and prone to slip under load
Solution Approach 1:
The patent replaces the traditional axial clamp contact with a spherical clamp contact surface. The clamp member includes a spherical contact surface that contacts the pivot member, creating a point contact that allows for self-centering and more uniform force distribution. This curved surface geometry improves the joint's ability to handle multi-directional loads while maintaining structural simplicity.
Solution Approach 2:
The patent introduces a spherical intermediate contact surface between the clamp member and pivot member. This spherical interface acts as a mediator that distributes forces more evenly and prevents direct sliding contact, thereby reducing wear and improving reliability without significantly increasing structural complexity.
2Device complexity
If conical pressure discs with coplanar contact line are used, then the mechanism is simple, but the contact line is prone to wear under repeated use
Solution Approach 1:
The patent replaces the coplanar contact line with a spherical contact surface. This curvature allows the contact point to move and distribute wear across a larger area over time, preventing concentrated wear at a single line location and extending the service life of the pressure discs.
3Ease of operation
If flat cone angle is used for pressure disks, then the system releases upon loosening, but the actuation curve is steep and the mechanism is highly sensitive to wear
Solution Approach 1:
The spherical contact surface modifies the actuation characteristics by distributing contact forces more evenly. This reduces the sensitivity to wear while maintaining the ability to release upon loosening, as the spherical geometry allows for more gradual engagement and disengagement.
4Device complexity
If equal clamping force is applied to all joints, then the structure is uniform, but joints at different distances from payload experience uneven torque and may fail
Solution Approach 1:
The patent implements different spring constants for springs at different locations along the utility arm. Joints closer to the payload (which experience higher torque) are equipped with stiffer springs that provide greater clamping force, while joints farther away use more compliant springs. This local differentiation of spring properties ensures that each joint experiences appropriate torque balance without requiring complex control systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design provides a utility arm with improved stability and adjustability, allowing for continuous variation of clamping force, reducing wear, and ensuring even torque distribution across joints, enabling secure and convenient positioning of payloads without tilting or failure.
Implementation Method 1
compression springs and frustoconical surfaces, reducing wear and enabling adjustable torque resistance across joints
Implementation Method 2
upper conical pressure disc 26 and lower conical pressure disc 27, arranged so that their conical surfaces face each other
Implementation Method 3
split pistons with roller bearings, allowing for variable and repeatable clamping force
Data Source
AI summary
A utility arm includes a first arm, terminating in first universal joint, locked by a first piston, and a second arm, terminating in second universal joint, locked by a second piston. These are joined by an intermediate joint positioned between the first universal joint and second universal joint, and there is a locking means on the intermediate joint. The intermediate joint has a first housing, with a first pressure piece having an inclined surface which abuts the first piston, the first pressure piece having a conical or frustoconical surface a second housing, with a second pressure piece having an inclined surface which abuts the second piston, the second pressure piece having a conical or frustoconical surface. The first pressure piece and second pressure piece interlocks with corresponding conical or frustoconical surfaces, so that pressure exerted by the locking means presses the first pressure piece and second pressure piece together, such that the inclined surface of the first pressure piece acts on the first piston to lock the first universal joint, the inclined surface of the second pressure piece acts on the second piston to lock the second universal joint, and the corresponding conical or frustoconical surfaces lock the intermediate joint.