Torque-Limiting Wrench with Pivotable Handle Shank
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wrenches with adjustable maximum operational torque hinder user convenience by preventing further tightening of screws beyond a predetermined torque value, leading to user discomfort and inconvenient two-handed operation.
Innovation Solution
A wrench design featuring a rotatable body with a pivotable handle that can switch between coaxial and storage positions, allowing for efficient one-handed operation by either finger rotation or palm grip, without exceeding a preset torque value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wrench has a cylindrical protrusion on top to prevent over-tightening, then the maximum operational torque is controlled, but the transmission of rotational force is hindered causing loss in rotational force and user discomfort
Solution Approach 1:
The handle is segmented into a handle body and a separate shank portion. The shank can rotate independently relative to the handle body through a rotating connection structure, allowing the user's rotational force to be transmitted effectively to the wrench mechanism while the handle body remains stable for gripping.
Solution Approach 2:
The connection between the shank and handle body is made dynamic rather than rigid. The shank can rotate relative to the handle body, enabling adaptive force transmission that accommodates both user comfort and torque control requirements during the tightening operation.
2Force
If the user holds the wrench with the whole palm to increase rotational force, then more torque can be applied, but the cylindrical protrusion causes loss in rotational force and pain or discomfort to the palm
Solution Approach 1:
By separating the force application area (handle body for palm gripping) from the force transmission path (shank for rotational movement), the design allows users to apply maximum force comfortably with their palm while the rotating shank efficiently transmits this force to tighten the screw.
Solution Approach 2:
The rotating connection structure acts as an intermediary between the user's palm force and the screw tightening mechanism. It mediates the force transmission by allowing rotational movement, converting the user's gripping force into effective tightening torque without causing discomfort.
3Force
If the user rotates the wrench with both hands to achieve desired tightening extent, then the torque requirement is met, but the operation becomes inconvenient reducing purchase desire
Solution Approach 1:
The handle design separates the gripping function (handle body for one-handed palm grip) from the rotational control function (shank with rotating connection). This segmentation enables effective one-handed operation where the user can comfortably grip with the palm and rotate the shank to achieve the desired tightening torque.
Data Source
AI summary
A wrench includes a body and a rod pivotably received in a first end of the body. A pressing device is mounted in the rod and presses against the body. A handle includes a shank and a connection end pivotably connected to the first end of the body. When the handle is in a coaxial position, the shank protrudes beyond an outer face of the first end. A longitudinal axis of the shank is coincident to the working axis. The shank can be rapidly rotated by fingers of a user. When the handle is in a storage position, the shank is received in a groove in the outer face. A palm of the user can grip and rotate the body without hindrance by the shank.