2026-10-14T17:14:39Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34050195 2026-10-01T18:12:40Z category_1 category_915 category_7 category_16 category_734 category_931 category_106 portal_87 item_type_3 month_year_10_2026

A multi-impactor mechanism for passive force amplification in hand tools: Design, modelling, and validation Osama J. Aldraihem (25158189) Meshal Alajaji (25158192) Yazeed Alsalem (25158195) Biophysics Physical Sciences not elsewhere classified Medicine Physiology Biological Sciences not elsewhere classified Information Systems not elsewhere classified Science Policy Multi-impactor mechanism force amplification spring-loaded impactor simultaneous triggering ergonomic shovel spring stiffness <p>Conventional hand shovels rely on sustained operator force and perform poorly against compacted soils, often leading to significant physical strain. This study presents the Spring-Loaded Multi-Impactor Shovel (SLMIS), a non-electric hand tool that integrates multiple spring-loaded impact mechanisms between the shaft and blade to convert operator input into amplified impulsive loading. The system stores elastic energy during loading and releases it instantaneously upon reaching a triggering threshold.</p> <p>The work contributes at three levels. At the theoretical level, a closed-form trigger-efficiency function is derived showing that the fraction of stored spring energy converted to impact force depends only on the ratio of triggering displacement to total compression, providing a generalizable design guideline for spring-loaded impact mechanisms. At the component level, stiffness and peak impact force are characterized using theoretical modeling, compression testing, and Brinell hardness back-calculation, yielding <i>K_i</i> = 4823.55 N/m and <i>K_r</i> = 1217.25 N/m with strong agreement across methods. At the system level, a four-impactor configuration is calculated, by linear scaling of the single-impactor measurement rather than direct measurement of the assembled unit, to reach a combined blade-tip force of 620.6 N from a 417.3 N operator input, corresponding to a 48.71% amplification, with the single-impactor peak force of approximately 155 N showing agreement within 0.3% between the compression-test and Brinell-based estimates.</p> <p>A threshold test on a 5 mm laminated porcelain tile provides indirect evidence of coordinated multi-impactor activation: the single-impactor output falls below the estimated dynamic fracture threshold while the combined output exceeds it. Further work is required to validate the trigger-efficiency model against measured trigger displacements, evaluate performance under real soil conditions, and quantify ergonomic benefits through user studies.</p> 2026-10-01T18:12:40Z Dataset Dataset 10.6084/m9.figshare.34050195.v1 https://figshare.com/articles/dataset/A_multi-impactor_mechanism_for_passive_force_amplification_in_hand_tools_Design_modelling_and_validation/34050195 CC BY 4.0