Pocket spring balance with hand-held support strap - eliminates helical spring torque effect by mounting spring on suspension piece with rotational freedom

摘要

The pocket spring balance has a hand-held support strap (3) joined to the top of its housing which contains a helical spring (1) supporting a load hook (4) protruding through the bottom of the housing (2) and connected to an indicator moving w.r.t. a scale. The balance is designed so that spring torque effects are eliminated. These can cause lateral displacement of the measurement indicator in conventional spring balances. An upper fitting (5) has a hole (16) formed in its top plate (9) through which passes a spring (1) suspension piece (17). The suspension piece rotates about its own axis on a bearing surface (18) on the outside of the top plate. The fitting (5) is box-shaped with sidewall holes for the hand support (3) ends which are pref. pinched after fitting.