Auxiliary drive motor for building material mixer drum - operates only when measured main motor output is inadequate

摘要

A mixer drum (2) for building materials and additions such as water has generally equivalent sets of mixer tools (3,4) projecting drum end walls to engage journals (7,8) connected by transmision elements to a pair of electric motors (11,12). One motor (e.g. 1) is the main motor since it operates permanently while the second motor (12) operates as auxiliary drive during starting, after admission of fresh additives etc. The main motor (11) is coupled to a transducer (13) which measures its applied force. Should this drop below a set minimum no longer effective for sole drive of the mixer, a signal generator (14) emits a signal causing the auxiliary motor to share the drive. The shaft driven by the auxiliary motor incorporates a free-wheel unit (16). ADVANTAGE - Avoidance of unnecessary power consumption makes operation cheaper and quieter, with total mixer life prolonged.