CRANE OVERLOAD SAFEGUARD (VERSIONS) Russian patent published in 2000 - IPC

FIELD: material handling facilities. SUBSTANCE: proposed overload safeguard has housing installed on crane boom. Housing accommodates bell crank with deflecting roller engaging with hoisting rope and balancing member. Lever carrying limit switch is installed in housing for longitudinal and vibratory displacement relative to point of support. This lever is mechanically coupled with mechanism changing hook outreach from crane axis and with member engaging with shaped plate secured in housing for adjustment of its position. Limit switch is installed for engagement with first bell crank through fitted-on pressure plate. According to first and second design versions, lever carrying limit switch mounted on one of its arm is made as bell crank and it is coupled by its other arm either with above-indicated mechanism, with indicated member being arranged in point of support, or with above indicated member, with coupling in point of support with lever secured in housing and mechanically with indicated mechanism. According to third design version, limit switch, together with indicated member, is installed on one end of lever whose other end is mechanically coupled with indicated mechanism. According to fourth design version, limit switch is installed in middle part of bell crank on one end of which indicated member is installed, other end being mechanically coupled with indicated mechanism. EFFECT: enhanced safety of crane. 5 cl, 7 dwg