نمایش نتیجه 1 تا 2 از 2 نتیجه یافت شده برای crown saver:
n: a device mounted near the drawworks drum to keep the driller from inadvertently raising the travelling block into the crown block. A probe senses when too much line has been pulled onto the drum, indicating that the travel block is about to strike the crown. The probe activates a switch that simultaneously disconnects the drawworks from its power source and engages the drawworks brake.
a device that keeps the traveling block from being raised ito the crown block.
n: see crown saver:
© ۱۳۹۲-۱۳۹۷ این اثر شامل قانون حمایت از مولفین بوده و هرگونه کپی برداری از آن ممنوع است.
