PORTABLE RAIL DRILL Russian patent published in 2001 - IPC

FIELD: railway transport; mechanized track maintenance tools. SUBSTANCE: invention relates to portable tools for drilling and simultaneously strengthening holes for track bolts and rail bonds in bulk hardened rails type P50, P65, P75. Proposed drill has housing with drive of hollow spindle with tool. Drive has gear-type rotation transmission mechanism and two-step gear-and-cam spindle feed mechanism. Portable drill has also rail stop- grip with hold-down and replaceable contact members - templates whose outlines from opposite sides correspond to outlines of different rails and which are made for contact with rail feet and heads from side of spindle. Drive input shaft is provided with input gear wheel. Rotation transmission gear-type mechanism has idle train. One end of drive input shaft rests of bearing in housing and other end, provided with thread, is turned into threaded hole on end face of drive motor shaft. Rotation transmission mechanism input and output cylindrical gears of first step are made with pitch circle diameters d_w3 and d_w1 proportional to motor shaft speed n_m(rpm) in the following ratio: d_w3/d_w1= n_m(440-560). Output gear wheel of first step of two-step spindle feed mechanical installed on drive intermediate shaft is connected with adjustable safety clutch. Output and input cylindrical gears of second step of two-step spindle feed mechanism are made with pitch circle diameters d_w5 and d_w4 proportional to motor shaft speed n_m, spindle travel H (mm) and pitch circle diameters of d_w1 and d_w2 of input gear wheel and output gear wheel, respectively, of first step of spindle feed mechanism in ratio d_w5/d_w4= n_m(440-560). EFFECT: improved efficiency of operation owing to increase of fatigue range of rail metal in zone of drilled hole. 19 dwg