central section is designated by number 30 f and the arms are 39 a through 30 d the arms are welded to tubular housing 39 in which they are located as shown in fig3 and also fig3 a pins 36 a through 36 d are mounted in the wall of the housing and support pinions 28 a through 28 d for rotation as shown in fig3 fig3 a is the vertical section through fig3 taken along line 3 a u2014 3 a in fig3 consequently the pinion on pin 36 a is not shown as explained above drilling fluid will be pumped down through the center of mandrel 22 and when the fluid reaches the lower end of tube 22 the fluid will exit through large port 26 b and provide drilling fluid under pressure to the moyno pump 12 to rotate bit 10 that is connected to the lower end of the apparatus portions of the fluid in mandrel 22 will be diverted through smaller outlets 26 a and 26 c as explained above this fluid will flow through opening 26 b into the moyno pump to provide the force necessary to rotate motor shaft 16 of the moyno pump and bit 10 torque tube or mandrel 22 has opening 22 a as shown in fig2 a and c through which drilling fluid being pumped down the drill pipe into the motor will flow and exert a downward force on piston 60 causing the piston to move downwardly against spring 61 so that rachet teeth 62 that engage rachet teeth 63 on cutting arms 64 and 65 will rotate the cutting arms outwardly to a lateral position relative to the longitudinal axis of.