Raise drilling machine

Claim 2

In a raise drilling rig for enlarging a hole in the earth by means of an upward cutting bit, the combination of: a base, a mast mounted on the base, a crown block on the mast, a travelling block within the mast, a cable rove between the blocks, a carriage suspended from the travelling block, means on the mast guiding the carriage for movement longitudinally of the mast, a drill string extending into the hole and carrying the upward cutting bit at its lower end, means including a power head on the carriage for suspending the drill string and for rotating it, the mast being proportioned to absorb the reaction torque of the power head as applied to the carriage and to transmit it to said base, a spooling drum on the base for winding said cable, and variable speed power means on the base for applying torque to the spooling drum at zero to very low r.p.m. to tension the cable, whereby the drill string may be simultaneously rotated and pulled upward to enlarge the hole.

Claim 3

The combination set forth in claim 1 in which the mast is mounted for angular adjustment on the base, for inclined drilling.

Claim 4

The combination set forth in claim 1 in which said guide means comprises a track within the mast engaged by rollers on the carriage.

Claim 5

The combination set forth in claim 1 in which the variable speed power means includes an alternating current slip clutch motor.

Claim 6

The combination set forth in claim 4 in which the power head also includes an alternating current slip clutch motor.

Claim 7

In a rotary rig for raise drilling, the combination of: a base, a mast mounted on the base, a crown block on the mast, a travelling block within the mast, a cable rove between the blocks, a carriage suspended from the travelling block, means on the mast guiding the carriage for movement longitudinally of the mast, a drill string extending below the base, means including a power head oN the carriage for suspending the drill string and for rotating it, the mast being proportioned to absorb the reaction torque of the power head as applied to the carriage and to transmit it to said base, a spooling drum on the base for winding said cable, power means on the base for driving the drum, said power means including a prime mover and high-capacity transmission connections operatively connecting the prime mover to drive the drum for hoisting the drill string, said power means also including means for applying torque to the drum from a stalled position to a very low r.p.m. for raise drilling, and brake means for impeding rotation of the drum, whereby the drill string may be rotated and permitted to descend by gravity to form a hole in the earth when the drill string is supplied with downward cutting bit, and whereby the drill string may be rotated and pulled upward to enlarge the hole when the drill string is supplied with an upward cutting bit larger than the first.

Claim 8

In a rotary rig for raise drilling, the combination of: a base, a mast mounted on the base, a crown block on the mast, a travelling block within the mast, a cable rove between the blocks, a carriage suspended from the travelling block, means on the mast guiding the carriage for movement longitudinally of the mast, a drill string extending below the base, means including a power head oN the carriage for suspending the drill string and for rotating it, the mast being proportioned to absorb the reaction torque of the power head as applied to the carriage and to transmit it to said base, a spooling drum on the base for winding said cable, power means on the base for driving the drum, said power means including a prime mover and high-capacity transmission connections operatively connecting the prime mover to drive the drum for hoisting the drill string, said power means also including means for applying torque to the drum from a stalled position to a very low r.p.m. for raise drilling, and brake means for impeding rotation of the drum, whereby the drill string may be rotated and permitted to descend by gravity to form a hole in the earth when the drill string is supplied with downward cutting bit, and whereby the drill string may be rotated and pulled upward to enlarge the hole when the drill string is supplied with an upward cutting bit larger than the first.

Claim 9

The combination set forth in claim 6 in which the mast is mounted for angular adjustment on the base, for inclined drilling.

Claim 10

The combination set forth in claim 6 in which said guide means comprises a track within the mast engaged by rollers on the carriage.

Claim 11

The combination set forth in claim 6 in which the means for applying torque to the drum from a stalled position to a very low r.p.m. comprises an electric motor.