Patent ID: 8172002

Claim:
A method of controlling a plurality of hydraulic motors, comprising: operating a second motor in series with a first motor by: providing fluid from an outlet of a pump to a first motor to drive the first motor, directing the fluid from an outlet of the first motor to the second motor to drive the second motor; and selectively switching the second motor from operating in series with the first motor to operating in parallel with the first motor by: blocking the fluid from the outlet of the first motor from driving the second motor, directing a first portion of fluid from the outlet of the pump to the first motor to drive the first motor, and directing a second portion of fluid from the outlet of the pump to the second motor to drive the second motor; wherein: the first motor is operatively associated with a drill head such that driving the first motor rotates a drive shaft of the drill head, and the second motor is operatively associated with the drill head such that driving the second motor rotates the drive shaft of the drill head.