Patent ID: 7308953

Claim:
A mobile drilling rig comprising: a. a mast comprising an upper end and a lower end; b. a driller's side substructure comprising a first mast starting section; a driller's floor side box connected to the first mast starting section; a first driller's elevating leg; a second driller's elevating leg, wherein the first and second driller's elevating legs engage the driller's floor side box; a driller's subbase side box engaging the first and second driller's elevating legs; and a driller's raising cylinder engaging the driller's subbase side box; c. an off-driller's side substructure comprising a second mast starting section; an off-driller's floor side box connected to the second mast starting section; a first off-driller's elevating leg; a second off-driller's elevating leg, wherein the first and second driller's elevating legs engage the off-driller's floor side box; an off-driller's subbase side box engaging the first and second off-driller's elevating legs; and an off-driller's raising cylinder engaging the off-driller's subbase side box; wherein the lower end engages the first mast starting section and the second mast starting section; a first guide independently formed into the first starting mast section and a second guide formed into the second starting mast section; wherein the driller's raising cylinder follows the first guide and engages a first shoe independently formed into the first mast section when the first starting mast section is in a substantially vertical orientation; the off-driller's raising cylinder follows the second guide and engages a second shoe formed in the second mast section when the first mast starting section and second mast starting section are in a substantially vertical orientation; and wherein when the driller's raising cylinder is engaged with the first shoe the driller's raising cylinder raises the driller's side substructure and when the off driller's raising cylinder is engaged with the second shoe the off-driller's raising cylinder lifts the driller's side substructure.