Patent ID: 7389833
Filing Date: 2008-06-24
Classification: E21B

Abstract:
1. A method of coupling a shank with a drill bit to create a drill bit assembly that separates the application of force to separate parts of the drill bit assembly comprising: a. providing a shank having: a shank passage having a shank passage area; a shank percussive force member; and a shank complementary lug or pocket structure; the shank percussive force member and the shank complementary lug or pocket structure are independent from each other; b. providing a bit having: a bit passage having a bit passage area; a bit percussive force member; and a bit complementary lug or pocket structure; the bit percussive force member and the bit complementary lug or pocket structure are independent from each other; c. providing a retaining member having a retaining member area that is less than the shank passage area and the bit passage area; d. engaging the shank with the bit; e. engaging the shank complementary lug or pocket structure with the bit complementary lug or pocket structure; so that when the bit assembly is rotating, rotational forces are applied to the shank complementary lug or pocket structure and the bit complementary lug or pocket structure and not on the retaining member or the shank percussive force member or the bit percussive force member; f. inserting the retaining member through aligned passages of the shank and bit so that when the bit assembly is being extracted, extraction force is applied to the shank passage, the bit passage and the retaining member and not to the shank percussive force member or the bit percussive force member or the shank complementary lug or pocket structure or the bit complementary lug or pocket structure; and g. engaging the shank percussive force member and the bit percussive force member so that when the bit assembly is being impacted upon by percussive force, the percussive force is applied to the shank percussive force member and the bit percussive force member and not on the respective complementary lug or pocket structures of the shank and bit and not on the retaining member.