Self compensating seal apparatus

A self compensating seal apparatus for forming a seal between two rotary members to seal the space between said members from an external environment, said seal apparatus comprising:

• (a) a first closed sealing means mounted in a first of said members along the periphery thereof;
• (b) a second closed sealing means mounted in a second of said members along the periphery thereof, said first and second sealing means being positioned opposite to and in contact with one another along a contact plane and forming a seal therebetween around the periphery of the space between said members;
• (c) spring biasing means, fixedly mounted in said first member, for producing a force on said first sealing means in a direction perpendicular to the contact plane such that said first sealing means is held in contact with said second sealing means, wherein said spring biasing means is displaced (radially) inwardly with respect to said first and second sealing means in the space between said members;
• and
• (d) third sealing means for sealing said spring biasing means and said space from the external environment.

In a rotary drill for drilling a well in the surface of the earth, said drill comprising:

• (a) a drill bit including an upper portion for connection to a drill string, duct means including a fluid outlet into the well for carrying fluid to extract detritus and clean the bottom of the well and receiving means;
• (b) a cutting head comprising a conical head portion and a unitary stem portion, said conical head portion including holes therein and cutting elements inserted in said holes, said stem portion being received in said receiving means of said drill bit, wherein said stem and said receiving means include holding means for rotatably holding said cutting head in said drill bit;
• (c) bearing means between said drill bit and said conical head;
• (d) a lubrication system interconnected between said drill bit and said cutting head;
• and
• (e) a seal device between said upper portion and said cutting head;
• the improvement wherein said seal device is an automatic wear compensating seal device comprising:
• (f) a first closed seal means mounted in said drill bit along the periphery thereof;
• (g) a second closed seal means mounted in said cutting head along the periphery thereof, said first and second seal means being positioned opposite to and in contact with one another along a contact plane and forming a seal therebetween, for sealing the internal space within said drill bit along the periphery thereof;
• (h) spring biasing means for biasing said first sealing means in a direction perpendicular to the contact plane to maintain the contact between said first and second seal means, wherein said spring biasing means is positioned inwardly with respect to said first and second seal means in said internal space;
• (i) coupling means for coupling said spring biasing means to said first sealing means and for transmitting the biasing force of said spring biasing means to said first sealing means;
• and
• (j) third seal means for sealing said spring biasing means from an external environment.