Dome headed roof bolt

Abstract

A new bolt head design is disclosed and claimed. The bolt head has a radius between the shaft and the first side of a washer which spreads the shaft load more evenly to the washer. A concave dome is located between the second side of the washer and the driver of the head. These elements more evenly distribute the load, increase the bolt head strength and help prevent the washer, shaft and washer driver interfaces from failing when the bolt is loaded either in a linear or non-linear fashion.

1 . A bolt for attaching plates to the interior of excavations, the bolt comprising:
 a shaft, the shaft having a shaft end and the opposite end of the shaft terminating in an annular radius, the radius attached to a first side of a washer, a second side of the washer attached to a dome, the dome extending in a concave manner away from the washer, the dome attached to a driver, the driver having a hole and the hole having a surface and indicia located on the surface.   
   
   
       2 . The bolt of  claim 1 , further comprising:
 ribs extending along the shaft from near the radius to near the shaft end.   
   
   
       3 . The bolt of  claim 1 , further comprising:
 threads located on the shaft between the radius and the shaft end.   
   
   
       4 . A bolt for attaching plates to the interior of an excavation, the bolt comprising:
 a driver, the driver attached to a concave shaped dome, a hole in a head end of the driver, the hole terminating in a surface, indicia located on the surface;   a washer, the washer having a first side and a second side;   the dome terminating at the second side of the washer, the first side of the washer attached to an annular radius having a diameter less than that of the washer;   the radius joining the first side of the washer to a shaft, the shaft terminating in a shaft end; and   a plurality of ribs extending along the shaft from near the radius to near the shaft end.   
   
   
       5 . The bolt of  claim 4 , further comprising:
 the ribs replaced by threads located between the radius and the shaft end.   
   
   
       6 . A head for a bolt, the head comprising:
 a driver, the driver having a hole with a surface, indicia located on the surface;   the driver attached to a dome, the dome having a concave shape and extending towards the driver from a second side of a washer, the washer having a first side, the first side adjacent to an annular radius, the radius joined to a shaft, the shaft having a shaft end; and   whereby the radius provides a transition from the diameter of the shaft to the first side of the washer.   
   
   
       7 . The bolt of  claim 6 , further comprising:
 ribs extending along the shaft from near the radius to near the shaft end.   
   
   
       8 . The bolt of  claim 7 , further comprising:
 threads located on the shaft between the radius and the shaft end.   
   
   
       9 . A dome headed bolt for roof bolts, the bolt comprising:
 a driver on one end of the bolt, the driver adjacent to a dome which extends in a concave manner from a washer towards the driver, the dome terminating in a diameter that matches the diameter of a second side of the washer, the washer having a first side, an annular radius attached to the first side of the washer, the annular radius attached to a shaft and the shaft having a shaft end and ribs located on the shaft from the radius to the shaft end.   
   
   
       10 . The dome headed roof bolt of  claim 9 , further comprising:
 the driver having a hole with a surface and indicia on the surface.   
   
   
       11 . The dome headed roof bolt of  claim 9 , further comprising:
 the ribs replaced by threads.   
   
   
       12 . The dome headed roof bolt of  claim 9 , further comprising:
 the shaft surface is smooth with no ribs.