Dome mine roof plate

Abstract

A roof plate having a planar peripheral portion surrounding a dome. The dome portion defines an opening formed in a central portion therein and a tubular wall.

1 . A roof plate comprising:
 a generally planar peripheral portion having an engaging surface adapted to engage a mining structure,   a dome surrounded by the peripheral portion, the dome defining a generally round opening therein, the opening defining a generally in-turned portion which defines a generally tubular wall and the dome having an apex on a rim of the opening;   wherein a ratio of a distance across the rim to a distance from the engaging surface to the apex of the dome is within the range of from about 0.5 to about 1.5.   
     
     
         2 . The roof plate of  claim 1  further comprising a shoulder on an inner surface of the dome. 
     
     
         3 . The roof plate of  claim 2  wherein the generally tubular wall and the generally planar peripheral portion are generally perpendicular to each other. 
     
     
         4 . The roof plate of  claim 1  wherein the rim includes a generally rounded apex. 
     
     
         5 . The roof plate of  claim 4  wherein the generally tubular wall has a thickness and the generally planar peripheral portion has a thickness and the thickness of the generally tubular wall is within the range of from about seventy percent to about eighty percent of the thickness of the generally planar peripheral portion. 
     
     
         6 . The roof plate of  claim 1  wherein the opening is located in about the center of the dome. 
     
     
         7 . The roof plate of  claim 1  wherein the ratio of the distance across the rim to the distance from the apex on the rim of the opening to a terminus of the tubular wall is within the range of from about 1.8 to about 6.5 
     
     
         8 . The roof plate of  claim 7  wherein the generally tubular wall has a thickness and the generally planar peripheral portion has a thickness and the thickness of the generally tubular wall is within the range of from about seventy percent to about eighty percent of the thickness of the generally planar peripheral portion. 
     
     
         9 . The roof plate of  claim 7  wherein the roof plate is generally square. 
     
     
         10 . A roof plate comprising:
 a generally planar peripheral portion having an engaging surface adapted to engage a mining structure,   a dome surrounded by the peripheral portion, the dome defining a generally round opening therein, the opening defining a generally in-turned portion which defines a generally tubular wall and the dome having an apex on a rim of the opening;   wherein the ratio of the distance across the rim to the distance from the apex on the rim of the opening to a terminus of the tubular wall is within the range of from about 1.8 to about 6.5.   
     
     
         11 . The roof plate of  claim 10  further comprising a shoulder on an inner surface of the dome. 
     
     
         12 . The roof plate of  claim 12  wherein the generally tubular wall and generally planar peripheral portion are generally perpendicular. 
     
     
         13 . The roof plate of  claim 10  wherein the rim includes a generally rounded apex. 
     
     
         14 . The roof plate of  claim 10  wherein the generally tubular wall has a thickness and the generally planar peripheral portion has a thickness and the thickness of the generally tubular wall is within the range of from about seventy percent to about eighty percent of the thickness of the generally planar peripheral portion. 
     
     
         15 . A roof plate comprising:
 a generally planar peripheral portion having an engaging surface adapted to engage a mining structure,   a dome surrounded by the peripheral portion, the dome defining a generally round opening therein, the opening defining a generally in-turned portion which defines a generally tubular wall and the dome having an apex on a rim of the opening;   wherein the ratio of the distance across the rim to the distance from a shoulder on an inner surface of the dome to a terminus of the tubular wall is within the range of from about 2.6 to about 13.   
     
     
         16 . The roof plate of  claim 15  wherein the generally tubular wall and generally planar peripheral portion are generally perpendicular. 
     
     
         17 . The roof plate of  claim 15  wherein the rim includes a generally rounded apex. 
     
     
         18 . The roof plate of  claim 15  wherein the generally tubular wall has a thickness and the generally planar peripheral portion has a thickness and the thickness of the generally tubular wall is within the range of from about seventy percent to about eighty percent of the thickness of the generally planar peripheral portion. 
     
     
         19 . The roof plate of  claim 15  wherein the opening is located in about the center of the dome. 
     
     
         20 . The roof plate of  claim 19  wherein the roof plate is generally square.