Back plate
FIG. 1 is a front elevational view of a back plate embodying my new design; 
     FIG. 2 is a side elevational view thereof; 
     FIG. 3 is a top plan view thereof; 
     FIG. 4 is a bottom plan view thereof. 
     FIG. 5 is a sectional view through FIG. 1 on the plane of the line 5--5.