Hole Saw with Open End Cap Geometry

Abstract

A tool, such as a hole saw, including an open end cap geometry is provided. The end cap includes spokes extending between a hub and a rim. A plurality of openings are defined between the spokes, hub and rim. The area of the openings is substantially large relative to the area of the end cap such that the end cap is relatively lightweight and provides access into the hole saw for debris removal. The spokes are shaped and positioned to provide strength to the end cap.

What is claimed is: 
     
         1 . A hole saw comprising:
 a cylindrical body having a first edge located at a first end of the cylindrical body and a second edge located at a second end opposite the first end;   cutting teeth extending from the first end of the cylindrical body;   an end cap coupled to the second end of the cylindrical body, the end cap including a hub, the end cap including a plurality of end cap openings located radially between the hub and an outer perimeter edge of the end cap, wherein the plurality of end cap openings occupy a relatively large portion of the area of the end cap, the relatively large portion being at least 10% of the area bounded by the outer perimeter edge of the end cap; and   an arbor configured to couple the hole saw to a driving tool, the arbor coupled to the hub and extending outward from the end cap in a direction opposite from the cutting teeth.   
     
     
         2 . The hole saw of  claim 1 , wherein the relatively large portion of the area of the end cap occupied by the plurality of end cap openings is at least 50% of the area bounded by the outer perimeter edge of the end cap. 
     
     
         3 . The hole saw of  claim 1 , wherein the first end of the cylindrical body is a cutting end and the cutting teeth extend completely around the first edge of the cylindrical body, and the hub is a central hub positioned such that a center point of the area bounded by the outer perimeter edge of the end cap is located within the central hub. 
     
     
         4 . The hole saw of  claim 3 , wherein the central hub includes at least one coupling opening configured to receive a portion of the arbor to couple the arbor to the hub, wherein the plurality of end cap openings are located radially between the coupling opening of the hub and the outer perimeter edge of the end cap. 
     
     
         5 . The hole saw of  claim 4 , wherein the area of the end cap occupied by the plurality of end cap openings is at least five times the area occupied by the at least one coupling opening. 
     
     
         6 . The hole saw of  claim 3 , further comprising a plurality of spokes extending radially outward from the central hub toward the outer perimeter edge of the end cap, wherein each one of the plurality of end cap openings is defined between an adjacent pair of spokes. 
     
     
         7 . The hole saw of  claim 6 , wherein each of the spokes has a maximum width dimension measured in the circumferential direction and each of the plurality of end cap openings has a maximum width dimension measured in the circumferential direction, wherein the maximum width dimension of each end cap opening is larger than the maximum width dimensions of either the spokes adjacent to the end cap opening. 
     
     
         8 . The hole saw of  claim 7 , wherein each of the spokes has a concave clockwise-facing surface and a convex counterclockwise-facing surface. 
     
     
         9 . The hole saw of  claim 6 , wherein the plurality of spokes is at least four spokes, and the plurality of end cap openings is at least four end cap openings. 
     
     
         10 . The hole saw of  claim 9 , wherein at least two of the at least four end cap openings are smaller than the remaining end cap openings. 
     
     
         11 . The hole saw of  claim 6 , wherein each of the spokes has clockwise facing surface and a counterclockwise facing surface, wherein a length in the radial direction of at least one of the clockwise facing surface and the counterclockwise facing surface of each spoke is greater than 50% of a radius of the end cap. 
     
     
         12 . The hole saw of  claim 1 , wherein the ratio of the area of the plurality of end cap openings to the area of solid portions of the end cap is between 0.15 and 2. 
     
     
         13 . A hole saw comprising:
 a cylindrical body having a first edge located at a first end of the cylindrical body and a second edge located at a second end opposite the first end;   cutting teeth extending from the first end of the body; and   an end cap coupled to the second end of the body, the end cap comprising:
 a central hub; 
 an outer perimeter edge coupled to the second edge of the cylindrical body; 
 at least four spokes extending radially outward from the central hub toward the outer perimeter edge; and 
 a plurality of openings defined within the end cap, each of the plurality of openings located between an adjacent pair of spokes. 
   
     
     
         14 . The hole saw of  claim 13 , wherein the plurality of openings occupy at least 50% of the area of the end cap. 
     
     
         15 . The hole saw of  claim 13 , wherein the ratio of the area of the openings to the area of solid portions of the end cap is between 0.15 and 2. 
     
     
         16 . The hole saw of  claim 13 , wherein each of the at least four spokes has a clockwise facing surface and a counterclockwise facing surface, wherein a length in the radial direction of at least one of the clockwise facing surface and a counterclockwise facing surface of each spoke is greater than 50% of a radius of the end cap. 
     
     
         17 . The hole saw of  claim 16 , wherein the clockwise-facing surface of each spoke includes a concave portion and the counterclockwise-facing surface of each spoke includes a convex portion. 
     
     
         18 . The hole saw of  claim 17 , wherein two of the plurality of openings are smaller than at least two other of the plurality of openings. 
     
     
         19 . The hole saw of  claim 13 , wherein the plurality of openings occupy between 20% and 70% of the area of the end cap. 
     
     
         20 . A reduced-weight hole saw comprising:
 a body having a first end and a second end opposite the first end;   cutting teeth extending from the first end of the body;   an end cap coupled to the second end of the body and having an outer edge surrounded by and coupled to the second end of the body; and   an open area defined in the end cap, the open area extending between upper and lower surfaces of the end cap such that access through the end cap to an interior of the body is provided by the open area;   wherein the open area has a first area and the upper surface of the end cap has a second area, wherein the first area is between 20% and 70% of the second area.