Saw blade guard

• US 4,576,073 A
• Filed: 07/01/1983
• Issued: 03/18/1986
• Est. Priority Date: 07/01/1983
• Status: Expired due to Fees

• Current Assignee: Robert J. Stinson
• Original Assignee: Robert J. Stinson
• Inventors: Stinson, Robert J.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Knoble, John L.
• Application Number:
  US06/509,918
• Time in Patent Office: 991 Days
• Field of Search: 83/478, 83/544-546, 83/698-700, 83/477.2, 83/102.1, 83/481
• US Class Current: 83/102.1
• CPC Class Codes: B27G 19/02 for circular saws
• CPC Class Codes: Y10T 83/2077 By kerf entering guide
• CPC Class Codes: Y10T 83/7734 With guard for tool
• CPC Class Codes: Y10T 83/872 With guard means

Abstract

A saw blade guard for a table saw or the like includes a flat blade guard arm which is coplanar with the circular cutting blade and has a thickness no greater than that of the blade. The guard includes a yoke portion mounted on a bearing on the blade arbor below the table such that the yoke is allowed to rotate independently of the rotation of the arbor. The guard arm is semicircular in shape and extends through the kerf in the workpiece produced by the saw blade and down through the blade slot in the table to a point adjacent the yoke. The yoke includes a radially radial extension which supports the arm below the table. A roller mounted on the outer free extremity of the guard arm above the table is engaged by the leading edge of the workpiece and forces the arm to rotate a sufficient amount to expose the workpiece to the blade. A counterweight mounted on the yoke below the table biases the guard arm to normally rotate into covering relationship to the blade such that the roller bears against the workpiece at all times.

Claims

1. For use with a saw of the type including a circular cutting blade mounted for rotation with a motor driven arbor and a flat workpiece support surface having an opening therein through which a portion of the blade extends, a guard for the blade comprising:

a blade guard arm having a thickness no greater than the thickness of the blade whereby said arm may pass through a cut in a workpiece made by the blade, said arm extending through the support surface opening rearwardly of the blade and extending therefrom in curvilinear fashion over the blade to dispose the free leading end of said arm adjacent the support surface at the front of the blade so as to protectively cover the entire cutting edge of the blade portion;

means for mounting said arm on the saw for yieldable pivotal movement relative to said support surface about the rotational axis of the blade in response to engagement of said leading end thereof with a workpiece so as to expose a section of the blade portion to the leading edge of the approaching workpiece and allow cutting of the workpiece by the blade; and

means biasing said arm for pivotal movement about said blade axis in the direction of blade rotation so as to maintain said leading end of said arm adjacent the support surface at the front of the blade and maintain said arm in protectively covering relation to the entire cutting edge of the blade portion subject to selective and limited yieldable displacement by the leading edge of the approaching workpiece;

said mounting means including a first member mounted on said arbor for rotation with said arbor and a second member rotatably mounted on said first member whereby to rotate independently of the rotation of said arbor, said second member including a portion extending radially outward from said first member, said arm being secured to the outer extremity of said radially extending portion.

2. The guard of claim 1, wherein said biasing means includes means for generating sliding friction between said first and second members.

3. The guard of claim 1, wherein said biasing means includes a magnet connected with said second member and closely spaced from said blade, said magnet generating a magnetic field resulting in attractive forces between said magnet and said blade.

4. The guard of claim 1, including a bearing between said first and second members.

5. Apparatus for guarding the blade of a table saw, said table saw including a motor driven, rotatable arbor, a tooth circular saw blade mounted on said arbor for rotation with said arbor and a table having a support surface upon which a workpiece may be supported during sawing thereof, said support surface including a slot therein through which a portion of said blade extends above said support surface, comprising:

a first member mounted on said arbor for rotation with said arbor;

a second member rotatably mounted on said first member, said second member including a radial extension and an arcuately shaped flat guard arm, having a thickness no greater than the thickness of the blade and disposed coplanar with the blade, connected to said radial extension and extending upwardly therefrom through said slot above said support surface rearwardly of the blade and extending forwardly therefrom in curvilinear fashion over and in closely spaced relation to the teeth of the blade to dispose the free leading end of said arm adjacent the support surface at the front of the blade; and

means biasing said second member for rotation on said first member in the direction of rotation of the blade so as to bias said arm for pivotal movement about the arbor axis to maintain the leading end of said arm adjacent the support surface at the front of the blade and maintain said arm in protectively covering relation to the entire cutting edge of the blade portion subject to selective and limited yieldable displacement by the leading edge of the approaching workpiece.

6. The blade guard apparatus of claim 5, wherein said biasing means includes means for generating sliding friction between said first and second members.

7. The blade guard apparatus of claim 5, wherein said biasing means includes means for creating magnetic attraction between said second member and said blade.

8. The blade guard apparatus of claim 5, including a roller bearing between said first and second members.

9. The blade guard apparatus of claim 5 including a roller on the free end of said arm yieldably engaging a workpiece.

10. In a table saw of the type including a table on which a workpiece to be sawed is supported and including a slot therein through which the cutting edge of a saw blade may extend above said table, a motor driven rotatable arbor below said table, and a circular saw blade mounted for rotation on said arbor;

a guard for covering said cutting edge of said blade comprising;

a guard arm lying in the plane of said saw blade, having a thickness no greater than the thickness of said saw blade, having an arcuate inner edge closely spaced from the circular cutting edge of said saw blade so as to protectively cover said cutting edge above said table, and extending downwardly through said slot at the rear of the blade beneath said table;

a yoke including a first portion mounted on said arbor for rotation independent of the rotation of said arbor and a second portion connecting the rear end of said guard arm with said first portion; and

means coupled with said yoke for normally biasing said yoke for rotation about said arbor in the direction of blade rotation so as to bias said arm for pivotal movement about said arbor to maintain the free leading end of said arm adjacent the support surface at the front of the blade and maintain said arm in protectively covering relation to the entire cutting edge of the blade portion subject to selective and limited yieldable displacement by the leading edge of the approaching workpiece.

11. The guard of claim 10, wherein said yoke includes a substantially flat plate and said second portion includes a member which extends radially from said arbor.

12. The guard of claim 10, including a roller on the free end of said guard arm for yieldably engaging a workpiece.

13. In combination:

(A) an arbor adapted to be a power source;

(B) a circular saw blade fixedly secured to said arbor for rotation therewith upon actuation of the power source; and

(C) a blade guard assembly including;

(1) a mounting portion journalled for rotation on said arbor, adjacent said saw blade,

(2) a flat guard arm portion rigidly joined to said mounting portion, lying in the plane of said saw blade, having a thickness no greater than the thickness of said saw blade, and having an arcuate inner edge closely spaced from the circular cutting edge of said saw blade and concentric with the axis of said arbor, and

(3) counterweight means secured to said mounting portion in a position radially offset from said arbor axis.

14. For use with a saw of the type including a circular cutting blade mounted for rotation on a motor driven arbor and a flat workpiece support surface having an opening therein through which a portion of the blade extends, a guard for the blade comprising:

a blade guard arm having a thickness no greater than the thickness of said blade whereby said arm may pass through a cut in a workpiece made by said blade, said arm extending through said opening and protectively covering the entire cutting edge of said blade portion;

means for mounting said arm on said saw for yieldable pivotal movement relative to said support surface in response to engagement with a workpiece whereby to expose a section of said blade portion to the workpiece and allow cutting of the workpiece by said blade;

said mounting means including a first member mounted on said arbor for rotation with said arbor and a second member rotatably mounted on said first member to rotate independently of the rotation of said arbor, said second member including a portion extending radially outward from said first member, said arm being secured to the outer extremity of said radially extending portion;

said guard further including means for normally biasing said arm to rotate in the direction of rotation of said blade to maintain said arm in protectively covering relationship over said blade; and

said biasing means including a counter weight secured to said second member.

15. Apparatus for guarding the blade of a table saw, said table saw including a motor driven, rotatable arbor, a toothed circular saw blade mounted on said arbor for rotation with said arbor and a table having a support surface upon which a workpiece may be supported during sawing thereof, said support surface including a slot therein through which a portion of said blade extends above said support surface, comprising:

a first member mounted on said arbor for rotation with said arbor;

a second member rotatably mounted on said first member, said second member including a radial extension and an arcuately shaped guard arm connected to said radial extension and extending through said slot above said support surface, said guard arm covering and being closely spaced from the teeth of said blade along said blade portion;

said blade guard further including means for normally biasing said second member to rotate relative to said arbor in a direction which maintains said arm in covering relationship over said blade portion; and

said biasing means including a counterweight connected to said second member.

16. Apparatus for guarding the blade of a table saw, said table saw including a motor driven, rotatable arbor, a toothed circular saw blade mounted on said arbor for rotation with said arbor and a table having a support surface upon which a workpiece may be supported during sawing thereof, said support surface including a slot therein through which a portion of said blade extends above said support surface, comprising:

a first member mounted on said arbor for rotation with said arbor;

a second member rotatably mounted on said first member, said second member including a radial extension and an arcuately shaped guard arm connected to said radial extension and extending through said slot above said support surface, said guard arm covering and being closely spaced from the teeth of said blade along said blade portion;

said blade guard further including an insert removably mounted on said table and having an upper surface substantially coplanar with said support surface, said slot being defined in said upper surface of said insert, said slot including a recess in one side thereof defining an opening in said insert which is wider than said slot; and

said arm including means on one end thereof for engaging said workpiece and having a thickness greater than the thickness of said blade, said engaging means being insertable through said recess during installation and removal of said first and second members on said arbor.