Dust control cutting assembly for cutting sheet material

Claim 2

A circular saw including a horizontally extending flat base having a front end and a back end, a circular saw blade, means for supporting said blade partially above and partially below said base in a predetermined vertical plane, means for rotating said blade in a direction which causes the outer edge of said blade to rotate up at the front end of said base and down at the back end of said base, a top blade guard fixedly located relative to and around a top outer edge portion of said blade and having a front end vertically spaced above the front end of said base, and a bottom blade guard located around a bottom outer edge portion of said blade and movable towards and around the back end of said base, the improvement comprising: a. a shroud having a substantially U-shaped cross section and being positioned around an outer edge portion of said blade between said front end of said top blade guard and the front end of said base, said shroud having one end substantially vacuum seal connected with said front end of said top blade guard, an opposite end substantially vacuum seal connected with the front end of said base and an opening extending through said shroud; and b. a main suction conveyance tube having one open end adapted for connection with suction producing means and the other open end vacuum seal conected with said shroud around said opening through said shroud, said other open end defining a suction tube opening located approximately in the plane of and in front of said saw blade adjacent said base and said blade.

Claim 3

The improvement of claim 1 wherein said suction tube opening is approximately located on a line which is tangent to said blade and which passes through the forwardmost intersection of said blade and said base.

Claim 4

The improvement of claim 1 wherein said suction tube opening is square in configuration, each side of said square being between approximately 5/8 and 6/8 in length.

Claim 5

The improvement according to claim 3 wherein an end segment of said tube including said suction tube opening extends out and up from the opening in said shroud in a curvilinear fashion.

Claim 6

The improvement according to claim 1 including a secondary suction conveyance tube having one open end adapted for connection with suction producing means and the other open end vacuum seal connected with said top blade guard around an opening through said top blade guard, said other open end of said secondary tube defining a secondary suction tube opening located approximately in the plane of said saw blade adjacent said top blade guard and forwardly of a vertical plane which is normal to said saw blade plane and which passes through the center of said blade.

Claim 7

The improvement oF claim 5 wherein said secondary suction tube opening is located in a plane which is normal to said blade plane and which passes through the center of said blade, said last-mentioned plane being at approximately a 30*angle with said vertical plane.

Claim 8

The improvement according to claim 6 wherein said secondary suction tube is square in configuration, each side of said square being between approximately 5/8 and 6/8 in length.

Claim 9

An assembly for cutting sheet material, comprising: a. a circular saw including a horizonally extending flalt base having a front end and a back end and under and against which said sheet material is adapted to pass for cutting said material, a circular saw blade means for supporting said blade partially above and partially below said base in a predetermined vertical plane, means for rotating said blade in a direction which causes the outer edge of said blade to rotate up at the front end of said base and down at the back end of said base, a top blade guard fixedly located around a top outer edge portion of said blade and having a front end vertically spaced above the front end of said base, said top blade guard having an opening extending therethrough, a bottom blade guard located around a bottom outer edge portion of said blade and movable towards and around the back end of said base, a shroud having a substantially U-shaped cross section and being positioned around an outer edge portion of said blade between said front end of said top blade guard and the front end of said base, said shroud having one end substantially vacuum seal connected with said front end of said top blade guard, an opposite end substantially vacuum seal connected with the front end of said base and an opening extending through said shroud, a main suction conveyance tube having one open end adapted for connection with suction producing means and the other open end vacuum seal connected with said shroud around said opening through said shroud, said other open end defining a main suction tube opening located in the plane of and in front of said saw blade on a line which is tangent to the outer edge of said blade and which pases through the forwardmost intersection of said blade and said base, and a secondary suction conveyance tube having one open end adapted for connection with said suction producing means and the other open end vacuum seal connected with said top blade guard around said opening through said top blade guard, said other open end of said secondary tube defining a secondary suction tube opening located in the plane of said saw blade adjacent said top blade guard and approximately 30*forwardly of a vertical plane which is normal to said saw plane and which passes through the center of said blade, each of said main and secondary openings being square, each side of said square being between approximately 5/8 and 6/8 in length; b. suction producing means connected with said one end of said main tube and with said one end of said secondary tube, said suction producing means providing sufficient suction to produce between approximately 2.50 and 3.00 in. hg. suction pressure at each of said suction openings, whereby to cause dust which is produced from cutting said sheet material and which is located at the front end of said base to pass into said suction tube openings and through said suction conveyance tubes; and c. means for preventing dust produced from cutting said sheet material at the back end of said base from passing into the ambient surroundings.

Claim 10

An assembly for cutting sheet material, comprising: a. a circular saw including a horizonally extending flalt base having a front end and a back end and under and against which said sheet material is adapted to pass for cutting said material, a circular saw blade means for supporting said blade partially above and partially below said base in a predetermined vertical plane, means for rotating said blade in a direction which causes the outer edge of said blade to rotate up at the front end of said base and down at the back end of said base, a top blade guard fixedly located around a top outer edge portion of said blade and having a front end vertically spaced above the front end of said base, said top blade guard having an opening extending therethrough, a bottom blade guard located around a bottom outer edge portion of said blade and movable towards and around the back end of said base, a shroud having a substantially U-shaped cross section and being positioned around an outer edge portion of said blade between said front end of said top blade guard and the front end of said base, said shroud having one end substantially vacuum seal connected with said front end of said top blade guard, an opposite end substantially vacuum seal connected with the front end of said base and an opening extending through said shroud, a main suction conveyance tube having one open end adapted for connection with suction producing means and the other open end vacuum seal connected with said shroud around said opening through said shroud, said other open end defining a main suction tube opening located in the plane of and in front of said saw blade on a line which is tangent to the outer edge of said blade and which pases through the forwardmost intersection of said blade and said base, and a secondary suction conveyance tube having one open end adapted for connection with said suction producing means and the other open end vacuum seal connected with said top blade guard around said opening through said top blade guard, said other open end of said secondary tube defining a secondary suction tube opening located in the plane of said saw blade adjacent said top blade guard and approximately 30*forwardly of a vertical plane which is normal to said saw plane and which passes through the center of said blade, each of said main and secondary openings being square, each side of said square being between approximately 5/8 and 6/8 in length; b. suction producing means connected with said one end of said main tube and with said one end of said secondary tube, said suction producing means providing sufficient suction to produce between approximately 2.50 and 3.00 in. hg. suction pressure at each of said suction openings, whereby to cause dust which is produced from cutting said sheet material and which is located at the front end of said base to pass into said suction tube openings and through said suction conveyance tubes; and c. means for preventing dust produced from cutting said sheet material at the back end of said base from passing into the ambient surroundings.

Claim 11

An assembly according to claim 8 wherein said dust preventing means includes a solid sheet of material adapted to support the sheet of material to be cut, said support sheet being sufficiently thick so that said saw blade does not cut completely therethrough when cutting said sheet to be cut.

Claim 12

An assembly according to claim 9 wherein said dust preventing means includes a support having a horizontally extending circumferential top edge tO support the sheet material to be cut, means for vacuum sealing said sheet material to said top surface, a bottom surface, sidewall means, a flat bottom surface tapering down from one segment of said top edge to said side wall means directly below an opposite end segment of said top edge, said top edge, side wall means and bottom surface and said sheet material together defining a vacuum sealed compartment, and means for drawing out air and any dust within said compartment at a point directly below said opposite end segment.

Claim 13

An assembly according to claim 8 wherein said sheet material to be cut is hollow and opened at opposite ends, said assembly including first means for vacuum sealing one open end of said sheet material, second means for vacuum sealing the opposite open end of said material and means for drawing out any air and dust within said sheet material through said second means at a corner of said sheet material.