Anti-kickback system
First Claim
1. For use with a table saw of the type having a table top for supporting a workpiece and a motor-driven circular saw blade, an anti-kickback system comprising:
- splitter means adapted to be mounted on a table saw and including slot means therethrough inclined relative to an associated table top;
cam means having a peripheral, work-engaging surface including a spiral segment;
pin means attached to said cam means and extending through said slot means to form a pivot axis for said cam means at approximately a center of said spiral segment; and
said slot means being sized to slidably receive said pin means and including an upper, elongate edge having detent means shaped to receive said pin means;
whereby upward and rearward movement of a workpiece in a kickback condition beneath said cam means causes said cam means to be pivoted and be displaced to a locked configuration such that said pin means engages said detent means and a portion of said spiral segment contacts an upper surface of a workpiece thereunder in a wedging engagement with an associated table top.
1 Assignment
0 Petitions
Accused Products
Abstract
An anti-kickback system for use with a table saw or the like consists of a splitter adapted to be mounted on the table saw and including an elongated slot therethrough inclined relative to the table top, a pair of cams, each having peripheral, work-engaging surface including a spiral segment, and a pin attached to the cams and extending through the slot to form a pivot axis for the cams at approximately the centers of the spiral segments. The slot is sized to slidably receive the pin and includes an upper, elongated edge having a plurality of arcuate shaped detents sized to receive the pin. Movement of a workpiece in a kickback condition beneath the cams causes the cams to be pivoted and displaced upwardly to lock the pin against one of the detents so that the workpiece is clamped between the table top and a portion of the spiral segment of the cams. The spiral is shaped such that any point of contact of the segment with a workpiece in a kickback condition is at a radius extending to the pivot center of a cam which makes an angle of approximately 8° with a line extending through the pivot axis perpendicularly to the table top.
107 Citations
15 Claims
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1. For use with a table saw of the type having a table top for supporting a workpiece and a motor-driven circular saw blade, an anti-kickback system comprising:
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splitter means adapted to be mounted on a table saw and including slot means therethrough inclined relative to an associated table top; cam means having a peripheral, work-engaging surface including a spiral segment; pin means attached to said cam means and extending through said slot means to form a pivot axis for said cam means at approximately a center of said spiral segment; and said slot means being sized to slidably receive said pin means and including an upper, elongate edge having detent means shaped to receive said pin means;
whereby upward and rearward movement of a workpiece in a kickback condition beneath said cam means causes said cam means to be pivoted and be displaced to a locked configuration such that said pin means engages said detent means and a portion of said spiral segment contacts an upper surface of a workpiece thereunder in a wedging engagement with an associated table top. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 11)
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4. The system of claim 1 wherein said work-engaging surface includes a substantially rectilinear segment positioned adjacent to said spiral segment such that said rectilinear segment engages an upper surface of a workpiece passing beneath said cam means during a feeding operation.
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5. The system of claim 3 wherein said work-engaging surface includes a substantially rectilinear segment extending from said datum radius opposite said spiral segment, whereby said cam means pivots about said pivot point so that said rectilinear segment engages an upper surface of a workpiece passing thereunder during a feeding operation.
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6. The system of claim 5 wherein said cam means is positioned relative to said splitter means such that said rectilinear segment extends from said datum radius in a direction opposite a workpiece feeding direction.
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7. The system of claim 6 wherein said cam means is positioned relative to said splitter such that said work-engaging surface spirals outwardly from said pivot axis in a workpiece feeding direction.
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8. The system of claim 1 wherein said detent means includes a plurality of concave portions, each sized to receive said pin means therein.
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9. The system of claim 8 wherein said slot means is elongate in shape and makes an angle of about 45°
- with an associated table top.
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11. The anti-kickback system of claim 9 wherein said spiral segment is shaped such that a radius extending from a point of contact between said spiral segment and a workpiece to said pivot means makes an angle not greater than about 8°
- with a line perpendicular to an associated table top.
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10. For use with a table saw of the type having a table top for supporting a workpiece and a motor-driven, circular saw blade, an anti-kickback system comprising:
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cam means having a peripheral, work-engaging surface including a spiral segment; means for mounting said cam means above a table of table saw; and means for pivotally attaching said cam means to said mounting means at approximately a center of said spiral segment.
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12. For use with a table saw of the type having a flat table top and a saw blade rotatably mounted therebeneath and protruding upwardly therethrough, an anti-kickback system comprising:
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a splitter adapted to be attached at a lower portion thereof to a table saw and extend upwardly from a table top thereof, said splitter having an elongate slot therein inclined upwardly and forwardly relative to an associated table top and including an upper edge having a plurality of arcuate detents therealong and a relatively smooth lower edge; a pair of cams disposed on either side of said splitter, each of said cams having a peripheral, work-engaging surface including a spiral segment having a curvature defined by
space="preserve" listing-type="equation">r=(sin 8°
)θ
+C,where r is a length of a radius from a point on said spiral segment to a center thereof, θ
is an angle said radius makes with a selected datum radius, and C is a selected length of said datum radius from said spiral center to a point on said spiral segment at said datum, said spiral being oriented such that r increases in a rearward, work feeding direction, and a rectilinear segment extending from said datum radius in a forward direction opposite said spiral segment;a cylindrical pin extending through said slot and said cams at said centers of said spiral segments thereof, thereby forming pivot axes for said cams, said pin having a diameter sized to fit within said arcuate detents; and spacer means mounted on said pin between said cams and said splitter, whereby upward and rearward movement of a workpiece in a kickback condition beneath said cams causes said cams to be pivoted and displaced to a locked configuration such that said pin engages one of said detents and a portion of said spiral segment contacts an upper surface of a workpiece thereunder in locking engagement with an associated table top.
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13. In a table saw of the type having a table top for supporting a workpiece and a motor-driven, circular saw blade, an anti-kickback system comprising;
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cam means having a peripheral, work-engaging surface includng a spiral segment; means for mounting said cam means above said table top; and means for pivotally attaching said cam means to said mounting means at approximately a center of said spiral segment. - View Dependent Claims (14)
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15. In a table saw of the type having a flat table top and a saw blade rotatably mounted therebeneath and protruding upwardly therethrough, an anti-kickback system comprising;
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a splitter adapted to be attached at a lower portion thereof to said table saw and extend upwardly from said table top thereof, said splitter having an elongate slot therein inclined upwardly and rearwardly relative to said table top and including an upper edge having a plurality of arcuate detents therealong and a relatively smooth lower edge; a pair of cams disposed on either side of said splitter, each of said cams having a peripheral, work-engaging surface including a spiral segment having a curvature defined by
space="preserve" listing-type="equation">r=(sin 8°
)θ
+C,where r is a length of a radius from a point on said spiral segment to a center thereof, θ
is an angle said radius makes with selected datum radius, and C is a selected of said datum radius from said spiral center to a point on said spiral segment at said datum, said spiral being oriented such that r increases in a rearward, work-feeding direction, and a rectilinear segment extending from said datum radius in a forward direction opposite said spiral segment;a cylindrical pin extending through said slot and said cams at said centers of said spiral segments thereof, thereby forming pivot axes for said cams, said pin having a diameter sized to fit within said arcuate detents; and spacer means mounted on said pin between said cams and said splitter, whereby upward and rearward movement of a workpiece in a kickback condition beneath said cams causes said cams to be pivoted and displaced to a locked configuration such that said pin engages one of said detents and a portion of said spiral segment contacts an upper surface of a workpiece thereunder in locking engagement with said table top.
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Specification