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US 5,842,913 AGranted
Rotary drum sander
AssigneeRyobi North America, Inc.
InventorJohn E. Nemazi
Life of this patent
Estimating the term…
Abstract
A rotary drum sander is provided with a horizontal boom orienting a rotatable cylindrical drum to cover the spirally wound strip of abrasive material above a work supporting platen. The abrasive material is affixed to the drum by a first and second anchor, the second anchor is pivotally mounted relative to the drum and rotatably biased by a spring to cause the second anchor to rotate relative to the drum to maintain tension in the abrasive strip as the abrasive strip stretches during use.
Claims20
A rotary drum sander comprising:
- a frame having a lower platen, at least one vertical member, and a horizontal boom cooperating with the at least one vertical member, the boom being vertically adjustable relative to the platen;
- a circular cylindrical drum have an axial shaft;
- the drum being pivotably supported upon the horizontal boom and rotatable about a generally horizontal drum axis, the cylindrical drum having opposed ends and a cylindrical outer periphery for supporting an elongated strip of abrasive material which is spirally wound thereabout;
- a drive motor operatively connected to the cylindrical drum to rotate the drum relative to the frame;
- first and second abrasive anchors cooperating with the opposed ends of the cylindrical drum for affixing the ends of the elongated strip of abrasive material about the drum, wherein the second abrasive anchor is pivotably mounted on the axial shaft and rotatable relative the cylindrical drum about the drum axis and provided with a clamp for releasably affixing an end of the elongated strip of abrasive material to the second anchor at a location spaced radially from the drum axis;
- and
- a spring cooperating with the cylindrical drum and the second abrasive anchor to urge the second abrasive anchor to rotate relative to the cylindrical drum about the drum axis in a direction to continuously tighten the elongated strip of abrasive material about the periphery of the cylindrical drum, maintaining the elongated strip of abrasive material taut when it stretches during use.
4 more elements
A drum assembly for a rotary drum sander comprising:
- an axial shaft;
- a circular cylindrical drum concentrically affixed to the axial shaft and rotatable therewith about a shaft axis, the cylindrical drum having opposed ends and a cylindrical outer peripheral wall for supporting an elongated strip of abrasive material wound thereabout, the cylindrical drum outer peripheral wall having a slot oriented at each opposed end thereof sized to enable the elongated strip of abrasive material to pass therethrough;
- first and second abrasive anchors cooperating with the cylindrical drum and oriented radially inboard of the cylindrical drum outer periphery and axially inboard of the cylindrical drum opposed ends for affixing the ends of the elongated strip of abrasive material once wound about a cylindrical drum and pass through the pair of slots, wherein the second abrasive anchor is pivotably mounted on the axial shaft and rotatable relative the cylindrical drum about the drum axis and provided with a clamp for releasably affixing an end of the elongated strip of abrasive material to the second anchor at a location spaced radially from the drum axis;
- and
- a spring cooperating with the cylindrical drum and the second abrasive anchor to urge the second abrasive anchor to rotate relative to the cylindrical drum about the drum axis in a direction to continuously tighten the elongated strip of abrasive material about the periphery of the cylindrical drum, maintaining the elongated strip of abrasive material taut when it stretches during use.
2 more elements
A rotary drum sander comprising:
- a frame having a lower platen and a horizontal boom spaced thereabove vertically adjustable relative to the lower platen to vary the distance therebetween;
- a circular cylindrical drum pivotally supported upon the horizontal boom and rotatable about a generally horizontal drum axis, the cylindrical drum having a central axial shaft, a cylindrical drum wall concentrically affixed to the axial shaft and rotatable therewith about a shaft axis, the cylindrical drum having opposed ends and a cylindrical outer peripheral wall for supporting an elongated strip of abrasive material wound thereabout, the cylindrical drum outer peripheral wall having a slot oriented at each opposed end thereof sized to enable the elongated strip of abrasive material to pass therethrough;
- first and second abrasive anchors cooperating with the cylindrical drum and oriented radially inboard of the cylindrical drum outer periphery and axially inboard of the cylindrical drum opposed ends to balance the rotational mass of the drum, the anchors affixing the ends of the elongated strip of abrasive material once wound about a cylindrical drum and passing through the pair of slots, wherein the second abrasive anchor is pivotably mounted on the axial shaft and rotatable relative the cylindrical drum about the drum axis and provided with a clamp for releasably affixing an end of the elongated sheet of abrasive material to the second anchor at a location spaced radially from the drum axis;
- and
- a torsional spring cooperating with the cylindrical drum and the second abrasive anchor to urge the second abrasive anchor to rotate relative to the cylindrical drum about the drum axis in a direction to continuously tighten the elongated strip of abrasive material about the periphery of the cylindrical drum, maintaining the elongated strip of abrasive material taut when it stretches during use.
2 more elements
Dependencies are inferred from the claim text.