Vacuum sander

Claim 2

A vacuum sanding apparatus comprising in combination, a disc shaped backup pad for connection to driving means and having an abrasive sanding disc detachably secured thereto, a vacuum housing mounted on the upper surface of the backup pad; a plurality of apertures in the operative surface of the abrasive disc and being in registry with apertures in the bottom surface of the backup pad, all said apertures being in communication with the interior of said vacuum housing; means on the housing for adjusting the amount of vacuum created therein; said housing being connectable to the driving means and being adapted to receive the same centrally in the housing; and a resilient collar intermediate the peripheral lower edge of the housing and the upper surface of the backup pad whereby the housing may flex relative to the plane of the backup pad.

Claim 3

Apparatus according to claim 1 wherein the diameter of the housing is less than that of the backup pad; said housing including an outlet for connection to vacuum means, the vacuum adjusting means comprising a plate member on the inner wall of the housing and slidable between an inoperative position in which the outlet is uncovered and an operative position in which the outlet is covered.

Claim 4

Apparatus according to claim 2, including a slot in the sidewall of the housing and an arm projection from the plate outwardly through the slot for manual adjustment of the vacuum.

Claim 5

Apparatus according to claim 1 wherein the vacuum adjusting means comprises a plurality of concentrated perforations in the wall of said housing and an adjustable spring loaded plate covering said perforations.

Claim 6

Apparatus according to claim 1 wherein the backup pad comprises a relatively soft and resilient lower section bonded to a relatively hard and stiff upper section and a hard cover overlying the upper section and positioned intermediate the pad upper section and the lower peripheral edge of the housing.

Claim 7

Apparatus according to claim 5 wherein the upper section of the pad includes a plurality of radially extending ribs, one between each aperture in the pad, each pair of ribs defining between them an interior vacuum chamber enclosed by said cover; and a plurality of apertures in the outer sidewall of the pad, and extending into said chambers, the outer sidewall aperture being smaller in diameter than the apertures in the bottom surface of the pad.

Claim 8

Apparatus according to claim 1 wherein the abrasive disc comprises an abrasive central portion equal in diameter to the bottom of the backup pad and a peripheral flexible skirt extending beyond the outer edge of the abrasive portion and adapted to extend up over the sidewall of the pad; and a plurality of openings in said skirt in registry with the aperture in the sidewall of the backup pad.

Claim 9

A vacuum housing for use on a vacuum sanding device of the type driving a backup pad with an abrasive disc thereon, said housing comprising: a. a cylindrical body portion having a central aperture in the top thereof for passage of the sanding device driving means; b. an outlet for connection to vacuum applying means; c. a peripheral, resilient collar on the lower end of the body portion for flexible engagement with the upper surface of the backup pad; and d. means on the body portion for adjusting the amount of air going through said vacuum outlet.

Claim 10

A vacuum housing for use on a vacuum sanding device of the type driving a backup pad with an abrasive disc thereon, said housing comprising: a. a cylindrical body portion having a central aperture in the top thereof for passage of the sanding device driving means; b. an outlet for connection to vacuum applying means; c. a peripheral, resilient collar on the lower end of the body portion for flexible engagement with the upper surface of the backup pad; and d. means on the body portion for adjusting the amount of air going through said vacuum outlet.

Claim 11

A housing according to claim 8 wherein the air adjusting means comprises a plate member on the inner wall of the body portion and slidable between open and closed positions over the outlet; a slot in said sidewall and an arm connected to said plate and projecting through said slot for manual adjustment of the plate.

Claim 12

A housing according to claim 8 wherein the air adjusting means comprises a plurality of concentrated perforations in the wall of the housing and an adjustable spring loaded plate covering the perforations on the inside of said housing.

Claim 13

A disc shaped backup pad for use in a vacuum sanding device, said pad comprising: a. upper and lower portions with a first group of apertures extending upwardly through the pad normal thereto; b. said lower portion being a soft, resilient material adapted to conform to work surfaces; c. said upper portion being bonded to said lower portion and being of relatively firm material; d. the outer periphery of said pad tapering inwardly and upwardly and including a peripheral groove for receiving a resilient snap ring therein; e. said firm upper portion including a central boss for connection, a driving means and a plurality of ribs extending radially outwardly from the boss to an upstanding peripheral lip defining with said radial ribs, a plurality of vacuum chambers; f. each of said first group of normally extending apertures terminating at its upper end in one of said chambers; and g. a plurality of apertures in the tapered side wall, each extending inwardly to terminate in one of said chambers.

Claim 14

A disc shaped backup pad for use in a vacuum sanding device, said pad comprising: a. upper and lower portions with a first group of apertures extending upwardly through the pad normal thereto; b. said lower portion being a soft, resilient material adapted to conform to work surfaces; c. said upper portion being bonded to said lower portion and being of relatively firm material; d. the outer periphery of said pad tapering inwardly and upwardly and including a peripheral groove for receiving a resilient snap ring therein; e. said firm upper portion including a central boss for connection, a driving means and a plurality of ribs extending radially outwardly from the boss to an upstanding peripheral lip defining with said radial ribs, a plurality of vacuum chambers; f. each of said first group of normally extending apertures terminating at its upper end in one of said chambers; and g. a plurality of apertures in the tapered side wall, each extending inwardly to terminate in one of said chambers.

Claim 15

A backup pad according to claim 11 and a cover concentrically positioned over the upper surface of said pad to enclose the top of said chambers, and a plurality of apertures in said cover in registry with said chambers.

Claim 16

An abrasive disc for mounting on a backup pad of a vacuum sander, said disc comprising an abrasive central portion and a concentric, flexible skirt, larger in diameter than said abrasive central portion for connection to the sidewall of said backup pad; a plurality of apertures in the abrasive central portion for registry with like apertures in the bottom of said backup pad; and a plurality of openings in the flexible skirt for registry with apertures in the sidewall of the pad when the skirt is secured thereon.

Claim 17

An abrasive disc for mounting on a backup pad of a vacuum sander, said disc comprising an abrasive central portion and a concentric, flexible skirt, larger in diameter than said abrasive central portion for connection to the sidewall of said backup pad; a plurality of apertures in the abrasive central portion for registry with like apertures in the bottom of said backup pad; and a plurality of openings in the flexible skirt for registry with apertures in the sidewall of the pad when the skirt is secured thereon.

Claim 18

An abrasive sanding disc according to claim 13 comprising a central portion equal in diameter to the supporting surface of the backup pad and projections extending radially from the central portion, grit distributed over the central portion and the projections, and a strong flexible member backing and reinforcing the central portion and the projections; said projections being greater in width at their extreme ends than they are at the perimeter of the central portion.

Claim 19

A loader for use in affixing an abrasive sanding disc to a backup pad of a vacuum sander comprising a. a loader housing of circular configuration having a bottom wall and a peripheral sidewall; b. a vertical centering pin mounted in the centre of the bottom wall of the loader housing, c. a spring means concentrically positioned in association with the centering pin, and d. a centering plate mounted on the spring means and having a surface contour conforming the surface contour of the bottom of a pad and paper being loader therein.

Claim 20

A loader for use in affixing an abrasive sanding disc to a backup pad of a vacuum sander comprising a. a loader housing of circular configuration having a bottom wall and a peripheral sidewall; b. a vertical centering pin mounted in the centre of the bottom wall of the loader housing, c. a spring means concentrically positioned in association with the centering pin, and d. a centering plate mounted on the spring means and having a surface contour conforming the surface contour of the bottom of a pad and paper being loader therein.