Hole saw and guide
AssigneeOffice Depot, Inc.
InventorsGrant John Bell, James Watson
Life of this patent
Estimating the term…
Abstract
An apparatus for enlarging an existing hole in an object includes a separate hole saw with a center pilot shaft. A guide tube with a disk attached at one end inserts into the preexisting hole in the object and receives a bridging web with a plurality of tapered radial arms cumulatively forming a cone shape on the other end. The space between the bridging web and the disk is reduced by a threaded fitting to clamp the guide tube on the object within the existing hole. When the cone-shaped web wedges into the pre-existing hole, the guide tube is moved toward the axis of the pre-existing hole. The bore of the guide tube slideably receives the pilot member to guide the hole saw to rotate coaxially relative to the bore when cutting the second hole. A flat web may be used for non-coaxial cutting.
Claims15
A guide for a hole saw having a pilot member and a cutting member for cutting a second hole in an object having a pre-existing hole, the second hole at least partially overlapping the pre-existing hole, comprising:
- a guide member having a bore therein, the guide member capable of being positioned in the pre-existing hole and held in the pre-existing hole by at least a first support member attached to the guide member, the bore adapted to slideably receive the pilot member to guide the hole saw to rotate coaxially relative to the bore when cutting the second hole, the first support member having a component of extension perpendicular to the axis of the bore of the guide member;
- a second support member having a component of extension perpendicular to the axis of the bore of the guide member, removably attachable to the guide member, the first and second support members capable of at least partially bridging the pre-existing hole when the guide member is positioned in the pre-existing hole with the first and second support members attached, the second support member having a plurality of radial arms extending from a hub and wherein the guide member is attached to the second support member proximate the hub,
- the hub having a first side and a second side, the first side disposed towards one end of the guide member and the second side disposed toward the other end of the guide member when attached thereto, a diameter of the hub being less than a diameter of the pre-existing hole, the radial arms tapering in thickness in a direction parallel to the direction of extension of the hub from the first side to the second side and having a greater thickness proximate the hub and a lesser thickness distal to the hub.
A hole cutting assembly for cutting a second hole in an object having a pre-existing hole, the second hole at least partially overlapping the pre-existing hole, comprising:
- a hole saw having a pilot member and a cutting member;
- a guide tube having a bore therein and being threaded at at least one end;
- a first support member in the form of a disk attached to the guide tube proximate one end at an approximately perpendicular relative orientation;
- a second support member having a hub and a plurality of radial arms extending from the hub and attached to the guide tube proximate the hub, the hub having a first side and a second side and an axial aperture running from the first side to the second side of the hub, the axial aperture receiving the guide tube, the first side of the hub disposed towards one end of the guide tube and the second side disposed toward the other end of the guide tube when the guide tube is extended there through, the radial arms tapering in thickness in a direction parallel to the direction of extension of the hub from the first side to the second side and having a greater thickness proximate the hub and a lesser thickness distal to the hub;
- a threaded fastener receivable on the threaded end of the guide tube to retain the second support member on the guide tube and to control the position of the second support member on the guide tube relative to the first support member, the first support member being positionable on one side of the object with the guide tube attached and extending through the pre-existing hole and the second support member being attached to the guide tube by the threaded fastener on the other side of the object, the tapering radial arms defining sloped surfaces which cumulatively approximate a portion of a virtual cone, such that when the guide tube is positioned in the pre-existing hole with the virtual cone pointed toward the first support member, the virtual cone progressively wedges into the pre-existing hole as the adjustable fastener urges the first and second support members closer together, moving the guide tube toward the axis of the pre-existing hole and holding the guide tube at a given position relative to the axis of the pre-existing hole, the bore of the guide tube adapted to slideably receive the pilot member to guide the hole saw to rotate coaxially relative to the bore when cutting the second hole.
Dependencies are inferred from the claim text.