Apparatus, method, and system for orienting a saw chain link on a sprocket
AssigneeBlount, Inc.
InventorsMike Goettel, Michael D. Harfst, Christopher D. Seigneur
Life of this patent
Estimating the term…
Abstract
Embodiments herein provide a modified pitch sprocket to provide an orientation of a saw chain link, such as a cutter link or drive link, with respect to the direction of travel of the link, as it traverses the sprocket that is different than the orientation of the link as it traverses a straight portion of the guide bar. In some embodiments, the modified pitch sprocket may orient the cutter link to provide radial extension for a depth gauge of the cutter link relative to a cutting element of the cutter link. This may facilitate shaping of the depth gauge and/or cutting element, such as by a sharpening element, as the cutter link traverses the sprocket.
Claims16
A sprocket for a chainsaw, the sprocket comprising:
- a spur configured to drive a saw chain around a drive end of a guide bar of a chainsaw, wherein the saw chain includes cutter links that have a first orientation as the cutter links traverse a straight portion of the guide bar;
- and
- a plurality of pockets disposed in the spur to engage the saw chain, wherein the pockets are asymmetrical with respect to a radius of the sprocket to cause the cutter links to have a second orientation as the cutter links traverse the sprocket, wherein the second orientation is different from the first orientation by an offset angle, and wherein the second orientation positions a depth gauge of the cutter link with a radial extension with respect to a center of rotation of the sprocket that is equal to or greater than a radial extension of a cutting element of the cutter link to facilitate engagement of the depth gauge with a sharpening element.
A system for a chainsaw comprising:
- a guide bar including:
- a straight portion;
- a drive sprocket disposed on a drive end of the guide bar and coupled to the straight portion, the drive sprocket including a pocket that is asymmetrical with respect to a radius of the drive sprocket;
- a saw chain configured to ride on the guide bar, the saw chain including a cutter drive link configured to be disposed in the pocket as the cutter drive link traverses the drive sprocket, and the cutter drive link including:
- a cutting element;
- a depth gauge;
- a first rivet hole below the cutting element;
- and
- a second rivet hole below the depth gauge;
- wherein the straight portion orients the cutter drive link at a first orientation with respect to a direction of travel as the cutter drive link traverses the straight portion of the guide bar, wherein the pocket of the sprocket orients the cutter drive link at a second orientation with respect to the direction of travel as the cutter drive link traverses the drive sprocket, wherein the second orientation is different from the first orientation by an offset angle, and wherein, in the second orientation, a first radial extension distance between the first rivet hole and a center of rotation of the drive sprocket is less than a second radial extension distance between the second rivet hole and the center of rotation of the drive sprocket.
Dependencies are inferred from the claim text.