대표
청구항
▼
What is claimed is: 1. A chain saw having a retaining assembly for a tensioning arrangement for adjusting the tension of a cutting chain, the chain saw having an engine chassis, a clutch cover, and a guide bar for the cutting chain, the retaining assembly comprising: a rotatable knob operatively cooperative with the engine chassis, the clutch cover, and the guide bar, wherein the knob may be rotated about a rotational axis between a tightened position, in which the guide bar is fixed in place between the engine chassis and the clutch cover, and a loosen...
What is claimed is: 1. A chain saw having a retaining assembly for a tensioning arrangement for adjusting the tension of a cutting chain, the chain saw having an engine chassis, a clutch cover, and a guide bar for the cutting chain, the retaining assembly comprising: a rotatable knob operatively cooperative with the engine chassis, the clutch cover, and the guide bar, wherein the knob may be rotated about a rotational axis between a tightened position, in which the guide bar is fixed in place between the engine chassis and the clutch cover, and a loosened position, in which the guide bar is loosened and may be repositioned using the tensioning arrangement so as to adjust the tension of the cutting chain on the guide bar; a plurality of engagement points fixed relative to the clutch cover; and a locking mechanism connected to the rotatable knob for alternatively locking the rotatable knob against rotation about its rotational axis and unlocking the rotatable knob to enable the rotatable knob to be rotated about its rotational axis, the locking mechanism including a plurality of moveable engagement points and means for moving the movable engagement points alternatively outwardly and inwardly of the confines of the rotatable knob into and out of engagement, respectively, with the engagement points fixed relative to the clutch cover; wherein the means for moving the movable engagement points moves the movable engagement points alternatively radially outwardly and inwardly of, and substantially perpendicularly to, the rotational axis of the rotatable knob into and out of engagement, respectively, with the engagement points fixed relative to the clutch cover; and wherein the locking mechanism includes a lock on which the moveable engagement points are located, the lock being slidably mounted within the rotatable knob for alternative movement radially outwardly and inwardly of, and substantially perpendicularly to, the rotational axis of the rotatable knob, whereby the movable engagement points are, respectively, extended beyond the confines of the rotatable knob and into engagement with the engagement points fixed relative to the clutch cover and retracted within the confines of the rotatable knob and out of engagement with the engagement points fixed relative to the clutch cover. 2. The chain saw of claim 1, wherein the locking mechanism further includes a lever having a portion in contact with the lock, the lever being mounted to the rotatable knob such that movement of the lever in a first direction causes the portion of the lever in contact with the lock to move the lock radially outwardly of the rotational axis of the rotatable knob, whereby the moveable engagement points on the lock are placed into engagement with the engagement points fixed relative to the clutch cover, and movement of the lever in a second direction causes the portion of the lever in contact with the lock to move radially inwardly of the rotational axis of the rotatable knob, whereby the lock also moves radially inwardly of the rotational axis of the rotatable knob to take the moveable engagement points on the lock out of engagement with the engagement points fixed relative to the clutch cover. 3. The chain saw of claim 2, wherein the lever has an end portion pivotally connected to the rotatable knob for pivotal movement of the lever between the first direction and the second direction, and the portion of the lever in contact with the lock comprises a cam that moves the lock radially outwardly of the rotational axis of the rotatable knob and disposes the moveable engagement points on the lock into engagement with the engagement points fixed relative to the clutch cover when the lever is moved in the first direction and allows the lock to move radially inwardly of the rotational axis of the rotatable knob to dispose the moveable engagement points on the lock out of engagement with the engagement points fixed relative to the clutch cover when the lever is moved in the second direction. 4. The chain saw of claim 3, including a resilient means in contact with the lock and the rotatable knob for continually urging the lock inwardly radially of the rotational axis of the rotatable knob. 5. The chain saw of claim 1, 2, 3 or 4 wherein the moveable engagement points are slidably positioned on the lock for independent movement in relation to the lock in the same radial outward and radial inward direction as the radial outward and radial inward movement of the lock, and resilient means in contact with the lock and the moveable engagement points for continually urging the moveable engagement points in said radial outward direction in relation to the lock. 6. A chain saw having a retaining assembly for a tensioning arrangement for adjusting the tension of a cuffing chain, the chain saw having an engine chassis, a clutch cover, and a guide bar for the cuffing chain, the retaining assembly comprising: a rotatable knob operatively cooperative with the engine chassis, the clutch cover, and the guide bar, wherein the knob may be rotated about a rotational axis between a tightened position, in which the guide bar is fixed in place between the engine chassis and the clutch cover, and a loosened position, in which the guide bar is loosened and may be repositioned using the tensioning arrangement so as to adjust the tension of the cuffing chain on the guide bar, and wherein the rotatable knob includes a radially outermost peripheral wall; a plurality of engagement points fixed relative to the clutch cover; and a locking mechanism connected to the rotatable knob for alternatively locking the rotatable knob against rotation about its rotational axis and unlocking the rotatable knob to enable the rotatable knob to be rotated about its rotational axis, the locking mechanism including a plurality of moveable engagement points and means for moving the movable engagement points alternatively outwardly for locking, wherein the movable engagement points are located outside of the peripheral wall of the rotatable knob, and inwardly for unlocking, of the confines of the rotatable knob into and out of engagement, respectively, with the engagement points fixed relative to the clutch cover, wherein the means for moving the movable engagement points moves the movable engagement points alternatively radially outwardly and inwardly of the rotational axis of the rotatable knob into and out engagement, respectively, with the engagement points fixed relative to the clutch cover, and wherein the locking mechanism includes a lock on which the moveable engagement points are located, the lock being slidably mounted within the rotatable knob for alternative movement radially outwardly and inwardly of the rotational axis of the rotatable knob, whereby the movable engagement points are, respectively, extended beyond the confines of the rotatable knob and into engagement with the engagement points fixed relative to the clutch cover and retracted within the confines of the rotatable knob and out of engagement with the engagement points fixed relative to the clutch cover. 7. The chain saw of claim 6, wherein the means for moving the movable engagement points moves the movable engagement points substantially perpendicularly to the rotational axis of the rotatable knob into and out engagement, respectively, with the engagement points fixed relative to the clutch cover. 8. The chain saw of claim 7, wherein the lock is slidably mounted within the rotatable knob for alternative movement radially outwardly and inwardly of, and substantially perpendicularly to, the rotational axis of the rotatable knob. 9. The chain saw of claim 6, wherein the locking mechanism further includes a lever having a portion in contact with the lock, the lever being mounted to the rotatable knob such that movement of the lever in a first direction causes the portion of the lever in contact with the lock to move the lock radially outwardly of the rotational axis of the rotatable knob, whereby the moveable engagement points on the lock are placed into engagement with the engagement points fixed relative to the clutch cover, and movement of the lever in a second direction causes the portion of the lever in contact with the lock to move radially inwardly of the rotational axis of the rotatable knob, whereby the lock also moves radially inwardly of the rotational axis of the rotatable knob to take the moveable engagement points on the lock out of engagement with the engagement points fixed relative to the clutch cover. 10. The chain saw of claim 9, wherein the lever has an end portion pivotally connected to the rotatable knob for pivotal movement of the lever between the first direction and the second direction, and the portion of the lever in contact with the lock comprises a cam that moves the lock radially outwardly of the rotational axis of the rotatable knob and disposes the moveable engagement points on the lock into engagement with the engagement points fixed relative to the clutch cover when the lever is moved in the first direction and allows the lock to move radially inwardly of the rotational axis of the rotatable knob to dispose the moveable engagement points on the lock out of engagement with the engagement points fixed relative to the clutch cover when the lever is moved in the second direction. 11. The chain saw of claim 10, including a resilient means in contact with the lock and the rotatable knob for continually urging the lock inwardly radially of the rotational axis of the rotatable knob. 12. The chain saw of claim 11, wherein the moveable engagement points are slidably positioned on the lock for independent movement in relation to the lock in the same radial outward and radial inward direction as the radial outward and radial inward movement of the lock, and resilient means in contact with the lock and the moveable engagement points for continually urging the moveable engagement points in said radial outward direction in relation to the lock. 13. A chain saw having a retaining assembly for a tensioning arrangement for adjusting the tension of a cutting chain, the chain saw having an engine chassis, a clutch cover, and a guide bar for the cutting chain, the retaining assembly comprising: a rotatable knob operatively cooperative with the engine chassis, the clutch cover, and the guide bar, wherein the knob may be rotated about a rotational axis between a tightened position, in which the guide bar is fixed in place between the engine chassis and the clutch cover, and a loosened position, in which the guide bar is loosened and may be repositioned using the tensioning arrangement so as to adjust the tension of the cutting chain on the guide bar, and wherein the rotatable knob includes a radially outermost peripheral wall; a plurality of engagement points fixed relative to the clutch cover; and a locking mechanism connected to the rotatable knob for alternatively locking the rotatable knob against rotation about its rotational axis and unlocking the rotatable knob to enable the rotatable knob to be rotated about its rotational axis, the locking mechanism including a plurality of moveable engagement points and means for moving the movable engagement points alternatively outwardly and inwardly of the confines of the rotatable knob into and out of engagement, respectively, with the engagement points fixed relative to the clutch cover, wherein during locking of the rotatable knob against rotation the movable engagement points are located outside of the peripheral wall of the rotatable knob, wherein the locking mechanism includes a lock and a floating support slidably mounted on the lock, the moveable engagement points being located on the floating support, and wherein the lock is slidably mounted within the rotatable knob for alternative movement radially outwardly and inwardly of, and substantially perpendicularly to, the rotational axis of the knob, the lock being operatively connected to the floating support whereby the movable engagement points are, respectively, extended beyond the confines of the rotatable knob and into engagement with the engagement points fixed relative to the clutch cover and retracted within the confines of the rotatable knob and out of engagement with the engagement points fixed relative to the clutch cover. 14. The chain saw of claim 13, wherein the lock further includes an anchoring pin and a spring connected to the anchoring pin, the spring having an end connected to an arm of the floating support for biasing the floating support in a direction radially outwardly of the lock. 15. The chain saw of claim 13, wherein the locking mechanism further includes a lever having a portion in contact with the lock, the lever being mounted to the rotatable knob such that movement of the lever in a first direction causes the portion of the lever in contact with the lock to move the lock radially outwardly of the rotational axis of the rotatable knob, whereby the moveable engagement points on the floating support are placed into engagement with the engagement points fixed relative to the clutch cover, and movement of the lever in a second direction causes the portion of the lever in contact with the lock to move radially inwardly of the rotational axis of the rotatable knob, whereby the lock also moves radially inwardly of the rotational axis of the rotatable knob to take the moveable engagement points on the floating support out of engagement with the engagement points fixed relative to the clutch cover. 16. The chain saw of claim 13, including a resilient means in contact with the lock and the rotatable knob for continually urging the lock inwardly radially of the rotational axis of the rotatable knob.
