Retarding device for a handheld cutting machine

14-23. (canceled)

Retarding device according to claim 1, wherein the drive engine is an internal combustion engine with a centrifugal clutch (52), which drives the transmission.

Retarding device according to claim 1, wherein the drive engine is an electric engine.

Retarding device according to claim 1, wherein said transmission drives a rotational cutting tool such as in a cut-off saw, clearing saw or brush cutter.

Retarding device according to claim 1, wherein the transmission is a belt transmission having a first belt pulley (3′) arranged close to and being driven by the drive engine and a second belt pulley (2;

• 3) being driven by a belt driven by the first belt pulley and said brake means being arranged to put a brake force either on the second or on the first belt pulley.

Retarding device according to claim 1, wherein the transmission is a chain transmission having a first chain pulley (3″) arranged close to and being driven by the drive engine and a second chain pulley being driven by a chain (59) driven by the first chain pulley (3″) such that the transmission drives the chain and said brake means being arranged to put a brake force on the first chain pulley and thereby brake the chain.

Retarding device according to claim 6, wherein the chain is a saw chain (59) in a chain saw, i.e. the saw chain is a cutting tool partly performing a rotational motion, i.e. a semi rotational cutting tool.

Retarding device according to claim 1, wherein the transmission has a drive shaft driven by the drive engine, which drive shaft drives a rotational cutting tool either directly or indirectly through a gear reduction, such as in a clearing saw or brush cutter.

Retarding device according to claim 1, wherein said brake means comprises a brake drum 16 having an axially extending flange (17) fixed to said housing (1, 1′) and at least one brake shoe (12) which is arranged to act against said axially extending flange.

Retarding device according to claim 9, wherein said brake means comprises elastic means (13, 22) urging on said at least one brake shoe (12) so that when the speed of rotation of said pulley (2) falls below said predetermined value the elastic means is arranged to press the brake shoe so that the brake shoe moves inwards and comes into contact with a radially outer surface of said radially extending flange (17).

Retarding device according to claim 10, wherein said elastic means comprises a circular spring member (13) arranged to urge against said at least one brake shoe (12).

Retarding device according to claim 11, wherein said circular spring member (13) is a circular helically wounded spring member arranged to urge against said at least one brake shoe.

Retarding device according to claim 11, wherein said circular spring member (13) is a circular elastic band arranged to urge against said at least one brake shoe (12).

Retarding device according to claim 10, wherein said elastic means comprises at least one pressing spring (22) arranged to urge against said at least one brake shoe (12).

Retarding device according to claim 10, wherein said elastic means comprises at least one pulling spring arranged to urge against said at least one brake shoe (12).

Retarding device according to claim 5, wherein said brake means comprises a friction member (36) which is rotationally fixed relative to said housing (1) and a brake member (34) fixed to either of said pulleys (3;

• 3′) and arranged to act against said friction member.

Retarding device according to claim 16, wherein said brake means comprises a friction disc (34) fixed to a radially extending flange (35) of said pulley (3), and a brake disc (36) having the form of a ring which is axially movable and on which a spring (38) is arranged to urge when the brake force is actuated between said friction disc and said brake disc.

Retarding device according to claim 6, wherein said brake means comprises a friction member (36′) which is rotationally fixed relative to said housing (1′) and a brake member (34′) fixed to said “first chain pulley (3″) and arranged to act against said friction member.

Retarding device according to claim 18, wherein said friction member (36′) is axially fixed relative to said housing (1) and the brake member (34′) has the shape of a ring preferably with an axial offset of its outer part away from the first chain pulley.

Retarding device according to claim 16, wherein said pulley (3;

• 3′;
• 3″) is connected to said shaft by means of a helical gear assembly (33) or angled splines which provides that the pulley can be automatically movable in the axial direction of the shaft (32) when a retarding action is applied on said shaft.

Cut-off saw including a retarding device according to claim 5.

Chain saw including a retarding device according to claims 6.

Brush cutter or clearing saw including a retarding device according to claim 8.