US 2002/0157265 A1Published application

Circular saw with an improved lower blade guard

AssigneeMakita Corporation

InventorsKatsuji Haneda, Shingo Tsuchiya, Hirotaka Noguchi

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Abstract

A circular saw (1) includes a base plate (2) and a saw blade assembly (3) which in turn includes a lower blade guard (9) for covering a saw blade (6). The blade guard includes a sleeve portion (10) rotatably fitted on a bearing box (8) coupled to the saw blade assembly and a sectoral portion (11) which extends radially from the sleeve portion in the rear of the blade. A connecting bar (13) projects radially rearward from the sectoral portion at a 40-degree angle to the base plate. A spring (14) is stretched between the top of the connecting bar (13) and a lower rear portion of an upper blade guard (4) close to the base plate. When not in use, the blade guard is rotated to the closed position by the torque generated as the product of the spring's tensile force and the perpendicular distance (S) from the line of action or the force to the axis of rotation (O).

Claims14

Dependent claims

A circular saw comprising:

a base plate having a plane extending therethrough;
a saw blade assembly mounted on the base plate, the saw blade assembly including a rotatably driven saw blade;
a lower blade guard capable of rotation about an axis for covering a portion of the saw blade protruding below the base plate;
and
an extension spring which has a longitudinal axis and is stretched between a first portion of the saw blade assembly and a second portion of the lower blade guard decentered from the axis of rotation of the blade guard, the extension spring being adapted to rotatably bias the lower blade guard to a closed position in which the blade guard covers the saw blade,
wherein the second decentered portion, at which the extension spring is connected to the lower blade guard, is selected such that the angle between the line from the decentered portion to the axis of rotation of the lower blade guard and the line of action of the tensile force of the spring gradually decreases as the lower blade guard is rotated from the closed position to expose the saw blade.

3 more elements

A circular saw comprising:

a base plate having a plane extending therethrough;
a saw blade assembly mounted on the base plate, the saw blade assembly including a rotatably driven saw blade;
a lower blade guard capable of rotation about an axis for covering a portion of the saw blade protruding below the base plate;
and
an extension spring having a forward end and a rear end and a longitudinal axis therethrough, wherein the extension spring is stretched between the rear end fastened to the saw blade assembly and the forward end connected to a portion of the lower blade guard decentered from the axis of rotation and is adapted to rotatably bias the lower blade guard to a closed position in which the blade guard covers the saw blade,
wherein the forward end of the extension spring is slidable from the decentered portion toward the axis of rotation of the lower blade guard as the guard is rotated from the closed position to expose the saw blade.

3 more elements

Dependencies are inferred from the claim text.