ISO 6533 Figure 3 / 4 / 5 for Testing Forestry machinery Portable chain-saw front hand-guard

6.2 When the machine is designed in such a way that a type A gauge of 100 mm length cannot be inserted
between the handle and the housing, and X0 cannot be determined using such a gauge, the gauge length
can be shortened (though no more than necessary). Using this modified gauge, X0 shall be determined
according to all other requirements of 6.1.

6.3 If no contact between the gauge, the housing and the front handle can be achieved, then X0 shall be
determined as the intersection point, transposed to the front handle along the line of sight, between the
upper right edge of the type A gauge and a virtual surface that is created by a line of sight, parallel to the
guide bar centre line, following the right inner surface contour of the front handle (see Figure 3)

Key
1 type A gauge
2 type A gauge centreline
3 guide bar
4 chain saw body
5 front handle

Figure 3 — Definition of reference point X0 when there is no contact between the gauge and
the front handle

7 Front hand-guard dimensions
7.1 Front hand-guard width, W1
The front hand-guard width, W1, is the distance from X0, left, to the point at which the requirement for the
front hand-guard height over the front handle, H1 and H1A, respectively (see 7.2), is not fulfilled. See Figure 4.
The front hand-guard width, W1, shall in both cases (H1 and H1A) be at least 100 mm.

Figure 4 — Front hand-guard width, W1, from the rear view of the machine

7.2 Front hand-guard height over front handle, H1 and H1A
The measurement of the vertical height H1 and H1A shall be made in a plane parallel to the guide bar
plane and perpendicular to the guide bar centreline (see Figure 5).
Any free play in the guide bar fixing shall be taken up by tightening the guide bar to the saw body in its
uppermost position.
The height, H1, above top of front handle shall be at least 20 mm.
When the front hand-guard also activates the chain brake, this height shall be at least
— 20 mm with disengaged chain brake (H1), and
— 0 mm for engaged chain brake (H1A).

Key
1 intersection point
2 unprotected part of saw chain
Figure 6 — Line between X0 and rearmost part of unprotected saw chain