Appeal No. 2004-0390 Page 7
Application No. 09/727,397
wrench sockets and other well-known tools. Ratchet lever 12 is used to reverse the
ratchet action of ratchet device 8 in a well-known manner. Thus, the ratchet device can
be adjusted so that drive member 10 rotates in a clockwise or counterclockwise
direction with respect to ratchet head 6.
Kohal teaches that it is desirable to prevent ratchet head 6 from pivoting beyond
45° with respect to ratchet housing 4. Thus, the pivot angle between the ratchet head 6
and the ratchet housing 4 should be limited to 45°. In actual practice, Kohal discovered
that it is preferable if this pivot angle is limited to ±30°since this ensures that the
majority of force applied to wrench handle 2 is transmitted as torque in drive member
10. To prevent the pivot angle from exceeding 30°, ratchet housing 4 includes a
cylindrical pin 14 tangentially mounted within the hole in ratchet housing 4 so as
to be parallel with axis 103 (see Figure 2). Pin 14 is fixed in ratchet housing 4. Ratchet
head 6 has a circumferential detent 16 (see Figures 3 and 6) which co-acts with pin 14
to prevent the pivot angle from exceeding 30°.
Kohal further teaches that it is preferable that means be provided to temporarily
fix the angle between ratchet head 6 and ratchet housing 4 so that stability may be
provided for the operator and so that the majority of force applied to wrench handle 2 is
properly transmitted to drive member 10. To perform such a function, a ball 18 is
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Last modified: November 3, 2007