两位说的都没错，我的看法也是这样；
我觉得2是可以接受的方式，得到说明书支持，也有必要技术特征；但是范围最小。
还是看看原来人家说的吧；
As already mentioned, a method claim to the upgrading of an old type sewing machine was also expected. It could for example read:
a) A method of upgrading a sewing machine
b) comprising a shaft,
c) the method comprising the step of mounting a pulley and one-way clutch ssembly on the shaft, so that the shaft is drivable by theassembly to rotate.
Such a claim was marked out of a maximum of 10 points.Alternative formulations were acceptable, provided they covered the process ofupgrading.
The use of wording such as “inserting a one-way clutch between the shaft and a pulley mounted on the shaft” or “replacing a pulley mounted on the shaft with a pulley and one-way clutch assembly” was not penalised, although such formulations lead to a more limited scope of protection.
Comments relating to the apparatus claim above also apply by analogy to the
method claim.
其中的代码如下：
one-way clutch -----B
shaft----C
pulley ---A |
