Patent ID: 8740118

Claim:
A grinding device, comprising: a body configured as a hollow barrel having an opening, a first fixing element positioned close to said opening, and an external thread configured on an outer wall of an end close to said opening of said body; an inner cap configured to mount to an inner wall of an end close to said opening of said body having a second fixing element corresponding to said first fixing element; wherein said second fixing element is configured to anchor with said first fixing element; wherein an aperture is provided on said inner cap, and a first leak-proof seal is configured to surround said aperture; an outer cover having an inner thread, a second leak-proof seal and a projection; wherein said inner thread is configured to lock with said external thread of said body, and thereby said second leak-proof seal is made joint said first leak-proof seal for leak-proofing; and a grinding element positioned inside said body and capable of moving therein freely; wherein an area of any cross section of said grinding element is bigger than said aperture of said inner cap.