Curb pins

Curb Curb, n. 1. That which curbs, restrains, or subdues; a check or hindrance; esp., a chain or strap attached to the upper part of the branches of a bit, and capable of being drawn tightly against the lower jaw of the horse. [1913 Webster]

He that before ran in the pastures wild Felt the stiff curb control his angry jaws. --Drayton. [1913 Webster]

By these men, religion,that should be The curb, is made the spur of tyranny. --Denham. [1913 Webster]

2. (Arch.) An assemblage of three or more pieces of timber, or a metal member, forming a frame around an opening, and serving to maintain the integrity of that opening; also, a ring of stone serving a similar purpose, as at the eye of a dome. [1913 Webster]

3. A frame or wall round the mouth of a well; also, a frame within a well to prevent the earth caving in. [1913 Webster]

4. A curbstone. [1913 Webster]

5. (Far.) A swelling on the back part of the hind leg of a horse, just behind the lowest part of the hock joint, generally causing lameness. --James Law. [1913 Webster]

{Curb bit}, a stiff bit having branches by which a leverage is obtained upon the jaws of horse. --Knight.

{Curb pins} (Horology), the pins on the regulator which restrain the hairspring.

{Curb plate} (Arch.), a plate serving the purpose of a curb.

{Deck curb}. See under {Deck}. [1913 Webster]