To provide the subject loom having an engaging clutch for a yarn roller, breast beam of a woven fabric winding mechanism and a twitch roller of each specific structure, designed to weave a high-density textile fabric >200 in weave density in favorable operational state by an ordinary cotton loom.

The claw clutch 26 and clutch pawls 27 of the engaging clutch 17 of a yarn roller 16 are formed with square gears, and half of the contact surfaces of both along the axial line are tilted at a specified angle relative to the axial line in slope so as to advance a drive shaft 21 side relative to the rotational direction and delay the yarn roller 16 side behind, thus preventing a yarn beam from getting out of its holding part due to wear between the claw clutch and clutch pawls. An iron plate is stuck via a cushioning material onto the surface of a breast beam, a rubber material is wrapped on the surface of a twitch roller, thereby, relaxing abnormally high tension on a woven fabric even if such tension is developed, along with correcting the slack and/or shaking of the woven fabric.