a lubrication device for a rotating hook in a sewing machine , having a hook shaft provided with a hollow interior axially thereof , an inlet and an outlet communicating with the hollow interior for prevention of oil pressure build - up therein as oil is supplied from an oil reservoir , a restriction between the inlet and the outlet for decreasing the diametrical extent of the hollow interior , and a closure for one end of the hollow interior provided with an oil supply channel communicating with the hollow interior , the oil supply channel having an axis positioned either eccentrically or concentrically of a longitudinal axis of the hook - shaft and an insert part to prevent the porous material from resting at the bottom of the interior of the hook - shaft , when the machine is stopped .