Patent ID: 7823697

Claim:
A lubricating plug adapted to fit into a lubrication hole formed in a roller bearing with a tracking wheel and a stud movable relative to one another to apply a lubricant between the tracking wheel and the stud, said plug comprising: a radially enlarged portion having a cylindrical contour to fit into the lubrication hole, and a radially reduced portion extending in an axial direction from one end of the radially enlarged portion, having a cylindrical contour and being formed as a unit with the radially enlarged portion, the radially enlarged and reduced portions being formed as a unit by molding synthetic resin, wherein the radially reduced portion provides an annular clearance extending around the cylindrical contour thereof to ensure flow of lubricant around the radially reduced portion when the radially enlarged portion is fitted into the lubrication hole, wherein both the radially enlarged and reduced portions have an injection hole extending in an axial direction through the plug, the injection hole being configured to receive a lubricant feeder nozzle therein, wherein the injection hole extends through an ingress area open at an axial end of the radially enlarged portion and continues inwards in the axial direction to accommodate the lubricant feeder nozzle therein, and through an egress area which is adjacent to and smaller in diameter than the ingress area so as to communicate with the ingress area, wherein the ingress area tapers off from the axial end of the radially enlarged portion towards the egress area, wherein a boundary between the ingress area and the egress area has a flat abutment against which the lubricant feeder nozzle fitted into the injection hole in the axial direction through the plug comes into abutted engagement therewith, and wherein the radially reduced portion has two slots formed therein which extend to the outer circumference of the cylindrical contour, and which cross each other and communicate the egress area with the annular clearance around the radially reduced portion.