| 摘要 |
PROBLEM TO BE SOLVED: To provide a screw including a looseness prevention washer for preventing a looseness and removal or dropping under application of load and environment of continuous vibration for a prolonged period.SOLUTION: This invention relates to a screw with looseness prevention washer in which a washer 10 made of rigid and high hardness metal, steel material having a wedge function is mounted at a contact surface between a fastening surface of a member to be fixed and a screw head seat surface, a wedge 10a integral with the washer 10 is driven into a clearance automatically formed between the member to be fixed of the fastening part and a screw shaft as the screw 1 is fastened. The screw shaft below the screw head seat surface is set to be a smaller diameter than the maximum diameter 12 when the screw is started to make a thread in such a manner that the washer 10 is mounted and a clearance for driving a wedge therein is formed, a recess 11 is formed, the mounted washer 10 causes the screw to be smoothly rotated to enable the screw to be fastened and at the same time, the wedge 10a mounted at the fastening part of the washer 10 is driven and fastened into a clearance between the member to be fixed and the screw shaft, the screw is rigidly fixed and its looseness is prevented.SELECTED DRAWING: Figure 1 |
