Abstract: A coupling instrument is provided that can easily attach or detach a main body to or from a cleaning part in a cleaning device. The coupling instrument includes a first coupling member including a bulging part having a slant part. A side peripheral part of the slant part is tapered toward a tip thereof. A first protruding part is formed in a protruding manner around the bulging part. The coupling instrument further includes a second coupling member including a fitted part in which the bulging part can be loosely fitted, and a second protruding part formed in a protruding manner around the fitted part. The second protruding part is adjacent to the first protruding part; and the second coupling member has a plurality of engaging parts arranged around the fitted part.

Abstract: An engaging mechanism includes an engaging member and an engaged member freely detachably engageable with the engaging member. The engaging member includes an engaging main part and an engaging claw part formed on the engaging main part, both resiliently deformable. The engaging claw part has an inwardly curved engaging surface defined by a first curvature continuous curve. The engaged member includes an engaged part engageable with the engaging claw part and having an outwardly curved engaged surface defined by a second curvature continuous curve. The engaging surface and the engaged surface contact each other at a linear contact area at a time from when the engaging claw part and the engaged part are in engagement with each other through to when the engaging claw part is disengaged from the engaged part. A curvature of the engaging surface at the linear contact area is smaller than a curvature of the engaged surface at the linear contact area.

Abstract: To provide a cleaning device coupling instrument that can easily attach or detach a main body to or from a cleaning part in a cleaning device, and the cleaning device including the cleaning device coupling instrument. A cleaning device coupling instrument 1 which can couple a main body in a cleaning device to a cleaning part to be fixed to the main body has: a first coupling member 10 including a bulging part 100 having a slant part the side peripheral part of which is tapered toward a tip thereof; and a second coupling member 20 including a fitted part 200 in which the bulging part 100 can be loosely fitted.

Abstract: An engaging mechanism includes an engaging member and an engaged member freely detachably engageable with the engaging member. The engaging member includes an engaging main part and an engaging claw part formed on the engaging main part, both resiliently deformable. The engaging claw part has an inwardly curved engaging surface defined by a first curvature continuous curve. The engaged member includes an engaged part engageable with the engaging claw part and having an outwardly curved engaged surface defined by a second curvature continuous curve. The engaging surface and the engaged surface contact each other at a linear contact area at a time from when the engaging claw part and the engaged part are in engagement with each other through to when the engaging claw part is disengaged from the engaged part. A curvature of the engaging surface at the linear contact area is smaller than a curvature of the engaged surface at the linear contact area.

Abstract: To provide a cleaning device coupling instrument that can easily attach or detach a main body to or from a cleaning part in a cleaning device, and the cleaning device including the cleaning device coupling instrument. A cleaning device coupling instrument 1 which can couple a main body in a cleaning device to a cleaning part to be fixed to the main body has: a first coupling member 10 including a bulging part 100 having a slant part the side peripheral part of which is tapered toward a tip thereof; and a second coupling member 20 including a fitted part 200 in which the bulging part 100 can be loosely fitted.