Patent ID: 8089014
Filing Date: 2012-01-03
Classification: H01H

Abstract:
1. A waterproof push button switch comprising: a push button member that is in a first position when a pushing force is not applied, and is linearly moved from the first position to a second position when the pushing force is applied; a switch mechanism that is turned on by the force applied from the push button member when the push button member is in the second position, and is turned off when the push button member is not in the second position; a base case comprising a bottom wall portion and a cylindrical peripheral wall portion, and provided with a switch mechanism receiving chamber that has an opening portion, which opens in a direction where the push button member is located, and receives the switch mechanism; a cover case having a through-hole through which a part of the push button member slidably passes, and comprising: a waterproofing seal member that is elastic and is arranged and compressed between the end surface of the peripheral wall portion of the base case and the opposite surface of the cover case to cover the opening portion of the base case; and a coupling mechanism that couples the second cylindrical wall portion of the cover case and the peripheral wall portion of the base case, with the base case fitted into the base case fitting chamber of the cover case, wherein a thickness of the waterproofing seal member and a structure of the coupling mechanism are determined so that the waterproofing seal member is compressed to form an annular watertight seal portion between the end surface of the peripheral wall portion of the base case and the opposite surface of the cover case, with the base case fitted into the base case fitting chamber; a gap is formed between the peripheral wall portion of the base case and the second cylindrical wall portion of the cover case and between the opposite surface and the waterproofing seal member, the gap extending from an opening portion of the base case fitting chamber to the annular watertight seal portion to completely surround the watertight seal portion; and a thickness of the gap is determined to allow a resin entered into the gap from the opening portion of the base case fitting chamber to reach the watertight seal portion by surface tension; the cover case is integrally formed of a flexible synthetic resin material; a plurality of window portions that communicate with the base case fitting chamber are formed in the second cylindrical wall portion of the cover case in a peripheral direction of the second cylindrical wall portion at predetermined intervals; a plurality of engaging proiections are formed integrally with and outwardly from the peripheral wall portion of the base case, the engaging proiections deforming the second cylindrical wall portion to push it radially outwardly when the base case gets fitted into the base case fitting chamber, and being fitted in the window portions and engaged with borders of the window portions when the base case is completely fitted into the base case fitting chamber; the coupling mechanism is constituted from the borders of the window portions and the engaging projections; and the window portions are formed to expose a part of an outer peripheral surface of the waterproofing seal member therefrom.