| 摘要 |
<p>PURPOSE:To provide an inexpensive and sure dustproof structure at the mating surface of an upper case section and a lower case section constituting the external case of a digital multimeter as well as in the area surrounding an operation member laid on the upper surface of the external case. CONSTITUTION:A packing 11 as the elastic seal material is interposed between an upper case section 3 and a lower case section 4 forming the external case of a digital multimeter in such state as collapsed in an aslant direction relative to the thickness direction of the case, thereby forming a sealing structure. Also, a double sealing structure is provided around a rubber key 62 as an operation member, using projected and recessed surface formed on the side of the key 62 and the upper case 3. Furthermore, a sealing structure is formed around a rotary switch 6, using an O-ring 54 clamped in a direction orthogonal with the thickness direction of the case. According to this construction, a sealing structure for waterproof and dustproof purposes can be formed via the application of simple constitution and with reliability.</p> |
