| 摘要 |
1,194,231. Measuring strain electrically. AUTOMATION INDUSTRIES Inc. Aug. 11, 1967 [Aug.29, 1966], No.37080/67. Heading G1N. A strain gauge unit, before it is put in use, comprises an active grid portion 20, Fig. 5 suspended in an aperture 36 of a frame 35 so that both sides of the grid are exposed, by extended end terminal portions 26 and tab leads 30, which are attached to the frame. The strain gauge is formed by a micro-photo etching process on a carrier sheet (21), Fig. 1 (not shown), to which it is adhesively secured. Part of this sheet is subsequently removed and tab leads 30 welded to the gauge terminals (25). The frame 35, consisting of two layers, one (37), Fig.3 (not shown), of thin transparent paper provided with adhesive on its inner side and a second backing sheet (39), Fig. 3 (not shown) of paper or plastics, a section of the latter being removed at one end at an area 42 to expose the adhesive, is then placed over the strain gauge with the area 42 in contact with the terminal portions 26, the tab leads being secured to the frame by adhesive tapes 43, 44. Finally the carrier sheet (21) is removed. For transport the unit may be enclosed in a protective envelope. In use, the backing sheet (39) is removed and the adhesived side of the sheet (37) applied to the surface whose strain is to be measured, a base coating (47), Figs.8-12 (not shown), of electrically insulating material having first been applied to the surface. An adhesive bonding material is then applied to the grid portion 20 of the unit whereby it is bonded to the coating 47. The frame together with the terminal portions 26 are then removed, apertures 27 assisting in the removal of the latter, and the gauge is ready for use. |
