| 摘要 |
<p>870,201. Thermal switches. MINNESOTA MINING & MANUFACTURING CO. Aug. 7, 1958 [Aug. 15, 1957], No. 25389/58. Class 38 (5). [Also in Group XIII] A column consisting alternately of N-type elements 27 and P-type elements 28 separated by insulators 29 is arranged between two members 10, 11, the differential expansion and contraction of which is used to actuate a contact 16 movable between fixed contacts 17, 18. The elements 27, 28 are connected in series by members 30, 31 which are electrically insulated from the members 10, 11 but in good heat transfer relation therewith. If current from a D.C. source 36 flows upwards from terminal 32 to terminal 33, the left-hand side of the column is cooled and the right-hand side heated, thereby causing member 10 to contract and 11 to expand. The contact 16 is thus moved to engage contact 18. If the polarity of the D.C. is reversed, contact 16 engages contact 17. In a modification, Fig. 2 (not shown), the contact 16 is carried on an arm integral with the members 10, 11. Specifications 765,884, 766,999, 806,640 and 814,594 are referred to.</p> |
