| 摘要 |
1,105,556. Nuts; Screw-and-nut gearing. ALLM€NNA SVENSKA ELEKTRISKA, A.B. 10 June, 1965 [12 June, 1964], No. 24533/65. Headings F2H and F2Q. [Also in Division B3] A screw-and-nut gearing system has a twopart nut comprising an inner threaded bushing 1, preferably made of graphite, and an outer bushing 2 which may be made of steel. The bushing 1 is prestressed by a ring 3 screwed into the bushing 2 by means of a tool inserted into a central polygonal opening 4 or in recesses 5. Ring 3 is tightened when the nut has been heated to a temperature equal to or above the intended working temperature and the thread 6 is cut after the nut has cooled. The bushing 2 may have a coefficient of expansion 3% above that of a screw used with the nut. In a modification (Fig. 2, not shown), the bushing (2) has a longitudinal slot to allow the insertion of tangentially arranged screws (8) for tightening the bushing (2) around bushing (1), which is threaded on its inner and outer surfaces. Compression rings (11) are held against the ends of sleeve (1) by end-pieces (15) secured by bolts (12) extending longitudinally through the bushing (2). The bushing (1) is pre-stressed by passing a bolt (13) (Fig. 3, not shown), through the assembly consisting of bushing (1) and rings (11) before insertion in the outer bushing. |
