| 摘要 |
576,774. Blasting cartridges and charges. HERCULES POWDER CO. Nov. 17, 1943, No. 19213. Convention date, June 30. [Class 9 (i)] [Also in Group XXV] Two or more blasting cartridges 1 are assembled in end-to-end propagating relationship by an internally threaded sleeve, or sleeves, 2 with the threads 3 of which lugs 5 on the cartridge wrappings are engaged. Alternatively, the threads may be formed on the wrappings and' the lugs in the sleeves. In other forms, the threads may be provided at the ends only of the sleeve or cartridge elements. The sleeves, which may be of paper, cardboard, metal or plastic, may be made by feeding a thread-forming strip on to a mandrel at the correct pitch and then winding over the thread a strip of material to form the outer wall 6 of the sleeve, adhesive being applied to the inner surface of the strip. The lugs 5 may be adhered to the cartridge wrapping by winding a strip carrying them at suitable spacings on to the wrapping, and applying pressure. |
