GB296417A - Improvements in mining cartridges - Google Patents

Abstract

296,417. Frantz, S. G. Aug. 31, 1927, [Convention date]. Flexible tubes.-A non-explosive cartridge for mining and blasting comprises a tube or bag which is adapted to be expanded by fluid pressure after being inserted in a bore-hole. The bag preferably consists of rubber or the like surrounded by metallic armouring. In the construction shown in Figs. 1, 6, and 9, the ends of a rubber bag 10 are clamped between parts 5, 9 mounted at each end of a conduit member passing through the bag. The conduit conists of two parts 11, 11<a>, telescoping within a cylinder 12, which contains springs pressing the parts 11, 11<a> in opposite directions and thereby tending to keep the rubber bag extended. A series of longitudinal rods 6, forming part of the armouring described below, carry nuts 7 bearing against the parts 5, and by this means the extension of the rubber bag, due to the springs, is limited. Fluid such as air or water is admitted to the expansible bag through a pipe 2, passing through a handle 1 and connected to the conduit member 11. A check valve 15 is provided at the outer end of the exhaust member 11<a>. The armouring shown is mainly built up of sections, each consisting of a flattened metal helix such as 21, extending along the whole length of the rubber bag, and being tapered at each end. Rods 19<a>, preferably of spring steel, pass longitudinally through each helix, and connect each section to the adjacent ones, the ends of these rods passing slidably through the end members 5. The sections are not all of the same width, each section 21 having on either side of it a narrower section 20, whilst between the sections 20, and connected thereto by longitudinal fulcrum rods, are members 24 formed of slotted flattened tubing. The tie-rods 6, mentioned above, pass centrally through each helical section, and, in addition, longitudinal "filler rods " 22 of varying lengths pass through the helices. The rods 22 as well as the rods 6 are preferably welded to the helices. Fig. 6 shows the bag 10 deflated, and shows the positions which the sections of the metal covering assume in longitudinal corrugations moulded in the bag. In the modification shown in Figs. 13, 14, the rubber bag 10<a> is moulded with longitudinal projections 10<b>, and the armouring consists of links 26, joined together by means of parallel rods 27 of spring steel &c., extending throughout the length of the cartridge. The ends of these rods are anchored in a mass of metal 28, such as zinc, which is cast into a recess formed in the head 5 at each end of the cartridge. Two further modified forms of armoured covering are also described, one consisting of intertwined wires attached to the bag, and the other comprising a series of similar flattened helices combined with longitudinal rods. For certain purposes, a metallic armoured covering for the expansible - bag may be dispensed with, the bag being then made of material such as that used for motor tyres.