Patent GB-822348-A (GB)
Title: A method of repairing tubeless tyres on the wheel rim, and a material and tools for performing the same
IPC: B29C73/06
Filed: 1956-04-12
Abstract: 822,348. Plugging tubeless tyre punctures. GRUBER, O., GRUBER, W., and GRUBER, M., [trading as STAHLGRUBER O. GRUBER & CO.]. April 12, 1956 [April 16, 1955; June 14, 1955 (2); July 15, 1955; July 16, 1955], No. 11186/56. Class 144 (1). A tubeless tyre puncture is plugged by a plug of rubber having a hardness less than that of the tyre tread and comprising a shaft portion 1, Fig. 3, and an enlarged mushroom-shaped head portion 3, by securing the plug in a tube 4 and pushing the assembly, plug-head first, through the puncture from outside the tyre until the plug-head 3 is clear of the inside of the tyre, Fig. 3, and then passing bonding material through the tube around the plug and, via perforations 4a in the tube, on to the puncture walls so that on withdrawal of the tube 4 the plug head 3 abuts, and is bonded to, the tyre inner surface. In an alternative arrangement, the tube is surrounded by a sleeve for passage of the bonding material. In use, the puncture is first reamed out by a tool, Fig. 5B, comprising a handle 5 at one end of a cylindrical rasp 6, the outer end 7 of which is tapered from an intermediate cutting-edge 7a, which is of larger diameter than the rasp 6 and faces the handle 5, towards a terminal needle-like probe 8. The handle 5 has two wing portions 9, 10 pivoted thereto which fold around the rasp 6 to provide a circular cutting-edge at their free ends effective to cut an enlarged recess 27, Fig. 5A, in the tread surface surrounding the puncture prior to the reaming thereof. After reaming, the puncture is coated with a lubricating and bonding paste composed of 100 parts of unvulcanized rubber, 5 to 30 parts of diffusing softeners; 1-2.5 parts of activated zinc oxide, 5-15 parts of a metal (aluminium) powder, ultra-accelerators and solvent. This paste is packed in a cylindrical cartridge 21, Fig. 4, having a domed bottom 22 and an internally-fitted sealing-lid 18. The cartridge is received in a tool comprising an elongated frame member 11 having a base-plate 12 on which the cartridge 21 sits with its dome 22 aligned with a hole in a headpiece 13 of the frame 11. A handle grip 14 is pivoted at its lower end to the frame 11 and carries a link rod 15 which bears on a spring- loaded plunger 16 guided in the frame to press on the cap 18 of the cartridge. For coating the puncture, the cartridge is pierced and placed on the base-plate 12, and a nozzle 19 pivoted to the frame 11 is swung into alignment with the headpiece 13, Fig. 6c, and placed over the puncture. The handle 14 is operated to squeeze a limited quantity of the paste into the puncture, after which the nozzle is swung clear and the tube 4 is attached by a bayonet catch 20 to the headpiece 13. The tube 4 and plug 1 are pushed into the puncture and the handle 14 operated to squeeze the remainder of the paste from the cartridge through the tube 4 and perforations 4a to form a mound 26 on the inside of the tyre. On withdrawal of the tube 4 the plug-head 3 abuts and is bonded to the tyre inside, and the puncture constricts and bonds around the plug body 1. The protruding tail of the plug 1 is cut flush with the tread surface to leave an expanded rivet-like portion in the tread recess 27.