Abstract: The present invention relates to a roll blind comprising a rolling device provided at a lower end of a vertically suspending curtain sheet to roll the curtain sheet, and a shaft rolling and releasing a traction rod vertically extending from a head rail at an upper end to move up and down the rolling device at a lower end, the roll blind further comprising a driving gear rotating together with the shaft around a fixed shaft and having a cylindrical drum extending in an axial direction; a friction spring tightly wound around the drum and having a protruding end protruding in a radial direction; and a tube wheel rotating together with the friction wheel via the protruding end, wherein the curtain sheet comprises a front sheet and a rear sheet disposed front and rear with a predetermined horizontal interval therebetween, and a number of blind sheets connecting the front sheet and the rear sheet, the rear sheet is relatively fixed to the head rail at its upper end to be fixed in the horizontal direction, the front

Abstract: The present invention relates to a rolling device for roll blind comprising a roll pipe assembly having a tunner therein in an extending direction; a pair of cover assemblies inserted into and coupled to both end parts of the roll pipe assembly; a fixing shaft accommodated in the tunnel of the roll pipe assembly and having both end parts prevented from being rotated by each cover assembly; and a spring assembly being an elastic rotating element which is accommodated in the roll pipe assembly and accommodates the fixing shaft therein, and having one end part which is integrally rotated with the roll pipe assembly and the other end part whose rotation is prevented by the fixing shaft. According to the present invention, various curtain sheets with different kinds of material and a blind made of bamboo, reed or other whose rolling thickness is increased as well can be used in the roll blind.

Abstract: A packet processing method using a multiple fault tolerant network structure capable of performing communication of a whole ring and disusing a useless packet when a fault occurs on a plurality of connection lines and nodes by using a dual ring structure. Nodes are connected as a ring shape separately having two input lines and two output lines, and each node selects one packet after receiving two inputs and disuses the other packet and transmits the select packet through the two output lines at the same time. The present invention can solve the fault problem occurred on a multiple link or nodes, can perform network function efficiently by disusing a useless packet, accordingly it is possible to perform stable operation for several years or several decades after the network installation and decrease maintenance expenses.

Abstract: The present invention relates to a packet processing method using a multiple fault tolerant network structure, in particular to a packet processing method using a multiple fault tolerant network structure which is capable of performing communication of a whole ring and disusing a useless packet when a fault occurs on a plurality of connection lines and nodes by using a dual ring structure.