Second machine for sub-dividing the ribands

Fig. 369. —The riband is engaged between the circular knives, C , C , which are mounted upon the rollers R , R ; thin bra washers keep these knives apart at a distance which may be varied, and two extreme washers mounted with screws on each roller maintain the whole system. The axes of these rollers traverse two uprights M , M , furnished with bra es, and with adjusting screws to approximate them at pleasure. The axis of the lower roller carries a wheel r , which takes into another smaller wheel r′ , placed upon the same shaft as the pulley P , which is driven by a cord. The diameter of the wheel r is three times greater than the wheel r′ . The pulley P is twice the size of the wheel r′ ; and its cord pa es round a drum B , which drives the rest of the machine. The threads when brought to this state of slenderne , are put succe ively into tubs filled with cold water; they are next softened in hot water, and elongated as much as po ible in the following manner:—They are wound upon a reel turned quickly, while the operative stretches the caoutchouc thread with his hand. In this way it is rendered 8 or 10 times longer. The reels when thus filled are placed during some days in a cold apartment, where the threads become firm, and seem to change their nature. This state of stiffne is e ential for the succe of the subsequent operations. The threads are commonly covered with a sheath of silk, cotton, or linen, by a braiding machine, and are then placed as warp in a loom, in order to form a narrow web for braces, garters, . If the gum were to exercise its elasticity during this operation, the different threads would be lengthened and shortened in an irregular manner, so as to form a puckered ti ue. It is requisite therefore to weave the threads in their rigid and inextensible, or at least in contractile condition, and after the fabric is woven to restore to the threads of caoutchouc their appropriate elasticity. This restoration is easily effected by pa ing a hot smoothing iron over the ti ue laid smoothly upon a table covered with blanket stuff. See Braiding Machine .