Recep Eren, Gülcan Özkan, Comparison of Heald Frame Motion Mehmet Karahan* Generated by Rotary Dobby Department of Textile Engineering Faculty of Engineering and Architecture and Crank & Cam Shedding Motions University of Uludag, Abstract * Uludag University, Vacational School of Technical Sciences, Mechanism models are introduced for rotary dobby, crank & cam shedding motions. Textile Program, Equations governing heald frame motion are derived. Heald frame motion curves are Görükle Campus, obtained and compared with each other. It is shown that higher heald frame maximum Görükle, 16059 Bursa, TURKEY velocity & maximum acceleration, as well as a longer approximate heald frame dwell, are E-mail:
[email protected] generated by the rotary dobby rather than the crank or cam shedding motions, due to the intermittent nature of the rotary dobby shaft’s motion. Key words: rotary dobby, cam shedding motion, crank shedding motion, weaving, weaving machine. n Introduction frame dwell period, the maximum heald tween its foremost and rearmost positions. frame speed and the maximum heald The slider crank mechanism converts the Shedding is one of the principal op- frame acceleration. angular displacement of link 4 to the lin- erations in the weaving process, which ear displacement of the heald frame. The separates warp yarns into two layers to foremost position of link 4 corresponds form an opening for weft insertion called n Working principle of crank, to the bottom position, and the rearmost a shed. Crank, cam and dobby are shed- cam and rotary dobby position of link 4 corresponds to the upper ding motions which use a heald frame shedding motions position of the heald frame.