Patent DE-19802994-C1 (DE)
Title: Laying system for yarn bands, used in knitter
Inventor: ERTH DIETER
IPC: D04B23/10
Filed: 1998-01-28
Granted: 1999-05-20
Abstract: System has a layer with guides to lay yarn diagonally to and fro between the hooks at transport chains at a warp knitter. To form layers of yarns with diagonal yarns at different angles together with parallel single yarns, a single band of yarns has a width \- 50% of the gap between the transport chains (3, 3'). A diagonal yarn guide lays the yarns in a zigzag between the hooks of the chains (3, 3'). The chains (3,3') are moved constantly round the width (32) of the yarn band during the double stroke movement of the diagonal yarn layer (4). The downwards section of the yarn band from the guide is accelerated, directly after the layer has passed over the hooks, for an opposite reversing movement, and is pressed down by a press rail (42) moving with the diagonal guide under the openings into the chain hooks. On a direction changes, a further and similar press rail (43) depresses the yarn band.  Diagonal yarn guide moves between the transport chains (3, 3') with a constant and lower speed in the laying direction. The guide is accelerated, shortly before reaching the points of the hooks at the chains (3, 3') to be moved in the opposite direction shortly after passing over them at the same speed, to move at a slower rate towards the opposite chain. On passing over the hooks, at the chains (3, 3'), the diagonal guide is stopped, for the press rail (42) to be lowered rapidly while the layer is at rest. While the press rail is being depressed, the guide is rapidly moved in the opposite direction to pass back over the hook points at a high speed, to decelerate for movement to the opposite chain. While the diagonal guide is positioned outside the transport chains (3, 3'), it has an additional longitudinal movement component with the chains. An Independent claim is also included for a yarn laying mechanism with a diagonal yarn guide with a width equal to or more than half the gap (32) between the transport chains (3, 3') parallel to them. The yarn guide moves on a path parallel to the bisection of the intersecting diagonal yarn bands (11, 11'). The diagonal yarn layer has a guide for each yarn along a straight line, moving close above the hook points at the transport chains (3, 3'). Each press rail (42, 43) has a drive (51, 51'), operated independently of each transport chain (3, 3') with stroke movements and timings. The width of the diagonal yarn guide equals the product of twice the chain gap (32) and the tangents of 30 deg  or 45 deg . The layer guides (44, 44') are at right angles to the transport chains (3, 3'). The knitting point (2) has an additional feed (21) for the tensed warps (14) to be bonded in place. A further layer (6) for the wefts is at the transport chains (3, 3'), to lay the bands of parallel wefts at right angles to them. Each press rail (42, 43) has a control head near the transport chains (3, 3'), with a control bar and a monitor, with one at the bar and the other at the drive. Each bar drive (51, 51') is fixed to the frame, near the transport chains (3,3'), with control line (71-73) connections. The press rail drives (51, 51') are at the chain guides, as control pistons (51, 51'). The gap (32) between the transport chains (3, 3') at the diagonal yarn layer is smaller than the gap (32') between the chains (3,3') directly at the knitting point (2) of the warp knitter. One of the gaps (32, 32') can be adjusted to increase the tension on the laid diagonal yarns between the chains (3, 3'). Fixed yarn guides with yarn brakes and intermediate yarn stores for the diagonal yarns are near the diagonal yarn layer. The drive motor (47) for the diagonal yarn layer (4) and the drives (51, 51') for the press rails are operated by a control unit (7), to synchronize their actions with the yarn laying and warp knitting cycles.