GB967042A - Needle loom - Google Patents

Abstract

967,042. Needling fibrous webs. FIBERWOVEN CORPORATION. March 6, 1963 [March 16, 1962], No. 8876/63. Heading D1R. A needle loom comprises means to oscillate the needle board 50, 54, 66 or 70 to and fro between predetermined points so that the needles thereon penetrate into and are withdrawn from the fibrous web to be needled and resilient means to apply a force to assist the means to oscillate the needle board to change direction at each of said predetermined points. The web 38 to be needled may be formed by depositing fibres from an air stream and fibres of the layers comprising the web may be oriented with respect to the length of the web as the web passes through the needle loom. In one embodiment, Fig. 2, the web 38 is advanced by intermittently driven rollers 40, 42, 44, 46, 48 to pass between two pairs of needle boards 34, 36 and may be needled only when stationary or may be moving when the needles begin penetration and stationary as the penetration is continued. The needle boards 50, 54, 66, 70 of each pair are carried on identical rocker arm structures 58, 60, 74, 76, respectively, pivoted to the machine frame 10 at 62, 64, 78, 80, respectively. The paths of penetration of needles 52, 56 of the boards 50, 54 are a mirror image of one another and the needles 52, 56 are preferably inclined at an angle which is a tangent to an arc having a centre of curvature at 62, 64 respectively, and similarly for the needles 68, 72 of the boards 66, 70. Perforated web-guide plates 82, 84, 86, 88 are provided. The needles 56 penetrate the web 38 at the same time as the needles 68 and the needles 52 at the same time as the needles 72. The structure 76 includes an axle 90, Fig. 3, having a number of spar members 96 secured thereto. A tubular member 98 is rigidly secured to each spar 96, a beam 100 extends through each spar 96 and the needle board 70 is secured to one end of each of the spars 96 by clamps 104, 106, Fig. 2. The structures 58, 60, 74, 76 are oscillated by equal-length connecting rods 108,110 operating off of a crank shaft 112 having eccentrics 114,116 arranged 180 degrees out of phase with each other sothat the pairs 34, 36 move in opposite directions to each other, the structures 58, 60 being pivotally connected by a link 118 and the structures 74, 76 by a link 126. An auxiliary motor (not shown) may be provided in addition to that for driving the shaft 112 to assist in starting the oscillation of the pairs 34, 36 to overcome initial compression of the resilient drive means described below. The resilient means comprises a number of air springs 144, 152, 158, 160 positioned between one of a number of cross beams 142 and the member 98 or the beam 100. Each spring 144 comprises a flexible wall 150 extending between plates 146, 148. Clockwise rotation of the structure 70 causes compression of air in the springs 152 and build up of potential energy therein. Upon change of direction of rotation of the structure 76 the potential energy stored up in the springs 152 is released as kinetic energy to apply a driving force to the board 70 and a build up of potential energy takes place in the springs 144. The mean air pressure in each spring and therefore the spring constant may be varied by the air system of Fig. 18 (not shown). In a modification, Fig. 12, steel coil springs 144<SP>1</SP>, 152<SP>1</SP> are positioned one each side of the pivot P of the structure 76 and may be employed either as compression springs or tension springs or both. In a further modification, Fig. 14, two separate air springs 144<SP>11</SP>, 152<SP>11</SP> are separated by a portion 10<SP>1</SP> of the frame 10. A yoke 190 having a plate 192 over the spring 144<SP>11</SP> is provided with bolts 193 secured to the structure 76. This air spring arrangement may also be applied to a needle loom in which the needle board is oscillated in a linear path, Fig. 17 (not shown). In a still further modification Fig. 15 (not shown), one air spring is provided on each side of the structure 76. In another modification, Fig. 11 (not shown), the air springs of Fig. 14, are replaced by coil springs. In yet another modification, Fig. 10, a single leaf spring 200 is moved by a stop 204 or a shoulder 206 on a pin 202 secured to the structure 76 to either position B or position A respectively. In a further modification, Fig. 16, a torsion bar spring 181 is rigidly connected to the structure 76 and pivoted at P to the frame 10 so that the needle board 70 oscillates angularly. An arm 183 is rigidly connected to the spring 181 and has at its free ends two pairs of air springs 143 secured to the frame 10 to resist the spring 181 turning about its axis. In an alternative embodiment, Fig. 4, four pairs of needle boards 250 are carried by pivoted structures 230, 232, 234, 236. Crank cams 256, 258, driven by a belt 270 are each provided with a pair of eccentrics having equal rods 260, 262, 264, 266 secured thereto and connected to the structures 232, 236, 230, 234, respectively, so that the web 248 is penetrated at four different places, two places on each side of the web. Air springs 280, 282 are mounted on opposite sides of crossbeams 278, the springs 282 being supported on a cross beam 276 of the respective structure. Specifications 923,762, 950,260 and 967,043 are referred to.