US2381398A

US2381398A - Apparatus for processing cord

Info

Publication number: US2381398A
Application number: US534127A
Authority: US
Inventors: George P Bosomworth
Original assignee: Firestone Tire and Rubber Co
Current assignee: Bridgestone Firestone Inc
Priority date: 1944-05-04
Filing date: 1944-05-04
Publication date: 1945-08-07
Anticipated expiration: 1962-08-07

Description

Aug. 7,1945. G. P. BosoMwoRTl-l APPARATUS FOR PROCESSING CORD Filed May 4, 1944 .NJ-MHD :NQS 2 1 E954 moho: maan man? .z .5z8 Swan Pzmzoo mn I ..mv.mn.nmmmw..rz hnz8 @U zu azi F2 n zozE.. l :mi I! Q l @.39 v

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Patented Aug. 7, 1945*` 2,381,398 i ArrAnA'rUs Fon PROCESSING com) George nl. Bosomworth, Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron, `Ohio, a corporation of Ohio Application May 4, 1944, Serial No. 534,127 (C1. zzz-59.5)

4 Claims.

This invention relates to means for processing cord, and especially relates to apparatus for pro-v ducing 'improved rubber-reinforcing cord.

.. One process of the type relating to the present invention is that wherein cord which is to be used as reinforcing in a fan belt is immersed in a latex bath and then dried, the cord initially being drawn from one spool and ultimately being4 wound up upon a second spool. Ordinarily this process involves Athe use of a constant speed windup mechanism and tension is obtained on the cord by the use of a brake on the letoff means that controls unrolling the cord from the spool on which it is initially wound. In this process, the factors of speed and tension of the cords are so interlocked that it is difficult to obtain either to any predetermined figure, with any degree of accuracy. Furthermore, the tension on the cord at the wind-up means is equal to the drag on the cord at the let-oft' means, plus whateverintermediatefriction may develop between the two points. 'I'his means that the cord is subjected to a rather unknown or uncontrollable maximum tension, with the tension, of course, on the cord varying at various places in the cord vprocessing apparatus.

It is an object of the present invention to provide a novel, improved apparatus for processing,

cord uniformly to produce high tensile strength rubber-reinforcing cord of uniform properties.

Another object of the invention is to provide an uncomplicated cord treating apparatus in which the wind-upspeed of the cord does notl control the tensioning'of the cord as it is being treated. Afurther object of the invention is to provide v an easily operated, inexpensive apparatus for processing vvarious portions of a continuous cord or other elastic material, such as fabric, uniformly as it passes through the apparatus.

v The foregoing and other objects will be manliest as the specication proceeds.

In the accompanying drawing:

Figure 1 is a diagrammatic elevation of one embodiment o f the invention; and

Figure 2 is a diagrammatic plan View of.cord driving means ofthe apparatus of Figure 1.

have the cord wound therearound in several convolutions so as to obtain a purchase, or grip on the cord. The rolls I3 have a plurality of annular corrugations in their faces, as shown, but may comprise a plurality of narrow pulleys which are abutted on and turn with a common shaft. One

`o1' the rolls I3 may be driven through a non-reversible Worm gear 34 by any suitable means, such as an induction motor 35, to rotate the roll ata constant speed. Usually the second roll I3 is not positively driven except by the cord passing therearound.

In being drawn from the spool II, the cord may passover a guide pulley I 4,- and next pass to a liquid bath, in this instance latex I6, contained in a tank I5. The latex is of any suitable composition andy properties and may be either naturally or artificially created. 'I'he cord I0 is ler around vertically aligned rolls I1 and I 8' while in the tank I5. Auxiliary rolls I9 under spring pressure hold the cord against the rolls I1 and I 8, as it passes therearound and cause a certain amount of deformation to facilitate impregnation. Wet cord from the tank I5 then passes around the rolls I3 which are 'adapted to advance the cord convolutions along the rolls whereby the cord is led into the rolls at one end thereof and drawn off at the other end of same,

' as shown in Figure 2.

After the cord passes around the constant speed rolls I3, I3 it is then drawn through a drying oven 22, and the cord is subjected to -a uniform constant tensional 'pull set up thereon through

rolls

23, 23, which are similar to the rolls I3 and also obtain a, purchase or grip on the cord I0. However, the rolls 23 diier from the rolls I3 in one material regard in that one of the rolls 23 usually is driven by a direct current, constant torque motor 36 which is of the permanent magnet type and has a wound rotor. Since the radius of the rolls 23 is constant, the constant torque motor sets up a constant tension on the cord so that, in all events, the cord, as it Referring in detail to the accompanying draw ing', there is shown a, vcontinuous length of cord I0, which originally is wound upon a spool II, that is journaled on a shaft I2 and that usually has a drag yor brake not shown) associated therewith to keep the cord taut as it is drawn from the spool. The cord I0 is drawn from the spool II by means of cylindrical rolls I3, I3 which are driven at constant vspeed and which 23, has a constant tension exerted thereon, which tension is uniform through out any length of material processed. A feature of the invention is that this tension is controlled solely by the peripheral speed of the rolls 23 with relation to the peripheral speed of the rolls I3. The motor driving the rolls 23 should have a constant torque over a fairly wide speed range in order to maintain constant tensionI on the cord I0.

Any suitable means may be used to heat the drying oven 22, thus a current of hot air may be latex 26. As the cord is drawn out of the bath 26, it is led around a guide pulley 21 and into a drying oven 29, the cord being wound around av series of pulleys 28 suitably journaled in the dry ing oven 29. Ordinarily the pulleys 28 should be vertically spaced and be positioned at the end of the oven, as shown. The oven 29, may be` associated with or be part of the oven 22, and may be heated in any desired manner.

The dry cord from the oven 29 is led around a roller 3l and then to a wind-up reel 32, which `has level Winding means 33 associated therewith to distribute cord evenly over the reel 32. A further feature of the process is that the reel 32 is driven by a motor 31 which has a constant horsepower output over about at least a 3 to l speed range and which exerts a constant tensional force upon the cord Il) between the rollers 23, 23'

and the wind-up reel 32 and winds up the cord I at a speed equal to the let-off lineal speed of the cord from the spool II plus the increase in length of the cord due to its stretch under tension. The motor driving the reel 32 produces this tension upon the cord regardless of the amount of cord wrapped upon the reel, so that the radius of pull, or torque set up by the reel 32 may vary but the actual tensional force on the cord remains constant for a large increase over the original radius ofthe reel 32; for example, an increase in diameter of the reel from 3 to I2 inches due to the cord wound thereon. The wind-up rate is substantially constant but varies slightly to compensate for slight variations in the degree of stretch of the cord under the constant tension exerted thereon.

In the apparatus disclosed it is essential that the rolls I3 .be driven at a constant speed and the

rolls

23, 23 have a constant torque drive applied thereto. Preferably, the reel 32 has a means of driving same so that the pull set up on the cord and the wind-up rate of same is substantially constant. One electrical motor that has proved suitable for use as a driving means 31 for the reel 32 is a series type direct current motor with a large external resistance and with the field for the motor being in series with the armature. Then by using a three phase alternating current driving motor 35 to drive the 'rolls I3, which motor operates at the desired speed, the cord I0 Will be drawn off the spool II at the desired rate, and the speed of the motor approaches but does not exceed the synchronous speed thereof. The non-reversible worm gear 34 connecting the motor to the roll will not overrun the motor so as to change the speed at which the cord is drawn off the spool I I.

It is generally desirable to apply the maximum tension to the'cord during the heating step immediately following the initial dipping operation, that is, between rolls I3, I3 and

rolls

23, 23. A tension in the order of 60 pounds has been found satisfactory in this stage when the cord being the higher tension existing in the cord between rolls I3 and 23 is localized therebetween, and is not transmitted to the cord traveling from rolls 23.A In the case of a conventional fan belt cord, a tension in the order of 35 pounds has been found suitable to apply by means of the driven wind-up means 32.

Now it will be seen that the tensional force exerted on the cord in the rst step of processing same is a known, controllable tension which can .be uniformly exerted on various lengths of cord.

" Furthermore, the rate of wind-up of processed cord upon 'theWind-up reels does not determine processed was a conventional cotton or rayon fan the tension'of the cord when wound up, nor does it control the tensional force set up on the cord during the rst stages of processing same. lt will beseen that this principle applies to cord,

o'r fabric treating processes regardless of the specific steps of same, as long as the cord is to be tensioned and wound up or used at a rate which is .to be independent of the tensioning treatment of the cord but which sets up a substantially uniform tension and a uniform residual stretch in the cord.

From the foregoing it will he seen that an uncomplicated, easily operated apparatus is provided for processing various lengths of cord or fabric or the like uniformly. At the same time, the apparatus serves to divide, Vor separate the stretching of the cord from the wind-up rate of the cord, thereby providing two separate, controllable operations which are exerted upon the cord.

The finished cord produced by the present invention has been found to be unusually uniform and of high quality. The cord may be produced to exhibit a' very high tensile strength, which does not vary appreciably between various lengths or among diierent lots of the processed cord. The cord also possesses more uniform cross-sectional dimensions than conventional processed cord, and imparts a. longer useful life to a rubber article, such as a fan belt, pneumatic tire or other reinforced rubber article incorporating the cord.

While one embodiment Aof apparatus of the process of the invention has been completely illustrated and described herein, it will be appreciated that modification may be made without departing from the scope of the invention, as defined inthe appended claims.

' What is claimed is:

1. In apparatus for uniformly stretching rubber-reinforcing cord, means driven by a constant speed motor for propelling the cord, means driven by a constant torque motor for thereafter applying a predetermined stretching tension to the cord, a third means driven by a motor having a constant power output for winding up the cord, said constant speed motor driving said rstnamed means through a non-reversible Worm gear, whereby the cord is propelled at a constant rate which is independent of the thereafter applied predetermined tension.

2. In apparatus for processing cord, means driven by a. constant speed motor through a nonreversible Worm gear for propelling the cord, means driven by a constant torque motor for thereafter applying a predetermined stretching tension to the cord, means for releasing a portion of said stretching tension ,from the cord, and an additional means for advancing theV cord under a diminished but uniform tension.

3. In apparatus for processing cord, means driven by a motor for propelling the cord, and a second means driven by a constant torque motor for thereafter applying a predetermined stretching tension to :the cord, said first-named motor driving said first-named means througha nonreversible worm gear, whereby the cord is propelled at a constant rate which is independent of Ithe thereafter applied predetermined tension.

4. .In apparatus for uniformly processing rubber-reinforcing cord, means for impregnating the stant torque motor for thereafter applying a predetermined` stretching tension to the cord, means for drying the c'ord under the stretching tension, means for releasing a portion of said stretching ltension from the cord, an additional means for advancing the cord under a diminished but uniform Itension, means for impreg` nating the cord while under said diminished tension, and means for drying the cord while cord with latex, means driven by a constant 10 under said diminished tension.

speed motor through a non-reversible worm gear for propelling the cord, means driven .by a con- .GEORGE P. BOSOMWORTH.