US2517861A

US2517861A - Web feeding device for roll type driers

Info

Publication number: US2517861A
Application number: US93934A
Authority: US
Inventors: John J Franklin
Original assignee: Proctor and Schwartz Inc
Current assignee: Proctor and Schwartz Inc
Priority date: 1949-05-18
Filing date: 1949-05-18
Publication date: 1950-08-08
Anticipated expiration: 1967-08-08

Description

l! 5 7 44.1. FRANKLIN ,5 ,8

' m'm:nmc DEVICE .FOR ROLL ms DRIERS Filed my .18,- 1949 v z-sneet's-sheet 1 1950 J. J. FRANKLIN 2,517,861 ,IEB FEEDING DEVICE FOR ROLL TYPE nRIERs 7 Filed lay 18, 1949 -2 Sheds-Sheet 2 7 7 ilk 5/ Patented- Aug. 8, i950 2,517,861 was FEEDING nnvrcn'roa' ROLL mi; nnmas John J. Franklin, Glenside, Pa., assignortolroctor & Schwartz, Inc., Philadelphia, Pin, acorporation of Pennsylvania Application May 18, 1949, Serial No. 93,934

- 8 Claims. -1

This invention relates to new and useful improvements in roll type driers, and more particularly to driers for continuous web materials wherein the material is threaded back and forth vertically between and around two vertically spaced sets or series of rolls and advanced thereby in one general direction.

In driers of this type the problem exists of effectively controlling tension in the web resulting in shrinkage of the material as it passes through the drier. It has been proposed to minimize tension in the web in roll type driers by providing a separate individual driving motor of the shaded-pole typeior each roll, and while this was a stepin the right direction it did not completely overcome the difficulty because one characteristic of this arrangement is that excess driving power existing in a motor toward the delivery end of the drier is added to the excess power of the preceding driving motor cumulatively back to the feed end of the drier. This places the maximum tension on the material at thepoint where it contains the most moisture and is most subject to stretch. In the past this condition has been put up with due to insufficient public interest in the shrinkproof properties of materials. However, in ,recent years the public has become quite shrinkproof minded, and it has become increasingly more important to eliminate stretch in a material during the process of drying.

With the foregoing in mind, one object of the present invention is to provide a roll drier of the type described wherein tension in the material and resulting stretch thereof is substantially set forth and described with reference to the acv companying drawings, in which:

, 2 lar to Fig. 3 but showing a modified form of the invention; and

Fig. 5 is a diagrammatic elevational view showing still another modification of the invention.

Referring now more particularly to the drawings, a roll drier of the type to which the present invention pertains may comprise a housing i including a top 2 and oppositely disposed side and end walls 3 and 4, respectively.

Arranged within the housing longitudinally thereof is an upper series or set 01' rolls 5, SJ, 8, 9, l0 and II, and a lower series of similar rolls I2, 13,, l5, l6, l1 and [8, respectively. Each of these rollsis provided with a shaft or trunnions which extend axially beyond the ends of the roll and project outwardly through suitable openings 2l in the housing side walls 3 where they are rotatably mounted in suitable bearings IQ, for example, as shown in Fig. 2 of the drawing.

A continuous web a. enters the housing I I through an inlet opening 22 therein and then outwardly of the housing I through a delivery opening 23 at the opposite end of the housing from the inlet 22.

The path of travel of the web a: is defined by relatively transverse partitions 24 arran ed interiorly of the housing I and disposed adjacent the several courses of the web in a manner subdividing the housing into upper and lower chambers. Into these chambers air heated by sets of coils 25 is forced by pumps 26, the heated air ultimately discharging through slots 24a in said partitions into contact with the traveling web 3:.

According to the present invention the web 2:.

is withdrawn from the drier by means of a suitable pull-out roll 3| which is driven at a pre- Fig. 1 is a side elevational view, partially section, showing a roll type drier embodying the present invention;

Fig. 2 is a sectional view on line 2-2, Fig. 1;

Fig. 3 is a diagrammatic elevational view illustrating the invention and particularly the control for the motor which drives the pull-out roll at the delivery end of the drier; I

determined speed, and each of only the lower rolls l2, l3, ll, l5, l6, l1 and IS in the drier are driven at a surface speed faster than the surface speed of the said pull-out roll 3|.

In the embodiment of the invention shown in Figs. 1 and 3 each of only the lower rolls l2, l3, ll, l5, l6, l1 and I8 is provided with a separate individual and independent drive in the form of an electric motor 21 which may drive its roll through a suitable speed reducing pulley and belt arrangement 28 of conventional type. Also, the web a: is fed into the housing I at a predetermined definite linear speed with relation to the s n'faqe peed. of the lower series of rolls, for exelectric motor 32, for example, through a pulley and belt drive 33.

After passing between the quetch rolls 29 and 30 and before entering the drier, the web :2: passes about a pair of idler r0115 '34 and and an intermediate compensator roll 35. The compensator roll 33 is mounted in suspended relation from a cable 31 which passes over a pulley 38 and has a counterbalance weight 39 fixed to its other end. The counterweight 39 is calibrated to cause the compensator roll 36 to rise and fall according to the slackness and tension, respectively, in the web at.

Connected to'the pulley 38 to rotate therewith is a smaller pulley 40 which drives through a belt 4|, a pulley 42 that actuates a rheostat 43 in the electric circuit of the motor 32 which drives the pull-out ro1l 3|. The rheostat 43 is arranged so that in the event of slack in the web a: at the inlet to the drier the resulting upward movement or rise of the compensator roll 36 will operate the rheostat to speed up the motor 32 and, conversely. in the event of increased tension on the web at 'the inlet causing the roll 36 to be drawn downwardly, the rheostat is operated-to slow down the said motor 32, thereby synchronizing the speed of the pull-out roll 3| with the quetch rolls 29 and 30. 1

As previously pointed out, a particular requirement of the present invention is that each of the lower series of rolls be driven at a surface speed faster than the surface speed of the pull-out roll 3 I. This can be accomplished, for example, either by utilizing conventional type electric motors for individually driving the rolls of the lower series together with suitable mechanical devices to provide and maintain the required surface speed of the rolls with relation to the rates of feed and delivery, respectively, of the web at, or by the use of low powered electric motors of the type known as single phase shaded-pole motors, which have a normal operating speed to drive therolls of the lower series at a surface speed faster than that of the pull-out roll 3|.

Preferably, however, the motors 21 are of the shaded-pole type. These motors are particularly adapted for use in the present instance because of certain characteristics of this type of motor which permits the motor to be stopped, as by overloading, for indefinite periods of time, with current flowing through the motor windings, without the motor becoming overheated or damaged. These same characteristics permit the motor to be restricted to any speed within its full range, from its maximum number of revolutions per minute, when under minimum load, to zero or full stop, under load, without harm, by variations occurring in the torque load applied to the motor. The characteristics of this type of motor also allow the motor to start under full load from a dead stop.

In operation of the drier in accordance with the present invention, the quetch rolls 29 and are driven at a predetermined fixed speed required to feed the web a: to the. drier at the desired rate, and each of the rolls l2, l3, l4, l5, l6, l1 and I8 of the lower series is driven at a surface speed greater than that of the quetch rolls as previously described. Also, the speed of operation of the pull-out roll is less than the speed 9i il? S lower series of rolls.

the web a: at the roll l9 which decreases the pull.

4 By driving the pull-out roll at a slower speed than the lower series of rolls in the drier it will be apparent that there is a tendency to produce slack in the web 2 between the pull-out roll 3| and the last drier roll I 3. 1 This produces slack in of the roll i8 on the web with the result that a similar slack is produced at the preceding roll IT. This condition progresses from roll to roll of the bottom series thereof until a similar slack exists in the web a: at the first roll l2. This slack in the web at and ahead of the roll l2 allows the compensator roll 36 to rise under the influence of the counterweight 39 so that the rheostat 43 is operated to speed up the motor 32 and pull-out roll 3| which immediately corrects the slack condition between pull-out roll 3| and the last drier roll it, and so on, back through the drier.

The overall range of variation in the speed of the 'pull-out roll is small and as it is speeded-up in the described manner the moderately taut condition of the web a: is re-established between pullout roll 3| and roll l8, and ultimately through the entire length of the fabric from the quetch rolls through the drier to said pull-out roll. Since the rolls l2, l3, l4, l5, l6, "and II are each driven at a speed faster than the top speed of the pullout roll 3| it will be apparent that no substantial tension will be created in the web a: and what occurs is that the web in the drier assumes a balanced substantially tensionless condition in which the lower series of rolls have just enough driving power to overcome the friction of the upper series of rolls and move the web a: forward through the drier. The tension in the web a: at the inlet end of the drier never exceeds the tension produced by the counterweight 39 which, of course, can be determined to give any desired maximum tension in the web being dried.

It is not necessary to the present invention that a positive feed, such as the quetch rolls 29 and 30, be employed to feed the web a: to the drier, and the web may be drawn into the drier simply by the pull exerted thereon by the driven lower series of rolls in the drier. Thus, in the embodiment of the invention shown in Fig. 4 of the drawings the web 3: is drawn from a small truck or other support 50 over a series of idler rolls 5|, 52 and 53 and thence into the drier by the driven lower series of rolls l2, l3, l4, l5, I6, I! and I8, respectively. In passing from the idler 52 to the idler 53 the web 1: contacts a spreader bar 54 which operates to remove wrinkles from the said web.

In the arrangement of Fig. 4 the pull-out roll 3| is driven at a fixed constant speed from its motor 32 and, according to the present invention, each of only the lower series of rolls in the drier is driven at a surface speed faster than the surface speed of the pull-out roll 3| In the embodiment illustrated, each of the lower rolls is provided with a separate individual and independent drive in the form of an electric motor 21, preferably of the shaded-pole type, which may drive its roll through a pulley and belt arrangement 28 as aforesaid. I

In operation of this form of the invention, at the start the faster speed of the lower drier rolls tends to produce a slack condition in the web :0 between the pull-out roll 3| and the last drier roll l9 which decreases the pull of the roll I 8 on the web with the result that a similar slack is produced at the roll I! and so on back to the first roll l2. The existence of a slack condition at the first roll l2 reduces the pull on the web with the result that the speed of the web is momentarily lessened until the web again is brought into driving 'relationwith the first roll I2 and progressively through the drier to establish, after a brief interval, a balanced substantially tensionless condition in which the lower series of drier rolls have just enough driving power to move the web x into and through the drier.

Another modification of the invention is shown in Fig. 5 of the drawings wherein, instead of providing separate drive means for the individual lower rolls of the drier as previously described, the lowerseries of rolls l2, l3, ll, IS, I6, I! and I8 are driven mechanically from a single power source. In the arrangement illustrated the lower series of rolls are driven by a common or single chain or belt 55 which may be driven, for example, from the pull-out motor '32, through a conventional drive arrangement 56. However, in this embodiment, as in the case of those previously described, it is essential that the surface speed of the lower drier rolls be faster than the surface speed of the pull-out roll 3|, and the operation of the drier will be as set forth herein.

From the foregoing description, it will be apparent that the present invention provides a roll drier wherein tension in material and resulting stretch thereof is substantially eliminated. The invention further provides a substantially tension-free roll type drier which is automatic in operation and entirely efilcient and foolproof in use.

While a particular embodiment of the present invention has been illustrated and described herein it is not intended that the invention be limited to such disclosure and changes and modifications may be made therein and thereto within the scope of the following claims.

I claim:

1. In a web-treating apparatus, upper and lower series of a plurality of web rolls around which a web is passed up and down and between the succeeding rolls of each series, means to feed the web to said web rolls at a predetermined rate of speed, pull-out means operable to (raw the web from the web rolls at a rate of speed controlled by variations in tension in the web at the feed thereof, and drive means for the lower series only of said web rolls operable to drive each. of said lower series rolls at a surface speed greater than the rate of feed of the web and greater than the rate of withdrawal of the web by said pull-out means.

2. In a web-treating apparatus, upper and lower series of a plurality of web rolls around which a web is passed up and down and between the succeeding rolls of each series, feed means for said web operable to feed the web to the web rolls at a predetermined rate of speed, pull-out means operable to draw the web from said web rolls, variable speed drive means for said pull-out means controlled by variations in tension in the web, and drive means for the lower series only of said web rolls operable to drive each of said lower series rolls at a surface speed slightly greater than the rate of feed of the web by said feed means and greater than the rate of withdrawal of the web by said pull-out means.

w 3. In a web-treating apparatus, upper and said web rolls, variable speed drive means for said pull-out means, control means operable in response to variations in tension in the web between said feed means and first web roll to vary the speed of said pull-out means, and drive means, for the lower series only of said web rolls operable to drive each of said lower series rolls at a surface speed slightly greater than the rate of feed of the web thereto by said feed means and greater than the rate of withdrawal of the web by said pull-out means.

4. In a web-treating apparatus, upper and lower series of a plurality of web rolls around which a web is passed upv and down and between the succeeding rolls of each series, feed means operable to feed the web to the first roll in said lower seriesat a predetermined rate of speed, pull-out means operable to di aw the web from the said web rolls, variable speed drive means for said pull-out means, a movable compensator roll about which the web passes disposed between said feed means and the lower series of web rolls, control means actuable by said compensator roll in response to variations in tension in the web operable to vary the speed of said pull-out means, and drive means for the lower series only of said web rolls operable to drive each of said lower series rolls at a surface speed slightly greater than the rate of feed of the web thereto by said feed means and greater than the rate of withdrawal of the web by said pull-out means.

5. In a web-treating apparatus, a housing, upper and lower series of a plurality of web rolls in said housing around which a web is passed up and down and between the succeeding rolls of each series, feed rolls adjacent one end of the housing operable to feed the web thereto and to the web rolls at a, predetermined rate of speed, a pull-out roll adjacent the other end of the housing operable to draw the web from the series of web rolls, means operable in response to variations in tension in the web between the feed and web rolls operable to vary the speed of said pull-out roll, and driving means for the lower series only of said web rolls operable to drive each of said lower series rolls at a surface speed slightly greater than the rate of feed of the web thereto by said feed rolls and greater than the rate of withdrawal of the web by said pull-out roll.

6. In a web-treating apparatus, upper and lower series of a plurality of web rolls around which a web is passed up and down and between the succeeding rolls of each series, feed rolls operable to feed the web to the web rolls at a predetermined rate of speed, a pull-out roll operable to draw the web from the said web rolls, means between the feed and web rolls operable in response to variations in tension in the web operable to vary the speed of said pull-out roll, and a separate independently operable driving means for each of the lower series only of said web rolls operable to drive each of said lower series rolls at a surface speed slightly greater than the rate of feed of the web thereto by said feed rolls and greater than the rate of withdrawal of the web by said pull-out roll.

, 7. In a web-treating apparatus, upper and lower series of a plurality of web rolls around which a web'is passed up and down and between the succeeding rolls of each series, feed rolls operable to feed the web to the web rolls at a predetermined rate of speed, a pull-out roll operable to draw the web from the web rolls, variable speed drive means for said pull-out roll, a movable compensator roll-about which the web passes disposed between said feed rolls and the web rolls, control means actuable by said compensator roll in re- 7 spouse to variations in tension in the web operableto vary the speed of said pull-out roll, and

driving means for the lower series only 01' said web rolls operable to drive each of said lower series rolls at a surface speedslightly greater than the rate of feed of'the web thereto'by said feed rolls and greater than the rate of withdrawal of the web by said pull-out roll.

8. In a web-treating apparatus, upper and lower series of a plurality of web rolls around which a. web is passed up and down and between the succeeding rolls of each series, feed rolls operable to feed the web to the first r011 in said lower series at a predetermined rate of speed, a pull-out roll operable to draw the web from the last roll in the upperseries, variable speed drive means for said pull-out roll, a movable compensator roll about which the web passes disposed between said feed rolls and the web rolls, control means actuable by said compensator roll in response to variadrive each of said lower series rolls at a surface I speed slightly greater than the rate of feed of the web thereto by said feed rolls and greater than the rate oi withdrawal of the web. by said pullout roll.

JOHN J. FRANKIm.

REFERENCES CITED The following references are of record in the flle of this patent:

UNI'IED STATES PATEN'I'B Number Name Date 2,135,516 Hurxthal Nov. 8, 1938 2,474,717 Belcher June 28, 1949