US 3654781 A
Apparatus for the continuous extraction of water from flat material such as leather comprising a drum and at least one counter pressure roller contiguous therewith. A permeable belt is arranged to run between the rollers to carry the material in contact with the surface of the drum. The rollers are angularly positionable about the periphery of the drum, and the belt is adjustable in its envelopment of the drum.
Description (OCR text may contain errors)
United States Patent Plechac [151 3,654,781 [451 Apr. 11, 1972 APPARATUS FOR THE CONTINUOUS EXTRACTION OF WATER FROM FLAT MATERIAL Inventor: Bohuslav Plechac, Otrokovice,
Czechoslovakia Assignee: Statni vyzhumny ustav kozedelny, Gottwaldov, Czechoslovakia Filed: Apr. 3, 1970 Appl. No.: 25,415
Foreign Application Priority Data Apr. 17, 1969 Czechoslovakia ..PV 2727-69 U.S. Cl ..69/41, 68/45 Int. Cl. ..C 14b 1/08 Field of Search ..69/41, 43; 100/160, 176, 153, 100/154; 68/45, 242, 267, 244, 245; 162/358, 360
References Cited UNITED STATES PATENTS 77,861 5/1868 Baker ..68/45 Wenk ..100/154 Quirin Cooley 2,365,658 12/1944 Schumacher..... 3,198,695 8/1965 Justus ..l62/360X FOREIGN PATENTS 0R APPLICATIONS 2,096 1392 Great Britain 5.....68/45 Primary Examiner-Alfred R. Guest Attorney-Richard Low and Murray Schaffer  ABSTRACT Apparatus for the continuous extraction of water from flat material such as leather comprising a drum and at least one counter pressure roller contiguous therewith. A permeable belt is arranged to run between the rollers to carry the material in contact with the surface of the drum. The rollers are angularly positionable about the periphery of the drum, and the belt is adjustable in its envelopment of the drum.
7 Claims, 1 Drawing Figure PATENTEDAPR 11 I972 3,654,781
INVENTOR V BOHusLm/ PLECHHQ APPARATUS FOR THE CONTINUOUS EXTRACTIONOF WATER FROM FLAT MATERIAL BACKGROUND OF THE INVENTION The present invention relates to apparatus for the continuous extraction of water from flat material and in particular leather.
During the treatment of hides, the tanning and drying steps cause the resultant leather to become saturated with water which before any subsequent operation must be drained and at least 40 percent of its moisture extracted. This may be accomplished through a variety of techniques whereby the surface water and the water retained by capillary action is removed from the leather. Small pieces of leather may be merely squeezed to obtain the above result, however, for large pieces of leather mechanical extracting means must be employed.
In one such apparatus, the material is pressed between a pair of hydraulic or screw actuated plates. This technique is effective in batch operation but it requires an unnecessarily long working time and because the leather is not perfectly uniform, the efficient extraction of the water is difficult.
Further, since the material is pressed between a pair of static plates it is difficult to stretch or flatten.
A rotary drum drying press is much faster and is capable of continuous operation. In this type of device the material is passed through a pair of opposed drum rollers pressed against each other. However, certain drawbacks occur. An unusually high pressure is generally required to be exerted on the drums in order to remove the water within the interval of travel between them. This requires not only the great application of mechanical force upon the rollers but a high energy input to cause rotation of the drums. Furthermore, since the material is not uniform in thickness, great care and attention must be paid to the insertion of the leather between the drums.
An endless supporting band is sometimes provided to support the material as it enters and passes between the rolling drums. This technique is effective in holding the material but requires a rather expensive band which is made from a felt material which must be carefully maintained during operation against tearing or other damage. Further, a felt band, because of its stiffness, thickness and low porosity does not extract water from the leather at high speeds and with the use of such bands the apparatus must be run slower than usual. This reduction in the overall efficiency of the apparatus is often compensated by enlarging the active drying drum as well as other components of the machine to create a longer pressing interval. As a consequence the machine becomes more costly and complex.
It is an object of the present invention to provide a rotary drum apparatus overcoming the drawbacks of the prior art.
It is a further object of the present invention to provide a rotary drum water extractor which is capable of operating at high speeds and at high efiiciency and effectiveness.
It is a further object of the present invention to provide a rotary drum water extracting device which employs an endless material supporting band of highly durable material and long lasting material.
It is a further object of the present invention to provide a drum type water extracting apparatus wherein the counter pressure rollers are resiliently mounted so as to be radially forced against the drying drum in a manner to exert a variable pressure upon the material being dried.
It is another object of the present invention to provide a rotary drum drying apparatus wherein the endless belt may be variably enveloped about the drum so as to adjust the length at which the belt is contiguous with the drum and the length of the pressing interval.
Other objects and advantages of the present invention will be apparent from the description which follows hereafter.
2 SUMMARY or INVENTION "An endless water permeable belt, adapted to support the material contiguous to the surface of the drum is arranged to run between the drum and cooperating rollers. The belt is provided with supporting idler rollers which are adjustable relative to the drum so that the belt may be caused to variably envelop the outer surface of the drum, thereby the length of the time the material is pressed between the drum can be predetermined.
In the preferred form there are at least a pair of counter rollers each being angularly adjustable about the periphery of the drum and each being resiliently biased to force against the surface of the drum. Further it is preferred the belt be made of metallic, or strong plastic like material and that each of the drums and the rollers be covered with a absorbent material such as a felt cloth or jute cover.
BRIEE DESCRIPTION OF THE DRAWING In the following description reference is made to the attached drawing in which the single FIGURE represents a schematic view in side elevation of a drum type water extracting device embodying the principles of the present invention.
DESCRIPTION OF INVENTION As seen in the drawing the apparatus comprises a rotary drum 1 of relatively large diameter which is freely mounted about an axle 2. Beneath the drum 1 are located a pair of counter pressure rollers 3 and 4, of smaller diameter. Each of the counter rollers 3 and 4 are arranged on their own axles 5 and 6 respectively which are connected to the axle 2 of the drum 1 by an inwardly directed constantly acting resilient actuator 7. The actuator 7 may be mechanical, hydraulic or pneumatic devices of a conventional nature providing a radially inwardly pulling force on the counter rollers 3 and 4 directed toward the center of the drum 1 which in operation may be somewhere between 10-150 Kp/cm. Preferably the actuators 7 are provided with self-regulating devices so that the rollers 3 and 4 may accommodate varying thicknesses of material between them and the drum 1 while constantly maintaining the inward pressure at a sufficient level to efficiently extract the water. In addition the actuators 7 and the connecting rods, between the axle 2 and the roller axles 5 and 6, are adjustable angularly with respect to each other. That is, they are conventionally mounted to the axle 2 so that they can be arcuately moved, through an angle a, about the outer periphery of the drum surface. In this manner the pressure area between the respective rollers 3 and 4 and the active drum 1 can be selectively defined and predetermined.
Both the drum 1 and the counter rollers 3 and 4 are covered with an absorbent material 8 such as a felt cloth or jute covering. It is preferred that these coverings be in the nature of absorbent pads which when compressed act to withdraw the moisture retained within the leather. In this manner the drum 1 and the rollers 3 and 4 can be adapted to act both to squeeze and to suck out the water during travel of the material between it.
Located to run between the drum 1 and the counter rollers 3 and 4 is a water permeable endless band 9. The band which is preferably permeable can be made of a strong woven or knit cloth, or of a metal sheet having holes or of a cloth or metal screen. Plastic material may also be used. The band 9 is carried at either end over driving wheels 10 and over intermediate idler wheels 11 positioned on either side of the drum 1. The idler wheels 11 are mounted on a conventional shaft and individually adjustable frame housings so as to be movable radially, inwardly and outwardly of the axle 2 of the drum 1 as well as in a direction parallel to a tangent to the surface of the drum 1. In this manner the idler wheels 11 may be selectively positioned about the drum so as to lengthen the contiguous portions of the upper surface of the belt 9 and the surface of the drum 1, or to vary the envelopment of the band 9 about the drum 1, as may be seen from the dotted line position shown in the Figure.
The drive wheels are connected in conventional fashion to suitable means including a motor and gearing mechanism so that they can be driven in unison or individually to carry the belt in the direction shown by arrow A. The return portion of the belt 9 preferably passes in contact with the lower tangential edge of the counter rollers 3 and 4 as clearly seen in the Figure. The drive mechanism for the wheels 10 are also provided with adjustable control mechanisms so that the speed of the belt 9 can be increased or decreased as desired. Suitable interlocking mechanisms and automatic control systems between the drive means and the pressure actuators 7 may also be provided.
The belt 9 serves as a stretcher and carrier for the flat material 12 which, for preferable use of this apparatus, is leather. The material is conventionally withdrawn from the water tanning or drying bath and rolled on to the upper surface of the belt 9 where it may be suitably flattened and stretched. As the belt 9 is moved in the direction of arrow A the material is carried into contact with the drum 1 and subsequently is pressed between the drum and the counter pressure rollers 3 and 4. Because of the structure of the belt the material moves in a secure and continuous path and is carried without any stress on the material (i.e., in a loose and slack condition) into the pressure contact area and in the manner as it was initially laid on the belt.
The belt 9 further functions to rotate the drums 1 and the counter pressure rollers 3 and 4 in the direction of the arrows B. Consequently separate drive means for the drum and/or counter rollers 3 and 4 are unnecessary although if desired they may be used. The curved or convex face of the drum 1 when combined with the approaching belt 9, as positioned by the idler roller 1] establishes an advantageous condition for the smooth and soft entry of the flat material into the pressure area between the drum 1 and the pressure roller 3 preventing creasing of the flat leather material and maintain the material in stretched condition during the entire water extraction process. It is preferred that the force between the counter roller 3 and the drum 1 be maintained at such a degree as to permit the free passage of the material even though water is pressed from it. The material passes from the roller 3, while still in contact with the drum 1, into the pressure area between the counter roller 4 and the drum 1. It is preferred that the pressure between the counter roller 4 and the drum 1 be maintained at a level substantially higher than that maintained at the initial pressure area between the counter roller 3 and the drum 1. This can be done because by the time the material reaches the area of counter roller 4 it has already been somewhat flattened and somewhat relieved of a large portion of the water so that a higher degree of pressure may be exerted upon it without fear of creasing or dislodging its position on the belt 9. After the material passes the pressure area of counter roller 4, it continues pressed along the surface of drum 1, being held there by the belt 9. This continues until the material moves over the exiting roller 11.
By properly selecting the position of the belt 9, the speed at which it moves and the pressures of the counter rollers 3 and 4 the maximum amount of water may be extracted from the material in the shortest amount of time. It has been found under numerous occasions that the speed of the drum 1 (that is, the speed at which the operation can be accomplished) can be anywhere between 5-30 m per minute for most leather goods. I
During operation the water is extracted from the material primarily by the pressure of the counter rollers 3 and 4 against the main active drum 1, escaping through the holes in the permeable belt 9. The use of a permeable strong and durable belt rather than an absorbent felt belt is advantageous, since it will, by itself, readily support the material and can be adapted so that it too acts to compress the material against the surface of drum 1. Water also runs over the edges of the belt 9 and accumulates below the apparatus for discharge out of a suitable outlet. The absorbent pad 8 located both about the drum 1 and the counter rollers 3 and 4 also act to absorb by capillary action moisture which lies on or rises to the surface of the material. This effect is enhanced by arranging the idler roller 11 on the exit side of the drum I in such a position that the belt 9 maintains a maximum contiguous length with the drum 1 increasing the effective length the absorbent pad 8 on the drum 1 is maintained against the material 12.
-' An additional advantage lies in the fact that the resilient connecting means between the axle hub 2 and the axles 5 and 6 are angularly positionable about the center of the drum 1 so that the counter rollers 3 and 4 may be spaced at selective positions about the periphery of the drum 1. In this manner they may be spaced from each other a more or less distance, enabling the contact surface between the belt 9 and the drum 1 and consequently the length of the arc during which the material 12 is compressed between the belt 9 and the surface of the drum 1 to be lengthened or shortened, as desired.
It will be appreciated that the present invention is disclosed with reference to a FIGURE drawn in schematic form. This FIGURE omits from its conventional construction details such as the mounting of the wheels 10 and as well as their aforementioned drive means. The drum 1, it has been noted, is of a large diameter, and it may be of an axial length chosen to accommodate particular material or of a size capable of accommodating a variety of materials. Its mounting details and those of the counter rollers are also omitted. It will thus be apparent that various structural details may be employed in the present invention and that various and numerous modifications may be made to them. It is accordingly the intention of this disclosure to be illustrative only of the principles of the invention and not limiting in any manner.
What is claimed:
1. Apparatus for the continuous extraction of water from flat materials such as leather comprising a drum and at least one compression roler arranged contiguous to the drum, an endless water permeable belt supporting said material on its upper surface, said belt being arranged to run between said drum and said roller so as to compress the material between said drum and said belt, idler rollers supporting said belt in contiguous contact with a portion of the periphery of said drum, said idler rollers being selectively adjustable relation the exterior of said drum so as to vary the length of the contiguous'portion of said belt and thereby the length of time said material is located therebetween.
2. The apparatus according to claim 1 wherein said drum has a substantially large diameter and said idler rollers are mounted for free rotation about their central axes, and said water permeable belt is provided with means for driving the same, said idler rollers being rotatably actuated by the movement of said belt.
3. The apparatus according to claim 1 wherein there are two compression rollers spaced from each other and means for supporting said compression rollers in contact with the surface of that portion of said belt which is in contact with said drum, said means including biasing means acting radially of said drum to force said rollers into contact with said belt.
4. The apparatus according to claim 3 wherein the supporting means are angularly adjustable and positionable with respect to eachother to thereby vary the position of said compression rollers about the periphery of said drum.
5. The apparatus according to claim 4 wherein the radial biasing means comprises variable resilient mechanism whereby the force exerted between each compression roller and the drum may be preselected.
6. The apparatus according to claim 5 wherein the force between the drum and the initial compression roller, in the direction of belt travel, is less than the force between the drum and the other compression roller.
7. The apparatus according to claim 6 wherein the drum and compression rollers are provided with absorbent pad covers cooperating with said belt to remove moisture from the surface of the material passing therebetween.