US3872695A

US3872695A - Wringer

Info

Publication number: US3872695A
Application number: US404004A
Authority: US
Inventors: Josef Busek
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-10-09
Filing date: 1973-10-05
Publication date: 1975-03-25
Anticipated expiration: 1992-03-25
Also published as: FR2202160A1; DE2249369A1; FR2202160B1; DE2249369C3; CS171292B2; GB1444246A; IT995686B; DE2249369B2

Abstract

A device for wringing fluid out of laminar articles by compressing the articles between two platens, one of which is covered on its article contacting face by an inflatable membrane and at least one of which is covered by a flexible web forming the article-contacting surface and made of porous material which has pores to permit water draining from the articles to be channelled to the side edges of the platen. The porous web allows efficient drainage of fluid and the inflatable membrane allows the exertion of a constant pressure over the article even when the article has an uneven surface, and is thus particularly suitable for the drying of treated leather.

Description

United States Patent Busek Mar. 25, 1975 [541 WRINGER FOREIGN PATENTS OR APPLICATIONS 1 Josef Busek, (iartenstrasse 16, 986,006 3/1963 United Kingdom 69/48 D-8190 Wolfratsha sen, rm ny 118.943 6/1958 U.S.S.R a. 69/48 [22] Filed: Oct. 5, 1973 1 Primary E.\'aminerAlfretl R. Guest [21] Appl 404004 Attorney, Agent or Firm-Spencer & Kaye [30] Foreign Application Priority Data [57] ABSTRACT O t. 9, 1972 G 2 Y 2249369 c erm m) A device for wrlngmg fluid out of lammar art1cles by 52 us. c1 69/47 69/48 100/222 Compressing the articles between two platens" one of 68/242 which is covered on its article contacting face by an [51] Int Cl I Cl4b 17/00 inflatable membrane and at least one of which is cov- [58] Field 43; 68/242 ered by a flexible web forming the article-contacting 68/21. ii 29/121 surface and made of porous material which has pores to permit water draining from the articles to be chan- [56] References Cited nelled to the side edges of the platen.

UNITED STATES PATENTS The porous web allows efficient drainage of fluid and l 3 W970 the inflatable membrane allows the exertion of a 53 Q 3 constant pressure over the article even when the 3/1911 article has an uneven surface, and is thus particularly 6/1953 suitable for the drying of treated leather.

3.160.553 12/1964 3.181409 6/1965 GIZISS 29/121 R x 8 Clam, 2 Drawmg Flgules PATENTED MARZS I975 SHEET 2 or 2 WRINGER BACKGROUND OF THE INVENTION The invention relates to a device for wringing laminar articles, the device being particularly, though not exclusively, suited to the wringing of articles of irregularly varying cross-sectional thickness, such as leather.

Leather that has just been tanned is still extremely wet, and this moisture needs to be removed. In the early days spindle presses were employed for this purpose, a plurality of leather skins being arranged in superimposed layers between the platens, the platens depressed and the press left for some considerable time while the liquid being wrung out trickled laterally out of the compressed material. However it was not possible with these presses to remove sufficient moisture.

The technology therefore changed to water extracting machines operating essentially on the same principle as a laundry calender and having two co-operating pressure rollers driven in opposite directions to squeeze the leather therebetween. In order to compensate for the irregularly varing cross-sectional thickness of leather being processed, each of these rollers may be covered with a layer of felt. It has been found however that in use this felt covering is subject to considerable wear and tear since the rollers must not only fulfil the task of wringing but also that of conveying the skins through the machine. More-over, operation of such machines requires considerable skill on the part of the operators in order to ensure that the leather skin is correctly fed into the machine and to prevent the leather from creasing. Finally, because such machines must operate at a very high roller pressure, for example of the order of some 70 atmospheres, in order to effect a satisfactory degree of wringing, the surface structure of the felt covering becomes impressed in the surface of the leather, thereby restricting the use to which the processed leather may be put.

SUMMARY OF THE INVENTION According to the present invention I provide a device for wringing a laminar article comprising an article treatment station, first and second pressure members disposed within said treatment station and having respective article-contacting surfaces; means for effecting approach and separation of said pressure members; inflatable membrane carried by said first pressure member and facing said second pressure member; and a web of porous flexible material interposed between said membrane and said second pressure member to form one of the article-contacting surfaces, the pores of said porous web communicating between its edges and said one article-contacting surface to enable liquid to drain away from said one article-contacting surface.

The invention can thus provide an apparatus with a considerably higher throughput than other noncalendering devices, without the quality of the end product or the efficiency of liquid extraction being impaired.

Tests carried out with a device according to the invention have shown that a pressure of as little as to atmospheres suffices for the device to operate at the same level of effectiveness as conventional machines. It is, moreover, easier to prevent creasing when wringing, especially in the border region of the skins being processed than with the conventional machines. Finally, the comparatively low wringing pressure makes it possible to wring out doubled or folded skins, without the crease remaining visible in the finished, wrung out skin. Finally, a plurality of superimposed leather skins can be wrung out with this device.

Advantageously an intermediate layer is associated with each of the pressure surfaces. It has proved particularly advantageous to produce the intermediate layers of a fabric woven of monofilament fibers since such woven fabrics are non-absorbent and enable without any difficulty lateral drainage of the wrung out liquid.

The membrane may be pneumatically or hydraulically inflated. Water is suitably utilized as hydraulic inflation medium and has no detrimental effect on the leather when leakages occur in the membranous system.

For facilitating feeding the skin into the device and removal of the leather after completion of the wringing operation, at least one run of at least one conveyor belt is guided between the pressure members. The material of the conveyor belt should have substantially the same properties as the porous flexible webs so as not to hamper the lateral discharge of the extracted liquid. Alternatively it would even be possible to provide for the conveyor belt itself to serve as the porous flexible web.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a cross-section of one embodiment of the device according to the invention; and

FIG. 2 shows a cross-section analogous to FIG. 1 of a slightly modified embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIG. 1, the upper pressure surface is designated by the reference numeral 1, the lower one by the reference numeral .2. The lower pressure surface 2 is in the form ofa rubber membrane 4 spanning a support 3. The support 3 is stationary and forms part of the frame of the device. The gap between the membrane 4 and the support 3 communicates via a supply line 5 with a hydraulic accumulator (not shown). The head of the device is designated by the numeral 6, and is stationary like the support 3. In the head 6 a press ram 7 is longitudinally reciprocable in the direction of arrow 8 along guideways schematically indicated at 9 and 10. The pressure surface 1 is covered by a porous flexible web 11 and the pressure surface 2 is covered by a similar web 12, both webs being laterally secured in the region of securing

rails

13 and 14, respectively. The

webs

11, 12 are of a non-absorbent material, e.g. a synthetic 7 material, and more suitably consist of a woven fabric of monofilament fibers. The cross-sectional thickness of the webs must be so dimensioned that an adequate draining towards the side is possible.

The upper web 11 is backed with a layer 15 of an absorbent material. The absorbent layer 15 is elastically compressible, and may thus be formed of a sponge or foam material.

The ram 7 is lockable in final adjusted position. To this end it is provided with wedge-like sloping surfaces 16 on the reverse side. Two wedges 18 are adapted to be pushed into the gap between the sloping surfaces 16 and the oppositely located face 17 when the ram 7 is in its adjusted end position (not shown). The two wedges 18 are interconnected by a rod 19 which is guided for longitudinal displacement in the direction of the arrow 20 in the head 6.

Between the two webs l1, 12 passes the upper run 22 of a conveyor belt 21. The lower run 23 of the conveyor 21 may be so routed that it also passes through the gap 24 between the two

webs

11, 12. The conveyor belt 21 is of a porous, flexible material having passages which enable lateral drainage of liquid. The material of the conveyor belt is non-absorbent; the conveyor belt more particularly consists of a synthetic material, and in the exemplary embodiment it consists of a monofilament fiber fabric.

In the embodiment according to FIG. 2 the upper pressure surface 1 of the ram 7 is heatable by means of a heating coil 25.

The pressure surface 1 of the ram 7 of FIG. 1 is provided with spaced air ducts 26 communicating with a compressed air line 26a. In addition, these air ducts 26 may be connected with a suction line (not shown) for the purposes of aiding liquid removal by suction during the processing step. After the liquid removal operation air is blown through the same air ducts 26 so as to be able to detach any leather 27 which may adhere to the web 11.

The device operates in the following manner. A leather skin 27 is positioned, optionally in folded form, exteriorly of the device on the conveyor belt 21, e.g. in the region of an end roller 28. The skin is then introduced into the gap 24 between the ram 7 and the support 3 by moving the conveyor belt in the direction of arrow 29. While the skin 27 is being fed into the gap 24, the ram 7 remains in its retracted position (FIG. 1). Thereafter the ram 7 is moved toward the support 3. This is done by means of a hydraulic drive 30 in the head 6. The adjustment is executed such that the ram 7 thrusts the skin 27 against the as yet untensioned membrane 4 and holds it there, optionally under slight compression. The ram 7 having been so positioned is then positively locked by shifting the rail 19 toward the left as seen in FIG. 1 (arrow direction 20). The wedges 18 are thereby positioned between the slopes 16 on the reverse side of the ram 7 and the head 6 of the device.

Hydraulic liquid is now pumped in the direction of arrow 31 through the hydraulic line into the gap between the membrane 4 and the support 3. The membrane is thereby slightly inflated. The full pressure of the hydraulic liquid urges the membrane against the skin 27. This pressure may amount to about atmospheres for example. The flexibility of the rubber membrane 4 ensures that a pressure of equal magnitude is exerted on all points of the skin 27, although the skin is not of the same cross-sectional thickness throughout. By virtue of the pressure exerted by the membrane 4 on the skin 27 the skin is compressed. The liquid contained in the skin issues at both surfaces from the skin 27. The liquid enters the transverse passages created by the porosity of the conveyor belt 21 and the webs l1, l2 and flows out from the sides of upper run 22 of the conveyor belt 21 and the websll, 12. The peripheral regions from which the liquid issues are situated outside the contour surfaces of the skin 27 so that the latter is not contacted by the liquid being squeezed out. It is clear that the cross-sectional thickness and the structure of the webs ll, 12 and of the conveyor belt 21 must be so arranged that lateral draining of the liquid issuing from the skin 27 during the wringing operation is ensured. This can additionally be assisted, for example, by a reduced pressure being produced in the region of the air ducts 26 so that the issuing, liquid is in addition being sucked off. It is also possible to blow compressed air through the ducts 26 during the wringing operation, so as to assist the lateral motion of the liquid squeezed from the webs ll, 12 and the conveyor belt 21.

After completion of the wringing operation the membrane 4 is deflated, the ram 7 is driven up, and compressed air is optionally blown through the ducts 26 to prevent the skin 27 from sticking to the web 11. The conveyor belt is then moved on in the direction of arrow 29 so that the wrung-out skin can be removed from the belt at a station to the left, as viewed, for example, in FIG. 1.

While the

webs

11, 12 have been described as nonabsorbent, it is to be understood that the device of the invention may readily be constructed with webs which exert suction, for example by capillary forces.

We claim:

1. A device for wringing flat articles of irregular thickness, having a stationary lower pressure member; a movable upper pressure member oriented towards the stationary presssure member; means for moving the movable pressure member towards and away from the stationary pressure member; an expansible membrane secured to the stationary pressure member and having a face oriented towards the movable pressure member; means for expanding the membrane by liquid pressure for pressing the membrane face against the flat article situated between the two pressure members; a conveyor belt extending between the pressure members for positioning the flat article therebetween, the conveyor belt being structured to allow liquid pressed from the article to flow parallel to the belt faces; the improvement comprising: a first web affixed to said stationary pressure member and extending over said membrane and said stationary pressure member, said first web having a web face oriented towards said conveyor belt; and a second web affixed to and extending over said movable pressure member, said second web having a web face oriented towards said conveyor belt; said first and second webs being of a porous, essentially nonabsorbent structure for providing a drainage of the liquid, pressed from the flat article, within each said web in a direction parallel to said web faces.

2. A device as defined in claim 1, further comprising pneumatic means connected to said movable pressure member for forcing air through said first web selectively in the one or the other direction.

3. A device as defined in claim 1, wherein said webs are made of a synthetic fiber.

4. A device as defined in claim 1, wherein said webs are made of a woven fabric of monofilament fibers.

5. A device as defined in claim 1, further comprising a liquid-absorbent sponge layer disposed between said movable pressure member and said first web.

6. A device as defined in claim 1, further comprising means for heating at least that portion of said movable pressure member that is oriented towards said second web.

7. A device as claimed in claim 1, wherein the conveyor belt is constructed of a non-absorbent material.

8. A device as claimed in claim 1, wherein the conveyor belt is constructed of a fabric of woven monofilamentary fibers.

Claims

1. A device for wringing flat articles of irregular thickness, having a stationary lower pressure member; a movable upper pressure member oriented towards the stationary presssure member; means for moving the movable pressure member towards and away from the stationary pressure member; an expansible membrane secured to the stationary pressure member and having a face oriented towards the movable pressure member; means for expanding the membrane by liquid pressure for pressing the membrane face against the flat article situated between the two pressure members; a conveyor belt extending between the pressure members for positioning the flat article therebetween, the conveyor belt being structured to allow liquid pressed from the article to flow parallel to the belt faces; the improvement comprising: a first web affixed to said stationary pressure member and extending over said membrane and said stationary pressure member, said first web having a web face oriented towards said conveyor belt; and a second web affixed to and extending over said movable pressure member, said second web having a web face oriented towards said conveyor belt; said first and second webs being of a porous, essentially non-absorbent structure for providing a drainage of the liquid, pressed from the flat article, within each said web in a direction parallel to said web faces.