US2422825A - Delinting screen - Google Patents

Description

June 24, 1947. DAVlS, JR

DELINTING SCREEN Filed Ndv. 18, 1945 2 Sheets-Sheet l OUOUU FIG. a

INVENTOR. 'ARGHIBALD H. DAVIS JR.

A TTMNEY June 24, 1947. v s, JR 7 2,422,825

DELINTING SCREEN 4 Filed Nov. 18, 1943 2 Sheets-Sheet 2 FIG.3

IN VEN TOR. ARCHIBALD H. DAVIS JR.

- 48 EMOCALZ/z,

AT ORNEY cylinder while the latter is rotating.

is allowed to reenter the cylinder.

Patented June 24, 1947 UNITED STATES PATENT OFFICE DELINTING SCREEN.

Archibald'H. Davis, J r., Cleveland, Ohio, assignor to American Machine and Metals, Inc., East Moline, Ill., a corporation of Delaware Application November 18, 1943, Serial No. 510,735

rangement oi the delinting device which forms a part of such drying tumblers. In drying tumblers such as are used in laundries, the wet clothes are put in a cylinder and dried therein by passing heated air through the As the clothes fall through the stream of heated air they are dried. As the air passes through the clothes it picks up loose fibers, or lint. For reasons of heat economy it is desirable to circulate the same body of air repeatedly through the cylinders. Each time the air recirculates it picks up additional lint. At the end of the operation cold air is passed through the cylinder to cool the clothes. It is common in the art to provide such drying tumblers, particularly if recirculation of the air is to be used, with a device for separating out the lint which was picked up by the air on its way through the cylinder before the air Usually delinting devices take the form of one or several screens made of fine wire-mesh through which the air passes. The screens soon clog up, thus impedingth'e ci culation of the air, necessitating the removal of he lint from the screen at short intervals. It has been found difiicult to remove the lint from such wire mesh screens, and

cleaning devices of various kinds have been sug- 30 gested for the purpose of brushing off or other- .wise removing the fibers which have settled on A the screens. Attempts to l low the lint off by reversing the air flow through screen have failed,- probably because the lint fibres are often wrapped around the wire of the screens and the air current has twisted the ends of such fibers together.

It is an object of this invention to provide a delinting device which will not permit the lint fibres to become tangled around the elements of this device.

It is a further object of the invention to provide a delinting devic composed of open-ended cells which have substantial depth in the direction of the air flow. I A

A still further object of theinvention is to provide a delinting device of ribbon-shaped material, the edges of the ribbon facing the air stream. s p

Another object of th invention is to provide a delinting device from which lint fibers which have been caught by the device can easily be, blown off.

Another object of the invention is the combination in a drying tumbler of a delinting device which prevents the tangling of lint fibers with the parts of the device, with means for changing the direction 01' the flow of the air through the delinting device.

Still another object of the invention is to provide a self-cleaning screen that is cleaned by shifting the dampers m the tumbler from their recirculating position to their cooling position.

A still further object of the invention is to, provide, in a drying tumbler, two alternately functioning air paths, both oi which extend from the same side of the fan used for creating the air circulation'through thetumbler but lead to opposite sides of the delinting device, the one path leading out to the atmosphere.

Other objects of the invention will appear as the description proceeds, reference being made to the accompanying drawings, in which:

Figured is a. sectional elevation of a drying tumbler, illustrating by way of example one embodiment of the invention:

Figure 2 is a plan view of one form oi. a delinting' deviceaccording to the invention;

Figure 3'is a section on line 3-3 of Figure 2;

Figures 4 and 5 are plan views of the two modified forms of delinting devices, and

Figure 6 is a fragmental perspective view of another modified form of the delinting device. Referring first to Figure 1, l0 designates generally a housing, comprising a base li, a front wall [2, a rear wall l3, and a, top H. Rotatably mounted in housing It! is a cylinder 53 having foraminous side walls through which air may pass, said walls being generally made of aheavy, coarse wire mesh. The housing 10 further con-' tains a fan or blower l5 adapted to create a forced air circulation through the tumbler, a heater l6, partition walls l1, l8, I9, 20 and 2|, three dampers '22, 23 and 24, and a delinting device generally indicated at 25. The device 25 may be arranged between the walls l3 and I1 like a drawer that may he slipped out of the housing l0 through an opening in the rear wall i3. 26 denotes air inlet openings in-the top part H of 22, 23 can be moved together but in opposite directions.

The dellnting device 25 which forms an essential partiof this invention comprises a series of cells 28. The cells 28 have open ends permitting the passage of air in the direction of the arrows shown in Figure 3 and are of substantial length in this direction. As distinguished from wire mesh screens, the walls or bridges separating the 1 a core 3| in such a manner that the flat ribbon 30 serves as a spacer between consecutive turns of the corrugated-ribbon 29. The ribbons 29 and 30 are kept in place in-a suitable supporting frame 32.

Figure 4 shows a cell screen wherein corrugated ribbons 34 alternating with fiat ribbons 35 are arranged in a rectangular ,frame 36' whereby again a great number of cells 28 are formed.

Figure 5 illustrates another cell screen of rectagular shape having several layers of corrugated or crimped ribbon 31 arranged in staggered relationship to one another so that the depressed parts 38 of one layer are resting directly upon the upstanding parts 39 of the layer underneath. No fiat ribbons between the corrugated ribbon are needed in this case.

The corrugated ribbons shown in Figures 2 and 4 are of regularly undulated shape. Whereas in Figure 5 a different type of corrugation is used, the ribbons having relatively wide, fiat portions separated by short, upstanding portions. The invention is, however, not limited to any particular shape of crimping or corrugating, nor is the invention limited to cell screens using corrugated v ribbons. For example, flat material may be used throughout for forming the cells of the cell screen, as is shown in an example in Figure 6 wherein fiat plates 41 which are separated by spacing members 48, form cells 28.

If the length of the. cells 28 in the direction of the flow of the air is chosen so that the material of the plates on edge (29 and 30 in Figures 2 and 3, 34 and 35 in Figure 4, 3'! in Figure 5, and 41 in Figure 6), forming the bridges between the cells 28, has in every cross sectional plane a perimeter which is greater than the length of the longest fibres which may be reasonably expected to be carried along by the air stream arriving at the screen, the fibers will not be able to wrap completely around those bridges. The lint fibers will be arrested by the plates on edge in the manner indicated at 33 in Figure 3 and at 49, 50 and Bi in Figure 6. That is to say, the lint fibers will either lie across the edges of two or more plates as shown in Figure 6 for the fiber 50, or otherwise will extend into the interior of one or two cells 28 alongside of the walls thereof, as the fibers 33 in Figure 3, of the fibers 49 and 5| in Figure 6. Defined in another way, the fibers will be prevented from tangling if the length of the cells 28 in the direction of the air flow is greater than half the length of these fibers. Iprefer to use cells of a length which will take care of fibers of even extraordinary length, although a cell screen which will safely prevent tangling of fibers up to an ordinary maximum length may be regarded as satisfactory. A cell screen made of plates or ribbons having a width of 1% or more will assure good results for laundry drying tumblers.

Returning now to Figure 1 and following first the air flow taking place when the damper 24 is 5 in the position shown in dotted lines, it will be seen that under the action of the fan or blower l5 air entering the housing Ill through the air inlet openings 26 will pass through the revolving cylinder 53 and the fan l5, the latter discharging the air into a pressure chamber 40. If circulation of the air through the heater l6 and again through the cylinder 53 is desired, the dampers 22, 23, and 24 are brought into the positions shown in full lines. This establishes a communication between the pressure chamber 40 and the space 4| below the cell screen 25. The air following this path between the discharge side of the fan I5 and the cell screen 25 traverses the screen in the upward direction, thus reaching a space 42 above the screen and flowing from there through the heater [6 and a duct 43 formed between the walls l4 and iii of the housing ill to the upper end of the cylinder 53. From here the air follows the path already described which is indicated in Fig- 5 ure 1 by arrows shown in full lines, through the revolving cylinder 53, fan l5, chamber 40, space 4|, screen 25, space 42, heater l6 and through duct 43 back to the cylinder 53.

When it is desired to feed cold air to the tumbler, for instance to cool the clothes in the cylinder 53 after theyhave been sufllciently dried by the heated air repeatedly circulated through the tumbler, dampers 22, 23 and 24 are moved into the positions shown by dotted lines. This opens an air path from the discharge end of the fan l5 to the cell screen 25, through space 42 above that screen. Reaching the upper side of cell screen 25 the air passes through it in a downward direction, carrying the lint away from the screen, reaches space 4|, and leaves the machine through the outlet openings 21 as indicated by the arrows shown in dotted lines in Figure l.

' .This outlet 21 may be connected by a duct (not shown) to the outside of the building.

45 It will be seen that the air must pass through the screen 25 whether the dampers 22, 23 are in the position shown in full lines for recirculation of air heated by heater I6, or in the position shown in dotted lines for the one-way passage of cold air. The two air paths which result from the two alternate positions of the dampers 22, 23, 26 both pass through the screen 25 but traverse the cells of this screen in opposite directions. A has been'mentioned before,

the flow of air through the cells is upward for recirculation and downward for the discharge ofthe air from the tumbler through the outlet 21. Lint carried by the heated air arriving at the lower side of the screen 25 during circulation is deposited on this screen. For the reasons pointed out, fibers deposited on the screen 25 are unable to wrap themselves around the bridges of the cell screen. The ends of .such fibers cannot twist together, regardless of the strength of the o5 blast of blower l5. Thus, when the dampers are shifted to the position in which they permit the one-way passage of cold air through the tumbler the direction of. the air stream through the cell screen 25 is reversed as compared with the direction of the air stream through 'the cell screen during the recirculation period of heated air. The cold air stream will be able to pick up and remove from the screen the lint previously deposited thereon. In this manner a really eiiective automatic cleaning. of the screen at the end of each recirculation period is assured, leav ing the screen in perfect condition for the next operation of the tumbler.

In Figure 1 the cell screen is shown as located between the discharge end of the fan l5 and the heater I6. It will be understood, however, that the screen may be arranged at some other convenient place within the tumbler, such as between the cylinder 53 and the fan IS in which case the delinting of the air is taking place before the air enters the fan.

While I have shown and described certain embodiments of the invention, it is understood that these embodiments have been given by way of example only and that various changes, rearrangements and modifications may be made without departing from the spirit of the invention or from the scope of the appended claims.

What I claim is:

1. In a drying tumbler, in combination, a housing having an air inlet and an air outlet, a stationary delinting screen and a fan in said housing, means for forming two air paths alternately leading from the same side of said fan to opposite sides of said delinting screen, said means including dampers controlling said two air paths for reversing the air flow through said stationary screen, said screen comprising a series of adjoining walls forming cells, said walls, in orderto prevent the lint fibers arriving at the screen from wrapping completely around the elements of the screen, consisting of closely spaced plates facing the air stream with their edges and extending over a substantial length in the direction of said air stream.

2. In a drying tumbler, in combination, a housing having an air inlet and an air outlet, a stationary delinting screen and a fan in said housing, means for forming two air paths alternately leading from the same side of said fan to opposite sides of said delinting screen, said means including dampers controlling said two air paths for reversing the air flow through said stationary screen, said screen comprising a series of ad- Joining walls forming cells, said walls, in order to prevent the lint fibers arriving at the screen from wrapping completely around the elements of the screen, being of a length in the direction of the air stream many times greater than the thickness of said walls,

3. In a drying tumbler, in combination, a housing having an air inlet and an air outlet, a stationary delinting screen and a fan in said housing, means for forming two air paths alternately connectable to the same side of said fan to opposite sides of said delinting screen, said means including dampers controlling said two air paths for reversing the air flow through said stationary screen, said screen comprising a series of ad- Joining cells, formed at least partly by adjacent layers of corrugated ribbon facing the air stream with its edges.

4. In a machine for drying clothes or the kind in which each batch of clothes is subjected first to heated air recirculating repeatedly through tion and the air passing. to the atmosphere through the same passage in the other direction, a stationary delinting screen in the passage, said delinting screen having plates extending in the direction of the air stream over a substantial length whereby the lint deposited during recirculation on the screen is automatically removed during the period when the dried clothes are cooled by air flowing to the atmosphere, an air path for the flow in one direction of the recirculating air, a second air path for the flow in the opposite direction of the air that is not recirculated, said stationary delinting screen intercepting both said air paths, dampers controlling said two airpaths for reversing the air flow through said screen, in which screen the lint is caught on the edges of said plates during the period of recirculation, and is automatically blown off when the air current is reversed.

5. In a drying tumbler, in combination, a housing having an air inlet and an air outlet, 8. stationary delinting screen and a fan in said housing, means for forming two air paths alternately leading from the same side of said fan to opposite sides of said delinting screen, said means including dampers controlling said two air paths for reversing the air flow through said stationary screen, said screen comprising a series of adjoining cells formed by several layers of corrugated ribbon facing the air stream with their edges, the corrugations in, said layers being arranged in staggered relationship to those in adjacent layers sothat the depressed parts of one layer rest directly upon upstanding parts of an adjacent layer.

ARCHIBALD H. DAVIS, JR.

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

UNITED STATES PA'I'ENTS France May 3, 1932

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