US2685939A - Lint trap - Google Patents

Description

W. S. PARRETT LINT TRAP Filed June 8, 1951l Aug. 10, 1954 Patented Aug. 10, 1954 UNITED STATES -TsNr 3 Glaims. 1

This .invention relates to :lint 'traps :for use with maehines from which .litift and fibres are blown, such as clothes z'dri'era and the like.

`it is, of cem-'se desirable te catch lint blown from ra machine to prevent its beiii'g fearrie'dofut into the openair. Lintftraps 2in common use in the past have generaily 'consisted simplyof a basket-ofscreen mesh for lthe likemeuiited on the end of the exhaust duet fof the machine. The major diiiiculty with this type of 'deviee is that the lintJ will adhere ite -the 'inside surface of the basket until the dirait from the exhaust duct :is completely 'eut Off. This in :turn may vlead to overeheating 'of the machine and, any event, to its inefficient dpefation; Als'e ih these' lint ttap's 4used heretofore; 'dficulty was experienced inel'eani-ng them while the mach-ine was inepere atioin in fact, that could lee 'accomplished at all.

One of 'the ehectsef this invention is te .preiv'ide a rsuhsteihtiwl'ly self-'cleaning llint train.k

lieri-ether object is to provide sisieh a lint trap which is simple, efEitit-:nt,V dependable-and cheap; Other yobjects will become `apparent v to these skilled in the art .in the ylight yo'f the following disclosures.

In yaccordance with this vinvent-ieri, `generally stated, a lint trap is provided with a lint catching sereen mounted within the trap 1in such fa Way as to be maintained :in lint catching positie-n against the force of the exhaust -d-raft While the screen is Lfree -of `lint but to be swung operi by the `force of the 'exhaust draft when flint accumulated over a :predetermined area ef the vscreeri. The force of the draft itself may be utilized to maintain the screen closed against the lferee of the' dra-it.A This may be vaceci-malished -by so pivot= ing' the screen that a large .area ef screen is expesed to the 4force of the exhaust draft I*on one side of the pivot While a smaller area of sereen oierihg a relatively great resistaneev-jt'o the -exhaast draft is exposed on the other. The resistance pf the screen on the short sideef thepive't is suieien-tly greater than that voi the screen of the side of the larger areay that the for-ee of` the dra-ft against the more highly resistant side Yis sutcieht to gkeep the screen closed. '-owever., as the long side of the sereen becomes eeveredr with linti its resistance te the draft increases te the point Where the screen opens with the draft against the force er1' the Vshort side. Means can befprovide'dfor adjusting the 'resistance of the screen on Veitlfi'er side to vary the opening :andcles-n ing action of the screens. A similar efedt can be achieved by restraininigfthe openingef. 'a screen, pveted at orieside fe'f the .1irttrap,by e

(Cl. 18S-62) with a qui-ck 'operi-i131? detexi't arrangement te pre"- verlt a balance 'being reached between the forse the spring and the'ioart'ly peri screen. Combinatiene 'ei the tvvo met-leeds Yalso be 'ii-sed.

.A plulrality df such Ascreens Amay Ainstalled such a Way that fordiriari'ly they Willi not open at the same time. With "such an ara'fngement, no lint will 'he blevmfdiectltf trom the .machine irito the air.

screens may be so positioned as te er1- eoia-rage the a'eeiinlatien "ef lint progressively ffi'iii end of the screen to the other. :Fu-re therefore, they may be, and prefer'ablf7 lare; so arranged as to use the tforee of the rdraft -te i'ell the Afe'lltedlin-tv Sironi the face" of 'the screen te 1jr@- diice a rell 'Grit/afd 'elf material which is veasily handled.

The 'lint be-se eens-trusted as to' slide inte the eid-faust diiet and 'to he removable thereL from -as a unit. f

In the drawings:

Figure :lis a view iperspeetive ef a lint tra@ constructed vim aecerdaiice iifith one emee'diment of this invention.;

Figure 2 .is ia-seetiohal View taken :along the' line 5 15 of `Figure 11;

Figure 3 is 'a view `in trent -elev-atioi ef the device shown iii Figure- 1;;

e view eeispee een tiseivith ef the-emessi; tnventien, she-wn ecm-e ef and Fig trier em-sediment and iiiparL tiet-fiar tov desi-gried t v Y dt Y2. A tr ver V attahedrte the outer e'd ef thedilct if te' ieei 'Walid-ed in't fi'in the trap i. Tristram self c erneress having sides t, e ettom t' d iep e; 'The tee 6 in' the eirir'oieht 'sh' is ""prvided a vhamiie; i by whn tiieftraiimay te puiiee fr the" 'exhaust' 'dii-Ct' r2'. Pivtallv rroiinte'd 'xi/it the frame are' 'twoI screens 52'; 'The V'pivots it; which the screens ate iho are secured 5to' divide the seleris mit@ Teilig 'side a side with respeettefthe pivot. i-eng side,` as

used in the specification and claims, is a side of greater area than the short side. The pivots IIJ of the screens 8 are mounted in suitable bearings in the bottom 5 and the top 6. The screens 8 are provided with a frame 9 within which, on the long side of the screen, is wire mesh I I. Within the frame on the short side of the screens is a solid sheet l2, as well as a section of wire mesh II. When the screens 8 are assembled with the frame their travel in the closing direction is limited by strips I3 and I4. Strip I3 bears against the longer edge of the frame 9 with respect to the pivot I0 while strip Iii on the opposite side of the frame bears against the shorter. The strips I3 and I4 serve as seals as well as stops. A stop I6 may be provided to limit the amount of opening of the screens. It can be seen that the latter function can be accomplished by the proper positioning of the strips I3 and I4 as well. A lip I is provided along the front edge of' the bottom 5 to limit the sliding of the frame within the exhaust duct 2 and to conduct the rolled, felted lint into the box 3.

A detent I1, as shown somewhat diagrammatically in Figure 6, may be provided. In the embodiment shown in Figure 6, the detent or latch i1 consists of a housing I8, a spring IS, and a ball 2@ seating in a slight depression ZI in the top of the frame 9.

In the operation of the embodiment of this invention shown in Figures 1-6 of the drawing, the draft blowing from the exhaust against the solid sheet I2 maintains the screens 8 in a closed position as long as the screens are clean. By setting the screens at an angle with respect to the frame, as shown particularly in Figures 2 and 5, a uniform coating of lint tends to form over the face of the screen from the short side to the long. When the force of the draft on the lint obstructed screen mesh on the long side of the pivot exceeds the force on the other side of the screen, the screen will swing open until it meets the stop It. The lint, which has a tendency to felt on the surface of the screen will be rolled from the short end of the innermost screen along the entire face of the screen mesh and off, leaving the screen mesh clear and free of lint. When the innermost screen mesh is thus cleaned the force of the draft on the solid sheet I2 closes the screen and the cycle is repeated. Meanwhile the roll of felted lint is urged along the sloping outer screen toward the end of that screens longer side. When sufficient of the felted lint accumulates on the longer side of the outer screen mesh that screen will also open to allow the felted lint to be blown out. However, the rolls of lint generally have suiiicient body so that they do not blow into the room but simply drop into the box 3 provided therefor.

When a latch or detent I'I is used, its detaining force is made less than the differential force on the obstructed screen mesh. The detentequipped screen opens more abruptly and is less subject to fluttering than the unequipped screen.

Various other forms of detent or latch may be employed for this purpose. For example the detent may consist of a semiciroular piece carried by a lever so pivoted in the frame that the wedging action of the piece holds the screen frame when that frame is closed until enough force is applied to the screen to raise the piece. When the screen swings shut after it has been cleaned, the momentum of the screen carries it under the semicircular piece, raising the piece. Also, hy extending the lever beyond its pivot on (III the side away from the semicircular piece, and putting a slidable weight thereon, the amount of retention of the piece may be varied to suit the needs of the machine, by varying the amount of counter-balancing by the weight of the semicircular piece. Another suitable latch is one similar to a common screen door latch, wherein a U-shaped member, the legs of which straddle the frame, is pivoted at its center and constructed in such a way that sucient force applied to the inside of one of the legs of the U causes the U to snap in one direction to release the frame, while force applied to the inside of the other leg by the frame snaps the U in the other `direction to hold the frame closed.

It may also be found desirable to provide an adjustable plate, which may be fastened to the pivot shaft within the frame, which plate may be moved toward the shorter or longer side to regulate the opening and closing characteristics of the screen. Such a plate is shown at 5@ in Figure 8. That plate 50 is provided with slots 5I and wing nuts 52 by which the adjustment can be made. Also the pivot itself may be so mounted on the screen and in the frame so as to be adjustable with respect to the two sections of the screen. Another means for adjusting the relative resistances of the two sides of the screen, shown in Figure 8, is the sliding sheet tt, backed either by the fixed plate I2 or screen mesh. The screen mesh I IIJ shown in Figure 8 on the short side of the screen is finer than the screen mesh II on the longer side. It can be seen that certain of the elements shown in Figure 8 may be dispensed With in any one installation.

In the embodiment of this invention shown in Figure "l a screen 3U is hinged or pivoted along one edge SI. The screen 30, like the screen 8 in the previous embodiment, is provided with a frame 33 within which is screen mesh 34. A stop I6 performs the same function as that stop in the previous embodiment. Sealing strips, not here shown, may also be used. In the illustrative embodiment shown, the screen is maintained in its closed position by a simple spring 4ball detent 36. The screen is swung back, after it has blown open and been cleaned, against the force of the exhaust draft, by a spring 3l indicated more or less diagrammatically in the drawing. In this ,f embodiment it is necessary that a detent of some sort be employed. However, the detents or latches described in connection with the embodiment shown in Figures 1-6 may be used satisfactorily.

In the operation of the embodiment shown in ,:Figure 7 the detent 36 maintains the screen closed against the force of the exhaust draft until lint has covered a sufficient area of the screen to a sufficient depth so that the force of the exhaust draft swings open the screen about its pivot and against the force of the spring 3l. The spring 3i may be so arranged as to take effect only after the door has escaped the detent 3E. The fact that the lint tends to be rolled from the screen from the inner to the outer ends of v the screen keeps the screen in a relatively wide open position until the roll of lint passes the outer end of the screen, since the product of the resistance and the distance from the pivot point remains large. When the roll of felted lint leaves the outer end of the screen the screen is swung back against the force of the exhaust draft with sufficient momentum to close against the resistance of the detent.

Even in the embodiment of screen shown in Figure 7 it may be found desirable to provide a blank sheet, or section of finely woven screen mesh at the pivoted inner end of the screen to facilitate the peeling oi of the felted lint from that end.

It can be see-n that a plurality of screens like those of the embodiment shown in Figure 7 may be used in the same manner as those of the embodiment shown in Figures 1-6.

Combinations of the two embodiments described are also contemplated wherein a spring (which as in the embodiment shown in Figure 7 may be a coil spring, a torsion bar, or the like) is used in connection with an ecoentrically pivoted screen of the first embodiment.

It may be found desirable to cut out the bottom of the frame between the screens and to place a box below that opening. In this way the felted lint from the inner screen may be removed immediately after it leaves that screen while the second screen may function to pick up any unfelted lint which remains. It is, of course, entirely practical -to eliminate the outer screen completely in those installations in which the momentary opening of the screen during which the lint is pulled off the screen mesh by the draft, is not undesirable. While a rectangular screen has been illustrated it can be seen that the shape of the screen may be varied in any way desired so long as the screen may be eccentrically mounted to pivot within its frame. It can also be seen that the frame need not have solid sides, top, and bottom but that a Skeleton framework is suiicient so long as it provides bearings for the pivots (or support for the hinges in the other embodiment) and sealing means around the screen frame. It can further be seen that no frame at all is needed if the screens are mounted directly in the exhaust duct itself. The only disadvantage of this latter system is that the screens cannot so easily be Withdrawn for inspection. The frame has the additional advantage of making the lint trap readily adaptable to existing installations.

Numerous variations of this invention withinY Having thus described my invention, what is` claimed and desired to be secured by Letters Patent is:

l. A self-cleaning lint trap for apparatus from which lint is blown through a duct comprising a screen pivoted within said duct for movement between duct opening and duct closing position, detent means for said screen releasable under a predetermined force less than that capable of being exerted by the draft from said apparatus against the said screen when said screen is completely blocked, and positioned to holdthe screen in a duct closing position until the screen is blocked sufficiently to permit the force of said draft to release said detent, and means constantly biasing the screen toward its duct closing position with a force greater than that of the draft against the screen when said screen is clean and less than that exerted by the draft against the screen when said screen blocked for restoring said screen to its duet closing position when said screen is unbioclred.

2. A self-cleaning lint trap mounted within the I exhaust duct of apparatus from which lint is blown by a draft of substantial force, comprising arscreen mounted in said duct to obstruct the whole cross-sectional area of said duct when said screen is in closed position and pivoted in said duct to swing to an open position at which less than the whole of the cross-sectional area of the duct is obstructed, said screen being ecoentrically pivoted to provide on one side of the axis on which it swings a section of smaller area exposed to the force of the draft than the area of the section on the other side of the said axis, the said section of smaller area being positioned on a side of the pivot axis such that the force of the draft upon it tends to move the screen to closed position while the force of the draft upon the section of larger area tends to move the screen to open position, said section of smaller area being constructed to offer sufficiently greater total resistance to the force of the draft than the section of larger area when both are free of lint to permit the force of the draft to maintain the screen closed, but to offer sufficiently less total resistance to the force of the draft than the section of larger area when the section of .larger area is blocked with lint to permit the force of the draft to swing the screen to open position.

3. A lint trap of the character described in claim- 2 wherein detent means are provided tending to hold the screen in closed position, the construction of the sections of larger and smaller area being such that the force of the draft on the blocked section of larger area is suiciently greater than the force of the draft on the section of smaller area to overcome the screen-holding force of the detent means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 342,099 Howe May 18, 1886 526,828 Bell Oct. 2, 1894 986,599 Sizer Mar. 14, 1911 1,914,667 Kolla June 20, 1933 2,125,574 Knight et al. Aug. 2, 1938 2,203,776 Danils June 11, 1940 2,599,139 Stevenson June 3, 1952

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