US2482775A - Method of removing dust from leather - Google Patents

Description

Sept. 27, 1949.

J. ca. HOI LICK METHOD OF REMOVIN DUST FROM LEATHER Filed Au 16, 1946 Inventor John a h'olliqk Patented Sept. 27, 1949 METHOD OF REMOVING DUST FROM LEATHER a I John G. HollickQ Beverly, Mass., assignor:v to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey 7 -Application August 16, 1946, Serial No. 691,090

. 1 This invention relates to a method of removing dust particles from. the surface of tanned hides or skins, and is morespecifically concerned with the freeing of leather surfaces from 'fine fibrous dust by means of a forced jet of gaseous fluid such as air. 1,. Tanned hides or skins .are usually subjected to a bufiing operation to improve their appearance, after which thedust produced by that operation is removed fromv the .leather surface. Such removal is for the. purpose-of presenting the leather in the best possible condition for subsequent finishing operations. If:the dust were not removed, the resulting finishwouldbe cloudy, streaked andunsightly. g .5 S

Dust, and particularly that dust produced from bufling, is fine and fibrous and great. difiiculties are encountered in satisfactorily removing it from leather surfaces. Thev problemsencountered are unique and quite unlike those-involved in clean ing other types of sheet materials. f

Heretofore it has-been the practice to employ. brushing machines to, remove, dustfrom leather. In using such machinesdust would momentarily. be lifted by the brush from the leather surface. After such mechanical dislodgment, means would remove some of the dust suspended in the air. As the brushing action led to generation of static charges inthedust particles and also in the leather there has beena strong tend-; ency for some of thedislodgeddust to return to the leather despite the suction means. 1 Asa result, the finish and appearances of. the work has suffered and the difficulties. have not been avoided by the development and improvements in complicated brushing machines which are costly to manufacture and. expensive, tomaintain. It has now been discoveredthat dust may be removed from leathersurfaces, by anair jet to a degree not approached by the best brushing machines and that the capacity of the air han--v dling equipment may be quite modest. The method is therefore economical and is aidediin this direction by the discovery that the cleaning effect takes placesubstantially instantaneously and that the rate of feed of a work piece surface relative to a cleaning jet may be greatly increased as compared with the rate with which leather may be dusted'in a conventional brushing machine. It has also been found that the dust dislodged by an airjet or blast may easily be controlled so that it will not return to the cleaned leather surface. I I

An object of the invention is to provide an my.

suction v T 1 Claim. (01. 69-21) e 2 latter being in the form of a hide or skin, which method is simple, efficient'and economical.

In the accomplishment of the object in View and in accordance with the method herein illustrated, a forced jet of gaseous fluid such as air is directed against a narrow area of the surface of a spread-out leather work piece to be treated and at an angle such as to cause the jet to impinge against the surfaceand dislodge dust therefrom. All portions ofthe surface to be treated are progressively passed through the zone of impact of the jet. Thus not only is the dust most effectively dislodged from the leather under treatment but thedust laden air, after impingement, is forcibly directed away from the cleaned surface as an incident ofthe cleaning operation. The jet, before impingement, is given a limited width dimension "of a few thousandths of an inch.

The invention will now be more particularly described by reference to the accompanying drawings and thereafter pointed out in the claim.

In thedrawings, l

Fig. 1 is a. perspective view of one form of apparatus by means of which the method may be carried out; and 1 a 1 Fig. 2 is a view, in section, and drawn to a larger scale, showing the relation of the main operative parts of Fig. 1 in treating a leather work piece.

Inthe illustrated machine, a horizontal table or platform I0 is utilized upon which 'a leather work piece l2 maybe supported and spread out and from which it ma y be progressively fed through the treatment zone or zone of impact. Bearing blocks l4 and 'lG are rigidly attached to the opposite sides andat the end of the platform I0 and rotatively support the shaft I8 of an elongated rotary brush 20 having sufficient length to extend across and slightly beyond each side of the widest work piece the treatment of which is contemplated. A vertical bracket 22 is adjustably mounted-and supported upon the bearing block [6 by suitable bolts 24 and 26. Each of these bolts passesthrough a vertical slot made in the bracket 22. --A slot 28 is formed in the block it permitting angular: adjustment of the bracket 22 about the bolt 24.' The bearing block I4 supports asecond vertical bracket 30 similar in all respects to the bracket: 22 and likewise adjustably mounted. A horizontal bar 32 is supported Lon brackets 22. and 39 by flanges 34 and 36 boltedto the upper endsof the brackets 22 and30.

As seen in Fig. 2,-the barv 32 is formed with a recess 35 running longitudinallythereof and enproved method ofrem yinedust from. leather, the. 555 closed by two longitudinal plates 31 and 38. The

recess 35 does not extend the full length of the bar 32 but terminates adjacent each end thereof. The plate 38 is attached to the bar 32 by a multiplicity of screws 40 one of which is shown in Fig. 2. The longitudinal plate 31 extends from one longitudinal side of the bar 32 and almost abuts the plate 38 thereby leaving a'slot 42 of slight width between its edge and the inner side of the plate 38. A multiplicity of cylindrical pins 44 are attached to the bar 32 by means of screws 46 (only one shown and that Fig. 2) passing through the plate 31 into the bar 32. The cyline drical bars or pins 44 extend at an angle up over the platform or table In, as shown in Fig. 2, and are smoothly contoured to guide the work into the bite between the plate 38 and the brush 22.

One end of the bar 32 is provided with piping connections 50 and a conduit 52, these devices serving as means for conducting gaseous fluid such as air under positive pressure from a source of supply to the recess 35. A pressure gage 54. is shown in Fig. 1. One end-of the rotary brush shaft [8 has keyed thereto. a pulley 6.0 through Whichpower is applied to. the machine by a belt $2 driven from motor means not shown.

In carrying outv the method the pulley 60 and brush 20 are rotated in the direction shown by the, arrows in Figs. 1 and 2: and air under pressure permitted to enter the hose 52, piping connections 50, and the recess 35. The bar 32 is ad-. iusted to a position such as shown in Fig. 2. The operator then places, and spreads out a hide or l2 upon the table t0. and slides it in between the rods or pins. 44 and the rotating brush 20.. Regardless of the irregularities in the contours of the work piece the brush serves. to progressively pull the work piece 12 by and in contact with the wer ed e of the plate 38. and air, emanating in the form of a sheet, from the slot. 42 betweenthe plates; 31, and; 38, impinges. upon the surface of the spread-out. work piece 12, dislodging dust therefrom. Before impingement, the thickness dimension of the jet is not. excessively increased as the work piece is retained close up to. the slot As preferred and as disclosed in the apparatus shown, the dustrladcn air then sweeps back over that. or ion. o he work piece surfa e n t y cleanedand the treated; portion 64. of the work piece surface emerges, from the machine freed ir mcl st.

The op rator m y ho d a k; on a hide or skin and retard its passage if; he so desires and, as a matter of fact. he may pull; the work piece back toward him then permit it. to be treated again by the jet. Usually one. passage of a. portion of a r pi ce past he slotor through the zone o mpac ssniiicientto remove the dust but. it is; obvious that the operator may Without Iemmling' the work; from the machine, repeat the treatment of a given work piece any number of times, or he may prolong the treatment during a single pas-. sageby retarding the. rate of feed.

A hood; for the removal. of the dust-laden air, is not essential essential. as the blast of air from the slot removes the dust such a distance that it does not return. to the leather. It is preferable that the method be so carried out-that the dustladen air flies back overthe leather portions yetto be fed. by the slot. With the apparatus shown, the. plate. 38: and the bar 32- prevent dust-laden; air from flying out over thedusted portion- 64 of the leather. It is to be appreciated, however, that a. hood may be used to'insure'that all dust is removed from the leather and will not return thereto.

An air pressure of from three to twelve pounds per square inch within the recess has been found very satisfactory with a slot width of from .002" to .003. A pressure of three pounds per square inch performed work equivalent to that performed on the best brushing machines. The use of a twelve-pound pressure resulted in a far superior cleaning job. r

It is preferred that the air be impinged against the Work from a slot but it is clear that a number of closely arranged or staggered orifices of small thickness dimensions may be used and that these may constitute the cleaning jet. It is also permissible to reciprocate the slotted or perforated jet member to secure adequate coverage of the surface area to be treated. In some cases it may be well to increase the width dimension of the orifices or slots to as much as .015" or .020 although such increase will necessitate a great increase in the capacity of the blower and the power output. I

Various. velocities of feed for the work piece have been found satisfactory. The cleaning effect is substantially instantaneous. for any given spot on a. work piece: despite the small width of the slot and cleaning jet as work-feed velocities of up to 325 feet. per minute have been successfully used.

The specific apparatus. disclosed includes the rotary brush 20 for feeding the work piece resiliently in contactwith. or closely adjacent to the plate 38.. As the dust-laden air discharges, the Bernoulli effect is evident potentialenergy is changed to kinetic energy and the pressure of the air within the jet is reduced and the leather is actually held (not repelled) adjacent to the slot 42 by the air jet. A rotary brush need not be used for feeding the work piece as that operation may obviously be carried out by hand or by a belt conveyor;

It may be seen from the above that the velocity of feed and the pressure of the fluid used are not. critical conditions in so far as the invention is concerned. The impingement or impact angle of the jet (asmeasured with respect to the surface being treated and before impingement) should not be much.- lower than degrees (although the 40-.d'egree value is not critical) if the advantageous results are to besecured. The impingement angle of the jet has been found most satisfactory when approximately 90 degrees and the cleaning effect diminishes if the angle-is adjusted or changedtoapproach zero.

It is preferred thatthe method be carried out as disclosed in Fig. 2 but it'is not essential that the dust-laden air be discharged over the untreated portion ofthe work piece. The dustladen air maybe discharged in the other direction-.-i. e., over the treated work portion 6&-

and be separated therefromby a thin plate or sheet and/or by causing the work piece to bend sharply away from the direction of movement of the dust-laden air;

Having described my invention, what I claim as new and desire-to'secure by Letters Patent of the United States is:

A method: of removing dust from leather'which comprises the spreading out of a work piece such as a hide-or skin upon a support and passingsaid work piece progressively through a zone of treatment, and forcibly projecting a jet of air undera pressure of substantially three to twelve pounds per square inch directly against and also across the full width'of the work piece to treat the entire length of" said work plece-asit passes through said zone, the impingement angle of the jet being above 40 degrees and the thickness dimension of said jet before impact being within the range of .002" to .020".

JOHN G. HOLLICK.

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

Number 6 UNITED STATES PATENTS Name Date Scharrer May 5, 1896 Thurman Mar. 25, 1902 Thurman Apr. 14, 1903 Thurman Nov. 17, 1903 Hubbard Feb. 21, 1922 Bagshaw Oct. 7, 1941

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