US1694447A - Method of and apparatus for treating hides and skins - Google Patents

Description

Dec. 11, 1928. 1,694,447

M. M. MERRITT METHOD OF ANDAPPARATUS FOR TREATING HIDES AND SKINS Filed se t. 16, 1 22 2 Sheets-Sheet 1 Dec. 11, 1 928.

M. M. MERRITT METHOD OF AND APPARATUS FOR TREATING HIDES AND SKINS Filed Sept.

922 2 Sheets-Shed 2 I I, gm 5 N luveiaioa": flaiiiaewj'ljvrriii Patented Ba. 11, 1928.

UNITED STATES 1,694,447 PATENT OFFICE.

MATTHEW M; MERRITT, OF MIDDLETON, MASSACHUSETTS, ASSIGNOB TO UNITED SHOE "MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, A COBPORATION'OF NEW JERSEY.

METEOD OF AND APPARATUS FOR TREATING HIDES AND SKINS.

Application filed September 16, 1922 Serial No. 588,606;

This invention relates to methods of and apparatus for treating-hides and skins by liquids and by various liquors containing chemical bodies, intended to effect either '5 physical or chemical changes in the substance of the hides and skins.

While the invention is particularly appli- .cable to the treatment of hidesin tanning operations thereon, itwill lee-understood that 10 the invention is not so limited in its application since it may be utilized in the treatment of skins as Well as ,hides and for a variety of purposes such as those which relate to' the removal of hair from the skins l or hides, and to bleaching, drenching, coloring and other similar operations.

Numerous machines orapparatuses have heretofore been proposed for utilization in the tanning of hides'iwith the idea of re- 2 ducing the time required in the tanning while maintaining a high standard of ual ity and of uniformity in the product 0 the tanning operations. In this country, "hides for sole leather, for belting, for harness, and for other purposes Where a heavy leather is required are almost universally tanned in pits or vats, it being a common practice to shift the hides by hand from one pit .to another while progressively increasing the strength of the tanning liquor. 3 This process involves an immense amount of manual labor. Since the work isboth heavy and disagreeable the supply of workers is rather limited. In the attempts that have heretofore been made looking to the tanning of hides by machines in order to reduce the time and the labor incident to the handling-of the hides, a number of difficulties were-encountered which rendered these prior attempts unsuccessful and which discouraged the tanners so generally that machine tanning of hides is practically unknown in this country. In the past, hides which had been machine tanned were found to haveareas in which the grain side of the tanned hide was roughened" and cracked to such an extent that the hide was unsaleableexcept as a damaged product. Furthermore there was no insurance of uniformity in the product of there was failure to tan properly throughout the thickness of the hide so that the product soon deteriorated and became worthless,

thetanning operations and in many cases In view of theforegoing, the present ini-'/ .vention provides an improved method of tannin in accordance with which the hides while eing immerse in the tanning liquor and while being Withdrawn therefrom are handled with care topi'event excessive bendmg or flexing of any portion of the hide. The reason for this treatment resides in the fact that frequent and excessive bending ofportions of the hide will cause thoseportions to be excessively tanned on the surface, thus causing a; tan burn on that portion with e a raised and roughened grain that makes the. portion unsuitable for the uses to which the properly tanned portions of the. hide -maybe put. Hence, it is an important characteristic of applicants method that each hide is gently flexed at intervals, throughout the whole length thereof, since this operation has the effect-of facilitating the penetration of the treating liquor, while at the same time avoiding excessive bending or rough handlingof any kind.

In order-v that the treating liquor may drain from the hides, thus removin the exhausted liquor from the-surfaces of it the latter are suspended vertically, above and clear'of the liquor for a considerable period of time, and subsequentlythey are drawn along through the treating liquor and thus immersed for about the same length of time to" subject them to the action of a con-- sta'ntly replenished supply of liquid and, treating substance.-

While-the hides-are immersed in the treating liquor the latter is forced in a stream which moves in the same direction in which the hides are moving sothat the latter are floated on thestream of liquor and separated so that .all parts of the hides are equally bathed in the liquor, .thus facilitating the treatment and securing uniformity in the results attained.

When the hides are first introducedintqthe treating liquor, a relatively weak liquor preferably is provided and the hides are moved slowly through the liquor which may then penetrate gradually to the interior of I the hide asit is alternately immersed in the liquor and suspended to drain and to be exposed to the atmosphere. Subsequently the i liquor is strengthened and at the same time the hides are moved .more rapidly through the liquor and gently flexed while being ine hides, 80 I the appended claims.

troduced into and removed from the liquor. The liquor is strengthened several times at the proper intervals so that with the gentle flexing of the hides the process of getting the chemicals of the treating liquor into the hide is hastened.

The illustrated apparatus and various important features thereof while especially adapted to facilitate the tanning of hides according to the method already described may obviously have other applications and uses. In accordance with importantfeatures of the invention in its apparatus aspect, as shown, a carrier is provided coniprising rods or other supports upon which the hides or skins may be attached so as to extend interiorly of the carrier, and means is provided at the head end of-the carrier for introducing the hides gently into the treating liquor while maintaining them substantially in extended condition. In the preferred form of the invention the means just described is shown as a drum of such a size that the whole body of the folded hidemay rest upon it and be gently flexed as the drum turns to carry the hides down into the treating liquor.' At the other end of the carrier the rotatable members which support the carrier are spaced apart, with no intervening shaft, so that the hides may be gradually withdrawn from the liquor with a gentle bending movement and finally suspended along the upper run of the carrier. An important feature of the carrierarrangement is that the hides on the lower run are supported on the upper surface of this run and are not dragged along the bottom of the vat which holds the treating liquor. Other important features of the apparatus relate to means for securing a rapid circulation of the treating liquor which is preferably directed in a stream that is particularly effective in floating the hides and in reaching all portions of the surface of the hides so that the product is uniformly treated. Means is also provided for moving the carrier at different rates of speed so that the hides may be drawn more slowly through the weak treating liquor and more rapidly through the treating liquor as the latter becomes stronger. Other features of the invention and novel combinations of parts will described in the detailed specificaton and pointed out in In he drawings, which "show one illustrative embodiment of my invention i Figure 1 is a plan view ofthe preferred form of material treating apparatus particularly adapted for tanning leather;-

Fig. 2 is a vertical section on the line 2-2 of Fig. 1;

Fig. 3 is a side elevation of a link used in the conveyor illustrated in Figs. 1 and 2, and providing a preferred arrangement for attaching hide-carrying bars to the conveyor link; and

Fig. 4: is an elevation of a portion of a hide-carrying bar, a portion of a hide carried thereby, and a preferred form of attaching means, particularly useful in connection with the apparatus and method.

Referring to the drawings and to the preferred form of my invention selected for illustrative purposes, I have shown an endless carrier for the hides resenting an upper run 0 and a lower run 7 etween which the hides 8 are carried interior-1y of. the carrier as a Whole.

The preferred form of carrier illustrated includes front and rear rotary parts acting as pulleys or sprockets, over which the end less carrier passes. The flexible elements of the carrier are herein shown as two chains, which are preferably formed of wood or other material which will not ali'ect the tanning or other liquor deleteriously, and which in turn will not be dcleteriously acted upon by the liquor. Between these chains, I have provided removable dowels or bars 9, preferably of wood, over which the hides may be lapped or to which the hides maybe attached in any suitable way, but preferably by attaching means hereinafter described.

The diameters of pulleys or sprockets 10 and 13. over which the chains pass are preferably such that the largest hide to be treated in the machine, when hanging over the dowel in the upper run of the carrier, will not contact with the hides lying upon the I lower run of the carrier, nor dip into the tanning liquor which preferabl is just sufficient to cover the hides on he lower run of the carrier. The head pulleys or sprockets 10 are preferably provided with an inner drum, spider or other support 11, stationary in space at one end of the carrier but moving therewith and over which the-hides, suspended from the upper run of the carrier ,may lap as they-approach the head end of 110 the carrier, the diameter of this drum or spider 11 preferably being such that the hides will fold one upon the other without any sharp bending but with a gentle flexing progressive throughout the length of each hide, 115 and such that the hides, as they 'are'drawn around and with this inner drum, will remain in substantially the overlapped extended relationship which they take when initially folded upon the drum until they are gently 120 passed or released from the drum as they rest upon the upper side of the lower run 7 of the conveyor. In order to minimize shp: page of the hides relative -to the surface of the drum as they are being let down into the treating liquor, said surface isprovided with peripheral ridges as clearly shown in Fig. 2 of the drawings.

The tanning or other material treating liquor may be contained in a suitable container, tank or vat 16 surroundingv the lower .portion of the carrier, and preferably relatively close to the carrier.

"to pass between them and tothisend each is supported by an. independent trunnion 14 or 15, leaving the space between them free, so

that each hide as it is drawn upward by the carrier at the rear end of the conveyor will be first slightly flexed against the interior of the carrier and the adjacent hides andthen straightened so that it hangs straight down from its hide-carrying bar as the latter approaches the upper run of the carrier, and

this without that distortion and extreme flexin that would be likely to occur if the rear pu leys or sprockets 13 were provided with i an intervening drum or spider. It will be oliserved that thereis produced a gentle flexing of the hides both at the time of entering and at-the time of leaving the tannlng liquor, whereby penetration of the tanning agents is facilitated. Moreover, the flexing takes place throughout practically the whole length of each hide:

In the illustrative machine, the axesofthe head and tail pulleys or sprockets are'spaced apart a considerable distance so that the carrier passing around the sprockets may be of a suitable length to provide the desired period (if time during which the hides on the upper run may hang vertically with theirsurfaces exposed to the air and spaced from every adjacent surface, thereby permitting material.

the treat-ing liquor to, drain therefrom'and permitting the material completely to relieve itself of any strains or distortions arising from flexure during the operation. This also provides an extended period during which the hides on the lower run of the carrier are immersed in the treating liquor. The apparatus described provides a mini- -mum disturbance of the material being treated which is consistent with. insuring complete and sufiicient exposure thereof to the action of the'material treating liquor in a comparatively short time, and while also providin'g for ,those advantages attending alternate immersion and 'emersion of the In the preferred embodiment-of my invention illustrated, the liquor in the tank 16 may be kept at a relatively low level, preferably that at which the hides or other materials on the lower run of the carrier will be merely covered, and the action of the liquor on the hides or other material may be Circulating means for the liquor comprises preferably a centrifugal pump 17 which draws the material from the tank through a discharge pipe 18, thence preferably discharging it into a mixing tank or chamber 19 where the liquor'may be heated, if desired, by a steam coil-20, and thenback into the main tank through pipes 21. .The discharge pipe 18 is preferably adjacent that end of the tank where the rear or tail pulleys or sprockets 13 are located and the inlet of the pipe where the headpulleys or sprockets 10 are located so that the circulation of the liquor tends to force it between pipes 21 are preferably adjacent that end I the hides, thereby to assist in the floating or lower run 7 of the carrier lie relatively close;

ly together, while permitting suflicient circulation of the liquor between them, in effect floating in the liquor, preferably assisted .in this by the circulation of the l1quorby the pump, I am enabled to treat a relatively large number of hides over their entire area witlT a comparatively small body of liquor. The tank 19, where utilized in connection with my circulating system, is preferably relatively small so that the liquor therein is kept .in a state of agitation, and, where chemicals are added to the treating liquor during operation either to maintain its strength or to increase its strength, these materials may be conveniently added gradually in the smallertankwhere, byreasonv of the agitation, they will be very rapidly heaviest sole leather, takes from five to six days, operating the machine on a ten-hour shift, the operation of the machine preferably being continued for about ten hours each day and the liquor then being withdrawn from the tank, leaving the hides in a practically saturated state in the machine during the remaining fourteen'of each twenty-four hours.

In treating some continued circulation by the pump is not necessary or desirable, but I recommend that classes of materials, the v a pump or equivalent apparatus be provided so that the main tank may be quickly has four bars or dowels removably connected thereto, preferably by means (best shown inFig. 3) wherein the bars 9 are squared at the ends and enter rectangular depressions in the link, being held therein by slats 3O removably secured in any suitable way,

exemplified by a cleat 31 and screw 32. Where the bars or dowels are thus removably secured, the loading of the machine may be very conveniently effected by first securing the hides to the dowels or bars, in any suitable way as by tacking. but'preferably by the clamp arrangement illustrated in Fig. 4 wherein a bar 33 provided at one end with-a point 34, may be pressed against the hide bya sliding loop or ring'35, which may be held against slipping by suitable serrations 36 on the under side of the bar. When the loop or ring, 35 is moved to the left, as viewed in Fig. 4, the pressure on the point 34 will be relieved and the hide may be removed; while slipping the ring 35 to the right, as viewed in Fig. 4, increases the pressure on the point 34, the bar 33 being more or less flexible. Change speed gearing is provided so that the rate of travel of the carrier may be slowed down to permit rela tively slow continuous movement thereof as the bars 9 with the hides depending therefrom are slid in place adjacent the top of the rear pulley or sprocket on the carrier during the loading operations. The bars 9 with theirattached hides may be conveniently removed adjacent the head end of the carrier, being slid out as they approachthe center of the down-going side of the head pulley or sprocket 10.

I have found that where the sprockets or c pulleys ars approximately six feet in. diameter, providing six feet between the upper and lower runs, and the distance between the axes of the head and rear pulleys or sprockets is approximately thirteen feet, that the best results are attained by starting the tanning orvother operation with the carrier moving at a relatively low speed, a complete cycle being completed inapproximately three minutes, this being continued until sufiicient tanning has been effected to set the grain and generally toughen the hide 0 structure. After this has been done, the

nature of the hides or other material being treated. Any suitable arrangement of step pulleys 40 or gearing may be utilized to give the desired range of speeds. A carrier of the dimensions just described has a shape in longitudinal section of an ellipse with flattened sides.

The apparatus and method described is particularly useful in connection with the treatment of hides, especially in the tanning thereof. Hides in a green state'as they come from the drenching operation prior to tanning are very delicate and any undue wrinkling thereof caused by sharp bending or crumpling results not only in a leather of unpleasing appearance, but in ridges in the finished product which render'the leather unusable.

In the use of the apparatus described, no hide is normally permitted appreciably to slip or fall at any point of the cycle, and the likelihood of wrinkling is thus greatly lessened if not eliminated. Because of the.

manner in which the hides are subjected to the treatment of the liquor, only a very small body of liquor need be utilized, which 'tinuously with fresh liquor, the tannin operation thereby being speeded up an assisted. The weakened liquor cannot remain in the pores and is constantly washed out and replaced by fresh liquor. Each hide necessarily receives the same uniform treat-' ment and the leather when tanned is very satisfactorily plumped, because thesurface of the hides during tanning has been kept relatively open and free, so that-the fibres near the center of the hide become thoroughly tanned and an opportunity for greater swelling of the central structure of the hide is therefore afforded.

Reduction of the aggregate time of tan- Ding not only results in great saving in the apparatus required, cutting down the space necessary, but reduces the aggregate number of hideswhich it is necessary to carry onhand for a given plant capacity. The. labor'saving is very considerable over other rapid tannage operations, because the bandling of' the hides from one apparatus to another for different treatments is done away with or eatly reduced, and because of the simplicity and ease of loading the speed may be gradually increased until. at s VVhile- I' have shown and described one fullspeed the carrier preferably completes a cycle in approximately one minute. The

speeds may be varied in accordance with the paratus and method may be considerably preferred formof apparatus and a preferred method, it will be understood the ap- 4o porting and guiding means for said carrier,

' material .to be treated is carried, meansfor throughout its length.

actuating said carrier to move the material being treated during the treating operation,

- bination, a carrier, front and rear supportsaid carrier providing forsuspension of the material from the interior of the upper run of the carrier and for supporting the material above the lower run of the carrier in' a treating liquor, and a member stationary in space at one end of the carrier and opera 'tive to bend the material progressively 2. Apparatus for tanning or otherwisetreating hides or leather comprising, in

combination, a conveyor carrier, front and rearsupportingand guiding means for said carrier, said carrier enclosing the hides dun mg thetanning or treating operation, and

-means for maintaining the-hides in extended condition while introducing them into the. treatingliquor.

3. Apparatus for tanning or otherwise treating hides. or 'leather comprising, in combination, a carrier presenting upper and lower runs, and front and rear supporting and gu ding means for said carrier, said supporting and guiding means carrier enclosing the hides and providing for suspension of the hides secured in spaced relationship interiorly of said carrier, depending fromthe upper run thereof and resting upon the lower'run thereof.

4 Apparatus for tanning or otherwise treating hides or leather. comprising, in' combination, a carrier, front and rear slipthe front presenting interior supporting means over'which each hide is wrapped as it approaches the front. of the carrier, said interior supporting means being operative to deliver each hide in extended condition to the upper side of the lower run of the "carrier.

5. Apparatus for tanning or otherwise in said carrier enclosing the hides,

porting and guiding means for said carrier,

, said carrier having supports for suspendingthe hides insidethe .carrie'r, said rear supporting and guiding means including two rotatable members over which said carrier passes, the space between j said;,rotatable members being substantially unobstructed to permit each hide to hang substantially per-. pendicularly as it is lifted from the bottom run of the carrier'and passed to the upper run thereof.

6. Tanning apparatus comprising, in combination, a carrier, front and rear supportthe treating liquor.

' front and rear sup- I ing and guiding means for said carrier, said said rear guiding and supportfront and rear guiding means each'including a plurality of rotatable members over which sald carrier passes, hide-supporting means between the rotatable members of said front guiding and supporting means, and separate tI'llIlIllOIlSiOljhG rotatable members .of said rear guiding and supporting means. having the space between the rotatable members of said rear guiding and supporting means substantially unobstructed. i

8. Material treating apparatus comprising, in combination, ible elements, each continuous and supported in substantially parallel planes, bar's between said flexible 'car'ryin elements, said carrier providing upper and lower runs, meansfor guiding and supporting said flexible elements permitting hides to be attached to said bars while exte'ndinginteriorly of said I carrier, and means for maintaining the hides in extended condition while introducing them into and removing them from 9. Hide treating apparatus comprising, 1n combination, a tank, two flexible chains, each provided with, a head sprocket and a tail sprocket and arranged in generally parallel planes, bars extending between said chains, to 'formsacarri'er having upper and lower runs," said chains comprising links to wh1ch .said' bars are conncted. with thehides interiorly of the carrier, and means for lowering the hides into the tank in extended Goverlapped relation to-each other." Y 10. Hide treating apparatus 'comprlsing, in combination, a tank, two-flexible chains; each.piovided with a head sprocket and a .tail sprocket and arranged in generally parallel planes, bars extending between sa d chains to form' a' carrier-having upperand lowerruns, said chains comprising links to the exterior of which said bars are deta-ch- "ably-connected, and a drum at oneend of the carrier operative to lower the hides'into the -tank gently and in'extended conditien.

11. Tanning apparatus comprising, in

. combination, av carrier presenting a hide-. carrying chain, guiding and 'supportlng means therefor, a tank surroundfiig the lower portion of said carrierand adapted to contain hide-treating liquor, means providing for supporting 'hides interior-1y of fsaid carrier, driving means for said carrier for causing alternate immersion and emersion of said hides in said liquor and a rotatable member for causing the hides to enter the li nor in extended condition.

-12. anning apparatus comprising, in combination, a carrier presenting a hidecarrying chain, guiding and supporting means therefor, a tank surrounding the lower portion of said carrier and adapted to contain hide-treating liquor means providing for supporting hides interiorly of said carrier, driving means for said carrier for causing alternate immersion and emersion of said hides in said liquor, and liquor circulating means for procuring a rapid circulation of liquor in said tank and for directing a stream of liquor against the hides to assist in the floating and separation of the hides.

13. Tanning apparatus comprising, in combination, a carrier presenting a hidecarrying chain, guiding and supporting means therefor, a tank surrounding the lower portion of said carrier and adapted to contain hide-treating liquor, driving means for said carrier for causing alternative inn-- mersion andemersion of said hides in said liquor, and liquor circulating means for procuring a rapid circulation of liquor in saidtank, said circulatory means admitting liquor to the end of said tank where the hides are first immersed. and withdrawing liquor from the other end thereof.

14. Tanning apparatus comprising, in combination, acarrier presenting a hidecarrying chain, guiding and supporting means therefor, a tank surrounding the lower portion of said carrier and adapted to contain hide-treating liquor, driving means for said carrier permitting alternate immersion and 'emersion of ,said hides in said liquor, and liquor circulating means for procuring a rapid circulation of liquor in said tank, said circulatory means admitting liquor to one end of said tank and withdrawing liquor from the other end thereof, the liquor in the tank being circulated in that direction in which the hides are drawn through the tank by the carrier so that the hides are floated and separated from each.

other in the liquor.

15. Tanning apparatus comprising, in

' combination, a carrier, presenting a plurality rocket means of hide-carrying bars, head and tail sprocket means, and hide-supporting means associated withv the head sprocket means and presenting peripheral ridges for engagement with the hides to minimize slippage thereof relative to 'said hide-supporting means.

16. Tanning apparatus comprising, in

said tank to preclude abrasion of said hides on the bottom of said tank.

17. In an apparatus for treating hides,

skins and other like pieces of work, a carrier having upper and lower runs arranged to suppport pieces of work and movable in in elliptical. path, and a container for treat ing liquor along the bottom of which the lower run of the carrier is dragged with the 'vide for uniform drainage from all of the surfaces of the pieces of work.

18. In an apparatus for treating hides,

skins and other like pieces of work, a carrier having upper and lower runs spaced from each other to support pieces of work suspended from the upper run clear'of other pieces of work on the lower run, said carrier being of a length considerably greater than the spacing between'the runs, a container-for treating liquor adaptedto receive the lower run of the carrier, and means for suspending the pieces of work from the lower side of the upper run whereby they rest upon the upper side of the lower run during passage through the treating liquor, the arrangement being such that the pieces of work are'alternately immersed and ex osed to the atmos here for substantial perio s of time.

19. 11 an apparatus for treating hides, skins and other like pieces of work, a carrier having upper and lower runs, a support located adjacent to one endof the carrier and having a surface movable at substantially the same rate as the carrier, and a container for treatin liquor arranged to receive the. lower run ofithe carrier, said support being so positioned as to receive in overlapped extended relation pieces of work presented by the'carrier and being operative to deliver them in extended condition to the upper side of the lower run of the *arrier as the latter enters the treating liquor.

20. In an apparatus for treating hides, skins and other like pieces of work, ,acarrier having u )per and lower runs, a shaft at one end of the carrier, a drum on the shaft located within the carrier so that both drum and carrier turn about the shaft, and spaced trunnions for supporting the other end of the carrier for turning movement about the common axis of'the trunnions, the arrangement being such that pieces of workas they move with the carrier from the lower to the upper run are gently flexed against the intenor of the last-mentioned end of the carrier.

combination, a carrier presenting two 111118021. In an apparatus for treating hides,

for moving the hides in an elliptical path, and an associated tank, a run of said carrier skins and other like ieces of work, a carrier having upper an lower runs, a shaft at being interposed between said hides and one end of the carrier, a drum on the shaft the carrier from thelower to the upper runare gently flexed against the interior of the last-mentioned end of the carrier, and means forsuppo'rtingthe pieces of work from the under side of the upper run of the carrier, the drum bein" operative gently to flex the pieces of worfi as they are moved to the upper side of the lower run in their travel with the carrier. a

22. The method of handling hides during tanning or other treatmentwhich comprises passiiigthem on-noncircular flexible carrying medium of considerable length into and out of the treating liquor while alternately permitting them to lie floating generally horizontally in the liquor and to hang generally perpendicularly out of the.treatingliquor with their surfaces spaced from each otherto secure drainage of the treating liquor from all the surfaces.

The method of handling hides during tanning or other treatment which comprises passing them on a noncircular flexible car'- rying medium of considerable lengthinto and out of the treating liquor while alternately permitting them to lie floating generally horizontallyin the liquor and to hang generally perpendicularly out of .the trenting liquor, and causing only gentle flexin of. the hidesiduring their passage to and from the before-described positions. 24. That improvement in methods of treatinghides which comprises immersing the hides in treating liquor gently while maintaining them in extended condition, moving the hides through the liquor, lifting them from theliquor, suspending them so that they hang substantially vertically with their surfaces in spaced relation to each other to drain the liquor from the surfaces of the hides and then again immersing the hides and repeating the steps already. recited. 25. .That improvement in methods of treating hides which comprises immersing the hides in treating liquor, drawing them through the liquor allin one direction, producing a rapid circulation of the liquor in the direction of movement -ofthe hides whereby the latter are-floated and separated from each other so that the liquor bathes all thesurfacespf the hides, removing the hid es Q fFom the liquor and suspending themsub stantially vertically, so that the liquor, is

, 6o drained from all of the surfaces. of the hides,

then again immersing the hides and repeating the steps already recited.

' 26. That improvement in methods of treating' hides and skins which comprises immersing the-hides or skins in relatively weak extent described.

treating liquor, moving the hidesor skins through the treating liquor at relatively slow speed, removing the hides and suspending them to drain the liquor fromallv surfaces of the hides or skins, repeating the steps already recited for a considerable time, then introducing a stronger li uor into the vat, immersing the-hides or skins as before, drawing them through the. liquor at a considerably higher rate'of speed, and withdrawing the hides Lor skins from the liquor and suspending them to: drain at intervals between-repeated immersions until the completion of the treatment.

" 27. That improvement in methods of treating hides and skins which comprises. immersing the hides or skins in treating liquor while m aintainin' them inextended condition, moving the hides or skinsthrough the treating liquor, then withdrawing them from the liquor and suspending, them to drain the liquor from all surfaces of the hides or skins, and during theintroduction ofthe hides or skins into the liquor and also during their removal therefrom gently flex-v 00 ing the hides or skins to facilitate the penetration of the treating liquor.

28. In an apparatus of the character described, a vat for containing the treating liquor, a carrier for hides or skins having 05 an upper and a lower run spaced from each other so that the. hides or skins on'the upper run may be suspended clear of the liquor which covers the skins or hides on the lower run, and rotatable members at each end of I the carrier each of a size'to space the upper and lower runs in the mannerand to the v 29. In an apparatus for treating hides and skins, a vat for treating liquor, a carrier 5 having spaced substantially hozizontal upper and lowerruns, said runs being constructed and arranged to suspend hides from the upper run over and above the treating liquor in the vat an to p t hides on the lower run substantially immersed in the treating liquor, rotatable members for supporting therarrier, and'means' to actuate I the rotatablemembers at selected rates of speed so that the hides or skins on the car-. 5 rier maybe subjected to immersion in the treatingliquor for various periods of time.

in accordance with the strength of the treating liquor.

5' 30. In an apparatus for treating hides and skins, a vat for holding the treating liquor, a carrier having upper and lower runs spaced from each other'so that the hides or skins suspended from the upper run may clear the tanning liquor which covers the hides or 12 5 ating with the carrier at one end thereof 13Q liquor so that as the skins or hides are drawn through the li nor on the lower runof the carrier the hi es or skins lie uniformly in extended condition with the folded .portion in advance of the other portions thereof, andmeans for causing a rapid flow or stream of the treating liquor in the direction of movement of the lower run of the carrier whereby the skins or hides are floated and separated from each other so that all surfaces of the hides 0r skins are bathed by the treating liquor.

31. In an apparatus for treatinghides and skins, a vat for the treating liquor, a carrier having upper and lower runs and movable to draw the skins or hides through the liquor in the "at, and means for causing a rapid stream of the treating liquor to flow in the direction of movement of the lower run of the carrier, said means comprising a re1atively small tank connected by relatively large pipes to the vat at the head end thereof to, irect the stream of liquor in the manner described, and a pump at the other end of theyat to withdraw the liquor from the vat and deliver-it to the tank. e v

32. That improvement in methods of treatin hides and 'skins which comprises immersing the hides or skins in treating liquor while maintaining them in extended condition, moving the hides or skins through the treating liquor, and during the introduction of the hides or skins into the liquor and also during their movement there-.

through gently flexing the hides or skins to facilitate the penetration of the treating liquor.

In ap aratus for tanning or other-' wise treating P ides or other leather substances, a carrier having supporting members to which the hides are temporarily attached so as to be enclosed by the carrier, and a circular member having a portion only of its curved surface substantially concentric with the adjacent surface of the carrier and stationary in space within the carrier, said member bein operative to flex the hides gently throng out their lengths during rotation of the carrier.

34. In an apparatus for tanning or otherwise treating hides or other leather sub stances,- a carrier havmg supporting members to which the hides are temporarily stances, a carrier turning about front and rear axes and having upper and lower runs between which the pieces of material to be treated" are carried, and a .drum within the carrier rotatable about one' of the axes'and operative to support the pieces of material as they are passing from the upper to thelower run and to flex them gently. meanwhile 7 throughout the length of each piece.

36.'That improvement in methods of treating hidesand skins-which comprises immersing the hides or skins in treatingv liquor, moving the hides or skins through the treating liquor, and gently flexing the hides or skins to facilitate the treating'liquor.

37. That improvement in methods of treatin hides and skins which comprises immers ng the hides orl skins in treating liquor while maintaining them in substans tially extended condition, mov' or skins. through'the' treating 'quor, and

gently flexing the hides or skins while main taining them in the described extended con--. dition whereby penetration of the treating liquor is facilitated.

penetration ofxthe the hides 38. That improvement. in methods of]v treating hides and/skins which comprises immersing the hides or skins in a treating liquor, suspending them with all their sur-' faces exposed to the atmosphere to secure uniform drainage, and subsequently re immersing them while holding them in ex.-

tended overlapped relation and causing gentle flexing throughout'the whole lengt of each hide or skin.

In testimony whereof, I have signedmy name to this specification.

MATTHEW M. MERRITT. 1

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