US1571973A - Leather belt and process of producing same - Google Patents

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Feb. 9 ,1926. y 1571,5173

, H.-J. SHIVELL ET AL LEATHER BELT AND PROCESS OF PRODUCING SAME Filed Dec. 5, 1920 H W/ m ,45 a] 4 4? avwewtoz' 359ml Qua/W Patented Feb. 9, 1926.

UNITED STATES PATENT. OFFICE.

HOMER J. SHIVE IfL AND KARL If.v KOENIGER, OF KINGSPORT, TENNESSEE, AS- SIGNORS TO GRANT LEATHER CORPORATION, A CORPORATION OF VIRGINIA.

LEATHER BELT AND rnocnss OF rnonucme SAME.

Application filed December 8, 1920. Serial No. 428,160.

To (all "ILIIOIIL it may concern:

Be it known that we, HOMER J. SHIVELL and KARI. lV. Kormean, citizens of the United States, both residing at Kingsport,

Tennessee, have invented certain new and useful In'iprovements in Leather Belts and Processes of Producing Same, of which the following is a clear, full, and exact description.

W Our invention relates to an improvement in leather belts and process of producing same. Our object is to improve the construction and produce a belt which will be stronger and more efficient particularly when first applied. It is well known that the ordinary leather belt when first applied does not give its maximum tractive effect or attain its maximum efficiency. After it has been run for a while, its surface will show a somewhat mottled appearance, portions thereof being lighter than others. This 1s caused by the surface not contacting at all points with the pulley over which it runs, with consequent loss of efficiency. As the belt continues in use, the mottled appearance gradually disappears, due to the fact that the friction surface thereof gradually becomes set so as to contact to a greater extent over its entire area. The maximum tractive effect is therefore not attained in the ordinary leather belt until after a considerable period of use. lVe are able to produce a belt which, when new, willbe more efficient and will much more nearly approach its maximum frictional efficiency, besides attainingother advantages.

An unhaired hide is not homogeneous from the upper surface down but consists of-several layers having different characteristics. A section thereof is illustrated in Fig. 1, in which 1 represents the epidermis or outer layer, 2 the so-called real skin, 3 the socalled middle portion and 4 the remain der or so-called fibre. It will be under stood that in the illustration the thickness of the first three layers not only with relation to themselves but with relation .tothe thickness of the fiber layer has been exaggerated for clarity of illustration. The epidermis and real skin contain pores. These are very fine passages in the real skin illustrated, for example at 5, which open out in the epidermis, as illustrated at- 6. In them or some of them, the' hair roots indicated, for example at 7, are located. The relative size of these pores is of course greatly exaggerated 1n the illustratlon.

These pores, While they are minute, are mulcondition, the presence of the pores in their original form decreases quite materially the tensile strength of the leather. WVe believe this is caused, at least in part, by the pores, particularly the roughly inverted-conical shape of the upper portion thereof, presenting what is in effect a multitude of embryonic cracks extending part way through the leather from the upper or contacting surface where the greatest strain occurs down into or through the upper layers. The hair side of the belt is used as the surface which contacts with the pulley, as it. has been found that this is the most efficient. side. The problem of producing a more efficient belt therefore presents these two apparently irreconcilable desiderata. By g5 our method of manufacture, we have been able substantially to reconcile to a great extent these two things and produce a belt which is considerably more efficient even when new than the leather belts heretofore made.

Incarrying out our invention in the manner we prefer, we remove the upper portion of the leather. This may be done by various methods but a conven ent method is by splitting it as indicated diagrammatically in Fig. 2, in which 8 indicates the leather passed through between yielding rolls 9 and 10 and split by a straight-edged knife 11.

This will give a smooth upper surface to the remaining portion 12. We split the leather above the lower margin of the real skin 2, preferably between the lower and 11 per margin thereof,- as indicated for exampfia at the dotted line 13 in Fig. 1. This consequently removes much, and preferably all,

of the epidermis which contains the enlarge-- ments of the pores but does not remove all forcing it into the leather from the up the real skin which contains the more minute portions of the pores. It therefore retains the advantage 'of leavlng part of the real skin in place for its tractive effect while reducing the area of the pore openings at the surface, thus not only reducing the tendency of the surface to split under tension but increasing the area of leather which actually contacts with the pulley.

lVhilc a belt made from leather merely so split would accomplish some of the results we have attained, the belt should be internally lubricated and preferably the remaining pores of the upper surface should be filled up by a filler which is of such a character as permanently to till the pores and consequently increase the total area of the belt which contacts with the pulley- The belt may be impregnated with various oily substances such as the oils or greases ordinarily used in rendering leather pliable, such for example as paraffin oil, tallow, etc. The filler for the pores may be and preferably is rubber. It may be applied in different ways to the upper surface. o, however, have found that a successful manner of applying it is to finely divide it, for examp e by dissolvin the crude rubber in gasoline or other volati e solvent which will evaporate after having thorou hly filled the pores. The yubber obviously as aconsiderably higher melting point than the lubricant mentioned.

We prefer to mixthe rubber, dissolved as above described, with the lubricant and apply the mixture to the belt, preferably by er surface. This carries the lubricant zi nd finely divided rubber through the pores. The lubricant passes on into and impregnates the lower layers thoroughly and will work into all portions thereof. The filler, however, need not pass into the lower layers, as its purpose is mainly to fill up the exposed pores. and as they are very minute in the real skin, the filler will be retained mainly in the and resulting in a substantially continuous surface over belt. The rubber solvent is then allowed to evaporate, leaving the pores'completelv filled with the riibber. The surplus may then be scraped or brushed oil, leaving the upper or contacting surface smooth and without unfilled pores, yet with the general ore apearance of the hair side of the hi e. The elt has considerabh greater tractive effect even when first applied, its tensile strength is-increased, and-1n short it is a considerably pores, filling them completely the entire upper area of the more efiicient belt than one manufactured in the ordinary manner.

We are aware that variations in the foreoing steps may be made without departing lflm the scope of our invention as claime and we therefore do not desire to be limited to the exact features above described.

What we claim isl. The process of manufacturing leather for power transmission belts and the like, which comprises removing the epidermis, the grain and a ortion of the real skin of the leather, t ereby removing that part of the leather containing the enlargements 0fthe pores and leaving the upper surface smooth, and impregnating the remaining portion of the leather with an oily lubrlcant, and filling up the pores in the real skin with a finely divided filler which has a considerably higher melting point than said lubricant, and which is 01' such a character as permanently to fill said pores.

2. The process 0 manufacturing leather for power transmission belts and the like, which comprises removing the epidermis, the grain and a portion of the real skin of the leather, thereby removing that part of the leather which contains the enlargements of the pores and leaving the upper surface smooth, impregnating the remaining portion of the leather with an" oily lubricant and filling up the pores in the real skin with a finely divided rubber filler.

3. The process of manufacturing leather for power transmission belts and the like, which comprises removing the epidermis, the grain and a portion of the real skin. thereby removing that portion of the leather containing the enlargements of the pores and leaving the uppersurface smooth, impregnating the remaining portion of the leather with a mixture of an oily lubricant with a solution of rubber without other ingredients to impregnate the leather with the lubricant and to'fill the pores in the real skin with rubber.

4. A leather belt in which the epidermis, the grain ands.

having a. smooth upper surface, the beltfbe-ing impregnated with an oily lubricantland same being filled with a. which has aconsiderably point than said lubricant.

Signed at Kina'sport, of November, 1920.

HOMER J. SHIVELL. KARL w. KoENIoEa.

higher melting the pores in"thej' permanent filler portionfof the real skin have been removed: and

Term, this 26 day

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