US1975349A - Grinder for dressing skins - Google Patents

Description

Oct. 2, 1934. M CURTI 1,975,349

GRINDER FOR DRESSING SKINS Filed April 23, 1934 f. INVENTOR.

GEORGE M. CUPT/IY.

oi W

ATTORNEY.

Patented Get. 2, 1934 I UNITED STATES PATENT OFFICE I 1,975,329 GRINDER FOR DRESSING SKINS George M. Curtin, Gloversville, N. Y. Application April 23, 1934, Serial No. 721,902 6 Claims. (Cl. 149-14) This invention broadly relates to improvements in abrading machinery especially of the wide faced drum type adapted to dress fine tanned leather goods for glove making and the like purposes, and is more particularly concerned with certain protective devices that prevent the treated skins from unduly hugging or being inadvertently wrapped around an abrasive drum surface when operatively fed thereto.

The present instrumentalities are applicable to a dry skin grinder of the type disclosed in the Feix Patent No. 1,241,363 dated September 25,

I 1917. Such a machine may comprise a rapidly revolving abrasive drum together with a feed or so-called presser roller that is reversely driven but at a relatively slower speed and made bodily shiftable toward or away from its cooperating abrasive drum. A marginal portion of a skin while longitudinally stretched in an unwrinkled condition, is dextrously manipulated and gradually fed to this machine with its flesh side pressed snugly toward the abrading drum to remove its superfluous material. This operation results in a tanned leather product that is made uniformly thin. After reaching the medial surface region, the treated skin is generally withdrawn by selectively releasing the presser roller and the skin then reversed from end to end to similarly process its remaining unfinished flesh surface. During such procedure it is not an infrequent occurrence that the skin adheres unduly to the abrasive roller and is carried around therewith with a resulting abnormal wastage of material. Whenever the skin tends to grip in such fashion, the operator manually reaches underneath the fast rotating abrasive drum to free the skin during its incipient seizing period, but such practice is attended with considerable hazard and has in the past, frequently led to'serious maiming of many experienced machine attendants.

The preventive measures herein embodied are centered in jet means which preferably eject a blast of air or other gaseous fiuid tangentially against the abrasive drum in a direction counterwise to the path of the incoming treated product. The nozzle for my continuous air stream is so disposed that .it will efficiently pick off and surmount the drum hugging tendency displayed by machine treated skins, it having been found that such unremittent safeguard effectively obviates the fabrication difliculties usually encountered when skin seizure occurs.

The abrasive drums are commonlybuilt up from heavy cardboard discs or the like compressed fibrous material and the cylindrical surface of which has granules of abrasive glued thereto. After becoming dull or worn, such superimposed cutting surface is renewed in place, and

in order to avoid clogging and otherwise defiling my safety appurtenances, the entire blower equipment is preferably installed as a demountable machine accessory.

The-object of my invention is to provide for a trustworthy yet extremely simple device of the character indicated and one that can readily be applied to either existing or new grinders without requiring extensive changes in the structure thereof. .Other objectives will appear in due course and all of which aspects will hereinafter be set forth in detail.

Reference is had to the accompanying one sheet of drawings which is illustrative of a specific embodiment of my invention and in which draw- Fig. 1 schem tically represents an elevational cross-section of a grinder machine as taken transversely of the medial region of its abrasive roller and equipt with my improved devices; while Fig. 2 shows a horizontal'view thereof as seen from line 2-2 of Fig. 1.

Referring first to the more conventional elements of a dry skin grinder assembly of the kind comprised in the cited Feix patent, these prima- 'rily include a belt driven abrasive drum 10 which relatively massive part may be mounted between a pair of shaft journals such as 11 and rotated at a relatively high speed by the pulley 12. Said journals may respectively be carried upon complementary horizontal girders such as 13 that are spacedly supported by the upright framework 14. The lowermost portion of the framework may be equipt with a pair of crossbars such as 15 which respectively lie beneath said complementary girders. These crossbars may respectively be provided with an auxiliary journal such as 16, having a cross-shaft 17 mounted therebetween.

Each upturned girder face may be fitted with a separate guideway 18; respectively resting thereon is a shiftable carriage element 19 and across which is suspended a work table 36 for holding treated skins. Rack and pinion means such as 20 may serve to' simultaneously actuate the respective carriage elements toward or radially away from the drum axis. To this end, a pinion rockshaft may be extended laterally to have a toggle arm 21 attached thereto, said arm being linked to the pivoted foot treadle 22. If desired, an adjustable counterweight 24 or its equivalent may be used to load and thereby automatically thrust the carriage elements 19 inwardly toward the abrasive drum surface in released treadle position. Mounted between said carriage elements is a sheathed presser or feed roller 25 which may be brought closely contiguous to the abrasive drum surface but which roller may be withdrawn whenever the treadle is depressed. Said roller lightly presses the interposed skin against the abrading drum surface.

It is preferred to positively and continuously rotate the shiftable feed roller from the pulley 12 in a reverse direction from that of the drum. In the present instance, the drive is accomplished by the conventional chain and sprocket reduction gear 26 represented in Fig. 1. As indicated in dotted outline, supplementary guide rollers 27 and 28 may be installed to cooperate with the feed roller, but all such subordinate members merely assist in properly guiding the treated skin 29 between the drum l0 and the feed roller 25.

Referring now more specifically to the improvements applied to the described conventional grinder members, these may comprise a blast means of any suitable type or design but preferably such that includes a casing 30 and a rotatable fan or blower 31 which may be independently driven in unison with the drum 10- by a direct connected motor 32. As an alternative, saidblower may also be driven from the pulley 12 or the blast taken from any other convenient source, the intent being to insure an adequate blast supply during the period of grinder operation.

The blower casing 30 is shown provided with a flange 33 which may be detachably secured to a contiguous portion of the framework 14. Said casing may further be equipt with a contracted delivery spout 34, preferably of the multiple nozzle type adapted to distribute the air blast lengthwise of the drum through a series of laterally disposed jets 35A, 353, etc.

Each such nozzle may be arranged underneath the rotating drum closely contiguous to but distant from the abrading surface so as to eject upwardly toward the rotating drum in tangentially counterwise or other opposed relation to the surface movement, as shown. The use of a plurality of such jets is however, not essential since a single nozzle blowing medially of the drum will normally suffice to start the leading extremity of a relatively small skin away from the abrasive surface, which in turn effectively extricates and overcomes the inherent tendency possessed by such treated skins to carry wholly aroundwith the rotating drum.

It is thought the function of my tangentially directed air stream will now be apparent to those skilled in this art. When the treated skin is descendingly fed through the described machine, its leading extremity usually drops away from the drum, but should its initial surface grip persist in dragging said skin into the operative region of my air blast,. such jet or jets serve in the capacity of a sentinel to promptly pick up and cause the loosened leading skin end to pull away from the drum, whereupon its overhanging weight assists in drawing the remaining trailing skin portion free from the abrading surface. Should it, after repeated dressing of the drum surface, become necessasry to renew the glued abrasive material, it is preferred to bodily remove the blast nozzle out of the way in order not to clog or otherwise befoul the same with drippings.

As a further outstanding feature, all working parts required to loosen the treated. skin, are

herein deliberately kept spaced from the drum profile; that is to say, by the use of an air blast as projected to play upon the distant drum, none of the accessory elements need actually contact with its cutting surface nor be subjected to rapid abrasive action. In addition, my fluid spray when given sufficient penetration, tends to cleanse the abrasive drum surface from any abnormal accumulation of adhering foreign matter which might otherwise be deposited thereon because of skin treatment.

It is to be understood that various other structural modifications may be resorted to in likewise carrying out my illustrative embodiments, all without departing from the spirit and scope of my invention heretofore described and more particularly pointed out in the appended claims.

I claim:

1. In a machine for treating skins or the like, the combination of rotatably mounted drum means provided with an abrasive surface, feed roller means cooperating with said drum, drive means for rotating the drum surface, and blast means ejecting a gaseous fluid toward the drum in an opposed direction to the drum surface movement.

2. A skin processing machine comprising r0- tatably mounted drum means having a cylindrical abrasive surface, feed roller means cooperating with said drum, drive means for rotating the drum surface, and air blast means including a nozzle that is kept spaced from said drum surface and directs a jet of air thereagainst for skin piekoif purposes.

3. A skin processing machine comprising rotatably mounted drum means having a cylindrical abrasive surface, feed roller means cooperating with said drum, drive means for rotatlng the drum surface, and blast means including a plurality of nozzles that are distributed lengthwise along said abrasive surface and respect-ively disposed to eject thereagainst.

4. A skin dressing machine comprising mounted drum means having an abrasive surface, cooperating feed roller means that are selectively movable toward or away from said drum, drive means for positively rotating the drum and the roller at different speeds, blast means including a rotatable blower element togetherwith a nozzle ejecting toward the abrasive drum surface, and means for rotating said blower in unison with the drum. 5. In a skin treating machine, the combination of drum means having an abrasive surfaceand which drum is rotatably supported by an underlying framework, feed roller means cooperating with said drum, drive means for rotating the drum, and blast means including a jet nozzle that is detachably upheld beneath said drum by said framework and which nozzle is directed to eject upwardly against the abrasive drum surface.

6. In a machine for treating skins or the like, the combination of rotatably mounted drum means provided with a cylindrical abrasive surface, presser roller means cooperating with said drum in contiguous perimetric relation to receive a skin therebetween, drive means for rotating the drum, and means ejecting a fluid stream toward the abrasive surface and which stream loosens a leading skin portion from said surface after having passed through the aforesaid perimetric reion.

GEORGE M. CURTIN.

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