US2248191A

US2248191A - Abrading machine

Info

Publication number: US2248191A
Application number: US267119A
Authority: US
Inventors: Pratt John William
Original assignee: United Shoe Machinery Corp
Current assignee: United Shoe Machinery Corp
Priority date: 1938-04-22
Filing date: 1939-04-10
Publication date: 1941-07-08
Anticipated expiration: 1958-07-08

Description

July 8, 1941. '.1. w. PRATT l ABRADING MACHINE Filed April 10, 1939 5 Sheets-Sheet 1 Jly 8, 1941. I J, w PRATT 2,248,191

ABRADING MACHINE Filed April 1Q. v1939 3 Sheets-Sheet 2 www gmag- Patentecl .uly 8, 1941 i UNITED. STATES PATENT OFFICE to. United Shoe vMachinery Corporation, Borvough of Flemington, N. J., a corporation ofNew Jersey Application April 10, 1939, Serial No. 267,119 l In Great Britain April 22, 1938 This invention relates to abrading machines and is herein illustrated vand described as fembodied in 4a machine suitable for scouring or buffing work pieces of sheet material suchV as leather or rubber outsoles or insoles, box toe pieces, counter stiffeners, or other shoe parts. For an example of machines of this general type reference may be had lto United States Letters Patent No. 1,280,639, granted October -`8, 1918, upon the application of P.- T. Beier and?. Bock and to United States Letters vPatent No. 1,710,728, granted April V30, 1929,- upon lthe application of J. Gouldbourn. These machines are arranged to enable a workpiece to--be fed along a table by a feed roll engaging'one surface of the work piece past a scouring roll engaging the opposite surface. One or'more'auxiliary feed rolls may be provided, as well asa rotarybrush for cleaning dust from'the work pieces.

It is an object of the-present invention to provide an improved machine of the type above referred to. In the illustrated machine provision is made for a relative adjustment'between the scouring roll and the principal feedroll to enable one of these rolls to engage the workpiece at a greater or less distance in advance of the other. In the illustrated construction it is the Afeed roll which is thus adjusted.' It has been found d'esirable in many cases to h'ave'the 'feed roll engage the work piece slightly in advance of the abrading roll `to avoid positive pressure at the locality of operation. In the case of relatively stift Work pieces the feed roll of themachine disclosed herein may be adjusted kat a relatively greater distance in advance of the/,scouring roll than'in the case of thin, flimsy work pieces. l

Further features of the 'invention Y relate to an improved mounting'of thefeed roll to enable the feed roll to yieldduring operation upon the work and also to be movedawayfromthe scouring roll when access -tothat roll is desired; lto a main, yieldingly mounted-presser Plate-f'orllffiiding the work against auxiliaryfeed rolls after the work has been scoured ;,-a ,ndy to r an auxiliary presser plate yieldabler-independently of the mainv presser plate lfor .holdingthe scoured work against a-cleaning brush. g

These and other features of cluding certain Vdetails of yconstruction and com'- binations of parts, willzbe-set forth in connection with an illustrative machine Tand willbe pointed out in the appended claims. 1 c

Referring now to the accompanying drawings:

Fig. l is .an elevation Sof the wright-iliandside'of 'the invention, -in,

an improved machine in 'which the present in-y ventionisembodied;

Fig. 2 is a plan view of the machine;

1 Fig -l3 is a plan View of fthe upper portion of 'r the machine with the .feed Vroll (not shown) i carried by 'the upper portion of the column I0.

A pulley L6 (Fig. i2) vsecured upon the left-hand end of `the shaft -l4 is fdriven by a belt vl8`from a pulley 20 (Fig. 11) secured uponva counter shaft 22 journaled in .bearings .carried at the rear of the base plate l2; The counter shaft 22 may be drivenY from any suitable, source of power. Secured rupon the shaft `Mfis 'a ro-ll 2'4 about four inches in diameterrand which,`as shown in Fig. 4, comprisesa .central :hub 26 on which is mounted a sleeve 28 of rubber about seven-shiteenths'v of an inch in thickness, this rubber being relatively hard and only slightly resilient. An endless band 30 oi abrasive sheet material passes around the roll 24 and around a flanged pulley 32 (Fig. 1) which is freely rotatable on a shaft 34 below the roll 24 ,and 'inside of the column l0. 'The shaft 34 passes 'through an arcuate slot in the lefthand wall of `the column and is supported ron a lever tlll'iig. 1f) Apivoted for movement about z ahorizontal axis extending from left to right of sired to replace the abrasive band the lever may be `lifted by its handle to relieve the tension, The upper part of the right-hand side of the column is .provided with a removable cover plate 3l which may be vtakenzoff :to provide access to the abrasive band for purpose of replacement. Provision Afor angular adjustmentV of the shaft 34,130, insure proper runningy of the `abrasive band maybe made in accordance with British LettersPatent No. 394,720, dated January 6, 1932, granted upon the vapplication of R. B. Woodcock `and Arthur A. Rivington.

The dust which arises vby the operation of the abrasive Vband 30 upon the work is drawn down downwardly 'within the hollow column I0 by a fan enclosed in a housing 38 (Fig. 1) at the base of vlthe column, The fan is carried by Ia horizon- The shaft 45 is carried by a lever to enable the brush to be moved by the operator against the abrasive band.

The opening at the top of the column is normally closed by a work table V46 the :upper surface of which is substantially horizontal and which has an opening therein through which the extreme upper portion of the band `38 projects slightly to enable it to operate on a Work piece advanced over the Work table by a feed or presser roll 48 presently to be described. The work table 46 hastwo lugs 41 (Fig.- 2) projecting downwardly andrearwardly, these lugs having bearings by which the work table is fulcrumed for tilting movement about a horizontal stationary shaft 49 extending across the rear of the machine land supported by two lugs 50 extending `upwardly from a bracket 5I bolted to the rear of the column I I). Pivoted to the work table adjacent to the forward edge thereof is a screw bolt 52 (Fig. 1) which normally passes through a bifurcated lug 53 projecting forwardly from the front side of the column. The work table is normally retained in its substantially horizontal operating position by the engagement of the upper surface of the lug 53 with a collar 54 threaded on the bolt 52, the lower surface of the lug 53 being engaged by -a head 55 threaded on the bolt 52. evident that adjustment of the collar 54 and the head 55 on the bolt 52 will serve to vary the level of the work table about the fulcrum shaft 49 to control the extent to which the abrasive band 30 may project above the upper surface of the work table. When the Work table is to be lifted to facilitate replacement of the abrasive band the head 55 is loosened and the bolt 52 is swung out of the lug 53.

The feed roll 48 above mentioned is carried by a frame 56 having two rearwardly extending',

arms 51 which carry bearings by which the frame 56 is fulcrumed for swinging movement about the shaft 49. The direction of this swinging movement is substantially that of the line joining the centers of the

rolls

48 and 24, that is, the common radius. As will hereinafter be described, it may be desirable to adjust the position of the feed roll 48 forwardly or rearwardly, that is, ina direction tangential to the roll 48 at its work-engaging locality. Provision for such adjustment is made byA a pair of eccentric bushings 58 which are keyed to the shaft 49, the frame 56 being fulcrumed upon these bushingsrather than upon the shaft 49 directly. Extending from the shaft 49 is an arm 59 in which is rotatably mounted a horizontal stud 6I through which is kthreaded a screw 60. The lower end of the screw 60 is received in a` block 62 projecting laterally from and xedto the bracket 5l. The screw 66 is freely .rotatable in the block 62 but is held against .axial movement relatively to the block. The arrangement is such that when the screw 60 (which has a square head adapted tobe engaged 'by'a suitable tool forrotating the screw) is turnedfthe shaft 4S is *rotated about its axis. The eccentric* bush- It is ings 58 are thus rotated also and cause the position of the frame to be adjusted forwardly or rearwardly in the machine.

The feed roll which is about ve inches in diameter is carried by a substantially horizontal shaft 63 which, in turn, is mounted in bearings carried by arms projecting forwardly from the frame 56. The feed roll comprises a central metal hub 64 (Fig. 4) which carries a. sleeve 65 about three and one-half inches in diameter of relatively hard rubber on which is secured an intermediate sleeve 66 of about one-half an inch in thickness of softer rubber on which is a cover 61 of yet softer rubber about one-quarter of an inch in thickness. 'I'he last-mentioned layer may be of sponge rubber, although preferably with a smooth outer surface. The feed roll is of a considerably more yielding character than is the roll 24 over which the abrasive band 30 passes. The feed roll 48 is driven from the counter shaft 22 through a train of connections comprising a shaft 68 (Fig. 1) journaled in bearings carried by the bracket 5I. The shaft 68 carries a pulley 69 driven by a belt 10 which, in turn, is driven by a smaller pulley secured to the counter shaft 22. Fastened upon the shaft 68 is a small pinion 1| which meshes with a large pinion 12 secured toa short shaft 13 also journaled in bearings in the bracket 5I. The left-hand end of the shaft 13 projects to the left ,of the lbracket 5| and carries a sprocket 14 (shown in dotted lines in Fig. 1) around which passes an endless chain 15 which drives another sprocket 16 freely rotatable on the left-hand( end of the pivot shaft 49. The hub of the sprocket 16 has a tongue and groove connection with the hub of another sprocket 11 (Fig. 2) which is also freely rotatable 4on the pivot shaft 49 and which is thus driven by the sprocket 16. A second chain 18 passes around the sprocket 11 and drives a sprocket 19 secured upon the left-hand end of Ithe feed roll shaft 63. The feed roll 48 is driven through the above connections from the countershaft 22 in a direction to feed the work over the abrasive band 30 from the front to the rear of the machine. 'Ihe feed roll has a peripheral speed considerably less than that of the roll 24 over which the abrasive band runs. The -feed roll may be rotated at a speed of about 2 2 revolutions per minute While the roll 24 isy rotated at a speed of about 3300 revolutions per minute. The Work engaging portion ofthe abrasive band 3U travels in the direction of feed and if it were not for the feed roll would tend to carry Vthe work with it at a high speed. The feed roll engages the upper surface, of the Work with sufclent friction to prevent the Work being fed rearwardly by theabrasive lbland more rapidly than thespeed of rotation of the feed roll allows.

It is evident that the frame 56 may be swung upwardly about the axis of the shaft 49 to move lthe feed roll away Ifrom the scouring roll in a substantially radialy direction without disconnecting any of the driving parts above described, although ordinarily the counter shaft 22 will be stopped before the frame is lifted. On each side of the forward portion ofthe frame 56 is threaded a stop screw (Fig. 1) the lowerends of these stop screws being engagea'ble with the surface of the work table to limit the movement of the lfeed roll toward the abrasive band 30. Acljustment of these stop screws varies thedegree of separation between the feed roll and the scouring roll to accommodate the thickness of the work. Set screws 8| are providedfor securing the stops'crews 80 in'adjusted position.

As the work is fed between the feed roll"48 'and the abrasive band 36 the feed roll may yield upwardly to accommodate variations in thickness of lthe work piece. rIvhe feed roll presses the work piece against thev abrasive band with a force derived from the weight Yof the feed roll and of the frame 56'and also from the tension of twosprings 82 attached to the respective sides of the frame. The lower ends of the springs 82 are connected to the forward portions of two arms 83 respectively, which armsare pivotally mounted for heightwise swinging movement yto the rearward part o-f the frame 56. The pivotal mountings of the arms are loose enough to provide for some degree of lateral movement and the forward end of each arm constitutes a' handle conveniently accessible 'to the operator. A latching member 84 having a horizontal flange engagea-ble with the upper surface of each of the arms 83 is secured .to the work table at each side thereof. When the feed roll is in operative position the arms 83 are held down by these 'latching members from which the arms are readily disengageable by a slight lateral movement. The frame 56 may then be swung upwardly about the shaft 49 carrying the arms 83 with it. Stop members 85 secured to each side of the frame 56 engage the arms 83 to maintain tension in the springs 82 when the' arms are released from the latch members 84.

The forward part of the opening inthe work table through which the abrasive band projects is masked by a cover plate 86 (Fig. 3) the forward end of which is inclined downwardly and forwardly. The underlying portion of the work table is vlikewise inclined in the same direction to provide an easy passage for the work pieces.

The plate 86 is secured to the work table by screws 81 which extend through counterbored slots in the plate to provide for adjustment of the cover plate forwardly or rearwardly. The rearward portion of the plate 86 is beveled to a thin edge and the plate is normally so adjusted as to bring this edge almost in contact with the abrasive band 30 with a reasonable allowance for clearance. The rearward part of the opening in the. work table is masked by la metal strip 88 which bridges the opening and is secured to the work table by screws 89 extending through slots in the strip 88 to provide for forward or rearward adjustment of the strip. At its forward marginal portion the strip 88 has a plurality of teeth 90 projecting forwardly therefrom in comb fashion and the position of the strip is so; adjusted that the forward edges of the teeth are almost in contact with the abrasive band, allowance being made for reasonable clearance. 'Ihese teeth likewise are beveled from their under surface to enable them to be brought 'close to the band. It is evident that when the levelA of the work table 46 is varied by adjustment the cover plate v86 and the strip 88 kmay both be adjusted to retain them in desired relation -to the band 30. Measured in a direction from front to rear of the machine the portion of the band exposed between the rear edge of the cover plate 86 and the front edges of the teeth 90 on the strip 88 will normally be a little over an inch in length.

The upper surfaces of the rear margin of the plate 86 and of the teeth 90 lie in a plane and the adjustment of the level of the work table will normally be such that the highest portion of the band (i. e. the part lying in the vertical plane which `contains the axis vof 'the roll 24) will l-ie a-short distance, foi` example aboutonesixteenth of an inch, above this plane.

As has already been mentioned,` the eccentric bushings 58 provide for forward and rearward adjustment of the frame 56. The position of this frame will 'normally be so adjusted as to bring the laxis of the feed roll 48 ya short distance,` for example `about three-eighties of an inch, Ain front of the vertical .plane containing the axis of the roll 24. Thus as work is fed over the work table past the abrasive band the vfeed roll 48, by reason of its position and yielding character, is effective to press the work against the abrasive V'band and also to press the portion of 'the work which'at any given instant has lnot reached the band against the portion of the work table constituted by the t rear marginal portion of the cover plate 86. It will be observed that the pressure thus exerted byV the feed roll to hold the work piece -against 'the scouring roll is not positive inasmuch as the work piece is free to vflex slightly. A smoother, more uniform'nish is thereby obtained on the work piece. However, in order toinsure requisite pressure between'the work piece and the scouring roll it may be desirable .to adjust the feed roll forwardly or rearwardly in accordance with the stiffness of the work pieces to be treated. In the case of a relatively'thin, flimsy work piece the axis of the feed roll'should be only slightly in advance of that of the scouring roll, while for stiffer workpieces a greater degree of separation should be provided. As has already been pointed out, it is the pressure exerted upon the work between the feed roll 48 and the cover plate 86 which controls the feed of the work, and the feed ro'll is therefore always adjusted far enough inl advance of the scouring roll to insure such control.

For cleaning the work piece of dust Aafter ithas passed the scouring roll there is provided a rotary brush 9| (Fig. 4). The feed of the work piece past the brush is effected by driven feed rolls 92 and '93 disposed in front of and in the rear of the brush respectively. The brush 9| is mounted on a horizontal shaft 94 ,journaled in bearings 'carried by the work table and extending across a rearward extension of the opening inthe work table. The shaft 94 at its right-hand end carries a pulley 95 (Figs. 1 and 2) over which passes a belt guided by two idler pulleys v96 and 9! freely rotatable on the right-hand end'of the shaft '49. This belt' is driven by a pulley 98 Asecured upon the right-hand end of the shaft `68. This 'arrangement for driving the brush shaft 94 does not interfere with the raising of the work table 46. Secured to the brush shaft 94 is a pinion 99 (Figs. 2 and 3) which meshes with two pinions |06 and IUI fixed on two horizontal shafts which carry the 'auxiliary feed rolls 92 and k93 respectively. These .feed rolls are thus driven from the brush shaft 94 and their lupper surfaces which engage the work move in the direction of feed to impart substantially the same rate of 'feed to the work as the feed roll 4B. The brush 9| is driven in the opposite direction and at a greater speed. The auxiliary feed rolls 92 and 93 are each about one inch in diameter and their surfaces are covered with rubber, while the brush is about two inches in diameter. The upper part of each auxiliary feed roll extends slightly above the level of the surfaceof the work table, as does also the upper part of the brush, the brush extending slightly above theauxiliary feed rolls. The rear edge of 'thestrip 88 is 'beveled and is located immediately in front of the exposed portion of the forward auxiliary -Yfeed roll 92.

Secured to the work table is a `plate |02 having a rectangular recess'with beveled front andfrear edges through which the exposed portion of the brush projects. The front edge of this plate'is beveled and is located immediately to vthe`rear of the exposed portion ofthe forward auxiliary feed roll 92. The rear edge of the plate |02 is also beveled and is located immediately in front of the exposed portion of the rear auxiliary feed roll 93. The rear edge of the opening in the work tablel is located immediately to the rearof theprear auxiliary feed roll. The arrangement is suchthat a piece of work fed lover the work table from front to rear passes first over the abrasive band 30, then over the front auxiliary feed roll 92, then over the brush 9|, and finally over the rear auxiliary feed roll 93, from whence it is discharged into a suitable receptacle (not shown) at the rear of the machine, there being no substantial gaps in the path of the Work between the work table and the abrasive band, auxiliary feed rolls or brush through which a piece of work could be diverted out Aof its proper course. Since the bristles of the brush are yielding and might possibly permit a work piece to pass down through the rectangular opening in the plate |02 through'which the brush projects, said opening is spanned by a number of spaced bars |03v (Figs. 3 and'4) which extend in the direction of feed and the upper surfaces of which are level with the remainder of the upper surfaces of the plate. These bars |03 pass through the bristles of the brush but are suniciently narrow to avoid interference with the rotation of the brush or with the proper action of the brush on the work. The bars are spaced close enough together to prevent the work piece passing between them.

For holding a work piece against the auxiliary feed rolls and the brush there is provided an arrangement comprising two coaxial pivot studs |04 (Fig. 4) at the opposite sides of the frame 56, upon which studs are mounted two bell crank levers |05. Each of these levers |05 has a forwardly extending arm and to the forward ends of these arms are pivoted on ball and socket joints the opposite side walls of a presser plate |06. Each of the levers |05 has also an upwardly extending arm which engages a portion of the frame 56 as a stop when the frame is raised.` When the frame is in its normal lowered position the presser plate is located a short distance above the level of the work table @determined by four adjustable stop screws -|07 (Fig. 4) threaded into the respective corners of the presser plate and engaging the work table to maintain the presser plate substantially parallel to the surface of the work table. The pivot studs |04 carryv crank arms |03 extending upwardly and forwardly. Adjustably secured by screws |00 to the forward upper ends of the arms |08 are tension spring Il the lower ends of which are anchored to the arms 83. Thus the arms 83 when latched in operating position to hold down the feed roll frame 56 serve also through the springs H0 to urge the levers |05 in a direction to force the presser plate |06 downwardly toward the work table. By tightening or loosening thumb nuts on the screws |09 the degree of tension of the springs ||0 may be adjusted as desired. Since the springs 0 may yield independently of each other and since the presser plate is mounted onV the levers |05, it is evident that the presser plate is free to -tilt in all directions to' accommodate a work piece passing beneath it.

The presser plate |06 overlies the two auxiliary feed rolls 92 and 93 and also the brush 9| but has a rectangular opening above the b-rush which is filled by an auxiliary plate I||. The auxiliary plate has four laterally projecting lugs ||2 positioned at its four respective corners and these lugs are normally held down against the upper surface of the presser plate |06 by two relatively weak compression springs ||3 (one of which is shown in Fig. 4) which are held between the upper surface of the auxiliary plate I and overhanging lugs H4 on the presser plate. `When the parts are in this position the lower surface of the auxiliary plate is located in substantially the'same plane as the lower surface of the presser plate..

A work piece, after passing the abrasive band 30, is pressed against the forward auxiliary feed roll 92v by the front marginal portion of the presser plate |06 and against the rear auxiliary feed r'oll by the rear marginal portion of the presser plate |06. The presser plate |06 may move the upwardly or cant against the action of the tension springs IIU as may be required during passage of the work. The work, however, is not pressed against the brush by the presser plate |06 but by the auxiliary plate which may move upwardly or cant relatively to the plate |06 against the force of the compression springs H3 since these springs are weaker than the tension springs l0. Thus the Work piece at the locality of the brush may be urged upwardly by the action of the brush to lift the auxiliary plate without necessarily raising the presserplate |06. The pressure of the plate |06 is thus at all times available to hold the work piece against the auxiliary feed rolls 92 and 93. It will be appreciated that if the action of the brush were permitted to lift the presser plate |06 the work might move out of engagement with the auxiliary feed rolls and the feed might thus be inter- 4 rupted inasmuch as the brush rotates against the direction of feed. The arrangement of the presser plate and auxiliary plate above described has proved effective in providing an adequate feed of the work past the brush by the auxiliary feed rolls even in cases where the length of the work in the direction of feed is relatively small.

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

1. A machine for scouring shoe parts and like i articles, comprising a scouring roll, a feed roll for feeding workpieces past said scouring roll, a support for one of said rolls, and a pivotal mounting for said support, said support being capable of swinging movement about said pivotal mounting to enable the roll carried by the support to move away from the other roll in accordance with the thickness of a work piece passing between the rolls, and said pivotal mounting being constructed and arranged for adjustment of the position of the support to enable the roll carried by the support to be maintained ata desired position along the direction of feed.

2.l A machine for scouring shoe parts and like articles, comprising a scouring roll, a feed roll for feeding work pieces past said scouring roll, a carrier for said feed roll, a pivotal support for said carrier to enable said feed roll to be moved away from said scouring roll, and an eccentric bearing in which said pivotal support is4 rotatably mounted to enable said feed roll to be adjusted to engage the work at a desired point along the line of feed.

3. A machine for scouring shoe parts and like articles, comprising a scouring roll, a feed roll for feeding work pieces past said scouring roll, a support for one of said rolls constructed and arranged for movement of that roll away from the other roll, a pivotally mounted arm, a spring between said support and said arm for urging said one roll toward the other roll, and a latch for holding said arm in position to stress said spring, said arm being readily disengageable from said latch to enable said one roll to be moved away from the other roll.

4. A machine for scouring shoe parts and like articles, comprising a scouring roll, a feed roll for feeding work pieces past said scouring roll, a work table for guiding work pieces to said rolls, a pivotally mounted support for said feed roll constructed and arranged to enable said feed roll to be moved away from said scouring roll, a support upon which said work -table is pivotally mounted to enable the Work table to be moved away from said scouring roll, disengageable means for securing said work table in operating position, a spring connected at one end to said feed roll support, and a disengageable device for securing the other end of said spring to said work table, said spring serving to hold said feed roll yieldably in operative relation to said scouring roll when the work table is secured in operating position, and the Idisengagement of said device serving to render said feed roll free for movement to an out-of-the-way position indep-endently of said work table.

5. A machine for scouring shoe parts and like articles, comprising a scouring roll, a plurality of feed rolls engageable with one surface of a work piece for feeding the work piece past said scouring roll, a presser plate engageable with the opposite surface of the work piece, a pair of parallel arms pivotally mounted for swinging movement, a universal pivot connection between the lateral portions of said presser plate and said arms respectively, and a spring acting upon each arm to urge the arms independently f each other in a direction to cause the presser plate to hold the work piece against said feed rolls.

6t In a machine for scouring shoe parts and like articles, a brush for cleaning the scoured surface of a work piece, a pair of feed rolls positioned in advance of and rearwardly of said brush respectively and engageable with said scoured surface of the work piece to feed the work piece past said brush, a presser plate engageable with the opposite surface of the work piece, yieldable means acting through said presser plate to hold the work piece against said feed rolls, said presser plate having an opening to avoid engaging the work piece at the locality of engagement between the work piece and said brush, an auxiliary presser plate normally closing said opening, and means yieldable independently of the rst-mentioned presser plate for causing said auxiliary presser plate to hold the work piece against the brush.

'7. In a machine for scouring shoe parts and like articles, a rotary driven brush for cleaning the scoured surface of a work piece, a pair of feed rolls positioned in advance of and rearwardly of said brush respectively and engageable with said scoured surface of the work piece to feed the work piece past said brush, a presser plate engageable with tho opposite surface of the work piece, a support constructed and arranged t0 enable said presser plate to tilt universally to accommodate the work piece, a relatively strong spring acting upon said support to cause the presser plate to hold the work piece against said feed rolls, said presser plate having an opening to avoid engaging the work piece at the locality of engagement of the Work piece with the brush, an auxiliary presser plate normally closing said opening, and a relatively weak spring for causing said auxiliary presser plate to hold the work piece against said brush, said relatively weak spring operating normally to hold the auxiliary presser plate in a stop position determined by the first-mentioned presser plate, from which stop position the auxiliary presser plate may yield independently of the first-mentioned presser plate.

8. A machine for scouring shoe parts and like articles, comprising a scouring roll engageable with one surface of a work piece, a feed roll engageable with the opposite surface of the work piece, an auxiliary feed roll engageable with the mst-mentioned surface of the work piece, a cleaning brush engageable with the first-mentioned surface of the work piece, a presser plate engageable with said opposite surface of the work piece, a spring acting upon said presser plate for causing the presser plate to hold the work piece against the auxiliary feed roll, an auxiliary presser plate engageable with said opposite surface of the work piece, and a spring acting upon said auxiliary presser plate for causing the auxiliary presser plate to hold the work piecesagainst said cleaning brush while enabling the auxiliary presser plate to yield independently of the main presser plate.

9. A machine for scouring shoe parts and like articles, comprising a scouring roll engageable with one surface of a work piece, a feed roll engageable with the opposite surface of the work piece, a carrier for said feed roll pivotally mounted for swinging movement to enable said feed roll to be moved away from said scouring roll, an auxiliary feed roll engageable with the first-mentioned surface of the work piece, a presser plate movably mounted on said feed roll support engageable with said opposite surface of the work piece, a pivotally mounted arm, a spring interposed between said arm and said feed roll carrier, a spring interposed between said arm and said presser plate, and a latch for disengageably holding said arm in an operating position wherein said feed roll and said presser plate yieldably press against the work piece to hold the work piece against said scouring roll and said auxiliary feed roll respectively.

JOHN WILLIAM PRATT.