US2507677A

US2507677A - Polishing machine

Info

Publication number: US2507677A
Application number: US761198A
Authority: US
Inventors: Clifford I Packer; Paul R Nickerson; John F Harper
Original assignee: PACKER MACHINE Co
Current assignee: PACKER MACHINE Co
Priority date: 1947-07-16
Filing date: 1947-07-16
Publication date: 1950-05-16
Anticipated expiration: 1967-05-16

Description

y 3950 c. 1. PACKER ET AL 2,507,677

POLISHING MACHINE Filed July 16, 1947 5 Sheets-Sheet l y 1950 c. a. PACKER ET AL 2,507,677

POLISHING MACHINE Filed July 16, 1947 3 Sheets-Sheet 2 %85 a2 a? gg we y 1950 c. 1. PACKER ETAL 2$507,677

POLISHING MACHINE Filed July 16, 1947 5 Sheetg-Sheet 3 Patented May 16, 1950 STATES PATENT OFFICE 2,597.67": ror snmc mourns Application July 16, 1947, Serial No."761,198

11 Claims.

The present invention relates in general to abrading machines and especially to a machine for polishing work-pieces and, in particular, work-pieces having curvilinear surfaces.

Polishing and buifing machines and, more especially, automatic machines for polishing work-pieces embody, in general, work-piece supportingand indexing-means and one or more polishing-units associated therewith for successively polishing the work-pieces as each is indexed opposite the polishing-unit. The workpiece indexing-means may be designed either to move the work-pieces longitudinaliy or in a circumferential direction, depending upon such factors the nature and shape of the work-pieces and the area thereof to be polished. The polishlug-units may be formed in some instances as integral parts of the worh-piece indexing-means or, as is more often the case, as independent units adapted to be moved relative to the indexing-means, so as to bring the polishing-Wheel of the unit into the desired position with respect to the workpieces. While such machines have been adapted generally to almost all types of polishing operations, certain limitations inherent in the machines and, in particular, in the polishing units have held down production schedules and kept the unit-cost of polishing operations at a relatively-high level. Of these inherent limitations, the most flagrant are the polishing-wheels themselves which havea relatively-short life, require approximately fortyeight hours for restoration and, due to their peculiar construction, are restricted to compare.- tively few types of polishing operations, that is to say, in order to polish a large variety of articles each having surfaces to be polished of different contours, a large inventory of poiishing-wheels must be maintained, each wheel having the specinc peripheral contour required for a specific job. Moreover, the polishing-units, quite generally, have been cumbersome and adjustable only with difiiculty and considerable loss of time.

An object of the present invention is to provide a superior polishing machine wherein the polishing-means has a relatively-long life, is mounted for multi-directional movement and when Worn out is replaceable in a matter of minutes.

A further object of the invention is to provide a polishing machine having a superior polishing-means, which is relatively inexpensive and adapted automatically to conform to the shape of the various articles to be polished.

A still further object of the invention is to provide a polishing machine with an improved mounting-mean forthe' polishing-unit, whereby the surface of the polishing-means may be oriented into substantially any desired position in a vertical plane with relative ease and dispatch.

With the above and other objects in View, aswill appear to those skilled in the art from the present disclosure, this invention includes all features in the said 'disclosure'which are novel over the prior art.

In the accompanying drawings, in which certain modes of carrying'out the present invention are shown for illustrative purposes? Fig. 1 isa s ide 'elevationpartly in section of the improved polishing machine of this invention including the base and jack for supporting the polishing-unit, the latter being shown in full lines we substantially-vertical position and in broken lines a' substantially-horizontal position;

Fig. 2 is a plan view of the polishing-unit in the direction of arrows 2-'-2 of Fig. 1;

Fig. 3 1s a fragmentary side elevation of the boom online 3 3 of Fig. 2;

Fig. 4 is an enlarged front end elevation of the polishing-unit in the direction of arrows 44 of Fig. 2;

Fi 5 is an enlarged end elevation of the polishi g unit on section line 5-501? Fig. 1;

Fig. 6 is an enlarged end elevation of the polishing-unit on section line .66 of Fig. 2;

Fig. '7 is a perspective view of one of the crank-arms used to connect the polishing-unit to the upper end of the boom;

Fig. 3 is a perspective view of the carriermember tor supporting the pulleys of the polishing-belt;

Fig. 9 is a perspective view of one of the pulley supporting plates oi the'carrier-member;

Fig, .10 is a schematic fragmentary side elevation of thepolis'h'ing machine with the polishing-unit shown full lines in its normal position and by broken lines rotated in a counterclockwise direction about the upper pivot-pin of the crankarnilthe latter being shown swung upwardly into a substantially-verticalposition from its horizontal position shown in' Fig. 1. Fig' 10 'also'indicates'in broken lines the polishing-unit in an inverted position from that shown in tull'linesj Fig. 11 is a schematic fragmentary side elevation of the polishing machine showing the polishing-unit in full lines at an an'gle'of substantially 4;5 vfrom its full line position shown in'Fig'. 10,

w 1m bein mine a ut e l we pivot of 3 the crank-arm. The broken lines indicate other positions of the polishing-unit when rotated about the upper pivot of the crank-arm; and

Fig. 12 is a schematic fragmentary side elevation of the polishing machine showing by full lines the polishing-unit supported at an angle of substantially to the vertical and making an angle with respect to the longitudinal axis of the crank-arms. The broken lines indicate the reversed position of the polishing-unit.

For the purpose of describing the invention, an exemplary embodiment thereof is disclosed below, but it will be understood that the particular embodiment shown is for the purpose of illustration only and that the invention includes all modifications and equivalencies thereof Within the scope of the appended claims.

Referring to the drawings, the improved polishing-unit and polishing-means thereof is shown without reference to work-piece indexingmeans and comprises supporting-means indicated generally at consisting in general of a relatively-heavy forged or cast substantially-rectangular metal base It provided on its upper surface and at substantially its geometric center with a substantially-vertical screw-jack indicated generally at IT. The latter comprises a hollow column I3 having a lifting-head IE slidably supported therein and arranged to be moved vertically by means of an elevating-screw 20 which is supported within the hollow column and arranged to engage in a suitable nut 2! of the lifting-head. The screw 20 is adapted to be rotated by a worm-and-wheel drive indicated generally at 22, the operation of which is controlled by means of a manually-operated hand-wheel 23 connected to the worm-and-wheel drive 22 by means of a worm-shaft 24 and inter-engaged bevel-gears 25.

A key and key-operating means indicated generally at 20 is provided for normally locking the lifting-head 59 from rotation about the vertical axis of the elevating-screw 20; and, when desirable, for unlocking the lifting-head so as to permit the latter to be turned through 360.

The screw-jack I! described above comprises highly satisfactory means for supporting the improved polishing-unit of this invention. Its construction, however, is well known to those skilled in the art and, hence, further description of the details of the jack are omitted.

The polishing-unit is indicated generally at 21 in Fig. 1 and is adapted to be supported for substantially multi-directional movement vertically by means of a boom 28 and a pair of crank-arms 29. The phrase multi-directional movement vertically or multi-directional movement in a vertical plane as used herein, shall be understood to include oscillatory and pivotal movements in a vertical plane as well as movement in a vertical plane resulting from the combination of the oscillatory and pivotal movements therein. To this end, the lower end of the boom is adapted to be adjustably secured, as hereinafter described, to the upper end Of the jack lifting-head [9 for pivotal movement in a vertical plane thereof, while the upper end of the boom is connected by transverse pivot-means to the lower ends of the pair of crank-arms 29, which, in turn, are adjustably secured at their upper ends to the polishingunit 2: whereby the latter is adapted to have pivotal movement in the vertical plane of the crank-arms.

Turning now to the boom 28, the latter comprises a reticulated arm consisting of two spaced- 4 parallel substantially-rectangular side-plates 30, each of which tapers slightly in width from its relatively-wide upper end 31 to its somewhat narrower lower end 32, both ends of each sideplate 30 being substantially semicircular. The two side-plates are held in spaced parallel relationship by a pair of transverse webs, indicated generally at 33 and 34 respectively, joined integrally with the inside walls of the respective side-plates 36 and a longitudinally-spaced-apart points intermediate the opposite ends thereof. The rear ends 32 of the side-plates are provided with transverse axially-aligned apertures 35 and 'arcuate adjusting-slots 36, both the aperture 35 and the corresponding adjusting-slot 36 of each respective side-plate being concentric with its semicircular rear end 3-2. The arcuate adjusting-slots 36 describe arcs of slightly more than The rear end of the boom is adapted to be pivotally mounted on the upper end of the liftinghead is so as to rotate in a vertical plane of the longitudinal axis thereof and, hence, the distance between the respective inside faces of the ends 32 of the boom corresponds substantially to the width of the lifting-head, so as to make a nice fit thereon, suitable pivotal-means such, for example, as the bolt 37, being adapted to extend through the axially-aligned apertures 35 of the boom and a transverse aperture in the upper end of the lifting-head to secure the boom thereto. In order to adjustably secure the boom in any position in the vertical plane of the jack, throughout an arc of substantially 180, 22. pair of adjusting-bolts 39 are provided which extend through the arcuate slots 36 into transverse apertures in the lifting-head ill of the jack. Thus, by loosening the adjusting-bolts 38, the boom may be swung in a vertical plane about the pivotal supportingbolt 31 to a predetermined position and then locked by tightening up the adjusting-bolts 38.

The upper or opposite end of the boom is provided with a pair of axially-aligned apertures 39 (see Fig. 5) which extend transversely through each side-plate 38 respectively and through corresponding bosses 39 formed integrally on the inside faces of the respective side-plates. The outer face of each side-plate is provided at its upper end 3| with an integral embossed outwardly-projecting substantially-flat finished surface 4| which is substantially circular and concentric with its respective transverse axial aperture 39. Moreover, each circular finished surface 4| is provided with a plurality of transverse apertures 42 which extend through the respective sideplates and are in axial alignment with corresponding apertures .2 formed in the finished surface 4! of the opposite side-plate 3D, the apertures 42 being spaced circumferentially on circles of less diameter than that of their respective finished surfaces 4! and concentric with the transverse axial apertures 39 thereof.

The aforementioned transverse web comprises a substantially-rectangular solid member, whereas the transverse web, indicated generally at 34, comprises two substantially-identical bridge-members 4-3- (see Figs. 1 and 3) arranged to span the two side-plates 30, the opposite ends of the bridge members 43 being joined integrally to the respective inside faces of the side-plates adjacent the upper and lower longitudinal edges thereof respectively. The inner oppositely-disposed faces of the bridge-members 43 are provided with integral cylindrical bosses 44 which are intermediate the opposite ends thereof and which have axially-aligned bushed apertures 45, each of which extends through. its respective bridge-meme ber 43 substantially perpendicular to a plane through the longitudinal edgesthereof. Rotatably supported in the bushed apertures 45 is ashaft 45cm which is mounted a worm 41, keyed or otherwise secured thereto between the cylindrical bosses M. The opposite ends of the worm-shaft 46 extend outwardly beyond the outer faces of the respective bridge-members i3 and are provided with squarediends 48 for accommodating a wrench or equivalent means for rotating the worm. An end thrust-collar 45 is secured on each end of the.

worm-shaft in engagement with the respective bridge-members to prevent longitudinal displace-- ment of the shaft.

Mounted between the apertured bosses 40 at the upper end of the boom is a worm-gear 50 (see Fig. having a transversely-apertured hub which is substantially equal in width to the distance between the oppositely-disposed faces of the respective bosses, so that the worm-gear will be held therebetween free from lateral movement. The worm-gear mounting-means comprises a king-pin 5| which is provided with longitudinal keyways 52 in the diametrically-opposite sides thereof and which is arranged'to extend through the axially-aligned. apertures of the respective bosses 45 and the hub of the worm-gear 50 to support. the latter in the upper end of the boom in engagement with the worm 41, the worm-gear 55 being keyed to the king-pin 5| by a pair of longitudinal keys 53 as shown in Fig. 3. It will beclear that by rotating the worm 41, the wormgear 5!! and king-pin 5| will be rotated.

Referring now to Fig. 5, the opposite ends of the king-pin 5| are adapted to extend outwardly beyond the respective finished surfaces 4| of the boom and to engage-in axially-aligned transverse apertures 54 provided in the rear or lower ends respectively of the aforementioned crank-arms'29, whereby the latter are pivotally secured on the upper end of the'boomin contact with the finished surfaces 4! of its respective side-plates. Referring to Fig. 7, the rear endof each crankarm 29 comprises a substantially-rectangular body-portion 55 having a semicircular radius 55 at its rear end; and a substantially disk-shaped portion 51 formedintegrally with the body-portion 55 at its upper or forward end, the diskshaped portion 51 being somewhat thicker than the body-portion 55 of the crank-arm and offset, so that the inner face of the disk-shaped portion is substantially in the plane of the outer face of the body-portion. In addition to the transverse axial apertures 51 in the'body-portion of each crank-arm, each body-portion is provided also with a pair of arcuate slots 58 arranged substantially diametrically on opposite sides of its respective axial aperture 54 and concentric therewith for accommodating adjusting-bolts 59, each of which is adapted to extend through itsrespective slot 58 (see Fig.1) and engage in one of the several apertures 42 in the corresponding finished surface 4! of the boom to hold the crank-arm rigidly in any adjusted position with respect thereto. The pivotal adjustment of each crankarm is limited to the length of its slot 58 for any given setting of its adjusting-bolt 59, but it will be appreciated that the latter may be put in any one of the several apertures 42 which completely encircle the king-pin 5| and that, therefore, the crank-arms may be rotatably adjusted in the vertical plane ofthe boom through 360 and held atany predetermined position by tightening upthe adjusting bolts 59.

Rotating of the crank-arms effectedby pro vidingone crank-armsuch, forexample, as the; right-hand crank-arm with: a:boss aB WhiCh"p1 0-rjects outwardlyfrom the :outerface ofthe body portion 55. of the crank-arm concentric .withthe axial aperture 54' thereof, the boss 65- beingslote ted transversely to provide aapair-of spaced par.-

allel walls 6| on opposite sides of the axialaper-- ture 54. The distancebetweenthe wallsfii corresponds substantially to the distance betweendiametrically-opposite flats of the head 62 of the king-pin 5i, as a consequence of which the kingpinhead 62 is keyed to .the right-hand crank-arm 29 so as to rotate the latter when theking-pin 5 I.

is rotated by the worm and worm-gear drivedescribed above.

Turning now' to the disk-shaped portion 51 of;

each crank-arm, the former is provided with a plurality of transverse apertures 53 which are equally spaced apart circumferentially on a circleconoentric with an axial aperture 5-? extending transversely through the disk-shaped portion 51 of the crank-arm. As shown in Fig. 5, the inside or back face of each disk 51 is provided with an. integral boss 55 having a transverse slot 66 in.

axial alignment with the axial aperturefi l of the disk. Mounted in the transverse aperture 54 of each crank-arm is a bolt 61, the hexagonal or rectangular head 5?!) of which is adapted to engage the opposite side of its respective transverse slot 65 so as to lock the bolt 61 against rotationin its aperture 64. Each bolt 6'! constitutes fas-. tening-means for securing the polishing-unit 2'1 to the upper ends of the crank-arms 29 and to this end the externally-threaded ends of the bolts 61 extend outwardly beyond the outer faces of the disk-portions 5'! of the respective crank-arms to provide trunnions on which to pivotally support the polishing-unit 21.

The latter, as shown in Figs. 2 and 6, com prises a yoke-member consisting of two spacedparallel substantially-identical rectangular sideplates 68, the corresponding rear ends of which are connected by an integral, transverse, substantially-rectangular end-plate 55 which con-- stitutes. a supporting-means for the base 10 of amotor II. To this end, the end-plate 59 is provided with suitable bolt-apertures to receive bolts" 12 for securing the motor-base 15 to the plate. It will be noted, onreference to Fig. 2, that the motor is mounted symmetrically with respect to the longitudinal axis of a transverse plane intersecting the longitudinal edges of the side-plates of the yoke, but that the center line of the motor is below the longitudinal axis of a plane at substantially right angles thereto.

Intermediate the opposite ends of each sideplate 58 of the yoke, the inner and outer faces thereof are formed with integral embossed substantially-circular finished surfaces 13 and 14 respectively. A central aperture 15 extends trans.- Versely through the finished surfaces of each respective side-plate, each aperture 15 being in. axial alignment with the correspondingtransverseaperture 15 of the opposite side plate. Moreover, a pair of arcuate concentric slots 16 is provided in each finished surface on substantially-diametrically-opposite sides of its respective axial aperture 15.

The axial apertures 15 are adapted to receive the outwardly-projecting trunnions of the bolts 6! whereby the respective side-plates 58 of the yoke are pivotally supported on the outer faces ofthe disk-shaped portions 51 of the crank armaangular adjustment being through substantially 2= From the foregoing description, it will be appreciated that by means of the adjustable pivotal connections joining the opposite ends of the crank-arms to the boom and yoke respectively, the latter is connected to the boom by what constitutes, in effect, an articulated connection. Thus, assuming the yoke 21 is secured rigidly by the adjusting-bolts 1'3 to the upper ends of the crank-arms and at substantially right angles thereto, as shown in Fig. 1, the yoke is then capable of unrestricted rotational movement through an arc of substantially 180 about the king-pin 5! in the vertical plane of the boom. However, by temporarily removing the hereinafter described pulley-mounting means #9 from one end of the yoke, the spaced parallel sideplates 68 of the latter may be swung past the boom 28, whereupon the pulley-mounting means may be replaced and the yoke 27 swung through an additional arc of substantially 180. Assuming now that the crank-arms are rigidly secured to the upper end of the boom by the adjustingbolts 59 and in outwardly-extending relationship thereto, as shown in Figs. 10 and 11, then the yoke 21 may be rotated unrestrictedly about the pivotal fastening-bolts 6'! through substantially 180 in the vertical plane of the jack, further rotation through an arc of 180 again being permitted by temporary removal of the pulley-mounting means at one end of the yoke. Further, it will be clear that the crank-arms themselves may be rotated about the king-pin 5! through substantially 360 so as to displace the connecting-bolts 6'! of the crank-arms through arcs of substantially 360. Moreover, as pointed out above, the boom itself is mounted on the upper end of the jack for pivotal movement through an angle of substantially 180 in the vertical plane thereof.

The above described adjustments may be made with the yoke supported on the crank-arms so that the motor H is below the center line of the yok and to the left of the king-pin 5!, as shown by the broken lines in Fig. 1. It will be appreciated, however, hat by removing the adjustingbolts and connecting-bolts of the yoke, the latter may be inverted, as indicated by the broken lines in Fig. 10, so that the motor is above the center line of the yoke; or the yoke 21 may be reversed end-to-end so that the motor may be to the right of the king-pin, as indicated in Fig. 12, and either above or below the center line of the yoke.

As a consequence of the improved connectingmeans of this invention for supporting the yoke on the jack, the yoke may have pivotal movement, oscillatory movement and combinations thereof in vefiical plane through the longitudinal axis of the jack for the purposes hereinafter described, the various adjustments being readily effected by manipulation of the worm and wormwheel drive and the adjusting-bolts of the boom, crank-arms and yoke.

Referring more especially to Fig. 1, the outer ends of the side-plates 68 of the yoke 27 are adapted to support the pulley mounting-means indicated generally at 19 and to this end are provided with longitudinal parallel slots adjacent the upper and lower longitudinal edges respectively of the side-plates, each slot 80 having a finished peripheral surface on opposite sides thereof. Moreover, as indicated clearly in Figs. 2 and 6, the inside face of each side-plate is provided with an embossed way 8! which is substantially rectangular and extends longitudinally between the slots 80 of each side-plate from the outer extremity of the side-plate rearwardly of the rear ends of the slots. These embossed ways Bl constitute guide-means for controlling the longitudinal movement of a carrier-member, indicated generally at 82, of the pulley mountingmeans 19, the carrier 82 being adapted to be mounted on the ways 8| at the outer ends of the yoke as hereinafter described, and to be adjustably secured at predetermined longitudinal positions thereon to allow for variations in the length of the polishing-belt hereinafter described. To this end, suitable adjusting-bolts 83 are adapted to extend through the respective slots 80 of the side-plates of the yoke and to engage the carrier, as indicated clearly in Fig. 6.

The carrier-member 82 is shown more clearly in Fig. 8 and comprises a substantially-flat baseplate 85 shaped generally like a Greek cross, the outer edges of each of its four arms being provided with a substantially-rectangular shoe 85 extending perpendicularly to the base-plate 84, each shoe being formed integrally at its lower edge with the corresponding arm of the baseplate and braced by a hypotenuse web 86 formed integrally on the respective inside faces of the arm and shoe. The outer face of each shoe is provided with a shallow substantially-rectangular groove 8'! which is symmetrical with respect to the longitudinal axis of the shoe and which intersects the upper and lower edges thereof, the groove 8'! being dimensioned to make a smooth sliding fit on the corresponding way 8| at the forward end of the side-plates 68 of the yoke, so as to slidingly support the carrier-member 82 therein. The aforementioned adjusting bolts 83 of the longitudinal slots 80 are adapted to engage in suitable threaded apertures 88 provided in the outer faces of the shoes, whereby the carriermember may be held in a predetermined adjusted position at the forward end of the yoke by tightening up the bolts. It should be pointed out that since the carrier and, in particular, its shoes 85 are symmetrically located with respect to the center thereof, the carrier may be mounted in the yoke with either of its two pairs of oppositely-disposed shoes 85 slidingly engaged on the ways 8| of the yoke, that is to say, the carrier may be pulled off of the ways at the forward end of the yoke, rotated through and then slid back onto the ways for the purpose hereinafter described.

Referring particularly to Fig. 8, the two transversely-disposed arms of the base-plate 84 are provided with perpendicular apertures 89 drilled or otherwise formed therethrough, each aperture intersecting the upper and lower edges respectively of its respective arm. Each longitudinal aperture 89 is adapted to accommodate a shaft 90 (see Fig. 6) which extends both above and below the respective upper and lower edges of its respective arm to provide upper and lower trunnions 9|. Each pair of upper and lower trunnions 9| is adapted to pivotally support a pulley mounting-plate 92 which, as shown in Figs. 2 and 9, is a flat substantially-rectangular metal :plate .having a pair of parallel brackets 93 formed integrally at its rear end adjacent the upper and lower edges thereof and projecting outwardly therefrom at substantially right angles to a plane through the longitudinal edges thereof, each bracket being stiiiened by a hypotenuse web 94 and spaced apart vertically from each other a distance corresponding substantially to the height of the respecti e arms of the carrier-member, so

as to seat on the upper and lower edges thereof.

Each bracket as is provided with a longitudinal aperture in axial alignment with the respective trunnions 9-! of the shafts 9%, so as to be pivotally :mounted thereon, suitable washers and cotter- .pins 95 being provided on the upper and lower free ends of the trunnions to hold the brackets against longitudinal displacement.

The length of each pulley mounting-plate 92 is such that its forward end extends beyond the forward end of the yoke 27, as shown in Fig. 2, while the height of each plate 5.2 (see Fig. 6) corresponds substantially to the vertical distance between the inside laces of the oppositely-disposed shoesiiii of the carrier-member, so that the upper and lower edges of the plates 92 are adjacent thereto but clear thereof. In the preferred construction, it is desirable to provide means whereby each plate 92 may be lockedirom pivotal movement about its res ective trunnions 9| and to this end, suitable bolts S6 are adapted to be mounted in apertures formed at opposite sides respectively of the upper and lower shoes 85 and to engage in axially-aligned apertures 91 formed in the upper and lower edges respectively of each pivoted plate 92. .In normal operation,

.only one plate 92 is locked by the bolts 95, the

other plate being free so as to swing relative to the first plate, for the purpose hereinafter described. Formed integrally orotherwise secured adjacent the outer end of each pivoted plate 92 and at the upper and lower edges thereof respectively, is a pair of outwardly-projecting lugs 99 (see Fig. 2), each of which is provided with a threaded aperture substantially parallel to the longitudinal axis of its respective side-plate. Each of these apertured lugs is adapted to support an adjusting-screw I01! provided with a locknut HM, for the purpose hereinafter described.

The outer extremity of each pivoted :pulley mounting-plate 92 is provided with .a pair of :slots I92 adjacent the upper andlower .edges thereof respectively, as shown in Fig. 9, each slot being adapted to accommodate an attaching 'bolt 23, the head :of which isengaged against'the inside face of its respective pulley-mountingplate 92. The threaded .end of each attaching-bolt is adapted toproject through its respective plate to the outside thereof, where it is .threadedly engaged in an aperture of pulley-shaft casing indicated generally at 34, for fixedly securing the latter to the corresponding end of the pulleymounting plate. Each pulley-shaft casing 194 comprises a longitudinal member substantially equal in lengthto the height of its respective pivoted plate 92 and substantially rectangular in cross section, three of its sides being fiatsur-faces and the fourth or outer side being-a substantially-cylindrical surface of. revolution, .as' shown in Fig. 2. The flat surface of eachcasi-ngiild, opposite its cylindrical outer surface, is adapted to be held tightly against the outer surfaceof its respective pivoted plate 92 by the aforesaid at- 'tachingebolts I03 which are threadedlyengaged in apertures inthe aforesaid flat surface thereof, the rear side of each casing being located in proximity to the aforesaid upper and lower adjusting-screws I09. Consequently, by loosening the attaching-bolts Ill? and turning-up or backlug-off the adjusting-screws I96, each casing I04 may be adjusted on the outer face of its respective pulley-amounting plate so that the longitudinal axis of the casing is precisely at right angles to the longitudinal axis of the pul1ey-mounti-ng plate; or slight variations may be introduced in the angular relationship of each casing to its respective plate 92, as circumstances may require.

Referring to Fig. each pulley-shaft casing we is adapted to support a pulley-shaft I05 which normally is fixedly secured therein, but which is adapted to have longitudinal adjustment therein for the purpose described below. To this end, the lower end of each pulley-shaft is provided with external screw threads and extends downwardly below thelower end of its respective casing lll, so as to receive a nut Illa thereon. The upper end of each pulley-shaft projects above the upper end of its respective casing and is provided with a compound pulley comprising a cylindrical hubrnernber i989 (see Fig. l), rotatably mounted and secured thereon by a nut I09 on the corresponding end of the pulley-shaft; and a sleeve-like pulley-face I03, hereinafter referred to as the pulley, adapted to fit snugly on its respective hub-member i889 and to be secured thereto by suitable fastening-means such, for example, as..a.;r.ad=ial locking-screw. Mounted on each pulley-shaft between the inner end of :its respective hub-member H.189 and the adjacent end of its respective casing 104 is .a spacer- ..collar lfll.

This construction is particularly adapted to increase the scope of usefulness of the machine by providing for the interchange of polishing-belts of different widths. Thus, if a wider belt than that shown in the drawings is required for a specific polishing operation, then it is necessary only to remove the pulley-faces I98 from their respective hub-members H289 and to replace the former by pulley-faces corresponding in width to the wider belt. At the same time, the spacerco'llars may be replaced by shorter collars and the nuts it at the opposite ends of the shafts may be turned up to adjust the shafts longitudinally in the casing in So as to bring the center line of the wider belt inwardly closer to the longitudinal center line of the yoke 21. It will be understood that corresponding changes would be made also in .thewidth and position of the motor-drive pulley hereinafter described.

Thus, polishing belts .of many .difierent widths .may be used interchangeably with the polishingunit, thereby adapting the machine to a wide variety of polishing operations.

Asindicated in Fig. 2, the pulleys IE8 are thus :rotatably supported on the pivoted plates 92 at the .forward end of the yoke and in laterallyspaced relationship to each other. In order to hold the two pulleys in laterally-spaced relationship, a -.compression-spring ii! is provided which iss-upported at its opposite ends between the plates 92 by means of suitable spring-pilots HI, the inner ends of which are engaged in the corresponding ends of the springs and the outer ends :01 which are threadedly engaged in apertures of the respective pivoted pulley-supporting plates 92. The force of the compression-spring H0 is thus adapted to spread the pulleys apart and, when the polishing-belt H2 is mounted thereon, to

11 keep taut that portion thereof which spans the distance between the respective pulleys I88.

The aforesaid polishing-belt l 52 constitutes the improved polishing-means of this invention and comprises an endless belt of fabric, leather or other suitable material adapted to be engaged over the two pulleys I03 and a conventional drivepulley IIS mounted on the upper end of the motor-shaft IM, the drive-pulley H3 being held in adjusted position longitudinally on the shaft I M by a spacer-collar and nut (see Fig. 1) and of relatively-large diameter so that the path of the belt is substantially rectangular. As pointed out above, the drive-pulley H3 is mounted on the motor-shaft in any convenient manner such that it may be readily removed therefrom and replaced by a pulley having a wider or narrower face. The belt H2 is provided on its outer face with an abradant for polishing work-pieces and is adapted to be readily mounted on the three pulleys by first pressing or otherwise holding one of the pulleys I08 inwardly with respect to the opposite pulley I03 against the force of the compressionspring H and then slipping the belt thereover, and over the motor-pulley I I3, whereupon, on releasing the aforesaid pulley I68, the force of the compression-spring I ID will spread apart the two pulleys I08 so as to tighten up the belt.

Thus, in the operation of the machine, the polishing-belt I I2 will be driven linearly by the pulley II3 of the yoke-mounted motor II, and inasmuch as the belt is supported on pulleys IE8 which are, in turn, mounted on the yoke of the polishing-unit, the belt is adapted to enjoy the same multi-directional movement as that of the yoke, as hereinabove described. That is to say, the polishing-belt I I2 may be driven substantially vertically or horizontally, as shown in Fig. 1, or at any intermediate angle, as indicated in Figs. 10, 11 and 12. Moreover, by rotating the crankarms 29 about the king-pin 5|, the yoke may be raised or lowered vertically with respect to the king-pin, as indicated in Figs. 11 and 12, so as to provide an oscillatory motion to the yoke, or, by inverting the yoke, the belt may be dropped down to a position below the king-pin, as indicated by the broken lines in Fig. 107 Further, the working surface of the belt, that is to say, that portion which traverses the distance between the two pulleys Hi8, may be transferred from the right-hand side of the boom to the left-hand side thereof by reversing the yoke, as indicated in Fig. 12.

It is also possible to make additional changes in the position of the belt with respect to the yoke. For example, the motor-base I0 may be disconnected from the mounting-plate 69 of the yoke and turned through 90 and refastened thereto, whereby the motor-pulley shaft l I4 extends outwardly from one side or the other of the yoke at substantially right angles thereto, the pulley-carrier 82 at the forward end of the yoke being similarly detached and rotated through 90 to bring the pulleys I08 and motor-pulley I I3 into a common plane.

Although the foregoing adjustments may be made with the boom in one angular position vertically with respect to the jack, or in any one of a plurality of vertical angular positions, as determined by the arcuate slots 36 and adjusting-bolts 38, the jack, in turn, is movable vertically on its base by means of the elevatingscrew 28, and is adapted to rotate thereon through 360, as described above. Such comprehensive movement of the linearly-moving polishing-belt I i2 is adapted thus to bring the polishing-surface thereof and, in particular, its working portion, i. e., the portion which spans the two pulleys I08, into engagement with the work-pieces and, more especially, surfaces thereof which have been heretofore inaccessible or accessible only with difficulty by conventional po1ishing-means.

As an additional feature of the improved polishing-means, the belt II2 provides an abrading surface which, in effect, is equal in length to the total length of the belt as a consequence of which the abracling surface has a much longer life than that of the conventional abrading wheel. Moreover, when worn to a condition where replacement is necessary, the removal of the belt may be effected in a minute or less by simply pulling in one of the pivoted pulley-plates 92 to loosen the belt, whereupon the latter may be slipped off of the pulleys and a new belt engaged thereon.

As pointed out above, the working portion of the linearly-moving polishing-belt H2 is preferably that portion thereof which, at any instant, spans the distance between the two pulleys 508. Since one of the pulleys IDS is mounted so as to move laterally with respect to the other. then as the working portion of the belt is moved against a work-piece, tension on the belt will pull the pivotally-mounted pulley I08 inwardly, thereby slackening the belt so as to enable it to automatically conform to the shape of the workpiece, as shown in Fig. 2, the conformation of the polishing-belt to the work-piece bein both linearly and transversely of the belt when the work-piece is of curvilinear configuration. It will be appreciated at once that a single relatively-inexpensive and readily-replaceable polishing-belt incorporates all of the functions of a large inventory of expensive polishing wheels, each of which has a relatively-short life and a relatively-long restoration period. Moreover, the polishing-belt is equally effective for polishing flat surfaces, that is to say, no belt change is necessary to alternately polish fiat and curvilinear surfaces being fed successively to the polishing-belt; and. when necessary, or desirable, the portion of the belt which is backed by one of the pulleys, preferably the motor-pulley i I3, may be used as the polishing portion of the belt. In this connection, it is within the purview of the invention to provide a flat plate to back up the working portion of the belt between the pulleys I98 for polishing relatively-large flat surfaces.

Although the machine has been described as one having a belt provided with a dry abradant for polishing articles, it will be understood that the belt may be one adapted for deburring, for use in a wet polishing operation and for similar finishing operations known in the art. Moreover, the universality of the polishing-unit or -head 2'! embraces the use of a conventional polishingor bufling-wheel on the motor-shaft II4 instead of the pulley-wheel H3 and polishingbelt II2 wherever such substitution would be especially suitable for a particular polishing or bufiing operation.

The invention may be carried out in other specific ways that those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

atoms? We claim:

1. In amachine'of'the-class described;.a base; a jack mounted on said base, said jackhaving a-lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and to move vertically thereon; a polishing-unit; means to support said polishing-unitaon said. liiting-head, said supportingemeans comprising a boom adjustably secured at its lower: end to said lifting-head and having acrank-arm at :its onposite end for connecting said boonnto said polishing-unit and arranged to provide multi-directional movement for said polishing-unit in avertical plane; and self-locking adjusting means interconnecting'saidboom and said crank-arm and arranged to rotate said crank-arm and the said polishing-unit in the vertical plane of said boom.

2. In a machine of the class described, a base; a jack mounted on said base, said jack having alifting-head constructed and arranged to rotate about the substantially-vertical axis=thereof and to move vertically thereon; a polishing-unit; means to support said polishingeunit on said lift ing-head, said supporting-meanscomprising. a boom secured to said lifting-head and .a crankarm connecting said boom to said polishing-unit and arranged to provide multi-directional movementfor saidpolishing-unit in anvertical plane; and aworm and gear carried by said boom and interconnecting said boom and said crank-arm to rotate said crank-arm and said polishing-unit in the vertical plane of said boom.

3. In a machine of the class described, a base; a jack mounted on said base, said jack having a lifting-head constructed and arrangedto rotate aboutthe substantially-vertical,axis thereof and to move vertically thereon; a polishing-unit; means to support said polishing-unit on said lifting-head, said supporting-means comprising a boom adjustably mounted'at its lowerend .on said lifting-head and havinga crank-arm at its opposite endv for connecting. said boomto. said polishing-unit adjustable connecting-means between said crank-arm and said polishing-unit arranged both to provide multi-directional movement for said polishing-unit in a vertical plane and inversion of said polishing-unit relative to said boom; and an adjusting-device connecting said boom to said lifting-head to permit adjustment of said boom in the vertical plane thereof.

4. In a machine of the class described, a base; a jack mounted on said base, said jack having a lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and to move vertically thereon; a polishing-unit; means to support said polishing-unit on said lifting-head, said supporting-means comprising a boom mounted on said lifting-head and a crankarm connecting said polishing-unit and arranged to provide multi-directiona1 movement for said polishing-unit in a vertical plane; a Worm and gear carried by said boom and interconnecting said boom and said crank-arm to rotate said crank-arm and said polishing-unit in the vertical plane of said boom; and an adjusting-device connecting said boom to said lifting-head to permit adjustment of said boom in the vertical plane thereof.

5. In a machine of the class described, a base; a jack mounted on said base, said jack having a lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and to move vertically thereon; a polishing-unit comprising a yoke, a motor; means to reversibly mount said motor on said yoke, a pulley-carrier,

means-to reversibly" mount said 1 pulley-carrier :on said yoke. and an endless. polishing-belt mounted on the-pulleys of said 'carrierand driven by said motor; means to support said yokecomprising a boom adjustably secured atlits lower end to said lifting-headand a crank-.armconnected to the opposite end of said boom and to said yoke to permit said yoke to have multi-directional movementin the vertical plane of said'boom; and an adjusting-device interconnectin said boomand said crank-arm to rotate said crank-arm and said yoke in the vertical plane of said boom.

6; In a machine of the class described, a base; a jack-mountedzon said base, said jack having a lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and tomove vertically thereon; a polishing-unit comprising a substantially-rectangular yoke, a motor mounted on one end of said yoke, a'pair of laterally-spaced pulleys supported at the opposite end of said yoke and'an endless polishing-belt connecting said pulleys and. said motor; means to support said yoke for inulti-directional movement in av vertical. plane comprising a boom -mounted on said lifting-head anda crank-arm pivotally connected at one end-to said boom and at its opposite end to said yoke substantially intermediate the opposite ends thereof; and a worm and gear carried by said boom and arranged to pivot said crank-arm in the vertical plane thereof.

'7 In a machine of the class described, a base; ajack mounted on said base, saidjack having a lifting-head constructed and; arranged to rotate -about-the substantially-vertical axis thereof and tomoye vertically thereon; a polishing-unit comprising; a substantially-rectangular yoke; a motor, fastening-means to adjustably support said motor on one end of said yoke, a carrier-member, fastening means-to adjustably support said carrier-member on; the opposite end'of said yoke, said;.carrier-membenhaving;a pair of laterallyspaced pulleys pivotally mounted thereon and an endless polishing-belt connecting said pulley and said motor; means to support said yoke for multi-directional movement in a vertical plane comprising a boom mounted on said lifting-head and a crank-arm plvotally connected at one end to said boom and at its opposite end to said yoke substantially intermediate the opposite ends thereof; and a worm and gear carried by said boom and arranged to pivot said crank-arm in the vertical plane thereof.

8. In a polishing machine, the combination including a base; a jack; means to mount said jack on said base, said jack having a lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and to move vertically thereon; a boom; fastening-means to secure one end of said boom to said lifting-head for adjustment in the vertical plane thereof; a, pair of crank-arms pivotally mounted at the opposite end of said boom; a worm and gear carried by said boom and constructed and arranged to rotate said crank-arms in the vertical plane of said boom; a yoke pivotally mounted on the outer ends of said crank-arms; adjusting-means to secure said yoke in any desired position in the vertical plane of said boom; and a polishing-assembly mounted on said yoke comprising a drivemeans and an endless polishing-belt driven by said drive-means.

9. In a polishing machine, the combination in-- eluding a base; a jack; means to mount said jack on said base, said jack having a lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and to move vertically thereon; a boom; fastening-means to secure one end of said boom to said lifting-head for adjustment in the vertical plane thereof; a pair of crank-arms pivotally mounted at the opposite end of said boom; a worm and gear carried by said boom and constructed and arranged to rotate said crank-arms in the vertical plane of said boom; a yoke pivotally mounted on the outer ends of said crank-arms; adjusting-means to secure said yoke in any desired position in the vertical plane of said boom; and a polishingassembly mounted on said yoke comprising a motor at one end of said yoke having a, pulley,

a pair of 1aterallyspaced idler-pulleys at the opposite end of said yoke, and an endless polishing-belt connecting said idler-pulleys and said motor-pulley.

10. In a polishing machine, the combination including a base; a jack; means to mount said jack on said base, said jack having a lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and to move vertically thereon; a boom; fastening-means to secure one end of said boom to said lifting-head for adjustment in the vertical plane thereof; a pair of crank-arms pivotally mounted at the opposite end of said boom; a worm and gear carried by said boom and constructed and arranged to rotate said crank-arms in the vertical plane of said boom; a yoke pivotally mounted on th outer ends of said crank-arms; adjusting-means to secure said yoke in any desired position in the vertical plane of said boom; and a polishingassembly mounted on said yoke comprising a motor at one end of said yoke having a pulley, a pair of laterally-spaced idler-pulleys at the opposite end of said yoke, a pivotal support for one of said idler-pulleys, resilient-means to hold said pivotally-supported idler-pulle in laterallyspaced relationship with respect to the other of 16 said idler-pulleys, and an endless polishing-belt connecting said motor-pulley and said idlerpulleys.

11. In a polishing machine, the combination including a base; a jack; means to mount said jack on said base, said jack having a lifting-head constructed and arranged to rotate about the substantially-vertical axis thereof and to moves vertically thereon; a boom; fastening-means to secure one end of said boom to said lilting-head for adjustment in the vertical plane thereof; a pair of crank-arms pivotally mounted at the opposite end of said boom; a worm and gear carried by said boom and constructed and arranged to rotate said crank-arms in the vertical plane of said boom; a yoke pivotally mounted on the outer ends of said crank-arms; adjusting-means to secure said yoke in any desired position in the vertical plane of said boom; and a polishingassembl mounted on said yoke comprising a motor at one end of said yoke having a pulley, a carrier-member adjustably mounted at the opposite end of said yoke, said carrier-member having a pair of laterally-spaced pivotally-mounted arms each provided with an idler-pulley, resilientmeans to hold said arms in laterally-spaced relationship, and an endless polishing-belt connecting said motor-pulley and said idler-pulley.

CLIFFORD I. PACKER. PAUL R. NICKERSON. JOHN F. HARPER.

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

UNITED STATES PATENTS Number Name Date 1,621,931 Johnson Mar. 22, 1927 1,829,440 Erickson Oct. 27, 1931 2,273,696 Ducker Feb. 1'7, 1942 2,324,416 Murray July 13, 1943