US2185344A

US2185344A - Grinding apparatus

Info

Publication number: US2185344A
Application number: US89631A
Authority: US
Inventors: Knight Albert Breakenridge
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-07-08
Filing date: 1936-07-08
Publication date: 1940-01-02
Anticipated expiration: 1957-01-02

Description

Jan. 2, 1940. B KNlGHT 2,185,344

GRINDING APPARATUS Filed July 8, 1956. 5 Sheets-Sheet 1 Jam. 2, 1940. A. B. KNIGHT 2,185,344

GRINDING APPARATUS Filed July 8, 1936 5 Sheets-Sheet 2 340 A. B. KNHGHT GRINDING APPARATUS Film July 8, 1936 5 Sheets-Sheet 4 A. B. W/V/G'HT A. B. KNIGHT 2,185,344

GRINDING APPARATUS Filed July 8, 1936 5 Sheets-Sheet 5 Patented Jan. 2, 1940 STATE i T'i res 13 Claims.

This invention relates to grinding apparatus, and more particularly to an apparatus for grinding the edges of glassware.

" In the manufacture of articles of glass, such as a tumblers, sherbets, etc., the glass, after being blown, contains the usual excess glass above what is to be the upper limit of the glass article. The glassware is then subjected to the operation of etching andcracking, which consists in etching lo a line approximately at what is to be the upper limit of the glassware, and then subjecting the ware to the action of a burner which causes the ware to crack off around the etched line.

The glassware does not crack off perfectly l5 straight, that, is in an exact plane, and accordingly the ware, after being cracked off, is subjected to a grinding action to smooth and level on the upper edge of the ware, after which it is subjected to the action of a glazing burner,

20 which smooths the surface of the were and softens the upper ground edge thereof to give it a perfectly smooth glazed edge.

The various forms of apparatus which have been employed. for grinding glassware in the g5 manner stated have been unsatisfactory for a number of reasons. For example, grinding machines have been developed wherein the grinding action takes place with the glassware supported in a horizontal position. Extreme difficulty has 30 been encountered in properly supporting the were during the grinding operation, and a substantial amount of breakage occurs through the action of the vibration of the apparatus. This is particularly true in connection with stem ware,

35 in which the stems are frequently broken by ibration. This fault is largely overcome in vertical grinding machines in which the ware is ground by means of rotating stone disposed iherebeneath. However, the ware is not particularly easy to handle in an apparatus of this character and since water must be constantly supplied at the grinding point, the water flows downwardly into the operating parts of the mechanism.

An important object of the present invention is to provide novel glassware grinding machine wherein the ware is ground in a vertical position and is moved relative to the rotating stone to the bottom face thereof.

A further object is to provide an apparatus of the character referred to wherein the point of grinding arranged wholly below the main opersting parts of the apparatus, thus permitting water to be fed freely to the point of grinding without flowing to the operating parts of the apparatus.

A further object is to provide an apparatus of this character having a vertical rotating hollow spindle with a grinding stone at the lower end thereof, and to provide novel means for feeding water to the point of grinding by arranging a water supply pipe in the interior of the spindle.

A further object is to provide, novel chuck means for supporting the glassware during the grinding operation.

A further object is to provide a chuck wherein the glass properly centers itself to be ground with its upper edge in a plane at right angles to the axis of the glass. 1

A further object is to provide novel means for vertically moving the chuck with respect to the grinding stone to facilitate the loading and unloading or the chucks.

A further object is to provide novel counterweight means for determining the pressure at which the glassware is held against the grinding stone during the grinding operation.

A further object is to provide novel driving means for the grinding spindles.

A further object is to provide novel means for retaining the glass holding chucks retracted from the grinding stones.

A further object is to provide a novel chuck holder for the glass supporting chuck, and to provide means adapted to be supported by the chuck holder and operative for smoothing the grinding face of the stone where it becomes rough or grooved.

Other objects and advantages of the invention will become apparent during the course of the following description.

'In the drawings I have shown one embodiment of the invention. In this showing- Figure 1 is afront elevation,

Figure 2 is a rear elevation,

Figure 3 is a section on line 3-3 of Figure 1,

Figure 4 is an enlarged fragmentary sectional view of one of the grinding stones and associated elements,

Figure 5 is an enlarged fragmentary sectional View on line 5--5 of Figure 4,

Figure 6 is a plan view of one of the chucks,

Figure 7 is an enlarged detail sectional view on line 'l! of Figure 3, 5

Figure 8 is an enlarged fragmentary elevation of the grinding stone and associated parts, showing the stone smoothing means in position,

Figure 9 is a section on line 9-43 of Figure 8, n

Figure 10is a horizontal section on line Ill-l6 of Figure 9.

Referring to the drawings, the numeral designates a relatively heavy cast base forming the main support for the apparatus. This base is provided in its upper face with a depression ii, for a purpose to be described. The base may be surrounded by an angle iron frame l2 to which are secured a plurality of corner posts I3. These posts are connected at their upper ends by a rectangular angle iron frame l4, and between the frames I2 and i l, the end of the apparatus may be closed by plates l5.

The frame I 4 supports a pair of upstanding relatively heavy channel members it connected at their upper ends by a similar member ll. A horizontal relatively heavy channeled member l8 extends across the supports it and is bolted at its ends thereto as at IS. The channeled member l8 forms a support for a plurality of pairs of bearing brackets 20, as shown in Figures 1, 3 and 4. Each of the brackets 28 supports an anti-friction bearing unit 2| to which lubricant may be supplied through a fitting 22. Each pair of bearing units 2! supports a hollow vertical spindle 23 to the upper end of which is secured a pulley 24 around which passes a belt 25 preferably of the V-type. The lower end of each spindle 23 has a plate 26 threaded thereon, and a grinding stone 2'! is clamped as at 28 to each plate 26, each grinding stone having an axial opening 29 therethrough.

Means to be described are employed for moving an article of glassware upwardly into engagement with the lower face of each stone 2'! to be ground thereby, and water is supplied at the. point of grinding. Referring to Figures 1 and 3, the numeral 36) designates a water manifold supplied from a suitable source by a pipe 3| having a control valve 32 therein. The manifold 30 is supported in position by brackets 33, secured to the supports l5, while one ofthese supports carries a bracket 34 supporting the supply pipe 3!. The manifold 30 is provided with a plurality of Ts 35, each of which is provided with a control valve 36. One end of a rubber hose 31 is connected to each valve 36 and has its other end connected to the other end of a brass or similar tube 38 extending downwardly through each of the spindles 23. Each tube 38 is supported by a bracket 39 secured as at 40 to the upper flange of the horzontal support l8. Each tube 38 is obviously stationary while the spindles 23 rotate, and accordingly each tube is preferably smaller than the opening through its associated spindle so that these elements do not wear against each other. To prevent the accumulation of water around the tubes 38 within the spindles 23, the latter are preferably provided just above their associated plates 26 with one or more outlet openings 4 I.

To prevent outward splashing of water, each stone 2'! isprovided with a hood comprising an inner stationary portion 42 and an outer portion 43 hinged at one side with respect to the section M as at M and latched at the other side thereto as at 45 (see Figure The stationary portion of each hood is secured against the bottom of one of the bearing brackets 29, as at 46.

A chuck holder indicated as a whole by the numeral 4? is provided for each of the grinding stones and associated elements. This chuck holder is provided with an upper ring portion 48 split at the front thereof as at 49 and one end of the ring adjacent the split is provided with a recess 50 for a purpose to be described. The ring portion 48 of each chuck holder is provided at opposite sides with depending skirt portions 5| connected by a cross member 52 at their lower ends and such cross member is bolted as at 53 to a crosshead 54.

A glass supporting chuck is adapted to be received in the ring 48 of each chuck holder. Each chuck comprises a ring 55 split at one side as at 56 and provided with a depending skirt portion 51 fitting within the ring of the chuck holder. The inner face 58 of the chuck is shaped to correspond to the shape of the article of glassware to be supported thereby. In the drawings, the chuck is shown as being shaped to receive stemmed glassware such as sherbets, champagne glasses, etc., one of such articles of glassware being indicated as comprising a bowl portion 59, a stem 60 and a base Si The bowl of the glassware is adapted to be supported by a relatively thick felt or similar member 52 arranged in a recess 63 formed in the chuck, the felt 62 forming a cushion extending inwardly beyond the inner surface 53 of the chuck to prevent the bowl 59 from contacting with the metal of the chuck. The chuck is provided adjacent the split 56 with a radial pin 64 arranged in the recess 5!! when the apparatus is in operation. In such position of the parts the splits 49 of the chuck holder and 56 of the chuck are in registration to permit the movement therethrough of the stem Ell, whereby the article of glassware may be positioned in the chuck.

The chuck 55 and the elements movable therewith are counter-weighted to determine the pressure of the article of glassware against each grinding stone. Each crosshead 54 is provided at its ends with cylindrical bosses 65 receiving the 3 lower end portions of vertical rods 66 secured thereto as at 61. The upper ends of the rods 66 of each pair are connected by a cross member 68 to the center of which is connected a chain 69. Each of these chains passes over a sprocket T0 rotatable on a shaft H supported by the upper ends of a bearing bracket 12. The lower ends of these brackets are secured to the transverse support H. The other end of each chain 69 is provided with a depending stem 13 on which is mounted a main counter-weight M, supplemental counter-weights 15 being supported on the main counter-weight 14 in accordance with the desired weight to be suspended by the chain 69. It will be apparent that the counter-weights tend to move downwardly, thus tending to move the chucks upwardly to hold the upper edges of the glassware in engagement with the grinding stones 2?, the pressure of the grinding engagement depending upon the counter-weights employed.

As previously stated, water is supplied to each of the'tubes 38, the latter filling the glassware and leaking over the upper edges thereof. Water, after the glassware has been filled, also overflows through the openings ll, and the water thus discharged from the lower ends of the tubes 38 falls into an elongated trough 16. Above the frame members It a tray 11, preferably of aluminum, collects any water which may splash outwardly and causes such water to flow into the trough 76. This trough is provided with an outlet pipe 18 by means of which the water in the trough 15 may be carried off.

Means are provided for lowering the chucks for the purpose of placing glasses therein and for removing the glasses therefrom. The lower ends of each pair of rods 56 are provided with a transverse connecting member 19 through the center of which is connected the upper end of a vertical pull rod 80. Such rod extends downwardly through the bottom of the trough 16 and is surrounded by an upstanding bearing 8i carried by the bottom of the trough to minimize any leakage of water around the pull rod. The lower 5 end of each rod 86 is provided with a yoke 82 'votally connected as at 83 to the inner end 01 lever 85, operation of this lever in a manner to be described pulls the associated chuck downwardly for the purpose stated. A plurality of vertical supports 85 are carried by the bottom of the pan l8 and a vertical rod 86 extends through each support 85. One of the rods 86 is in axial alinement with each of the grinding spindles, its upper end is adapted to engage bottom of an article of glassware, upon the ring of the associated chuck to release the ware from the chuck. According to the -t of the glassware, each rod 86 may be usted as to height by an adjusting collar 81.

plurality of pairs of vertical angle irons 38 bolted at their lower ends as at 89 to a nsverse bar at extending between the two corforward posts 13. The upper ends of the a e irons are secured as at iii to a hori- 'al angle iron $2 also secured at its ends to corner post Iii. A pair of the angle irons is employed for each grinding unit, and the forward of each lever 8t is pivotally connected as at 93 between the angle irons 3i! of e pair. Either or both of the pivotal conicns 33 or 953 may be sufliciently loose to t the vertical axial movement of the rods .epending link fi is pivotally connected at i iner end as at B5 to each of the levers 34, pivotally connected at its lower end as to an operating lever iii. The rear end of operating lever ill is p-ivotally connected as t between pair of vertically extending paced angle irons 9t, secured at their lower ends the frame if? and at their upper ends to a transverse connection l8!) extending between the members It. The forward end of each o rating lever 52? is provided with a treadle Edi.

will be apparent that downward movement of either treadle llll will transmit movement the link and lever 84 to the associated i ting the movement of the parts to prengagen'lent of each chuck with its assod stone if the chuck is released without an le of gassware arranged therein. A vertibar i preferably square in cross-section, ts low-r extremity forked to engage the o Ler end portion of each of the levers 9i and it s slidahle in a guide Hit connected to the adjaangle irons 85%. The upper end of .h tilt. is provided with a threaded extension ertending slidably through the horiof the angle iron $2 and through .1 plate M35, spaced above the angle connected at its to the forward A nut N38 is arranged on each ,ded extension Hid in the space between the ital flange of the angle iron 92 and the eiements preventing vertical .ines the upper limit of movement of each die the levers 8? may be locked in its lowermost posit u. Referring to Figure 1. the

numeral ifil' indicates a plurality of locking levers each pivotally connected intermediate its ends as at M8 to the vertical flange of the angle iron 92 and the upper end of each lever lfi'i is provided with an outwardly extending operating handle 39. Each lever Ill! lies approximately in the plane of the outer flanges of the pairs of vertical angle irons lit, and each lever I8! is provided at its lower end with a laterally extending fork HE! receiving the adjacent outer flange of one of the angle iron supports 88. The outer arm of each fork H9 is adapted to assume a position over one of ihe levers 97 to lock the latter in its lower position, as shown in dotted lines in Figure 3.

Means are provided for driving the spindles 23, and in the drawings, one source of power has been illu:=;trated as being provided for each pair of spindles. It will be apparent, however, that the nun'i'ter of power sources employed is unimpcrto 0 far as the present invention is concerned. The horizontal support it is provided with a pair of rearwardly extending supports i ll bolted thereto as at HZ. Each support Hi is provided with a horizontal upper wall H3 in the upper of which is formed a. guideway H4, plate iii-i forming the top of the guideway at each side thereof. A crosshead indicated as a whole the numeral He has the edges of its case portion slidable in the guideways of each support ill, and carries an upstanding support ill carrying a bearing H3. Each hearing lid supports a shaft H9 carrying a pulley I26 adjacent each end thereof. The belts 25, carried by the spindles pass around the respective pulleys i253 to be driven thereby. It will be apparthat the two spindles at each end of the ap peraius will be driven from one of the shafts Each support l I l is provided with an outwardly and upwardly extending arm iii in which is roiatahly mounted a shaft 922, and this shaft is provided at its outer end with a wheel 523 having a handle lid. The inner end of this shaft E22 is threaded in a lug I25 carried by the base of the crcsshead lit, and accordingly it will be apparent that th handle I23 and wheel I23 may-be rotated to move the crosshead H and thus properly tension the belts 25.

In the present embodiment of the invention a separate motor is employed for driving each of the shafts H9, and variable speed transmission means is preferably provided between each motor and the shaft H9 driven thereby. Referring to 1 es 2 and 3, the numeral Hit designates a pair of independent supporting plates each hinged at its inner end as at 521 to a relatively heavy plate 92%, arranged in a vertical plane and extending across the apparatus. The piate 23 is boited at its ends as at 25 to the vertical supports 36. It will be noted that the plate E28 is arranged against the bottom of the horizontal channeled. support it and forms a continuation of the base portion of the latter. These elements therefore provide a wall separating the grinding side of he apparatus from the driving side there of, thus preventing any cuttings or the like from the finding operation from coming into contact with the driving apparatus.

Each supporting plate [is is provided. with depending lug 629 to which is swiveled a block i535}. A screw iBl, having a handle Hi2, has its upper end rotatably supported by each block iii-El and is threaded in a block 53 swiveled to an outstanding lug 32 carried by the adjacent horizontal frame member i i. Downward l'ii vement of the other end of each supporting plate I26 is limited by a screw I33 (Figure 2) threaded in a bracket I34! also carried by the adjacent horizontal frame member I4.

Each supporting plate I26 carries a motor I35 adjacent one end thereof as shown in Figure 2.

Each motor drives a shaft I36 on which is mounted a pair of relatively axially movable driving cones I37, urged toward each other by compression springs I33, the end of each shaft I36 remote from its associated motor I35 being supported in a bearing I39 carried by the associated plate I26. A belt Mt passes around each pair of cones I31 and around a pulley I II carried by each shaft H9. The specific structure of the cones I3l and associated parts form no part of the present invention except in the combination claimed, such elements being fully disclosed in my copending application Serial No. 84,941, filed June 12, 1936, now Patent No. 2,107,483, dated February 8, 1938.

The apparatus is provided with means for smoothing the stones 2? after the latter have become grooved or roughened in use. The chuck holders described are adapted to support the means for cutting and smoothing the stones. Referring to Figures 8, 9 and 10, the numeral I 42 designates a cylindrical member fitting and receivable in either of the chuck holders and provided with a pin E63 projecting from one side thereof and adapted to be arranged in the recess 59, previously described. The skirt N52 is formed integral with a horizontal member I44 which is supported on the ring 48 of the chuck holder when in operative position. A pair of parallel guides M5 is formed integral with the member IMI and is provided in opposite ends with bearing portions M6 and I I'I rotatably supporting a shaft I48. The portion of the shaft which extends through the bearing I 43 is shouldered as at I 49, and the adjacent projecting extremity of this shaft is provided with a collar I59. Accordingly the shaft is prevented from moving longitudinally, but is free to rotate. The shaft I48 is provided with a wheel I5I having a handle I52 projecting therefrom to facilitate the rotation of the shaft.

A diamond point or similar cutting implement I53 is supported by a holder I54 having outstanding flanges I55 slidable on the upper faces of the guides I 45. The holder I54 is further provided with a depending block I56 slidable between the guides M5 and threaded on the shaft I48. A shield I5? is carried by the holder I54 and is provided at its edges with depending flanges I58 extending downwardly beyond the upper outer edges of the guides M5. The ends of the shield I57 are turned upwardly as at I59, and the shield is sufficiently elongated to prevent cuttings from dropping between the guides M5.

The shield 32 is provided with a bracket I M secured thereto as at I5I, and an internally threaded bearing I62 is carried by this bracket. A stem I63 is threaded in the bearing I 62 and carries a knurled head I64 at its upper end. The lower end of the screw I63 is adapted to contact with an arm I65 extending laterally from the member HM and preferably formed integral therewith. The contact of the arm I65 with the screw Hi3 limits the upward movement of the stone cutting implement.

The operation of the apparatus is as follows:

The spindles 23 are driven by the motors I35, as will be apparent. Each motor drives one of the pair of cones I31, and the belts passing around these cones drive the shafts I I9 through the belts I40. Power is transmitted from each shaft II 9 to the spindles associated therewith by means of the belts 25. The rotational speed of the spindles readily may be varied by rotating the handles I32. This operation obviously raises or lowers the supporting plates I26, thus varying the distance between the shafts I I9 and I36. The I minimum driving speed of the spindles is reached when the supporting plates I26 are in their lower or horizontal position in engagement with the screws I33, under which conditions, the increased distance between the shafts H9 and I36 causes the belts M to move inwardly toward the centers of the cones I31. The positions of the parts for the minimum driving speed are shown at the left side of Figure 2. For an increased driving ratio, one or both of the. handles I32 may be rotated to elevate the supporting plates I253, as shown at the right hand side of Figure 2. Under such conditions the distance between the shafts II 9 and I36 will be reduced, thus permitting the springs I33 to move the cones I31 inwardly whereby the belt I 40 will engage the cones I3! adjacent the periphery thereof. The two sup porting plates I26 obviously are independently adjustable, thus permitting two of the spindles to be driven at a higher rate of speed than the other two spindles, if desired.

When it is desired to grind an article of glassware, one of the treadles Ill! may be depressed to lower the associated chuck, whereupon the article of glassware is inserted in position in the chuck. In the case of stem ware, the splits 56 of the chuck and 49 of the chuck holder permit the entrance of the stem directly into the chuck, whereupon the article may be lowered to permit the bowl portion thereof to be supported by the felt member 62. It will be apparent that various chucks are employed in accordance with the article of glassware.

With the article in position in the chuck, the operator permits the treadle IOI to move upwardly, the counter-weights M and I effecting such movement until the upper edge of the glassware comes into engagement with the rotating stone 27. The pressure at which the glassware is maintained against the stone is determined by the counter-weights. Particular attention is invited to the fact that the nature of the chuck is such that an article of glassware will automatically center itself in the chuck and axially align itself with respect to the spindle which drives the stone. Accordingly the glass will be ground in a true horizontal plane.

During the grinding operation, water is fed downwardly through the pipe 38 and through the opening 29 in the center of the stone, such water quickly filling the bowl of the glassware to maintain it in a cool condition during the grinding operation. This fact is of substantial importance since the effective cooling of the glassware thus provided minimizes breakage to a remarkable extent. Excess water overflows through the openings iI (Figure 4:) thus preventing the building up of a column of water in the spindle and the overflowing of the water from the top of the spindle. Some of the water obviously will leak over the edge of the glassware, particularly before the grinding is completed, and all of the discharging of the water takes place within the shield members t2 and 43. The shield members prevent the outward splashing of the water, and the water is discharged wholly beneath the operating parts of the spindle, such as the supporting bearings thereof. The cuttings, of course, pass downward- 1y from the shield members with the water, and thus all operating parts of the apparatus are protected from the action of water and from the abrasive action of the cuttings.

Water passing downwardly from the shield members flows into the trough 46, from which it is preferably constantly drained by the pipe 18. Obviously the level or" the water in the trough never reaches the upper ends of the bearings 8i and supports 85, and practically no water leaks through these members. Over substantial periods of operation, the amount of water leaking around the stems 8H and will be insufficient to fill the shallow recess l i of the base iii, the recess being provided to collect what negligible leakage occurs.

The grinding operation for each article of glassware is carried out to the extent necessary to grind the edge of the glass to the proper point, and the extent to which the grinding operation will be carried out is limited by the stop members H32. These members are adjusted by rotating the nuts lflli to limit the upward movement of the levers 9i, and thus limit the upward movement of the glassware as the grinding operation progresses. When one of the levers 9'! contacts with the lower end of its stop member i232, the grinding of the glass in the associated chuck is completed.

After an article has been ground to the desired extent, the associated treadle till is depressed, whereupon the lever 9! pulls the lever 8d downwardly together with the associated chuck, the operator exerting suflicient pressure on the treadle to overcome the counterbalancing effect of the counter-weights. The chuck supporting the ground article will be lowered until the rod 85 contacts with the bottom of the glassware, whereupon the latter will be loosened from the chuck and readily may be removed by hand. While the chuck is still in lowered position, another glass article may be placed in position therein to be ground in the manner stated.

Any number of grinding units may be employed and in the present instance four units have been illustrated. Accordingly, an ehicient apparatus has been provided for use by one operator, the desired operation consisting in filling the successive chucks from one end of the machine, and then starting from the same end of the machine to progressively remove the ground articlesand replace them with articles to be ground.

As previously stated, the present apparatus constitutes in several respects an improvement over prior structures of which I am, aware. For example, in some constructions which have been commercially used, the glass article is moved downwardly against the upper face of a rotating stone, in which case the cooling water and cuttings iind their way into the supporting bearings of the spindle, as well as other operating parts, thus causing mechanical difilculties and shortening the life of the apparatus. Moreover, an insufficient cooling effect is maintained in an apparatus of this character due to the inversion of the article of glassware rendering it incapable of holding water. In the present case, the glass ware is supported in normal position and promptly becomes filled with water to be maintained in a cooled condition during the grinding operation, thus greatly minimizing breakage due to overheating. Moreover, the grinding operation and the discharging of water and cuttings occurs beneath the spindle bearings, while the shield members :32 and i3 and the wall comprising the members 18 and I28 between the grinding side and driving side of the apparatus afford protection for the driving units.

'In another prior form of apparatus, the grinding spindle is arranged horizontally, thus requiring that the glass be arranged in a horizontal position for movement against the stone. Great difliculty has been experienced in supporting glassware in an apparatus of this character, substantial breakage occurring through the diificulty in properly supporting the ware. Since it is difficult to balance glassware in an apparatus of such character, the grinding operation usually takes place unevenly, it being extremely difficult to provide a ground upper edge which lies in a horizontal plane when the glass is in normal position,

In the present apparatus, the grinding takes place with the articles in their normal position, and the nature of the spindle and the supporting of the articles adjacent the upper ends thereof causes the ware to center and gravitate to a correct position for grinding in the desired plane.

The several chucks may be readily locked in their lower positions when desired, for example, when it is desired to place in inoperative position the stone smoothing means shown in Figures 8, 9 and 10. Eitherof the treadles it! may be depressed, whereupon the handle H39 of the corresponding lever It! may be moved in the proper direction to engage the associated fork Hill with the depressed lever 91. This lever thus will be held in its lower position, and the associated chuck will be held ina corresponding position.

When either of the stones becomes grooved or roughened, the corresponding chuck holder is moved to its lower position and locked in such position in the manner just described. The corresponding chuck is removed from its holder by rotating it slightly to move the pin 64 out of the recess 50, whereupon the chuck may be lifted from position. The stone smoothing unit then may be placed in position by aligning the pin M3 (Figures 8 and 9) with the split 39 in the chuck holder, lowering the sleeve I42 in-positicn, and then rotating the unit to engage the pin M3 in the recess 50. The screw IE3 is then adjusted to engage the arm I65 with the cutting point I53 arranged approximately as shown in Figure 9, very slightly above the lower face of the stone. The handle 152 is then revolved to gradually move the block I56 inwardly, together with the holder lfi l and cutting point 153. The inward movement is continued until the cutting point reaches the opening through the center of the stone. This operation may be repeated as many times as necessary to completely smooth the lower surface of the stone, the screw I63 being moved upwardly to a slight extent for each repetition of the operation to guide the cutting point for perfect horizontal movement.

When the stone smoothing operation is completed, it will be obvious that the lower face of the stone will be smooth and trued in a plane perpendicular to the axis of the associated spindle. The chuck holder then may be lowered and latched in its lower position to permit the removal of the stone smoothing device, whereupon the glass supporting chuck may be replaced in position for further grinding operations. Accordingly it will be apparent that the apparatus employs the same chuck holders for supporting chucks and for supporting the stone smoothing mechanism, thus increasing the efliciency of the apparatus and minimizing the cost of extra operations for smoothing the stones. Each appa- Gil ratus need be provided with only one stone smoothing mechanism, as will be apparent.

It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

l. A grinding apparatus comprising a vertical rotatable spindle, a grinding stone supported at the lower end of said spindle, a glassware receiving chuck arranged beneath said stone, means for supplying water to the edge of an article of glassware supported by said chuck against the lower face of said stone, a stationary water trough arranged beneath said chuck, an upstanding bearing carried by said trough, and a rod vertically movable in said bearing and supporting said chuck.

2. A grinding apparatus comprising a Vertical rotatable spindle, a grinding stone supported at the lower end of said spindle, a glassware receiving chuck arranged beneath said stone, means for supplying water tothe edge of an article of glassware supported by said chuck against the lower face of said stone, a water trough arranged beneath said chuck, an upstanding bearing carried by said trough, a rod vertically movable in said bearing and supporting said chuck, lever means for vertically moving said rod, including a treadle movable downwardly to move said rod downwardly, and means biasing said rod upwardly.

3. A grinding apparatus comprising a vertical rotatable spindle, a grinding stone supported at the lower end of said spindle, a glassware receiving chuck arranged beneath said stone, means for supplying water to the edge of an article of glassware supported by said chuck against the lower face of said stone, a water trough arranged beneath said chuck, an upstanding bearing carried by said trough, a rod vertically movable in said bearing and supporting said chuck, lever means for vertically moving said rod, including a treadle movable downwardly to move aid rod downwardly, means biasing said rod upwardly, and means for latching said treadle in lower position.

4. A grinding apparatus comprising a vertical rotatable spindle, a grinding stone supported at the lower end of said spindle, a glassware receiving chuck arranged beneath said stone, means for supplying water to the edge of an article of glassware supported by said chuck against the lower face of said stone, a water trough arranged beneath. said chuck, an upstanding bearing carried by said trough, a rod vertically movable in said bearing supporting said chuck, lever means for vertically moving said rod, including a treadle movable downwardly to move said rod downwardly, means biasing said rod upwardly, and adjustable means engaging said lever means for limiting the upward movement of said rod and said chuck.

5. A grinding apparatus comprising a vertical rotatable spindle, a grinding s one supported at the lower end of said spindle, a glassware receiving chuck arranged beneath said stone, means for supplying water to the edge of an article of glassware supported by said chuck against the lower oi said stone, a water trough arranged beneath said chuck, an upstanding bearing carried by said trough, a rod vertically movable in said bearing and supporting said chuck, lever means for vertically moving said rod, including a treadle movable downwardly to move said rod downwardly, means biasing said rod upwardly, a pulley arranged above said chuck, a flexible element passing over said pulley and having two depending ends one of which is connected to said chuck, and a counter-weight carried by the other end of said flexible element.

6. A work holder for a grinding apparatus having a spindle and a grinding stone carried by said spindle, said holder being mounted for movement parallel to the axis of said spindle and comprising a ring portion at right angles to the axis of said spindle and having a split in one side thereof, said ring portion being provided within said split with a recess, and an article holding structure comprising a portion adapted to seat on said ring portion, a skirt portion receivable within said ring portion, and a pin carried by said structure and engageable in said recess for definitely positioning said structure with respect to said ring portion.

'7. A work holder for a grinding apparatus having a spindle and a grinding stone carried by said spindle, said holder being mounted for movement parallel to the axis of said spindle and comprising a ring portion at right angles to the axis of said spindle and having a split in one side thereof, said ring portion being provided within said split with a recess, and a chuck comprising a flange portion adapted to seat on said ring portion, a skirt portion receivable within said ring portion, and a pin engageable in said recess, said chuck having a radial split therein aligning "with the split in said ring portion when said pin is arranged in said recess.

8. A work holder for a grinding apparatus having a spindle and a grinding stone carried by said spindle, said holder being mounted for movement parallel to the axis of said spindle and comprising a ring portion at right angles to the axis of said spindle and having a split in one side thereof, said ring portion being provided within said split with a recess, and a chuck having a split ring portion including an upper flange portion 1;

adapted to seat on said first named ring portion and a skirt receivable within said first named ring portion, a pin carried by said chuck and engageable in said recess when the splits in said ring portions are in registration, the inner surface of said chuck being tapered to decrease in size away from said grinding stone, and a cushion element projecting inwardly from the inner face of said chuck.

9. A grinding apparatus comprising a plurality of vertical rotatable spindles, a grinding stone sup-ported at the lower end of each spindle, a glassware receiving chuck arranged beneath each stone, means for supplying water to the edge of an article of glassware supported by each chuck, a stationary water trough arranged beneath said chucks, a plurality of vertical bearings carried by said trough and corresponding in number and arrangement to said chucks, and a rod vertically movable in each bearing and supporting one of said chucks.

10. A grinding apparatus comprising a plurality of vertical rotatable spindles, a grinding stone supported at the lower end of each spindle, a glassware receiving chuck arranged beneath each stone, means for supplying water to the edge of an article of glassware supported by each chuck, a stationary water trough arranged beneath said chucks, a plurality of upstanding bearings carried by said trough and corresponding in number and arrangement to said chucks, a rod vertically movable in each bearing and supporting one of said chucks, treadle lever means for vertically moving each of said rods, and means biasing each of said rods upwardly.

ii. A grinding apparatus comprising a plurality of vertical rotatable spindles, a grinding stone supported at the lower end of each spindle, a chuck arranged beneath each stone, means for supplying water to the edge of an article supported by each chuck against the lower face of the associated stone, a single stationary water trough extending beneath all of said chucks, a plurality of upstanding bearings carried by said trough, and a rod vertically movable in each bearing and supporting one of said chucks.

12. in a grinding apparatus comprising a vertical spindle and a grinding stone supported at the lower end of said spindle, the improvement which comprises a ring arranged beneath and in axial alineinent with said spindle and provided with a slit extending throughout the length of one side thereof, a chuck engageable with said ring to be supported thereby in axial alinernent therewith, saidchuck having a slit extending throughout the length of one side thereof in registration with the slit in said ring to facilitate the entrance of an article of glassware into said chuck, said chuck being constructed to receive and engage an article of glassware solely near the top thereof, and vertically movable means for supporting said ring, said supporting means being circumferentially spaced from said slits and being horizontally offset from said ring.

13.A work holder for a grinding machine, comprising a sup-porting ring having a slit extending throughout the length of one side thereof, a chuck of ring-like shape engageable with said ring to be supported thereby coaxially therewith, said chuck having a slit extending throughout the length of one side thereof, and interengaging means between said ring and said chuck for ma ntaining said slits in registration with each other to facilitate radial movement of the Work into position in said chuck.

ALBERT BREAKENRIDGE KNIGHT.