US2578789A

US2578789A - Glass beveling apparatus

Info

Publication number: US2578789A
Application number: US52707A
Authority: US
Inventors: Donneily John Fenlon
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-10-04
Filing date: 1948-10-04
Publication date: 1951-12-18
Anticipated expiration: 1968-12-18

Description

Dec; 18, 1951 Filed Oct. 4, 1948 J. F. DQNNELLY 2,578,789

GLASS -BEVELING APPARATUS 3 Sheets-Sheet Dec."C 18, 1951 J, F DONNELLY 2,578,789

GLASS BEVELING APPARATUS Filed Oct. 4, 1948 3 Sheets-Sheet 2 Dec. 18, 1951 J. F. DONNELLY 2,578,789

GLASS BEVELING APPARATUS Filed Oct. 4, 1948 3 Sheets-Sheet 3 f77/@wr Patented Dec. 18, 19521 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to the beveling of plate ror other sheets of glass, and among other objects, aims to provide an apparatus for perform- `ing all grinding and polishing operations simultaneously in a single cycle of the apparatus.

'Another object of the'invention is to provide' apparatus of this type wherein the grinding and polishing compounds and glass particles do not reach and destroy the bearings of the grinding and polishing wheel and also wherein inequalities in glass thickness are not multiplied in the width of the bevel.

A further Objectis to provide apparatus wherein the grinding operation results in a smoother nishwhich. may beV more easily polished.

A still further objectV is to provide an appa- Aratus which insures the formation of a perfectly flat instead of a convex bevel.v Other objects and advantages and the nature ofthe invention, will appear from the following .description of one illustrative apparatus shown showing a sheet of glass in operative position;

Fig.v 3 is a front elevation of the apparatus viewed from thev direction of the left side of Fig. 1;

4 is a transverse section through the appa- ,'ratus taken on the plane 4 4 of Fig. 3;

Fig. 5 is a detailed section taken on the plane Fig. 6`is a view similar to Fig. 4, showing the initial position of the glass-holding assembly for vpositioning and holding a sheet of glass; and

Figf? is a diagram of an illustrative carriage operating and reversing mechanism. The details are conventional' and are therefore not illustrated.

The beveling of glass for mirrors, windows,

etc. involves a succession of grinding and polishing Operations. Generally three grinding opierations (coarse, medium and ne) are employed,

followed by one or more polishing operations. Handling of the glass during and between operations has required skill and has often resulted in breakage. The cost was excessive. Heretofcre yattempts to perform these operations without interveninghandling has resulted in excessive glass breakage, due, among other causes, to vibration of the grinding wheels.

In the illustrative apparatus, all grinding and polishing operations are. performed successively .without intervening handling of the. glass, in a'single simple operation wherein variations in glass thickness are not multiplied in the width of the bevel and wherein the glass grindings, polishing compounds, etc. cannot reach the bearings of the various grinding and polishing wheels.

In the illustrative apparatus the grinding and polishing wheels, of which, in the present apparatus, there are three grinding wheels IS, H and l2 (coarse, medium and fine) and two polishing wheels I3 and lli, are arranged with their axes above and generally perpendicular to the beveled surface. The under side faces i5 of the several wheels therefore engage the glass I6 and these are substantially co-planar so that each performs its operation without requiring any adjustment of the glass. Independent adjustment of the faces of the several wheels toward and away from the glass ispreferably provided to secure the desired degree cf cutting and to compensate for wear, if any.

The grinding wheels lil, il and l2 are advantageously small diameter (about 6") diamond cutting wheels. They are slightly tapered near their periphery to equalize or distribute the grinding action and generation of heat over a larger area of the wheels. If the faces of the wheels were perfectly at the area near the periphery, having the greatest surface speed, would perform the major portion of the cutting, with a corresponding concentration of generated heat, which might result in cracking of the glass. In such wheels the diamond powder or dust is partially embedded in a matrix of bronze or the equivalent constituting the body of the Wheel which, while holding the diamond particles firmly, will wear away more rapidly than,v the diamond particles. Such wheels can be made with extreme accuracy and balance so that their grinding surfaces are absolutely true and will not subject the glass to vibration during rotation. A plurality of such wheels may therefore simultaneously engage the glass without subjecting it to any substantial vibration or stresses. They wear very slowly, and once adjusted to the desired depth of cut, require little readjustment.

A feed pipe delivers water to the grinding faces of the wheels to facilitate grinding and to carry away heat.

The wheels are preferably carried at the ends of shafts mounted in bearings I'l at an elevation above the plane of cutting to prevent access to the bearings of any glass cuttings, polishing compounds, etc. which might damage the bearings. The several shafts and wheels are driven at the desired speed by motors E8 and I9 through belts 2E. In the present instance, motor i3 drives all three grinding wheels, for which purpose it carries three V-pulleys with belts leading to the re- `coactiva grinding wheel shaft pulleys. Motor I9 3 is similarly arranged to drive both polishing wheels.

The motors i8 and I9 and bearings I1 are mounted on an adjustable base 22 by which the angle of the grinding and polishing faces l may be adjusted relative to the glass to secure the desired angle of bevel on the glass. In this case, base 22 is pivoted at 23 and its remote edge is supported and positioned by adjustable supporting brackets 24. In this case adjustability is provided by a series of holes 25 in the brackets.

An edge grinding wheel 21 mounted on a shaft also carried on base 22 is advantageously provided for simultaneously grinding the edge of the glass at the bevel (see Fig. 2)

Wheel 21 is preferably a small diameter diamond Wheel having diamond dust embedded in its periphery, which is preferably grooved to grind the edge of the glass to a rounded or convex contour. Like the grinding wheels, Wheel 21 may be accurately made and balanced to eliminate vibration. Wheel 21 is driven by motor 28 mounted on base 22 through pulleys 29 and belt 3|.

The sheet of glass to be beveled is supported on table 32 located to position the beveled surface parallel to the faces I5 of the grinding and polishing wheels. A positioning member 33 adapted to be engaged by that face of the glass to receive the bevel is employed to locate the glass relative to the grinding surfaces by reference to such face. Variations in glass thickness are thus not multiplied in the width of the bevel. In the customary angle of bevel, variations in glass thickness would be multiplied about twenty times in the variations in the width of the bevel, if the glass were positioned for grinding by reference to the face opposite that to be beveled. In the present instance, the positioning member 33 is in the form of a bar extending transversely across the glass adjacent the edge to be beveled. The bar is made quite stiff and with a true under face. It is preferably trussed by a truss rod 34 to eliminate deflection under the pressure of the glass. Table 32 is preferably surfaced with a cushioning material such as a sheet of rubber, to distribute over the glass, the pressure of the table in pressing the glass against the positioning member 33. Table 32 is made movable toward and away from member 33, and in this case is hinged at 35 (Fig. 4) along an axis parallel to member 33 and adjacent the remote edge of the glass. Table 32 may thus be dropped to release the glass and pressed upwardly to hold the glass in position for grinding.

. The table operating mechanism is here shown in the form of levers 31 (one adjacent each side edge of the table, Fig. 3) pivoted at one end 38 to bracket 39 and connected at the other end to lifting posts 4i carried by and projecting downwardly from the under face of table 32. Levers 31 and table 32 are locked in elevated positiony to clamp the glass by locking mechanism here shown in the form of

toggle links

42 and 43, the former pivoted to bracket 39 and the latter linking the former with lever 31. Link 42 is extended to form an operating lever 44 Which extends upwardly into position for convenient manipulation by the operator. In Fig. 6 table 32 is shown in its depressed position with the toggle links unlocked. When levers 44 are rocked to carry

links

42 and 43 past ytheir dead center position (as in Fig. 1 and 4) table 32 is elevated and locked to clamp the glass against the positioning-member 33. The levers 44'are advantageously connected adjacent their upper ends by a conveniently located horizontal operating handle 45.

The glass is located edgewise relative to the -grinding and polishing wheels by a stop, here shown in the form of a xed member 41 extending longitudinally of the edge of the glass (Fig. 6) and supported by posts 48 just beyond the lower edge of table 32. After the edge of the glass sheet has been located by the stop, it is then elevated slightly (to the dotted line position in Fig. 1) by table 32 to clamp it against the member 33 as aforesaid. Stop 41 is suiclently Wide to hold the edge of the glass in predetermined position relative to the grinding wheels While it is being thus clamped.

The glass holding assembly is advantageously vertically movable to clear the stop during grinding and polishing operations and simultaneously to bring the edge of the glass into operative relation to the grinding and polishing wheels. In the lpresent instance, positioning member 33, table 32, and its operating mechanism is carried by a movable base member or sub-table 5|. The latter is advantageously hinged at 52 co-axially with hinge 35 of table 32, to a shaft 53 carried in brackets 55 extending upwardly from the base 55 of the apparatus. Thus after the edge positioning and clamping operations, the entire assembly may be elevated (Fig. 4) by upwardly swinging sub-table 5| about its pivots 52. In such elevated position the portion of the glass to be edged and beveled is located in operative position. The sub-table operating mechanism is here shown in the form of a pair of plungers 6I (one adjacent each end of the sub-table) actuated by levers 62 extending upwardly into position for convenient manipulation by the operator. Levers 62 are pivoted at 63 and carry a transversely extending bar 64 adapted to bear against the ends of plungers 6| to move them for raising the subtable. Plungers 6| in this case move substantially horizontally and their motion is converted into table elevating motion by links 65 extending upwardly at an angle and connected to the under side of sub-table 5I. The sub-table assembly is held in elevated operative position independently of levers 52 (thereby to relieve the operator) by locking mechanism here shown in the form of latches 63 (one of each plunger) which enter appropriately located notches 61 in the plungers to hold them against return movement. Levers 62 are operatively connected adjacent their upper ends by a conveniently located horizontal operating handle 68.

Relative movement between the glass and grinding and polishing wheels may be effected either by moving the base 22 and its assembly of grinding and polishing wheels along the edge of the glass, or, as here shown, by moving the glass along the assembly of grinding and polishing wheels. As here shown, base 56, carrying the sub-table and its associated devices, is in the form of a carriage mounted on wheels 1| and 12 for longitudinal movement on tracks 13 and 14 parallel to the faces of the grinding and polishing Wheels. Wheel 12 and its track 14 are provided with an angular contour, (in this case V-shaped) to prevent movement of the glass laterally relative to the grinding and polishing wheels. Thus, after the glass has been position, clamped and elevated to operative position (Fig. 4) the carriage is moved longitudinally to carry the glass successively across the several grinding and p01- ishing wheels. Such Wheels are advantageously located with their axes in alignment with the cent'erof the beveled surface so' that every portion of the surface receives equal grinding and polishing treatment and' the bevel is ground. flat instead of convex, as is the case: where one portion of` the surface to be beveled receivesv more severe or different grinding treatment than other portions. With the present arrangement, each grinding wheel in effectv performs` two grinding operations: theleading portion of the wheel takes the heavier cut and the trailingl portion, operating underv lighter pressure, takes ar lighter cutandV therefore gives a smoother finish for thenext' wheel, whether itbe grindingl or polishing, resulting in a superior ground and polished surface.

The true balance and lack of vibration of the small diameter diamond wheels makes possible simultaneous grinding by a plurality of wheels (three, in this case) without danger of breaking the glass.

The carriage operating mechanism is here shown in the form of an electric motor 11S' operatingy the cable T8 connected at 'I9- through the front and rear ends of thev carriage, respectively'. At the extreme end of the track the. cable passes over pulley 8I1 and the return iiight under the carriage to the driving. pulleyv 82.

The carriage operating mechanism alsof includes two speed reducers 83 and 84 (to permit return travel of the carriage at a.l faster rate ;1

than its forward operative travel) and a solenoid operated clutch 85` for selectively engaging the driving elements of the respective speed reducers to inaugurate the forward and return travel respectively. Any conventional driving mechanism may be employed; the' details of" the present mechanism are conventional and are not` involved in the present invention.

When the carriage reaches the end of itsI for-'- wardtravel (at which time the glass has been carried completly past all grinding and polishing wheels and the; bevel is. completely ground and polished) a depending stop on the carriage en-V gages` a reversing device, in this case an electric switch 86' which energizes and shifts the clutch mechanism to the faster' return travel driving element to return the carriageto initial position. At such time the same depending stop engages: another switch 81 to shift the clutch to forward drive. During the interval of reversing travel the finished sheet of glass. may be released and re-positioned, or removed (if it be finished) and replaced by the next sheet. This interyal may be increased by stopping the driving motor.

'For the return travel. the beveled edge of" the glass is advantageously moved out of operative alignment with the grinding and polishing wheels so as not to be marred thereby. This is eiected, in this instance. by releasing. latches 6.6 (by withdrawing them from notches 61 in plungers 6I) thereby permitting the sub-table to drop.- of its own weight and lower the glass to initial position (Fig 6) As here shown, latches 66 are pivoted at 88, and theirv opposite ends project downwardly at 89.. A fixed stop 90 is located in the path of portion 89 of the leading latch aty such point as to release the latch just before the carriage starts its return travel. Latch 66 at the rear of the carriage. is simultaneously operated by rod 9| 4(lig. 3) connecting the ends 8.9 of the respective latches. Appropriate. springs 92. bias the latches toward the notches* B1 in their respec tive plungers. Polishing wheels I3 and I4 .which'arev faced with felt, cork or the'4 like, are advantageously intermittently' supplied with polishing compound by an intermittently' actuated applicator 94. v(-lilg. l). Applicator 94. is carriedon ahorizontalf arm 95' mounted for vertical travel on guidingv rods` 96. The applicator is immersed" (in its lower position.) in a reservoir 9.1 containing` a slurry in which the polishing compound is. dispersed. Periodically the applicator'is elevated in contact with the-polishing wheels tol transfer the. polishing compound to the wheels. Thus the polishing wheels are kept sufficiently dry to polishV the glass and not so dry as to overheat and break the glass. The reciprocating movement' of the applicator is effected by any convenient. oscillating mecha nism, that here shown being in the form of a slowly oscillating arm 98 having widelyl forked extremities il!)v engaging the applicator cross head |700, thereby allowing the applicator to rem-ain in its extreme upward and lower position momentarily during the application of compound to the wheels and absorption of further compound in the.H reservoir. Arm 9B is oscillated slowly by operating motor iI'II through speed reducing mechanism H12 which carries a crank. Ill3` operatively connected W-ith the` arm.

Obviously the invention is not. limited to the detailsA of the illustrative apparatus', since; these may be variously modified. Moreoven, ity is not indispensable, that all features of the invention be used conjointly, since various features. may be used to advantage in diierent. combinations and sub-combinations.

Having.v described my invention, I claim;

1. Glassbeveling apparatus comprising comhina-tion a glass. holding` assembly having a glass positioning member adapted to engage the face of the glass to be beveled toA position the glass by reference to the face to be beveled, a plurality of small diameter balance grinding wheels having their flat grinding faces arranged in co-planar relationship and above the surface to be beveled. Wheel: supporting bearings. located above said` surface to. position the axes of saidl wheels substantially in line with the bevel' so that thel wheels contact. with the glass along their respective diameters, the balance of said grindingv wheels reducing. the vibration to the point where a plurality of said wheels may simultaneously grind a bevel on the glass without danger of breakage, means for Inova-bly supporting said assembly to raise and lower the glass into: and out of engagement with said wheels, means for moving said assembly forward to carry the glass across said grinding wheels and to return the assembly to initial position after the grinding operation, an edge locating stop oiset from the edge of the glass when in grinding position locating the edge of the glass in. said assembly when said assembly isflowered out. of operative engagement with said wheels.

2.. Glass beveling' apparatus comprising in combination a glass holding` assembly havingv a glass positioning member adapted to engage the face of the glass to be beveled to position the glass by reference to the face to be beveled, a plurality of small diameter balanced grinding wheelsv having their flat grinding faces arranged in co-planar relationship and above the surface to be beveled, wheel supporting bearings located above said surface. to. position the axes of said wheels substantially in line with the bevel so that the wheels contact with the glass along their respective diameters, the balance oisaid grinding wheels reducing the vibration to the point where a' plurality of said. -wh'eels may simultaneously grind a bevel on the glass without danger of breakage, means for movably supporting said assembly to raise and lower the glass into and out of engagement with said wheels, means for moving said assembly forward to carry the glass across said grinding wheels and to return the assembly to initial position after the grinding operation, an edge locating stop offset from the edge of the glass when in grinding position locating the edge of the glass in said assembly when said assembly is lowered out of operative engagement with said wheels, releasable means for holding said assembly in operative engagement with said wheels, and a stop adapted to engage said releasable means at 'the end of said forward movement to allow the glass to move out of operative engagement with said wheels on said return movement.

3. Glass beveling apparatus comprising in combination a glass holding assembly having a glass positioning member adaptedl to engage the face of the glass to be beveled to position the "glass by reference to the face to be beveled, a plurality of small diameter balanced grinding wheels having their flat grinding -faces arranged in coplanar relationshipand above the surface to be beveled, said wheels not substantially exceeding six inches in diameter and being balanced metal wheels with diamond dust embedded in the grinding faces, the axes of said wheels being substantially in line with the bevel so that thewheels contact window glass along their respective diameters, the balance of said grinding Wheels reducing the vibration to the point where a plurality of said wheels may simultaneously grind a bevel on the glass without danger of breakage, means for. movably supporting said assembly to raise and lower the glass into and out of engagement with said wheels, means for moving said assembly forward to carry the glass across said grinding wheels and to return the assembly to .g

initial position after the grinding operation, an edge locating stop 'offset from the edge of the glassjwhen in grinding position locating the edge of the glass in said assembly when said assembly is lowered out of operative engagement with said wheels.

4. Glass beveling apparatuscomprising in combination a plurality of small diameter grinding Wheels having flat grinding faces located in coplanar relationship, said Wheelsv not substantially exceeding 6". in diameter and' being balanced metal wheels with diamond dust embedded in the grinding faces, the balance of said grinding wheels reducing vibration to the point where a plurality may engage and grind a bevel on the glass without danger of glass breakage, a movable glass holder, a positioning member adapted to engage the face of the glass to be beveled and having a predetermined location relative to the grinding faces of said wheels, bearings above the level of the portion of the glass to be ground and removed from access of abrasive particles thereto `for supporting the grinding faces'of said wheels in grinding relationship to the glass, said bearings being arranged to position the axes of the wheels substantially in line with the bevel so that the wheels contact the glass along a diameter, mean for moving said glass holder to position said glass against said positioning member for the gr-inding operation, and means for relatively moving said glass and wheels to cause said grinding faces to travel over the portion. of the glass to be ground.

5. Glass beveling apparatus comprising in cornpinationa base,l a glass holdingfassembly hinged thereto on a substantially horizontal axis so as to be capable of raising and lowering' movement, a plurality of small diameter balanced grinding wheels having their flat grinding facesA arranged in co-planar relationship and above the portion of the glass to be ground for simultaneously grinding said glass, a glass positioning member included in said assembly for engaging the face of the glass to be beveled to position the same relative vto the grinding faces of said wheels, a glass supporting table in said assembly for supporting a sheet of glass and movable to move the glass into and out of engagement with said positioning member, mechanism for moving said assembly about said axis to carry the glass into operative engagement with said grinding wheels, releasable means for locking said assembly in operative position, means for relatively moving said assembly and grinding wheels to carry the glass across said grinding wheels, and a stop located to engage said releasable means at the end of said relative movement to release said assembly to move downwardly away from grinding position at'the end of the grinding operation.

i 6. Glass beveling apparatus comprising in combination a base, a glass holding assembly hinged thereto for holding and raising and lowering the glass to be beveled, a plurality of small diameter balanced grinding wheels having their nat grinding faces arranged in co-planar relationship and located adjacent the portion of the glass to be ground for simultaneously grinding said glass, a positioning member carried by said assembly for engaging the face of said glass to be beveled to position the same relative to the grinding faces of said Wheels, a glass supporting table included in said assembly for supporting a sheet of glass and movable to move the glass into and out of engagement with said positioning member, mechanism for moving said assembly to carry the glass into operative engagement with said grinding wheels, releasable means for locking said assembly in operative position, means for relatively moving said assembly and grinding wheels to i carry the glass across said grinding wheels, and

a stop adapted to engage said releasable means at vthe end of said relative movement to permit said assembly to move away from grinding position at the end of the grinding operation.

'7. Glass beveling apparatus comprising in combination a plurality of small diameter balanced grinding wheels having their flat grinding faces arranged in co-planar relationship above the surface to be beveled for simultaneously grinding a bevel on a sheet of glass, the balance of said grinding wheels reducing vibration to a point where a plurality of wheels may engage and grind a bevel on the glass withoutv danger of glass breakage, a glass supporting face carrying a glass holding assembly hinged on a substantially horizontal axis to hold the glass and movable to move the glass against said grinding faces and away from said grinding faces after the grinding operation, a positioning member included in said assembly and adapted to engage the surface of the glass to be beveled to position the same relativerto said grinding faces, and a supporting table included in said assembly and hinged co-axially therewith and adapted to move the glass against said positioning member, a stationary edge locating stop separate from said assembly for locating the edge of the glass in saidassembly in a predetermined position relative to the grinding faces ofA said wheels, said stop being offset from the position of the edge of the 9 glass in grinding position, and means for moving said glass holding assembly to shift the glass so as to clear said stop during the grinding operation.

JOHN FENLON DONNELLY.

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

Number Number Name Date Stutz May 17, 1904 Goehring et al. Dec. 27, 1904 Bailey Oct. 26, 1909 Owen Feb. 28, 1928 Jones Dec. 23, 1930 Hitchcock Mar. 24, 1931 Sommer et a1 Mar. 13, 1934 Walker Aug. 8, 1944 Kratky Oct. 15, 1946 FOREIGN PATENTS Country Date Great Britain Jan. 24, 1895