US3574976A

US3574976A - Method for cutting and grinding glass

Info

Publication number: US3574976A
Authority: US
Inventors: Harold A Mcmaster
Original assignee: Permaglass Inc
Current assignee: Permaglass Inc
Priority date: 1968-02-05
Filing date: 1968-02-05
Publication date: 1971-04-13
Anticipated expiration: 1988-04-13
Also published as: DE1905092A1; BE725867A; GB1251364A; US3678628A

Abstract

A method for sizing a sheet of glass wherein the sheet of glass is disposed in a predetermined position on an axis and rotated relative to a cutting means so that the sheet is cut in a predetermined peripheral pattern relative to the axis and wherein the sheet is maintained in the same predetermined position relative to the axis (i.e., the axis passes through the same point in the sheet) while the sheet is again rotated relative to a grinding means so that the periphery of the cut sheet is ground.

Description

United States Patent Inventor Harold A. McMaster Woodville, Ohio Appl. No. 702,978 Filed Feb. 5, 1968 Patented Apr. 13, 1971 Assignee Permaglass, Inc.

Millbury, Ohio METHOD FOR CUTTING AND GRINDING GLASS 20 Claims, 16 Drawing Figs.

US. Cl 51/283, 5 1/324, 83/411 Int. Cl B24b 1/00, B26d 7/06 Field of Search 29/565; 51/281, 5, 283,101, 324; 83/411 References Cited UNITED STATES PATENTS 1,798,512 3/1931 Young 51/5X 2,608,800 9/1952 Ritter 5 1/5 1,906,739 5/1933 Carruthers 51/5 2,579,337 12/1951 Reaser 51/101 2,597,180 5/1952 Reaser 51/101 2,651,889 9/1953 Hannum.. 5 l/l65.40 2,581,759 1/1952 Green 51/101 2,464,293 3/ 1949 Cooke 5 l/165.40

Primary Examiner-Harold D. Whitehead AttorneyBarnard, McGlynn and Reising ABSTRACT: A method for sizing a sheet of glass wherein the sheet of glass is disposed in a predetermined position on an axis and rotated relative to a cutting means so that the sheet is cut in a predetermined peripheral pattern relative to the axis and wherein the sheet is maintained in the same predetermined position relative to the axis (i.e., the axis passes through the same point in the sheet) while the sheet is again rotated relative to a grinding means so that the periphery of the cut sheet is ground.

Patented Aril13, 1971 3,574,97

9 Sheets-Sheet 1 INVENTOR.

AT TOR Patented April 13, 1971 3,574,976

9 Sheets-Sheet 5 |-LsERvo-vALvE HMOTOR I341 61 INVENTOR.

f/aro/a fljficlil asfer m/ ATTOQ/VEKS HSERVO-VALVE HCYLINDER n4 1 Patented April 13, 1971 9 Sheets-Sheet 4 I N V E N TO R Harold A. [Zia/Ziasfer BY A T TORNEV Patented April 13, 1971 3,574,976,

9 Sheets-Sheet 5 INVENTOK Harola A, ZYZc/Fusler AT TOQ/VEY Patented A ril 13, 1971 I 3,574,976

9 Sheets-Sheet 6 INVENTOR.

TOR IVE Y5 Harold fl. 1770271115322 Y Patented April 13, 1971 9 Sheets-Sheet 7 IN VENTOR. Hamid A ZZYCZZZas fer Patented April 13, 1971 3,574,976

9 Sheets-Sheet 8 "mws' IN VENTOR.

I Haro/a fl. [We/7715121 M ATTORNEY Patented April 13, 1971 3,574,976

9 Sheets-Sheet 9 "Q INVENTOR.

Haro/d A. fife/Ziaszer TORNE Y5 METHOD FOR CUTTING AND GRINDING GLASS As is well known in the glass treating art, a sheet of glass after having been cut, frequently has its peripheral edges ground before being used or receiving further treatment, such as annealing or tempering. By utilizing the present state of the art techniques, the peripheral edges of a sheet of glass may be ground to a tolerance of approximately plus or minus 30/ I 000 of an inch. By utilizing the instant invention, this tolerance will be plus or minus lO/lOOO of an inch or less. Additionally, in utilizing the present state of the art techniques for cutting and grinding a sheet of glass, an exorbitant amount of downtime is necessary in converting presently used machines from one peripheral glass pattern to another. By utilizing the instant invention such downtime will be practically insignificant.

Furthermore, a relatively large amount of glass is removed from the periphery of a sheet during the grinding known in the prior art and the instant invention greatly reduces the amount of glass ground away. This in turn increases the rate of production over prior art techniques and increases the life of abrading devices utilized to grind the sheets of glass.

A typical prior art technique for obtaining a ground piece of glass is to cut a flat sheet of raw glass while the sheet of glass is resting on a fiat table, the table usually being covered with a soft material such as felt. A cutting pattern is provided and the cutter follows the cutting pattern to cut the sheet of glass in accordance with the cutting pattern. After the sheet of glass is cut it is moved to a grinding machine so that the peripheral edges may be ground.

Typical of the grinding machines utilized is one wherein a sheet of cut glass is positioned coaxially with a pattern and held in position either by clamping or a vacuum and is thereafter rotated in unison with the pattern. Positioned adjacent the pattern and sheet of glass respectively are a rotating grinding wheel and a cam follower, the wheel and follower being coaxially supported on an arm which is pivotal relative to the support structure. The cam follower engages the rotating pattern to control the position of the grinding wheel.

The object in grinding a sheet of glass is of course to obtain a sheet of glass with a ground periphery which is as close as possible in dimension to the desired configuration. One problem with the prior art systems is to obtain close tolerances. The problem occurs because in cutting a sheet of glass, one cutting pattern is utilized, while in grinding a sheet of glass, another pattern is utilized. It is necessary to overcut the glass to make sure there is sufficient glass about the periphery to be ground away. The setup time for setting up these respective cutting and grinding assemblies is extremely long and it is not uncommon to cut and grind 200 pieces of glass before the ground sheet of glass meets tolerance specifications. The problem is that the sheet of glass, in being moved from the cuttingposition to the grinding machine, is positioned in the grinding machine by abutting its, edges with gauge blocks. The positioning of the sheet of glass in the grinder is, of course, no better than the tolerance in the cutting and the position of the gauge blocks. if the cutting is out of tolerance, the tolerance in the grinding will be unsatisfactory even if the gauge block is precisely in the selected position because the cut edge is placed against a gauge block. Normally, if after the first sheet of glass has been cut and ground, it does not meet tolerance specifications, the gauge blocks on the grinding machine, against which the cut sheet of glass is positioned before grinding, are repositioned. Frequently, the cutting setup or pattern must be altered. As stated above, it is not uncommon to cut and subsequently grind 200 or more sheets of glass before satisfactory positioning of the cutting and grinding assemblies is attained so that the ground sheet of glass meets the tolerance specifications.

Accordingly, it is an object and feature of this invention to provide a method for cutting and grinding a sheet of glass to tolerances heretofore not regularly obtainable.

Another object and feature of this invention is to provide a method and apparatus for cutting and grinding a sheet of glass wherein the downtime for changing from one peripheral pattern to another is greatly reduced whereby a sheet of glass having the desired dimensional tolerances can be produced after cutting and grinding merely two or three sheets of glass.

A further object and feature of this invention is to provide a method wherein a sheet of glass is disposed in a predetermined position relative to a first axis and is cut in a predetermined peripheral pattern relative to the axis with the periphery of the cut sheet of glass thereafter ground while the sheet is maintained in the predetermined position relative to the axis.

Yet another object and feature of the instant invention is to provide a method wherein an uncut sheet of glass is positioned in a predetermined position relative to a first axis at a first station axially along the axis and is rotated while cut to a predetermined pattern and is thereafter moved to a second station axially along said axis while maintained in the predetermined position as a second uncut sheet of glass is placed in the predetermined position at the first station with both sheets being thereafter rotated in unison while the cut sheet is being ground and the uncut sheet is being cut to the desired peripheral pattern.

In correlation with the foregoing object and feature, another object and feature is to also position a pattern on the first axis and control the respective positions of the cutting means and grinding means as a function of the periphery of the pattern as the pattern and both sheets of glass are rotated in unison.

These and other objects and features of this invention may be obtained in an apparatus which includes upper and lower clamping members which are axially aligned on a first axis. The upper clamping member is supported on the lower end of a vertical shaft. A sleeve means is rotatably supported in the apparatus and supports the vertical shaft to allow the vertical shaft to move along the first axis. A pattern means is attached to the lower end of the sleeve means for rotation therewith. There is included an actuation means comprising a cylinder piston operatively connected to the vertical shaft for moving the latter along the first axis. A shuttle block is normally disposed between the upper and lower clamping members so that a first sheet may be clamped between the upper clamping member and the shuttle block while a second sheet is clamped between the lower clamping member and the shuttle block. A conveying means moves the shuttle block into and out of position between the clamping members for moving an uncut sheet of glass into position between the clamping members and to move a ground sheet out of position from between the clamping members. The sheet of glass disposed above the shuttle block is uncut while the sheet of glass below the shuttle block is cut and is to be ground. The upper clamping member has a vacuum associated therewith and the opposite faces of the shuttle block have vacuum means associated therewith. Thus, the upper sheet of glass, after being cut, will be held to the upper clamping member by a vacuum while a ground sheet of glass below the shuttle block will be removed by the shuttle block and thereafter the cut sheet of glass will be moved downwardly and onto the lower clamping member. A carriage means is rectilinearly movable on a pair of bars toward and away from the first axis and an arm means is rotatably supported on the carriage means for rotation about a second axis which is parallel and spaced from the first axis. A rotating grinding wheel, a cutting device, and a following means for following the pattern means are all supported on the arm means. The following means follows the periphery of the pattern means so that the upper sheet of glass is cut with a predetermined peripheral pattern while the lower sheet is ground with the same predetermined peripheral pattern. There are two preferred embodiments of the instant invention. In one embodiment, the following means is a light sensing means for following a pattern defined by a line dividing areas of different light reflectivity to control various servomotors to position the cutting and grinding means. in another embodiment, the following means comprises a plurality of cam rollers which are in rolling engagement with a pattern defined by a cam track with at least one of the rollers being driven to position the cutting and grinding means.

Other objects and attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a preferred embodiment of an apparatus constructed in accordance with the instant invention;

FIG. 2 is a fragmentary cross-sectional view of the upper clamping member and associated components;

FIG. 3 is a fragmentary cross-sectional view of the lower clamping member and associated components;

FIG. 4 is a schematic view of a preferred sensing means for controlling the position of the respective cutting and grinding means;

FIG. 5 is a bottom view looking upwardly to the carriage means;

FIG. 6 is a fragmentary cross-sectional view of the cutting means;

FIG. 7 is an enlarged cross-sectional view taken substantially along line 7-7 of FIG. 9;

FIG. 8 is an enlarged fragmentary cross-sectional view of the carriage means;

FIGS. 9 and 9a provide an enlarged fragmentary view of the shuttle block and the conveyor means associated therewith;

FIG. 10 is a fragmentary cross-sectional view disclosing the shuttle block and the conveyor means associated therewith;

FIG. 11 is an enlarged fragmentary cross-sectional view of the shuttle block;

FIG. 12 is a reduced view taken substantially along line 12-12 ofFlG. II;

FIG. 13 is a view similar to FIG. 9 and showing another preferred embodiment;

FIG. 14 is a fragmentary cross-sectional view taken substantially along line 14-14 of FIG. 13; and

FIG. 15 is a fragmentary cross-sectional view taken substantially along line 15-15 of FIG. 14.

Referring now to the drawings wherein like numerals indicate like or corresponding parts throughout the several views, a preferred embodiment of an apparatus constructed in accordance with the instant invention, which sizes a sheet of material such as glass, is generally shown at in FIG. I. The apparatus 20 includes a support structure 22 for operatively supporting a positioning means generally indicated at 24, the positioning means 24 disposes sheets of glass, such as those indicated at A and B, in predetermined positions relative to a first vertical axis 26. Cutting means and grinding means are collectively generally indicated at 27 and are included for cutting a predetermined peripheral pattern in a sheet A relative to the axis 26 and for grinding the periphery of a cut sheet B while the sheet B is in the predetermined position relative to the axis 26. The cutting means and the grinding means, which are collectively shown at 28, either together or separately comprise a sizing means for sizing a sheet of glass to a predetermined peripheral configuration. There is also disclosed generally at 30 in FIG. I a conveying means for moving sheets of glass into and out of the apparatus 20.

The positioning means 24 includes clamping means comprising the upper and

lower clamping members

32 and 34 for clamping the sheets A and B in a predetermined position on the axis 26. In the embodiments disclosed, the respective sheets A and B are in the predetermined position when the axis 26 extends through a precise point in the respective sheets and is perpendicular thereto. The clamping means also includes the shuttle means comprising the shuttle block 36 which will be explained more fully hereinafter.

As the description proceeds, it will be clear that there is also included control means for effecting relative movement between the sheets A and B and each of the cutting means and the grinding means 28 respectively and for controlling the respective positions of the cutting means and the grinding means relative to the axis 26. This control means, in the first embodiment, in part includes a rotary means comprising a motor 38 (FIG. 3) for rotating the lower clamping member 34 to rotate the sheets A and B about the axis 26. The motor 38 may be either electric or hydraulic and controlled by servovalves. A housing 40 is formed by the support structure 22 and the motor 38 is secured thereto. A gear reduction box 42 is supported within the housing 40 and a shaft 44 extends from the motor 38 and into driving relationship with the gearbox 42. The lower clamping member 34 is rotatably supported in the housing 40 through the bearing 45. The lower clamping member 34 includes an internal gear 46 and a pinion gear 47 is in driving engagement with the internal gear 46. The gear 47 is rotated by the shaft 48 which in turn extends from the gearbox 42. Thus, the rotary means, which comprises the motor 38, is operatively connected to the' lower clamping member 34 for rotating the clamping member 34 about the axis 26. In other words, the lower clamping member 34 forms a rotary table which rotates about the vertical axis 26.

As best illustrated in FIG. 2, the clamping means also includes an actuating means taking the form of the cylinder piston 50 for moving the upper clamping member 32 along the axis 26. More specifically, the upper clamping member 32 is connected to the lower end of a vertical shaft 51. The vertical shaft 51 is coaxial with the axis 26, i.e., the longitudinal axis of the shaft 51 coincides with the axis 26. A sleeve means 52 is rotatably supported in a housing 53 formed by the support structure 22. The housing 53 includes the tubular support 54 in which the sleeve means 52 is rotatably supported through bearings 55. The sleeve means 52 comprises the tubular member 56 and a plate 57. A boot 58 is secured to a housing 59 at its upper end and is in sealing engagement with the plate 57 at its lower end while allowing the plate 57 to rotate relative thereto. The shaft 51 is rotatably supported in the housing 59 through the bearing 60. The shaft 51 is in splined relationship with the sleeve means 52 through the members 61 and the splines 62. Thus, the sleeve means 52 supports the vertical shaft 51 to allow the latter to move along the axis 26. The piston 63 of the actuation means 50 moves the housing 59 vertically along the axis 26; this in turn moves the shaft 51 vertically, thus resulting in vertical movement of the upper clamping member 32. As stated above, the actuation means 50 preferably comprises a cylinder piston actuated hydraulically by hydraulic fluid supplied through the lines 64 and 100. Another boot 65 expands and collapses upon vertical movement of the shaft 51 and protects the shaft 51 from foreign matter.

A pattern means 66 is secured to a plate 67. The plate 67 is attached to the tubular member 56 which forms a part of the sleeve means 52. The pattern means 66 thus rotates with the sleeve means 52 as the sleeve means 52 is rotated by the shaft 51, the shaft in turn being rotated by the upper clamping member 32. The upper clamping member 32 is rotated by the lower clamping member 34 when one or more sheets of glass are clamped therebetween against the shuttle block 36. Thus, the pattern means 66 and the glass sheets A and B are locked together for positive axial and rotational alignment while the cutting and grinding proceed.

As will become more clear hereinafter, the sheets of glass A and B are first respectively positioned between the upper surface of the shuttle block 36 and the upper clamping member 32, and between the lower surface of the shuttle block 36 and the lower clamping member 34. Thereafter the upper clamping member 32 is moved downwardly to clamp the sheets A and B in position. Subsequently, the motor 38 is activated to rotate the lower clamping member 34. As the lower clamping member 34 is rotated, the clamping force prevents relative rotation between the respective sheets of glass A and B, the shuttle means 36, and the upper clamping member 32; thus, all of these components rotate together to rotate the sleeve means 52 and the pattern means 66.

As will become more clear hereinafter, an uncut sheet of glass is moved into position to be clamped between the upper surface of the shuttle block 36 and the upper clamping member 32, i.e., to the position of sheet A. Sheet A is in a predetermined position relative to the axis 26 and is at a first station axially along the axis 26. While the sheet A is at the first station along the axis 26, it is cut to the desired peripheral configuration. Thereafter, the cut sheet is moved axially along the axis 26 to a second station. i.e., the station in which the sheet B is positioned. As the sheet thusly moves, it is maintained in its predetermined position relative to the axis 26. In other words, during this operation the sheet does not move laterally or tilt or rotate relative to the axis 26; it only moves axially along the axis 26. A vacuum means is utilized to move a sheet of glass through such a sequence. Before describing this vacuum means, however, it is necessary to describe the shuttle block-36 and its associated conveying means.

The shuttle block 36, as alluded to above, is normally disposed between the upper and

lower clamping members

32 and 34 so that a first sheet of glass A may be clamped between the upper clamping member 32 and the shuttle block 36, and a second sheet of glass 13 may be clamped between the lower clamping member 34 and the shuttle block 36. The conveying means 30 moves the shuttle block 36 into and out of position between the clamping

members

32 and 34 and in so doing. an uncut sheet of glass is moved into position for clamping between the upper clamping member 32 and the shuttle block 36 while at the same time a ground sheet of glass is removed from the lower clamping member 34 to make room for the next cut sheet. More specifically, and as best illustrated in FIGS. 9, 9a and 10, the conveying means 30 includes a housing 70 and a flexible support means comprising a pair of support shafts 71 extending from opposite sides of the housing 70. As illustrated in FIGS. 7 and 10, the outward end 72 of each shaft 71 is connected to a carrier 73. Each carrier 73 is L-shaped in configuration. There is also included a pair of spaced endless loop V-belts 74. Each carrier 73 has a groove 75 which is supported on one of the belts so that upon movement of the belts 74, the shuttle block 36 moves into and out of position between the clamping

members

32 and 34. Each V-belt 74 extends about a pair of

pulleys

76 and 77. The pulleys 77 are driven by a shaft 78. The shaft 78 is rotated in alternate or opposite directions by a gear 79 which is in turn rotated by an appropriate means such as a rack oscillated back and forth by a hydraulic cylinder. The position of each pulley 76 may be adjusted to provide the desired tension on the belts. More specifically, each pulley 76 is supported by a stud 80 which extends through and is adjustably relative to a bracket 81. A plurality of rollers 82 are supported by the members 83 and support the bottom reach of the belts 74. The members 83 are secured to the longitudinally extending support braces 84 by the bolts 85. There is also included a guide pulley 86 associated with each belt 74.

The axis of the shuttle block 36 need not be precisely or accurately aligned with the axis 26 of the clamping

members

32 and 34 since the shuttle block 36 is flexibly supported. The shuttle block 36 is flexibly supported because of the flexibility of the shafts 71, allowing the carriers 73 to slip on the belts 74, and allowing the belts to slide on the backup rollers 82. The support of the shuttle block 36 is deliberately flexible so that the axis of the rotating upper and lower material engaging surfaces need not be precisely or accurately aligned with the axis 26 of the clamping

members

32 and 34 while clamped therebetween. This prevents the possibility of misalignment between the clamping

members

32 and 34.

Returning to the shuttle block 36 and more specifically to FIGS. 11 and 12, the shuttle block 36 is rotatably supported in the housing 70 through the bearing 87. The lower face of the shuttle block 36 has grooves 88 therein. The grooves 88 communicate with an annular recess 89 by way of the passages 90. The annular recess 89 communicates with a passage 91 in one of the shafts 71. In a like manner, the upper surface of the shuttle block 36 has grooves 83 therein which communicate with the annular recess 89 by way of the passages 90', and the annular recess 89 communicates with the passage 91' in the other shaft 71. An appropriate source of vacuum is in communication with the

passages

91 and 91 respectively as, for example, a flexible hose being attached to each of the respective shafts 71. The seals 92 prevent air from moving into the

respective passages

91 and 91 The conveying means 30 also includes a suction plate 93 which may be moved vertically by a cylinder piston 94. There is also included a roller conveyor generally indicated at 95.

Now to explain the operation of the apparatus as thus far described. A sheet of uncut raw glass is moved by the roller conveyor 95 to the right as viewed in FIG. 10 to a position beneath the suction plate 93. The cylinder piston 94 is actuated so that the suction plate moves downwardly to contact and lift a sheet of glass by vacuum vertically upward to the position illustrated in FIG. 10. The gear 79is then rotated in the proper direction to move the belts 74. This in turn moves the shuttle block 36 to a position beneath the sheet of glass held by the suction plate 93 through a vacuum; this position of the shuttle block is shown in phantom in FIG. 9a. The suction plate 93 is then moved downwardly and the vacuum removed therefrom while at the same time a vacuum is applied to passage 91 so that a vacuum is applied to the grooves or passages 88' in the top of the shuttle block 36 to hold the sheet of glass thereto. The gear 79 is then rotated in the opposite direction to move the shuttle block 36 to the left as viewed in FIG. 9a to the position between the clamping

members

32 and 34 as shown in full lines in FIG. 9. When the shuttle block 36 reaches the position between the clamping

members

32 and 34, the clamping member 32 is moved vertically downwardly to clamp the uncut sheet of glass between the top of the shuttle block 36 and the upper clamping member 32; that is, the sheet of glass A as represented in FIG. 1. As will be more fully described hereinafter, the sheet of glass A is then cut to the desired peripheral configuration. After the sheet of glass A has been cut to the desired peripheral configuration, a vacuum is applied to the grooves 96 in the upper clamping member 32. This vacuum is applied through the passage 97 in the shaft 51. The passage 97 communicates with a stationary chamber box 98 which is rotatable relative to shaft 51 and communicates with the vacuum line through the opening 99. Thus, when the sheet A has been cut to the proper configuration, the vacuum is applied to the upper clamping member 32 while the vacuum is no longer applied to the upper surface of the shuttle block 36. The upper clamping member 32 is then moved slightly upward and the shuttle block 36 is moved to the position illustrated in phantom in FIG. 9a to receive a new uncut sheet of glass on the upper surface thereof. In the meantime, the upper clamping member 32 is moved vertically downward to move the cut sheet of glass A to the position where it rests upon the lower clamping member 34, i.e., to the position of sheet B as illustrated in FIG. 1. Since a vacuum is applied to the sheet by the upper clamping member 32 as the sheet is moved axially downward along the axis 26 from a first station to a second station, the sheet is maintained in a constant predetermined position or relationship with respect to the axis 26 as it is moved from the upper station downward to the lower station where it rests upon the lower clamping member 34. The vacuum applied to upper clamping member 32 is thereafter released to allow the sheet to rest upon the lower clamping member 34.

It is also very important that, in addition to maintaining axial alignment during the transfer, rotational alignment must also be maintainedsln other words, it is important to prevent rotation of the clamping

members

32 and 34, which necessarily includes the pattern means 66, and the shuttle block 36 during the transfer. The shuttle block 36 is prevented from rotating by a detent means 101 as shown in FIG. 12. The roller of the detent means 101 coacts with a groove or recess in the shuttle block 36 to prevent the shuttle block 36 from rotating unless a rotational force is applied thereto from the motor 38 through the clamping member 34 and a sheet of glass. A similar detent means is generally shown at 102 in FIG. 2 for preventing rotation of the clamping member 32 and pattern means 66 during the transfer of sheets of glass. The detent means 102 includes a roller movably supported by the housing 53 and biased into engagement with the plate 57. The plate 57 has a groove or recess in its periphery and the roller engages the groove or recess (as shown in FIG. 2) to prevent rotation of clamping member 32. The clamping member 34 is prevented from rotating during the transfer by the motor 38. Hence, means is provided to prevent rotation of the clamping

members

32 and 34, the pattern means 66, and shuttle block 36 during the transfer.

The glass which is cut from the uncut sheet frequently does not fall from the sheet. Therefore, the upper clamping member may move the cut sheet downwardly against the lower clamping member 34 so that the sheet comes to an abrupt stop causing the cut glass to break and fall away from the sheet. The upper surface of clamping member 34 may be shaped similar to but slightly smaller than the glass to keep the useful part of the glass from breaking as a result of the abrupt stop while allowing the trim to fall away. In some embodiments it is desirous to apply a vacuum to the lower clamping member 34 to make sure the sheet does not move laterally or transversely relative to the axis 26. After the clamping member 32 has moved upwardly, the shuttle block 36 is again moved into position between the clamping members while supporting a new sheet of uncut glass. The upper clamping member 32 then moves downwardly so that the uncut sheet of glass A is clamped between the shuttle block 36 and the upper clamping member 32, and the cut sheet of glass B is clamped between the shuttle block 36 and the lower clamping member 34. The motor 38 is then activated to rotate the lower clamping member 34 whereby the sheets of glass A and B and the pattern means 66 rotate together in unison about the axis 26. As will become more clear hereinafter, during this rotation the upper sheet A is being cut while the lower sheet B is simultaneously being ground. Once this is accomplished by one complete revolution of the sheets, the upper cut sheet A is again moved upwardly by a vacuum applied thereto from the upper clamping member 32 and at the same time a vacuum is applied through the passage 91 to the lower surface of the shuttle block 36 (which may spring slightly upward) to lift the ground sheet of glass B from the lower clamping member 34. Thereafter, the shuttle means 36 moves to the position illustrated in phantom in FIG. 9a, and moves the ground sheet of glass B therewith. Once the block 36 is in position illustrated in phantom in FIG. 9a, the vacuum applied to the bottom surface is released so that the sheet of glass falls upon the rollers of the conveyor 95 and is moved thereby to the right as viewed in FIG. 10. As explained above, thereafter a vacuum is applied to the top of the shuttle block 36 for receiving a new sheet of uncut glass thereon. This new uncut sheet of glass will then be moved into position between the clamping members. In this manner, a series of sheets of glass are sequentially moved through the apparatus for being cut and then ground.

To summarize, the shuttle block 36 includes a first vacuum means for moving an uncut sheet into the first station, as illustrated by the sheet A in FIG. 1, for being clamped in a predetermined position between the shuttle block 36 and the upper clamping member 32. The shuttle block 36 also includes a second vacuum means for moving a ground sheet, as illustrated by the sheet B in FIG. 1, out of the second station, the second station being axially spaced along the axis 26 from the first station. In addition, the upper clamping member 32 includes a third vacuum means for holding a cut sheet thereto when at the first station and for moving the cut sheet to the second station along the axis 26 while maintaining the sheet in the predetermined position, i.e., without the sheet rotating or moving laterally whereby the sheet only moves axially from one station to another along the axis 26 and maintains its position relative to the axis 26.

The description now turns to the cutting means and grinding means which are collectively generally indicated at 28. There is included a carriage means which is rectilinearly movable toward and away from the axis 26. More specifically, the support structure 22 supports a pair of parallel spaced guide bars 111, as best illustrated in FIG. 5. The carriage means includes the saddle portions 112 surrounding the bars 111 for slidable movement therealong. The boots 113 expand and collapse to protect the surface of the slide bars 111 from foreign matter. A hydraulic cylinder 114 and piston 115 operatively interconnect the support structure 22 and the carriage means 110 for moving the carriage means 110 along the guide bars 111 to move the carriage means 110 toward and away from the axis 26. Another boot 116 surrounds the piston 114. As noted above, FIG. 5 is a bottom view of the carriage means 110. Instead of the cylinder 114 and piston 115 a screw and nut assembly may be utilized with either the screw or nut being rotated.

As best illustrated in FIG. 8, the grinding means comprises a grinding wheel 117 operatively supported on the carriage means 110. More specifically, a motor 118 is supported on the carriage means 110 and rotates the grinding wheel 117 about a second axis 119, the axis 119 being the axis of rotation of the motor 118 and grinding wheel 117. A splash cover 120 surrounds the grinding wheel 117 and is rotatably supported on the carriage means 110 through the bearing 121. The splash housing 120 has a slot 122 therein through which a sheet of glass B projects for having its periphery ground by the grinding wheel 117. These is also included a U-shaped member 123 having an upper leg 124 and a lower leg 125. The lower leg 125 is adjustably supported in the cradle 126 on the splash shield 120. The position of the U-shaped member 123 may be adjusted by the bolt 127 illustrated in FIG. 8. The U- shaped member 123 defines an arm means supported on the carriage means 110 for rotation about the second axis 119. The second axis 119 is parallel to the axis 26 and is spaced therefrom. The cutting means, which comprises a glass cutter wheel 128, is operatively supported on the arm means (the upper leg 124) in spaced relationshipto the second axis 119. The axis of cutting tool 128 is in fact disposed on a line which extends radially from the second axis 119.

The glass cutter wheel 128 is rotatably supported on a plunger 130 which includes a piston 132. The piston 132 is moved up and down by fluid pressure such as hydraulic fluid. Such fluid is supplied and returned through the passages 133. In most embodiments it is desirable to utilize a backup such as a roller 129 to engage the opposite face of the sheet of glass for the plunger 130 to act against.

A second motor 134 is supported on the carriage means 110 and drives a pinion 135 which engages the gear 136. Thus, upon rotation of the pinion 135, the splash shield 120 and the arm means, comprising the

legs

124 and 125, rotate about the axis 119. The control means also includes means to control the rotation of the arm means about the axis 119 and the movement of the carriage means 110 along the guide bars 111 for maintaining the line, which extends radially from the axis 119 and passes to the cutting tool 128, substantially perpendicular to the cut periphery of the sheet A and the periphery of sheet B. v

A sensing means is disposed on the leg 124 of the arm means to read the pattern means 66 for controlling the respective movements of the carriage means 110 and the arm means. It will be noted that the sensing means 140, the cutting means, and the grinding means are generally aligned in a direction parallel to the axis 26, i.e., are aligned along a vertical axis. That is, the cutting tool 128, the point of grinding on the grinding wheel 117, and the sensing means 140 are all vertically aligned. Therefore, the cutting means is operatively supported on the arm means along a line which extends radially from the axis 119 and is spaced from the grinding means in a direction generally parallel to the first axis 26; thus, the cutting means cuts a first sheet A at the first station as the grinding means simultaneously grinds a second sheet B at a second station, which is spaced axially along the axis 26 from the first station, while both sheets A and B are in the same predetermined position relative to the axis 26. Hence, the sheets may be sequenced through the apparatus by being moved into the predetermined position relative to the axis 26 at the first station and thereafter moved axially along the axis 26 to the second station while maintained in the predetermined position for being ground at the second station.

Although variousdevices may be utilized as the sensing means 140, in the first preferred embodiment, a pair of photocells or light sensing means 141 and 142 are utilized. As illustrated schematically in FIG. 4, the pattern means 66 is made of aluminum, paper, or the like, and has a periphery defined by a line 143 dividing areas of different light reflectivity. 1n other words, white paper may be disposed on one side of line 143 of the pattern means 66 whereas black paper may be disposed on the other side. The dividing line 143 between the two color areas defines the peripheral pattern which will be followed by the sensing means 140 to cut and grind sheets of glass to conform to the same peripheral pattern. The light cell means 141 and 142 measure the differences in light reflected by the different areas on opposite sides of the line 143 for positioning the cutting means and the grinding means in correlation with the position of the line 143. More specifically, the light cells 141 and 142 are connected through a differential amplifier to a servovalve which in turn controls the motor 134 heretofore described. The other light cell 142 is connected though an amplifier to a servovalve which in turn supplies fluid to cylinder 114 to control movement of the piston 115. The hydraulic motor 134 rotates the arm means about the axis 119, and the flow of hydraulic fluid to and from the cylinder 114 controls the position of the carriage 110. It will be understood, of course, that various peripheral configurations in sheets of glass will be cut and ground with the machine. All that is needed to process different peripheral configurations is to change the pattern means 66.

The longitudinal axis of the

legs

124 and 125 or the arm means, i.e., the radial line extending from the axis 119 upon which the cutter is disposed, is maintained substantially perpendicular to the cut periphery of the sheet of glass A and to the periphery of the sheet B being ground. This is accomplished by appropriate control of the hydraulic motor 134 and the movement of the piston 115. If the pattern line 143 falls equally on the light cells 141 and 142 as illustrated, the arm is perpendicular to the periphery of the sheets of glass. That is, the line 143 should divide both light cells in the same manner. However, should the arm become nonperpendicular, the line defining the periphery of the pattern means will assume a position such as that illustrated at 143 in FIG. 4, ie, a position where both light cells are not divided in the same manner. The light cell 141 is set to balance its output with cell 142 when both cells are equally illuminated. Therefore, when the pattern line moves to the position illustrated at 143, a signal will be sent through the differential amplifier to the servovalves. The servovalves will supply the appropriate hydraulic fluid pressure to the motor 134 to rotate the pinion 135, which in turn rotates the arm means about the axis 119 so that the arm will return to its position perpendicular to the periphery of the pattern and the glass. The other light cell 142 minimizes the cutter and grinder on the proper path and prevents their movement any substantial distance transversely to the desired periphery. In other words, the light cell 142 is calibrated so that no signal will be sent when the pattern line 143 is positioned to be illuminated to a predetermined degree such as illustrated in FIG. 4; however, should the light cell 142 move so that the line 143 is displaced to one side or the other of its predetermined position relative to the light cell 142, such as to the position illustrated at 143", a signal will be sent through the amplifier to the servovalves. The servovalves will then send the appropriate hydraulic signal to the cylinder 114 to move the carriage means 110 an appropriate distance toward or away from the axis 26.

The control means includes one other important means as a part of this apparatus; to wit, the measuring wheel 144 which is supported on the upper leg 124 of the arm means and rolls along the periphery of the pattern means 66. This wheel 144 is attached through a tachometer and electrical circuitry to the motor 38 to comprise a means to control the motor 38 for maintaining substantially constant the tangential velocity between the periphery of the sheet and the grinding wheel 117, More specifically, the wheel 144 is a measuring means coacting with the periphery of the pattern means 66 to measure the deviation from a predetermined value of the linear velocity of the periphery of the pattern means 66 for correcting the speed of rotation of the sheets A and B in correlation therewith. ln other words, an electrical circuit is preset to receive a predetermined voltage from the wheel 144 and the wheel 144 produces this voltage upon rotating at a certain r.p.m. 1f the motor 38 is rotating too fast, the wheel 44 will supply a voltage above the norm or predetermined voltage because the periphery of the pattern means 66 is moving too fast. In such a situation, a signal will be sent to the motor 38 to decrease its r.p.m. so that the linear velocity of the periphery of the pattern means 66 is at the preselected norm which is a predetermined constant value. Of course, it will be understood that other devices may be utilized to control the speed of rotation of the sheets relative to a sizing means, whether it be a grinder or cutter, to maintain substantially constant the tangential velocity between the sizing means and the periphery formed thereby.

Another embodiment of the instant invention is illustrated in FIGS. 13 through 15. Like numerals are utilized in FIGS. 13 through 15 to indicate components and elements which are identical to those utilized in the first embodiment described hereinabove. Furthermore, the same terminology utilized above is to be applied to the embodiment of FIGS. 13 through 15. Therefore, only the differences in the embodiment of FIGS. 13 through 15 will be described here.

The pattern means in this embodiment comprises a cam track 202 connected to the clamping means 32 by a plate 67' which is in turn removably secured to the bottom end of the sleeve means 52. The cam track 202 is an endless loop larger by the radius of the roller 206 than in the shape of the final periphery desired in the sheet of glass. Since the cam track 202 is secured to the sleeve means 52, it rotates in unison with the clamping

members

32 and 34.

The means to control the rotation of the arm means and the movement of the carriage means includes cam follower means for engaging the cam track 202. The cam follower means includes a first roller 206 and second and third rollers 208. The first roller 206 is rotatably supported by shaft 210. The shaft 210 is supported on a block 212 which is rigidly attached to the leg 124 of the arm means. The first roller 206 is in rolling engaging with the endless loop cam track 202. The second and third rollers 208 are also in rolling engagement with the cam track 202 and coact with the first roller 206 for maintaining the line extending from the second axis, on which the cutting wheel 128 is disposed, substantially perpendicular to the periphery of the sheet being rotated therepast. More specifically, the rollers 208 are supported on shafts 214 which are in turn rotatably supported in the member 216. The member 216 is slidably connected to the leg 124 of the arm means by a bracket 218. The member 216 has a slot 217 in the bottom thereof and a key 219 extends upwardly from the arm 124 to maintain the member 216 perpendicular to the arm 124 while allowing the member 216 to move along the arm 124. The rotary means comprises a motor and means to control the motor, both of which are collectively shown at 220 and are supported on the member 216 by the upright members 222. The motor drives the shafts 214 through an appropriate gearbox to rotate the rollers 208. The rollers 208 are in driving engagement with the cam track 202. Thus, the rollers 208 rotate the cam track 202 and the clamping

members

32 and 34 about the axis 26. In other words, the cam track 202 moves through the

rollers

206 and 208 as illustrated in FIG. 14. The

second and third rollers 208 are on the opposite side of the cam track 202 from the first roller 206. In addition, the second and third rollers 208 are normally disposed at the respective apexes at the ends of equal legs of an isosceles triangle and the first roller 206 is at the apex of the two equal legs. In other words, the distances from the shaft 210 to the respective shafts 214 are normally equal. A biasing means comprising the springs 224 urges the first roller 206 toward the second and third rollers 208. Because of the isosceles triangle relationship and the springs 224, a line perpendicular to the member 216 and midway between the shafts 214 will remain perpendicular to the track 202, thus, maintaining the arm means perpendicular to the cut periphery of the sheet A and perpendicular to the periphery of the sheet B. That is to say, as the member 216 pivots about a vertical axis it coacts with the bracket 218 to rotate the arm means so as to maintain the line on which the cutter is disposed perpendicular to the periphery of the sheet of glass being cut. The axis of the first roller 206 or shaft 210, the cutting tool 128, and the grinding position on the periphery of the grinding wheel 117 are all generally aligned in a direction parallel to the axis 26. Thus, it is in the inside face of the cam track 202 which defines the periphery of the sheet being cut and of the sheet being ground. The rotary means 220 also includes a means to control the speed of rotation of the motor to maintain the speed of rotation of the driving wheels 208 substantially constant for maintaining substantially constant the tangential velocity between the periphery of the sheet B and the grinding wheel 117. In other words, by maintaining the speed of rotation of the rollers 208 substantially constant, the periphery of the cam track 202 moves at a constant linear velocity so that the periphery of the sheet B moves past the grinding wheel 117 at a constant linear velocity and the cut periphery of sheet A moves by the cutting tool 128 at a constant linear velocity.

It will be noted that in the embodiment illustrated in FIGS. 13 through 15, there is no need for a motor such as that shown at 38 in the first embodiment for rotating the lower clamping member 34. The lower clamping member 34 in the second embodiment is rotated in unison with the upper clamping member 32 by way of the sleeve means 52, to which the plate 67 is attached, as the cam track 202 moves through the

rollers

206 and 208. Furthermore, there is no need for a cylinder piston such as that shown at 114 in FIG. 1 to reciprocate the carriage means 110 since the carriage means will be reciprocated relative to the axis 26 by coaction between the

rollers

206, 208 and the cam track 202. Furthermore, there will be no need for a motor such as that illustrated at 134 in the first embodiment to rotate the arm means about the second axis since the rotation of the arm means about the second axis in the embodiment of FIG. 13 is controlled by the coaction of the

rollers

206 and 208 with the cam track 202.

The foregoing description therefore makes it amply clear that the instant invention provides a novel method and apparatus wherein a sheet of glass is disposed in a predetermined position relative to an axis and the sheet is cut with a predetermined peripheral pattern relative to the axis and thereafter the periphery of the cut sheet is ground while the sheet is maintained in the same predetermined position relative to the axis. In this manner, the ground periphery of the sheet is maintained within a very close tolerance since the sheet is always in the same position relative to the axis 26 and the position of the cutting means and grinding means are controlled relative to the axis 26.

Each sheet of glass is therefore moved into position between the clamping members and clamped so that the axis 26 is generally perpendicular to the sheet while the sheet is in a predetermined position relative to the axis at a first vertical station on the axis 26. A cutting means is disposed in axially spaced relationship relative to a grinding means and the sheet, after being cut, is moved axially along the axis to a second station in axial alignment with the cutting means while it is maintained in the same predetermined position relative to the axis 26. It will therefore be understood that the only variance in tolerance between the cutting and the grinding will be because of the differences in the respective positions between the cutting means and the grinding means relative to the axis 26. However, it is to be understood that both of the cutting means and the grinding means will have adjustments so that they may be adjusted to the exact desired position relative to one another and relative to the axis 26.

Although the pattern means in both embodiments or modifications illustrated are substantially the same size as the cut and ground sheets, it will be understood that the pattern means may be a completely different size so long as its periphery is proportional to the desired but and ground sheets, i.e., the pattern means may be a different size but it will have the desired shape or peripheral configuration.

The invention has been described in an illustrative manner and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

lclaim:

1. A method of sizing a sheet of material comprising the steps of: disposing a sheet in a predetermined position relative to an axis, cutting the sheet by engaging at least one surface thereof in spaced relation to the original periphery thereof to cut an edge in a predetermined peripheral pattern relative to said axis and removing the cutaway trim portion of the sheet between the original periphery and the edge to expose the edge, and grinding the edge of the cut sheet while maintaining the sheet in said predetermined position relative to said axis.

2. A method as set forth in claim 1 including utilizing cutting means and grinding means for sizing by respectively cutting and grinding the sheet, effecting relative movement between the sheet and the respective cutting and grinding means, controlling the position of said cutting means relative to said axis during said relative movement to cut said predetermined pattern in said sheet.

3. A method as set forth in claim 2 including controlling the position of said grinding means relative to said axis during said relative movement to grind the edge of a cut sheet.

4. A method as set forth in claim 3 including moving a pattern means in unison with the sheet and simultaneously controlling the respective positions of the cutting means and grinding means with said pattern means so that both the cut sheet and the ground sheet have identical peripheral patterns as the pattern means.

5. A method as set forth in claim 2 including disposing the sheet on said axis so that said axis passes therethrough in said predetermined position, and effecting rotation of the sheet about said axis to provide said relative movement of the sheet relative to said cutting means and said grinding means.

6. A method as set forth in claim 5 including disposing the sheet on said axis so that said axis is generally perpendicular to the sheet in said predetermined position, disposing said cutting means in axially spaced relationship relative to said grinding means, and moving the sheet axially along said axis after cutting thereof for axial alignment with said grinding means while maintaining said predetermined position.

7. A method as set forth in claim 6 including the steps of positioning a first sheet in said predetermined position relative to said axis for cutting thereof and moving said first sheet axially along said axis while maintaining said predetermined position for grinding thereof and disposing a second sheet in said predetermined position on said axis and axially spaced from said first sheet for cutting thereof while said first sheet is being ground.

8. A method as set forth in claim 7 including moving a pattern means in unison with the sheet and simultaneously controlling the respective positions of the cutting means and grinding means with said pattern means so that both the cut sheet and the ground sheet have identical peripheral patterns as the pattern means.

9. A method as set forth in claim controlling the speed of rotation of the sheet about said axis to maintain substantially constant the tangential velocity between'the periphery of the sheet and the grinding means.

10. A method as set forth in claim 1 disposing the cutting means at a fixed distance along a line extending from a second axis which is parallel to said first mentioned axis, moving said second axis toward and away from said first mentioned axis to move the cutting means and the grinding means relative to said first mentioned axis.

11. A method as set forth in claim including rotating the cutting means about said second axis while maintaining said line substantially perpendicular to the edge of the sheet being rotated therepast.

12. A method of sizing a sheet of glass comprising the steps of: positioning a sheet in a predetermined position relative to a first axis and at a first station along said axis and in parallel spaced relationship to pattern means, rotating the sheet and the pattern means in unison about said axis, positioning a cutting means in contact with the sheet at a position in correlation with the periphery of the pattern means as the sheet and pattern means rotate to size the sheet in conformance to the periphery of the pattern means, and moving the cut sheet axially along said axis to a second station while maintaining the sheet in said predetermined position, rotating the cut sheet and utilizing a grinding means to grind the periphery of the cut sheet as it is rotated.

13. A method as set forth in claim 12 including positioning the grinding means in contact with the cut sheet at a position in correlation with the periphery of the pattern means as the sheet and pattern means rotate to grind the cut sheet in conformance to the periphery of the pattern means.

14. A method as set forth in claim 12 including clamping a second uncut sheet in said predetermined position at said first station as the cut sheet is clamped coaxially therewith at said second station, and cutting the sheet at the first station while simultaneously grinding the sheet at the second station as both sheets are rotated in unison about said axis.

15. A method as set forth in claim 14 including sequentially clamping a series of sheets at each of said stations for continually producing ground sheets.

16. A method of sizing a sheet of glass comprising the steps of: positioning a sheet in a predetermined position relative to a first axis and in parallel spaced relationship to pattern means, rotating the sheet and the pattern means in unison about said axis, positioning a cutting means in contact with the sheet at a position in correlation with the periphery of the pattern means as the sheet and pattern means rotate to size the sheet in conformance to the periphery of the pattern means, providing pattern means having a periphery defined by a line dividing areas of different light reflectivity, and measuring the differences in the light reflected to position the cutting means in correlation with the position of said line as the pattern means and sheet rotate.

17. A method as set forth in claim 12 including controlling the speed of rotation of the sheet about said axis to maintain substantially constant the tangential velocity between the edge of the sheet and the grinding means.

18. In a method of sizing a sheet of glass by utilizing a pattern means having a periphery and sizing means to define a periphery in the sheet, the improvement comprising: rotating the sheet relative to the sizing means, rotating the pattern means in unison with the sheet, controlling the speed of rotation of the sheet to maintain substantially constant the tangential velocity between the sizing means and the periphery defined thereby including measuring the deviation from a predetermined value of the linear velocity of the periphery of the pattern means and correcting the speed of rotation of the sheet in correlation therewith.

19. A method of sizing a sheet of material comprising the steps of: disposing a sheet in a predetermined position relative to an axis passing transversely therethrough; cutting the sheet in a predetermined peripheral pattern relative to said axis; moving the cut sheet axially along said axis while maintaining its predetermined position relative to said axis after the cutting thereof for axial alignment with a grinding means; and grinding the periphery of the cut sheet while maintaining the sheet in said predetermined position.

20. A method as set forth in claim 19 including moving a pattern means in unison with the sheet and simultaneously controlling the respective positions of the cutting means and grinding means with said pattern means so that both the cut sheet and the ground sheet have peripheral patterns the same as the pattern means.

Claims

9. A method as set forth in claim 5 controlling the speed of rotation of the sheet about said axis to maintain substantially constant the tangential velocity between the periphery of the sheet and the grinding means.

11. A method as set forth in claim 10 including rotating the cutting means about said second axis while maintaining said line substantially perpendicular to the edge of the sheet being rotated therepast.