US3525181A

US3525181A - Edge grinding apparatus

Info

Publication number: US3525181A
Application number: US734076A
Authority: US
Inventors: Frank J Carson
Original assignee: Libbey Owens Ford Co
Current assignee: Pilkington North America Inc
Priority date: 1968-06-03
Filing date: 1968-06-03
Publication date: 1970-08-25
Anticipated expiration: 1987-08-25
Also published as: GB1265028A; ES367963A1; DE1928162A1; LU58771A1; IE33122L; NL6908425A; IE33122B1; FR2010048A1; BE733951A

Description

F. J. CARSON EDGE GRINDING APPARATUS Aug. 25, 1970 Filed June 5, 1968 5 Sheets-Sheet l T.; W l l l i VLM. f--r TJ O5 a?, /245 Co V 1 62. (j ,f O HO A 30 /Q kd] M@ 10o 5U] 18 A l\ y 29 15 ZJ v f'i/ A5 66 f 2l A mi zzzz 56 7 A1 54 55 5 AA A9 .7% y Q INVENTOR.

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@@fv/Lnm ATTORNEYS Aug. 25, 1970 F. J. CARSON EDGE GRINDING APPARATUS 3 Sheets-Sheet :3

Filed June 5, 1968 q l N VEN TORA @@eeaq/mm' ATTORNEYS ug. 25, 1970 F. J. CARSON 3,52581 u EDGE GRINDING APPARATUS Filed June s, 196e s sheets-sheet 5 BY v @mwm

ATTORNEYS` United States Patent O 3,525,181 EDGE GRINDING APPARATUS Frank J. Carson, Toledo, Ohio, assignor to Libbey-Owens- Ford Company, Toledo, Ohio, a corporation of Ohio Filed June 3, 1968, Ser. No. 734,076 Int. Cl. B24b 9/10 U.S. Cl. 51-101 4 Claims ABSTRACT OF THE DISCLOSURE Edge grinding apparatus comprising a rotatable worksupport table and a main template having a patterncontoured edge to which the exposed edge of a workpiece is to be ground. A main grinding unit includes a main grinding wheel and a template follower roll adapted to traverse the main template. The main grinding unit is yieldingly urged toward the worktable to maintain the follower roll against the main template and the main grinding wheel in engagement with the edge of the workpiece. An auxiliary grinding unit is mounted adjacent the worktable and includes a grinding wheel of relatively small diameter and template follower roll which engages an auxiliary template carried by the main template. Control means are actuated during rotation of the worktable to bring the auxiliary template follower roll into engagement with an out-of-engagement with the auxiliary template whereby to effect grinding action by the wheel of the auxiliary grinding unit along a selected area of the workpiece.

The present invention relates to improvements in edge grinding machines and more particularly to machines for grinding the edges of pattern-cut sheets of glass or other materials and to an auxiliary grinding unit adapted to iinish the edge portion of a selected area of the sheets.

This invention contemplates the use of an auxiliary grinding unit in combination with an edge grinding machine embodying two main grinding units mounted in side-by-side parallel relation on a vertical support member; each unit having a grinding wheel of relatively larger diameter than the grinding wheel of the auxiliary grinding unit. The edging machine also includes a rotary worktable for supporting a workpiece or workpieces to be ground and a main template, carried by the worktable, having a contour conforming substantially to the desired curved contour to which the exposed edges of the workpieces are to be ground. Template follower rollers are carried by the support member to engage the main template and gage the grinding action of the respective main grinding wheels as they traverse the contoured edges of the glass sheets.

These main grinding wheels however are not of a diameter and are not carried in a manner to achieve similar grinding of selected areas that include curved edge portions of a relatively smaller radius than the curvature of the major length of the edge. This situation would arise in the finishing of substantially triangular sheets of glass, or other material, such as are employed to enclose the ventilator opening in the side door of an automobile. These sheets possess two adjoining sides that are disposed in converging relation to one another and the apex area there-between is formed by a curved end edge portion of relatively small radius. To conform to certain requirements of use of the workpiece, complete grinding of such a selected area of the edge of a workpiece could therefore include a portion of the exposed edge, the curved end edge portion and even a portion of the edge continuing into the unexposed side of the workpiece. Thus an auxiliary grinding unit is herein employed, in combination with the main grinding units, to automati- 3,525,181 Patented Aug. 25, 1970 rice cally carry the grinding wheel thereof of relatively smaller diameter into engagement with a selected area of a glass sheet and to then remove said grinding wheel from active engagement.

It is therefore the primary object of the invention to provide the combination with an edging machine, including grinding units with grinding wheels adapted to grind the major portion of the edge of a workpiece, of an auxiliary grinding unit with a grinding wheel of relatively smaller diameter adapted to grind a selected area of the edge of said workpiece.

Another object of the invention is to provide an edging machine of the character above described wherein the main grinding units include template followers adapted to traverse the contoured curvature of a rotary main template and the auxiliary grinding unit includes a template follower adapted to traverse an auxiliary template carried by the rotary main template and having a contour corresponding to the selected area of the curved outline of a workpiece.

Another object of the invention is to provide for an auxiliary grinding unit of the above character pivotal mounting means and means moving said auxiliary grinding unit toward and away from the worktable to engage the edge of a workpiece in a selected area and then disengage the same.

A further object of the invention is to provide control means activated during rotation of the worktable to automatically operate the said moving means to move the auxiliary grinding unit toward and away from the worktable.

Other objects and advantages of the invention will become more apparent during the course of the following description when read in connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

FIG. l is a side elevation of an edging machine with an auxiliary grinding unit constructed in accordance with the invention;

FIG. 2 is a horizontal sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is an enlarged plan view of the auxiliary grinding unit;

FIG. 4 is an end elevation of the grinding unit, parts thereof being shown in section;

FIG. 45 is a vertical sectional view taken along the line 5-5 of FIG. 3;

FIG. 6 is a diagrammatic view of a control system; and

FIGS. 7 and 8 are diagrammatic views of operation of the auxiliary grinding unit.

Referring now to the drawings and particularly to FIGS. l and 2, the improved auxiliary grinding unit of this invention is adapted to use in combination with an edging machine which comprises an annular supporting base 10 provided with a centrally located worktable 11 mounted ou the upper end of a vertically disposed rotatable spindle 12. Generally speaking, the worktable 11 carries a horizontal main template 13 on its lower surface and a platform 14, constituting its upper surface, for supporting workpieces 15, such as sheets or plates of glass.

As herein described and viewed in FIG. 2, the outline of the edge of the template 13 is preferably formed to include at least two contoured areas 16 in each of which the edge of the template is curved and shaped to correspond to the curvature to which the exposed edges 17 of the Workpieces 15 have been pattern-cut and are to be nish ground. The worktable 11 is thus provided with platform means 14 for carrying at least two glass sheets or workpieces 15 that are positioned in diametrically spaced relation to one another and with the corresponding contoured areas 16 of the template 1.3 located in vertically spaced relation beneath the edges 17 of the sheets. As herein disclosed, the periphery of the template 13 continues from one contoured or curved area 16 into the second area 16 through intervening and oppositely disposed dwell areas 18.

Each workpiece is held on the platform 14 by clamping plates 20, having a non-abrasive surface for engaging the workpiece. The clamping plates 20 are mounted for vertical reciprocal movement by powered mechanisms such as air-actuated cylinders 21 mounted on opposite sides of a vertically disposed wall 22 extending above the platform of the worktable 11; with the piston rods 23 of the air cylinders being attached to the upper surfaces of the clamping plates. As shown, two' such clamping plates 20 and air cylinders 21 are provided for securing each of the respective workpieces 15 against the surface of the platform 14, with the workpieces positioned in such a manner that the edges 17 toi be ground extend beyond the platform as shown in FIG. 1. With this arrangement, one glass sheet or workpiece can be secured on the worktable and subsequently removed in an area remote from the grinding mechanism, generally designated by the numeral 25, while the worktable is being rotated and the grinding mechanism is acting upon the exposed edge of the diametrically-located second workpiece clamped on the opposite side of the platform 14.

The grindnig mechanism 25 for edge-finishing the workpieoes generally comprises two

grinding units

26 and 27; each including a grinding wheel 28 which is adapted to 'be rotatively driven about a vertical axis by means of an electric motor 29. The two grinding units are mounted in spaced side-by-side parallel relation on a vertically disposed support member 30 that is structurally carried to pivot freely about one vertical axis, with the

grinding units

26 and 27 and the support member 30 being, adapted to simultaneously pivot or swing bodily about a second vertical axis. Thus, as viewed in FIG. 2, the support member 30 is pivotally mounted by a shaft 31 at the free end 32 of an arm 33 which is pivotally mounted on a vertically disposed axle 34 carried by bearings on the frame 35 of the base 10. Although not shown in detail, it will be understood that by means of the cable 36, attached to a weighted member, the arm 33 is pivotally swung about the rst axis or that of the axle 34 and yieldingly urged toward the worktable 11. Each

grinding unit

26 and 27 is provided with a template follower roll 38 arranged in vertical axial alignment with a related grinding wheel 28 and mounted on the support member 30 by means of a bracket 39.

It is believed apparent that as the follower rolls 38 engage the edge of the template 13, the grinding mechanisrn 25 is adapted to swing toward and sway from the worktable 11 about the axis of the axle 34, or the aforementioned first vertical axis, to urge and maintain the grinding wheels 28 of the

units

26 and 27 in active engagement with the exposed edges of the workpieces. Simultaneously, the

grinding units

26 and 27 together with the support member 30 will pivotally swing about the second vertical axis, or that of the shaft 31 at the free end of the arm 33, as the template follower rolls 38 of said grinding units traverse the

areas

16 and 18 of the template 13 and in so doing cause the related grinding wheels 28 to produce the desired ground finish on the edges of the workpieces or to be held in outwardly spaced relation.

As noted in FIG. 2, the contoured edge areas 16 of template are interjoined by continuations or the dwell portions 18 and these dwell areas or portions support the follower rollers 38 and grinding wheels 2-8 from a point adjacent an end area of one workpiece to the adjoining end area of an oppositely disposed workpiece. For certain uses to which the glass sheets or workpieces are to be put, it has been found practical to employ the use of an auxiliary grinding unit, generally designated by the numeral 41, having grinding wheel 42 driven by an electric motor 43. The grinding wheel 42 is of a diameter relatively smaller than the diameter of either of the grinding wheels 28. Accordingly it is herein contemplated, by the embodiment of the instant invention, to finish grind a selected area of at least one end of each workpiece. During this grinding action, the auxiliary grinding unit 41 is caused to` move in a path determined by the contour of an auxiliary template 44 by means of a follower roll 45. As viewed in FIGS. 2 and 5, the auxiliary template 44 is mounted by a spacer plate 46 on the main template 13 and located in registration with the selected area of a workpiece; said area including the leading end of the workpiece.

It is also contemplated that the edge of auxiliary template 44 can be contoured to conform to areas other than an area defining the leading end of a workpiece. Thus, the auxiliary template 44 can be provided with an edge having a curvature of any selected portion of the contoured areas 16 of the main template 13. In fact, by using an auxiliary grinding wheel having a surface other than one similar to that of the main grinding wheel, and such as an angled or concave surface, any selected area of the workpiece can be finished with a beveled or convexedly rounded edge portion. In these conditions of operation, the controls for producing inward and outward movement of the auxiliary grinding unit 41 would be located to cause such movements in accordance with the selected area 0r areas of the workpiece to be acted upon.

Generally described, the auxiliary grinding unit 41 is adapted to be moved in a substantially radial or arcuate path and, by means of each auxiliary template, carry the grinding wheel 42 into engagement with leading end of the edge of the exposed side of a workpiece, about the curved end thereof and even along a portion of the edge of the unexposed side of the workpiece. As above mentioned, the contour of the edge of the template 44 can also be shaped to cause the grinding wheel 42 to act upon selected areas of a workpiece other than around the leading edge. However, by way of example, the substantially V-shaped contour of the edge of each auxiliary template 44 includes a leading sector 47 conforming to the entry end of the previously considered unexposed edge of a workpiece, a sharply curved end sector 48 and a trailing sector 49 conforming substantially to a similar area of the main template 13 therebeneath. The actual path of movement of the auxiliary grinding unit 41 is thus a resulting sequence or combination of forward and rearward motions. To produce this combination of motions, the auxiliary grinding unit 41 is brought into and removed from operative position with reference to the Worktable 11 upon the sequential actuation of

switch devices

52 and 53 by vertically disposed

posts

54 and 55 carried by the wall 22. That is to say, as one workpiece is being acted upon by the main grinding wheels 28, the post 54 will be located to engage the switch device 52 when the auxiliary template follower roll 45 is to be brought into contact with the edge of the template 44, such as the leading sector 47 as herein shown. The post 54 subsequently engages the switch device 53 as the follower roll 45 traverses the trailing sector 49. The same is also true with regard to the post 55 when the opposite workpiece is being ground.

More particularly, the auxiliary grinding unit 41 comprises a support structure 60 mounted by a base 61 on the base 10 of the edging machine and having an upper horizontally disposed surface or platform 62. Generally speaking, the unit 41 is carried on the support structure 60 by an arm 65 pivotally supported by a frame 66 that is adjustably mounted on the platform 62 by a bracket 67. The arm 65, as seen in FIG. 5, has an integral plate 70 at its free or outer end for supporting the motor 43 and a bracket 71 on which the auxiliary follower roll 45 is rotatably journaled by bearings 72 on an axle 73. At its opposite and inwardly disposed end, the arm 65 is provided with a vertically disposed trunnion member 75 having axially aligned

bearings

76 and 77 in the upper and lower ends thereof. Each bearing is formed with a conical surface 78 which in one instance receives the tapered end of a bolt 79 and the other the end of a similar |bolt 80. The bolts 79 and '80 are carried by internally threaded cap blocks 81 and 82 in the outwardly directed flanges 83 and 84, respectively of the frame. The bolts 79 and `80 are aligned with an axial line a and are equipped with locknuts 85 which when released from the adjacent surfaces of the cap blocks permit the

bolts

79 and 80 to adjust the elevation of the arm as they are turned upwardly or downwardly relative to the cap blocks 81 and 82.

The vertical wall 87 of the frame 66 is supported on the opposed vertical wall 88 of the bracket 67 by an axle bolt 89 passed through a hub `90 of the wall 87 and aligned hub 91 of the wall 88. When the nut 92 is turned against washers 93 facing the hub 91, the head 94 of the axle bolt 89 acts to rmly secure the mounted relation of the frame 66 on the bracket 67. However, the frame 66 is adapted to be adjusted angularly with reference to the bracket 67 in order that the auxiliary grind unit 41 can be bodily shifted to ensure that the axis b of the grinding wheel 42 and motor 43 is prependicularly plumbf For this purpose, the wall 88 of bracket 67 is formed with radially -disposed slots 96 through which securing screws 97 are passed and threaded into tapped holes 98 'm the wall 88 of frame 66.

The arm 65 is caused to swing about the axial line a to move the grinding wheel 42 and template follower roll 45 toward and away from the workpiece and auxiliary template 44, by a piston and cylinder arrangement of which the piston rod 100 is pivotally connected by a pin 101 at clevis 102 to the arm 65. As herein shown, the cylinder 103 is mounted in a bearing block 104 for swinging movement about the aligned axis of

journal studs

105 and 106, forming parts of the cylinder case 107, in response to movement of the contained piston 108. The head end of the cylinder 103 is connected by pipe 109 to a source of pneumatic pressure and the rod end is similarly connected by pipe 110. The block 104 is adjustably mounted on the platform 62 of support structure 61 by a base 112; suitable screws 113 being threaded through angle members 114 and adapted to shift the block 104 relative to the base 112. Since the axis c of the pin 101 swings through a ixed arc about the axis a, the axis d about which the cylinder 103 will swing can thus be adjusted relative to the axis a.

Referring now to FIG. 6, there is shown an exemplary form of electric control system for connection of

pipes

109 and 110 to a valve 117 in alternating sequences of operation. During location of the auxiliary grinding unit 41 in the rest or non-operating position, as in FIG, 2, the valve 117 directs pressure from a supply pipe 118 to the pipe 109 and the head end of the cylinder 103. Valve 117 is actuated in response to circuits established through a relay switch RS 120 having contact pairs 121 and 122 and

opposed solenoids

123 and 124.

Now, when the worktable carries the post 54, for example, into engagement with the switch device LS 52, a circuit is made from source line 126 by way of manually operable switch 127. When closed, LS 52 completes a circuit by line 128 through solenoid 123 of RS 120 to opposite source line 129. This will disengage contact pair 121 and engage contact pair 122 to make a circuit from source line 126 by line 130 through the end 131 of the cylinder 103 to source line 129. Direction of pressure through pipe 109 to the head end of cylinder 103 'will result in outward movement of the piston rod 100x This will act to swing the grinding unit 41 toward the worktable 11 to carry out the grinding action of the smaller grinding wheel 42.

With continued rotation of the worktable 11, the post 54 will be carried from engagement with LS 52 to break the circuit of line 128 and eventually into engagement lwith switch device LS 53 to close the same. This will complete a circuit from source line 126 by line 135 through opposed solenoid 124 of RS 120 to source line 129. While energized, solenoid 124 is operated to disengage contacts 122, opening the circuit of line 130, and to engage contact pair 121 thereby establishing a circuit from source line 126 and line 136 through the end 137 of valve 117 to source line 129. Thereupon the direction of pressure through said valve |will be reversed from pipe 109 to pipe 110. This will serve to retract the piston 108 and rod 100 to return the auxiliary grinding unit 42 to its rest or inactive position, as in FIG. 2.

OPERATION As diagrammatically illustrated in FIG. 7, the solid line from axis a to axis b indicates the rest position of the arm 65; line 141, to axis c of the clevis 102, and line 142 from axis c to axis d the positional relation of piston rod 100. When these lines are swung to the phantom lines 140', 141 and 142', the template follower roll 45 will be brought into contact with the leading sector 47 of auxiliary template 44 and the smaller grinding wheel 42 into engagement with the selected area of the edge of the workpiece. As herein indicated, this point of engagement is along the so-called unexposed edge 0f the workpiece. As the roll 45 traverses the sector 47 and around the curved end sector 48, it is expected that the roll 45 will cause outward motion of the grinding wheel 42 and momentary retraction of the piston rod 100. This is a temporarily imposed mechanical thrust against the pressure behind the piston 108. However, as rotation of the worktable 11 continues in a clockwise direction, the roll 45 enters the trailing sector 49, the mechanical thrust is progressively dissipated and the pressure in cylinder 108 again becomes eifective to maintain the template follower roll against the auxiliary template 44.

As shown in FIG. 8, and as the follower roll 45 approaches the end of the sector 49, the then

active post

54 or 55 will actuate the switch device 53 to cause reversal of pressure through the valve 117 to cylinder 103. The positions of the arm 65 and the rod 100, as indicated by the

phantom lines

143 and 144, will be swung rearwardly until the line 143 coincides with the original line 140 of FIG. 6 with the auxiliary grinding unit 41 in the rest position.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred embodiment 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.

I claim:

1. In edge grinding apparatus, the combination including rotatable worktable for holding a flat workpiece with at least one edge thereof exposed, a main grinding unit including at least one rotatable grinding wheel adapted to engage said exposed edge of the workpiece, a template carried by said worktable and rotatable therewith, a template follower roll carried by said main grinding unit and riding against said template to gage the grinding action of said grinding wheel, an auxiliary grinding unit mounted adjacent said worktable and including an auxiliary grinding wheel o f relatively smaller diameter than the grinding wheel of said main grinding unit, an auxiliary ternplate also carried by said worktable, a template follower roll carried by said auxiliary grinding unit and engageable with said auxiliary template to gage the grinding action of said auxiliary grinding wheel, means for mounting said auxiliary grinding unit and for moving the grinding wheel thereof toward and into engagement with a selected area of the exposed edge of the workpiece and the related follower roll into engagement with said auxiliary template and subsequently away therefrom, and control means activated by rotation of the Iworktable to move 7 the template follower roll of said auxiliary grinding unit into engagement with said auxiliary template and subsequently out of engagement therewith.

2. In edge grinding apparatus, as defined in claim 1, in Which said auxiliary template has an edge contour corresponding in curvature to a selected area only of the edge of the workpiece to be ground.

3. In edge grinding apparatus, as defined in claim 2, in which the auxiliary grinding unit comprises means for pivotally mounting said auxiliary grinding unit, means for swingably moving said auxiliary grinding unit about the axis of said pivotal mountng means, means activated upon rotation of said Worktable to operate said moving means to swing said auxiliary grinding unit and the grinding wheel thereof into engagement with a selected area of the exposed edge of the workpiece, in which said last-named means comprises switch means operatively connected with the moving means and means carried by the worktable to actuate said switch means during rotation thereof.

4. In edge grinding apparatus, as defined in claim 3, in

which said switch means includes a rst switch engaged by the actuator means to swingably move said auxiliary grinding unit and the template follower roll thereof toward the said auxiliary template and grinding wheel toward the workpiece at the leading portion of the selected area to be ground and a second switch subsequently engaged by said actuator means to swingably move said auxiliary grinding unit to remove the template follower roll from said auxiliary template and said grinding wheel from the workpiece at the trailing portion of the selected area to be ground.

References Cited UNITED STATES PATENTS 2,826,872 3/1958 Robbins 51-101 X 3,158,967 12/1964 Reaser 51-89 OTHELL M. SIMPSON, Primary Examiner