US2865142A

US2865142A - Apparatus for surfacing glass sheets

Info

Publication number: US2865142A
Application number: US522017A
Authority: US
Inventors: Donald W Dunipace; John M Byal
Original assignee: Libbey Owens Ford Glass Co
Current assignee: Libbey Owens Ford Glass Co
Priority date: 1955-07-14
Filing date: 1955-07-14
Publication date: 1958-12-23
Anticipated expiration: 1975-12-23

Description

Dec. 23, 1958 v D. w. DUNIPACE ETAL I 2,365,142

' APPARATUS FOR SURFACING GLASS SHEETS Filed July 14, 1955 2 Sheets-Sheet 1 INVENTORS Jonah C206 A TTORN E YS 1958 D. w. DUNIPACE ETAL 2,865,142

APPARATUS FOR SURFACING GLASS SHEETS Filed July 14, 1955 2 Sheets-Sheet 2 E 5 2 (f1 23 Z9 7 54 b (m -Q 1 2 ,|ii- 21 mg l l l m 65 /fllll 'l H INVENTORS BY -d/ndgo/i nm 5 @666 fizzle 2e ATTORNEYS polished and unpolished areas.

nited States APPARATUS FOR SURFACING GLASS SHEETS Application July 14, 1955, Serial No. 522,017

3 Claims. (Cl. 51-420) The present invention relates broadly to an apparatus for polishing plate glass and is particularly adapted for use in the so-called continuous system for surfacing plate glass.

In the continuous system, a plurality of sheets of glass to be surfaced are mounted upon a series or train of cars or tables and passed in a definite substantially horizontal path first beneath a series of grinding machines and then beneath a series of polishing machines to surface one side of the sheets, after which the said sheets are turned over upon the tables, and again passed beneath the same or a second series of grinding and polishing machines, to surface the second side.

The polishingymachines employed in this system ordinarily include a horizontal runner frame carried at the lower end of a vertical drive spindle and being in turn provided with a plurality of polishing blocks or runners, the operative faces of which are covered with pads of felt or the like which are adaptedto come into contact with and polish the surface of the glass. The polishing action is accomplished by the relative movement between the polishing pads and glass in conjunction with a polishingmediumsuch as rouge or the like which is .usually supplied upon the glass and carried thereby beneath said pads.

Various arrangements of the polishing pads orblocks have been employed in the past, each of these having certain advantages and certain disadvantages. It has been found that it is advantageous to provide movements of the polishing blocks such that the polishing block will overlap the edge of the glass sheet during atntpart of its movement so that the edge of the glass sheet provides a cleaning .action on the polishing block. It has also been found that variations of movements of the polishing blocks are necessary to provide a uniformity of polishing action to prevent streaks of comparatively Further, it isbelieved that the amount of. polishing which takes place is directly proportional to the amount-0f energy applied to the polishingblocks.

It is aprimary object of this invention to provide an apparatus for polishing glass in which the polishing blocks are selfcleaning during the polishing process and in which the sheet is uniformly polished throughout.

Another object of this invention is to provide a polishing apparatus. havingpolishing blocks which are arranged in a special pattern and are of lightweight structureand easily removable.

A further object of this invention is to providea polishing apparatus having means for distributing a polishing medium such as rouge at. a controlled ratefrom a single feeding source to a series of outlet means having substantially: the same movement as the polishing blocks of the apparatus.

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

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

2,865,142 Patented Dec. 23, 1958 Fig. l is an elevation of a polishing apparatus, partly in section, and constructed in accordance with the present invention;

Fig. 2 is a plan view of the apparatus of Fig. 1 taken substantially along the line 22 of Fig. I;

Fig. 3 is'an elevational view, partly in section, taken substantially along the line 3-3 of Fig. 2; v

Fig. 4 is a plan view of the polishing block of this invention;

Fig. 5 is a cross-sectional, elevational view of the polishing block of Fig. 4; and

Fig. 6 is an enlarged, fragmentary, plan view illustrating the fastening means of the polishing block shown in Figs. 4 and 5.

The present invention is particularly advantageous when wide sheets or ribbons of glass are being polished. As wider sheets are polished, more polishing energy is required from a given polishing machine in order to provide the required amount of polishing in a given length of polishing line. This energy is supplied by increasing the motion on the polishing block. In order to provide a self-cleaning action the motion of the blocks is desig hated to be such that every polishing block will go across the edge of the sheet during the polishing motion thereof. Heretofore, when such blocks were used, more polishing took place in the areas close to each edge of the sheet than in the area in the middle of the sheet so that excessive polishing was required on the sides of the sheet in order to provide the required finish in the center portion thereof. 7

We have found that by providing a cluster of relative large polishing blocks which are rotatable around a common axis and of group size sufiicient to polish a circular area of a diameter substantially equal to one half of the width of the sheet being polished, polishing blocks are provided that may all overlap the edges and still polish the central portion of the sheet as much as the outside portions. When wide glass sheets are being polished this requires the use of large polishing blocks so that it is important that the polishing blocks be of light weight con struction and readily removable.

In accordance with the present invention, the glass sheets to be surfaced are adapted to be secured to the tops of tables or carriers 11 mounted upon wheels 12 rolling upon a trackway 13, in a substantially horizontal path to carry glass sheets 14 mounted upon the tops thereof and preferably secured thereto by a layer of plaster of Paris or the like 15.

The polishing'machine is supported from a stationary framework which consists of a hub 16 and a plurality of substantially horizontal supporting arms 17 which are mounted on supporting columns 18. The polishing head which is generally designated by the letter A is supported by a spindle 19 which is journalled in the hub 16. The spindle 19 also has rotational motion imparted to it in the hub 16 by a worm gear driving mechanism which is activated by the motor 20 through the shaft 21. Below the hub 16 and rigidly secured thereto is a planetary gear 22 as best showniin Fig. 3. This stationary, planetary .gear has an opening in the center thereof through which the rotating shaft 19 is-fitted. A rotatable runner frame 23 is rigidly secured as by bolts 24 to a flange 25 of the spindle '19, and the spindle 19 is positioned in a location substantially midway between the sides of the table 11 so that the attached polishing frame Will rotate around this central axis.

On opposite sides of the runner frame 23, there is located a hub 26 in which-a group of polishing blocks generally designated bythe letter B are supported. The groups of polishing blocks B. comprise a plurality of individual polishing blocks 27 which are suspended from a frame 28 by shafts 29 rotatably mounted in journals 30. Frame 28 is rotatably supported by shaft 31 and secured thereto by fastening means such as a nut 31' and suitably keyed thereto so that on rotation of the shaft 31, rotation of the frame 28 of the group of polishing blocks B takes p ace.

The shaft 31 is rotatably mounted in the hub 26 of the frame 23 and rotation is imparted to said axle by means of the gear 32 which is suitably keyed to the shaft 31 and mounted at the upper end thereof. Power is supplied to the gear 32 by means of the gear 33 which engages the stationary planetary gear 22 so that as the frame 23 is rotated, relative rotational movement between the gear 33 and the stationary gear is effected. Suitable mounting for the gear 33 is provided on a hub 34 of a frame 23 on which a shaft 35 is rotatably mounted.

It is thus seen that as the shaft 19 is rotated, the frame 23 is rotated, which causes all of the polishing blocks mounted therefrom to travel in a circular motion. Also it is seen that the group B of polishing blocks has an additional circular motion due to the rotation of the shaft 31, which rotation is caused by the planetary gear 22 as hereinbefore described. Accordingly, there are three dif- 4 ferent types of motion between the glass sheet 14 and the center of the polishing blocks 27; namely, the transverse horizontal movement of the sheet due to the movement of the table 11, the rotational movement of the entire set of polishing blocks of the polishing head A, and the rotational movement around the axis of the shaft 31 of the polishing blocks located in the group of polishing blocks B.

Preferably, each group of polishing blocks B contains three polishing blocks 27 which are large enough to cover a circular area of a diameter equal to approximate y one half and preferably between one half and three fifths of the width of the sheet being polished and which are placed in close spaced relation as illustrated in Fig. 2. In order to provide further polishing areas, other polishing blocks 27a are rotatably mounted directly on the frame 23 as illustrated in Fig. 2 in which four such polishing blocks are shown. Especially good results are achieved when the four blocks 27a are used in combination with two groups of polishing blocks B as shown in the drawing. These polishing blocks 27a engage the glass sheet in two motions; namely, the transverse movement of the glass sheet 14 and the rotational movement of the polishing machine A about the axis of the shaft 19. It is contemplated that designs other than the preferred design which is illustrated in Fig. 2 may be used, but it is important that the polishing blocks are positioned and moved in such a way that both a uniform polishing action is achieved as well as a motion which causes all of the polishing blocks to cross over the edge of the glass sheet during the poli hing process.

In the preferred design, which is illustrated in the drawings, the following dimensions are used based on a width of the glass sheet of 100 units. Each shaft 31 is located 30.25 units from the shaft 19, and the shafts 29 of the polishing blocks 27 are located 16.25 units from its corresponding shaft 31. Accordingly, the polishing blocks 27 of the group of polishing blocks B rotate about a radius of 30.25 units due to the rotation of the frame 23, and simultaneously rotate about a radius of 16.25 units due to the rotation of the frame 28. The pad contact diameter of the polishing blocks 27 and the polishing blocks 27a are 25.4 units, and the centers of the polishing blocks 27a are located 46.5 units from the shaft 19 so that the polishing blocks 27a rotate about a radius of 46.5 units due to the rotation of the frame 23.

When these dimensions are used with two groups of polishing blocks 27 and four polishing blocks 27a, an especially uniform smooth is achieved.

In order to provide a polishing block 27 of sufiicient size topolish wide glass sheets using the design herein illustrated, it is important to use a lightweight felt mounting structure having means for easy removal so that the polishing felts can easily be replaced when worn out or in need of repairs for some unforeseen cause. A preferred form of polishing block is illustrated in Figs. 4 to 6 and comprises the shaft 29, a block 37, a pan 38, felt pad 39, and a band 40. The shaft 29 has a rounded end 41 which fits into the block 37 and since the shaft 29 is rotatably mounted, thewhole polishing block 27 is free to rotate thereby providing a further polishing motion. In order to secure the block 37 to the shaft 29, there is a recessed portion 42 near the end of the shaft 29 in which a collar 43 is fit, thereby securing the shaft 29 when the collar 43 is secured to the blank 37 by means of the bolts 44. The block 37 fits into a metal drum-like pan 38 which is of shallow, lightweight, circular construction having a vertically upstanding flange 45. A felt polishing pad 39 is placed on the pan 38 and the band 40 is forced thereover and around the flange 45 to secure the felt pad in place.

The unit consisting of the pan 38, pad 39, and band 40 is easily removed from the remainder of the polishing block 27 because it is secured thereto by three evenly spaced securing means or clamping devices 46 as best illustrated in Fig. 6. On the inner surface of the pan 38, lugs 47 are provided which are gripped by the fingers 48 of the securing means 46, which fingers pivotally engage a surface 51 of the block 37 and are each provided with a slot 49 through which is fit a bolt 50. As the finger 48 is pivoted it grips the lug 47 to secure the pan 38 and this pivoting is manually controlled through the use of handle 52, and the final securing is accomplished by the use of the nut 53 which is threaded over the bolt 50. As the nut 53 is threaded down, the finger 48 pivotally engages the pan 38 and clampingly secures it on the block 37.

In order to adjust the weight of individual polishing blocks, guide posts 55 may be threaded in the blocks 37 and weights placed thereover as indicated in phantom in Fig. 5. This allows for individual adjustment of each polishing block.

In order to supply the polishing material or rouge to the glass in the path of the various polishing blocks 27, feeding means are located on the various frames of the polishing heads 30. The rouge slurry or polishing material is added in controlled amounts through a tube 56 and allowed to drop into a circular trough 57 which is secured to the frame 23. Accordingly, the rouge drops from the tube 56 into the trough 57 during the rotation of the trough and may be applied at any time. The. trough is constructed in such a way that the slurry is not caused to spill by the centrifugal force due to the rotation of the trough. In the form shown herein the trough has a bottom wall 58, a vertically upstanding inner wall 59, and an oblique outer wall 60 which slants inwardly from the bottom. During rotation the polishing slurry is confined against the effect of centrifugal force by the bottom 58 and outer wall 60. Two types of outlets are provided on the main feed trough 57, one type supplying polishing material in front of the polishing heads mounted on the frame 23 and another type such as the outlet 61 shown in Fig. 3 which supplies polishing material to the trough 62 located on the frame 28 of the group of polishing blocks B. These outlets have inlet openings near the junction of bottom 58 and, wall 60 which is where the slurry is positioned clue to the centrifugal force as the trough 57 is rotated. The trough 62 rotates along with the frame 28 to which it is attached so that the upper opening is continuously in position to receive slurry from the outlet 58 of trough 57. Outlet 63 is provided on feed trough 62 to supply polishing material in the path of movement of polishing blocks 27 belonging to the group of polishing blocks B. Accordingly, the polishing material is fed in a controlled rate from a single tube 56 to aplurality of outlet tubes having various types of movement.

It is contemplated that the amount of rotation imparted to the polishing blocks B about their central axis may be varied. In fact, satisfactory results may be achieved when no direct drive is connected to the groups B and said group is caused to rotate as a result of uneven frictional force caused by the rotation of the polish ing head A.

The polishing head A may be lifted to the position shown in Fig. l, by lifting the spindle 19 when it is desired to take one of the polishing machines out of operation. Means are provided for elevating the spindle such as the means disclosed in United States Patent No. 1,961,- 441,'issued June 5, 1934, to J. C. Gipe et al. In order to change a polishing pad, the polishing head A is lifted, and the securing means 46 are loosened so that the pan and felt is removed. A new pan and felt is then put in place on the block 37, the fingers 48 are set in place, and secured by means of the nuts 53. The polishing head A is then rotated and lowered to the polishing position as shown in Fig. 3.

It is to be understood that the form of the invention disclosed herein is to be taken as the preferred embodiment thereof, and that various changes in the shape, size and arrangement of parts as well as various procedural changes may be resorted to without departing from the spirit of the invention or the scope of the following claims.

We claim:

1. In an apparatus adapted to substantially uniformly polish the surface area of a glass sheet passing thereby across the width of the sheet, a supporting framework, a first shaft rotatably mounted in said framework, a main frame carried by said shaft, means for rotating said first shaft to cause said main frame to follow a substantially circular path about said first shaft, two downwardly directed second shafts rotatably supported in said main frame and diametrically opposed from each other, an auxiliary frame afiixed to each of said downwardly directed second shafts, means for imparting the drive of said means for rotating said first shaft to each of said second shafts to rotate each of said second shafts simultaneously with the rotation of said first shaft, a pair of diametrically opposed first polishing means individually carried by said main frame between said auxiliary frames, each of said first polishing means including two downwardly directed shafts individually mounted to said main frame for free rotation and a polishing block for contacting the surface of the glass sheet afiixed individually to each of said downwardly directed freely rotatable shafts of each of said first polishing means and a pair of diametrically opposed second polishing means individually mounted to said auxiliary frames, each of said second polishing means including three downwardly directed shafts mounted to its respective auxiliary frame for free rotation and a polishing block for contacting the surface of the glass sheet afiixed individually to each of said downwardly directed freely rotatable shafts of each of said second polishing means.

2. In an apparatus adapted to substantially uniformly polish the surface area of a glass sheet, passing thereby, across the width of the sheet as defined in claim 1, wherein with the Width of the sheet polished being represented by units, the distance between each of said freely rotatable shafts, supporting the polishing blocks constituting said opposed first polishing means, and said first shaft is 46.5 units and the distance between each of said second shafts and said first shaft is 30.25 units.

3. In an apparatus adapted to substantially uniformly polish the upper surface area of a glass sheet, passing thereby, across the width of the sheet as defined in claim 2, wherein the distance between each of said freely rotatable shafts, supporting the polishing blocks constituting one of said opposed second polishing means,-and said second shaft, about which the same means rotates, is 16.25 units, and all said polishing blocks have a glass sheet contacting portion diameter of 25.4 units.

References Cited in the file of this patent UNITED STATES PATENTS 1,430,214 Carrie Sept. 26, 1922 1,510,976 Carrie Oct. 7, 1924 1,735,565 Drake Nov. 12, 1929 1,767,123 Drake June 24, 1930 1,771,408 Hitchcock July 29, 1930 1,788,931 Pedersen Jan. 13, 1931 1,811,044 Drake June 23, 1931 1,836,542 Miller Dec. 15, 1931 1,872,694 Drake Aug. 23, 1932 1,982,648 Drake Dec. 4, 1934