US 1198402 A
Description (OCR text may contain errors)
(MSS GmNDiNG TABLE.
APPLBCAYION FMH) NOVy 30, IMS.
1,1 98,402. lunmmmm. 19,1915
2 SHEETSWSHEET l.
GLASS GRHwDiNG TABLE.
APPLICATION FILED N(}\.30,19i5.
l. D STATES PATENT GFFIC P'i..
EDWARD BAGNALL, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOB T0 ZOHFFEB PLATE GLASS MANUFACTURING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A. CORPO- BATION 0F WEST VIRGINIA.
Specication of Letters Patent.
Patented Sept. 19, 1916.
Application led November 30, 1915. Serial No. 64,245.
To all whom it may concern:
Be it known that I, EDWARD BAGNALL, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Glass- Grinding Tables, of which the following is a specification.
My invention relates to improvements in apparatus for grinding, smoothing and polishing plate glass, and it has for its object to provide effective and economical means for cushioning and holding the glass plates upon the upper portion of the rotating table, in connection with the operations performed by the usual superimposed runners and abrasive material.
In carrying out my invention, the rotatable supporting table is provided with means for exhausting the air from its interior, anda plurality of numerous somewhat closely adjacent specially shaped perforating apertures communicating with the interior suction cavity of the table, adapted to support a pervious resilient bedding, upon which the glass plates are laid, whereby to provide for the necessary degiee of Vcompression of the bedding and the exhaustion of the air therethrough in effectinga partial vacuum and a resulting holding; air pressure. U
referred embodiments of the invention are shown in the accompanying drawings, in which- Fi Ve l is a plan view of the apparatus showing certain of the exposed aircirculation cavities, a Aportieri of the bedding, and a portion of the glass plates carried thereby. Fig. 2 is a vertical cross sectiomindicated by the line Il. Il. of Fig. 1. Fig. 3 is a de tail sectional view, enlarged, showing the action of the apparatus when the table is covered with glass plates. Fig. 4 is a similar view, showing the pervious bedding as composed of a plurality of layers of material, as canton annel. Fi 5 is a similar view, and showing a resil ent supporting bed interposed between thel table and the pervious bedding." Fig. 6 isa/view similar larged vertical sectional view of the hollow supporting mast and the surrounding packed -air circulation collar, taken on the line VII. VII. of Fig. 8. Fig. 8 is a cross section on the line VIII. VIII. of Fig. '1.
The rotatable glass supporting table A is ieerably made of an upper wall 2 and a ower wall 3, providing an interior air cavity 4. The table is preferably made in a plurality of sections and divided at the line 5, the sections constituting units of the complete table connected, as shown, and providing for the continuous circulation of the air throughout its entire interior by means of the central common rotatable air conduit or hollow spindle 6. Said spindlemay be connected with the interior of the table in any suitable manner, operatingas a hollow mast which may act as the main supporting The central hollow spindle 6 ismounted in anyzsuitable packed bearing, as indicated, and is in constant communication b 'suction pipe 10 with any suitable air ex austing mechanism. By this arrangement it will be readily seen that the interior of the table is in suction communication with'. such exhausting means -at all times durngits 'operation. y "A The upper wall 2 of the table, which is level and substantially smooth, is provided with numerous somewhat adjacent coniform-shaped openings 11 flaring outwardly and providing a series of cuprshaped downwardly tapering cavities throughout the entire supporting area of the table, -each of which is in communication with the main interior cavity 4 by means of a reduced communicating port 12.
`For the purpose of providing a supporting bed for the plate glass, I 'lay completely.
over the entire area of the table A, and covering all of the cavities lllfa bedding 13 consisting of canton flannel, gliraiiv"telt, cloth,
or other suitable oervious material having ullicient body to provide a'eompressible supporting cushion `for the plates 14. Sur- ."ounding the periphery ot' the table and closing the exposed edges of bedding 13 to the atmosphere, after tlie plates 14 are. laid, l may, it desired, provide a surrounding packing 15, which may be of'- plaster of Paris or other suitable material easily appliedor removed, and which will e'ectually seal the edges of the bedding 18 against access of air, upon. creation of the suction vacuum. The. packing 15 is however, not absolutely necessary.` The table being thus covered and the plates being in position, exhaustion of the air from cavity 4 will create a suction of the air through tiie'pervious beddingr 13 and cavities 11v and ports 12, resulting in a. corresponding external. air pressure. which will bind :the platesli firmly upon the bedding.. i
At locations corresponding tothe openings l1, the bedding will be somewhat depressednnder outside air pressure, as indicated at 16', thereby )roviding collecting pockets for Nthe air which is exhausted from beneath the. entire surrouiuling area of the plates hert-ver.they are in close contact with the other rou'iyu'essed supporting portions ofthe bedding. B v this means the exhaustion othe air isfaunilitated and its conetant action l in vmaintaining suctionv and resnltingr compression upon the plates is maintained.
The' pervious bedding layer 13 may be in one continuous pietxf.. laid acrossthe entire surfac'eof thestable. butif necessary, it may be in two .or more parts, having tightly contacting edges. whereby age, and it will thusserve to provide a prat'4 tically uniform, level,v resilient' support for the glassplatesl ln practice, l have used a plurality of circular layers 13 of canton flannel, made of normal widths of material, laid edge'to edge and stitched, as indicated at 13". the seams thus vnot increasingY the normal thickness. and preferably laid across the. 'seams of the next' under and upper layer, as clearly shown' in Fig. 1. Spaces between the plates M may, itdesired'.l be filled with narrow strips of wood, plaster of Paris, or other suitable sealing material. as is commonly ldone in ordinary bedding of the glass, without, hoivever, allowing any of the plaster to accmnula'te beneath-'the plates or `to interfere. with t-he porosity of the bedding. The bedding inay 'he's ml cd .with water, if desired`v` or `riff-,rely dampened or used dry, depending upon the conditions present or the material used. l have also used oil in treatv ingv the flannel layers with goed success. the
oil tendini! to add to the resistance of theflannel to passage of moist-ure, and increas 'ing its flexibility. The degree of suction or of flannel 13,
to avoid undue leak.- Y
may be variously changed or modified b v the skilled mechanic.
ln Fig.' 5, l show a supporting mat or pad 17 of rubber or other Suitable somewhat resilient material having a flat under and upper surface, and a. series of transverse openings 18 corresponding .to and registering with the suction openings 1.1. lly this means l prevent the injurious ellect of inequalities in the surface of the table and retain the full advantage ofthe upper cushion as described. Said ligure also shows the edges of the pervious bedding;r as exposed, the suction being ordinarily ample to overcome any lat-eral leakage.
ln Fig. (i the several parts ofthe table and its driving mechanism are the same as above described, indicated by correspoiidingr numeruls primed. the vhollow mast also having a supplen'u'utal bearing lllaud the gearing being driven b v a motor 20 and suitable intervening gearing 21. 22. lqurroumling the mast. l and forming u rotatable.. hart with it is unemlu'ucing collar 23 through which extends into the hollow interior of the.
tween flanges .13 is a n annular cavityl() thus in constant communication with the interior of the hollow mast. and also in communica-- tion with the air exhausting mechanism lby pipe 10. Said pipe leads to a vacuum tank 5l] with un intervening b v-pass4 pipe 51'. leading tf: a water collecting tank 325 havinga valve controlled exliaustpipe 154, for collection and disposal of any water which may find its \va \r to the, suctioli pipe. An air pump f'l is connected by pipe G with'thi: vacuum tank ill, which is alsoprovided with a vacuum gage 2li".
The, advantages of the. invention wil-l be readily luiderstoml and appreciated by all those familiar with the construction .and operation of glass grinding und polishing mechanism. lt obviates the necessity of the usual -cemenling or other laborious and expensive methods in vogue for holding the glassplates to the table, providing for their easy and quick removal or reversal upon admission of air to the interior; it obviates the danger of breakage incideht to the placing of the glass plates directly upon the metal Q!) adapted to be` surface. of the table, and it provides a certain degree of cushioning action beneath the rotating superimposed runners, While compensating for any unevenness or inaccuracy in the plane of the table.
What I claim is:
1. A rotatable glass grinding table having a hollow interior and a plurality of adjal cent circular upwardly diverging openings through theupper wall of the table, means for exhausting the air from the hollow interior, and 'a superimposed porous bedding of compressible material.
2. A rotatable glass grinding table having a hollow interior and a plurality of adjacent circular upwardly diverging openings through the upper Wall of the table, means for exhausting the airfrom the hollow interior, a superimposed porous bedding of compressible material, and a surrounding peripheral air sealing covering for the edges of said bedding.
3. A rotatable glass grinding table having a hollow interior and a plurality of adjacent openings through the upper wall of the table, means for exhausting the air from the hollow interior, a layer of impervious material on the surface of the table having openings registering with the table openings, and a superimposed bedding of oompressible material.
4. In a rotatable glass supporting table of the class described having an interior vacuum cavity and an upper supporting wall provided with a plurality of adjacent upwardly flaring transverse openings communicating through diminished openings with the interior; the combination with said upper wall, of a layer of compressible porous material, and glass plates laid thereovern 5. In a rotatable glass supporting table of the class described having an interior vacuum cavity and an upper supporting Wall provided with a plurality of adjacent upwardly flaring transverse openings communicating through diminished openings with the interior; the combination with Said upper wall, of a layer of compressible porous material`r glass plates laid thereover, and a surrounding sealing material inclosing the peripheral edges of the bedding and glass plates and preventingA the entrance of air.
In testimony whereof I hereunto affix my signature in the presence of two witnesses.
- y EDWARD BAGNALL. Witnesses:
YV. A. HECKMAN, C. M. CLARKE.