US1194520A - l lewis - Google Patents

Description

H. F. LEWlS.

PROCESS OF LAYING SHEET GLASS.

APPLICATION FILED N0v.3.1915.'

l. A M mmy" Emma Aug. 15, 1915.

iNVENTO H WA TOWNEV HARRY J. LEWIS, 01? FORD CITY, PENNSYLVANIA, ASSIGNOB T0 PITTSBURGH PLATE GLASS (WMPANY, 01? PITTSBURGH, PEINTNSYLVANIA, A CORPORATION OF PENNSYL- .VMIA.

PROCEEZS Oil LAYING SHEET-GLASS. I

( Application filed November 3, 1915. serial No. 59,334..

To all whom may concern:

Be it known that l, HARRY F. Lewis, a' citizen of the United States, residing .at

Ford City, Armstrong county, and State of 6 Pennsylvania, have invented a certain new and useful Process of Laying Sheet-Glass, of wl ich the following is a specification.

The invention relates to a process for laying sheet glass upon the grinding and polish- 10 ing tables and securing it thereto by means of plaster of Paris or similar material capable of being hydrated and setting rapidly. It has for its primary objects; the provision of an improved process having the following advantages as compared with the process now in use; (1). a saving of time in the application of the plaster, (2) a saving in the amount of plaster, (3) increased strength in the holding layer of plaster, (4) a saving in 0 the labor required in applying the plaster, and a more uniform distribution of the plaster. The process is illustrated in the ac-. companying drawings wherein Figure 1 is'a side elevation of the apparatus employed with certain parts in section; Fig. 2 is a perspective view showing the up plication of the hydrated plaster of Paris to the grinding table to which the glass is to be applied; and Fig. 5 is a perspe tive new showing the applied to the table.

Plate glass is secured upon the grinding and polishing tables by meansof plaster of Paris. lleretoforc it has been custon'iary to mix the plaster of Paris with water and ap: ply it by means of buckets to the surface of the table, the plaster being spread as uniformly as possible over the surfaceof the table and the glass then pressed into position in the layer of plaster. Thcrc are certain well known disadvantages incident to this process of laying glass. Considerable time is consui'ned in getting the plaster on the table and properly sn'ioothed before the glass is applied, and in this period a certain setis imparted to the plaster and as a result the bond between the glass and the table is not as secure if the glass were applied before the initial set of the plaster. it is also dillicult to spread the plaster in a layer of m uniform thickness, and as a result it often happens that parts of the surface of tl'ie glass are higher than otl'u-irs. so that in the grinding operation the sheet is unduly thin at some parts. The high parts of'the glass M sheets are usually the central portioi'is, as

there is more resistance of the plaster against lateral movement at these points when pressure is applied to the surface of the lass to press it into position and squeeze out the surplus plaster from between the table and the 00 glass. As the application is not uniform and the layer must be of sutlicient thickness at all points, an excess of plaster must be used, and this excess is lost or Wasted when the sheet 15 pressed into position. There is also an additional loss of plaster incident to the mixing in the buckets and to the handling. It is the ptrrpose of my invention to provide a proeesswvhich is free from the forcgo ng objections, and to that end I provide a means whereby the powdered laster of Paris is projected in a stream, and hydrated during its passage through the air so that the mixed plaster of Paris and Water is sprayed upon the table to form a layer of an desired thickness. I I

I The apparatus which I ')refcrably employ in carrying out this process is illustrated in Fig. 1, wherein 1 is a container for the powdered plaster of Paris 3 and 4- are pipes su 'iplied with air under pressure from the pipe 5 leading from a source of com 'iressml air 3; .7 is a. flexible tube leading to the nozzle H; and 9 is a flexible water supply pip'e leading to the casing 10.

The lower end of the pipe 3 is guided in the block 11 secured to the pipe 4, and the pipe 4 is adjustal'ilc back and forth in the casing by means of the screw 12 so that the space between the block 11 and the inclined bottom of the casing 1 can be varied to adjust the feed of the plaster .of Paris. The connection 13 is flexible to permit this movement, and the pipe 4 is perforated.throughout its length to permit the air to pass tlirough the plaster of Paris and feed it forward. A valve 14 in the air pipe gov erned by the connections 15. permits of the regulation of the air supply. It will be seen thatthisarrangement provides for the 'n-ojcr.:tion under pressure of a mixture of plaster of Paris and air through the pipe 7 and the nozzle 8. The nozzle 8 is provided with 'aseries of forwardly projecting openings 16 by means of which water is admitted .to the nozzle from the casing 10.

in operation, the nozzle is used to spray .the mixed plaster and water upon the surface of the table 17 asdndicatrd' in Fig, 2, the method of application correspomling to that in painting with an air brush. The material. is sprayed over the area to wh ch the sheet of glass is to be applied until a layer of the desired thickness is provided,

' plied ,little excess plaster to after which the sheet of and pressed into osition. In case another sheet is to be app ied to the same table, the process is repeated, the sheets 18 and 19 as applied to the table being illustrated in Fig. 3.-

I have found that by the use of this method, the plaster of Paris can be apin,a fraction of the time required by the old process, and that it can he applied in glass is applied a, layer of uniform thickness, thus securing a, saving in time and in plaster. Since-the plaster can be applied uniformly there is be squeezed out and the upper surface of the glass is more level than was the case with the old process. I also find that the bond between the plaster and the glass ismuch stronger than with the old process and this, I believe, is due to the fact that the period of application ofthe glass is much less than with the, old process, so that there is a timehetween the. imixture of the plaster and water and the smaller less of strength due to the initial set occurrmg betore the glass is in position. The mixing of the plaster and water is also more thorough since there is no opportunity for the materials to become unmixed as is the case where the mix ng is done in buckets, and as a result the mixture is more uniform with my process and the strength of the plaster is greater. A further saving of time with the new process occurs in the 0peration of pressing the glass down into the plaster of Paris in a stream, hydrating the said stream as it moves forward, directing' the said stream upon the table to form a bed of uniform thickness, and then apply ing a glass sheet upon the said hcd.

HARRY F. LEWIS.

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