US 1887288 A
Description (OCR text may contain errors)
Patented Nov. 8, 1932 UNITED STATES CARL Il'. CLAUSEN, OF GRAYSLAKE, ILLINOIS nnArTsMANs TABLE Application filed. March 29, 1930. Serial No. 440,135.
My invention relates to improvements in 'draftsmens tables, and it consists in the combinations, constructions, and arrangements herein described and claimed- An object of my invention is to provide a draftsmans table which is intended primarily for use in tracing, but which may he used for ordinary7 drafting purposes as well, and in which details, such as fine lines, may be readily located land traced, owing to the novel arrangement of lights underneath the surface upon which the drawing is made.
A further object of the invention is to provide a draftsmans table which is illuminated by electric lights placed underneath the drawing surface, and in which special provision is made for Ventilating the under side of thedrawing surface so as to prevent undue heating thereof.
A furtherobject is to provide a drawing table having atransparent drawing surface in which means is provided for permitting the needle points of the drawing instruments to enter a suiicient distance to permit the effective use of the` instruments, but which will not permit them to lenter too far, thereby obviating the danger of making large holes in the drawing. y
A further object is to provide a device of the type described in which the light from the lamps is evenly distributed, thus obviating the danger of glare and shadows.
A further object is to provide a drafts mans table partly of wood and partly of metal in which the top may be readily removed or replaced to have access to the lamps.
Other objects and advantages will appear in the following specification, and the vnovel features of theinvention will be particularly pointed out in the appendedclaims.
My invention is illustrated in the accompanyiiig drawing, forming part of this application, in which Figure 1 is a plan view of the device, certain parts being shown in section,
Figure 2 is an enlarged sectional detail view of aportion of the device, the section being taken along the line 2-2 of Figure 1, 50
Figure 8 is a sectional detail view along the line 3-3 of Figure 2, and
Figure 4 is a sectional detail View along the line 4 4 of Figure' 3.
In carrying out my invent-ion I provide a central support 1 having a series of sockets 2 for incandescent lamps 3. This central support 1 in reality forms the bottom of a tray, the sides consisting of metal portions 4 which are inclined upwardly and outwardly andhave at their extremities integral vertically extending portions 5. The portions 5 are bent outwardly at their tops and then downwardly to provide flanges 6.
Ventilating openings or slots 7 are provided in the member las shown in Figures 1 and 2, While Ventilating slots 8 are provided in the vertically extending portions 5.
Secured to the inclined portion 4 are legs or brackets 9 which support at their top a baille plate 10. The latter may be made of heat-resisting material such as transparent or translucent glass which will permit the passage of light, but will shield the drawing surface from heat, as hereinafter explained.
Legs 11 are provided, the upper portions of these legs entering between the members 5 and 6 and being secured in position by means of bolts such as that shown at 12. At 13, I have shown a series of rectangular lugs, these lugs-being secured to the metal portions `by means of screws, such as that shown at 14, see Figure 4, and being spaced symmetrically.
The top consists of a rectangular wooden frame 15 having a groove 16 arranged to receive a' plate of glass 17. Surmounting this v glass plate is a transparent sheet of celluloid 18 which, as shown in the drawing, is of a thickness to come-flush with the upper surface of the frame member 15 so as to provide an 90 `ing surface. yceive thumb tacks for .holding the drawing unobstructed drawing surface. The frame member 15, as will be seen from the drawing, extends beyond the legs 11. To the under side of the frame member 15 are secured lugs 19 having a recess arranged to receive the lugs 13. The lugs 19 may be secured to the frame in any suitable manner as by means of screws 20, see Figure 4.
From the foregoing description of the various parts of the device, the operation thereof may be readily understood. Vith the device as assembled and the lamps connected with any suitable source of current supply, not shown, the light is partially reflected by the baille plate 10 and is reflected by the metal surfaces 4 and 5 so as to illuminate the draw- The wooden frame 15 will repaper or tracing cloth inv position, and the light coming through the drawing surface 'will show up details such as fine lines.
T he heat from the lamps is shielded by the` plate 1() andk is carried by the convection currents entering the openin s 7 andpassing out through the openings 8.
of the Celluloid sheet as stated gives a good layer consisting of a sheet of celluloid contacting the upper surface of the plate, said table being provided with a depending lamp supporting member extending underneath said glass plate, and a diaphanous heat det the same time the drawing surfaceis sutliciently heated to cause `the ink to dry in a short time. The provision anchorage for the needle point of the drawing instrument, preventing the-drawings from being mutilated by large holes. l
When it is desired to replace or remove the lamps, the top may be lifted upwardly and may be replaced' after the lamps have been removed or replaced since the lugs 19 form guide means for the lugs 13 'so' that the top iseasily brought to the initial position.
1. A tracing table of the class described, said tracing table including a supported diaphanous flat top portion, said top portion comprising a relatively lrigid diaphanous plate having a tough resilientdiaphanous Lto - the upper surface ofsaidtop portion, said plate beingmade of vitreous material, saidV layer superlmposed on the upper surface thereof forreceiving pointed instruments whereby Aa sheet of paper may be `secured on the-upper 'surface of said top portion, said table being provided with a depending lamp supporting member extending underneath said glass plate,y and a diaphanous heat deflecting member secured to said lamp support# ing member, said heat deflecting member and said plate being spaced apart fromeach other for permitting air to I'nove between the plate andthe heat deiecting member. 1 2. A tracing table of the class described, said tracing tablje including a supported diaphanous flat top portion, said. top portion comprising a relatively A,rigid diaphanous plate havin'g a tough resilient diaphanous layer superimposed 011 the /upper surface thereof vfor receiving pointed instruments whereby a sheet of paper may be secured on