Bed
A term applied to numerous things occurring in foundry practice. When a prepared surface is formed in the floor on which to lay the pattern it is usually called a bottom bed. Sand that has been rammed on the bottom of a cupola or furnace, for the molten metal to rest upon, is the cupola, or furnace-bed. Open sand-plates are cast on beds, constructed by means of two straight-edges,--a parallel straight-edge and a level,--thus: one straight-edge is packed until it agrees with the level; the other is the set at the required distance, and, by means of the parallel straight-edge, each of its ends are made to agree with the level, the proof of which is obtained by trying the level on the second straight-edge, when the level will be exact if the operation has been correctly performed. The sand within the straight-edges is then brought to the requisite density, extending some little above, when another straight-edge, long enough to reach across, will serve to strike off the superfluous sand and leave a bed that will be level in every direction. See BEDDING-IN; SAND-BED; LEVEL; STRICKLE.
TABLE, SHOWING THE WEIGHT OR PRESSURE A BEAM OF CAST IRON, 1 INCH IN BREADTH, WILL SUSTAIN, WITHOUT DESTROYING ITS ELASTIC FORCE, WHEN IT IS SUPPORTED AT EACH END AND LOADED IN THE MIDDLE OF ITS LENGTH, AND ALSO THE DEFLECTION IN THE MIDDLE WHICH THAT WEIGHT WILL PRODUCE. BY MR. HODGKINSON, MANCHESTER. Length. 6 feet. 7 feet. 8 feet. 9 feet. 10 feet. Depth in In. Weight in Lbs. Defl. in In. Weight in Lbs. Defl. in In Weight in Lbs. Defl in In. Weight in Lbs. Defl. in In. Weight in Lbs. Defl. in In. 3 1,278 .24 1,089 .33 954 .426 855 .54 765 .66 3 1/2 1,739 .205 1,482 .28 1,298 .365 1,164 .46 1,041 .57 4 2,272 .18 1,936 .245 1,700 .32 1,520 .405 1,360 .5 4 1/2 2,875 .16 2,450 .217 2,146 .284 1,924 .36 1,721 .443 5 3,560 .144 3,050 .196 2,650 .256 2,375 .32 2,125 .4 6 5,112 .12 4,356 .163 3,816 .213 3,420 .27 3,060 33 7 6,958 .103 5,929 .14 5,194 .183 4,655 .23 4,165 .29 8 9,088 .09 7,744 .123 6,784 .16 6,080 .203 5,440 .25 9 9,801 .109 8,586 .142 7,695 .18 6,885 .22 10 12,100 .098 10,600 .128 9,500 .162 8,500 .2 11 12,826 .117 11,495 .15 10,285 .182 12 15,264 .107 13,680 .135 12,240 .17 13 16,100 .125 14,400 .154 14 18,600 .115 16,700 .143 12 feet. 14 feet. 16 feet. 18 feet. 20 feet. 6 2,548 .48 2,184 .65 1,912 .85 1,699 1.08 1,530 1.34 7 3,471 .41 2,975 .58 2,603 .73 2,314 .93 2,082 1.14 8 4,532 .36 3,884 .49 3,396 .64 3,020 .81 2,720 1.00 9 5,733 .32 4,914 .44 4,302 .57 3,825 .72 3,438 .89 10 7,083 .28 6,071 .39 5,312 .51 4,722 .64 4,250 .8 11 8,570 .26 7,346 .36 6,428 .47 5,714 .59 5,142 .73 12 10,192 .24 8,736 .33 7,648 .43 6,796 .54 6,120 .67 13 11,971 .22 10,260 .31 8,978 .39 7,980 .49 7,182 .61 14 13,883 .21 11,900 .28 10,412 36 9,255 .46 8,330 .57 15 15,937 .19 13,660 .26 11,952 .34 10,624 .43 9,562 .53 16 18,128 .18 15,536 .24 13,584 .32 12,080 .40 10,880 .5 17 20,500 .17 17,500 .23 15,353 .30 13,647 .38 12,282 .47 18 22,932 .16 19,656 .21 17,208 .28 15,700 .36 13,752 .44 NOTE.--This table shows the greatest weight that ever ought to be laid upon a beam for permanent load; and if there be any liability to jerks, etc., ample allowance must be made; also, the weight of the beam itself must be included.