Pattern making and foundry practice; a plain statement of the methods of wood pattern making, as practiced in modern pattern shops, with complete instructions for sweep work and notes on foundry practice, together with numerous drawings taken from actual patterns .. . se of two half-circles of plank ofthe desired radius, secured in position with threestrips of wood, as shown in Fig. 6Q. The core ispacked in this frame and swept off with a straight-edge. Or it may be required to sweep up astraight, round core of different diameters, hav-ing offsets, etc. To do this, get out a plankwhich is of t


Pattern making and foundry practice; a plain statement of the methods of wood pattern making, as practiced in modern pattern shops, with complete instructions for sweep work and notes on foundry practice, together with numerous drawings taken from actual patterns .. . se of two half-circles of plank ofthe desired radius, secured in position with threestrips of wood, as shown in Fig. 6Q. The core ispacked in this frame and swept off with a straight-edge. Or it may be required to sweep up astraight, round core of different diameters, hav-ing offsets, etc. To do this, get out a plankwhich is of the shape and size of a longitudinalsection through the center of the core, as at 6 inFig. 67a, allowing for the thickness of the halfcircles / /. Fasten the half circles / / in place,and if possible secure them from warping withgood heavy angle irons let in flush with the AND FOUNDRY PRACTICE 115 wood, as at c c, Fig. 67a. Now get out asweep, a. Fig. 67a, which exactly fits the side ofthis plank or bottom board. Hang the sweepby the two arms c c to the center pins d d; allof which will be easily understood by referring toFig. 67a and Fig. G7b, The sweep a should bebeveled on both sides towards the center on theworking edge, so that it will press the sand in as. T^ould for fhited ceRumn ma^t entirely ef core^ it passes back and forth over it. To make ahalf core on this device it is only necessary topack the sand on the bottom board and pass thesweep a backwards and forwards over it, fillingin sand until the desired form is obtained. Fig. 68 is designed to illustrate the manner inwhich bolt holes, etc., are moulded at rightangles to each other through a casting. By 116 PATTERN MAKING referring to the drawing, Fig. 68, it will beobserved that the holes 6 6, if slightly tapered sothey can be drawn out of the sand, will leavetheir own core; while the hole a, Fig. 68, willnot draw out of the sand with any core yet de-scribed. For ai] such work a peculiar core andcore box, called a st


Size: 1692px × 1477px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: ., bookcentury1900, bookdecade1900, bookpublisherchicagofjdrakeco