Locomotive boiler construction; a practical treatise for boilermakers, boiler users and inspectors .. . Figure 67Punch for cutting along curved lines. and that to fulfill the conditions of a boiler, water shouldcirculate freely about the tubes. The space should there-fore be made liberal. The tendency is also toward fewertubes and more space between them. One of the most useful things in connection with thepunching machine is the cutting punch shown in Fig. is used for cutting along long curved lines. The shear-ing machine is used for removing metal on the outsideof any curve and the cut
Locomotive boiler construction; a practical treatise for boilermakers, boiler users and inspectors .. . Figure 67Punch for cutting along curved lines. and that to fulfill the conditions of a boiler, water shouldcirculate freely about the tubes. The space should there-fore be made liberal. The tendency is also toward fewertubes and more space between them. One of the most useful things in connection with thepunching machine is the cutting punch shown in Fig. is used for cutting along long curved lines. The shear-ing machine is used for removing metal on the outsideof any curve and the cutting punch for removing themetal on the inside of such a curve. The punch is shown 105 Operation of cutting punch. at P, and it is seen to have a tit portion P from J4 to J^$in diameter, and also a taper portion S which is the cut-ting portion of the punch. The stroke of the machine is. The Derry-Jollard Co. Figure 68Smoke box sheet with bridges. such that the tit T always remains in the sheet. As thepunch returns, the sheet K is pushed into the inclinationS until it touches the tit, when it is ready for the nextstroke. S is usually made to cut from iy2 to 2 plan view of the punch is shown at A being semi-circular at both ends. Fig. 68 shows a smoke box sheet which has beenpunched with a cutting punch, allowing the bridge A, Band C, to remain in order to make a more satisfactory jobof the sheet when it is put through the bending rolls. Thenecessity for leaving these bridges together with the metalthey support will be mentioned again in another section. The stake portion of a horizontal punching machineis shown in Fig. 69. All flanges as they come from themachine are irregular in shape as will be seen by referenceto the line A in the figure. E is the height of the flangethat is required to suit the boiler. The sheet is held inposition and the metal A remove
Size: 2800px × 892px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidlocomotivebo, bookyear1912
