Flange-Coupling Pattern for Hand Molding. In Fig. 296 is illustrated one half of a flange coupling such as is commonly used on mill shafting. Fig. 297 illustrates a radial section view of a pattern for hand-molding this coupling.
The web c is to be made of glued and splined segments, as recommended for the web of the disk crank in Part II, Pattern Making. A shoulder is turned at the edge of the web to receive the rim, which is built of several layers of segments, the whole being turned on a faceplate. The hub d and core prints e and f are to be made loose. The hub stock will have a 1-inch hole through its center and be turned on a hard-wood or steel arbor. A rabbet is turned at one end, and five or six segments fitted, glued, and nailed into this rabbet to form the stock for the fillet. The hub should have a normal draft - 1/8 inch per foot - and a small chamfer or rounded edge on its outer end. The grain of the stock should be parallel to the axis of the hub, whether the stock is made of glued stock or not. The dowel pin m should be glued in the hub. Having the hub and core prints loose allows the coupling to be adapted to several diameters of shaft. This requirement occurs when an increase or reduction of the diameter of a line of shafting is made.
Fig. 296. One-Half of Complete Flange Coupling.
It is now desired to construct a molding machine, Fig. 298, with as little expense and delay as possible, whereby a machine molder may produce the casting. The principle used will be a hand roll over stripping-plate process. Figs. 298, 299, 300, and 301 are used to show the equipment requirements, and like letters represent like parts in all figures. Fig. 299 illustrates a section of the completed machine, on a center line through the flask pins ii. Pattern. The only alteration in the pattern for the flange and web of the couplings will be in the thickness of the web c, which must be thick enough to reach through the stripping plate b and is to be fastened to the draw plate a with three or four flat-head wooden screws. Follow the process already established when making the web, flange, and hub. The hub shall be made loose, and the core prints also, unless the diameter of the cored hole is standard to the hub, when it will be best to make the nowel core print a part of the hub.
The stripping plate, Figs. 298 and 299, at 6, and the core plate, Fig. 298, at n, are alike in size. The width should not be greater than the flask, Fig. 301, so that what sand falls over the outside of the flask should fall to the floor. The length, however, should extend beyond the flask far enough to include the flask pins i. The stock for these plates is to be about 1 3/6 inches thick, and had better be made of narrow strips of stock glued together, with the heart side reversed on alternate pieces so as to prevent warping. The stock should be dry, and have a heavy spline glued in each end, as shown.
The draw plate should be about the same length and thickness as the stripping plate. The width may be somewhat less than the stripping plate, but not less than the diameter of the pattern, and not so as to cause the outfit to tip during the ramming of the mold. This plate is not splined at the ends, but heavy cleats are glued and screwed in place, as shown in Figs. 298 and 299, first cutting out stock at the ends of the plate to form hand holes.
On both the stripping and draw plates lay out a center line for the location of the pattern and the flask pins, and also a checking line parallel to this center line, spaced off exactly one-half of the diameter of the flange of the pattern, c/2. After establishing the location of the pattern and flask pins, the 1-inch hole can be bored in the cope plate, and the hole in the stripping plate for the flange c can be carefully sawed with a jig saw or keyhole saw. This hole should be fitted over the pattern by blue-chalking the outside of the flange and trimming the stripping-plate stock where the chalk shows. This hole will have to be about 1/22 inch larger in diameter than the pattern so there will not be any binding when the pattern is drawn through the stripping plate. The stock is bound to swell to some extent, but a small amount of sand getting between pattern and stripping plate will grind out the stock, so there will be little trouble from this source.
The flask pins i are to be made of cast iron or machine steel. The diameter of the pin is to be about 3/4 inch, and the flange about 2 inches in diameter and 3/8 inch thick. The diameter of the pin should be parallel, to a height of about 1/2 inch, and slightly tapered above this point to a total height of about 1 1/4 inches. The flange should be drilled and counterbored for three flat-head wooden screws, or, better yet, tapped for three flat-head stove bolts, which will be passed up through the plate stock. Coun-terbore holes in the stripping plate and cope plate, for the flanges of these flask pins, being very careful to center these holes accurately.
Fasten the pattern to the draw plate and place the stripping plate in position. Test the dimensions gg with inside calipers, as shown in Fig. 299 also check the dimension h with the flaskpin jig shown in Fig. 300. This jig is made of flat steel stock, and the holes are drilled with the same jig which is used for drilling the holes in the flask, Fig. 301. Test the distance from the checking line to the flask pins with hermaphrodite calipers, as shown in Fig. 298. Test the location of the cope core print in the same manner. The flask pins can be adjusted by loosening the screws and driving a wedge between the pin and the plate stock so as to force the pin into the correct location. The alignment of the pattern and the flask pins should be such that the mold can be closed with the cope either way around; however, the location of the sprue will determine this.
Fig. 300. Jig for Looting Centers of Flask Pine on Machines.
Fig. 301. Sketches of Cast-iron Flask Showing Closing Pins.
The pattern for the gate k, Fig. 298, is crescent shaped and is nailed to the stripping plate. The pattern maker had better consult the experienced molder for the dimensions of this gate. A small hole should be drilled in the cope plate at o, Fig. 298, so as to locate the sprue opposite the center of the gate pattern.
Pattern numbers, size of coupling, or other means of identification should be marked on each end of the stripping plate. In this location they can readily be seen when the patterns are on the storage rack. Do not place these marks on the ends of the draw plate, as the pattern is rapped by striking the ends of the draw plate before the pattern is drawn. Closing pins, Fig. 301, are used while closing the mold, and these are then to be removed.