Manufacturing Operations on a Combination Sugar Bowl
SYNOPSIS — In this article are shown some of the operations required in making a combination sugar bowl. All the tools are not shown, as similar work is done on various elements. Examples of drawing, forming and trimming dies are, however, illustrated. Types of wooden chuck used for the final turning are also shown.
The H. O. Rogers Silver Co., Taunton, Mass., has recently commenced the manufacture of the combination sugar bowl seen in Fig. 1. The most important and interesting operations in making this piece of plated silverware are here described. With the exception of the ornamental bird, the handles and spoon holders, which are cast, the bowl is pressed.
In making the body of the bowl the material, which is hard white metal 0.0312 in. thick (No. 22 gage) is first blanked and then given its first drawing operation. The blank is placed in the die. Fig. 2, and receives its second draw with the punch A. By this process the body is formed into an almost semicircular shape, as shown by the part alongside the die.
Finish-Forming the Body
In Fig. 3 is illustrated the punch press for finish-forming the body. The die is made from tool steel and the force from hard white metal. The manner in which the force is made is interesting. After the die block has been machined on the inside to suit the part to be shaped, it is fastened on the machine with four screws, as shown. Molten metal is then poured into the die and the drop A is lowered. The metal is allowed to solidify, some of it entering the slots in the drop. When it has cooled, the drop is raised and any superfluous metal removed. The force thus produced has the correct shape for stamping out the pieces. One of the parts to be formed is shown in the die; another, which has been finish-formed, is tilted against the die.
The next operation is trimming the edges of the body. This work is performed with the press and tools shown in Fig. 4. The piece is placed in the die, as shown, and the punch, which has a circular cutting edge, is fed onto the part, trimming the edge.
Making the Neck
For making the neck, the stock, which is also of the same thickness as the body, is first blanked and then given a drawing operation, the purpose being to assist in the next operation, which is forming. The tools used are shown in Fig. 5. The die A is made of tool steel, and the force B is obtained in a manner similar to that described for the body force. These tools are fitted to a drop press similar to that shown in Fig. 3. One of the necks after being formed may be seen.
The center of the neck is then cut out as the next operation. The formed piece is put in a die, being located by its outside diameter. A punch of the correct size is fed down and removes the center of the neck. The edge of the piece is rolled with the tools illustrated in Fig. 6. The neck is placed in the die A, which is fastened on the bed of a punch press. The punch B, as it is fed down, turns over, or rolls, the upper edge of the neck, following the contour of the punch.
The piece shown on the die has had this operation performed and gives a good idea of the work that is done. The outside edge of the neck is then trimmed to size with the tools illustrated in Fig. 7. The piece is placed in the die A and is located by its outside diameter. The punch B is brought down to trim the edge, leaving it the correct diameter for attaching to the body punching. For the cover, the stock is first blanked, then drawn, after which the forming operation is completed with the tools shown in Fig. 8. The die and force are made in a manner similar to that previously described. One of the formed covers may be seen near the die. The cover is then trimmed on the edge to the correct diam€ter, and the edge is rolled in the same manner as described for the neck. The various parts of the sugar bowl are turned, or skimmed up, so that their outside surfaces will be smooth. For this purpose the pieces are held on wooden chucks, and the machining is done in a speed lathe.
One of the bodies A, Fig. 9, is shown held in the chuck, ready to be turned. Other chucks and parts are on the bed of the lathe. The base, body, neck, spoon holder and handles are then fastened together with solder, and the ornament is attached to the cover in a similar manner. The body is afterward engraved with a design or left plain, as desired.
The final operation is silver-plating and polishing, after which the sugar bowl is ready for the purchaser.
Source: American Machinist - 6th September 1917
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