In the formation of such caps the construction of the internal spring sleeve is expensive, both on account of the cost'of the original blank and the subsequent operations of forming it to the required shape.
According to the present invention, I construct such sleeve of flat sheet metal, thereby much simplifying the subsequent operations and considerably cheapening the cost.
In thedrawin'gs which illustrate one embodiment of the invention, I Figure 1 is a plan-of the blank after the first operation;
Fig. 2 shows the second step.
Fig. 3 is a perspective view of the blank I partly bent.
Fig. 1 is a similar view showing the blank completely bent to circular form;
Fig. 5 is a view of the blank after the contracting and screw threading operations.
Fig. 6 is a view of the completed cap.
In practicing the invention the **blanks are cut from a strip of sheet meta***l, the first operation cutting the blank A to its proper -dimensions and punching holes B B and marginal semi-circular recesses B B; also smaller holes C C are punched in the required number. I I .The blank is then slotted by a suitable press, as shown at D D, the slots extending to a portion close to the upper edge of the **blank **and joining the holes B B at their Specification of Letters Patent.
provide certain improve-- Patented Jan. 31,1922.

https://patents.google.com/patent/US1405042A/en

tambem https://www.crifer.com.br/servicos/corte-transversal/ Corte Transversal de Chapa (Blank)
» Espessura de corte: 0,28 a 3,00 mm

» Largura de corte: 20 a 1900 mm

» Comprimento de corte: até 12000 mm

» Capacidade de desbobinamento: 15 toneladas