| 摘要 |
The present invention relates to a method for making aluminium boiler units for coffee making machines, in particular boiler units having a faceted upwardly tapering side surface. The method comprises the step of drawing an aluminium disc, so as to provide a hollow body, having substantially the configuration of the boiler unit to be made, but provided with a closed top end and an open bottom end. About the top end portion of the hollow body is formed, by a rolling operation, a thread for screw engaging with the top portion of the coffee making machine. Then, by a cutting operation, is removed the metal disc closing the top end portion of the boiler unit body, whereas the bottom end portion thereof is closed by an aluminium bottom element which is clamped to the boiler unit body. <IMAGE> |
