| 摘要 |
An arrangement in nail driving machines having a nail magazine 6 and feed lines 7 for conveying nails 23 therefrom to one or more nail hammers 1. The latter comprise a pneumatic ram cylinder 8. The said cylinder 9 is connected to a compressed air source by way of a pressure valve 10, and the ram 12 thereof is connected to at least one driving bolt 13 This is displaceable forwards and backwards through a head 14, 31, which is a part of the nail hammer 1, and to which one or more feed lines 7 are connected. In order to specify a pneumatic nail driving machine, which operates with great force and speed despite a low operating air pressure, thereby requiring a less hefty frame construction than previously known nail driving machines, the valve construction comprises a control valve 11, which in response to a pressure pulse shuts off the air outlet line from the cylinder 9 and at the same time opens the pressure valve 10, as a result of which the ram applies a working force. When the pressure pulse ceases, the control valve 11 at the excess pressure still prevailing in the cylinder 9 is made to open the air outlet line again and close the pressure valve 10. A connecting duct 26, 32 carries compressed air down to the underside of the ram 12, so that this is brought back to the ejection position. <IMAGE> |
