Internal combustion powered device for setting fastening elements
AssigneeHilti Aktiengesellschaft
InventorsHans Gschwend, Johann Buechel
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Abstract
A portable, internal combustion powered work device, such as a device for setting or driving fastening elements into a receiving material, includes a combustion chamber (9) wherein an air-fuel mixture is ignited. A guide cylinder (8) and a piston (7) are axially displaceably guided within the combustion chamber. When the air-fuel mixture is ignited, the piston (7) is driven and, in turn, drives a fastening element into the receiving material. Following the ignition of the air-fuel mixture and the driving of the fastening element, the combustion chamber volume is reduced to approximately zero, whereby a purely mechanical clearing of the combustion chamber is effected without the necessity of an additional flushing air flow.
Claims9
Portable, internal combustion powered work device, such as a setting device for driving fastening elements into a receiving material, comprising an axially extending combustion chamber (9) for receiving and igniting therein an air-fuel mixture, an axially extending piston (7, 7a) guided in the axial direction thereof in an axially extending guide cylinder (8) located within and axially displaceable relative to said combustion chamber, wherein the improvement comprises means (11,12,13,20) in said combustion chamber (9) for reducing the volume thereof to approximately zero after the air-fuel mixture introduced into the combustion chamber is ignited and drives said piston, said means comprising movable combustion chamber wall parts (11, 12, 13) extending transversely of the axis of said combustion chamber (9) and displaceable toward a rear wall (14) of said combustion chamber for reducing the volume thereof.
Dependencies are inferred from the claim text.