Abstract: An apparatus for end face welding of plastic parts that includes two spaces clamping devices for retaining the plastic parts, a heating device movable into an operative position between the clamping devices, and a stop element for retaining the heating device in its operating position, and in which the stop element is automatically disengaged from the heating device upon a return movement of a carriage supporting one of the clamping devices after heating of the ends of the parts to enable automatic return of the heating device to its initial position.

Abstract: An explosive powder charge operated tool for driving nails includes a housing with a muzzle part mounted in and projecting axially outwardly from the housing. By moving the muzzle part rearwardly into the housing, the tool is in the ready-to-fire condition. A magazine is supported at one end within the muzzle part and extends generally radially outwardly from it. A slide in the magazine feeds individual nails in a nail strip into the bore in muzzle part into position to be driven by a piston located within the housing. When all of the nails in the strip have been driven from the tool, one end of the strip projects into the muzzle bore. A stop shoulder on the one end of the strip faces toward an end face on the housing and contacts the end face when the muzzle part is pressed into the housing, preventing the placement of the tool in the ready-to-fire condition.

Abstract: An explosive powder charge operated fastening member driving tool has a muzzle part which can be locked within and released and removed from the tool housing by rotational movement and axial movement relative to the housing. When the tool is not ready to be fired, a contact pressure sensor projects from the front end of the muzzle part. By pressing the sensor opposite to the firing direction it compresses a firing mechanism spring and the tool is ready to be fired. Stop elements are provided on the muzzle part and stop surfaces are located on the tool housing. When the muzzle part is in the unlocked condition, the stop elements can abut the stop surfaces and block the displacement of the contact pressure sensor preventing it from compressing the firing spring mechanism so that the driving tool cannot be placed in the ready-to-fire condition.

Abstract: A device for driving fastening elements, such as nails, staples and the like, includes a magazine extending transversely from a driving unit. A follower is located within the magazine for supplying fastening elements to the driving unit. For filling the magazine with fastening elements, the follower can be secured in a loading position. The follower is secured by a stop pivotally attached to the follower which engages an abutment on the magazine. The follower is released from the loading position by an actuating member movably mounted on the magazine so that it can contact an engagement part on the follower and pivot the stop out of engagement with the abutment.

Abstract: In a pneumatic nailer using compressed air for driving nails, a work chamber contains a drive piston and is in communication with a storage chamber for effecting the return of the drive piston after it has driven a nail. A valve unit controls the supply of additional compressed air into the storage chamber. A switching element is arranged to react when a predetermined compressed air pressure is exceeded for controlling the flow of compressed air through the valve unit to the storage chamber. The switching element can be a pressure limiting valve. The combination of the switching element and valve unit avoids unnecessary compressed air losses in the higher pressure operating ranges.