Abstract: A modification of a fuel filter for use with an internal combustion engine is described. The modification provides a switch element that, in conjunction with the water level sensor conventionally provided in the filter, enables detection of the presence or absence of a filter insert or whether an improper insert has been installed in the filter housing. When the filter insert is inserted or removed, the switch element makes or breaks an electrical circuit that is part of the water level sensor. The control unit is thus able to detect switch states of three different variables in the filter: the water level is/is not too high; the filter insert is/is not installed; or the correct filter is/is not installed. The control unit accordingly allows or prevents operation of the motor, depending on the detected switch state.

Abstract: The invention relates to a fuel filter comprising a housing, an interchangeable filter cartridge that is located in the housing, a water collection chamber and a water level sensor. Said water level sensor has two electric conductors, which can be electrically interconnected by means of water if there is a correspondingly high water level. The filter is provided with a switching element that can move between a contact position and an interruption position, said switching element making contact with the two conductors in the contact position and the contact between the switching element and at least one of the two conductors is interrupted when the switching element is in the interruption position. The electric resistance that occurs between the two conductors has a first value, when the switching element is in the first contact position and a second value that differs from the first, if the switching element is in the interruption position.

Abstract: A free-jet centrifuge for the cleaning of lubricating oil comprising, a housing with a removable cover, a rotor rotatably arranged in the housing and with channels for feeding and removing the lubricating oil. The rotor is of split design with a drive part and a dirt trapping part which can each be flowed through by their own partial lubricating oil flow and which are designed with a torque transmission device which is engageable and disengageable. The dirt trapping part is separable from the drive part. A device is provided to prevent or restrict the axial mobility of the dirt trapping part relative to the drive part, which is ineffective or detachable when the cover is removed. The drive part extends from the bottom towards the top into the dirt trapping part or entirely through it. The drive part comprises all parts serving for the rotatable bearing of the rotor and the drive part is securely positioned against axial removal with an opened cover.

Abstract: A free-jet centrifuge for the cleaning of lubricating oil comprising, a housing with a removable cover, a rotor rotatable arranged in the housing and with channels for feeding and removing the lubricating oil. The rotor is of split design with a drive part and a dirt trapping part which can each be flowed through by their own partial lubricating oil flow and which are designed with torque transmission means which are engageable and disengageable. The dirt trapping part is separable from the drive part. Means are provided to prevent or restrict the axial mobility of the dirt trapping part relative to the drive part, which are ineffective or detachable when the cover is removed. The drive part extends from the bottom towards the top into the dirt trapping part or entirely through it. The drive part comprises all parts serving for the rotatable bearing of the rotor and the drive part is securely positioned against axial removal with an opened cover.

Abstract: A drilled hole (1) is produced by means of a drilling rod assembly comprig a succession of rod elements (7d) to be arranged end to end. For this purpose, a vertical shaft (2) is produced in the ground, of constant horizontal section and preferably insufficient for a man to be able to work towards the bottom of it, the rod assembly is displaced therein from an opening located in a front wall of the shaft, and the elements (7) of the rod assembly are selected so that they have an axial length less than the distance separating the said opening in the front wall of the shaft from the opposite rear wall.

Abstract: The invention relates to a filter for cleaning lubricating oil, especially for internal combustion engines of motor vehicles, with a filter case which, when installed, is in an at least approximately upright position. It has a cylinder-shaped oil filter cartridge and an inlet for the dirty oil flowing through the filter cartridge, plus an outlet for clean oil connected to the central interior part of the filter case and situated in a base at the bottom end of the filter case. A drain passage at the bottom end of the filter case becomes connected to the inlet chamber of the filter case whenever the filter cartridge is removed, plus a closure which cuts the drain passage off from the filter case.

Abstract: The invention relates to a filter for cleaning lubricating oil, especially for internal combustion engines of motor vehicles, with a filter case which, when installed, is in an at least approximately upright position. It has a cylinder-shaped oil filter cartridge and an inlet for the dirty oil flowing through the filter cartridge, plus an outlet for clean oil connected to the central interior part of the filter case and situated in a base at the bottom end of the filter case. A drain passage at the bottom end of the filter case becomes connected to the inlet chamber of the filter case whenever the filter cartridge is removed, plus a closure which cuts the drain passage off from the filter case.