Abstract: A self-propelled work apparatus, especially a lawnmower, includes a chassis, at least one tool and a drive motor for driving the tool. The tool is height-adjustable with respect to the chassis. A setting unit is provided to set the relative position of the tool with respect to the chassis. The setting unit includes an actuating motor and a setting gear. The setting gear rotates by less than one full revolution between a first, lower end position of the tool and a second, upper end position of the tool. A detection device is provided to detect the height position of the tool. The detection device includes encoding elements on the setting gear and at least one detector. The at least one first encoding element for the first end position differs from the at least one second encoding element for the second end position.

Abstract: Laser processing methods, systems and apparatus having a super-modulating power supply or pumping subsystem and high beam quality (i.e., brightness) are disclosed. The methods, systems and apparatus have significant benefits, improved operation characteristics and material processing capability over currently available methods, systems and apparatus. In at least one embodiment, the beam quality of a high power solid state laser is improved in the presence of thermal lensing. High power laser cutting, scribing, and welding results are improved with a combination of modulation and high beam quality while providing for improved processing speeds.

Abstract: Laser processing methods, systems and apparatus having a super-modulating power supply (6) or pumping subsystem (5) and high beam quality (i.e., brightness) are disclosed. The methods, systems and apparatus have significant benefits, improved operation characteristics and material processing capability over currently available methods, systems and apparatus. In at least one embodiment, the beam quality of a high power solid state laser (2) is improved in the presence of thermal lensing. High power laser cutting, scribing, and welding results are improved with a combination of modulation and high beam quality while providing for improved processing speeds.

Abstract: A method for generating a circuit-breaking signal in dependence upon the magnitude and duration of an excess current, where a measured quantity, derived from the excess current, is sampled, is converted into digital values, and these values are weighted in accordance with a predetermined function and are added in order to obtain a circuit-breaking signal when the sum exceeds a predetermined comparison value. In order to improve upon a method of this kind in such a manner that, in the case of a diminishing excess current, a false interruption of the circuit is safely prevented, an auxiliary quantity (.DELTA.i) is formed which corresponds to the difference quotient or differential quotient of the measured quantity (M) and when the absolute amount of the auxiliary quantity (.DELTA.i) is already below a predetermined limit value and the sampled value of the excess current is below a predetermined threshold (S), the addition is interrupted.

Abstract: A shock absorber for the absorption of vibrations acting horizontally between foundation and base of an apparatus includes two shock absorbing components which are connected to each other through a pendulum. The free ends of the pendulum are linked in wobble-like fashion to respective ones of the shock absorbing components and at least one friction surface is disposed between the shock absorbing components for absorbing the vibrations and translating the same into heat.