Abstract: A power tool, particularly a hand-held power tool, has a striking mechanism with a striker transmitting impact energy to a tool, a drive operative for actuating the striker through an air cushion, and a heat insulating element which is associated with the striker and insulates the same from heat generated in the air cushion during the operation of the power tool. The heat insulating element may simultaneously be formed as a mechanical buffer.

Abstract: A jig for mounting workpieces which are to be doweled together, with the jig including two workpiece receiving spaces disposed one above the other and separated by a spacer member. Flat sides of the workpieces are adapted to be clamped against the spacer member with front edge surfaces thereof being brought into abutment with a base plate of the jig. At least one drill accommodating hole communicates with the receiving spaces for the workpieces for enabling of a drill accommodating hole in the workpieces. At least one additional drill hole, communicating with the other workpiece receiving space is provided in the base plate at the same distance from the spacer member as the first drill accommodating hole and in the same vertical plane so as to enable the use of the jig for a front to front side doweling of the workpieces.

Abstract: Disclosed is a method and device for regulating the preparation of fuel-and-air mixture in a carburetor, fuel injection system and the like of an internal combustion engine. The device includes an oxygen probe directly communicating with the combustion chamber of the engine. Periodically fluctuating output signal of the probe is applied to an averaging circuit which produces an average output signal over a predetermined number of engine cycles. The shape and length of the averaged output signal is indicative whether the mixture ratio is lean or rich. The averaging can be made by means of a lowpass filter, an integrator or at least one counter counting in response to the angular position of the crankshaft or the predetermined time intervals. When the probe output voltage has the form of a hump or bulge, its length or area is used for determining the actual .lambda. value in the rich range of ratios of the mixture.

Abstract: A method of and a device for a self-diagnosis of setting members in complex controlling and regulating systems, particularly for the self-diagnosis of an idling speed air charge adjustor of an internal combustion engine, includes the following functional stages: the self-diagnosis is performed at certain operational conditions at which a regulating path governed by a regulating subsystem pertaining to the setting member does not react to a change of the latter and the operation of a motor vehicle thus remains unaffected; the comparing of plausibility of the control signals for the setting member with a second control signal from another regulating subsystem is performed by comparing both control signals with a known, previously determined relation, which is stored in a memory.

Abstract: A rosary device on a wrist watch or clock has electrically energizable elements in a pattern, the elements having different characteristics corresponding to different rosary prayers.

Abstract: An automatic mail banding apparatus is disclosed in which mail is positioned in a stack in a mail receiving tray and is clamped to a movable portion of the tray. A rubber band applying assembly receives a rubber band at a position along the side of the tray, expands the band while axially aligning the expanded band with the stack of mail, moves the band axially toward the stack to surround the stack with the expanded band, and then releases the band around the stack. The movable portion of the tray pivots to move the stack to a new orientation while the stack of mail remains clamped to the movable portion of the tray, and a second band is applied to the stack by the band applying assembly in a transverse orientation to the first band.

Abstract: For saving lateral space in a multitrack magnetic head, the connection lead paths (11, 12) run separately side by side along the outside surface of one magnetic layer (13) of the yoke and connect with the conducting strip that runs between the magnetic layers at the open end of the yoke by straps (18, 19) running around the side edges of the upper magnetic layer. Outside the region of the yoke these conductor straps are wider and are superposed one on the other, with an insulating layer between them, for lower resistance loss (see lower part of figure).

Abstract: A method and apparatus for shielding an air flow rate meter, in particular a hot wire air flow rate meter, or protecting it, from air column fluctuations in the intake tube on an internal combustion engine arising from the non-uniform aspiration of air by the engine. Before the air flow rate meter as viewed from the inlet valve area of the intake tube, elastic diaphragm means are disposed such that they form an interior chamber in the intake tube which is sealed off from the atmosphere on the one hand, yet is embodied such that a virtually constant pressure, which corresponds to atmospheric pressure, can be maintained in it. As a result, pressure waves arriving from the intake tube are absorbed prior to contact with the air flow rate meter and transmitted in terms of their energetic effects to the ambient air, so that the air flow rate meter is uncoupled from the air column fluctuations in the intake tube that are generated by the engine.

Abstract: To reliably provide ignition energy only to specific spark plugs (11, 12; 14, 15) of a multi-cylinder internal combustion engine (ICE), a double-E core has a main or common or central branch, and separate primary (6, 8) and secondary windings (10, 13) located in shunt core branches (18', 19'), each secondary winding being associated with respective spark plugs. The magnetic circuits of the primary windings including the common branch and single air gaps (20, 21), each in the shunt magnetic paths (18, 19), so that the flux change generated upon interruption of current flow through the respective primary windings need pass through one air gap only for the associated concentric secondary, buth through two magnetically serially placed air gaps for the other secondary.

Abstract: An apparatus for illuminating passive liquid crystal displays is proposed, in which bright display elements appear in negative contrast against a dark background. Masks (21) in the vicinity of the support points (18) of the liquid crystal display (10) are supposed to effectively disappear from the apparent image of the display. To this end, a photoconductor (22) into which light outside the display enters is disposed in front of the liquid crystal display (10), and this photoconductor has surface regions (22a), in the vicinity of the masks (21), which put out a portion of the light toward the front (drawing figure).

Abstract: To simplify the anti-lock brake system in which two brake circuits (I,II) are used, connected to diagonally located wheels (2,3; 1,4), magnetic valves are provided in which one braking circuit fully controls the wheels thereof and the wheels of the other braking circuits are controlled by a slave or follower valve system (9,10) which includes a biassed valve (10) controlling the braking pressure at the front wheel of the second braking circuit (1) with a difference pressure, so that the second slave control valve operates as a differential pressure control valve (10,32). The differential can be controlled as a function of absolute braking pressure, as sensed, for example, by a brake pressure piston (30) and a biassing spring (30a) therefor.

Abstract: A planar semiconductor structure is proposed which has a monocrystalline semiconductor chip (10) of a specific conductivity type, a first zone (11) of the opposite conductivity type introduced into the semiconductor chip (10) by diffusion from a main surface and together with the material making up the semiconductor chip (10) forming a p-n junction (12), and a passivation layer (13) covering this same main surface of the semiconductor chip (10) with the exception of contact windows. A second, annular zone (14) acting as a stop ring and having the same conductivity type as the basic material making up the semiconductor chip (10) but a higher concentration of impurities is introduced into the semiconductor chip (10) from the same main surface such that it surrounds the first zone (11).

Abstract: A household slicing machine wherein a disc-shaped knife is rotatable in a vertical plane in response to starting of an electric motor as a result of depression of a trip which is mounted in the housing of the slicing machine. The trip can be depressed only when a detachable guard for the knife is held in an intermediate position in which the guard and an abutment for the foodstuff to be sliced define a gap wide enough for movement of the foodstuff into the range of the rotating knife. The guard causes a spring-biased blocking device to prevent depression of the trip when the guard is shifted to a position in which it cooperates with the abutment to prevent access to the knife as well as when the guard is actually detached or is held in a position in which it is detachable from the housing.

Abstract: A fuel injection nozzle for internal combustion engines, having a valve needle loaded with a closing spring and having a damping device which damps the end stroke (h.sub.2), leading into the fully open position of the valve needle, in accordance with the number of strokes and/or stroke length of the valve needle or with the quantity of fuel put through per injection event. The valve needle is coupled with a second damping device, which in partial-load and full-load operation also, at least intermittently, damps the initial stroke (h.sub.1), leading out of the closing position, of the valve needle. As a result it is attained that for a wide range of the performance graph, the ratio of the injection quantity to the duration of injection can be optimized in terms of the fuel consumption and emission of toxic substances, without having to accept increased combustion noise in the critical ranges.

Abstract: For optimization of the ignition timing of an internal combustion engine, the crankshaft angle at which the maximum combustion chamber pressure is measured is determined for one or all of the cylinders of the engine, and is used as the report value for comparison with reference value to produce an error signal that is capable of shifting the ignition timing to an optimal value. Optimization is accomplished by modifying the reference value in a manner controlled by the measurement of the work done in each of the cylinders, as computed from a crankshaft angle signal in a combustion chamber pressure signal, the work done signal being multiplied by the error signal before being furnished to an integrating controller that averages the multiplier output with the results obtained for previous cycles of the engine to produce the reference value signal. The multiplication of the work done signal by the error signal makes the jist of the reference value signal proportional to the error signal magnitude.

Abstract: A wide band constant duty cycle pulse train processing circuit where the pulse train frequency varies is proposed. The circuit serves primarily to obtain the basic clock in decoding signals encoded in the bi-phase mark code and includes a pulse-shaping or wave-shaping circuit, which receives the data signals and is followed by a low-pass filter; a differential amplifier circuit, one input of which is connected to the output of the low-pass filter and the other input of which is connected to a variable voltage source; and a current source, controlled by the differential amplifier circuit, at the input of the wave-shaping circuit determining the pulse length. The closed control loop between the output and the input of the wave-shaping circuit that determines the pulse length causes the duty cycle established at the variable voltage source to be maintained over wide ranges of the incident pulse train frequency.

Abstract: A load-dependent brake force governor is proposed, in which the actuation linkage which influences the governor valve is additionally used for the purpose of actuating a signal transducer which then produces a load-dependent signal. The signal transducer can be either a control valve (FIG. 1) or an inductive transducer (FIG. 2). In this manner, even when the brake is not actuated, a load-dependent signal is available for use, with which further devices, such as an engine brake or a retarder, an axle load indicator or a headlight range control means, can be actuated. A supplementary pickup of the movement of the vehicle chassis can be omitted. The brake force governor is preferably applicable to motor vehicles.

Abstract: An electromagnetically actuatable valve is proposed, which serves in particular to inject fuel into the intake tube of internal combustion engines having fuel injection systems. The fuel injection valve includes a valve housing, a core having a magnetic coil and an armature, which is guided by a guide diaphragm and is firmly connected to a bearing tube. Protruding into the bearing tube is a spherical pivot segment of a valve member, which is on the one hand partially surrounded and engaged by a pan-shaped segment of the bearing tube and on the other hand is axially fixed by means of a retainer ring. Joined to the pivot segment is an elongation segment, on the other end of which a spherical sealing segment is secured, and which is further radially guided by means of a guide ring and thereby cooperates with a valve seat in a nozzle body. Since the pivot segment is pivotably supported in the bearing tube, shear forces at the armature have no effect on the sealing segment.