Abstract: The invention relates to a process and device for deburring mechanical pieces by laser radiation. The device makes it possible to generate a laser beam of determined power Pa. The laser beam is focused in a focusing spot of a diameter 2.omega.o on the edges of the mechanical piece to be deburred. The focused laser beam causes a volatilization of the burrs of the edge considered: axis ZZ' of the laser beam is approximately concurrent with the edge to be treated and the material is vitrified over a width .omega.o. To obtain, on the edge, a given angle of sharpening .alpha. of a skew surface constituting the edge of a given radius of curvature R, the emission power ##EQU1## where K represents the heat conductivity coefficient of the material of the pieces and Tv and Ts its vaporization and fusion temperatures respectively.

Abstract: A portable communication apparatus (10) for communication between a first person of normal hearing ability and a second person whose hearing is impaired is disclosed. The communication apparatus includes a first housing (12) enclosing a microphone and an amplifier, the first housing (12) being adaptable for being carried in a coat pocket or the like of the first person. The communication apparatus further includes a second housing (22) constructed and arranged to fit over the ear of the second person. The second housing (22) includes means for receiving electrical signals from the amplifier and converting the electrical signals into sound. An electrical connector (20) electrically connects the receiving means in the second housing (22) with the amplifier in the first housing (12) whereby the voice of the first person is amplified and transmitted to the receiving means in the second housing (22), thereby enabling the second person to hear the first person.

Abstract: A television camera system using any television lens and camera in combination achieves automatic video control. The television camera actually used in the television camera system has an erasable memory having memorized therein optical and/or electrical regulation values of the television camera with respect to a standardized television lens for forming the best images or the intended images. Similarly, the television lens actually used in the television camera system has an erasable memory having memorized therein optical and/or electric regulation values of the television camera with respect to a standardized television camera for forming the best images or the intended images. The regulation values read out from these memories are used to control the amount of regulation of the camera control unit.

Abstract: A door interlock switch is provided for an elevator. The switch means is mounted in a housing adjacent the door, the housing having an opening which permits the entrance of a permanent magnet actuating means. A barrier is mounted in the housing to prevent access to the switch by mechanical devices but which will permit the switch to be operated by the permanent magnet.

Abstract: An ink jet printing method by means of an electrostatic type ink jet printing apparatus, in which charging stages forming one scanning line on a recording sheet paper are divided into groups, ink droplets for printing each group being so charged that they impinge on the scanning line at intervals of a predetermined number of stages, the groups having starting stages different from each other, which results in that the influence of the aerodynamic resistance due to the preceding ink droplets on the ink droplet concerned and that of the Coulomb's force due to the preceding and neighboring ink droplets on the ink droplet concerned are suppressed to the minimum and, consequently, the quality of printing is considerably improved.

Abstract: A motor driven drapery closure is provided with means for operating the closure between defined opened and closed positions without the use of limit switches. Means are also provided to stop the operation of the motor and back it up slightly if a significant resistance is met by the closure at a point midway of its travel or as a result of coming to the designed end of its travel. Additional means are provided for operating the closure in response to means for sensing an outside ambient condition such as the level of infrared light.

Abstract: A hearing aid having an earplug that is inserted wholly within the auditory canal of the ear of a user to leave the concha portion of the user's ear exposed for the collection of sound waves for transmission to a microphone as located in the outermost end of the ear plug; the component parts of the hearing aid being wholly contained within the ear plug, thereby avoiding the use of the conventional exposed tubing, wiring and behind-the-ear housing which normally contains the hearing aid controls therein, and a cover member being pivotally mounted on the outer surface of the earplug for concealing the controls thereon and for effecting a smooth uninterrupted outer surface that is aesthetically pleasing as located in the user's ear.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units each include a radio transmitter and a radio receiver. Also included in the base unit is bimodal tuned circuit operable as a filter and as an oscillator.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Included in both the base and extension units are a radio receiver and a radio transmitter. Also included in the remote unit is a bimodal tuned circuit operable as both a filter and as an oscillator.

Abstract: To match the operation of a digital hearing aid directly to user requirements, and to reprogram the hearing aid as the hearing aid and/or user response characteristics change, a digital data processing element (12) processing digitized audio signals is connected to a programmable memory such as an EEPROM or an EARAM which stores predetermined frequency vs. amplitude transfer functions in accordance with user requirements or preference and/or hearing aid operation. Additionally, a memory (ROM 17) is provided storing a test program which causes the digital processor to generate test frequencies or tones at varying amplitudes, so that the transfer function in the programmable memory (15) can be changed or modified by operation of a switch (19) which can be manually user-operated or automatically, for example by measuring stapedius reflexes.

Abstract: A beeper simulator for a telephone answering apparatus which produces onto the telephone line a beeper signal to operate the apparatus in response to digits being dialed onto the telephone from a remote telephone. When preselected digits representing a code are entered onto a remote telephone, the digits are detected by the beeper simulator. It then causes a signal generating means to emit the particular beeper signal needed for operation of the telephone answering apparatus. The beeper simulator can be initialized so that it will produce the particular beeper signal needed to operate the particular telephone answering apparatus.

Abstract: A sectoral horn type loudspeaker includes a throat section and a sectoral part where the width of the horn at the connection therebetween is less than the wavelength of the upper limit frequency. In order to make the sound pressure characteristic flat throughout the frequency range, the directivity angle is changed for frequency bands in correspondence to the horn driver energy conversion characteristic. In particular, the side walls of the horn are bent polygonally at at least one point to increase the opening angle stepwise.

Abstract: The presence of such signals is detected each time the following detection condition is satisfied, namely: that, for the duration of a predetermined "prior activity" period the amplitude of the signal on the telephone channel exceeds a threshold level while successive maximum values taken at short time intervals remain fairly constant in level. Apparatus for performing the method comprises a threshold level comparator (10) and a difference comparator (11) which control a detector (50) followed by a holdover circuit (60). The invention is particularly applicable to inhibiting echo suppressor circuits during telephone signalling or data transfer by telephone line.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units each include a radio receiver and a radio transmitter. The remote unit transmits tone signals of a first amplitude for line seizure and of a second amplitude for line pulsing in response to manually initiated dial pulses. A dial pulse detection circuit at the base unit differentiates between the two types of pulses breaking connections to the telephone line in response to incoming dial signals of the second amplitude.

Abstract: A machine having a conveyor for carrying a workpiece to be magnetized therethrough. It includes two demagnetizing magnets arranged at a mutual angle of 90.degree. and both at 45.degree. to the direction of travel on the conveyor. The magnets are arranged respectively above and below the conveyor, and hence above and below the workpiece on the conveyor, and are spaced apart in the direction of travel of the conveyor. The conveyor, structurally, includes a stationary base, and endless belts carrying paddles, the paddles engaging the workpieces and moving them along the base. The workpieces "float, " capable of moving to any position according to the condition of magnetism in them and the position and shape of the demagnetizing magnets, and upon encountering the field of the demagnetizing magnet that is disposed above the workpieces, the workpieces are capable of being attracted up to that demagnetizing magnet, off of the base of the conveyor.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units each include a radio receiver and a radio transmitter. Also included in the remote unit is a modulator connected to the radio transmitter and circuitry limiting the amplitude of modulated signals produced by said transmitter. A dialing circuit connected to the modulator causes the amplitude of each outgoing signal representing a dial pulse to be transmitted at a level substantially higher than when no dial pulses are present. At the base unit a dial pulse detection circuit differentiates between the modulated signals received by the associated radio receiver, providing connections to the telephone line in response to signals of a first amplitude and breaking the line in response to each received pulse of a higher level amplitude.

Abstract: A driving circuit for a Hall motor comprises a threshold voltage applying circuit for applying a predetermined threshold voltage, a comparing circuit for comparing an output voltage of the Hall element which varies according to the rotation of a rotor of the Hall motor with the threshold voltage, a voltage applying circuit for periodically applying a high input voltage of a pulse-form to a Hall element of the Hall motor, with a period according to an output of the comparing circuit, and a coil driving circuit supplied with the output of the comparing circuit, for producing an activating current to coils of the Hall motor. The period with which the high input voltage of the pulse-form is applied to the Hall element is equal to a period with which a specific magnetic pole position of the rotor opposes the Hall element.

Abstract: A wireless extension telephone system including a base unit connected to a telephone line and a remote extension unit. Both base and remote units including a radio receiver and a radio transmitter. Also included in both base and remote units is a bimodal tuned circuit operable as a filter and operable as an oscillator.

Abstract: A motor control system for a rotating anode type of X-ray tube comprising an axially rotatable rotor provided with a radially extended target disc, an electrically wound stator encircling a portion of the rotor, and a motor controller electrically connected to the stator. The motor controller includes circuitry for initially energizing the stator a predetermined interval of time to accelerate rotation of the rotor, and then periodically energizing and de-energizing the stator at a frequency to utilize the inertia of the rotor and the target disc in maintaining the rotation of the rotor when the stator is deenergized.

Abstract: A two-directional percussion implement selectively adaptable both for driving in and for extracting, e.g. piles, from the ground, includes two coaxial electromagnetic coils whose movable armatures are represented by extremities of a reciprocable ram. Opposite anvils, one of which is adapted to be coupled with a driven element, are interlinked by a non-magnetic shaft traversing the ram. When the implement is intended for drilling operations, a rotary drive imparts rotation to one of the anvils via a connection permitting independent rotation and reciprocation. The shaft in this case has a central channel for taking samples or for conducting drilling fluids. When adapted only for axial percussions, the implement is vertically suspended on a cable via a shock absorber.