摘要:
The smoke detector includes a light source (1), a measurement section (3) with a measuring receiver (5), a reference section (2) with a reference receiver (4), and an analyzer circuit (6) connected to the receivers. The receivers are of like construction and receive like amounts of radiation from the light source (1). A difference signal (.DELTA.I) formed from the current signal (I.sub.r) of the reference receiver and the current signal (I.sub.m) of the measuring receiver is fed to the analyzer circuit. A reference current (I.sub.k) is superimposed upon the current signal (I.sub.r) of the reference receiver, and the light source is connected to a control circuit and regulated by the control circuit for compensation of the reference current (I.sub.k) by the reference current signal (I.sub.r). The difference signal (.DELTA.I) is superimposed with a compensation signal (I.sub.k ') for zero compensation.
摘要:
An apparatus for manufacturing a welded connection of tubular components of thermoplastic material includes a bracing device and a heating device to be inserted into the tubular components. The heating device has an expandable hollow body, in the interior of which are arranged an electric heating element and a liquid which expands when heated. When the heating device is heated, the hollow body rests against the ends of the tubular components to be welded together and the necessary welding temperature is transmitted to these components. Since the hollow body rests against the inner circumference of the tubular components, the formation of a welding bead is prevented. After welding has been carried out, the hollow body which has cooled and shrunk is removed by means of a traction strand.
摘要:
A coupling for rotatably connecting a reel with a drive shaft has a support which is fast with the drive shaft. The support is provided with a recess which is designed to receive a complementary stub shaft fixed to the reel. The recess has an open side via which the stub shaft may be inserted in and removed from the recess, and an arresting element in the form of a wheel is provided to close the open side. The arresting wheel is pivotally mounted on the support for movement between a release position in which the open side of the recess is exposed to permit insertion of the stub shaft in, and removal of the latter from, the recess, and an arrest position in which the open side of the recess is closed to prevent release of the stub shaft. The pivot axis of the arresting wheel extends at right angles to the axis of rotation of the support. A pawl is pivotally mounted on the arresting wheel for movement between an operative and an inoperative position, and the pivot axis of the pawl is parallel to that of the arresting wheel. The pawl has a free end portion, and the support is provided with a cutout which receives this end portion when the arresting wheel is in its arrest position and the pawl is in its operative position. The pawl an the cutout are designed in such a manner that, in the operative position of the pawl, the latter prevents unintentional movement of the arresting wheel from its arrest position to its release position. The pawl has an arm which may be gripped in order to pivot the pawl to the inoperative position in which the pawl is clear of the cutout. The arresting wheel may then be moved to its release position.
摘要:
A method and an apparatus for the production of industrial lead oxide involving mixing molten lead and air in a reactor. A particularly advantageous, having a desired particle size can be obtained with a PbO content of considerably more than 99%. The lead flow is introduced at a constant and even rate and the air flow is altered very slightly in order to maintain the pre-determined reaction temperature having fluctuations of a maximum of .+-.5.degree. C.The constant and steady infeed of the lead flow is achieved by using an apparatus according to the invention. The apparatus, which is situated above the reactor, includes a supply vessel charged with molten lead from a melt container, the supply vessel having an exchangeable nozzle which is provided with a control-operated cleaning pin. The nozzle extends into a reaction space and the supply vessel is connected to the melt container via a feed line and an overflow. The nozzle can also be of a known spray nozzle type which is fed with heated compressed air via a line running through the said melt container.
摘要:
The infrared detector contains an emitter (4), a receiver (5) and an analysis circuit (2') for obtaining a working signal (Un). The analysis circuit (2') contains a controller (29) for outputting a compensating signal (Ik) superimposed over the incoming signal (Ie), which on the one hand receives the working signal (Un) and on the other hand is connected to the output of the receiver (5). The compensating signal (Ik) is selected so that the working signal (Un) is corrected to the value zero so that the maximum sensitivity is retained at all times.
摘要:
Weighing apparatus of the electromagnetic load compensation type includes a ferromagnetic yoke member (19), that is secured at a single point to the frame (3), thereby a permit the frame to be formed of a non-ferromagnetic material, such as aluminum, having a different coefficient of expansion than the yoke member. Preferably the yoke member is secured to the frame by a single screw (33,103) arranged at the axis of symmetry of the yoke member. Owing to the small contact surface between the yoke member and the frame, the production of temperature-responsive forces which would otherwise stress or distort the apparatus to adversely affect the accuracy of the weighing operation is avoided.
摘要:
In a scale wherein the force or load receiver is guided along a vertical path by a parallel guidance system having an upper and a lower plate, the lower plate cooperates with a recess in the lower part of the housing to form an air damper. Specifically, the lower plate of the parallel guidance system constitutes the piston of the air damper. For the scale with a capacitive sensor, the plate constituting the piston of the air damper is a metallic plate which also constitutes the movable plate of the measuring capacitor.
摘要:
A weighing apparatus with electromagnetic force compensation is disclosed, including a load portion having a first compensation or load coil, and a reference portion having a second compensation or reference coil. An associated permanent magnet system is provided in the form of a partially closed housing having an intermediate wall on which flat permanent magnets are mounted, preferably in pairs. The load coil and the reference coil are arranged on opposite sides of the intermediate wall, thereby providing a compact arrangement which is easy to assemble and which has particular properties in regard to mutual decoupling of the two compensation coils.
摘要:
Weighing apparatus of the electromagnetic load compensation type is disclosed, including a load support connected for movement relative to a frame, a mechanical-transmission ratio-establishing lever connecting the load support with a compensation coil arranged for displacement relative to a permanent magnet arrangement connected with the frame, a position-responsive circuit for supplying compensation current to the coil for creating an electromagnetic force that reacts with the permanent magnet field to maintain the load support in its initial no-load condition, and indicating means for displaying the magnitude of the applied load as a function of the compensation current. To permit the use of the lever in different lever-ratio-establishing environments without the use of attendant balancing weights, the compensation coil is tapped to define a pair of coil portions (28a, 28b) that are alternately energized by a switching device (42) to apply different forces upon the load support.
摘要:
Weighing apparatus of the electromagnetic load compensation type is disclosed, including a permanent magnet system connected with the stationary frame, a compensation coil connected with the movable scale member, a system for supplying compensating current to the coil to produce a force for returning the movable scale member to its initial no-load position, and an indicating device for displaying the magnitude of the load applied to the movable scale member as a function of the compensating current, characterized by the mounting of a slotted generally U-shaped conductive metal plate in spaced insulated relation concentrically about the core portion of the permanent magnet system. After the weighing apparatus has been completely assembled, the leg portions of the plate are transformer connected with an alternating-current source for calibrating and/or conditioning the permanent magnet system.