摘要:
A calibration weight arrangement (4, 104) for an electronic balance with a force-transmitting mechanism (1) has a calibration weight (3, 103) adapted to be coupled to the force-transmitting mechanism. The arrangement also has a transfer mechanism and a drive source to manipulate the calibration weight in a guided movement. The drive source includes an actuator (18) cooperating with the transfer mechanism and at least one piezoelectric element (19) which drives the movement of the actuator. The piezoelectric element interacts with a drive wheel (17, 117) that is centrally positioned relative to the calibration weight arrangement and drives a likewise centrally positioned shaft (16, 126). The interaction between the piezoelectric element and the drive wheel occurs during the advance movement in one direction through the repeated engagement and release of a frictional contact force.
摘要:
A force-measuring cell is designed for a receiving structure having multiple force-measuring cells of the same type. Each cell in the receiving structure occupies a design space whose dimensions, projected into a plane orthogonal to the load direction, is delimited by the design spaces of neighboring and/or is equal to the largest dimension of the cell in the plane. The cell has parallel-guiding diaphragms arranged on upper and lower surfaces thereof. The cell includes a calibration weight arrangement with a calibration weight which can be coupled to the cell, as well as a drive mechanism and a transfer mechanism for guidedly moving the calibration weight. An actuator works together with the transfer mechanism and a piezoelectric element that drives the actuator. The actuator has at least two interacting elements to repeatedly engage and release each other by frictional contact force which occurs during the travel movement in one direction.
摘要:
A weighing module 1 has a force-transmitting linkage 13 arranged between the load-receiving portion 3 of the weighing cell 2 and the load receiver 5, with an overload protection device that precisely maintains its position being an integral part of the force-transmitting linkage 13. By means of a positioning element 7, 107, 207, the load receiver 5 is positioned without play relative to the load-receiving portion 3 in the plane that extends orthogonal to the load direction, and the load receiver 5 is also guided in the load direction without play. When forces in excess of the pre-tension force of the elastic element 8 act on the load receiver 5, the latter has the capability of being displaced in the load direction and to tip in all directions that are orthogonal to the load direction. The housing part 18 serves to delimit at least the range of linear downward deflection as well the tipping movement of the load receiver 5 when the load receiver 5 is exposed to transverse forces and to overloads. The rotation constraint 20 is rigidly connected to the load receiver 5 and engages a housing-connected recess 21. To position the load receiver 5 relative to its operating environment, a positioning device 16 is provided, whose central longitudinal axis coincides with the central longitudinal axis of the load receiver 5.
摘要:
A method for driving an electroluminescent lamp to emit light at a brightness set level includes providing a variable bias voltage to the electroluminescent lamp. The variable bias voltage is increased with the duration of the on-time of the electroluminescent lamp. To stabilize the electroluminescent lamp at the brightness set level against aging, a closed loop control of the brightness of the electroluminescent lamp is applied, which is subject to said duration of the on-time the electroluminescent lamp.
摘要:
The invention relates to a device for measuring properties of a longitudinally moved test material in a measuring cell. In order to provide a device which is easier to adapt to the requirements of a customer and to the special conditions of a production machine for longitudinally moved test material, the measuring cell (1) is connected to a processor (6), which is associated exclusively with the measuring cell.
摘要:
The invention relates to a device for monitoring a yarn (1), which is moving in its longitudinal direction, using a measuring head and an evaluation unit (7) which is spatially separate from and connected to the measuring head. To enable optimum use of measuring heads operating according to different physical principles without unduly increasing the outlay, the measuring head includes a first part (2) operating according to a first measuring principle and having a connection (5) to a first part (6) of the evaluation unit for making an evaluation according to the first measuring principle. The measuring head then comprises a further part (9) operating according to a further measuring principle and having a releasable connection (8, 10) to the first part. In addition, the evaluation unit likewise comprises a further part connected by a releasable connection for the evaluation according to the further measuring principle.
摘要:
This invention relates to rapid set, medium set, and slow set anionic emulsions prepared from straight bitumen or bitumen modified by the incorporation of polymers such as styrene butadiene rubbers (SBR), styrene block copolymers (SBS), ethylene vinyl acetate copolymers (EVA), and other suitable modifiers. The invention also relates to emulsions modified by the incorporation of solvents (such as diesel oil or kerosene) or by the addition of polymer latices (such as SBR-latex or natural rubber latex). More particularly, the invention relates to improved methods for enhancing adhesion between asphalt and aggregate in anionic solventless and solvent-containing bituminous emulsions wherein the emulsifiers are alkali earth salts of tall oil fatty acids, fortified tall oil fatty acids, tall oil rosin and fortified rosin as well as combinations of kraft lignin and nonionic emulsifiers. The novel adhesion promoters utilized in these improved methods are the polyamidoamine condensation reaction products of polyalkylene polyamines with monomeric tall oil fatty acids and polymerized linoleic acids. Further improvement in adhesion can be obtained via adding paraformaldehyde to the reaction.
摘要:
This invention relates to the manufacture and application of uniquely suitable emulsifiers for anionic bituminous emulsions. In particular, this invention relates to emulsifiers for slow-setting aqueous emulsions suitable for use in applications where a high degree of chemical, mechanical, and rheological stability is required (such as in slurry seal applications and thixotropic industrial emulsion applications). In such applications, fine aggregate, clay, or polymer latex is mixed with the emulsion to obtain a homogenous storage-stable composite which can be applied for coatings, floorings, roofings, and as a roadway sealant.
摘要:
The present invention relates to mixing-grade, quick-setting, and slow-setting cationic aqueous bituminous emulsion-aggregate paving slurry seal mixtures. More particularly, this invention relates to paving slurry seal mixtures formed with cationic emulsions prepared by emulsifying bitumen (e.g. asphalt) in water with a cation-active emulsifier. The emulsifier is the product of the reaction of polyamines with certain fatty acids and rosins, and a quaternizing agent such as 2,3-epoxy-propyl-trimethyl ammonium chloride or 3-chloro-2-hydroxy propyl-trimethyl ammonium chloride.
摘要:
A hydraulic cement mix including hydraulic cement, aggregate, sufficient water to effect hydraulic setting of the cement, and a polyamidoamine additive, the additive being present in an amount sufficient to increase the bonding strength of the hardened mix. Generally, the additive is present in a total amount of about 0.025 to 0.25% by weight based upon the weight of the cement, preferably in an amount in the range of about 0.075 to 0.15% by weight.