3326 results about "Pre stressing" patented technology

The present invention relates to the mounting of pre-stressed electroactive material in such a manner that large displacement actuators or sensors result. The invention comprises mounting the pre-stressed electroactive material to a support layer. This combination of a pre-stressed electroactive material and support layer may in turn be attached to a mounting surface. The pre-stressed electroactive material may be a ferroelectric, pyroelectric, piezoelectric, or magnetostrictive material. The size, stiffness, mass, and material of the support layer is selected to result in the electroactive device having dynamic response properties, environmental capability characteristics, and the required resilience optimized for a given application. The capacity to connect the support layer to a surface expands the arenas in which the pre-stressed electroactive device may be used. Application for which the invention may be used include actuators, sensors, or as a component in a pumps, switches, relays, pressure transducers and acoustic devices.

A hearing-aid device and a method for transmitting sound through bone conduction are disclosed. The hearing-aid device comprises a piezoelectric-type actuator, housing and connector. The piezoelectric actuator is preferably a circular flextensional-type actuator mounted along its peripheral edge in a specifically designed circular structure of the housing. During operation, the bone-conduction transducer is placed against the mastoid area behind the ear of the patient. When the device is energized with an alternating electrical voltage, it flexes back and forth like a circular membrane sustained along its periphery and thus, vibrates as a consequence of the inverse piezoelectric effect. Due to the specific and unique designs proposed, these vibrations are directly transferred trough the human skin to the bone structure (the skull) and provide a means for the sound to be transmitted for patients with hearing malfunctions. The housing acts as a holder for the actuators, as a pre-stress application platform, and as a mass which tailors the frequency spectrum of the device. The apparatus exhibits a performance with a very flat response in the frequency spectrum 200 Hz to 10 kHz, which is a greater spectrum range than any other prior art devices disclosed for bone-conduction transduction which are typically limited to less than 4 kHz.

A pipette device has a coupling stud on which a pipette tip can be stuck in a slipping-on direction for coupling. The coupling stud has an adjustable pre-stress member that can be adjusted into a prestress state and a release state via an actuation device which is provided in the coupling stud. The pipette tip has an axial stop which interacts with a counter-stop of the coupling stud in an axial coupling position of the pipette tip. The prestress member in its prestress state acts upon a working surface of the stuck-on pipette tip having a surface component of the pipette tip, which extends radially inward, turned away from the stuck on direction, in such a way that it abuts sealingly on the working surface, and prestresses the pipette tip on the pipette unit into the axial coupling position. The prestress member, in its releasing state, substantially releases the working surface of the pipette tip (101).

A lift-type turbine comprising at least three blades at circumferentially spaced positions is supported for rotation about a vertical axis. Each blade has an airfoil shape to generate a torque about the axis responsive to wind across the blades. A support comprising cables under tension is connected between adjacent ones of the blades to extend generally circumferentially about the turbine. Accordingly a minimum number of parts form the structure of the blades while minimizing the drag produced during rotation thereof due to the support members lying in a common circumferential path. The tension of the support members can support the blades in a pre-stressed condition to optimize the shape and performance thereof.

The invention relates to an oscillatory drive having an output shaft that can be driven to perform a rotationally oscillating movement about its longitudinal axis and that comprises a free end, a holding fixture at the free end of the output shaft comprising a contact surface for attachment of a tool, a mounting section on the holding fixture, raised relative to the contact surface, that projects to the outside in the direction of the longitudinal axis and that is designed for form-locking connection with a mounting opening of a tool placed in contact with the contact surface, and having a securement for fixing the tool with its mounting opening on the holding fixture, the securement permitting the tool to yield in axial direction under the action of a torque, against a pre-stress, and the mounting section permitting the tool to rotate by a certain angle of rotation when the tool gives way axially.

Various high-strength microwave antenna assemblies are described herein. The microwave antenna has a radiating portion connected by a feedline to a power generating source, e.g., a generator. The antenna is a dipole antenna with the distal end of the radiating portion being tapered and terminating at a tip to allow for direct insertion into tissue. Antenna rigidity comes from placing distal and proximal radiating portions in a pre-stressed state, assembling them via threaded or overlapping joints, or fixedly attaching an inner conductor to the distal portion. The inner conductor is affixed to the distal portion by, e.g., welding, brazing, soldering, or by adhesives. A junction member made from a hard dielectric material, e.g., ceramic, can be placed between the two portions and can have uniform or non-uniform shapes to accommodate varying antenna designs. Electrical chokes may also be used to contain returning currents to the distal end of the antenna.

A treatment for bioprosthetic tissue used in implants or for assembled bioprosthetic heart valves to reduce in vivo calcification is disclosed. The method includes preconditioning, pre-stressing, or pre-damaging fixed bioprosthetic tissue in a manner that mimics the damage associated with post-implant use, while, and/or subsequently applying a calcification mitigant such as a capping agent or a linking agent to the damaged tissue. The capping agent suppresses the formation of binding sites in the tissue that are exposed or generated by the damage process (service stress) and otherwise would, upon implant, attract calcium, phosphate, immunogenic factors, or other precursors to calcification. The linking agent will act as an elastic reinforcement or shock-absorbing spring element in the tissue structure at the site of damage from the pre-stressing. In one method, tissue leaflets in assembled bioprosthetic heart valves are preconditioned by simulating actual flow conditions for a predetermined number of cycles, during or after which the valve is exposed to the capping agent.

The invention belongs to the building support component technology field including the stress automatic control and monitoring as well as the structural safety, and relates to a steel tube supporting internal force automatic compensating and displacement controlling system. The system comprises an upper system, a PLC control system module and a field executive system. A steel support is arranged on a reinforced concrete diaphragm wall, a hydraulic jack is arranged on the steel support, and real time pressure monitoring values are fed back through a pressure sensor. The steel support and the hydraulic jack form a pre-stressed steel support structure, the hydraulic jack is connected with a hydraulic pump station through an oil circuit, and is connected with the PLC control system module through the pressure sensor, the hydraulic pump station is connected with the PLC control system module, and a PLC controlling device is connected with the upper system. Through auto-control software and a PLC control system, the automatic control to the axial force of the steel support is realized, thereby controlling the displacement and the settlement of the deep excavation supporting structure and the adjacent basic facilities.

The invention discloses a damage-controllable self-resetting section prefabricated assembled steel pipe concrete bridge pier and a manufacturing method thereof, and belongs to the field of bridge engineering. An exposed node connecting piece consists of a foot plate, anchor bolts, end connecting plates and buckling restraining sleeves. A connecting plate is mounted between prefabricated steel pipe concrete sections through high-strength bolts; the exposed node connecting piece is connected with each of a cover beam and a bearing platform by utilizing the anchor bolts, and is connected with a prefabricated steel pipe concrete section through the high-strength bolts relying on the end connecting plates. A pre-stressed tendon penetrates through a section prefabricated steel pipe concrete pier; the two ends of the pre-stressed tendon are respectively anchored to the interiors of the bearing platform and the cover beam by using anchorage devices. The energy consumption-controllable self-resetting section prefabricated assembled steel pipe concrete bridge pier disclosed by the invention has the characteristics of small post-seismic residual displacement, high energy consumption capacity, controllable energy consumption, high assembling degree, convenience and quickness in construction process, greenness, high efficiency, energy conservation, environment friendliness, easiness in factory production, convenience and quickness in construction, and the like; the construction period of the pier can be remarkably shortened.

Methods of using a guide catheter employ a retractable inner guide movably disposed within an open lumen of a splittable outer guide. The outer guide includes a longitudinal pre-stress line extending from distal to proximal ends. The inner guide includes an open lumen adapted to receive a payload. The inner guide is translatable and rotatable relative to the outer guide. The guide catheter further includes a proximally attached guide handle which is separable into at least two sections. Separation of the guide handle splits the proximal end of the outer guide. Proximal outer guide retraction continues the splitting of the outer guide along the longitudinal pre-stress line.

The invention relates to the technical field of fabricated concrete frame structures, and discloses a pre-stressing-force fabricated concrete-frame-joint connecting structure and a construction method thereof. The pre-stressing-force fabricated concrete-frame-joint connecting structure comprises a prefabricated concrete column, a prefabricated concrete superposed beam, a composite floor slab, a post-tensioned pre-stressing tendon, an anti-bending and energy-consuming reinforcing steel bar and a shear-resistant and high-strength reinforcing steel bar, wherein the post-tensioned pre-stressing tendon, the anti-bending and energy-consuming reinforcing steel bar and the shear-resistant and high-strength reinforcing steel bar are connected with the prefabricated concrete column and the prefabricated concrete superposed beam. A beam post-pour layer of the prefabricated concrete superposed beam and a slab post-pour layer of the composite floor slab are poured integrally, the inner portion of a beam column seam between the prefabricated concrete superposed beam and the prefabricated concrete column is filled with high-strength crack-pouring binding materials, the anti-bending and energy-consuming reinforcing steel bar and the shear-resistant and high-strength reinforcing steel bar are laid in the beam post-pour layer of the upper portion of the prefabricated concrete superposed beam, and the anti-bending and energy-consuming reinforcing steel bar is located above the shear-resistant and high-strength reinforcing steel bar. According to the pre-stressing-force fabricated concrete-frame-joint connecting structure and the construction method thereof, efficient construction can be achieved, the anti-seismic property and the progressive-collapse-resistant capability are good, and post-earthquake repairing is facilitated.

The invention involves a kind of data organization project area of technology to guard against the flexure to consume energy the steel plate shearing force wall. Its characteristic causes to state the shearing force wall to inlay the steel plate and two sides periphery concrete lap by in is composed; In states inlays the steel plate to use the low yield point high ductility steel products or the high strength high ductility steel products; States the periphery concrete lap to use the common concrete slab; States the edge component is composed by the marginal beam and the edge column; In states inlays the steel plate with to state between the concrete lap through to penetrate three blocks the bolts or the pre-stressed bold fastening, in states on the concrete lap to open the ellipse hole in order to the bolt passed through also has the enough slipping space; In states the concrete lap to open the hole site with to bury the trough section to give strengthens. And is strengthening the channel steel the corresponding position to open oval hole. The invention provides guards against the flexure steel plate shearing force wall is the high-rise construction structure or other structures a kind of new anti- lateral force components, it has the earthquake resistance performance well, the ductility is high, consumes energy stagnates winds full and so on the characteristic, is a kind of superior earthquake resistance consumes energy the component.

The invention discloses an external prestressing construction method for box bridge maintenance, which is characterized in that: 1). The position of an anchor block, a redirector and a shock absorber are decided according to external cable arranging mode for external prestressing; 2). The installation of the anchor block: 2.1). concrete base surface processing; 2.2). hole drilling, hole cleaning and reinforcing bar planting; 2.3). the installation of steel-bonded steel plate: the anchor block comprises a steel-bonded steel plate, a connecting plate and a stiffening plate; all anchor bolts are penetrated through a corresponding fixing hole on the steel-bonded steel plate; 2.4). the installation of other steel plates for the anchor block; the connecting plate is welded with the steel-bonded steel plate, the stiffening plate is welded with the steel-bonded steel plate and is provided with a through hole for external cable; 2.5). glue pouring for the steel-bonded steel plate: glue pouring is made between the steel-bonded steel plate and the concrete base surface for the anchor block; 3). Horizontal partition wall perforation; 4). The installation of a redirecting support and a damping support; 5). The installation of the redirector; 6). Penetrating and tension of prestressing steel strand; 7). The installation of the shock absorber. The invention has the advantages of convenient construction, flexibility and stronger reliability.

The invention discloses a pre-stressed continuous concrete beam design method based on the BIM technology. The pre-stressed continuous concrete beam design method includes the following steps that according to a file format, pre-stressed continuous beam design information is input; a finite element model is formed, and the structure size is analyzed and determined through the numerical value; an information-model parameterization cross section library is built; according to the structure size, a cross section is automatically instantiated to generate a continuous beam three-dimensional model containing user information; according to the characteristics of the cross section of the continuous beam, a reinforcing-steel-bar-net space node coordinate database is automatically built; instantiation data is sequentially comprises all parts of arrangement space reinforcing steel bars of the continuous beam, and user information is added; according to an information module, two-dimensional drawings are automatically established, quantity statistics is automatically completed. By means of the pre-stressed continuous concrete beam design method based on the BIM technology, rapid forming of universal data, the three-dimensional information model and the reinforcing-steel-bar drawings is achieved, and the pre-stressed continuous concrete beam design method has good popularization value and the good application value.