Abstract:
The invention relates to a process valve (10) comprising a valve seat (14), a flow restrictor (12), a valve rod (16) and a drive unit (18) acting thereon, with a force measuring device (20, 44) being connected between said drive unit (18) and said flow restrictor (12). The invention is characterized in that said force measuring device (49) includes a spring (30, 46), and said force measuring device (29, 44) comprises a travel measuring device (38, 42, 50, 52) so as to allow the force acting on it to be determined based on the change in the deflection of the spring (30, 46) caused by the force acting on it.
Abstract:
One aspect of the invention is a test assembly comprising a prime mover, an actuator assembly and a torque transfer coupling. The actuator assembly has an end configured to be attached to a shaft of a portion of a test specimen such as a wind turbine assembly. The actuator assembly has a shaft supported for rotation by hydraulic bearings. The torque transfer coupling connects the primer mover to the actuator assembly.
Abstract:
A pressure sensor is provided with a carrier (2), which in an inner region includes a membrane (4) on which at least one first measurement element (R1−) for detecting a pressure impingement of the membrane (4) is arranged. Additionally, at least one second measurement element (R3−) for detecting a pressure impingement of the membrane (4) is arranged on the membrane. The first measurement element (R1−) and the second measurement element (R3−) are arranged distanced differently far from the edge of the membrane. The output signals of the first and the second measurement element (R1−, R3−) are evaluated together in a manner such that the two measurement elements (R1−, R3−) detect a differential pressure acting on the membrane (4), and thereby compensate the influence of the system pressure acting on both sides of the membrane (4).
Abstract:
The invention relates to a device and method for detecting a force on an injection moulding machine for processing plastic materials. According to said invention, a first element (100) interacting with a mechanical drive and movable at least indirectly thereby in a direction of movement (x) is displaced during said displacement with respect to a second element (200) positioned near the first element (100) or oppositely thereto. A force measuring device (D) is used for determining the force applied on the first (100) and/or second (200) element by the actuation of the injection moulding machine produced by the relative displacement thereof between the first (100) and second (200) elements. A hydraulic chamber whose size is modifiable during the relative displacement associated with a change in pressure of a fluid medium in said hydraulic chamber is firmed between the first (100) and second (200) elements, wherein said change in pressure forms an input signal for adjusting the force or pressure and a pressure-relief valve (30) is used for bypassing the hydraulic medium to a hydraulic medium container (35), when the predetermined or predeterminable presser is exceeded in the hydraulic chamber (10), thereby making it possible to obtain a device and method for detecting a force on an injection moulding machine which makes it possible to determine said force in a favourable alternative manner and simultaneously ensure an overload protection.
Abstract:
A method for reducing force and position control tracking errors caused by changes in hydraulic pressure at the actuator ports of a hydraulic servo valve. The method may use either the force command signal or the load cell signal in conjunction with a mathematical algorithm to compensate for changes in the flow capacity in the servo valve caused by changes in pressure at its ports. Good performance can be attained using the load cell signal. Alternatively, the algorithm can use the force command signal. The performance of the control loop with proper velocity feed-forward compensation keeps the feedback signal largely in phase with the command. Pressure sensors for detecting pressure changes at the actuator ports of the servo valve are not required for load droop compensation.
Abstract:
A seat bladder weight estimation apparatus includes an interface panel having multiple regions of substantial rigidity separated by regions of insubstantial rigidity. The regions of substantial rigidity limit sensitivity to seat foam variations, and the regions of insubstantial rigidity permit differential movement and angulation of the rigid regions for regional transfer of occupant weight to the bladder. The regional transfer of occupant weight to the bladder allows regional variation of the bladder sensitivity to occupant weight through various bladder geometry design features.
Abstract:
A contact pressure detecting sensor having a simplified structure. The sensor includes a pair of air-impermeable sheets and at least one foamed plastic member interposedly arranged between the air-impermeable sheets while being kept from being uncompressed. The foamed plastic member is capable of resuming its original configuration after compression. The sensor also includes at least one tube arranged so as to extend from the vicinity of the foamed plastic member to outside the air-impermeable sheets. The air-impermeable sheets are joined to each other at portions thereof positioned around the foamed plastic member and tube.
Abstract:
An improved weight estimation apparatus in which a closed, multiple cell elastomeric bladder filled with fluid is installed in the foam cushion of a vehicle seat bottom, with at least one pressure sensor installed in a closed exit port of the bladder. The multiple cells of the bladder are formed by a pattern of spot welds between the top and bottom layers of the bladder, creating an array of generally circular or hexagonal cells between which the fluid can freely flow. The array of cells maximizes the pressure response for improved sensitivity, and minimizes the amount of fluid required to detect occupant weight, thereby minimizing the weight of the fluid-filled bladder. The pattern of spot welds in the vicinity of the pressure sensing location may be altered to reduce sensitivity to forces applied in proximity to the exit port. In a first embodiment, a more dense pattern of spot welds is provided in the vicinity of the exit port, while in a second embodiment, continuous welding is used to form a pattern of closed fluid-free pockets in the vicinity of the exit port.
Abstract:
Several force sensor assemblies are disposed within a vehicle seat to determine seat loading and assist in safety device activation. Each force sensor assembly has a sealed body filled with a liquid or a gel. A pressure transducer, together with a supporting integrated circuit, is positioned to respond to the pressure of the liquid or gel. Loads are applied to the pressure transducer through the gel by a piston riding within the body. Compressive loads are thereby transformed into a pressure on the sensor and its support electronics, resulting in a low cost, accurate, and durable sensor. The sensor functions well for relatively low loads of less than a few hundred pounds.
Abstract:
A pressure sensor is provided which can detect the presence, absence or magnitude of pressure, as well as a pressure profile. The pressure sensor includes a sensor membrane and a sensor device. The sensor membrane is flexible and may be constructed of a conductive material or may include a flexible film attached to a conductive film. The sensor device includes a sensor strip, a voltage source, and an electrical sensor. The sensor strip includes both a conductive strip and a resistive strip. The conductive strip is arranged parallel to the resistive strip. As pressure is applied to the sensor membrane, the sensor membrane distends or deforms towards the sensor strip. As sufficient pressure is applied, the sensor membrane will make both electrical and mechanical contact with both the conductive strip and the resistive strip at a point along the length of the sensor strip. Since the sensor membrane is conductive, the conductive strip and the resistive strip will be in electrical connection with each other. As the point of application of pressure is varied, the point at which the conductive strip and the resistive strip are connected will vary. As a result, the pressure profile exerted on the sensor membrane may be determined. The pressure sensor may be utilized in a variety of environments to sense a wide variety of pressures including either fluid pressure or physical contact pressure.