62results about How to "Avoid pressure spikes" patented technology

A casting mould is disclosed for manufacturing a casting from a metal melt (S) in a hollow moulding cavity (5) for reproducing a casting, and through an inlet for pouring a metal melt (M) into the hollow moulding cavity (5), as well as a device and a process for casting such metal melts. The disclosed casting mould also makes it possible to achieve a further optimised casting result, even in the hard operation conditions found in casting practice. Moreover, the use of the claimed device and process minimises the risk of jamming because of a pressure build-up during casting. This is achieved in that the casting mould comprises at least one compensation chamber (8, 9) linked to the moulding cavity (5) by a channel (10, 11) and having at least one section (8a, 9a) located above the maximum filling level (Fmax) of the casting mould (1) during the solidification of the metal melt (S).

A measurement device for measuring the mass of a medium flowing along a flow direction, in particular the intake air mass of an internal combustion engine, has a plate-shaped sensor element, which is inserted into a recess of a sensor support. The sensor element includes a membrane that supports a measuring element, which membrane encloses a hollow space embodied in the sensor element on the side remote from the sensor support. The sensor element is secured in the recess by means of a glue between the sensor support and a bottom face of the sensor element oriented toward the sensor support. According to the invention, the glue constitutes a glue seam that extends around the hollow space of the sensor element between the sensor support and the bottom face of the sensor element and is only open on the side remote from the flow direction by means of at least one recess in order to ventilate the hollow space.

A pump system for conveying lubricating oil to a cutting chain of a chain saw is provided. The pump system comprises at least one first oil pump, wherein a quantity of oil being conveyed thereby is adjustable by an operator of the chain saw.

There is described a method for operating an injection molding machine, which comprises a forming tool, an injecting device and a digital regulating and / or control device at least for regulating and / or controlling the injecting device. When regulating and / or controlling the injecting device, a pressure regulation and / or pressure control for regulating and / or controlling the injection device is switched over subject to the reaching of a transition criterion, whereby a value is established that is used for determining the transition criterion. At least one extrapolation value is established for at least one measured value, whereupon the extrapolation value is compared with the transition criterion and the pressure regulation and / or control of the injection molding machine or is switched over to the pressure regulation and / or the pressure control.

The invention concerns a hydraulic machine with a set of teeth, having a toothed ring with an inner toothing and a gear wheel with an outer toothing, the gear wheel rotating and orbiting in the toothed ring, the inner toothing and the outer toothing touching each other in contact areas, thus separating pressure chambers, and with a valve arrangement controlling a connection between a connection arrangement having a high pressure connection and a low pressure connection, and the pressure chambers. It is endeavoured to achieve a stable operation, particularly with low speeds. For this purpose, each contact area is provided with an opening, which, at the time when a pressure chamber reaches an extreme value of its volume, produces a short-circuiting with the neighbouring pressure chamber.

The invention relates to a compressed air supply installation (10, 11, 12, 20, 30) for operating a pneumatic installation (90), especially an air suspension installation of a vehicle, comprising a compressed air supply unit (1), a compressed air port (2) towards the pneumatic installation (90), a venting port (3) towards the surroundings, a first pneumatic connection between the compressed air supply (1) and the compressed air port (2), said pneumatic connection having an air drier (61) and a shut-off valve, and a second pneumatic connection between the compressed air port (2) and the venting port (3). According to the invention, the shut-off valve is designed as a pneumatically pilot-controlled check valve (63, 64).

In a gear pump with variable throughput volume, with two meshed gears with external toothing which are rotatably held in the working chamber of a pump housing, at least one of the two gears is driven from a drive shaft and one of the gears, preferably the driven gear, is shiftable in the direction of its axis. In order to realize a control mechanism in a simple manner a gap width defined as the distance measured in axial direction between an essentially plane first interior side wall of the working chamber of the pump housing and a first front face of the shiftable gear, is designed to be variable.

Device and method for regulating the temperature of a substrate, in particular of a wafer, by means of a device comprising two temperature-regulating circuits that are operated with different temperature-regulating fluids.

Side channel blowers having devices for minimizing noise emissions are known that do not, however, sufficiently reduce noise when the control valve is closed. The invention therefore proposes a side channel blower, in which further recesses (72, 64) are formed in the interruption region (32, 34) before the inlet (8) and after the outlet (22), the smallest distance therebetween being 0.5 to 3 times the distance between two conveying blades (26). Such an embodiment achieves further noise reduction, even when the control valve is closed, without reducing the maximum flow rate.

A hydraulic control and operating system is provided for a railroad car retarder to control the movement of railroad cars in railroad classification yard. The system utilizes a double-acting hydraulic cylinder to operate the retarder mechanism and includes a hydraulic control circuit that provides protection against pressure spikes and high pressure excursions, high and low temperature excursions, low oil levels and oil filter fouling. The above system not only shuts itself down to prevent damage, but provides a warning to maintenance staff that service should be performed long before a need for system shut-down is required. The system includes a central operating panel in the rail yard control center, remote control panel located at the position of the retarder and the system can be connected for operation from a completely remote location.

A knee orthosis (1) for support of a knee joint in the case of instability comprises a thigh portion (4), which is attachable on the thigh, and a lower leg portion (5), which is attachable on the lower leg, which lower leg portion (5) is provided with splint elements (12), which are connected in an articulated way, via articulation means (13), to hinge plates (14) attached on the thigh portion (4). The lower leg portion (5) has a lower half shell (9), which in the region remote from the knee is borne in the splint elements (12) in a way pivotable about a pivot axis (15). Via a longitudinally stable, flexible traction (17) the lower half shell (9) is pushed ventrally against the lower leg, the pressure increasing with bending of the knee. An optimal support of the knee joint is thereby achieved, especially when the cruciate ligaments are injured.

A pump unit includes a main pump (4) and a charge pump (5), the pump capacity of which is adjustable via an adjusting element. To adjust the pump capacity of the charge pump (5), an adjusting element of the charge pump (5) is acted upon by an adjusting force which is dependent on the inlet pressure of the main pump (4).

The present invention relates to a system for forming a product from a food mass, the system comprising a mould member, e.g. a mould drum with an axis of rotation and a feed pump.

The invention relates to a method for replacing a fabric in a web forming machine. In the method, the front side (42) of the web forming machine comprises beams (21) between which beams (21) a gap is created for replacing a fabric forming a closed loop (24). After creating the gap, the gap is maintained with a medium lifting device (10), in which medium lifting device (10) pressurizable chambers (30) defined by sealing elements (32) are arranged on both sides of the fabric (24). The sealing elements (32) are sealed against the fabric (24) when pressurizing the chambers (30). The invention also relates to a corresponding lifting device, arrangement, and web forming machine.

A regulator for in-line modulation of the flow rate of fluid during blood collection includes a fluid transfer device for transferring fluid from a patient to a collection device. The fluid transfer device comprises a fluid passageway defined by a tubular sidewall and a flexible member associated with a portion of the tubular sidewall. The flexible member is configured for movement with respect to the fluid passageway upon exposure of the fluid transfer device to a differential pressure during a blood collection procedure to prevent collapse of a patients blood vessel. The flexible member of the regulator can be a frame surrounding a flexible diaphragm. Alternatively, the flexible member can include a flexible material integrally formed within the tubular sidewall of the pressure regulator.

A pump system for conveying lubricating oil to a cutting chain of a chain saw is provided. The pump system comprises at least one first oil pump, wherein a quantity of oil being conveyed thereby is adjustable by an operator of the chain saw. The pump system also includes a basic oil pump that is connected in parallel to the adjustable oil pump.

A shaving unit for a shaving apparatus includes at least first and second cutting units which respectively include first and second external cutting members having a plurality of hair entry openings respectively defining first and second shaving tracks. The cutting units further include first and second internal cutting members which are rotatable relative to, respectively, the first and the second external cutting members about first and second axis of rotations, respectively. The first cutting unit is pivotal about a first primary pivot axis which, seen in a direction parallel to the first axis of rotation, is arranged between the first shaving track and the second axis of rotation. Similarly, the second cutting unit is pivotal about a second primary pivot axis which, seen in a direction parallel to the second axis of rotation, is arranged between the second shaving track and the first axis of rotation.

The invention relates to a fluid pump, in particular liquid pump, with a rotor, with a rotor shaft (11) and with at least one rotor blade for delivering the fluid, wherein the rotor with regard to its diameter may be changed between a first, compressed condition, and a second expanded condition, wherein the at least one rotor blade comprises at least two erection elements (12, 13, 14) which are distanced to one another along the longitudinal axis (18) of the rotor shaft (11) and which project away from the shaft in the expanded condition of the rotor, as well as at least two limp rib elements (25, 26, 27, 28, 29, 30) which run at a distance to one another from one erection element (12, 13, 14) at least up to a further erection element, wherein a limp membrane (10) is held between the rib elements, which is tautened in the expanded condition of the rotor. A good compressibility of the rotor with low counter-forces, as well as a simple setting-up of the rotor may be achieved by the membrane-like design of the rotor blades. The membrane may for example be manufactured with the immersion method.

The invention relates to a metering pump, the object of which is to enable simple fluid metering, to have an extended service life and to be of compact construction. Said metering pump is characterised in that the piston rod (12) is in operative connection with a control body (30) which has a circumferential sealing zone (37), in that the internal circumference of the sealing cylinder (20) radially surrounds the sealing zone (37), in that, on the piston rod side, a compensating zone (39), which is at a greater radial distance from the sealing cylinder (20) than the sealing zone (37), adjoins the sealing zone (37) at least in portions, and in that the control body (30), after passing beyond the control edge (34) in the actuation direction (F) of the actuator (10), at least largely severs the fluid connection.

The invention relates to a method for preventing pressure peaks in a working medium cycle in which a hydrodynamic machine is operated, wherein the hydrodynamic machine comprises a primary wheel and a secondary wheel which together form a toroidal working chamber that can be filled and emptied via a working medium inlet and working medium outlet in order to hydrodynamically transmit torque from the primary wheel to the secondary wheel. The invention is characterized in that the rate of change of the flow cross-section for the working medium that flows into and / or out of the working chamber is changed depending on a predetermined input variable when connecting and disconnecting the hydrodynamic machine.

A bone anchoring device is provided comprising an anchoring element having a shank (2) to be anchored in a bone or a vertebra, a rod (9) for connecting at least two anchoring elements, the rod being made of an elastic material, a receiving part (3) being connected to the shank (2) for receiving the rod, a seat (8) for the rod being provided in the receiving part the seat having a rod contacting surface, a locking device (10) cooperating with the receiving part for fixation of the rod in the seat, the locking device comprising a rod contacting surface, wherein the rod contacting surface of the seat and / or the rod contacting surface of the locking device comprises an engagement structure (11,12) for engaging the rod, the engagement structure having an asymmetric cross section.

The invention concerns a hydraulic machine with a set of teeth, having a toothed ring with an inner toothing and a gear wheel with an outer toothing, the gear wheel rotating and orbiting in the toothed ring, the inner toothing and the outer toothing touching each other in contact areas, thus separating pressure chambers, and with a valve arrangement controlling a connection between a connection arrangement having a high pressure connection and a low pressure connection, and the pressure chambers. It is endeavoured to achieve a stable operation, particularly with low speeds. For this purpose, each contact area is provided with an opening, which, at the time when a pressure chamber reaches an extreme value of its volume, produces a short-circuiting with the neighbouring pressure chamber.

The invention relates to a valve block (10) comprising a plurality of main sliders (40), which are supplied in parallel with pressure fluid via a first and a second pump conduit (80; 81), the fluid stream, which flows in from the respective pump conduits (80; 81), being controllable by means of an associated first and second auxiliary slider (60; 61). All main sliders (40) are surrounded by a first and a second annular groove (46; 47) in the housing (20) so as to form an adjustable third main aperture (43) that connects the first annular groove to the second annular groove (46; 47), the first annular groove (46) of a first main slider being connected to the first pump connection, the first annular groove (46) of a second main slider being connected to the second pump connection, the second annular groove (47) of a third and of a fourth main slider being connected to a tank connection on the housing (20), furthermore, the first annular groove (46) of a main slider (40) being connected to the second annular groove (47) of an adjacent main slider (40), the third main aperture (43) becoming smaller when the first or the second main aperture (41; 42) of the same main slider (40) becomes larger.

The invention relates to a hydraulic assembly comprising at least one variable displacement pump (4, 6), which is set by a pump controller (8, 10) depending on a target pressure. The at least one variable displacement pump is used to supply at least one load with a pressure medium quantity. Furthermore, a comparison valve (12, 14) is provided, by means of which the outlet pressure is reduced to the target pressure starting at a certain pressure difference, which is to say, when the outlet pressure exceeds the target pressure by a predetermined value, the outlet pressure is lowered directly or indirectly by means of the comparison valve.