摘要:
A transmission with variable mechanical prestress, comprising a pinion (7) driven by an electric motor (3), a driven gearwheel (9) with its bearings in a housing (15), and an electromagnetic actuator (21) for applying a prestress force which is controllable in dependence on an instantaneous load to be handled by the transmission. The electric motor (3) with the pinion (7) is so supported that it can be tilted relative to the housing (15). Owing to a tilting movement of the electric motor (3) caused by the actuator (21), the pinion (7) is pressed against the gearwheel (9) with a certain prestress force in radial direction. The transmission is free from play, while the virtual play arising from friction and hysteresis is strongly reduced, and the positioning accuracy is enhanced as a result.
摘要:
A magnetic-tape apparatus (1) having a magnetic-head unit (28) comprises a head support (40) which is rotatably mounted by means of a mounting device (49) and has a duct (72) through which a flexible conductor board (109) is passed which for connection to a signal processing circuit (108) comprises a widened connecting portion (116, 117). The head support (40) has at least one slot (120) which extends at least over the entire length of the duct (72), passes through the head support (40) and terminates in the duct (72), through which slot the flexible conductor board (109) can be passed while its original flat shape is maintained.
摘要:
An in-the-ear canal hearing aid comprises a microphone (1), an amplifier (2), an electromechanical transducer (3), for example in the form of a telephone, and an infrared detector (15). The hearing aid further includes an extraction means (12) for extracting the hearing aid from the ear canal. The extraction means (13) is in the form of an optical conductor for conducting infrared radiation. One end (20) of the conductor (13) is mechanically attached to the hearing aid housing (4,6) in a place so that the end (20) of the conductor (13) is optically coupled to the detector (15). As a result, the extraction means (12) has as its second function conducting the infrared radiation to the detector of the hearing aid.
摘要:
A depilation apparatus having a number of disc-shaped pinching plates (19) provided on a drive shaft (7) and a number of thrust cogs (41) provided on an auxiliary shaft (21), by means of which cogs the pinching plates are each tiltable about a first and a second tilting axis (81, 91) from a catching position into a pinching position in which the relevant pinching plate (19) exerts a pinching force on an adjacent pinching plate (19) tilted into the pinching position. Each pair of pinching plates positioned next to one another (19a, 19b), (19b, 19c), (19c, 19a) has a unique thrust cog (41a, 41b, 41c), so that each pinching plate (19) is in cooperation with each of its two adjacent pinching plates (19) and the hair catching range of the pinching plates (19) extends over the entire depilation opening (3). The thrust cogs (41a, 41b, 41c) are provided on the auxiliary shaft (21) at mutual angles of 120°, so that an even operation of the depilation apparatus in time is achieved and an undesirable contact between the pinching plates (19) at a side of the drive shaft (7) remote from the depilation opening (3) is prevented. The pinching plates (19) each have a central, star- shaped opening (65, 67, 69, 71) by means of which the relevant pinching plate (19) is mounted in recesses (59, 61, 63) of three comb-shaped support ridges (51, 53, 55) of the drive shaft (7), which ridges extend parallel to a central portion (57) of the drive shaft (7) at mutual angles of 120°. A favourable moment arm ratio for the pinching force and a stable support of the pinching plates (19) in the pinching position are achieved by this.
摘要:
Method for operating an engine having a piston reciprocable in a cylinder, an intake port for admitting air, an exhaust valve controlled by a valve actuator independently of crankshaft position, spark ignition, and fuel injection. During a first stroke the piston moves from BDC to TDC, the intake port is closed, the exhaust valve is closed, and fuel is injected. During a second stroke (TDC to BDC) the exhaust valve remains closed, lowering the pressure and causing some evaporation of the fuel-air mixture. During a third stroke (BDC to TDC), the pressure of the fuel-air mixture is again increased and finally ignited. During a fourth stroke (TDC to BDC) the ignited mixture expands, followed by opening the exhaust valve and the intake port. The second and third strokes enhance evaporation thus permit ignition of low vapor pressure fuel in a cold engine. Once the engine is hot, the valve actuators permit transition to a two-stroke-cycle.
摘要:
An actuator which uses a double-ended hydraulic spring (15,16) to propel an internal combustion engine poppet valve (21) back and forth between a closed and an open positions. Timed delivery of supplemental pressure to a separate latching piston (1) provides a means to fully "re-cock" the rebounding springs in each position. Activation is accomplished by releasing the supplemental pressure to allow the compressed fluid spring (15,16) to propel the poppet valve (21) in either one of two directions. A valve arrangement is also provided to allow a timed bypass of fluid around the latching piston during most of its transitioning to minimize the quantity of high pressure fluid consumption to that which is required to overcome friction losses.
摘要:
A two position straight line motion actuator utilizes a double ended pneumatic spring to provide most of the energy required to transit back and forth between the two positions. The actuator is held in its initial position against the force of the pneumatic spring (6) by hydraulic pressure applied to a latching piston (2). Transition from the initial or first position to the second position is initiated by opening a flow path around the latching piston to cancel the effects of the high pressure latch thus allowing the air spring (6) to power the actuator to its second position. As the actuator moves toward the second position, the second air spring (17) dampens actuator motion converting the kinetic energy of the actuator moving portion into potential energy in the form of highly compressed air, thus cocking the pneumatic spring (17). Return of the actuator is blocked by the fluid latch. Upon command, a valve (9) opens the flow path around the latch, allowing the latch to release the actuator to return to its initial position. Supplemental hydraulic pressure is valved into the latching chamber (14) during the latter part of travel of the moving portion of the actuator to overcome system friction and to assure that the actuator moves fully to its initial position. Both the speed and the distance travelled by the moving actuator portion may be controlled by pre-pressurization of the air chambers.
摘要:
Eine Kassette (1) für einen Aufzeichnungsträger (10) ist zum Verschließen mindestens einer Öffnung (13, 14, 15, 16, 17, 18, 19, 20, 21) im Kassettengehäuse (3) mit einem verstellbaren Verschlußschieber (2) versehen, der zwischen einer Abdeckposition und einer Freigabeposition verstellbar ist und der in Richtung zu seiner Abdeckposition von einer Feder (44) belastet ist, die sich am Kassettengehäuse (3) abstützt und die in einer gehäuseaußenseitigen Aussparung (45) im Kassettengehäuse (3) angeordnet ist. Dabei ist die in der Aussparung (45) angeordnete Feder (44) vorteilhafterweise sowohl bei in seiner Abdeckposition als auch bei in seiner Freigabeposition befindlichem Verschlußschieber (2) von dem Verschlußschieber (2) zur Gänze überdeckt.
摘要:
A lithographic device with a lithographic irradiation system (1, 13) which is fastened near a lower side to a mounting member (5) of a frame (7). The device is provided with a unit (65) which is formed by a positioning device (37), with which an object table (21) arranged below the irradiation system (1,13) is displaceable, and by a support member (35), over which the object table (21) is guided by means of an aerostatic foot (31). In an operational position, the unit (65) is coupled to a carrier (67) by means of coupling members (73), the carrier (67) being suspended from the mounting member (5) by means of suspension elements (79, 81, 83), so that the unit (65) is arranged between lower frame supports (25) of the frame (7) and a compact construction is obtained. The unit (65) can be rotated from the operational position to an end position, in which the unit (65) is entirely outside the frame (7) and is easily accessible for maintainance, by means of a rotation mechanism (87) and a swivel mechanism (89). The lithographic device can be used inter alia for irradiating semiconductor substrates, a semiconductor pattern provided on a mask (11) being imaged on a semiconductor substrate (19) provided on the object table (21) by means of the irradiation system (1, 13).
摘要:
A machine tool for machining a workpiece (11), the workpiece (11) being fastened to a support (9) which has its bearings in a frame (1) of the machine tool and is rotatable about an axis of rotation (13), while a tool (37) is movable relative to the workpiece (11) by means of a positioning device (35) provided on a carrier (17) of the machine tool. The carrier (17) is movably guided relative to the support (9) along a straight guide (23, 25) of the frame (1) in a direction parallel to the axis of rotation (13) by means of static fluid bearings (19, 21), so that a space easily accessible to an operator is created between the carrier (17) and the support (9) through displacement of the carrier (17). The carrier (17) can be coupled to the frame (1) by means of coupling members (51) provided with bolts (75), a head of each bolt (75) forming a piston (73) which can be moved in a cylinder (59), which is hinged to the carrier (17). In the operational condition of the machine tool, in which the workpiece (11) is machined with the tool (37), each bolt (75) is subjected to a tensile stress which is achieved through the supply of pressurized fluid to the cylinders (59), so that a particularly rigid coupling of the carrier (17) to the frame (1) is obtained. In particular, so-called masters for projection television screens in the form of circular Fresnel lenses of a comparatively large diameter are manufactured with these machine tools.