Abstract: A rotary actuator includes a shaft rotatably mounted on a body, and a servovalve arranged to operate a vane motor for selectively rotating the shaft relative to the body. A portion of the shaft extends beyond the body. Supply and return passages are provided to the body and shaft so that fluid power supplied to the body is supplied to the servovalve and is also available at the end of the shaft beyond the body. Two or more such rotary actuators may be connected by intermediate brackets to provide a wrist actuator capable of movement about axes.
Abstract: A method for implanting a tubular graft within a preselected blood vessel utilizes apparatus embodiments for inserting the graft endwise and axially through the blood vessel into place therein and for operatively securing the graft to the inside wall of the blood vessel with surgical staple-like clips. For inserting the graft through the blood vessel, an apparatus embodiment includes a lengthy conduit for insertion through the blood vessel and having a distal end adapted to selectively expand and contract for cooperating with a preformed hole in the sidewall of the graft for binding the graft to or releasing the graft from the distal end.
Abstract: A valve (10) has a body (11) provided with two separate but parallel flow passages therethrough. A first diaphragm assembly (14) is held between a lower bonnet (12) and the body, and is movable toward and away from a seat (48). A second diaphragm assembly (15) is held between an upper bonnet (13) and the body. A follower (16) is arranged between the diaphragms. An actuator (20) is arranged to cause substantially parallel motion of the diaphragms in response to movement of the actuator.
Abstract: A push-pull exercise device has a pair of parallel first rods and a pair of parallel second rods. The second rods are arranged to straddle the first rods. The two pairs of rods are longitudinally overlapped. A first member is mounted fast to the overlapped marginal end portions of the first rods and has openings therethrough to accommodate sliding passage of the second rods. A second member has a pair of first openings to accommodate sliding passage of the first rods, and has a pair of second openings to accommodate sliding passage of the second rods. A first handle is mounted to the outer ends of the first rods, and a second handle is mounted fast to the outer ends of the second rods. The first and second rods carry various abutment stops. A first pair of coil springs surround the first rods and are arranged to act between the first and second members. A second pair of coil springs surrounds the second rods and are arranged between the first member and the second handle.
Abstract: An automatically-operated bottom structure for an eight-sided container includes a pair of bottom flaps (66,69) pivotally connected to pair of opposed first panels (13,18), and band pivotally connected to an opposed pair of second panels (11,15) arranged substantially perpendicular to the first panels. The band and bottom flaps are folded within the container when the container is in a folded-flat condition, but are adapted to automatically form an operative bottom structure when the folded-flat container is moved to a fully-expanded condition.
Abstract: A prosthetic valve and an associated method of implanting the valve within a blood vein utilize a valve support ring and a pair of leaflet members pivotally connected to the ring. The valve is positionable within a radial plane of the blood vessel for permitting substantially unidirectional flow through the blood vein. The support ring is not required to be sutured within a blood vein and instead includes an outer surface defining a radially outwardly-directed annular groove, so that the valve can be secured within the blood vein by means of a cord tied around of the blood vein and in a tightened condition within the annular groove. The support ring is held in such fixed position along the length of the blood vein because the blood vein is held between the support ring outer surface and the cord.
Abstract: An improved energy-conserving servoactuator has at least one valve operatively associated with a double-acting fluid-powered actuator. When a load is applied to the actuator, the pressure in one actuator chamber will be greater than in the other. If the load is "opposing" with respect to the desired direction of actuator movement, fluid is supplied to the higher pressure chamber and is permitted to flow from the lower pressure chamber. However, if the load is "aiding" with respect to the desired direction of actuator movement, fluid in the higher pressure chamber is permitted to flow into the lower pressure chamber without drawing fresh fluid from the source.
Abstract: A heat exchanger comprising a stack of metal cloth or wire screens partitioned by sealant material into different regions through which separate fluids flow to exchange heat by way of conduction through the metal wires.
Abstract: The second stage (10) of a fail-fixed flow-control servovalve has a five-lobed valve spool (12) slidably mounted in a body bore (19). At null, the end lobes (41,45) are substantially zero-lapped with respect to supply pressure slots (22,26), the middle lobe (43) is substantially zero-lapped with respect to a pair of return slots (23,24), and the intermediate control lobes (42,45) are both symmetrically underlapped with respect to their associated control slots (29,30). Stops (34,35) limit movement of the spool in either axial direction. When the spool is at null or in either hard-over position, deliberate flow with respect to the control slots is blocked, and relative leakage flows are controlled. Such leakage flows may be balanced such that there is substantially-zero net leakage flow with respect to each control slots. Alternatively, such leakage flows may be deliberately mismatched to provide for desired net leakage flows with respect to control slots.
Abstract: A piezoelectric torque motor (10) includes a body (11), a pair of opposed nozzle assemblies (12,13) mounted on the body, a pair of piezoelectric actuators (14,15) extending upwardly away from the body, and a lever assembly (16) having an upper portion (95) engaging the upper ends of the actuators and having depending leg portions (96,98). A foot plate (94) is mounted on the lower marginal end portions of the lever legs, and is positioned between the nozzles. The piezoelectric actuators are supplied with differential voltages to cause swinging movement of the lever assembly between the nozzles. The improved torque motor may be used in the first- or pilot-stage of a two-stage electrohydraulic servovalve.
Abstract: A fluid-powered actuator has a piston slidably mounted in a cylinder. The piston subdivides the cylinder into first and second end chambers. A plurality of solenoid valves are arranged to selectively inject fuel and oxidizer into either chamber, or to inject liquid oxidizer to react with a solid fuel. Upon contact with one another, the fuel and oxidizer undergo a hypergolic reaction, and the products of this reaction create a pressure sufficient to displace the piston. Alternatively, a mono-propellant fluid fuel may be injected into such chamber. Upon contact with a catalyst in the chamber, the fuel undergoes a disassociation reaction, and the products thereof may be used to displace the piston.
Abstract: An instrumented test hammer for use in vibrationally exciting a test object includes a head assembly having an impact tip and a transducer operatively arranged to sense the force of an impact between the tip and object and to convert such sensed force into a proportional electrical signal, a handle extending away from the head assembly, and a cushioned grip surrounding a portion of the handle at a location spaced from the head assembly. The hammer is "tuned", by proper selection of the grip material and by selection of the ratio of the total mass of the head assembly to the combined mass of the handle and grip, such that the node of the first translational resonant mode of the hammer, after impacting against an object, is located substantially proximate the head assembly, independently of the manner by which the grip is held. The improved hammer substantially avoids the generation of spurious electrical signals due to post-impact vibration of the head assembly.
Abstract: A two-axis force motor (10) has an armature (12) mounted within a body (11) for omni-directional pivotal movement relative to the body. The motor has an electrical section for causing the armature to pivot selectively in either or both of two mutually-perpendicular intersecting planes (x-x,y-y). The motor also has a fluidic section, which includes a plurality of valve members (64) spaced about the armature. These valve members are biased to engage the armature and are closed when the armature is in a null position. When the armature is pivoted off-null, some of the valve members will be opened, while others will remain closed.
Abstract: A temperature measuring device comprises an optical temperature probe (20) and a control module (21). Thermal emission from a recess (28a, 28b) in the tip end portion (23) of an optical fiber (22) is transmitted to the remote end (26) of the fiber for detection by the control module. The recess provides improved sensor capability with regard to maintaining constant emissivity and rapid response time. The recess is suitable for both single crystal optical fiber and optical fiber with a core-and-cladding construction.
Abstract: A vehicle suspension system (10) has a spring (11) operatively arranged to act between sprung (15) and unsprung (13) masses. The coil (24) of an LVDT (22) is mounted on the sprung mass. The core (23) of the LVDT is connected to an intermediate portion (25) of the spring. Thus, displacement of the core relative to the coil will be a proportional fraction of the relative displacement between the masses. This arrangement allows the use of a short-stroke position-sensing transducer to measure the relative displacement between the two masses.
Abstract: Overhead door construction for a truck van or the like including metal door sections pivotally connected by the rigid part of a dual durometer plastic hinge member having a flexible part for sealing the joint between adjacent door sections when the door is closed.
Abstract: The invention provides an improved method of operating a pulse-width-modulated solenoid valve so as to improve the proportionality of the flow-to-command pulse width characteristics of the valve. A train of command pulses (P.sub.1, P.sub.2, . . . P.sub.n), having widths corresponding to the desired flow through the valve, is superimposed on another train of pre-pulses (p.sub.1, p.sub.2, . . . p.sub.n). Each pre-pulse is timed to appear immediately ahead of an associated command pulse so that their widths will be effectively summed. The pre-pulses have widths necessary to substantially eliminate the "deadzone" in the flow-to-pulse width characteristics of the valve. Hence, the proportionality of the flow-to-command pulse width characteristics of the valve will be substantially improved.
Abstract: An improved clamping mechanism is used to mount a transducer (11) on a motor housing (12). The motor housing has an inclined surface (18). The clamp (13) has one portion (32) engaging the inclined housing surface, and has another portion (30) engaging the transducer. A fastener (33) is used to move the clamp relative to the motor housing. The radial force exerted by the clamp on the transducer is greater than the axial force exerted by the clamp on the transducer.