Abstract: A rupture prevention ring consists of two coaxially arranged, spaced-apart stiff end rings wrapped in several layers of fiber cloth. Resin bonding is used around the end rings while in the intermediate area between the end rings, the fibers are not free of resin and hence not stiffened. Owing to the high energy absorption capability of the structure including the elastic yielding of the fibers without the resin, an excellent containment ability is obtained at a low weight. Fragments are effectively retained without jeopardizing the rotating blade and disk assembly of the damaged stage.

Abstract: An anti-rupture ring is slit axially at least at one location and is provided thereat with clamping devices which permit a rapid tightening and loosening of the anti-rupture ring. In one embodiment, the clamping of the anti-rupture ring can be varied hydraulically so as to minimize clearance losses in operation. The invention can be used in all types of turbo engines endangered by breakage of rotor blades, particularly in aircraft gas turbine construction, and it permits simple, damage-free mounting and a well-defined clamping of the anti-rupture ring.

Abstract: This invention relates to a device for controlling and synchronizing the guide vanes of a distributor of hydraulic machines, particulalry of turbines, which comprises ramps borne by spaced apart radial tabs secured with the synchronization ring. Each lever fitted angularly on the journal of each guide vane presents a free end which cooperates with the corresponding ramp by a roller. The profile of the guide vanes is such that the hydrodynamic force tend to close them.

Abstract: A burst guard ring for stopping and retaining blade fragments thrown from a failing rotor of a turbine engine includes an outer fiber belt of a highly elastic material, preferably aramid fibers in a silicone rubber matrix surrounding the engine housing. Ceramic tiles are provided radially inwardly of the fiber belt or in the fiber belt exclusively at certain critical locations where any bulging of the fiber ring due to blade fragment impact would damage auxiliary devices or pipelines arranged adjacent or close to the engine at such critical locations. In non-critical areas the fiber belt provides sufficient protection without the ceramic tiles. The high energy absorbing protective effect of elastic fibers is advantageously combined with the low straining or expansion of ceramic, so that a low total weight is achieved.

Abstract: A fan casing of a turbofan gas turbine engine has a slot which extends generally in a circumferential direction and which has an aerofoil section. A variable pitch fan blade may be removed from the turbofan by rotating the fan blade about its axis of rotation to fine pitch setting, and rotating the fan rotor so as to align the tip of the fan blade with the slot. The fan blade is detached from the fan rotor and the tip of the fan blade is inserted radially into the slot. The root portion of the fan blade is then moved in a radially outwards and axial direction to remove the fan blade. The slot in the casing allows the fan blade to be loaded by the reverse procedure. Loading/unloading of a fan blade is made possible without removing the fan casing.

Abstract: A turbo-machine compressor which includes variable incidence stator vanes the angular adjustment of which is controlled by a control ring coupled to individual vanes by individual links. Each link has at least one contact surface on each of its longitudinal edges, such surfaces being either plane or convex. In the event of failure of any link, the change in orientation is controlled within narrow limits by contact with the contact surfaces of adjacent links which have not failed.

Abstract: A hand vacuum cleaner is provided comprising a lightweight motor housing containing a revolving brush. A bag assembly is selectively separable from the housing and is sealable to the housing with an elastomeric retaining ring including a sealing and retaining bead for reception in a recessed slot area of a housing bag attachment collar. A fan is mounted to the motor on a motor shaft locking surface including a wall portion tapering towards the fan. The shaft is in locking cooperation with a mating fan bore locking surface including a wall portion tapered for close reception of the motor shaft locking surface. A shaft extension is threadedly received on the motor shaft and is urged into engagement against the fan by resistance of a revolving brush operated by a belt received on the shaft extension which continually tightens the shaft extension to the motor shaft and fixes the fan to the motor shaft.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component and a radial component of velocity is disclosed. The apparatus is comprised of a support structure 46 and a fabric 44 wrapped under tension about the support structure such that the installed length of the fabric is greater than the free length of the fabric. In one particular embodiment the fabric is coated with a layer of epoxy resin such that the resin penetrates only the top layer of the fabric to form a shield 95 which protects the containment fabric from injury. A method for forming the circumferentially extending structure is disclosed which includes the steps of forming a support structure and wrapping a fabric about the support structure under a preload to cause an elongation of the fabric and tension in the fabric in the installed condition.

Abstract: An air intake for a gas turbine engine compressor comprises an arcuate primary duct which is in communication with the compressor of the gas turbine engine and which is provided with frangible wall portion. The frangible wall portion provides a barrier between the primary duct and a secondary duct and is so positioned and adapted as to be impacted and penetrated by a foreign body, such as a bird, which is above a predetermined weight and which has been ingested through the inlet of the primary duct. After penetrating the wall portion the foreign body passes through the secondary duct and is discharged therefrom at a location remote from the primary duct.

Abstract: Retaining structure for a turbo-machine forming an annulus having a complex ircumferential construction comprising a cylindrical sector of a high mechanical strength material protecting a member secured on the casing of the machine. The complementary sector of the annulus is a honeycomb structure mounted between an internal and an external skin. The cylindrical sector is formed by a thickening of the internal skin. A strap of a material with a high elastic modulus serves to secure at least the complementary sector.

Abstract: Disclosed is an actuator for rotating a plurality of circumferentially spaced variable vanes each having a spindle extending through a casing about which the vane is rotatable. The actuator includes an arcuate unison member and a plurality of levers each having first and second ends, respective ones of the levers being fixedly attached to a vane spindle at the lever first end and rotatably attached to the unison member at the lever second end. Frangible means are provided for allowing at least one of the vanes to be rotated to an angular position different from the position of adjacent ones of the vanes upon impact of the one vane by a foreign object, and limit means are provided for maintaining the angular position of the one vane within predetermined limits with respect to the angular position of adjacent vanes to prevent 1/REV excitation.

Abstract: A gas turbine engine has an axial flow compressor, the inner wall of which is provided with a lining adapted to capture and retain any small hard foreign objects impinging upon it. The lining consists of an aluminum alloy sheet having a silicone rubber coating bonded to one side and a stainless steel honeycomb structure bonded to the other side. The honeycomb structure is bonded in turn to the inner wall of the compressor casing. The silicone rubber coating has a plurality of finely divided hollow silica microspheres dispersed within it.

Abstract: The invention discloses a confinement structure for a turbojet engine to retain and confine fragments of a rotor blade. The structure has three zones of varying vulnerability to the blade fragments so as to maximize the confinement of such fragments, while minimizing the weight of the structure. A first zone, located in the plane of rotation of the rotor blade wheel confines the small fragments which may impact in this zone. A second zone, adjacent to the first, but located downstream, contains a retention belt structure to absorb the energy generated by contact with the larger blade fragments. Finally, a third zone, downstream of the second zone, defines a containment chamber to retain the larger blade fragments.

Abstract: Axial dislocation of a containment ring for a turbine is avoided through the use of housings having portions overlapping and extending across a radially inwardly opening containment groove in a containment ring. Upon separation of a blade from a turbine wheel, the sleeves are deformed into the groove thereby locking the ring in the desired axial location.

Abstract: A breakaway base for use with an ultracentrifuge rotor wherein the base is designed to fracture when the rotor is above a specified speed so that the rotor will disengage from the drive spindle of the centrifuge. The base has cutout areas to establish a high stress region that is designed to fracture above a specified rotor speed. The cutout areas are designed to receive lugs projecting from the bottom of the rotor. The cutout areas have slotted ledges through which fastening bolts connect to the lugs on the rotor. The fracture of the base in the high stress region in conjunction with the slotted ledges will result in the base fracturing into two parts which will cause rotor disengagement from the drive spindle of the centrifuge and prevent the rotor from spinning at a greater speed.

Abstract: A centrifugal pump comprises an impeller which rotates at the center of a volute casing. The open side of the casing is closed by means of a wear plate which is fixed relative to the casing and which has a central inlet opening. The impeller includes a rear plate and a plurality of curved blades radiating from an open central portion of the rear plate. An annular plate is fixed to the outermost edges of the blades at the inlet side of the impeller. A cylindrical sleeve extends in an axial direction from near the inner edge of the annular plate through the opening in the wear plate. The annular plate and sleeve protect the edge of the wear plate and impede grit and sand entering between the annular plate and around the opening and the wear plate causing wear when the pump is used to pump slurry containing grit or sand.

Abstract: Method of containing fractured turbine engine components, for example rotor and blade fragments within turbine engine casings, comprising diffusing and impeding motion of the fractured blade fragment by encircling the turbine engine with an honeycomb structure; shielding the honeycomb with an outer shell which has a high bending stiffness and which encloses a series of subdivided compartments in juxtaposition with the honeycomb; and absorbing energy of the fractured blade fragments by supporting a series of ceramic blocks within the confined compartments adjacent said honeycomb. A suggested ceramic for use in the blocks is a hot-pressed silicon carbide. The method is distinguished from the prior art in its ability to sustain the subsonic velocities.

Abstract: A blade containment structure employs a two-layer honeycomb region radially outward of a fan blade rub strip. The two layers are separated by a septum and each layer contributes independently to strength and stiffness of the structure. A Kevlar blanket radially outward of the honeycomb region retains blade fragments which may be broken loose by ingestion of large objects such as, for example, birds. The radially inner honeycomb region is deep enough to position the septum out of the orbit of blade tips in an engine made unbalanced by loss of one or more fan blades. The septum and outer honeycomb region retains sufficient strength in the structure for supporting forward components.

Abstract: A rotor is distinguished by parts including a radially innermost part and a radially outermost part which is actually a separate element. The two parts are normally coupled for their conjoint rotation by pins anchored to project radially from the innermost part and freely into apertures in the radially outermost part. The pins provide a bearing mount thereon of the outermost part which is fabricated to radially expand and contract in correspondence with the speed of rotation of the rotor and to have a benign failure in the location of one of the apertures upon excessive speed of the rotor. By virtue of such failure the radially outermost part opens and expands to be braked by engagement with the particular surface most adjacent its outer periphery. This rotor is particularly advantageous for use in providing a turbine drive unit, in which event its power transmitting outer peripheral portion is formed by turbine buckets.

Abstract: As originally fabricated the rotor of the invention is a unitized structure an outer portion of which, including its outer peripheral surface, is designed to separate shortly after the start of its rotation. As illustrated, this outer peripheral portion is a ring-shaped structure which is initially incorporated by an interference fit which establishes it in a fixed bounding relation to the rotor part immediately inward thereof. At the point in time that said outer portion of the rotor is separated, guide means are rendered operative to maintain a drive coupling as between the outer and inward rotor parts and such guide means then serve as bearings accommodating the radial movement of the outer separated part in correspondence with its changing radius in response to changing speeds of rotation of the rotor. Any failure of the rotor is benign in that at such time the rotor exceeds the designed limit of its speed of rotation the outer part expands sufficient to brake against its adjacent shield or housing.

Abstract: A mechanism 25 for preventing a turbine rotor 14 exceeding a predetermined speed in the event that a shaft 24 connecting the turbine rotor 14 to a compressor rotor 12 of the engine breaks and releases its torsional and axial constraint on the turbine rotor. The mechanism 25 comprises a segmented nozzle guide vane assembly 26 downstream of a stage of the turbine rotor 14. Each of the segments 26 is pivotally mounted (hinge pins 40) on an outer casing 34 at a region adjacent a radially outer upstream end of each segment 26. The structure of the engine on which the radially innermost ends of the segments 26 are mounted includes a releasable means 46. When the structure 46 is struck by the turbine rotor 14 the innermost ends of the segments 26 are released and allowed to swing rearwards and outwards about the pivotal attachment of the segments 26 to the outer casing 34.

Abstract: A turbine rotor 14 of a gas turbine engine is provided with a mechanism 25 designed to tilt into the path of the turbine rotor blades to decelerate the rotor if a shaft 24, which connects the turbine rotor 14 to a compressor rotor 12 breaks. The mechanism 25 comprises a segmented stator vane assembly 26 in which the segments are supported at an upstream region of their radial inner ends on a deflectable strut 44 and by means of a tie 46 at a downstream region of their radial inner ends. When the shaft 24 breaks, the rearward movement of the rotor 14 is used to unlatch the strut 44 causing the NGV segments 26 to collapse inwards and tilt forwards into the path of the turbine rotor blades to decelerate the rotor. The NGV segments 26 and the turbine rotor blades destroy each other and the resulting debris is ejected out of the jet pipe 22 destroying further downstream turbine stages.

Abstract: An annular beam 46 which is hollow and which extends circumferentially about an annular flow path 22, 24 for working medium gases is disclosed. The annular beam supports and positions both a shroud 42 and a fabric 44 for containing particles having axial and radial velocity. The annular beam has a first wall 48 and a second wall 50. The second wall is spaced radially from the first wall. A plurality of annular plates 52 extending circumferentially about the interior of the beam. The plates are attached to the first wall and to the second wall. In one detailed embodiment the annular plates have a C-shaped cross section formed of a circumferentially extending rib 58 and two axially oriented legs 60, 62. The radial height of the rib is many times greater than the radial height of the legs. A method of fabricating the annular beam is disclosed.

Abstract: A mechanism 25 for preventing a turbine rotor 14 from exceeding a predetermined speed if a shaft 24, connecting the turbine rotor 14 to a compressor rotor 12 of the engine, breaks and releases its axial and torsional constraint on the turbine rotor 14. The mechanism 25 comprises a segmented stator vane assembly 26 downstream of a stage of the turbine rotor 14. Each segment 26 has first and second members 38,40 projecting radially inwards. The first and second members 38,40 are provided respectively at an upstream and downstream region of the inner end of each segment 26. A constraining means 34,36 is provided to constrain the segments 26 against displacement bodily on an axial direction. Static structure of the engine 56 engages the first and second members 38,40 and provides radially outwards and axially rearwards constraint on the first members 38 and radially inwards and axially forwards constraint on the second member 40.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component and a radial component of velocity is disclosed. The apparatus is comprised of a support structure 46 and a fabric 44 wrapped under tension about the support structure such that the installed length of the fabric is greater than the free length of the fabric. In one particular embodiment the fabric is coated with a layer of epoxy resin such that the resin penetrates only the top layer of the fabric to form a shield 95 which protects the containment fabric from injury. A method for forming the circumferentially extending structure is disclosed which includes the steps of forming a support structure and wrapping a fabric about the support structure under a preload to cause an elongation of the fabric and tension in the fabric in the installed condition.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component of velocity and a radial component of velocity is disclosed. The structure includes an inner casing, such as the first casing 48, and an outer casing, such as the second casing 50. The outer casing is flexible. The outer casing is formed of a plurality of layers of fabric and a means for applying a load to the fabric such as a plurality of bars 80, 82 and turnbuckles 74. A method of forming the structure is disclosed. The method includes the step of wrapping a fabric having a first length about the inner casing and the step of stretching the fabric to a second length to affect the operative response of the fabric to the impact of a particle.

Abstract: A circumferentially extending apparatus 46 for containing particles having an axial component and a radial component of velocity is disclosed. The apparatus is comprised of a support structure 48 and a flexible casing 50 formed of a fabric 78. The external surface of the support structure has a first diameter and a second diameter not equal to the first diameter at a location spaced axially from the location of the first diameter. The fabric is preloaded to increase the length of the fabric and is wrapped under tension about the surface of the support structure such that the installed length of the fabric is greater than the free length of the fabric. A method for forming the circumferentially extending structure is disclosed which includes the steps of forming a support structure and wrapping a preloaded fabric about the support structure to cause an elongation of the fabric and tension in the fabric in the installed condition, which varies depending on the diameter of the support structure.

Abstract: Aircraft gas-turbine engines (10) are often mounted and supported by strut type structures (12) which contain fuel, oil, electrical and hydraulic engine supply lines. The engine fan (18) is surrounded by a belt (24) made of tough flexible material designed to restrict travel of broken fan blade pieces, ingested objects or other debris (20). The forward strut section (12), adjacent the belt (24), is located outside of the maximum belt deflection envelope (26) except for the engine right and left cowl hinges (62 and 64) and its support structure (30), which structure (30) is made collapsible. This collapsible cowl hinge structure (30) utilizes mechanical fuse connections (68) which upon a dislocation force from the belt (24) allows the structure (30) to disconnect from the strut support structure (12).

Abstract: An annular inlet stator vane assembly positioned upstream of the bypass and core flow passages of a turbofan jet engine is provided with energy-absorbing bendable vanes which are fixedly secured to an outer support shroud assembly and extended through slots in an inner shroud assembly. The inner ends of the vanes are releasably secured to the inner shroud by specially designed deformable retention clips which are welded to the inner vane ends and shroud. These features of the vane assembly cooperate to limit the circumferential extent of inlet vane damage caused by engine-ingested objects, and to help prevent damaged vane assembly structure from being drawn through the core passage of the engine or blocking such core passage.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component and a radial component of velocity is disclosed. The apparatus is comprised of a hollow annular beam 48 and a fabric 46 wrapped under tension about the annular beam such that the installed length of the fabric is greater than the free length of the fabric. In one particular embodiment the fabric is coated with a layer 116 of epoxy resin such that the resin penetrates only the top layer of the fabric to form a shield. The shield layer protects the containment fabric from injury.

Abstract: A circumferentially extending structure 30 for containing particles having an axial component of velocity and a radial component of velocity is disclosed. The structure includes an inner casing 48 and an outer casing 50. The outer casing is formed of a plurality of layers of flexible fabric and includes layers having differing masses per unit length in the fabric. The layers of fabric extend about the inner casing. A means for applying a load to the fabric engages the fabric to place the fabric in tension. One such means is a plurality of bars 80, 82 and turnbuckles 74. In one embodiment, the fabric has a greater mass per unit length in the leading edge region and a greater tension is applied to the leading edge region than other regions of the fabric. A method of forming the structures is disclosed.

Abstract: A fan drive system comprising a main drive shaft 13 which drives the fan through a frangible coupling 27 and an auxilliary drive shaft 30 which by-passes the coupling 27. The auxilliary shaft 30 is pre-twisted elastically in the opposite direction to the direction of rotation of the main shaft 13, and is held in the pre-twisted state by the coupling 27. When the coupling 27 disconnects the drive from the main shaft 13, for example when the fan becomes unbalanced and transverse loads exceed a predetermined magnitude, the auxilliary shaft 30 unwinds. Unwinding of the shaft 30 cushions the fan against suddenly applied loads when the coupling 27 breaks and also reduces the loads on the coupling 27 during normal balanced running.

Abstract: A containment ring for a gas turbine engine consists of a substantially rigid inner cylinder around the periphery of which is wound layers of fibrous material, a plurality of axially extending strips are located upon the outermost curved surface of the layers of fibrous material and are secured thereto by self-tapping screws.

Abstract: A ferrule surrounding the blading of a rotor is lined externally with an assembly of elements of revolution. These elements are in the form of cylindrical rings, circular rings or of tori supported between blocking elements. The assembly is formed by alternating rings made of a composite or metallic material and a winding of fibers encased in a polymerizable resin.

Abstract: A turbine missile shield is formed by a series of substantially semi-cylindrical, concentric stainless steel shells joined and spaced apart by longitudinal and transverse spreader beams. The longitudinal peripheries of the shells are joined to form mounting rims with bolt holes formed therein to enable mounting on a turbine pedestal or operating floor.

Abstract: A ring is secured to the casing of the compressor or of the turbine of a turbine engine, and has an inner envelope, a first ring of segments of a honeycomb material, a winding of wire sections encased in a polymerizable resin, a second ring of honeycomb segments and an external envelope of a thin material.

Abstract: An exhaust fan comprising rotatable fan blades, a motor for rotating the blades, a case for mounting and surrounding the blades, and a band detachably disposed and surrounding the case for permitting removal of a coating film from the case, the film being a coating for covering the case and the band for protecting the case from dirt, especially cooking grease.

Abstract: A nuclear power plant comprising a control building for receiving therein control instruments which make controls of the nuclear energy plant, a reactor building for receiving a nuclear reactor therein, a turbine building for receiving therein turbines and a generator which are driven by steam supplied from the nuclear reactor, said buildings being arrayed in a straight line, and scattering fragments-checking means disposed on the inner wall of a turbine casing, said means functioning so that when a turbine rotary body breaks and scatters, the scattering fragments may collide against it and have their rescattering directions limited.

Abstract: A guide vane protecting device for use in a hydraulic turbine. The device has a braking system having a first and a second braking members by which an initial braking power is imparted to a first control member interposed therebetween. The braking system further has a translational sliding mechanism which permits the translational sliding movement of the first braking member onto the first control member so so to cause a uniform increase of the braking force exerted by the braking members on the first control member, when a weakened pin incorporated in the protecting device is broken by an extraordinary force caused by, for example, jamming of foreign matter between adjacent guide vanes.

Abstract: An aircraft engine starter including a pneumatic motor driven by pressurized gas upon opening of an upstream control valve. A fusible plug valve automatically closes the control valve and shuts down the pneumatic motor whenever temperature of the lubricating oil of the motor exceeds a preselected level.

Abstract: A mounting arrangement for the fan rotor of a ducted fan engine includes a first drive which supports and rotates the fan under normal operating conditions but which includes a frangible connection which breaks when an excessive out-of-balance force is applied to the fan rotor for example after loss of one or more blades. A second supporting and driving structure is provided which has built-in transverse flexibility but which can transmit torque. This structure is redundant during normal operation of the engine but comes into use when the frangible connection is broken and allows the fan rotor to rotate eccentrically around a new axis in an inverted condition.

Abstract: A turbine for a gas turbine engine is provided with a rotary stage comprising an annular array of rotor blades surrounded by an annular shroud member. The shroud member is hollow, the hollow interior being provided with a heat transfer medium which, in operation, functions as a condensable vapor and liquid whereby the shroud member is a heat pipe. The shroud member is further provided with a wall adjacent the aerofoil blade which is adapted to be penetrable by a detached blade or blade portion. The wall of the shroud member is dimensioned so that any such detached blade or blade portion which penetrates the wall enters the hollow shroud ring and is retained within it.

Abstract: A device to eject a fragment of a broken blade of an axially rotating mace by damping its kinetic energy, in order to prevent perforating the housing of the machine and the rupture of adjacent blades. The device is in the form of a helical ramp carried by the internal wall of the housing of the machine.

Abstract: A device is provided for containing blades of rotating turbomachinery comprising a high-strength ring supported in radial spacial relationship over the blade tips by means of a stationary support structure. The ring is supported in such a manner that it is capable of spinning with respect to the support structure when acted upon by a predetermined blade force.

Abstract: An inertial energy storage device is disclosed employing a safety flywheel which is made of flexible material such as a twisted rope ring. The rigidity required for such a device is achieved through centrifugal forces inherent in such a device when it is operating. A small number of the strands of the rope ring have a tensile strength that is lower than the vast majority of the strands of the rope ring whereby should any of these strands fail, they will begin to whiplash allowing such a failure to be detected and braked before a castastrophic failure occurs. This is accomplished by the inclusion of glass tubes located around the periphery of the flywheel. The tubes are in communication with a braking fluid reservoir. The flywheel and glass tubes are enclosed within a vacuum-tight housing. The whiplashing of a broken strand breaks one or more glass tubes. This causes the housing to be flooded with the braking fluid thereby braking the rotation of the flywheel.

Abstract: A shielding means which has a continuous sidewall made up of a first set of multiple layers of ballistic nylon. An open end of the sidewall is closed with a second set of multiple layers of ballastic nylon. The other open end of the sidewall fits over and is securable to a housing cover to be shielded.

Abstract: In the connection between the unison ring and the actuating arms carried by the several vanes of a variable stator ring in an axial flow compressor and providing for turning the vanes as the unison ring is moved, the pivot that must permit angular misalignment, relative rotation and axial movement is an elliptical-shaped bushing mounted on either the ring or arm and engaging a cylindrical surface on the other of the ring or arm. The bushing is normally mounted on a pin and the cylindrical surface is provided by a sleeve, the elliptical element having slidable engagement with the sleeve. The bushing may be a metallic spring or may be made of an elastomer.

Abstract: A containment shroud is attached to the exhaust outlet of a pneumatically powered turbine engine starter for containing the turbine wheel should it be inadvertently disengaged and expelled from the starter motor. The shroud includes a radially flared annularly shaped member attached to and extending outwardly or rearwardly from the exhaust outlet of the motor. A relatively massive central cylindrical member or button is positioned within the annularly shaped member adjacent the outer opening of the annularly shaped member. Four circumferentially spaced, radially outwardly extending bars tie the button to the annularly shaped member and position it adjacent the outer opening of the annularly shaped member. Should the turbine wheel dislodge from the starter motor, it will exit through the starter exhaust opening into the annular member and contact the button and inner surface of the annular member.

Abstract: In a wicket gate protecting device for hydraulic machines, a pair of link plates transmitting a force between a gate control ring and a gate lever, is connected to the gate lever through a shear pin. The gate lever disposed between the link plates, and rotatably supported about the shear pin. When the movement of the wicket gate is restricted by obstacles entered between adjacent gate vanes, the shear pin is cut and a part of the shear pin supporting the gate lever moves along between the link plates for a distance and is stopped by friction between the link plates and the shear pin, thereby preventing damage to the neighboring gate vanes.

Abstract: An inlet guide vane for a turbofan engine comprises a principal airfoil portion fabricated of metal and a radially outward and rearward corner portion fabricated of a frangible material which is attached to the metal portion and completes the airfoil structure. When foreign objects are ingested into the airstream to cause the closely spaced fan blades to deform forwardly to impact against the inlet guide vane, the frangible rearward corner of the inlet guide vane is caused to break off into small pieces and pass through the system without causing any significant secondary damage, thereby leaving the principal portion of the inlet guide vane to function as a relatively efficient airfoil.