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US 4,069,706 AGranted
Complex vibration tester
AssigneeMRAD Corporation
InventorsPhilip Marshall, Albert Paul Laber, Ugo Cauteruccio
Life of this patent
Estimating the term…
Abstract
A mechanical complex vibration tester is provided which is capable of simultaneously applying a plurality of discrete frequencies to a workpiece positioned on a test surface of the device to simulate random vibration testing. The vibrations may be varied in amplitude and they may be applied in either the vertical or the horizontal direction. Means are provided for isolating the tester from its environment in order to simulate vibration testing in inertial space.
Claims23
Apparatus for vibration testing a work piece adapted to be positioned on a test surface comprising:
- a substantially rigid support structure including said test surface;
- means for generating vibrations including at least one resonator assembly mounted on said structure, said resonator assembly comprising an elongated cantilever beam including a fixed end and a free end respectively;
- and
- means mounted on said structure for setting said cantilever beam into free vibration to cause said resonator assembly to vibrate substantially at its own resonant frequency;
- whereby the vibrations of said resonator assembly are adapted to be imparted to said test surface through said support structure.
2 more elements
Apparatus for vibration testing a work piece adapted to be positioned on a test surface comprising:
- a substantially rigid support structure including said test surface;
- means for generating vibrations including a plurality of resonator assemblies mounted to said structure each adapted to vibrate at its own discrete frequency, each of said resonator assemblies comprising an elongated cantilever beam including a fixed end and a free end respectively;
- a mass of predetermined magnitude affixed to each of said beams inwardly of its free beam end, said mass being effective to determine the resonant frequency of beam vibrations in conjunction with the other parameters of the corresponding resonator assembly;
- and
- means for setting said cantilever beams into vibration to cause said resonator assemblies to vibrate concurrently at their discrete resonant freqencies, said vibration setting means comprising means corresponding to each of said cantilever beams for mechanically deflecting the free beam end thereof from its normal rest position, said last-recited means being further adapted to release said deflected free beam end a predetermined distance from said rest position to permit said beam to vibrate freely about said rest position;
- whereby complex vibration is imparted to said test surface through said support structure, said complex vibration having substantially said discrete resonant frequencies as its constituent components.
3 more elements
Mechanical vibration apparatus comprising:
- a frame;
- a work piece support platform mounted to the top of said frame and including a horizontal test surface adapted to hold a work piece under test;
- said frame and said platform jointly forming a substantially rigid, integral structure defining an enclosed interior space;
- a plurality of resonator assemblies mounted on said structure in said interior space;
- each of said resonator assemblies including an elongated flexible cantilever beam having a free end adapted to be vertically deflected from a rest position, said beam terminating in a mounting block opposite its free end;
- each of said resonator assemblies further including a mass affixed to said cantilever beam inwardly of said free end, the resonant frequency of free beam vibrations about said rest position being determined by said mass in conjunction with the other parameters of said resonator assembly, the magnitude of each mass being selected to provide a discrete resonant frequency of vibration for each of said resonator assemblies;
- said plurality of resonator assemblies being arranged in successive pairs aligned to form two parallel rows, the free beam ends of each of said pairs of resonator assemblies being spaced from each other in mutually facing relationship;
- a rotatable shaft positioned between said rows and parallel thereto;
- means for rotating said shaft;
- a plurality of striker assemblies mounted on said shaft and adapted to rotate therewith, each of said striker assemblies including a plurality of rollers uniformly disposed around said shaft and radially spaced thereform, said rollers being in alignment with a pair of said mutually facing free beam ends in a vertical plane normal to said shaft;
- said rollers of each rotating striker assembly being adapted to periodically deflect said pair of mutually facing free beam ends a selected distance in opposite substantially vertical directions prior to their release to produce free beam vibrations in said vertical plane, said selected deflection distance being determinative of the amplitude of said free beam vibrations;
- and
- a plurality of springs supporting said frame on a substantially horizontal load surface, the natural frequency of said springs being no greater than one half of the lowest one of said discrete resonant frequencies;
- whereby the vibrations of each of said cantilever beams are transmitted through said structure to impart complex vibration in a vertical direction to said test surface, the constituent components of said complex vibration consisting substantially of said discrete frequencies of vibration.
11 more elements
Mechanical vibration apparatus comprising:
- a frame;
- a work piece support platform mounted to the top of said frame and including a horizontal test surface adapted to hold a work piece under test;
- said frame and said platform jointly forming a substantially rigid, integral structure defining an enclosed interior space;
- a plurality of resonator assemblies including an elongated flexible cantilever beam having a free end adapted to be vertically deflected from a rest position, said beam terminating in a mounting block opposite its free end;
- each of said resonator assemblies further including a mass affixed to said cantilever beam inwardly of said free end, the resonant frequency of free beam vibrations about said rest position being determined by said mass in conjunction with the other parameters of said reonator assembly, the magnitude of each mass being selected to provide a discrete resonant frequency of vibration for each of said resonator assemblies;
- said plurality of resonator assemblies being positioned with said free beam ends facing outward from the center of said interior space and being aligned in two parallel rows;
- a pair of rotatable shafts each positioned outwardly of one of said rows and parallel thereto;
- a drive shaft coupled to said pair of shafts;
- means for rotating said drive shaft;
- a plurality of striker assemblies mounted on each one of said pair of shafts and being adapted to rotate therewith, each of said striker assemblies including at least one cam surface radially spaced from its corresponding shaft and in alignment with one of said free beam ends in a vertical plane;
- said cam surface being adapted to periodically deflect said aligned free beam end a selected distance in a substantially vertical direction prior to its release to produce free beam vibrations in said vertical plane, said selected distance being determinative of the amplitude of said free beam vibrations;
- and
- a plurality of springs supporting said frame on a substantially horizontal load surface, the natural frequency of said springs being no greater than one half of the lowest one of said discrete resonant frequencies;
- whereby the vibrations of each of said cantilever beams are transmitted through said structure to impart complex vibration in a vertical direction to said test surface, the constituent components of said complex vibration consisting substantially of said discrete frequencies of vibration.
11 more elements
Mechanical vibration apparatus comprising:
- a frame;
- a workpiece support platform mounted to the top of said frame and including a horizontal test surface adapted to hold a work piece under test;
- said frame and said platform jointly forming a substantially rigid, integral structure defining an enclosed interior space;
- a plurality of resonator assemblies mounted on said structure in said interior space;
- each of said resonator assemblies including a flexible cantilever beam having a free end adapted to be horizontally deflected from a rest position, said beam terminating in a mounting block opposite its free end;
- each of said resonator assemblies further including a mass affixed to said cantilever beam inwardly of said free end, the resonant frequency of free beam vibrations about said rest position being determined by said mass in conjunction with the other parameters of said resonator assembly, the magnitude of each mass being selected to provide a discrete resonant frequency of vibration for each of said resonator assemblies;
- said plurality of resonator assemblies being arranged in successive pairs aligned to form two parallel rows, the free beam ends of each of said pairs of resonator assemblies being spaced from each other in mutually facing relationship;
- a plurality of rotatable vertical shafts each positioned between one of said pairs of resonator assemblies;
- means for rotating said shafts;
- a striker assembly mounted on each of said vertical shafts and adapted to rotate therewith, each of said striker assemblies including a plurality of rollers uniformly disposed around its corresponding shaft and radially spaced therefrom, said rollers being in alignment with a pair of said mutually facing free beam ends in a horizontal plane;
- said rollers of each rotating striker assembly being adapted to periodically deflect said pair of mutually facing free beam ends a selected distance in opposite substantially horizontal directions prior to their release to produce free beam vibrations in said horizontal plane, said selected deflection distance being determinative of the amplitude of said free beam vibrations;
- a granite slip table including a substantially horizontal load bearing surface;
- an oil film disposed on said load bearing surface;
- said structure being positioned on said oil film to provide substantially frictionless freedom of motion in the plane of said load bearing surface;
- a plurality of brackets affixed to said slip table each extending above said load bearing surface opposite said structure;
- and
- spring means disposed between each of said brackets and said structure in a manner adapted to filter out horizontal vibrations of said load bearing surface, the natural frequency of said spring means being no greater than one half of the lowest one of said discrete resonant frequencies;
- whereby the vibrations of each of said cantilever beams are transmitted through said structure to impart complex vibration in a horizontal direction to said test surface;
- the constituent components of said complex vibration consisting substantially of said discrete frequencies of vibration.
16 more elements
Apparatus for vibration testing a work piece adapted to be positioned on a test surface comprising:
- a substantially rigid support structure including said test surface;
- a plurality of resonator assemblies mounted on said structure each having a discrete resonant frequency, each of said resonator assemblies comprising an elongated beam fixed at least at one end thereof;
- and
- means mounted on said structure for setting said beams into free vibration so as to produce concurrent vibrations of the corresponding resonator assemblies at their respective discrete resonant frequencies;
- whereby complex vibration is imparted to said test surface through said support structure, said complex vibration having substantially said discrete resonant frequencies as its constituent components.
2 more elements
Dependencies are inferred from the claim text.