Metal deforming – Process – Tube making or reshaping
Patent
1997-10-31
1999-11-16
Brock, Michael
Metal deforming
Process
Tube making or reshaping
7351436, 367179, G01V 118, H01H 3514
Patent
active
059836997
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to seismometers and like instruments.
BACKGROUND OF THE INVENTION
The invention is particularly concerned with sensitive precision instruments of the kind in which a mass which is sufficiently great to constitute an inertial frame of reference is suspended so as to be free to move, by rotation or by translation, with respect to the instrument as a whole, so that motion of the instrument can be detected or measured. For ease of reference, such instruments as a class will be referred to herein as pendulum instruments. Pendulum instruments include accelerometers, velocimeters, displacement meters including inclinometers, gravity meters, and some kinds of inertial navigation instruments, as well as seismometers of the kind in which a mass is suspended in a frame which is intended in use to contact, and be moved by, the surface of the earth (or any other body whose seismic vibrations are to be measured). In principle, the vibrations cause the frame to move, and the mass is sufficiently freely suspended and sufficiently massive to form its own frame of reference, and the relative motion between the mass and the frame is detected and measured.
By limiting the degrees of freedom relative to the frame in which the mass can move, the seismometer can be set up to measure movement on one particular axis. This may be rectilinear motion, and this is approximated to in many pendulum-type seismometers by arcuate motion, when a long pendulum moves in a short arc.
In general, therefore, the invention is concerned with pendulum instruments in which a mass is prevented from moving in undesired directions, but is allowed to move as freely as possible in one or more other directions. The invention is specifically concerned with such instruments in which there is a mechanical linkage by which the mass is suspended and constrained with respect to the frame.
In instruments of this kind, the design of the suspension can be critical to the performance of the instrument. The suspension must be strong enough to reliably support the mass and prevent its movement in unwanted directions, yet be stable, smooth and substantially free of friction.
Given that the suspension must be resistant to movement of the mass off its intended axis, but compliant to movement of the mass in a direction in which the desired seismic disturbances are to be detected, and considering the magnitude of the mass involved and the desired sensitivity of the instrument, it is clearly desirable to provide means for locking the mass against movement with respect to the frame, so that the instrument can be transported and handled safely, without risk of damaging the delicate components. In practice, this poses problems, because it is extremely difficult to manufacture a locking mechanism that perfectly engages the mass without exerting unwanted stresses on the suspension. Indeed, it is common for suspension components to be stressed and ultimately to fracture after repeated locking and unlocking cycles.
SUMMARY OF THE INVENTION
It is an object of this invention to address this problem.
We have found that, rather than trying to solve this problem by ever more precise manufacturing, or strengthening the suspension, the problem can in fact be avoided.
According to the invention a pendulum instrument mechanism, and a method of locking it, comprise some or all of the elements and features disclosed in the following description. The scope of the invention extends to all novel aspects whether individually or in combination with other features as described herein.
More specifically, in one aspect of the invention a pendulum instrument mechanism of the kind comprising a mass connected to a frame by suspension means which constrains the mass to move substantially freely within a limited set of degrees of freedom comprises means for sequentially disengaging the mass from the frame at the suspension means, clamping the mass to the frame to lock the mechanism, unclamping the mass from the frame to unlock the mechanism, and re-en
REFERENCES:
patent: 2536870 (1951-01-01), Burmist
patent: 3656567 (1972-04-01), Knothe et al.
patent: 3713088 (1973-01-01), Lehner et al.
patent: 3828870 (1974-08-01), Schwarz
patent: 4189945 (1980-02-01), Whiting
patent: 4280206 (1981-07-01), Guralp
patent: 4368637 (1983-01-01), Anderson
patent: 4630483 (1986-12-01), Engdahl
Vrashchenie I Prilivnye Deformatsii Zemli 1974, Ukrainan SSR, USSR P3-15 X P00 212384 Balenko et al: Horizontal Pendulum with Tselinerov Wire Suspension P6 Line 30-38 Fig 4+5.
Guralp Cansun Mustafa
Humphries Derek Roy
Brock Michael
Guralp Systems Limited
Kwok Helen C.
Usher Robert W. J.
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