Single ended tuning fork internal sensor and method
First Claim
1. In a method for sensing rate by the use of a single ended tuning fork mounted in a housing and having first and second tines lying in a plane and having an axis of symmetry and a body formed integral with the first and second tines and having drive electrodes and pickup electrodes mounted on the tines, the method comprising supplying an oscillator frequency to the drive electrodes to drive them in a drive mode and sensing an angular rate signal provided by the pickup electrodes in response to rotation about said axis of symmetry, the improvement comprising forming each of the first and second tines so that they are rectangular in cross section and having a width which is different from the thickness to separate by a delta f frequency the pickup mode from the drive mode and forming a stem in the body which has width and length that causes reduction in the delta f frequency.
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Reexamination
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Abstract
Single ended tuning fork inertial sensor having a housing and a single ended tuning fork of a quartz-like material of a predetermined thickness, the tuning fork has first and second tines lying in a plane and having an axis of symmetry and has a body formed integral with said first and second tines. The body is rigidly secured to the housing. The tines have a rectangular cross section and have a width which is different from the thickness. The body has a stem formed therein which has a width less than that of the body. Drive electrodes are secured to the tines. An oscillatory frequency is supplied to the above drive electrodes to excite the tines in a drive mode and in the presence of an axial angular rate to cause the tines to operate in a pickup mode which is substantially separated in frequency from the drive mode. The width and thickness of the tines are chosen so as to provide a frequency difference between the frequency of the pickup mode and the frequency of the drive mode, and width and length of the stem are chosen so as to a reduce the frequency difference.
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Citations
3 Claims
- 1. In a method for sensing rate by the use of a single ended tuning fork mounted in a housing and having first and second tines lying in a plane and having an axis of symmetry and a body formed integral with the first and second tines and having drive electrodes and pickup electrodes mounted on the tines, the method comprising supplying an oscillator frequency to the drive electrodes to drive them in a drive mode and sensing an angular rate signal provided by the pickup electrodes in response to rotation about said axis of symmetry, the improvement comprising forming each of the first and second tines so that they are rectangular in cross section and having a width which is different from the thickness to separate by a delta f frequency the pickup mode from the drive mode and forming a stem in the body which has width and length that causes reduction in the delta f frequency.
Specification
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- Resources
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Current AssigneeBEI Sensors & Systems Company Incorporated (Schneider Electric SE)
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Original AssigneeNew SD, Inc.
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InventorsMacy, David F.
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Primary Examiner(s)CHAPMAN JR, JOHN E
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Application NumberUS08/152,822Time in Patent Office526 DaysField of Search73/1 D, 73/1 DV, 73/505, 310/329, 310/370, 29/25.35, 29/595US Class Current73/504.16CPC Class CodesG01C 19/5607 using vibrating tuning fork...
