Title of Invention

"A DEVICE USEFUL FOR HOLDING A SENSOR INSIDE A DRILLED HOLE"

Abstract

A device useful for holding a sensor inside a drilled hole, characterized by an externally threaded tube (2), one end of the said threaded tube also being provided with internal threading capable of holding a threaded stem (13) of a sensor (1), the said sensor end of the tube (2) being provided with one or more hemispherical perforated covers (4), the said tube (2) being provided with an internally threaded male tapered wedge (5) so as to be position two cylindrical semi circular halves (3) having a matching female tapered wedge opening, the said cylindrical halves(3) having external threads and being held together around the said tube (2) by one or more spring circlips (12), the said cylindrical halves (3) being provided at the bottom with a spacer tube (6), the said spacer tube (6) resting on a base plate (8) through which the other end of externally threaded tube (2) protrudes, the said protruding end of the externally threaded tube being provided with lockable nut (7,9,10,11).

Full Text

This invention relates to a device useful for holding a sensor inside a drilled hole. This invention particularly relates to a device suitable for holding a sensor within a drilled hole preferably in the roof/ wall of an underground tunnel/mine. It is always necessary to monitor the condition of surrounding strata/ wall of rock in an underground excavation/opening. Therefore, many instruments are required to be inserted in the surrounding strata to provide an alarm for the safety of men and equipment within a tunnel/mine. For the purpose, generally holes are drilled within the strata of surrounding excavation to insert sensor of an instrument to get the seismic or micro seismic effect due to the movement of strata and prior to the failure of the rock mass. However, the sensors (may be seismic, microseismic etc.) are required to be inserted properly in the hole such that it does not dislodge from the hole and is also not affected by the water percolation or dust in the hole, which is a common phenomenon in underground tunnels/mines. Also, it is economic and necessary that the sensors can be reused for the purpose, i.e. the setting should preferably not be permanent rather, the setting device should be withdrawable, then it will be economical for the industry. At present to our knowledge there is no such device available which can properly set the sensor within the hole and at the same time withdrawable and reusable and also protected from water and dust. The present process for setting the sensor inside the hole in underground tunnels / mines is generally done by a wedge system such as inserting in the hole or by putting cementitious material at the mouth of the hole to avoid dislogdging of the sensor. All these are generally a non-recoverable process. The objective of the present invention is to provide a device useful for holding a sensor inside a drilled hole, which obviates the drawbacks mentioned above. Another objective is to provide a device for holding the sensor Protecting it from the seepage of water and making it reusable and easily withdraw able. The device of the present invention is described in the drawings accompanying this specification. Figure-1 shows the schematic diagram of the sensor holder along with the sensor. Figure-2 shows the section of bottom plate resting against the rock face and over which the fixing and withdrawing device will work. Accordingly the present invention provides a device useful for holding a sensor inside a drilled hole, characterized by an externally threaded tube (2), one end of the said threaded tube also being provided with internal threading capable of holding a threaded stem (13) of a sensor (1), the said sensor end of the tube (2) being provided with one or more hemispherical perforated covers (4), the said tube (2) being provided with an internally threaded male tapered wedge (5) so as to be position two cylindrical semi circular halves (3) having a matching female tapered wedge opening, the said cylindrical halves(3) having external threads and being held together around the said tube (2) by one or more spring circlips (12), the said cylindrical halves (3) being provided at the bottom with a spacer tube (6), the said spacer tube (6) resting on a base plate (8) through which the other end of externally threaded tube (2) protrudes, the said protruding end of the externally threaded tube being provided with lockable nut (7,9,10,11). At the time of installation of the device inside the drill hole, the two cylindrical semicircular halves (3) are initially in closed condition with the help of spring clips. The bottom platter (8) is to be held upon the face of rock floor on which the hole is drilled and the nut (7) is to be rotated against the plate such that the threaded vertical member (2) moves in the outward direction. Thus the wedge (5) will get into the semi circular cylindrical halves (3) and try to expand them outwardly. Therefore, the outer threads of the cylindrical halves will press against the wall fo the hole and thus the sensor will be tightly held on the top of the vertical member (2). The nut (7) can be locked within flange (9) by the help of pins and lock. At the time of withdrawal the nut is to be unlocked first and then it is to be rotated in opposite direction such that the vertical member gets inside the hole. Thus the two circular halves close again in normal position such that it can be taken out from the hole easily. The perforated covers over the sensor keeps it protected from debris, water seepage and the outer disturbance but does not prevent the seismic events to come in. The main advantages of the present invention: 1) The device can properly hold a sensor in a sensitive manner, such that it can receive seismic/ microseismic responses from its surrounding. 2) It can hold a sensor within a drilled hole or in any tubular opening by instantly fixing arrangement. 3) It can be easily withdrawn from the hole after the study is over and it can be re-installed in other positions. 4) It protect the sensor from the seepage of water and debris. 5) It is very light in weight and economic. 6) It is portable and easily operable. 7) It can be locked and therefore it is safe from theft and also it can not be disturbed by curious trespassers/unauthorised persons. We Claim: 1. A device useful for holding a sensor inside a drilled hole, characterized by an externally threaded tube (2), one end of the said threaded tube also being provided with internal threading capable of holding a threaded stem (13) of a sensor (1), the said sensor end of the tube (2) being provided with one or more hemispherical perforated covers (4), the said tube (2) being provided with an internally threaded male tapered wedge (5) so as to be position two cylindrical semi circular halves (3) having a matching female tapered wedge opening, the said cylindrical halves(3) having external threads and being held together around the said tube (2) by one or more spring circlips (12), the said cylindrical halves (3) being provided at the bottom with a spacer tube (6), the said spacer tube (6) resting on a base plate (8) through which the other end of externally threaded tube (2) protrudes, the said protruding end of the externally threaded tube being provided with lockable nut (7,9,10,11). 2. A device useful for holding a sensor inside a drilled hole substantially as herein described with reference to Rgures 1 and 2 of the drawings accompanying this specification.

Documents:

297-del-2000-abstract.pdf

297-del-2000-claims.pdf

297-del-2000-correspondence-others.pdf

297-del-2000-correspondence-po.pdf

297-del-2000-description (complete).pdf

297-del-2000-drawings.pdf

297-del-2000-form-1.pdf

297-del-2000-form-19.pdf

297-del-2000-form-2.pdf