Abstract An apparatus to indicate deformation of a surface such as the interior of a mine, to which it is attached. An anchor bolt assembly with one electrical contact is rigidly fixed into the surface. A movable pressure plate assembly with another electrical contact, engageable by the first contact on the bolt assembly is placed against the surface. When this plate is moved by surface deformations, it causes the contacts to engage each other which results in the actuation of a sensing device. The sensing device can either actuate a transmitter to transmit a frequency modulated signal of a fixed or variable frequency or it can actuate a recording device that records data on the deformation. Several extendable arms may also be included to actuate a transmitter when overhead rocks or other objects fall near the apparatus. The arms may be arranged in a spider-like pattern around the periphery of the pressure plate assembly to which it is pivotally attached. Two spaced electrical contact rings associated with the arms are closed when an object pivots one of the arms. This closure can then actuate the same transmitter the deformation plate could actuate which results in a fixed frequency warning signal being transmitted. A series of the signals from several transmitters may be fed to a common receiver. By making each signal different and associating the physical location of a given transmitter with a given signal, the deformation that occurs at a given point may be readily segregated from the others. This allows the sending of a warning signal or other type signal to persons in the danger zone.
Inventors
👤 Vey J Mc
👤 T Meyer
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-27 05:39
CPC Classifications
E; E21; E21F; E21F17/00; E21F17/18; E21F17/185
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
An apparatus for indicating surface deformations comprising in combination: an anchor bolt assembly rigidly attached into the surface whose deformation is to be measured extending therefrom to an outer surface wall; two normally inoperative electrical contacts, one of which is fixed to said anchor bolt assembly and comprises a conductive spirally wound foil on a tubular member; means for operatively adjusting said electrical contacts to determine a predetermined setting at which surface deformations are indicated once a specific surface displacement force has been applied; a pressure plate assembly movably mounted on said anchor bolt assembly and having the other of said electrical contacts attached thereon such that it can be operatively engaged by the bolt contact; and means for sensing the operative state of said plate assembly to indicate a surface deformation in excess of the determined setting.
Claim 2
Independent Claim
138 words
An apparatus for indicating surface deformations comprising in combination: an anchor bolt assembly rigidly attached into the surface whose deformation is to be measured extending therefrom to an outer surface wall; two normally inoperative electrical contacts, one of which is fixed to said anchor bolt assembly and comprises a conductive spirally wound foil on a tubular member; means for operatively adjusting said electrical contacts to determine a predetermined setting at which surface deformations are indicated once a specific surface displacement force has been applied; a pressure plate assembly movably mounted on said anchor bolt assembly and having the other of said electrical contacts attached thereon such that it can be operatively engaged by the bolt contact; and means for sensing the operative state of said plate assembly to indicate a surface deformation in excess of the determined setting.
Claim 3
Dependent Claim
34 words
The apparatus of claim 1 wherein said means for sensing the operative state includes a frequency modulated transmitter that transmits a signal of a known frequency when said contacts are in an operative position.
Claim 4
Dependent Claim
24 words
The apparatus of claim 2 wherein the frequency of the signal transmitted varies depending upon the amount of displacement of the pressure plate assembly.
Claim 5
Dependent Claim
78 words
The apparatus of claim 1 wherein said pressure plate assembly comprises: a generally flat surfaced plate adapted to engage the surface whose deformation is to be measured and also including pivotally mounted elongated arm members extending outwardly from the periphery of said assembly plate and having electrical contacts such that objects falling on any one of said members will pivot it to cause its associated contacts to be closed and said means for sensing to be rendered operative.
Claim 6
Dependent Claim
23 words
The apparatus of claim 4 wherein said sensing means comprises: a frequency modulated transmitter that can be rendered operative to emit a signal.
Claim 7
Dependent Claim
29 words
The apparatus of claim 1 wherein said conductive spirally wound foil tube has an electrical contact that is connected to a movable conductive rod on the pressure plate assembly.
Claim 8
Dependent Claim
26 words
The apparatus of claim 6 wherein the electrical contact on the pressure plate assembly is connected to a movable metal sleeve concentric with the foil tube.