US 4,063,366 AGranted

Grade level

OwnerPhillip A. Baneinventor

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Abstract

A grade level comprising a hollow, fluid-tight cylindrical housing having its central axis normally disposed in a horizontal attitude. The housing comprises an annular wall portion and spaced-apart end members mounted on opposite sides thereof. A horizontally disposed shaft is mounted in the housing and extends between the end members and has a float-weight mechanism operatively rotatively mounted thereon. The mechanism comprises a float portion which extends upwardly from the shaft and a counterbalacing weight which extends downwardly from the shaft. A pair of baffles are secured to the annular wall portion at opposite sides thereof and extend substantially horizontally inwardly therefrom towards the shaft. A fluid is provided within the housing to dampen the movement of the mechanism as the housing is moved to various attitudes. A ballast material is provided in the weight portion to cause the mechanism to normally be positioned in an upright positive relative to horizontal. A sensing apparatus is provided on the housing adjacent the upper end of the float portion for sensing the movement of the mechanism relative to the housing. A read-out mechanism is operatively connected to the sensing apparatus to enable the operator to determine the grade.

Claims1

Dependent claims

A grade level comprising,

a hollow, fluid-tight cylindrical housing having its central axis disposed in a horizontal attitude, said housing comprising an annular wall portion and end members mounted on opposite sides of said wall portion,
a horizontally disposed shaft centrally mounted in said housing and extending between said end members,
a float-weight combination operatively rotatably mounted on said shaft,
a fluid in said housing substantially filling the interior thereof, said float-weight having a width substantially equal to the distance between said end members,
means for causing said float-weight to normally be positioned in an upright position relative to the shaft axis,
sensing means for sensing the position of said float-weight relative to said housing,
and visual read-out means operatively connected to said sensing means for indicating the attitude of said housing and support means relative to horizitonal,
said float-weight comprising a float portion extending upwardly from said shaft and a couterbalancing weight extending downwardly from said shaft,
said sensing means comprising a cam surface on the upper end of said float portion, a linear variable differential transformer on the upper end of said housing and having a core in engagement with said cam surface, and electrical circuit means connecting said transformer to said read-out means.

6 more elements

Dependencies are inferred from the claim text.