Frost line indicator

Claim 2

A frost line depth indicator for measuring the frost line depth of a material comprising: a first hollow tube being closed at one end by an end cap inserted into said tube and open at its other end; a second hollow tube closed at one end by a first end cap having a hole through the center thereof, closed at its other end by a second end cap, and filled with a material that exhibits one color at temperatures at and below a certain temperature and a second color at temperatures above said certain temperatures, said second hollow tube being shorter than said first hollow tube and being of such size that said second hollow tube fits inside said first hollow tube; a rope having one of its ends threaded through said hole in said first end cap of said second hollow tube and secured to said first end cap of said second hollow tube; means to secure said first end cap inside said one end of said second hollow tube; means to secure said second end cap of said second hollow tube inside said other end of said second hollow tube; a cap having a hole through the center thereof and being adapted to fit over and be secured to said open end of said first hollow tube, said rope having the other of its said ends threaded through said hole in said cap and being secured to said cap; and a distance measuring scale formed on the surface of said second hollow tube along the length of said second hollow tube.

Claim 3

A frost line indicator as defined in claim 1 wherein said material in said second hollow tube is a mixture of white sand and fluorescein dye.

Claim 4

A frost line indicator as defined in claim 2, said first color is yellow and said second color is green.

Claim 5

A frost line indicator as defined in claim 3 wherein said means for securing said first end cap inside said one end of said second hollow tube includes first and second screws and said means for securing said second end cap inside said other end of said second hollow tube includes first and second screws.

Claim 6

A frost line indicator as defined in claim 4 wherein said cap is secured to said first hollow tube by means of threads formed internally in said cap and threads formed externally adjacent said open end of said first hollow tube.

Claim 7

A frost line indicator as defined in claim 5 wherein an extension tube having external threads adjacent both its ends is coupled to said open end of said first hollow tube by a threaded coupler, said threaded coupler having internal threads for mating with said threads adjacent said open end of said first hollow tube and for mating with said threads adjacent one end of said extension tube, said cap being secured to said threads adjacent the end of said extension tube opposite the end of said extension tube secured to said coupler when said extension tube is coupled to said open end of said first hollow tube.

Claim 8

A frost line indicator as defined in claim 6 wherein a narrow band different in color than the color of said first hollow tube is provided around the outside of said first hollow tube a predetermined distance from said open end of said first hollow tube.

Claim 9

A frost line indicator as defined in claim 7 wherein said second hollow tube is equal in length to the distance between said narrow band and said closed end of said first hollow tube.

Claim 10

A frost line depth indicator as defined in claim 8 wherein said cap is fluorescent orange in color.

Claim 11

A frost line depth indicator as defined in claim 9 wherein said fluorescein dye is a 0.1% solution and said sand is a medium size clean white sand-blasting sand.

Claim 12

A frost line indicator as defined in claim 10 wherein the frost line depth to be measured is the frost line depth of the ground and said first hollow tube is implanted in said ground with the bottom edge of said narrow band even with the surface of said ground and said second hollow tube is inserted into said first hollow tube with said cap secured to said open end of first hollow tube.

Claim 13

A frost line depth indicator for measuring the frost line depth of the ground comprising: a first hollow tube being closed at one end, open at its other end, having external threads formed adjacent its open end and having a narrow band formed around its outer surface a predetermined distance from said open end, said narrow band being different in color than the outside surface of said first hollow tube; a second hollow tube being closed at both ends and being filled with a mixture of white sand and fluorescein dye, said second hollow tube being equal in length to the distance between said closed end of said first hollow tube and the bottom edge of said narrow band and being of such a diameter that said second hollow tube fits inside said first hollow tube; a brightly colored screw cap adapted to mate with said threads adjacent said open end of said first hollow tube to thereby secure said screw cap to said open end of said first hollow tube to cover said open end of said first hollow tube; a rope having one end secured to one end of said second hollow tube and having its other end secured to said screw cap such that said rope provides a means of withdrawing said second hollow tube from inside said first hollow tube; and a distance measuring scale formed on the surface of said second hollow tube along the length of said second hollow tube, whereby a frost line depth measurement of said ground is taken by implanting said first hollow tube in said ground such that the bottom edge of said narrow band is even with the surface of said ground, inserting said second hollow tube in said first hollow tube, securing said screw cap to said open end of said first hollow tube, and at the time said frost line depth measurement is to be taken by withdrawing said second hollow tube from said first hollow tube by unscrewing said screw cap from said open end of said first hollow tube and pulling said second hollow tube out of said first hollow tube by means of said rope and observing the color of said mixture of sand and fluorescein dye, said mixture being yellow to the depth which said ground is frozen and green in color below this depth, said scale formed on said second hollow cylinder providing a direct reading of the frost line depth.

Claim 14

A frost line depth indicator for measuring the frost line depth of the ground comprising: a first hollow tube being closed at one end, open at its other end, having external threads formed adjacent its open end and having a narrow band formed around its outer surface a predetermined distance from said open end, said narrow band being different in color than the outside surface of said first hollow tube; a second hollow tube being closed at both ends and being filled with a mixture of white sand and fluorescein dye, said second hollow tube being equal in length to the distance between said closed end of said first hollow tube and the bottom edge of said narrow band and being of such a diameter that said second hollow tube fits inside said first hollow tube; a brightly colored screw cap adapted to mate with said threads adjacent said open end of said first hollow tube to thereby secure said screw cap to said open end of said first hollow tube to cover said open end of said first hollow tube; a rope having one end secured to one end of said second hollow tube and having its other end secured to said screw cap such that said rope provides a means of withdrawing said second hollow tube from inside said first hollow tube; and a distance measuring scale formed on the surface of said second hollow tube along the length of said second hollow tube, whereby a frost line depth measurement of said ground is taken by implanting said first hollow tube in said ground such that the bottom edge of said narrow band is even with the surface of said ground, inserting said second hollow tube in said first hollow tube, securing said screw cap to said open end of said first hollow tube, and at the time said frost line depth measurement is to be taken by withdrawing said second hollow tube from said first hollow tube by unscrewing said screw cap from said open end of said first hollow tube and pulling said second hollow tube out of said first hollow tube by means of said rope and observing the color of said mixture of sand and fluorescein dye, said mixture being yellow to the depth which said ground is frozen and green in color below this depth, said scale formed on said second hollow cylinder providing a direct reading of the frost line depth.

Claim 15

A frost line depth indicator as defined in claim 12 wherein an extension tube is coupled to said first hollow tube by means of a threaded coupler.

Claim 16

A frost line depth indicator as defined in claim 13 wherein said mixture that is yellow in color turns green in color when the temperature of said mixture rises above the freezing temperature of said ground.