Granted Patent B2

US 12,680,240 · App. 18/315,925 · Granted Jul 14, 2026

Inventors: Peter A. Ligman (Darien, WI); Gary Ligman (Jeffersonville, IN)

Assignee: Ligchine International Corporation

E01C19/402E01C19/40E01C19/42E04F21/242E04G21/10

Abstract

Claims (61)

1 . A concrete screed apparatus having a frame comprising:

a screed head secured to said frame at a front portion thereof whereby vertical movement of said frame assembly effects vertical movement of said screed head;

an electric leveling system having at least one rear vertically adjustable leveling leg and a pair of opposed front vertically adjustable leveling legs spaced around said frame assembly, and secured thereto at one end thereof, and each of said leveling legs secured to a driven rotatable wheel at another end thereof, each of said leveling legs having a linear actuator secured thereto for adjusting an elevation of said frame and thereby said screed head with respect to a desired grade setting during operation; and

wherein said pair of opposed front vertically adjustable leveling legs adjusts the vertical position of said screed head, and;

wherein said at least one rear vertically adjustable leveling leg adjusts a tilt of said screed head.

2 . An apparatus as claimed in claim 1 wherein said plurality of leveling legs comprises:

a single leveling leg secured to a rear of said frame.

3 . An apparatus as claimed in claim 1 wherein said linear actuators are gear driven actuators.

4 . An apparatus as claimed in claim 1 wherein said leveling system comprises:

a plurality of sleeves secured to said frame at a plurality of points;

a plurality of leveling legs disposed in said plurality of sleeves and vertically movable.

5 . An apparatus as claimed in claim 4 comprising:

a plurality of electrical actuators secured to said leveling legs and to said sleeves for extending and retracting said legs.

6 . An apparatus as claimed in claim 1 comprising:

a controller having a processor, a data memory, and a plurality of inputs and outputs for receiving and accepting signals; and

wherein said leveling assembly is operatively coupled to an input from said controller representative of a grade setting.

7 . An apparatus as claimed in claim 6 comprising:

a plurality of laser leveling eyes having outputs representative of an elevation of said screed head with respect to a reference plane, said outputs operatively coupled to a plurality of inputs of said controller whereby said leveling system maintains a desired elevation of said screed head.

8 . An apparatus as claimed in claim 6 comprising:

a slope sensor having an output representative of a front to back tilt of said apparatus operatively coupled to said processor, whereby said leveling system maintains a desired tilt of said apparatus.

9 . An apparatus as claimed in claim 6 comprising:

a user interface operatively coupled to said controller, whereby said leveling system is responsive to a command provided from said user interface.

10 . An apparatus as claimed in claim 1 comprising:

a controller having a processor, a data memory, and a plurality of inputs and outputs for receiving and accepting signals; and

wherein said linear actuators are operatively coupled to a plurality of inputs from said controller representative of a grade setting.

11 . An apparatus as claimed in claim 10 comprising:

a plurality of laser leveling eyes having outputs representative of an elevation of said screed head with respect to a reference plane, said outputs operatively coupled to a plurality of inputs of said controller whereby said linear actuators maintain a desired elevation of said screed head.

12 . An apparatus as claimed in claim 11 comprising:

a slope sensor having an output representative of a front to back tilt of said apparatus operatively coupled to said processor, whereby said electrical actuators maintain a desired tilt of said apparatus.

13 . An apparatus as claimed in claim 10 comprising:

a user interface operatively coupled to said controller, whereby said linear actuators are responsive to a command provided from said user interface.

14 . An apparatus as claimed in claim 10 where said plurality of leveling legs comprises:

a pair of spaced leveling legs secured to a front of said frame; and

a single leveling leg secured to a rear of said frame.

15 . A concrete screed apparatus having a frame comprising:

a screed head secured directly to said frame whereby vertical movement of said frame assembly effects vertical movement of said screed head;

an electrical leveling system, said leveling system comprising:

at least one rear vertically adjustable leveling leg and a pair of spaced vertically adjustable leveling legs secured at a first end to said frame end thereof, each leveling leg having a linear actuator secured thereto for adjusting an elevation of said frame responsive to said leveling system; and

a plurality of spaced drive wheels, each of said drive wheels rotatably and pivotably secured to said vertically adjustable leveling legs at a second end thereof.

16 . An apparatus as claimed in claim 15 comprising:

a plurality of electrical actuators secured to said leveling legs for extending and retracting said legs;

a controller having a processor, a data memory, and a plurality of inputs and outputs for receiving and accepting signals; and

wherein said linear actuators are operatively coupled to a plurality of inputs from said controller representative of a grade setting to level said frame.

17 . A concrete screed apparatus having a frame comprising:

a screed head secured to said frame whereby vertical movement of said frame assembly effects vertical movement of said screed head;

a leveling system having a single rear vertically adjustable leveling leg and a pair of opposed front vertically adjustable leveling legs secured at one end thereof to said frame assembly, each of said leveling legs having a linear actuator secured thereto for adjusting an elevation of said frame and thereby said screed head relative to a desired grade setting; and

a rear driven wheel rotatably secured to a second end of said rear vertically adjustable leveling leg for adjusting a tilt of said screed head, and a pair of opposed front driven wheels rotatably secured to a second end of said opposed front vertically adjustable leveling legs, whereby said opposed front vertically adjustable leveling legs adjust the elevation of said screed head to a desired grade.

18 . An apparatus as claimed in claim 17 wherein said leveling system comprises:

a plurality of sleeves secured to said frame at a plurality of points;

a plurality of leveling legs disposed in said plurality of sleeves and vertically movable.

19 . An apparatus as claimed in claim 18 comprising:

a plurality of linear actuators secured to said leveling legs and to said sleeves for extending and retracting said legs.

20 . An apparatus as claimed in claim 18 comprising:

a controller having a processor, a data memory, and a plurality of inputs and outputs for receiving and accepting signals; and

wherein said leveling assembly is operatively coupled to an input from said controller representative of a grade setting.

21 . An apparatus as claimed in claim 20 comprising:

a plurality of laser leveling eyes having outputs representative of an elevation of said screed head with respect to a reference plane, said outputs operatively coupled to a plurality of inputs of said controller whereby said leveling system maintains a desired elevation of said screed head.

22 . An apparatus as claimed in claim 21 comprising:

a slope sensor having an output representative of a front to back tilt of said apparatus operatively coupled to said processor, whereby said leveling system maintains a desired tilt of said apparatus.

23 . An apparatus as claimed in claim 21 comprising:

a user interface operatively coupled to said controller, whereby said leveling system is responsive to a command provided from said user interface.

Assignments (1)

Continuity (5)

References Cited (274)