Paving material machine having a tunnel with automatic gate control

• US 5,452,966 A
• Filed: 01/21/1994
• Issued: 09/26/1995
• Est. Priority Date: 04/08/1993
• Status: Expired due to Fees

• Current Assignee: George W. Swisher Jr
• Original Assignee: George W. Swisher Jr
• Inventors: Swisher, George W. Jr.
• Primary Examiner(s): Britts, Ramon S.
• Assistant Examiner(s): LISEHORA, JAMES
• Application Number:
  US08/185,428
• Time in Patent Office: 613 Days
• Field of Search: 404/72, 404/84.05, 404/84.1, 404/101, 404/108
• US Class Current: 404/72
• CPC Class Codes: E01C 19/48 for laying-down the materials and consolidating them, or finishing the surface , e.g. slip forms therefor, forming kerbs or gutters in a continuous operation in situ E01C19/002, E01C23/065 take precedence; devices for guiding or controlling the machines along a predetermined path E01C19/004
• CPC Class Codes: E01C 23/04 Devices for laying inserting or positioning reinforcing elements or dowel bars with or without joint bodies installing or inserting joint bodies per se E01C23/023, E01C23/026; Removable supports for reinforcing or load transfer elements non- removable supports therefor E01C11/02 E01C11/16; side forms adapted to supporting reinforcement E01C19/50; Devices, e.g. removable forms, for making essentially horizontal ducts in paving, e.g. for prestressed reinforcements
• CPC Class Codes: E01C 2301/04 Independent shuttles
• CPC Class Codes: E01C 2301/06 Windrow pickup
• CPC Class Codes: G05D 7/0605 specially adapted for solid materials

Abstract

A paving machine having a gate control system for maintaining a target depth of paving material on the surface to be paved. The paving machine includes a wheeled frame having a lengthwise tunnel and a conveyor for moving paving material through the tunnel. A pair of gates are provided to control the volume of paving material being conveyed from the rear of the tunnel. The position of each gate is automatically adjusted by a hydraulic cylinder, a control valve, an electro-hydraulic control system, an ultrasonic sensor assembly and a cable assembly. Each sensor assembly includes a sensor which is positioned to define a target distance between the sensor and the paving material. The target distance corresponds to the target depth for the paving material. The sensor detects the actual distance between the sensor and the paving material and produces an electrical output proportional to this actual distance. The electro-hydraulic control system utilizes the electrical output of the sensors to open or close the rear gates to adjust the volume of paving material being discharged to the surface. A cable assembly links the movement of each rear gate with the corresponding sensor assembly to lower and elevate the sensor in response to the closing and opening of the rear gate.

Claims

1. A machine for placing paving material on a road surface, the machine comprising:

a mobile frame having a front end, a rear end and a tunnel extending from the front end to the rear end thereof, the tunnel having a discharge opening for placing a target depth for discharged paving material upon the road surface at the rear end of said frame;

a gate mounted to said frame for controlling the volume of paving material being discharged from the tunnel;

a sensor mounted to said frame and adapted to measure the actual distance between said sensor and the discharged paving material, said sensor being positioned to define a target distance between said sensor and the discharged paving material, the target distance corresponding to the target depth for discharged paving material;

means for opening said gate when the actual distance is greater than the target distance and for closing said gate when the actual distance is less than the target distance; and

means for moving said sensor toward the discharged paving material when said gate is being opened and for moving said sensor away from the discharged paving material when said gate is being closed.

2. The machine of claim 1 further comprising:

conveyor means for transferring paving material through the tunnel to the discharge opening.

3. The machine of claim 1 wherein said sensor is an ultrasonic sensor.

4. The machine of claim 1 wherein said gate is curved.

5. The machine of claim 1 wherein said means for opening and closing said gate comprises a hydraulic cylinder.

6. The machine of claim 1 wherein said means for moving said sensor further comprises:

a pulley mounted to said frame above said gate and said sensor; and

a cable suspended by said pulley and having one end attached to said gate and an opposite end operatively connected to said sensor.

7. A machine for placing paving material on a road surface, the machine comprising:

a mobile frame having a front end, a rear end and a tunnel extending from the front end to the rear end thereof, the tunnel having an opening for placing a target depth for discharged paving material upon the road surface at the rear end of said frame;

a pair of side-by-side gates mounted to said frame for controlling the volume of paving material being discharged from the tunnel;

a pair of sensors mounted to said frame for substantially vertical movement, each one of said sensors being positioned behind a corresponding one of said gates and being adapted to measure the actual distance between said sensor and the discharged paving material, said sensor being positioned to define a target distance between said sensor and the discharged paving material, the target distance corresponding to the target depth for discharged paving material;

means for opening each one of said gates when the actual distance of the corresponding one of said sensors is greater than the target distance and for closing the each one of said gates when the actual distance of the corresponding one of said sensors is less than the target distance; and

means for moving each one of said sensors toward the discharged paving material when the corresponding one of said gates is being opened and for moving each one of said sensors away from the discharged paving material when the corresponding one of said gates is being closed.

8. The machine of claim 7 further comprising:

conveyor means for transferring paving material through the tunnel to the discharge opening.

9. The machine of claim 7 wherein said sensors are ultrasonic sensors.

10. The machine of claim 7 wherein said gates are curved.

11. The machine of claim 7 wherein said means for opening and closing each one of said gates comprises a hydraulic cylinder.

12. The machine of claim 7 wherein said means for moving each one of said sensors further comprises:

a pulley mounted to said frame above said gate and said sensor; and

a cable suspended by said pulley and having one end attached to said gate and an opposite end operatively connected to said sensor.

13. A method of maintaining a target depth of paving material being discharged to a surface, the steps of the method comprising:

providing a machine having a tunnel with a discharge opening for transfer of paving material from the tunnel onto a surface, a gate movable to adjust the volume of paving material being transferred from the discharge opening, and a sensor mounted behind the gate and linked to the gate for movement toward the discharged paving material when the gate is being opened and away from the discharged paving material when the gate is being closed;

selecting a target depth for paving material discharged from the tunnel to the surface below the sensor;

determining a target distance between the sensor and the discharged paving material corresponding to the target depth;

utilizing the sensor to continuously measure the actual distance between the sensor and the discharged paving material;

when the actual distance is greater than the target distance, opening the gate until the actual distance is substantially equal to the target distance; and

when the actual distance is less than the target distance, closing the gate until the actual distance is substantially equal to the target distance.

14. A method of maintaining a target depth of paving material being discharged to a surface, the steps of the method comprising:

providing a machine having a tunnel with a discharge opening for transfer of paving material from the tunnel onto a surface, a gate movable to adjust the volume of paving material being transferred from the discharge opening, and a sensor located behind the gate;

selecting a target depth for paving material discharged from the tunnel onto the surface below the sensor;

determining a target distance between the sensor and the discharged paving material corresponding to the target depth;

utilizing the sensor to continuously measure the actual distance between the sensor and the discharged paving material;

when the actual distance is greater than the target distance, opening the gate until the actual distance is substantially equal to the target distance;

when the actual distance is less than the target distance, closing the gate until the actual distance is substantially equal to the target distance;

moving the sensor toward the discharged paving material while the gate is being opened; and

moving the sensor away from the discharged paving material while the gate is being closed.