Self-contained laser-activated depth sensor for excavator

• US 4,884,939 A
• Filed: 12/28/1987
• Issued: 12/05/1989
• Est. Priority Date: 12/28/1987
• Status: Expired due to Term

• Current Assignee: Laser Alignment, Inc. (Hexagon AB)
• Original Assignee: Laser Alignment, Inc. (Hexagon AB)
• Inventors: Nielsen, Edward G.
• Primary Examiner(s): Spar, Robert J.
• Assistant Examiner(s): Underwood, Donald W.
• Application Number:
  US07/138,301
• Time in Patent Office: 708 Days
• Field of Search: 414/698, 37/DIG. 1, 37/DIG. 19, 356/375, 356/72, 901/47
• US Class Current: 414/698
• CPC Class Codes: E02F 3/435 for dipper-arms, backhoes or the like
• CPC Class Codes: E02F 9/264 Sensors and their calibration for indicating the position of the work tool
• CPC Class Codes: G01C 15/006 Detectors therefor

Abstract

A laser-actuated depth sensor for an excavator, including a laser receiver, an inclination sensor assembly and indicators to inform the operator of the position and inclination of the excavator stick, is completely self-contained in a housing that may be mounted to the stick of an excavator. The indicators, which are each an array of LEDs, and corresponding indicia are readily visible to the operator who does not have to take his or her eyes off the excavation work zone.

Claims

1. In an excavator apparatus including a stick controllable by an operator located in an operator compartment spaced a distance from said stick, said stick being capable of movement to a vertical orientation and to different inclined orientations;

a cutting edge connected to said stick and;

a depth sensor mounted to said stick;

the improvement comprising;

said depth sensor comprising a self-contained laser actuated sensor including housing means having exterior wall means, said housing means including an electronic assembly for determining depth of said cutting edge and inclination of said stick;

said electronic assembly including a plurality of light responsive cells exposed on at least one side of said housing means on and responsive to contact with a laser beam to provide a first signal;

said electronic assembly further including first indicator means and a first lighted visual indicator;

said indicator means located in said housing and responsive to said first signal when a laser beam contacts said cell for displaying on said first lighted visual indicator a first lighted visual indication to the operator indicative of the depth of said cutting edge, said first lighted visual indicator being located and exposed on one side of said housing means so as to face said operator compartment;

said electronic assembly also including inclination sensing means within said wall means responsive to the orientation of said housing means for producing a second signal when the housing means is substantially at a predetermined relationship to said earth'"'"'s vertical and for producing one of a third and fourth signal when said housing means is not substantially at said relationship;

said electronic assembly including second indicator means including second, third and fourth lighted visual indicators exposed on the same one side of said housing means as said first lighted visual indicator, said second indicator means responsive to said inclination sensing means for displaying on said second lighted visual indicator a second lighted visual indication when said second signal is present and for displaying on one of said third and fourth lighted visual indicators one of a third and fourth lighted visual indication when one of said third and fourth signals is present, respectively;

said second indicator means displaying at any one time one of said second, third or fourth lighted visual indications; and

said first, second, third and fourth lighted visual indicators being sufficiently large and intense to be visible and observable from the operator compartment whereby, with said housing means mounted to the stick and said first, second, third and fourth lighted visual indicators facing the operator compartment, the excavator operator can view said lighted visual indicators from said operator compartment and adjust the position of the stick while simultaneously looking at it and the work area and observing which of said second, third or fourth signals are being displayed by the lighted visual indicators of said second indicator means.

2. The depth sensor in claim 1 in which each of said lighted indicators comprises an LED.

3. The depth sensor in claim 2 in which each of said lighted indicators comprises an array of LEDs.

4. The depth sensor in claim 1 in which said inclination means produces said third signal when said stick is not substantially vertical such that said stick is pivoted too far from said cab and produces said fourth signal when said stick is not substantially vertical such that said stick is pivoted too close to said cab.

5. The depth sensor in claim 4 in which said inclination sensing means further includes delay means for preventing said second signal from being present for less than a predetermined time period.

6. The depth sensor in claim 1 in which said inclination sensing means further includes delay means for preventing said second signal from being present for less than a predetermined time period.

7. The depth sensor in claim 1 further including indicia adjacent each of said indicators, said indicia observable from a substantial distance from said housing.

18. The depth sensor of claim 1 in which the housing means is a single housing including said exterior wall means facing the operator compartment of the excavator, said first lighted visual indicator including a plurality of vertically arranged and spaced lights adapted to be lighted only one at a time;

said second third and fourth lighted visual indicators each including a light spaced horizontally one from the other immediately adjacent the lights of said first lighted visual indicator and adapted to be lighted only one at a time whereby an operator can easily read the illumination of both sets of lights while operating the cutting edge of the excavator and while viewing the stick, cutting edge and work area in which the excavation is taking place.

8. In an excavator apparatus including a cutting means mounted on a stick which is controllable by an operator located in an operator compartment spaced a distance from said cutting means, said stick and cutting means being capable of movement to various angular positions with respect to the earth;

a laser-actuated depth sensor mounted on said excavator and movable with said cutting means for determining the depth of the cutting means to determine the depth of an excavation being dug by said cutting means, the improvement comprising;

wall means defining an enclosed housing means;

an electronic assembly in said housing means including a laser receiver exposed on said housing means, inclination sensing means mounted within said housing means and responsive to gravity for determining the inclination of a plane traversing said housing means with respect to the earth'"'"'s vertical, indicating means within said housing means and responsive to said laser receiver and said inclination sensing means for providing an indication of the position of said laser receiver relative to the plane of said laser beam and at the position of the stick with respect to said earth'"'"'s vertical so as to determine in what direction the stick and cutting means is to be moved whereby the direction of movement of said stick and cutting means can be made for substantially aligning said stick in a predetermined relationship to said earth'"'"'s vertical while positioning said cutting means at a desired depth;

said indicating means including lighted display means exposed on a side of said housing means facing the operator compartment of the excavator and responsive to said indicating means for displaying said indication, said display means being of sufficient intensity whereby an excavator operator in said operator compartment can view said lighted display means while simultaneously viewing the stick, cutting means and the work area in which the excavation is taking place.

9. The depth sensor in claim 8 further including mounting means for mounting said housing to the stick of an excavator.

10. The depth sensor in claim 9 in which said mounting means includes adjustment means for adjustably positioning said housing in said plane.

11. The depth sensor in claim 8 in which said inclination sensing means includes two surfaces inclined with respect to said plane and a gravity sensing switch on each of said surfaces.

12. The depth sensor in claim 8 in which said lighted display means includes said wall having a transparent portion juxtaposed a light means.

13. The depth sensor in claim 12 in which said display means includes a first indicator light that is illuminated when said receiver is being contacted by a laser beam and a second indicator light that is illuminated when said stick is aligned with earth vertical.

14. The depth sensor in claim 13 in which said display means further includes a third indicator light that is illuminated when said plane is pivoted a first direction away from earth vertical and a fourth indicator light that is illuminated when said plane is pivoted a second direction away from earth vertical opposite said first direction.

15. The depth sensor in claim 14 in which said display means comprises an array of LEDS.

16. The depth sensor in claim 14 further including delay means for preventing said second indicator light from being illuminated for less than a predetermined time period.

17. The depth sensor in claim 14 further including indicia adjacent each of said indicators light illustrative of the meaning of the respective said indicator light.