DEVICE FOR SCANNING A FUNCTION AND METHOD OF OPERATING THE SAME

• US 3,866,199 A
• Filed: 04/19/1972
• Issued: 02/11/1975
• Est. Priority Date: 04/19/1971
• Status: Expired due to Term

• Current Assignee: Ludwi Pietzsch GmbH & Company
• Original Assignee: Gerd Huhne, Hans-Joachim Eberhard, Knud Overlach, Ludwig Pietzsch
• Inventors: Overlach, Knud, Huhne, Gerd, Eberhard, Hans-Joachim, Pietzsch, Ludwig
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US05/245,573
• Time in Patent Office: 1,028 Days
• Field of Search: 250/202 340/267C,213Q,419 33/23H 353/50
• US Class Current: 340/685
• CPC Class Codes: G06K 11/02 Automatic curve followers , i.e. arrangements in which an exploring member or beam is forced to follow the curve

Abstract

Device for tracking the image of a function including combination means for carrying at least one graphical representation of the pattern of a function; an optical imageforming system for the function including an image-viewing screen, a source of illumination, means forming a defined path of illumination between the source and the screen, means for interposing the pattern in the path between the source and the screen, a sensor for tracking the image of the pattern on the screen, means for effecting a relative movement between the image projected on the screen and the sensor according to respective variables of the function in relation to a fixed coordinate system; and method of operating the device.

Claims

1. Device for tracking the image of a function, comprising in combination carrier means for carrying at least one graphical representation of the pattern of a function, said carrier means including a rotary disc and a plurality of pattern representations disposed thereon about the circumference thereof, means for driving said rotary disc, and means for energizing said driving means with a signal representative of one variable of said function;

an optical image-forming system for said function including an image-viewing screen, a source of illumination, means forming a defined path of illumination between said source and said screen, means for interposing said pattern in said path between said source and said screen, and means for displaying an image of said pattern on the screen; and

a sensor operable to sense the image of the pattern on said screen; and

means for effecting a relative movement between the image projected on the screen and said sensor according to variables of said function in relation to a fixed coordinate system.

2. Device according to claim 1 wherein said movement effecting means includes means for driving said sensor relative to the image in one principal coordinate direction in accordance with the independent variable of said function, and further including means for deriving a correctional signal from the movement of said sensor, and means for applying said correctional signal to said sensor driving means whereby said sensor reverses its movement in respect to one principle coordinate.

3. Method for operating the device of claim 1 in connection with load hoisting for signalling the overrunning of a threshold limiting value as for an operating quantity of a process which is variable with at least one physical quantity subject to change during the process, comprising the step of optically displaying said threshold limiting values, operating a sensor relative to said displayed values, and providing a threshold value signal by the sensor in response to an overrunning of said threshold value function by said sensor.

4. Method according to claim 3, wherein said operating quantity comprises a loading quantity and the physical quantity is a geometric quantity indicative of the operating position of the hoisting apparatus.

5. Method according to claim 4 applied as an overload protection for a derrick-type crane having generators for providing signals indicative respectively of crane loading and crane overhang, wherein the operating quantity is the crane load and the physical quantity is the crane jib length.

6. Method according to claim 5 including the step of obtaining signals in response to overruns thereof by said sensor for use as early warning and disconnect signals.

7. Device according to claim 1 wherein there is included a rotary mirror disposed between said graphical representation and said sensor, said sensor being a photoelectric device.

8. Device according to claim 1 wherein said movement effecting means iNcludes two rotatable mirrors disposed between said graphical representation and said sensor, the sensor being a photoelectric device, the mirrors being respectively pivotable in response to one and a second variable.

9. Device according to claim 1 wherein said sensor is a photoelectric device, and said representation comprises a graph separating image portions having different transparencies to light.

10. Device according to claim 1 wherein said sensor is a photoelectric device and said representation includes a plurality of graphs which respectively separate image portions having different transparencies to light.

11. Device according to claim 1, including means for selecting one of said graphical representations on said carrier means for disposition in said defined path.

12. Device according to claim 11, wherein said means for selecting includes a reed relay in association with a respective pattern representation, electrical means for driving said carrier, said relay controlling said electrical means, means for energizing said relay in response to the selection of given parameters corresponding to a representation, a magnet in said device disposed to inactivate said selected relay, and means for stopping said carrier at the selected position for the representation in response to said relay being deactivated.

13. Device for tracking the image of a function, comprising in combination carrier means for carrying at least one graphical representation of the pattern of a function including a film strip having a plurality of pattern representations disposed thereon;

an optical image-forming system for said function including an image-viewing screen, a source of illumination, means forming a defined path of illumination between said source and said screen, means for interposing said pattern in said path between said source and said screen, and means for displaying an image of said pattern on said screen; and

a sensor operable to sense the image of the pattern on said screen; and

means for effecting a relative movement between the image projected on the screen and said sensor according to variables of said function in relation to a fixed coordinate system.