Inertial system for detecting foreign objects between contra-rotating rolls

• US 6,637,179 B2
• Filed: 12/20/2001
• Issued: 10/28/2003
• Est. Priority Date: 12/20/2001
• Status: Expired due to Term

• Current Assignee: 555656 AB Ltd., WD AG. Tech., Inc.
• Original Assignee: Kasha Farm Supplies Ltd.
• Inventors: Duncan, Wayne
• Primary Examiner(s): FABIAN-KOVACS, ARPAD
• Application Number:
  US10/022,273
• Publication Number:
  US 20030115846A1
• Time in Patent Office: 677 Days
• Field of Search: 56/102.J, 56/102.R, 562/95, 562/96, 562/57, 56D/IG.15, 56D/IG.24, 460/2, 460/3, 340/684, 340/503
• US Class Current: 56/10.20J
• CPC Class Codes: A01D 75/187 Removing foreign objects
• CPC Class Codes: A01F 29/16 Safety devices, e.g. emergency brake arrangements

Abstract

A foreign object detector comprises an inertial sensor mounted for displacement with one of the displaceable rolls in the feed mechanism of a forage harvester. When a foreign object is forced through the rolls, the acceleration of the rolls'"'"' displacement exceeds a predetermined threshold and the detector stops the feed mechanism. Preferably, the detector'"'"'s sensor is a microswitch having an inertially-actuable lever and which is mounted for displacement with the upper feed roll. The detector'"'"'s circuitry ties into existing metal detector circuitry.

Claims

1. Apparatus for detecting the presence of a substantially non-compressible foreign object between contra-rotating, substantially parallel and opposing rotating rolls, the apparatus comprising:

a first rotating rolls, rotatable on a shaft supported by a frame;

a second rotating roll which is displaceable relative to the first roll for adjusting the spacing therebetween; and

wherein the first and second contra-rotating rolls are oriented one above the other;

microswitch, mounted for displacement with the second rotating roll, and having an inertially activated lever pivotally mounted for actuating the microswitch at a predetermined level of acceleration for emitting a signal when said acceleration of the second rotating roll and microswitch exceeds a predetermined level of acceleration said signal being indicative of the presence of a foreign object between the first and second rolls; and

means for stopping the rotation of at least one of the first and second rolls upon said signal indicating the presence of a foreign object between the first and second rolls.

2. The apparatus of claim 1 wherein the contra-rotating rolls comprise upper and lower feed rolls of a harvester, the upper feed roll being displaceable relative to the lower feed roll and the microswitch being mounted for displacement with the upper feed roll.

3. The apparatus of claim 1 further comprising two or more microswitches, each of the two or more microswitches having an inertial levers which is actuable at one or more a predetermined level of acceleration.

4. The apparatus of claim 1 further comprising:

a first microswitch having an inertial lever which is calibrated for actuation at a first level of acceleration;

at least a second microswitch, having an inertial lever which is calibrated for actuation at a second or higher thresholds of acceleration; and

means for selecting between the first and at least the second microswitches as being the microswitch which is indicative of the presence of a foreign object.

5. The apparatus of claim 1 wherein the means for stopping the rotation of one of the first and second rolls, is a circuit wherein, when the signal indicates the presence of a foreign object between the feed rolls, the signal switches a state of the circuit.

6. The apparatus as described in claim 4 wherein a sensitivity of the microswitch is altered by adjusting one of either a length or a weight of the inertially actuated lever.

7. The apparatus as described in claim 4 wherein a sensitivity of the microswitch is altered by orienting the inertially activated lever relative to horizontal.