Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C18/00—Disintegrating by knives or other cutting or tearing members which chop material into fragments
  • B02C18/06—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
  • B02C18/16—Details
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C18/00—Disintegrating by knives or other cutting or tearing members which chop material into fragments
  • B02C18/06—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
  • B02C18/16—Details
  • B02C18/24—Drives
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C25/00—Control arrangements specially adapted for crushing or disintegrating
• • E—FIXED CONSTRUCTIONS
  • E03—WATER SUPPLY; SEWERAGE
  • E03C—DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER; SINKS
  • E03C1/00—Domestic plumbing installations for fresh water or waste water; Sinks
  • E03C1/12—Plumbing installations for waste water; Basins or fountains connected thereto; Sinks
  • E03C1/26—Object-catching inserts or similar devices for waste pipes or outlets
  • E03C1/266—Arrangement of disintegrating apparatus in waste pipes or outlets; Disintegrating apparatus specially adapted for installation in waste pipes or outlets
  • E03C1/2665—Disintegrating apparatus specially adapted for installation in waste pipes or outlets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C18/00—Disintegrating by knives or other cutting or tearing members which chop material into fragments
  • B02C18/06—Disintegrating by knives or other cutting or tearing members which chop material into fragments with rotating knives
  • B02C18/16—Details
  • B02C2018/164—Prevention of jamming and/or overload

Definitions

• the present disclosure relates to rotating devices such as the rotating portions of a food waste disposer grind mechanism.
• a conventional disposer includes a food conveying section, a motor section, and a grinding mechanism disposed between the food conveying section and the motor section.
• the food conveying section includes a housing that forms an inlet for receiving food waste and water.
• the food conveying section conveys the food waste to the grinding mechanism, and the motor section includes a motor imparting rotational movement to a motor shaft to operate the grinding mechanism.
• the grind mechanism that accomplishes the comminution is typically composed of a rotating shredder assembly with lugs and a stationary grind ring.
• the motor turns the shredder plate and the lugs force the food waste against the grind ring where it is broken down into small pieces. Once the particles are small enough to pass out of the grinding mechanism, they are flushed out into the household plumbing.
• Grind mechanisms that utilize a fixed lug on the rotating shredder assembly are often susceptible to jams when grinding hard food waste, such as beef bones.
• the use of an induction motor may contribute to the probability of experiencing a jam because of its relatively low stall torque.
• swivel, or rotatable, lugs that move out of the way before a jam can occur are employed.
• the energy displaced to the food waste is less and therefore can result in compromised grind performance and still lead to jams.
• the present disclosure provides an automatic method of clearing a jam of a rotating member, such as a food waste disposer's rotating grinding plate without any manual intervention by the consumer.
• Actions such as automatically generating a pulsed torque and reversing the direction of rotation clear a very high percentage of jams, requiring minimal manual intervention in clearing jams over the life of the system.
• the circuit automatically senses when the motor is stalling or a jam occurs.
• the motor automatically reverses, and if this does not free the jam, the pulsating torque is automatically generated. Since all of this action is automatic, it requires no manual action by the operator of the unit and also does not interfere with the normal starting of the motor.
• a method for operating a device driven by a motor such as a food waste disposer.
• the method includes determining if a shredder plate of the food waste disposer is jammed. If the shredder plate is jammed, a pulsed torque is applied to the shredder plate. The pulsed torque may be applied for a predetermined time period. Additionally, the rotational direction of the shredder plate is reversed in certain embodiments.
• the speed of the shredder plate is monitored. If it fails to reach a predetermined speed during a predetermined time period or if it falls below a predetermined speed, a jam is indicated. In some embodiments, the disposer motor's run winding and/or start winding is monitored.
• a controller is coupled to the motor and determines whether the shredder plate is jammed. In response to a jam, the controller applies a pulsed torque to the shredder plate. The pulsed torque is applied for a predetermined time period in some embodiments. The controller may also reverse the rotational direction of the sliredder plate.
• the controller monitors the speed of the rotating shredder plate to determine whether the sliredder plate is jammed. For instance, the controller may determine if the rotating sliredder plate reaches a predetermined speed during a predetermined time period, or if the rotating shredder plate falls below a predetermined rotation speed.
• the controller monitors run windings and/or start windings of the motor to determine if the rotating shredder plate is jammed.
• the controller may activate an SCR connected in parallel with the motor start winding.
• a start capacitor may be connected in series with the start winding.
• an oscillator is connected to a gate terminal of the' SCR.
• Figure 1 is a diagram illustrating a food waste disposer in accordance with certain teachings of the present disclosure.
• Figure 2 is schematic diagram conceptually illustrating portions of the system shown in Figure 1.
• Figure 3 is a simplified flow diagram conceptually illustrating a method of automatically freeing a jammed rotating member in accordance with aspects of the present disclosure.
• Figures 4A and 4B are a circuit diagram of an exemplary motor control circuit.
• Figures 5 A and 5B are a flow diagram of a method for sensing and freeing a jam in a rotating member.
• Figure 6 is a circuit diagram illustrating an alternative motor control circuit.
• FIG. 1 is a diagram conceptually illustrating a food waste disposer system in accordance with certain teachings of the present disclosure.
• the food waste disposer 100 includes a food conveying section 102 and a grinding mechanism 110, which is disposed between the food conveying section and a motor section 104.
• the food conveying section 102 includes an inlet for receiving food waste and water.
• the food waste is conveyed to the grinding mechanism 110, and the motor section 104 includes a motor 119 imparting rotational movement to a motor shaft 118 to operate the grinding mechanism 110.
• the motor may be any suitable type of motor, such as an induction motor, bmshless permanent magnet motor (BLPM), DC motor, etc.
• the grinding mechanism 110 includes a rotating sliredder plate assembly 112 . is rotated relative to a stationary grind ring by the motor shaft 118 to reduce food waste delivered by the food conveying section to small pieces.
• the shredder plate includes lugs 114 extending therefrom that force the food waste against the grind ring. When the food waste is reduced to particulate matter sufficiently small, it passes from above the shredder plate assembly 112, and along with water passing through the food conveying section, is then discharged from the disposer through a discharge outlet 120.
• a controller 200 is connected to the motor to control operation of the disposer 100. In Figure 1, the controller 200 is shown external to the disposer housing for simplicity, though it could be situated inside the disposer housing.
• Figure 2 illustrates portions of the motor 119, which includes a run winding 130 and a start winding 132 that is connected to a start capacitor 134.
• the motor 119 receives power from a power source 136 in response to a user operated on/off switch 140.
• the controller 200 is connected to control application of power to the windings to cause a rotating part (rotor) to turn relative to a stationary part (stator) to turn the shaft 118 connected to the rotating shredder plate 112. Additionally, the controller 200 is connected to monitor power applied to the windings 130, 132 and implement a de-jamming operation as necessary.
• FIG 3 is a simplified flow diagram conceptually illustrating a method of automatically freeing a jammed rotating member, such as the rotating sliredder plate 112 of the disposer 100.
• the controller 200 monitors operation of the motor to determine whether the rotating shredder plate 112 has become jammed (block 10). If the sliredder plate 112 is jammed as determined in decision block 12, the rotational direction is reversed and a pulsed torque is applied to the shredder plate 112 by the motor 119 in block 14.
• a rotating member such as the rotating shredder plate 112 of the food waste disposer's grind mechanism 110, fails to reach its desired operating speed during a predetermined time period, or if the rotating member's speed drops below the desired operating speed, it may be assumed that the rotating member is jammed.
• any mechanism using a rotating member driven by a motor there are many situations that cause rotating member to become stuck or jammed. As discussed in the Background section herein above, a jam can occur in a food waste disposer's rotating grind mechanism when a food particle or other hard object becomes wedged between a lug and the stationary portion of the grind mechanism.
• the controller 200 In response to sensing a jam, the controller 200 reverses the rotational direction of the sliredder plate 112 and a pulsed torque is applied to the shredder plate 112 for a predetermined time period to free the jam.
• the motor's run winding 130 is monitored to determine whether the rotating member is operating at or above the desired speed.
• the motor's start winding 132 is monitored to determine whether the rotating member is operating at or above the desired speed. Normally, current is removed from the start winding 132 once the motor 119 has reached the desired speed. Under normal conditions, the motor 119 should reach the desired speed within a predetermined time period. Thus, if current or voltage is applied to the start winding 132 longer than this predetermined time period, it may be assumed that a jam is preventing the rotating member 112 from reaching the desired speed
• FIGS 4 A and 4B illustrate an electronic circuit 300 in accordance with one exemplary embodiment
• Figures 5A and 5B show a corresponding flow diagram.
• the circuit 300 functions to electronically start the motor 119 and automatically reverse and activate a pulsating torque when the rotating portion of the motor becomes jammed 119.
• a novel sensing technique in the circuit allows the motor to start under normal conditions.
• the on/off switch 140 When the disposer 100 is not in use, the on/off switch 140 is open, the motor protector is closed and no current is flowing tlirough the electronic circuit.
• the electronic circuit 300 senses the current in the run winding 130. When the current reaches a predetermined level, a start relay is activated for some predetermined time period — 200ms in the illustrated embodiment. The electronic circuit 300 checks for current drop in the run winding 130. If the current drops below the predetermined value, which will occur when the motor 119 comes up to speed, the electronic circuit 300 goes into run mode and monitors the run winding 130 current until the on/off switch 140 is opened by the user and no current flows through the electronic circuit.
• the electronic circuit 300 senses no current in the run winding 130 it will hold in memory (approximately 1 minute) the last rotation direction and if reactivated will toggle the relays 310 to start the motor in the opposite direction. If reactivated after 1 minute, the direction of rotation will be random. If a jam occurs during the initial start or after the initial start where the circuit enters a run mode, the circuit functions as follows in one exemplary implementation.
• the circuit 300 enters the de-jam mode.
• the circuit 300 toggles relays 310 to reverse rotational direction, activates the start winding 132 for 500ms and 40ms later activates the de-jam circuit for 200ms of the 500ms.
• the de- jam circuit consists of a simple SCR 312 in parallel across the start winding 132.
• the electronic circuit 300 then checks the current level in the run winding 130.
• the circuit toggles relays 310 to reverse rotational direction and activates the de-jam circuit as described above until the jam is free and the run winding 130 current falls or the user switches the on/off switch 140 to the off position or a motor protector switch opens.
• the SCR 312 is triggered on for only the positive or negative half cycles.
• the start winding 132 is not active and the motor start capacitor 134 is being charged to the applied voltage.
• the SCR 312 is not active.
• the start winding 132 is in series with the motor start capacitor 134, which has been charged to a voltage that adds to the applied voltage. This action and the relative phase relationships of the start and run windings 130, 132, generates a small torque to momentarily reverse the motor 119 and then applies a much larger positive torque to the rotating member. This positive torque may be as much as two to five times the normal starting torque of the motor 119.
• the current drawn tlirough the motor windings is somewhat less than the current value when the rotating member is jammed since the start winding 132 is only active and allowing current flow every other half cycle of the alternating current.
• a thermal protector will open in about seven seconds to protect the motor windings from over heating. If a jam occurs that the pulsating torque cannot clear, the thermal protector will remove power and terminate the de-jam mode in approximately 7 seconds. At that point the user will have to reset the protector and remove the jam manually.
• the circuit 300 toggles relays 310 to reverse the rotational direction and monitor the run current to determine if reversing the unit freed the jam. If the current remains above the set point after reversing, the electronic circuit reactivates the start winding in the same rotational direction for 500ms and 40ms later activates the de-jam circuit for 200ms of the 500ms (or some other predetermined time period). The electronic circuit then checks the current level in the run winding.
• a centrifugal actuator 410 allows the motor 119 to start under normal conditions. Referring to Figure 6, the circuit 400 functions as follows:
• the on/off switch 140 When the disposer is not in use, the on/off switch 140 is open, and the protector 412 and centrifugal actuator (C/A) switch 410 contacts are closed.
• the start winding 132 When the user applies power to the motor 119 by closing the on/off switch 140, the start winding 132 is energized through the start capacitor 134 and the motor 119 starts up. The start winding 132 remains energized as long as the protector 412 and C/A 410 switches remain closed. Under normal starting conditions, the C/A switch 410 opens when the motor shaft speed reaches about 1000 RPM. This occurs on average in 70 milliseconds.
• the on/off switch 140 is closed, power is applied to the de-jam circuit tlirough the C/A switch 410.
• the de-jam circuit consists of a simple oscillator (555) 420 that produces a 2.5Hz square wave at a 50% duty cycle, and an SCR 422 in parallel across the start winding 132.
• 555 simple oscil
• the oscillator 420 is configured such that for the first 200 milliseconds, the output is in the low state, (or off), and the next 200 milliseconds the output is switched high. This sequence will continue indefinitely until power is removed from the circuit by the opening of the C/A switch 410, on/off switch 140, or the protector 412.
• the SCR 422 When the oscillator 420 is in the low state, the SCR 422 is gated off, and the start winding 132 is allowed to operate in its normal mode.
• the SCR 422 is gated on and shunts the start winding 132 so the pulsating torque mode is produced. Since under normal starting conditions the C/A switch 410 opens on average in 70 milliseconds, the oscillator 420 should never have time to reach the high state since power will be removed before the 200 milliseconds transition point.
• the motor 119 will not be able to accelerate and the C/A switch 410 will not have opened in 200 milliseconds.
• the oscillator 420 will transition to the high state and gate the SCR 422 on, producing the pulsating torque.
• the pulsating torque will be produced for 200 milliseconds (or some other appropriate predetermined time period) in an attempt to clear the jam. If after 200 milliseconds the jam is cleared, the motor 119 will then be able to accelerate normally and open the C/A switch 410 during the subsequent oscillator low state. This will terminate the oscillator cycle. If the jam is not cleared, the oscillator 420 will continue to run producing a pulsating torque at a 200 milliseconds on, 200 milliseconds off rate (2.5 Hz).
• the de-jam circuit will activate when the motor RPM drops below the C/A switch 410 closure speed of about 800 RPM. Once this happens, the pulsating torque will be produced at a 200 milliseconds on, 200 milliseconds off rate as described above until the jam is cleared or the thermal protector 412 opens.

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• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Environmental & Geological Engineering (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Public Health (AREA)
• Water Supply & Treatment (AREA)
• Crushing And Pulverization Processes (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (3)

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Citations (4)

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• 2005
  • 2005-04-27 CN CN2005800202271A patent/CN1968755B/zh not_active Expired - Lifetime
  • 2005-04-27 ES ES05742150.5T patent/ES2474196T3/es not_active Expired - Lifetime
  • 2005-04-27 CA CA002563047A patent/CA2563047A1/en not_active Abandoned
  • 2005-04-27 WO PCT/US2005/014587 patent/WO2005105313A1/en not_active Ceased
  • 2005-04-27 AU AU2005238083A patent/AU2005238083A1/en not_active Abandoned
  • 2005-04-27 JP JP2007510970A patent/JP4956422B2/ja not_active Expired - Fee Related
  • 2005-04-27 US US10/908,096 patent/US7448563B2/en not_active Expired - Lifetime
  • 2005-04-27 EP EP05742150.5A patent/EP1750844B1/en not_active Expired - Lifetime

Patent Citations (4)

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