US3078051A

US3078051A - Automatic crusher

Info

Publication number: US3078051A
Application number: US61997A
Authority: US
Inventors: Warren R Patterson
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1960-10-11
Filing date: 1960-10-11
Publication date: 1963-02-19
Anticipated expiration: 1980-02-19
Also published as: GB922912A

Description

Feb. 19, 1963 w. R. PATTERSON AUTOMATIC CRUSHER k @QQ MGMQ @Sm ub@ 3 43 remains off while the time sequence device is operating and until the feed speed has been changed. However, if the low horsepower per ton per hour signal persists after the feed change is completed, the entire feed increase sequence is repeated until the condition is corrected or the feed exceeds its predetermined limit.

As mentioned above, the signal from the horsepower per ton per hour instrument 30 is also applied to a decrease sctting switching device 48. This setting device 48 is biased to a greater value than the feed increase device 43 and hence will not conduct until an additional signal is supplied. lf the horsepower per ton low condition persists until a further increase in the feed would exceed the capacity of the crusher, a switch is actuated which prevents further increases in feed and directs an additional signal to the decrease setting device. When the chamber 11 of the crusher 10 lls, a suitable limit switch is closed to direct a current to a chamber full switching device 50. This current overcomes the bias on the chamber full switching device Se (another magnetic amplifier or transistor) and causes it to go to full output. One output of the chamber full switching device Si) is applied to the feed increase device 43 to stop any further feed increases. A second output of the chamber full switching device 50 is applied to the decrease setting switching device 48.

The output from the chamber full device 50 plus the output from horsepower per ton per hour device 30 overcomes the bias on the decrease setting switch 48 and causes it to conduct to a time sequence switch 52 after a predetermined time delay. The time sequence switch 52 operates a motor 54 which in turn operates rheostat 36 to change its position. 'This causes an unbalance between the

rheostats

35, 36 which results in a current flow in setting motor control circuit 55. This closes contacts 56 which connect the setting motor 59` to a source of power not shown. A current then flows in the setting motor 59 causing it to operate and drive the hydraulic lift means 14 to decrease the setting of the crusher. Decreasing the setting of the crusher means to decrease the minimum clearance between the mantle and the chamber casing 11. If the signals from the chamber full switch 50 and horsepower per ton per hour instrument 30 persist after the setting change has been made, the crusher setting will be lowered further periodically in preset time increments until the desired horsepower per ton per hour is restored.

When the operation of the crusher is such that the horsepower per ton per hour is higher than the preset range, an electric signal is transmitted from the horsepower per ton per hour instrument 30 to the feed decrease switching device 61 and the increase setting device 66. The feed decrease switching device 61 after a predetermined time delay causes a time sequence unit 62 to conduct to produce a feed decrease in substantially the same way as' was described above in connection with the feed increase except that it decreases the rate of feed rather than increasing the rate.

Asl mentioned in connection with decrease `setting device 48, the increase setting switching device 66 is biased to a greater value than the feed decrease device 61 and will have no output from the horsepower per ton per hour signal alone. Therefore, the feed speed will thus be decreased periodically in preset increments until the load condition is corrected or until the tonnage indicated on the tons per hour instrument becomes lower than a predetermined minimum tonnage desired, in which case a switch 68 on the tons per hour instrument 21 is closed to apply a signal to the feed decrease switching device '61 to stop any further decrease in the feed rate. Closing of the minimum tonnage switch 68 also applies a further signal to the increased setting switch 66 which supplements the signal from the horsepower per ton per hour instrument 30 to overcome the bias and cause the increase setting switch to go to full output. The output of switch 66 after a time delay goes to time sequence device which operates motor 54 to change the setting of rheostat 36. This causes an unbalance between

rheostats

35, 36 which in turn causes the position setting motor `59 to operate as explained above. The motor in this case actuates the hydraulic lift means 14 to increase the sett-ing of the crusher. If the signals from the horsepower per ton per hour instrument and the minimum tonnage switch persist after the crusher setting has been changed, the entire sequence will be repeated and the setting of the crusher will be increased in periodic time increments until the horsepower per ton per hour is returned to the desired range or the amount of tonnage processed goes above the preset minimum value.

If for any reason the feed rate is such that the hopper 60 which is above the crusher chamber 11 is filled to an overow condition, an electric signal is applied to the feed decrease switching device 61 by the hopper full switch 63 which will cause periodic decreases in the feed speed until the amount of material in the hopper is reduced below the chamber full level. In the illustrated system this is accomplished by cutting olf the bias on the hopper full switch 63 (a magnetic amplifier) so that it conducts and supplies a signal to the feed decrease device 61.

If the feed overflows the hopper 60, the start-stop switch 71 is opened to cut olf feed to the hopper. This is accomplished by removing or overcoming the bias on the feed stop magnetic amplifier 72 so that it no longer conducts -to the solenoid 73 which normally holds the start-stop switch 71 in a conducting position. The switch 71 when open prevents the ow of current to the variable speed drive 17 that drives the feed conveyor 16.

If for any reason, such as lack of feed on the conveyor, the horsepower being drawn `by the crusher falls below -the preset range of the motor, a signal is sent that stops further changes in the feed and sounds a warning that the machine is not operating Within the desired range. This signal could come from either the horsepower or the tons per hour instrument but as shown in the drawing it goes from the horsepower instrument 29 to the feed increase device 43, the feed decrease device 61 and a warning light 81.

As it has been pointed out in connection with the graph in FIG. 1, it is desirable to maintain the operation of the crusher as close as possible to its maximum horsepower per ton per hour output short of packing. To facilitate this an electric pulse device 83 is provided which periodically sends a short time signal to the feed increase device 43. This of course tends to increase the feed. However, if the feed change takes the crusher out of the desired operating range, which is up along the flared portion of the curve in FIG. 1, the crusher would start to pack and the horsepower per ton per hour instrument would send a signal to reduce the feed and -bring it back within the desired r-ange of operation for the machine. The pur-pose of the pulsing device is to keep the crusher operating near the upper limit of the desired operating range of horsepower per ton per hour by periodically trying to increase the feed to the crusher.

When the feed falls back within the hopper 60, the solenoid operated start-stop switch 71 is closed. This again connects the variable speed drive 17 to a source of power and starts the feed drive under automatic control. All of the

instruments

21, 29, 30; the feed device 43, 44; the setting devices 48, 66; the

time sequence devices

44, 52, 62, S0; the pulsing device 83; the chamber full device 50; the hopper full device 63; and the feed stop device 72 are connected to a suitable source of power such as a standard volt supply. For simplicity, the wiring to all of these elements is not shown in the drawing but anyone skilled in electronics could provide suitable wiring to supply power as indicated.

There are electronic devices readily available on the commercial market for performing the functions set out in connection with the feed increase switch, the Iltime sequence switch and other elements mentioned above. For example, the described feed increase switch, the time sequence switches and the setting devices can be either magnetic amplifiers or transistors. These elements can be biased by methods well-known in the electronics field to have the characteristic indicated for the devices described. The time delay means can be a suitable capacitor or any other well-known electronic element that provides a time del-ay lbefore conducting.

The above-mentioned electronic devices are especially suitable for a control system such as described because of the-ir .rugged characteristics, their com-plete lack of moving parts and their inherent freedom from maintenance attention. Many of the indicated devices are capable of receiving one `or more input signal-s to produce the desired output function. Although but lone embodiment has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications maybe made therein without departing from the spirit of the invention or from the scope Iof the appended claims.

Having now particularly described and ascertained the nature of my said invention and 4the manner in which it is to be performed, I declare that what I claim is: Y

l. In a crusher having a mantle mounted for rotation within a chamber; means for feeding material into said chamber; means for setting the position of said mantle relative to said chamber; means for measuring the horsepower consumed by the crusher per ton of material crushed per hour; means for producing a first electric signal when the horsepower per ton per hour of said crusher deviates `from a predetermined range; means responsive to said first signal for varying the volume of feed to said crusher within predetermined limits and means for producing a second electric signal after said feed has reached its predetermined limit, and means responsive to the sum of said signals for Varying the setting of said mantle relative to said chamber.

2. In a crusher having a mantle mounted for rotation Within a chamber; means for feeding m-aterial into said chamber; means for setting the position of said mantle relative to said chamber; means for measuring the horsepower consumed by the crusher per ton of material crushed per hour; means for producing a first electric signal when the horsepower per ton per hour of said crusher deviates fro-m Ia predetermined range; means responsive to said first signal for Varying the volume of feed to said crusher within predetermined limits and means for producing a second electric signal when said chamber is full of feed; means responsive to said second signal to prevent further increases in the rate of feed to said crusher, and means respon-sive to the sum of said signals for decreasing the minimum space between said mantle and said chamber.

3. In a crusher having a mantle mounted for rotation within a chamber; means for feed-ing material into said chamber; means for setting the position of said mantle relative to said chamber; means for measuring the horsepower consumed by the crusher per ton of material crushed per hour; mean-s for producing the first signal when a horsepower' per ton per hour of said crusher deviates from a predetermined range; means responsive to said signal for varying the volume of feed to said crusher within predetermined limits; means for producing a second electric signal when the weight of material passing through said chamber falls below a predetermined limit, means responsive to said second signal to prevent further decreases in the rate of feed to said crusher, and means responsive to the sum of said signals for increasing the minimum space between said mantle and said chamber.

4. In a crusher having a mantle mounted for rotation within a chamber; means lfor feeding material into said chamber and removing material that has passed through said chamber; means for setting the position of said mantle relative to said chamber; means for measuring the horsepower consumed by the crusher per ton of material crushed per hour; means for producing a first electric signal when the horsepower per ton per hour of said crusher deviates from a predetermined range; means responsive to said first signal for varying the volume of feed to said crusher; means for producing a second electric signal when said crusher chamber is full of feed; means responsive to said second signal for preventing further increases of the rate of feed to said crusher, means responsive to the sum of said first and second signals for decreasing the setting of said mantle relative to said chamber; means for producing a third signal when the rate of material being crushed by said crusher falls below a predetermined value, means responsive to said third signal .to prevent further decreases in the rate of feed to said crusher, means responsive to the sum of said first and third signals for increasing the setting of said mantle relative to said chamber.

5. In a crusher having a mantle mounted for rotation within a chamber; means for feeding material into said chamber and removing material that has passed through said chamber; means for setting the position of said mantle relative to said chamber; means for measuring the horsepower consumed by the crusher per ton of material crushed per hour; means for producing a first electric signal when the horsepower per t0n per hour of said crusher exceeds a predetermined range; means responsive to said first signal for decreasing the rate of feed to said crusher; means for producing a second signal when the horsepower per ton per hour of said crusher falls below said predetermined range, means responsive to said second signal for increasing the rate of feed to said crusher, means for producing a third electric signal when said crusher chamber is full of feed; means responsive to said tlL'rd signal for preventing further increases in the rate of feed to said crusher, means responsive to the sum of said lsecond and third signals for decreasing the minimum space between said mantle and said chamber; means for producing a fourth signal when the rate of material being crushed by said crusher falls below a predetermined value, means responsive to said fourth signal to prevent further decreases in the rate of feed to said crusher, means responsive to the sum of said first and fourth signals for increasing the minimum space between said mantle and said chamber.

6. The apparatus of claim 5 having a hopper positioned above said chamber for receiving and directing feed into said chamber, and means associated with said hopper for producing an electric signal when said hopper is full, said means responsive to said first signal being responsive to said hopper full signal for decreasing the rate of feed to said chamber.

7. The apparatus of claim 5 having means for producing an electric signal when the horsepower being used by said motor falls below a predetermined value, said means responsive to said first and second signals, being responsive to said horsepower low signal to prevent further changes in the rate of feed to said chamber.

8. The apparatus of claim 5 having a pulse means for periodically sending a signal to said means responsive to said second signal to increase the rate of feed to said chamber.

9. In a crusher having a mantle mounted for rotation Iwithin a chamber; a variable speed drive for feeding material into said chamber, conveyer means for removing material that has passed through said chamber; means for setting the position of said mantle relative to said chamber; means for measuring the horsepower consumed by the crusher per ton of material crushed per hour; means for producing a first electric signal when the horsepower per ton per hour of said crusher exceeds a predetermined range; means responsive, to said iirst signal for decreasing the speed of said drive to decrease `the rate of feed to said crusher; means for producing a second signal when the horsepower per ton per hour ofl said crusher falls below said predetermined range, means responsive to said second signal for increasing the speed of said drive toincrease the rate of feed to said Crusher;- means for producing a third electric signal when said crusher chamber is fulllof feed; means responsive to said third signal for preventing further increases in the speed of said drive, means responsive to the sum of said second and third signals for decreasing the minimum space between said mantle and said chamber; means for producing a fourth signal when the amount of material being crushed per hour by said crusher falls below a predetermined value, means responsive to said fourth signal to prevent further decreases in the speed of said drive, means responsive to the sum of said first and fourth signals forincreasing the minimum space between said mantle and said chamber.

10. In a Crusher having a mantle mounted for rotation within a chamber; means for feeding material into said chamber, a hydraulic lift connected operatively to said mantle to vary the position of said mantle relative to said chamber; means for measuring the horsepower consumed by the Crusher per ton of material crushed per hour; means for producing -a first electric signal when the horsepower per ton per, hour of said crushcr exceeds a predetermined range; means responsive to said first signal for decreasing the' rate` of feed to said Crusher; means for producing a second signal when the horsepower per ton per hour of said` Crusher falls below said predetermined range, means responsive to said second signal for increasing the rate of feed to said Crusher; means for producing a third electric signal when said crusher chamber is full of feed; means responsive to said third signal for preventing yfurther increases in the rate of feed to said Crusher, means responsive to the sum of said second and third signals for operating said lift to decrease the minimum space between said mantle and said chamber; means for producing a fourth signal when the rate of material, being crushed by said crusher falls below a predetermined value, means responsive to said fourth signal to prevent further decreases in the rate of feed to said Crusher, means responsive to the sum of said first and fourth signals for operating said lift to increase the minimum space between said mantle and said chamber.

References Cited in the. tile of this patent UNITED STATES PATENTS Re. 24,185 Staege July 24, 1956 1,815,155 Lewellen e July 2l, 1931 2,613,878 Hailey Oct. 14, 1952

Claims

1. IN A CRUSHER HAVING A MANTLE MOUNTED FOR ROTATION WITHIN A CHAMBER; MEANS FOR FEEDING MATERIAL INTO SAID CHAMBER; MEANS FOR SETTING THE POSITION OF SAID MANTLE RELATIVE TO SAID CHAMBER; MEANS FOR MEASURING THE HORSEPOWER CONSUMED BY THE CRUSHER PER TON OF MATERIAL CRUSHED PER HOUR; MEANS FOR PRODUCING A FIRST ELECTRIC SIGNAL WHEN THE HORSEPOWER PER TON PER HOUR OF SAID CRUSHER DEVIATES FROM A PREDETERMINED RANGE; MEANS RESPONSIVE TO SAID FIRST SIGNAL FOR VARYING THE VOLUME OF FEED TO SAID CRUSHER WITHIN PREDETERMINED LIMITS AND MEANS FOR PRODUCING A SECOND ELECTRIC SIGNAL AFTER SAID FEED HAS REACHED ITS PREDETERMINED LIMIT, AND MEANS RESPONSIVE TO THE SUM OF SAID SIGNALS FOR VARYING THE SETTING OF SAID MANTLE RELATIVE TO SAID CHAMBER.