US2015939A

US2015939A - Pressure operated circuit controller

Info

Publication number: US2015939A
Application number: US630889A
Authority: US
Inventors: Homer R Justus
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-08-29
Filing date: 1932-08-29
Publication date: 1935-10-01
Anticipated expiration: 1952-10-01

Description

I Octgl, 1 935. H. R. JUSTUS PRESSURE OPERATED CIRCUIT CONTROLLER Filed Aug. 29, 1932 [0mer]E.(7211:2 21:

ATTORNEY Patented a. 1, 1935 PRESSURE OPERATED CIRCUIT CONTROLLER Homerlt. Justus, Kansas City, Mo. Application August 29, 1932, Serial No. 630,889

4 Claims.

for motor driven devices and more particularly to means for controlling the motor circuit of said devices.

In the present instance I have shown my invention applied to apparatus for feeding pulverized or slack coal into furnaces, boilers and the like, whereinthe coalis conveyed by a feeder from a hopper into the furnace or boiler. The

feeder is driven by anelectric motor which heretofore continued to operate even after the hopper had been emptied, thereby imposing unnecessary wearand tear upon theworking parts.

The object of my invention is to'provide simpie and inexpensive means whereby the motor circuit is automatically .opened before all of the coal has been fed to the furnace or boiler, and in order that said invention may be fully understood, reference will now be had to the accompanying drawing, in which;

' Fig. l is a broken vertical sectional view of the feeding apparatus equipped with my invention. Fig. 2 is a detail longitudinal section of the controlling means.

Fig. 3 is an enlarged sectional view of the upper portion of the controlling means, taken on line 3-3 of Fig. 1.

Fig. 4 is a diagram of the motor circuit. Referring in detail to the different parts, 2

designates a hopper which communicates with a feeder comprising a screw 4 and a trough 6 for conducting the coal from the hopper to the furnace or boiler, not shown. 8 designates an electric motor for driving the screw 4. The foregoing may be of any well-known or preferred form.

Referring now more particularly to my motor circuit controlling means, i0 designates a pressure actuated element consisting in its present form of a lever mounted upon a fulcrum I 2 carried by ears i4 projecting from the lower end of a protective tube l6 located within the hopper 2.

The inner end of the lever I0 is connected to a plunger It which extends upwardly through guides 20 in the tube l6 and into a case 22 fixed to the upper end of said tube I6.

24 designates a switch, preferably of the mercury type, which is mounted upon one end of an 50 arm 26 pivotally connected at its opposite end to the interior of the case 22. The arm 26 has an aperture 28 through which the upper end of the plunger I 8 projects as shown by Fig. 3.

When the device is in operation the arm 26 is 55 held in raised position by means of a coil spring My invention relates generally to controllers 30 interposed between said arm and a collar 32 fixed to the plunger l8.

34 designates a manually controlled switch adapted to remain in either open or closed position. Said switch 34 is adapted to close against 5 a contact 36 and is provided with a push-button 38 which projects upwardly through an aperture in the top of the case 22.

As shown by the diagram Fig. 4, the switch 24 and the contact 36 are arranged in the motor 10 circuit 40, while the switch 34 is connected to a loop 42 extending around the switch 24 and connected to one side of the motor circuit.

The operation briefly stated is as follows: When the hopper 2 is supplied with fuel the 15 weight of the latter depresses the lever ID to the full line position shown by Fig. 1, thereby causing. the inner end of said lever to raise the plunger l8 to the full line position shown by Fig. 3. As the plunger I8 moves upwardly it,'throughthe 20 intermediary of the spring 30, raises the arm 26 and the switch 24, thereby causing the mercury in the latter to flow downwardly into contact with the switch terminals 43 and thus close the motor circuit 40. After a sufiicient amount 25 of coal has been fed from the hopper 2 to relieve the lever IU of pressure the latter is immediately forced to the full line position shown by Fig. 2 and the dotted line position shown by Fig. 1, by an expansible spring 44 interposed between 30 the adjacent guide 26 and the enlarged lower portion of the plunger l8. The foregoing operation carries the plunger I 2 downwardly thereby permitting the arm 26 and the switch 24 to descend by the force oi. gravity to the dotted line 35 position, Fig. 3, so that the mercury switch 24 will uncover the contacts 43 and thus automatically open the motor circuit 40. The motor circuit remains open until the hopper 2 is replenished with suflicient coal to again depress 40 the lever to. In some instances, however, enough coal may lodge under the lever ID to prevent the same from moving downwardly and eflecting the reclosing of the switch 24. Under these circumstances the circuit 40 may bemanually closed by 45 forcing the switch 34 into engagement with the contact 36, thereby providing a path for the current around the switch 24 through means of the loop 42. When the circuit is closed as stated the motor 8 again starts to operate and just as soon as the'coal lodged beneath the lever III has moved down into the trough 6 and permitted the lever Hi to be forced downwardly to the full line position, Fig. 1, by the weight of the coal thereon said lever pushes the plunger I8 upward- 17, thereby causing the same to effect closing of the switch 24 and opening of the switch It.

Prom the foregoing description it is apparent that I have provided controlling means which is well adapted for the purpose intended, and while I have shown and described a preferred arrangement of the invention I reserve all rights to such changes and modifications thereof as properly fall within the spirit and scope of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

l. lncontrolling means of the character described, the combination with a hopper, a feeder for conveying material from said hopper, an electric motor for driving said feeder, and a circuit for said motor, of a switch for controlling said circuit, a pivotally mounted member arranged within the hopper and adapted to be held in a depressed position by the material, a plunger adapted to be held in such position by the depressed lever as to close the switch, and spring means for shifting said plunger to another position so that the switch may open the circuit.

2. In controlling means of the character described, the combination with a hopper, a feeder for conveying material from said hopper, an electric motor for driving said feeder, and a circuit for said motor, of a self-opening switch for controlling said circuit, a pivotally, mounted member arranged within the hopper and adapted to be held in adepressed position by the material. a plunger adapted to be held in such position by the depressed member as to close the switch. a d spring means for shifting said plunger to another position so that the switch may open the circuit.

3. In controlling means of the character described, the combination with a" hopper, a feeder for conveying material from said hopper, an electric motor for driving said feeder, and a circuit for said motor, a protective tube extending downwardly into the hopper, a member pivotally mounted at the lower portion of said tube and adapted to be held in a depressed position by the material in the hopper, a plunger pivotally con- 5 nected at its lower end to the pivotally mounted member and extending upwardly through the protective tube, a self-opening switch adapted to be held in closed position by said plunger when the pivotally mounted member is held in a dem pressed position by the material, and spring means for forcing the plunger downwardly so that said switch may open when the pivotally mounted member is relieved of the weight of the material. g

4. In controlling means of the character described, the combination with a hopper, a feeder for conveying material from said hopper, an electric motor for driving said feeder, and a circuit for said motor, a protective tube extending m downwardly into the hopper, a member pivotally mounted at the lower portion of said tube and adapted to be held in a depressed position by the material in the hopper, a plunger pivotally connected at its lower end to the pivotally mounted a member and extending upwardly through the protective tube, a self-opening switch adapted to be .held in closed position by said plunger when the pivotally mounted member is held in a depressed position by the material, spring means a for forcing the plunger downwardly so that raid switch may open when the pivotally mounted member is relieved of the weight of the material, a loop extending around the self-opening switch and connected to the motor circuitfand a switch 35 adapted to be manually operated to close said loop, said last-mentioned switch being arranged in the path of the plunger so that the latter may open the former when the pivotally mounted member is depressed.

noun a. .ms'ros.