US2081604A - Centrifugal circuit breaker - Google Patents

Description

May A25, 1937.

F. scHAuM CENTRIFUGAL CIRCUIT BREAKER Filed Feb. 1, 1935 3 Sheets-Sheet l u@ bw ZOPFDQ ZImLObO SEN.

INVENTOR FLETCHER Gef/AUM sy??? AT1-o N s j May 25, 1937. F, SCHAUM m 2,081,604

CENTR-IFUGAL CIRCUIT BREAKER Filed Feb. 1, V1935 3 Sheets-Sheet 2 May 25, 1937.

F. SCHAUM CENTRIFUGAL CIRCUIT BREAKER v5 sheets-sheet s Filed Feb. l, 1935 Patented May 25, 10937y UNITED STATES FATENT OFFECE CENTRIFUGAL CIRCUIT BREAKER Application February 1, 1935, Serial No. 4,438

6 Claims.

This invention relates to circuit breakers and is particularly well adapted for use in connection with centrifugal machines wherein various speeds are desired. I shall, therefore, in the description of my invention refer specificallyY to circuit breakers in connection with centrifugals, although it is to be understood that I do not wish to be limited to the use of my improved circuit breaker on centrifugals, inasmuch as the sam-e can be applied to many other devices wherein various speeds are desired.

In the operation of a batch centrifugal machine, such as disclosed in United States Patent No. 1,543,289, for example, when the centrifugal is started and reaches what is known as the loading speed of about 400 R. P. M., the charge vis run into the basket. This charge usually consists of a sludge containing part liquid and part solid. At this loading speed the charge is i, distributed over the wall of the basket. After the machine has been charged the centrifugal is brought up to running speed, usually about 930 or 1290 R. P. M., to cause the liquid to be thrown out through the perforations in the basket and the solids to remain in the basket. After the M material is sufficiently dry, the rotation of the basket is stopped and the cover over the openings in the bottom of the basket is removed. The basket then again rotated at what is known as the unloading speed of about 100 to 150 R. P. M.

and the unloader plow then dug into the mata rial to scrape the material from the sides of the basket and discharge the same through the open- :ings in the bottom of the basket. The basket is 5 then stopped, the cover replaced over the openings in the bottom of the basket and the machine spceded up to loading speed of about A00 R. P. M. again and the cycle repeated.

in the operation of centrifugals as at present 4o constructed these various speeds are usually obtained by having a two-speed motor, the high speed being used for drying the material and the low speed for charging the material. In such machines, however, during the unloading stage,

l5 for example, it is customary tohave a jogging button connected with a contacter, the operator holding the jogging button in contact to complete the motor circuit until the approximate speed of i0() to 150 R. P. M. is reached. The button is o then released by the operator, thereby breaking the circuit to the motor, whereupon the operator uses the unloader plow. In such constructions the basket will naturally slow down when the 55 circuit to the motor is open; hence it becomes necessary to jog the motor occasionally to keep up the speed necessary for unloading.

@ne of the objects of the present invention is to provide a construction wherein a single-speed motor may be employed which by the use of the circuitbreakers of the present invention is capable of being run at running speed, loading speed and unloading speed, as will be brought out hereinafter.

Another object of the invention is the provision l0 of a device of the character indicated which will automatically operate at the various desired speeds without the constant attention of the operator.

Another object of the invention is the provi- 15 sion of circuit breakers commonly known as mercoids which are set at different angles relative to the shaft by which they are driven so that the motor circuit will automatically be broken when the desired speed corresponding to the angular setting of each breaker is reached.

A further object of the invention resides in mounting the circuit breakers adjustably so that their angular setting may be adjusted and hence their breaking or circuit opening speed.

Further objects of my invention will be manifest from the following description and the accompanying drawings in which drawings:

Fig. l is an elevational View of a centrifugal having my improved circuit breaker attached thereto;

Fig. 2 is a wiring diagram of the device;

Fig. 3 is asectional elevation of the circuit breaker;

Fig. 4 is ak plan View of the same;

Fig. 5 is a wiring diagram of another embodiment of my invention; and

Fig. 6 is a plan view of the stop button switch.

Referring to the drawings in detail, i designates a centrifugal support on which is mounted a. driving motor 2 having a motor shaft 3 supporting a basket 4. To the lower end of the shaft 3 is secured a flexible shaft E which extends to the circuit breaker mechanism carried by a bracket 6. mounted on the support l. The circuit breaker is mounted in a housing 'l and comprises a vertical shaft 8 connected to the flexible shaft 5, the end of the shaft 8 carrying a loading mercoid S and an unloading mercoid l0. These mercoids each comprise an elongated glass 50 tube or casing containing electrical conductive fluid such as mercury. These mercods 9 and l0 are mounted in holders ll and i 2 respectively which are securedV to the shaft 8 by means of a, bolt I3 in such a manner that the same can be 55 adjusted with respect to the vertical shaft 8 to vary the angle between the mercoid and the longitudinal axis of the shaft. A bushing I4 of insulating material is keyed to the shaft 8 within the housing and is provided with collector rings I5, I3 and I1. The ring I5 is common to both the mercoids in that a common conductor I8 extending from this ring terminates in conductors I9 and 2U. The conductor I9 terminates in a contact 2| within the loading mercoid 9 and the conductor terminates in a contact 22 within the unloading mercoid Il). A conductor 23 extends from the collector ring I Ei and terminates in a contact 24 within the loading mercoid 9 and a conductor 25 extends from the collector ring I1 and terminates in a contact 2B within the unloading mercoid I9.

Brushes 21, 28 and 29 are mounted within the housing 1 and adapted to engage the collector rings I5, I6 and I1`, respectively.

It will be noted from Fig. 3 that the mercoids 9 and I0 are set at different angles with respect to the longitudinal axis of the shaft 8 so that upon rotation of the shaft B the mercury in mercoid 9 will be thrown outwardly by centrifugal force away from its contacts 2I and 24 at one speed while the mercury in mercoid ID will be thrown outwardly by centrifugal force away from its contacts 22 and 26 at a different speed.

It will be appreciated, therefore, that the angularity at which the mercoids 9 and I0 are set is predetermined depending on the speed at which the circuit breakers are to operate. For example, the mercoid I0 is set at such an angle as to operate, i. e., open the circuit of the driving motor when the centrifugal reaches a speed of about 100 to 150 R. P. M. and the mercoid 9 is set so as to operate when the centrifugal has reached a speed of about 400 R. P. M.

Referring to the wiring diagram shown in Fig. 2 the switches 3I and 32, also the main motor switches 33, 34 and 35 are shown open while the brake switch 35 is shown closed. When the centrifugal is at rest and the brake on the brake switch 36 is open.

The circuits illustrated and their sequence of operation for a complete cycle are as follows: starting, holding, loading, running (full speed) and unloading.

In starting, the control switch 31 is thrown to the left as viewed in Fig. 2 to contact the loading" terminal 38; the brake is released, closing the brake switch 35, and the starting button 39 is pressed to complete the starting circuit. This circuit may be traced as follows: From the source of supply through conductors 40, 4I, 42, 43, starting button 39, conductor 44, brake switch 36, conductors and 45, winding 41, conductors 48, 49, to source of supply. The winding 41 now being energized the switches 3I and 32 will close. The closing of the switch 32 completes a holding circuit for the winding 41 and hence the starting button may be released. This holding circuit may be traced as follows: From source of supply through conductors 4I), 5I, 52, 53, 54, switch 32, conductors 55, 60, 6I, stopping button 62, conductor 63, brake switch 3B, conductors 45, 43, winding 41, conductors 48, 49 and 50 to source of supply. This circuit will, until broken, retain the switches 3l and 32 closed.

If, now, the control switch 31 be thrown to the left as viewed in Fig. 2 into engagement with contact 38 the circuit to the loading mercoid 9 is completed. This circuit may be traced as iollows: From source of supply through conductors 4u, 51, 52, 52, switch 3|, conductors en, e5, sa, c1, collector ring I5, conductors I8, (E, contact 2l of loading mercoid 9, mercury 3d, contact 24, conductor 23, collector ring It, conductors 63, 59, 10, control switch 31, conductors l2, 13, winding 14, conductors 'l5 and 53 to source of supply. The winding 14 now being energized the motor switches 33, 34 and 35 will close to close the motor circuit.

The motor now running will drive the centriugal 4 and the shaft 3 on which the merccids 9 and l! are mounted. When the speed of rotation of the centrifugal reaches about 400 R. P. M. loading speed) the mercury 33 in the loading mercoid 9 will be thrown out by centrifugal force away from the contacts 2l and 2li thereby breaking the circuit to the winding 14 to allow the motor switches 33, 34 and 35 to open. As the motor slows down due to the breaking ol its circuit, the mercury 3G in the mercoid 9 will flow back by gravity to the lower end ci its tube again to close the circuit across the contacts 2l and 24 thereby closing the circuit to the winding 'I4 again to close the motor switches 35, 34, 35. This making and breaking ol the motor circuit will continue as long as the control switch 3l is in loading position. With the centrifugal running at loading speed as just described the charge is run into the centrifugal basket and distributed over the wall ol the saine as will be understood. When loading has been completed the operator throws the control switch 31 to vertical or running position to break the loading circuit and close the running circuit to drive the centrifugal at running speed (about i200 R. P. M.) to dry the material in the basket in a well-known manner. This running" circuit may be traced as follows: From source ol supply through conductors lli), 5i, 52, E53 and switch 3l, conductors switch 3l', conductors 12, 13, winding 14, conductors and El.) to source ol' supply. This winding ld now being energized the motor switches 33, 34 and 35 will close as above described thereby closing the circuit to the motor 2.

When the drying operation has been completed the rotation of the basket is stopped and the cover over the openings in the bottom of the basket is removed for unloading. The stopping of the basket is accomplished by pressing the stopping button S2 which breaks the holding circuit previously described and deenerglzes the winding Vlv causing switch 3| to open to deenergize wlnding 'ill to allow main motor switches 33, 3 4 and 35 to open.

The machine may now be started for the unloading operation during which the unloader plow is dug into the material in the basket to scrape the material from 'the sides and discharge the saine through the openings in the bottoni of the basket as is usual.

In starting the machine lor the unloading operation the starting button is pressed to close the starting circuit and to complete the holding circuit as hereinbeiore described. switch 31 at this time is moved to the right as viewed in Fig. 2 or to unloading position complete the circuit to the unloading mercoid I0, which circuit may be traced as follows: From the source of supply through conductors IV), 5i 52, 53, switch 3l, conductors 64, El, collector ring E5, conductors I8, 20, contact 22, mercury 33 of mercoid I0, Contact 25, conductor 25, collector ring il, conductors Bil, BI, contact Sii, switch arm 31, conductors 12, i3, winding 14, conductors 'i5 The control and 50 to` source of supply. This circuit as in the case of the loading circuit will lclose the motor switches 33, 34 and 35 to complete the motor circuit.

The unloading mercoid I it will be noted is set at a smaller angle with respect to the shaft 8 than the mercoid consequently the mercury 30 in the unloading mercoid l0 will-be thrown out by centrifugal force at a lower speed of rotation than the mercury in loading mercoid 9. The angularity of the mercoid is determined by the speed desired. In the unloading operation it is desired to have the unloading mercoidY l0 operate at a speed of about 100 to 150 R. P. M. When the speed of rotation exceeds the speed for which the mercoid is set, the mercury is thrown out of contact with the contacts 22 and 28 to break the unloading circuit in the same manner as the loading circuit is broken and as hereinbefore described. As the speed drops below 100 R. P. M. the mercury will ilo-w back again into contact with the contacts 22 and 20 again to complete the circuit. This making and breaking of the unloading circuit Will continue as long as the control switch remains in unloading position.

In the form shown in the wiring diagram of Fig. 5- the mercury when thrown out by centrifugal force closes a circuit across the contacts in the casing to energize a winding which in turn breaks the holding circuit for the motor switches as distinguished from the form above described wherein the mercury opens a circuit across the contacts to break the motor cir-cuit.

In starting the device of Fig. 5, the operator follows the same procedure as in the preferred form and the sequence of operation of this form is the same as in the wiring diagram of Fig. 2, namely, starting, holding, loading, running (full speed) and unloading.

In starting, the control switch |00 is thrown to the left as viewed in Fig. 5 to contact loading terminal |0l, the brake is released closing the brake switch |02 and the starting button |03 is pressed to complete the starting circuit. This circuit may be traced as follows: From source of supply through conductors |04, |05, |06 and |01, starting button |03, stopping button |08, conductor |09, brake switch |02, conductors ||0 and winding H2, conductors ||3, ||4 and H5 to the source of supply. The completion of this circuit will energize the winding ||2 to close switches ||6 and ||1'. The closing of the switch I0 will complete a holding circuit for the winding H2 which may be traced as follows: From the source of supply through con-ductors |04, I9, and |2|, switch H0, conductors |22, |23 and |24, stop switch or stopping button |08, conductor |09, brake switch |02, conductors l0 and winding H2, conductors H3, ||4 and ||5 to the source of supply. This circuit will remain closed until the stopping button |08 is pressed to break the same.

The closing of switch ||1, above referred to, will in turn complete a circuit to winding which circuit may be traced as follows: From the source of supply through conductors |04, I8 and |20, switch ||1, conductors |31, |36 and |35, switch |34, conductors |33 and |32, winding |30, conductors |3I and ||5 to the source of supply. The energizing of this winding |30 will close motor switches |40, |4| and |42 whereby the motor 2 is set in operation driving the shaft carrying collector rings |50, |5| and |52 and loading mercoid |53 and unloading mercoid |54.

These mercoids as in` the case of theform already described' are mounted for angular adjustment with respect to the shaft 8.

When the speed of rotation of the centrifugal reaches about 4001?.. P. M. (loading speed), the mercury in the loading' mercoid r|53 will be thrown out by centrifugal force into bridging relation with respect to contacts |50 and |51. The bridging of these contacts closes a circuit to a winding |58 which when energized will open switch |34 to break the circuit oi the winding |30 whereby the motor switches |40, |41 and |42 will be opened. The circuit to this winding |58 may be traced as follows: From source of supply through conductors |04, |05, |06, |01 and EEO, control switch arm |00., conductors |59, |00 and |0|, collector ring |152, conductor |62, contact |50, mercury |55, contact |51, conductor |03, collector ring |5|, conductors |04, |05, |00, |01 and |08, winding |58, conductors |69, |10 and |15 to the source of supply.

It will be obvious that upon the energization of this winding |58 and the opening of the circuit to the winding |30 that the motor will cease operation and the shaft ilv likewise will stop rotating whereupon the mercury will move by gravity to the bottom of its casing |53 away from the contacts |50 and |51, thereby breaking the circuit to the winding |58 permitting the switch |34 by means of spring |1| to return to its pleted the control switch |00 is moved to Vertical or running position as shown in Fig. 5 to break the loading circuit and close the running circuit to drive the centrifugal at running speed, about 1200 R. P. M., to dry the material in the basket as hereinbefore described. This running circuit may be traced as follows: From source of supply through conductors |04, |05, |86, |01 and H8, switch arm |00,conductors |25 and |09,brake switch |02, conductors H0 and lll, winding ||2, conductors H3, ||4 and ||5 to source of supply.

As will be seen from Fig. 6, the connections |00 and |25 are spaced from each other so as to make separate contact with the stop button |03.

When the drying operation has been completed the rotation of the basket is stopped by pressing the stopping button |08 which breaks the holding circuit previously described and deenergizes the winding ||2 causing the switches H6 and ||1 to open; the opening of switch ||1 which is in the circuit or" the winding |30 causing the winding |30 to be deenergized whereby the motor switches |40, |4| and |42 will be opened.

The machine may now be started for the un loading operation during which the unloader plow is dug into the material in the basket as described with respect to the other form oi my invention. In starting themotor for the unloading operation the starting button |03 is pressed to close the starting circuit and complete the holding circuit as hereinbefore described. The control switch |00 at this time is moved to the right as viewed in Fig. 5 or to unloading position so that when the motor attains unloading speed a circuit will be closed through unloading mercoid |54. This circuit may be traced as follows: From source of supply through conductors |04, |05, |06, |01 and H8, control switch arm |00, contact |25, conductor |80, collector ring |50, conductor |8| and contact |82, mercury |83, contact |84, conductor |85, collector ring |5|, conductors |64, |65, |66,

|6`| and |68, winding |58, conductors |69, |10 and to the source of supply. It will be obvious that energization of the winding |58 by the completion of this circuit as just described will open the switch |34 to break the circuit of the winding whereby the motor switches |40, |4| and |42 will be opened to break the motor circuit.

When the unloading operation has been completed and the basket prepared for the next run the cycle of operation above described is repeated.

It is obvious that the number of speeds can be increased by increasing the number of mercoids each of which will be set at a different angle with respect to the shaft 8 depending upon the speed desired.

It will be appreciated that with the present n vention the necessity of the operator constantly pressing a jogging button to maintain the desired speed during loading and unloading is entirely eliminated, the device operating at the desired speed automatically depending upon the position of the control switch.

It is to be understood that various modifications and changes may be made in the construction and arrangement of the various cooperating parts herein shown and described without departing from the spirit and scope of my invention.

What I claim is:

1. A circuit breaker comprising in combination a motor, a circuit therefor, a rotatable shaft driven by said motor, a casing mounted on said shaft at an angle thereto, fixed spaced contacts in said casing, and an electrically conductive body in said casing cooperable with said contacts, said body being moved relatively to said contacts by centrifugal force when said shaft is rotating at a predetermined speed to break said motor circuit, said casing being adjustable with respect to said shaft to vary the angle which the casing makes with the shaft thereby to vary the shaft speed at which the body will be moved in said casing.

2. In combination a centrifugal machine, a motor for driving the same, a motor circuit, a motor shaft, a circuit breaker comprising a shaft, a flexible connection between said motor shaft and said circuit breaker shaft, a plurality of elongated casings, a bracket for each of said casings, said brackets being mounted on said circuit breaker shaft and being adjustable angularly with respect thereto, spaced contacts in the end of each of said casings adjacent said circuit breaker shaft, a circuit for each pair of contacts for controlling said motor circuit, a body of electrically conductive fluid in each of said casings adapted to bridge the contacts thereof, the fluid in said casings being thrown by centrifugal force upon the rotation of said shafts at predetermined speeds out of engagement with said contacts thereby to open the motor circuit and prevent rotation of said centrifugal at speeds other than said predetermined speeds,

3. In combination a centrifugal machine, a motor for driving the same, a circuit for said motor, a motor shaft, a circuit breaker comprising a shaft, a flexible connection between said motor shaft and said circuit breaker shaft, a plurality of elongated casings mounted on said circuit breaker shaft, said casings being adjustable angularly with respect to said circuit breaker shaft and set at different angles thereto, a pair of spaced contacts in the end of each of said casings, a body of electrically conductive fluid in each of said casings adapted to contact with the spaced contacts of each of said casings, an electric circuit for each pair of contacts adapted to control the motor circuit, a central switch for selecting any of said circuits, the rotation of said shaft at predetermined different speeds throwing the fluid out of engagement with its respective contacts to break the circuit selected, thereby to hold the centrifugal to different speeds.

4. In combination a centrifugal machine, a motor for driving the same, a circuit for said motor, a motor shaft, a circuit breaker for controlling the circuit of said motor and comprising a shaft, a flexible connection between said motor shaft and said circuit breaker shaft, a plurality of elongated casings mounted on said circuit breaker shaft, said casings being adjustable angularly with respect to said circuit breaker shaft and set at different angles thereto, spaced contacts in the end of each of said casings, an electric circuit for each pair of contacts for controlling said motor circuit, a body of electrically conductive fluid in each of said casings normally in contact with the spaced contacts of said casings, the fluid in said casings being thrown out of normal position by centrifugal force upon the rotation of said shafts at predetermined speeds thereby to hold the motor speed and hence the centrifugal speed to said predetermined speeds.

5. In combination a centrifugal machine, a motor for driving the same, a circuit for said motor, a motor shaft, a circuit breaker comprising a shaft, a flexible connection between said motor shaft and said circuit breaker shaft, a. plurality of elongated casings mounted on said circuit breaker shaft said casings being independently adjustable angularly with respect to said circuit breaker shaft, spaced contacts in the end of each of said casings, a body of electrically conductive fluid in each of said casings normally in contact with the spaced contacts thereof, an electric circuit for each pair of said contacts for controlling said motor circuit, the fluid in said casings being thrown out of normal position by centrifugal force upon the rotation of said shafts at predetermined speeds, whereby the speed of f the motor and hence that of the centrifugal are held to said predetermined speeds.

6. In combination an electric motor, a starting circuit therefor including a winding, a pair of switches closed by the energizing of said winding, a holding circuit for said winding including one of said switches, a main switch for said motor, a winding for closing the same, said winding being controlled by the other of said pair of switches and a centrifugal switch in series with the last-mentioned switch and with the winding for the main motor switch, whereby winding for the main motor switch will be automatically deenergized upon the motor exceeding a predetermined speed and automatically reenergized upon the speed of the motor decreasing below said predetermined speed.

FLETCHER SCHAUM.

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