US2826728A - Reversing machines for regenerative ovens or the like - Google Patents

Description

March 11, 1958 H. HEINE ET AL 2,826,728

REVERSING MACHINES FOR REGENERATIVE ovENs 0R THE LIKE Filed Jan. 5, 1951 l3 SheetS-Sheet l NVENTRS.

March 11, 1958 H. HEINE ET AL 2,826,728

REVERSING MACHINES FOR REGENERATIVE OVENS OR THE LIKE Filed Jan. 5, 1951 5 sheets-sheet 2 March 11, 1958 H. HEINE ET AL 2,826,728

REVERSING MACHINES FOR REGENERATIVE OVES OR THE LIKE Filed Jan. 5, 1951 3 Sheets-Sheet 3 United States Patent Olice 2,826,728 Patented Mar, 11, 1958 REVERSING MACHINES FR REGENERATIVE OVENS 0R THE LIKE Heinrich Heine, Essen-Borbeck, Germany, and Friedrich Koppitz, deceased, late of Essen, Germany, by Engeiine Koppitz, executrix, Dusseldorf-Heerdt, Germany, assignors, by rnesne assignments, to Koppers Company, Inc., Pittsburgh, Pa., a corporation of Delaware Application January 3, 1951, Serial No. 264,238 8 Claims. (Cl. S18-283) The invention relates to an electrically driven unit for the timing of the reversing machine of regeneratively operated coke ovens, regenerative heaters or the like, comprising an automatic rotor switch unit for the interruption ot' the reversing machine, wherein the rotor switch is synchronized with the main shaft of the reversing machine T he switch gear for reversing machines in previously known constructions was usually connected through its individual members with the reversing machine and its driving motor. Such an arrangement necessitated a complicated wiring system and considerable installation costs. If in addition the reversing machine happened to be stationed in a place where it was exposed to gases as is the case where it is used in combination with gasheated coke ovens, the danger of explosion owing to sparking at the electrical contacts in the switch gear necessitated either the use ot very long lines and wires which were located outside rooms which were liable to permeation by gas, or of a suitable protective covering or casing for those members in the switch unit which were likely to produce electrical sparks during the operation. Such explosion proof protective covering or casing of the individual spark producing members in the switch gear caused an additional increase in production costs.

The present invention provides a material simplification in the known arrangement of the switch unit for reversing machines, consisting in that the rotor switch, connected with the main control shaft either directly or by means of a transmission gear, together with the remaining switch elements and all contacts, are housed in one single housing which is attached as a whole unit to the supporting structure of the reversing machine.

Such an arrangement of the switch unit in accordance with the invention will eliminate a great deal of assembly work of individual elements including complicated wiring at the site of installation. In accordance with the invention the switch unit is manufactured in serial production at the workshop complete in its housingand including all contacts, wires and other elements so that at the actual site of installation it requires only toY be connectedwith the main electrical conduit on one side of the unit and with the main cam shaft of the reversing machine. on the other side of the unit.

lf desired, or necessary in view of special conditions, the switch unit can be made completely explosion proof by being filled with oil. However, the unit can also be made explosion proof against fire-damp by a suitable reinforced pressure-resisting casing in conformity with oficial safety regulations on this subject.

According to a further feature of the invention the housing in which the switch unit is contained has connection on its upper side with a second housing, with cable conduits leading into said second housing, at the bottom of which are also provided.V the terminals for those wires whichl are to connect the switch device with the control means. Lastly this easily accessible housing comprises a lever which is arranged on a hollow sleeve around the driving shaft of the rotor switch, and this lever is connected with an emergency disconnector for the rotor switch, which is also in itself a feature of this invention.

In accordance with the invention this emergency disconnector automatically disconnects the driving motor from the electrical supply in the event the magnetic interrupi-or, which controls the supply of electric current to the motor, does not return into its initial cut-out position after the reversing operation for the heating system of the oven has been duly completed. If this should occur tl driving shaft of the rotor switch must be turned back after the upper housing has been opened so that the contact elements to be actuated by the driving shaft can be rte-engaged with their associated segmental cams on the driving shaft, and it is not necessary to interfere in any way with the explosion-proof primary switch housing.

One embodiment of the invention is diagrammatically illustrated by way of example in the accompanying drawings in which:

Figure l represents the reversing associated switch unit complete in its housing.

Figure 2 is a vertical sectional view through a switch unit as employed in Figure l and built in accordance with this invention.

Figure 3 is a vertical section through the same switch unit along the line H-H in Figure 2.

Figure 4 is a horizontal sectional View through the automatic disconnector along the line llllll in Figure 2.

Figure 5 is wiring diagram of the whole driving unit.

In the illustrated construction, shown as one embodiment of the present invention, it is assumed that the unit is used in combination with a regeneratively heated coke oven battery which is operated by lean gas (i. e. low caloriric value gas) wherein one set of gas valves are initially closed to 01T position at each reversing of the heating system and wherein the opening to on position of another set of gas supply valves, then in oil position together with the adjustment of all other valves (air and waste heat gas) is effected only after a short purge interval has elapsed in order to allow for complete combustion of all the heating gas still contained in the regenerate-r before the ott gas valves are turned on.

As will be seen from Figure 1 the main reversing shaft lill of the reversing machine is mounted on a supporting structure lill?. Said shaft 101 is driven by a motor 39 which motor is connected to shaft 101 through a transmission unit and gear wheel ltlZ. Segmental cams ll, rtl4, i535, are also keyed to this main shaft 101, said cams, according to their respective positions, acting upon levers tlti, lli?, 198 disposed on the one side of the cam shaft ll as well as a number of auxiliary levers ld?, ttl, lll, disposed on the other side of said shaft itil. Said levers are supported at their lower ends at M3 in brackets which are fastened to the supporting structure itl@ whilst they are connected together in pairs by rods .H2 extending horizontally at the upper level of the auxiliary levers 109, 110, 111. The upper ends the long levers 165, 107 and 108 are connected at to chains or the like which lead to the respective valves Lo be reversed thereby in the regenerator heating system of the oven battery.

The lever idd is connected by its chain with one set of the lean gas valves at one side of an oven battery whereas the lever 107 is similarly connected by its chain with the other set or" lean gas valves at the other side or" the oven battery` The lever w8 is connected to the waste heat and air valves of the oven battery by means of a rope or other actuating member which extends around or along both sides of the battery.

machine including the the gas valves of the corresponding side or" the oven battery are closed. After a shor purge interval during which all the gas contained in the regcnerators oi this battery side has been completely burnt, the cam shari ltil continues its rotary movement thereby causing the cam ltll to press against lever i537 and cam against side lever ltiS whereby the gas valves on the opposit of the battery are opened, and the air and v gas valves are adjusted accordingly throng battery.

These operations are controlled by a switch unit which times the driving of the motor 3l) and gea vheel for the cam shaft it, said switch unit ll being located in a housing i715 Fig. l. Said housing i' supported by a bracket lig forming part of the supporting structure lili?. The rotor switch il which is disposed within s. d housing ll is connected to the cam shaft lill by a flange 2li on the rotor switch shaft 23. At each reversing operation ot the heating system the direction of rotation of the motor 34B for gear wheel le@ is reversed and the aforesaid levers idd-i528 are actuated accordingly reversely to the direction of the previous operation.

The switch unit is shown in detail in Figures 2, 3 and fl..

A supporting frame 3 is removably located within the housing l, 115, the bottom of said housing being marked 2 in Figs. 2 and 3. Said supporting trarne 3 is suspended from the top 4 which top t constitutes at the same time the bottom of a smaller housing 5. Said housing 5 is closed by a lid 05, the lid o being adapted to be opened and closed about a hinge 7. The lid 6 is fastened by a screw 8 which can be operated by a suitably shaped key.

The top d of housing l and the lid 6 of housing 5 are both provided at their lower edge with recesses 9 containing resilient sealing means. The top d which also constitutes vthe bottom of housing 5 is fastened to the housing l by means of pins or screws l.

The housing l, lle essentially contains the following members:

The rotor switch 1l, the magnetically operated interrupter members l2., l and the timing device On either side of the housing 5 (Figure 3) there are provided cable conduits l5, le for the reception and protection of the supply cables which contain the necessary phasc Wires for energising the dilerent circuits required for the various operations. These wires (Fi which, for simplicity, are not shown in Figs. 2, 3, 4 or' the drawing, are connected to terminals i7 (Fig. 3) which are secured to the bottom 4 of housing 5 and respectively connect the main supply wires with the rotor switch ll, the magnetically operated interrupters l2, i3 and with the timing device ld. rPhe housing l is iilled with oil up to a level which is indicated in the drawing by line (Figures 2 and 3) that is to say, the uppermost contact point which is liable to produce electrical sparks is still fully submerged and covered by at least 6C- mrn. (approximately 23s inches) of oil. A sight glass l? is provided for maintenance of this oil level i3 which can be replenished through an opening which is closed by a plug 2li.

The magnetic interruptor 1.2 provides the contact between the electric line main and those lines which cause rotation of the driving motor for gearwheels N2 in one direction of rotation, whereas the magnetic i rupter 13 closes the circuit between the electric line main and those lines by which the motor for gearwheel liZ is driven in the opposite direction of rotation.

Accordingly the rotor switch ll is provided with sag- 4 mental cams 2l which make contact with associated contact elements which are not shown in Figs. 2 and 3 of the drawing. Said contact elements are secured to insulated holders 22.

Ffhe horizontal shaft is connected through flange 24 with shaft 161 and extends from outside the housing ll, through one ot its side walls into the upper housing 5 and serves to transmit the rotary movement the main earn shaft ibi of the reversing ina-chine (r N re l) by means of a bevel gear drive 2o to a vertical shalt 25, the latter extending through the bottom of housing l, 5 into the lower housing where it is connected to drive the rotor switch ll.

The switch unit operates as shown in detail on the wiring diagram in Figure 5.

The main electric conductors S. T. can be broken by an interrnpter rEhe conductors supply current to the motor 3d which, through gearwheel ith?, drives the main cam shalt lili. (Figure l) of the reversing machine as well as the shaft 23, 25 of rotor switch vl, 29 connected therewith in the above described manner. in addition conductors R1, S1, T1 are connected with said driving motor 36, a further Yinterrupter 32 being included in the line so that the phases ll and S are now interchanged in such a manner as to reverse the direction of rotation of the motor.

Upon pressing button 33 an auxiliary circuit obtains current which leads from the phase wire T to the contact cam 37 of the rotor switch fil, 29 via lines 34, press button 33, magnet coil 3S (which is associated with the interrupter 3l) and bridge contact 35, the latter being connected with interrupter 32 as well as over a further contact element which is not shown in the drawing.

The segmental cam 37 has connection with cam 3S and this, by virtue of the connection of contact elements with cam 39, is in turn connected to cam f2-ii. The current is conducted from cam ttl along lines fil to phase wire S. Y

ln this Way the magnet coil 35 is energised, the armature Vcore is drawn up whereby the interrupter 3l is closed. The bridge contact 42 which is associated with interrupter 3l breaks the flow of current through a further auxiliary circuit comprising the magnet coil 43 and its associated interrupter 32, thus preventing said auxiliary circuit from being energized at this stage.

Assuming that the rotor switch 11, 29 is now rotated in the direction of yarrow 44 by the motor 30 and with the aid of the main shaft 45, lill of the reversing machine (101 in Figure 1) to which it is connected, it follows that thecontact elements which are associated with segmental cams 38 and 39V will be moved out of reach of these cams after the gas valves in the oven battery have been closed by their respective levers 106 (Figure l) on the reversing machine. As soon as the said contact elements are disengaged from their associated cams the current supply to auxiliary circuit 35, 34, 41 is interrupted, and the core of magnet coil 35 drops back into its initial position, whereby the current supply to motor 30 is similarly interrupted. Thereupon the bridge contact 42 closes again which provides the means for closing the interrupter 32 by its associated magnet coil 43 whose energization from the said auxiliary circuit is dependent on said bridge contact 42. However, this auxiliary circuit will not be supplied .with current until the timing device 46 which is actuated by a motor 47 has completed its predetermined period.

When the rotor switch 29 and with it the cam shaft of the reversing machine stop moving, the closing of the gas valves is completed. The necessary purge interval which must elapse before the other valves can be adjusted in the heating system of the oven is determined by the correspondingly ladjusted timing device 46 whose associated motor 47 receives power after the rotor switch 29 has stopped moving. The supply of current to the motor 47 is established in the following manner:

As soon as the associated contact elements of cams 38, 39 are disengaged from said cams, contact is established between the contact element of line48 and another cam 27, said cam 27 being conductively connected with cam 40. Consequently the :current flows from phase wire S via line 41, cams 27 and 40, line 48, motor 47 and lines 49, and 34 to phase wire T.

After the timing device 46 has completed one period the trip switch 59 closes the lines 51, 52. The current now flows from phase wire S via lines 41, 52, 51, cams 53, 37, lines 34 and associated magnet coil 35 and press button switch 33, to phase wire T. 1n this way the interrupter 31 is closed again. Consequently the driving motor 3i) continues to rotate the rotor switch 11, 29 in the direction of arrow 44. By the time the co-operating contact element is disengaged from cam 37 the reversing machine has completed the movement of all valves. The current supply to magnet coil 35 is now interrupted and the interrupter 31 cut out once more.

The operative stages involved at the next reversal of valves are performed in a similar manner, whereby the motor 3Q and rotor switch 11, 29 is caused to rotate in the opposite direction, which is achieved upon reversal of switch 33 with the laid of magnetic interruptor and associated coil 32.

If however, owing so some fault or break down, either of the magnetic interrupters 31 and 32 does not return to its initial position after the associated magnet coil has been de-energized, it would mean that the driving motor 30 would continue to rotate after all oven valves have been adjusted. In order to prevent this an automatic emergency switch (Figure 5) is provided to disconnect the motor from its electrical supply. Said emergency disconnector comprises a switch 54 in lines RT and ST which is slidably secured to the end of a hollow sleevelike shaft 55 around the shaft 25, which is driven through main shaft 101 by the motor 30. The opposite end of said hollow shaft 55 terminates in a right-angle hook end 56 which engages with a correspondingly shaped rightangle lever 57, this lever being pivoted about 5S and subject to the pressure of spring 59. If now the rotor switch 11, 29 is rotated beyond the stage at which the valve adjustment is completed and either of the magnetic interrupters 31, 32 fails to break the circuit, the rotating eccentric element 8).which is keyed on the drivin-g shaft 25 of the rotor switch presses the said right-angle lever S7 out of engagement with the right-angle hook endv 56 of the hollow shaft 55. Thereupon the pressure of spring 6) urges the interrupter 54 away from the associatedV contact surfaces,'thus 'effectively breaking the main circuit.

One preferred practical constructional application of the said automatic disconnection device as shown diagrammatioally in Figure 5, is illustrated in Figures 2, 3 and 4. A loose sleeve-like hollow shaft 61 is disposed on the driving shaft 25 of the rotor switch, said hollow shaft being at its lower end rigidly connected to a disc 62 of electrically non-conductive material and said shaft 61 extending with its upper portion through the top 4 of housing 1. Inside of housing 5 this hollow shaft 61 is firmly yconnected to a lever 63. In addition, the hollow shaft 61 is connected with a further disc 64 of the same dimensions and configuration as disc 62 and slightly spaced therefrom. Contact rods 65 are provided between the two discs 62 and 64. Contact elements 66, 67 are fastened to contact holders 22 and are in contact with the said contact rods 65, and placed in the line of two phases of the main wires leading to the driving motor 30 of rotor switch 11. A horizontal cylindrical housing 78 (Figure 4) is fastened to the frame 3 and this housing contains a spring 68 acting on a bolt 69 which extends out of the housing 78 at the lower side thereof. Said bolt 69 is axially slidable in a slot in the housing 78, which slot cannot be seen in the drawing since it is disposed at the 6 underside of the housing. The protruding end of the bolt under pressure of the spring 68 is engaged in a recess provided in the circumference of disc 64. In this way the disc 64 is held in the position shown in Figure 4.

A torsion spring 70 is arranged on the hollow shaft 61 between the two discs 62 and 64, the end 71 of which torsion spring is supported on the frame 3 whilst the opposite end 72 is supported on a pin 73 which is connected with the discs 62 and 64. This torsion spring 70, when in the position shown in Figure 4 is under tension in such a manner that it acts upon the retained discs 64 and 62 in the direction of arrow 74.

Another disc 79 is firmly secured to the shaft 25 of the rotor switch at a position slightly below the disc 64, and this disc 79 carries crescent-shaped boss plates 75 and 76. These plates have laterally curved engaging surfaces and are fastened by small pins in holes 77 around the circumference of disc 79. The relative distance between these boss plates and 76 and the bolt 69 is adjusted so that when the disc 79 rotates the respective boss plates strike the bolt 69 only when the rotor switch 11, 29 continues moving after all the valves in the regenerative heating system have been operated, that is to say in the event of a break down `or failure of the particular magnetic interrupter, 12, 31; 13, 32, concerned, as shown in the wiring diagram in Figure 5. In this event, the boss plate 75 strikes the lbolt during rotation of the rotor switch in one direction of rotation, and plate 76 strikes it during the other direction of rotation. The impact of these plates presses the bolt 69 out of the recess in the disc 64 where it is located thus releasing discs 62 and 64 which are now rotated in the direction of arrow 74 under the stress of the torsion spring 7G. In this way the contact elements 66 are disengaged from contact rods 65 thus cutting out the phase in which they are positioned and disconnecting the driving motor 30 of the rotor switch 11, 29, and of the reversing machine shaft 101 from the electric supply R. S. T.

After the failure of the magnetic interrupters 12, 13, 31, 32, has been repaired, the reversing machine shaft 101 and synchronized rotor switch 11, 29, are turned backwardly in order to bring the respective boss plate 75 or 76 back into a position out of engagement with the bolt 69. After that, it is possible to re-tension the torsion spring 70 by means of lever 63 which is accessible from the upper housing 5, until the bolt 69 once again is engaged in the recess in disc 64, thus retaining in position the respective discs 62 and 64 and re-establishing the contact between contact rods 65 and Contact elements 66, 67.

It is obvious that various changes may be made in details within the scope of the claims without departing from the spirit of the invention. It is, therefore, to be understood that the invention is not to be limited to the specific details shown and described.

What is claimed is:

l. A spark-proof electrically driven switch gear unit for timing the operation of reversing machines for regeneratively operated furnaces in which a rotary shaft of the reversing machine is driven by an electric motor served by a source of electric power by outside phase lead lines, comprising: a housing adapted to be mounted adjacent the reversing machine; a supporting frame structure for electrical switch gear equipment removably positionable within said housing as a single unitary whole and adapted to be sealed within the same when positioned therein; a rotor switch, magnetically operated interrupter means, and a timing device, all mounted on said supporting frame for insertion and removal as a unit with said frame into and out of said housing; said rotor switch having a driving connection arranged in said supporting structure and a driven member extending outside the housing for connection with the rotary shaft of the reversing machine to be driven thereby, for operation of the rotor switch in synchronism with such a motor driven rotary shaft, when the rotary shaft of the reversing machine is operated by the motor outside the housing, and said housing having conduit means for reception of the ends of outside phase lead lines leading thereto from a source of electric power outside the housing and leading therefrom to such a said motor outside the housing, and terminals in the housing for attachment of the ends of said outside phase lead lines; electric motor circuit lead lines arranged in the supporting structure and including phase lead lines leading to and from the interruptor means to the terminals in the housing for connection with the outside phase lead lines; an initial energizing branch circuit of lead lines arranged in said supporting structure and connecting the phase lead lines and the magnetically operated interrupter means to initially energize the latter; a second branch circuit in cluding a time delay switch arranged in the supporting structure and likewise connecting the phase lead lines and the magnetically operated interrupter means, to subsequently energize the interruptor means at an interval of time after the initial energization of the same by the initial energizing branch circuit, and a third branch circuit arranged in said supporting structure and connecting the phase lead lines with the timer to energize the latter to operate the time delay switch; and connections on said rotor switch located Within said supporting structure for opening and closing said branch circuits in the housing in timed relation when the rotor switch within the housing is driven by the rotary shaft outside the housing on operation of its said motor by the closing of the magnetically operated interrupter means inside the housing.

2. Apparatus as claimed in claim 1, and in which the electric motor circuit lead lines and magnetically operated interruptor means in the supporting frame comprises a motor reversing circuit with a plurality of interrupters therefor, and in which the rotor switch has connections for energizing of the plurality of interrupters sequentially for the reverse operation of the motor as well as connections for the second and third branch circuits for the timed delay reverse operations of the motor.

3. Apparatus as claimed in claim 1, and in which the switch-gear is submerged in oil within the housing.

4. Apparatus as claimed in claim 1, and in which an emergency disconnecting device is connected to the rotor switch and is arranged in the supporting frame in the housing for disconnecting the driving motor circuit in case `of a failure of the magnetic interrupter means, said device comprising tappets operable by the over-running of the rotor switch for operating the disconnecting device.

5. Apparatus as claimed in claim 4, and in which said emergency disconnecting device also comprises a spring loaded member having contacts which are normally retained in circuit in contact positionrby locking means, said locking means being releasable by said tappets on overrunning of the rotor switch for movement of the contacts out of contact position by the spring action of the spring loaded member. Y n

6. Apparatus as claimed in claim 5, and in which the emergency disconnecting device is secured to a shaft extending through the housing, which shaft carries a resetting lever outside the housing for resetting the emergency disconnec-ng device.

7. Apparatus as claimed in claim l, and in which the housing comprises a primary chamber and a secondary chamber, the secondary chamber being adapted to be opened, closed and locked, and being disposed above and g the primary chamber, the bottom of the secondary forming the top of the primary chamber, and the connecting terminals for the lead lines and the conduit means for the housing being disposed in the secondary chamber for access thereto without opening the primary chamber in which the rotor switch, magnetically operated interrupter means, and the timer, as well as said circuits are sealed.

8. Apparatus as claimed in claim 7 and in which an emergency disconnecting device is connected to the rotor switch and arranged in the supporting frame in the primary housing chamber for disconnecting the driving circuits or the motor in case of a failure of the magnetic interrupter circuit means, said device comprising a spring loaded member having contacts which are normally retained in circuit in contact position by locking means, and tappets operable by the over-running of the rotor switch for releasing the locking means for movement of the contacts out of contact position under the spring action of the spring loaded member, a shaft secured to the disconnecting device and extending from the primary chamber into the secondary chamber and a resetting lever in the secondary chamber for manipulating the shaft to reset the emergency disconnecting device in the primary charnber of the housing.

References Cited in the tile of this patent UNITED STATES PATENTS

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