US1414709A - Rheostat - Google Patents

Description

(12B. REISBACH.

RHEOSTAT.

I APPLICATION FILED APR. 2, 1921- ,4:l4,709. Patented May 2, 1922.

I I 4 SHEETS-SHEET L &'. 1,

49+ 3 4:8 z 1 L L L50 45 INVNTOR.

R1 I B. W

ATTORNEY G. B. REISBACH.

R HEOSTAT. APPLICATION FILED APR- 2', 192].

ATTORNEY saw.

6., s.. REISBACH. RHEOSIAT. v APPLICATION FILED APR- 2, I921 1,414,709; Patented May 2, 1922'.

4 SHEETS-SHEET 3.

- INVEN TOR. Qua km ATTORNEY.-

G. B.- REISBACH.

RHEQSTAT. APPLICATION FILED APR. 2, 1921- 4 SHEETS-SHEET 4.

1,414,709. I Patehted May 2,1922.

Sign 5,

- INVENTOR.

A TTORNEYV UNITED STATES PATENT OFFICE.

GUSTAV B. REISBAGE, 01 MILwAUKEE, WISCONSIN, ASSIGNOB. TO THE CUTLER HAMIMER MFG. 60., O1 KILWAUKEE, WISCOHSIN, A ,COBPORA'IIONQI' WIS- CONSIN.

Specification of Letter: Patent.

Patented May 2,1922.

Application filed April .2, 1921. sem m. 457,9so

To all whom it may concern:

' Be it known that I, GUSTAV B. Rmsnaon, a citizen of. the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Rheostats, ofwhich the following is a full, clear concise, and

exact description, reference belng had to the accompanying drawing, forming a part of this specification.

This invention relates to improvements in the crosshead or similar type driven by ,a pilot motor under the control of push button stations and having means insuring given operations of the rheostat when initiated bysuch stations .and instantaneously arresting the rheostat upon attainment of the position thcreofselected by the operative.

Another object is to provide a rheostat of the aforesaid character which will overcome the difficulties heretofore met with in effecting relatively small increments of adjustment at the will of the operative or in other words to provide a suflicient time element whereby the operative is afforded ample time to operate and release the'selected push button without overtravel of the driven element.

Another object is to provide a rheostat of the crosshead pilot motor operated type hav ing control means adapted to insure de-energization of the pilot motor and instantaneousarrest of the crosshead upon movement-of the latter into a selected position.

Another object is to provide a rheostat of the aforesaid character wherein provision is made for effecting instantaneous arrest ,of

. the crosshead in a selected position without excessive strains on the driving means.

Various other obgects and advantages will hereinafter appear.

The invention is susceptible of embodiments in various different forms one of which is illustrated in the accompanying drawings. w i

In the drawings,

' Fig. 1 is a schematicviewof a rheostat I embodying the invention;

Fig. 2 is a diagrammatic view illustrating at; modified arrangement of the rheostatconacts; Y

3 is a front elevational view of a' mechamcal embodiment of the rheostat shown 1n Fig. 1; i

4 is a side eli'avational view thereof;

Fig. 5 is an enlarged side elevational view partly in section of the driving means shown in Fig. 1;-

.Fig. 6 is a. sectional view taken substantially on lines 66 of-Fig. 4;

Flg. 7 is an enlarged vertical 'sectional view of certain of the control parts shown'in Fi 1; and i Fig. 8 is a plan view of said controlparts.

Referring to Fig. 1, the same illustrates a rheostat of the crosshead pilot motor operated type comprising two series of parallel contacts 1 and 2 over which is movable a cross-. head bridging contact 3. Said crosshead is operated by a screw shaft 4'driven, by a pilot motor 5 through a pinion 6 and gear wheel '7, the latter being operatively connected to said screw shaft by a slip pose hereinafter set-forth.

The rheostat is illustrated as controlling the continnit of a circuit illustrated by lines "M and 1' and also. as controlling resistanees R- and R in said circuit. In connection with the resistances R and R, it may be assumed that' the same are, employed for regulating the speed'of a motor and that the crosshead is adapted to be'checked in any.

the crosshead in either direction and while said motor may be-of any preferred type, it has been shown as provided with an-armature A and a series field windin This clutch 8 for a pur motor is controlled by a pair 0 reversing switches 9 and 10 for starting the same and determining the direction of operation thereof.

Reversing switches 9 and 10 are. of the double pole type, the same being biased to open position and being independently operable by windings 9 and 10 respectively. Winding 9 is controlled by a normally open push button 11 through a normally closed limit switch 12 arranged to be opened by crosshead 3 in its upper position while winding 10 is controlled by a normally open push button 13 through a normally closed limit switch 14 arranged to be opened by crosshead 3 in its lower position. Winding 10 is also controlled by a normally open relay 15 adapted to establish a shunt circuit around push button 13 and said relay is controlled by a normally open push button 16 and a normally closed limit switch 17 to be opened by crosshead 3 in its lower position.

Screw shaft 4is provided with a right hand thread and reversing switch 9 provides for operation of motor 5 in a direction whereby screw 4 is rotated in a clockwise direction for upward movement of crosshead 3, while reversing switch 10 provides for operation of the pilot motor in an opposite direction for downward movement of the crossheach While the aforedescribed control means provides for operation of the crosshead of the rheostat either direction at will and for 'arrest of the crosshead in any desired position considerable care would have to be exercised in order to stop the crosshead squarely on the desired contacts, but means which will now. be described insures against stopping of the crosshead except when centered on the selected contacts 1 and 2.

- With the contacts 1 and 2 arranged in horizontal alignment as shown in Fig. 1, screw 4 is so designed that one complete revolution thereof moves crosshead 3 a distance correspondingto center spacing of said contacts. However, if desired the contacts 1 and 2 can be staggered as shown in Fig. 2 and when the same are so arranged screw 4 is designed so that one complete revolution thereof moves crosshead' 3 a distance equal to one-half the center to center distance between the contacts or in other words from the position indicated in full lines to the position indicated in dotted lines. Thus it is apparent that during rotation of'screw 4 crosshead 3 will always assume a centered position on certain of the contacts 1 and 2 as screw 4 passes through a given angular position and to insure arrest of said screw in such angular position the rheostat is provided with a locking device 18 and a commutating device 19. 9

Locking device 18 includes a ratchet wheel 20 fixed to shaft 4 and having upwardly projecting shoulders 21 and 22 to be engaged y pawls 23 and 24 respectively when said shaft is in the aforesaid given angular position. Pawls 23 and 24 are. pivotally mounted on a shaft 25 and the same are biased downwardly ried by said shaft. W1 23 is operatively connected to the armature of reversing switch 9 through the medium of a lever 28 pivotally mounted on shaft 25 and a link 29 pivotally connecting the free end of said lever to the upper end of the armature of reversing switch 9. Lever 28 has a projecting lug 28 for engaging the under side of pawl 23 and upon closure of reversing switch 9 said lug moves upwardly to release said pawl from shoulder 21 to permit clockwise rotation of screw 4 for upward movement of crosshead 3 and upon opening of said switch said lug returns to normal position to permit return of said pawl to locking position under the action of spring 27. Pawl 24 is similarly connected to reversing switch 10 through the mediumof a lever 30, pivotally mounted on sliaft'25 and having a lug 30 for engaging pawl 24 and a link 31 connecting said lever to the armature of saidswitch.

Closure of reversing switch 10 releases pawl 24 to permit counter-clockwise rotation of screw 4 for downward movement of crosshead 3 and opening of said switch causes return of said pawl to locking position. Pawls 23 and 24 are provided with inclined faces 23 and 24 respectively, the former face serving to raise pawl 23 when shoulder- 22 passes under the same and the latter face serving to raise pawl 24 when shoulder 21 passes under the same.

Commutating device 19 includes insulated circular contact segments 32 and 33 fixed to shaft 4, the former to be engaged by oppositely disposed stationary contact finers 34 and 35 and the latter to be engaged by oppositely disposed stationary contact fingers 36 and 37. Segments 32 and 33 are so formed that when the screw shaft 4 is in its locked position the contact fingers associated with said segments disengage the same. As hereinafter setforth the fingers associated with segment 32 serve to estab lish amaintaining circuit for winding 10 through a normally open auxiliary switch 38 associated with reversing switch 10 while the contact fingers associated with segment 33 serve to establish a maintaining circuit for winding 9 through a normally open auxiliary switch 39 associated with reversing switch 9.

v The operation and circuit connections of the aforedescribed controller will now be more fully described. As aforestated, the

reversing switches 9 and 10 provide for establishment of reverse power connections for pilot motor 5. Closure of reversing switch 9, establishes a power circuit for said motor extending from line L through the left hand pole ,of said reversing switch by conductors 45 and 46 through armature A from right to left by conductor 47 through the right hand pole of said reversbly coil springs 27 car the series field F and by conductor 50 toing switch by conductors 48 and 49 through line L Closure of reversing switch 10 establishes a power circuit for pilot motor 5 extending from line L by conductors 51 and 52 through the right hand pole of reversing switch 10 by conductors 53 and -47 through armature.A from left tofright by conductors 46 and 54 through the left hand pole of reversing-switch 10 by conductors 55 and 49 throughfield F and by conductor to line L Assuming that it is desired to move crosshead -3 upwardly push button 11 is depressed to establish an energizing circuit for winding 9 of reversing switch 9. Such energizing circuit extends from line L by conductor 56 through windin 9 by conductor 57 through limit switch 12 y conductor 58 through push button 11 and by conductors 59 and 60 to line L As before set forth, upon response of switch 9 pilot motor 5 operates in a direction for effecting clockwise rotation of screw 4- and saic switch in responding releases pawl 23 from shoulder 21 to permit rotation of said screw in such direction. Crosshead 3 moves upwardly subject to opening of push button 11 and assuming that said push button is'released when crosshead 3 is in centered relation with respect to contacts 1 and 2 reversing switch 9 immediately opens and causes instantaneous arrest of screw shaft 4 by movement of vpawl 23 into engagemen't with shoulder 21. It-is apparent that upon arrest of screw shaft 4 by pawl 23 th'e motor 5 will tend to coast and slip clutch 8 then acts to friotionally overcome the acquired momentum of motor 5 to thereby prevent excessive strains on the driving means. Assuming that push button 11 is released while crosshead 3 is out of centered relation with contacts 1 and .2, segment 33 establishes a shunt maintain ng circuit around push button 11 for winding 9 which extends from line L by conductor 56 through winding 9* by conductors 57 and 61 through auxiliary switch 39 by conductor 62 through contact finger 36,

segment 33, contact finger 37 and by, conductors 63, 64 and to line L Upon movement of crosshead 3 ihto centered relation with contacts, 1 and 2 contactsegment 33 moves out of engagement with contact finger 37 to interrupt the aforedescribed maintaining circuit and reversing switch 9 then opens to arrest crosshead 3 in the manner above set forth. Upon opening of reversing switch 9, auxiliary switch 39 opens to prevent energization 6f reversing switch 9 through segment 33 and itscooperating fingers during counter-clockwise rotation of screw shaft 4. If push button 11 is maintained depressed until crosshead 3 moves into its upper limit, limit switch 12 switch 10 thereupon closes to energize motor 5 for counterclockwise rotation of screw shaft 4 and upon closure of said switch pawl 24 is released from shoulder 22 to permitsuch rotation of the screw. If crosshead 3 is 'in centered relation with contacts 1 and 2 at the instant push button 13 is released, winding 10 is immediately de-energized to cause reversing switch 10 to open, whereupon pawl 24 engages shoulder 22 to lock screw shaft 4 against further rotation and slip clutch 8 acts to overcome the acquired momentum of pilot motor 5. If push button 13 is released while crosshead 3 is out of centered relation with contacts 1 and 2, contact segment 32 and its associated fingers establishes a maintaining circuit around push button 13 for winding 10, said circuit extending from line L through winding 10 as already traced by conductors 66 and 69 through auxiliary switch 38 by conductor 70 through contact finger 34, segment 32 and contact finger 35 and'by'conductors 63, 64 and 60 to line L When crosshead 3 moves into centered relation with contacts 1 and 2, segment 32 moves out of engagement with finger 35 to interrupt said maintaining circuit and. reversing switch 10 opens to arrest screw 4 inthe manner above noted. Upon opening of reversing switch 10, auxiliary switch 38 opens to insure against subsequent energization of winding 10 by commutating device 19. If push button 13 is maintained depressed until crosshead 3 moves into its lower position, limit switch 14 is opened by said crosshead to interrupt the aforedescribed energizing circuit for winding 10;

If crosshead 3 is raised andit is desired to return the same directly to 06:1 position push button 16 is depressed to energize relay 15 through a circuit extending from line L by conductors51 and 71 through limit switch 17 by conductor 72 through winding 15 of relay 15 by conductor 73 through push button 16 and by conductor 60 to line L In responding, relay l5 establishes a shunt maintaining circuit for winding 15 around push button 16 through contacts 15 and contacts 15 thereof vestablishing an energigiag circuit for winding 10 of reversing switch 10, extending from line L through winding 10 and limit switch 14 as already traced; by

conductors 67 and 74 through the contacts 15 and by conductors 68, 64 and 60 to line L Relay 15 remains closed to maintain winding 10 energized until crosshead 3 moves into its lower limit whereupon limit switch l7 is opened by said crosshead to interrupt the energizing circuit of winding 15.

Referring to Figs. 3 to 8 inclusive, wherein is illustrated a mechanical embodiment of the aforedescribed controller, the various parts of the rheostat are mounted upon an insulating panel 75. Contacts 1 and 2 are supported by insulating panels 76 and 77 arranged in a parallel relation and mounted at rightvangles to insulating panel 75. Panels 76 and 77 are supported at their upper ends by a bracket 78 and at their lower ends by a bracket 7 9,-said brackets being secured .to the face of panel 75.' Crosshead 3 comprises a frame 80 provided with the usual traveling nut 81 and said bracket has mounted on opposite sides thereof a plurality of contact shoes 82, said shoes being of a conventional type. As is understood, the upper shoes 82 serve to control the amount of resistance included in circuit and the aforeclescribed centering means is arranged to effect centering of said upper contacts with respect to stationary contacts 1 and 2. Frame 80 is also provided with additional contact shoes on the rear thereof for engaging contacts mounted on the face of panel 75, the latter contacts being provided for controlling the field circuit of a motor.

Screw shaft 4 is rotatably mounted in bearings 83 and 84. carried by brackets 78 and 79 respectively and gear wheel 7 is rotatably mounted on said screw shaft adjacent the lower end thereof between friction rings 85-. As best illustrated in Fig. 5, the lower friction ring 85 rests on a flange 86 secured to the lower end of screw shaft 4 and the upper friction ring has a flanged member 87 bearin thereon the latter being pressed downwar ly by a spring 88. Pilot motor 5 is secured to the face of panel 75 and the reversing switches9 and 10 are of a conventional type and are arranged on opposite sides of said motor. As best illustrated in Figs. 3', 4 and 6, bracket 79 is provided with downwardly projecting. lugs 89 for supporting shaft 25 of the locking means.

Commutating device 19 is arranged'above bracket 79 and as shown in Fig. 7, said device includes a hub 90 arranged to be keyed to screw shaft 4, said hub carrying insulating discs 91 and 92 on opposite ends thereof which are secured to contact segments 32 and 33 to support the latter. As shown in Fig. 8 contact fingers 34 to 37 are each provided with a supporting bracket 93 secured to panel 75 and each of said fingers is se-- ventional type and as shown in Fig. 4 the same are mounted on the rear of panel 75 and each is provided with a reciprocablc operating member 95 extending through an opening in said panel. The operating members 95 are biased to move towards the left and are movable towards the right to open their respective switches by rollers carried by frame 80, one of said rollers being illustrated at 96 in Fig. 4.

\V hat I claim is new and desire to secure by Letters Patent is:

1. In a device of the character set forth, in combination, a power operated member having different positions of rest, control means for effecting operation of said member in opposite directions, means associated with said formermeans insuring against stopping of said member in positions other than the aforesaid positions said latter .means including means for positively locking said member in a selected position.

2, In a device of the character set forth, in combination, a power operated member movable in opposite directions and having 90 a plurality of positions of rest, control means therefor providing for movement thereof ineither direction and insuring against arrest thereof in positions other than the aforesaid positions, said control means including a '95 positive locking device adapted to act automatically to arrest said member in a selected position.

3. In a controlling device, in combination, a plurality of contacts, a power oper- 100 ated member movable into engagement with any selected one of the same, and controlling means for said member insuring substantial centering thereof with respect to the selected contact, said control means including a de vice for positively locking said member in substantially centered relation with respect to the selected contact.

4. Ina controlling device in combination,

a plurality of contacts,'a power operated 0 member movable into engagement with any one of the same, control means for said member to effect movement thereof in opposite directions, and means associated with said control means, including a positive locking connected to said switches for locking said member against movement beyond the selected contact.

6. In a controlling device in combination, a plurality of contacts, an electromag netically operated member movable into engagement with any one of the same, reversing switches operable selectively to effect movement of said member in opposite directions, selective control means for i said switches including means for preventing topping of said member in positions between said contacts and a locking device mechanically connected to said reversing switches for arresting said member-to insure substantial centering thereof with respect to a selected contact. I

7. In a controlling device in combination, a plurality of contacts, a. contact member movable into engagement with any one of the same, a reversible electric driving motor for eifecting operation of said member in opposite directions, control means for'said motor, means associated with said control means for insuring de-energization of said motor and simultaneous arrest of said memher when the latter is brought into centered relation with a selected-contact and means for frictionally overcoming the acquired momentum of said motor upon arrest of said member. I

8. In a controlling device, in combination, a plurality of contacts, a contactmember movable in opposite directions into engagement with any one of the same, an adjusting screw for said member, a reversible electric driving motor, a driving connection between said motor and said screw including a slip clutch, control means for said motor, and means associated with said control means for insuring interruption of the power cir-. cult of said motor and simultaneous lock-.

an electric driving motor therefor, sepa rately operable electro responsive switches for starting said motor in opposite direction for reverse adjustments of said rheo-' stat, selective control means for said switches to direct operation of said motor and adjust mentof said rheostat, means associated with -.'said rheostat to insure energization of said switches independently of said former means i when said'rheostat is in any other than predetermined positions of rest and to insure de-energization of said switches in such positions of rest, and means actuated by said switches upon opening thereof forlocking said rheostat in said positions of 'rest.

10. In combination, an, adjustable rheoan, electric driving'motor therefor, separately operable electro-resp'onsive switches rect operation of said motor and adjustment of said rheostat, means associated with" said rheostat to insure ,energization of said switches independently of said directing means when said rheostat is in any other than predetermined positions of rest and to insure de-energization of said switches in such positions of rest, means actuated by said switches upon de-energization thereof for locking said rheostat in said positions of rest, and means for frictionally overcoming the acquired momentum of saidmotor upon locking of said rheostat.

11. In a device of the character set forth in combination, a contact member movable in opposite directions to any oneof a plurality of positions of rest, an operatingscrew therefor adapted during each revolution to move said member to a degreecorresponding tothe distance betweensuch positions,

a reversibleelectric driving motor for said in opposite directions to any one of a'plura-lity of positions of rest, an operating screw therefor adapted during each revolution to move said member to a degree corresponding to the distance between such positions, a reversible electric driving motor for said screw, control means for said motor for effecting operation ihereofin either direction and for insuring against de-energization thereof until said-member moves into the selected position of rest, means associated with said control means for positively locking said screw for arrest of said member 1n the selected position, and means for frictionally overcoming the acquired momentum of said motor upon locking of said'screw.

'13. In a rheostat, in combination, a contact member movable in opposite directions to any one of a plurality of positions of rest, -'an operating screw therefor adapted during each'grevolution to move said member to a degree corresponding to the distance between. jsuch positions, an electric driving motor for said screw, control means for said motor including a pair of reversing switches operable selectively to efl'ect ad3ustment of said contact member in opposite directions, means associated with said control means for insuring against opening of said reversing switches except upon movement of said member into a selected position of rest, and locking means directly connected to said reversing switches and adapted upon opening of the latter to lock said shaft in a predetermined angular position to prevent movement of said member beyond the selected position.

14. In a rheostat, in combination, a contact member movable in opposite directions to any one of a plurality of positions of rest, an operating screw therefor adapted during each revolution to move said crosshead to a degree corresponding to the distance between such positions, a driving motor, a driving connection between said motor and said screw including a slip clutch, a pair of reversing switches for said motor operable selectively to move said crosshead into a selected position of rest, and locking means associated with said reversing switches for arresting said screw upon movement of said crosshead into a selected position, said slip clutch acting upon arrest of said screw to overcome the acquired momentum of said motor.

15.In a rheostat, in combination, a contact member movable in opposite directions to any one of a plurality of positions of rest, an operating screw therefor adapted during each revolution to move said member to a degree corresponding to the distance between such positions, a driving motor, a driving connection between said motor and said screw including a slip clutch, control means for said motor including a pair of reverslng switches operable selectively to establish reverse power connections for said motor for adjustment of said contact memher 111 opposite directions, means for looking said screw in a given angular position for arrest of said contact member in the selected position, said means including a ratchet member secured to said screw and cooperating pawls respectively connected to said reversing switches, each of the latter being releasable from said ratchet wheel upon closure of its respective switch and being adapted to lock said screw against movement upon opening of said switch.

16. In a rheostat, in combination, a movable contact element having a plurality of positions of'rest, an operating screw therefor adapted during each revolution to move said member to a degree corresponding to the distance between said positions, a driving motor, an operating connection between said screw and said driving motor including a slip clutch, control means for said motor adapted to effect operation there of in opposite directions, and means as sociated with said control means for arresting said screw in a given angular position for arrest of said element, and for simultaneously de-energizing said motor, said slip clutch acting upon arrest of said screw to overcome the acquired momentum of said motor.

17. In a rheostat, in combination, a movable contact element' having a plurality of positions of rest, an operating screw therefor, a driving motor for said screw, a pair of reversing switches for establishing reverse power connections for said motor, control means for said switches, including means for insuring opening of said reversing switches upon movement of said contact element in opposite directions to given limits, and means insuring against opening of said reversing switches upon positioning of said contact element between said positions of rest and provding for positive locking of said screw in a given angular position to insure against overtravel of said member beyond the selected position.

18. In a rheostat, in combination, a power operated contact element having a plurality of definite positions of rest, control means for directing adjustment of said element from one position to another and requiring manual retention of a part thereof to effect continuous operation of said element through any of said positions, said means including means insuring movement of said element into one of said definite positions upon release of said manually retained part in any intermediate position of said element and additional control means acting upon momentary operation of a part thereof to effect continuous operation of said element through a number of said definite positions to another of said positions.

In witness whereof, I have hereunto subscribed my name.

GUSTAV B. REISBACH.

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