US2512880A

US2512880A - Electrical controlling apparatus

Info

Publication number: US2512880A
Application number: US24622A
Authority: US
Inventors: John D Russell
Original assignee: Joy Manufacturing Co
Current assignee: Joy Manufacturing Co
Priority date: 1948-05-01
Filing date: 1948-05-01
Publication date: 1950-06-27
Anticipated expiration: 1967-06-27

Description

June 27, 1950 J. D. RUSSELL ELECTRICAL CONTROLLING APPARATUS Filed May 1, 1948 74 wif 2 Sheets-Sheet l June 27, 1950 J. D, RUSSELL 2,512,880

ELECTRICAL coNTRoLLING APPARATUS Filed May 1, 1948 2 Sheets-Sheet 2 nveza: @/0222212 Zai/551922.

Patented June 27, 1950 2,512,880 ELECTRICAL CONTROLLING APPARATUS .l'chn D. Russell, Franklin, Pa., assigner to Joy Manufacturing Compan corporation of Pennsylva y, Pittsburgh, Pa., a nia Application May 1, 1948, Serial N o. 24,622

20 Claims.

My invention relates to electrical controlling apparatus, and more particularly to motor reversing apparatus having means for preventing destructive arcing.

An object of my invention is to provide an improved motor reversing apparatus. Another object is to provide an improved motor reversing apparatus for preventing arcing. Still another object is to provide an improved motor reversing apparatus associated with a motor having a pilot circuit and including means for interrupting the pilot circuit before the reverse switch elements receive any movement. A further object is to provide an improved reversing apparatus having improved means for eliminating arcing. Still a further object of my invention is to provide an improved motor controlling and reversing apparatus having separate control elements for respectively separating and moving to diierent relations for reverse operation, the contact elements of a reverse switch. Yet another object of my invention is to provide an improved reverse switch mechanism having separate control elements one for separating reverse switch contacts and another for changing their relative positions to eiect reverse operation, with means coacting with said elements to hold said second element until the first element has eiected the separation it is adapted to accomplish. Other objects and advantages of the invention will hereinafter more fully appear.

In the accompanying drawings, in which one illustrative embodiment of my invention is shown for purposes of illustration,

Fig. 1 is a wiring diagram showing the controlling apparatus cf the invention in use in a simple circuit.

Fig. 2 is an end view, the pilot switch end view, of the controlling apparatus.

Fig. 3 is a longitudinal sectional view on the plane of the line 3 3 of Fig. 2.

Fig. 4 is a similar View showing the parts in a different position, a position with the pilot circuit broken and connections for resistance arc elimination effected.

Fig. 5 is a vieW similar to Figs. 3 and 4, showing the parts in still a different position with the movable reverse switch contacts separated from the relatively stationary contacts and the parts in position for effecting a reversal of the motor connections.

j Fig. 6 is a transverse section on the plane of the line 6-5 of Fig. 3.

Fig. 7 is a transverse section on the plane of the line I-'I of Fig. 3.

Fig. 8 is a view similar to Fig. 6 showing the parts in a different position.

Fig. 9 is a View similar to Fig. 7 showing the parts in a different position.

Fig. 10 is a transverse sectional View on the plane of the line I -I 0 of Fig. 3.

For the purpose of illustrating the invention in use, I have shown in Fig. 1 a very much simplified wiring diagram showing the control system for a direct current motor of such size that the progressive cutting out of resistance during motor starting is unnecessary, and I have omitted certain conventional protective devices, such as overload protection means, to keep the drawing as simple as possible.

The power lines I and 2 are connectible respectively with

conductors

3 and 4 by switch elements 5 and 6 which are connected for movement together by an appropriate connecting element 'I of insulating material. An armature 8 is adapted under force exerted thereon by a solenoid 9 to control the movement of the switch including the parts 5, 6 and 1, which switch may be characterized as a main line switch. The conductor 3 is connected to the series eld II of a motor I2, and also to the shunt Iield I3 of such motor. The armature of the motor I2 is designated I4, and has associated with it a commutating winding I5. A conductor I6 connects the shunt field to the conductor 4. At I8 there is diagrammatically shown in Fig. 1 the reverse switch mechanism which constitutes the subject matter of this application. It will be observed that this has a contact 25 connected to the conductor 4; another contact 2I connected by a conductor 22 to the end of the series eld which is not connected to the conductor 3; a contact 23 connected to the commutatng winding I5; and a contact 24 connected by a conductor 25, through appropriate brush means, with the armature I4. A pilot switch element 2E, ringlike in shape and constituting a conductor and contact element and forming a portion of the apparatus later more fully described in detail, is adapted to connect stationary contacts 21 and 28, of which 21 is connected by a conductor 29 to one end of the solenoid 9, while 28 is connected by a conductor 30 to the power line I. The other end of the solenoid 9 is connected to a conductor 3| between which and a further conductor 32 connected to the power line 2 there are arranged a suitable starting switch 33 and a suitable stop switch 34, both illustrated as of the push button type. These switches are connected by a conductor 35 which is connected in turn by a condiictor 36 to a contact element 31 which is connectibl-e by 'a movable contact 38 with another contact element 39 connected as at `Ml to the conductor 3|. The contact element 38 is connected by a suitable non-conducting element di with the solenoid 9.

The mode of operation of this structure will be understoodv without extensive `description. Upon closing'movement of the starting push button 33 a circuit will be established from power line 2 through conductor 32, stop switch 34, conductor 35, start switch 33, conductor 3 1, solenoid 9, conductor 29, then-

closedpilot'switch

21,25, 28, and conductor 38 back to the' power" line I.

When the main line switch ris moved `to 'closed-' position, the interlock 33 will move with it and establish a holding circuit through the solenoid by which the starting push button switch 33 and a portion of the conductor 3l will be shunted 4by the conductor 36, interlock switch 3l, 38, 39 and `the 'conductor .46.. Then'funtilthe' stop switch 34 is opened, with the structre'il'lu'stratedthe niain l'ine switch vwill be maintained closed even though the switch 33"is'a'llowedto "openj 'On closure of the mainline switchythe motor IZ'will operate in one direction or" the other, Idepending upon .th position" of "the reversejswitch ymechanism mythe` diierent lpositions '"of this reverse switch beingleiective selectively `to con'nect' contacts`2ll'and '23"and"contacts' 24 and 2|"to'e'ie'ct motor "rotation" in one direction; and contacts 2@ andr 24`..and`contacts 23 and '2| to'eiec't'motor rotationinthe"other direction. :Whenever the reverseswitch is' torbe moved,`the'pilot"switch 26 will be opened, as willlate'r beunderstood, re-

sulting in breaking the circuit throughthe solenoid 9A and movementto open po'sitionof'themain line 'contacts 5 and 6.

Now'turn'ing morep'aiiticularly to Figs. v2 to' 1D inclusivefit will be. observed thatthe improved controlling 'apparatusv thereindisclosed includes aj Icasing 50 'providing a chamber 5 Vth'ereinV v"and havingspaced-'from itsf shell by aseries of 'insulatngspools``3 a'plate of insulating material a54. The lit'il 'and z`S`D`01S '55"`a1ehe1d`to Athe shell 5`Uby screws 52. The'pl'ate'54 carries'suit- 'ably fXdfWth lfspectto"t,"`and herein ndicated 'as' constructed Vir'itegrally with it;- a' series ofrpur'sek'etluke" members'- 55A; 55Bfs5c-and 55D each' of sai'dsocket members Thaving formed therein abore 55 withwhich there `communicates adopening" 51 of smaller diameter extending through -they plateVA member 54. Yieldably` supportedin"eachl of the bores'ES vis ai contact element 58, fthese contacteleme'nts being" respectively desyigriated KI,"K2,`K3, and K4. Each of these contact m'mbers" Kl`, K2, K3 and'K includes a AStem portionv Si' having a connector A,device 'EvZjTfor lSfecuri'ng al conductor to it' at' oneend of-` itand a cupped` herein generally cbnicallyf bored, Contact element' proper "63, the boreofWhich is dsignated'. The fcontact elements Kl, K2, K3 and K4 1nay "be regarded asV lthe relatively stationary contacts `in that'they are stationary "except for theiryielding mountings, and it Vwill"` be' under` stood ythat" 'these' contact elements" may, in 'the orderme'ntio'ned, beconsidered to be" connected, 'for'illustratiom to the'conductor il, to lthe-'commutating winding`l5, to the 'conductor 22, and to the conductor'25.

"There are' "four I movableV contacts`"ada`pted to cooperate with lthe stationary'cohtacts KLKZ, K'andKd to ei'ect' motor reversal, and! these movable .coitactsare resp ectively designated C I C2, C3, 'and C4; "Eacli'has'a"c01allrntact`sur The movable contacts Ci, C2, C3 and Cit and their conductor bars are adapted to connect the YArelatively stationary contacts KI and K2 and the relatively stationary contacts K3 and KQ to effect the contactsKl and K4 and the contacts K2 and 'ii'l'otofr't'ationin one direction, and to connect 33, `in ajQO"turned position of the plate 68, to

eiectreverse operation of the motor.

` The plate 5ft also has secured to it by suitable clamping and conductor attaching devices 1|, resilient conductor elements 12 and "l 3 "which" frespectively carryV at ltheir free 'ends the

contact elements

2 and 28. Theplate '54 is" cut awayfatits -center to provide a cylindricalpening""15into which' at diametrically oppositely*spacedpoints the resilient conductor elements '12"'and i3 project, andthe conductor element 25'; which is inerein of 'annular orm,'carries foun'contact'buttons "il, each spaced fromthos at'opposite `sides o1" it, for engagement wi'ththestatio'n'ary contacts 2 and28. This resultsiin a connectionfofthe contact elements 21 and ZBineach of the different, QO apart, circuit closing" positbn's"v o f the' reverse switch mechanism; and 'to"'impr`ve?dra bility the contactbiitt'ons' H 'are'providedj s'othat the pilot circuit mayr bebrken byf'o'ntact lelements of suitable material, suchias silver, or other arc resistant material.

Theplate'l has a centralp'enihg'il'formed through it surroundedjoy a projecting annular wall` ldi of thelsa'rfne internal contounas the 'opeifiing'l'Bil.Y From 'the -"other sideAl of'the 'plate 'e8 there'extevn'ds an annular: wall'SZ surrounding a yrecess of larger diameterA than" thejpening' 80 and leaving an annular shoulde"surromiding such 'opening Sli for` engagementby a pingi wl'ic-seI opposite end'rests againstuthe?"intern-al wallof the ca'sirigzii). VThe casingli Yhas an opening '85 ormed'th'erein surroundedl at y*its inner end lby aprojecting"collar-like portion 86 which supports *the*Y springvl"againstvl lateral displacement. A 'tubularn operatingn elein`ent'9|l 'extends through the Vopeningfl fand' at itsp'ou ion received in said openinglis cylindricaliii-"cross section, whereby" itis 'freely rotatable 'in' such opening. AThis members!) hasfange'nl'agedinner end !A which is polygonal-herein hwnfas .heXago'naL'in external form so asfto lii able but non-rotatable rel'atively'to walllfw -i'chfis also hexagonalmanol-there isa'"sh'oul`-de1jv 92 4at "the outer end of the enlarged prtionlwhifchc acts with the end'of'the collar-like'portion S shaft Si) isf'rotatable b y a `handle device'' includes a portion Vtill! non-'r`otatably"se "ur the shaft and having arm portions S51-s' ing a pivot'g Ion whichthestirruplike'io tion 9i?" oan operating handleenleverflffisE pivotally "mounted The folderatinghandleproper 99" may, exceptV as'restricte'd as hereinafte"'x plained, be'swn'g 'outwardly and 'rdly about the axis ofthe pivot pin 96 and'hfiay'fbe'utilied t@ 'tum the shaft 9o and thejparts wiicnfre turnable with that shaft. The stirrup portion 9i has an outwardly projecting'noseil which normally lies within the annulaf'wall `7`|B'l""o`a |01, an enlarged externally threaded portion I08,.

and inwardly of the portion |08 there is a reduced stem portion |09 having a stop element I secured to its innermost end. A deeply dishedf carrier element H2, of insulating material, is supported as at |I3 for sliding movement on the stem portion |09, and a spring H4 is arranged between the inner end of the member H2 and the stop collar H0. The interior of the deeply dished member H2 is similar in cross section to the shape of wall III-here shown hexagonalin order to be slidable but non-rotatable relatively to wall 8| and member 08. The outer periphery of this member H2 is in the form of a flange H5 having mutually opposite ears H5 projecting therefrom. A high resistance element R of ann-ular form but with projecting ears R! and R2 is secured to the member H2, with the ears RI and R2 thereof overlying the ears H5 of the member I I2. It will be observed that the ears RI and R2 are in such relation to the bars 69 and 10 that the resistance element is adapted to connect the bars 69 and 10 after the main line switch has been opened, thereby to vbring the motor to a stop by shortcircuiting its rotor through the high resistance element R.

The switch element 26 is supported by holdn ing elements I |8 extending through the resistance element R and through the ange H5 and surrounded by spacing sleeves H9 and springs |20. The spacing sleeves are short enough so that there is possible a substantial amount of yieldv of the contact element 26 longitudinally of the4 holding elements H8, and longitudinally also of the axis of rotation of the reverse switch. A spring |2| is provided between the shoulder which surrounds the reduced stem portion |09- and the bottom of the recess'inthe member H2.

To recapitulate, reversing is controlled by the lever 98 which turns a hollow shaft 90 with which the support member 68 is slidably connected while being held against relative rota.

tion. The support member I|2 is slidable relative to the member E8 but held against rotation with respect to it. The inner member |03, turnable by the hand wheel |02, is adjustable longitudinally of the hollow shaft 90 by the screw thread arrangement previously described. It is adapted to move the support member H2 and through the latter, when the resistance member R has engaged the bars 69 and 10, the support member 68 also. The sleeve portion 8| ofthe member 68, it will be remembered, is polygonal, herein shown as hexagonal exteriorly,l and the recess in the deeply dished support member II2 is also correspondingly polygonal in cross section, with the result that when the shaft 95 rotates, it turns with it the support member 68 and that support member turns with it the support member H2. Due to the presence of the sleeve H4', movement outwardly of the member |03 a short distancea distance sufficient to effect separation of the contacts 11 from the contacts 21 and 28--will cause the member H2 to be picked up by the outwardly moving member |03 and moved from the position shown in Fig. 3 to the position shown in Fig. 5, that is, moved to a position to cause the resistance element R to engage the conductor bars 69 and 10. Then ayeryfshort further outward movement of the support 'H2 will cause the picking up of the support element 68 and the movement of the contacts CI, C2, C3 and C4 out of cooperative relation with the contacts KI, K2, K3 and K4, the spring 84 yielding to permit this to occur. It will be noted that the contacts KI, K2, K3 and K4 can move only a short distance before the members 62 engage the member 54. When extreme outward movement of the element |03 occurs, the parts will occupy the relative positions shown in Fig. 5, and it will be noted that the lever 98 may, since the annular wall I0| will no longer obstruct movement of the projection |00, be swung outwardly to the dotted line position shown in Fig. 5, and thus move out of a notch |23 in a notched arcuate rib |24 until it overlies another notch |25 a quadrant away from the notch |23, and it may then be swung into that notch after having positioned the movable contacts CI,v C2, C3 and C4 so that they wille-stablish connections for reverse operation of the motor.

Before describing the general mode of operation of the apparatus, it will be noted that when the hand wheel |02 is rotated in a direction to move the shaft |03 to the left in Fig. 3, the spring I I4 will be the irst one to yield, and the spacing sleeve H4 will come up against the base of the carrier element H2 and move this element and when the heads I3 move up against the member 26 the pilot circuit will be opened. When the member 25 exerts pressure through the spacing sleeves Hd on the member H2, that member will move relative to the member 68 until the resistance arc member R is brought against the contact bars 09 and T0. When this engagement occurs', further rotation of the hand wheel |02 will cause the member 68 to move to the left in Fig. 3 and pull the conical Contact elements CI, C2, C3" and C4 out of the socketed contact elements Kl, K2, K3 and K4 to some position such as shown in Fig. 5. Fig. 5 well shows the result of these operations. It will be noted that the spring H4 is compressed and that the sleeve H4 extends solidly between the stop member H0 and the member H2. It will be noted that the elements H5 have pulled the switch element 26 firmly up against the sleeves H9. It will be observed that the resistance element R is held firmly against the conductor bar 10, and it is also against the bar 69. Finally, it will be noted that through the contact between the resistance element R andthe bars 59 and 10, the support member 63 has been moved to move the contact elements Cl, etc. out of the sockets 64. When the hand wheel |02 is turned in the opposite direction and the parts move toward the right, the rst thing that will occur will be the seating of the contacts CI, etc. in the recessed contact elements( KI, etc. Then the resistance element R will leave its position of engagement with the bars 59 and 10. Then the contacts 11 carried by the contact element 2li will engage the contacts 21 and 28. Further movement of the hand wheel |02 will cause the sleeve H 4 to exert a pressure on the member H2, and it, through the springs |20, will press the contact element 26 in a manner to press the contacts 11 against the contacts 21 and 28, but over-turning of the hand wheel |02 can cause no breakage. The mode o1 25a-.rasee between the'fc'onta'cts 21,228 by thelcc'ntact 29am its bontact elements 1.11. 'The resistor elementfR is spaced'fromthemonductor barsi69 and'l on' thesreversefswitch. The'l-conicalcontacts C I 02,5 G3 1 and# G41' of4` thereverse'switchfare yieldin'gly' but -rmly pressed -byforceieerted by the Spring 584 intozthe A.yieldingly mounted foontactsKl, KIZ, 'K3 andfK. The lever 98 "cannot be swungfbecause'ther-positionL ofrtheihand vwheel prevents" its being lifted outfof'thefnotch v[23.

If itnowf bedesired itofstop the motori t2 Tand to yreverse it, the hand wheel Vft2 will 'be 'turned in: a 'direction to move 'thefmember l 3ioutwa`rd1y, that is =tOWard2ther leftlin :lFig'J '3. The" Spring `|=l`4 will-be 'slightly compressediandthen, through the pacing sleeve M4?, the support member HZwill be :started tomove'toitheileftpand-as soon as this motion f progresses far enough tmcause the heads ofthe-bolts I'lf--to engage the c'ontactiring 26,-thiscontact ring willbe moved out .to's'eparate the contacts 'l1 from the stationary contactsfZ'I and v28, and-the circuit through Athe-solenoid@ will'beopenedand the mainline contactors vr5 and -6 will .dropopen' and current supply tofthel motor will be interrupted. Further rotationfof` thejhandwheel I fto lmove the member |03- still further to the -lef-t willbringthe-high resistance element-R vinto-contact with the bars-69and-10 and short-circuit vthe motor Varmature ythrough thehigh resistance of the member R andf'thus eiect dynamic braking. The motor mayprobably-have slowed down somewhat during the period between opening of themain'line switchl and contact bytheresistance-element R ofthe conductorbars 69, it. Further movementofthe hand 'wheel `H32 in` a direction-to move the member teil3 to the left will cause liftingof the contactsCl, C2, C3V and-C4 out of the yieldably mounted contacts with which they have -been engagedV-` `Only after this movement haslproceeded to:such an extent that itis .possibleto rotate the vvmember 58 without -interferencebetween the vmovable `contacts Cl C2, yC3 Aand andthe stationary contacts KI, K2, K3-and .K4 can the -leverA $28 be lifted Afar enough outrof -the notchlEi to rotate the-hollowshaft-9U,v support member 1' 68 and support member 4 I l2. When this rotary movement is .-possible, lever 98 can be swungfabout the axis-of the shaft SIR-counterclockwise in Fig. l3, and then moved, counterclockwise in Fig. 6, about the horizontal aX-is of rotation of the shaft 9B to effect Lthe establishment, through the rotation of that-shaft, of -a positioning of contacts CI,C2, C3 and C4 for reversernotor connections. vPremature swing of the leve'r98 is preventedby the cooperationf the'eiitension lil'with the innerwalll'l of the haild Wheel l 32. "hen the'pbst'n bf 'the 'CI- tacts "Cl, C2, C3 and lCil has been changed, 'to alineth'ern'I with the contacts Kl; K2, K3 and Kfin'a proper'manner for the establishm'er'it'of` permitrseparationofnthe-resisterfelementlR from This-"will the barst@ land 10, and nallywill permit contacts Num tlef-ringto engage contactslZ and 2'8 l'andtherebyclose fthe-'pilot circuit with the resulttha't ithef motorcarr"y again I be set in operation, butfin a/.reverseidi'rectiom by the closure of the Fstartingiswitchf. ADesirably currentsupply-tothe fmoto'r; may-110e: interrupted by opening ofthe stopfswitchbefore the 'handwheel m2 lwill be l`turned, ibut Ytlrrisfis f' obviously not imperative,

10 as thesswitch2'61controis the same circuit.

While 'therei'is in this application specically described on'e form which my invention may assume 'in epraci'.ice,.itl will rbe understood that thisfornrofithefinventionfis shown for purposes of iillustz'fationand 'that'the invention may be modied'andembodied invarious other forms without departing Ifrom its spirit or the scope of fthe :appendedl claims.

vWhat Iclaim f as new 1 and desire tov secure by Letters *Patent is:

25 A- function, va highesistance element, and means for'u moving said 'resistance element and said movable :contacts requiring interconnection of said movable contacts` through 'said resistance element -'asa".prerequisite to the opening of the circuitvbetweenfsaid movable contacts and the reverse I@switchcontacts "with `which they cooperate.

2. In an lapparatus v ofthe character described, infcombinatioiiga rever-se switch including mov- 3.5 -able contactsJandecontactsiwith which said movable Acontacts" cooperate in -effecting a reversing function, 51a Ihigh -resistance element, and means includingi a. lostmotion.y connection between said resistance-'elementand said movable contacts o-for'moving fsaid .resistance `element and said movable contacts requiring :interconnectionoi said movable-contacts through said resistance element as. Fa prerequisite to the vopening of the circuit f between.v said movable contacts and the' l reverse-'switch contacts with which they 'cooperate.

3'. Inifanapparatus of the' character described, inl combination; :a i reverse switch including movablelcontacts andfcontacts with "which said movable f contacts @cooperate finfeiecting a reversing moving saidire'si'stance-elementy and said vrnovable contactslat right-anglesto such planesrof rotary movement .i requiringlthe f' interconnection of said movable contacts through :said resistance elementu-asa vprerequisitePto'the opening of a cir- 5'0 l cuit between said fmovable Ycontacts and' the reverseIswitchmontacts 'fwith which they cooperate.

4. Infanfapparatus ofztheicharacter described, in 4`cornbinatonyafrcverseL switch 'including movable'rcontacts'f and"contactsvwith which said 1 movable :contacts recuperate in eiecting/ a reversing function, high-resistance means; and means `for short-circuiting one iof. said 'sets of contacts through -zfsaid high/resistance. means as a prer requisite to the opening fof 'a .circuitby the separationrffsaidvmovable-'contacts'from the reverse `swit`ch rco'ritacts `Twith which Vthey cooperate.

5. anapparatusffithe :character described, Y

7'5" in xzenmnationgafreverse: switch. including` movable contacts andicontacts with which said movable contacts'cooperate in effecting a reversing function, high resistance means, means for supporting the same for bodily movement, and means for bodily moving said high resistance means for short-circuiting one of said sets of contacts through said resistance means as a prerequisite to the opening of a circuit by the separation of said movable contacts from the reverse switch contacts with which they cooperate.

6. In-an apparatus of the character described, in combination, a reverse switch including movable contacts and contacts with which said movable contacts cooperate in effecting a reversing function, high resistance means, connections between said movable contacts in pairs, and means for electrically connecting said connections between 'said movable contacts through said high resistance means as a prerequisite to the opening of a circuit by the separation of said movable contacts from the reverse switch contacts with which they cooperate.

'7. In an apparatus of the character described, a pilot switch including at least one stationary contact and a relatively movable contact adapted to be moved between positions in which it respectively engages and is separated from said at least stationary contact, areverse switch including a set of relatively stationary contacts and a cooperating set of relatively movable contacts, a movably supported, high resistance, short-circuiting contact, and means for controlling said several movable contacts in a predetermined sequence, first moving said first movable contact to open circuit position, then moving said short-circuiting contact to interconnect said set of relatively movable contacts, and finally moving said cooperating set of relatively movable contacts to open circuit position.

8. In an apparatus of the character described, a pilot switch including stationary contacts and a relatively movable contact adapted to be moved between positions in which it respectively engages and is sepa-rated from said contacts, a reverse switch including a second set of relatively stationary contacts and a cooperating set of relatively movable contacts, a movably supported, high resistance, short-circuiting contact, and means for controlling said several movable contacts in a predetermined sequence, first moving said first movable contact to open circuit position, then moving said short-circuiting contact to interconnect said set of relatively movable contacts, and finally moving said cooperating set of relatively movable contacts to open circuit position, said several movable contacts all movable in a common direction in the foregoing movements thereof.

9. In an apparatus of the character described, a pilot switch including stationary contacts and a relatively movable contact adapted to be moved between positions in which it respectively engages and is separated from said contacts, a reverse switch including a second set of relatively stationary contacts'and a cooperating set of relatively movable contacts, a movably supported, high resistance, short-circuiting contact, and means for controlling said several movable contacts in a predetermined sequence, rst moving said first movable contact to open circuit position, then moving said short-circuiting contact to interconnect said set of relatively movable contacts, and finally moving said cooperating set of relatively movable vcontacts to open circuit position, said controlling means including an element yieldingly supporting said first movable contact and carrying said short-circuiting contact.

l0. In a reverse switch, a shaft, support means slidably supported on said shaft but fixed against rotation relative to the latter, reverse switch contacts carried by said support means, relatively stationary reverse switch contacts, a handle mounted on said shaft for swinging about an axis disposed transversely to the axis of said shaft, means for holding said handle against rotation about the axis of said shaft when in predetermined angular relation to said shaft, a second shaft coaxial with said first mentioned shaft and having a connection with the latter operative on relative rotation of the second shaft with respect to the rst shaft to effect movement of said second shaft axially of said first shaft, means for rotating said second mentioned shaft operative except in certain predetermined relative axial positions between said shafts to hold said handle engaged by said handle holding means, a pilot switch arranged for opening by said second mentioned shaft, and means movable by said second mentioned shaft for moving said first mentioned reverse switch contacts axially of said first shaft to open circuit position before the rotating means for said second mentioned shaft releases the handle of said first mentioned shaft for rotation.

1l. In a reverse switch, a hollow shaft, support means slidably supported on said shaft but fixed against rotation relative to the latter, reverse switch contacts carried by said support means, relatively stationary reverse switch contacts, a handle pivot member secured to said shaft, a handle mounted on said pivot member for swinging about an axis disposed transversely to the axis of said shaft, means for holding said handle against rotation about the axis of said shaft when in predetermined angular relation to said shaft, a second shaft coaxial with said first mentioned shaft and having a connection with the latter operative on relative rotation of the second shaft with respect to the first shaft to effect movement of said second shaft axially within said first shaft, means for rotating said second mentioned shaft operative except in certain predetermined relative axial positions between said shafts to hold said handle engaged by said handle holding means, a pilot switch arranged for opening by said second mentioned shaft, and means movable by said second mentioned shaft for moving said rst mentioned reverse switch contacts axially of said first shaft to open circuit position before the rotating means for said second mentioned shaft releases the handle of said rst mentioned shaft for rotation.

l2. In a reverse switch,a hollow shaft, support means slidably supported on said shaft but fixed against rotation relative to the latter, reverse switch contacts carried by said support means, relatively stationary reverse switch contacts, a handle pivot member secured to said shaft, a handle mounted on said pivot member for swinging about an axis disposed transversely to the axis of said shaft, a notched rib for holding said handle against rotation about the axis of said shaft when in predetermined angular relation to said shaft, a second shaft coaxial with said first mentioned shaft and having a connection with the latter operative on relative rotation 0f the second shaft with respect to the first shaft to effect movement of said second shaft axially within said first shaft, means for rotating said second mentioned shaft operative except in certain predetermined relative axial positions between said asflasso -rotation relative to the latter, reverseswitch contacts carriediby said support means, relatively stationary reverse switch contacts, a handle mounted on said shaft forV swinging about an,v

axi'sdisposedr transversely to the axisofssaid shaft, projections for holding said handle against rotation abo-utlthe axis ofk saidshaft when in predeterminedangular relation to said shaft, a second shaft coaxialwith `said first mentionedlshaft andl having'a connection with the latter operative on relative'rotationof the secondishaft'with respect torthehrst shaft 'tot effect" movement vof saidi secondshaftV axiallyof said first shaft, means for rotating said secondmentioned shaft'. operative: except in certain predetermined relative axial positionsbetween said shafts to holdJ-saidhandle against release from said projections, a pilot ,switch Larranged for opening-by. said secondmentioned. shaft, and-f means movable .byfsaid` second' mentioned shaft-formoving said first mentioned reverse switch contacts axially ofV saidfirstshaft to .open circuit positionbeforethe rotating-means for .said second mentioned shaft releases the handle off saidf first mentioned` shaft for movementout of constraint by said projections.

14'. InV combinatiorrfmeansforming a casing, relatively stationary reversevcontacts carried by said. casing, relatively stationary pilot contacts carried by said casing, said contacts arranged symmetrically with respect tofanA axis-extending through saidV casing, two shafts having theircenters in the sameline with said axis, means for `effecting rotation of each of said shafts-means for elfecting relative. axial movement between saidshafts. upon rotation of'Y one of said shafts relative to the other;y a` member slidabl'yv supported on one 4of said' shafts,..a. member slidably supported-onthe other of said shafts, said members havingA portions in telescoping"relationA with respect to each other, said' telescoping portions formed to'prevent rotation "between said members, a pilot switch element -yieldingly connected toV one ofsaid'members.reverse switch contacts and conductor bars fixed. to the yother of said members, and a high. resistance element carried by. said-.member which1 carries ar pilot switch element-and engageable in a predeterminedlrelative position between said-members with said4 conductonbars.

ported-on the otherofsaid shafts, said-members Ihaving' portionsin--telescoping relation with respect to each other, said telescoping portions.

formed to Y preventrotation` between said members', a =pilot-s-witcli element yieldinglye connected to. one of said members; reverse switch contacts andfconductor barsfixed to the other oi? said member s land a high resistance'element'v carried by'saidfmember whichcarriesA a pilot `switch element'andengageable in a predetermined'relative positionfbetween said members with said conductorbars; saidshaftfrotating` means including members rotating with each ofsaidl shafts and onefihavingt a projection and the other' a cooperating rim.

'16; In a switch mechanism, in combination, meansfforming-a casing, `at least onestationary pilots-witch element-carriedV by the casing, reverse switch elements carriedby the casing, re-

-versefswitch'elements relatively movable with respect v`to said ii'rst 'mentioned reverse switch elements, supporting meansfor-said relatively'movable reverse switch contact elements, a support member' movable bodilyrelative to said vsupporting means but held against `relative rotation with respect to the latter, at leastonelpil'ot switch* element carried by'said support member, contact bars mounted onsaid supporting means and connecting certain ofsaidmovable contact' elements, and a-'highresistance element for establishing a high-resistance circuit between said'bars carried by-said support member and movable by the latter into contact with'said bars when said support memberI is in a position with said pilot circuit switch elements out off contact with each other.

'17L In an apparatus of the character described, means forming a casingfhaving a chamber therein and having anendplate, pilot switch contacts supported by saidl end plate, recessed reverse switch contacts supported by said end plate, coaxial shafts rotatably supported by said casing, oneof saidshaf-ts conned against' axial movement and the other being axially movable and having associated with it means for effecting its axial n'iovementv upon rotation thereof, a plurality` of support members telescopically arranged with respect to each other and to said shaft which is rotatable only and having means for preventing relative rotation with respect to each other and to said shaft whichy is. rotatable only, a pilot switch element yieldingly connected to one of said support' members, reverse contacts carried ,by the other of said support members, means for vfor moving` said second mentioned shaft aidally relative to said rstmentioned shaft, means for preventing rotationof said first mentioned shaft except when said second mentioned shaft occupies -a predetermined longitudinal relation with respectto said first mentioned shaft, a pilot switch lmovable between open and closed positions by said second mentioned shaft', reverse contacts rotatable by rotationzof said rstmentioned shaft, and means for movingl said reverse contacts axially of. said casing to open circuitposition during 13 movement of said second mentioned shaft to said predetermined position.

19. In an apparatus of the character described, in combination, a casing, a rotating shaft supported in said casing, another shaft movable axially of said first mentioned shaft, means for rotating said rst mentioned shaft, means for moving said second mentioned shaft axially relative to said first mentioned shaft, means for preventing rotation of said Iirst mentioned shaft except When said second mentioned shaft occupies a predetermined longitudinal relation with respect to said rst mentioned shaft, a pilot switch movable between open and closed positions by said second mentioned shaft, reverse contacts rotatable by rotation of said rst mentioned shaft, and means actuated by said second mentioned shaft for moving said reverse contacts axially of said casing to open circuit position during movement of said second mentioned shaft to said predetermined position.

20. In an electrical controlling apparatus, in combination, means forming a casing, relatively stationary pilot contacts supported by said casing, relatively stationary reverse switch contacts 14 supported by said casing, a pilot switch element movable bodily axially of said casing, reverse switch contacts movable axially of said casing and also rotatable about the axis of said casing, means for rotating said latter reverse switch contacts between different positions having a connection with the same enabling axial movement of said contacts with respect to said rotating means, means for moving said pilot switch elements and said movable reverse switch contacts successively axially of said casing, and means for effecting an interlocking relation between said rotating means and said axial movement effecting means.

JOI-1N D. RUSSELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 748,635 Muschenheim et al. Jan. 5, 1904 821,009 Whittingham May 22, 1906 2,231,598 Shroyer Feb. 11, 1941 2,451,224 Johnson Oct. 12, 1948