US1606946A - Electric starting apparatus - Google Patents

Description

Noir. 16 1926.

R. KELLENDORFER ELECTRIC STARTING APPARATUS Filed sept. 15y e sheets-sheet 1 Il Il m f r n .m s m n w m u n r e m a IM |l J wu. W y/., w w n1 4. F 2

Nov. 16 1926.

1,606,946 R. KELLENDORFER ELECTRIC STARTING APPARATUS 6 Sheets-Sheet 2 Filed sept. 15

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R. KELLENDORFER ELECTRIC STARTING APPARATUS Filved sept. 15, .1924 @Sheets-sheet s Nov. 16 1926.

R. KELLENDORFER ELECTRIC STARTING APPARATUS 1924 6 Sheets-Sheet 4 Filed Sept. 15I

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Patented Nov. 16, 1926.

UNITED STATES PTENT GFFICE.

RICHARD KELLENDORFER, OF MUNICH, GERMANY, ASSIGNOR TO BAYERISCHE ELEK- TRIZITA'TS-INDUSTRIE ROTT Se CO., OIF MUNICI-ll, GERMANY, AND AART IETER VISSER, OF ROTTERDAM, NETHERLANDS.

ELECTRIC STARTING APBARATUS. Y

Application filed September 15, 1924, Serial No` 737,939, and inlGermany May 5, 1923. v

This invention relates to a tilting 'switch intended to be used as an electric starter` and 1t consists in this that a solid tilting resistance is inserted in the circuit of the appaing the tilting by an electrically conductiveratus or machine to be started and that said resistance is gradually short-circuited dur .apparatus or machine in different ways acfill cording to the particular application. lVhen the switch is used for starting a continuous current motor it is preferably inserted in the armature circuit. When it is used for the starting of a three-phase motor with short-circuit armature it is preferably inserted in the circuit of the rotor and after the tilting, and when in its end position, it inserts the short-circuit connections between the rotor windings. When it is used for the starting of any `other three-phase motor it is inserted in the stator leads thereby connecting the stator winding directlyonto the supply circuit or to the feeding transformer at the end of its tilting movement. It is however to be understood that the starter according to the present invention may be.

connected in any other way.

The great advantage of the apparatus according to the present invention consists in this that the disconnection of the starting resistanccs is effected gradually without any sparking being produced.` Moreover by suitably choosing the form of the resistance that is gradually short-circuited bythe electrically conductive liquid, any desired -starting characteristic may be obtained. Thus use may be made of a resistance, the cross section of whichy isuniform or varies 'according to a definite law; similarly the channels through which the liquid lowsand in which it rises during the tilting may be made of any desired form thereby causing that during a uniform tilting movement, the disconnection of the resistances` is effected in equal steps which are exceedingly small, or that during the disconnection the inserted resistance decreases uniformly or more quickly or more slowly according to the general requirements that have to be fulfilled witlrrespect to the apparatus or machine that is to be connected up.

Instead of adapting the starter according to the invention to the electric requirement of the starting operation, the mechanical tilting movement may be eifected according to a predetermined law, for instance in such a manner that the controllinglever, in spite of its uniform controlling movement, effects a diiferent tilting movement of the starter such as by using a cam or other suitable transmission mechanism interposed between the `lever and the starter. In this way, if the controlling lever is operated at a uniform speed, during the starting operation the electrical part of the starter will, in spite of this, follow a different law when moving from its disconnected into its shortcircuiting position. d Link mechanisms, cam discs and other mechanical arrangements may be used for transmitting the motion required in these cases.

Instead of, or in addition to, the mechanical transmission means just referred to,juse

may be made of braking devices either acting upon the controlling lever or, in the case when there 1s an elastic connection between the electrical part and the controlling member for instance a spring, on one of these transmission means or on a stopping device or the like, in order t-o cause the starting to follow a definite law or in order to ensure a 'definite speed of starting.

The starter according to the invention may also be used for disconnecting the controlled apparatus or machine. Generally the law that the starting operation has to follow is followed in the opposite direct-ion when the apparatus `or machine is disconnected. In that case the switch can be Vused for controlling the two operations. When this'is not the case the movement to be performed during the disconnecting operation has to `follow the law that is required for that purpose. As theelectriccomponents as suoli cannot be altered, the mechanical driving or stopping device used for thedisconnection must be different from that used for the starting. This switching-over mayfor instance be effected by causing the fixing means to follow in a known manner two different lpaths during the starting and itsdisconnecting 'operation respectively. For this purpose the said fixing means is preferably guided in two slits one of which is provided for the starting operation and the othei one fer the disconnecting operation, and the controlling member when reaching its end positions, is shifted over by a transverse movement from the one slit into the other as is well known in the art. Y

The invention also consists in two forms of construction of atilting switch as above referred to. The resistances which are to bev short-circuited by the Velectrically conductive liquid are mounted in a conducting casing, being connected at one end to the latter and provided at the other end with electric terminals outside the casing and insulate-d therefrom. The starter is inserted into the circuit to be controlled, being connected thereto through the conducting casing and through the said terminals. The conducting casing is also provided with a chamber for the reception of the short circuiting liquid and passages in the proximity of the resistances and also with inlet and outlet openings or conduits for the shoitcircuiting liquid which are provided in such a manner that when the apparatus is tilted for starting purposes the liquid iiows from the said chamber into the passages in the proximity of theresistances and can rise along the latter in direct contact therewith vuntil the resistances are short-circuited, whilst during the tilting for disconnecting the apparatus or machine the same or other Openings or passages are used through which the short-circuiting liquid returns from the short-circuiting passages into the chamber above referred to.

Various forms of construction for carry- 'ing the invention into effect are illustrated by way of example in the accompanying drawings.

Figure l is a sectional elevation of a starter intended for use in connection with threephase. current.

Figure 1il is a sectional plan view along the line I-I of Figure l.

Figure 2 is a sectional elevation of another forni of construction.

1 Figure 2u is a transverse section along the line II-II in Figure 2.

VFigure 3 is an elevation of another form yof construction.

Figure .4 is a sectional elevation of another forin of construction intended for use struction and Figure 10 a sectional end elevation thereof.

Referring to Figures fl and l, l is a casing of conducting material which is made slightly conical and contains three resistances 2, 3 and 4, a space being .eft freelfetween them and the casing; each of these resistances is a portion of a cone, its lower end either being in direct contact with the casing l or being separated therefrom, the upper ends of the resistance being provided with Vterminals 6 and l5 which pass outside the Vpasses through an opening 2l into an overflow pipe 8 which con'ununicates by openings shown at the lefthand end thereof with the chamber 7. For manufacturing reasons the passage 22 is carried as far as the end of the casing l and is then sealed up by means of a stopper 24 which may for instance be vscrewed on. The whole of the device is mounted on the rotary axle 1l.

The resistances 2, 3 and 4 are separated from one another by walls 14 of insulating material so thattlie resistances are ositively insulated from one another at their upper .ends as is also the case with the terminals 5, 6 and 15.

In the case of a short-circuit induction motor the device liereinbefore described is appliedas follows: The three ends of the three-phase rotor winding are connected to the terminals 5, 6 and l5 through the slip rings. If the resistanees 2, 3 and 4 are conductively connected with the casing l, a small magnetizing current limited by these resistances can be induced in and flow through the'armature immediately upon the stator being inserted into the circuit. However if the resistances are insulated from the casingl nor current will as yet flow through the'rotor. This'frstposition is attained when thel device illustrated in Figure l is tiltedthrough about 90 in an anticlockwise vdirection in which case the conductive liquid lies entirely in the chamber 7. Now, if the device is tilted in a clockwise direction. theI liquid flows through the passage 22 and opening 23 into the intermediate space 12 whereby a conductive connection is effected between the three resistances, corresponding parts of the resistances being gradually disconnected. Then the device reaches the position illustrated in Figure l, the liquid has completely left the chamber 7 and has passed over intot-he intei-mediate fspace 12,"standing thereinand Valso in tliepassage 2-which does not come Aclockwise direction the liquid flows 4back into' the chamber 7 partly tliroughthe passage 22 and partly through the Vpassage 17, opening 21 and overflow pipe 8.

The casing and the resistance have purposely been made of conical shape in order lto ensure a complete return of the liquid and the overflow pipe 8 has been .provided in order to prevent an unintentional return of the liquid for instance through the yopening 21 `during the starting operation. It is howl ever to be understood that the casing and the resistances may be made ot any other shape. For instance `they may be made of asymmetrical shape with the object of ensuringa uniform disconnection of the resistances 2, 3 and 4, it being clear that during the starting operation the resistance 2 and partly the resistance 4 will in the first instance be covered by the liquid to a larger extent than the resistance 3, the three resistances being equally covered'atter the iinal short-circuiting passage has been attained. However the latter conditions can be effected by suitably shaping` the resistances and the passages.

A form of construction in which thisl asymmetry of the starting and disconnecting operation which is sometimes disturbing in practice is absent, is illustrated in Figures 2 and 2a. The parts corresponding to those hereinbefore described with reference to Figures 1y and 1a have been indicatedby the same reference letters. rlhe resistances 2, 3 and 1 have again been shown therein as being of tapered shape for the reasons hereinbetore given." The overflow `pipe has not been shown, forlthe sake of simplicity, seeing more especially that it is not always required.

The `arrangement diers- `from` that hereinbefore described in this, that the 17 leading to a return opening` 21 provided in the latter insulator for each individual resistance. The terminals 5, 6 and `15 pass through the lid 19 of the device, being suitably insulated therefrom.

"Assuming it is desired to connect the device to the three phases 'of the rotor of a. short-circuit motor through the three terminals 5, 6A and 15, as in the case of the arrangement illustiated in Figures 1 and l, the operation is as follows: 'Y

lVhen the device is in its disconnected position (not shown on the. drawing) the liquid is exclusively contained in the-chainber 7. By tilting the device in clockwise direction'V the liquid flows through the passages 22 and openings 23 first ci' all in the space 12 shown on the lefthand side of Figure 2a and whence'through passages 83 provided in the insulating casing 18 into the passage 12 shown on the righthand side of Figure 2a, the liquid rising therein as the tilting continues, until ittouches the sleeves 80 whereby the resistances 2, 3 and L are short-circuitedand entirely disconnected.

` .In this arrangement the -i'esistances 2, Il

and t as wellas the passages v12and are assumed to be 'of rectangular cross section. As `will be seen vfrom Figure 2, the Vwalls 16 do not touch the passages 12, so that the liquid in these passages covers in a contin- V.nous manner all the three resistances siinultaneously. However, it not .absolutely necessary that the walls 16 should terminate in the manner described as they may extend until they reach the inner surface ot the casing 1,\since the casing 1 is of conducting i material andthe current flows for instance from the sleeves 80through the liquid to the casing and'is short-circuited bythe same.

ThisV is also one of the reasons why the casing V1 has to be made of conducting material. Another ground therefor 'is that it is easy to manufacture it of metal. VIt is however to be understood that in this form ot construction as well as in any of the other toi-ins herein described for carrying the invention into effect, the casing may be made of nonconducting material, the current being conducted andy short-circuited solely vthrough the liquid. v f C Y Y i l-fthe `device istilted from the position shownin Figure 2a inv an anti-clockwise direction in order Vto effect the disconnection, the liquid will iiow partly through the passage 22 and partly through the passage 17 and the opening 21 completely back into the `chamber 7. t

It will be `clearly seen that a complete interruption of the, current will take place only when the rvarious resistances are insulated from the conducting-casing 1 or rent outside the starter and it is often desir-` trated in Figure 3 in connection with thev device for instance as illustrated in Figure 2. It is assumed that the device is not used for starting a motor armature but for starting the stator winding or another apparatus.

The supply circuit is connected vonto the terminal 27 (Figure 3) which is connected with a. fixed contact The casing 1 is electrically connected with a knife contact 25 which is pivoted at 11. In the disconnected position (not shown on the drawing) the knife contact 25 is not Ain contact with the fixed contact 26. At the beginningof the movement for effecting the connection the knife cont-act 25 is 'moved into the con-.

tact 26 being in advance ot the tilting'movement of the starter, the supply circuit being thus connected up. As thev tilting continues, the resistances are short-circuited and the apparatus finally receives the full voltage of the supply circuit. The apparatus is connected thereto with the terminal 5 which is connected to the resistances in the manner shown in Figure 2.

The apparatus hereinbefore described may be used alone or in combination with several similar apparatus, in connection with cont-inuous' alternating current or three-phase current.

In the various forms of' construction hereinbefore described the resistances 2, 3 and 4 have been assumed to be insulated from one another ink orderV to be able to control theapparatus according to the invention mayalso be usedfor other purposes. Another form of construction showing the applica-` tion of the invention to another apparatus is illustrated in Figures 4 and 4a.

Referring'to Figures 4 and 4a let us first of all assume that it is desired uniformly to start three different apparatus which are connected together in parallel. Moreover the consti'uction is such that the non-uniform starting of the different phases in the case of an induction motor by means of an apparatus as illustrated in Figure 1, is prevented. f

yIn this case the resistances 2, 3 and 4 are made of cylindrical form. The terminals 5, 6 and'15 are extended into sleeves 28, 29 and 30 or are connected therewith, these sleeves being completely inserted in the resistances. An immediate short-circuit between these sleeves for instance through the conducting casing 1 or by the first admisksion of the liquid, is prevented by the insulating insertions 84 which are provided all vflows into the passage 22 and finally rises through the opening 23 in the three passages 12 between the insulating insertions 84 until it reaches the level 81 indicated in Figure 4, and short-circuits the three sleeves 2S, 29, 30. YVhen the apparatus has returned into its original position the liquid flows back along the same path trom the passage 12 and more particularly through the opening 21-along the partition wall It-jis advisable to tilt the starter lback into the position illustrated in Figure4a through an angle of more than 90C. The motor winding is A'connected to the terminals 5, 6 and 15 and in any case a minimum current will ilow through the armature when the stator is connected up, which minimum current is determined'by the resistances 2, 3. The apparatus operates in a similar manner when the supply circuit is connected to the sleeve 31 whilst one pole of the consuming apparatus is connected to the terminal 5, 6, 15. In the original position the current will flow from the terminal 32 through. the resistances 4, 3 and 2 to the terminals 15, 5, 6, theresistances being gradually disconnected during the tilting and being graially inserted during the return tilting movement.

The arrangement just described also shows how an induction motor can be startedl with only two resistances 2 and 3 since the resistance 4 and the terminal 32 may be dispensed with.

VIt is also to be pointed out that the passage 712 shown on the righthand side in Figure 4 is filled up with liquid only when the same has risen to such a height that it passes the upper recess of the insertion 84 and enters into this passage 12.

In the forms of construction hereinbefore described the starting resistances are arranged in one single casing and the shortcircuit takes place through the contact liquid itself. However thev same result may` be obtained by providing separate devices each of which embodies one .single resistance. In that case a single apparatus may be inserted in each conductor when the invention is applied to a multi-phase arrangement of alternating current or to a double pole connection of continuous current which apparatus comprises a solid resistance capable of being tilted and short-circuited or inserted into the circuit by a conducting liquid during the tilting.

Various diagrams of connections with such separate apparatus will now be de.- scribe'd, separate switch-es being used in this case in order to etect a complete disconnection ot the starter from the circuit to be controlled.

Referring to Figure 5, 34 is the stator of an induction motor which is connected through the main switch 35 to the supply circuit the rotor being connected through the slip rings with the separate and insulated casings l. ot a starter according to the present invention. The resistances V2, 3, 4 have to be short-circuited together as indicated at 38. 50 are the insulating terminals of the casings l which terminals are insulated trom one another. 36 are the terminals by which the stators are connected to the switch 35 and 37 are the terminals by which this switch is connected to the supply circuit.

All the three .starting resistances are secured to a common 'tilting axle 1l (indicated in dotted line) which also moves the. knife contacts 35 in such a manner that the said knife contacts 35 effect the contact immediately at the commencement of the starting` operation and remain in the contact position until the tilting apparatus reaches its initial position during the disconnecting operation.

Figure 7 illustrates a diagram ot connections intended for a continuous current or alternating current shunt machine. The connections will be readily understood. The field winding 39 is first inserted into the circuit by the switch 35 and thereupon the armature 40 is gradually inserted into the circuit through the intermediary of the tilting apparatus l, 2 according to the invention.

All the required movements for the operation ot the tilting apparatus and of the main switch are derived in a positive mechanical Way from the movement of the controlling lever for instance by means ot stops, cams, etc.

Figures 8, 9 and 10 illustrate, by way of example, arrangements which may be used with the diagram of connections illustrated in Figure 5.

Each of the three casings l together with its axle 11, is pivotally mounted on a conducting supporting arm 5l connected to the terminal 50. These are the terminals to which the stator, illustrated in Figure 5, is connected.

The resistances 2, (see Fig. 10) are connected to the terminals 5, 6 and 15 (see Fig. 9) which are connected together by a shortcircuiting connection 38 as indicated in Figure 5.

In order to effect the tilting movement, all the casings l are mechanically connected together by means of a rigid bridger42 of insulating material. with lthe bridge 42, the said arm being secured to the axle 44 ot the controlling member 45. Y

Moreover a sleeve 45 is rotatably mounted on the axle 44 and is attached to the said axle through a helical spring 54. The sleeve 45 carries a disc 46 ot insulating material which is provided on both sides with spring contacts 35. lThe spring contact on the one side is conductively 'connected with an opposite spring contact 35 provided on the other side. lin the arrangement tor threephase current, three pairs ot such contacts are provided these contacts Vbeing preferably displaced relatively to one another through an angle ot 1200. The fixed cont-acts 49 cooperating with the spring contacts 45 are mounted on suitable shields provided on both sides of the disc 46, these fixed contacts being connected onv the one side with the terminal 36 and on the other side with the terminal 37.

An adjust-able spring 46 tends to bring the apparatus into the connecting position or to fix it in the disconnecting position in the same way as a bell crank lever. An insulating rod 52 which is mounted in the two shields provided on both sides ot' the disc 46, passes through the slot provided in the disc 46 and serves for the purpose of limiting the movement ot. the disc. The rod 32 is secured in position by means of screw nuts 53.

The stator winding illustrated in Figure 5 is connected to the terminals 36 whilst the supply circuit is connected tothe terminals 37.

The operation of the device just referred to is as follows:-

By moving the controlling member 45 from the disconnected into the connected position, the disc 46 is first of all taken along and thereby the stator' is connected to the terminals 37, 36 and the contact knives 35 to the supply circuit. As the rotation continues, the casings l are tilted by the arm 43 by means of the bridge 42 until the resistances are completely disconnected. reverse process takes place during the disconnecting operation. The object of the spring 54 is that according to the adjustment of its normal tension the switch 35 shall be disconnected before the resistances in the casing l are completely inserted into the circuit, similar to a quick-brake switch or the spring is tensioned sutiiciently to disconnect the switch only when the resistances in the casings l are again completely inserted into the circuit.

As regards the construction illustrated in Figure 10 the overflow pipe 56 is to be specially mentioned, as it prevents any undesired overflow of the conducting liquid in An arm 43 engages The n the passages 12 also in the case of a quick operation.

55 is a protecting casing for the Whole of the apparatus, which casing` is secured in such a vay that it can be removed only when the apparatus is disconnected and the switch contacts are. open, so that the construction of the casing 1 of conducting material cannot in any Way become dangerous.

It is also to be pointed out that the solid re-` sistance may be made ot any suitable material which would not be affected by the conducting liquid. Carbon has been found to he especially tavouraliile. Instead oit using; mercury ior the conductingl liquid, any other liquid may be used `which would not adhere to the substance used as the resistance, for instance Water with av conducting; addition, for instance salt or the like.

When the casing is not made of conductin; material an electrode will necessarily have to be used which will have to be ot' such material. that it will notI be affected by the conducting substance.

vifihat I claim is:-

'1. ln an apparatus of the character described adapted toi control a plurality otl circuits, a tiltable rheostat including solid resistances. each resistance being' adapted to be coordinated to each circuit, a chamber, a passage for liquid associated with each resistance, each passage being connected with said chamber, and a conducting liquid, said liquid being` received within the chamber in one position of the rheostat and adaptedfu'hen the rheostat is tilted, to flow into the passage and partly or Wholly short-circuit the resistances, according to the position of the rhcostat.

A rheostatas claimed in claim l characterized in that the chamber is common to all passages ior all resistances.

3. A rheostat as claimed in claim l characterised by the provision oi means insulating' the r ces from each other.

Ji. A tiitablcfrheostat including solid electrically connected resistances, a conducting casing.;- 'or the i'esistauces, a chamber in said casina', a pas ge iu said casing for liquid associated with cach resistance, each passage being,` connected with said chamber and a conductingl iiquid, said liquid being received within the Achamber in one posit-ion of the rhcostat and adapted when the rheostat is tilted to iow into the passage and partly or wholly short-circiut the resistance, according to the position o'l the rheostat.

5. A rheostat as ciaimed in claim l characterized in that the resistances are shaped as portions of cones.

(S. A rheostat as laimed in claim l characterized in that the resistances are shaped as portions of cones and are insulated from one another.

In testimony whereof I have signed my ame to this speciiication.

RICHARD VKELLENDORFER.

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