US2654846A

US2654846A - Step-by-step electric motor

Info

Publication number: US2654846A
Application number: US259076A
Authority: US
Inventors: Lohs Willy; Sommer Friedrich
Original assignee: Siemens AG
Current assignee: Siemens and Halske AG; Siemens AG
Priority date: 1950-12-13
Filing date: 1951-11-30
Publication date: 1953-10-06
Anticipated expiration: 1970-10-06

Description

UCL 5, 1953 w. LoHs ET AL STEP-BY-STEP ELECTRIC MOTOR Filed Nov. 30, 1951 Patented Oct. 6, 1953 STEP-BY-ISTEP ELECTRIC MOTOR Willy iIiohs, Berlin-'Siemensstad`t, and Friedrich Sommer, Berlin-Nikolassee, Germany, assignors to Siemens & Halske Aktiengesellschaft, Munich and Berlin, Germany, va corporation of `Germany Application November 30, 1951, Serial No. 259,076 In JGermany December 13, 1950 (Cl. S-49) -6 Claims. .1

This invention is concerned with :a .telephone switching mechanism, :and `particular-ly with a motor for driving it.

The particular 'switching mechanism Ato Awhich the invention relates is ofthe class :requiring a motor having sets 'of contacts controlled by the motor armature for alternately switching in the field or stator 'coils Lto :obtain step-by-.step rota-- tion of the motor shaft' and thereby correspond- 4ing rotation of the switching elements, e. rg., oi the wipers, `of fa :switching .device .geared to the motor shaft. An example of such :a motor is shown in Patent No. 2,992,546, dated'Ma'y 28, 1935. The operation of the above mentioned contacts, that is, the closing .as well as the opening thereof, must take .place in predetermined armature positions. AThe proper operation of such a mechanism, e. g., of a selector switch, therefore requires .an accurate :adiustment of the contacts. The adjustment was .heretofore carried out by the use of `special gages.

The intention eliminates the :necessity for special gages by providingfor each set of .contacts two adjusting members.A One of .these .adjusting members determines the .beginning and the other the termination of the `contact operation through the .medium of a cam `on the motor shaft. The adjustment of the corresponding contact set by the second adjusting member does .not alter the functions of the contact position determined .by the irst adjusting member.

The motor :armature is .provided with an adjusting 'disk having a Y--plurality of straight edges, and a stationary motor ,part forms a .straight coacting adjusting surface. The .adjustment of the contacts is carried out biyhol-ding the motor shaft and therewith the armature and a contactactuating cam on .the .motor :shaft indefinite wangular positions, by inserting between .the straight edges of the .adjusting disk 1and the coaoting :stationary `adjusting surface a wedge-shaped member .for holding the armature against rotation in the critical Vangular `position thereof in which .the cam is in deiinite position relative to ythe `contacts controlled thereby.

The adjusting disk on the 'motor shaft .is also employed for determining the armature Vpositions in 'which the wipers of the :switch controlled by the motor `are infpredetermined resting or loperating positions, respectively. This Vis-done by placing .the motor armaturein Va .certain yangular position 'in Which'a detent spring engages anotch in a detent ratchet to hold `the armature in the angular position corresponding to the desired operating 'positions oithe Aswitch wipers, The correct position of 'the detent spring relative to the detent ratchet Vis adjusted after determining the correct angular position of the armature. `rlhis phase of the adjustment operations r-therefore also is accomplished'without the use/of 'special gages.

The vinvention is illustrated in the accompanying drawings, in which Fig. l is a View, partly .in elevation and partly in section, of the parts oi the drive motor lfor a switch of the type mentioned before, which are required :for the understanding of the invention.;

Fig. 2 is a side view with certain parts in .section;

Figs. 3-6 show details in elevational .and Asectional views, respectively; and

Fig. 7 illustrates a circuit.

The .parts shown in Figs. 3-5 are on a :somewhat .smaller scale than they appear in Figs. l., 2 and 6.

Num-eral l indicates parts of the stationary mounting frame, which .is made of nonmagn'etic material. On this frame fare .fastened the -

core members

2 and 3 of the field .or vstator v:coils of the motor. The frame I also carries the rbearing for the armature shaft I4. `One such bearing is indicated in Fig. 2. Also mounted Xon the frame I are the carriers for the control contacts 1 and S which are governed .by the cam disk 6. 'These contacts govern the alternate switching vin and out of the iield or stator coils coacting with the cores 2 and Y3. Numeral S (Fig. 16) .is a 'Camportion which opens the normally `closed contacts 'I and 8 incident to ,passing between the corresponding 'contact springs. The two Vpositions or this cam portion are indicated at `and II.

Disposed Yon the armature shaft 4 is .the pinion Il yhich meshes with the ldrive wheel (not shown) of the associated switch, for example, a selector switch. The Aswitch has ybeen omitted from the drawings to keep them simple. Also disposed on the .shaft 4 are the detent ratchet I2 and four stacks of armature laminations I3 which are separated -by spacers I4 and i5. Finally, the shaft 4 also carries the cam Vdisk 5 for operating the

contacts

1 and 8. The spacer I5 between the second and third laminated armature stacks is a pentagonal disk having ve straight sides or edges 30-34. These edges are provided for coaction with the wedge-shaped holder member -28 (Fig. l) `to carry out the various adjustments in 'deiinite angular positions of the armature. The edge) vserves for holding the armature in the angular position which it must assume in normal position and in Working position, respectively, ofthe switch Wipers, The edges 3 I-Sfl are employed in the adjustment of the contacts I and 8 which control the field or stator coils. The various disks, armature laminations, spacers and the cam are held axially against the pinion I I, which is press-tted on the shaft '4, by the nut I'G. `The various elements are keyed to the shaft 4 by engagement of recessed portions with a flattened surface on the shaft and are thus held against rotation.

Each'contact pair I and l8 is mounted on a 'carrier which is formed by an adjusting lever or member provided with a handle. The pair of contact springs 'I is thus mounted on the carrier forming the lever having the handle II, and the pair of contact springs 8 is similarly mounted on the carrier forming the leverlike adjusting member having the handle I8.V The adjusting lever II is pivotally mounted at 20 on the platelike adjusting member I9 and may be secured in adjusted position by means of the screw 2l. The adjusting lever I8 is similarly pivotally mounted on the coacting platelike adjusting member 22 at 23 and may be secured in position by the

screw

2,4. The platelike adjusting members I9 and 22 are rotatably mounted on the bearing that is, they are angularly, rotatably adjustable concentric to 4the axis of shaft II. These platelike adjusting members I9 and 22 may be secured in adjusted position by the

screws

25, 25 and 27.

The plate member I9, which overlies the adjusting lever II, is shown in Fig. 5 broken away in order to illustrate the shape of the adjusting lever II and the manner in which it is rotatable about the pivot 2Q. The adjusting lever i3 carrying the contacts 8 is similarly formed and coacts in a similar manner with its associated platelike adjusting member 22.

In order to adjust the contacts, the screws 2i and 24 are rst tightened so as to connect or couple together the adjusting levers I'i and I3 with the respective coacting platelike adjusting i members I9 and 22. With the

screws

25, 25 and 2 loosened, the contact set 8 Ycan now be pivotally moved about the journal 5 by means of the lever I8, since the platelike adjusting member 22 has been clutched to or coupled with the lever I8 by the screw 25. The contact set t is rotated clockwise to a position in which the cam t oi the disk 6 is in the positionV I in which it begins to open the springs forming the contactset 8. The

platelike adjusting member 22 is then in the ad- Y justed position secured on the motor frame by tightening the screw 25 which has its head in a recess 32 in the platelike adjusting member i9.

The armature and therewith the cam disk 5 are held during this adjusting operation in an angular position in which the cam part 9. Vis in the position I. This holding operation is accomplished by the insertion of the wedge-shaped holding member 28 in coaction with one of the b straight edges of the disk I5.

The motor armature must also assume a deiinite angular position in the normal and in the resting positions of the switching mechanism operated by the motor. In this position, and as shown in Fig. 2, the cam 9 of the disk 5 has opened the contact 3 (see also Fig. 7). Contact 'I is closed. Contact an will'be closed to complete a circuit for the stator coil MI (Figs. 3 and 7) so as to start the motor. The armature now rotates and contact 8 will be closed so as'to switch in the stator coil M2. opened. Incident to further rotation the contact 'I will be closedV to switch in the stator coil MI and the contact 8 will be opened to disconnect the coil M2. This interplay continues.

termined by placing the armaturevand therewith the adjusting disk I5V into the angular position shown in Fig. l. The adjusting edge 56 of the The restingorr normal position of the motor armature is de- 4 example, it may extend at right angles thereto. The armature is held in this angular adjusting position by inserting the wedge-shaped holder member 28 between the adjusting edge 30 and the straight backing surface 29 formed on the motor frame I. The detent spring is adjustably mounted on the frame I and such spring is now manipulated intoengagement with the notch 36 on the detent ratchet I2, and is then secured in this position on the motor frame. It is understood of course that the baking surface 29 may be provided on a different part, for example, on an extension of a magnet core such as the core 3.

If the adjusting edge 3&3 of the disk I5 is positioned to extend in a plane parallel to or perpendicular to the axis of symmetry of the stator coils, which bisects the angle formed by the axes 2' and 3', as described, it is possible to change the direction of rotation (right or left hand rotation) of the motor without altering the determined armature position, simply by loosening the nut I5 and displacing the laminated armature stacks with their spacers by ninety degrees. The correct angular operating position of the armature results rom the angular position oi the detent ratchet as determined by the setting of the detent 35, which remains unaltered irrespective of the angular positions of the laminated armature stacks for either direction of rotation.

The angular armature positions in which the contacts I and 3 have to be respectively opened and closed do not correspond with the position of the armature, which has been determined by the aid of the adjusting edge 30 of the disk I5. The reason resides in the fact that the stator coil,

which is in circuit at the beginning otraV switch- Contact Ti is thereupon ing step of the mechanism, is disconnected aiter one half-step subsequent to the switching in of the other stator coil. During the second halfstep takes place the disconnection of the second stator coil subsequent to the re-connection of the rst stator coil, leaving this coil alone in circuit at the beginning of the next step of the switch.

The adjusting edges 3 I-Sll are provided on the disk I5 in order to hold the armature in the posiy tions in which the two contacts I and 8 are opened and closed by the cams on the cam disk 6. The cam 9 (Fig. 6) is, for example, in position I at the time when the armature is angularly positioned, so that one of the edges Bi-B- as-V sumes the position in which the edge 30 is shown in Fig. 1. The armature is then held by inserting the wedgelike holding member 28, and the adjusting lever and contact carrier I8 is adjusted as described before.

In order to place the cam 9 into the position II, the holder member 28 is removed and the armatureis rotated until another edge of the disk I5 is in position for the described coaction with the holder member 28. Y

The screw 24 is loosened, and the contact carrier having the adjustinglever I8 canY then be rotated about the pivot point 23. This pivot point is placed Vso that, incident to the angular displacement of the lever I8, the point of contact at the contact springs will move nearly in parallel with the edge ofthe cam when the cam is disk I5 is in this position parallel to the axis of symmetry of `the eld or stator coils, which bisects the angle formed by the axes 2 and 3.V

in position I; The adjustment ofthe contact 8k now rotated counterclockwise untilV the camV begins to separatethe contact springs. |Ifhe lever I8 carrying `the contacts Bis then secured in ad.-

ju'sted position by tightening the screw 2li;

The contacts 8 are now adjusted so that they always open and close at the proper moments during the operation of the switch controlled by the motor.

The adjustment of the contacts 'l takes place in two other positions of the armature and of the cam 9, which are again determined by means of the angular positions of the adjusting disk I5 in cooperation with the wedge-shaped holder 28. In the first of these two armature positions, the cam 9 assumes the position relative to the contact 'I which corresponds to the position I incident to the adjustment of the contacts 8. The adjustment carried out by the displacement of the platelike adjusting member I9, which is coupled with or clutched to the adjusting lever I1, is secured by the screw 21, thereby connecting the platelike adjusting member I9 with the platelike adjusting member 22 which is secured on the motor frame l by the screw 25. This latter screw does not impede the adjustment of the platelike adjusting member I9 due to the recess 32 formed therein. The second adjustment of the contacts 'I is then carried out, after loosening the screw 2|, in a further position of the cam 9 which corresponds to the position II, and such adjustment is secured by tightening the screws 2| and 26.

We claim:

l. A telephone switching device of the class described comprising a drive motor, said drive motor comprising a stationary frame, a shaft journalled in said frame, said shaft carrying a control cam and an armature, a plurality of coil-carrying cores on said frame for magnetic coaction with said armature to rotate said shaft, a plurality of contact sets operable by said cam responsive to rotation thereof for governing the actuation of said coils, and a device for adjusting the positions of said contact sets relative to the angular positions of said control cam to bring about actuation of said contact sets in predetermined angular positions of said armature, said device comprising a carrier for each contact set, a mounting member for each contact set, means for pivotally mounting each carrier on its associated mounting member, means for pivo-tally mounting said mounting members on a common axis, a polygonal adjusting disk carried on said motor shaft, said disk forming a plurality of straight edges, a straight baking surface formed on a stationary motor part, and a holder member for insertion between any one of the straight edges formed by said adjusting disk and said stationary surface to hold the motor shaft and associated parts including said cam and said armature in predetermined angular position for subsequent angular displacement of the respective carrier and mounting members of said contact sets to adjust said contact sets for predetermined actuation by said cam.

2. The structure dened in claim 1, together with a detent ratchet on said motor shaft which is rotatable therewith, a detent spring for cooperation with said detent ratchet and means for adjustably mounting said detent spring, one of said straight edges on said polygonal adjusting device determining responsive to insertion of said holder member the angular position of said armature which corresponds to a predetermined operating position of the switching device controlled by said drive moto-r, and means for adjusting in this angular position of said armature said detent spring for coaction with said detent ratchet.

3. In a telephone switch of the class described having a motor including a shaft carrying an armature which is rotatable responsive to energization of associated stator coils in circuits including two control contacts, one control contact for the circuit of each stator coil, a device for adjusting the angular positions of said control contacts relative to said armature to secure proper operation of said stator coils, said device comprising a control cam disposed on said shaft for governing the actuation of said contacts in different angular positions of said armature, a pair of adjusting members for each of said contacts, means for successively holding said armature in two successive predetermined angular positions, means for angularly adjusting in one of said positions of said armature concentrically with respect to the axis of said shaft a rst one of the adjusting members of one of said pair of adjusting members associated with one of said control contacts to place such contact into an angular position in which actuation thereof can be started by said control cam and fixing such adjusted position of said rst adjusting member, and means for thereafter angularly adjusting in the other held position of said armature a second one of said adjusting members associated with the same contact eccentrically with respect to the axis of said shaft to place such contact into an angular position in which operation thereof by said control cam is completed without altering the position of said contact effected by the adjustment of said rst adjusting member.

4. The structure dened in claim 3, comprising means for rotatably mounting said second adjusting member on said nrst adjusting member, and means for xing said second adjusting member in the adjusted position.

5. The structure defined in claim 3, comprising means for mounting the associated contact on said second adjusting member, means for rotatably mounting said second adjusting member on said first adjusting member, means for securing said second adjusting member in adjusted position on said first adjusting member, and a handle for said second adjusting member to carry out adjustment thereof and also 'adjustment of said rst adjusting member.

6. The structure defined in claim 3, wherein said means for holding said armature in predetermined positions comprises a polygonal disk having a plurality of straight edges mounted on said motor shaft and rotatable therewith, a fixed member forming a straight backing surface, and a wedge-shaped `auxiliary removable member for insertion in engagement with said straight surface and selectively with one of said straight edges.

WILLY LOI-IS. FRIEDRICH SOMMER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 787,292 Hatch Apr. 1l, 1905 1,649,060 Decker Nov. 15, 1927 1,805,164 Carter May 12, 1931 2,002,546 Muller et al May 28, 1935 2,202,698 Latta May 28, 1940 2,433,608 Handley Dec. 30, 1947 FOREIGN PATENTS Number Country Date 19,146 Australia of 1929