US1693027A

US1693027A - Automatic switch

Info

Publication number: US1693027A
Application number: US465356A
Authority: US
Inventors: Erickson John
Original assignee: Automatic Electric Inc
Current assignee: Automatic Electric Inc
Priority date: 1921-04-29
Filing date: 1921-04-29
Publication date: 1928-11-27
Anticipated expiration: 1945-11-27
Also published as: GB179157A; FR550743A

Description

Nov. 27, 1928. 1,693,027

J. ERICKSON AUTOMATIC SWITCH Filed April 29, 1921 l'm ran [Jr-- Patented Nov. 27, 1928.

UNITED STATES PATENT OFFICE.

JOHN ERIGKSON, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

AUTOMATIG ELECTRIC INC.; OF CHICAGO, ILLINOIS, A CORPORATION OF DELA- WARE.

AUTOMATIC SWITCH.

" Application filed April 29, 1921.

The present invention relates in general to automatic switches, although certain details are not confined specifically thereto; and has for its object the provision of certain mechanical improvements tending to make such switches more easily adj ustable, together with the addition of other desirable features that will not be specifically mentioned now, but I will be explained in the detailed description which is to follow and pointed out in the appended claims.

The invention is illustrated in the accompanying drawings, in which Fig. 1 is a side view of the switch which is of the same general type as that described in United States patent to Clement, #1,107,153, granted August 11, 1914, being, however, of the-particular type shown and described in the book entitled Automatic Telephone Practice, by Harry E. Hershey, third edition. Fig. 2 is a detail as seen from the other side and has parts cut away to expose more of the special indicator shown therein. Fig. 3 is an end view of the driving magnet. 25. Referring now particularly to Fig. 1, the bank of contacts shown therein is denoted generally by the reference character 2. This bank of contacts is adapted to be wiped over by the wiper 3 and is so arranged that as soon as one wiper arm passes off the last bank contact, in rotating,-the other wiper arm comes into engagement with the first contact. In this specific switch there is no common plate in the bank with which one of thewiper arms is in constant engagement, but the terminal 29 is oneterminal of a brush which extends to and makes continuous contact with the wiper 3, while the terminal 30, Fig. 2, is one terminal of a brush which makes contact with the wiper 4. The wiper 3, being a test wiper, has its two contact tlps flattened out so as to be able to come into engagement with a second contact before it is out of engagement with the one from which it is passing. Wiper 4, however, being a line wiper has its tips so shaped that it is never in engagement with more than one contact at a time. The ratchet wheel 28 and the wipers 3 and 4, together with Serial No. 465,356.

as many other wipers as may be desired are rigidly secured to a common spindle which is rotatably mounted in the frame 20.

The ratchet wheel 28, and likewise. the aforesaid wipers, are driven, in a forward direction only, by the driving magnet indicated by the reference character 5. Each time the said magnet is energized, it attracts the armaure 6, the top end of which is forced to the right against the tension of the spring 7. The pawl 8, carried by armature 6, is caused to engage another tooth in the ratchet wheel 28 00 by the spring 9. When the said magnet deenergizes, the spring 7 forces the armature 6, and likewise the pawl 8, to the left until the former comes into engagement with the back stop 26.- The pawl 8 in returning to its resting on position advances the wipers 3 and 4 into engagement with the next set of contacts. This operation may be repeated as often as desired.

In order to be able to adjust the normal position of the armature 6, the back stop 26 is eccentrically pivoted on the screw 25. It is obvious then that by rotating the back stop 26 back and forth, the normal position of armature 6 may be adjusted as desired.

In order to limit the forward stroke of armature 6, the machine screw 14 is screwed into a threaded hole in the said armature.

.This screw, being made of soft iron, is really an extension of the armature. The head of the screw is provided with a number of teeth, as shown, which engage a projection 13 on the locking spring washer 12. In order to keep the spring washer from turning, two ears formed thereon fit snugly in corresponding holes in the armature 6 as is seen most clearly in Fig. 3. It is now seen that by turning the screw 14 one way or the other, the forward stroke of armature 6 is easily adjusted, the adjustment being maintained by the locking washer l2.

Referring to the construction of the bank 2, it is seen that it is assembled entirely on the bank frame 21, which is cut from a single piece of heavy sheet metal. This construction has been found to be very economical and satisfactory, but it sometimes happens that the frame 21 becomes warped due to its being tightly screwed to an uneven shelf, or it may happen that it is not mechanically'perfect. In any event it often happens that the spindle to which the wipers 3 and 4 are secured does not come exactly in the center of the circle of which the bank contacts form a part, when the switch is finally assembled and mounted in the place in which it is to remain permanently. In that event it is desirable to be able to adjust the relative positions of the bank frame 21 and the switch frame 20 so that the center of the spindle to which the wipers are secured coincides with the center of the circle of which the bank contacts form a part. It will be noticed that the before mentioned frames are fastened together by the two screws 22 and 24. In addition there is provided a hollow set screw 23 which is screwed into a threaded hole in the frame 20. By loosening the screw 22 and turning the set screw 23 backward and forward and again tightening the screw 22, the frames 20 and 21 are brought closer together or pushed farther apart, thereby adjusting the before mentioned centers in one direction. In order to provide for a slidin adjustment between the frames 20 and 21, t e hole in the set screw 28 is purposely made larger than the screw 22, and the hole in the frame 20, through which the screw 24 passes, is slotted lengthwise the frame so as to allow the latter to slide backward and forward.

Another feature of the present invention relates to the pawl spring 9, which is peculiarly constructed so as to facilitate its easy removal. The spring normally fits into a groove, cut in the extended pivot 10. Now, when it is desired to remove the said spring it is necessary only to unclip the same from the armature 6 and remove it from the pivot 10, as the coil in the said spring is made sufficiently large to allow it to come off easily.

Referring now particularly to Fig. 3, the rod 35 on which the armature 6 is pivoted is recessed at both'endsand the slotted spring 36 engages the rod at the recesses in the manner shown, so as to retain the rod in position.

As has been mentioned before, Fig. 2 is a detailed showing of'an indicator, denoted by the reference character 27. Little need be said in this connection except that the pointer 31 points to the number on the rotatable indicator 27 that corresponds with the set of contacts upon which the wipers are standing.

.Having described my invention, what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim as my invention is:

1. In a step by step switch, a driving magnet, an armature for said magnet, and a pole piece inserted in said armature adjacent to the core of said magnet adapted to engage the core when said armature is attracted, said pole piece being adjustable relative to the armature to limit the stroke thereof.

2. In a step by step switch, a driving magnet, an armature for said magnet, a threaded hole in said armature opposite the pole of said magnet, an adjustable pole piece screwed in said, hole and adapted to register with the core of said magnet when the same is ener gized, and means for preventing said pole piece from turning in said hole. I

3. In a step by step switch, a driving magnet, an armature for said magnet, a threaded hole in said armature opposite the pole of said magnet, an adjustable pole piece screwed in said hole and adapted to register with the core of said magnet when the same is energized, a head for said pole piece on the opposite side of the armature from the magnet, and a spring washer between the head and the armature to keep the pole piece from turning.

4:. In a step by step switch, a switch frame, rotatable wipers and driving mechanism therefor mounted on said frame, a series of bank cont-acts mounted in the arc of a circle on another frame separate from said switch frame, means for securing the two frames together with the axis of the wipers approximately in the center of the banks, and means for adjusting one frame relative to the other to exactly position said wipers.

5. In a driving mechanism for an automatic switch, a ratchet wheel, an armature, a pawl pivoted on said armature and adapted to engage the teeth of said ratchet, a projection on the pivot and an enlarged head forming a recess between the head and pawl, and a coil spring mounted on the pivot in said recess, one end of said spring engaging the pawl and the other the armature, and the diameter of the coils being large enough to permit the spring to he slipped over the said head.

6. In a step by step switch, a switch frame, movable Wipers and driving mechanism therefor mounted on said frame, a series of sets of bank contacts mounted on another frame,

means for securing said frames together to enable said wipers to engage said contact sets successively, and means for adjusting one frame relative to the other in order to exactly position the wipers on any contact set which they engage.

7 In a step by step rotary switch, a series of bank contact sets arranged in a semi-circle, two sets of wipers 180 apart adapted to engage said contact sets successively, and means for indicating the number of the bank contact set with which the wipers are engaged, said means comprising a pointer and a dial bearing duplicate series of numerals, one series for each wiper set, arranged in a complete circle.

8. In a switching device, bank contacts, a wiper adapted to successively engage said contacts, a dnving magnet, an armature for said magnet, a pawl pivoted to said armature, a crum, the coil being large enough to pass over serrated driving wheel for moving said wiper, said head when either end of said spring is 10 a removable coil spring formaintaining said not in position, and being reduced in size pawl in operative relation with said wheel, and held in position by said head when both and a fulcrum for said coil spring having a ends are in position.

flattened head, the ends of said spring engag- In Witness whereof, I hereunto subscribe ing the armature and pawl, respectively, and my name this 22d day of April, A. D. 1921.

the coil of said spring encircling said ful- JOHN ERIGKSON,