US1519343A - Restoring means for automatic switches - Google Patents

Description

Dec. 16, 1 24- 1,519,343

A. H. ADAMS RESTORING MEANS FOR AUTOMATIC SWITCHES Filed Jan. 18 1922 am M.

INVENTOR BY [mi (ii-WV ATTORNEY Patented De ARTHUR H. ADAMS, OF LAKEVILLE, CONNECTICUT,

PATENT OFFICE.

nssrenon 'ro THE NORTH nLno- TBIG MANUFACTURING COMPANY, OF GALION, OHIO, A CORPORATION OF OHIO.

T all whom it may Application filed. January 18, 1922. Serial No. 530,135.

Be it known that I, ARTHUR H. ADAMS, a citizen of the United States, residing at Lakeville, in the county of Litchfield and State of Connecticut, have invented certain new and useful Improvements in Means for Automatic Sw tches,

the following Restoring of which is a specification.

My invention relates to automatic s vitches of the two motion type such as are used 111 automatic telephone exchanges, and particularly to means for restoring the switch to its normal position when released. Switches of this character are provided with a large number of accurately aligned terminals with which movable switch elements, commonly termed wipers, contact. Electromagnetic means is provided to move the wipers into operative engagement with the desired terminals, the wipers being held in this position by a latch. Upon the release of this la'tch, the wipers are restored to normal through the in the force of gr In switches strumentality of a spring and avity.

where the wipers have two components of motion at right angles, in

order ternnnals,

to reacha large number of contact considerable difficulty has been experienced in arranging spring restoring means so as not to produce inequality of pressure between the wipers and terminals in different parts of the contact bank sufficient to impair the operation of the switch. In the first rows of the contact bank, the contact between the wipers and fixed terminals electrical connection is established, while the wipers may perhaps bind or last rows of the bank. restoring means,

stick to the terminals in the With the usual spring a rather delicate adjustment of the switch Wipers is required on account of the restoring spring.

It is the ob variation in the tension of the ect of my invention to pro vide improved restoring means for a machine element motion. A further object having two components of 18 to provide an automatic switch of the type described with spring restoring means wh ch will not cause the wipers an stick together.

d; fixed terminals to bind or My invention may be readily comprehended from a consideration of the switch structure disclosed in the accompanying drawing which illustrates an automatic switch embodying a preferred form of the invention.

Referring to the drawing, the switch comprises a series of fixed terminals, 1, assembled into a semi-cylindrical contact bank, 2, and movable wipers, 3, carried by the shaft, 4, and adapted to contact with the fixed terminals of the bank. Other wipers, 5, may be provided upon the shaft, 4, and adapted to contact. with a second terminal bank, 6. The shaft, 4, is mounted for rotary and longitudinal movement in suitable ball-bearings, such as 7, in the switch frame. The terminal banks, 2 and 6, are carried by the frame in fixed relation to the wipers, 3 and 5. Secured to or integral with the shaft, 4, is the ratchet, 8. Mounted on the shaft, 4, are the longitudinal ratchet, 9, and the latch rack 10, adapted to move longitudinally with the shaft, 4, but not to rotate therewith. A ratchet pawl, 11, operated by an electromagnet (not shown) is adapted to engage the ratchet, S, to rotate the shaft and wipers. A similar paw, 12, co-operates with the ratchet, 9, to lift the shaft and wipers vertically, it being understood. that the number and spacing of the teeth upon the ratchets 8 and 9, corresponds with the number and spacing of the rows and the contacts per row in the contact banks, 2 and 6, so that the wipers, 3 and 5, may be rotated into alignment with a desired row and then raised into engagement with any desired contact of the row. A latch, 13, co-operates with the rack, 10, to maintain the wipers in the actuated position until the latch is released by an electro-magnet or other means.

Rot-atably mounted upon the shaft, 4, is a collar, 14-, adapted to have a. slight lost motion or play along the shaft as shown. Attached to this collar is a coiled spring, 15, the other end of which is fixed to the shaft, 4. A pin, 16, projects from the collar, 14, and co-operatcs with an upstanding rod, 17, mounted in a switch frame parallel to the shaft, 4. The points of attachment of the gularly displaced around the shaft so as to provide a component of spring tension tending to twist the collar and thereby to hold the pin, 16, in engagement with the guide rod, 17.

In the operation of the switch, it will be seen that the top of the spring, 15, will be twisted still further around the shaft while the lower end of the spring is held practically stationary. To avoid increasing the longitudinal component of the spring tension, I permit the collar, 14, to have considerable longitudinal play along the shaft. A broken rod, 18, is inserted in the convolutions of ,the spring, 15, to prevent the latter from twisting into a helical shape about the shaft. In the vertical movement .of the wipers, the collar, ll, is carried along by the shaft, 4, and there is no change in the relation ofthe spring to its associated elements.

Supposing the switch has into 0 e-rative position as described above, with tile wipers, 3 and 5, in engagement with certain contacts in the terminal banks, 2 and 6, when return of the switch to normal is desired, :the latch, 13, is removed from engagement with the co-operating tooth on the rack, '10. The weight of the shaft and wipers carries them vertically downward until the wipers clear the bottom contacts of the bank, whereu on the rotary component of the tension 0 the spring, 15, returns them to the normal position shown,

It will be apparent that the rotative force of the return spring 15 depends upon the tension of the spring and the amount of twist between the ends of the spring with respect to the shaft. This is the force which tends to cause binding of the wipers upon the bank contacts. On account of the length of the spring 15 and the fact that its tension is hardly changed when the wipers are rotated from the first to the last row, tative force upon the wipers does not vary appreciably in different parts of the contact bank. Accordingly the tendency of the wipers to bind or stick u on the contacts in the last rows "of the bank is materially reduced, as it is possible to adjust the switch for a definite rotary tension but not for a widely varying tension.

do not consider my invention to be limit ed to the precise embodiment herein shown and described, as it may be applied to other devices of a similar nature, and various modifications will suggest themselves to those skilled in the art.

I claim:

1. 'In combination, a frame, a shaft mounted for longitudinal and rotary movement therein, shaft. means engagingthe collar to limit its rotation in one'clirection with respect to the frame, and a helical coiled spring fastened been brought a collar rotatably mounted on the to said collar and shaft, the points of at tachment of said spring to the collar and shaft being twisted with respect to the shaft to provide a rotary com onent of force.

2, In combination, a ramem shalt mounted therein, means for rotating the shaft, means for moving the shaft longitudinally, and restoring means for the shaft WW ing a helical coiled spring attached thereto and a rod inserted within the convolutions of the spring.

3. In combination, a frame, a shaft mounted therein for rotary and longitudinal movement, a collar rotatably mounted on the shaft, said collar having .a limited amount of play along the shaft, means for linutin the rotation of the collar on the shaft wit respect to the frame, andahelical coiled having its ends attached to the collar the shaft re ctively.

4. In com ination, a shaft, means for rotating the shaft, means for moving the shaft longitudinally, a non-rotatable element ads:- cent said shaft and means for restoring e shaft comprising a helical coiled spring having one and secured to said shaft and the other end secured to said non-rotatable element the ends of said spring being twisted with respect to the shaft to provide a rotary component of force.

5. In a switch of the type described, a plurali of fixed terminals arranged in yertical an' horizontal planes, a movable switch wiper, actuating means for moving said wiper into engagement with any of said terminals, and resiient means acting with substantially uniform tension upon said wiper to restore it to normal.

6. In a switch of the type described, a vertical shaft, means for rotating the shaft, means for moving the shaft vertically, a

wiper on said shaft, a plurality of fixed terminals arranged inrows in the path of said wiper, and means for rotatlng the shaftback to its normal position compris ng a helical coiled spring secured to said shaft and arran d to exert a substantially uniform rotatrve tension thereon.

In a switch of the type described, a vertical shaft, means for rotating the shaft, means for movin the shaft vertically, a wiper on said sha t, a plurality of fixed terminals arranged in rows in the path of san! wiper, a movable member adapted to move vertically with said shaft but not to rotate therewith, and restoring means for the shaft comprisin r a coiled spring secured to said shaft an said movable member and arranged to exert a substantially uni-form rotative tension upon the shaft.

8. In a switch of the type described, a frame, a vertical shaft therein, means for rotati-ngthc shaft, means for moving the shaft vertically, a wiper on said shaft, a plurality of fixed terminals arranged in rows in the path of said wiper, a collar rotatably mounted on said shaft and having a limited amount of vertical play thereon, means for limiting the rotation of said collar in one 5 direction with respect to said frame, and a helical coiled spring attached to said shaft and said collar, the points of attachment be- ARTHUR H. ADAMS.

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