US2262471A - Selective electric switch apparatus - Google Patents

Description

, 1941. M H. SHOENBERG SELECTIVE ELECTRIC SWITCH APPARATUS Filed Sept. 16, 1958 2 Sheets-Sheet l m W Wm Pl 1 I \S l m m Z M M m -i--- m m v M Fl ATTORNEY.

N v,-11,1 41. v M. H. SHQENBERG 2,262,411

SELECTIVE ELECTRIC SWITCH APPARATUS Filed Sept. 16, 1938 2 Sheets-Sheet 2 III/ 7 F EL INVENTOR. MILTON H $HOENBER6 ATTORNEY.

Patented Nov. 11, 1941 :UNITED SELECTIVE ELECTRIC swrrcn APPARATUS Milton H. Shoenberg, San Francisco; Calif.,

assignorto Julian Kay Application September 16, 1938, Serial Natl-30,303

7 Claims (01. 177-342) This invention relates principally to selective electric call systems adapted to signal any one of the plurality of stations on the line without signalling the other stations, and the invention has for its principal objects improvements in the 1 apparatus used in such systems whereby the mechanism is rendered simple and reliable; also "selective switch apparatus which will operate in any position without regard to gravity may be set for any desired code by use of aninterchangeablematrix; and also which will respond to regular code signal impulses made and timed manually through ordinary callbell operation, or an automatic transmitter.

Other features and advantages of tion appear in the following description and ac companying drawings, and are specifically set out in the appended claims.

In the drawings: l l

Figure 1 is a diagrammatic plan of the apparatus and electrical connections showing all of the principal elements of the invention.

Figure 2 is a cross section of a portion of Figure 1 as seen from the line 2-2 thereof.

Figure 3 is a side view of the matrix or interchangeable code plate, as seen from. the line 33 of Figur 1. l

the inven Figure fl is a fragmentary crosssection of a Figure 1, as seen from the line 4-4 thereof.

, Figure 5 is a detailed and enlarged plan view h of one of the timers to determine the timeinments of the mechanism. Figure 6 is a perspective terval between some of the contacts and movesketch showing the cord wound clock drumarrangement.

Briefly described, the apparatus may be said tobe an arrangement of selector switch elements preferably including a local operating circuit, and adapted to be hooked up through means of a relay to the call bell circuit'of any-of a plurality of stations on the line, one of the apparatuses being connected at each'stationin place of its call bell, so that its receiving relay will be operated by the incoming electrical impulses set upby any of the other'stati ons sending in a call as by turning the bell ringing crank 'for the desired number of short and long. calls for the particular station wanted, or by otherwise 'manually closingand opening a call switch, or "pressing a button switch successively forthe long and short bells constituting the call of the particular station desired. p The var'ious short and long calls operate suitable magnets to consecutively move a plurality of pivoted stops or fingers to a predetermined position; and'at which a movable matrix or code 7 plate arranged to fit over the stops or fingers. (when in such predetermined position only) moves and causes the signal circuit to be actuated for operating the signal, and which may be either a bellor a lamp, or other device which it is desired to operate. After a predetermined time of operating the signal, or predetermined time interval in case the signal does not operate (as when a wrong code has been sent) an automatically timed release returns all elements to their starting points. i

.In the drawings, l and 2 represent the common line wireswhich extend to any number of stations. Theelementsenclcsed within the dot and dash lines 33 constitute the selective switch elements andits local circuit.

At each station is a receiving or line relay A which, upon beingenergized by a currentimpulse: from the line wires, will close the local. cir-- cult at 4 as long as the impulse continues, and if the impulses received are those set up by the manual operation of an ordinary telephone bell magneto, a shaded magnet is used in the relay to stay closed with the slow alternating current, generally about 25 cycles per secondfrequency.

The local circuit includes a battery B or other source of switch operating current, for simplicity I here shown as grounded to the frame of the apparatus or common ground wire at one side, as

likewise arethe elements operated thereby, all I as conventionally indicated. B'efore describingthe construction of my improved selective switch assembly, its principal elementswill be named and each given a letter designation. C is the main operating magnet energized by the incoming call signals either directly or by Way of the line relay l 1 Dis a set of pivotally mounted superimposed fingers; or stops, the ends of which cooperate with 'the matrix orcode plate when the fingers are moved to various positions.

c E is the matrix or perforated code plate.

Fis a push rod which is operated by movement V of armature 5 of magnet Cto consecutively push the fingers to various positions depending on the lengthof time magnet C is energized;

G is a series of superimposed pivoted ratchet bars-respectively arranged for locking one of the r fingers D in whatever position it may be moved to by th push rod.

is a magnet which draws the code plate towards the ends of the fingers after a predetermined time following the last signal impulse.

I is any signal device, here indicated as a bell.

J, K are two clockwork mechanisms for controlling the time intervals between certain electrical contacts.

L indicates a plurality of coacting electric contact elements which successively come into action after the last signal impulse.

M and N are magnets which determine the length of the push rod stroke on any finger or fingers corresponding to the length of the signal impulse.

P is the resetting magnet which trips all of the ratchet bars G so that the fingers will return to starting position, and also lifts the push rod to its starting position resting upon the upper finger.

R indicates an anchor or frame portion to which a lever or rod is pivotally mounted.

S indicates fixed stops to limit motion of the various levers.

6 is the pivoted armature of the resetting magnet P.

1 is a pivoted lever on which the code plate E is removably secured as by sliding into grooves or retainers 8 at its ends and/or side.

9 is a sliding rod pivotally connected at In to the armature 6 of the resetting magnet.

II is an arm pivoted at l2 to a fixed point R and pivoted slotteclly at I3 to rod 9, and formed with a hooked outer end l4 extending under the push rod so as to lift the same over the topmost finger of the stack of fingers D when rod 9 is moved toward the push rod upon energizing of the resetting magnet. Rod 9 is slidably supported as in brackets l5, [6 (see Figure 4) and is provided with an upstanding'lug I! which engages all of the ratchet bars G to move them against the force of their individual return springs 42 enough to free the engaged ends of the fingers D so that they can all return to starting position by their individual springs [8 as soon as the push rod is lifted.

The timing clock mechanisms J and K each comprise the features shown in Figure 5, a cylindrical drum l9 pivoted on its axis 3| to a suitable frame (indicated generally as K) and provided at one end with a large spur gear meshing with a pinion 21 fast on a shaft 22 which also carries an escapement wheel 23 engaged by an escapement 24 mounted on a shaft 25 and the slotted arm 25 of which escapement is engaged by a pin 21 on a balance wheel 28 mounted on shaft 29 and fitted with the common type of hair spring 36 which may be provided with the usual adjustments for determining its speed of oscillation.

Passing about the drum I9 is a flexible cord, braided wire, belt, or very small chain 32 which takes about two turns around it (see Figure 6) and secures at one end to a small spiral tension spring 33 anchored at 34 to a fixed part R, all so that when this cord or string is pulled in the direction of the arrow (of Figure 5) it will at once grip the drum and revolve the clock mechanism under control of the balance wheel escapement, and under a given pull exerted upon it (superior to the pull'of tension spring 33) will only yield in the direction of the arrow at a definite rate of speed, yet if the cord 32 were suddenly released by the pulling agent, spring 33 would instantly twirl the thereby loosened cord loops about the drum (without materially reversing the clock) until the energy of spring 33 was spent or was balanced by resistance applied at the other end of the cord.

This timer is thus instantly started by a pull on the cord and as quickly stopped by relaxing the cord, and is applied to control the time interval between electric contacts by linking the cords of both clockworks through yielding connection to the movable armature 5 of magnet C as will now be described.

Armature 5 is pivoted at 35 to a fixed point R and is normally retracted by a coiled tension spring 36 connected to a lever 31 pivoted at 38 to a fixed point and which lever is also loosely pivoted at 39 to the push rod F so as to move the push rod to the left each time magnet C is energized, lever 31 being returned to starting point (against stop S when spring 36 is relaxed) by a weaker tension spring 4 I.

Armature 5 is also pivotally and insulatingly linked as by a wire link 43 with another lever 44 pivoted at 45 to a fixed point, but which latter link 43 has interposed in its length a spiral tension spring 46 of somewhat greater strength than spring 33 of the clockwork.

Clockwork J on the opposite side of armature 5 is similarly connected to armature 5 through the intermediary of a lever 41 (corresponding to 44) pivoted at 48 to a fixed point and to which the cord 32 of clock J connects, and which lever 41 is pivotally linked to armature 5 as by a wire link 49 interposed in which is a spiral tension spring 50 corresponding to spring 46 in strength so as to overcome the cord pull back spring 33 of clockwork J while having sufficient force in excess to do the work required.

Lever 4'! is also pivotally and insulatingly linked as at 5| with a spring return contact arm 52 of the group of contact elements L for operation as will later be described.

The wiring from the battery B to the various grounded magnets and movable contacts is generally designated W and since it is easily traced in the drawings the various leads need not be specifically described to unnecessarily prolong the description.

The superimposed fingers D are spaced apart as by washers or hubs 53 surrounding their common fixed pivot 54, the lower ends are each beveled as at 55 to fit any of the several notches 56 of the ratchet bars G which are also spaced to match and pivoted to a fixed axis 51. The outer ends of the fingers or stops D are reduced in size as indicated at 58 so as to readily pass through openings or slots provided in the matrix or code plate E when in certain positions. The openings and slots are indicated best in Figure 3 at 59, 60, 61 and 62.

Code plate lever 1 which is pivoted at one end at 40 carries an armature 63 adjacent the opposite end adapted to be attracted by magnet H and is normally retracted by a pull back spring 64 so that the code plate will clear the ends of the fingers D and also to hold open bell circuit operating contacts 65 at the extreme and of the lever.

All of the superimposed fingers normally are positioned at the right hand position against the stop S, and any of them may occupy any of the four positions indicated when moved from the first position by push rod F and held in the new position by the ratchet bars G.

Push rod F moves longitudinally back and forth between guides 61 upon lever 31 being rocked, and is formed with an offset 66 at its outer end adapted to overlie the uppermost of the fingers and drop to the next finger below upon each retraction of the rod, a small spring 68. being provided to insurethis' action sov as. to make it independentof. gravity, even if the whole switch assembly be mounted upside down.

To limit the forward. (left hand) movement of the pushrodto definite strokes, so as to selectively move the fingers from the: full line starting position to any of the three other positions D D D where they will be held by the ratchet bars G, I provide fixed and movable stops as follows: In starting position all fingers are to the? right in full line position against fixed stop S, and pushrod F- is retracted and its operating lever 3'! is to the right in full line position against stop 5. When magnetYC is energized and armature 5 is drawn to it, linking spring 36 at once pulls lever 31 to the left until its extreme end strikes a stop at 69' on pivoted armature arm of magnet M. and which arm is normally pulled down by a spring ll', andthis allows the push rod to move a finger from, the starting position to the second position D When magnet M is energized and its armature is lifted, lever 31 moves further to the left under the force of spring 36 until it is again arrested by a stop 12 formed at the end of pivoted armature arm 13 of magnet N, thus allowing. push rod to move the finger to the next position D When magnet N is energized its armature arm 13 is: drawn toward it against the: force of its. releasing spring", and thereby permits the push rod to move the finger to the thirdzpositionD against a common stop S for all. of the fingers and/or a final limit stop S for lever3].

If, new with. both magnets M and N holding their armatures out of the way of lever-61,. magnet C werede-energized, spring 4| would pull lever 31 and thepush rod back to starting position, but the. fingers would still be held by the ratchet bars G in the various positions to which they had beenmoved, and also the push rod would have dropped to the lowest finger not yet pushed from starting position or to the plane of the lowest one if that alsohad been moved.

T0 release the ratchet bars sothat the fingers can return to starting position under the action of their"individualsprings l8 and also to raise the push rod to thetop finger again, the resetting magnet P is energized to draw its pivoted armature arm 6 upward to release ratchet bars G from the fingers, so that they at once return to starting position.

The matrixor code plate E may be of sheet metal or composition material and its openings 59 to 62 are inline with the four positions which the ends of the'fingers may "assume, the hole or slot 59 being of a length to receive .all ofthe fingers not moved from starting position and the other openings being respectively of a length (across the plate) to only receive one or more fingers at their positions as the particular, code for that station may, require, thus the black dashes in the openings of the code plate of Fig. 3 indicate the ends of the fingers as properly moved for that plate, and show its code tobe:

One long, two short, and two extra long, and with one finger still being in starting position aligned in hole 59.

Itwillbe evident from a study of Figure 3 that with any other position of the fingers, the code plate would not fit over their ends and armature lever I could not be drawn toward magnet H to close the alarm bell circuit at 65, for if any of the six fingers were displaced in either direction from the positions shown they would be opposite the blank wall of the plate and form an effective stop against its movement.

While the illustration shows but six fingers and three positions of each, not counting the starting position, it is evident that a greater or lesser number of fingers or positions may be used if desired, though the number shown provides fora great many different codes, the simplest being but one short signal impulse to move the uppermost fingerto position D. As the push rod drops to the next finger upon each retraction, it is evident that the positions of the already moved fingers above do not interfere with any desired moving of successive fingers.

It will be evident from the above that in order to change the code at which a station can respond, it sufiices to merely slip the code plate or matrix, out of its retaining grooves or from any other securing means used, and substitute one with a different arrangement of holes and slots. It is also evident that the code of each code plate may be fread off as it were, by glancing at the plate, as explained for the plate ofFigure 3.

iii)

A description of operation of the various electric contacts to energize the various magnets in proper sequence will now be made.

Upon a short energizing impulse sent through magnet C as by a momentary pressure of a remote signal. button and release, or short twist of the magneto crank, lever 31 is instantly pulled to the left to stop 69 and the upper finger is moved to position D but as the current is broken again in a moment thelever 31 and push rod returnto starting position, but the push rod has fallen to the next finger.

Assume that the next impulse is a long onei. e. held closed for a few seconds (say two or three as may be predetermined by the initial setting of the apparatus), in such case lever 31 will first stop at 69 but as spring 46 is under tension clockwork K is: set in motion to gradually unwind or pay out cord 32 to permit lever 44 to slowly move to the left and close a contact at 15 which at once energized magnet M tolift stop 69 and permit'lever 31 to move to stop 12 to bring the finger to position D If the long signal contact made is extra long,

say five seconds or more (as may be predetermined), then contact 16 would also be closed by the moving lever 44 through the yielding of spring arm 96 to energize magnet N, and permit the push rod to move the finger to position D Assuming now that one extra long bell were the correct code for this station, there would only be a hole in the code plate over the end of this finger at position D while the unmoved fingers would still be opposite a hole or slot to accommodate them only formed in the plate. Now, upon release of the long signal, all the parts just considered including the clockwork controlled cord 32 return instantly to starting position, but as spring 36 is considerably superior to spring 56, it stretches the latter and yieldingly pulls on lever, 41 which at once starts clockwork J to slowly pay out cord32 and thus similarly control the speed of movement of lever 41.

Lever 41 being insulatingly linked at 5| to spring contact arm 52 will first close contacts 11 and thereby, through already closed contacts I8, will energize code plate magnet H to pull the plate down over the finger at D3 and at the same time close contact and ring the bell I.

Continued movement oflever 41, however, will break the code plate. magnetcircuit at contacts 18 by contacts 11 moving a dummy spring arm 'l9 to right, and through it will make contact at 80 to energize the resetting magnet P to trip all of the fingers and push rod back to starting position as previously explained,

The energizing of the resetting magnet is only momentary, however, as lever 47 still has a small way to go before it meets stop S and hence it continues to move spring dummy arm 1'9 as well as spring arm 8| to the right until it breaks the resetting magnet circuit at 82, and which is the final position of rest of the parts, until. a new signal comes in.

It should be noted that contact carrying arm 83 is not a spring arm or strip as are the others, but is fixed, though its contact point as well as any of the other contact points are either adjustable on their arms, or the arms may be individually bent more or less to yield the desired make or breaking point during the travel of lever 41. Such well known adjustability of the points is also presumed for contacts 15, 16 and 85 as is common in all electric contact apparatus of this kind.

When the next signal comes in and armature snaps to magnet C, spring 50 is completely slacked ofl, or sufliciently so for clockwork spring 33' to instantly return the cord around the drum and pull lever 4! to the left until it meets a stop S, and all of the contacts at L will be open except 82 and 18, which will be closed, and this is the position they are shown in the drawings as it is presumed that armature 5 has just this instant been released and lever 41 is just starting to move. Under such condition at least one of the fingers would be displaced from starting position as this would be before the tripping magnet P was energized, and it makes the action of the contacts easier understood to show it this way.

To minimize the battery drain when the magnets are energized, any of them may have a resistance automatically brought into its circuit after the initial contact as it requires but a fraction of the energy to hold the armature in place after the flux is built up. Such an arrangement is shown at magnet C where 84 is the resistance coil through which the energizing current must pass upon the moving armature 5 striking a spring contact arm 85, and breaking the direct energizing circuit at 88, the resistance coil 84 being figured to pass only enough current to hold the armature. This feature also reduces arcing at the terminals 4 when the contact is broken.

An important feature of the apparatus is that as each station is to be equipped with it, the successive positions of the fingers are clearly heard by the click set up by the lever 31 striking the stops as well as the snap of the spring ratchet bars as they engage the ends of the fingers. Thus one click tells that the short contact has done its work to move the finger to position D two clicks that the longer contact has moved the finger to the position D and so on. Yet if desired, a visible indicator hand 81 may be attached to lever 31, or to the push rod, to successively come to figures 88 arranged on a suitable dial 89, to show when the particular length of call has completed its action. In practice, however, as several seconds between lengths of call signals can easily be predetermined so as to correspond with the average manual operation of magneto call bells, such a visible or audible signal may be dispensed with.

Having thus described my improved selective switch apparatus and the manner of its operation, it will be evident to anyone skilled in the art that many changes in detailed construction may be resorted to without departing from the spirit of the invention, and also that although I show the apparatus arranged to operate on a normally open circuit, that it may be equally applied to a closed circuit system, and the words contact or making or breaking a circuit are equally applicable to the opposite terms for closed circuit work, and my appended claims are intended to cover either arrangement, as well as any variation in mechanical structure which produce the effect and results above set forth.

Also, while I show my apparatus arranged to operate a signal, it is manifest that the signal circuit may be any other circuit which it is desired to selectively make or break, and any such variation is intended to be covered in my claims.

Attention is called to the fact that on account of the exaggerated size and movement of the fingers shown in the drawings for clarity, the final positions of the ends of the fingers lie on a curved plane, whereas the code plate shown is flat, and hence it requires a much greater movement of the code plate to close the signal circuit, as some of the fingers are much further away from the plate than others. In actual construction, however, the ends of the fingers are very small and their different positions are relatively close together so that a flat code plate functions very nicely, though it is evident where the apparatus is made to give still more positions of the fingers or the arc of their positions requires too much movement of the code plate, the pivotal point of the fingers may be greatly extended to give a flatter arc of movement or the code plate may be bent to the same are and the pivotal point of its supporting lever placed to reduce the movement required to the minimum.

It will be noted from the above description that in an existing telephone installation operated with magneto bell code, my apparatus may be placed in any number of the stations while leaving some still without it, and that if the proper code plates be used the old hand-made signals may be made just as before without requiring any instructions to the users who need not even know that a selective apparatus was intercepting their hand-made bell calls, but in such stations as are fitted with the selective apparatus the bell will only ring when the code of impulses for that particular station is called, unless more than one station is equipped with the same code plate. The bell will, of course, simply ring but will not ring the code.

Certain claims covering the switch controlling means including a clockwork for determining the time between the making of switch contacts originally included herein, have been filed in a divisional application, Serial No. 413,882, filed October 6, 1941.

I claim:

1. In a selector switch of the character described, a plurality of movably mounted stops, means normally holding the stops in one position, electro-magnetic means arranged to move the stops to a second position one after the other respectively upon successive momentary energizing of said electro-magnetic means, said electromagnetic means arranged to move any of said stops past said second position to a third position upon maintaining the energizing of said electro-magnetic means for a longer period of time, a sign-a1 circuit rendered operative by a final predetermined position of said stops, and means for automatically returning all stops to starting position upon the energizing of said signal, or after a predeterminedtime interval upon a failure to energize said signal.

2. In a selector switch of the character described, a plurality of superimposed pivotally mounted fingers, means normally holding the fingers in one position, electro-magnetic means arranged to move the fingers separately to a second position one after the other respectively upon successive momentary energizing of said electro-magnetic means, said electro-magnetic means arranged to move any of said fingers separately past said second position to a third position upon maintaining the energizing of said electro-magnetic means for a longer period of time, and movably mounted means cooperating with the ends of all of said fingers including any unmoved fingers when in predetermined arrangement arranged to operate a signal.

3. In a selector switch of the character described, a plurality of superimposed pivotally mounted fingers, means normally holding the fingers in one position, electro-magnetic means arranged to move the fingers to a second position one after the other respectively upon successive momentary energizing of said eleotro-magnetic means, said electro-magnetic means arranged to move any of said fingers past said second position to a third position upon maintaining the energizing of said electro-magnetic means for a longer period of time, and a movably mounted apertured code plate with its apertures formed to cooperate with theends of all of said fingers including any unmoved fingers when in predetermined arrangement arranged to operate a signal.

plate coincide with the positions of the ends of said fingers when moved, and the plate being completely movable to a point with said ends projecting into said apertures when they do coincide with the positions of said ends, and an electric circuit operated upon the complete movement of said plate.

5. In a construction asset out in claim 4, electromagnetically operated means for successively moving said fingers to various positions over the area of said plate.

6. In a construction as set out in claim 4, said fingers being normally positioned in a row, and electromagnetically operated means for successively displacing any number of them from said row.

7. In a construction as set out in claim 4, said fingers being normally positioned in a row, and electromagnetically operated means for successively displacing any number of them from said row to position in a second row, and optionally to a third row, means holding the fingers in all of the various positions to which they may be moved, spring means urging all fingers to return to starting position, and delay action means releasing the finger holding means to permit all to return to starting position.

MILTON H. SHOENBERG.

Images