US2293671A - Signal chime - Google Patents

Description

Aug. 18, 1942. L. M. ALEXANDER 2293571 SIGNAL CHIME Fld Jan. 8, 1940 2 Sheets-Sheet l i z INVENTOR.

W-'v6 f W ATTORNEY Aug. 18, 1942. L. M. ALExA-NDER 2.293.671

SIGNAL CHIME Filed Jan. 8. 1940 2 Sheets-Sheet 2 ATTORNEY5 Patente ug. 18, 1942 SIGNAL CHIME Lowell M. Alexander, Cincinnati, Ohio, assig'nor to Nu Tone Chimes Inc., New York,v N. Y., a corporation of New York Application January 8.1940, Serial No. 312,869

3 Claims. (Cl. 200-122) p yor tubes placed adjacent resonators for amplifying the sound. In some cases, the solenoids are arranged to operate between reeds, the

strikers of the solenoid being impelled flrst in thedirection of the one reed and then rebounding under the influence of a spring to strike the other reed to sound a second note. In many instances the lsound from the chimes of this type fail to attract the attention desired and the signals are unnoticed.

In some of the more expensive chime devices motor driven rotary switches have been used, both forrepeat signaling and for sounding a succession of notes of different`tone. However,

the construction of these chimes is quite complex; motor` are requisite, special transformers are required in most instanees and the chimes.

on the whole, have been much too costly to meet the public demand.

The present invention provides chimes which are capable of repeatedly sounding signals at periodic intervals when they are energized through 'a push button. For instance, four, five, eight or ten notes may be sounded at intervals of fractions of a second. The number of notes and the length of time elapsing between successive notes may be varied to suit the conditions desirable in the particular use of the chimes.

A primary objective of the present invention has been to provide a simple but rugged apparatus which can be constructed at low cost and which is capable of sounding automatically a succession of signals in response to primary manual control through a push' button.

A further object has been to provide a chime device embodying an automatic controller for I .repeat signaling which is sufllciently compact to be incorporated with the sound-producing appai'atus,` in order that the entire assembly may i tractive appearance.

A further object has been to provide a chime signal capable of Operating from the usual low voltage transformer of. forinstance, six, eight or fourteen volts, and capable of being installed readily in homes and oiiloes by connection to the wire outlets varranged to supply the usual bells or buzzers.

A still further object has been to provide at low cost. chime apparatus which is capable of sounding signals automatically at periodic intervals when energized initially by the mo- `mentary .depression of a push button.

Briefiy, the chimes of the present invention are energized repetitivelyln response to a primary manual control through a push button or the like, through. automatically operating thermoresponsive control elements. These preferably are bimetallic strips which are arranged to cooperate with one another and move or Warp in the same direction when heated.

For a chime tooperate satisfactorlly it must respond promptlv 'when a push button of the' type conventionally used is operated. Ifa sin-A g'le bmetallic element equipped with a heater is used to cooperate with a stationary contact several difflcultles are encountered in obtaining proper operation of the signals. The intensity of heat provided by the heater determines the rapidity with which the bimetallic element responds to the operation of a push button. If the heater is adjusted so that it heats the bimetallic element quickly to pbtain prompt response, then it is impossible to obtain the desired interval of time between the succession of signals, and a hammering or chattering effect isproduced. On the other hand, if the size of the heater is reduced so as to obtain the desired time interval between signals, then there is a long period, for instance, four to six seconds, elapsing before the first signal note is sounded after. the push button is operated.

The problem has been to obtain a signal which responds promptly to the operation of a push button andwhich also thereafter continues to sound a succession of notes at spaced time intervals so long as the push button continues to be depressed. This desirable result is obtained by using cooperating bimetallic strips each having a heating element, with the heating elements beinggso adjusted in relation to the bimeta'llic strips which they influence and in relation to each other that clrcuit making contact is es'- tablished promptly upon the operationof a push button, so that there is an immediatesignal response and that signals are sounded at spaced flcient to operate the sounding unit when all rei sistances are in circuit, but is sufllcient to operate the sounding unit when the resistance of the circuit is of lesser magntude.

The thermoresponsive elements operate to control the amount of lresistance in the circuit, periodically shunting a portion of it so as to permit to flow a current of sufl'lcient magnitude to operate the sounding unit.

In the preferred structure the bimetallic strips operate contacts which, when in engagement, shunt or`short circuit one of the heating coils. It is recommended that this latter heater. be of relatively high resistance, in comparison with the other, in order that the device respond promptly when the push button is depressed. The contacts normally may be either spaced apart or be in engagement with one another, as desired. In the following specification theyare 'shown and described as being spaced apart when they are in repose. Since the thermoresponsive elements move 'in the same directionthey are self-compensating in respect tochanges in am-l bient temperature.

In but a second or a fraction after the current flows lin the circuit, 'the high resistance heater warps its bimetallic element more than w the adjacent one so that the contacts are closed,

heater on the other element heats it and causes it to move away from the first and break the contact. This operation restores the first resistance in circuit and it in turn heats the first element to cause it to move toward the other and reestablish contact for repetition of the cycle.

Thus, the contact on the first bimetallic element moves toward the second. and the second then moves away from the first. Or otherwise expressed, the one contact is driven to uchase the other which recedes from itafter momentary engagement. At each engagement a note i's struck. These relative uchasing" Operations continue, according to one arrangement of the invention; so long as the push button is depresaed, with notes being sounded at intervals' of frac- 'tions of seconds more or less depending upon the electrical conditions and the' spacing of the contacts. It is to be noted that neither of the -re- 'sistances by which the bimetallic elements are warped is heated or energized continuously, and it is also to be noted that when the heaters are not energized they are cooling and therefore receding. It ls for this reason that the chasing of one bimetallic element by the-other takes illustrated generaliy at and comprises electri-I pressed. The term n`:hasing, as used in the' one moving toward the other when it is heated and the second moving away from the first when it is heated, the first thus relatively chasing the second.

In some instances it is desirable to have chime signals controlled from several different points. for instance, from a front door and from a back door. In vaccordance with the present construction, an individual solenoid striker is provided to respond to individual switches located at the various points of control. The switches are connected in parallel so that one or a plurality of strikers likewise connected may be controlled from but a single thermocontroller unit. This feature is. of course, very important from a cost standpoint.

These principles upon which the invention is predicated may be utilized in various modes of construction. A preferred embodiment of the invention and several illustrative modiflcations are shown in the accompanying drawings and those skilled in the art readily will comprehend the other modiflcations to which the invention is susceptible.

In the drawings:

'Figure l is a diagrammatic illustration of the' typical circuit of a chime adapted to be operated from two points of control such as a front door and a rear door.

Figure 2 is an illustration showing the striker mechanism for a tubular or gong type chime which may be used in place of thev resonator sounder of Fisur'e 1.

Figure 3 is a modiflcation of the circuit shown in Figure l. v

Figure 4 is a further modiflcation of the circuit shown in Flgure l. y

Figures 5 and .6 are diagrams illustrating the operation of the circuit of Figure 4.

Figure 7 is an illustration of a push button arranged to hold the primary circuit for auto-7 matic operation of a chime. I

Figure 8 is an illustration of a modified thermocontroller unit.

In'Figure l, the chime sounding mechanism ,is

cally operated Striker units 2, a resonator I. and a reed or chime bar 4 placed adJacent the resonator. Each of the Striker units comprises an armature I which is adapted to be moved magnetically when its surrounding solenoid coil is ener-V gized electrically. One of the strikers may be arranged to strike one bar then rebound to strike the other, for sounding double notes. if desirable. The details of the construction of these elements form no part of the invention, areA well known in the art and further description of them is not believed necessary.

The thermocontroller unit is indicated gen'- erally at 8 and comprises bimetallic element 'I and. a bimetallic element 8 placed adiacent one another and both preferably mounted upon an insulator block (not shown). It is contemplated that the thermocontroller unit and the sounding assembly I -be mounted upon a base plate and housed within an appropriate dust cover, although if desirable the thermocontroller can be installed independently of the sounding mechanism. The thermocontroller may be 'of very small size, so that the space it occupies is inconsequential.

.Bimetallic elements 1 and 8 carry cooperating contacts 9 and Ill. These contacts normally are spaced apartbut are sumciently closetogether so that theymay engage one anotherupon warpage of. one of the elements. The Spacing of the contacts governs, to an appreciable degree, the

promptness of response of the apparatus. In most instances satis'factory results are `obtained if they are spaced apartabout .001 inch, when in repose.

The strip 'I carries, preferably wound about it; In the remainder of the' a resistance-coil ll. speciflcation this coil is termed the low resistance heater. The strip I carries wound about it in similar fashion a resistance element |2 which, in the remainder of the specification, is termed the high resistance heater. Nichrome wire prefusually installed in the homes; therefore.. froxn the' manufacturing point of view, the-apparatus need only be provided with' terminals ll and li for connection of the 'device with terminals from the transformer. v

Two-respectiveterminals o the solenoids 2 are connected together through t r e leads IB and |1 to the lead I! taken from the terminal ll. The leads I 6 and |1 include push button switches IQ and 20. These may correspond respectively to the'front door and rear door push buttons in a home. i

The two other respective terminals of the solenoids 2 are connected together through leads 2i and 22, to a connector 23 which is fastened electrically to the -bimetallic strip I of the thermocontroller. One of the ends of the high resistance heater |2 is also fastened electrically to the bimetallic strip I and the otherend is likewise fastened to the bimetallic strip 1. A terminal of the low resistance heater il is fastened to the bimetallic strip 1 and the other end of this resistance heater is connected, through lead 24, to the other terminal IS of the apparatus. If desirable, the terminal of high resistance coil may be connected to lead 24 instead of to the bimetallic strip 1. Likewise, if desirable, only one eleotrostriker'unit need be employed in place of the two illustrated, with appropriate parallel connection to it of the switch leads IB and |1.

In the preferred construction, assuming that the device is to be operated on approximately 14 volts, the high resistance heater is of approximately 80 ohms and the low resistance heater of approximately 3.0 to 6.0 ohms. Under these conditions a currentl of approximately .3 ampere fiows through the circuit when the contacts I and" are separated. and the solenoids are adiusted so that they are capable of throwing the armatures i upon a current of approximately .85 ampere, but incapable of throwing the armatures if the current be approximately .3 ampere or thereabouts. These values are variable'over substantial limits and they are provided in this specification soleiy to illustrate typical conditions.

The .operation of the circuit is as follows:

When a given one of the push buttons i! or m 2| is depressed a current flowsv from the transformer through the push button to the solenoid with which it is in circuit and through the solenoid and the lead 23 to the thermocontroller. The solenoids are so connected that the deprescontrol.

Current ilowing through the lead 23 passes through the bimetalllc strip I, the high resistance heater I 2, through the bimetallic strip 1 and through the low resistance heater H back to the -transformer. At this time, the contacts I and ID are separated fromone another and the values of the resistances are such that the total resistance in the circuit may permit a current of approximately .3 ampere to flow, that is, a current insuillcient to operate the selected solenoid.

While the high resistance and low resistance coils are heated in unison more energy is expended in the high resistance coil and, therefore. the bimetallic strip` l is warped to a greater degree than the bimetallic strip 1, whereupon contact is-made between the contacts 9 and i..

With contact ll being in engagement with contact 8, the high resistance coil |2 is shunted, the

current flowing from the lead 23 through the bi-` metallic strip, the contacts O and 1| and the low resistance heater H back to the transformer. The current now increases to a magnitude suillcient to operate the solenoid 2 (for instance, .85

ampere) "and, therefore, its armature is actuated to strike the bar 4 and sound the signal. Meanwhile, however, the current of greater magnitude is also fiowing through the low resistance coil and it, in turn, is being heated substantially independently of the high resistance coil. Therefore the element 1 now warps away from the element 8 to break the engagement between contacts 9 and Ill.

But as soon as the contact is broken the high resistance is restorecl in the circuit. the current drops and the high resistance coil is heated causing further relative movement of the bimetallic e elements and causing consecutive contact of element ifl with element 9. While elementfl is short circuited it cools, andconversely, when the element is being heated, element 1 is not being warped appreciably since the resistance of its heater is, comparatively, small. By virtue of these conditions the elements do not move beyond a fleld of movement determined by the relative equilibrium which is reached through the alternate heating and cooling of them.

In the l'circuit of'Figure 3 the thermocontroller is the same as thatshown in Figure 1 and the same reference numerals are applied to the various parts 'of the circuit. However, a resistance 25 is connected across the lead 2| and the bimetallic element 1 so as to be in parallel. with the low resistance il. This arrangement presents several advantages. If the current required for the operation of the solenoid is in the neighborhood of approximately' ampere, (and y large to carry the current without undue heating, there is difnculty in wrapping the strip because of the stiffness of the wire. By the installation of`a resistor 2! in shunt with the low resistance heating coil ||,'the burdens imposed upon the latter are reduced and, therefore. the wire of this heater element may be of smaller size. The wire of smaller gauge does not stiffen the bimetallic element and, therefore. the bimetal'lic element 1 responds promptly when heat is 3 sion of either vpush button effects the same applied to it. .As a typical illustration of the electrical conditions employed in the circuit of Figure 3, the resistor 25 may be approximately 14 ohms, the low resistance heatenapproximately ll ohms and the high resistance heater the same as previously described.

The circuit of Figure 4 is similar to that of Figure 1 but is disclosed to show the utilization of a variable'resistance for adiusting the periodicity to which the signal notes are sounded, so that the beat of the signals may be decreased or increased according to the desires of the user.

The circuit shown in Figure 4 comprises front and rear door sol'enoid striker units 26 and 21 which are connected, through the leads 28 and 22 to a lead 30 from the terminal |4. The leads 2| and 2| include. respectively, the front door and rear door push buttons 3| and 32. The remaining terminals of the solenoids 28 and 21 are connected respectively through leads 33 and 34, to a common lead 2,5 which includes a variable resistance indicated generally at 18. This resistance is attached through lead 31 to the bimetallic element I, around which is wrapped the high resistance heater |2.. .as previously described. One of the terminala of the high resistance heater is attached to the bimetallic element 8 and the other to the'bimetallic element 1. and a connection ll is taken from the element 1 to the terminal li.

The low resistance heater ll is carried by the bi-metalllc element 1, but one terminal of this heater is connected to the lead 29 and the other to the lead 2|.

The variable resistance 26 is'employed so that adjustments for different supply potentials may bemade. For a given line potential. Variation of the rheostat effects Variation of the time intervals between successive notes. -As a typieal illustration of the electrical conditions which have been found satisfactory for this circuit. as-

- suming that the solenoids would throw their armatures when supplied with current of approxlmately .85 ampere and will fail to operate at approximately .3 ampere, the low resistance heater may be of 'approximately 24 ohms, the high reslstance heater may be as previously described, and the rheostat may be variable from approximately l to 'I ohms. As previously stated, these conditions are variable over substantially wide ranges and are provided to illustrate a typical embodiment for the beneflt of those skilled in the art.

The operation of the circuit of Figure 4,18 'shown diagrammaticaily in Flgures 5 and 6-. As inl/Figure 5, when the front door button is depressed the low resistance heater H is connected in series with the solenoid winding 21 and these stitution for the push buttons shown in the circuits of Figures 1, 3 and 4.

The holding apparatus comprises a bimetallic element 4|. carrying` a heating coil 42, one terminal of 'which is in connection with the lead 4| and the other with'the bimetallic element.

. The element 4| is provided with a latch 43 and two elements in turn are connected in parallel with the winding of the solenoid 20 which operates to sound the front door signal.-

w, As illustrated in Figure 6, when the push button 22 at the rear door is operated, the low reaistance'element ll is connected in series with the windins ofthe solenoid 2|, and these in mm are connected inparallel with the windins ot the solenoid 21 which operates the rear door nimal.

'rue push-button. mmm nie amator P18'- ure '1, is capable of holding the circuit to'the` chime for a predetermined interval of time when the push button is depressed. load: 8| and 4| with wmen this 'push button i: provided m connected in the circuit in the usual manner in subis resiliently mounted at the end opposite the latch. as upon a flexible member 44. A latch 45 carried on a shank 46 of the push button 41 is arranged to engage the latch 43 when the push button is depressed. The push button itself slides through a collar 48 which is in electrical connection with the lead i! and the collar in t'urn is carried in an insulating housing 49 which may be mounted to a door frame in vthe usual manner. The shank 46 carries a washer III within the housing for engagement with a compression spring 5|.

The latch 4| is conilgurated to move past the latch 4| and then be caught by it when the push button is depressed. An electrical connection is made through the lead 39, the collar 4|, the shanl: of the device and the latch 43, through the heating coil 42 and the lead 40. When current ilows the heating lcoil- 42 warps the element 4| causing it to drag the latch 48 from engagement with the latch 45 and permit the push button to be released under the influence of the spring 5|. The interval of time required is dependent upon the extent of eng'agement of the latches and the intensity'of the heat generated in the coil 42. In a typical apparatus the push button, once depressed, may be released after approximately 6 or 8 seconds, during whichl time the pushy button completes the circuit to the chime apparatus so that a succession of signais is sounded automatically.

The thermocontroller element shown 'in Figure 8 is of a modified form and comprises a strip portion 52 and a strip portion 53 which are welded or connected at adiacent endwise portions to form a lsubstantially continuous strip element. Portion 53 carries a contact 54 which cooperates with a contact 55. These contacts function in the same manner as the contacts land lflasshowninFlguresl and 2.

The portion", at the end opposite the contact S4, is supported in a suitable pillar or mounting member-55 and the portions 52'and 53 are so connected that they warp in opposite directions whe they are heated, that is, the extremity of the portion 52 moving in the direction of the upper arrow and the portion 52 moving in the direction of the lower' arrow, as shown.

' The portion 52 carries the high resistance heater |2 and the portion 52 the low resistance heater ll. The electrical connections to these heater elements may be as descrlbed in connection with Flgure l or exactly the same as those shown in Figure 2 and, therefore, further description is unnecessary.

When the heater coil |2 is energized the blmetallic element' 52 is warped upwardly and carries contact ll into ensaement with con- -tact II. Conversely, when the contact is made and heater, |.2 is shunted, the heater element il of v warps the latter element downwardly to open the contact. 4

It will be noted from the foregoing description of all of the circuits that th'e arransements provide several important advantages. The thermocontrollers are self-compensating. Variations in the temperatures of the atmospheres surrcunding them will not change their mode or frequency of operation. Sparking at the contacts through which resistance is shunted is greatly reduced since the current through the contacts is not cut off completely when the contacts are opened, but only changes from a relatively high value to a relatively low value. Moreover, there is no difiiculty in the making of contact whether the tension be relatively strong or relatively weak.

Having described my invention, I claim:

1. A circuit interrupter comprising a high resistance thermoresponsive element' and a low resistance thermoresponsive element having portions free to move relatively in the same direction, the said resistances of said thermore'sponsive elements being interconnected whereby, when energized in unison the high resistance thermoelement approaches the low resistance element and the low resistance element relatively recedes from the high resistance element when the latter is shunted and means for shunting the high resistance heater comprising contacts' closed when the thermoresponsive elements are in predetermined relative positions, whereby the high resistance and the low resistance heaters alternately cause said contacts to open and close.

2. An electrical circuit interrupter comprising a high resistance, a low resistance, bimetallic elements respectively physically associated with the high resistance and the low resistance so as to be heated respectively by the high resistance and the low resistance, and contact making means, controlled by said bimetallic elements, adapted to shunt the high resistance from the circuit when the high resistance has caused one of the bimetallic elements to Warp to a predetermined degree.

3. An interrupter device comprising a pair of thermalresponsive elements, mutual cooperable contact members operated by said thermalresponsive elements, electrical resistance heaters arrange'd adjacent said thermalresponsive elements respectively for heating them, one of said resistances being arranged to exert a greater heating effect upon its thermalresponsive element than the other, the said thermal elements beingarranged to warp in the same direction when they are heated, the said contacts being arranged to shunt one of the resistances when they are in engagement with one another, whereby the unshunted resistance exerts a heating effect upon its'thermalresponsive element to move the contacts out of engagement with one another.

LOWELL M. ALEXANDER.

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