US2451778A - Thermotemporal responsive device - Google Patents

Description

Oct-19, 1948. w SAMBUR THERMOTEMPORAL RESPONSIVE DEVICE INVENTOR.

2 Sheets-Sheet 2 Filed Nov. 13, 1942 l atented Oct. 19, 194

UNITED STATES PATENT OFFICE THERMOTEMPORAL RESPONSIVE DEVICE "William Sambur, Jamaica, N. Y.

'Application'November 13, 1942, Serial No. 465,43?

an improved control device of the character described which shall be simple in design, relatively inexpensive to manufacture and install,- easy to assemble, rugged in construction, neatin appear ance, and which at thesame time shall operate with a high degree of usefulnessand efficiency.

ther objectsof the invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists of-thereatures of construction, combinations ofoelements, and arrangement of parts which will be exemplified in the construction hereinafter describedand of which the scope of' application will be indicated in the appended claims.

'In the accompanying drawings, in which is shown one of the various possibleembodiments of the-invention,

Fig. 1 is a schematic circuit diagram of. the improved control device;

Fig. 2 is a perspective view'of-the trolbox;

Fig. 3 is a detail view of one of the variably positioned temporally responsive control elements mounted in the control box;

Fig. 4 is adetailface-view which-is illustrative of the cooperation between such element and a clock-controlled contact arm;

Fig. 5 is a sectional viewthrough said element and arm and further shows in dotted lines the position the arm assumes when it is-out ofcontact with theelement; and

Fig. 6 is a front view of a control switch-used indoorconin the control device.

selected periods to be easily and readily .varied Y to accommodate for-long range changesin the quantity of demandpto automatically shut off the mechanism when the ambient temperature .-ex-

ceeds the preselected higher temperature; to

automatically continuously operate the mechanism when the ambient temperature falls below the lower of the two preselected ambient temperatures; to enable the'preselected temperatures to be easily and readily varied-toaccommodate for long range changes in the quality of demand; and'to lengthen the periodic operations of the, device in proportion to the fall of ambient temperature when the ambient temperature fluctuates between the higher and lower preselected temperatures.

- Heretofore, these several functions werecar- 'ried out by control devices comprisinga-combination of a large number of means of which certain, such as the high temperature shut off, were independently operating mechanisms, 7 and of which practicall all were-complicated mechanicalsstructures requiring many accurately machined parts. As a result previous controls of the character described were large and bulky mechanisms which were difiicult and expensive to manufacture, install and repair and often broke down during use.

In accordance with the present invention there is provided a control device of the character described which avoids the foregoing difiiculties and drawbacks by employing a thermally responsive electrical means-and aplurality of temporally responsive electricmeans all of which mutually coact in combination with other electrical means to obtain the desired functions. Thethermally and temporally responsivemeans may be mechanically operated b simple, ruggedmechanisms but, preferably,-only the temporally responsive means is so-actuated and the thermally responsive means instead employs a well-known, non-mechanical, thermoelectric phenomenon.

More specifically the improved control device comprises an .outdoor element which includes an electrical means whoseimpedance varies .toconform tochangesin ambient temperature. Such means can comprise tin-inductance, a capacitance, or a resistance where alternating current is-used as a source of power. For reasons which will shortly be apparent,-the preferred form of the invention, hereinafter described in detail, employs a resistance. The impedance value of. the electrical means can be varied by any simple, ruggedmechanism, such-as a bellows or bimetallic element-but as previously noted, it is desirable although the invention is not so limited, to.employ a well-known thermoelectric phenomenon,

.:to wit: the variation in resistance'of a resistor with change of temperature.

The control device also comprises an indoor control .box which essentially includes a plurality of electric means whose impedance varies with the passage of time. Such means can, like the outdoor element comprise an inductance, a capacitance or a resistance, although the invention is most easily carried out by use of a resistance. The impedance value of the electrical means is preferably varied by a clock-controlled mechanism, it being understood however, that other time measuring means are within the scope of the invention.

The indoor control box further includes a switch which closes upon application of a certain potential. Examples of such switches are the glow heated bimetallic switch and electronic tube. When switches such as these are employed it is additionally necessary to use an independent high ambient temperature cut-oft or low ambient temperature lock-in means. There is, therefore, preferably employed a switch which in addition to the foregoing characteristic opens when, after closing, the applied potential drops below a certain potential, lower than the potential' required to close the switch. Switches of the electro-magnetic type have both these characteristics.

The switch, thermally responsive electrical means, and temporally responsive electrical means are electrically connected in a circuit such that the period of operation of the mechanism being controlled, following a minimum period of operation, is a function of the ambient temperature. To this end the thermally responsive and temporally responsive electrical means may be connected in a series, parallel, or series-parallel circuit depending upon whether in these various electrical means the impedance increases or lowers with a rise in temperature and the passage of time.

Finally the indoor control box includes sundry means for rendering the operation of the control device highly flexible, for increasing safety, and for simplifying installation.

Referring now in detail to the drawings, there is disclosed an outdoor element I6 (Fig. 1) comprising a weatherproof, watertight housing l2 of an electrically non-conductive material such as Bakelite or mica, on which is supported in conventional manner, as by winding or traversing, a coiled resistor l6 of a material whose resistance varies with its temperature. A typical material which is satisfactory for this purpose is an ironnickel alloy consisting of 70% nickel and 30% iron. This allo has about twice the resistance of commercially pure nickel and the slope of its temperature-resistance curve is straight from C. to over 100 C. Saidalloy is known as Balco. The two ends of the resistor 16 lead to terminals I8, 26 which are detachably received in a conventional socket (not shown). In order to facilitate description the resistance value for such resistor will now be assigned, it being understood however, that such value, as well as all other values hereinafter assigned to the various elements of the control device, are given by way of example only, and are in no way to be construed as a limitation upon the invention. The resistance value of the resistor I6 is 175 ohms at a temperature of 60 F. and 153 ohms at 20 F. The resistance value between said temperatures is a linear function of the temperature.

The indoor control box 22 (Fig. 2) comprises a metallic box 24 closed by a hinged cover 26. A panel 28 is firmly secured to the box 24 by screws 30 and angle irons (not shown). Said panel is fabricated from an electrically non-conductive with the clock shaft 34.

material of appreciable strength, such as Bakelite or Fibreboard and supports all indoor operative elements of the control device. The panel carries on its rear face a synchronous twentyfour hour electric clock 32 (Fig. 1) whose shaft 34 (Fig. 5) projects through an aperture 36 in said panel. A knob 33 facilitates setting of the shaft. The clock terminals 40, 42 are electrically connected to line terminals 44, 46 for an alternating current source by lead wires 48, 56, 52, 54 through a single-throw double-pole manually operated switch 56 accessibly mounted on the panel 28. Line terminals 44, 46 are also connected by lead wires 56, 54 to the primary 58 of a step down transformer 60. The opposite ends of the transformer secondar 62 are connected to a full wave rectifier 64 by lead wires 65, 68. The output potential of said rectifier is 9.5 volts. The center tap ill of the transformer is connected by a lead wire 12 to an iron-core solenoid 14 mounted on the rear of the panel 28. Said solenoid acts as the electro-magnetic actuating element of a control switch generally indicated by the numeral 16. This switch also includes a glass envelope 78 rigidly secured to the panel. An arm 86 is pivotally mounted in said envelope on a spiral spring 82 which biases the arm away from the solenoid 14 disposed adjacent the glass envelope i8. An iron bar carried on the arm increases its attraction for the solenoid when the same is sufficiently energized. The lower end of the envelope contains a pool 84 of mercury which with the free end of the arm 80 forms the two operating contacts of the switch 16. When the solenoid is fully energized the free end of the arm is in the pool 84 and when the solenoid is de-energized the free end of the arm is spaced from said pool.

The switch parts are so proportioned and arranged that when a total impedance of ohms is interposed between the rectifier 64 and the solenoid T4 the switch will close and that when this impedance is increased to 230 ohms, the switch will open. By virtue of the differential, the total impedance must drop to 180 ohms to close the switch and be raised to 230 ohms to open the switch.

Suitable means is provided to vary the impedance interposed between the rectifier 6d and switch 16 in accordance with a predetermined minimum control schedule, and the ambient temperature and passage of time between the minimum operation periods of such schedule. Such means comprises a contact arm 86 which rotates Said arm is electrically connected by a lead wire 88 to the rectifier 64. The arm is of a resilient electrically conductive material such as phosphor bronze and is adapted to have a portion thereof adjacent the free end ride on the surface of an electrically conductive ring :50 imbedded in the panel 28. To simplify the wiring diagram, the bottom portion of the ring is broken away in Fig. 1. Said ring is disposed concentrically of the clock shaft 34 and projects from the front face of the panel. The ring is connected by lead wire 92 to a compensating resistance 94 of 10 ohms. The contact arm 96 associated with this resistance is manually rotated by a handle 98 having an index pointer which cooperates with temperature indicating markings lllil on the control panel. As will soon be seen, the position of the handle 98 regulates the indoor temperature of a building heated by a burner which is controlled by the device being described.

The resistor arm 95. is connected by leadwire IOZto a Contact 55 3 for the outdoor eler'n'e'nt'lfl. This'contact we and the other outdoor element contact] 96 arecon'nected to said outdoor element by a panel" thermostat wires I98, 'I I0. Because the potential applied to these wires can never be re'atrthan the rectified. potential or volts", theiri'stallatioribf such wires is an extremely simple affair and their short c'ircuiting cannot createa fire hazard. The second element 'termi nal M16. is connected to the solenoid'by lead wire H2 completing'the energizing circuit.

The switch contact Bil is connected to the burner terminal I i l by lead wire H6. 'The other switch'co'ntac't 85 is connectedtoburnerterminal i lflbyle'ad wire i 25, contact pointji22 of athree way switch i2 3, c ontact'arm 1250f "said switch lead' wirfe I28 and finally twoepole swltchfit." Of,

I32 and close-the circuit between the burner ter'- minalsj'and when the handle pointer is regis-' tere d' with the Automatic indicia. the circuit connecting the burner terminals will include the switch contacts 86, 84.

There are alsoprovided a plurality of temporally responsive control elements I38 comprising a thin flexible strip I 38 of an electrically non conductive material such as Bakelite. Wound upon this strip are two series-connected resistors I48, M2. The resistor Mfi'has a value of'50 ohms and consists of high'resistance wire closely wound so 'as to occupy a relatively small space "for rea-' sons-which will soon be apparent. The resistor M2 on the other hand is of a lower resistance wire and has its turns more WidBly' spaced. 'The end'of said resistor M2 spaced from the resistor Mil is anchored to the strip 58 by an eyelet 144. The" end of the resistor Mi? spaced from resistor M2 is caught under a sloping electrically con ductive clip l lfi held to the strip Hi8 by an eyelet M8 having an integral electrically conductive tail 150., The elements E36 are removably, snugly and firmly received in a circular groove I52 having the same center as the ring 98 but of larger diameter. Said. elements are so fashioned that when positioned inihe groove #52 they will ex tend further from the panel 28, than said ring. The sloping clip is designed so that its higher end is level with the top edge of the wound resistors Mil, I42 andits lower edge approximately level with a silver contact 154 at the end of the clock contact armed-when said arm is riding on the' ring 95. the ring 99.

There is also inserted in the groove I51 anight The tail 550 is curved torcontact strip I55 comprising a strip of Bakelite? for the major portion of its length. On the end of the night strip, near morning operation of theburner,

a long 22 ohm resistance 55 8 is provided similar to the resistance M2. Thisresistanoehasacon; tact tail 55 similar to the elements 13,6.

The several elementslat and night strip J55 e arran e? in the sw re. 5.? 9. e. eave the tails I 56 employed on 6.. space therebetween which, as will soon be. apparent, govern the minimum schedule'of opera; tionsof the mechanismvgoverne'd by the control y The operation otthe device Wlllbg CQIlSideIielcompensating resistance which: for ordinary operation is set midway will have a. resistance of 5 ohms' 'Tliusl'whe n the contactarm 8 6 i s riding on the'fin lgg; 179.5. chin will beinterposed in series between the rectifier 64 an d the solenoid 14.v 'Under tlfiese "ci cumstances the switch Hi-will be closed. After the arm reaches theendof he sh rt. r quicklybe added tototal 229.5 oh' ns'so that when the arm reaches theendiof; said resistorv I40 the switch 'lfi will still e, closed; marks the. end of a predetermined minimum operating period. As the; arm 86,.trave ls'iurther it will soon cut in 0,5 ohm of thelong 22' ohm resistorl l? so that shortly after the arm has commenced to ride on said resistor I42 a total of 230-ohms will be in er i ih en l ndcause h Switch contacts 80, 8 l .t o separate shutting oil; the oil. burner.

At 4 0? F.- the outdoor element will have a resistance ofabout 1:6 4 ohms so that the switch '16; wlllremain closed. until the'contact arm 86 has ail r nou h alone e es tor 1. .2 t t in 11 ohms and open the contacts 80, 84. It will thus be seen that the length of the resistance I42 governs thelength of operation added to the min imum period of operation. The elements I36 may be set in accordance with theknown demand for the mechanism (oil burner) regulated by the control device;

At 20 F. the outside element has a resistance value of .153 ohms sothatwhen the contact arm 86.reaches the end of the resistance I42 230 ohms will be cut in to open the switch 76. However as soon as this happens the arm 86;.wi11 drop back raised, It will also decrease and raise, respectively, the mean temperature .of. a, building heated withanoilburner governedby the control device.

The actionofthe night strip 156 is as follows:

Whenthe contact armflfirideson thebare portionof the strip 15 6 it will be raised ofi' the ring 90 and openthe energizingcircuit for the solenoid. 16 so that for a givenperiod of time, for example irom 1 a, m. to 5;a. m. (Fig. 2) the oil burner will beshut cit-regardless of ambient temp a u e i The foregoing is true if no resistance winding I58 is employed. If such winding is used, then,

when the arn B G rides thereon, a resistance equal ling the sum, of the outdoor resistance Hi, the

compensating resistance 94, and the resistance ohm'resistor I40 resistance will 158 is again placed in circuit, It should be noted that movement of the arm 86 along the resistance I58 decreases the resistance in circuit as contrasted to movement of the arm 85 along one of the resistances I42 which increases the resistance in circuit.

To explain the operation of the resistance i58 an ambient temperature of 40 F. will be considered. At this temperature the outside element 50 has a resistance value of 164 ohms, the compensating resistance a value of ohms, and when the arm 86 first rides on the resistance 158, said resistance has a value of 22 ohms. Thus when said arm 86 first touches the resistance I58 a total of i9! is in circuit and the switch 16 will remain open. When the arm 86 reaches the middle of the resistance Q58 the total resistance will have decreased to 180 ohms, enough to close the switch 16 and start the oil burner. At higher temperatures the burner will start later, and at lower temperatures earlier.

If any surge potential is noted which tends to start operation when the arm 86 first contacts the resistance I58, an additional short high resistance (not shown) similar to the resistance M0 can be placed at the end of the resistor I58 remote from the tail I 50.

It will be understood, of course, that as long as the switch 50 is open, the control device will not function.

It may be mentioned that variation in the rectified potential arising from aging of the rectifier 64 over long periods of time (12,000 hours) can be corrected by adjusting the compensating resistance 94.

It will thus be seen that there is provided a device which achieves the several objects of this invention and which is Well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention and as various changes might be made in the embodiments above set forth, it is to be understood that all matters herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A control device for intermittently operating a mechanism with respect to a predetermined outdoor temperature range for periods of time which increase in proportion to decreases of temperature within said range, said device comprising a control switch for turning said mechanism off and on and an energizing circuit including an electric actuating means for said switch, the operation of said actuating means being governed by the value of the potential applied thereto, said circuit including time controlled means to render said actuating means operative .to set said mechanism in operation at a preselected time of the day, means to vary the potential applied to said actuating means in proportion to temperature, and time controlled means to vary the potential applied to said actuating means in proportion to the time elapsed after a preselected period of time following the beginning of a period of .operation of the mechanism at said preselected time so as to stop operation of said mechanism after a time lapse following the preselected period of time, said lapse being proportional to temperature.

2. A control device for intermittently operating a mechanism with respect to a predetermined outdoor temperature range for periods of time 8 which increase in proportion to decreases of temperature within said range, said device comprising a control switch for turning said mechanism oil and on and an energizing circuit including an electric actuating means for said switch, the operation of said actuating means being governed by the value of the potential applied thereto, said circuit including time controlled means to render said actuating means operative to set said mechanism in operation at a preselected time of the day, means to vary the potential applied to said actuating means in proportion to temperature, and time controlled means to vary the potential applied .to said actuating means in proportion to the time elapsed after a preselected period of time following the beginning of a period of operation of the mechanism at said preselected time so as to stop operation of said mechanism after a time lapse following the preselected period of time, said lapse being proportional to temperature, said last named means varying the potential in a direction opposite to that in which it is varied by a decrease in temperature.

3. A control device for intermittently operating a mechanism with respect to a predetermined outdoor temperature range for periods of time which increase in proportion to decreases of temperature within said range, said device comprising a control switch for turning said mechanism off and on and an energizing circuit including an electric actuating means for said switch, the operation of said actuating means being governed by the value of the potential applied thereto, said circuit including time controlled means to render said actuating means operative to set said mech anism in operation at a preselected time of the day, means .to vary the potential applied to said actuating means in proportion to temperature, and time controlled means to vary the potential applied to said actuating means in proportion to the time elapsed after a preselected period of time following the beginning of a period of operation of the mechanism at said preselected time, said last named means varying the potential in a direction opposite to that in which it is varied by a decrease in temperature so as to stop operation of said mechanism after a time lapse following the preselected period of time, which lapse is inversely proportional to temperature.

4. A control device for intermittently operating a mechanism with respect to a predetermined out-door temperature range for periods of time which increase in proportion to decreases of temperature within said range, said device comprising a control switch for turning said mechanism ofi and on and an energizing circuit including an electric actuating means for said switch, the operation of said actuating means being governed by the value of the potential applied thereto, said circuit including a plurality of time controlled means to render said actuating means operative to set said mechanism in operation at different preselected times of the day, means to vary the potential applied to said actuating means in proportion to temperature, and a plurality of time controlled means to vary the potential applied to said actuating means in proportion to the time elapsed after preselected periods of time following the beginnings of period-s of operation of the mechanism at said preselected times so as to stop operations of said mechanisms after time lapses following the preselected period of time, which lapses are inversely proportional to temperature, said last named means varying the potential in 9 a direction opposite to that in which it is varied by a decrease in temperature.

5. A control device for intermittently operating a mechanism with respect to a predetermined outdoor temperature range for periods of time which increase in proportion to decreases of temperature within said range, said device comprising a control switch for turning said mechanism oil and on and an energizing circuit including an electric actuating means for said switch, the operation of said actuating mean-s being governed by the value of the potential applied thereto, said circuit including time controlled means to ren der said actuating means operative to set said mechanism in operation at a preselected time of the day, means to vary the potential applied to said actuating means in proportion to temperature, and time controlled means to vary the potential applied to said actuating means in proportion .to the time elapsed after a preselected period of time following the beginning of a period of operation of the mechanism at said preselected time so as .to stop operation of said mechanism after a time lapse following the preselected period of time, which lapse is proportional to temperature, said last named means varying the potential in a direction opposite to that in which it is varied by a decrease in temperature, the overall change in potential effected by the potential varying temperature responsive means over its full range of operation being of the same order as the over-all change in potential effected by the potential varying time controlled means over the latters full range of operation.

6. A control device for intermittently operating a mechanism with respect to a predetermined outdoor temperature range for periods of time which increase in proportion to decreases of temperature within said range, said device comprising a control switch for turning said mechanism off and on and an energizing circuit including an electric actuating means for said switch, the operation of said actuating means being governed by the value of the potential applied thereto, said circuit including time controlled means to render said actuating means operative to set said mechanism in operation at a preselected time of the day, means to vary the potential applied to said actuating means in proportion to temperature and in such direction upon a decrease in temperature as to inhibit an actuation of the switch which would stop the mechanism from operating, and time controlled means to vary the potential applied to said actuating means in proportion to the'time elapsed after a preselected period of time following the beginning of a period of operation of the mechanism at said preselected time and in a direction opposite to that in which it is varied by a decrease in temperature so as to stop operation of said mechanism after a time lapse following the preselected period of time, which lapse is inversely proportional to temperature, whereby a change in the potential applied to said actuating means, which change is efiected by the potential varying temperature responsive means and results from a decrease in temperature, is counteracted with the passage of time following said preselected period of time by the change in potential which is effected by the potential varying time controlled means, and the period of opcontrolled means are variable impe-dances.

8. A control device as set forth in claim 6 wherein the potential varying temperature responsive means and the potential varying time controlled means are variable resistances.

9. A control device as set forth in claim 6 wherein the potential governing the operation of the actuating means is such that the change in potential effected by the potential varying temperature responsive means at temperatures above the predetermined temperature range renders the first named time controlled means ineffective to set the mechanism in operation at a preselected time of the day.

10. A control device as set forth in claim 6 wherein the potential governing the operation of the actuating means is such that the change in potential effected by the potential varying temperature responsive means at temperatures below the predetermined temperature range renders the potential varying time controlled means ineffective to stop operation Of the mechanism.

11. A control device for intermittently operating a mechanism with respect to a predetermined outdoor temperature range for periods of time which increase in proportion to decreases of temperature within said range, said device comprising a control switch for turning said mechanism off and on and an energizing circuit including an electric actuating means for said switch, the operation of said actuating means being governed by the value of the potential applied thereto, said circuit including time con trolled means to render said actuating means operative to set said mechanism in operation at a preselected time of the day, and time controlled means for varying the potential applied to said actuating means in such manner as to cause interruption of the operation of said mechanism after an interval, determined by temperature, starting after a preselected period of time following the beginning of a period of operation of the mechanism at said preselected time.

WILLIAM SAMBUR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Great Britain Apr. 20, 1936

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