US1938612A - Temperature controlled make and break apparatus - Google Patents

Description

D. F. SMITH Dec. 12, 1933.

TEMPERATURE CONTROLLED MAKE AND BREAK APPARATUS Filed Aug. 10, 1928 2 Sheets-Sheet, l

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pmikankl Dec. 12, 1933. D, sMlTH 1,938,612

TEMPERATURE CONTROLLED MAKE AND BREAK APPARATUS Filed Aug. 10, 1928 2 Sheets$heet. 2

-Znve7fl'or:

David Fkanklin Smith,

Patented Dec. 12, 1933 OFFICE f TEMPERATURE CONTROLLED MAKE AND BREAK APPARATUS David Franklin Smith, Washington, 1). o.

Application August '10, 1928. Serial No. 298,641 4 Claims. (01. 175-375) Thelinvention is designed to provide means whereby a refrigerating apparatus can be regulated so that it will be put into operation auto-' matically, when a' prescribed upper limit of temperature is reached. and will cease to operate when a prescribed low temperature is reached. A further object of the invention isto provide means by which the apparatus can be set for various temperature ranges, that is to say, it may be set to begin working when any chosen upper temperature is reached and to cease work ing when any chosen low temperature is attained, or the reverse when used with a heating apparatus.

A further object is to provide means whereby different temperature ranges may be automatically established at different times.

The invention shown in the accompanying drawings in which: I

Fig. 1 is a diagrammatic drawing of my in- Vention used in connection with refrigerating apparatus.

Fig. 2 is a diagrammatic drawing of my invention used in connection with heating apparatus.

Fig. 3 is a plan view of the brushes and contacts on the clock.

; Fig. 4 is a View ofthe commutator disc.

Fig. 5 is a sectional view of the series of plugin connections and the. structure of the mercury tube.

In Fig. l of the drawings. the motor for the refrigerating apparatus is indicated at I. This is adapted to be driven electrically through circuit wires 2, 3 leading from contacts 4, 5, when solenoid operated contacts 6, '7 close with said contacts 1, 5. The solenoid contacts 6, 7 are carried by an insulating bar 8 which is secured to thestem 9 arranged axially within the solenoid coil 10. To contact 6 is connected the cir- 40 cuit wire 11 which is connected with a source of electric power'sueh as city system and the contact 7 has connected to it the other lead wire 12 of this system. c

The solenoidhas one lead wire 13 connected with power lead wire 12 (or it may be connected with lead wire 11) the other power lead wire 11 (or 12) being connected through wire 16 with the mercury infa bulb 17 from which atube-18 extends upwardly and is graduated as shown forming virtually a thermometer.

The other end of the solenoid coil is connected to high limit conducting wire. 19 which can be plugged in to any of the. contact sockets. 20 arranged in a row alongside the thermometer tube to determine the upper limit of temperatureat which the motor will begin to work. These sockets'are connected electrically with the interior of the mercury tube at heights correspondto the height of the respective sockets. There. is a low limit conducting wire 21 which 3 extends to a contact 22 companion to.contact 23 carried by the insulated cross head 8 of the stem 9 of the solenoid. The contact 23 is connected by conducting wire 24 with wire 19.

The low limit conducting .wire. 21 can be plug ed into any one of the sockets 20 to determine thelow limit of temperature at which themotor will cease its operation. The solenoid coreis shown at 10a. I

With the parts in the position shown, it will be understood. that the motorfhas driven the refrigerating apparatus. until the chosen low temperature. has been reached; i. e., 46 degrees F. and said motor has ceased operation- The range of rising temperature during which the motor and consequentlythe regfrigerating apparatus will remain out of work is, according to the set up shown in .the diagram, between 46 and 50 F. because the leads 21 and'19 respectively have been plugged into those sockets of the series 20 corresponding to these degrees of temperature. Consequently, there is established the range of temperature during'which, when rising from the low limit 46 to the high limit 50, the motor and refrigerating apparatus will remain at rest and when falling from 50 to 46 the motor and refrigerating "appara'tuswill be at work. I The diagram represents that the low limit 46 has been reached. The motor contacts 4-6 and 5-7 are open and the motor is at rest. The contacts 22, 23, are alsoopen. Now' upon a rise in temperature the mercury will move upwardly in the tube. 18 and when 50? is reached, lead 19 having been plugged into the socket corresponding ing to 50, electric contact will be established between the mercury and the lead 19 and we-will then have a circuit established through lead 19, solenoid coil 10,.wire 13, lead 12, then through the other side 11 offlthe power source through wire 16 to mercury in bulb l7.

The solenoid will be energized, draw up its core 10a, raise thev stem 9 with its cross head 8, closing contacts 4'6 and5 7 so that the motor will be thrown into circuit with the power circuit 11, 12. v r c g Y The motor will now start up operating the refrigerating apparatus and temperature will As soon as mercury falls fromthe contact point begin to reduce, and mercury will begin to fall. 2

at the upper limit 50 the circuit of the solenoid no-longer would be maintained at this point, and.

the solenoid would deenergize and open the contacts 46, 5--7, and the motor would stop unless means were provided to prevent this. This means consists of the lead 21 which is plugged into the socket corresponding to the low limit 46 through'which the solenoid circuitis maintained until after the mercury falls below this low limit 46. This lead 21 maintains a circuit through contacts 22, 23, wire 24, wire 19, solenoid coil,

wire 13, wire 12, wire 11,wire. 16 back to the column of mercury. The solenoid thus being maintained energized, contacts 4-6 and 5-'7 v will remain closed and the motor and'refrigerat taining circuit just described and the refrigerat.

ing apparatus will remain at rest until the temperature rises throu h theprescribed range of 46 to 50. It will be understood that the range of temperature may be varied at will because lead21 may be plugged into the sockets cor- 'respondingto any of the degrees indicated to determine the 10w limit and 1 lead 19 may be plugged into the socket ofv any of the'indicated temperatures to determine the upper limit of the range of temperature.

,While I have described the inventionspecifically'thus far, as applicable to refrigeration, it will be understood that it may be used in connection with heating apparatus to establish a range of temperature, the low limit, of which would be the point at which the apparatus would be put in operation and the'high limit the point at which the apparatus would cease to operate. Such apparatus might be an oil burningfurnace or means for opening and closing the drafts of a. coal burning furnace.

The solenoid core may comprise a single piece of iron if desired. In place ofthe solenoid, any other form of electromagnet may be used. More solenoid or magnet contacts may be provided if needed, as in three phase alternating current, for the motor, if desired. w I In Fig. 2 isshown a diagrammatic drawing of my invention adapted to be used in connection with heating apparatus instead of refrigerating apparatus, and this diagram shows the use of a clock for establishing automatically different effectiv e temperature ranges at different times.

In Fig. 2, the motor for the heating apparatus is'indicated at 1; This is adaptedto be driven electrically through circuit wires 2' and 3" leading" from contacts 4' and 5', when solenoid Joperated contacts 6. close with said contacts 4 and 5'. The solenoid contacts 6 'l are carried by the lower portions of the'solenoid core, which in the solenoid 'ShOWIllS the'iron'portion of energizing core A above which and separate therefrom is the'brass core or stem 13, which does not energizer When the solenoidis operated, the iron core A tends to move to the center thereof and so moves stem B. 7

The solenoid contacts 6 .and T are thus mounted at one end of the core while another solenoid contact 23 is carried at the other end of the core,so that when 6 and 7 are closed with 4 and .5, contact 23' is open and vice versa.

The contacts 6' and 7 are carried by an insulating bar 8 which is secured to the core A,

which is within the solenoid coil 10'. To contact 6 is connected the circuit wire 11' which is connected with a source of electric power such as a city system and the contact 7' has connected I to it the other leadwire 12 of this system or power source. v

The solenoid has one lead wire 13 connected with power lead wire 12' (or it may be connected with lead wire 11'), theother power lead wire 11 (or 12) being connected through wire 16 with the mercury in a bulb 17 from which a tube 18' extends upwardly andis graduated as shown. r a

The other end of the solenoid coil is connected by wire 19 to high limit conducting wire 20' through clock D; that is, through axle E, wire L, segment G, and brush C. Said high limit wire 20' is adapted'to be plugged into any of the contact sockets 22' arranged in a row alongside the thermometer tube to determine the upper limit of temperature at. which the motor will cease working.

These sockets are connected electrically with the interior of the mercury tube at heights corresponding to the height of the respective sockets.

There is "a low limit conducting wire 21, which extends to a contact 23; companion to contact 24", said contact 23 being carried by the insulated cross head 9 of the stem portion B of the solenoid core. The contact 24' is connected by conducting wire 25 with wire20' at the end of the contact brush C. v

The low limit conducting wire '21 can be plugged into any one of the sockets 22 to determine the low limit of temperature at which the motor will resume its operation. 7

With the parts in the position shown, it will be understood that the motor has driven the heating apparatus until the; chosen high temperature has been reached and the motor has ceased operation. The leads 20' and 21 having been plugged in as shown, there is established a range of temperature during'which in rising to the upper limit at lead 20, the motor and heating apparatus will be at work and when the upper limit is reached, the motcr'and heatr ing apparatus will cease work and will remain'at rest during the falling of temperature from the upper limit to the lower limit, the motor and heater again working upon the temperature fall- 7 ing below the lower limit at lead 21.

The diagram represents that the upper limit at lead 20 has beenreached. The motor .con-

tacts' i -+6 and 5"1 are open and the motor isat rest. The contacts 23'24 are closed, the solenoid having operated upon the closing of the circuit through "wire 20 and the mercury to drawlthe coreupwardly to break the motor circuit and establish the maintaining circuit through contacts 23-24.-', wire 21 and the mercury. The circuit through wire 20' and the mercury is established through wire 20', brush C, block D, wire 19f, solenoid coil 10, wire 13, lead 12', then through the other power lead 11, wire lfi to the mercury in bulb l'l'. l The solenoid will be energized, draw up its core comprising core A and stem B, opening contacts 4-- '6' and 5'-7' and closing contacts 23'--24 so that the motor will be thrown'out of operation and the maintaining circuit through wire 21' closed, maintaining the solenoid in raised position' and maintaining the motor and heating apparatus out of operation.

The motor and heater being outof operation, the temperature will reduce and the mercury will drop. As soon as the mercury falls fromcontact with wire 20 at the upper limit, the solenoid circuit no longer is maintained at the point,

and the solenoid would de-energize and close the contacts 4'6' and 5'7 and the motor and heater would start, were it not for the maintaining circuit through lead 21' plugged into the described will be broken, contacts 23-24' will be opened and: contacts 4.'6 and 5'--7' will be closed by deenergizing of the solenoid and the motor will commence operation and further reduction in temperature will be stopped and the mercury will begin to rise again under the effect of the heating apparatus. The heating apparatus will continue to operate until the mercury rises to the upper limit at lead 20.

It will be understood that the range of temperature may be varied at will by plugging leads 20 and 21 into different sockets 22'.

:The purpose of the clock is to automatically provide diflerent temperature ranges and it will be understood that the clock is not necessary to the operation of the device with a heating apparatus as just described and the operation would be the same as to the upper temperature range established' by leads 20 and 21' were the clock omitted and wire 19' connected directly to wire 20. The sole purpose of the clock is to establish automatically difierent temperature ranges at difierent times and the shaft E of the clock works is provided with a commutator disc F having arcuate contact surfaces G and H thereon. As shown in Fig. 3, the disc Fis of substantial width and the contact surfaces G and'H-are disposed-on the opposite peripheral edges of the disc, contact G to be engaged by brush C and contact H to be engaged by brush K. Since, as, shown, the segmental contacts G and H together complete a circleoi contact surface, there is always contact of one brush or the other with the corresponding contact. It will be understood that the number of brushes and the number of segmental contacts together making up the full circle and spaced apart across the width of the disc, may be varied as desired, the invention not being limited to the embodiment shown. As shown in Fig. 2, the segmental contact H is onehalf of the extent of contact G, making the former represent 8 hours and the latter 16 hours, the complete revolution of the disc taking place every 24 hours. When brush C is in contact with. the contact G, there is no contact between brush K and contact H, and vice versa, so that current thru wire 19', which is in contact in any suitable way with shaft E of the clock works, is transmitted from shaft E either through wire L to brush C as shown or through wire M to brush K, but never through both. Brush K is connected to wire 26 continue to operate which is connected to wire 25, and which is plugged into a chosen socket 22' to form the upper limit of the lower temperature range. Lower limit wire 27 of the lower temperature range'is plugged in a lower socket 22' and said wire 27 is connected to wire 21'. With these connections two temperature ranges are provided for, which will becomeseparately efiective at different times as controlled by the clock works. The lower temperature range operates in exactly the same'way as does the upper temperature range and at the end of 16 hours the upper range will become disconnected and the lower 8 hour range rendered effective.

In the diagram of Fig.2,assuming .the clock is set so that the upper range is to be effective from 6 A. M. to 10 P. M. and the lower range .to be effective from 10 P. M. to'6 A. M., at 10 P. M., the contact G will break contact with the brush C to throw on the upper range, and the contact H will establish contact with the brush K to throw in the lower range. Then the temperature and mercury can drop down to the lower limit of the lower range at wire 27 and the solenoid will be maintained energized andthe motor and heating apparatus maintained out of operation until the mercury drops below wire 27. Upon the mercury dropping below wire 27, the motor and heater will. operate and will continue to operate until the mercury reaches wire 26 when it will be thrown out of operation in'the manner heretofore described, circuit being established through wire 26, wire 25, brush K, clock D, wire 19', solenoid coil 10, wire 13, lead 12, then through the other power lead 11, wire 1 16' to the mercury in tube 1'7. The maintaining circuit for the lower temperature range is established throughwire' 27, wire 21', contact 23, contact 24",wire 25', brush K, etc., as before, and the motor and heater will not again I operate until this circuit is broken by the mercury dropping below wire 27.

At the end of 8 hours, the contact H will break contact with brush K and contact G will make contact with brush C to. throw out the lower 1 range and to establish the upper range, thus allowing the motor and heating apparatus to until the mercuryrises to wire 20'. I

It will thusbe apparent thatby means of the 1 clock works and. structureand connectionsv as shown, diflerent temperature rangesmay be es-. tablished accordinglto time.- The two range connections and clock disc structure may -be increased to anydesired number of ranges, as 1 will be readily apparent.

I do not. limit myself'to the exact connections shown since these may be altered, within the scope of the invention to suit conditions.

The tube 18 of my thermometer isformed of 1 bakelite which is non-breakable and a non-conductor of electricity, and preferably,- 1 use transparent or clear bakelite. In place of bakelite, a

like.

Many difiiculties encountered in the manufac- -ture or use ofa glass tube and bulb are overcome by the present invention, consisting in the combination of a composition tube of'bakelite with a metal bulb. In the use of glass, platinum or titanium, wires mustbe used, since the glass tube afterbeing molded in tube'form is broken to provide for the insertion of the wires and the divided parts subsequently fused together with the wires therein. Any other metal would melt before the glass would fuse, and thus. iron or steel wirecould not be used in glass. It is practically impossibleto drill glass to provide holes for the wires, as may be done by the use of bakelite according, to the present invention, in which iron or steel wires may beused and secured by a drive fit.

In the use of glass, the glass bulb must be thin in orderto be accurately sensitive to temperature change, i. e., in order to transmit heat to the mercury. This prevents the use'of-a large quantity of mercury since the thin glass will not stand'the weight, and therefore, in a glass thermometer, the bore and bulb must be of small capacity. A small bore is undesirablebecause the capillary attractiornor friction on'the side I of the bore makes the mercury hang. A large bore such as may be used in the bakelite tube is desirable since it is'more accurate due to less capillary attraction. The metal bulb to which the bakelitetube is secured is responsive and readily transmits temperature change to the large quantity of mercury which itcontains.

The bulb may be of iron or other metal which will ,not amalgamate with mercury. A large bore cannot be made in glass as it can in bakelite or celluloid because a large bore requires a bulb of: large capacity in order to have enough mercury to respond accurately to temperature change, and it being necessary-to have thin glass in the bulb to'. respond properly, the glass will not support the weight of the mercury. 'Glass is a conductor of heat but not if it is too thick.

The bakelite or celluloid can be drilled and graduated much more effectively and accurately than glass andat lesscost. v r p Bakelite is preferable for this purpose since it is capableof withstanding higher temperatures than celluloid. :LCelluloid, though well adapted for cold storage systems, is not, as good as bakelite in heating systems with high temperatures.

Iclaim: 1.-In combination, in temperature controlled apparatus ofthe typeemployin'ga clock operated switch for changing from one" chosen temperaturerange to another,..a. mercury tube, an

upper pair of contacts adapted'to be electrically engaged by the mercury and v establishing upper and lower. limits of a chosen temperature range,

a lower-pair of contacts establishing upper'and.

lower limits of a second temperature range, an electromagnetic device'for controlling a tempera.-

ture changing circuit anda circuit closer forxa maintaining circuit for saidelectromagnetic device commonto thetwo said pairs of contacts, saidcircuit closer comprising a pair of'coopera'ting contacts one of which is movable by the core of said electromagnetic device, said pair of contactsbeing independent of any other contacts in said apparatus and solely adapted to maintain f the electromagnet circuit closed during the change of temperature through the operating temperature range.

. 2. Apparatus according to claim 1 in which said solenoid circuit maintaining means includes a connection in common from the lower limit contacts of each of said pairs of contacts to the one of said independent cooperating contacts which is movable by the solenoid core, and 'a connection in common from the upper limit. contacts of each of said-pairs of contacts to the other of said independent cooperating contacts.

3. In combination in temperature controlled apparatus, a mercury tube having a series of electric contacts disposed along 'the'samei with which the mercury makes electric connection, leads adapted to be plugged into connection with said contacts and including -a pair of leads to be connected to determine the upper and lower limits of a chosen temperature range,

one lead of said pairto be connected to de-' termine the upper temperature limit and the other lead of said pair to be connected to'determine the lower temperature limit of the range, a circuit including a solenoid controlling a temperature changing circuit, means for closing the circuit to operate thesolenoid when one noid, said pair of contacts being independent of any other contacts in saidap'paratus and solely adapted to maintain the solenoid circuit closed during the change of temperature throughout the chosen range of degrees, said solenoid having a core actuated member carrying a pair of contacts connected directly one to each side of the power line, a pair of contacts controlling a temperature changing circuit anddisposed to engage with said pair of contacts on the solenoid, said one of said pair of cooperating solenoidcircuit maintaining contacts which is mountedto move with the core of the solenoid being mounted independently of said other contacts.

4. Apparatus according to claim 1 in which said electromagnet circuit maintaining" circuit includes aconnection in common from the lower-

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