US827698A - Automatic alarm and stopping device for engines. - Google Patents

Automatic alarm and stopping device for engines. Download PDF

Info

Publication number
US827698A
US827698A US17517303A US1903175173A US827698A US 827698 A US827698 A US 827698A US 17517303 A US17517303 A US 17517303A US 1903175173 A US1903175173 A US 1903175173A US 827698 A US827698 A US 827698A
Authority
US
United States
Prior art keywords
engine
circuit
contact
ignition
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US17517303A
Inventor
Daniel B Adams
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US17517303A priority Critical patent/US827698A/en
Application granted granted Critical
Publication of US827698A publication Critical patent/US827698A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01MLUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M1/00Pressure lubrication
    • F01M1/18Indicating or safety devices
    • F01M1/20Indicating or safety devices concerning lubricant pressure
    • F01M1/22Indicating or safety devices concerning lubricant pressure rendering machines or engines inoperative or idling on pressure failure
    • F01M1/26Indicating or safety devices concerning lubricant pressure rendering machines or engines inoperative or idling on pressure failure acting on engine ignition system

Definitions

  • DANIEL B ADAMS, oF SUMMITVILLE, NEW YoRK.
  • My invention relates to automatic alarms and stopping devices for internal-combustion eng1nessuch, for example, as oil and gas engmes.
  • Figure 1 is a dia ammatic view showing a portion of the cy inder of a gas'or oil enginehaving my im roved alarm and stopping devices applied t ereto, showi g likewise onesystem of wiring which may b employed, the hydraulic and thermostatic contactdevices being shown in section.
  • FIG. 2 shows a central vertical section of an alternative form of thermostatic contact device which may be employed.
  • Fig. 3 shows a second alternative form of thermostatic contact device which may be employed.
  • Fig. 4 shows a vertical section of a diaphra m contact device which may be substitute for thehydraulically-operated swinging-plate contact device shown in Fig.- 1.
  • Fig. 5 indicates an alternative arrangement of the alarmcir'cuits which may be employed.
  • the cylinder becomes .overheated, and this may result in burning out the gasket' between the cylinder and cylinder-head and in scoring, burning, or cracking of the cylinder. It is important, therefore, that provision be made for stopping the engine automatically in case the circulation of cooling-water ceases or becomes deficient; but it is important also that warning shall be given somewhat in advance of the actual stopping of the engine that the engine it about to be stopped, so that the load of the engine may be thrown off to facilitate restarting of the engine and to permit the engine attendant, if possible, to remedy the trouble in the circulating system in time to avoid stopping the engine.
  • I provide means actuated directly by diminution'in Water-pressure in the circulating system for operating an alarm to give warning that the engine is about to be stopped, and I provide means ac tuated by rise of temperature of the engine cylinder or jacket for stopping the engine. Such rise in temperature necessarily occurs somewhat after the alarm begins to ring, opportunity being thus given to overcome the trouble in the circulating system, if possible, and to throw off the load of the engine.
  • FIG. 1 said figure shows an engine-cylinder 1, provided with a water-supply pipe 2 and and consisting of a casing ,5, in which the pipe 3 terminates, said'casmg carrying within it a flexible spring-plate 6, a portion of 'ch is opposite the mouth of. ipe 3, said plate adapted normally tobe held against a contact-point 7 by the stream of water issuing from pipe 3, but arranged to spring away from said contact pointwhen the flow of water through pi e 3 ceases or decreases seriously.
  • This hy raulically-operated contact device is included in the. ignition-circuit of the engine. .In Fig. 1 Ihave indicated an ignition-circuit such as may be.
  • the said circuit inc udes a battery 9, a wire 10, leading from one terminal thereof through a spark-coil 11 to one terminal of the igniter 4, another ,wire 12, leading from the other terminal of the igniter to cas- 1ng5, and so to spring 6, and a third wire 13,
  • a branch circuit 14 leads from wire '12 through a bell 15 to wire 13, such circuit ineluding.
  • resistance 33 suflicient to prevent ringing of the bell when contactis closed bei tween points 6 and 7 such resistancebeing ordinarily merely the magnet-coils of the bell, the resistance of whichis usually sufficient for the purpose.
  • a relay may of course be substituted for the eulia the circuits above described; 7 and'caused to close the circuit of a separate bell-circuit, the extension of an alarm-circuit by means of a relay in this inanner being a familiar expedient.
  • ment above described 'I may employ that shown in Fig. 5, in which the circuits arethe .7 Instead of employing the circuit arrangesame, except that the casing 5 has a back contact 8, the bell 15 being located in a branch circuit 16, leading fromcontact 8 to wire 13., Whenthe flow of water ceases or becomes deficient, plate 6 breaks contact with point. 7 and springs back into contact with point 8, thus shunting the ignition-circuit through the bell.
  • the cap may screw upon the top of the tube,'a'nd said tubemay i' be screwed into the'base, as in Fig.3, or-may .be secured in place in the base by'plaste'r orother cement, as-shown in Fig. 1.
  • the tube I preferably has at each end an enlargement of itsbore, the intervening portion of the bore being of small diameter.
  • a displacementscrew 32 is provided for regulating'the level of the mercury. The height of the mercury column should be so regulated that in normal 20 engine will stop.
  • the stopping device may operate by the closing of its circuit to cause the operation-of'other
  • a bell is preferably included in the circuit of the thermostatic stopping device, because some resistance is preferably employed in said circuit to avoid running down the ignition-battery while the igniter is short-circuited and because the bell, while serving as suchresistance,
  • Such bell may be located, when desired, at a point distant from 3 5 the engine where some person is continuously employed.
  • the stopping sides acting to stop the engine before the same becomes seriously overheated serves to give 0 visual indication of the temperature atwhich the engine is running and to assure the engine attendant that the circulating system is operating efficiently,.the mercury being always in sight in the tube while the engine is run- 5 ning normally.
  • the thermostat having a second tube 25, exactly similar to tube 19.
  • the contact-screw of the second tube may, when-desired, be set to make .contact with the mercury. before the corresponding screw of tube 19 makes contact, so that the bell will be rung somewhat in advance of the stopping of the engine.
  • thermostats shown in Figs. 1 and 2 are adapted to be screwed to the jacket of the engine, but to be insulated electrically there- "from by insulating material 26, Fig. 1, such as mica, which will not interfere materially with the transmission of heat.
  • the thermostat may be arranged to device above described, be-
  • a swinging'contactp ate I may employ a diaphragm device, as
  • the wiring employed may be the same as thatof Fig. 1 or Fig. 5.
  • the water-pipe Sis preferably provided with a contraction 31 just beyond the diaphragm device to provide the pressure necessary to operate'the same.
  • the contact-screw 21 and also the binding screw of cap 20 may have heads of insula'tmg LOO.
  • the alarm-operating device When these devices are to be fitted to an engine having ajump-spark system of 1g nition, in which the ignition-battery is in a primarycircuit of an induction-coil, which circuit is arranged to be broken by a vibrator 0r interrupter operated bythe engineor otherwise and the igniter-contacts are in a secondary circuit of the inductionwoil, the alarm-operating device will" be caused to shunt the primary circuit of the coitthi'ough the alarm when theflow of cooling-water d1- minishes, and likewise the thermostat will be bustion engine having an electric ignition circuit, of an electrically-operated alarm, and

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)

Description

PATENTED AUG. 7, 1906.
V n. B. ADAMS. AUTOMATIC ALARM AND STOPPING DEVICE FOR ENGINES.
APPLICATION FILED SEPT.30. 1903.
ATTO R N EYS WITNESSES:
DANIEL B. ADAMS, oF SUMMITVILLE, NEW YoRK.
' AUTOMATIC ALARM AND STOPPING DEVICE FOR ENGINES.
Specification of Letters Patent.
Patented Aug. 7, 1906.
Application filed September 30, 1903. Serial No. 175,173.
' mitville, in the county of Sullivan and State of New York, have invented certain new and useful Improvements in Automatic Alarms and Stopping Devices for'Engines; and I (lo hereby declare the following to be a full, clear, and-exact description of the invention,
such as will enable others skilled in the art to ,q
which it appertains to make and use the same.
My invention relates to automatic alarms and stopping devices for internal-combustion eng1nessuch, for example, as oil and gas engmes.
I other machines having cylinders which require to be cooled, to improve the constructron of the contact devices employed, to indicate to the eye the temperature of the en,-
, gine-cylinder, to simplify the wiring and reduce the number of batteries required, and to render the apparatus reliable, efficient, and comparatively inexpensive.
I will now proceed to describe my inven- I tion with reference to the accompanying drawings, illustrating certain forms of my invention, and will features in claims.
In the said drawings, Figure 1 is a dia ammatic view showing a portion of the cy inder of a gas'or oil enginehaving my im roved alarm and stopping devices applied t ereto, showi g likewise onesystem of wiring which may b employed, the hydraulic and thermostatic contactdevices being shown in section.
then point out the novel Fig. 2 shows a central vertical section of an alternative form of thermostatic contact device which may be employed. Fig. 3 shows a second alternative form of thermostatic contact device which may be employed. Fig. 4 shows a vertical section of a diaphra m contact device which may be substitute for thehydraulically-operated swinging-plate contact device shown in Fig.- 1. Fig. 5 indicates an alternative arrangement of the alarmcir'cuits which may be employed.
.I will describe my invention as applied'to a gas or oil engine having a water-j acketed cylinder. From such description the application of the inventionto internal-combustion engines having other systems of cooling and to other machines having cylinders whichreuire to be cooled Will be obvious to those skilled in the art.
In the operation of water-cooled explosive or internal-combustion engines it sometimes happens that the circulation of cooling-water ceases or 'becomes deficient. This may be due to a variety of-causes, such as failure of the water-supply, the accidental closing of a valve, the derangement of a circulatingpump, a leak in the Water-supply pipe or the jacket, an obstruction in the water pipes or jacket, and a variety ofv other causes Well known to those having experience in the use of such engines. If the engine is allowed to run after the circulation ceases or becomes deficient, the cylinder becomes .overheated, and this may result in burning out the gasket' between the cylinder and cylinder-head and in scoring, burning, or cracking of the cylinder, It is important, therefore, that provision be made for stopping the engine automatically in case the circulation of cooling-water ceases or becomes deficient; but it is important also that warning shall be given somewhat in advance of the actual stopping of the engine that the engine it about to be stopped, so that the load of the engine may be thrown off to facilitate restarting of the engine and to permit the engine attendant, if possible, to remedy the trouble in the circulating system in time to avoid stopping the engine.
In the automatic alarm and stopping device herein described I provide means actuated directly by diminution'in Water-pressure in the circulating system for operating an alarm to give warning that the engine is about to be stopped, and I provide means ac tuated by rise of temperature of the engine cylinder or jacket for stopping the engine. Such rise in temperature necessarily occurs somewhat after the alarm begins to ring, opportunity being thus given to overcome the trouble in the circulating system, if possible, and to throw off the load of the engine.
Referring now to the drawings and at first .to Fig. 1, said figure shows an engine-cylinder 1, provided with a water-supply pipe 2 and and consisting of a casing ,5, in which the pipe 3 terminates, said'casmg carrying within it a flexible spring-plate 6, a portion of 'ch is opposite the mouth of. ipe 3, said plate adapted normally tobe held against a contact-point 7 by the stream of water issuing from pipe 3, but arranged to spring away from said contact pointwhen the flow of water through pi e 3 ceases or decreases seriously. This hy raulically-operated contact device .is included in the. ignition-circuit of the engine. .In Fig. 1 Ihave indicated an ignition-circuit such as may be. employed with the touch-spark system of ignition, in which the igniter'has a movable contactpoint actuated by some movin portion of the engine. The said circuit inc udes a battery 9, a wire 10, leading from one terminal thereof through a spark-coil 11 to one terminal of the igniter 4, another ,wire 12, leading from the other terminal of the igniter to cas- 1ng5, and so to spring 6, and a third wire 13,
leading from contact-point 7 back to battery. A branch circuit 14 leads from wire '12 through a bell 15 to wire 13, such circuit ineluding. resistance 33 suflicient to prevent ringing of the bell when contactis closed bei tween points 6 and 7 such resistancebeing ordinarily merely the magnet-coils of the bell, the resistance of whichis usually sufficient for the purpose.
So long as the circulation of water continuesi with sufiicient volume'the plate 6 will betheld in, contact with point 7 and the bell will not ring, being short-circuited by the circuit of less resistance through contacts 6 and u 7; but when the flow of water ceases or becomes deficient the plate 6 leaves contact 7,
thus shunting ,the ignition-circuit through,
bell 15 and causing the bell to ring. I preferably employ a bell of the single-stroke Va.-
riety-viz., a bell having no vibrating springi supplies p0werthis being Very desirable when, as often happens, the engine does not have constant supervision. If it is not desired to extend the igniter-circuit to a dis- 6 5 tance, a relay may of course be substituted for the eulia the circuits above described; 7 and'caused to close the circuit of a separate bell-circuit, the extension of an alarm-circuit by means of a relay in this inanner being a familiar expedient.
ment above described 'I may employ that shown in Fig. 5, in which the circuits arethe .7 Instead of employing the circuit arrangesame, except that the casing 5 has a back contact 8, the bell 15 being located in a branch circuit 16, leading fromcontact 8 to wire 13., Whenthe flow of water ceases or becomes deficient, plate 6 breaks contact with point. 7 and springs back into contact with point 8, thus shunting the ignition-circuit through the bell.
The above circuits andtapp aratus are em ployed to give warning that the engine is aboutto be: stopped. For stopping the engine I employ a deviceactuat'ed by the rise in'temperature of the engine-cylinder which follows the stoppage or serious diminution of p This I do because it is 1 the flow of water. not necessary to stop the engine instantly when the flow of cooling-water ceases or be.- comes deficient.
A few minutes will elapse before the water remaining in the jacket will have evaporated and the cylinder heated to such a temperature as to endanger the gasket or the cylinder itself, and it is desirable tobe able to utilize the intervenin time in endeavoring to overcome the-di culty in the] circulating system, if possible, and to throw off the load on the engine before it stops and also when. the ,engine drives machinery through a line-shaft to throw oif the load on I the line-shaft and stop the machinery in such fashion that it may be started again without. 7'
difficulty]; Various forms of devicesactu-f ated by rise'in temperature may be em ployed but the'one which I prefer consists of a base 17 of material, such as m'etal which will conduct heat readily, said base having a chamber 18, containing mercury or other expansible fluid which is also a' good electrical Iro conducton' Ina socket in said base is secured a tube 19,- of glass or other suitable electrical insulating material, and uponsaid' 1 tube is a cap 20, can'yinga contactrs'crew,
as leather, is interposed between the cap'a-nd the top of the tube to exclude air and prevent escape of the mercury; The cap may screw upon the top of the tube,'a'nd said tubemay i' be screwed into the'base, as in Fig.3, or-may .be secured in place in the base by'plaste'r orother cement, as-shown in Fig. 1. The tube I preferably has at each end an enlargement of itsbore, the intervening portion of the bore being of small diameter. A displacementscrew 32 is provided for regulating'the level of the mercury. The height of the mercury column should be so regulated that in normal 20 engine will stop.
2 5 means for stopping the engine.
operationwhen the engine is running --at I proper temperature the mercury will rise into I the' contracted portion of thebore of the glass tube 1 9, so as to bevisible' therein, but will 5 not rise into the upper enlargement of the tact with contact-screw 21, so as to complete an electric circuit. In the arrangement of circuits shown a 'wire 22 leads from wire 10 of the ignition-circuit to the base of the thermostatic. stopping device, and another wire I 5 23 leads from the top cap of said device to the returnin13 of the ignition-circuit through a bell 24.' Therefore when contact is completed between theme'rcury and the contactfiled May 23, 1902, Serial No. 108,630, I have screw 21 the igniter is short-circuited' and the It is obvious that instead of stopping the engine by short-circuiting the igniter the stopping device may operate by the closing of its circuit to cause the operation-of'other A bell is preferably included in the circuit of the thermostatic stopping device, because some resistance is preferably employed in said circuit to avoid running down the ignition-battery while the igniter is short-circuited and because the bell, while serving as suchresistance,
also rings continuously to announce that the engine has stopped. Such bell may be located, when desired, at a point distant from 3 5 the engine where some person is continuously employed.
The stopping sides acting to stop the engine before the same becomes seriously overheated, serves to give 0 visual indication of the temperature atwhich the engine is running and to assure the engine attendant that the circulating system is operating efficiently,.the mercury being always in sight in the tube while the engine is run- 5 ning normally.
Instead of locating the alarm-bell 24 in the circuit through'which the ignition-current is short-circuited it may be located in a separate circuit, as shown in Fig. 2, the thermostat having a second tube 25, exactly similar to tube 19. In such case the contact-screw of the second tubemay, when-desired, be set to make .contact with the mercury. before the corresponding screw of tube 19 makes contact, so that the bell will be rung somewhat in advance of the stopping of the engine.
The thermostats shown in Figs. 1 and 2 are adapted to be screwed to the jacket of the engine, but to be insulated electrically there- "from by insulating material 26, Fig. 1, such as mica, which will not interfere materially with the transmission of heat. When insulation ofthe thermostat from-the engine is not required, the thermostat may be arranged to device above described, be-
screw into asuitable hole inthe engine-j acket Such a thermostat is shown in Fig. 3.
. Instead of employing in the hydraulicallyo erated contact device a swinging'contactp ate I may employ a diaphragm device, as
shown in Fig. 4; the diaphragm 27, carrying a contact-piece 28, adapted to make contact with'a contact-point 29 when the water is flowing properly and to make contact with a contact-piece 30 when the flow decreases or ceases. The wiring employed may be the same as thatof Fig. 1 or Fig. 5. In employing the diaphragm device the water-pipe Sis preferably provided with a contraction 31 just beyond the diaphragm device to provide the pressure necessary to operate'the same.
In another application for Letters Patent,
claimed the general construction of the hycircuit when the flow ofcooling-water ceases or decreases; also, means for operating an alarm coincidently with diminution in waterpressure in the jacket. In a fur'therapplication for Letters Patent, filed August 29, 1902, Serial No. 121,416, I have claimed the use of athermostat located in-proximty to the engine-jacket for breaking the ignition-circuit to stop the engine. Therefore I do not claim such inventions herein.
It is obvious that the devices described above are only particular-embodiments of my invention and that the same is susceptible of many variations and modifications without departing from the s irit and scope thereofi I do not limit myse f to the particular details of construction and arrangement here-in illustrated and described. i 1
The contact-screw 21 and also the binding screw of cap 20 may have heads of insula'tmg LOO.
material to prevent possible shocks to the op-j circuits of a touch-spark system of igni- I tion. When these devices are to be fitted to an engine having ajump-spark system of 1g nition, in which the ignition-battery is in a primarycircuit of an induction-coil, which circuit is arranged to be broken by a vibrator 0r interrupter operated bythe engineor otherwise and the igniter-contacts are in a secondary circuit of the inductionwoil, the alarm-operating device will" be caused to shunt the primary circuit of the coitthi'ough the alarm when theflow of cooling-water d1- minishes, and likewise the thermostat will be bustion engine having an electric ignition circuit, of an electrically-operated alarm, and
means automaticallyoperated for operating the same from the ignition-circuit. I
2. The combination with an iinternal-com bustion engine having an electric ignition circuit, of an electrically-operated alarm, and
means automatically, operated for switching the same into said ignition-circuit.
3. The combination with an internal-com bustion engine having an electric ignition-circuit, and having-also means for supplying cooling water, of an electrically operated alarm, and a hydraulically-operated switch-" ing device operated bydiminution in flow of cooling-Water, and, arranged to switch said alarm into said ignition-circuit 4. The combination with an-i'nt'ernal com bustion' engineh'aving an electric ignition-circuit, of an automatic stopping device 1' vided with means for short-circuiting said ig nition-circuit.;
5. Thecombination an internal-com-' bustion engine having an electric ignition-circuit, ofa thermostatic stopping device pro vided with means for short-ci cuiting said ig nition-circuit.
, 6. The combinationwith an internal-combu'stion engine'ha'ving an electric ignition-circuit and having means for sup lying coolingwater to its cylinder,' of a arm-operating means arranged to. cause operation of an alarm by said circuit upon diminution in the flowof cooling-water, and anautomatic stopp g device arranged tolshort-circu-it said ignition-circuit;
- -7.' The combination with an internal-com-' bustionengine having an electric'ignition-circuit, of a thermostat arranged to be affected by rise of temperatureof the engine-cylmder',
and comprising -a chamber containing anex'e pansible electrically-conductive fluid, and a contact member with which such fluid may make contact upon expansion, said fluidand contact member electrically connected to the ignition-circuit and arranged, when they.
make contact, to complete a shunt-circuit by which ignition is prevented.
8. The comb' ation with bustion' engine having an ignition-circuit, of
an internal-com; 5 5 an electrically-operated alarm connected to J saidcircuit, and an automatic contact de-;
vice arranged to complete or break a short circuit across the terminals of said alarm.
, 9'; The combination with an en ine-cylin' der havingmeans for supplying coo ing-Wate'r j thereto, an electric circuit, and anelectrically-operated alarm connected thereto, of
' meansautomaticallyoperated upon diminug tion in the fioW of cooling-Water, normally completing a short circuit across-the terminals'of said-alarm, but arranged when oper-',
ated to break said short circuit.
' In testimony whereof I afiix my signature in the presenceof two witnesses.
I DANIEL B. Witnessesz-1 I U "O. F. CARRINGTON,
' MINERYA POPE.
US17517303A 1903-09-30 1903-09-30 Automatic alarm and stopping device for engines. Expired - Lifetime US827698A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17517303A US827698A (en) 1903-09-30 1903-09-30 Automatic alarm and stopping device for engines.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US17517303A US827698A (en) 1903-09-30 1903-09-30 Automatic alarm and stopping device for engines.

Publications (1)

Publication Number Publication Date
US827698A true US827698A (en) 1906-08-07

Family

ID=2896178

Family Applications (1)

Application Number Title Priority Date Filing Date
US17517303A Expired - Lifetime US827698A (en) 1903-09-30 1903-09-30 Automatic alarm and stopping device for engines.

Country Status (1)

Country Link
US (1) US827698A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2433124A (en) * 1945-04-20 1947-12-23 Casco Products Corp Electric flatiron
US2468645A (en) * 1944-05-19 1949-04-26 Line Material Co Protective device and signal means for circuit breakers
US2612147A (en) * 1948-12-06 1952-09-30 Engineering Controls Inc Low water alarm
US4931776A (en) * 1988-05-19 1990-06-05 Varian Associates, Inc. Fluid flow sensor with flexible vane

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2468645A (en) * 1944-05-19 1949-04-26 Line Material Co Protective device and signal means for circuit breakers
US2433124A (en) * 1945-04-20 1947-12-23 Casco Products Corp Electric flatiron
US2612147A (en) * 1948-12-06 1952-09-30 Engineering Controls Inc Low water alarm
US4931776A (en) * 1988-05-19 1990-06-05 Varian Associates, Inc. Fluid flow sensor with flexible vane

Similar Documents

Publication Publication Date Title
US1738540A (en) System of generating and storing electricity
US872039A (en) Automatic alarm and stopping device for engines.
US827698A (en) Automatic alarm and stopping device for engines.
US1229939A (en) Electrical thermostat and circuit.
US2073676A (en) Control device and circuits for hot water heating systems
US1653685A (en) Device for producing flashing signals for engine-temperature indicators
US828262A (en) Automatic stopping device and alarm.
US2115027A (en) Warning signal for hydrotherapeutic systems
US3906440A (en) Engine warning device
US2063703A (en) Fire and temperature alarm system
US2294830A (en) Lubricating oil pressure alarm system
US1596836A (en) Oil-burner control
US1735911A (en) Automatic oil burner
US1803852A (en) Signal system and apparatus for boilers
US4442395A (en) Pump failure protection for liquid transmission pipelines
US3288933A (en) Automatic dial telephone alarm with two-speed motor
US2399171A (en) Lubricating apparatus
US983861A (en) Thermostatic alarm.
US782703A (en) Low-water and circulation alarm for gasolene-engines.
US2762998A (en) Fire alarm system
US981840A (en) Automatic controlling mechanism for refrigerating systems.
US788871A (en) Automatic stopping device for engines or the like.
US2095087A (en) Fire alarm system
US1320696A (en) Island
US1718857A (en) Automatic fire alarm