US2576688A - Electric heater for stock watering tanks - Google Patents

Description

NOV. 27. 1951 J, T, LANDGRAF 2,576,688

ELECTRIC HEATER FOR STOCK WATERING TANKS Filed Jan. 8. 1948 Patented Nov. 27, 1951 2,576,688 ELECTRIC HEATER FOR STOCK WATERING TANKS Jacob T. Landgraf, Freeport, 111., assignor to H. D. Hudson Manufacturing Company, Chicago, 111., a corporation of Minnesota Application January 8, 1948, Serial No. 1,237

8 Claims.

This invention relates to a new and improved portable electric heater unit for application to stock Watering tanks and the like.

The principal object of my invention is to provide an immersion type heater of the kind mentioned designed for quick and easy, as well as secure, fastening to the side wall of a tank, whether it be of steel or concrete construction, and to transfer heat to the water in a horizontal plane at a depth of about eighteen inches, or less, below the surface, so as to insure maintaining in cold weather an unfrozen opening in the vicinity of the heater large enough for drinking purposes. Important features of this heater are as follows:

(1) The L-shape of the copper tube heatin coil, in which the electrical heating element is housed, facilitates secure attachment to the, side wall of the tank, and enables heat transfer from the enlarged horizontal loop on the lower end of the coil in the horizontal plane at the desired depth, and predetermines more or less the location and area of the unfrozen opening, besides reducing to a minimum the danger of stock upsetting or damaging the heater when drinking.

(2) The substantially parallel vertical legs of the heating coil are attached at their upper ends to the switch housing, in which a switch is mounted, and this switch is operated mechanically by a thermostat, the heat sensitive capsule part of which is disposed between the lower end portions of said legs and clamped thereto by heat conducting plates, whereby automatically to maintain at least in the zone of the heater 9. water temperature of about 42 F., while the heater is in use on a tank, and automatically to break the circuit through the unit at a like low temperature, to avoid accidentally burning out the heating element, and also wasting current, if the unit happens to be left connected to a current source when the tank is empty or nearly so or when the heater is not in use in a water-filled tank, as, for example, after having been demonstrated by a salesman, or when being first tried out by a farmer at the time of delivery, or when it may be later carelessly mishandled by an unskilled farm-hand. r (3) A vertical sheet metal shield is fastened at its upper end to the switch housing and encloses the vertical legs of the heating coil and serves to protect the animals against contact with the hot coil while the unit is in operation in a tank, and excludes a certain amount of trash and dirt fromthe coil and the thermostat.

The invention is illustrated in the accompanying drawing, in which- Fig. l is a vertical section through a portion of a stock watering tank of steel construction showing, in side elevation, a heater made in accordance with my invention applied thereto;

Fig. 2 is a rear view of the heater removed from the tank;

Fig. 3 is a top view of the heater with the cover of the switch housing removed to show the switch therein and its connections with the electrical heating element in the heating coil;

Fig. 4 is a section on the line 4-4 of Fig. 2, to show the heat conducting mounting of the thermostats capsule on the heating coil;

Fig. 5 is an enlarged section on the line 55 of Fig. 3, to show the operating connection between the thermostat and the switch, and

Fig. 6 is a sectional detail showing the method of attaching the heater of Figs. 1-5 to a concrete tank.

Similar reference numerals are applied to corresponding parts.

' Referring to Figs. 1-5, the reference numeral 1 designates the electric heater of my invention shown applied to the rim 8 of a steel tank 9. The heater 1 comprises a generally L-shaped heating coil In containing an electrical heating element, indicated diagrammatically in Fig. 3 in dotted lines at II, that is connected at one end, as shown at 12, with one terminal of the micro-switch l3. The latter is mounted on a frame [4 which is bolted, as at I5, in a switch housing IS. The coil l0 has its two ends entered in and suitably rigidly secured to the housing I5, so that the electrical connections between the heating element l l and switch 13 can be enclosed in said housing. A flexible conduit I! attached to the bottom of the housing 16 contains two wires 18 and I9, one of which is connected to the other end of the heating element l I and the other to the remaining terminal of switch l3. A third wire 20 extending through the conduit IT is grounded, as at 2!, to the switch housing I6 at its inner end and is suitably connected at its outer end to a pipe or rod driven into the ground, whereby to provide a thoroughly reliable ground connection in case of insulation failure in the heater. The switch [3 is closed by a predetermined downward movement of its plunger 22, and, contrariwise, is opened by a predetermined upward movement of said plunger. A thermostat consisting of a capsule 23 connected by means of a small tube 24 with a collapsible and expansible bellows in the housing 25 is arranged to operate cordingly for a given temperature. The tempera ture controller is of a well known type and forms no part of my invention, excepting only in so far as it and its associated thermostat 23-25 cooperate in a novel manner with the associated ele-- ments of the heating unit of myqinvention. A cap or cover '23 fits down over the rim of the housing l6 to enclose the switch [3 and the asso ciated mechanism against damage by the animals and for protection against rain or snowor any moisture, and is fastened by screws that thread i in holes 3| in the housing. It should be clear from the description thus far that,.assuming the thermostat capsule 23 is subjectto the rise and fall intemperature of the water in the tank 9,

the circuit for the heating element. H in coil ||l will be opened and closed by means of switch l3 operated in response to said thermostat, whereby to maintain a substantially constant temperature inthe, water around the coil ID.

A U-sh'aped attaching bracket 32 isinverted and bolted by its cross-portion to the bottom of the housing l6,'as indicated at 33, and is of a size to fit freelyover the rim 8 of the tank 9, as shown in .Fig. 1. A thumb screw ,34, threaded in a hole in the outer portion of the bracket extends below therim 8 and can be tightened in abutment with the side wallof the tank to clamp the heater firmly and securely in place on the tank. Then a e ut 35 threading. on the thumb screw 34, can be tightened against the bracket 32, to lock the screw against accidental loosening. It is obvious at with t is oun ing here is no, danger of the heater being upset and damaged by the stock when drinking, and the farmer does not have to uild an in on the tank to. a mmodate this heater, as was the case with some others with which I amv familiar; this heater comesready toinstall and is made to fit the existing tanks. In the case of concrete tanks, likethat indicated at M in Fig. ,6, which are not nearly as common as I steel tanks, it is necessary to builda ,small inverted. L-shaped wooden-- bracket 36 to rest on top of the side wall, as shown, providing laterally Spaced substantially parallel side pieces 31 and, 38 with a cross-piece 39 fastened between their inner ends for the bracket 32 to straddle and be clamped on, using the thumb screw Stpreviously mentioned.

With either installation, it will be seen that; the L-shape of the heating coil l0 not only facilitates the secure attachment of the unit to the side-wall of the tank. but it insures heating of the water in a horizontal plane bythe wideelongated hori zontal loop 40- at the desired depth in relation to the top of the tank 9 or 911 topredetermine more or less the location and area of the unfrozen opening through which the stock can drink at any timeregardless of the weather.- Ifthe tank has a hog-drinker in it, the heater i should be located so'that one side of the loop 40 touches it. That will prevent freezing of thewater inthe hog drinker, r

Y The substantially parallel-and closely spaced vertical legs-4| of the heating coil iii are enclosed the maj portion .oftheimength 1.11.1.2. channel-.1

shaped sheet metal shield 42, which has inturned longitudinal flanges 42a on the back thereof to prevent displacement from the legs 4| and which is fastened at its upper end, as indicated at 43, to the downwardly projectin flange 44 on the bottom of the housing It. This shield protects the animals against contact with the hot coil while the unit is in operation in a tank, and it also excludes a certain amount of trash and dirt from the coil and its associated thermostat. The capsule 23 of the thermostat projects down below the lower end of the shield 32, so as to be maintained at a temperature close to the temperature of the water surroundingv the loop 40. This capsule is clamped in a mideposition between and parallel to the. legs 4| by means of two sheet metal plates 45 and 46, which are disposed in cross-wise relation to the capsule 23 and legs 4|, with their opposite end portions enclosed in the side portions of the channel-shaped shield 42 behind the flanges. 42a, these plates, being heldin tight engagement with the three parts 234| by two bolts 41 disposed on opposite sides of the capsule 23. The bolts 41, therefore, also positively space the capsule 23 from the legs 4| of the heater. This positive positioning of the capsule is very important, because if the capsule were to be brought into contact with either leg4| of the heater or be disposed in too close proximity thereto, the heater would not be controlled properly and the water would, most likely, freeze in cold weather. There is, however, a further and almost equally important reason for this method of assembling the capsule in'the heater, and that is to avoid having the heating element burn out-if the unit happens to be left connected to a current source when not in use in a water-filled tank, as, for example, if it has been demonstrated by a salesman, or when it is first being tried out by a farmer at the time of delivery, or when it may be later carelessly mishandled by an unskilled farm-hand. Under these conditions, the plates 45 and 46 con duct enough heat from the legs 4| to the capsule 23 to break the circuit through the heating element in the coil I0 at about 42 R, which is the temperature at whichv the thermostat maintains the water when the unit is in operation in a tank. The coil ID will, of; course, heat up tothat tem perature quickly when exposed to the air and the current will then be promptly shut off by reason of the heat conductedfrom; thecoil: |0 through the plates 45' and 43 to the capsule 23.. At that low temperature there is no dangerof the heating element being burned out, and, 0f

Goursathere is also much less current consumpa 1 tion.

Itis believed theforegoing description conveys a d u rstanding f theobiects and advan: tages of my invention. The appended claims have been drawn to cover all legitimatemodificae tions and adaptations.

I claim:

1. An immersion type tank heater comprising a generally 'L-shaped heating coil of rigid metallic tubing including a substantially horizontal loop and two spaced substantially parallel upright end portions extending from the endsof-saidloopin rigid substantially right angle relationship there to and adapted to serve as supports-for the coil, a housing attached to the upperends of said upright end portions having a bracket attached thereto for detachable connection with the rim of a tank for supporting said coil by means of the housing on the side wallof a tank the 'fiuid contents of which'are to be heated, an electric heating element in at 'least thehorizontal loop portion'ofsaid heating coil, switch means in the housing connectedwith said heating elementto control current flow thereto from a source of electric current supply, a shield for the upright end portions of the coil extending down from the housing, and thermostatic means responsive to change in the temperature of the fluid contents of. the tank connected for openin and closing said switch means and including a temperature responsive part to be heated immersible in the fluid with the horizontal loop of the heating coil but housed within and protected by said shield.

2. An immersion type tank heater comprising a generally L-shaped heating coil of rigid metallic tubing including a substantially horizontal loop and two spaced substantially parallel upright end portions extending from the ends or said loop in rigid substantially right angle relationship thereto and adapted to serve as supports for the coil, a housing on the upper ends of said upright end portions containing a switch, an electric heating element in at least the horizontal loop portion of said heating coil electrically connected in an electric circuit with said switch, so that the switch controls current flow through said heating element from a source of current supply, a bracket on the housing for detachable connection with the'rim of a tank, whereby the housing supports the heating coil in the tank, and a thermostat mechanically connected with the switch in the housing and having a thermally responsive element extending downwardly from said housing out of contact with the upright end portions of the coil for immersion of its lower end portion in the fluid so as to be heated thereby.

3. An immersion type tank heater comprising a generally L-shaped heating coil including a substantially horizontal loop and two spaced substantially parallel upright end portions extendin from the ends of said loop, a housing on the upper ends of said upright end portions containing a switch, an electric heating element in said heating coil electrically connected in an electric circuit with said switch, so that the switch controls current flow through said heating element from a source of current supply, attaching means on said housing for mounting said heater on the side wall of a tank the fluid contents of which are to be heated, a sheet metal shielding enclosure for the upright end portions of said heating coil attached at its upper end to the housing for support, a thermostat of the bulb and capillary tube type disposed between the upright end portions of said heating coil and therefore protected also by the shielding enclosure, means mechanically connecting the thermostat at its upper end with the switch in said housing, the bulb of said thermostat being disposed lowermost for immersion in the fluid in the tank, whereby to operate the switch in response to temperature change of the fluid, and means spacing the bulb from the upright end portions of the heatin coil.

4. An immersion type heater comprising a generally L-shaped heating coil including a substan tially horizontal loop and two spaced substantially parallel upright end portions extending from the ends of said loop, a housing on the upper ends of said upright end portions containing a switch, an electric heating element in at least the horizontal loop portion of said heating coil electrically connected in an electric circuit with said switch, so that the switch controls current flow through said heating element from a source of current supply, a bracket on the housing for detachable connection with the rim of a tank, whereby the housing supports the heating coil in the tank, a thermostat of elongated form and vertically disposed substantially in parallelism with the up.- right end portions of said coil and having the lower end in proximity to the plane of the horizontal loop portion of the coil so as to be immersed in the fluid being heated by said coil and having the upper end operatively connected with said switch to make and break the circuit in response to temperature change so as to maintain the fluid at a predetermined temperature, and a heat conductor mechanically connecting said thermostat and a lower portion of said heating coil so as to subject the thermostat to temperature rise in direct proportion with the heating coil when it is disposed in space, said heat conductor being so located on the heater as to be immersed in the fluid to be heated with the heating coil and thermostat, whereby under normal operating conditions the fluid abstracts heat therefrom to make the thermostat responsive to temperature change in the fluid.

5. An immersion type tank heater comprising a generally L-shaped heating coil including a substantially horizontal loop and two spaced substantially parallel upright end portions extending from the ends of said loop, a housing on the upper ends of said upright end portions containing a switch, an electric heating element in said heating coil electrically connected in an electric circuit with said switch, so that the switch controls current flow through said heating element from a source of current supply, a thermostat mounted on said heater so that it is immersed in the fluid .to be heated with the heating coil, said thermostat being operatively connected with said switch to make and break the circuit in response to temperature change so as to maintain the fluid at a predetermined temperature, attaching means on said housing for mounting said heater on the side wall of a tank the fluid contents of which are to be heated, a sheet metal shielding enclosure of channelshaped section fitting over the upright end portions of said heating coil on that side away from the side wall of the tank and attached at its upper end to the housing for support, said thermostat including an elongated part adapted to be heated by immersion in the fluid and disposed between the lower end portions of the upright end portions of said heating coil, whereby the same is subjected to the heat of the fluid in the vicinity of the horizontal loop portion of said coil and yet is shielded by said sheet metal enclosure, a pair of spaced heat conducting plates in contact at their opposite ends with the lower end portions of the upright end portions of said heating coil and also with the elongated thermostat part intermediate their ends, and a pair of laterally spaced bolts disposed on opposite sides of the elongated thermostat part clamping the plates to the coil and to the elongated thermostat part while positively spacing said thermostat part from both end portions of the coil.

6. An immersion type heater as set forth in claim 4, including an elongated sheet metal shield which is vertically disposed and adapted to cover that side of the upright end portions of the heating coil away from the side wall of the tank and secured at its upper end to the housing for support, said shield having inwardly bent edge portions contacting the upright end portions of said heating coil and also contacting the heat conductor, whereby said shield serves both to dissipate heat from the heating coil to the atmosphere by radiation when it is disposed in space and also help to conduct heat from the heating coil to the heat conductor when the heating coil is disposed in space.

- 7. An immersion type tank heater comprising a generally L-shaped heating coil including a substantially horizontal loop and two spacedsubstantially parallel upright end portions extending from the ends of said loop, a housing on the upper ends of said upright end portions containing a switch, an electric heating element in said heating coil electrically connected in an electric circuit withsaid switch, so that theswitch controls current flow-through said heating element from a source of current supply, attaching means on said housing for mounting said heater on the side wall of a tank the fluid contents of which are to be heated, a sheet metal shieldingrenclosure for the upright end portions of said heating coil attached at its upper end to the housing for sup port. a thermostat having an elongated part adapted to be heated by immersion in'the fluid and disposed between the upright end portions of said heating coil and therefore protected also by the shielding enclosure, means operatively connecting the thermostat with the switch in said housing, whereby to operate the switch in response to temperature change of the fluid, and means fixedlyv spacing the elongated heatable part of the thermostat from the upright end por tions of the heating coil.

8. An immersion type tank heater comprising a generally L-shaped heating coil including a substantially horizontal loop and two spaced substantially parallel upright end portions extending from the ends of said loop, a housing on the upper ends of said upright end portions containing a switch, an electric heating element in said heating coil electrically connected in an electric circuit with said switch, sov that the switch con trols current flow through said heating element from a source of current supply, attaching means on said housing for mounting said heater on the side wall of a tank the fluid contents of which are to be heated, a sheet metal shielding enclosure for the upright end portions of said heating coil attached at its upper end to the housing for sup-- port, a thermostat of elongated form disposed substantially vertically inside said shielding, enclosure having its lower end portion arranged for immersion in the fluid, and means operatively connecting the thermostat with the switch to operate the latter in response to temperature change of the fluid,

JACOB T. LANDGRAF.

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

UNITED STATES PATENTS Number Name Date I 1,117,277 Supplee Nov. 17, 1914 1,209,862 Lidberg Dec. 26, 1916 1,930,551 Blashfield Oct. 17, 1933 1,994,909 Ehrgott Mar. 19, 1935 2,133,388 Henderson Oct. 18,1938 2,134,675 Shroyer Oct. 25, 1938 2,208,397 Shawber et al. July 16, 1940 2,232,998 Cernohouz etal. Feb. 25, 1941

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