US1232598A - Heating and ventilating apparatus. - Google Patents

Description

J. K. NORSTROM & G. C. BREIDERT. HEATING AND VENTILATING APPARATUS.

APPLICATION FILED NOV. 5, l9l3- 1,232,598. Patented July 10, 1917.

5 SHEETS-SHEET l.

J. K. NORSTROM & G. C. BREIDERT.

HEATING AND VENTELATING APPARATUS.

APPLICATION FILED NOV. 5.1913.

Patentefi July 10, 1917.

5 SHEETS-SHEET 2- J. K. NORSTROM & G. C. BREIDERT.

HEATING AND VENTILATING APPARATUS.

- APPLICATION FILED NOV. 5, 1913- 1,232,598. Patented July 10, 1917.

5 SHEETS-SHEET 3 n. m m u RNN Mm MM a ww J. K. NORSTROM 61 G. C. BREIDERT.

HEATING AND VENTILATING APPARATUS.

APPLICATION FILED NOV- 5,1913- J. K. NORSTROM & G. C. BREIDERT. HEATING AND VENTILATING APPARATUS.

. APPLICATION FILED NOV. 51 1913. 1,232,598. Patented July 10, 1917.

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m Gear Gfireiderf unrrnn STATES PATENT onnrcn.

JOHN K. NORSTROM AND GEORGE C. BREIDERT, OF CHICAGO, ILLINOIS.

especially well adapted for use in street- HEATING AND VENTILATING APIEARATUS.

Specification of Letters gatent.

- Patented Jul 10, 191 "1.

Application filed November 5, 1913. Serial No. 799,276.

To all whom it may concern:

1 Be it known that we, JOHN K. NoRs'rnoM and GEORGE C. BREIDERT, citizens of the United States, all residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Heating and Ventilating Apparatus, of which the following is a specification.

This invention relates to improvements in heating and ventilating apparatus, and particularly to an automatically controlled system for electric-heating and forced draft ventilating. v i

In some of itsfeatures our invention is railway cars, and we have shown herein an embodiment particularly designed to such use, but it will be understood that we donot limit our invention in its broader aspects to such installations In the system nowmost generally inuse for heating street-cars, a series of heating coils are placed under the seats of the car and thefcurrent turned on or cut ofi by the motor-man or conductor whenever he thinks a change in the temperature of the car should be made. It is a-well known fact that thissystem is most unsatisfactory as .it vdepends for its eiiiciency upon the care andattention given to it 'by 'the operators.

' theheater element controllerzconstructed to provide a shiftable member movable 1n op- In our improved. system we have provided for automatic heat control, thecontroller,

automatically governed in its movements by a thermostat, operating to start or stop, if desired) a ventilating fan and acting to vary the heat-supply, as by cutting in o .out a'plurality of electric heating coils '90- sitioned within the delivery duct of the fan. A particular feature of our invention is posite directions respectively, in responseto a-thermostats response to rise and fall of temperature; to provide. a positive lock for said shiftable member in eachpositlon, and. to govern the controlling circuit: for-its electro responsive devices so that said. circuit is active only when the thermostat I re-= sponds to temperature changes.

A further featureof heating is the mounting'of the thermostat our 1nvention.re'sides'- in the provision of an adequate thermo-re sponsive apparatus for and-connections for governing the controller. 'Another feature of our invention, especially relating to -c,ar-

and ventilated, whereby it is more responsive to temperature changes, thereby varying the heating capacity of the apparatus and preparing the interior of the compartment, prior to its being actually afi'ected by the outside change. A further feature of our invention relates to the electrical heating installation, for provision of adequate, readily-variable heater, in association with an air duct to give minimum obstruction to air flow.

Whereas we have shown and described the apparatus as applied to a street railway car, it is obvious that it would'be equally efiicient when used for heating and ventilating dwelling houses, public. buildings or in fact any compartment or'inclosure.

In the drawings, wherein we have illus trated a particular embodiment of our invention,

Figure 1 is. a side elevation of a street railway car withparts broken away to show the installation of our apparatus.

Fig. 2 is a vertical longitudinal sectional view through the intake and discharge duct of .our Ventilatin fan showing our improved heating coils in position.

Fig. 3 is a perspective view of a heating unit.

Fig. 4. is a wiring diagram showing the and unlocking the slidable carriage of the p controller.

Fig. 9 is a plan view of the relay.

Fig. lO is a plan view with parts broken away of ,our improved thermostat.

casing broken away, and;

Fig. 12 is a fragmentary side elevation of Y the ratchet pawls raised for actuating the carriage. 1 p

{In .Fig. '1 is shown a street railway car Fig. 11 is a side elevation ofthe thermo- .stat shown in Fig. 10 with parts of the 10 upon the floor 11', on which is mounted a venti'lating fan 12 driven by an electric -motor 13. This is positioned at one end of a the car, 'the eye of the fanbeing connected with an intake duct 14 extending along the side of the car up at the opposite end at 15, extending through the roof, the opening being: provided with a grating or screen 16.

he delivery duct 17 leading from the fan extends from the discharge opening 18,

7 along the, inner side of the inlet duct 14 bemginset therein so as to be inclosed upon three of its sides. A plurality of openings 19 are provided in the .duct 17 for the passage of the air out into the car. The inlet duct 14 preferably surrounds three sides of the outlet for the heated air, throughout its length, or particularly the length of the heater-containing area of said outlet duct, in order topartially warm the air before its introduction into the fan. The outlet duct 17 for a short distance from its connection with the outlet of the fan at 18 is enlarged as at 17' and within this enlarged sect" on are mounted a series of heating coils 19' which serve to heat the air. as .it isdelivered from the fan into the car.

Whereas we have shown but a single ven-I tilating fan, together with its inlet and discharge ducts, it is obvious that if such a fan has notsuflicient capacity to ventilate a car, a similar set may be mounted upon the opposite side of the car. adjacent to the floor withits inlet opening running out of the opposite" end, from that with which the otherventivlatin set communicates, thus compensating for c anges in direction of car-travel.

The controller is indicated at 20 in dotted lines Fig; 1 as positioned in the roof of the compartment at one end of the car, the relay 21 being mounted adjacent. We have found that it is of advantage to have the thermostat 22 positioned outside of the car so that it is su current through a lead 24 connected to one terminal 25 of a generator 26, the other-terminal 27' of which is grounded at 28. A thermostat arm indicated diagrammatically at 29, carrying at one end a spring presser roller 30 makes progressive contact. with aseries of points 31, 32, 33, 34, 35, 36, 37, 38,

and 39. v The thermostat arm is pivoted on a pin and from its pivotal point a conductor 41 leads through a variable resistance 42 to the trolley arm 43, the wheel 440i which p makes contact with the trolleyline 23' The contact points 31 to 39 respectively are positioned'in anarc described about the pivot pin 40 of the thermostat arm and since the wheel 30 is spring pressed in contactwith the points, it is obvious that the progressive movement upward and downward of the arm is in a series of jumps'or steps, the roller always occupying, except when in motion, a position between and in contact with ject to the changes of temperature outside of, rather than inside of- I the car. In Fig. 4 is shown a wiringildiagram which 23 represents a trolley e receiving 1 4 5 operation of two of the pins. Any slight changes in tem- [perature, such as would effect a sensitive i thermostat are insuflicien'tto operate our improved thermostat, as its movement is resisted by the spring pressed wheel 30 until the change is suficient to force the roller over one of the pins and into its next contact position. I

The moving part of our controllercomprises a carriage or slide, 45" mounted in a frame and free to move backward or forward except as controlled by, the ratchet mechanism connected with the magnets 46, and 47 The movements of this carriage are controlled by the thermostat, and'the carriage movement governs the operation of the heating devices and the connections be tween the carriage-operating electro-responsive devices and the thermostat. In order to clarify the wiring diagram the sliding car,-

riage is split into three parts showing in'the directly these magnets are. controlled by respective relays, 54, 54 and the circuits for each relay is controlled by the thermostatic switch, 29, by switch mechanism on the slide itself (lowestsection) and by a switch 53 or 53 moved bythe armature of the respective carriage-moving magnet. This, in order that thermostat movement, completing a relay circuit otherwise closed, may cause actuation of" the carriage-moving magnet, the

activity of which breaks the relay circuit to permit retraction of the magnet-armature, such armature retraction moving the carriage to kill, or open, the just-used connection from the thermostat and prepare the carriage-movingdevices for appropriate response to a succeeding movement of the thermostat switch in either direction.

' Directly in "front of the adjacent ends of the cores of the magnets 46 and 47 are slidablymounted the two armatures 48 and 48' normally held away from the magnets 'the' armature-connecting springs 49.

Ratchet pawls 50 and 50' are pivotally connected to' the armaturesand engage with oppositely disposed ratchet teeth 51 and 51" carried by the slide 45. Rods 52 and 52 are connected to the armature 48 and 48' and on their opposite ends they coact with the movable parts, of the switch 53, 53.

It; is obvious that in the mechanism as shown in' the wiring diagram,.movement of the carriage could not be obtained by the either of thamagirets, owing to the locking effect-of the pawl on the other magnet. We have provided howeve'rin our controller, which we will later describe in detail, a mechanical release mechanism interconnecting the two pawls so that when one is moved backward over a tooth into position to be advanced by the spring and move the slide, the other is automatically disengaged to permit such movement.

Relays 54 and 54, operating switches 55 and 55 connected in series with the respective magnets 46 and 47 are energized through the medium of the sliding contact bars 56 and 57 operating across the contact fingers 58, 59, 60, 61, 62, 63 and 64.

On the side of the carriage opposite to that carrying the sliding contacts 56 and 57 are mounted two contact strips 65 and 66 together with pins 67 and 68 which pass through the carriage making contact at proper intervals with fingers on opposite sides thereof. On the upper side of the frame extending over the carriage are positioned the contact fingers 69, 70, 71, 72 and- 73 and on the lower tact fingers 74, 75, 76.

Before describing in detail the instrumen'talities whereby we obtain the various movements and control the various parts, we will first describe the general operation of side are mounted conthe system as illustrated in Fig. 4.

' and 32.

,nection no change takes place until the arm For convenient positions of the carriage the letters A, B, C, D and E are placed opposite the points occupied by the right hand end of the carriage in its various positions as moved forward or backward by the operation of the ratchet pawls 50 and 50 upon the ratchet teeth 51 and 51. Considering the carriage at the extreme right hand position indicated by letter A as shown in the diagram, the first upward movement of the thermostat arm 29 due to a decrease in temperature, will bring the roller 30 in'contact with the pin 31. The pin 31 is connected by means of a wire 77 with the finger 63. In-the position shown this finger 63 is out of contact with either of the slides 56 or 57 and no current will flow. As the temperature continues to decrease the thermostat arm.29 will it occupies the position between the pins 31 As the pin 32 has no outside con- 29 moves still farther upward throwing the roller into position between pins 32 and 33. Pin 33 isconne'cted by the lead 78 with contact finger 62 and as this is in engagement with slide 56 current will flow through the following circuit: from the line wire .23,

through trolley 43, resistance 42, over the wire 41, through the arm of the thermostat 29, to contact pin 33, through lead 78'to spring .finger, 62, into the slide 56, out through the spring finger 58, through wires 79 and 100 to swltch 53, over the wire 80 reference to the various move forward until from the trolley 43, throu to relay magnet 54 and ground at 81. Cur-- rent flowing through this circuit energizes the relay 54, closing the switch 55. This magnet 47 through tooth of the ratchet 51 and forcing the rod 52 back to open the switch 53. Opening the switch 53 deenergizes the relay 54, consequently opening the circuit through the magnet 47 permitting the spring 49 to draw the armature 48 away from the magnet and move the sliding carriage to the left one step or notch. This movement throws the carriage with contact strip 56 to the left to position B taking it away fromunder finger 62' and breaking the control circuit, killing the connection of thermostat-point 33. Current flow only momentary. The contact 33-being now dead, no further advance movement of the carriage can take place until thermostat arm 29 reaches the next live contact 35. The carriage-movement, however, moves strip over to connect fingers 64-63. This potentiates the connection 77 for the thermostat contact 31, which initially was dead as described, and prepares the electro-responsive devices to move the carriage.

back to initial position should thermostat arm 29 return to contact with point 31.'

to accomplish these results is fingers 71, 70 and 69,- respectively. The

other ends of X and Y are connected through wires 109 110 to fingers 75 and 74 respectively, and t e opposite end of coil Z is connected through wire 111 to wire 112 which is connected at one end to spring finger 76 and at the other end to the wire 83 leading to the trolley.

The next upward step of the thermostat throws the wheel 30 into position between the pins 33 and 34 without in any way effecting thecontroller. On a further decrease in temperature the thermostat arm will be thrown up another step until the wheel 30 is positioned between contact pin 34-and 35. Current will instantly flow through h the. circuit 42, 41, 40, 29, 30,35, wire 113, ger 61, slide 56, finger 58-, wire 79 and through the relay circuit previously traced to ground at 81.

Y The magnet 47' will then be energized through the circuit previously traced and the carriage moved to point C.- This carries the slide 56' out from under contact finger J 61- and breaks the operating circuit. on in this position the circuit for the heating coils will be as follows, the fan still remaining in circuit: from the trolley 43 through wires 82, 83, 112,111, to coil Z, wire. 108, finger 69 through pin 67, spring finger 74,

wire-110, coil Y, wire 107, spring finger 7 0,

' pin 68, finger 75, wire 109, coil X, wire106,

spring finger 71, contact bar 65, wire 104 and to ground at ,105. The fan circuit through wire. 103, slide 65, and wire 104v to ground 105 remains closed.

Still further upward movement of the thermostat arm 29 brings the roller 30 into engagement with the, contact point 37 causing current to flow through the wire 114 to. finger 60 and thence through the-relay circuit previously traced; This again energizes the magnet 47 causing the carriage to move to the left another notch and into 'po-' sition indicated at D. As this'movement is due to a lowering of the temperature butside'the car it isessential that greater heat. be radiated from the coils X, and Z4to' maintain the interior of the 'car at a com-..

fortable temperature; '7 This motion of the carriage disconnects the coils from seriesre lation and places colls Y. and Z 1n ser1es and the'coil X directly across the line. This placing of the coils, two in series and one in parallel will increase the heat radiated from the coils and raise the temperature of the car, through the medium of the heated air .flowing through they delivery duct from' the fan. e

The next step up of the rheostat arm 29.

. causes the roller 30 to contact with the pin to be met where the apparatus is installed.

' slide, killing the It will be observed that each step of the v oint of the thermostat with which arm 29 hen coacts, cuts into potential condition: the formerly-dead contact of the thermostat previously passed by the arm 29, and it will be observed that .the slide 57 which'so potentiatesthe passed contacts is connected with relay 54. Thuslwhile the contact bar 56,.when the carriage is in .positionE, is ata point where its-right hand end is betweenthe two spring fingers 58 and 59, and no current can flow through the wire 115, the contact bar 57 is now in a position where it engages with contact fingers 60, 61, 62-, 63, and 64. With a rise in temperature the roller 30 will drop down away from the contact 39 and make contact with pin 37. Current will then flow from the trolley 43 to resistance 42, through wire 41, arm 29, roller 30, pin 37, wire 114, spring finger 60, slide 57 spring finger 64, wires 116 and 117 through the switch 53, wire 118, into the relay 54, out through wire 119 and to groundat 120., The relay 54 being energized causes the closure of the switch 55 permitting current to flow from trolley 43 through wires 82, 121, 122 through the switch 55, wire 123, through magnet 46, out to wire 124,-to ground at 125. Energizing the magnet 46 draws the armature 48 against the resistance of the'spring 49, slipping the pawl 50 back over one of the ratchet teeth 51 and at the same time through the medium of the rod 52 .breaking contact at the switch '53 and permitting-the spring to draw the carriage or slide one step to theright. This bringsthe slide back into the position indicated. at D and 'it is obvious that further movement of the thermostat arm 29 downward will cause subsequent steps or jumps of the slide to the right through positions C, B and "back to A.

At any intermediate point on the. downward travel should a change in temperature.

vcause the rheostat.-to reverse its movement the magnet at the opposite end of the slide will be energized and the carriage thrown back one step throwing the coils into the position occupied prior to the last step.

The apparatus and circuits outlined pro- I 1 v1de for posltlve movement in one direction one direction causes first the starting of a ventilating fan, then the introduction of three heating coils'i'n series, subsequently the introduction of-two coils in series and one in or. the other of a controller member, respon-- 'sive to thermal changes. The movement in parallel and lastly introducing all of the coils in parallel with the line. The reverse movement of the controller first cuts out the coils connected in parallel and connects two' in series and one in-parallel, the. next step cutsthem all in series, the next step cutting out the coils entirely and the last" step cutting ogt. the fan. As a result we have a system which automatically cares for itself and positions the controller at the proper point in direct changes' Whereas we in Fig.4 appliances for the practice of our invention we will now describe mechanisms response to temperature which are well adapted for the commercial embodiment of our invention, and some of which we believe to be novel. -In Figs-10 and 11 we have have shown diagrammatically shown a particular form of thermostat which we prefer I to use. This comprises a base 126 of some suitableinsulating material, upon the lower end of which is mounted a pivot pin carrying an L shaped arm 29. This arm may be of sheet metal and is provided at the endof the shorter leg with an aperture 127 in which is connected one end of a spring 128, the other end of which is connected to a pin 129* secured to the base 126'. Thespring is normally in tension and tends to throw the longer leg of the arm to the left.

The upper end of the arm 29 is slotted out as at 130, to receive a rod 131 of less width than the slot and upon the upper end of which is mounted a wheel 30. The lower end of the rod 131 is guided and held in its plane of movement by the strip 132 bent around and secured to arm 29 near the bottom of slot 130. Cross bars 133 extend across the open end of the arm 29 and carry the upper end of the spring 134, the lower end of which is connected to 'a pin extending through the lower end of rod 131. The spring is normally in tension tending t6 force the arm up and consequently pressing the wheel 30 against a series of pins numbered 31 to 39 inclusive, every other one of which, as already described forms a terminal contact for one of the wires. 77, 78, 113, 114, and 115, the other ends of which are connected with the controller. The motion of the spring pressed roller contact from one live pin to another is quick and-positive in movement due to the pressure of the spring, together with the side motion of the arm 131 within thefslot 130 and sparking and wearingtaway of the contacts is prevented.

. order to insure the proper movement of the arm 29 in response to thermal changes we have provided a long tube 135 made of some, such material as hard rubber,'having a high coeflicient of expansion, with its lower end abutting against a lug 136 pivoted to the shorter end of the L shaped arm 29 intermediate the pivot point 40 and the aperture 127. The upper end of the tube 135 abuts against a fixed rod 137, the upper end of which is threaded and secured in position on the lug 139 by the-lock nuts 138. In order that the tube 135 may be held in proper position in alinement wtih the rod 137 and the lu 136, we inclosethe same in a metallic tu e 140, the lower end of which is pinned to the lug 136 and the upper-end of which slidably engages the exterior of the rod 137 It is obvious that an elongation of the tube 135 due to an increase in temperature will cause movement of the roller or wheel 30 to the right across the contacts 39, 38, 37, 36,

35, 34 and33. A shortening of the rod, due

to contraction responsive to a lowering of the temperature permits the spring 128- to throw the arm .29 with its roller 30 backward across the contacts in reverse order;

nets.

In Figs. 5, 6, 7 and 8 is illustrated a speclfic controller mechanism for actuating the fan motor and heating coil circuits in response to the thermostat. .The numeral 141 represents abase or support of suitable insulating material within an opening 143, in

which isslidably mounted the carriage 45,-

. the frame and sliding carriage in the same relation as shown in Fig. 4. The contacts Y 67 and 68 are short rods of conducting material positioned vertically in openings formed in the sliding carriage which is of a suitable insulating material.

' On the opposite side of the frame from that carrying the springfingers 69 to 76, are positioned the spring fingers 58 to 64 inclusive, contacting with the slide bars 56 and 57 mounted on the carriage.

.At each end of the opening 143 in the frame are mounted the actuating magnets 46 and .47 in front of which are positioned the sliding armatures 48 and 48. These armatures are carried by the rod 52-52 which in turn are slidable within the supports 144,

145 and 144 and 145, which carry the mag- At the other ends of the rods 52 and 52 are positioned the single throw switches 53 and 53 already described in connection with the wiring diagram in Fig. 4. The

switch members 53 and 53 are pivoted to the support at 146 and 146 and carry at their inner ends yokes 147 and 147 The outer ends of the rods 52 and 52 are threaded to receive elongated nuts 142 and 142- which are drawn by the springs 49 up into contact with the magnet supports 144 and 144.

-Adjustment of-the nuts 142 and 142 permits variations in the length of throw of pawls 50 and 50'. Depending arms 148 and 148 of insulating material are carried on the ends of the'rods 52jand 52 between the nuts/142, 142 and lock nuts 142, 142". ,The lower ends of the 'arms 'l'48'and 148 extend between the finger of the yokes 147 and 147 and into slots 148 and 148 in the'base.

The engagement of the downward extending arms in the slots provides'proper guidance for the armatures holdingthem horizontal.

The yokes permit of a slight lost motion so that the armatures on approaching their magnets are permitted. to acquire suflicient velocity to carry the ratchet 50 or '50 over the ratchet teeth before throwing the switches 53 or 53 deenergizing the magnets.

Brackets 150 and 150 are secured to the frame in front of the armatures 48 and 48 to limit their motion toward oneanother.

.These strips have upward extending ears to which are secured the'two parallel side bars- 152, extending along each side of the ratchet tooth bars 51 and 51. The ratchet culiarshapeand are provided with an interconnecting mechanism whereby when one pawl is drawn back over a ratchet tooth, the

. opposite pawl is raised from engagement with its rack so as to permit the other ratchet on its forward motion under the influence of the springs to move thecarriage. The active ends of the ratchet pawls 50 and 50 are shaped with downward extending thumbs 153 and 153 which engage with the ratchet teeth 51 and 51 respectively. Extendingupward at an angle to the thumbs .153 and 153 are fingers 154 and 154 terminating at .their ends in downward extending hook parts 155 and 155'. Pins 156 and 156' extend outward from each of the pawls near the juncture of the thumbs and fingers and carry on their ends the links 157 and 157 through engagement with the slots 158 and 158 The forward ends of the links 157 and 157 carry inward projecting dogs 159 and 159 which extend into the openings formed by the thumbs 153, 153 and hooks 155ml 155. The dogs 159 and "159 also carry short levers 160 and 160 which extend backward at acute angles to the links 157 and 157 terminating in pins 161 and 161 pivoted in the side rails 152- The operation of the ratchet pawls is as;

follows. Supposing for example that the .magnet 46 is energized drawing backward the armature 48, the first rearward move ment of the pawl 50. will carry the thumb 159 upward on the inclined tooth of the ratchet 51 untilthe pin 156 reaches the end of the slot .158.- This point will be just prior to the dropping of the-thumb'158 over the top of one of the ratchet teeth. On engagement of the'pin 156 with the end of the slot 158 the link 157 is drawn backward pivoting on the pin 161 and raising the dog 159. Thenpward movementof thedog 159 causes its engagement with the finger 154 with the result that the ratchet pawl 50 with its operating thumb 153- is raised out of engagement with its ratchet teeth.- This lifting of the pawl 154' continuesuntil' link .157 throws'dog 159pas'tjthej nub 154, the engagement of which holds pawl 154 raised. 7 By thist'nne the thumb 153 has dropped down into the next ratchet tooth and the armature 48 is ready for retraction. When springs 49 retractthe armature. to move the carriage pin 156' travels the-length of .its-

Zslot, releases the latch dog .159 and allows pawl 50"to dro back into the next tooth .pocket of its rac c. At the end-of this move lessees -ment the ratchets are both in engagement with their teeth and the carriage is positively locked against further movement until one of the magnets 46 or 47 is again energized. i

The springs 49 are secured to the movable parts of the armatures 48 and 48 by engagement with the ends of the rods 162- heating coils 167 formed from'wire having a relatively low coeficient of conductivity. Oneterminal of each heating coil 167 is secured to asuitably formed insulator and extends outward adjacent the rod 164. The convolutions of the first coil, as illustrated in Fig. 3, extend outward around the curves of the frame in a plane at right angles to the axis of the rod 164 to a point 168 at its outer end. At this point the coil is bent over parallel with rod 164 to a point somewhat removed from the first section and there extends inward in a series of coils down to the rod 164. It is then carried along the rod 164 around a suitable insulating sheath 169 and again run outward around theconformation of the frame to form a second unit.

This method of forming the heatingcoils is so flexible and simple that the required length of Wire for properly heating the air passing through'thedu'ct 17 is readily placed the embodiment of the invention shown three sets of coils X, Y- and Z are used.

Each 'set of coils'maycomprise any number. of spirals, and it is obvious that more or within the'enlargement of the duct 17 In v scribed" it is evident that various changes- 'may made in order to adaptitto particular environments." In. some instances it may be found necessary to use a large num-' her-of heating units and consequently use.

a controller having morethan five steps or I jumps to operate the units. Again in some instances 1t may be found desirable to locate the thermostat withinthe area to be heated j and "ventilated, though we have found that in street car work or infact in any work where. the compartment to be heated is;

poorly insulated from the surrounding at .mosphere', it is most desirable to have the thermostat exposed to the outside tempera:

ture in order to properly condition or prepare the interior for changes due to outside temperature changes. Whereas in the system shown the ventilating fan is connected through the controller, in some instances it may be advisable to bridge over a circuit for the fan so as to permit its operation independent of the thermostat.

ereas We have illustrated and described a particular embodiment of our invention, it is obvious that various changes in the wiring and in the arrangement of controller contacts may be made without departing from its spirit and scope.

Having described our invention, what we claim is p 1. In an automatic heat controlling system, the combination of an arm movable to various positions in .response to thermal changes, a plurality of contact points in the path of said arm, a controller having a movable part, means responsive to the engagement of said arm with the contact points for moving said controller part from one position to another, a source of current supply, electrical heating coils and switches operated-by the movement of said controller for connecting said coils in various relations to the line. I

2. In an automatic heat controlling system, the combination of an. arm movable to various positions in response to thermal changes, a plurality of contact points in the path of said arm adapted to be progressively engaged thereby, a controller having a part movable step by step in either direction; means responsive to the engagement of said arm with the. contact points for moving said controller part step by step from one posi tion to another, a source of current supply, a plurality of electrical heating coils, and switches operated bv the movement of said controller part for connecting said coils in various relations to the source of current supply. 7

.3. In an automatic heat controlling system, the combination of an arm movable to varying positions in response to thermal changes, a plurality of contact points in the path of said arm, .and adapted to be pro gressively engaged thereby, a controller having an electro-magnetically controlled part movable step by step in either direc tion, circuits including said arm and contacts for operating the electro-magnetically controlled part, a source of current supply, electrical heating coils, a plurality of switches operated by the movement of said controller part for connecting the coils in various relations to the source of current supply.

4:. In an automatic'heat controlling sys tem, the combination of a thermostat, a controller having a movable part, means connected with the thermostat for moving said controller part in response to thermal changes, a ventilating fan motor, a series of heating coils in the discharge duct of said fan and switches operated by the movements of said controller part for connecting the said fan motor and heating coils in circuit with a source of current supply.

5. In an automatic heat controlling sys-' tem, the combination of a thermostat, a controller having a movable part, meansconnected with the thermostat for moving said controller part in response to thermal changes, a ventilating fan motor, heating coils in the discharge duct of said fan and switches operated by the movements of said controller parts for connecting said fan motor and heating coils in circuit with a source of current supply, said switches being arranged to include the fan motor in circuit the heating coils are in circuit.

6. In an automatic heat controllingsystem, the combination of a thermostat, a controller having a slidable carriage, electric motors operatively connected with the said -with the source of current supply whenever carriage for moving it from one position to' another, a plurality of contact points adapted to be'engaged by said thermostat in its 1 from one position to another, means for mo mentarily energizing said'electro-responsive meansin response to movement of the. said thermostat, a plurality of heating coils, I

contact fingers positioned adjacent the carriage and connected to. the said coils, contact fingers similarly placed and connected with a source of current supply, and-contact strips movable with said can-riagejand:

adapted to engage with the said fingers and cut the said coils in or out of the source of current supply.

In ,an' automatic heat controlling sys tem, the combination of a thermostat, a controllerl having a movable part, electro-responsive means for moving said movable part of the controller in response to movements of the thermostat, a fan operating.

motor, a plurality of heating coils, positioned in the discharge ofthe fan, a source said controller moving part, whereby movejment'of the controller part one direction of current supply, switches operated by the.

' first connects the fan motor with the source of supply, then the coils in series and lastly the coils in parallel.

9. .In an automatic heat control system, the combination ofa controller hav1ng a slidable carriage, electro-responsive means for moving the said carriage in a step by step motion, a thermostat having progressive engagement with a plurality of contact plns, electrical connections between the said pins and a series ofcontact fingers adjacent the sliding carriage; a source of current supply, contacts on the said carriage adapted to engage all'but one of the said fingers and connections between the said contacts and the electro-responsive means.

10. In an automatic heat control system,

rality of strips extending outward in spiral formation from the'rod, and spaced from each other, insulating rods; parallel to the supporting rod and carried by said strips, and electrical heating wires carried by the said insulating rods.

12. In an automatic heat controlling system a movable member, heating means controlled by said member for increase or decrease of heating effect as said memiber moves in one direction or the other, electroresponsive means for imparting step by step movement to said member-in either direction, and a thermostat controlling said electro-responsive means.

13. In an automatic heat controlling system, a movable member, heating means controlled thereby for increase or decrease of the heating efiect as said member moves in one direction or the other, electro-responsive means for imparting step by step movement to said member in either direction, switches controlled by movement of said member, a thermostat having a movable contact and a plurality of temperature indicating contacts, and circuit connections for said electro-responsive means governed by the thermostat contact and controlled by said switches for connecting all temperature contacts on one side of the movable contact to operate said step by step means in one direction and on the other side of the movable contact to operate said step by step meansi the op osite direction.

14L. ii an automatic heat controlling system for street cars or the like, the combination of a thermostat positioned outside of the car, a controller having a movable part, means connected with the thermostat for moving said controller in response to outside thermal changes, a ventilating fan having inlet and discharge ducts, a motor for driving said fan, a series of heating coils in the discharge duct of said fan, the inlet duct opening outside the car, and switches operated by the movements of said controller part for connecting the said fan motor and heating coils in circuit with a source of current supply.

15. In an automatic heat controlling system for street cars or the like, the combination of a movable member, heating means within the car controlled by said member for increase or decrease of heating effect as said member moves in one direction or the other,

' electro-responsive -means for impartingstep by step movement to said memberin either directlon, and a thermostat positioned outside of the car and controlling said electroresponsive means.

In testimony whereof we hereunto set our hands.

JOHN K. NORSTROM. GEORGE O. BREIDERT. In the presence of STANLEY'W. COOK, MARY F. ALLEN]

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