US 2258482 A
Description (OCR text may contain errors)
ROASTER Filed Dec. 22, 1938 5 Sheets-Sheet l z w zkw as 6 T v. 3 NMHE v M NP 0 J R r A T A M J W fl/ H N/ h/ Emu .m M mV Oct. 7, 1941. w, CARPENTER 2,258,482
ROASTER Filed Dec. 22, 1938 5 Sheets-Sheet 2 [/vvE/w-oe 4e FRANK WC'ARPENTEE I Oct. 7, 1941. w CARPENTER 2,258,482
ROASTER Filed Dec. 22, 1938 5 Sheets-Sh 3 [vvszvrohe FRANK W CARPENTER A'rroms Y;
Oct. 7, 1941.
F. W. CARPENTER ROASTER Filed Dec. 22, 1 938 5 Sheets-Sheet 4 .ZI-VVE'NTOB I33 FRANK W CARPENTER Patented Oct. 7, 1941 V UNITED STATES PATENTFOFFICE.
ROASTE-R- Frank W. Carpenter, Minneapolis, Minn., assignor to Woolsey Manufacturing Company, Minneapolis, Minn., a corporation of Minnesota Application December 22, 19-38, Serial No. 247,200
This invention relates to new and useful improvements-in portable masters and more particularly to such an apparatus for roasting peanuts and various other commodities such, for example, as cofiee.
An object of the present invention is to provide a roaster which is substantially automatic in operation and has means for controlling the roasting period.
- A. furtherobject is to provide an electrically operated roaster having meansfor automatically interrupting the operation of the entire apparatus at the end of the roasting period.
Other objects of the invention reside in the simple and inexpensive construction of the con- .trol means; in the unique arrangement and con.-
'struetion of the heating elements within the oven, whereby they may readily be removed ovenbefore the oven has cooled. sufiiciently to permit the thermostatically controlled switch to open; and in the simple means for varying the length of the roasting period. I
Other objects of the invention will appear from the following description and accompanying drawings and will be pointed out in the annexed claims.
In the accompanying drawings, there has been disclosed a structure designed to carry out the.
various objects; of the: invention, but it is to be understood that the invention: is not confined to Figure 4 is a detail sectional view showing the manually operable means for preventing the doors of the oven from opening, in the event that a fresh supply of peanuts is introduced into the oven, while the oven is still at roasting temperature;
Figure 5 is a sectional view on the line 5--5 of Figure 9, showing themain operatingswitch, and the-means for automatically operating it to shut on. the current at the end of the roasting period;
Figure 6 isv a sectional plan view on the line- 6--6 of Figure 5;
Figure '7 is a view similar to Figure 5 partially in section with the parts positioned as when the doors-are opened;
' Figure 8 is a detailsectional view on the line 8-8 of Figure'l, showing the thermostat;
Figure 9 is an enlarged detail sectional View substantially on the line" 9--9- of Figure 3, showing the means for driving the agitator and other associated parts;
Figure 10 is a wiring diagram; and:
Figure 11 is a detail sectional view on the line I l--l| of Figure 1, showing ameans for retaining the upper door partially open to vent the oven.
The casing of the novel roaster herein disclosed, generally indicated by the numeral 2*, is similar in some respects to the one shown and. described in Patent No. 2,1413586, granted to John K. Woolsey and Frank W. Carpenter, on December 2'7, 1938, and comprises a cylindrical wall 3-, and end walls 4 and=-5. These walls are constructed of a suitable non-conductive matei rial; so as to-preventthe conduction of heat from the oven 6, defined bysaid walls.
A suitable door 1 is provided in the upper portion of the casing and is pivotally supported upona suitable pivot 8:, as shown in Figure 5. Suitable doors 99 are provided in the bottom of the oven, whereby the: contents of the oven may readily be discharged therefrom at the end of. the roasting period. The bottom doors 9 are supported on suitable pivots l l and have arms I 2 secured thereto, to which the lower ends of a pair of links l3 are connected. The upper ends of the links are pivotally connected to a cross head |4= supported ona' rod- I5; This rod carries a pivot 16 at its upper end, to which one'end of a connecting rod H is pivotally connected.
A. coiled spring I8 is shown'coiled about the rod I51' between the cross. head l4 and a nut l9 receivedin threaded engagement with the rod. A tension spring 2| has one: end connected to the lower. end of the rod. l5 and. its opposite end to a bracket 22 secured to the end wall of the oven, as best shown in Figure 1.
The upper end of the rod I! has a head 23 which is slidable in a guide 24. The guide 24 has its upper end pivotally connected to an arm 25 secured to the pivot 8 of the upper door 1. The above described mechanism operatively connects together-the upper doors I and lower doors 9-9, so that when the upper door is opened, as indicated in dotted lines in Figure 5, the lower doors are closed. Thereafter, the upper door I may readily be closed and locked in such position without transmitting any motion to the lower doors 9. The above described mechanism is shown and described in detail in the patent hereinbefore mentioned.
A feature of the present invention resides in the novel means provided for heating the oven 6. As best shown in Figures 1 and 2, a pair of heating elements, generally indicated by th numeral L 26, are mounted upon the end walls 4 and 5 of the oven. These heating elements are alike in construction, and but one will therefore be described in detail. Each heating element comprises a body portion 27 of a suitable non-conductive material such, for example, as porcelain. The periphery of the body portion 21 is spirally grooved to receive the resistance wire 28 of the heating element. The ends of this resistance wire are electrically connected to a pair of terminal posts 29 and 3|, mounted in the base 32 of the heating element. The terminal posts 29 and 3| have split terminals 33 and 34, respectively, adapted to be detachably received in sockets 35 and 36, respectively, shown mounted in the lining 31 of theend walls of the oven and suitably insulated therefrom. By thus constructing the heating elements, it will readily be noted, by reference to Figure 2, that they may readily be detached or removed from the oven, when desired, for repairs or replacement. A suitable shield 38 is preferably provided over each heating element 26 to prevent the material being roasted from contacting therewith, during the roasting period. The shields 38 also prevent the peanuts from coming in contact with the heat ing elements during the loading operation.
Means is provided within the oven for constantly agitating the peanuts or other products within the oven during the roasting period. The means provided for thus agitating the peanuts is shown comprising a suitable agitator, generally indicated by the numeral 39. This agitator comprises a shaft 4|, one end of which is mounted in a bearing 42 provided in the wall 4 of the oven. The opposite end of the shaft 4|' is shown provided with an enlarged portion 42 which passes through an opening 43 in the end wall 5 of the oven. The terminal of the enlarged portion 42 of the shaft 4| has a socket 44 adapted to receive the adjacent terminal of a drive shaft 45, having a transverse driving pin 46 received in oppositely disposed slots or notches 41 provided in the wall of the socket 44.
The agitator is shown comprising a pair of arms 48 having suitable blades 49 secured to the ends thereof adapted toengage and agitate the material in the oven when the agitator isrotated.
The shaft is shown having one end mounted in a suitable bearing 5| provided in a fixed portion 52 of a suitable housing, generally indicated by the numeral 53. Th opposite end of the shaft45 is supported in a bearing 54 prov ded in the removable part or cover 55 of the housing 53. A gear 56 is keyed to the shaft 45 and meshes with a pinion 51 secured to a shaft 58, one end of which is mounted in the wall of the part 52 of the housing 53. The opposite or intermediate end portion of the shaft 58 is shown rotatably supported in a cylindrical portion 59 of a gear casing 6|, and has a worm gear 62 secured thereto, which meshes with a worm 63 provided on a shaft 64, one end of which is mounted in a bearing provided in the gear casing 6| and its opposite end in a removable bearing 65 received in threaded engagement with the gear casing 6|, as best shown in Figure 3.
A cylindrical portion 59 of the gear casing 6| is received in a hub 66 provided in the wall of the cover 55 of the housing 53, and is secured against movement therein by suitable means, not shown. The gear casing 6| has a removable cover 61,- whereby access may be had to the interior thereof. A flanged pulley 68 is shown secured to the drive shaft 64. The pulley 68 is driven by a belt 69 engaged with a pulley 1| provided upon a suitable motor 12, the base of which is supported on a suitable pivot 13 provided on the bottom wall 14 of the outer enclosing casing of the roaster. By thus pivotally supporting the motor, the belt 69 is constantly under tension by the weight of the pulley.
The means for controlling the operation of the roaster will next be described. As best shown in Figures 5, 7 and 9 the pivot l6 connecting the rods l5 and I1, is supported in an arm 15 secured to a short shaft 16 mounted in a suitable bearing 1'! provided in the rear wall of the housing 52. An arm 18 is secured to the shaft 16 within the housing 53, and has a roller 19 secured to the outer end thereof adapted to be received in a notch 8| provided in a latch 82, secured to a shaft 83. The shaft 83 may be mounted in a bearing provided in the front wall or cover 55 of the housing 53. An arm 84 is secured to the shaft 83 exteriorly of the housing 53, and has a finger 85 received in a slot 86 provided in the armature 8'! of a suitable solenoid coil 88. The solenoid is suitably supported on the cover 55 by such means as a bracket 89.
The latch 82 serves to lock the lower doors 9 in closed position, as shown in Figure5, wherein it will be seen that the roller 79 of the arm 18 is engaged with the notch 8| in the arm 82. A suitable stop pin 9| may be provided for limiting swinging movement of the latch 82 in a direction towards the right, when viewed as shown in Figures 5 and 7. When the arm 18 is swung into locking engagement with the latch 82, the spring 2| will be placed under tension because of the rod l5 being moved upwardly, as the arms I 2|2 of the doors swing upwardly, in the operation of closing the lower doors.
The electric control means comprises a pair of contacts 92 and '93 which are in electrical contact with each other, when the lower doors ar closed as shown in Figure 5. These contacts are adapted to be opened when the lower doors are swung open, by a pin 94 secured to the arm 18, and which pin is shown positioned between the resilient arms of the contacts 92 and 93, as shown in Figures 5 and '7. When the lower doors are closed, as shown in Figure 5, the pin 94 is out of contact with the lower arm 92. When the doors 9 are released and the arm 18 swings downwardly to the position shown in Figure 7, the pin 94 will engage the arm of the contact 92 and move it downwardly, thereby breaking the circuit through the contacts 92 and 93.
The resilient or flexible arms ofthe contacts 92 and 93 are shown electrically connected to suitable terminals 95 and 9,6, respectively, mou nted in the wall of the housing 53 and suitably insulated therefrom. Wires 9"! and 98 connect the terminals 95 and 96 to. a pair of binding posts 99 and IN, respectively, as best shown in the wiring diagram'Figure 10. A wire I92 electrically connects the binding post 99 to the contact I03 of a main control switch, generally indicated by the numeral I04. This switch may be of conventional design, and is preferably of the double pole, toggle type. The main line circuit is indicated by the numeral I05. The terminal IOI has a wire I96 connecting it to one side of the motor 12, and a suitable fuse I! is, preferably interposed in the wire I96. The wire I08 connects the other side of the motor to the terminal I09 of the main switch [94,. lhus, when the contacts 92- and 93 are in electrical contact with one another, a complete circuit is provided for the motor I2, whereby the apparatus may be started.
lhe motor circuit thus includes wire I02, terminals 99 and NH, contacts92 and 93, terminals 95 and 96, wires 91 and 98, fuse I01, wire I06, motor I2, and wire I08.
The heating circuit comprises the heating elements 26, and wires I II and I I2, connecting them to the terminal posts I0;I and I09, respectively as shown in Figure 10.
Means is provided for automatically interrupting the operation of the roaster by opening the circuits to the motor and heating elements at the end of each cycle of operation and: whereby the 1* parts will always come to rest in the, same rela tive positions. Such means is shown comprising a pair of contacts '3 and II 4 supported upon flexible arms secured to terminal posts H5. and I I6, respectively, similar toterminal posts 95. and 99. A wire II'I connects theterm-inal post M5 to the binding post I01, and a similar wire ,8 connects the terminal post M6 to a binding post N9, the latter having a wire I21 connecting it to a contact I22 of a suitable thermostat, generally indicated by the numeral I23.,
The thermostat I23 comprises a movable contact I24 adapted to be actuated by a bi-metal bar I25, secured at one end to th cylindrical wall 3'! of the casing, as best shown in Figures 7 and 8. The swingable nd of the bi-metal bar I25 is adapted to engage the flexible arm I29, carrying the movable contact I24, when the oven has been heated, and thereby moves the contact I24 into electrical engagement with the relatively fixed contact I22 of the thermostat. A wire I21 connects the arm I26. of the thermostat to one end of the solenoid coil 88, the opposite end of which has a wire I28 connecting it to the contact I99 of the mainline switch I04.
The above described circuit, including the wire I", terminal H5, contacts I13 and H4, terminals H6 and H9, wires H8 and I2I, contacts I22 and I24, wire I21, solenoid 88, and wire I28, will here! inafter be referred to as the control circuit.
The bi-metal bar I25 of the thermostat is so mounted as to be influenced by the heat of the oven, and for practical purposes, may be mounted directly on the inner lining 31 of the cylindrical wall of the drum to which it may be secured by such means as a rivet I29. A housing I3I, shown open at both ends, shields the con-l tacts I22 and I24, and also serves to confine the heat around the bi-metal bar I25, so that it readily responds to variations in thev temperture within the oven.
, Meansv p aovided for varying the gap between the contacts I22 and I24 to vary the roasting period. Themeans provided for thus varying the gap between said contacts is shown comprising a finger; knob I32, mounted exteriorly of the casing and having a shaft I33 received in thread ed engagement with a fixed bracket I34, shown secured to the shield or housing I3I- of the thermostat. The inner end of the shaft I33 engages a resilient. fin er I35 which, contacts a spacing element l36g', one end of which engages the finger I35 and its: opposite nd the arm of the fixed contact I22 of the thermostat. By rotating the shaft I;33, the finger I35 is flexed and imparts axial;- movement to the spacing element I38, whereby the contact I;22 may be moved towards or away from the movable, contact I24, thereby to vary the roasting period, as will readily be understood. A suitable dial I3! is secured to the outer end of'the shaft I33 as shown in Figures 1 and 7.. This dial is provided with suitable indicia to indicate the position of the movable contact I24 of the thermostat I23.
The main control switch I04 may be of conventional design, and is, shown comprising a tog-. gle lever I38, pivotally connected, to a yoke I39 having a rod I4I. secured to one end which is slidable in a guide opening in a wall of the easing. .A suitable finger grip I42 is secured to the rod: I41: to facilitate operating it. A block I43 18113171003113 connected to the inner ends of the yoke I39, and has one end of a rod I44 slidably mounted therein. The opposite end of the rod I44 is pivotally connected to a. pin I45. secured to the adjacent. arm- I2. of the door operating mechanism. A collar I46. is secured to the rod I -44-and is. adapted to engage the block I433, when the lower doors are. opened, whereby the fork [3191115 moved outwardly to the position shown in Figures 5: and 6, wherein the main switch I04 is opened to interrupt the supply of current to the apparatus.
Means is also provided whereby the control mechanism. may be rendered inoperative to open the bottom doors 9., should the oven be sufficient- 1y hot, when a fresh supply of peanuts, is introduced therein, to retain the contacts of the thermostat in closed: position.
The means provided for thus preventing the doors from opening, when a fresh supply of peanuts is introduced into the oven, while the latter is still at roasting temperature, comprises an auxiliary rod I41, one end. of which is slidably supported ina wall of the casing and has a; finger knob. I418. Theopposite end of the rod I41; isv pivotally connected to a cam element I49 rotatably supported on a stud I 50 secured to. the cover.55. of the housing 5.3, as best shown in Figures 4 and. 9. The cam element I49, as best shownin Figures 3 and 4, is provided with a low spot I5I: in its periphery. A resilient finger I52- is secured to one end of the arm 84 and engages the periphery of the cam element I49. In Figure 4, the cam element is shown in its normal position, wherein it will be seen that the knob I48 is depressed. When this knob is pulled outwardly to the position shown in Figures 3 and 6, the flat or low: spot of the cam element I149 will; move out of contact with the finger I52, whereby the latter will be flexed so as to exert an increased downward pressure on the finger 85 at the outerend of the arm 84. The downwardw pressurethus exerted on the outer end of the arm 84 is sufi'icient to overcome the magnetic pull of the solenoid coil 89, whereby when the contacts I I3 and H4, and also the contacts I22 and I24 are closed, the solenoid cannot release the latch 82 and permit the lower doors 9 to open. The finger knob or button thus serves as a safety button or device for preventing premature opening of the lower doors, in the event the oven is charged with a fresh supply of peanuts immediately after dumping its load, and before the contacts of the thermostat have cooled sufiiciently to break the circuit therethrough. The temperature of the oven immediately drops when a fresh supply of peanuts is introduced therein, whereby the contacts of the thermostat are opened. The safety button I48 may then be pushed inwardly, as shown in Figure 4, whereby the cam face I5I is moved into contact with the finger I52 of the arm 84, thereby to lessen the downward pressure on the armature 81 of the solenoid 88.
The rod I41 is operatively connected to the main cutout switch I04 by a rod I53, one end of which is slidably connected with the rod I41 and its opposite end pivotally connected to the pin I45 of the arm I2. Under normal operating conditions, the push button I48 is retained in its depressed position, shown in Figure 4, whereby the cam element I49 has no eifect upon the arm 84.
In some instances it may be found necessary to vent the oven, when the apparatus is initially started, because of moisture in the peanuts or other products to be roasted. To thus vent the oven, a suitable spring I50 is shown secured to the edge I60 of the upper door I. The free end of this spring frictionally engages the adjacent edge of the door opening with suflicient pressure to retain the door I in the position shown in Figure 11. By thus slightly cracking the door, any vapor generated within the oven may readily escape therefrom, as indicated by the arrows in Figure 11.
Operation The novel roaster herein disclosed is very simple to operate. When in its normal position, the lower doors 9 may be open, as shown in dotted lines in Figure '7, as these doors assume the positions indicated in dotted lines in this figure when the current supply to the motor and heating elements is out 01f by the control means. Such opening of the bottom doors, however, does not affect the upper door I.
Before starting the roaster, the bottom doors are closed by opening the top door. This results because of the operative connection between the upper and lower doors through the connections I3, I4, I1, 24 and 25. When the lower doors are closed, the pin 94 carried by the arm I8 moves upwardly out of engagement with the fiexible arm of the movable contact 92, whereby the contacts 92 and 93 of the motor circuit electrically engage each other to permit the flow of current therethrough. When the contacts 92 and 93 thus electrically engage one another, current is supplied to the motor I2 through the wire I06 and also to the heating elements 26 through the wire I I I, as these two wires are electrically connected to the terminal post I0 I to which current is supplied to the motor through the closed contacts 92 and 93. The motor and heating circuits are completed by the wire I08 and I I2 which respectively connect the motor I2 and heating elements 26 to the contact post I09 of the main switch I04,
It is to be understood that the main switch is closed prior to starting the roaster.
When desired, a quantity of peanuts or other material to be roasted is delivered into the oven, the top cover I is closed and the main switch I04 is then closed, whereby current will immediately be supplied to the motor I2 and heating elements 26, as will readily be understood by reference to the wiring diagram Figure 10. When current is thus supplied to the motor and the heating elements, the roasting operation is under way and the agitator will be constantly rotated by the motor simultaneously as the heating elements raise the temperature in the oven sufficiently to roast the peanuts. When the temperature of the oven reaches a predetermined figure, the heat transmitted through the casing wall 31 will warp the bi-metal bar I25 until it eventually forces the movable contact I24 of the thermostat into electrical engagement with the relatively fixed contact I22, whereby the control circuit is conditioned for operation. The control circuit, however, is not completed until the movable contact H4 is eventually moved into electrical engagement with the contact II3 by the pin I5I on the gear wheel 56. When the solenoid is energized, it raises its armature 81 with sufficient force to impart a hammer-like blow to the finger B5 of the arm 84, whereby the arm 84 is moved upwardly to the dotted line position, shown in Figure 3. Such upward movement of the arm 84 will throw the latch 82 out of engagement with the roller I9 of the arm I8, whereupon the spring 2! will pull the rod I5 downwardly and thereby open the lower doors 9, as indicated in dotted lines in Figure '7.
The solenoid 88, however, cannot be energized until the contacts II3 and H4 are closed, regardless of the condition of the thermostat I23. In other words, before current can be supplied to the solenoid 88, the contact I24 of the thermostat I23 must engage the contact I22 and, in like manner, the contacts II3 and II 4 must be in contact with one another.
The contact H4 is secured to a flexible arm I having its end portion I56 positioned in the path of a pin I5I secured to the gear wheel 56, so that each time the gear 55 makes one revolution, the pin I5! will engage and move the contact II 4 into electrical engagement with the contact II3 to close the circuit therebetween.
Thus, when the roaster is initially started, the contacts 92 and 93 are engaged, whereby current is supplied to the motor and heating elements, as hereinbefore stated. The roaster will continue to operate until the temperature in the oven reaches a predetermined figure, whereupon the thermostatic bar I25 will warp suificiently to move the contact I24 into electrical engagement with the contact I22. When this occurs. a circuit will be presented to the solenoid coil 88. This circuit, hereinbefore referred to as the control circuit, will not be completed, however, until the pin I5I in the gear wheel I56 engages the arm I 55 of the movable contact H4, and moves the contact II4 into engagement with the contact II3. At the instant the contact II4 engages the contact II3, the solenoid is energized and moves the latch 82 out of engagement with the end of the arm l8, whereby the rod I5 is pulled downwardly by the spring 2i, and thereby opens the lower doors 9, and interrupts the operation of the entire apparatus, because of the main line switch I04 being automatically as hereinbefore stated.
If a fresh supply of peanuts is delivered into the oven immediately after it has discharged a load, the oven may be suifi ciently hot to prevent the thermostaticbar I25 to-return to its normal positionand permit the 'contact- I24 of the thermostatto move out of engagement with thefixed contact I 2-2; If thethermostatic bar does not release the contact I-44'from the'contact I 22, each time the pin I51 engages the contact arm I55 andmomentarily closes the circuit through the contacts II-3 and I14, the solenoid will be energized and thus cause the doors to open. This, obviously, would be objectionable, because the peanuts in the oven might be discharged or dumped therefrom before being sufliciently roasted.
To prevent the doors from opening before the peanuts have been sufficiently roasted, the manually operated button I48 is pulled outwardly, as hereinbefore stated, whereby the arm 84 will be held downwardly with sufiicient tension by the action of the finger I52, to prevent the solenoid 88 from actuating the arm 84. As soon as the oven has cooled sufficiently to permit the contacts of the thermostat to open, the operator will push the button I48 inwardly to the position shown in Figure 4, whereby closing of the circuit through the contacts H3 and H4 by the pin I51 will have no effect upon the solenoid coil 88 because of the circuit being open through the thermostat. The roasting period will then continue until the thermostatic bar or element I25 moves the contact I24 into engagement with the contact I22 and thereby completes the circuit to the solenoid whereupon the cycle of operation is completed, and the entire operation of the roaster is interrupted.
The novel roaster herein disclosed has been found very practical and economical in operation. It is very attractive in-appearance and is so constructed that the toasting period may be accurately controlled to provide the desired results. It may be used for roasting peanuts, cofiee and various other materials requiring such treatment, as the adjustment of the thermostat makes it possible to vary the roasting period to suit almost any commodity of the class usually requiring roasting.
I claim as my invention:
1. A roaster comprising an oven having a door in its upper wall, a door in the lower wall of the oven through which the product may be discharged when roasted, an agitator for agitating the product during the roasting period, driving means for the agitator including a member mounted for rotary movement, a motor having a driving connection with said member, a circuit for the motor including a cutout switch, means for heating the oven associated with the motor circuit, a control circuit including a pair of normally open contacts, a thermostatic device associated with said contacts and responsive to variations in the temperature in the oven, whereby when the oven attains a predetermined temperature, said device will close said contacts and partially complete the control circuit, cutout switch opening means associated with the control circuit and adapted to be operated to open the cutout switch, when the control circuit is completed, and means carried by said rotatable member adapted to complete the control circuit subsequent tothe closing of said contacts by the thermostatic d'evice, whereby the cutout switch opening means is rendered operative to open the cutout switch and thereby automatically interruptthe operation of the apparatus.
. 21 A roaster eomprising an even having a door i'nitsu-pper wall, a door in the lower 'wall of the oven through which the productmay be charged when roasted, an a'g-itator for agitating the product duringthe roasting periodi driving means-"for the agitator including a. member" mounted for rotary movement, a-' motor having a driving connection withsaidmember, a circuit torthe motor including a cutoutswitch, a heating circuit electrically associated with the motor circuit, a control circuit including a pair of normally open contacts, a thermostatic device associated with said contacts and responsive to variations in the temperature in the oven, whereby when the oven attains a predetermined temperature, said device will close said contacts and partially complete the control circuit, cutout switch opening means associated with the control circuit for opening the cutout switch, when the control circuit is closed, a pair of secondary contacts in the control circuit, and means carried by said rotatable member adapted to close said secondary contacts to complete the control circuit subsequent to the closing of said first mentioned contacts by the thermostatic device, whereby the cutout switch opening means is rendered operative to open the cutout switch and thereby automatically interrupt the operation of the apparatus.
3. A roaster comprising an oven having a door in its upper wall, a door in the lower wall of the oven through which the product may be discharged when roasted, means for retaining the lower wall door in closed position during the roasting period, an agitator for agitating the product in the oven, driving means for the agitator including a member mounted for rotary movement, a motor having a driving connection with said member, a circuit for the motor including a cutout switch operatively associated with said retaining means, a heating circuit electrically associated with the motor circuit, a control circuit including a solenoid adapted to operate said retaining means, said control circuit also including a pair of normally open contacts, a thermostatic device associated with said contacts and responsive to variations in the temperature in the oven, whereby when the oven attains a predetermined temperature, said device will close said contacts, and a pair of normally open secondary contacts also in the control circuit adapted to be closed by said rotary member, subsequent to the closing of said thermostatically actuated contacts, whereby the control circuit is completed to the solenoid and causes the latter to releas said retaining means and permit the lower wall door to open, and whereby the cutout switch is opened to automatically interrupt the operation of the entire apparatus.
4. A roaster comprising an oven having a door in its upper wall, and a door in its lower wall through which the contents of the oven may be motor circuit, an 'arm'operatively connected to the lower door and having means adapted to engageone of said contacts to open the motor circuit, when the door is opened at the end of the roasting period, said means permitting said contacts to close when the lower door is closed, whereby current may be supplied to the motor, a main control switch for the motor circuit operatively associated with the latch, and a control circuit comprising a solenoid having an armature operatively connected with said latch, said control circuit also including a normally open thermostatically controlled switch adapted to respond to variations in the oven temperature,
whereby when the oven attains a predetermined temperature, said thermostatically controlled switch will close and partially complete the controlcircuit, a pair of normally open secondary contacts in the control circuit, and means carried by said rotary member adapted to close said secondary contacts subsequent to the closing of said thermostatically controlled switch, whereby the solenoid is energized and actuates said latch, whereby the lower door is automatically opened and the motor circuit simultaneously opened to interrupt operation of the entire apparatus.
FRANK W. CARPENTER.