US2180232A - Electric timer for toasters - Google Patents

Description

Nov. 14, 1939. J. GEIER ELECTRIC TIMER FOR TOASTERS Original Filed March 23, 1935 4 Sheets-Sheet l l W I I w M W W W w w w W M W W W W INVENTOR. J /MES 6 5/516,

ATTORNEYS Nov. 14, 1939. I J, GEER 2,180,232

ELECTRIC TIMER FOR TOASTERS Original Filed March 25, 1935 4 SheetS-Sheet 2 INVENTOR. Jq/vgs 65/52.

ATTORNEYS Nov. 14, 1939. J. GEZER I I 23 80,232

' ELECTRIC TIMER FOR TOASTEZRS Original Filed March 23, 1935 4 Sheets-Sheet 3 INVENTOR. J MES 65/51 BY- wand,

ATTORNEYS Nov. 14, 1939. J. GEIER 2.180232 I ELECTRIC TIMER FOR TOASTERS Original Filed March 23, 1935 4 Sheets-Sheet 4 I III 65 E-IIIIII um 60 Ill 6'7 65 :a-mmnmm llllllll 83 V INVENTOR.

J4I7ES 65/52.

Patented Nov. 14, 1939 UNITED STATES ELECTRIC TIMER FOB TOASTEBS James Geler, Troy, N. Y., assignor, by mesne assignments, to McGraw Electric Company, Chlcago, lll., a corporation of Delaware Application March 23, 1935, Serial No. 12,587 Renewed October 16, 1939 19 Claims.

or any other suitable electrical device is operated;

can be easily and conveniently adjusted.

A further object is the provision of an electrical heating device comprising an indicating device in the form of a bell and the like, for the purpose of indicating the interruption of the flow 20 of electrical current through the heating re sistances.

The above and other objects of the present invention may be realized through the provision of an automatic circuit breaker comprising an expansible and contractible heat-responsive member, such as a bi-metallic strip, adapted to maintain a switch in its closed position for a predetermined period of time, which corresponds to the time during which the heating resistances 01' a toaster are supplied with. an electrical current and which may be varied by varying the period of contact between the bimetallic strip and the switch.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings showing preferred embodiments of the inventive idea.

In the drawings:

Figure 1 shows a toaster in side elevation.

Figure 2 shows in vertical section the automatic cut-ofl' switch of the toaster, the section being taken along the line 22 of Figure 3.

Figures 3, 4 and 5 illustrate diagrammatically the automatic cut-ofi switch ot the toaster in three different positions in a bottom plan view.

Figure 6 shows in side elevation a toaster provided with a separate cut-ofi switch.

Figures '7, 8 and 9 are top views of the switch shown in Figure 6, with the cover removed, illustrating the switch in three difierent positions.

The toaster illustrated in Figures 1 to 5 of the drawings, comprises a casing I containing the usual heating elements or resistances II (Figs. 3, 4 and and provided with acover I 2. The toaster is supported by a casing I3 which contains the automatic cut-ofi switch and which is provided with a suitable opening for the cable I4 containing a pair of conducting wires I5 and I6, il- 60 lustrated diagrammatically in Figures 3 to 5.

The wire I5 is connected with a switch or a contact I6 The switch I6 comprises a conducting piece II connected with the wire I5 and a conducting piece I8 connected with a wire I3. The conducting pieces I1 and I8 are separated from each other by insulation and may be operatively connected with each other by a conducting abutment 20, for the purpose of transmitting an electrical current from the wire I5 to the wire I3, as will be described hereinafter.

The abutment 20 forms a portion or a lever 2| which is rotatably mounted upon a pivot 22 situated intermediate the two ends of the lever 2I. One end of the lever 2| is connected with a spring 23 attached at 24 to the casing I3. The opposite end of the lever 2I carries a pin 25 which is adapted to come in contact with an abutment 45 of a bi-metallic strip 42.

A stop 26 is fixed to the casing I3 and is used for preventing the rotation of the lever 2| beyond the position shown in Figure 3.

The pivot 22 also passes through one end of an adjusting lever 21 which is rotatably mounted upon a pivot 28 and which may be set by the operator in any one of the different positions indicated by the openings 29.

The opposite end of the wire I3 is connected to the main heating resistances I I.

A wire 30 connected to the opposite end of the heating resistances II is attached to a conducting piece 3| of a contact or switch 32.

The switch 32 which is similar to the switches I6 and 33 is shown in end elevation in Figure 2 of the drawings and comprises a conducting piece 3| which is separated from the conducting piece 34 by a piece of insulation 35. The conducting piece 34 is attached to one end of the wire I6.

A lever 36 may be used for the purpose of establishing an electrical connection between the wires 30 and I6. This is accomplished when a portion of the lever 36 is situated between the conducting pieces 3| and 34.

The lever 36 comprises an insulated end 31 projecting out of the casing I3 and used for the purpose of switching on the electrical toaster.

The lever 36 is rotatably mounted upon a pivot 38 situated intermediate the two ends 31 and 39 of the lever 36.

The end 39 of the lever 36 is curved and adapted to come in contact with the lever 2|, so that the lever 2| is actuated when the lever 36 is moved.

The lever 36 also carries a projection 40 made of an insulating material and adapted to project into an opening 4I formed in the bi-metallic strip 42, as will be described hereinafter.

The bi-metallic strip 42 is attached by bolts or rivets 43 to a bracket 44 connected to the walls of the casing I3, and is heated by a wire 46 surrounding a portion of the strip 42 and having one end which is connected to the wire l6 at 59. The opposite end of wire 46 is connected to a conducting piece 41o! the contact or switch 33. Another conducting piece 46, separated by insulation from the conducting piece 41, is attached to one end of a wire 46 which is connected at 50 to the wire 36 leading from the resistances II to the contact 32.

The lever 36 is usually maintained in the position shown in Figure 3 by the spring 6|, one end of which is attached to the lever 36, while its opposite end is connected to the casing l3.

In the position shown in Figure 3, the lever 36 is situated between the conducting pieces 3| and 34, so that an operative electrical connection is established between the wires 30 and I6.. However, in this position, no electrical current will flow through the circuit as there is no electrical connection between the wires l5 and I9, since there are no conductors operatively interconnecting the conducting pieces I! and I8. Furthermore, there is no electrical connection between the wires 46 and 49, since no conductors interconnect the conducting pieces 41 and 48 of the switch 33. p

In order to switch the toaster on; the end 31 of the lever 36 is moved by hand from the position shown in Figure 3 to the position shown in Figure 4. In the course of this movement, the lever 36 rotates clockwise and its end 39 pushes the lever 2|, which also swings in a clockwise direction, until the projection 20 of the lever 2| is inserted between the two conducting pieces l1 and I8 of the switch IS.

The lever 36 is moved in this direction until its projection 40 snaps into the opening 4| provided in the bi-metallic strip 42. Then the lever 36 is held in the position shown in Figure 4-by the projection 46. In this position, the lever is situated between the conducting pieces 41 and 48 of the contact 33, so that an operative electrical connection is established between the wires 46 and 49.

The electrical energy supplied by any suitable source of electrical energy will cause the flow of an electrical current through the wire IS, the contact piece H, the projection 20, the contact piece IS, the wire l9, and the electrical heating resistances II.

In the position shown in Figure 4, there is no operative electrical connection between the conducting pieces 3| and 34 of the switch 32, so that the electrical current leaving the resistances flows through the wire 30 as far as the connecting point 50, and then flowsthrough the wine 49, the conducting piece 48 of the switch 33, the adjacent portion of the lever 36, the conducting piece 41 and thewire 46 connected at 59 with the wire l6.

Therefore, in the position shown in Figure 4, both the resistances II and the bi-metallic strip 42 are heated by the current flowing through the electrical circuit.

The wire 46 will gradually heat the bi-metallic strip 42 until this strip begins to expand and moves from the position shown in Figure 4 to the position shown in Figure 5. When the bimetallic strip 42 is moved to this extent, it moves out of reach of the projection 40 carried by the lever 36, so that the projection 40 is freed from the opening -4| provided in the bi-metallic strip 42.

As soon as the projection 40 loses its contac with the edges of the opening 4|, the spring 6| pulls the lever back from the position shown in Figure 4 to the position shown in Figure 5. which is substantially the same position as that illustrated in Figure 3. In these positions a portion oi! the lever. is inserted between the conducting pieces 3| and 34 of the contact 32, so that a positive electrical connection is established between the wires 30 and I6.

Although the lever 36, by swinging counterclockwise, moves out of contact with the lever 2|, the lever 2| will not be moved to any considerable extent by its spring 23, since, due to the expansion of the bi-metallic strip42, its abutment 45 is brought in contact with the pin 25 carried by the lever 2|; consequently, in the position shown in Figure 5, the lever 2| is maintained by the abutment 45 in substantially the same position as that shown in Figure 4, so that the projection 20 of the lever 2| continues to maintain an operative connection between the conducting pieces l1 and I6 of the switch I6 In the position shown in Figure 5, an electrical current flows through the wire l5, the conducting piece I], the projection 26 of the lever 2|, the conducting piece I6, the wire l9 and the electrical heating resistances Since the connection between 49 and 46 is interrupted, the current leaving the resistances II will flow through the entire wire 30, the conducting piece 3|, the adjacent portion of the lever 36 the conducting piece 34 and the wire l6.

Therefore, in the position shown in- Figure 5, the electrical heating resistances continue to be supplied by the electrical current while the bi-metallic strip 42 is not heated any more by the coil 46. Consequently, the bi-metallic strip 42 will gradually cool ofi and will slowly move from. the position shown in Figure 5 back into the position shown in Figure 3. In the course of this movement, the bi-metallic strip 42 will assume a certain intermediate position in which the contact between the pin 25 carried by the lever 2|, and the abutment 45 forming a part of the bi-metallic strip 42 will be interrupted, so that the spring 23 will be able to pull the lever 2| from the position shown in Figure 5 to the position shown in Figure 3, thereby interrupting the, electrical connection between the wires I! and I5.

The object of the lever 21 is to vary the time of this interruption of contact between the pin 25 and the abutment 45. The various positions of the lever 21 correspond to the diiierent positions of the pin 25 in relation to the abutment 45 at the time when the strip 42 moves out of contact with the lever 2|, while the various positions of the pin 25 correspond to different periods of time during which the pin 25 is maintained in contact with the abutment 45 and the electrical heating resistances II are supplied with the electrical current.

The modification shown in Figs. 6 to 9 comprise a separate automatic circuit breaker situated in a casing 60 and connected by a cable 6| with the heating resistances situated within the toaster 62 (Fig. 6).

As shown in Figures '7 to 9, the circuit breaker situated within the casing 60 comprises a socket 63 adapted to carry a plug 64 attached to one end of the cable 6|. The socket 63 carries two ends of conducting wires 65 and 66.

The opposite end of the wire 65 is attached to a bolt 61 operatively connected to and supporting ai rlesilient strip 68 made of a conducting mater a A lever 69 is rotatably mounted upon a pivot 10.

One end or the lever 69 is'attached at 1| to an end of a coil spring 12, which tends to maintain the lever 69 in the position shown in Figure 7. The middle portion of the lever 69 is provided with curved edges 18 which may come in contact with the edges 14 01' a lever 15. The opposite end 16 of the lever 69 carries a rod 11 provided with a hammer 18 which is adapted to strike a bell 19 attached to the casing 69. The lever 69, the rod 11 and the hammer 18 are usually stamped of one piece.

The lever 69 also carries a pivot 80; both the pivot 89 and the lever 69 are made of a conducting material.

The lever 15 is rotatably mounted intermediate its ends upon a pivot 8| and is provided with a curved end portion 82 having the edges 14. The opposite end 83 oi the lever 15 projects outside of the casing 68 and is made of an insulating material. The end portion 83 of the lever 15 is used as a handle in a manner which will be described hereinafter.

A lever 84 is mounted upon a pivot 85 and carries the pivot 8| around which the lever 15 may be rotated. The opposite end portion 86 of the lever 84 is bent and is provided with an insulated handle 81 which projects out of the casing 60. The position of the lever 84 may be adjusted by moving the handle 81, thereby adjusting the position of the pivot 8| and of the lever 15.

The casing 60 carries a stop 88 which limits the movement of the lever 15.

The lever 15 also carries a pin 89 which is made 01' insulated material and which is adapted to come in contact with the edges 90 of the bimetallic strip 9|.

In the position shown in Figure 8, the pin 89 is in contact with the shoulder 92 of the strip 9|.

The strip 9| is connected by bolts 93 with a bracket 94 which is attached to the casing 60.

The lever 15 is maintained in the position shown in Figure 7 by means of a spring 95 one end of which is attached to the lever 15, while its opposite end is connected to a pin carried by the casing 69.

The bi-metallic strip 9| is heated by a coil 96 surrounding a portion of the strip 9|. One end of the coil 96 is connected to one of the bolts 99, while the opposite end of the coil 96 is attached to the pivot 85.

One end of the wire 91 is connected to one of the bolts 93 made of a conducting material. The two wires 66 and 91 are insulated from each other and are surrounded by insulation forming a cable 98. As shown in Figure 6, the cable 98 is provided with a plug 99 which may be connected to any suitabe source of electrical energy.

In the position shown in Figure '7, no current will flow through the device, since there is no connection between the strip 68 and the lever 69. Furthermore, there is no electrical connection between the bi-metallic strip 9| and the lever 69.

In order to switch on the device, the handle 89 is moved by hand from the posittion shown in Figure 7 to the position shown in Figure 8. In the course of this movement, the lever 15 rotates clockwise and the edges 14 of its end portion 82 come in contact with the edges 13 of the lever 69. The lever 69 is caused to swing counter-clockwise by the lever 15 until it assumes the position shown in Figure 8 of the drawings.

In this position, the lever 69 is in contact with the strip 68 so that a positive electrical connection is established between these two members.

While the lever 15 is moved clockwise, its insulated pin 89 slides along the edges 98 of the bi-metallic strip 9| until the pin 89 passes beyond the shoulder 92 of the strip 9|.

As shown in Figure 8, the pin 89 is then held by the shoulder 92 so that the lever 15 is prevented from returning to its original position shown in Figure '7. In the position shown in Figure 8, the edges 14 01' the lever 15 are in contact with the edges 13 of the lever 69. An operative electrical connection is thereby established between the lever 69 and the lever 15.

' The electrical energy supplied by any suitable source not shown in the drawings, will cause a flow of' electrical current through the plug 99 and the cable 98. This electrical current will flow through'the socket 63, the plug 64 and the cable 6|. passing through the electrical heating resistances situated in the toaster 62 and heating these resistances. An electrical current will flow through the wire 65, the strip 68, the lever 69,

the lever 15, and the lever 84. The current passing through the lever 84, will flow through the coil 96, and the wire 91, returning to the source of electrical energy through the cable 98.

Therefore, in the position shown in Figure 8, the resistances situated in the toaster 62 and the bi-imetafllic strip 9|, are both heated by the current flowing through the electrical circuit.

The coil 96 will gradually heat the bi-metallic strip 9| until the strip begins to expand and moves from the position shown in Figure 8 to the position shown in Figure 9. While the bimetallic strip 9| is moved to this extent, the

shoulder 92 is moved out of reach of the pin 89.

carried by the lever 15, with the result that the lever 15 is freed and is pulled back by its spring 95, moving from the position shown in Figure 8 to the position shown in Figure 9, which is similar to that shown in Figure '7.

In this position, there is no electrical contact any more between the lever 69 and the lever 15, so that there is no electrical current flowing through the coil 96.

Although the lever 15, by swinging counterclockwise, moves out of contact with the lever 69, the lever 69 will not be moved to any considerable extent by its spring 12, since the pin 80 of the lever 69 will drop upon the surface Hill of the bi-metallic strip 9| and will be supported by this surface as soon as the lever 15 is moved out of reach of the lever 69. This position is shown in Figure 9 of the drawings. In this position, the lever 69 is maintained in contact with the strip 68 by the surface I of the bi-metallic strip 9|. The electrical current will, therefore, continue to flow through the heating resistances situated within the toaster 62 and will also flow through the wire 65, the strip 68, the lever 69, the pin 89, the bi-metallic strip 9|, and the wire 91. a 7

While an electrical current is thus caused to fiow through the heating resistances situated within the toaster 62, the coil 96 will not be heated any more, so that the bi-metallic strip 9| will gradually begin to cool oiT and will slowly move from the position shown in Figure 9 back to the position shown in Figure 7. While the bi-metallic strip 9| is carrying out this movement, the pin 80 of the lever 69 slides along the surface 18 of the strip 9| until it reaches the edge ll of this strip. As soon as the pin 80 passes beyond this edge, the lever 69 is freed from contact with the strip 9| with the result that the spring 12 is able to pull the lever 69 from the position shown in Figure 9 to the position shown in Figure '7, thereby interrupting the operative electrical connection between the strip 68 and the lever 69; the hammer l8 strikes against the bell 19, thus indicating that the heating operation has 7 been completed.

The object of the lever 84 is to vary the time of this interruption of contact between the pin 80 and the surface Hill of the bi-metallic strip 9|. The position of the lever 84 may be adjusted by the insulated handle 81 projecting out of the casing 80. The various positions of the lever 84 correspond to different positions of the pin or pivot 8| around which the lever 15 is oscillated. The different positions of the pin Bl correspond to different positions of the lever 15 at the time when the insulated pin 89 is engaged by the shoulder 92 of the bi-metallic strip SI. On the other hand, these various positions of the lever 15 correspond to different positions of the pin 80 at the time when the pin 80 is brought in contact with the surface I of the bi-metallic strip 9!. Finally the different positions of the pin 80 at the time of its contact with the surface I00 correspond to difierent periods of time during which an electrical circuit is maintained which supplies an electrical current to the heating resistances within the toaster 52.

What is claimed is:

1. Means for automatically interrupting the flow of electrical current to a main heating resistance, said means comprising a switch, means connecting said switch to the main heating resistance and to a source of electrical energy, a heat-responsive expansible and contractible member, means connected with said heat-responsive member to maintain said switch in its closed position while said heat-responsive member is expanded, electrical heating means for heating said heat-responsive member to expand the same, means connecting said electrical heating means to said source of electrical energy, a lever which is movable from an inoperative position to an operative position, said'lever while so moved moving said switch and closing the same and thereby establishing an electrical circuit causing a flow of electrical current from said source and through said main heating resistance, a member which is carried by said lever, means constituting a part of said heat-responsive member for locking the last-mentioned member, said lever being maintained in its operative position while said heatresponsive member is not expanded when the last-mentioned member is locked by the lastmentioned means, means connected with said electrical heating means for causing a flow of said electrical current through said, electrical heating means while said lever is in its operative position, and means connected with said lever for returning the same to its inoperative position after the expansion of said heat-responsive member, whereby the flow of electricalcurrent through said electrical heating means is interrupted while said heat-responsive member, while expanded, maintains said switch in its closed position.

2. Means for automatically interrupting the flow of electrical current to a main heating resistance, said means comprising a switch, means connecting said switch to the main heating resistance and to a source of electrical energy, said switch. comprising a rotatable member movable to an operative position wherein said switch is closed; a heat-responsive expansible and contractible member, means connected with said heat-responsive member to maintain said rotatable member in its operative position while said heat-responsive member is expanded, a coil connected to said source of electrical energy for heating said heat-responsive member, a pair of conducting pieces, one of which is connected with said coil, the other being connected to the main heating resistance, another pair of conducting pieces, one of which is connected to said source of electrical energy, the other one being connected to the main heating resistance, a rotatable lever which is movable from an inoperative to an operative position said lever in its inoperative position interconnecting electrically the lastmentioned pair of conducting pieces, said lever in its operative position interconnecting electrically the first-mentioned pair of conducting pieces, and means for moving said lever into its inoperative position after the expansion of said heat-responsive member.

3. Means for automatically interrupting the flow of electrical current to a main heating resistance, said means comprising a pair of conducting pieces, means connecting one of .said

connecting pieces with said main heating resistsaid pin after the expansion of said heat-responsive member, whereby said lever is maintained in its closed position while said heatresponsive member is expanded, a coil surrounding a part of said heat-responsive member and connected to said source of electrical energy, another pair of conducting pieces, one of which is connected with said coil, the other being connected to the main heating resistance, a third pair of conducting pieces, one of which is connected to said source of electrical energy, the other one being connected to the main heating resistance, a rotatable lever movable from an operative to an inoperative position, the last-mentioned lever interconnecting electrically the lastmentioned pair of conducting pieces in its inoperative position, the last-mentioned lever in its operative position interconnecting electrically the second-mentioned pair of conducting pieces and maintaining the first-mentioned lever in its closed position, a projection carried by the'last-mentioned lever and projecting through an opening formed in said heat-responsive member in the operative position of the last-mentioned lever and while the heat-responsive member is not expanded, and a spring connected with the lastmentioned lever and moving it into its inoperative position after the expansion of said heatresponsive member.

4. Means for automatically interrupting the flow of electrical current to a main heating resistance, said means comprising a pair of conducting pieces, means connecting one of said connecting pieces with said main heating resistance, means connecting the other one of said conducting pieces to a source of electrical energy,

a rotatable lever movable from an open position to a closed position, said lever interconnecting electrically said pair of conducting pieces in the closed position of said lever, a pin carried by said lever, a heat-responsive expansible and contractible member, a member carried by said heatresponsive member and establishing a contact with said pin after the expansion of said heatresponsive member, whereby said lever is maintained in its closed position while said heat-responsive member is expanded, a coil surrounding a part of said heat-responsive member and connected to said source of electrical energy, another pair of conducting pieces, one of which is connected with said coil, the other being connected to the main heating resistance, a third pair of conducting pieces, one of which is connected to said source of electrical energy, the other one being connected to the main heating resistance, a rotatable lever movable from an operative to an inoperative position, the last-mentioned lever interconnecting electrically the last-mentioned pair of conducting pieces in its inoperative position, the last-mentioned lever in its operative position interconecting electrically the secondmentioned pair of conducting pieces and'maintaining the first-mentioned lever in its closed position, a projection carried by the last-mentioned lever and projecting through an opening formed in said heat-responsive member in the operative position of the last-mentioned lever and While the heatresponsive member is not expanded, and a spring connected with the last-mentioned lever and moving it into its inoperative position after the expansion of said heat-responsive member, a spring connected with the first-mentioned lever to return the same to its open position, and means connected with the first-mentioned lever for ad-- justing the position thereof 'relatively to said heat-responsive member, thereby varying the time during which the first-mentioned lever is maintained in its closed position by the heatresponsive member.

5. Means for automatically interrupting the flow of electrical current to a main heating resistance, said means comprising a strip connected with said main heating resistance and with a source of electrical energy, a lever movable from an inoperative position to an operative position, a pin carried by said lever, a spring connected with one end of said lever to maintain the same in its inoperative position, a heat-responsive expansible and contractible member having a shoulder and a surface which, while said heat-responsive member is expanded, contacts said pin, thereby maintaining said lever in its operative position, in which said lever is in electrical contact with said strip, a coil surrounding a part of said heatresponsivc member for heating the same and connected with said source of electrical energy, a lever movable from an operative position to an inoperative position, the second-mentioned lever contacting the first-mentioned lever to maintain the same in contact with said strip while the second-mentioned lever is in its operative position, a pin carried by the second-mentioned lever and engaging said shoulder in the operative position of the second-mentioned lever and while said heat-responsive member is not expanded, a spring connected with the second-mentioned lever for moving the same into its inoperative position after the last-mentioned pin has been released by the expansion of the heat-responsive member, and means electrically connecting said coil with the last-mentioned lever.

6. Means for automatically interrupting the flow of electrical current to a main heating resistance, said means comprising a strip connected with said main heating resistance and with a source of electrical energy, a lever movable from an inoperative position to an operative position,

a pin carried by said lever, a spring connected with one end of said lever to maintain the same in its inoperative position, a heat-responsive expansible and contractible member having a shoulder and a surface which, while said heat-responsive member is expanded, contacts said pin, thereby maintaining said lever in its operative position, in which said lever is in electrical contact with said strip, a coil surrounding a part of said heat-responsive member for heating the same and connected with said source of electrical energy a lever movable from an operative to an inoperative position, the second-mentioned lever contacting the first-mentioned lever to maintain the same in contact with said strip while the second-mentioned lever is in its operative position, a pin carried by the second-mentioned lever and engaging said shoulder in the operative position of the second-mentioned lever, and while said heat-responsive member is not expanded; a spring connected with the secondmentioned lever for moving the same into its inoperative position after the last-mentioned pin has been released by the expansion of the heatresponsive member, and an adjusting lever connected with said coil and with the second-mentioned lever for adjusting the position thereof relatively to the first-mentioned lever.

'7. In a bread toaster, a toasting compartment, a thermally responsive device, means mechanically connected to said thermally responsive device during cooling thereof for directly terminat ing the toasting of a bread slice in said toaster responsive to movement and return of said thermally responsive device by heating and cooling the same.

8. In a heat treating apparatus, means for establishing intervals of the heat treating action including, a thermally responsive member, and means mechanically connected to said thermally responsive member for directly terminating a heat treating action in response to cooling of said thermally responsive member.

9. In a cooking device having food heating means, timing means for establishing intervals of the cooking action including a thermally responsive member having a portion movable in response to temperature changes, and a heater operative on said member only until the latter has reached a predetermined high temperature;

and means mechanically connected to said thermally responsive member for directly terminating the cooking action by said food heating means in response to cooling movement of said thermally responsive member, said thermally re sponsive member being permitted to cool after said predetermined high temperature is reached and said food heating means being operative during the cooling of said member.

10. In a toaster adapted to be used in carrying out a plurality of successive toasting operations and having an electrical toast heating element energized only during toasting operations, a main electric switch for said main toast heating element, a timer for establishing intervals of the toasting action including a thermally responsive member, an electric heater for heating said member thereby to cause movement thereof, means for energizing said heater, and means responsive to heating movement of said thermally responsive member for rendering said heater inoperative thereby to permit said member to cool; means for energizing said toast heating element, and means mechanically connecting said main switch and said thermally responsive member during cooling thereof for opening said main switch responsive to cooling movement of the thermally responsive member after the heater is rendered inoperative.

11. In a cooking device of the type adapted to be used in carrying out a plurality of successive actions, a timer for establishing intervals of the cooking action including a thermally responsive member, a heater for heating said member thereby to cause movement thereof, means for instituting operation of said heater upon the institution of a cooking interval, and means responsive to heating movement of said thermally responsive device for rendering said heater inoperative thereby to permit the thermally responsive member to cool; and means mechanically connected to said thermally responsive member during cooling thereof for directly terminating a cooking action responsive to cooling movement of said thermally responsive member after said heater is rendered inoperative, for interrupting the cooking action of said device.

12. In a heat treating apparatus, means for establishing intervals of the heat treating action including, a. thermally responsive member having a portion movable in response to temperature changes, and means mechanically connected to said thermally responsive member and biasing the same in cooling direction during cooling thereof for directly terminating a cooking action in response to cooling of said thermally responsive member.

13. In a cooking device of the type adapted to be used in carrying out a plurality of successive cooking actions, having an electrical cooking element and a main switch therefor, a timer for establishing intervals of the cooking action including a bimetallic warp acting member, a heater for heating said member to cause movement thereof, means for instituting operation of said heater upon institution of a cooking interval, and means responsive to heating movement of said bimetallic member for rendering said heater inoperative thereby to permit the thermally responsive member to cool; means normally biasing said switch to open position, and mechanical means connecting said bimetallic member and said switch during cooling thereof, said thermally responsive member being biased in cooling direction during cooling thereof by said switch biasing means and being operative to prevent opening of said switch by said biasing means until said member has cooled to a predetermined temperature.

14. The combination with an electric heating means, of means for timing the operation thereof, said means comprising a thermally-responsive element, a support therefor, means for moving a part of said thermally responsive element while setting up an increasing force therein and for returning it by heating and cooling the thermally responsive element, and means for utilizing a decrease of force of said thermally responsive element when cooling to time the duration of operation of said heating means.

15. Means for controlling the energization of an electric heating means comprising a switch normally biased to open position, means for closing said switch and holding it closed, a bimetal bar constructed and arranged to mechanically hold said switch closing means in switch-holding position, an auxiliary electric heater energized by said switch closing means to heat said bimetal bar and cause it to release said switch closing and holding means to deenergize the auxiliary heater, and to hold said switch in closed position when the temperature of the bar has been raised to a given value, the bimetal bar then cooling and holding said switch closed with decreasing force until the temperature of the bar has been reduced to a given value.

16. In a heat treatment apparatus, an electric heating means, a control switch therefor movable into closed and open positions, means for causing opening of said switch set by closing movement of the switch, a bimetal bar, means including said bimetal bar for locking said switch in closed position, means for heating and cooling said bimetal bar, means controlled by said bimetal bar when it has been heated to a given temperature for causing release movement of the switch locking means, and for holding said switch in closed position until a. predetermined degree of cooling of the bimetal bar has taken place.

17. Means for controlling the energization of an electric heating means comprising a control switch therefor, means normally yieldingly biasing said switch into open position, a bimetal bar, means movable into locking engagement with said bimetal bar to cause closing of said switch and holding it in closed position, means for moving the free end of said bar and returning it by heating and cooling the bar, the bar releasing said switch closing means when heated to a given temperature and then causing holding of the switch in closed position against the transmitted stress of the switch biasing means until it movement incident to its cooling causes opening movement of the switch.

18. Means for automatically interrupting current flow through anelectric heating means comprising a thermal element, an auxiliary electric heater therefor, a lever arm, means actuatable byv said lever arm to cause energization of said electric heating means and said electric heater, means on said lever arm engageable with said thermal element when the latter is below a predetermined temperature for holding said lever arm in said energizing position, means for returning said lever arm to heater deenergizing position when said thermal element has reached a predetermined high temperature, the thermal element then acting to cause continuance of the energization of the electric heating means until the temperature of the thermal element has reached a predetermined low value.

19. In an automatic toaster, a toasting heater, a control switch therefor, a bimetal bar, an electric heater for the bar, a lever arm movable to cause closing of the switch and also cause energization of the. heater for the bar, means on the bar engageable with said lever arm to hold the latter in'switch-closing position when the bar is below a predetermined temperature but operative to release said arm when said temperature is exceeded, means connected with the lever arm to move the same when disengaged from the bar when the latter has been heated to thereby deenergize the bar heater, and means on the bar eifective when the bar is heated to hold the switch closed and to retain it closed until the temperature of the bar has decreased to a given value.

JAMES GEIER.

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