US2404976A - Automatic toaster - Google Patents

Description

July 39f1946 P. J. MccULLoUGH ET AL 2,404,976

AUTOMATIC TOASTER Filed May l2, 1943 2 Sheets-Sheet 1 FIGZ.

INvENToRsz PAUL J. MclggLLouGl-a CHARLES .TauaER Byx ToRN Y W Q3 FIGA.

AUTOMTI G TOAS TER Filed may 12, 1943 @BAUL J. Ms; @Um CHARLES Patented July 30, 1946 AUTOMATIC TOASTER Paul J. McCullough and Charles H. Steuber, St. Louis, Mo., assignors to .L'oseph Pavelka, St.

Louis, Mo.

Application May 12, 1943, Serial No. 486.641

3 Claims.

The invention relates to automatic electric toasters of the general type illustrated and described in McCullough Patent No. 2,253,637, issued August 26, 1941, and consists in all the novel features of construction referred to below.

One of the objects of the invention is to simplify the assembly of the timing mechanism with the toasting chambers and toaster frame or casing so that the timing mechanism may be constructed as a relatively small unit which may be readily installed, removed and replaced without disassembling many parts of the machine.

A similar object of the invention is to facilitate the assembly and application of heater units independently of the timing mechanism and without disconnecting a plurality of wires or other parts.

Another object of the invention is to provide for accurate adjustment of the timing period by directly limiting the movement of a clock winding member, as distinguished from the limitation of an intermediate member actuating the clock winding member which leaves the clock winding member free to move by its own momentum to a greater extent than indicated by the adjustable stop.

Another object of the invention is to provide thermostatic control for the toasting period in which the thermostat will be free of a Weight or load tending to hamper its movement or to give it a permanent set.

These and other detail objects of the invention as will appear from the following description are attained by the structure illustrated in the accompanying drawings, in which- Figure 1 is a vertical longitudinal section through one end of the toaster.

Figure 2 is a top View of the structure shown in Figure 1, the casing top cover being removed and some of the parts sectioned for clearer illustration.

Figure 3 is a vertical longitudinal section taken approximately on the line 3-3 of Figure 2 and indicating part of the timing unit and the associated thermostat control thereof when the device is cold.

Figure 4 is a similar illustration showing the thermostat control in a position assumed when heated.

Figure 5 is a vertical transverse section taken approximately on the line 5--5 of Figure 2 and illustrating the timing mechanism.

Figure 6 is a vertical longitudinal section taken approximately on the line 6 6 of Figure 2, i. e.

looking at the opposite direction from the direction of View of Figures 3 and 4, and illustrating the timing mechanism and showing the parts in the normal inoperative position.

Figure 7 corresponds to Figure 6 which shows the parts in a position assumed at the beginning of a toasting operation.

Figure 8 is a detail horizontal section and View taken on the line 8 8 of Figurel 5.

Figure 9 is a detail View taken approximately on the line 9-9 of Figure 5.

Figure 10 is a detail front elevation of the structure shown in Figures 1 and 2 and is drawn on a smaller scale.

The toaster body or casing is of sheet material of substantial thickness and includes a front Wall I, a rear wall 2, and end Walls 3, only one of which is shown. These walls are substantially continuous and comprise the frame upon which the remaining parts are mounted. A pan-like top cover 4 nts over the casing and is detachably secured thereto by readily removable screws 4a. A bottom cover 5 is detachably secured to the casing by screws 'da and angle clips 6 and is provided with offset straps I to which supporting feet 8 are attached. The bottom cover is provided with louvers 9 to facilitate ventilation.

An upright partition I0 extends longitudinally of the casing from end to end and is spaced inwardly from the front wall I. It is secured to the end walls by bolts 3a. Upright partitions II extend transversely of and between wall 2 and partition I3. A horizontal bottom partition I2 extends from end to end of the toaster and from partition I0 to rear wall 2. Members I0 and II form the sides and front walls of a plurality of toasting compartments each of which is provided with a pair of electric resistance heating elements H positioned adjacent to but spaced slightly from the respective partition walls II. Horizontal angular strips I3 on each partition II space the heating element from the surface of the partition. Member I2 forms the bottom of the compartments and is slotted at S between each pair of heaters to provide circulation of air between them.

Each element H is of familiar construction comprising sheets of mica with resistance wires mounted thereon. The elements are seated in slotted clips Iiia, secured to partition I0, and I2a, secured to partition I2. The upright rear edge of each heater element is positioned by vertical anges Mr'. on a member I4 secured to rear wall 2 and having a top flange Mb through 'which a screw I5 is threaded. An obtuse angle clip I6 has one end bearing against the under- Vzontal slots 3 I.

side of flange I4b and may be drawn up by tightening screw I5 so that its other leg engages a terminal of the adjacent heating element and thrusts it against flange I4a. An electrical connection I7 extends between flange |41) and the corresponding flange of an associated member I4 mounting the .adjacent heater element. Certain flanges I4?) are connected by wiring to the toasting bus bars and complete the electrical circuit, but these details are not included in the present application. The heads of screws l5 are readily accessible when the top cover .4 is removed and upon loosening these screws .and .clips IS, the heating element is readily withdrawn for inspection, repair or replacement. Guard wires 31 extend alongside but are spaced from heating elements H and are suspended from a U-shaped frame I8, each leg of which overlies one -of the heating elements and the cross bar of which is secured by a screw I8a to a clip 2a projecting upwardly from the rear wall. A dat plate lsb anged at its upper end is slidable in opposing grooves in the legs of member I8 and forms the rear wall `of the toasting compartment.

Toasting unita- A single slice Icarrying and timing unit is provided for two adjacent toasting compartments and cooperates with the four heating elements H therein. Each unit is mounted in the casing so that it may be readily removed for inspection, repair and replacement. Each unit includes an upright mounting member detachably secured to front wall I by screws I9 and has an inturned upper flange 2I and a lower flange 22. Rods. 23 are secured at their upper and lower edges to flanges 2| and 22 and a carrier plate 24 has inturned upper and lower flanges 25 and 26 apertured to receive rods 23 so as to slide vertically on the latter. Carrier Y24 is biased to an elevated position by a coil spring 21 hooked at its opposite ends to flanges 2I and 26 `respectively.

A Z-shaped bracket 28 (Figures 5, 6 and 7) has an upper outeriiange 28 secured to carrier 24 and a lower inner ange '38 adjacent to partition wall I0 and provided with a pair of hori- Slice supporting bars 32, one in each compartment, are mounted upon the legs 33 of a U-shaped yoke (Figure 8) extending `through lslots, 35 in wall I0. The yoke cross bar 34 is provided with headed studs 35 extending through slots 3| in bracket flange 30 and support the yoke and slice bars so they may move freely transversely of the unit and the toasting compartments. This arrangement readily eccommodaites variations in the assembly of the toaster parts and particularly in the alignment -of the heating units, the heating elements, their guard wires 37 and the slots 36 in wall I8 through which the legs 33 of the yoke slide,

Each carrier 24 with the parts thereon is manipulated manually by a handle 48 mounted on an arm. 4I which extends through a slot la in front wall I and also through a slot 280; in mounting plate 28 and through an opening 24a in carrier 2 The portion of the arm. passing through carrier 24 is notched at 43 to engage opposite sides of carrier 24 and is pivotally supported on carrier 24 by a notched portion of ange 29 of bracket 28.

Timing mechanism-A Iclockwork escapernent mechanism is indicated generally at C, the main gear wheel 44 being driven by a ratchet disc 45 which may be connected by an L-shaped winding bar 48 and a trip latch member 4'I pivotedthereon to member 28 and the parts associated therewith. The disc connection of the clock escapement to the winding bar is described in detail in McCullough Patent 2,302,131, issued November 17, 1942. When handle Il!! is depressed and carrier Z4, member 28 and slice bars 32 are moved downwardly (Figure '7) hook 48 projects through a slot 48 therefor in the web of member 28 to hold the vlatter to the clockwork mechanism against the pull of spring 2l'. At the same time, shoulder 54 on bar 4@ is engaged by the lower face of member 28 so that further downward movement of member 28 forces bar 45 downward- 1y rotating ratchet disc 45 in an anticlockwise direction. .Spring 58 thrusts member 47 clockwlse.

As disc 45 rotates in a clockwise direction, unn der control of the clock mechanism, and bar 45. members 4'! and 28, slice bars 32 and carriage 24 rise, tail 5l of latch trip member 41 projecting from member 47 approaches the lower end of an larm 53 pivoted at 54 on an angle vstrip 55 adjustably secured by screws 55 to wall I!) (see Figures 3 and Li). After tail 5I engages the lower end of arm 53, further upward movement of member 4l causes rotation of the member about its pivot on bar 45 resulting in the disengagement of latch @-8 and member 28, Vwhereupon spring 21 immediately raises carriage 24 and the parts mounted thereon to their uppermost position, as indicated in Figure 5. The end of the upward movement cf carriage 24 is cushioned by springs 51 compressed between flanges 2I and 25. Spring 59 linked to arm 46 continues the unwinding of the clockwork so that arm 45 eventually returns to its highest position.

Thermostatic control.--As is well known in the toaster art, the toasting period may be shortened after the cold toaster parts have been heated by one or more successive toasting operations and, to automatically shorten later successive toasting periods, it is customary to modify the timing mechanism by a thermostat. In the present structure, a thermostat device is associated with arm 53 for this purpose. The novel features of this thermostat-and associated structure lform the subject matter of a divisional application filed November 23, 1945, Serial No. 630,487. The transverse partition I2 nearest the end ofthe 'toaster has an elongated opening 6D. A spacer and heat conducting member 6I extends abreast of slot E!) and its ends are secured to partition l! beyond the ends of opening @Il but its intermediate portion Vis offset from partition II. The voiiset portion contacts the mica of the adjacent heating element H and hence its temperature corresponds more closely to that of the heater than does the temperature of the partition. A bimetal thermostat bar 62 is secured at its inner end 62a to strip E'l. When bar d2 is cold, it assumes the substantially straight full-line position at the inner side of partition l I and against strip el, as indicated-in Figure 2. When the bar is heated, it deflects towards the broken line position, moving through opening 68 to the outer Vside of partition H.

A flat spring 64 is secured at one end tothe lower end of arm 53 and is connected at its upper end by a link 53 to an extension B2b on the movable end of thermostat 82. Spring E4 is 4stii enough to move arm 53 in accordance with the movement of the swinging end of thermostat 52 unless movement of arm 53 is resisted by its engagement with tail 5I, in which case spring '64 willyield to accommodate the deflection ofthe thermostat.

As a. substantial portion of thermostat bar 62 moves through the restricted aperture 60 in the right hand partition Il, it is subject to the temperature of the air in the space between partition I l and the adjacent end Wall 3 of the casing and the warmer the air in this space the more rapidly the thermostat and bar 53 will be moved to the right (Figures 2, 3 and 4) and the shorter will be the toasting period. During the first few closely successive toasting operations initiated when the toaster is cold, the air in the space between the partition and the end of the toaster will check the movement of the thermostat to the right and prolong the toasting operation accordingly. Hence the thermostat tends to maintain a substantially uniform degree of toasting for a given setting irrespective of whether the toasting operation is an isolated one or one of several closely successive operations.

The lower end of arm 53 1s slotted to receive the upper portion of a clip 65 to guide the movement of the arm. The outer end of this clip is flanged at 66 to form a stop limiting the movement of arm 53 to the right so that it will not interfere with other adjacent toaster parts. If, due to carelessness, switch control failure, an intentional exhaustive test, or other unusual circumstances, the thermostat is subject to such a high temperature that it tends to move beyond the position shown in full lines in Figure 4, such movement is accommodated by deflection of spring 64 after arm 53 engages stop 66. The yielding connection between the thermostat and the arm avoids the thermostat taking a permanent set as would result if there were no yielding connection.

Adjustment of timing period.-It is customary in toasters of this general type to provide selective means for varying the length of the toasting operation so as to produce light, medium or dark toast as desired. Such adjustment is provided in the present device by a manually operated knob mounted on a shaft 'H journalled in the casing front wall and carrying a cam 12 on its inner end positioned in the path of movement of a horizontal flange T3 on a slide 14 slidably mounted on plate 2Q, slide 14 having vertical slots 15 receiving headed studs 15 on plate 2Q to slidably mount member 'I4 on plate 29. A flange 'Il on the lower end of slide 'I4 projects beneath a shoulder 18 on arm 46 and forms a stop for the latter when handle 40 and the parts associated therewith are lowered. Obviously, the position of cam l2 controls the height of slide 14 and thereby limits the downward movement of arm 46 and carrier 24 when a toasting operation is initiated. Hence the period elapsing before the return movement causes the release of latch 48` and the termination of the toasting operation is controlled by the position of slide 14. The direct engagement of the clock winding arm 45 by a manually adjustable stop possesses an advantage over the previous adjustment stop arrangement of McCullough Patent No. 2,253,637, issued August 26, 1941, in which a part corresponding to carrier 24 is engaged by an adjustable stop. It has been found that a quick, forceful, downward thrust on the carrier may cause some momentum in the clock winding arm resulting in the arm moving downwardly after the carrier contacts with the stop, Accordingly, the timing period would be lengthened and there would be no assurance of the desired degree of toast being produced, particularly if light toast were desired. The present arrangement avoids such a result because the winding arm itself directly contacts the stop. By placing control knob and its cam and stop flange 13 at one side of handle arm 4| and the winding arm shoulder 'I3 beneath the handle arm and the clockwork at the other side of the handle arm, these parts are balanced on the removable unit and the knob "id does not interfere with movement of handle 4S.

Manual termination of toasting operation.- irrespective of the manual adjustment for dark or light toast just described or the control of the toasting operation by the thermostat as previously described, it may be desirable to interrupt or to terminate the toasting operation at any time manually and this is accomplished by extending handle arm 4| into the plane of latch t8, as indicated at 4ta (Figures 5 and 7). When members e8 and 28 are engaged, as shown in Figure 7, and handle 4i? is raised manually so as to tilt about its pivotal support on flange 29, its extension 4in will move downwardly, thrusting latch 4S to the left (Figure 7) to disengage bracket 22 and permit spring 21 to raise carriage 24 and slice bars 32 and projecting the toast so it may be removed. This release of latch 48 may be operated for the purpose of inspecting the toast, and the handle carrier 24 and the slice bars may be lowered immediately afterwards to again engage latch 48 and bracket 28 but Without applying suilicient pressure to overcome spring 59 between arm 46 and iiange 2l as would be necessary to rewind the clock. Hence the toasting operation may proceed from the point interrupted by the manual tripping of latch 48 without substantially affecting the toasting period.

An arm 'I9 on carrier 24 is connected to a switch 8! which controls the heater circuit, and it will be understood that lowering of handle 40 and carrier 24 closes switch 80 and that the switch is opened when the carrier is raised whether by the timing mechanism or manually. The details of the switch and its control do not constitute the present invention and may be varied without aiecting the other arrangements described.

The toaster front wall l has a horizontal slot 8| for receiving a crumb tray 82 and partition EU is similarly slotted at 83 for the crumb tray. The crumb tray has a slot S in line with the slot S in bottom partition I2 to permit `ventilation of the toasting chamber.

The structure illustrated and described provides a simple, eiective and durable construction which is readily manufactured and in which the toasting periods are readily controlled and the timing units and heating units are readily removed and replaced independently of each other and without disassembly of any of the body walls or framing.

The details of the construction may be varied substantially Without departing from the spirit of the invention and the exclusive use of such modifications as come within the scope of the claims is contemplated.

What is claimed is:

l. In a toaster, a casing including a toasting compartment, a heater therein, a slice support, means for moving said support from an elevated non-toasting position to a lower toasting position and return, a clockwork escapement mechanism for controlling the return movement of said support and the toasting period, an arm pivoted at one end on the casing and movable at its other yend to lform kan adjustable stop-to limit the clock controlled .movement of the support, a thermo stat .subject to the temperature in the toasting compartment, and a connection between said thermostat and arm vfor movingthe latter about its pivot, said connection normally causing the :arm to follow the movement of thethermostat but being constructed to yield to accommodate relative movement of the thermostat and arm if the latter is held against movement.

2. In Va toaster, a casing including a toasting compartment, a heater therein, a slice support, .means for'moving said support from an elevated non-'toasting position to a lower toasting position and return, a clockwork escapement mechanism for controlling the return movement of said support and the toasting period, there being interengaging latch elements on the mechanism and the support 4movable with the support, one of said -elements having an elongated tail inclined vto the .path of movement of the elements and by which it ymay be tilted to disengage-the latch elements, ran `arm pivoted Aat one end on the casing and movable at `its lother end lengthwise o'f said. tail Ito engage the latter at 'different points in the partment provided with a heater, a timing vmechanism including a Ypart movable relative to the framework, an adjustable stop associated with the framework and arranged -to coact with said part to `'terminate the toasting operati-on, a thermostat subject to the temperature in the toasting compartment, and a connection-between said thermostat and stop for adjusting the latter, said connection being constructed to yield to accommodate movement of the thermostat relative to -the stop if the latter is held against adjusting movement.

PAUL J. MCCULLOUGH. CHARLES H. STEUBER.

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