US2082985A - Heating appliance with timer - Google Patents

Description

June 8, 1937. R. D. SMITH HEATING APPLIANCE WITH TIMER Filed Feb. 1'7, 192B Patented June 8, 1937 UNITED STATES PATENT OFFICE HEATING APPLIANCE WITH TIMER Reproduced as 4 Claims.

This invention relates to heating appliances having timing mechanism incorporated therewith for automatically governing the current supply to the appliance, or for other purposes.

The invention aims to provide an improved form and an improved disposition of the timing mechanism as to its structural association with typical types of appliances, such as .toasters, percolators, wailie irons, chafing dishes, and the like now in general use in the home and in restaurants, hotels, etc.

Another object is to provide timing mechanism for this purpose which shall have an operating handle disposed for more convenient manipulation and more easily selected accuracy of setting to predetermine a time interval.

Another object is to provide a control switch for the appliance arranged to be operated di-" rectly by the time setting handle and independently, if desired, of the timing mechanism.

A particular object is to avail of the usually wasted space comprised by the base of the smaller types of domestic heating appliances exemplified by the ordinary table toaster herein employed to illustrate the principles of my invention, and to locate my improved timing mechanism within the confines of such base with the following advantages. For increase of stability of the relatively light appliance as compared with the practice heretofore of incorporating timing mechanism within the structure of such appliances but above the base. For the universal adaptation of a single type of timing mechanism to theqnany and variegated designs of heating appliances whose structural similarity is limited to the common possession of such a base. For the consequential small amount of change and expense of pr'cduction involved in applying my improved timing mechanism to different types of existing appliances. For the ability to retain the original size, proportions and decorative design of existing appliances to which the qualities cited are of great commercial importance. For the easy converting of an-ordinary, non-automatic heating appliance into an automatic time controlled appliance by the mere application to same of my improved timing mechanism according to the principles herein disclosed and claimed. A still further and particular object is to so mount the timing mechanism that the noise of the running of its movement shall be deadened as much as possible and the transmission of this noise .or of the vibrations which cause the sameto any parts of the appliance which might act to amplify the same be prevented or minimized. Other objects will appear hereafter.

In the drawing, Fig. 1 is a side view of an ordinary table toaster showing an example of the improved application of timing mechanism thereto. I

Fig. 2 is an end view looking from the right at Fig. '1.

Fig. 3 is a plan view of the base of the toaster taken in section on the plane 33 in Figs. 1 and 10 2 looking downwardly.

Fig. 4 isa wiring diagram of the electrical connections.

Fig. 5 is an isometric view of my improved timing mechanism and the electric switch together with the means for silent mounting of same removed from the base of the toaster.

Fig. 6 is an enlarged fragmentary view of the toaster base seen as in Fig. 2 with the addition of a time setting adjustable stop.

2 Fig. 7 is a fragmentary view in section on the 0 plane |I in Fig. 6 looking in the -direction of the arrows.

Fig. 8 is a plan view of the time limit switch unit of Fig. 5 but showing a switch and backset mechanism employed of the type disclosed in my co-pending application Serial No. 183,838, Patent No. 1,984,204 of December 11, 1934.

Fig. 9 is an edge view looking from the right at Fig. 8.

, Fig. 10 is a view of the back-set mechanism of Fig. 9 taken in vertical section on thepIane l0--l0 of Fig. 8.

Fig. 11 shows the parts which engage whereby the turning of pinions' exterior of the movement plates is caused to operate the switch.

Fig. 12 is a rear view taken on'the vertical plane l2-l2 in Fig. 10 looking in the direction of the arrows and showing details" of the backsetting clutch and stop parts associatedthere- 40 with I Fig. 13 is a view similar to Fig. 12 o'n'an en- Y larged scale showing certain of the parts broken away to reveal'the flip stop whereby the power spring of the movement is wound, certain parts being sectioned on the plane l3-l3 in Fig. 10. In Figs. 1, 2 and 3 the superstructure of the toaster which 1 have chosen to showmerely as the heat of element iii, the carriers II, the details of which are immaterial to the scope ofthe present invention.

As is almost universal in the construction of toasters and other heating appliances the base I3 is hollow and in the particular example here pictured comprises an inverted tray supported in slightly elevated position by four leg pieces it.

Within this hollow of the base I may mount in any convenient way a timing mechanism comprised between the movement plates It and H, the mounting means for which in the present example of construction comprise two longitudlnal strips i4 which may to good eflect be made of thin tempered steel to give them a resilient quality less disposed to transmit the vibration of sound from the movement to the base It and as added precaution against such transmission of sound, I may space strips II from the base II by washers ll of felt or other sound absorptive material at their extremities where they are fastened to the base. I may introduce similar washers 24 to separate strips II from the lateral bars 2| where attached thereto and which bars are fixedly secured to the movement plate ll. Strips i4 may be given an s-shaped or other non-straight configuration to increase their effective length.

Movement plates i4 and II are rigidly spaced and connected by posts 22, two of which at the left end of the movement may carry secured thereto the electric snap switch 24 having the stationary contacts 4l--4i and the movable contacts 42-42 to be operated by the timing mechanism, which as before stated occupies the space between plates i4 and II or between corresponding plates il4-li4 of Figs. 8 to '13, inclusive.

illustrated, the exact nature of which, however, may be varied at will within the scope of this invention, the external pinion 24 serves as the sole means of operating not only the timing mechanism but also the switch 24 and is itself operated by a segment 24 carried on the lever 2t pivoted at 21 and having the handle 24 at its end. The spring 2| may act upOn'lever 24 to urge it into its normal position indicated by full lines in Fig. 5. The use of-this spring would not be necessary if the time giving mechanism carried by the plates l4 and II is to comprise in itself a complete spring motor motivated by me conventional form of power spring such that indicated at III in Fig. 9, but ina more simple form ,of time movement any additional power spring equivalent to Iii might be eliminated in which case throwing lever 24 from its full line position to its broken line position in Fig. 5 will rotate the pinion 24 as permittedby one way slippage of any conventional form oi winding ratchet which after permitting this winding movement of pinion 24 will permit its reverse movement under theimpulseofspringflonlysofsstastherunning of a retarding train may permit. Mechanical connection between the timing movement and the-switch 28 operated thereby may be such that in the full line position oi lever 24 the switch will, be open and the nirrent received from the attachment cord 44 by prongs II will be cut oil from circuit through the heating unit l4, and

that when lever 24 is slightly displaced from its full line position the consequent movement of pinion 24 will act to close the switch and supply current to element l4 until such time as the reverse action of pinion 24 under the power of spring 24 shall return lever 24 to its iull line posiaosaoss tion and automatically open switch 2! cutting on the current to element II to prevent the toast from burning.

I may mention that the construction of prongs 3i may be conventional and of fully standardized commercial form and that the connection from one of these prongs direct to the left end of heating element II is by means of wire 42 and that the connection from the other of said prongs to the opposite end of heating element I0 is through wire 34 leading to binding post 34 of switch 24 and through wire 25 from the binding post 34 of switch 24 to the right hand end of the heating element Ill (see diagram of connections in Fig. 4) and all electrically alive parts are, of course, thoroughly insulated from the metallic portions of the toaster structure and timing mechanism.

Particular attention is called to a stationary abutment or rest 31 at the left end of slot 34 in base I! for lever 24 and to a corresponding abutment or rest 2! near the right end of said slot. Both of these abutments are preferably somewhat lower than the center of lever 24 as only one of them is used at a time and its purpose is, in the case of abutment 21, for resting the thumb 42 against same while the index or second finger 44 of the operator's same hand grasps the handle 24 for pulling it to the left in Figs. 2 and 3, after which if it be desired to move the lever 2 in the opposite direction the thumb is placed against handle 24 and some finger of the operator's same hand grasps the rest 34 as a corresponding means of moving handle 28 a definite desired amount to the right in Figs. 2 and 3. I do not, of course. limit my invention to this precise manner of I manipulating handle 24 and may eliminate one In the particular form of timing mechanism here or both of abutments 31 and 3!, the sides of the toaster being graspable for the purpose of rests l1 and if same are absent, but they are extremely useful and I believe the idea is novel in this art for the convenient and accurate accomplishment of a desired time setting of a handle such as 2! to register with graduations 40 which may be marked on the base II.

This disposition of a time setting lever to protrude from the wall of a utensil in such relation to adjacent corners of the utensil contour or as a substitute for same the finger rests I! and 3! respectively useable to assist in the control oi! pulling the handle 24 just the desired distance in both directions, is of particular use when I employ for operation by means of a lever in a utensil a time limit switch unit incorporating the backset principle disclosed in several of my co-pending applications illustrative of which I have copied in i s. 8 to 13 inclusive certain parts of the structure disclosed in my co-pending application Serial No. 183,838 and in said figures show same equipped with the same operating lever 28, gear segment 24 and pinion 24. It will not be necessary to describe the details of this optional form of time limit switch beyond malging clear an example of mechanism which aifords the back-set feature, meaning the ability, after any original displacement of lever 24 for closing the switch and at the same time winding and starting the time movement, of manually returning lever 2' any desired amount of its displacement from itsstarting position thereby to reduce or to cancel the effective time setting initially given, or to manually turn the switch "on and "of!" if desired as though the time mechanism were not present.

In Figs. 8 to 13 inclusive I show a simpler form of snap switch I00 the details of which will not be vdescribed other than to explain that rocking movements of the operating fork ml at any speed snaps the movable contact I02 to and from its broken line position in Fig. 8 where it conductively bridges the contact bracket I03 and the contact bracket i04 carrying the screws I05 for connection to the circuit wires. Brackets I03 and I04 are secured in insulated relation on the body 106 of the switch,'itself composed of insulating material and mounted by means of cap or frame portion I01 carrying the pivot pin I08 for the switch fork IOI. In Fig. 16 this fork is seen to beformed with. an offset for engagement by the cam finger I09 secured on the periphery of cam IIO by the screw III.

The cam H is loosely rotatable on the shaft I I2 pivoted at its rear end in the frame plate I I3 and at its forward end in the frame plate II4, which shaft carries pinned to its forward or upper end the pinion 24 and is retained at its rear end by the screw II5.

Shaft I I2 is slabbed or fiatted for some distance from its end engaged by screw H and engaging this flatted portion so as to turn fixedly with the shaft is the trip I I6, a forwardly extending tongue II1 on which, engages an opening I I8 in the cam for propelling the latter in both directions of rotation but with a small amount of play or lost motion owing to the opening I I8 being wider than the tongue I I1. The trip I I6 further has a rearward bent tongue or terminal I I9 in the path of which a swinging stop member I20 is swivelled on a bushing I2I carried by the pivot pin I 08 at the side of the switch cap and positively backed up by tongues I22 and I23 which may be struck from the frame plate I I3. Thus while the stop member I20 precludes more than a complete turn of the trip H6, it affords the full extent of a complete turn because of its limited ability to swivel between tongues I22 and I23 as described. The extra space between trip I I6 and the frame plate I I3i's taken up by a spacer collar I24. The shaft II2 further carries a radially projecting pin I25.

From referenceto Figs. 10, 12, and 13 the pin I25, or the projecting portion thereof, is seen to ride freely in an annular recess I26 in the gear I21 except for its engagement at one point with the L-shaped flipstop I28 pivoted in the wall of gear I21, extending into the recess I26 and limited in its shifting movement by abutment against opposite corners of anoutward extension of the recess I26. As with the case of the stop member I20 this limited swing movement of flipstop I28 permits a full relative circle of movement of shaft II2 relative to gear I21 but precludes any substantially greater amount of relative movement.

The gear I21 is in mesh with a winding gear I29 given bearing between the frame plates H3 and H4 and fixed to rotate positively with the winding spindle I30 of an ordinary time movement which may be disposed in any p0s1ti0nal relation to the frame plates I I3, I I4 to fall therebetween or exterior thereof as here shown, the band spring I3I connecting the spindle I30 to some frame post in the usual manner, and the usual parts of a retarding train being in part indicated without detailed description.

After any winding of the spring I3I by turning of the spindle I30 in a contra-clockwise direction in Fig. 8 the power of this spring governed by the retarding train slowly rotates spindle I30 in the reverse or clockwise direction in Fig. 8 and thereby rotates the gear I21. The flipstop I28 will pick up and engage the shaft pin I25 whereby the shaft and the trip II6'will be rotated contra-clockwise in Fig. 8 or clockwise in toward its broken line position, segment 25'will impel pinion 24 in a clockwise direction. Pin I25 will engage flipstop I28 and thereby impel gear I21 in corresponding direction and gear I29 will be rotated to again wind the spring I3I for another cycle of timing action.

From the foregoing description it will be plain that whereas all of these rotating parts are strictly limited to a stop determined normal or zero position corresponding always to a given state of unwinding of the spring I3I, all of these parts except the two gears. I21 and I29 are free for manual return'to this normal zero or starting position (see Figs. 11 and 12) at any time and without waiting for the corresponding return of gear I21, which will be effected only by running of the time movement, because the shaft pin I25 acts only as a pusher with respect to the flipstop I28 and can recede from same at any time for return to its starting position. This much of the construction alone would give the ability to throw the switch off manually without waiting for the set time to elapse but it may sometimes be desired that in addition to this ability of cancelling the effective time setting there shall be provided a means of reducing the effective time setting and yet leave the timing mechanism with some smaller period to run before it shall act to break the circuit. This may be accomplished by a slippable ratchet clutch consisting of the ratchet wheel I32 secured fixedly to the side of gear I21 and engaged by a pawl I33 pivoted to the cam IIO by the stud I34 and urged by the spring I35 into engagement with the teeth of ratchet wheel I32. An ear I36 falls closely adjacent to a tripping projection I31 on the trip II6 so that the slight relative movement of trip II6 relative to cam H0 is sufficient to lift the pawl I33 free of the ratchet wheel I32 for adjustment of cam IIO to different rotative positions with respect to gear I21 so that pawl I33 may seat itself in any desired tooth of the ratchet wheel I32 to be clutched and impelled thereby in the absence of flipstop I28 and shaft pin I25 being in engagement. It will be noted, however, that if the trip H6 is impelled back to its normal or starting position by means of this ratchet clutch mechanism, and there stopped 'by the member I20, the running down of spring I3I does not cease until the flipstop I28 has caught up with and becomes obstructed in its running by the shaft pin I25, because when the rotative travel of trip H6 is prevented by the stop member I20, each tooth-of ratchet wheel I32 is enabled to escape and pass the engaging pawl I33 owing to the lost motion relation of the cam IIO to the trip H6 and the consequent tripping or releas-; ing action of pawl I33 which otherwise would constitute a positively impelling clutch so long as trip H6 is unimpeded in its travel. For instance, were the cam H0 to be stopped instead of the trip II6, ratchet wheel I32 could not continue to pass the pawl I33 and the running of ously with the remote side of the toaster base, or in fact either side of the toaster base whatever its position, is a material factor in the conthe case with most modern table appliances, that otherwise in order to operate a time limit switch by a horizontal lever, the appliance would have to be held down by one hand while the lever was moved by the other hand of the operator, requiring the employment of two hands, whereas the timer of these improvements not only has the space saving merit of being horizontally disposed, but so disposed, can be operated in its entirety either as a. plain switch-on" and switch-off device or as an automatic time limit cut-oil by the operators either hand alone.

From the foregoing description and from a comparison of Fig. 3 with Fig. 8, it will be noted that as an incidentto the direction of rotation of parts, the scale of time graduations as shown in Fig. 3 would need to be reversed to place the normal or zero point end of such scale at the left instead of at the right end of slot II for accord with the timer mechanism of Figs. 8 to 13 because in plan view and looking downward the operating lever 26 as shown in zero or normal position by full lines is at the end of its swing opposite to the functionally corresponding position of this same lever as shown in full lines in Fig. 8. This will serve to illustrate the inter changeability of the directions in which the operating lever may be constructed to move and still partake of the benefits of the features comprising the present improvements.

In connection with the foregoing description I believe that there are many points of novelty in the herein disclosed arrangement of timing mechanism which do not depend upon the location of same in the base of the toaster but which would be equally advantageous in any arrangement of timing mechanism associated with the superstructure of the toaster above the base and the claims hereto appended will not, therefore, be understood to limit the location of the timing mechanism to any particular portion of the structure of a toaster except where same is explicitly stated.

In Figs. 6 and '1 for, purposes of making it possible to repeatedly set the timer for the same duration of run and by the sense of feel, if desired,

rather than by reference to the graduations til. I

mentioned slot could as well be used for this purpose. The stop 48 having the hub it has a corresponding rectangular hole fitting the shank II and kept from turning thereby and by the engagement of shank 46 with slot 41 but freely slidable on said shank so that tightening the thumb nut 50 clamps the head I! against the inner surface of the side of base I! and the stop ll against the outer surface providing convenient means to vary the position of stop ll and secure it in place. In these figures also is better shown a pointer II which may depend from lever 20 to register. with graduations ll when same are employed.

die 28 so that same may be grasped simultane-' The attachment prongs Ii may be located elsewhere on the toaster. The handle 2| may be mounted to protrude from other sides or portions of the toastenstructure onother heating appliance, in some of which appliances such as percolators or wafiie irons, the base, while commonly shallow, may be in plan view of other geometrical shapes than square or rectangular, such as iound, octagonal, etc. Also the slot ll or its equivalent may be formed in'the top or horizontal portion of base II and the handle 28 up-turned to protrude, such slot in that case made curved if handle 28 is to swing with lever 26, but such handle may be given gear and rack connection to lever 28 instead of travelling fixedly therewith, or may be carried by a rack meshed directly with pinion in which arrangement the path of travel of handle I8 would be straight instead of curved. I may also operate pinion 24 by a worm gear, or bevel gear connection, or the equivalent, eventuating in a dial, knob, or handle the equivalent of handle it in my co-pending application Serial No. 183,838 filed April 14, 1927, and protruding from any part of the appliance or itsbase. The circuit connections and the exact type of switch employed may be varied at will as may also the location of the switch in the toaster. Where a switch is omitted and the iunction of the timing mechanism is, instead of or in conjunction with a switching operation, to move the food or material being treated or in any way vary its effective relation to the heat in the appliance, it will be appreciated that my novel arrangement and disposition of timer is equally advantageous.

I do not consider it new in this art broadly to combine a timing mechanism with a heating element within the structure of a toaster but I do believe it to be novel and of great practical advantage to locate and construct a timing mechanism in a way characterized by the several features hereinbefore described and particularly pointed out in the appended claims.

I claim:

1. In combination with a timing mechanism, a

handle for operating same pivoted 'for limited swinging travel, a rest positioned near one end of said travel and sufficiently close to the other end of said travel to permit the simultaneous grasping of said rest and said handle by the thumb and a finger of one hand in all positions of said handle, said rest being outside the plane of movement of said handleto expose the latter for easy grasping when displacing said handle from proximity to said rest.

2. In combination, a timing mechanism carried between two spaced and rigidly connected bearing plates, a supportonwhich said mechanism is mounted, and means for mounting said mechanism on said support including fastening projectlons overlying the edges of said plate and mounting strips extending from said projections to said supports and separated from direct contact with both by relatively yielding means.

3-. In an automatic appliance, a timing device connected to control the action of said applianceand housed therewithin, a time setting lever, a wall of said appliance having an opening through which said lever protrudes, graduations to represent intervals of time arranged lengthwise of said opening, connections between said lever and said timing device whereby displacement of said lever from a limit position winds the power spring of the timing device a proportional amount indicated by said graduations, said connections acting to impel said lever slowly back to its limit position as the power spring plays out, and auxiliary connections between said lever and said timing device causing said lever to be so impelled to its limit position within a space of time proportional to its displacement from said position irrespective of the extent of winding of said power spring.

4. In combination with the hollow base of a table appliance shaped to afford a shallow compartment having a top horizontal wall, a com- 10 bined electric snap switch and cooperative time control movement assembled to comprise a structural unit to be housed within said compartment.

and including a train of time Wheels, spaced metallic plates pivotally supporting the wheels 15 therebetween, electric circuit terminals, an insulative switch body carrying said terminals and deriving support from one of said plates and located on the same side thereof as is'the other plate for compacting the overall thickness of the combined switch and movement unit to a minimum dimension, a handle pivoted to swing for operating said movement, a switch member insulated from said handle and movable to make and break circuit through said terminals, and spring toggle mechanism enabling said handle to propel said switch member with a lagging snap action in both directions, together with means to mount the said unit as an integral structure upon the lower surface of said wall in a manner to be accessible from the bottom of the appliance with-

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