US1949250A - Heat control device - Google Patents

Description

Feb. 27, 1934. E, L o s c 1,949,250

HEAT CONTROL DEVICE Filed April 24, 1931 Z4 L N v 5 9 3 g; H 1 i si i i/ 43 ATTORNEY9 Patented Feb. 27, 1934 UNITED STATES HEAT CONTROL DEVICE Edward L. Fonseca, Newark, N. J assignor to The Wilcolator Company, Newark, N. J., a corporation of Delaware Application April 24, 1931. Serial No. 532,449

14 Claims. (Cl. 236-15) This invention relates to thermostatic control devices of the kind used for controlling the temperature within the oven of a gas range, and it is concerned more particularly with a novel device of this sort especially adapted for installation in gas ranges of the console type.

Recently there has been developed a new form of combined gas stove and oven known as the console model, which is now being produced by many stove manufacturers. This new range is distinguished from former ranges by the disposition of the oven which is much lower than heretofore so that the top of the oven lies only a few inches above the open burners of the stove. Since substantially all thermostatic control devices for ovens are installed in the side wall of the oven adjacent the open burners of the stove and with their operating handles on the outside of this wall, it will be apparent that when the ordinary type of device is installed in a console range, its operating handle lies within the zone of temperature developed by the adjacent stove burner. As a consequence, the adjusting knob is likely to be heated by the stove burner to a temperature uncomfortable to the touch and in addition there is a possibility that the clothing of the user may become ignited in adjusting the device.

Also, in the control devices as heretofore constructed, the adjusting handles projected a considerable distance from the oven wall. This was not objectionable in the former ranges, since the devices could be placed at a substantial height above the open burners, but in-the console range with the limited space available for installation, the handles occupy a position in which they not only interfere with the use of the burners but are also liable to injury by being struck by cooking utensils.

Oven temperature control devices as heretofore constructed also commonly included a nut and screw combination by which on manipulation of the handle, the fuel control valve was set at varying distances from its seat, depending upon the temperatureto be maintained. Such nut and screw combinations were formed with a substantial number of threads to insure proper alignment and, on occasion, the nut and screw might be turned a complete turn more or less than was required for proper calibration, and there would be no way of telling that the calibration was incorrect.

The new heat control device of this invention is particularly adapted for use on the console type of range; although its utility is by no means limited to the particular range on which it is to be installed. In the new device, the operating handle does not extend outwardly a substantial distance beyond the side wall of the oven in which the device is mounted, but has a considerable extension in a plane parallel to the wall so that that portion of the handle which is grapsed by the user may lie entirely outside the zone of temperature developed by a stove burner. Since the handle does not project out over the burners, it does not interfere with the use of those burners in any way and is, therefore, not likely to be injured during the use of the range.

The device includes a thermostatic element of the'rod and tube type and interposed between the element and the fuel control valve in a place ordinarily occupied by a nut and screw combination is a cam and follower. The use of thecam and its follower makes it possible to obtain an adjustment of the device throughout its complete range by a movement of the follower through an arc'not in excess of 360 and preferably much less, for example, as In the particular cam and follower provided in the preferred form of my invention; the design 01. the cam is such that should the follower pass through an arc of more than 360, it passes over the high point of the cam and moves back to the low point so that the original setting of the valve is immediately restored. Accordingly, with this arrangement, there is no possibility of the calibration of the instrument being disturbed by reason of the parts being accidentally moved one or more complete turns from their proper positions.

The new instrument is so arranged that it can be calibrated by either the hot check or cold check method, and the device has numerous other features of novelty which will be made clear in the detailed explanation to follow.

For a better understanding of the invention, reference is made to the accompanying drawing, in which Fig. 1 is a view in perspective of the new console type of range provided with the heat control device of this invention;

Fig. 2 is an enlarged elevational view of this device with parts broken away;

Fig. 3 is a longitudinal section through the device on the line 3-3 of Fig. 2; and

Fig. 4 is a view in side elevation showing certain parts of the mechanism in one position of adjustment. 7

Referring now to the drawing, the gas range 10 of the console type is illustrated as being provided with an oven, the top of which lies only a short distance above the level of the open stove burners 11 so that the inner side wall 12 of the oven is relatively short, in most cases not exceeding six inches in height.

Mounted in an opening in the innerwall 12 of the oven is the thermostatic control device of this invention, this device including a fitting 13 within the oven secured in place on the oven wall by a screw 14. This fitting is provided with a pair of passages therethrough, one of these passages being in communication with a supply pipe 15 and the other with a discharge pipe not shown. The supply and discharge pipes lie side by side within the oven.

The device includes a cup shaped casing 16 secured to the fitting 13 by a tap screw 1'7. The casing 16 is provided with passages which communicate through nipples 18 with the passages in the fitting 13. The passages in the casing 16 lead to opposite sides of a fuel control valve disposed therein.

Inside the casing 18 is a central boss 19'in which is threaded the end of a tube 20 of material having a relatively high co-eflicient of expansion, such as copper. The free end of the tube is closed by a cap 21 and within the tube is a rod 22 of material having a low co-efllcient of expansion, such as a suitable nickel steel alloy. The rod and tube together constitute a heat responsive element.

One'end of rod 22 is seated in cap 21 and the other end is seated in a socket 23 in a part of a transmitting element which is interposed between the end of the rod and the fuel control valve 24. This valve divides the casing 16 into chambers 25 and 26 on opposite sides thereof, to and from which lead the passages in the casing which communicate with the gas passages in the fitting 13.

The valve 24 has a hub27 through which extends a short shaft 28 provided at one end with the socket member 23. Mounted rigidly on the rod is a cam member 29 formed with a helical cam surface 29'. The surface includes one complete convolution of the helix and the ends of the surface are connected by an axial portion 30. Mounted on the shaft 28 and cooperating with the cam member is a cam follower 31 which has a surface of the same configuration as the surface on the cam. The follower is in the form of a sleeve loosely mounted on the rod .28, the sleeve being held against rotation with rod 28 by means of an arm 32 extending radially therefrom and straddling a pin 33 mounted in the wall of casing 16.

The hub 27 of valve 24 loosely mounted on the shaft 28 abuts the follower 31 and upon rotation of the rod, the follower is forced axially of the rod by the action of' the cam which rotates relative to the follower. This axial movement of the follower causes a movement of the valve relative to its seat. when the cam and follower mate exactly as illustrated in Fig. 3, the valve lies in contact with its seat. Upon rotation of shaft 28 and the cam through an are just short of 360, as illustrated in Fig. 4, the follower is moved to the extreme limit of its axial movement and the valve is likewise moved to the farthest position away from its-seat. A slight further rotation of the shaft and cam causes the follower to mate with the cam so that the valve is restored to its original closed position.

I Wlththis arrangement, it will be apparent that a complete turn of the shaft and cam causes a movement of the follower and valve throughout their full range and as the turn is completed, the parts are restored to the position they occupy with the turning movement started.- With the prior constructions in which a nut and screw combination was employed for transmitting movement of the adjusting handle to the valve, it was possible for the nut to have various positions 360 apart relative to the screw. Although the parts might be 360 out of calibration, this misadjustment could not be detected from outside the instrument with the present arrangement, a rotation of the shaft beyond one complete turn causes the parts to be restored to their original setting and this overcomes the difficulties incidental to the prior constructions.

The valve 24 is held in place against the follower by means of a coil spring 24 hearing at one end against the valve and at the other in a channel in the inner face of a cover 34 threaded in the open end of the casing. The cover 34, which seals the casing gas-tight, is provided with an axial boss 35 having an opening through it for a stem 36. This stem carries on its inner end a head having a conical surface 37 which cooperates with a conical seat on the inner surface of the cover. Outside the casing, the stem 36 is provided with a disc 38 seated in a groove in the stem and serving as an abutment for one end of a coil spring 39, which bears at its other end against the end of the boss 35 and forces the stem to a position in which its head bears against the conical seat in the cover to make a gas-tight seal. Projecting from the head -on the stem is a key 40 which fits in a transverse slot 41 in the end of the shaft 28 and provides a means of connecting the stem and shaft together for rotation in unison.

The outer end of thestem 36 has a portion of reduced diameter which defines a shoulder and mounted on this portion of the stem is a disc or bushing 41' held against, the shoulder and against rotation on the stem by a screw 42 threaded into the end of the stem and passing through a lock washer 43 which contacts with the end of the busging. On the outer face of the bushing on a boss 4-is the enlarged end 45 of an adjusting lever or handle 46. This lever extends radially with respect to the stem 36 and is movable in a plane parallel to the wall 12 of the oven. Formed in the enlarged end 45 of the lever is a curved slot 47 through which passes a screw 48 threaded into bushing 41 and holding the lever against movement relative to the bushing. The slot and screw provide a means for varying the angular position of the lever 46 relative to the bushing.

As shown more clearly in Figs. 1 and 2, the adjusting lever extends out beyond the front wall of the oven to a substantial distance and its free end lies entirely outside the zone of temperature developed by the adjacent open burner 11. Also, the lever lies a sufficient distance away from the oven wall 12 so as not to be raised to an uncomfortably high temperature by heat radiated from that wall. If desired, the free end of the lever 46 may be provided with a handle 49 which may take the form of a decorative tassel connected to the end of the lever by a ring. The lever carries a pointer 50, which cooperates with a temperature indicating scale 51 mounted on the base plate 52 secured to the oven wall by screws 53 and screw 14.

The base plate 52 is provided with upstanding lugs 54 to which is secured a cover 55 by means of screws 55'. This cover has an opening through which the operating handle 46 extends and through which scale 51 may be observed, the top and bottom ends of the'opening in the cover limiting the movement of the lever 46. The base plate 52 is also providedwith an ear 56, through which projects'a boss 57 from fitting 13. This boss provides a housing for a screw for controlling a by-pass connection between the passages in fitting 13 and by providing the ear 56 on the base plate 52 through which the boss 5'7 extends, the boss serves as a convenient means for centering the base plate on the oven wall.

It will be apparent that the new heat control instrument is particularly useful in connection with the console or other ranges of the low oven type since in the new instrument, the operating handle terminates at a point well away from the zone of temperature developed by the open stove burners and at the same time the instrument does not project outwardly from the oven wall to such an extent as to interfere with or be injured by cooking utensils placed over the burners. In the operation of the device, the user moves the lever 46 until the pointer indicates the desired oven temperature on the scale and this movement of the lever causes a rotation of stem 36, of shaft 28, and cam 29 on the shaft. The rotational movement of the cam produces an axial movement of the follower and the valve, the valve approaching or receding from its seat to occupy a position which permits the amount of gas to flow to the burners that is required in order to maintain thedesired temperature in the oven. As the temperature in the oven rises, the

tube 20 of the thermostatic element expands,

thus moving the cap 21 in a direction away from the casing 16 and permitting the rod 22 to move in the same direction. The transmitting element composed of shaft 28, cam 29, and follower 31, and the rod 22 are moved by the action of valve spring 24 acting on the valve which abuts the follower 31. When the temperature for which the device is set is reached, the tube will have expanded to a point at which the valve is closed. As the oven temperature then begins to fall, the tube shrinks, moving the rod toward the valve and through the transmitting element, causing the valve to be moved away from its seat to permit additional fuel to be supplied to the burners.

In many respects, the present invention embodies features set forth and described in my copending application Serial No. 383,804, filed Au gust 6, 1929, but constitutes an improvement thereon in the transmitting element and in those features of the instrument which lie outside the oven.

I claim:

1. The combination with a gas range having an oven and an open burner adjacent the wall of the oven, of a thermostatic control device mounted on said wall above the open burner, means for adjusting the device, a lever secured to the means above the open burner and movable in a plane substantially parallel to said wall and having a portion projecting beyond the front wall of the oven, and a handle on the projecting portion of the lever located outside of the zone of heat developed by the open burner and also outside of the zone of heat radiated by. said wall.

2. The combination with an oven of a thermos static device on a wall thereof, rotatable means for adjusting said device and including a cam, a member having an adjustable connection with said means for actuating the same, a scale mounted on said oven, a pointer on said member cooperating with said scale, and a handle on said memberlying' outside the zone of heat radiated from said wall.

3. In -a heat control device, the combination of a rod and tube thermostat, a valve, means having an axially adjustable transmitting element for varying the relation between said valve and thermostat, a stem connected to said means, a disc on said stem, a crank secured to said disc, and means for adjusting the angular relation between said disc and said crank. I 4. In a heat control device, the combination of a rod and tube thermostat, a valve, means having an axially adjustable transmitting element for varying the relation between said valve'and thermostat, a stem connected to said means, a disc on the outer end of said stem, a crank secured to said stem, and means eccentric of the pivot point of said crank for varying the angular relation between said crank and disc.

5. In a heat control device, the combination of a rod and tube thermostat, a valve, means having an axially adjustable transmitting element for varying the relation between said valve and thermostat, adjusting means connected to said first means and including a crank, a housing having a slot for said crank, a scale on said housing, a handle atthe end of said crank, and a pointer on said crank between said element and said handle for cooperating with said scale.

6. In a heat control device, the combination of a thermostat, a fuel supply valve aligned axially with said thermostat, and crown cam means interposed between said thermostat and said valve for varying the relation between them.

7. In a heat control device, the combination of a thermostat, a fuel supply valve aligned axially with said thermostat, a rotatable cam aligned axially with said thermostat and said valve for varying their relationship, and means for rotating said cam.

.8. In a heat control device, the combination of a thermostat, a fuel supply valve aligned axially with said thermostat, means between said valve and said thermostat and rotatable about their common axis for adjusting their relationship, said means being restored to initial position upon one complete revolution thereof.

9. In a heat control device, the combination of a thermostat, a valve, a transmitting element interposed between said thermostat and said valve and consisting of a pair of members, one within the other, and a spiral cam of not more than one turn connecting said members for varying their axial relation, and means for rotating one of said members.

10. In a heat control device, the combination of a thermostat, a valve, a transmitting element interposed between said thermostat and said valve consisting of a crown cam element and an element engaging the cam, and means for rotating one of said elements for varying their axial relation.

11. In a heat control device for an oven, the combination of a thermostat, a valve, a valve body, a cam interposed between said thermostat and said valve for varying their relationship, a stem extending through said cam and having a follower engaging the cam surface, a crank connected to said stem for rotating the same and extending along the oven, and a scale mounted on the oven and cooperating with said crank.

12. In a thermostatic device, the combination of heat responsive means, a valve, and a transmitting element between the valve and said 14. 'In a thermostatic device, the combination of heat responsive means, a valve, and a transmitting elementbetween the valve and said means through which element the means actuates the valve, said element comprising a pair of parts relatively axially rotatable to vary their relative axial positions, the complete range of adjustment of said parts being effected within a full turn and further relative rotation causi said parts to be restored to their initial positions.

EDWARD L. FONSECA.

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