US2541410A

US2541410A - Gas burner safety control

Info

Publication number: US2541410A
Application number: US769082A
Authority: US
Inventors: Albert H Crone; Robert C Mclaughlin
Original assignee: Geo D Roper Corp
Current assignee: Geo D Roper Corp
Priority date: 1947-08-18
Filing date: 1947-08-18
Publication date: 1951-02-13
Anticipated expiration: 1968-02-13

Description

Feb. 13, A, H, CRONE ErAL 2,541,410

' Y GAS BURNER SAFETY CONTROL Filed Aug. 18, 1947 2 Sheets-Sheet l q zu :L 65 f' f- 45 6 s .5/ 54 55 55 6o 5a 42 67 Arne.

Feb. 13, 1951 A, H, CRONE mL 2,541,410

GAS BURNER SAFETY CONTROL Filed Aug. 18, 1947 2 Sheets-Sheet 2 haii 1| I Patented Feb. 13, 1951 GAS BURNER SAFETY CONTROL Albert H. Crone and Robert C. McLaughlin, Rockford, Ill., assignors to Geo. D. Roper Corporation, Rockford, Ill., a corporation of Illinois Application August 18, 1947, Serial No. 769,082

8 Claims.

siderable interconnecting tubing. For example,

When the main control Was in the form of an oven control, the oven control unit has been accessible from the front of the gas range whereas the reset cooking type safety mechanism has been disposed at a relatively inaccessible location in the gas range whi-ch required the removal ofplates, burners or the like before the latter could be reset in the event of pilot failure. As pointed out this construction has required the use of considerable tubing to effect connections. tion inherently introduces pressure drops in the gas system and results in a bulky control system.

Accordingly, one of the objects of our invention is to provide a control unit that combines the features of a main burner control unit and a cocking type safety control mechanism into a single compact unit in which the manual control means for actuating the unit are readily accessible to the user of the gas range.

Another object of the invention is to provide a control unit of the above character which can be connected directly to a gas manifold.

Another object of the invention is to provide a control unit of the above character which requires a minimum amount of space, which is rugged, and which is positive in its action.

Another object of the invention is to provide a control unit of the above character with a pilot burner control adjustment incorporated in the control unit so as to be accessible from-the front of the range.

Another object oi the invention is to provide a control unit of the above character with means wherein a 100% shut off of gas to all burners. main burners as well as pilot burners, in the controlled system is assured in the event of a pilot burner failure.

Heretofore in some control systems the main burner has been frequently controlled by a clock operated valve, in addition to the main control valve and the safety valve. In such instances the clock valve included a safety valve. Consequently anl object of the present invention is to construct Such a construc-` 2 a main burner control unit that effects shut oil of all gas to the burners so that all auxiliary safety valves may be omitted from the control system.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which- Figure 1 is a side elevational view of a control unit embodying our invention, with a cutaway portion;

Fig. 2 is an enlarged fragmentary view similar to Figure 1 with the parts in a different position;

Fig. 3 is similar to Fig. 2 with the parts in a still diilerent position;

Fig. 4 is a perspective view showing the control unit connected in an oven burner system;

Fig. 5 is a sectional view of a modification of our invention;

Fig. 6 is a view similar to Fig. 5 with the parts in a different relation;

Fig. 7 is a view similar to Fig. 6 with the parts in a still different relation;

Fig. 8 is a View substantially along the line 8-8 of Fig. 5; and

Fig. 9 is a sectional View taken along the line 9 9 of Fig. 8.

Our invention is concerned with a novel control -unit Il for gas burners and the like that requires a minimum of space, that minimizes the number of separate parts and interconnected parts required to control a main gas burner and an associated pilot burner and that can be utilized with any main burner and pilot burner while at the same time positively insuring a 100% shut off of gas to all burners in the event of failure of the pilot burner. For purposes of illustration, our invention is shown embodied in an oven burner control system. In this system (see Fig. 4), raw gas is supplied from a gas manifold I2 and flows to the oven burner I3 through the control unit I|, a gas tubing I4 connected to the control unitll and a mixing tube I5 in direct communication with the oven burner I3. The flow of gas to the oven burner is initially determined for a given oven heat requirement by adjusting a manually operated knob or dial I6 extending outwardly from the control unit. Thereafter the ow of gas to the oven burner for any oven setting is controlled by a thermoresponsive means disposed in the control unit (not shown). A thermobulb I'I disposed at a suitable location in the oven is connected to the control unit by a capillary tube I8 and reflects the heat condition of the oven to the thermoresponsive means in 'the control unit. The oven burner is normally lighted by a pilot burner I9 spaced in juxtaposed relation to the oven burner and connected to the control unit II by a tube 2I. As shown in Fig. 4 a clock operated valve 22 is disposed in the tubing I4 for the purpose of controlling the ignition of the oven burner at a predetermined time.

As shown in Figure 1 the control unit comprises a casing 23 formed by an upper part 23a and a lower part 23h removably secured to the upper part as by bolts 24 extending through the upper part 23a and threaded into the lower part 23h. Herein to prevent gas leakage a suitable gas sealing gasket 20 is disposed between the respective parts. The upper part 23a of the casing houses the oven control mechanism of the control unit and the lower part 23h of the casing houses the safety control mechanism.

'In the present embodiment of the invention the upper part 23a is provided with a passageway 25 opening on a ilat machined surface forned on its underside and an outlet port 26 opening on a rear surface of the casing for connection by a tube connector 21 to the tube I4 leading to the oven burner I3. Disposed within the upper part 23a is a valve element (not shown) for controlling the flow of gas to the main burner I3. The valve element is actuated manually by a rotatable stem 28 extending forwardly of the casing 23 and shaped to project through a manitold cover plate 29 at the front of the gas range in a readily accessible position. 'I'he control knob or dial I6 is secured to the outer end of the stem 28 as by a set screw 32. The dial is calibrated in degrees of temperature so that any desired oven temperature can be'readily obtained. A'

spring 33 disposed between a bezel 34 abutting against the manifold plate 29 and the end wall 35 of a recess formed on the interior of the knob maintains the bezel 34 seated against the manifold plate 29. Conventional means is also included in the upper part 23a for insuring that the predetermined temperature in an oven is maintained after the burner has been initially ignited.

Herein the lower part 23h of the casing 23 is formed with an inlet port 35 for direct connection to the manifold I2. To this end, the manifold is attened on one side and a ilange 36, threaded into the manifold I3, is secured to the part 23h, as by bolts 30 so that the passage in the flange is in register with the port 35. n the interior of the lower part of the casing 23, the port 35 is in communication with a generally horizontal passageway 31 leading to a vertical passageway 38 at the rear of the lower part oi the casing in communication with the chamber 39 disposed on a level below the horizontal passageway 31.

An outlet port 4I for connection to the vpilot burner I9 is formed at one side of the lower part 23h of the casing and is in communication with a chamber 42 formed in the lower part 23h adjacent the chamber 39 and below the passageway 31. A conventional disc valve element 43 movable between extreme positions, seats in its normal closed position against an annular seat 44 about the mouth of the chamber 42 to separate the chamber 39 from the chamber 42 and prevents the ilow of gas between the respective chambers. With this construction the gas pressure of the supply tends to seat the valve element in the closed position. Thus the valve element will not be aected by line surges and the like.

'cation with another .chamber 45 formed in the lower part 23h ofthe casing 23 beneath the Pssageway 31 and inl alignment with the-chambers 38 and 42 respectlvely.- The chamber 45 is in direct communication with the opening 25 formed in the upper part 23a of the casing. Herein the communication between the passageway 25 and the chamber 45 is established by a vertically extending tube 46 projecting through a wall 41 between the passageway 31 and the chamber'45, thai-passageway 31, and 'a wall 48 forming the upper wall of tle lower part 23h of the casing. It is important that the fit between the tube and the respective walls be a press ilt so as to prevent leakage of gas along the p iriphery of the tube. A valve element in the form of a conventional type disc valve 39 disposed in the chamber 45 for movement between extreme positions controls the ilow of gas from the chamber 42 to the chamber 45 and the tube 46 respectively. With the valve in its normal position the

chambers

42 and 45 are in direct communication with each other as shown in Figure l.

Actuation of the valve elements 43 and 49 is eiected by manual means extending outwardly from the lower part 23h of the casing 23 in spaced relation with the stem 28 utilized for controlling the valve in the upper part 23a of the casing. The manual operating means herein comprises a stem 5I slidably disposed in an elongated steinv guide 52 threaded into the forward end of a. recess which forms the chamber 45. The stem is of suilicient length so that it projects outwardly from the manifold cover plate 29 and it is readily accessible from the front of the gas range. At its inner' end the stem 5I extends through the valve disc 49 and is formed with a collar 53 for retaining the valve element 49 on the steh. The collar also forms an abutment for engaging the valve disc 49 for controlling the movement of the latter4 from one position to another in the chamber 45. A spring 53a linterposed between the bushing 52 and the valve element 49, urges the valve element to seat against the annular seat 50 formed about the opening of the chamber 42 adjacent the chamber 45. At its outer end the' stem 5I is threaded into a closed end of a sleeve member forming a cocking button 54. The sleeve member ts over an enlarged outer end ofthe stem guide 52 and is slidable relative thereto. A spring 55 disposed between the cocking button and an abutment 56 supported on the stem 5I in a recess formed in the enlarged outer end of the stem guide 52 maintains the Jocking button in an outer position as shown in Figure 1. The spring 55 exerts sucient force to normally seat the valved disc 49 against a gasket seat 51 encircling the stem 5I. The gasket seat is secured in position by a cap 58 fitting over an annular shoulder 60 formed on the inner end of the stem guide 52. The latter construction prevents leakage of gas along the stem 5I.

When the cocking button 54 is depressed as shown in Fig. 2, the stem 5I abuts the valve element 43 and moves the latter axially in the chamber 39 against the action of a spring 59. 'I'he latter is disposed between the valve element 43 and an end wall 6IA of a magnet housing 62 disposed in a cap 63 attached to the lower part 23h of the casing and forming the rear portion of the chamber 39. A stem 64 secured to the valve element 43 supports and guides the latter element in its movement in the chamber 39. On the end of the stem 64 disposed in the The chamber 42 is arranged to be in communi- 75 magnet housing 62, is formed a magnet keeper in the form of a disc 65. When the valve element and the stem 64 have been moved axially a sufcient distance the keeper 65 engages the legs 66 of a U-shaped magnet 61. The magnet is energized by coils 68 connected to a thermocouple 69 (see Fig. 4) associated with the pilot burner I9. Thus, when the pilot burner is ignited, the magnet 61 is energized and the keeper 65 engages the legs 66 to maintain the valve element 43 in the position shown in Figs. 2 and 3.

The operation of the control unit is apparent from the foregoing but may be summarized as broi1er control mechanism. Herein, this is effollows. As shown in Figure 1 the parts are in a normal position. The dial I6 controlling the position of the valve mechanism in the upper part 23a of the casing 23 may be set for any desired oven temperature or may b e in an ofi position. The valve element 43 is seated against seat 44 and gas is prevented from flowing to either the port 4| connected to the pilot burner I 9 or the port 26 connected to the main oven burner. To initially ignite the burner the cooking button 54 is depressed as shown in Fig. 2. This permits the valve element 49 to be moved axially to seat against the annular seat 56 and closes off the chamber 42 from the chamber 45. Concurrently, .valve element 43 is moved axially away from seat 44 so that gas is now permitted to flow from manifold I2 through the port 35, passageway 31, passageway 38,' chamber 39, chamber 42, through outlet port 4| to conduit 2| to the pilot burner I9. The pilot burner is then ignited and the cooking button 54 is held in for 10 or 15 seconds, long enough for the pilot burner to heat up the thermocouple 69 which energizes the coil 68 on the magnet 61. At a predetermined temperature the magnet 61 is energized suiiiciently to maintainthe Valve element 43 in the position shown in Fig. 2. Manual pressure on the cooking button 54 is removed and the spring 55 returns the cocking button to its original position. This causes the valve disc 49 to be moved away from the seat Y 50 and to be seated against the gasket seat 51.

Communication is then established between the chambers 42 and45 and gas is permitted to ow from the chamber 42, through the chamber 45, the tube 46, the passageway 25, to the oven control mechanism in the upper part 23a of the casing 23. If the oven control mechanism has been set for a predetermined temperature setting, the gas flows through the mechanism through the outlet port 26, the tubing I4, mixing chamber I5, to the burner I3, wherein the gas is ignited -by the pilot burner. If for any reason the pilot burner I9 fails, the thermocouple 69 cools ofi', the

magnet 61 becomes de-energized and the valve element 43 returns to position shown in Figure 1 by action of the spring 59 and stops the ow of gas to the pilot burner I9 and the oven burner I3, thereby assuring 100% shut oil.' of all gas.

Figs. 5, 6 and 7 show a modification of our in- 6 The latter passageway is in communication with a chamber |39 formed in the casing below the passageway |31. Disposed adjacent the latter chamber and beneath the horizontal passageway I31 is a chamber |45 in communication with the fected by a vertically extending tube |46 extendand the passageway |31, the passageway I31, and a wall |48 forming the upper wall of the lower part |23b of the casing |23.

which projects through the end wall of the magnet housing |6I to support a keeper I 65. The latl ter is engageable with legs |66 of a magnet |61 when the valve |43 is moved axially to the position shown in Figs. 6 and 7. The magnet is energized by coils |68 connected to a pilot burner thermocouple as described for the oven control system. The valve element |43 is actuated by a. mechanism very similar to that previously described and comprises a cooking button |54, a spring |55 for returning the cooking button to an initial .position, a stem |5| slidably disposed in a stem guide |52 threaded into the end of the recess forming the chamber |45. When the cocking button is depressed the stem moves the valve element I 43 to the right as shown in Figs. 6 and 7. The outlet port |4| for connection to the pilot burner is formed on one side of the casing |23 and 'is arranged to be in communication with the gas flowing through the lower part of the casing after it passes through the chamber |39. Herein the port |4| is in the form of an aperture in the wall |41 and'is in communication with the tube |46 intermediate the ends of the latter member. In operating this embodiment of the control unit the dial ||6 is first turned to an off position so that no gas iiows to the main burner. As shown in the normal position in Fig. 5 the valve |43 is seated against the seat |44 and gas is prevented from owing from the manifold |I2 to either the pilot burner port |4| or the tube |46. When the cocking button is depressed as shown in Fig. 6 the valve element |43 is moved axially.

vention. In this embodiment of our control unit thel upper part |23a of the casing |23 houses a broiler control mechanism actuated by a knob I|6 extending through the manifold plate |29. The lower part |231) of the casing |23 houses the safety control mechanism. An inlet port |35 formed in the lower part of casing |23 permits the casing to be directly connected to a gas manifold ||2 by a flange |36 threaded into the manifold and secured to the lower part |23b as by bolts |30. On the interior of the casing the port |35 is in communication with a horizontally extending passageway |31 in communication with a vertical passageway |38 at the rear oi. the casing |23.

This permits gas to flow from the manifold ||2 through the horizontal passageway I31, the vertical passageway |38, the chamber |39, the chamberv |65 is attracted to the legs |66 and thus the valve is retained in the open position shown in Fig. 6. Manual pressure is removed from the cocking button |54 and the spring |55 returns the cocking button to the position shown in Fig. 5. Upon failure of the pilot burner the coils |68 become dee-energized and the spring |59 returns the valve Il! to the position shown in Fig. which prevents the flow of all gas to the respective burners.

Provision is made in the control unit for adjusting the flow of gas to the pilot burner. For this purpose (see Figs. 8 and 9) an adjustment screw |10 is disposed with a suitable gas-tight t in an insert |1|, the latter being disposed in a horizontally extending recess |12 formed on one side of the lower part of the casing |23. At its inner end the adjustment screw |10 is formed with a chamber |14 in communication with an outlet port |15 in communication with a pilot burner tubing 2| such as shown in Fig. 4. Intermediate the ends of the screw the latter is provided with an elongated aperture |16 for eiecting communication between the port |4| and the chamber |14. By rotating the screw in the insert, the opening |16 in the screw is brought more or less into registry with the port as required to adjust the now of gas to the port |15. To prevent leakage of gas valong the periphery of the screw, a packing |11 is provided. The latter embraces the outer end of the screw adjacent the aperture |16 and is secured in place by a packing nut |18.

Fromthe aforegoing it is to be understood that our control unit can be universally vused with all types of burners and will positively assure 100% shut oi of gas ilowing to all burners controlled by our unit. It is also advantageous in that all manual adjustments for the respective controlled burners may be made quickly, easily, and conveniently from the front of the gas range without the necessity of first removing any part of the range. This latter construction is important in facilitating maintenance of the control unit. Another important feature of our control unit is that it is compact and requires the minimum amount of installation space since it has eliminated all extraneous tubings, couplings and t: tings which have heretofore been required in gas burner systems of the aforegoing character. Our construction also eliminates the necessity of auxiliary safety control mechanisms such vas formerly used on clock operated valves.

While we have shown several embodiments of our invention, it will be understood that we do not wish to be limited thereto since many modications may be made, and we therefore contemplate by the appended claims to cover any such modiications as fall within the true spirit and. scope of our invention.

We claim:

1. A control unit adapted to be connected to a front gas supply manifold behind a front manifold cover plate for controlling the ow of gas to a main gas burner and a pilot burner operatively associated with the main burner and having a thermocouple operatively associated therewith comprising a casing having an inlet port for direct connection to said gas manifold, a first outlet port for connection to the main' burner and a second outlet port disposed between said inletI port and said ilrst outlet port for connection to said pilot burner, valve means adjacent said outlet port for controlling the ilow of gas to said main burner, first manual means for controlling said valve means extending outwardly from one side of said casing, a second valve means comprising spaced valve membersmovable between extreme positions for controlling the ilow of gas to said rst valve means and to said pilot burner, second manual means extending outwardly from the same side of the casing in spaced relation with said nrst manual means for moving the spaced valve members from a rst position wherein gas is prevented from flowing through said casing to a second extreme position wherein gas ows to said pilot burner andis prevented from ilowing to the nrst valve means, said rst manual means and saidsecond manual means and said inlet port being in alignment with said rst manual means on one side of said inlet port and said second manual means on the opposite side of said inlet port, said first manual means and said second manual means being in spaced relation to permit straddling of the gas manifold and to project through said cover plate, electromagnetic means adapted to be responsive to a predetermined temperature of the thermocouple adjacent said pilot burner for holding one of said valve members in said second extreme position,

and means for returning said other valve member to said first position after release of pressure to said second manual means whereby gas iiows to both said iirst valve means and said pilot burner. 2. A control unit adapted to be directly connected to a front gas supply manifold for controlling the now of gas to a main gas burner and an associated pilot burner comprising, a casing having an inlet port arranged for direct connection to the gas manifold, an outlet port arranged to be connected to the gas burner and a second outlet port arranged to be connected to the pilot burner, a iirst valve means disposed adjacent said rst outlet port for controlling the now of gas through said casing, first manual means for controlling said iirst valve means, a second valve means disposed adjacent said inlet port for controlling the ow of gas through said casing, said Second valve means in one position preventing the iiow of gas to said first valve means and said pilot burner and said second valve means in a second position permitting gas to ow to both said nrst valve means and said pilot burner and second manual means for controlling the second valve means, said first and second manual means projecting outwardly from the same side of the l casing and being spaced apart a distance to receive the' gas manifold therebetween and of sufcient length to extend through a front manifold cover plate to be independently accessible from the front of a gas range.

3. A control unit adapted to be directly connected to a gas supply manifold for controlling the flow of gas to a main gas burner and an associated pilot burner, comprising a casing having an inlet port arranged for direct connection to the gas manifold, an outlet port arranged to be connected to the gas burner and a second outlet port arranged to be connected to the pilot burner, valve means mounted on said casing accessible from the exterior for adjusting the flow of gas to said pilot burner, a rst valve means disposed adjacent said outlet port for controlling the iiow of gas through said casing, a second valve means disposed adjacent said inlet port and movable between extreme positions for controlling the flow of gas through said casing, said second valve means in one position preventing the iiow of gas to said main burner and said pilot burner and said second valve means in a second position permitting gas to ilow to both said first valve means and said pilot burner.

4. A control unit arranged for direct connection with a manifold disposed behind a front cover plate for controlling the iiow of gas to a main burner and a pilot burner adjacent the main burner for lighting the latter, comprising a casing having exhaust ports for connection to the main burner and the pilot burner, a main control connection to the gas manifold formed interme/ diate said upper and lower portions and a passage- Way effecting communication between the inlet port and the safety valve means, aivetically extending tubular portion passing vertically through and spaced from the sidewalls of said passageway to define a second passageway effecting communication between the safety valve means and the main control valve, rst manual means for controlling the main valve projecting outwardly from the casing on one side of the gas manifold and extending through said cover plate and second manual means for controlling the safety valve means projecting outwardly from the same side of the casing on the opposite side of the gas manifold and projecting through the cover plate in spaced relation to the first manual means.

5. A control unit arranged for direct mounting on a manifold disposed behind a front cover plate for controlling the flow of gas to a main burner and a pilot burner adjacent the main burner for lighting the latter, comprising a main control valve for controlling the ilow of gas to the main burner, safety valve means spaced from said main control valve to shut off the flow of gas to the main burner and the pilot burner upon failure of the pilot burner, means between said safety valve means and said main valve for interconnecting them as a unit having an inlet por-t intermediate the safety valve and the main valve for direct connection with the gas manifold, said means having a passageway effecting communication between the inlet port and the safety valve, a tubular member passing transversely through said passageway to denne a second passageway effecting communication between the safety. valve means and the main control valve, first manual means for controlling the main valve projecting outwardly from the casing on one side of the gas manifold and extendingv through said cover plate and second manual means for controlling the safety valve projecting outwardly from the same side of the casing on the opposite side of the gas manifold and projecting through the cover plate in spaced relation to the rst manual means.

6.- A control unit arranged for direct connection with a manifold disposed behind a front cover plate for controlling the flow 0f gas to a main burner and a pilot burner adjacent the main burner for lighting the latter, comprising a casing having exhaust ports for connection to the main burner and the pilot burner, a main control valve disposed in the upper portion of the casing for controlling the lflow of gas to the main burner, safety valve means disposed in the lower portion operative to shut off the flow of gas to the pilot burner and main burner upon failure of the pilot burner, said casing having an inlet port for direct connection to the gas manifold formed intermediate said upper and lower portions and a passageway extending from said inlet port downwardly to said safety valve means, said casing having a vertically extending passageway effecting communication between the safety valve means and the main control valve, first manual means for controlling the main Valve projecting outwardly from the casing on one side of the gas manifold and extending through said cover plate and second manual means for controlling the safety valve means projecting outwardly from the same side of the casing on the opposite side of the gas manifold and projecting through the cover plate in spaced relation to the first manual means.

7. A control unit arranged for direct connection with a manifold disposed behind a front cover vplate for controlling the flow of gas to a main burner and a pilot burner adjacent the main burner for lighting the latter, comprising a casing having exhaust ports for connection to the main burner and the pilot burner, a main control valve disposed in one end portion of the casing for controlling the flow of gas to the main burner, safety valve means disposed in the opposite end portion operable to shut off the ow of gas to the pilot burner and main burner upon failure of the pilot burner, said casing having a plane surface on one side and an inlet port opening on said surface for direct connection to the gas manifold, said casing having a passageway extending from said inlet port to said safety valve means and a passageway effecting communication between the safety valve means and the main control valve, first manual means for controlling the main valve projecting outwardly from one sdeof the casing in substantially perpendicular relation to said surface and adapted to extend through said cover plate to be accessible from the front thereof and second manual means for controlling the safety valve means projecting outwardly from the same side of the casing in spaced relation to said rst manual means and in substantially perpendicular relation to said surface and adapted to project through the cover plate to be accessible from the front thereof.

8. A control unit for a range or the like arranged for direct connection with a manifold disposed behind a front cover plate for controlling the flow of gas to a main burner and a pilot burner adjacent the main burner for lighting the latter, comprising a casing having exhaust ports for connection to the main burner and the pilot burner, a main control valve disposed in one end portion of the casing for controlling the flow of gas to the main burner, safety valve means disposed n the opposite end portion operable to shut off the flow of gas to the pilot burner and main burner upon failure of the pilot burner, said casing having an inlet port opening on one side thereof for direct connection to the gas manifold, said casing having a passageway extending from said inlet port to said safety valve means and a passageway effecting communication between the safety valve means and the main control Valve, first manual means for controlling the main valve projecting outwardly from one side of the casing and having its longitudinal axis in substantially parallel relation to the centerline of said inlet port, said first manual means being of sufficient length to extend through said cover plate to be accessible from the front of the range and second manual means for controlling the safety valve means projecting outwardly from the same side of the casing and having its longitudinal axis in substantially parallel relation to the centerline of said inlet port, said second manual means being in spaced relation to said rst manual means and oi' suicient length to project through the cover plate to be accessible from the front of the range.

ALBERT H. CRONE. ROBERT C. MCLAUGHLIN. (References on following page) 11 l2 REFERENCES CITED Number Nam Date d in t 2,201,399 Jackson May 21 1940 millet gsugwmgpatenferens are of recor he 2,253,670 Wetzel Aug. 26: 1941 2,257,024 Ray sept. 29, 1941 UNITED STATES PATENTS 5 2,297,854 Alfery mt, 6, 1942 Number Name Date 2,318,136 Alfery May 4, 1943 1,926,218 valmore sept. 12, 1933 2,372,537 Wantz Mar. 2'1. 1945