US1317951A - Thermostatic controlling mechanism for water-heaters. - Google Patents

Description

C. A.BACKSTROM.. -THERMOSTAUC CONTROLLING MECHANISM FOR WATER HEATERS.

APPLICATION HLLD SEPT. $3, 1915.

Patented Out. I, 1919.

i N N N N N N N N N UNEETED STATES PATENT @FFMEE.

CHARLES A. BACKSTROM, 0F GRAFTON, PENNSYLVANIA, ASSIGNOR T0 PITTSBURGl' WATER HEATER COMPANY, OF YITTSBURGH, PENNsYLVANIA, A CORPORATION OF NEW JERSEY.

THERMOSTATIC CONTROLLING MECHANISM FOR HATER-HEATERS.

To all whom it may concern:

Be it known that I, CHARLES A. BACK- s'rRoM a citizen of the United States, residing at Grafton, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Thermostatic Controlling Mechanism for lVater-l-leaters, of which the following is a specification.

The invention relates to thermostatic controlling means for water heaters of the storage or other types. objects; the provision of a thermostatic controlling means which will give rapid opening and closing movements of the gas valve and in which the periods of low burning are reduced to a minimum, it being well known that low burning is wasteful of gas and hard upon the burners; the provision of a simplified mechanism for accomplishing the result above stated in which the complication incident to the use of the so-called snap valve mechanism now in use is eliminated; and the provision of a thermostatic control which is sensitive and not liable to et out of adjustment. One embodiment of the invention is shown in the accompanying drawing, wherein- Figure 1 is a full sized section through the Controlling mechanism constituting my invention, certain of the other cooperating parts being shown diagramnnitically in dotted lineaFig. 2 is a sectional view show ing the ball valve in the position of fullest opening, and Fig. 3 is a view similar to that of Fig. 2, but with the valve partially closed, although stilladmitting a maximum flow of gas.

My invention depends in part upon the fact that the eli ect from a thermostatic element and its auxiliaries as used in a water heater is most rapid during the latter portion of its movements, and I so arrange my apparatus that the gas valve is affected by these means to open and close during the periods of rapid movement. To this end I so arrange the operating parts of the thermostatic means that on the opening opera tion a considerable movement thereof occurs before the gas valve is engaged, the opening of the valve after such engagement being comparatively rapid. Further, the parts are so arranged that in the opening movement Specification of Letters Patent.

Application filed September 13, 1915.

Ithas for its primary a part of the gas conduit.

racemes Get. '2'. late.

Serial No. 50,315.

of the valve such valve is moved oft its seat 'to a, distance greater than that required to give a maximum flow of gas to the burners, so that on the reverse movement of thermostatic parts the throttling of the gas does not commence until the valve is-partially closed and the thermostatic parts are well under way in their movement, the cutting oil of the gas thus being quickly accomplished after the actual throttling movement of the valve starts. In other words, I provide for an over travel of the thermostat with respect to the gas valve in both directions, thus giving periods of complete cut off after the closing movement, in addition to the quick action of the valve.

In the drawing, 1 is the casin which carries a part of the mechanism ant, constitutes 2 is the gas inlet and 3 is the outlet leading to the burner 4 beneath the shell 5 of the water container.

The thermostat consists of the usual cop per tube 6 projecting into the water container and carrying at its inner end the plug 7 against which the inner end of the porcelain rod 8 abuts, the other end of the tube 6 being screwed into the coupling 9 to which the casing 1 is attached. The left hand end of the rod 8 bears against. the slidable plug 10 in which is mounted the pin 11. From this it will be seen that as the temperature of the water in the heater rises the tube 6 will expand to the right and permit the parts 8, 10, and 11, to move to the right, and when the ten'iperature ot the water drops the tube 6 will contract and move the parts specified above to the left.

The controlling valve is in the form of a ball 12 held against its seat 13 by a spring 14, so that. when the valve is not otherwise acted upon it is yieldingly seated by gravity and by the force of the spring. Interposed between the valve and the operating pin 11 is the multiplying device consisting of the levers15 and 16 and the connecting link 17 to which the right hand ends of the levers are pivoted, these parts being supported upon the adjustable frame piece 18 having its left hand end fitting in the plug 19 and its right hand end 20 fitting in the coupling 9. The frame piece is held in position. in the plug 19 by means of the threaded rod 21. The plug is locked in position by v 3/16 inches.

means of the nut 22, the outer end of the plug being made in the form of a nut 23 so that it can be adjusted. The. pin 21 is locked in position by means of the thumb screw 24, and the extreme outer end of the pin carries a nut 25 which serves to lock the protecting cap 26 in position. The adjustment of the thermostat and the point of cut off is accomplished by the adjustment of the frame piece 18, The lever 16 is pivoted to the frame piece at 27, and the lever 15 at 28, such lever 15 being provided with an upturned end 29 adapted to engage the valve 12. A spring 30 bears against the end of the plug 10 and serves to move the plug and the porcelain rod 8 to the right as the tube 6 expands, thus relieving the spring 14 of this work.

Fig. 1 illustrates the relative position. of the valve and the end 29 after the valve has been closed and the lever 15 has moved to its lowest position. At this time the space 0 between the ball and end in the specific embodiment illustrated is approximately As the water cools incident to the cutting off of the gas supply the tube (3 contracts to the left, thus moving the end 29 upward, the multiplication incident to the use of the levers illustrated being about to 1. This upward moven'ient does not cause the unseating of the valve until the distance C has been traversed, and when the engagement of the end 29 with the valve actually occurs the movement is much more rapid than "at the beginning, and the valve is raised at a comparatively rapid rate. It Will also be noted that in the period before the engagement of the valve by the end the valve remains seated so that no low burning occurs during this period.

The upward movement of the valve is continued until it reaches the position indicated in Fig. 2, at which time the valve has moved upward the distance indicated at A, such distance in the present embodiment being )proxin'iately 3/16 inches. The opening a t us provided gives an admission area in excess of the carrying capacity of the gas conduit, so that the valve is open farther than is necessary in order to give the burners their maximum amount of gas. The amount of opening necessary to give the burners their maximum quantity of gas is illustrated at B in Fig. 3, the distance B being fi/li-l inches. The valve can therefore move from the position of Fig. 2 to the position of Fig. 3, a distance of T/Gt inches, without any throttling of the gas and without any low burning.

lVith the valve in the position of Fig. 2, the water soon reaches its maximum temperature and the tube 6 expands to the right, permitting the end 29 and the valve 12 to move down, such movement being caused by gravity and by the springs 14 and 30. By the time the valve 12 reaches the position of Fig. 3 the parts are moving rapidly, so that the movement of the valve from the position oi. Fig. 3 to the position of Fig. 1 occurs rapidly and the period of low burning is relatively short. 2

It will be seen from the foregoing that the arrangement provides for the rapid opening and closing of the "as valve, thus reducing the periods of low burning, and that there is a period of some length when the parts are moving from the position of Fig. 1 to a position in which the end 29 engages the valve, in which there is a complete cut off of the gas. The quick movement of the parts is further facilitated by the use of the spring 30 which takes the strainof moving the thermostatic parts oil' of the multiplyingdevice and the spring ll. The parts of the multiplying device can be made relatively light, which increases the sensitiveness. and the strain upon these parts is so slight that even with a large multiplication there is no tendency to gct out of adjustment. Other advantages incident to the construction will readily occur to those skilled in the art.

\Vhat I claim is:

In con'ibination in a heater having a water container and a gas burner, a gas supply conduit, a valve in the conduit, a thermostat, a multiplying device having its last element which operates the valve movable with the expansion and contraction of the thermostat parts and at a speed having a fixed ratio to that of said thermostat parts at all times, such element being arranged to move the valve in opening it to an extent greater than that necessary to give a capacity equal to that of the conduit, the valve being moved only during the latter part of the movement of the therniostatically controlled multiplying device, and being arranged, on its reverse mowmcnt, to effect no throttling of the gas during the first part of such reverse movement.

CHARLES A. BACKSTROM.

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