US2060994A - Thermostatic valve - Google Patents

Description

Nov 179 93@ @({NDERVATER 2,969,994

THERMOS TAT I C VALVE Filed April 20, 1935 a WGA:

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ATT RNEY Patented Nov. 17, 1936 UNITED STATES THERMO STATIC VALVE Julius Kindervater, Richmond, Va., assignor to American Locomotive Company, New York, N. Y., a corporation of New York Application April 20, 1935, Serial No. 17,470

1 Claim.

This invention relates to signalling devices and more particularly to devices for use in connection with steam generators to signal to the attendant when the water in the generator reaches 5 a predetermined low safety level in order that he may replenish the supply.

The main object of the invention is to provide a, signalling device employing a bellows-like thermostat operating part, the device being simple in construction, reliable and easy to maintain.

A further object is to provide a device of the character aforesaid which is easy tol dismantle to facilitate cleaning of the various parts when occasion requires.

A further object is the provision, in a device of the character aforesaid, of means for adjustment of the position of the bellows-like thermostat part for regulating the extent of the exrequiredbefore a signal can be given.

Other and further objects of and advantages achieved by the present invention will be apparent from the following description of a preferred embodiment of the invention.

While the signalling device of the present invention may be employed in general in connection with any fluid container wherein the contents thereof will, by temperature variations, effect expansion and contraction of the bellowslike thermostat operating part to effect respectively the producing and terminating of a signal, the device is however intended more -particularly for steam generators and principally for locomotive boilers which require a high degree of watchfulness to insure a sufficient supply of water, especially when the locomative is travelling on grades which throw the water to one end or the other of the boiler thereby lowering the water level at the opposite end.` Therefore in the present instance the device is shown in connection with a locomotive boiler. While this is done partly for convenience of illustration, the locomotive shown is of the frebox type, which taken vin combination forms part-of the present invention.

In the accompanying drawing Fig. 1 is a fragmentary diagrammatic side elevation of the rear end of a locomotive boiler showing two of the signal operating means applied thereto, and Fig. 2 is an enlarged longitudinal vertical central section of the signaling device shown in connection with a fragment'of the rear end of a locomotive boiler shown in longitudinal vertical section,

pansion of said bellows-like part that will be certain of the parts of the device being shown in elevation.

Referring in Adetail to the drawing, the locomotive boiler with which the device is illustrated is indicated by the reference A and is of the rebox type, including the usual rebox a., water and steam container b, crown sheet c separating the iirebox from the container, and back wall d separating the container from the cab (not shown), these being the only parts of the locomotive necessary to be described in the present instance. The Water level in the container is indicated at e and the space above is for the generated steam.

The signalling device comprises an encasing structure indicated generally by the numeral I, which for convenience is madein two parts. One part, conveniently termed the outer end portion of the structure, forms a valve casing 2 of the valve indicated generally by the numeral 3, later to be more fully described, and the other part, conveniently termed the inner end portion of the structure, forms a casing or support ,4, for a bellows-like thermostat operating part, later to be more fully described.

The two casings 2 and 4 ofthe encasing structure I, are secured together by a threaded plug and socket joint 5, and a cavity 6 is provided in one of the parts adjacent the other part, in the present instance in the casing 4 adjacent the casing 2, which cavity is filled with packing 'I which is held under compression to make a uidtight joint (for a purpose later to be noted), by the tightening together of the parts of the joint, a pressure plate 8 being interposed between the packing and the casing 2.

The valve casing 2 is formed With a diagonal wall 9 dividing the interior into two chambers I0 and II. The outer end wall of the casing 2 is provided with an opening. principally for the purpose of assembly. The Wall of the opening is threaded and engages the threaded end of a closing plug I2. The wall 9 has a centrally disposed vertical orificed portion in which orifice is formed a seat within the chamber I0 for a valve element I3, which is also disposed in the chamber I0.

The encasing structure I, packing l and plate 8 are provided with aligned bores connecting the two casings 2 and 4 and the plug I2 is provided with a socket opening into chamber I0, said socket and bores being in line with the orifice in the wall 9.

The valve element I3 is secured on a valve stem I4 having one end, conveniently termed the inner end, slidably fitting in said bores and having its opposite or outer end slidably fitting in said socket, a spring I5 being mounted on said outer end between the plug I2 and the valve element I3 for maintaining the valve element I3 normally in closed position and for automatically returning said valve element to closed position when opened, as will later appear.

A fluid controlled whistle I6 is connected with the chamber II, and a pipe I1 is connected with chamber I0 for connection with a supply of compressed fluid, as for instance compressed air which may be the usual compressed air supply of a locomotive for the various purposes for which compressed air is employed. The pressure of the fluid will, in an obvious and usual manner, operate the whistle to produce a signal when the valve element I3 is opened. The whistle may be of any usual or preferred construction operable by fluid pressure, and is vtherefore not further described in detail. As will later appear more than one signal operating means may be employed with but one signalling means, that is to say one whistle, in which instance another uid pipe, such as the pipe I1d will be employed, but where, as in the ordinary case, but one signalling device will be employed this second pipe I1d will not be needed, and therefore all connection thereof with the whistle will be eliminated.

The casing 4 provides a chamber I8 which is in communication with the interior of the container,

in the present instance the container b, and is normally lled with water from the container.'

The casing or support 4 is, as shown, preferably cylindrical in shape, the cylindrical wall I9 thereof being disposed horizontally and its outer end wall 20 forming a closure for the chamber I8 at this end. The inner end of the casing 4 is open and interiorly threaded. The wall I9 is provided with holes 2l which, though not essential, are desirable to facilitate cleaning the device.

A socket 22 is formed on the inner face of the wall 20. A bellows-like thermostat, indicated generally by the numeral 23, forming part of the control means for the signalling means, is housed within the chamber I8. This bellows-like thermostat part comprises a bellows proper 24 which may be of any usual or preferred construction, the specific construction forming no part of the present invention. The bellows-like thermostat operates in the manner usual with thermostats of this type, namely when suitably heated it expands longitudinally and when cooled it contracts longitudinally. In the present instance the interior of the bellows structure is sealed and is illled with a suitable gas or liquid,'which readily expands and contracts when subjected to increasing and decreasing temperatures, mercury being a suitable liquid often employed for such a purpose.

A stem 25 projects outwardly from the outer end of the bellows 24 and is engaged and supported by a sliding fit within the socket 22. A stem 26 projects inwardly from the inner end of the bellows 24 and is supported by a head 21 which is exteriorly threaded and screwed into' the inner open threaded end of the casing 4. Openings 28 are formed through the head 21 to afford communication between the container b and chamber I 8.

A threaded opening 29 is formed through the head in line with the stem 26 which is similarly threaded and screwed into the threaded opening, a slot 36 being provided in the end of the stem 26 for a screw-driver to facilitate screwing the stern into the head and for adjusting the stem and consequently the benows in a longitudinau direction fora purpose that will presently appear.

A lock screw 3| is screwed into the threaded opening 29 to bear tightly against the end of the stem 26 to securely lock the stem in its adjusted position. In some instances it may be desired not to thread the stem 26, in which case it will merely rest against and be supported by the screw 3|. The screw 3| will in;such case coact with the bellows-like thermostatpart and serve as an adjusting means for adjusting said part', in which case a second screw (not shown) should be employed to serve as a lock screw.

A hollow plug-like member 32 provides a houslng for the casing 4, the cylindrical wall I9 of this casing being housed within the hollow or bore of the plug-likemember. A circular flange 33 is formed on the casing 4 and bears against the outer end of the member 32, a sealing Washer 34 being interposed between said end and flange to provide a fluid-tight connection. The ends of the member 32 are exteriorly threaded and a nur, 35, provided with lugs 36 for the application thereto of a wrench, engages the outer surface of the flange 33 and is screwed on the outer end of the member 32 so that when the nut is screwed tightly home the casing 4 will be firmly held in place and provide a fluid-tight joint with the member 32.

The wall d is provided with a threaded opening f which engagesthe threaded inner end of the member 32. The joint thus provided may be further secured by welding (not shown) if desired. The member 32 is provided with a squared flange 31 for the application of a wrench. A vent pipe 38, while not deemed usually necessary, may be provided, if desired, connecting the upper part of the container with the chamber I8. The valve stem I4 projects into the chamber I8 in line with the stem 25.

The operation of the-device is easily understood. It will be obvious that the valve stem I4 and the bellows stem 25 may be connected, in which case the bellows-like thermostat, when contracted, will positively draw the valve element to closed position, and in which case there will be no necessity for the automatic closing of the valve, such as by means of a preponderance of fluid pressure on the closing side of the valve, or by means of the spring as shown, in which case the stem 26 must be firmly anchored as shown. It is however believed desirable to make the closing of the valve automatic, as for instance by means ofthe closingspring as shown, in which case the head 21 need only serve as a support for the stem 26 (the threads on the stem not then being required) and the screw 3| serving to prevent the stem 26 from moving in a valve closing direction when the bellows-like thermostat is moving under expansion, and furtherserving to adjust the position of the thermostat as already explained.

Not only is it desirable to provide for automatic closing of the valve but it is further desirable that the valve stem I4 and the bellows stem 25 be made separate, the valve element and valve stern thereby constituting a control for the fluid employed in operating the signalling means and the bellows-like thermostat part providing an operating means for operating the valve or fluid control means. Furthermore by making the valve stem I4 and bellows stem 25 separate a slight space therebetween may be provided when the valve element is in closed position and the chamber I8 is lled with liquid, thus always insuring a sure closing of the valve when no signal is required. l

In locomotive practice it is well known that the crown sheet of the boiler of the flrebcx type (in the present instance the sheet c) is directly exposed to the dangerous iniluences of the heatingmedium employed for generating the steam. The boiler is purposely so constructed that the crown sheet will receive and transmit to the water in the container a maximum amount of heat from.

the heating-medium. Nevertheless the liquid in the container is relied upon to keep the temperature of the crown sheet down to a safe point; consequently there is a xed or predetermined minimum safety liquid level below which it would be dangerous to allow the liquid to fall. Obviously any liquid level above this minimum safety level is a safe level, and the signalling device of the present invention is tapped into the wall of the container at a position so that when the liquid reaches a relatively low but safe level, preferably a safety level somewhat above the minimum safety level, the liquid, which up to this point, has filled the chamber I8 will flow out of the chamber and be replaced by vapor.

The bellows-like thermostat part, in the preferred embodiment, is adjusted in a manner, as aforedescribed, so that when the chamber I8 is lled with liquid at maximum temperature the forward end of the stem 25 will just touch or preferably just clear the inner end of the valve stem l. It is obvious that when the chamber I8 fills with the generated vapor, which is of a higher temperature than the liquid, the increased heat imparted to the bellows-like thermostat part will `expand this part. This part being mounted, as previously described, to prevent its movement in a valve closing direction during said expansion, will laccordingly move in a valve opening direction and effect an opening of the valve element, thereby admitting fluid under pressure to the whistle to produce a signal. The attendant of the boiler is thus warned thatthe liquid has reached a low level making it advisable to replenish the supply. As soon as the supply is replenished the chamber it again fills with water upon the rising of the water level in the container. The bellows-like thermostat part being thereby brought in contact' with a cooler medium will accordingly cool and contract which will result in moving the stem 25 in a valve closing direction to its normal position, whereupon the spring, which is now free to react, effects an automatic closing of the valve element and consequently a termination of the signal.

Obviously the sensitiveness of the bellows-like thermostat part will depend upon the adjustment, that is to say the normal space allowed between the valve stem i@ and the stem 25.

Therefore in practice this space will be regulated to provide the best results.

A material advantage of the present invention resides in the ease with which the parts may be dismantled when it is desired to clean or repair them. While the parts are made preferably of non-rustable materials, the device will, nevertheless, require periodic cleaning, at which time all that is required is to unscrew the nut whereupon the entire encasing structure with its associated parts may be Withdrawn from the pluglike member 32 and thus be removed entirely from the boiler. To facilitate the assembling and disassembling of the encasing structure the casing d is preferably made a loose t, as shown, within the plug-like member.

While the device has been shown in the preferred embodiment with the parts, such as the encasing structure and interior associated parts, in a horizontal position, it is obvious that the entire device may be turned 90 degrees to a vertical position without departing in any way from the spirit of the invention. In this case the whistle which would then be horizontally disposed would preferably be connected to the valve casing by a right angle elbow, and likewise the plug-like member would be connected to the container wall by a right angle elbow. Or, instead of the right angle connection to the container, the inner end of the plug-like member may be entirely closed by a cap and the plug-like member may then be connected with the container by straight horizontal pipe couplings tapped into the member at or near the top and bottom thereof in a usual and well-known manner.

Referring more particularly to Fig. 1, it may be desirable, in certain cases, to employ two signal operating means, as for instance in a locomotive boiler where, when the locomotive enters a grade, the water level is instantaneously materially lowered at the high point of the boiler. Obviously two complete devices may be employed in such cases, but Fig. 1 illustrates a way of providing for this by providing a single whistle I6 and two signal operating means.

As shown both signal operating means are similar in all respects, one, denoted by the reference B, being mountedon the back end of the boiler, similar to that shown in Fig. 2, where the whistle is employed, within the cab (not shown) of the locomotive, and the other, denoted by the reference C, being connected through the side of the boiler with the interior thereof at a suitabledistance above and slightly in advance of the front end of the crown sheet c.

Each of the signal operatin-g means B and C is provided with a compressed air feed pipe il similar to the feed pipe shown in Fig. 2. The feed pipes l 'l-,ll' are connected by branches llaila to a common feed pipe llb, provided with a contr'ol valve llc, which leads from a common supply of compressed air.

Instead of the signal operating means C being equipped with a separate Whistle, the whistle connection thereof is employed for the connection to said signal operating means of a pipe iid which extends to the whistle l and is connected as shown to the fluid connection connecting the signal operating means B with the whistle i6.

It will be readily understood that when the 1ocomotive is on a grade and thereby disposed at an angle, the more elevated signal operating means will be the one to effect the operating of the whistle should the water be sufficiently lowered relative to said signal operating means to permit the steam to enter and to thereby effect expansion of the bellows-like thermostat part. Regardless which of the signal operating means is affected the attendant'will know that the -Water has reached a level at some part of the boiler making it desirable to increase the supply of water.

While there has been hereinbefore described an approved embodiment of this invention, it will be understood that many and various changes and modiiications in form, arrangement of parts and details of construction thereof may be made without'departing from the spirit of the invention and that all such changes and modifications as fall within the scope of the appended claim are contemplated as a part of this invention.

The invention claimed and desired to be secured by Letters Patent is:

A device for moving the stem of a uid-controlling valve, comprising a casing having means at its outer end for securing thereto the housing of said valve and having an opening in said end for receiving said stem; means for sealing said opening and for permitting said stem to extend therethrough in sealed sliding engagement therewith for preventing egress and ingress of fluid from and to said casing; a thermostat member disposed in said casing, adapted for operable response to temperature diierences in the contents of a iluid container, having a oating end adapted for operable engagement with the end of said stem; a support in the opposite end of said casing for supporting the opposite end of said member; means for adjusting the position of said opposite end of said member in a direction longitudinally oi' said member relative to said support whereby said oating end of said member will be adjusted for positioning same relative to said end of said stem for operation of said valve by said member; a plug-like member adapted for attachment to a wall of said container, said plug-like member being hollow and said casing being housed therein; and detachable means for securing said casing to said plug-like member in fluidtight connection therewith, said device being provided with an opening for communication with said container for receiving fluid therefrom.

JULIUS KINDERVATER.

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