US1500259A - Thermostat - Google Patents

Description

A. J. OTTO THERMOSTAT July 8 1924.-

2 Sheets-Sheet. l

Filed June 18 Patented July 8, 1924.

UNI/TED STATES ARTHUR J. OTTO, OF 'MILWAUKEE WISCONSIN, ASSIGNOR TO JOHNSON SERVICE COM- PAT-ENT OFFICE.

PANY, OF MILWAUKEE, WISCONSLNQA CORPORATION 'AOF WISCONSIN.

THERMOSTAT.

Application filed June 18,

To all whom t may concern:

Be it known that I, ARTHUR J. O'r'ro, a citizen of the United States, residing at Mil- Waukee, in the county of Milwaukee and v State of Wisconsin, have invented certain new and useful Improvements' in Thermostats, of which the following is a speoification.

The present invention relates to automatic control of atmospheric conditions such as temperature, humidity and the like, and resides in certain structural improve` ments in automatic control devices of th ,pressure operated relay type. The chief object ofthe invention is to produce a compact device of simple and inexpensive construction, capable of precise and certain operation and constructedof metal throughout so as to avoid packed joints and leather and fabric diaphragms heretofore commonly used in this art.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in'which--- A Fig. 1 is a front elevation ofthe device with parts broken away to show the internal construction ;r

Fig. 2 is a vertical sectional viewf differ-i ent portions of the device being sectioned on different planes soas to, illustrate various of the ports and chambers; y

Fig. 3 is a section on the line 8 3 of Fig: 1; y

ig. 4 is a sectionvontheV line 4-4 of 85 Fi 1.

the drawings the usual cover or casing is omitted as it forms no partd of the invention. Y The body 6 of the instrument consists of a casting formed with certain portsxand chambers hereinafter described in detail. The general form is subject to some variation, but that illustrated in the drawing is` pr`e ferred because it is compact` and because the 4.5 ports canl be easily formed by drilling.

The front of the body 6 is rovided with.

a cover 7 which is held inv lace by screws in the usual manner. The joint between the cover 7 andthe body 6 is sealed by means of an interposed gasket 8 and this gasket is provided with apertures which. register with the communicating ports inthe body 6 and cover 7. The cover 7 closes the front 1923. serial No. saloni. A,

face of the relay motor chamber 9 formed inthe body 6.

The` body 6 is formed with a seat 10 dev Vsigned to fit and seal against a pipe head tting familiar to those skilled in the art, and

notshown in the drawings. This fitting is this construction the body 6 is properly connected to theelipes by merely mounting i' it on the pipe h To effect this result, the seat 10 is formed with a supply recess 11 from which the supply ports lead. One of these, the main motor supply port, is indicated at 12 and leads to the main inlet valve chamber 13. The main inlet valve 14 is mounted in this chamber and seats in the direction of flow to the relay motor chamber 9.v The valve 144 is guided by a combined valve guide and spring seat 15 which isthreaded into the valve chamber 13 from the rear of the body 6, and which is provided with a vsealing Hang? so as tomake a fluid tight 'oint with the ody. A spring 16 confine between the member 15 and the valve 14 urges the velve in a' eieeed direction. u will be 0bserved that a-portion of the valve projects into the relay motor chamber 9 far enough l to be engaged by a plate or lever actuator hereinafter described. e

from the supply recess 11 is' Also leading a relay supp y port 17 which discharges past a restricting needle valve 18 into a continuing port 2O alsov formed in the body 6.

The needle valve 18 is threaded into an vented by 'alse'aling plug l19 inthe usual v manner.

vaperture inthebody 6 andleakage is pre-'fil i The port 20in the body 6 leads through f anpaperture in the gasket 8 to 'a'port 21 formed in the coverl 7.

the cover a branch 22 which leads to the diaphragm chamber 23. This diaphragm chamber is enclosed by a flexible front wall 24 and a flexible rear wall 25 composed of light sheet metal` formed with annular v corrugations. The frontwall and rear'wall-are 'connected This port extends 1 across the covervand, has at the center of controlled by a transparent' Celluloid valve 29 which is carried by a responsive element 30 in the usual manner and which is so moved by'the response of the element 30 to changes in atmospheric condition as to seat against the end of the leak tube or move morefor less far from the same, thus producing a variable throttling effect on the outflow through the leak port.

-In the use of the device the needle valve 18 is so adjusted' that the -flow past it is less than the capacity of the port in the leak tube 28. From this it results that the variable throttlingof the leak p ort by the valve 29 produces a variable pressure in the diaphragm chamber 23. i

' The responsive element 3() is illustrated as consisting of a bi-metallic thermostatic bar. Any other responsive element such, for example, as a hygrostatic element mightHi be substituted and such substitution would commonly involve minor changes in the,l mounting of the element such as to enable it to produce the desired movement of the valve member 29.

In the example illustrated, the responsive element 30 is mounted on a saddle 31 which, 1s supported by horizontal pivot screwrsr 32 i, 6. hisl` carried by brackets on the bod j saddle is urged to rotate A on t ese pivot screws bythe springs 33 so as to seat against the end of an auxililary adjusting. Screw 3 4 which serves to x its position. The screw 34 is threaded through a main adjustmg screw 35 which carries an arcuate dial against which reads a combined index and detent spring 37.` The auxiliary adjusting screw 34 provides an initial adjustment by which the instrument is zeroed when installed. The user adjusts the res onse. of the instrument from time to time Iby turning the dial 36 and conse uently the screw 35. Adjustments so made are indicated on the dial-by the index 37 (see 'Fig'. 1).

Communicating with the rear of the'relay motor chamber 9 is an exhaust valve chamber 38 formed with an exhaust valve seat' 39. The exhaust valve 40 seats outward against the seat 39 and is guided by the exhaust valve guide 41 threaded into the'inner end of the chamber 38 and provided with ports Aforl the passage of air.- The exhaust valve 491s urged open by the exhaust valve spring 42 and is provided with a portion which extends through the guide 41 and projects into the relay motor chamber 9.

The exhaust valve spring 42 is weaker than the inlet'valve spring 16 and the two valves are actuated through a triangular actuator plate 43 by the movements of the diaphragm member. This plate 43 is suscentral bossl 45 by the diaphragm and is supported in opposition to this stress at three points, namely: on the pin 44, the valve 14 and the valve 40.

Since the spring 16 is stronger than hthe spring 42 pressure exerted by the diaphragm on the plate 43 will lirst close the'exhaust valve 40 and then open the'inlet valve 14. On reverse movement the inlet valve will close before the exhaust valve ispermitted to open, therefore, the device will operate to establish a pressure in the diaphragm motor chamber 9 which follows the pressure created Within the diaphragm chamber 23 through the varying throttling action of valve 29 as it is moved by the responsive element 30.

The pressure so created in the chamber I9 is transmitted to the controlled motor by the motor control port 46 vwhich leads from `the chamber 9 vto a recess 47 in the seat 10. As is understood, the recess 47 communicates with a` pipe connection in the pipe head heretofore described7 such connection leading to l 'plate v43 produces a sim le construction which gives the desired serlal action of the inlet and exhaust valves.

-' It will be observed that all ports are ac` cessible for inspection and repair and that their construction is such as to permit inexpensive manufacture.-

v What is claimed is:

1. In anl automatic control device, the

on through said lever mechanism, and to exert a predominant resistance on oneof said valves, vvhereby said valves are caused to open, one at a time by the lever mechanism in different positlons thereof and both valves are closed in 'an intermediate position; a diaphragm subject on one side to the pressure controlled b said valves, and arranged to actuate said lever mechanism; a responsive element arranged to control a iuid pressure acting against the `other side of said diaphra and means for subjecting a controlle device to the first named pressure. v v

2. In an automatic control device, the combination of independently movable inlet and exhaust valves, a lever mechanism constructed and arranged to balance an openingstress exerted thereby on one of said valves against a closing stress simultaneously exerted thereby on the other of said valves;

resilient means arranged to resist movements of the valves under the stresses exerted thereon through said lever mechanism, and to exert a predominant resistance on one of said valves, whereby said valves are caused to open, one at a time, by the lever mechanism in different positions thereof and both valves are closed in an intermediate position;

a metallic diaphragm motor arranged to actuate said lever mechanism and urged in one direction by the pressure controlled by said valves; a responsive element arranged to control a luld pressure urging said diaphragm motor in the opposite direction; and means for subjecting a controlled device to the first named pressure.

3. A control device com rising fixed structural parts providing a uid pressure supply passa eand a dehvery passage connected y a supp y port, and having an exhaust port connectin said delivery passage to atmosphere; va ves controlling said supply port and said exhaust port; unequal springs, the dominant spring urging said supply valve closed and the other spring urging said ex- `haust valve open; a bearing plate loosely engaging said valves and serving when moved 1n one direction to urge said valves simul-V taneously in op osition to their springs; an expansible mem er positioned to engage said plate and ymove it in the direction aforesaid; means for supplying and exhausting pressure iluid to operate said expansible member;

andan element responsive to changes in the medium to be controlled serving to control said supplyingand exhausting means.

In testimony whereof I have signed my name 'to this specification.

ARTHUR J. OTTO.

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