US2600271A

US2600271A - Pressure-responsive device

Info

Publication number: US2600271A
Application number: US755561A
Authority: US
Inventors: Schaevitz Herman
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-06-19
Filing date: 1947-06-19
Publication date: 1952-06-10
Anticipated expiration: 1969-06-10

Description

June 10, 1952 H. SCHAEVITZ PRESSURE RESPONSIVE DEVICE fry/m [Ye/"mm Jcaevz? ww- 02 222 .y W him w 1 L 2 w 7. 5 e m 7 I n a 1i; M2

Patented June 10, 1952 UNITED STATES PATENT OFFICE 2,600,271 PRESSURE-RESBONSIVE DEVICE Herman Schaevitz, Collingswood, N. J

Application June 19, 1947, Serial No. 755,561

This invention relates to pressure-responsive devices and more particularly to a novel device of this character which is adapted to be operated by fluid pressure and which is substantially unaffected by temperature changes.

A common form of fluid pressure-responsive devices is one which employs a bellows member or the like wherein the fluid pressure acts on a diaphragm at one end of said member to move the diaphragm against the resisting action of the bellows. Where differential pressures are involved, two opposed bellows may be interconnected and may be subjected to the different pressures respectively. Prior devices such as those mentioned, are generally subject to the objection that they tend to be actuated undesirably by ambient temperature changes and/or changes of temperature of the fluid.

One object of the present invention is to provide a device which is responsive only to pressure variations and is substantially immune to temperature variations. 7 1

Another object of the invention is to provide such a device of simple construction and which may be manufactured easily and economically.

Other objects of the invention will be apparent from the following detailed description.

In the accompanying drawing,

Fig. 1 is a longitudinal sectional view of a device constructed according to the present invention;

Fig. 2 is a transverse sectional view taken along line 22 of Fig. 1; and

Fig. 3 is a view, partly in elevation and partly in section, showing the application of the device for a difierent purpose than that illustrated in Fig. 1.

Referring first to Figs. 1 and 2, in the form of the device illustrated there is provided a cupshaped member I and an associated inclosure member 2 threadedly secured to member I as at 3. The two members I and 2 form a fluid chamber 4 to which fluid under pressure may be supplied through the tubular extension 5 on member I, said extension having threads 6 for attachment to a conduit or other means through which the pressurized fluid may be transmitted from a suitable source. The member 2, which constitutes a wall of chamber 4, is centrally apertured to accommodate the elements now to be described.

A pair of bellows members I and 8 have extended end portions 9 and Ill respectively which extend into the aperture of wall 2 and are supported by said wall, e. g. by a retaining ring II and by being soldered or otherwise secured to the Wall. The wall 2 is of increased thickness about 3 Claims. (Cl. 137-786) the aperture therein to provide a relatively wide circular portion I2 which cooperates with the ring II to retain the end portions of the bellows members. It will be noted that the bellows member 1 extends exteriorly of the chamber 4 while the bellows member 8 extends interiorly of said chamber. The bellows member 'I has a closed end I3 constituting a diaphragm, while the bellows member 8 has a generally similar end portion I4 which however, is apertured to admit the pressurized fluid into the otherwise closed chamber I5 formed by the two bellows members. As shown in Fig. 2, the diaphragm I4 preferably has a plurality of circularly arranged openings I8 so as to freely admit the pressurized fluid to the chamber I5. The two opposed diaphragms" I3 and I4 are interconnected by a rigid member I! extending axially of the chamber I 5. The member I! may be in the form of a metal rod which is substantially unafiected by any temperature changes that may be expected to occur. It is to be understood however, that the said member may be formed of any suitable material other than metal.

It will be seen from the description thus far, that the pressurized fluid is supplied to the chamber [5 within the bellows members, and such fluid is also'applied to the exterior of the bellows member 8 within the compartment 4. Hence it will be seen that the head or diaphragm I3 of bellows I will be moved by the fluid pressure against the resisting action of both bellows members. Thus when the fluid pressure increases, the diaphragm I3 is moved toward the left against the tensional resistance of bellows I and against the compressional resistance of bellows 8. The interconnected opposed bellows members may be likened to two springs and these two members effectively provide a double restoring force for the diaphragm I3. Any change in ambient temperature or in the temperature of the fluid will have no efiect upon the diaphragm I3 due to the rigid connection between it and the opposing diaphragm I4. Consequently, the diaphragm I3 will be moved only by pressure variations of the fluid supplied to the device.

The movement of the diaphragm I3 in response to pressure variations may be utilized for any desired purpose. In Fig. 1 there is shown an electrical pick-up which may be utilized to indicate the movements or position of diaphragm I3 by converting them to corresponding magnitudes of self inductance or mutual inductance. As illustrated, the electrical pick-up comprises a plurality of coils I8 wound on a support I9 which is secured to the wall member 2- by means of suitable fastening elements 20. A magnetic core 2| is mounted on the extended end of member I! and is movable within the coils l8 to create a varying magnetic field. A cover 22 serves to enclose the pick-up device and the bellows I, the said cover being engaged with the member 2. Wires which would be necessary to supply power to the coils and to carry the signals from the coils to the electrical indicator or controller are not shown since the necessity for these connections is understood by those familiar with the art.

Fig. 3 is intended merely to show that the device of this invention is applicable to a wide variety of uses. As illustrated, the device may serve to actuate an indicating device comprising a dial 23 and a pointer 24. The device of the present invention is represented generally at 25 and it serves to actuate a gear sector 26 which meshes with a pinion 21 within the indicating device. In this instance, the member I! is extended and is connected to the gear sector 26 by means of a link 28. Thus the device of this invention may serve as part of a pressure gauge which also includes the dial indicator shown in Fig. 3.

From the illustration of Fig. 1 it will be seen that the'device provided according to the invention is extremely simple in construction, and the parts. thereof may be produced at low cost and may be. easily assembled. Thus the invention provides a simple pressure-responsive device which is substantially immune to temperature variations and which also has thedouble restoring action above mentioned.

It is tobe understood, of course, that the inventionzis. not limited to the specific structure shown and furthermoreit is applicable to any use where it is desired to translate pressure variations into mechanical movements for any desiredpurpose.

I claim:

1. A pressure-responsive device, comprising a pair of opposed expansible and contractible members having substantial tensional and compressional, resistance and constructed and arranged ,to form a chamber, one of said members having at least one unrestricted opening therein to admit fluid freel to said chamber, means for supplyingfluid under pressure to said opening andvfor applying such fluid to both sides of said one member, said chamber being closed to fluids other than the aforementioned fluid, and a rigid connection between the ends of said members,

whereby the end of the other member is movable by the fluid pressure applied only to its interior against the resisting action of both members and is substantially unaffected by changes in ambient temperature or changes in the temperature of said fluid.

2. A pressure-responsive device, comprising a fluid chamber, means for supplying fluid under pressure to said chamber, said chamber having an opening in a wall thereof, a first resistive bellows member extending from said wall exteriorly of said chamber and being closed at its end, a second resistive bellows member'extending from said wall interiorly of said chamber and forming with said first bellows member an auxiliary chamber which extends through said opening, said second bellows member having openings in its end through which said auxiliary chamber freely communicates with said first chamber, said'chambers being closed to fluids other than the aforementioned fluid, and a rigid connection between the ends of said bellows members whereby the closed end of said first bellows member is movable in response to thepressure of said fluid against the resisting action of both of said bellows members and is substantially unaffected by changes in ambient temperature or changes in the temperature of said fluid.

3. A pressure-responsive device, comprising a generally cylindrical member forming a chamber and fixedly supported centrall of its ends and the oppositely-extending halves of which are longitudinally expansible and contractible and having substantial tensional and compressional resistance,- said chamber having at least one unrestricted opening to admit freely fluid under pressure, means for supplying fluid under pressure to said chamber through said opening and for applying such fluid to the exterior surfaces of the half of the member containing said opening, said chamber being closed to fluids other than the aforementioned fluid, and a rigid connection between-the ends of said member, where by the end of the closed half of said member is movable by the fluid pressure applied only to its interior surface and is substantially unaffected by changes in ambient temperature or changes in the temperature of said fluid.

HERMAN SCI-IAEVITZ.

REFERENCES CITED The, following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,301,301 Mallory Nov. 10, 1942 2,400,048 Jones May 7, 1946 2,497,255 Brown Feb. 14, 1950