US2139411A

US2139411A - Pressure regulator

Info

Publication number: US2139411A
Application number: US24139A
Authority: US
Inventors: Irving C Jennings
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-05-29
Filing date: 1935-05-29
Publication date: 1938-12-06
Anticipated expiration: 1955-12-06

Description

Patented Dec. 6, 1938 UNITED STATES PATENT OFFICE Application May 29,

3 Claims.

The object of thisl invention is to improve the operationl of the electric switch, which is used in connection with the diaphragm of a vacuum or pressure regulator. Inv such an apparatus, the

actuating fluid operates on the surface of a spring or weight pressed diaphragm which is connected to the switch, and the parts are arranged so that when certain pressures or vacuums are reached, the switch will be thrown to cut the operating means, usually an electrically driven pump, out of and into operation.

An electrical switch'must open with a snap action to prevent arcing and for this purpose the switch is usually provided with a mechanically acting snap or tip over mechanism. In

using such a vacuum pressure regulator, I havel half inch below an average of twenty-one and one-half inches, or within a range of one inch of mercury. With the old arrangement, the finest range of adjustment possible was three inches of mercury and, therefore, it was necessary to have the pump start in operation at twenty-one inches and to cut out, to pull a vacuum up to twenty-four inches, which with hot returns often caused the pump to run all the time.

I discovered that this diiiiculty can be overcome by removing-the mechanical snap action switch from an ordinary vacuum pressure regulator and-by substituting therefor a single tilting mercury switch operated from the diaphragm and adjusted so that the drag of the mercury against the electrode or electrodes, as well as the friction of the mercury in its containing ture, will cause a delayed action, which will effect a small but actual diierence in pressure between the on and oi positions of the switch and which will cause the switch to open with a snap action. With this arrangement I can easily control the on and on positions of the switch within the range of an inch of mercury.

One embodiment of the invention is illustrated in the accompanying sheet of drawings, in which:-

Fig. l is a sectional plan view of the improved apparatus.

Fig. 2 is a central sectional elevation, and

1935, Serial No. 24,139

Figs. 3 and 4 are partial sectional elevation to illustrate the peculiar action.

Referring to the drawing and in detail,' I0 designates a bottom plate, and II a cover plate, a diaphragm I2 being secured between IU and 5 II, andv these parts being held together by screws I3.

The actuating fluid is permitted to operate on the upper side of the diaphragm I2 through a coupling III) on the upper or cover plate Ii, 10 to which coupling a pipe can be connected.

Where the switch is to be used asa pressure regulator, the actuating iluid is admitted to act on the lower side of the diaphragm through a coupling IDG, illustrated in dotted lines in Fig. 16 2, attached to the plate I0, the largevent opening in which is then closed.

Upper and lower plates I5 and I4 are placed on the sides of the diaphragm I2 and held thereto by a screw I6 threadedinto a nut I1. A supplemental diaphragm I8 is placed on top of the cover plate vII and held in position thereon by a packing ring I9, a plate 22, and screws 2i, threaded into the plate 22.

A supplemental contact 23 having a pin 24 bears on the supplemental diaphragm I8 and through the same on the large nut I1.

An inverted U--shaped bracket 25 is held on the base 22 by screws 26. An operating spring 21 is housed in the bracket 25, the lower end of the spring being contained in a thrust block or cup 28 in which the pin 24 is fitted. A screw 29 extends down inside of the spring 21, the screw head being fitted in the top of the bracket 25 and having an integral collar 30 bearing against said bracket. The spring 2'I bears on a nut 32 threaded on the screw 29 so that by turning the screw the pressure of the spring can be adjusted.

A tilting plate 33 is pivoted by screws 34 to the sides of the bracket 25. The thrust block 28 is provided with arms 35 which are connected lby screws 36 to tilting plate 33. One side of the tilting plate 33 is extended, as at 31, and is provided with' a screw 38 having a check nut 39, the screw being set in position to engage the head of a pin 40 sli-ding in a bracket 3I on plate 22, a spring 4I being arranged on the pin 40.

lWhen the screw 38 is backed "away so that it can never come in contact with the plate 40 throughout the travel of the extension arm 31, the switch will open and close with aminimum diierence in pressure.

By adjusting the screw 38 so that it comes in contact with the plate 40 through a portion of the travel of the extension arm 31, the switch may be adjusted to open and close with a greater diiferential in pressure.

The tilting plate 33 is provided with an arm 42 carrying a clamp 43 held thereto by screw 44.

A mercury switch 45 is secured in said clamp 43. This mercury switch consists of a tube from which the air is exhausted and a globule of mer` cury M. One`or more electrodes 48 and 41 is or are sealed into the tube of the mercury switch 45 and suitable lead in wires 48 and 49 are connected thereto.

The parts` as thus far described can be adjusted to get a very delicate operation with the switch.

Assuming that the device is used as a vacuum pressure regulator, under the gures previously described, when the switch is closed the same will be in the position shown in Fig. 2. As the vacuum on top of the diaphragm I2 is increased, the atmospheric air pressure on the under side of said diaphragm will tilt the left hand end of the mercury switch 45 to its critical position,v as shown in Fig. 3. In this position the globule of mercury M will tend to run or flow to the right, but will be held from so doing by the relud ance of the mercury to move past the electrode or electrodes.

As the vacuum now slightly increases, the tendency of the mercury to flow by gravityto the right will overcome this resistance to iiow, and the mercury switch will move to its open position, as shown in Fig. 4.

Thus there will be a snap action of the parts between the position shown in Figs. 3 and 4. which is measured by the said retarding effect of the mercury. This factor of resistance to dow can be made much less than the extra pressure necessary to obtain the throw of the switch to overcome any mechanical snap mechanism. Therefore, the mechanism described provides a snap switch which can be very delicately adjusted.

I am aware that itis common to tilt a mercury switch by a fluid acting on a diaphragm, corrugated bellows or piston, but so i'ar as I am aware, the resistance to flow of a globule of mercury has never been employed as the sole means of providing for the necessary snap action.

,The details and arrangements herein described may be greatly varied by a skilled mechanic without departing from the scope of my invention as expressed in the appended claims.

Having thus fully described my invention, what I claim and desire to secure by Letters Patent is:-

,1. A pressure regulator comprising a diaphragm on the surface of which an actuating fluid operates, adjusting means for determining the pressure at which said diaphragm operates, and a tilting mercury switch mounted for movement under the influence of said diaphragm, means to cushion movement'of said switch, said mercury switch having an electrode positioned at a substantial angle to and in the path of flow of the mercury and positioned to offer an obstruction to such flow of mercury whereby adhes'on of the mercury to the electrode will in itself cause a delayed action of the switch followed by an actuation of the switch with a snap action.

2. A pressure regulator comprising a diaphragm on the surface of which an actuating uid operates, adjusting means for determining the pressure at which said diaphragm operates, a tilting plate connected to said diaphragm for direct actuation thereby, adjustable means to cushion downward movement of said tilting plate, and a tilting mercury switch mounted on said plate for movement therewith, said mercury switch having an electrode positioned at a substantial angle to and in the path of flow of the mercury and positioned to oier an obstruction to such flow of mercury whereby adherence of the mercury to the electrode will in itself cause a delayed action of the switch followed by an actuation ofI the switch with a snap action.

3. A pressure regulator comprising a diaphragm on the surface of which an actuating uid operates, adjusting means for determining the pressure at which said diaphragm operates, a tilting plate fulcrumed upon said diaphragm for direct actuation thereby, adjustable means located at one side of the fulcrum to cushion downward movement of said tilting plate, and a tilting mercury switch mounted on said plate at the opposite side of said fulcrum for movement with the plate, said mercury switch having an electrode positioned at a substantial angle to and in the path of iiow of the mercury and positioned to offer an obstruction to such flow of mercury whereby adherence of the mercury to the electrode will in itself cause a delayed action of the switch followed by an actuation of the switch with a snap action.

IRVING C. JENNINGS-