US3657501A

US3657501A - Pressure actuated device with concentric piston stem actuators

Info

Publication number: US3657501A
Application number: US91979A
Authority: US
Inventors: Harold R Hoyt
Original assignee: W E ANDERSON Inc
Current assignee: W E ANDERSON Inc
Priority date: 1970-11-23
Filing date: 1970-11-23
Publication date: 1972-04-18
Anticipated expiration: 1989-04-18

Abstract

A high proof pressure device for either opening or closing a number of electrical circuits in response to a wide range of changing fluid pressures is provided with a switch for each circuit controlled by a flexible sensor common to concentric, switch actuating piston stems, all contained within a single envelope which is not only tamper proof and explosion proof but capable of protecting its components from adverse weather conditions.

Description

United States Patent Hoyt 1451 Apr. 18, 1972 [54] PRESSURE ACTUATED DEVICE WITH 2,975,251 3/1961 Beller et a1 ..200/8l.4 x CONCENTRIC PISTON STEM 3,182,149 5/1965 Noakes ..200/83 s x ACTUATORS FOREIGN PATENTS OR APPLICATIONS [721 Invent Shawnee M Kans' 1,218,588 6/1966 Germany ..200/83 s [73] Assignee: W. E. Anderson, Inc.

Primary ExaminerRobert K. Schaefer [22] Elled' 1970 Assistant Examiner--Robert A. Vanderhye [2 1] Appl. No.: 91,979 Attorney-Schmidt, Johnson, Hovey & Williams 52 us. or ..200/81.4, 200/83 J, 200/83 s, [571 ABSTRACT 200/81-5 Ahigh proof pressure device for either opening or closing a [51] lnLCl ..H0lh35[34,H0|h 35/24 numb?r f electrical circuits in response to a wide range of [58] Fleld of Search ..200/83 W, 83 S, 83 SA, 83 J, h i fl id pressures is provided with a switch for each zoo/8L4 153 v cult controlled by a flexible sensor common to concentric, I 6 R f d switch actuating piston stems, all contained within a single en- [5 1 e erences velope which is not only tamper proof and explosion proof but UNITED STATES p capzhtle osf protecting its components from adverse weather I C011 1101'! 3,557,329 l/l97l Gorgens "200/83 S 2,982,830 5/1961 Schaefer et al ..200/83 J X 5 Claims, 6 Drawing Figures 1\\\\\ I [86 I I I a6 /4 I 20 f l I 54 22: :1 i o I 90 72 I 62 l I I 1 F .t

PRESSURE ACTUATED DEVICE WITH CONCENTRIC PISTON STEM ACTUATORS An important object of my present invention is to provide within a single housing, a number of circuit controlling electric switches, common to a single sensor such as a diaphragm that is sensitive to changing fluid pressures, and operably associated with a novel arrangement of switch actuating pistons.

Another important object of the instant invention is the provision of a simple, compact system of separate pistons, one for each switch respectively, and operable successively upon progressive changes in fluid pressures acting on the sensor.

Still another object of the present invention is to provide an accurate, easily adjusted high pressure range assembly of parts for transmitting movement of the pistons to the actuators of their respective switches.

A further object of my present invention is the provision in the aforementioned improvements of components that are capable of withstanding relatively high surge pressures to which the device. may be subjected when it is coupled in a system that subjects the sensor thereof to fluids under a wide range of varying pressures.

In the drawing:

FIG. 1 is a plan view of a pressure actuated device made in accordance with the present invention, parts being broken away to reveal details of construction;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 2;

FIG. 5 is a cross-sectional view taken on irregular line 5-5 of FIG. 2; and

FIG. 6 is a perspective view of one of the primary piston actuated levers illustrated in FIGS. 1-4 inclusive.

All of the components of the pressure actuated device illustrated in the drawing are contained within a single envelope or housing broadly designated by the numeral 10 which includes an intermediate tubular portion 12 constituting the main body of the housing 10, a cup-like cap 14 releasably attached to and closing one end of the body portion 12, a plug 16 removably mounted within the body 12 at its opposite end and a plate 18 releasably attached to the plug 16 exteriorly of the housing 10. A sensor in the nature of a flexible diaphragm 20 is clamped between the plug 16 and the plate 18 in sealing relationship thereto across a cavity 22 within the inner face of the plate 18, across a port 24 in the plate 18 and communicating with the cavity 22 and across a continuous seal 26 recessed within the inner face of plate 18 and surrounding the cavity 22, it being understood that the diaphragm 20 is clamped tightly against the seal 26.

A tubular fitting 28 screw threaded into the port 24 is adapted for connection to a fluid pressure line (not shown), thereby subjecting the diaphragm 20 to the fluid itself as the seal 26 and the sealing relationship of the diaphragm 20 to the plug 16 and plate 18 prevent such fluid from escaping the cavity 22 for flow into the housing 10 or flow from between the plug 16 and the plate 18.

All of the components contained in the housing 10 are either supported or guideddirectly or indirectly by the plug 16, certain of such components being mounted upon a panel 30 secured to the inner face of the plug 16 diametrically thereof and extending inwardly therefrom, terminating within the cap 14.

Plug 16 has a cavity 32 facing outwardly in opposed relationship to the cavity 22 and receiving a disk type piston 34 that is in turn provided with a tubular stem 36 which is reciprocable within and therefore guided by a central bore 38 in plug 16 and communicating with the cavity 32.

The outer face of the piston 34 has a recess 40 in opposed relationship to the stem 36 which receives a second disk like piston 42 which, as in the case of the piston 34, faces the diaphragm 20, and which is provided with a stem 44 that is reciprocable within and therefore guided by a bore 46 extending centrally through the stem 36.

A pair of

primary levers

48 and 50 for

stems

36 and 44 respectively extend diametrically across the inner face of the plug 16, the elongated bar-like lever 48 having a central hole 52, as best shown in FIG. 6, for clearing the stem 44. A washer 53 loosely surrounding the stem 44 is interposed between the proximal end of the stem 36 and a pair of protuberances 54, one on each side respectively of the hole 52.

Perforations

56 and 58 in the lever 48 receive bolts 60and 62 respectively that are mounted on the plug 16 and extend inwardly therefrom. A nut 64 on the bolt 62 and a similar nut (not shown) on the bolt 60 maintain the lever 48 spaced from the plug 16 and preclude spring 66 from pressing the piston 34 against the diaphragm 20.

Spring 66 is coiled on the bolt 62 between the lever 48 and an adjusting nut 68 on the bolt 62. A nut 70 on the bolt 60 holds the lever 48 in place but nut 70 is not drawn tightly against the lever 48 because the bolt 60, fitting loosely within the perforation 56, serves as a fulcrum for lever 48 as the latter swings toward and away from the nut 64 against the action of the spring 66.

The lever 50 which overlaps the lever 48 in crossed relationship thereto is likewise provided with a pair of spaced perforations comparable to the

perforations

56 and 58 receiving bolt 72 and bolt 74 respectively comparable to

bolts

60 and 62 respectively. A spring 76 coiled on the bolt 74 between adjusting nut 78 and lever 50 holds the latter against a spacer 80 between plug 16 and lever 50, the spacer 80 maintaining the lever 50 spaced from the lever 48 and preventing spring 78 from pressing the piston 42 against the diaphragm 20.

As in the case of the bolt 60, bolt 72 serves as a fulcrum for the lever 50, the latter of which is held in place on the bolt 72 by a nut 82. No central hole is provided in the lever 50 comparable to the hole 52, lever 50 instead being in direct alignment centrally thereof with the inner end of the stem 44.

Electric switches

84 and 86 corresponding to

levers

48 and 50 respectively are attached to the panel 30 on opposite sides of the latter, the pigtail conductors 88 from the

switches

84 and 86 passing from the housing 10 through a lateral stub conduit 90.

A pair of

secondary levers

92 and 94 corresponding to

switches

84 and 86 respectively have a common fulcrum pin 96 traversing the panel 30.

Levers

92 and 94 are provided with adjusting

bolts

96 and 98 respectively which bear against the

corresponding bars

48 and 50.

Panel 30 is provided with graduations 100 adjacent washer 102 on bolt 62 as an aid in determining the position of nut 68 in adjusting the tension of spring 66 and a similar arrangement (not shown) is provided on the opposite face of the panel 30 as an aid in the adjustment of nut 78.

OPERATION If the device is positioned as illustrated in the drawings, pistons 34 and 42 will rest on diaphragm 20, but only a slight amount of pressure in port 124 is needed to move stem 44 against lever 50 and washer 53 against protuberances 54.

When the outer face of the diaphragm 20 is subjected to a predetermined rise in fluid pressure within the fitting 28, the port 24 and the cavity 22, it flexes away from the latter, acting on the piston 34 to shift the stem 36 inwardly along the bore 38 until the piston 34 bottoms out in the cavity 32.

Stem 36, acting on lever 48, swings the latter about the fulcrum bolt 60 to shift the lever 48 along the bolt 62 against the action of spring 66. It is understood at this juncture that the fluid pressure required to effect this action is dependent upon the tension in spring 66 as adjusted through use of the nut 68, the setting being readily ascertained by observing the position of the washer 102 with respect to the graduations 100. This movement of the lever 48 is transmitted to the bolt 96 and therefore to the lever 92, thereby actuating the switch 84 so as to open or close an electric circuit.

As the pressure in fittings 28, port 24 and cavity 22 increases still further to another preselected level, diaphragm 20 shifts the piston 42 until it bottoms out in the recess 40, thereby moving the stem 44 within the bore 46 and with respect to the stem 36. Such inward movement of the stem 44 is transmitted to the lever 50 causing the latter to swing about the fulcrum bolt 72 and shift along the bolt 74 against the action of spring 76. The pressure required to effect this action is determined by the tension in the spring 76 as adjusted by nut 78.

The inward movement of the lever 58 is transmitted to the bolt 98 and therefore to the lever 94, actuating the switch 86 and thereby opening or closing a second electrical circuit.

Manifestly, precise spacing so as to assure depression and release of the actuating buttons of the

switches

84 and 86 during swinging of the

levers

48 and 50 and therefore swinging of the

corresponding levers

92 and 94 may be made by manipulation of the

bolts

96 and 98.

It is also important to note at this juncture that by virtue of the fact that the piston 42 bottoms out in the recess 40 and the piston 34 bottoms out in the cavity 32, surge pressures are resistedby the plug 16 so that the relatively high pressures will have no effect adversely upon any of the component parts of the pressure actuated device housed within the envelope 10.

There is presented therefore a highly sensitive instrument which senses two changes in pressure as to open or close the

electrical switching elements

84 and 86 when predetermined pressure points are reached. The device is of course adaptable for use with either normally open or normally closed switching elements and the setting may obviously be set for actuation at any desired point on either rising or falling pressures. The above explanation of settings to actuate on increasing pressures is therefore understood to be for illustrative purposes only.

in this connection then, while the adjustable range of the device is determined by the settings of the

nuts

68 and 78, such range can be increased or decreased still further by selections of

springs

66 and 76 capable of differing degrees of yieldable pressure on the

levers

48 and 50, all without adverse effect upon the diaphragm 20 because, as above mentioned, the pistons 34 and 42 remain freely movable when the fluid pressure is below the points of piston actuation.

Still another manner of changing the range of the device is to use pistons 34 and 42 of various sizes insofar as surface area is concerned, i.e., those areas thereof which face toward and are subjected to the action of diaphragm 20. This may be done with devices that have greater or smaller overall dimensions or by substituting the pistons 34 and 42 with other pistons wherein the relative sizes of such areas are chosen to meet required uses.

While in the embodiment chosen for illustration there is provided but two

switches

84 and 86 together with their corresponding actuating assemblies and a common diaphragm type of sensor 22, the principles herein disclosed may be followed to permit opening and closing of a multitude of switches within a single envelope, limited only by space requirements and choice of components such as to maintain reliability, accurateness, pressure ranges and other desired characteristics.

Having thus described the invention, what is claimed as new and desired to be secured by Letters patent is:

1. A pressure actuated device comprising:

a pair of levers each having a fulcrum about which the same moves;

resilient means for each lever respectively yieldably biasing the same toward one end of its path of travel;

a switch associated with each lever respectively for actuation by its lever upon movement of the latter toward the opposite end of said path of travel thereof; and

pressure sensitive structure for moving the levers to said opposite ends of their paths of travel,

said structure including a shiftable element for each lever respectively and a sensor common to the elements and adapted to shift the latter when the sensor is subjected to varying fluid pressures,

said resilient means yielding under different pressures exerted on said sensor, said elements being reciprocable along a common axis with one of the elements surrounding the other of said elements.

2. A pressure actuated device as claimed in claim 1, said levers being relatively overlapped, one of the levers having a clearance opening for the element of the other lever.

3. A pressure actuated device comprising:

a pair of elements 'reciprocable along a common axis with one of the elements surrounding the other of said elements;

a sensor common to the elements and adapted to shift the latter in one direction when the sensor is subjected to varying fluid pressures;

resilient means for each element respectively yieldably biasing the same in the opposite direction,

said resilient means yielding under different pressures exerted on said sensor; and

an electric switch for each element respectively disposed for actuation by the latter when shifted in said one direction.

4. A pressure actuated device as claimed in claim 3, each element having a piston engageable at one face thereof by said sensor, each piston being provided with an elongated stem extending from its opposite face, one of the stems having an external guide and a longitudinal bore concentric to and reciprocably receiving the other stem.

5. A pressure actuated device as claimed in claim 4, said one stem having a cavity in said one face thereof for receiving the piston of the other stem.

Claims

1. A pressure actuated device comprising: a pair of levers each having a fulcrum about which the same moves; resilient means for each lever respectively yieldably biasing the same toward one end of its path of travel; a switch associated with each lever respectively for actuation by its lever upon movement of the latter toward the opposite end of said path of travel thereof; and pressure sensitive structure for moving the levers to said opposite ends of their paths of travel, said structure including a shiftable element for each lever respectively and a sensor common to the elements and adapted to shift the latter when the sensor is subjected to varying fluid pressures, said resilient means yielding under different pressures exerted on said sensor, said elements being reciprocable along a common axis with one of the elements surrounding the other of said elements.

3. A pressure actuated device comprising: a pair of elements reciprocable along a common axis with one of the elements surrounding the other of said elements; a sensor common to the elements and adapted to shift the latter in one direction when the sensor is subjected to varying fluid pressures; resilient means for each element respectively yieldably biasing the same in the opposite direction, said resilient means yielding under different pressures exerted on said sensor; and an electric switch for each element respectively disposed for actuation by the latter when shifted in said one direction.