US2030932A - Control device - Google Patents

Description

Feb. 18, 1936. M. PERSONS CONTROL DEVICE Filed Oct. 17, 1952 2 Sheets-Sheet 1- J 1 MW 1 )4. M. W, M f, f a fiJ l w M M \j was vb m v flu y 1 W "I 1 H H 1 Mam/w w b- 13, 19364 L. M. PERSONS 2,030,932

CONTROL 15EvIcE Filed; Oct. 17, 1932 2 Sheets-Sheet 2 Patented Feb. 18, 1936 2,030,932

UNITED STATES PATENT OFFICE CONTROL DEVICE Lawrence M. Persons, Des Moines, Iowa, assignmto Penn'Electric Switch 00., Des Moines, Iowa,

a corporation of Iowa Application October 17, 1932, Serial No. 638,114 3 Claims. (Cl. 6023) An object of my invention is to provide a con- Figure 5 is a sectional view on the line 5-5 of trol device which is electroheat responsive and Figure 4. which is simple in construction and readily Figure 6 isa sectional view through my conadapted for a number of dififerent uses or instaltrol device showing it designed for an air com- 5 lations. pressor unloader valve; and

A further object is to provide a control device Figure 7 shows it applied to the intake valve for an actuating or control member of movable of an air compressor and operative to unload the character, the control device including an elecair compressor at the beginning of its operation. trio resistance wire so supported that expansion In Figure 1, I have shown a gas valve A and my 10 thereof caused by a. current of electricity passing electroheat responsive control device B associated 10 through the wire and consequently heating and therewith for automatically operating it, dependexpanding it will operate the control member, ing on the supply of current to the control dethus making it electroresponsive. vice. The valve A comprises a body Ill, an intake Still a further object is to provide an electric l2, an outlet l4 and a valve seat IS. A valve resistance wire associated with a spring urged member I8 is adapted to seat against the suit Ii 15 control member so that upon energization of the and is carried by a control member which is wire, it will heat and expand and permit the slidably mounted and sealed relative to the valve spring to urge the control member toward movebody III by a diaphragm 22.

ment in one direction and will, when de-ener- On the valve body In, a base plate 24 is supzo gized, contract so as to move the control member ported and a housing 26 ismounted on the base 20 against the action of the spring thereon. plate for housing my electroheat responsive Still a further object is to provide a control mechanism. a device or heat motor which is electroresponsive The mechanism itself includes a support 2! and which develops considerable power as well as and a supporting bar 30 pivoted thereto by trunconsiderable movement in proportion to the acnions 32 extending into openings 34 of the sup- 35 tual longitudinal expansion of the resistance wire. port 28.

A further object is to provide an actuating de- The ends of the supporting bar are notched, vice which is electroheat responsive and which as indicated in Figure 3 and resistance wire supcan be readily applied to a variety of different ports 36 of cylindrical formation are asoclated 30 devices for controlling them such as gas, air comwith the ends of the bar 30. The supports 36 pressor unloader and air compressor intake valves are slotted, as indicated at 38, to receive the as well as relay switches and thelike. ends of the bar 30. Since the ends of the bar Still a further object is to provide a novel arare notched, lateral movement of the resistance range'ment and construction of parts for my conwire supports 36 relative to the bar 30 is ob- '35 trol device. viously prevented.

With these and other objects in view my in- The resistance wire supports 36 are grooved vention' consists in the construction,arrangement as indicated at 40 and a resistance wire 42 is and combination of the various parts of my decoiled aroundthe supports 36, thus having vice, whereby the objects contemplated-are att etch lying on pp Sides of 3.

40 tained, as hereinafter more fully set forth, pointbut p therefrome upp t are p ed out in my claims, and illustrated in the acof heat resisting insulation, to Prevent companymg drawings in which; short circuiting the successive turns of the re- Figure 1 is a vertical sectional view through a t. t fo t val e showin in control device associated Dun mgsa v g y bar so and the resistance wire 42 to be floatw v therewith and including snap acting mechanism interposed between the electroheat responsive like construction is pivoted at It carries an actuator and the movable gas valve parts. insulating rod 8 adapted to engage one stretch figure 2 horizontal sectmnal new 9D the of the coiled resistance wire II. The other stretch line of figure of the wire is engaged by a stationary insulat- Figure 3 is a perspective view of two, parts of mg rod and the yoke 4 is spring urged 111 my invention showing them separated from each one directionby prings 51 h causes th other to illustrate their manner of assembly. tr t h of th i 42 t be slightly bowed Figure 4 is a sectional v through a r lay ward each other, depending on the tightness or a it h with my control device connected thereto. the winding and the tension of the springs 52.; ll

ingly mounted. An actuating arm ll of yoke- A slot 48 is provided in each or the two side plates of the support 28 for the rod 48 to extend through. The slots 48 are curved on a radius from the pin 46.

5 If the normal position of the wire 42 is less bowed than shown in Figure 1, it will be obvious that when it is energized by a current of electricity, it will expandand the springs 52 will bow the'stretches thereof to the position oi! Figure 1. -Thus energization and de-energization of the wire is transformed into motion of the actuating arm 44. v

The arm 44 may be directly connected with some device which it is desired to control or 5 it may be connected therewith through snap acting mechanism as shown in Figure 1. The snap acting mechanism includes an arm 54 having pivot trlmnions 58, oscillatably mounted in perforations 51 of the support 28. The pivot go connection is similar to the one at 32-84. A spring 58 is provided for moving the lever 54 to opposite positions. The lever 54 is pivoted by trunnions 88 to the stem 28 of the valve l8 so as to snap it to open or closed position, depending on whether the wire 42 is energized or deenergized.

The stem 28 is provided with perforations 8i receiving the trunnions 88. The snap action is accomplished by the arm 44 moving the outer 30 end of the spring to a-point past a center line through'the trunnions 68 and 58 and the connection of the spring to the arm, whereupon the spring acts to complete the movement.-

The particular arrangement 01 the wire 42 whereby it is supported at spaced points-that is, by, the members 88 and spans the distance between them, provides for considerable actuating movement when the stretch or the wire isplaced under tension by a member which is adapted to move at right angles to the length of the stretch. Even the slightest expansive or contractive movement of the wire will be greatly'multiplied for moving the rod 48 and by pro-' viding a plurality of coils'for the wire 42, considerable power may be exerted.

As shown in Figure 4, the heat motor can be used for other purposes, a relay switch being shown. Some of the parts in this figure bear the same reference numerals as the parts in Fig- 50 ures l, 2, and 3. Additional parts are shown as will now be described.

The movable rod 48 is carried by a yoke 82 and a switch arm 64 is pivoted at 58. A pivot connection 88 is,provided between the yoke 82 5 and the. switch :arm 84 for moving ;the switch .arm in proportion to the movement of the rod '48.) The switch arm 'is constrained to move in direction by a spring 89 and carries a contact III for engagement with a stationary con- 00 tact I2, V

' A construction as shown in,Figure 4 is adapted for relay work, the resistance wire 42 when energized and. thereby. expanded, permitting the relay switch arm 84 and its contact 18 65 40 be, moved to the dotted line position by the spring 88. When the wire is deenergized, it

contracts and opens the contacts against the tension otthe spring. Figure 4 illustrates how expansion oi! the wire 42 can 'permit the movable bar to recede from the stationary bar 58 instead'oi advance toward it. v I

I find that a heat motor of the character disclosed is quite efllcient as an operating device for an air compressor unloader valve. In Figure 6,

' an unloader valve C is shown having a valve seat I4 anda valve member T8 for coaction therewith. .The valve is connected in an outlet pipe I8 of an air compressor and is normally held open, as shown in Figure 6, when the compressor is at rest. When the compressor commences to 5 operate, however, current is supplied to the resistance wire 42, this current being controlledby a switch 82 which also controls a motor 84 for the air compressor 80.

Thus whenever the compressor starts, the wire 10 42 is energized.

Energization of the wire 42 causes it to expand and a valve stem 88 will travel upwardly urgedby a spring 81 as the expanding wire permits it. The upwardly traveling stem 88 will )5 permit the valve member 18 to move to closed position against the seat 14, the valve member being spring loaded to accomplish this.

With an air compressor valve operated by an electroheat responsive device, as disclosed in 20 Figure 6, an air compressor unloader-tank can be eliminated inasmuch as the valve 16 closes slowly so that the air compressor can get up to speed'bei'ore the valve is completely closed. The valve C thus unloads the compressor during the 6 initial period while it is getting up to speed, and is thereafter closed so that air pumped by the compressor 88 goes into the storage tank instead of to atmosphere through the valve 0.

In Figure '7, I have shown how my heat motor 0 can be applied to the intake valve 88 of an air compressor 80. The intake valve is normally closed by a spring 88. The resistance wire 42, when energized from the switch whichcontrols the air compressor, will permit normal action of 35 the intake valve 88. When the air compressor stops, however, because 01' de-energizing its motor, the resistance wire 42 will also be de-energized, causing it to contract and force the valve 88 away from its seat. 40

The valve 88 will then be in open position when the air compressor starts and due to slow heating up of the wire 42, it will not be permitted to close until after the air compressor has worked up'to full speed or at least nearly so. This permits 45 pulsation of. the, air through the intake valve, without pumping action, while speed is being attained, as the pumping action can occur only after the valve 88 is permitted by the wire 42 to close so that it can function.

It will be seen that my electroheat responsive device can be used in a number of ways. Although I have shown one form in which it may be constructed, considerable change can be made in the details of construction without departing 55 from the real spirit and purpose or my invention and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope. so

I'claim as my invention: 1. In an actuating device of the class described,

- a support, a control member movable relative thereto, means constraining said control member toward movement in one direction, a sup- 5 porting bar pivoted to said support and having ends of insulating material, an, electric resistance wire coiled around said ends and spanning the distance therebetween on each side 01- said supporting bar, said control member engaging the 70.

stretches of. said wire on one side ofsaid supporting bar and being retained in engagement therewith by saidmeans constraining it toward movement in a' direction toward the supporting bar and a stationary abutment engaging the out- 75 side of the stretches 01' said wire on the other side of said supporting bar.

- 2; An actuating device comprising an abutment, a movable control member, means constraining said movable control member to move with respect to said abutment and electroresponsive means comprising a supporting bar pivotally mounted, insulating elements having slots receiving the ends thereof and a resistance wire wound around said insulating elements and the stretches of said resistance wire intermediate said insulating elements engaging said abutment and said control member respectively.

3. An actuating device comprising an abutment, a movable control. member, means constraining said movable control member to move in one direction with respect to said abutment and electro-responsive means comprising a supporting bar, insulating elements carried by the ends of said supporting bar, a resistance wire wound around said insulating elements, the stretches of said resistance wire intermediate said insulating elements engaging said abutment and said control member respectively, said supporting bar being pivotally mounted intermediate said abutment and one of said insulating elements.

LAWRENCE M. PERSONS.

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