US2417219A

US2417219A - High side cutout unit for switches

Info

Publication number: US2417219A
Application number: US492679A
Authority: US
Inventors: Burton E Shaw
Original assignee: Penn Electric Switch Co
Current assignee: Penn Electric Switch Co
Priority date: 1943-06-29
Filing date: 1943-06-29
Publication date: 1947-03-11
Anticipated expiration: 1964-03-11

Description

March 11, 1947. a E SHAW 2,417,219

HIGH SIDE CUT-OUT UNIT FOR SWITCHES Filed June 29, 1943 Patented Max'. 11, 1947 HIGH SIDE CUTOUT UNIT FOR SWITCHES Burton E. Shaw, Bristol, Ind., assigner to Penn Electric Switch C0.,

tion of Iowa Goshen, Ind., a corpora- Application June 29, 1943, Serial No. 492,679

claims. 1

My present invention relates to an actuating unit such as one operated by high `pressure in a refrigerant line and effecting opening of a switch which is normally and otherwise controlled by changes in temperature or refrigerant pressure.

One object of the invention is to provide an actuating device of this general character which may be used in a variety of installations and which primarily comprises a unit having self contained pressure responsive means, an actuating lever operated thereby, a toggle spring for imparting snap action to the actuating lever, and an adjustable range spring for the actuating lever, which is adjustable while the unit is detached from a control switch or the like on which it is to be later installed.

Another object is to provide an actuating unit which may be installed on a control device when required, thus eliminating the necessity of the dealer stocking both control devices with the actuating unit and others without them.

A further object is to provide an actuating unit in which all the mechanism is mounted in a casing of substantially the size and shape of the usual bellows housing of a refrigerant motor control switch, such casing being readily attached as by iour screws to the housing of a control switch in position for an actuating lever thereof to project into the housing and operate the main switch therein to ofi position upon an undesirable condition occurring, such as excessive pressure on the high side of the refrigerant compressor.

Still a further object is to provide an actuating unit having range adjusting means which can be adjusted while the unit is detached from a switch housing and thereby preset at the factory, so that it is merely necessary to attach it to the control device when a control device with the unit is desired for sale by the dealer, the unit having a range indicating scale and means to adjust a toggle spring and the range spring from the exterior of the unit casing.

With these and other objects in view, the invention resides in certain improvements and in a combination of parts of the device, all as will hereinafter more fully be described and the novel features will be pointed out in the claims appended to the application.

In the accompanying drawings:

Figure 1 is a front elevation of a switch such as shown in the application of Harold L. Hawthorn, Serial No. 492,678, filed June 29, 1943, with my high pressure cut-out unit mounted thereon;

(o1. o-s3) Figure 2 is an enlarged plan view of the cutout unit, omitting an actuating arm thereof;

Figure 3 is a vertical sectional view through the unit and looking upward in relation to Fig- 5 ure 2, and

Figure 4 is another vertical sectional View of the unit and looking toward the left in Figure 3.

On the accompanying drawing, I have used the reference numeral I0 to indicate generally a switch housing, from which the cover has been omitted. The housing Ill, as shown, has a back plate and bottom and top plates I2 and I4. A bracket I6 is mounted in the housing lil and carries a pivot pin i8. Pivoted on the pin E8 is an actuating lever 2Q having an extension 22. For automatically moving the lever 20 and its extension 22 in response to a condition such as refrigerant pressure, I provide a bellows 24 opposed by a range spring 2B. The bellows 24 is contained in a housing 28 with which a pressure connection can be made at a tting 3D. Secured to the head of the bellows is an operating stem 32 engaging the lower side of a pin 34 carried by the lever 20. Engaging the upper side of the pin is an end washer 36 for the lower end of the Spring 26. An end washer 38 is provided for the upper end of the spring and it is nonrotatable relative to an adjusting screw 40, in the usual manner.

The lever 20 and its extension 22 are adapted to actuate a switch arm 42 through toggle spring and link mechanism, fully described in said Haw- 'thorn application. This connection briefly includes a toggle lever 44 pivoted at V points 46 and connected by a toggle spring 48 to the lever extension 22, the lever 44 being connected by a toggle link 50 to the lower end of the switch arm 42, the upper end of the switch arm being pivoted at 52. The switch arm 42 carries a movable bridging contact 54 adapted to bridge a pair of stationary contacts 56. The bridging contact is mounted on a bar 58 extending loosely through the switch arm 42 and is urged in one direction relative thereto by a spring 60. The motion is limited by a pin 62. When the switch is in closed position, it may be opened while the linkage 44-48-50 remains in closed circuit position by engaging an extension 64 of the bridging contact and pushing it toward the left, as will hereinafter appear.

My actuating unit comprises a casing 66 adapted to be secured to the lower wall I2 of the housing I 0 by four screws 68. These screws pass 55 upwardly through openings 'I0 formed in a ange annale "12 around the base of the housing lit and are threaded into the wall |2.

Within the casing 66 is a frame I4 secured to a wall of the casing 66 as by two screws 76. The frame 14 has a pair of ears 'I8 for supporting a pivot pin 80. The frame further has a bottom plate 82 provided with an embossed central part having therein a perforation 8d, as shown in Figure 4. A bellows housing 8B has a tting 83 extending through the opening 84 and the bellows housing is thereby mounted in position relative to the frame ld, a lock nut 90 being screwed on the fitting for this purpose.

Within the housing 86, I provide a bellows 92 which is relatively small because it need respond only to very high pressures. The bellows has an actuating stem 94 extended out of the upper end of the housing 86.

An actuating lever in the form-of a plate 96 is pivoted to the pin 80, the plate having perforated ears 98 for this purpose. The plate 95 further has a plurality of flanges |00, |02, |04 and |06. The ange |06 is adapted to contact the upper end oi the bellows stem 9d, and to effect such contact a range spring |08 is provided. The upper end of the range spring is connected to the plate 9E and the lower end is mounted on a plug H0. An adjusting screw ||2 is threaded in the plug and passes through an opening ||l in the plate 82, the screw having' outside of the opening a slotted need llt. "he casing 66 has an opening IIS to receive the head and permit free rotation thereof. v

The plug |||l has an extension terminating in a pointer |22. The pointer |22 travels in a slot |20 of the casing l0 back of a transparent window |20. Suitable indicia are provided for cooperation with the pointer |22 to indicate the pressure at which the lever 96 will be moved to cut-out position, as shown in Figure 1.

For operating the lever 96 with snap action and to have a wide diiferential lfor its operation, so that alter high side cut-out occurs, cutin will not be permitted again until there is a substantial reduction in pressure in the bellows housing 86, I provide a toggle or over-center spring |20. Its ends are capped as at. and |32, the cap |30 engaging a knife edge lower end of the flange |02, and the cap |32 engaging an adjustable pivot |34. The pivot I3@ is threaded in the frame bottom plate 82 and there is an opening |36 in the casing 6B, permitting free rotation of the screw when adjusting it.

In Figure 3, I have shown a lever diagram for the over-center positions of the toggle spring |28. These are shown by dot and dash lines and the on position of the parts is shown in this figure. The off position corresponds to a center indicated by a black dot |38, where the pivot between the lower end of the flange |02 and the cap |30 occurs, after the high pressure cutout has operated to switch-onf position. The flange |02 is conned in a slot of the frame 'i4 having one side indicated at |40 and its other side indicated at |42. kThe sides |20 and |42 serve as stop surfaces for the flange |02 in the switch-on and switch-off positions of the actuating means.

The flange |04, when the actuating unit is mounted on the switch housing I0, extends upwardly through a slot |44 in the bottom wall I2, and an actuating arm |46, preferably of insulating material, is secured to the flange |06 by screws |48. The actuating lever is shown in the switch-on position in Figures 1 and 3, and it will be obvious that when it is rotated counterclockwise the arm |46 will swing toward the left at its upper end to engage the extension 64 of the bridging contact 54, thereby separating one of the movable contacts from one of the stationary contacts to break the circuit until such time as the pressure in the bellows housing 86 recedes to a value permitting the spring |08 to overcome the spring |38 and return the actuating unit to its normal position.

The arrangement of parts of my device is such that the entire unit is a sub-assembly that can be attached or not relative to a switch unit, depending on whether a high side pressure cutout is or is not desired. The device can be entirely fabricated and preadjust'ed at the factory, as it is unnecessary to have any cooperation between the unit and parts of the switch or control device to eifect the adjusting operation. At the same time, the device is capable of being readjusted in the field `as to range, the screw head IIB being accessible and upon rotation showing, by the pointer |22 just what the adjustment is by observance through the window |26. The diierential of operation can also be increased or decreased by moving the screw |34 up or down, respectively.

Some changes may be made in the construe tion and arrangement of the parts of my device without departing from the real spirit and purpose of 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 without sacrificing any of the advantages thereof,

I claim as my invention:

1. An actuating unit comprising a casing for attachment to a control housing, a frame in said casing, pressure responsive means within said casing `and having a threaded tting projecting through said frame and from said casing to the exterior thereof for attachment to a pressure line, a. lock nut on said fitting for mounting said pressure responsive means relative to said frame, an actuating lever pivoted to said frame, a range spring connected to said actuating lever and having an adjusting screw carried by said frame and projecting through said casing for operation from the exterior thereof, said range spring normally effecting engagement of said actuating lever with said pressure responsive means, and a toggle spring interposed between said actuating lever and said frame to eiect snap action of said actuating lever, said actuating lever, said range spring, said adjusting screw and said toggle spring being all mounted within said casing.

2. An actuating unit comprising a casing for attachment to a control housing, a frame in said casing, pressure responsive means mounted on said frame, an actuating lever pivoted to saidu frame, toggle means to effect snap action of said other.

An actuating unit comprising a casing for attachment to a control housing, a frame in said casing secured to one wall thereof, pressure responsive means mounted on said frame and having a tting projecting from said casing, thru said frame and to the exterior of said casing for attachment to a pressure line, a retainer coacting with said tting and said frame to retain the fitting and said pressure responsive means assembled relative to said frame, an actuating lever pivoted to said frame, a range spring connected to said actuating lever, said range spring normally eiecting engagement of said actuating lever with said pressure responsive means, and toggle means to elect snap action of said actuating lever said pressure responsive means, said actuating lever, said range spring and said toggle means being located within said casing.

4. An actuating unit of the character described for a control device having a housing, said unit comprising a cup-like casing for direct attachment to the housing, pressure operated means comprising a bellows and a chamber therefor, an actuating element controlled by said pressure operated means and extending from said casing and into said housing for engaging said device upon operation of said pressure operated means, said actuating element including a bell crank having one arm engageable with said bellows, a spring connected with said arm to effect such engagement, said spring and the other arm of said bell crank extending substantially parallel to said chamber, and toggle spring mechanism aligned with said other arm of said bell crank for imparting snap action to said actu- Number ating element, said bellows, its chamber, said spring and said toggle spring mechanism being all located within said cup-like casing.

5. In an actuating unit, a casing for attachment to a housing of a control device, frame in said casing, pressure responsive means in said casing and carried by said frame, an actuating element pivoted to said frame within said casing and projecting from the casing and into said housing for moving a controlling device therein to apredetermined position upon operation of said pressure responsive means, adjusting means within said casing and carried by said frame for adjusting the range of operation of said pressure responsive means, said adjustment means having a, manually actuatable part projecting to the exterior of said casing, and a tting for connection with .said pressure responsive means, said fitting being carried by said frame whereby the frame, the pressure responsive means, the actuating element and the adjusting means form a unitary structure independent of said casing.

BURTON E. SHAW.

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

UNITED STATES PATENTS Name Date 2.080,169 2,292,214

Dillman May 11, 1937 Dillman Aug. 4, 1942 Schaefer Dec. 27, 1938