US2799751A - Electrical relay devices - Google Patents

Description

July 16, 1957 H- C. HAUSMANN ELECTRICAL RELAY DEVICES Filed June 1, 1956 United States Patent 6 ELECTRICAL RELAY DEVICES Henry C. Hausmann, Forest Hills, N. Y.

Application June 1, 1956, Serial No. 588,779

3 Claims. (Cl. 200-140) The present invention relates to electrical relays and more particularly to the type which is thermally actuated. A relay of this sort includes a heating element in one electrical circuit, herein referred to as the primary circuit, which when actuated, will operate a switching means controlling another circuit herein called the secondary circuit.

An object of this invention is to provide a novel and improved thermally-operated relay, affording delayed operation of the secondary circuit and if desired, the period of delay may be adjustable.

Another object thereof is to provide a novel and improved relay of the character mentioned, which'is quickacting to operate the switching means for the secondary circuit upon deactuation of the primary circuit.

A further object is to provide a novel and improved relay construction of the class set forth, aifording a constant delay interval for the operation of the switching means for the secondary circuit, regardless of changes in atmospheric temperature, so that operation is a constant in all climates onland, at all altitudes in the air and at all depths in the sea.

Still a further object thereof is to provide a' novel and improved relay device of the type and character described, which is eflficient in carrying out the purposes for which is is designed.

Other objects and advantages will become apparent as this disclosure proceeds.

For the practice of this invention, one form it may assume comprises a casing within which is an electrical heating element. The casing is provided with electromagnetically operated valve means. There is also a pressure-responsive switch which closes when the pressure within the casing reaches a given intensity. This switch controls the secondary circuit. The valve-operating electro-magnets and the heating element receive power simultaneously upon the closing of a switch controlling their circuit, which is herein called the primary circuit. A bi-1netal strip mounted on the exterior of the casing, cooperates with the operating element of the pressure-sensitive switch to adjust for changes in atmospheric temperature to maintain a constant delay between the closing of the switches regardless of atmospheric conditions. Means are also provided for adjustment of the delay interval. Inclusion of the said features to accomplish any of the mentioned adjustments, is optional.

I will now proceed with a detailed description of the embodiment shown herein and its mode of operation.

In the accompanying drawing forming part of this specification, similar characters of reference indicate corresponding parts in all the views.

Fig. l is a central longitudinal sectional view showing a relay device embodying the teachings of this invention. The electrical connections are shown by a diagrammatic wiring diagram.

Fig. 2 is a top plan view of the relay device per se.

Fig. 3 is a longitudinal sectional view of a valve member, drawn to an enlarged scale.

Fig. 4 is atop plan view'of Fig. 3'.

Fig. 5 is a modified embodiment showing the relay device per se within. a hermetically sealed casing which isfilled with an inert gas. This view is drawn to. a reduced scale.

In the embodiment of this invention shown in the drawings, the numeral 15- designates generally a dielectric casing housing an electrical heating element 16. The casinglhas two' normally opened valves indicated generally'by the numerals 1'7 and 18, which control its interior; such valves being electro-magnetically operated. by the electro- magnets 19 and 20 respectively. Said heating element 16 and the valve- closing magnets 19, 20. are in an electrical circuit, which is here called the primary circuit, powered by a current supply 21 and controlled by the switch 22'. Said magnets are shown mounted on the casing and it is preferred that-the valves 17, 18 shall be in staggered relation. Compression springs 23', 24 interposedv between the valve stems 17', 18 and their associated magnet'poles 19', 20 respectively, act to maintain the valves open when there is no current flowing in the primary circuit.

The numeral 23 denotes generally the secondary circui t' controlled. by a switching device comprising the spaced-fixed contact points 24, 25 which are bridged by the metal piece 26 carried on the spring-loaded piston 27'which is exposed in the casing 15, providing a cylinder 28therefor. The parts 24, 2'5, 26, 27, 28' and the spring 29, constitute the switching device controlling the secondary circuit 23, and is of course responsive to changes in pressure within the casing 15. Disregarding for the'moment th'e presence of the. bimetal strip 30, the operation of the device is as follows.

In the embodiment illustrated, Fig. 1 shows both circuits inactive. The primary circuit control switch 22 is in open condition. So isthe. pressure-responsive switch means denoted generally by.- the numeral 33 which controls the secondary circuit 23. Upon. closingswitch 22, element 16 will become heated and the valves 17, 18 will close. As the temperature interior the sealed casiiig 15 increases, so will the pressure therein until sufficient to shift the piston 27 of the pressure-responsive switch means whereupon the secondary circuit will be closed. It is evident that a time interval will elapse between the closing of the primary circuit and the closing of the secondary circuit. Of course, in the make up of this device, the components thereof are designed as to size and character to effect a predetermined delay interval between the operation of the switches 22 and 33.

Upon opening of the switch 22, the valves 17 and 18 will open due to action of the return springs 23, 2 5 which are properly designed to so function against the pressure existing in the casing 15 upon deactuation of the magnets 19, 20. Upon the opening of said valves, the heated air within the casing 15 becomes purged and the pressure-responsive switch 33 will open the secondary circuit 23. The relay device is now again in its initial condition as shown in Fig. 1. The valve stems are provided with flutes 21 which communicate with the interior of the casing 15 when the valves are in open condition. To "adjust said time interval between the operation of switch means 33 after the closing of the switch 22, the initial stress in spring 29 is changed by shifting the position of the piston 27. This is accomplished by adjusting the screw 32, which in the embodiment shown acts to initially shift the piston through the strip 30, which latter acts on the pin 35. Such strip is quite springy so as not to interfere with operation of the switch 33 upon actuation of the primary circuit. For automatic adjustment of the biasing of the spring 29 to account for changes in atmospheric temperature and yet maintain a constant time interval aforementioned, the bimetal strip 30 is employed and of course, its composition and characteristics are chosen therefor in order so to act. Said bimetal strip 36 is of course exposed to the atmosphere and is preferably carried on the casing 15, so that the entire relay device and its adjustment means constitute a unitary structure.

To those versed in the art, it is readily understood without further illustration, that the pressure responsive switch means 33 may be of the type which is normally closed instead of the normally open switch as here specifically shown.

Additional means for the control of the time interval between the operation of the switch means 33 after the closing of the switch 22, can consist of a variable resistance 36 interposed in the primary circuit 23. This effects the adjustment electrically. The mechanical adjustment offered by screw 32 and the electrical adjustment offered by the variable resistance 36, may both be included, or any one of them or neither of them, as requirements permit or dictate.

At high altitudes where there is practically no atmosphere, the relay device per se is enclosed in an hermetically sealed casing 37 of suitable volume. Such casing is filled with an inert gas as nitrogen to offer atmosphere for the operation of this relay. In order to maintain the mechanical adjustment mentioned, part of the wall of the casing 37 is a resilient diaphragm 38 carrying fixed thereon the pin 38 which bears against the bimetal strip 30. This diaphragm may be part of a bellows 39 forming a chamber 40 within such casing 37. The adjustment screw 41 is threadedly mounted through the wall of the casing to act on the diaphragm and thereby adjust the bimetal strip.

This invention is capable of numerous forms and various applications without departing from the essential features herein disclosed. It is therefore intended and desired that the embodiment shown herein shall be deemed illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claims rather than to the specific description and shown embodiment to indicate the scope of this invention.

I claim:

1. In an electrical relay device of the character de- Cir scribed, the combination of a casing, electrically-operated normally open valve means controlling the interior of said casing, an electrically-operated heating element within the casing adapted when operated, to heat the gas confined within the casing upon operation of the valve means to close, whereby the pressure within the casing is increased, a circuit controlled by a switch for operating said element to become heated and said valve means to close, a pressure-responsive switch means controlled by the pressure within the casing, a hermetically sealed second casing housing such device and an inert gas filling both casings.

2. The device as defined in claim 1, including a bimetal member in fixed relation to and Within the second casing and outside the first casing; said bimetal member being associated with the pressure responsive switch to bias said switch; a portion of the wall of the second casing opposite said bimetal member being resilient, a rigid element extending from said resilient portion and bearing against said bimetal member and means exterior and on the second casing for adjustably pressing the said resilient wall portion into the second casing.

3. In an electrical relay device of the character described, the combination of a casing, two electricallyoperated normally open valve means controlling the interior of said casing; said valves being positioned opposite each other in staggered relation, an electricallyoperated heating element Within the casing adapted when operated, to heat the air confined within the casing upon operation to the valve means to close, whereby the pressure within the casing is increased, a circuit controlled by a switch for operating said element to become heated and said valve means to close and a pressure-responsive switch means controlled by the pressure within the casing.

References Cited in the file of this patent UNITED STATES PATENTS 1,265,765 Ferris May 14, 1918 2,266,975 Landon Dec. 23, 1941 2,707,737 Rich et al. May 3, 1955

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