US2968708A

US2968708A - Article for use in an electrical switch device or in a thermostatically-controlled mechanism

Info

Publication number: US2968708A
Application number: US624901A
Authority: US
Inventors: Sagona Charles
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-11-28
Filing date: 1956-11-28
Publication date: 1961-01-17
Anticipated expiration: 1978-01-17

Description

Jan. 17, 1961 c. SAGONA 2,968,708

ARTICLE FOR USE IN AN ELECTRICAL SWITCH DEVICE OR IN A THERMOSTATICALLY-CONTROLLED MECHANISM Filed Nov. 28. 1956 2 Sheets-Sheet 1 I PM 5 iam mm \5 I c I 2.6 l HIHIHHI HIHIHHH 1.1m

25 \t 26 as (Tmmuzs SAQQNA,

INVENTOR.

Aim-0mm- Jan. 17, 1961 c 5 G NA 2,968,708

A 0 ARTICLE FOR USE IN AN ELECTRICAL SWITCH DEVICE OR IN A THERMOSTATICALLY-CONTROLLED MECHANISM Filed Nov. 28. 1956 2 Sheets-Sheet 2 Fm Z #5 J? CH/IELESSAGONA,

INVENTOR ATTO/Q. NEH.

United States Patent ARTICLE FOR USE IN AN ELECTRICAL SWITCH DEVICE OR IN A THERMOSTATICALLY-CON- TROLLED MECHANISM Charles Sagona, 73 Bay 34th St., Brooklyn, N.Y.

Filed Nov. 28, 1956, Ser. No. 624,901

1 Claim. (Cl. 200-413) The present invention relates to devices adaptable in constructions of electrical switches, micro-switches, relays, circuit breakers and in various thermostat mechanisms. These are stated as particular examples ofits use.

An object of this invention is to provide a novel and improved device employing a blade spring which operates with a rapid snap action making it suitable in the types of apparatus mentioned.

Another object is to provide a novel and improved device of the character described, whose blade spring member is actuated by a new mode of operation.v

A further object is to provide a novel and improved device of the class set forth, in which a minimum of operating movement will cause a substantial shift in the blade spring member.

Still a further object is to provide a novel and improved device of the kind mentioned, which is simple in construction, cheap to manufacture and which is efiicient in carrying out the purposes for which it is designed.

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

For the practice of this invention, it is essential to have a frame on which a blade spring is so mounted that the ends of such blade spring are free for relative movement towards each other. In some embodiments, the blade spring in initial rest position, is straight, in others, bent. In still other embodiments, the blade spring is initially bowed and is mounted to be straight in normal rest position on the frame, or else bowed in the opposite direction, all of which will be shown and explained. In all embodiments, the device is made to operate by causing a change in the distance between the ends of the blade spring, by action and reaction acting at such ends. This is effected by application of a physical force or the creation of the equivalently acting forces caused by heat transference. Spring blade end movement may be caused by expansion or contraction of the spring per se or the frame. member or their relative expansion or contraction when subjected to a hot or cold environment as the case may be. Expansion of the blade spring may be effected by having it heated by an electric current. Regardless of the manner of causing force to deform the blade spring from its normal rest position, the gist of this invention remains the same.

I will now proceed with a more detailed description of various forms this invention may assume and the various manners in which such devices are operated and used. Of course, the specific embodiments illustrated and de scribed are to be deemed mere examples of the practice of this invention.

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

Fig. 1 is a front view of a preferred embodiment of this invention which will be shown can operate either as a micro-switch or as a thermostat control. Considered as a switch, it is here shown in condition when the operating button is pressed. Considered as a thermostat, the button being omitted, the device is here shown when the heated environment has reached a predetermined temperature- In this view, part of a coverplateisbroken away to expose the mechanism.

Fig. 2 is a top plan view of Fig. 1.

Fig. 3 is a section taken at lines 3-3 in Fig. 2'.

Fig. 4 is a section taken at lines 44 in Fig. 1.

Fig. 5 shows the blade spring in its unmounted condition. This view is taken of a longitudinal edge of said blade spring.

Fig. 6 is a side view of Fig. 5, showing a face of said blade spring.

Fig. 7 is a'view like Fig. 1, but of a modified embodiment; the blade spring being shown herein normal at rest position.

Fig. 8 is a similar view of another modified embodiment.

Fig. 9 is a similar view of another modified embodie ment.

. Fig. 10 shows the device of Fig. 9 set in a different initial condition.

In the drawings showing preferred embodiments of this invention, the numeral 15 designates generally a dielectric frame presenting an elongated straight wall 16 on one of its members, against which the initially convex face 17' of a bowed blade spring 17 rests straightened thereagainst andof course is therebycaused to be in flexed condition. Said blade spring isso held by having its ends anchored, one end to. the frame and its other end in an operating button 18. .The attachment to frame may be in a diametral V-notch in the head of the shankaof a headed an:- cho rage button l9iwhich is held tightly in a counterbored hole in the frame body by a screw 20 which is threadedly engaged in the bushing-21 as shown in Fig. 3. The other end of'the blade spring 17sets into a similar. and aligned V-notch in the head end of the inverted operating button 18 whose shank extends from the frame through thebushing 22, in which bushing said shank is slidable towards the anchorage button 19.

When the operating button 18 is pressed so that'it moveseven slightly, it will cause the blade spring 17 to become bowed and rapidly snap away from the'wall 16 because said blade spring can go nowhere else. From the normal rest position shown in Fig. 3, the blade spring 17 will automatically assume the condition shown in Fig. l, where the blade spring has been so bowed that its face 17" which when said blade spring was unmountedv was concave, is now convex.

The blade spring 17 at its mid-section may carry the

contact points

24, 25. To have a switch devicewhich is normally open, but ismade to assume closed condition upon pressing the operating button 18, the framecarries the contact point 24' in the path of movement of the blade spring 17 and normally spaced from the contact point 24 on the blade spring as in Fig. 3.

To have a switch device which is normally closed, but is made to assume open condition upon pressingthe operating button 18, the frame has mounted thereon the .contact point 25 so that at normal rest position of .the

blade spring, contacts 25 and 2S touch.

The contact points 24', 25 may be at the end of: the

screws

26, 27 respectively. These screws are threadedly engaged by the frame to serve as binding postsfor electrical connections. Screw 20, of course, also servesas a terminal for electrical connection to the circuit the switch is to control. Each of .the mentioned screws may have a lock nut as at 28 to fix the screws in any set position as adjustment. may require; and a second. nut as at 29 to secure wire connections.

It is advisable that the wall 16 extend substantially theqentire length of the blade spring.17 so that upon pressing theoperating button, the blade spring can move nowhere but away from such stop wall;

The blade spring is preferably of spring copper alloy and the frame may be of Bakelite, plastic, a ceramic or other suitable insulative material. In practical constructions for commercial use, the device would be about half the size shown. This is stated as mere suggestion in view of a working specimen which was so made. A cover plate 30 may be provided as shown in Figs. 1 and 2.

The device, even as illustrated, may be used as a thermostat, though the operating button in such instance is unnecessary. When in condition as shown in Fig. 3, the straightened spring 17 must be incapable of any longitudinal movement with respect to the frame 15. Since the screw 20 is stationary and the operating button 18 is stopped by the bushing 22, the required situation exists. When the blade spring 17 is subjected to a heat environment, the ensuing expansion thereof will cause a force to act on the blade spring effecting its snap movement to the position shown in Fig. 1. What actually occurs is that when the blade spring expands, it tends to lengthen. But increase in the distance between the ends of said blade spring is impossible. Hence there is a resulting force holding the blade springs ends apart less than such ends would be if they were free. This is the equivalent of applying a force to shorten the distance between the said ends and the device is made to assume the condition as in Fig. 1. Of course, when the device is so used as a thermostat, the material of the frame should be of the nature that has practically no expansion when subjected to heat. It may be noted, that when the embodiment is for thermostat use, the anchorage for each of the ends of the blade spring 17, may be as that anchoring its lower end inFig. 3. Such construction is shown in Fig. 9.

Inaddition to being used as a thermostat, each of the embodiments shown in Figs. 3 and 9 may also be used as a relay or as a circuit breaker when so interposed in a circuit that an electric current is made to pass through the blade spring to heat same upon attainment of a certain degree of heat, the blade spring in either instance will expand. Such expansion will cause either of said blade springs 17 or 31 to automatically assume the positions shown in Figs. 1 and respectively. As a circuit breaker, the blade spring movement will cause a break in the circuit in which the contact points 25, 25' are interposed as a switch. As a relay, such blade spring movement may be used either to cause a break in the circuit as explained, or to close a circuit in which the contact points 24, 24 are interposed as a switch, or both such incidents, depending upon the switch functions required. To adjust for the temperature the devices are to operate adjustment is made by different settings of the screw 20. Movement of such screw to loosen the blade spring in either device of Figs. 3 and 9 would cause blade spring shift .to that of Fig. 1 and Fig. 10 respectively at a higher increment of temperature.

The devices shown in Figs 3 and 9 may also be used for thermostat control where expansion and contraction of the frame is relied upon for operation. Of course in such instances, the material of the frame or 35 shall have an appreciably greater coefiicient of expansion than that of the associated blade spring. In such arrangement, the device in initial condition as shown in Fig. 9 may serve as a thermostat in cold environment. When the temperature of such environment falls to a certain temperature, the frame will contract and automatically the blade spring will assume the position shown in Fig. 10. If then the temperature of such environment shall rise to a certain degree, the frame will expand and the blade spring will automatically return to the position shown in Fig. 9. In such arrangement, the device in initial condition as shown in Fig. 10 may serve as a thermostat in a hot environment. When the heat of such environment rises to a certain temperature, the frame will expand and automatically the blade spring will assume the position shown in Fig. -9. If then the temperature of such environment shall fall to a certain degree, the frame will contract and the blade spring will automatically return to the position shown in Fig. 10.

Whereas the blade springs 17, 31 and 40 are electrically conductive, the blade spring 33 in the embodiment shown in Fig. 8 is of dielectric material. Hence such blade spring carries a contact button 34 to make simultaneous contact with the fixed contact points 38 and 39 to constitute a switch means.

In the embodiment shown in Fig. 7, the blade spring 4t. stands in space and is straight as it was in unmounted position. Pressing the button 41, or a contraction of its frame 42, would cause such blade spring to bend either to the right or to the left. Hence to serve as a switch means, such blade spring in the embodiment shown is electrically conductive and the contact points which are at either side thereof respectively would need be in electrical connection. In this embodiment, there is no rapid snap action. The blade springs of all the other embodiments may also be straight when unmounted, if rapid snap action is not required. Being up against a stop wall as 16, they could only move away from it when the ends of such blades are brought closer either by pushing of button 18, contraction of frame or expansion of such blade spring, as have been explained. It might also be noted that blade spring 40 may be set to be a bit bowed. For such, spring 17 may be used. When this is so, upon pressing the button 41, the convex face 17 will become more convex and then only one contact point at 44 would be required to complete a switch device.

As one example of an electrical circuit, reference is bad to Fig. 9 where a current supply 45 is controlled by a manual switch 46 to cause the blade spring 31 to become heated. Upon expansion of such blade spring, it will close the circuit of any electrically-operated apparatus 47, included as shown. To those versed in the electrical art, the many uses of the devices illustrated and appropriate circuits therefor will be apparent without further illustration.

Where the blade spring needs to be electrically cond-uctive, it is suggested that it be of a copper alloy as for instance beryllium copper and where it may be nonconductive, same could be of a suitable plastic as nylon. In embodiments which rely on expansion and retraction of the frame for operation, the frame may be made of such materials as Bakelite and the blade spring of Invar steel.

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 embodiments shown herein be deemed illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claim rather than to the specific description herein to indicate the scope of this invention.

I claim:

In an article for use in an electrical switch device or in a thermostatically controlled mechanism of the character described, the combination of a frame, a stop member thereon, a blade spring of a dielectric material held at its ends on said frame; said blade spring being in bowed condition before being mounted on the frame; said blade spring being positioned in straight condition with its initially convex surface against such stop member whereby said blade spring is in flexed condition; said stop member maintaining the major portion of said blade spring against movement in the direction towards said stop member; said spring being free to bend away from said stop member and then back again to be against said stop member means to impart a force to at least one end of said blade spring in a direction substantially along the line between said ends to' shorten the distance between said ends, whereupon the blade spring will automatically bend away from said stop member, a first electrically conductive element carried on said blade spring and a pair of spaced electrically conductive elements carried on the frame and electrically insulated from each other, whereby said pair of elements are in contact with said first element only at one position of the blade spring.

References Cited in the file of this patent UNITED STATES PATENTS 6 Vaughn Aug. 15, 1933 Mason July 5, 1938 Klahn Aug. 23, 1938 Gent Mar. 4, 1941 Platz Sept. 9, 1941 Henry Jan. 31, 1950 Brown Nov. 10, 1953 Immel et al Mar. 30, 1954 Schwaneke June 11, 1957 OTHER REFERENCES