US2637794A

US2637794A - Temperature alarm switch

Info

Publication number: US2637794A
Application number: US228689A
Authority: US
Inventors: James T Grotenhouse
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-05-28
Filing date: 1951-05-28
Publication date: 1953-05-05
Anticipated expiration: 1970-05-05

Description

May 5, 1953 J. T. GROTENHOUSE TEMPERATURE ALARM SWITCH Filed May 28, 1951 INVENTOR m m M N m/ H N m T T A Patented May 5, 1953 James T. Grotenhouse, Oianggfiitw Iowa.

Applicatlonlvfay'28, 1951, sis-name: 228E689 1' Claim. (01. 200-140 My invention pertains to anral arm switch..

An object of my invention is to provide" a switch having an adjustable arrangement wherein the switch will operate below a pre-determined point, and will further operate above a predetermined point, leaving a certain pre-selected range in which the alarm will not operate, the adjustment for the above purposes being relatively simple.

A further object of my invention is to provide the above mentioned in an economical construction.

With these and other objects in view, my invention consists in the construction, arrangement, and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claim, and illustrated in the accompanying drawings, in which:

Figure 1 is a plan view of the switch base with the cover being removed,

Figure 2 is a sectional elevation of the switch and casing, and

Figure 3 is a detail.

My invention contemplates the provision of a switch which is responsive to temperature conditions for use in brooders, or other locations and which switch will operate an alarm at predetermined temperatures, and yet leaving a certain range of temperature which will not operate the said alarm.

I have used the character In to designate the base of the switch, the character ll indicating a suitable outer casing having the openings l2.

Attached to the base Ill are the members l3 to which is pivoted at I 4 the U-shaped lever I5. Pivoted at I6 to the lever I is a further U-shaped lever ll which includes the transverse bar l8 attached thereto, to which is secured the spring H! which is attached at to the base l0. The member I! includes an opening 2| through which the spring I 3 can pass. A holder member 22 is secured to the base Ill and mounted in the member 22 is a micro-switch 23 which is suitably connected to any alarm circuit which switch includes the button 24, the switch being normally closed and completing the circuit when the button 24 is in its upper position.

Threadably engaging the top wall 25 of the member I5 is the vertically positioned stud 26 having the knurled end 21 and the lock-nut 28, the lower end 29 of the stud 26 being adapted to engage the upper end 30 of the temperature responsive bellows 3|, which expands according to the temperature.

which is adapted to bear against the lower wall of the lever ll as shown, the stud 32 having the knurled end 34 and lock-nut 35. The holder member 22 includes the inner flange 36 having the upper edge 31.

The device operates in the following manner.

The stud 26 is provided for the purpose of establishing the alarm point below a pre-determined temperature. For instance as shown in Figure 2 the alarm circuit is open, assuming that the end 30 of the bellows 3| has just contacted the lower end 29 of the stud 26, this causing the lever member [5 to pivot upwardly and at the same time causing the spring l9 to pivot the member l1 downwardly providing means for depressing the button 24 and keeping the circuit open. At any temperature lower than this the outer end 38 will swing upwardly out of engagement with the button 24 due to the fulcrum action at the point 31, thereby operating the alarm.

When the temperature increases beyond a predetermined point, since the member I! will abut against the end 33 of the stud 32, the bellows 3| will carry the entire unit upwardly as shown in Figure 3, thereby operating the alarm also. It will be noted that the adjustable positioning of the stud 32 provides any desired variation of temperature range within which the alarm will not be operated as will now be explained. For instance if the stud 32 is rotated, bringing the point 33 to a higher level, there will correspondingly be a longer range of action of the lever member I! as it fulcrums over the edge 31, thereby providing non-operation of the switch, or in other words maintaining the switch in opened position for a relatively longer interval.

Correspondingly, by rotating the stud 32 downwardly the lever action will not be over as long a period of time, thereby efiecting a shorter temperature range of non-operation. In this manner, the heated structure can be maintained at a certain temperature range without operating the alarm, beyond which point however the alarm will operate.

It should be noted that the spring H! has the tendency of pulling the end 38 downwardly at all times.

It will now be noted that I have provided all of the advantages mentioned in the objects of my invention with further advantages being readily apparent.

Some changes may be made in the construction and arrangement of the parts of my invention without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claim any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

A temperature alarm switch comprising an expansible temperature responsive member, a pivoted lever, a vertically positioned lengthened stud I threadably engaged with said lever, the lower terminal 'of said stud being adapted to engage said temperature responsive member at a pre-determined temperature, and whereby adjustable movement of said stud will correspondingly vary member upon which said further lever fulcrums incidental upon movement of said levers, means for adjustably positioning said further lever to maintain said switch button in switch opening position at a predetermined interval including a further stud threa'dably engaging said pivoted lever, the lower terminal of said further stud being adapted to engage the other end of said further lever, a base member, a spring attached between said base member and said further lever. adjustablepositioning of said further stud vertically causing said switch to be opened during said predetermined interval corresponding to the fulcruming interval between said further lever and said flange.

JAMES T. GROTENHOUSE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,123,672 Du Bois July 12, 1938 2,357,878 Crew Sept. 12, 1944