US1543557A - Thermostatic circuit closer - Google Patents

Description

' June 23, 1925.

' A. M. DE 5. GREAVES THERMOSTATIC CIRCUIT CLOSER Filed Jan. 1'7, 1922 i6 fig Q 20 if ja Q Him 7 30 27 Qwuwtm cfl. (/77. 5. Greaves Patented June 23, 1925.

UNITED STATES PATENT OFFICE.

THEBMOSTATIG CIRCUIT CLOSER.

Application filed January 17, 1922. Serial No. 529,865.

To all whom it may concern:

Be it known that I, Ammo M. DE SILVA GREAVES, a citizen of Portugal, residing at Cambrid e, in the county of Middlesex and State of assachusetts,.have invented new and useful Improvements in Thermostatic Circuit Closers, of which the following is a specification.

This invention relates to thermostatic circuit closers.

One object of my invention is to provide a circuit closer having an improved mounting for the thermostat per se and the circuit closing contacts.

Another object of my invention is to provide circuit-closing contacts which are adjustable to close the circuit at different predetermined temperatures.

Still another object of my invention is to provide a novel and convenient arrangement ofa plurality of sets of circuit-closing contacts for closing difi'erent circuits at different predetermined temperatures.

The invention consists of the features of .5 construct on, combination and arrangement of parts, hereinafter fully described andv claimed, reference being had to the accompanying drawing, in which:

Figure 1 is a view, partly infront elevation and partly in vertical transverse section, of a thermostatic circuit-closer embodying my invention. Figure 2 is a side elevation of the same.

Figure 3 is a top plan view. Figure 4 is a diagrammatic view of some of the sets of contacts illustrating the various levels of their contact points.

In carrying my invention into practice, I provide a thermostat comprising a mercur. tube 1, communicating at its lower end with a bulb or storage chamber 2 containing a supply of mercury, and having at its upper end an expansion chamber 3. This expansion chamber 3 communicates at its base with the bore 4 of the mercury tube, said bore being preferably enlarged at its point of communication with the base of the chamber 3, as indicated at 5, to permit free flow of the mercury between said bore and expansion chamber.

The thermostat as thus constructed is mounted upon a suitable sup ort 6, which preferably consists of a bloc of suitable the expanded portion or expansion chamber 3 of the thermostat, which chamber 3 is closed at its top by the top wall of said socket 10. The socket 8 communicates with side grooves 11 and a bottom groove 12.

formed in the lower portion of the front face of the block 6, which grooves expose the bulb 2 to a large extent 1n order to allow,

the mercury contents thereof to be sensitively subjected to and influenced by atmospheric temperature conditions. Any suitable means, such as a clip 13, may be employed to detachably secure the thermostat in position upon the supporting block.

The head of the block 6 is formed with a desired number of threaded passages 14,

leading from the top thereof down to the top of the expansion chamber 3 for the reception of a desired number of b nding posts 15', forming part of a desired number of pluralities of sets of circuit closing contacts. The passages 14: and binding posts. have a threaded engagement for adjustment of said binding posts, and the binding posts of each set or working pair are coupled to the terminal wires 16 and 17 of an electriccircuit. Each of these wires is clamped between an adjusting and clamping ,nut 18 and a jamb nut 19, which are employed to not only clamp the associated circuit wire in position but also to clamp the associated binding post in adjusted position upon the supporting block.

In the present instance I have shown the use of three pairs or sets of binding posts 15, which form supports for an equivalent number of sets of contact points, each set comprising a pair of contacts 20 and 21 extending fromthe posts downwardly into the expansion chamber 3. Each of these contact members comprises a metallic stem fixed at its upper end to its binding post and having with.

its lower end free and terminating at a rescribed level within the expansion cham er, the lower ends of the contact members of each working pair being arranged in proximity to each other so as to be connected electrically by contact with the mercury rising to such predetermined level, whereby the circuit of which said contact members constitute the termihals will beclosed for the energization of such circuit.

The thermostatic device and circuit closers constructed and arranged as described are adapted for use in controlling a plurality of circuits, and for closing the respective circuits at difi'erent predetermined temperatures. F or this purpose, the lower ends of the sets of contacts forming the respective circuit terminals are arranged at different horizontal levels, so that the contacts of one set or the other will be connected by the mercury as the latter rises to difierent predetermined scale points at different temperatures. The chamber 3 permits of the expansion of the mercury therein as it flows upwardly through the enlargement 5, to reduce the rapidity of its ascent from the time that the expanding mercury reaches said enlargement 5, whereby the mercury is permitted to expand beyond the points of one set of circuit contacts and rise a distance above the same, in closing the circuit of which said set of contacts forms a part, without liabilit of prematurely contacting with'the next liigher set of circuit closing contacts and improperly closing the circuit of which they form a part. In order to prevent interference between the sets of contacts, they may be grouped in a circular series, as shown, or otherwise suitably arranged to bring the points of each set of contacts in proper close relation, while they are at the same time not only disposed at a different level but laterally spaced with respect to the points of the other sets of contacts. It will be observed that while the sets of contacts are arranged at different working levels, the contacts of any of the sets may be vertically adjusted, by adjustment of their binding posts, so as to regulate the working levels of the difierent sets of contacts as desired, and so that the contacts of any set maybe properly adjusted to 7 dispose their points in working relationship and to ensure positive connection thereof andsensitive circuit closing action when the column of mercury comes in contact there- The circuit closer constructed in accordance with my invention may be used for many and various purposes, such as for controlling a fire alarm circuit, a damper governing circuit, and a fuel controlling circuit, and may be employed in households or other places for these generaluses, so that any one of a series of devices may be automatically meats"? governed by and operated under different temperature conditions to perform different service actions, all of such devices being controlled through the medium of a single thermostatic instrument. In practice, the block 6 may be mounted in any suitable manner upon a wall or other proper support, or may be mounted within a casing similarly applied in position, whereby the thermostat may be enclosed and protected against liability of possible injury.

Having thus fully described my invention, I claim:

1. A thermostatic circuit closer comprising an expansion chamber normally open at its top, a relatively contracted mercu column tube communicating with the bottom of said chamberfa support for the chamber and tube comprising a body having in its face a seat groove receiving the tube and having a recessed head portion receivin and closing the normally open top of the c amber, said head portion having a part jutting outwardly beyond the expansion chamber and face of the support body, and circuit closing contacts extending downwardly through the head portion of the support and into the expansion chamber.

2. A thermostatic circuit closer comprising a support in the form of a block having in its front face a partially circular longitudinal groove and a partially circular recess intersecting the lower end of said groove, said block having a head portion projecting beyond said face and said block and'face being provided with a recess, a mercury containing bulb set in the first-named recess and having extending therefrom a mere column tube seated in said groove, said tube being provided at its end remote from the bulb with an expansion chamber communicating with the top of'the tube and seated in the second-named recess, the top of said chamber being closed by a wall at the top of the recess conjointly formed upon the body of the block and the head and jutting forwardly beyond the expansion chamber.

and plane of the face of the block,'and circuit closing contacts extending downwardly through the top of the block and into said expansion chamber.

3. A thermostatic circuit closer comprising a support in the form of a block having in its front face a vertical lon itudinal groove and at its upper end a hear? portion projecting forwardly beyond said face, said block being provided at its lower end with a cavity intersecting the lower end of the groove and at its upper end with a cavity formed partially in the block and partially in the head portion, and said block having at its lower end a bottom groove intersecting the lower recess and side grooves lead ing outwardly from said recess to the opposite sides of the block, a mercury containing uau? 6 bulb fitted in the lower rem a' mercury chamber being closed by the top wall of the column tube extend' upw from said upper recess, and circuit closing contacts bulb and seated in sai vertical ongitudinal projecting downwardly through t e head of I. groove, a normally open to expansion the block and through said wall and into I chamber communicating with the u per end the expansion chamber.

of the bore of the tube and 6 In said Intestimony wbereofI afi'lx my si ature.

upper recess, the normally open top of 'said ABILIO M. on'SILVA GREA ES.

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