US747166A - Thermostatic circuit-closer. - Google Patents

Description

PATENTED DEC. 15, 1903.

R. W. W. GRIGSBY.

THERMOSTATIG CIRCUIT CLOSER.

APPLICATION FILED JUNE 15, 1903.

NO MODEL.

3 3 1 plw m y W UNITED STATES Patented December 15, 1903.

PATENT OFFICE.

REDMAN W. VrG'RIGSBST, OF CHRISNEY, INDIANA.

TH ERM OSTA'l'lC CiRCUlT-CLOSER.

SPECIFICATION forming part of Letters Patent No."747,166, dated De ember 15, 1903.

Application filed June 15,1903.

T0 whom it may concern:

Be it known that I, REDMAN W. W. GRIGS- BY, a citizen of the United States, residing at Ohrisney, in the county of Spencer and State of Indiana, have invented a new and useful Thermostatic Circuit-Closer, of which the following is a specification.

This invention relates to thermostatic circuit-closers, and is designed especially for use in connection with bearings of all sorts of machinery in which it is desirable to detect the presence of an undue amount of heat before the bearings have become sufiiciently heated to cause binding of the journals with the bearings.

The object of the invention is to provide a simple and effective form of thermostatic circuit-closer adapted for support upon bearings to cause the closure of a circuit through an electric hell or other signaling apparatus when the temperature of the bearings exceeds a predetermined degree.

A further object of the invention is to provide in a thermostatic circuit-closer of the type specified means for readily adjusting the apparatus, so that the circuit may be closed at any desired temperature.

With the objects above stated and others in view, which will appear as the invention is more fully disclosed, the same consists in the novel construction and combination of parts of a thermostatic circuit-closer hereinafter described and claimed, and illustrated in the accompanying drawings, forming a part of this specification, in which corresponding parts are designated by the same characters of reference throughout the several views, it being understood that various changes in the form, proportions, and exact mode of assemblage of the elements of the circuit-closer may be made without departing from the spirit of the invention or sacrificing any of its advan tages.

In the drawings, Figure 1 is a diagrammatic view showing a circuit-closer in position upon a bearing and suitably connected with electric wires leading to an ordinary electric hell or annunciator through which the circuit is closed by the operation of the closer. 2 is a view in side elevation of the circuit-closer detached from the bearing. Fig. 3 is a view in vertical section through the circuit-closer.

Serial No. 161,597. (No m0del.)l

Fig. 4: is a plan view of the circuit-closer with the cover removed. Fig. 5 is a detail view in plan of the sensitive member and its supporting-disk.

Referring to the drawings by reference characters, 1 designates the stem of the thermostat, which is made of a tube closed at the lower end, as shown.

The numeral 2 designates the main casing of the thermostat, which is provided at the bottom with a hollow downward extension 3, having a central opening within which the stem 1 is brazed. The extension from the casing terminates in a reduced threaded portion 4, above which are formed a plurality of shoulders 5 for the engagement of a Wrench. The casing 2 is open at the top and is provided with a seat for a cover 6, which fits down over the open top of the casing and is held againstany turning movement by means of ribs 7, provided at opposite sides of the easing 2 and entering slots in the downwardlyprojecting flange of the cover. At the top of each of the ribs 7 there is a rounded notch 8, which corresponds to a similar notch 9,formed at the top of each of the slots in the cover that engage with said ribs. The notches 8 and 9 in the casing-cover combine to form approximately circular openings for the passage of the wires (designated generally as W) which lead to the signal sounded by closing the circuit through the thermostat.

The entire interior of the casing, stem, and cover is lined with insulating material of any suitable kind, such as leather board or some other compact cellulose-fiber material. The lining comprises, preferably, a small disk 10 at the bottom of the stem, a tube 11, fitting within the bore of the stem, a disk 12, resting upon the bottom of the casing 2 and having a central opening through which passes the upper end of the tube 10, a ring 13, lining the side wall of the casing, a ring 14, lining the side wall of the cover, and a disk 15, lining the under surface of the top of the cover.

Withinthecasingavhhitsinsulating-lining, is supported a thermostat comprising a disk 16, of thin metal of any suitable kind, and a sensitive member consisting of a narrow loop 17, made of a compound strip of metal one side of which is composed of a metal having a different rate of expansion from that composing the other side. The metal having the higher rate of expansion will form the outer surface of the loop and that having the lower rate the inner surface of the loop, so that when the temperature of the loop rises the greater expansion of the metal forming the outer suri'ace thereof will force the ends of the loop together. The disk 16 has one end of the loop 17 soldered thereto, as best seen in Fig. 5, and the other end of the loop extends upward through a central opening in the disk to terminate in a small plate 18, of platinum, which is supported a little above the disk 16. The disk 16 is attached by means of screws 19 to a disk 20, of tolerably thick insulating material, which has a central opening registering with the opening in the disk 16, and on the upper surface of the disk 20 are riveted terminal plates 21 and 22, each of which is preferably of segmental form, as shown, and the former of which is provided with an upwardlyprojecting ing 23, having a threaded opening through which extends a screw 24, having a platinum tip 25, which is directed toward the platinum plate 18 at the free end. of the loop 17. The terminal plate 22 is electrically connected with the disk 16 by means of a bolt 26, which extends through the terminal plate, the disk 20, and the disk 16. Binding-screws 27 are provided one on each of the plates 21 and 22 and serve to bind the wires W to the terminal plates. In order to prevent electrical contact of the rivets by means of which the terminal plates are secured to the disk 20 with the disk 16, a disk of thin insulating material 28 is introduced between the disks 16 and 20.

The disk 28 is held in proper relation to disks 16 and 20 by screws 19, which have heads countersunk in the under side of disk 16 and the upper ends of which lie flush with the upper surface of the disk 20.

In order to prevent turning of the disk 20 and the members associated therewith inside the casing 2, the bottom of the casing 2 is pierced by threaded openings, and screws 29, mounted therein, extend upward through suitable openings in the disks 12, 28, and 20, the disk 16 having portions of its material cut away surrounding the screws 29 to prevent electrical contact therewith.

When the circuit-closer is in use, the stem will be introduced into an opening formed for that purpose in a bearing-block, as shown in Fig. 1, and the wires i/V will be introduced through the openings provided for that purpose in the upper margin of the side wall of the casing 2 and attached by means of the binding-screws 27 to the terminal plates 21 and 22. The screw 24c will then be turned until the platinum tip on the point thereof comes into contact with the platinum plate 18 on the free end of loop 17, when the bell to which the wires W lead will start to ring. If the bearing is running cool, the screw 24 will then be turned in the opposite direction to withdraw the tip thereof from contact with plate 18, and as soon as the bell ceases to ring the circuit-closer will be set. If now any increase of temperature occurs in the bearing, the expansion of the metal forming the outer surface of the loop 17 at a greater rate than that forming the inner surface will cause the free end of the loop bearing the platinum plate 18 to move into contact with the platinum tip of screw 24 and close the circuit, setting the bell to ringing again and indicating the presence of increased heat in the bearing soon enough for the machinery to be stopped and the trouble of Whatever charactercorrected before the heat becomes so intense as to do serious damage, such as melting the Babbitt or other antifriction metal of which the bearings may be formed.

In applying the circuit-closer to bearings it is desirable that the end of the stem 1 may always rest upon the Babbitt metal or other antifriction metal forming the interior surface of the bearings, and for this reason the circuit-closers will be made with stems of different lengths, so that the contact of the stem with the lining of the bearings may be insured.

When a large number of circuit-closers are used in connection with a complicated machine plant, it will be desirable to have the circuit-closers connected with an audible and with visible signals, so that the presence of too high temperature in any of the hearings may be manifested by an audible signal, and the location of the heated bearing indicated by a visible signal; but in view of the fact that the nature of the signals which are employed in connection with the circuit-closer is not a part of this invention any detailed description of such signals is regarded as unnecessary.

Having thus described the construction and operation of my invention, what I claim as new, and desire to secure by Letters Patent, 1s-- 1. In a thermostatic circuit-closer having a casing provided with a hollow stem for insertion into an opening in a bearing-block or the like, a pair of terminal plates one of which has electrically connected therewith one end of a loop disposed within the stem and formed of strips of nnequally-expansible metal and the other of which has an adjustable member disposed opposite to the free end of said loop.

2. In a circuit-closer having a casing and a hollow stem adapted for insertion into an opening in a bearing-block or the like, a pair of terminals to one of which is electrically connected one end of the loop formed of strips of unequally-expansible metal said loop being disposed within said hollow stem, and to the other of which is attached a lug bearing a screw with which the free end of said loop is adapted to contact.

3. In a circuit-closer having a casing and a hollow stem adapted for insertion into an opening in a bearing-block or the like, a noncondncting lining for said casing and stem, a

disk of non-conducting material within said 1 the terminal insulated from said loop and dicasing, a pair of terminal plates provided on I rected toward the free end of said loop.

the upper side of said disk of non-conducting In testimony that I claim the foregoing as material, a disk of metal electrically connectmy own I have hereto affixed my signature in 5 ed with one of said terminals and secured to the presence of two witnesses.

the under side of said disk of non-conducting material, a thin loop formed of strips of une- REDMAN GRIGSBY' qnally-expansible metal electrically connect- WVitnesses:

ed with said metallic disk and disposed with- HENRY KRATZ, 10 in said hollow stem, and a screw carried by ED BILLART.

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