US1882674A - Electric switch - Google Patents

Description

Oct. 18,1932. A Q ROWLEY .1,882,674

ELECTRIC SWITCH Filed July 24. 19:50

Patented Oct. 18, 1932 UNITED STATES PATENTl oFFicE ARTHUR C. ROWLEY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO GLOBE AUTO- MATIC SPRINKLER COMPANY,'OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA ELECTRIC SWITCH This invention relates toelectric switches, and more Yparticularly to a type of switch adapted for use in connection with fire-extinguishing and alarm apparatus.

A principalobject of the invention is to provide a switch of the stated character which shall be simple in form and eiiicient and positive in operation.

More specifically, an object of the invention is to provide a switch of improved design adapted for operative association with thermosensitive means whereby abnormal temperature conditions aecting the latter result in a predetermined actuation of the switch mechanism.

Another object of the invention is to provide improvedmeans for effecting a desired actuation of the switch mechanism under predetermined conditions.

Still another object of the invention is to provide .an electric switch including latching means for normally retaining the switch in an open position, together with novel and improved means for tripping the said latch to permit the switch to close.

The inventionv contemplates further the provision of aswitch incorporating a novel and highly desirable fluid control, as hereinafter fully described.

The invention further resides in certain novel mechanical and structural details and features hereinafter setforth and illustrated in the attached'drawing, in which Figure 1 is a front elevational view of a switch made in accordance with my inventionj the cover of the switch being` removed to render the interior working parts visible;

Fig. 2 is a section on the line 2-2, Fig. 1;

Fig. 3 is a view in perspective of one of the elements of the mechanism, and

Fig. 4 is a fragmentary sectional view on the line 4 4, Fig. 2.

With reference to the drawing, a device made in accordance with my invention may comprise a housing 1 having a removable cover-plate 2. Within the housing is assembled an electric switch comprising in the present instancea pair of relatively fixed contact or terminal elments 3, 3, these elements being mounted in the present instance upon an insulating block 4 shown attached to the l I rearwall of the housing by means of screws 5. Binding posts G are provided whereby wires (not shown), entering the housing .through a bottom opening 7, may be connect- `ed respectively to the contacts 3. The switch vmechanism further comprises a movable contact element in the form of a plate S flexibly secured by means of a screw 9 and a spring 11, the latter confined between the head of said screw and the outer face of the plate, to an linsulating member 12, this member being pivotally mounted upon a rod 13 within the housing and being adapted to rock in such manner as to bring contact points 14 on the plate 8 into engagement, respectively, with the terminal elements 3, thereby elecn ,trically connecting these terminal elements and closing the electric circuit of which the said vterminals form a part. The plate 8 has at its upper end a lip or flange 15 which projects inwardly into an aperture in the foi'- ward face of the insulator 12, and except for lthe restrictions imposed by this lip 15, the

screw 9, and the spring 11, the plate is free to move with respect to its insulating support 12.

Secured to the upper end of the insulator 12, by means in the present instance of screws 16, is an arm 17 the forward upturned end' 18 of which projects into an'aperture 19 in the cover-plate 2, while the rear end is piovided with an upwardly projecting flange 21. The arm 17 has operatively associated therewith a spring actuator consisting of an inverted hollow cylinder 22 containing a coiled spring 23 which surrounds a plunger 24 slidable in the cylinder, the spring being confined between the closed end of the cylinder 22 and the flanged head of the plunger l 24. The actuator itself is confined between a screwl 25 extending through the upper wall of the housing 1 and the upper surface of the arm 17, the arrangement being such that the spring 23 exerts a pressure tending to move the insulator 12 about the pivot rod 13 in such manner as to bring the contact plate 8 into engagement with the terminals 3, as previously set forth. Displacement of the yspring actuator 22-2324 from the confined Vao position is prevented by interlocking connections between the bottom of the plunger 24 and the arm 17 and between the cylinder 22 and the screw 25, the said plunger and screw each having an attenuated extremity, which extremities seat within suitable recesses in the arm 17 and in the plunger 22 respectively.

The contact element 8 normally is held out of engagement with the terminals 3 by a latch element 26 pivotally mounted upon a rod 27 extending between lugs 28, 28, within the housing, this latch having a shouldered projection 29 which hooks over the upper edge of the upstanding flange 21 of the member 17. Another depending arm 31 ofthe latch 26 is engaged and releasably retained by one arm of a detent 32 pivotally supported between the lugs 33, 33,which also support the rod 13 upon which the insulator 12 is mounted'. The other arm 34 of the detent 32 normally underlies a shoulder 35 on a depending bifurcated lever, 36, this lever being pivotally mounted upon a pin 37 extending between the lugs 28, 28. The lever has an extension 38 at the top to which is attached a spring 39, this spring tending to retain the lower depending portion of the lever in an advanced position interlocking with the detent 32, as described above and illustrated in the drawing. Retraction of the lever 36 inl a manner hereinafter set forth releases the detent 32 and the latch 26and permits the spring 23 to swing the pivoted insulator 12 into engagement with a stop 41 in the housing, the stop 41 being so positioned, however, as in no way to interfere with contact between the elements 14 of the plate 8 and the terminal elements 3. By reason of the flexible mounting of the plate 8, this member is self-adjustable in its contact with the terminals 3, insuring proper and intimate electrical connections.

Secured to the rear wall of the housing 1 are plates 42 and 43, these plates being dished in their inner faces to. form an interior chamber 44 which is intersected by a flexible disk or diaphragm 45 confined between the edges of the plates, as illustrated in Fig. 2. Both of the plates 42 and 43 are secured in the housing bymeans of a series of screws 46,the plates being thereby secured together upon the diaphragm 45 and to the housing in a osition overlying and closing an opening 4i) in the rear wall of said housing. The plate 43 has a boss 48 projecting outwardly into the housing opening 47 ,and this boss is threaded for reception of a hollow fixture 49 in which is secured, by means for example of solder 51, one end of'a duct 52, which thus has communication through the said fixture with the chamber 44. The duct 52 extends downwardly in the present instance through a channel 53 at therear of the housing 1, and the lower end of the channel is threaded for connection of a conduit, not shown. Secured t0 the center of the diaphragm is a pin 54 which projects through the plate 42 and between the bifurcations of the lever 36, and has at its extremity a head 55 overlapping the said bifurcations. The arrangement is such that evacuation of the chamber 44 through the duct 52 causes a deflection of the diaphragm 45 and retraction of the pin 54, and through this pin of the lever 36, this resulting in a release of the detent 32 and of the associated elements and a closing of the switch 3 8, all as previously set forth.

Following release of thc latching device and closing of the switch, as described above, the mechanism may be reset by pressing upon the end 18 of the arm 17, which when the switch is closed projects through the opening 19 in the cover-plate. The iiange 21 never clears the under side of the latch 26, so that pressure applied to the end of the arm 17 will cause the flange 21 to move inwardly behind the retaining shoulder. Further pressure will bring the-flange against theforward side of the depending arm 31 of the latch, and this arm will thus be made to react with the detent 32 to force the arm 34 of this member under the shoulder 35 of the lever 36, the latter being displaced inwardly to an extent sufficient to permit the arm 34 to move under the shoulder. It will be noted by reference to Fig. 4 that the detent 32 is supported or journaled on the inner ends of two pins 56, 56, which are threaded into the lugs 33, and that the detent has in its mid section a recess 57 in which the lower end of the arm 31 of the latch 26 is confined, the arm 31 thus being aorded the necessary bearing on the detent.

In practice, the duct 52 may be suitably connected with a thermally-controlled evacuating device, such as that illustrated in my copending application, Serial Number 314,-

511, whereby excessive temperatures at the point Vwhere this device is established results in an evacuation of the chamber 44 and release of the latching mechanism, as previously set forth, the switch thereby closing an electric circuit` which may be connected to the release device of a fire-extinguishing system, such for example as that illustrated in my copending application Serial Number 460,511, or to an alarm or to any other electrically-operated mechanism.

The herein described device is capable of considerable modiication without departure from the invention. It may be desirable, for example, to actuate the diaphragm 45 to release the associated latch mechanism by increasing the pressure at one side thereof instead of by evacuation, as described above, although evacuation is considered desirable. The invention is applicable also to actuation of switch mechanism to open an electric circuit, instead of to close the circuit as inI the illustrated embodiment.

I claim:

In a fluid-actuated electric switch, the combination with a fluid-actuated member, of switch elements relatively movable into alternative relative positions in which an electric circuit is closed and opened respectively, a system of latch levers in series arrangement operatively connecting said fluid-actuated member With the switch elements for normally retaining the elements in one of said alternative positions, and a spring tending to bring said elements into the other of said alternative positions, said latch system comprising a pivotally mounted bell crank lever one arm of Whichis adapted to releasably interlock with one of said switch elements, a second pivoted lever having a recess for reception of another arm of said lirst-named lever, and a third pivoted lever constituting a detent for said recessed lever and retractible from an operative position by movement of said fluid-actuated member under a relatively light fluid pressure.

ARTHUR C. ROWLEY.

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