US2632070A - Alarm signal station - Google Patents

Description

March 17, 1953 L. l.. vERKUn. 2,532,070

ALARM SIGNAL STATION Filed April 13, 1951 f /0 r i n 5 2.2 i E A 200 '.L/ A T in 36 20x n a i I t v2.?? o/ I L [n/47M 4 'EH 5 -L 4l. F .42

Patented Mar. 17, 1953 ALARM SIGNAL STATION Leo L. Verkuil, Norwalk, Conn., assignor to Edwards Company, Inc., Norwalk, Conn., a corporation of New York Application April 103, 1951, Serial No. 220,868

20 Claims.

This invention relates to signal stations, such as a iire or other alarm signalling station.

One of the objects of this invention is to provide a compact, inexpensive, and reliable signalling station that can be manufactured and assembled with facility and mounted or installed in a simple manner. Another object is to provide ya manually-a-ctuatable signalling station that will be neat in appearance, simple to operate, and capable of embodying therein a breakable element, like a glass member, as a deterrent, without detracting from compactness of construction and ease of operation. Another object is to provide an alarm signalling station having a'breakable element therein, in which moldable plastics may be structurally employed and the breaking mechanism so constructed that the substantial force necessary to break the breakable element, such as a glass member, may be dependably exerted without structural impairment of the molded plastic structure.

Another object is to provide a so-called breakglass alarm signalling station in which the breakable element is mounted and replaceable in a simple and practical manner and in which provision is made for selectable legend display according to the particular use to which the station is to be put, such as, for example, for Fire or Emergency, etc. Another object is to provide a signal station of the above-mentioned type in which switching mechanism and manual actuator may be assembled to the apparatus in a simple, speedy, and inexpensive way. Another object is to simplify, in an inexpensive manner, problems of electrical insulation met with in signal stations of this type and to achieve electrical safety in a simple and dependable manner. Another object is, in general, to provide an improved alarm signalling station of the above-mentioned nature.

Other objects will be in part pointed out hereinafter.

Y,The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts as will be exemplied in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

'In the accompanying drawings, in which similar reference characters refer to similar parts throughout the several views- Figure l is a front elevation of the signalling station'as it appears ready for installation;

Figure-2 is a rear elevation, as seen from the rear in-Figurelp y i I Figure 3 isa horizontal cross-section as seen along the line 3 3 of Figure 1 and of Figure'Z;

Figure 6 is a central vertical sectional view as seen along the line 6-6 of Figure 1 and of Fig-f.A

ure 2, but also showing one form of mounting of the signalling station in use;

Figure 7 is a fragmentary and enlarged rearf elevation, being an enlargement of a portion of Figure 2 to show more clearly the support for ai pivot pin, and

Figure Sis a horizontal sectional view along the line 8 3 of Figure 7.

Referring rst to Figures 1, 2, and 6, the signalling station comprises a support, generally indicated by the reference character IIJ, comprising a front wall l l, illustratively rectangular in outline, provided with a peripheral rearwardly extending flange I2 whose continuous peripheral edge can rest atwise against the face of a suitable support, usually a wall W, as indicated in Figure 6. At suitably distributed points, illustratively along the center line and near the topU and bottom, the support I0 is provided with counterbored holes or slots I3-I3 for the reception of securing means, such as screws I-M (Figure 6) which are screwed into the supporting wall or threaded into suitable threaded holes in lugs or ears or other parts associated with any suitable form or shape of outlet or conduit box l5 (Figure 6) y which may be set into a recess I1 in the wall W, as indicated in Figure 6. In the latter case. the expanse of the rearward ange I2 is greater than that of the recess I1 so that the ange engages the wall surface and holds-,the front wall Il of the support I IJ parallel to the wall, even though the screw hole bearing parts associated with the outlet box are out of alignment with the face of the wall W; the horizontal direction of the slots I3 (Figure l) permits adjustment of the support I 0 so that it is plumb. Preferably the screw holes I3--I 3 extend through bosses IIS- I6 (Figure 6) that are integrally formed in the support I0, the bosses being tapered and`terminating in the same plane with that of the edges of the peripheral flange I2. The support I0 may thus be tightly secured against the flat surface of a 'wall or the like. If desired.' shims orv washersmay be interposed between the bosses I6," I 6' and the threadedlugs'or ears ofthe outletbox I5 incase of substantial misalignment of the latter relative 'to' thefwall WJT "f i' The wfront wall! I 1 has an inwardlyv projecting' pocket-like portion, generally indicated by the reference character 2t, being integrally formed therewith and, in the illustrative embodiment, having a greater horizontal dimension than its vertical dimension, as better appears in Figure l; this portion comprises a baci; Wall 2da whose rear face preferably does not project beyond the plane of the edges of the peripheral flange i2 (see Figures 3 and 6) joined to the front Wall l i by opposed side walls 2th and Eiic and top and bottom walls 20e and Zilf. Opposed end Walls Elib and 26C are rearwardly convergent, as are alsopposed top and bottom walls e and Eef (Figures 3 and 6), and, being of substantially uniform thickness,

the spaces which they define from either front cr l rear are tapered and thus facilitate drawing or separation of the mold parts where the supporti il is cast or is made of molded plastic material. On the front face of back` wall 2da, in good-sized lettering, formed therein in relief, as indicated at 2l inoFigures 3 and 6, appears the legend PulL being arvi'sual instructionvas to how to operate a manual actuator, generally indicated by the reference characteril,y and a part of which is related` yto the pocket-forming portion 2li in a manner later described. Y

In another portion of the front wall i l, the latter is depressed or displaced to form a back wall 23 (Figures 4, 6, and 2) thatvis rectangular in shape and is peripherally surrounded by a rectangular ledge or rabbet 24. I provide a frangible eleirfient, preferably in the forin of a rectangular plate of glass (Figures 1, 4, and 6), which is dimensioned to just about fit against the front side of the back wall 23, being of. a'thickness just about equal to or less than` the height of the ledge 24 that surrounds the back wall 33 so that the small plate or sheet of glass 25 is peripherally surrounded by the rectangular ledge 2d and its front face, being the upper face as viewed in Figure 4, falls just aboutl inthe plane of the front face ofthe ledge or rabbe't 24. The glass element 25, thus easily and simply inserted into its seat against the rectangular back Wall 23, is held against removal or against falling out of itsseat by an open rectangular frame, generally indicated by the reference character 2l, shaped in outline substantially as yshown in Figure 1, It may also be ,made of molded plastic material. It restsv flatwise against the ledge 24 (see Figure 4), neatly tting into the above-mentioned rabbet of which the ledge 24 forms a part. It has upper and lower horizontal portions 2la and 2lb whose vertical dimensions, as seen in Figure l, are such that the vertical dimension of the opening 2F in the framev 2l is greater than the vertical dimension of the glass plate 25, and it has vertical side portions 21e and `Z'lf which are wider thanthe ledge 24 against which they rest and hence they overlap the left-hand and right-hand end portions of the glass plate 25, as is clearly shown in Figures l and 4. Screws Z-E (Figures 1l and 4) pass through holes in the vertical side portions 2le and 'Alf of the frame 2l andare threaded into rearwardly projecting rectangular bosses 2,9 and (Figures 4 and 2)` integrally formed with the front wall It., `As is bettersh'own in Figure 4, the screws 2S-28 thus secure the glass-holding frame ends 2l'e and Elf tightly against the ledge VZllvbut closely adjacent those frame portions thatV overlap the horizontal ends of the glass plate 25; the latter is thus not only securely held in place, but is' dependably anchored at its ends against the breaking stressappl'ied to it near the mid-point of its lengthby theanvil 3l formed on the manual actuator, 22 (see Figure 6) and extending through 4 a hole 23a in the back wall 23 against which the glass plate 25 rests.

Frame 2l bears a suitable legend, such as Fire as indicated at 32 (Figure l), across one of the horizontal portions of the frame, preferably the upper one 21e. rIShe frame 2l is readily detachable by removing the screws128, 2,8, vso that the broken glass 25 can be replaced. I make suitable provision for preventing reassembly of the frame 2l' to the support I0 in inverted or upsidedown position, and such provision I preferably carry out in a manner also to permit selective display ,of either o f twolegends, of which the one may be the word Firej as above noted, and the other may be the word Emergency Accordingly, the legend Firef appears on the front face of the upper cross-part Zla, in relief, as shown in Figures 4 and 6, and on the back face of the upper cross-part 2l'EL of the frame 2l appears the word Emergency, with its letters also in relief, as indicated at 33 in Figure 6. The upper horizontal part of the ledge 24 I provide with a rectangular recess 34, as shown in cross-section in Figure 6 g and in broken lines in Figure l. Recess 34 is deep enough to. accommodate the thickness of the relief lettering 32 and 33 and is of a length and breadth to let the projecting letterings of the two words Fire and Emergency project into it.

Accordingly, the vglass holding fra'rne 2l can be attached in either of two positions for holding the glass plate in place, in one of which the relief lettering Fire faces toward the front and the relief lettering fErnergency faces to therear, is

' not visible, and is snugly accommodated in the recess 34 in the ledge 24, and in the other position these relationships of the two words are reversed. The relief lettering in each case prevents attaching the frame 2l in upside-down position, for in such case the relief lettering on the inside face f the frame 2l has no recess in the lower hori- Zontal reach of the ledge 24 into which it can enter, it is impossible to align the frame 21 flush v-lith the front face of the wall I l, and this eiect is aided by the different widths of the upper and lower horizontal portions 2ln and 2lb of the frame 2l.` t The manual actuator @tis preferably in the form lof a lever of appropriate length and relationship to the frangible or glass part 25 to provide substantial force ,multiplication for breaking the member 2. As is better shown in Figure it has a straight portion 22a that ex,- tends vertically ,across the back of the b'acirwall Z3 ofthe seat for thegl'ass element @Stand an upper U-shaped portion `22? that forms a linger-v pi'ece and bridges across lthe pocket or well 23 formed by the `rearws-trdly bulging portions of the frontvwall i!,l as above described. The up` per and lower Walls 2de and .'itf of the well have slots 35 and |315 through', which the nger-piece portion 221 of the lever 22' extends. At itsv lower end, the lever 22 pivots about a horizontalaxis formed by a pivot pin y:il so that -`lever `f2?` can swing toward o'r away fromI the front wall Il of the support til. The anvil 3i., asshown in Figures 5 andY l, projects forwardly and' is positioned close tothe pivot p/injilv so thatit lhas a smaller shortliever arm compared to the very much longer lever arm of the knger-piece 22h, the ratio of the latter to theV former being the meas,- ure by which a relatively small pull on the fingerpiece 22h is multiplied into ajlarger and substantial force-to breakthe glass 215.

The lever 22 is normally biased `to hold the anvil t! in engagementwith the frang'ibleele- 5- ment 25,' as shown in Figure 6, the element' 25 serving to limit the outward swing of lever 22 and thereby position the vertical reach of the finger-piece 22b just beyond the plane of the front'face of the front wall I I, giving the fingerpiece sufficient visibility and, in conjunction with the well 2D and the instruction Pull, inviting the insertion of one or two ngers behind the finger-piece 22b and crosswise into the well 20. i

' To -bias the lever 22 as above described, I employ a suitable spring which I preferably construct to form a part of a signalling switch that is connected into the signalling circuit that is to be activated by the alarm station. A preferred form of construction is shown in Figures. 2 and 4 and comprises two switch elements. 4I; and 42 made of any suitable' sheet metal and appropriately shaped and dimensioned for easel of manufacture, as by a punch press operation. Thus the switch part;42 projects laterally from a base portion 43 (Figure 2) which is elongated to rest iiatwise against the rectangular boss 3i) to which it is secured by screws 44 threaded into the boss; one of the screws can serve as a connector for one of the circuit conductors, as indicated in Figure 2, or, if desired, the portion 43 can be provided with a slotted or apertured tablike end with which the conductor is engaged and to which it is preferably soldered. Switch contact part 42 extends crosswise toward the lever 22 and terminates short of it; as shown in Figure 4, part 42 can be bent for appropriate adjustment in relation to the coacting switch part 4I, the shaping of the various parts providing ample space for such bending.

The switch part 4I also extends laterally from a flat base part 45 which is secured to the at boss `29 in any suitable way, as by the screws 46; circuit conductors may be connected thereto, as by one of the screws 46 or by a tab end the same as above described for the other switch contact part.

The switch arm 4I extends crosswise and is of sufficient length to reach over and beyond the lever 122, and it may be bent, as shown in Figure 4, providing also an edge directed toward the stationary Contact part 42 and against which it can make rubbing contact. The switch arm 4I is made of a suitably springy sheet metal, such as brass orPhosphor bronze, and it bears against the lever 22` to bias it, as above described.

y Since the lever V2 is preferably made of metal, Iprovidefor anon-conductive engagement betweenv the switch partit! andlever 212, as by an interposed small sheet or stampingv 41 (Figures. 2 and 4) of i. suitable. insulating material, such as fiber or hard rubber. The sheet 41 is stamped out somewhat in the shape of the letter H (Figure 2), and the rear edge of the switch part 22a of lever 22 is 'cut awaysomewhat in the form ofv aldovetailed groove or slot, as is better shown in Figure 6. The insulating plate 4I is securely held assembled to the lever 22 by engaging the upper and lower edges of the cross bar of itsletter .H form beneath the overhanging upper and lower edges of the dovetailed cross slot 220. In assembly, this is easily done by slightly ilexing the insulating sheet 41.

As abovervnoted, the support I is preferably made of a material that cari-be molded and, as. thus` far described, its configuration lends itself Well forv molding with companion molds or mold. parts that are relatively separable in directionsY from front to rear, as viewed in Figure l1, or: from left to right, as viewed in Figure 6, thus also making use of the various converging or tapering wall surfaces earlier above described. However, with companion mold parts so separable, complications and difliculties are introduced if it is attempted to also mold a hole or holes to receive the lever pivot pin 31 whose axis extends transversely to the direction in which the companion mold parts have to be separated. On the other hand, drilling such a hole involves additional operations and complications, and also expense. These difficulties and obstacles I overcome while retaining the advantages of the above-described kind of mold-` ing operation, which is particularly desirable when the support Ill is to be made of any suitable moldable and curable plastic material.

The transverse pivot pin 31 is preferably positioned to the rear as viewed in Figure l,V and tothe right as viewed in Figure 6, of the lower horizontal partof the ledge 24 against which the glass-holding frame 21 rests, so that the lower horizontal part 2lb of frame `21 can normally close over and cover up the front end of a tapered recess `5I) of generally rectangular cross-section, as is better shown in Figures 5, `6, 7, and 8, the wall 23 being appropriately increased in thickness rearwardly to form in effect a boss 23b (Figures 7 and 8) which merges into the adjacent boss IS that is provided for the screw slot I3, the boss I 1S thereby strengthening and reinforcing the boss 23b at the inner end of which are formed the parts that support the pivot pin 31 and provide a good internallycylindrical seat or support therefor.

These support or bearing portions for the pivot pin comprise a number of parts spaced along the axis of the pin 31, certain of them, 5I and 52, providing a partial pin seat 53 of 180 degrees facing toward the front end of the recess 50 and the others, 54 and 55, providing a partial seat 56, 57 of 180 degrees for the pin facing to the rear, as is better shown in Figures 7 and 8. Parts 5I and 52 are spaced apart (Figures '7 and 8) to provide between them a slot 58 in which to receive the lever 2-2, as shown in Figure 5, that end of the lever being brought into the slot 58 after the upper end of the lever, as seen in Figure 6, is snaked through and into the slots 38 and 35 of the finger well 20. This operation of assembly is simple and quickly accomplished because, as the glass-breaking handle SI is entered into the hole 23a in the wall 23, which it can do only by having the lower end of the levell 22 enter into` the slot 53, the pivot pin hole in the lever 22 is thereby practically aligned with the complementary axially-spaced half- seats 56, 53, 53, and 51, the latter and the hole in the lever being of the same radius; pivot pin 31 is then easily inserted from the rear of the support and into the position better shown in Figure 5. The pin 31 may be held against axial displacement by any suitable means; for example, one of its end portions may be tapered or of slightly enlarged diameter or burred, or otherwise enlarged or deformed so as to cause it to bind in the two adjacent halfseats at that end of the pin, for example, the complementary half-seats formed by the parts 52 and 55.

The lever 22 is thus given a secure and strong 'accanto vfor .the :pini "3'1' need inot `be 'resorted ato; the half-seats y53, '53 lare :given their `desired conformation-during ymolding by a mold part'at the inner end of the vmold part that forms the recess 5t andwhich is to bel withdrawn `in-a direction toward the front of the structure, or upwardly as vViewed in Figure 8; 'while the half'- seats 5G and V51 are giventheir desired `13G-degree `configuration by mold 'parts that are separable or `to be `withdrawn ina direction toward the rear Vof the molded structure, or downwardly as viewed in Figure 8.

lBreaka'ge of the glass part 25 will be seen to be readily accomplished, the relatively Asmall force :applied at the linger-piece end 212h of level` 22..being considerably multiplied at the anvil 31| duetto the relatively short lever arm of the latter from the pivot pin 31. Once the glass part 2-5 .is broken, 'those portions of the molded structurel that are in front (to the left in Figure 6 ofthe flower or straight portion 22ab of lever 22 are protected against being subjected to detrimental strain by continued v'actuation of the lever, by limiting the extent of outward movement of the upper 'end of the lever where the actuating force is applied. Thus, as is better shown in Figure 16, the upper end of the U-shaped fingerpiece lever portion 22b passes through the slot 35 in the well wall '20e where it has an upward extension 22f 'that is directed toward the upper boss I through which a securing screw I4 passes. This end part 22f extends toward the adjacent inclined lface of the boss It from which, in normal position as shown in Figure 6, it is spaced by a short distance, and as the lever 22 is pulled in counterclockwise direction in Figure 6, the lever end -2'2f engages the wall -i lY after' a lever movement suilicient to break the glass 25 and resists further pull ofthe lever so that the lower 'end thereof cannot exert any Yforce against the wall 23 `'or other parts of 4the structure. This stoppage of lever lmovement is effected by engagement of the lever end 122f with a part of the molded support lthat is closely adjacent the upper securing screw i4, thus further'relieving the molded structure of detrimental strains and in effect imposing them upon the 'anchorage `of the dev'i'ce t0 the wall or other support, such as the upper screw 14. The location and support of the pivot pin l3l virtually at -or by the lowerboss I6, and hence closely 'adjacent to the lower anchoring screw M, contribute toward having the lower anchorage `distribute or take up stresses ofrea'ction at the ulcruni or pivot 3l during yglassbre'a-king action of the flever.

fffOverstraining of the device 'is thus' guarded against. Normallyf'svjitch 13h-M, where the 'Signalling system is of the open circuit type; stands open as vin Figure 4, being vheld 'open `because the glass 25 prevents lever 22 from swinging under thefb'ia's of the spring M; when the lever is pulled and the glass broken, spring contact 4i follows upfthe movement of the lever and closes the circuit at'x'ed contact d2'. Manual release of the lever leaves the latter under the bias of spring M, with the linger-piece part "22h materially -project'ed out of the well 20 to an extent permitted by the istop action of lever end 22f. The broken glass and this outward projectionV of the linger-piece 22h are visual indications that the signal station has #been pulled in addition to the `signal vactuation that results from closure of the circuit at contacts 4l, 42. ReplacementY of the broken glass restores the par-ts to normal positions.

1t lwill thus be seen that there has been'prov'idedirin-` this invention fatsgnalling station `and apparatus f'in which the-several-objects heretofore noted, together with Tmany thoroughly` practical advantages; fare successfullyvachieved. The `device is compact,*neat yfand :attractive -in appearance,v its fabricationby moldingoutof Lplastic materialsiis'ffacilitatedpand 'in practical use `it is -of reliable action. vReplacementr-ofa broken glass partiseasilyand readily accomplished and, moreover, selectivity of legends to be displayed is achieved -in"a -"s`imple and -:thoroughly practical manner.

many'ipossible embodiments maybe madeof the Aabove invention and as many `changes might be 'made ini the'embodiment above 'set forth, it is to beu'nder'stood fth'at'fall matter 'hereinbeforesetzcrorthforrishown the accompanying drawings 'is toub'e interpreted:asillustrative and no't ina 'limiting sense.

I claim:

f1. vhn valarm =signallingl station comprising fa molded plastic v:'casing-like structure vhaving a front-wall-withspacedrearwardly extending reinforcing bosses betweenwhich said frontwall is provided with l'a'fre'arwa'r'dly depressed pocket-like portion positionedadjacent 'one o'f said bosses and-"being fopen at the fron-t and formingfafii'n'ger Welland another rearwardly depressed portion adjacent the other of fsa'idfbossesfand forming a front' seat for afrangiblamember, a `lever eX- tending substantially from one of said bosses `to the other and in back of said second-:mentioned depressed 'portion but traversing `said first-mentioned 'depressed portion, 4the latter having opposed slots in thewal-ls there'o'ifor the passage therethrough yof said lever so that 'one end of the never terminates-adjacent sal-d first-mentioned boss, means mechanically lrelated to said ksecond.- mentioned =boss. forming arpivotal vsupport for the other end 'of 'said lever, said Isecond depressed portionhaving a'frangible member seated therein land having an aperture through which 'said lever acts upon said frangible member to` break it, means holding said ffrangible umember in the seat formed by'said second depressed'portion, and signal Vcontrol means responsive to actuation v'of said lever appropriate -to break fsaid frangible member, said two spaced bosses having lmeans for securing said casing-like structure to a supporting surface and 'being thereby anchored 'to mutually resist stresses exertedfby said lever.

A2. An valarm signalling *station according to claim 1 in which the portion of the lever that traverses s'aid first-mentioned depressed portion is curved forwardly' for saidA `casing--like structure to 'facilitate pas's'age'cfa "ngerbehind it and into said 'finger well.

3. An alarm signalling station according to claim 1 in which 's'aid first-mentioned end of said lever coactvs with a'portion'o'f said casing-like prisestwo enacting conductive #switfjhtelemts respectively directly secured at the rear to said molded plastic casing-like structure and thereby vinsulated from each other, one of said switch elements being in the form of a spring member biased toward the other switch element and having means whereby it insulatingly engages said lever and biases the latter in forward direction relative to said finger well whereby, upon breaking of said frangible member, said spring member swings said lever to project the portion that traverses said finger well in outward direction relative to the latter.

7. An alarm signalling station according to claim l in which said front wall is provided with integrally molded rearwardly projecting bosses spaced to either side of that portion or" the lever that passes in back of said second-mentioned Vdepressed portion, the aforesaid means for holding said frangible member in its seat comprising means engaging the frangible member at its respective ends and respectively secured to said last-mentioned spaced bosses.

8. An alarm signalling station according to claim 1 in which said front wall is provided with integrally mol-ded rearwardly projecting bosses spaced to either side of that portion of the lever that passes in back of said second-mentioned depressed portion, said frangible member comprising a quadrangular Apiece of glass and the holding means thereforcomprising a quadrangular open frame that overlaps said quadrangular glass only at two opposed ends oi the latter, and securing means coacting respectively with said last-mentioned spaced bosses and said overlapping frame portions for securing said frame in place.

9. An alarm signalling station according to claim l in which said pivotal support for said lever comprises a pivot pin that extends parallel to said front wall and, molded integrally with said front wall, a plurality of complementary half -seat-iorming portions spaced in the vdirection of the axis of said pin and molded respectively from the front side of said iront wall and the rear side of said front wall.

10. In signalling apparatus, in combination, a plate-like support having a rearwardly bulging portion forming a iinger well that is open toward the front and having adjacent thereto means forming a seat for receiving a frangible member at the front of said plate-like support, a frangible member in said seat and provided with means engaging said frangible member at two spaced points coacting tc hold said frangible member in said seat, an actuating member having means at the rear of said front wall for movably supporting it, said actuating member having a handle portion that extends into said nger well through an aperture in a wall of said well, said actuating member having force-applying means engageable with said frangible member to break it in response to manual force applied to the handle portion of said well, and signal control means actuated upon movement of said actuating member sufficient to break said frangible member.

11. A signalling apparatus according to claim in which said holding means for said frangible member comprises a part having a iront face and a rear face which bear respectively different legends, together with means reversibly securing said holding means to said support to selectively position it with either of said legend-bearing faces on the outside.

12. In signalling apparatus, in combination, a wall member having rearward thereof a manual actuator and having a rearwardly bulging portion lforming a finger well that is open toward the front and having slots in two opposed side walls of said well, said manual actuator traversing said linger well to present a portion thereof to said well for manual engagement from the front of said wall member and having divergent arms eX- tending respectively through said slots to the rear of said wall member whereby movement thereof is limited, one of said arms having an extension which has pivotal connection with said wall member at the rear of the latter, and a frangible member supported at the front of said wall member and adjacent said pivotal connection, said arm extension having force-applying means to break said frangible member.

13. In signalling apparatus, in combination, a wall member having a rearwardly bulging portion vforming a ringer well that is open toward the front and having slots in two opposed side walls of said well, a manual actuator having a forwardly bulging portion that traverses said iinger well so that a nger may be inserted into said well and behind said bulging portion of said actuator for manually actuating the latter, said bulging actuator portion having divergent arms extending respectively through said slots to the rear of said wall member whereby movement thereof is limited, and signal control means responsive to actuation of said actuating member.

lll. In signalling apparatus, in combination, a wall member having a rearwardly bulging portion forming a iinger well that is open toward the front, said finger well having a slot in a wall thereof, a manual actuator comprising a fingerpiece portion in said iinger well for manual actuation thereof from the iront of said wall member and an extension from said finger-piece portion and through said slot to the rear of said wall member whereby movement of said actuator is limited, said extension having pivotal connection with said wall member at the rear of the latter, signal switch means, and a frangible member carried by said wall member and coacting with said extension and said switch means to hold said actuator at or near one limit of its range of movement relative to said well and to hold said switch means in unactuated position.

l5. In signalling apparatus, in combination, a substantially rectangular frangible member, a wall member having means forming a seat at the front thereof for said frangible member, means for holding said frangible member in said seat to facilitate breaking thereof comprising an open rectangular frame having means for securing it to said wall member, two opposed sides of said frame having a spacing not less than the width of said frangiblel member and the other` two opposed sides of said frame having a spacing less than the length of said frangible member whereby the last-mentioned two opposed sides of the frame respectively overlap and hold two ends of said frangible member, and means for applying breaking force to said frangible member intermediate said overlapped ends thereof.

16. A signalling apparatus according to claim l5 in which the two faces of said open rectangular frame carry respectively different legends, said means for securing said frame to said wall member comprising means for detachably and reversibly securing said frame to said wall member to selectively face either of said legend-bearing faces toward the front.

17. An alarm signalling station comprising a molded plastic plate-like support having a wall` member, signal control means carried by said support comprising a member having a supporting pin therethrough with the aXis of said pin parallel to said wall member, and, molded integrally with said wall member, a plurality of complementary half-seat forming portions spaced and aligned along an axis parallel to said wall member foraxially receiving said pin, said complementary half-seat forming portions having their respective half-seats correspondingly spaced and aligned and facing respectively toward the front andv toward the rear of said wall member for engaging and holding the pin at axially spaced front and rear portions thereof, said wall member being apertured from the front opposite such of said half-seats as face toward the front. f

18. An alarm signalling station according to claimA 1'7 provided with a frangible member having means eoacting with said wall member for supporting it in a position where it is visible from thel front of said wall member, said pin-supported member having a part to engage and breaksaid frangible'member, said supporting means for said frangible'member covering over that portion of said'wall member that is apertured 'opposite such ofisaidihalbseats as face toward the front.

19. In signalling apparatus, in combination, a frangible member, a wall member having means fonspporting said frangible member comprising a holding element having two faces carryingrespectively diiTerent legends and means :forv detachably and reversibly securing said holding ele; ment to said wall member to selectivelyface either of said legend-bearing faces toward the front, and means for applying breaking force to said irangible member.

20.. In signalling apparatus, in combination, a Wall having a rearwardly bulgingl portion forming a fingerv well that is open toward the front, an actuating member positioned rearwardly of said wall member and having means for movably supporting it relative to the latter, said actuating member having a handle portion that extends into said finger well through an aperture ina wall of said well for manual actuation thereof from the front of said wall member, and signal control means responsive to actuation of said actuating 1nember.

LEO L. VERKUIAL.

REFERENCES CITED The following references are of record inthe file of this patent:

UNITED STATES PATENTS Number Name Date 2,083,324 Edwards June 8, 1937 2,356,989 Getz n Aug, 29, 1,944

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