US2600609A - Closure actuated mechanical alarm - Google Patents

Description

June 17, 1952 4 J. P. BARTON 2,600,609

CLOSURE ACTUATED MECHANICAL ALARM Filed Feb. 5, 1948 2 SHEETSSHEET l -u, 28 F w T? 50 IF fHV-EJ'JTDZ" 44 7 J63 P Barton June 17, 1952 J. P. BARTON 2,600,609

CLOSURE ACTUATED MECHANICAL ALARM Filed Feb. 5, 1948 2 SHEETS-SHEET2 .[271 517 Zbr J P Barton Patented June 17, 1952 CLOSURE ACTUATED MECHANICAL ALARM Jay P. Barton, Defiance, Ohio, assignor, by mesne assignments, to Defiance Automatic Screw Company, Defiance, Ohio, a corporation of Ohio Application February 3, 1948, Serial No. 5,938

16 Claims.

The present invention relates to improvements in mechanical alarms and more particularly concerns a device which embodies a clapper arrange-merit adapted to create an audible sound when released from restraint whereby to advise the hearer of an occurrence or a condition requiring attention, such as an unauthorized entr through a closure or the presence of fire, or the like.

An important object of the present invention is to provide an improved mechanical, nonelectrical alarm device for giving an audible alarm in the presence of certain conditions or upon the happening of some occurrence such as the opening of a window or door.

Another object of the invention is to provide a satisfactory low cost, simple, and efiicient practical mechanical alarm assembly.

A further object of the invention is to provide an improved wind-up type of spring actuated mechanical alarm.

Still another object of the invention is to provide an improved compact, easily assembled and installed burglar alarm device.

Yet another object of the invention is to provide an improved method for assembling the structure of mechanical alarm assembly.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings, in which:

Figure 1 is a fragmentary perspective view of a building interior showing part of a wall and window structure with an alarm device according to the present invention installed thereon.

Figure 2 is a fragmentary perspective view of a wall and door or casement window arrangement having an alarm device identical with Figure 1 applied thereto.

Figure 3 is an enlarged vertical sectional view taken substantially on the line III-III of Figure 1.

Figure 4 is a horizontal sectional view taken substantially on the line IVIV of Figure 3.

Figure 5 is a vertical sectional view taken substantially on the line V-V of Figure 4.

7 Figure 6 is a perspective view of the mechanism supporting member of the alarm unit prior to assembly thereof and demonstrating how assembly of the operating mechanism is facilitated.

Figure 7 is a fragmentary vertical sectional view through a modified form of the alarm de- V108.

, Having reference to Figures 1 and 2, a mechanical alarm unit It embodying the features of the invention is adapted to be mounted in such relation to an openable building closure such as a sliding window, a casement window, or adoor. that when the latter is opened by a person from the outside of the building, or in the case of a casement window or door accidently swings open, the alarm is released and gives audible evidence of the opening.

Having reference to Figures 3, 4, and 5, it will be observed that the mechanism of the alarm unit I0 is of relatively simple construction. It comprises an outer casing and supporting housing II, a mechanism supporting member I2 mounted within the housing and carrying a-windup clockwork and escapement mechanism l3 arranged to operate a clapper I4 which, in the nonoperating condition of the mechanism is held inoperative by a releasable pin I5. The construction and arrangement is such that when the pin i5 is withdrawn the clapper is free for actuation by the wind-up and escapement mechanism l3 and is vibrated thereby to strike an appropriate sounding member to give an audible alarm.

For economy in manufacture, and relatively low cost, efficient performance and attractive appearance, the housing I I is preferably formed from appropriate sheet metal shaped into substantially box-like outline. To this end the housing includes an outer relatively flat wall member I! of generally rectangular, elongated form with integral coextensive angularly extending end Wall members I8 and I9 extending from the ends thereof and providing respectively top and bottom wall members for the unit. The end wall members are provided with respective i1:- tegral outwardly extending, preferably coplanar attachment flanges 20 which are centrally perforated as at 2| and equipped with resilient mounting grommets 22. Attachment means such as wood screws 23 extending through the grommets 22 are adapted to secure the unit in place on a window frame board 24 (Figs.- 1 and 2) or a door frame 25 (Fig. 2). The grommets 22 serve to support the unit in spaced relation to the frame board to which attached and serve as vibration insulators.

The sides of the housing member II comprise integral coextensive inwardly extending side wall flanges 21 and 28 which, though integral with the outer face wall or panel H are preferably free from contact with the end wall flanges or panels 18 and I9. To this end the adjacent edges of the side and end wall panels are permanently spaced apart as shown.

The mechanism supporting member I2 is preferably also constructed from appropriate sheet metal and is arranged to have the mechanism mounted therein as an operative unit or subassembly prior to assembly of such subassembly with the housing H. In fabrication of the supporting memberi i2, a sheet metalLstrip is bent along parallel lines to provide a base or bottom panel 29 of a width and length preferably smaller than the bottom wall panel IQ of the outer housing, a rear panel 30 integral with and perpendicular to the bottom panel, a top flange or panel 3| integral with the rear panel'and overlying the bottom panel, and a front panel 32integral with the front edge of the bottom panel and opposing the rear panel. The rear panel is narrower and shorter than the front wall panel ll ofthe hous ing. The top panel flange 3| is slightly wider than the base panel 29. The front panel 32 is of the same width as the rear panel 30 but is substantially'shorter; The rearand. front panels 35 -and 32, respectively, provide support for the clockwork-mechanism or clapper-actuating motom.

Prior-to assembly of. the motor l3 with the supporting member l2, the rear and front panels 3ll 'and 32- are preferably generally divergently related-- (Fig. 6), that is with the front panel 32 diagonally related so that its upper edge is spaced an appropriate distance further from the O rearipanel 33 than the lower edge, for the purpose-off'faci'litating assembly of the works of the motor 'l'3 lwith' the: support member. Accordinglyythe b'ottompanel 29 is preferably formed iz't-itspreassembled condition-with a longitudinal; bend. on-aline 33 by which theforward marglrt-iof-the lower panel 29* is tilted downwardly relative to the major planef the lower panel. This causesthe front panel 32 to assumethe deslredt diverging-angularity. relative to the rear panel-3|!- while'nevertheless maintaining thefront panel32 in. proper substantially-right angular relatioirtotthe front'margin of theibottom panel 29. Therebyrafter the motor works have been assemblediwith the supporting member the'fron-t and rearportions of. the: bottom panel 29 can be brought back tocoplanar relationship by flattenin'g iout the'b'ottom panel along the line 33' and as a consequence the front and rear panel will assume substantially parallel relation. In order I toraenitate bending of the bottom panel along the line33, a substantial slot 330:. may be cut longitudinally on the line 33 whereby to reduce bending resistance of the remaining unsevered portions of the bottom panel metal beyond the opposite ends of the slot.

The motor' I'3' comprises" amore or less con ventionaltype of clockwork mechanism. This in'- eludesa relatively large driving gear and ratchet member 34 mounted relatively rotatably on a drive shaft 35 and having a uniform series of ratchet cut cuts 3-! in the body thereof dividing the sa'me into a uniformseries of ratchet spokes. Slidably abutting the ratchet gear and wheel member 34 facewi'se'andfixedly mounted on the shaft 35 is a disk ratchet spring member 38 which has a plurality of integral flexible ratchet teeth 39 (Figs. 4-and-5) which are adapted upon rotation of the shaft 35 in one direction to engage with the'ratchet' spokes of the wheel 34 and turn the same with the shaft. The opposite ends of theshaft 35 are formed with respective bearing portions or trunnions 49' and ll adapted to be journalled in ultimately coaxially aligned bearing apertures 42 and'43 in the rear and. frontpanels respectively of the supporting member (Figs. 4 and 6). A clock spring 44 is wound about the shaft and has a slot 45 in its inner end engaged upon an anchoring lug 41 on the shaft while the outer end of the spring has a slot 48 by which such end is engaged upon an angular anchoringlugfiil'which is'struck inwardly integrally from the front panel 32 (Figs. 4. 5 and 6) thus, the spring 44 is adapted to be wound up by turning the shaft in one direction, counterclockwise asseen. in. Fig. 5. To place it under load to drive the shaft 35 clockwise and through theratchet; disk .38' similarly drive the ratchet and gear wheel 34.

Motive power from the gear wheel 34 is transmitted to a pinion'50 with which it meshes and which: is carried fast upon a shaft 5| having its ends journalled in appropriate axially aligned journal apertures 52 and 53 in the rear and front panels 30 and 32, respectively, of the supporting member.

An escapement wheel 54 fixedly carried on the shaft 5| with the-pinion 53 coacts with an escapement lever-or pallet'55- whichv in turn transmits the motion of the clockwork mechanism. to the clapper M.-

By preference, the pallet 55 is formed as a simple sheet metal stamping comprising anelongated body portion 51 reduced at its opposite ends to provide appropriate trunnions 58 and 59 which are arranged to be received,- in appropriate journal apertures '60- and 6| in the. rear? and front panels'3i) and 32, respectively, of the supporting member. Projecting-toopposite sides of the body portion 51 are aligned- escapecheck arms 62 and 63. Herein, the check arm 62- is adapted tube at the trailing side of the escapement assembly and the arm 63 at the advancingside. For this purpose the check arm 62 is formed. of generally hook shape to provide a check face 64 for engagement with successive escapeteeth of theescape wheel 54; The check arm 63 is formedgenerally right angular and provides aninner check face 65 for engagement. with successive escape teeth alternately with the check face 64 of the check arm 62.

In assembling the-motor and escapementmechanism with the supporting member l2, the-shafts 35 and 5|, and-the pallet 55 are appropriately assembled. with one of the panels 30 or 32, and the panels are then brought into parallelism by straightening out-the bend 33, thus bringing, the front panel 32 from-the: full line position shown in Fig. 6 to thedashline position. This completes assembly of the operatingmechanismwhen the-spring 44 is attached to the shaft 35'and the anchoring lug-49;

This completed subassembly is thenv assembled with the housing I and secured in placed in appropriate manner such as by means of self-tapping sheet metalscrewsifil; For'this purpose the bottom wall panel l9: of the housing is formed with appropriate apertures 68 (Fig. 3) which are arranged to align with appropriate apertures definediby' upset flanges 69 in the bottom panel 29 of'the supporting member into which the screws 6'! are drivento draw the bottom panel 29 tight against the bottom wall panel IQ of the housing.

In the assembly-thus completed, the front panel 32 is disposed in slightly spaced relation to the front wall panel I! of'the housing and'the'top panel 3| of the'supporting member is disposed in spaced relation below the top'panel I8 of the housing and with the forward edge of thetop panel 3| engaging the front wall panel IT.

Winding of the clockwork motor i3 -is adapted to be effected through the medium of a conventional winding key which is threaded onto a forward extension of the shaft journal 4| and projecting through an enlarged clearance aperture H in the front wall I! of the housing coaxially aligned with the journal aperture 43.

Energy stored in the motor l3 and. transmitted to the pallet 55 is designed to vibrate the clapper l4 and cause the latter to strike resoundingly against resonant portions of the assembly.

To this end the clapper I4 is preferably formed from appropriate rod stock with the lower end portion thereof secured as by welding or brazing to the back of the clapper body portion 51 and from which the body of the clapper extends upwardly and preferably diagonallyin the ample space provided therefor above the motor below the top panel 3| of the supporting member. Short of the top panel the clapper is formed with an angular, generally horizontally extending clapper arm 12 which is provided with a striking head 13 joined to the arm by an angular offsetting portion 14 which functions as a latch shoulder engageable by the restraining pin Hi. In the absence of the pin l5, the clapper head 13 is adapted to be vibrated or swung to strike alternately against the side wall 21 of the housing II and against the top panel of the supporting member l2. The striking limits of the clapper are shown in dash and dot dash outline in Fig. 5 while-the restrained position of the clapper is shown in full line.

The sound effect produced by the clapper is resonant and loud but quite distinctive from the sound made by a bell or buzzer such as may be associated with a telephone, door bell, an alarm clock, or the like. This enables the sound of the alarm device 10 to be clearly distinguished and recognized. Contributing to the distinctive harmonic condition prevailing during operation of the clapper is the fact that the side wall 21, is attached only to the front wall I! and free from the top and bottom walls I 8 and I 9 and also freely spaced from the surface 24 against which the unit may be attached. Thus the side wall 2'! when struck sharply by the clapper head 13 is enabled to vibrate with audible frequency. While the overlying top panel 3| of the supporting unit I2 serves as an overthrow stop for the clapper on rebound,

and is held against any substantial vibration by reason of its integrality with the rear panel 30 and its abutment with the front wall panel l1, it does serve to some extent as a sounding board or device with a relatively dull tone as compared with the ringing tone of side wall 21 under clap per impact. Since the opposite side wall 23 of the housing is also free to vibrate in the same manner as the side wall 27 against which the clapper actually strikes, the side wall 28 serves as a harmonic sounding board opposite the vibrating side wall. Furthermore, by the partial closure provided by the supporting member i2 within the housing H,'a resonance chamber is provided that gives additional character and distinctiveness to the alarm tone'emanating from the unit. In further implementation of the tone quality of the unit the front panel 32 is extended upwardly a substantial distance beyond that actually required for motor mechanism support,

thus affording additional sympathetic reed-like vibrational harmonic characteristics to the overall tonal elTect. I

Normally, of course, it is desirable to retain the clapper l4 inoperative by means of the restrainthe housing II and the top panel 3| of the supporting member l2 are provided with coaxially aligned pin apertures 15 and 16 respectively so located that when the pin [5 is inserted therethrough the inner end portion of the pin is effectively interposed in the path of movement of the shoulder portion 14 of the clapper (Figs. 3, 5 and 6). In this relationship it is possible to wind up the motor spring 44 and the pallet 55 holds the escapement against movement so that the motor can be fully wound. Instantly upon withdrawal of the pin l5 the clapper is set into rapid motion to sound the alarm.

Since the top wall I8 and the top panel 3| are substantially spaced apart they serve to hold the clapper restraining pin 15 against skewing due to pressure of the clapper thereagainst.

Also the pin apertures 15 and 16 are assured of reasonably accurate alignment in assembly. where properly spotted on the respective panels, by the abutment of the edge of the panel 3| against the housing front panel I? which comp-ensates for any tendency there may be for the panel 3| to extend too far forwardly due to sprung condition of the back panel, or the like.

When the unit I9 is installed in association with a slide window as shown in Fig. 1, it is mounted on the inside of the window frame '24 with the top approximately level with the top of a window sash H, and a connecting cord 18 tied to an eye 19 at the upper end of the restraining pin !5 is connected through the medium of means such as a hook to an eye 8| secured in the window sash. When the window sash TI is raised as indicated in dash outline in Fig. 1, the cord 18 attached thereto as described withdraws the pin l5 and releases the clapper for operation to sound the alarm.

It should be understood, of course, that if it is desired to connect the alarm unit ID to the upper sash which on opening slides downwardly, the alarm will be mounted on the window frame 2 3 in an upside down relation as compared to the mounting shown in Fig. 1 and the pin IE will therefore be withdrawable from the bottom of the unit through connection of the cord 18 to a suitable eye or the like on the window sash.

When it is desired to disconnect the alarm from the window sash, the hook 86 can readily be disconnected from the eye 81 so that the window sash H can be moved freely.

Where the alarm unit I0 is to be used in connection with a door or casement window 82 which swings relative to the frame 25 as shown in Fig. 2, the alarm unit may be mounted in the same manner as shown in Fig. 1, that is in upright condition with the cord connected to the restraining pin l5, and identified at 78' running through a guide eye 83 on the frame 25 above the alarm unit and then over to an eye 84 secured in the swinging member 82 and to which the attaching hook 30 on the cord is detachably engaged. Thus, when the swinging member 82 is opened by an unauthorized individual, or accidentally swings open, the cord 18 is pulled through the eye 83 and the pin I 5 withdrawn from the alarm 'which promptly sounds off, When it is desired to open the swinging member 82 from within, the hook 80 is detached from the eye 8 and allowed to depend freely as indicated in dash outline in Fig. 2.

The alarm unit of the present invention is also adapted for use as a fire alarm. For this purpose, as shown in Fig. '7 the clapper of the device will be restrainedrn ttby asqwithdrawable restraining pin :buirqby means;;whi,ch is; respons ve to; heat of predeterminedtemperature to release the clapperwfor operation. To this; end an alarm unitrfllflvinzall essential'respectsthe same as the alarm unit Hl'may be'provided-having a clapper H8 includinga-striici-ng; head [4| which isadapted: to: strike 'resoundingly' against a side wall I21 andxis-limitedinrebound by striking against a top panel Hit of a supporting. member 12!. Normally; the clappenl lilis held: inoperative by meanssu'ch as-"a fusible linkv I50 Which-is connectedgat one end to the clapper I40 and at its other end to an opposite side wall I28 oi'the housing-f ;the device. The fire alarm unit Hill is mounted position such as on theceiling of a roomror in any othor appropriate position where heatifrom: a fire or an overheated heating apparatus or. the like will cause the link I50 to fuse cit-melt: and: thus release the clapper M3 for sounding the alarm;

It will, of course. be understood that various details of construction may be varied through a \v'idevrange without departing from the principles of this invention and it is, therefore, not the purposeto limit the patent granted hereon otherwisethan-necessitated by the scope of the appended claims.

Iclaim as myinvention:

1.- In combination inan alarm device of the character described, a housing having a wall adapted to vibrate with audible frequency, a second wall disposed angularly relative to said first mentioned wall, a clapper mounted in said housing: and adapted'to strike said first mentioned wall, motor means for actuating the clapper, anda' clapper restraining pin releasably carried by said secondwall and disposed for restrainingthe clapper against clapping movement and adapted-to be connected to-a-movableobject for withdrawal to release the clapper for sounding an alarmiwhen said object is moved.

2: In combination in an alarm device of the character described, a supporting member, a clockwork mechanism and a clapper to be operated: by the clockwork mechanism assembled with said supporting member as a subassembly, a housing encompassing said subassembly and including a sound creating element against which the clapper is adapted to strike, and means carried by the housing and extending interiorly thereof into engagement with-the clapper for releasably restraining the clapper against operation.

3'; In combination in an alarm device of the character described, a generally box-shaped casing: having opposite walls including attachment flanges 1 carrying resilient grommets, saidgrommetsadapting; the casing to be mounted on-a'supporting surface without direct contact between the casing and thesupporting. surface, another wall of said casing being disposed intermediate and free of said opposite walls and adapted to vibrate with audible frequency, a clapper mounted within the casing and adapted to strike said intermediate wall, and means Within the-casing for motivating the clapper.

4. Incombination in an alarm device of the character described; a generally box-shaped casing-having opposite walls including attachment flanges. carrying resilient grommets, saidgrommets adapting the casing to bemounted on a supporting surface without direct contact between thecasing and the-supporting surface, wall of saidcasing being disposed intermediate and free ofsaid: opposite walls and adapted to. vibrate with 4 audibiefr-equency, a clapper mounted with.-

in the casingand. adapted; tostrike said wall, a

wall of. said casing other than. said.- intermediate wall carrying a member for releasably restraining the clapper against operation, and means within the casing for motivating the clapper.

5; In combination. in an alarm; device orthe character described, ahousing, asupporting member-comprising an angularly shaped. sheet metal structure secured within said housing, said supporting. member having apair of spaced panels disposed-inspaced relation toall walls of theghousing, a motorbetween said panels and having a shaft-.journal-ledin; said panels, I a clapper; having a. pivotal mounting disposed. between; and journalledinsaid panels, means pro.- viding a: motivating connection between the clapperr and the motor, and. means disposed to.- be struckrby the clapper.

6'.- Incombination in an alarm deviceof the character described, asupporting member comprisingspaced panels, amotor mounted between said: panels, a clapper mounted between said panels and operative bythe motor, one of said panels having a flange disposed to limit movement of theclapper in operation in one direction, and sound creatingmeans arranged to be struck by the clapper on movement in the opposite direction.

7. Incombination in an alarm-device of the character described, a supporting member comprising spaced panels, a motor mounted between said panels, a clapper mounted between said panels andoperative-bythe-motor, one of said panels having a flange disposed to limit move ment of the clapper in operation in one direction, and sound creating means arran edv to be struck by the clapperon movement in the opposite direction, said flangehaving an aperture therethrough for passage of a releasable clapper restraining pin.

8. In combination in an alarm device of the character described, a housing, a supporting structure within said housing, amotor carried by said: supporting structure, aclapper carried by said supporting structure and arranged to be operated by the motor, said clapper having a free striking portion and said housing carrying sound-creating means in position to be struck by said portion; said supporting structure and said housing having spaced apart portions adjacent to the free striking portion of the clapper, and a releasablemember carried by said spaced apart portions and arranged to. hold the clapper normally inoperative but releasable by withdrawal relative to. said spaced apart portions to permitthe clapperto operate under themotivation of .said motor to strike said sound-creating means.

9. In an alarm. device of the character described, a' clapper, motivating mechanism including.anescapementwheel, and a pallet comprising a sheet metal member carrying the. clapper and havinga pair of escape arms coactively disposed with respect to the. escapement wheel and projecting to opposite sides of the pallet and a pair of trunnions on an axis-normal to the direction of said arms, said pallet and the arms and trunnionsthereon comprising a one-piece stampmg..

10. In analarm structure, a clapper comprising a rod body having a clapper head at one end, and apallet secured to the opposite end portion of the-clapper, said. pallet comprising a sheet metal member having an elongated body with the clapper secured to the back thereof and havin trunnions in one piece therewith at its ends, the body having integral cooperative oppositely extending escape arms extending from the sides thereof and arranged to engage operatively with an escapement wheel in a motivating assembly.

11. In combination in an alarm unit of the character described, a motor and clapper supporting member comprising a sheet metal structure including spaced apart panels and a connecting panel, said connecting panel having a bend running parallel to said panels and with a portion of the connecting panel extending diagonally to the remaining portion whereby to maintain one of the spaced panels divergently related to the other spaced panel, said spaced panels having apertures therein generally aligned for receiving clapper and operating mechanism journalled thereon, said panels being movable toward one another by flattening said portions of the connecting panel along said bend line after said mechanism has been assembled therewith.

12. The method of assembling alarm mechanism with a supporting structure wherein the supporting structure includes a sheet metal member comprising spaced mechanism supporting panels and a connecting panel and the connecting panel has a bend therein parallel to said spaced panels to maintain the panels divergently related prior to assembly, which comprises assembling the mechanism between said spaced panels and with the shafts of said mechanism journalled in said panels, and straightening the connecting panel to move said spaced panels into substantially parallel mechanism supporting relation in final assembly.

13. In a supporting structure for an alarm assembly, a sheet metal member having spaced apart mechanism supporting panels, an integral panel connecting said spaced apart panels and having a portion thereof bent angularly to the remainder of the connecting panel, the connecting panel having a slot extending longitudinally of the bend line between the portions thereof to facilitate bending along said line, whereby after assembly of the mechanism between said spaced panels such panels can be moved into closer spaced relation by straightening of the angularly related portions of the connecting panel.

14. In combination in a mechanical alarm of the character described, a housing having an outer wall panel and integral spaced angular supporting walls for said outer wall panel with spaced additional angular walls integral with the outer wall panel but separate from said supporting walls, all of the walls cooperating to provide with said outer wall panel a substantially boxlike structure, a supporting member mounted within the housing on one of said supporting walls and having a pair of spaced panels disposed in spaced relation to all of the housing walls, and clapper and actuating mechanism carried by said supporting member between said spaced panels, the clapper being arranged to strike one of said additional angular Walls of the housing as a sounding element while the remaining of said additional walls serves as a harmonic sounding board.

15. In combination in a mechanical alarm of the character described, a housing having an outer wall panel and angular spaced integral supporting walls for said outer wall panel with spaced additional angular walls integral with the outer wall panel and at least one of which is separate from said supporting walls, all of the walls cooperating to provide with said outer Wall panel a substantially box-like structure, a supporting member mounted within the housing on one of said supporting walls and having a pair of spaced panels disposed in spaced relation to all of the housing walls, and a clapper and clapper actuating mechanism carrried by said supporting member between said spaced panels, the clapper being arranged to strike said one additional housing wall as a sounding element, one of said supporting members panels including a sound improving portion.

16. In combination in a mechanical alarm of the character described, a generally box-like housing providing an enclosed chamber, means on said housing for attachment to a support, a mechanical motor unit including a sheet metal supporting member including a panel disposed in spaced opposing relation to a wall of the housing, said motor unit including a clapper, said clapper having an angular portion normally disposed adjacent to said panel on the side thereof opposite the housing wall, said panel and said housing wall having aligned apertures therein, and a clapper-restraining pin extending through said apertures and having a portion extending beyond said panel into the path of said angular portion of the clapper for restraining interengagement therewith, said pin having a portion exteriorly of the housing wall for withdrawal of the pin from the path of the clapper, the engagement of the pin by said panel and said wall holding the same rigidly against the pressure of the clapper tending to cant the pin.

JAY P. BARTON.

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

UNITED STATES PATENTS Number Name Date 314,450 Jacobi Mar. 24, 1885 1,042,025 Mosmann Oct. 22, 1912 1,562,067 Sprouse Nov. 17, 1925 1,771,691 Riley July 29, 1930 1,819,347 Uterholzner Aug. 18, 1931 2,430,850 Adolf Nov. 18, 1947

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