US2429867A - Dust guard - Google Patents

Description

Oct. 28, 1947.

D. D. BRYANT DUS T GUARD Filed Aug. 13, 1945 4 Sheets-Sheet 1 4 Sheets-Sheet 2 I Oct. 28.; 1947.

\ D. D. BRYANT DUST GUARD Filed Aug. 15, 1945 Oct. 28, 1947. D, [3,. BRYANT 'I 2,429,867

' Y DUST GUARD Filed Aug. 13, 1945 4 Sheets+Sheet 5 Fig.6.

i m||1w/////////// 7 2w I I 7o 11 Oct. 28, 1947. D. D'. BHRYYAIINT DUS '1 GUARD Filed Aug. 15, 1945 4 She et-Sheec 4 Patented Oct. 28, 1947 UNITEDSSTATES PATENT OFFICE DUST GUARD Donald D. Bryant, Huntington, W. Va. Application August 13, 1945, Serial No. 610,590

19 Claims.

This invention is a novel dustguard for the journal box housings as used in a freight car, a passenger car, and locomotive trucks and tenders, but may obviously be used in other types of journals, the present invention being an improvement upon the dustguard shown in my copending application, Serial No. 548,835, filed August 10, 1944, now Patent No. 2,391,121, issued December 18, 1945.

The'principal objects of the present invention are to provide novel improvements in the construction of the dustguard rack, and the mounting therein of the flexible dustguard band; also novel improvements'in the dustguard band per se, which will facilitate manufacture and improve the operation of the dustguard.

I will explain the invention with reference to the accompanying drawings which illustrate several practical embodiments thereof, to enable others familiar with the art to adopt and use the same; and will summarize in the claims the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawings:

Figure'l is a longitudinal section through a typical journal box housing provided with my novel dustguard rack housed in the customary cavity pocket which is cast at the inner end of the housing. ,7

Fig. 2 is a transverse section of the line 2-2, Fig. 1.

Fig. 3 is an enlarged transverse section on the line 33, Fig. 1. I

Fig. 4 is a section on the line 4-4, Fig. 3.

Fig. 5 is a plan view of one form of dustguard band, detached. 7

F Fig. 6 is an enlarged section on the line 6-6,

Fig. '7 is an extended side elevation of a modi 7 fied form of dustguard band.

Fig. 8 is an extended side elevation of a further modified form of dustguard band.

F1Fig. 9 is a top plan view of dustband shown in Fig. 10 is a transverse section, similar to Fig. 3, but showing a modified construction.

Fig. 11 is a vertical section on the line lll I, Fig. 10.

As shown in Figs. 1-4 inclusive, the journal J of the railway or other truck is entered in the normal manner in the .journal box B of usual construction, the same containing packing P saturated with a lubricant, the particular form of journal box B forming no part of my present invention. Such journal boxes B are customarily 2 provided at their inner ends with a cavity or pocket B for the reception of a dustguard, usually of rigid construction, formed of layers of plywood or fiber, riveted. or stapled together.

In place of the usual rigid dustguard, however, above mentioned, I provide a dustguard rack of size and dimensions to fit within the cavity B which is ordinarily open at its top, said rack being designated generally by the reference character I and making a snug fit within cavity B, as shown more particularly in Figs. 3 and 4.

Said dustguard rack l preferably comprises a box-like structure formed of spaced parallel plates la-lb of metal, plastic or other suitable material and of'shape and size conforming with the cross sectional area otcavity B, the plates la, lb being secured together in any desired manner. Back I has a peripheral plate is closing the sides and bottom of the rack, and plates la, lb are provided with journal receiving circular openings le of larger diameter than the journal J through which openings the journal extends. The edges of the openings la in the plates la, lb are preferably inturned as at lx, for the purpose hereafter described. The upper edges of plates la, lb are out-turned as at If (Figs. 3-4), said out-turned portions overlying the top of cavity B, and a closure plate 3 having guide slots at its side edges is slipped over the out-turned flanges l j and forms a removable top for the filler rack l to exclude dust and dirt from entering between the plates la, lb.

Extending for approximately half the width of the top of rack I from one side thereof is a flange or plate lg closing said half of the top of the rack, but leaving an opening I? at the top of the rack coextensive with the other half thereof, said opening being provided for the endwise insertion and removal of the flexible dustguard band l0 therethrough as hereinafter described.

A fixed support is provided near the top of the rack l adjacent the inner end of top wall lg, said support being formed in any desired manner and serving as an anchor for the fixed end of a flexible metallic band. As shown, the support comprises a tongue llc preferably struck out of the metal of one of the side plates la, lb, the tongue extending inwardly of the rack, and the fixed end 4a of a flexible metallic band 4 is anchored on said support lk in any desired manner. The band 4 beyond the support He is bent downwardly over the inner end thereof and is curved on an arc concentric with the openings le, the band continuing around on said arc to a point 4b spaced from the fixed end 4a of the band a distance suificient to permit endwise insertion and removal of the dustguard band ill in a tangential direction through the inner portion of the opening la. The flexible band 4 is preferably formed of steel and is of width slightly less than the distance between plates la, lb of the rack so as to be readily expansible and contractible therein, said band, however, being of greater width than the space between the inturned flanges la: at the openings ie of the rack, the flanges m preventing removal of the band 4 from the rack through the openings ie.

In order to guide and support the outer free end of the flexible band 4, a block or boXlik'e structure 5 is provided within the upper corner of the rack within the opening H, the upper edge to of block 5 forming a continuation of the top plate lg of the rack at the opposite side of opening ii; and said block 5 has an inclined face 51) disposed substantially tangent to the journal J at a point below the support lk of the fixed end of band 3. Block 5 may be mounted in the rack I in any desired manner so to be fikedly or removably positioned therein.

Cover plate 3 is provided with a 'slct 3a in its inner end of length to embrace that of the opening lgi between the walls IQ and Ed, said cover 3 also having a hand grip 35 on its outer end whereby the plate may be shifted upon the outturned flanges if of the rack.

Block 5 is further provided with an arcuate face fic containing a recess 5e housing a spring 6, one end of which is secured to a cross pin 1 within recess 5e adjacent its upper end, the other end of the spring 5 being fined as at fia t6 an outwardly projecting lug 40 on the flexible band 4 within recess 5e. Thus, 'r'eees's 5e houses the spring 6 which yieldably contracts the band 4 by urging the outer free end 41) thereof in the direction of the fixed support [k for the fixed end 411 of the band. In order te rhaintain the outer end 45 of flexible band 4 in its ncrinal relative position within rack l in event sprin 6 or its connections with the band or block 5 should break, a safety wire 8 is provided passin'gthrough an opening in the recess 5e of block 5 and having one end fiked to the lug 4c and its other end fixed to a pin 9. Thus, if springs should become unfastened or break, the wire 8 will limit the movement of the outer free end 415 of the band 4 and prevent same from becoming unduly flexed from its proper position, the wire 8, however, normally having no effect upon the action of spring 5 in contracting the band 4. Instead of utilizing a block gr boXlike structure 5 the arcuate grooved portion 5e for spring 6 may be formed by a tongue inturned from one of the side walls la, lb of the rack.

One form of du'st'guard band usable in the above assembly is illustrated in Figures 5-6, the same consisting of a length of yieldable and flexible packing material which may be woven, moulded, pressed, cast, knit, or may be impregnated so as to contain rubber or rubber composition, to with stand rugged wear, friction and oil saturation. Band H3 is made from material commonly known as packing material commonly used to make sealed joints and to keep substances such as liquid, solids, gases, steam, or vapors from penetrating beyond a point fixed by the packing seal. As shown in Fig. 5, the dustguard band It is preferably formed of circular shape corresponding generally with the diameter of the journal J, the band l6 being of thickness to fit between the flanges ax (Fig. 4) at the openings Ie so that its inner face will squarely contact the journal J, as shown more particularly in Fig. 4, while its outer face will squarely contact the flexible metallic band 4 which is mounted to yieldably contract the dustguard band In around the journal J. The band It] should have sufficient lateral play in the rack so that it will not bind or otherwise be cramped or prevented from a free sliding endwise movement. The band l0 should preferably be constructed as one cbntifiuous piece, with flat sides and faces. Band II] is provided with a bandle portion I0a which is substantially tangent to said end of the band, handle portion lDa being adapted to project through the opening [11' and through the end slot 3a in the cover plate 3, and to project above the cover plate 3, as clearly shown Fig. 3; In the sides of handle portion lfib aligned with the slot 3a in cover plate 3 are grooves Illa: (Fig. 3) adapted to receive the edges of the slot 3a in cover plate 3 when the cover is in position shown in Fig. 3 to prevent endwise Withdraw'al of the dustgua'rd band [0 from the rack until .ccve'r plate 3 is pulled off the end of the rack I. Preferably a pull II is provided on the projecting end of handle portion I'Ob to facilitate endwise withdrawal of the band ill from the rack l. The free end of the band I0 isreduced in thickness as at I'U'c (Fig. 6) adjacent the base of the handle portion lflb so that when the packing is inserted in the rack the end We will overlap atcorres cndihgiy thinned portion Ifld with the body of the band H1 adjacent the handle portion H121 and thereby form a continuous un-' broken surface around the entire circumference of journal J. The reduced sections 10c, Hid of band Ill overlap to form an oil seal; and preferably the reduced portion ltd is of suifiioi'en't length to extend beyond the outer end of the mating portion we to provide 'asp'ace permitting take=up for wear at the inner face ofthe band H]. In my b'and ill the trailing end l lle isreduced in thickness to approximately half of the wid'th of the band to fit in the slot or groove "id in the handle end of the band also reduced in thickness to approximatel y one-half or the band's actual thickness,

so that when encircling the journal J and held in place by the metal band 4, the reduced 'end Hie at the handle end, the two reduced portions 100, [0d thus eent'aet'ir'ig to form a circular seal around the journal J, the two reduced portions lilc, Ifl'd together building the band to its original thickness at said overlapping portions. by this slideor slip fit an adjustable circular sealing fit is maintained; The slot or groove lild near the handle Illa is cut or moulded to the correct angle s6 that when the band is entered in the rack I the trailing end enters into and slides along this r'edi'iced portion iud making a perfect seal.

By the aboveconstr'uctien, whenthe dustguard band in is inserted endmse into the filler more i through'the opening l'y', tangentially of journal J, the leading end file of the band ID will contact the metallic flexible band and will be guided thereby around the journal J and will be held by band 4 contract-ed around the journal. The metallicband 4 will adjust itself around the dustguardflll and will serve as a protector for the band l0. The 'dustguard band H1 is pushed inwardly of the rack tangentially of the journal J through the opening "I?" until the end 'IGc'OverIaps the reduced 'po'rtion I'Bd of "the band in which position the grooves like will lie o posite the sides of the slot 3a of theccv'er plate 3, whereupon the cover 3 may be pushed inwardly into the position shown in Fig. 3 with the sides of slot 3a entered in the grooves lilac. The dustguard band l will thereby be securely locked in the rack l and cannot be pulled outwardly until the cover plate 3 has been pulled endwise off of the rack I.

In place of the dustguard band l0 shown in Figs. 5-6, a modified band, shown in Fig. '7, may be used, same having a stiffening wire lllw extending entirely through the length of the band IE from end to end, the band It) being shown expanded in Fig. '7.

Also the band l0 may be further modified, as shown in Fig. 8, in which a stiffening wire lllw extends through the handle portion Illb only, the wire lliw being omitted throughout the remaining portion of the length of the band. However, throughout the major portion of the length of band l0 from the handle lBb to the thinned,

top portion lilc is provided on each side wall with corrugations lllp to facilitate flexing of the band ll] 1when being inserted and removed from the rac The rack l and its parts are thus completely covered and protected by cavity B in the journal box housing B. When assembled and placed in the dustguard cavity B it makes a solid seal between the opening in the wheel side of the journal box housing B and the interior of the journal box which contains the packing P, the journal bearing surface, and the burnished surface of the journal upon which the bearing rides. The dustguard excludes foreign material such as metal, dirt, sand, grit or other debris from entering the packing or lubricant which would cause a hot-box, journal box failure or would contribute to train delays, accidents or damage to material or equipment. My dustguard band not only excludes foreign matter from entering the journal box but also prevents by its self-sealing adjustable action, the oil within the journal box from leaking out of the dustguard side of the journal b'ox housing, thus retaining therein the free or loose oil, which otherwise would be lost due to the action of a car or train in motion and the movement of axle in said journal box, which would cause the oil to flow or splash or run along the journal or bearing surface and thence out of the journal box housing. My band Ii! also keeps the packing P from being pushed past the fillet on the burnished surface of the journal (this fillet being the lateral stop for the journal brass). In event the packing P is pushed past the fillet it would then be disposed on top of the dustguard surface of the axle, and if it extends through the journal box housing at this point it will act as a natural drain through wick action and draw the free or loose oil out between the wheel and the journal box to the ground. It is only necessary to look at the plates or face sides of passing wheels on the average freight car to see that a larger percentage of these wheel plates are covered with an oil film which is positive proof of the oil escaping from the journal box due to lack of seal to retain it, thus wasting many thousands of gallons of oil daily. My dustguard will also prevent the loss of oil to a great extent when applied to coal cars which are dumped by being turned mechanically over on their sides or ends.

In the modification shown in Figs. and 11, a simplified construction is illustrated in which the like parts are similarly numbered. In this construction, however, the rack plate la is flanged as at lc to form the side and bottom edges of the rack, the outer end of the flange Ic being inset as at l2, Fig. 11, to receive similar short flange Iy formed integrally with the rack plate lb, the flanges lb, lc being coextensive with the two ends and bottom edges of the rack. The upper ends of the walls la, lb of the rack are outturned as at If in the same manner shown in the preceding figures.

In this modification, an angularly inclined wall [5 having a flange l5a is welded or otherwise secured to the wall lb of the rack, the same extending from one edge of the opening la in the top of the rack downwardly and substantially tangent to the flexible dustguard band it); while a second inclined wall It extends from a point adjacent the opposite end of opening I2 and slopes downwardly substantially tangent to the journal J within the rack, the space between the walls l5 and I6 beingslightly greater than the height or depth of the dustguard band l0.

A cover plate lg extends over the upper end of the rack from the opening ii to the adjacent side of the rack and may be permanently secured thereto, the same preferably being provided with downwardly and inturned flanges underlying the outturned flanges If of the walls la, lb of the rack, in the manner shown in Fig. 11.

In this modification a. top plate lw extends from the opposite end of opening la' to the adjacent side of the rack, and is provided with downwardly and inturned flanges Iv underlying the outturned flanges If of the walls la, lb of the rack, as shown in Fig. 10, the inner end of top plate lw extending somewhat inwardly across the opening l7 beyond the adjacent end of the wall l6, forming a lip adapted to be engaged by a notch my in the adjacent edge of the handle portion lilb of dustguard band ill, to maintain the dustguard band l0 locked in its innermost position when inserted in the rack in' the manner shown in Fig. 10. When, however, it is desired to remove the dustguard band Id from the rack, it is merely necessary to flex the outer projecting end of handle portion lllb upwardly sufficiently to free the lower edge of notch lfiy from the underside of the lip of top plate lw, whereupon the dustguard band may be readily removed by endwise ull from the rack.

By the above construction dust and dirt are prevented from entering the interior of the rack, since the handle portion lfib completely fills the opening la in the top of the rack; and no movable or shiftable cover is necessary in order to lock the dustguard band in operative position within the rack.

As shown in Fig. 10, an arcuate wall H extends from the lower end of the inclined wall l6, and is spaced somewhat from the outer periphery of dustguard band ll said wall I! having a flange l'l'a which is spotwelded or the like to the inner face of the wall lb of the rack. Arcuate wall I! has a longitudinal slot l8 therein, for'the purpose hereinafter described. If desired, the walls l5, l6 and I! may be struck out of the metal of one or both walls of the rack, or formed in any other desired manner.

In this modification it is not necessary to provide the inturned flanges la: (shown in Fig. 3) at the circular openings le in the rack walls la, lb through which the journal J passes, since both ends of the flexible band 4 are securely held within the rack, thus preventing the flexible band 4 from being withdrawn through the openings le when the rack is removed from the pocket in the journal box housing. As shown, one end of the flexible band 4 is flanged over as at Ma over the top of the inclined wall l5 at one end of opening lg, to fix said end of the flexible band 4, the band l passing around the periphery of dust guard band ill with its free end disposed between the band ill and the arcuate wall II. The free end of band ll carries a post It! (Fig. of sufficient length to extend through the slot [8 in arcuate wall II, the same having a head or washer use on its outer end; and a spring 20 has one end engaged with the post l9 and its other end secured by welding or hooking to a fixed portion of the rack adjacent wall 16 the spring 28 normally contracting the flexible band 4 around the dustguard band l8 and the journal, the length of post id permitting the end of flexible band (i to shift radially inwardly or outwardly with respect to the journal, and the post I9 being sufficiently long to allow free play of the free end of the flexible band 4 in this respect while preventing the band l from being withdrawn from its relative position within the rack shown in Figure 10.

I do not limit my invention to the exact forms shown in the drawings, for obviously changes may be made therein within the scope of the claims.

I claim:

1. In combination with a journal, a journal box having a cavity pocket therein; a filler rack reinovably positioned in said pocket and having a bore therethrough through which said journal extends, said rack having an opening in its top offset from the axis of the journal; a top plate for said rack having a lip overlying the opening; and a flexible dustguard band within the rack encircling the journal and having one end ex tending through the slot in the closure piate and having a notch underlying said lip.

2. In a combination as set forth in claim 1, said top plate having a portion slidably mounted upon said rack and provided with a slot overlying said opening said slot being disposed at the inner end of the plate; and said notch in the dustguard band comprising a groove in the side of the band receiving the adjacent side wall of the slot to prevent withdrawal of the dust guard band until the top plate is removed.

3. In a combination as set forth in claim 1, said top plate being fixedly secured to the rack and having a portion extending over one end of the opening; and said notch being formed in the adjacent face of the band to prevent withdrawal oi the dustguard band until the band is flexed to disengage the notch from said lip.

4. In a combination as set forth in claim 1, said dustguard band comprising a split loop of 'flexible packing material conforming substantially with the curvature of the journal, said loop having one end extending substantially tangentially of the journal through said opening to form the locked end; the opposite end being reduced in width and engaging when positioned in the rack a correspondingly reduced portion in the band adjacent the inner end of the tangential portion, whereby the band will form an unbroken seal around the journal, the reduced portions being of suflicient extent to permit relative shifting of the ends of the loop to compensate for wear.

5. In a combination as set forth in claim 1, said dustguard band comprising a split loop of flexible packing material conforming "substantially with the curvature of the journal, a stifiening wire extending longitudinally through the dustguard, said loop having one end extending substantially tangentially of the journal through said opening to form the locked end; the opposite end being reduced in width and engaging when positioned in the rack a correspondingly reduced portion. in the band adjacent the inner end of the tangential portion, whereby the band will form an unbroken seal around the journal, the reduced portions being of sufficient extent to permit relative shifting of the ends of the loop to compensate for wear.

6. In a combination as set forth in claim 1, said dustguard band comprising a split loop of flexible packing material conforming substantially with the curvature of the journal, said loop having one end extending substantially tangentially of the journal through said opening to form the locked end; the opposite end being reduced in width and engaging when positioned in the rack a correspondingly reduced portion in the band adjacent the inner end of the tangential portion, whereby the band will form an unbroken seal around the journal, the reduced portions being of sufiicient extent to permit relative shifting of the ends of the loop to compensate for wear; a stiffening wire extending throughout the length of the tangential portion; and the side walls of the remaining portion of the loop between the reduced portions being corrugated to facilitate bending.

7. In combination with a journal, a journal box having a cavity pocket therein; a filler rack removably positioned in said pocket and having a bore therethrough through which said journal extends; said rack having an opening in its top offset from the axis of the journal; a top plate for said rack having a lip overlying said opening; a yieldable band within the rack around and spaced from the journal and having its ends secured at opposite sides of the opening; and a flexible dustguard band. within the rack encircling the journal. within the yieldable band; said dustguard band being insertable in and removable from the rack by endwise movement through said opening, and the trailing end thereof having a notch underlying the lip when inserted therein.

8. In a combination as set forth in claim '7, said top plate having a portion slidably mounted upon said rack and provided with a slot overlying said opening said slot being disposed at the inner end of the plate; and said notch in the dustguard band comprising a groove-in the side of the band receiving the adjacent side wall of the slot to prevent withdrawal of the dustguard band until the top plate is removed.

9. In a combination as set forth in claim 7, said top plate being fixedly secured to the rack and having a portion extending over one end of the opening; and said notch being formed in the adjacent face of the band to prevent withdrawal of the dustguard band until the band is flexed to disengage the notch from said lip.

10. Ina combination as set forth in claim 7, said dustguard band comprising a split loop of flexible packing material conforming substantially with the curvature of the journal, said loop having one end extending substantially tangentially of the journal through said opening to form the locked end; the opposite end being reduced in width and engaging when positioned in the rack a corresponding reduced portion in the band adjacent the inner end of the tangential portion, whereby the band will form an unbroken seal around the journal, the reduced portions being of sufficient extent to permit relative shifting of the ends of the loop to compensate for wear.

11. In a combination as set forth in claim 7, said dustguard band comprising a split loop of flexible packing material conforming substantially with the curvature of the journal, a stiffening wire extending longitudinally through the dustguard, said loop having one end extending substantially tangentially of the journal through said opening to form the locked end; the opposite end being reduced in width and engaging when positioned in the rack a correspondingly reduced portion in the band adjacent the inner end of the tangential portion, whereby the band will form an unbroken seal around the journal, the reduced portions being of sufiicient extent to permit relative shifting of the ends of the loop to compensate for Wear.

12. In a combination as set forth in claim '7, said dustguard band comprising a split loop of flexible packing material conforming substantially with the curvature of the journal, said loop having one end extending substantially tangentially of the journal through said opening to form the locked end; the opposite end being reduced in width and engaging when positioned in the rack a corresponding reduced portion in the band adjacent the inner end of the tangential portion, whereby the band will form an unbroken seal around the journal, the reduced portions being of suificient extent to permit relative shifting of the ends of the loop to compensate for wear; a stiffening wire extending throughout the length of the tangential portion and the side walls of the remaining portion of the loop between the reduced portions being corrugated to facilitate bending.

13. In a combination as set forth in claim '7, the end of the flexible band adjacent the trailing end of the dustguard band being anchored in the rack; and the other end of the flexible band engaging an arcuate guide adjacent the leading end of the dustguard band; said guide having a recess; and means in said recess engaging the guide and flexible band for yieldably contracting the flexible band around the dustguard band.

14. In a combination as set forth in claim 7, the end of the flexible band adjacent the trailing end of the dustguard band being anchored in the rack; and the other end of the flexible band. engaging an arcuate guide adjacent the leading end of the dustguard band; said guide having a recess; a spring in said recess having one end secured to the guide and the other end secured to the flexible band for yieldably contracting the flexible band around the dustguard band; and a normally flexed safety cord connecting the guide and adjacent end of the flexible band to hold the flexible band in relative position around the dustguard band in event the spring should break.

15. In a combination as set forth in claim 7,

the end of the flexible band adjacent the trailing end of the dustguard band being anchored in the rack; and the other end of the flexible band underlying an arcuate guide adjacent the leading end of the dustguard band; said guide having a slot; a post on the flexible band extending through said slot; and a spring having one end secured to said rack and its other end secured to said post for yieldably contracting the flexible band around the dust guard band while permitting the adjacent end of the flexible band to shift radially with respect to the journal.

16. A dustguard band for journal box housings or the like comprising a split loop of flexible packing material having one end extending substantially tangentially to form a handle end; the opposite end being reduced in width and engaging a correspondingly reduced portion in the band adjacent the inner end of the handle portion, the reduced portions being of suflicient extent to permit relative shifting of the ends of the loop.

17. In a band as set forth in claim 16, a stiffening Wire extending throughout the tangential portion; and the side walls of the remaining por tion of the band between the reduced portions being corrugated to facilitate bending.

18. In combination with a journal, a journal box having a cavity pocket therein; a filler rack removably positioned in said pocket and having a bore therethrough through which said journal extends; said rack having an opening in its top offset from the axis of the journal; a yieldable band within the rack around and spaced from the journal and having its ends secured at opposite sides of the opening; the flexible band having one end anchored in the rack, and the other end engaging an arcuate guide, said guide having a recess; a spring in said recess having one end secured to the guide and the other end secured to the flexible band for yieldably contracting the flexible band around the journal; and a flexible dustguard band within the rack encircling the journal within the yieldable band; said dustguard band being insertable in and removable from the rack by endwise movement through said opening, and means for locking the dustguard band in the rack.

19. In a combination as set forth in claim 18, a normally flexed safety cord connecting the guide and adjacent end of the flexible band to hold the flexible band in relative position around the dustguard band in event the spring should break.

DONALD D. BRYANT.

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

UNITED STATES PATENTS Number Name Date 272,508 Zeppenfield Feb. 20, 1883 1,553,460 Mowrey et a1 Sept. 15, 1925 411,100 Hayes Sept. 17, 1889 664,925 Born et al. Jan. 1, 1901 992,109 Campbell May 9, 1911 2,177,606 Bigelow Oct. 24, 1939

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