US1188855A - Stay-bolt for boilers. - Google Patents

Description

B.. E. D. STAFFORD & E. I. DODDS.

STAY BOLT FOR BOILERS.

IIIIIIIIIIIIIIIIIIIII 1914.

l ,l 8,855. f Patented June 27, 19m.

A rgizmunlun, f

IINITE STATES PATENT FFIQE.

BENJAMIN E. D. STAFFORD AND ETI-IAN I. DODDS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO FLANNERY BOLT COI/IPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT FOR BOITIERS.

messes.

Application filed November 24, 1914.

T0 all whom 'it may concern Be it known that we, BENJAMIN E. D. STAFFORD and Eri-IAN I. Donne, citizens of the United States, and residents of Pitts burgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Stay-Bolts for Boilers; and we do hereby declare the following to be a full, clear, and exact descriptien of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to an improvement in flexible stay bolts for boilers,the object being to provide a yielding coupling for the outer end of the bolt, whereby the latter' will be flexibly connected to the outer sheet so that it may be free to follow the movements of the lire box sheet without unduly straining eitherl of the sheets to which it is connected.

I/Vith this object in view our invention consists in a two part bushing adapted to be secured to the outer sheet of the boiler the inner member of said bushing having an internal seat for the head of a stay bolt, and a yielding member interposed between the head of the bolt and the inner face of the outer member' of the bushing whereby the said head will be yieldingly held against its seat.

In the accompanying drawings, Figures l to 5 inclusive are views in section of various forms embodying our invention. i

l represents a bushing externally threaded at one end .tor its attachment to the outer sheet of a boiler, and also threaded at its outer end for the attachment ot the cap Q. The bushing or sleeve l is provided internally with the curved seat 3 on which the 'rounded head 4 oi" the bolt rests, the opposite end ot' the bolt being secured to the inner sheet oi the boiler in the well known manner.

Located between the inner Jface of the cap, 2, and outer end of the head l of the bolt is a resilient or spring device designed to normally hold the bolt head on its seat, but which may yield or give so as to permit the bolt to move longitudinally, to accommodate itself to the movements of the inner sheet of the boiler to which the bolt is attached.

In the construction shown in Fig. l, the yielding member 6 is of spring metal ap- Speccaton of Letters Patent.

Patented June 27, 1916.

serial No. 873,795.

The head o'lf the bolt is VHat with a central concave recess to receive one end of the yielding member, 6, and the inner face of the cap 2 is similarly recessed to receive the other end oiC member (5, sutiicient space being lett between the end of the head of the bolt and the inner 'face ot' the cap, to accommodate all longitudinal movements to `which the bolt may ne subjected. The bolt head and a portion oi1 the bolt adjacent the head, is provided with atell-tale bore, and the spring member G is provided with holes 8, which communicate respectively with the tell-tale bore in the bolt, and the central opening 9 in the cap 2, to permit steam or water to escape, in the event the bolt should be broken. The spring member G makes a tight joint with the cap and bolt and is preferably compressed by the cap as the latter is secured in place, so that there never can be any leakage ot' steam around the head oir' the bolt and through the tell-tale hole 9 in the cap.

In Fig. 2 the yielding member (in made of spring metal is cylindrical in form and bellows shaped as shown. Its outer end is concave to receive the convex inner face et' the cap, and its inner end concave to receive the convex outer end of the head of the bolt. It also has a central bore or passage way which connects the tell tale in the bolt with the opening 9 in the ca'p. This bellows shaped or spring member, instead oit being cyliinlrical as in Fig. 2 may be spherical as in Fig. 3. In the latter construction we have shown the spring men'lbcr G" resting within a concave scat in the cap, and the head oi the bolt provided with a raised concave member l0, resting in a concave seat in the spring member, but it is clearly evident that the head of the bolt may have a concave seat, as in the cap, for the spring member, or the cap may have a convex seat to rest in a eoncavity in the spring member. It is also provided with a' central bore connecting the tell-tale in the bolt with the hole 9 in the cap.

In the construction shown in Fig. 4C the spring member 6C comprises a semi-spherical portion having a hollow threaded shank 1]. screwed to the head oit' the bolt. In Fig. 4,

we have shown it screwed into a recess in the head of the bolt, and in Fig. 5 we have shown the shank internally threaded to receive the internally threaded head of the bolt 5. In the construction shown in Fig. 4L the rounded bolt head rests on the curved seat in the bushing, whereas in F ig. 5, the spring member constitutes the head ol the bolt and rests on the curved seat in the bushing.

In both of the constructions, the spring member is substantially of bellows form so as to permit it to yield or give under the ini'luence of longitudinal stresses imparted to the bolt.

If desired the cap 2 oit' the bushing may be provided with an adjusting screw Il adapted to bear against the spring member whereby the same may be put under compression either at the start or in the event there should be any weakening ot' the spring a'lter usage. This screw may have a tell-tale bore l5.

In all ol the forms shown, the spring member tends to holdthe bolt head firmly on its seat in the bushing, but is free to give or yield to permit of longitudinal movement of the bolt, and when under compression by the bolt, 'lorms a steam tight joint with the latter and also with the cap so as to prevent the escape of steam or water. They also leave the bolt free to have universal movement on its seat 3 in the bushing, and also free to respond to all lateral movements of the inner sheet, without undulyA straining it, or the outer sheet to which the bushing is secured.

It is evident that many slight changes might be resorted to in the relative arrangement of parts shown and described without departing from the spirit and scope' of our invention. Hence we would have it understood that we do not wish to confine ourselves to the exact construction and arrangement of parts shown and described, except as required by the scope of the appended claims.

Having fully described our invention what we claim as new and desire to secure by Letters-Patent, is

1. In stay bolt construction, the fombination of a bushing, a cap for the same, a bolt engaging the bushing and a yielding member interposed between the head of the bolt and the cap.

2. In stay bolt construction, the combination of a bushing, a cap for the same, a bolt engaging the bushing and a yielding member interposed between the head of the bolt and the cap and forming a steam tight elo sure with the latter.

3. In stay bolt construction, the combination of a bushing, a boltV having a head seated on a sea-t in the bushing the said bolt having a tell-tale bore, a cap for the bushing, the said cap having a hole in line with the tell tale bore in the bolt and a spring member intermediate the head of the bolt and the cap, and having a central bore connecting the tell-tale in the bolt with the hole in the cap.

4C. In stay bolt construction the combination of a bushing, a bolt the head of which is seated in the bushing and is provided with a tell-tale bore, a cap having a centrally located hole, and a spring member interposed between the head of the bolt and the cap and having a central bore and steam tight contact with the bolt head and cap.

5. In stay bolt construction, the combination of a bushing, a cap for thesame, a bolt the head of which is seated inthe bushing, a yielding member interposed between the head of the bolt and the cap andan adjusting screw carried by the cap and bean ing on the spring member.

6. In stay bolt construction, the combination'of a bushing, a cap for the same, a bolt communicating telltale bores. V

In testimony whereof, we have signed this specification 1n the presence ofv two subscribing witnesses.

BENJAMIN n. n. saumronn. ETHAN I. nonns.

iVitnesses:

EDWIN S. Bron, Howano j O. Caernn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner o1' Patent.. Washington, D. C.

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