US1188913A - Stay-bolt for boilers. - Google Patents

Description

E. l. DDDS.

STAY BOLT FOR BOWERS.

APPLICATION FILED NOV` 30', 1914.

1,1 88,9 l 3. l Patented June 27, 1916.

"rl-IB COLUMBIA Puumwri WASHINGTON. D. c.

naar omen.

IETHAN I. DODDS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR 'IO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT FOR BOILERS.

Specification of Letters Patent.

Patented June 27, 191

To all whom t may concern:

Be it known that I, Eri-IAN I. DoDDs, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Stay-Bolts for Boilers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in stay bolts for boilers, the object being to provide a bolt the shank of which will be yielding or flexible so as to accommodate itself to the unequal movements of the two sheets to which it is secured, without impairing its efficiency to withstand longitudinal stresses to which it may be subjected when applying it to the sheets, or when the boiler is in use.

Ti-th this object in View my invention consists inthe details of construction as will be more fully explained and pointed out in the claims.

In the accompanying drawings, Figure 1 is a view of a bolt blank embodying my invention; Figs. 2, 3 and 4 are views in transverse section of the same; Fig. 5 is a view of the blank with its shank twisted. and Figs. 6 to 19 inclusive are views of modifications.

In the manufacture of the bolt, a bar of stay bolt metal, preferably cylindrical, is subjected to an upsetting heat and is swaged between dies or other tools to produce the reduced shank 1 and the enlarged heads 2 and 3. During the operation of swaging, or before or after the same, the shank l of the bolt is slotted at opposite sides as shown at 4 in dotted lines in Fig. 1. These slots are located diametrically opposite each other as shown in Figs. 1 to 4 inclusive, each of the slots being deepest adjacent one head and gradually and uniformly decreases in depth until it merges with the surface of the shank adjacent the other head, leaving a thin connecting web 5 intermediate the bases or floors of the slots throughout the entire lengths of the latter, and in no instance does either slot pass transversely through the shank. At each end of the shank, the web connecting the walls of the slots is at' the surface of the shank as shown in Figs. 2 and 4 but at intermediate points, where the slots overlap, the web separates the slots as shown in Fig. 3. After the blank has been shaped and slotted, the shank is twisted about 180o to carry the slots spirally around the shank as shown in Fig. 5.

In the construction shown in Figs. G to l0 inclusive I have simply duplicated the slots, that is to say, I have slotted the opposite faces twice, instead of once as in the previous construction, the slots on one side being` in the plane of the slots on the opposite sic e.

In Figs. 11 to 14 inclusive, I have shown the shank slotted as at 6, at one side from head 2 to approximately the center of the shank, and on its opposite side from head 3 to approximately the center as at 7, the bases of both slots being closed by the surface webs 8, and the two slots 6 and 7 separated at the center of the shank by the transverse web 9. lith this construction the two ends of the shank are made flexible so as to give under torsion or twisting strains, while the center of the shank is maintained in its original rigid condition.

Figs. 15 to 18 inclusive show the slots of Fig. 11 duplicated so as to increase the flexibility of the shank at its ends, and Fig. 19 shows the same twisted as in Fig. 5.

Slotting the bolt shank longitudinally as described1 does not materially affect its capacity to withstand strains exerted longitudinally thereon, nor the torsional or twisting strains to which it may be subjected in applying it to the sheets, but renders it sufliciently flexible laterally so that it may and will accommodate itself to the turning or twisting movement to which it is subjected by the unequal expansion and contraction of the inner and outer sheets of a boiler.

The slots above referred to are not formed by the removal of any metal, but simply by cutting or piercing it so that the capacity of the shank for endwise stresses is not weakened.

Having fully described my invention what I claim as new and desire to secure by LettersPatent, is

1. As a new article of manufacture, a stay bolt the shank of which is provided with oppositely disposed slots each extending part way through the shank, the slot on one side of the shank being separated from the slot at the other side by a thin web integral with the shank.

2.' As a new article of manufacture, a stay bolt the shank of which is provided with oppositely disposed slots, each slot being)` deepest adjacent one head of the bolts and merging with the surface adjacent the other head, the shallow end of each slot boing,` over the deepest end of the other slot.

3. As a new article of manufacture a stay bolt having oppositely disposed slots each extending approximately the length of the shank, and each extending nearly through the shank adjacent one head and'merging Copies of this patent may be obtained for've cents each, by addressing the `into the surface of the shank near the other ETHAN I. nonne.

lVtnesses Y WVM. CHARLES IBINGHAM,` EDWIN SPENCER RYGE.

' washington, n. c."

"Commissioner of Patents,

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