US1209946A - Stay-bolt for boilers. - Google Patents

Description

Aiforney Patented D66. 26,1916.

7 INVENTOR E. I. DODDS.

STAY BOLT FOR BOILERS.

APPUCATION FILED OCT. 19, 1914. 1,209,946.

Fill l Vvvv vv WIT ESSES rn rare.

COMPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT FOR BOILERS.

Specification of Letters Patent. v Patented D60. 26, 1916.

Application filed oetoberiaiem. Serial No. 367,412

To all whom it may concern:

Be it known that I, ETHAN I, DoDDs, 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 that will be free to yield or vibrate and accommodate itself to the lateral twisting and torsional movement of the boiler sheets, but of suflicient rigidity to prevent any collapsing of the sheets and any bending or twisting of the bolt while being applied.

With these objects in view my invention consists in the details of construction as will be more fully explained and pointed out in the claims.

In the accompanying drawings, Figure 1 is a blank; Fig. 2 shows the blank after it has been slotted; Fig. 3 is a view in cross section of the bolt; Fig. 4: is a view of the completed bolt; Fig. 5 is a view in cross section of same; Fig. 6 is a view in elevation of the complete bolt, and Figs. 7, 8 and 9 are views in cross section showing modified arrangement of slots.

Heretofore bolts designed to respond to the vibration and the lateral movements of boiler sheets have been slotted longitudinally all the way through and then twisted spirally, and in other instances they have been made of two half round sections twisted and threaded.

With such constructions the bolts will buckle and bend under compressive strains when applying them to the sheets and particularly so in the event the threads should bind.

In constructing the bolts I take a blank 1 of stay bolt iron and punch therein a series of comparatively short slots 2, the latter being out of line and preferably arranged spirally around the shank of the bolt from the head 3 to the threaded end 4. The depth of these slots may vary, but they extend past the center or neutral axis of the bolt, stopping more or less short of the opposite side so as to leave the bottom of the slots closed.

It is also desirable that the ends of the adjacent slots be approximately in the same plane or overlapping so that the flexing movement of the bolt may be continuous from the head to the threaded end of the shank.

After the shank has been slotted, the dilation caused by the slotting tool is reduced by dies or other suitable tools so as to close the walls thereof together, after which the head 8 is formed and the end 4: threaded. If desired the shank may be twisted as in Fig. 6 so as to impart a spiral twist to the slots. Instead of slotting it as above described, it may be slotted at the opposite sides as shown in Fig. 8, the slots of each pair being in the same plane and stopping short of the center so as to leave a thin web between the slots, or the slots may overlap as in Fig. 9, or be disposed diagonally as in Fig. 7

By thus constructing the bolts they are as rigid against longitudinal compression or pulling stresses as a rigid bolt, but are comparatively free to turn under torsional strains and lateral vibrations, hence are specially adapted for use in connecting boiler sheets where the vibration or torsional stresses frequently rupture the bolt.

I make no claim in this application to a single slot passing part way through the bolt, the shank being twisted to impart a spiral twist to the single slot; nor to a bar having slots at opposite sides and extending throughout the length of the shank, the shank being twisted to impart a spiral twist to the slots. as these features are covered by my applications serially numbered 867,413; 867,410 and 867,411.

It is evident that many slight changes might be resorted to in the relative arrange ment of parts shown and described and in the sequence of the steps of the operation without departing from the spirit and scope of my invention as defined by the appended claims. Hence I would have it understood that I do not wish to confine myself to the exact construction and arrangement of parts shown and described, but

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

1. A stay bolt having a series of slots, said slots extending longitudinally and said series arranged spirally around the bolt, the

said slots extending only part Way through In testimony whereof, I have signed this the bolt. specification in the presence of tWo sub- 2. A stay bolt having a series of slots said scribing Witnesses.

slots extending longitudinally and said se ETHAN I. DODDS.

5 ries arranged in spiral form, the said slots Witnesses:

passing the center of the bolt shank but not B. E. D. GAFFORD, passing through the same. EDWIN S. RYCE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G.

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