USRE1308E - Lewis hoening - Google Patents

Description

1. Yl HUMPHREY.-

Lamp Chimny.

Reissued May-13, |862.

PATENT OFFICE.

LEWIS HORNING, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNEE OF JAMES Y. HUMPHREY.

MICA CHIMNEY FOR LAMPS.

Specification forming part of Letters Patent No. 29,172, dated July 17, 1860; Reissue No. 1.308, dated May 13, 1862.

To all whom, it may concern:

Be it known that JAMEs Y. HUMPHREY, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, has invented a new and Improved Chimney for Lamps, of which said invention I, LEWIS HORNING, of the said city and county, am the assignee and sole owner; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this description and specification.

All burnin g-tluids which are burned in lamps for illuminating purposes and contain an excess of carbon require to have a proportionate amount of oxygen to support combustion and produce a proper illuminating-name. This supply ot' oxygen has hitherto been obtained by means of adraft of air produced by aglass chimney encompassing the flame, `the heat of the tlame rarefying the air within the chimney and causing a current to pass through it, which current impinges against the ame.

In order to avoid annealing glass chimneys and save expense, they are made extremely thin, so Aas not to b reak bya sudden expansion caused by the heat of the flame, the thin glass being heated quite equally throughout. This extreme thinness of the glass, although serving in a great degrte to prevent fracture by heat, still renders chimneys extremely liable to break by the slightest jar and concussion, a-nd the breaking of glass chimneys renders the use of coal-oil and other' hydrocarbons, which contain an excess of carbon and require their use, very expensive.

In order to obviate this difculty I construct a chimneyof micain the followingmanner: A thin sheet of mica, of proper size and shape, is bent into a cylindrical or conical form, as shown in the drawing, and connected at its edges by rivets or other equivalent fast- -enings and bound at its ends by metallic rings. ,For this purpose I prefer the use of an outer and an inner tiat ring to receive the mica, and I then rivet the whole firmly together, though it is evident that the use of either an outer or an inner flat ring by itself would serve as a support for the ends of the chimney when properly riveted thereto, and thus answer the purpose sought to be eiected by the binding above contemplated, though in an inferior degree.

A A is a mica tube forming the body of the chimney. g gis the outer upper ring; g g, the inner upper ring 5 C C', the outer lower ring; o c, the inner lower ring. c a are rivets, either passing through strips of metal or merely through the edges of the mica itself. b b is the upper cone, used to give a taper or contraction to the upper end of the chimney.

In all lamp-chimneys it is found indispensable that they should be made smaller at the top than the lower or central portions to avoid the smoke or disagreeable odor which would otherwise lbe emitted when coal-oil or other burning-huid containing an excess of carbon is used. When the chimney is made in the form of a cylinder or ot a truncated cone, with the base uppermost, I cause the upper outer ring to extend some distance above the top of the mica tube, which extended ring I contract to the proper size at the top; or this upper outer ring may be so constructed as to form the base of another truncated cone extending upward and contracted to the proper size, and which may be formed of mica or other transparent substance; or it may be made entirely of metal or other opaque substance.V When the tube of the lamp-chimney is made of a conical form, with the base downward, the construction is more simple. No upper ring, except the binding-ring at the upper extremity, is in that case necessary. By thus constructing the chimney the use of glass may be dispensed with, and equal, if not superior, advantages, as far as transparency is concerned, be obtained, and all the losses from breakage obviated.

The precise shape or form of the mica tubes is quite unimportant so far as the manufacture of them is concerned. They may be made upright, or inverted cones, or cylindrical, as shown in the drawing. The only rule to be specially observed is that the chimney at its 'upper lend should be made very considerably smaller than the middle or lower portions. I prefer making them of such proportions that the superficial arca of the section near the top shall not exceed one-halt of that at the largest part of the chimney; but I do not limit myself to this proportion, as it may be considera s v' 1,308 v ably varied without greatly affecting the working of the lamp.

The mica will not, of course, be affected by the heat of the ame, and will, with ordinary care, last indeuitely. These chimneys may be manufactured quite economically, and will in the end not only be far less expensive than glass chimneys, but the trouble and embar` rassment attending the use of the latter and the care requisite in handling and cleaning them, 85e., will be fully avoided.

I am aware that it has before been suggested that lamp-chimneys might be constructed of mica; but such chimneys were only proposed to be made of a cylindrical' form. Such chimneys would be worthless. For thereasons already stated I lay no claim to them; but- What is claimed as new, and desired to secure by Letters Patent, is-

l. The construction and use of Iamphimneys made mainly of mica when the upper end is contracted and made smaller than the lower or middle portions thereof, substantiallyin the manner aud for the purpose above described.

2. Binding the mica chimney of a lampwith rings of metal, substantially in the manner and for the purpose above described.

LEWIS HORNING.

Vitnesses:

JOHN H. STEINER, G. W. STEINER.

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