US988705A - Plumb rule and level. - Google Patents

Description

W. 0. GRAHAM. PLUMB RULE AND LEVEL. APPLICATION rILnn we. so, 1910.

988,7 O5. v Patented Apr. 4, 19 11.

kww ggc 2 I V b Attorneys WERTER O. GRAHAM, F HATTIESBURG, MISSISSIPPI.

PLUMB RULE AND LEVEL.

Specification of Letters Patent.

Patented Apr. 4, 1911.

Application filed August 29, 1910. Serial No. 579,522.

To all whom it may concern:

Be it known that I, WVERTER O. GRAHAM, a citizen of the United States, residing at Hattiesburg, in the county of Forrest and State of Mississippi, have invented a new and useful Plumb Rule and Level, of which the following is a specification.

My invention consists of a combined plumb and level and has for its principal object to provide a simple and effective means for visually indicating the difference in level between a true horizontal plane and the plane undergoing test or measurement.

A further object of the invention is to provide a device of this character in which the delicately balanced arbor will not be controlled by the usual gravitating poise or counter-weights depending therefrom.

A still further object is to provide a device of this character which will register the most inappreciable deviations and will be provided with double dials and needles in order that these indications may be visible from either side of the level.

With the above and other objects in view which will appear as the nature of the invention is better understood, my invention embraces the structure illustrated in the accompanying drawings and set forth in the following specification, it being understood that changes in the structure herein disclosed can be made within the scope of the claims without departing from the spirit of the invention.

In the accompanying drawings :-Figure l is a view in elevation of a combined plumb V and level constructed in accordance with my invention showing the needle dial and case complete and set in the level. Fig. 2 is a vertical section through the line A--B of Fig. .1 showing a needle arranged on each side of the dial. Fig. 3 is a view in elevation showing the reverse side of the combined plumb and level from Fig. 1. Fig. 4 is an enlarged sectional detail of the needle arbor and its bearings. Fig. 5 is an enlarged fragmentary detail showing the manner in which the ends of the arbor are journaled in the jeweled bearings.

Referring to the drawing for a detailed description of my invention in which like characters of reference designate similar parts in the different views 1, indicates a level stock substantially rectangular in contour and cross section and having its upper and lower plane edges formed into true planes. The level is referably made of well seasoned wood or li e materlal which will not warp or twist out of shape and may be ornamented if desired in order to give a neat and finished appearance to the article. Formed at the intersection of the longitudinal and cross center lines of the level is a transverse annular opening 2 sufiicient in size to receive and snugly fit the dial case.

The dial case is preferably formed of metal and comprises a substantially cylindrical shell 3, one end of which is provided with an outwardly extending flange 4; which is countersunk into the level, and at the other end the case terminates flush with the surface of the reverse side of the level and is provided with external screw threads 5 to engage the counter-sunk metal ring 6. This ring is provided with internal screw threads to engage the external screw threads of the dial case, and when in engagement therewith will securely bind the parts together and prevent any further movement of the same. Formed on the inner periphery of the dial case 3 intermediate the ends is an annular mortise 7 designed to receive the dial plate 8. The dial plate or sector 8 is preferably in the form of a ring, both faces of which are graduated by indices that divide the 360 of are into extremely small subdivisions in order that the minutest deflections of the needle may be indicated.

Mortised into the bore of the dial case on either side of the dial 8 are glass disks constituting observation plates 9 and 10 which form closures for the ends of the dial case and prevent dust and other foreign matter from gaining entrance to the delicate indicating mechanism contained therein, while at the same time clearly exposing the indices on both of the lateral faces of the dial to view. In the center of each observation plate is formed a circular openin 11 in alinement with the axis of the case esigned to receive the bearing studs 12. Each of these studs projects through the alined openings 11 and terminates at one end in an enlarged head 13 and at the other in a screw threaded end 14 adapted to engage the internal screw threads of a tubular bearing 15.

Each of the tubular bearings 15 is provided with an internal circular beveled groove 16 formed adjacent one end and adapted to seat two jewels 17 and 18. The

jewels 18 are preferably plane convex, as shown, the convex side of the ewels bearing bearings may be obtained. The bearings 17 are concavo-convex and are provlded at their centers with perforations in which the conical ends of the arbor 19 are journaled. In this manner the arbor is delicately swiveled in proper posit-ion.

Positioned on the arbor 1 9 are a pair of needles or dial pointers 20 21 which are positioned on either side of the longitudinal center of the arbor :and are .so spaced apart that they will operate on opposite sides of the .dial. The lower ends of the pointers are pneferabiy thickened, in order to cause the weight thereof to hold the pointers in true vertical positions at all times.

In order to permit the indicating mechanism to be inserted in the dial case, the case is made in two halves each of which are provided with alternate interfitting projections 22 and depressions 23, as shown, The case may be further secured to the level by screws or similar connectors 245 if desired. For the purpose of permitting the shell 3 to be rotated slightly so as to permit it to be accurately adjusted the screws 2% are extended through arcuate slots formed in the flange 4.

The device of the present invention is strong, simple, durable, and comparatively inexpensive in construction as well as thoropening thereon, transparent plates in said opening, a pivoted pointer between said plates, said pointer having cone shaped fulcruined points, jewel bearings secured to said plates, each of said bearings having a plane convex and a concavo-convex jewel therein, said concavo-convex jewel having an opening to receive the fulcrum of said pointer.

2. A level comprising a stock having a circular opening, a shell mounted in said opening and having outwardly extending flange flush with one face of the stock, said flange having a plurality of alienate slots, fastening members extending through said slots, a ring detac hab'ly secured to the side of the shell opposite said flange, a pair of transparent cover plates in said shell, an arbor journaled on said plates, a pair of spaced pointers fixed :on said arbor, and a circular sector secured to said shell between said pointers.

In testimony that I claim the foregoing as my own, I have hereto aflixed my signature in the presence of two witnesses;

VVERTER O. GRAHAM.

Witnesses:

J. M. BARLING, A, E. BARKER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0.?

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