US925082A - Measuring instrument. - Google Patents

Description

I. L. DAVENPORT. MEASURING INSTRUMENT. =AIPLIOATION FILED AUG-18.1908.

925,082. Patented June 15, 1909,

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UNIE STATES PATENT @FFIQE.

ISAAC L. DAVENPORT, OF CAMDEN, NEW JERSEY, ASSIGNOR OI ONE-HALF TO FRANK A. GAVANAGH, OF ASHBOURNE, PENNSYLVANIA.

MEASURING INSTRUIVIENT.

Specification of Letters Patent.

Application filed August 18,

Patented June 15, 1909. 1908. senarno. 4%,106.

To all whom it may concern:

Be it known that I, Isaac L. DAVENPORT, I a citizen of the United States, residing at- Uamden, in the county of Camden and State of New Jersey, have invented certain new and useful Improvements in Measuring Instruments, of which the following is a specitication.

This invention has relation to measuring instruments and has for its object the provision of a novel instrument for linear measurement which will be of simple and inexpensive construction and which can be easily carried in the pocket and readily employed in making measurements on straight or curved surfaces.

In carrying my invention into effect; I provide a flat disk of certain circumference, say six inches, and I place graduations and numerals on one or both fiat sides of the disk adjacent to the edge indicating inches and subdivisions of inches and I provide the disk with a loose central hub by means of which the disk can be held between the thumb and forefinger and rolled along the surface to be measured.

In the accompanying drawing in which I have illustrated my invention: Figure 1 is side elevation of the complete instrument. Fig. 2 is a central sectional view of Fig. 1.

The instrument as shown in the drawing is composed of a flat circular disk 1 of any suitable material such as wood, card board, paper fiber, celluloid or metal and of a definite and exact circumference say, for instance, of a circumference of exactly six inches. The disk 1 has radially disposed graduations on one or both sides adjacent to its edge, these graduations designating inches and fractions of an inch and being numbered as shown. The disk 1 has a hole in its center and on each side of this hole is arranged a washer 2, these washers being secured to the disk in any suitable manner, preferebly by means of small pins 3 or they may be glued, cemented, or otherwise attached to the disk if desired. A hollow hub t extends through the hole in the center of the disk 1 and through the washers 2 and has a flange 5 on each end, this hub fitting loosely in the hole and in the washers so as to turn easily therein.

A stick, lead pencil or other object may be inserted in the hub 4, so as to afford a means for holding the measuring instru ment while the disk 1 is being rolled along the surface to be measured, or the hub can be held during the measuring operation between the thumb and forefinger of one hand.

In using the instrument, the flanged ends 5 of the hub 4. are grasped between the thumb and forefinger or a stick, lead pencil or other object may be inserted in the hub and held in the operators hand, and the periphery of the disk is placed in contact with the surface to be measured with the line opposite the numeral 1 of the graduations at the starting point. The disk is then rolled along the surface to be measured and if more than one rotation of the disk is necessary, that is if the object to be measured is more than six inches long, a mental note is made of the number of revolutions and, finally, when the end of the surface being measured is reached, the fractional parts of an inch, if any, are added to the total number of inches gone over, each complete revolution of the disk indicating, of course, a length of six inches, and thus the total length of the object in inches and fractions of an inch is ascertained.

It is obvious that the instrument can be utilized to accurately determine the dimensions of objects which it would be impossible to accurately measure with a straight rule, as, for instance, the circumference of a cylindrical object, the circumference of a circular, oval, or irregular opening and a great many other dimensions which could not be measured by means of an ordinary straight rule.

The flat sides of the disk 1, present a surface which may be readily printed, stamped, or engraved and it is my purpose to utilize the surface to bear advertising matter, as the device can be made so cheaply that it can be given away as an advertising medium the advertising secured being sufficient remuneration for the cost of manufacture.

The hollow hub 1- has its bearing on the washers 2 and these washers therefore assist in preventing wear of the disk by its rotation on the hub.

I claim.

1. In a measuring instrument the combination of a circular disk having graduations adjacent its periphery and having a hole in its center with washers arranged on each side of the disk and surrounding the edges of the hole in the disk and a hollow hub passing loosely through the disk and adapted to receive in object by which the instrument may he held while in use.

2. In a measuring instrument, the combination with a flat disk having a circumference of definite size in inches, and having numbered graduations on its flat side inclicating' the circumference in inches and fractions of an inch, and having a central hole,

10 of Washers attached to the disk on each side of the central hole, and a hub fitting loosely in said hole and said Washers and having flanges externally of the Washers.

In testimony whereof I have aflixed my signature, in presence of two WItHQSSQS.

ISAAC L. DAVENPORT.

Vitnesses CHAS. B. CONNOLLY, BLANCI-IE STAPLES.

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