US229118A - William j - Google Patents

Description

m5 Model.)

' W. J. GURD.

lnterestflal oulator. No. 229,118. Patented June 22,1880.

KPETERS. PNOTO-UTHOGRAPHER. WASNIMTON. u c.

UNITED STATES PATENT OFFICE.

WILLIAM J. GURD, OF SARNIA, ONTARIO, CANADA.

INTEREST-CA LCULATO R.

SPECIFICATION forming part of Letters Patent No. 229,118, dated June 22, 1880.

Application filed April 15, 1880. (No model.)

To all whom it may concern:

Be it known that I, IVILLIAM J. GURD, of Sarnia, in the county of Lambton, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Calculators for Interest and Days; and I do hereby declare that the following is a full, clear, and exact description of the same.

The object of this invention is to combine two revolving disks and an indicator, whereby the days from one period to another can be read off by adjustment of the disks, and by the adjustment of a pointer to the days interest therefor at various rates is indicated along the edge of the pointer; and my invention consists in certain improvements in the details of construction of the parts, as hereinafter more fully set forth, and pointed out in the claim.

Figure 1 is a plan view. Fig. 2 is a sectional view enlarged. Fig. 3 is a central ver tical section.

In the accompanying drawings, which form a part of this specification, A represents an annular disk, and B a center disk, both revolvin g concentrically, or one may be fixed and the other movable. One of the disks is inscribed in concentric circles with calculations of interest from one to three hundred and sixty-five days, at rates varying from four to ten per cent, each rate occupying one circle. Another circle is inscribed with figures of days consecutively from 1 to 365.

O is a pointer pivoted to the center of the inner dial and extending radially over the outer dial. It is marked with subdivisions corresponding to the concentric lines of the dial, and inscribed with the denominations of the rate at which the-interest was calculated, whereby a ready reference is obtained and confusion avoided. In like manner the subdivisions are marked to denote the days circle of one year, and the sum of the interest is read from the disk along the radial edge of the pointer.

The other disk is inscribed concentrically with names of the months and days of each month, the pointer indicating the circles by marks on the subdivisions corresponding thereto.

By the adjustment of the disks A and B the number of days from one period of the year to another can be ascertained by placing the day of the month from which the period is to be calculated opposite figure l of the days in the year, and opposite the day of the month to which the period is to be calculated will be found the number of the days which intervene.

Preferably the sums in the concentric circle are the quotients calculated-say one hundred dollars at the specified rate of interest from one to three hundred and sixty-five days-and any number of concentric circles can be inscribed corresponding to the several rates at which the interest is calculated.

I) (see Fig. 3) represents a base-block for supporting thecalculator, provided with a central hub, F, adapted to fit in a central orifice in the circular plate E, to the upper face of the outer part of which is secured the ring or disk A. The plate E has a circular central recess adapted to receive the disk B, the upper face of which is flush with the ring A. The disk B is attached centrally to the upper, face of the hub F, and is stationary, while we ring A, secured to the outer part of the circular plate E, revolves with it.

The pointer O is pivoted by means of the screw a centrally in the hub F, and is free to revolve on it, so that it may be swung around to occupy any desired position in determining the interest on any uniform sum atone or more rates for any time, the divisions for rates on the pointer lying opposite thzc calculated interests between the concentric circles on the ring A, the edge of the pointer lying on the desired month and day on the disk B, and also along the interest-spaces between the concentric circles on the ring A, softhat the interests at different rates of a uniform sum can be readily read.

hat I claim as my invention is The combination of the fbase D, having the central hub, F, plate E, provided with a central orifice and central circular recess, revolving ring A, secured to the outer face of said plate, stationary disk B, flush with the ring attached to the hub and fitting in the recess in the plate, and revolving pointer O, centrally pivoted in the hub, substantially as described, and for the purpose set forth,

- XVILLIAM J. GURD. Witnesses i H. S. SPRAGUE, CHARLES J. HUNT.

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