Improvements in Ready Calculators
Year: 1895

page_text: Date of Application, 19th Oct., 1895-Accepted 23rd Nov., 1895
Improvements in Ready Calculators
I, MELVILLE JAMES OVERELL, of 477 East King Street, of the City of
Hamilton, in the County of Wentworth, in the Province of Ontario, Canada,
Book-keeper, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly descubed and ascertained in and' by
the following statement
My invention relates to improvements in ready calculators more especially
designed io computation of interest and the object of the invention is to devise a
simple apparatus whereby the exact number of days from one date to another
may be instantly ascertained without any mental calculation nor the uecessity of
employing the complicated tables at present in use and it consists essentially of a
circular tabulated card with the twelve months of the year arranged circularly
adjacent to the circumference of the circle and the dates of the months arranged
in qual radial spaces within then correspondingly designated months and of a
cncular disc pivoted in the centre of the cicularly arranged tabulated months and
having a corresponding number of spaces, which are always radially opposite the
radially arranged date spaces under the designated months, the said spaces being
numbered from one to three hundred and sixty-five, an indexed pointer and stop
being provided on the edge of the rotatable disc and an aim being pivoted on the
centie pm of the disc and having a slot and index pointer, the parts beig
arranged to be operated in the manner hereinafter more particularly set forth.
Fig. 1, is a plan view of my apparatus
Fig. 1, is a section through the apparatus on the hine x-y Fig 1
Fig. 2, is an enlarged view of portion of the apparatus.
Fig. 3, is a detail of the plate showing the edge stop and pointer for the
1otat ible disc.
In the drawings like letters of reference indicate corresponding parts in each
figure.
A is the bottom plate or card upon which is arranged within a circle the months
of the year, such months being divided off into twelve spaces a, which are sub-divided
radially within the name in the spaces & into smaller spaces a', which contain the
dates of the months from one to twenty-eight on thity-one as the case may be
Bisa dise, which is pivoted_centially preferably on a hollow vet C in the
centre of thecicle of months The cumferential edge of the disc B I divide
into spaces coresponding exactly in number and always designed to be radially
opposite the spaces a' in the cncle of months, each with the other.
D is an am pivoted at one end on the pivotal rivet C and having near the
opposite end a knob d Diametrically outside of the knob d, I provide a radial
slot d and diametically outside tins slot I provide an index pointer
E is a plate, which I secure by the cleats e and to the disc B. The cleats e
are passed, though the disc B and flattened down as indicated in Fig. 2, and the
cleats are passed over the edge of the disc B and flattened down.
E' is an midex pointer, which is situated radially opposite the space contaming
the number 365. This index pointer El forms poition of the plate E. E is a
stop also forming portion of the plate E and preferably timed vertically upward
close to the edge of the disc B.
Having now described the principal parts involved in my invention I shall now
briefly describe its operation. I will suppose as in Fig. 2, that it is desired to

page_text: find the number of days from the twenty-fourth of May to the fourth of July.
To do this the disc must be turned, so that the pomitei E' comes opposite the
twenty-fourth of May The arm is thrown so that the index pointer is against
the stop E³ as indicated by dotted lines in this figure. By bringing it to the
position shown in full lines vs with the index pointer opposite the fourth of
July it will be seen that though the slot the number 41 will be read thus
indicating that there are forty-one days from the twenty-fourth of May to the
fourth of July on which interest is to be reckoned
The same operation would take place in reckoning notes at two months or for
any given number of days or months.
The importance of my invention will be seen when it is understood that bankers,
financial corporations, manufacturers and the commercial world generally, in
1eckoning interest upon notes and commercial securities always calculate the
number of days that the security has to run in order to find the interest for the
portion of the year indicated by such number of days
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim 15
1. A ready calculator comprising a stationary cu cle of months tabulated with
radial date spaces, a rotatable dise with a corresponding number of radial space-
on the cucumferential edge and numbered from 1 to 365, a pointer on the edge of
the disc adually opposite the day number 365 and arranged to pass over the
stationary date spaces and an arm pivotally swung upon the same centre as the
disc and provided with an index pomiter as and for the purpose specified
2. A ready calculator comprising a stationary encle of months tabulated with
adial date spaces, a rotatable disc with a corresponding number of radial spaces
on the circumferential udge and numbered from 1 to 365, a pointer on the edge of
the disc adially opposite the day number 365 and arranged to pass over the
stationary date spaces, a stop adjacent to the pointer and extending upwardly
from the edge of the disc and an arm pivotally swung upon the same centre as the
disc and provided with an index pointer as and for the purpose specified
3. A ready calemiato compusing a stationary encle of months tabulated with
radial date spaces, a rotatable dise with a corresponding number of radial spaces
on the circumferential edge and numbered from 1 to 365, a pointer ou the edge of
the disc radially opposite the day number 365 and aanged to pass over the
stationary date spaces, an aim pivotally swung upon the same centie as the disc
and provided with an index pointer and a slot in the arm arranged to pass
cncumferentially over the day spaces on the disc as and for the purpose specified.
4. A ready calculator comprising a stationary circle of months tabulated with
radial date space, a rotatable disc with a corresponding number of madial spaces
on the encumferential edge and numbered from 1 to 365 a pointer on the edge of
the dise adially opposite the day number 365 and arranged to pass over the
stationary date spaces, an atm pivotally swung upon the same centic as the dise
and provided with an index pointer and knob airanged near the end of the arm
as and for the purpose specified.
5 The combination with the plate having a tabulated uncle of months with
spaces and a', of the disc B having the day spaces b, the am D provided with
an index pointer d and the plate E secured to the dise B by the cleats eel and
provided with a pointer E¹ and vertical stop E² forming portion of the plate as
and for the purpose specified.
G. F REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.