Improvements in Combined Drawing Instruments and Calliper Gauges and the like.
Year: 1899

page_text: Improvements in Combined Drawing Instruments and Calliper
Gauges and the like.
I, WILLIAM CURTIS DAY, of Rumford Falls, in the County of Oxford and State
of Maine, United States of America, Carpenter, do hereby declare the nature of
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:
This invention relates to dividers or compasses, callipers, and similar drafting
or measuring tools, and has for its object to facilitate the adjustment or spread
of the legs in tools of this character. To this end, the invention consists in
certain features of improvements in structure and arrangement which I shall
now proceed to describe and claim.
Of the accompanying drawings, forming a part of this specification,--
Figure 1 represents a side elevation of a tool constructed in accordance with
my invention and arranged to be used as dividers.
Figure 2 represents a similar view of the tool, arranged for use as outside
callipers.
Figure 3 represents a similar view, showing the same arranged for use as
inside callipers.
Figure 4 represents an edge view of the upper part of the tool, on an enlarged
scale.
Figure 5 represents a view of the same, with parts in side elevation and other
parts in section.
Figure represents a vertical sectional view.
Figure 7 represents a section on line 7-7 of Figure 5, on an enlarged scale.
Figure 8 represents a section on line 8-8 of Figure 5.
The same reference characters indicate the same parts in all the figures.
In the drawings,-
a a are the legs of the instrument, each of which is bent downwardly at a
small angle, near its middle point, as shown. The lower portion of each leg I
have represented as grooved and formed with a collar having a set-screw a
whereby end-pieces or points of different form may be secured to the legs and
readily removed, the form of the end-piece depending upon the use to which it
is desired to put the instrument. Thus in Figure 1 the end-pieces are rods i i

page_text: having sharpened points which adapt the instrument for use as dividers. The
substitution of a lead-pencil for one of these rods makes circle compasses of the
instrument. Figure 2 shows the instrument as provided with outside calliper-
legs; and Figure 3 shows it provided with inside calliper-legs kk.
The legs a a are formed at their upper ends with ears a¹ a², which embrace a
central pivot-block b, to which they are attached by two pivot-screws cc headed
and shouldered as represented, and screwing into the block b from opposite sides.
On the under sides of the arms a a, above the bends in the latter, are formed
recessed a a³, in which are pivoted, on pins el e¹, the upper ends of two links e e
of equal length. The lower ends of said links are pivoted on pins e²e between
ears formed on a collar f. Said collar slides on the lower end of a rod d depend-
ing centrally between the legs a a from the pivot-block b, and is provided with
a set-screw f having a milled head, whereby the collar may be clamped or
attached to said rod at any point on the latter. The spreading apart of the
legs a a, acting on the collar through the links e e, moves said collar upward
on the rod d, in the direction of the pivot-block b, while the closing of the legs
toward each other produces a reverse movement of the collar along the rod. By
screwing the set-screw fl tight against the rod and thereby clamping the
collar to said rod, the legs a a are held immovable at the distance apart to
which they have been moved, except when further adjusted by the slow-motion
screw which I shall now describe.
61 is a sleeve formed on the lower side of the pivot block b and surrounding a
socket 62 in which the upper end of the rod d operates. Said rod is held from
turning in the socket by means of a screw-stud m (Figure 6) passing through
the wall of the sleeve and entering a longitudinal groove in the side of said
rod d. In the upper end of said rod there is bored a socket 2, which is screw-
threaded to engage the lower end of a screw q. The screw passes centrally
through the pivot-block b, between the ends of the pivot screws cc, as represented
in Figure 6, and is provided at its upper end with a milled head g¹, by means of
which it may be turned. Said screw is further provided, below its head, with
a boss or shoulder occupying a recess in the top of the pivot-block and formed
with a circumferential groove g³. A pin h passing transversely through the
pivot-block and engaging the groove 72, as represented in Figures 5 and 7.
serves to prevent the screw from moving longitudinally with respect to said
pivot-block. Therefore, when the screw g is turned in one direction or the other.
the rod is raised or lowered in the socket 63. When the collar f is clamped
by means of its set-screw to the rod, such turning of the screw g varies the
spread of the legs a Al through a small distance.
In the operation of the instrument, the legs a a may be brought to their
approximate adjustment quickly by loosening the set-screw fll and moving said
legs apart or together. as required, and then having tightened said set-screw,
the screw g may be worked to bring the legs a a to an exact or minute adjustment.
The particular shape or office of the instrument-legs is immaterial to my inven-
tion.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. An instrument of the character specified, comprising a pair of legs pivoted
together, a longitudinally movable rod extending from the pivot between the
legs, a pair of links pivoted to the legs, a sleeve pivoted to the links and sur-
rounding the rod and holding it in central position between the legs, said sleeve
being normally loose on the rod so that the legs may be quickly adjusted in
unison, a fastening device on the sleeve whereby it mav be made fast to the rod
to move therewith, and a screw journalled to rotate in the said pivot and engaged
as described with the rod, said screw co-operating with the sleeve, its fastening
device, and the rod and links, to give the legs a minute adjustment in unison,

page_text: and the said sleeve serving to equalize the adjustment of the legs each side of the
rod during either quick or minute adjustment.
2. An instrument of the character described, comprising the pivot-block b, the
legs a a pivoted together, the rod d internally screw-threaded at its upper end,
the sleeve fitted to slide on the rod, the links e e pivoted to said legs and sleeve,
means for clamping the sleeve to said rod, the screw g engaged with the internally
screw-threaded portion of the rod, and a retaining connection between said screw
and the pivot-block.
3. An instrument of the character specified, comprising the pivot-block b, the
legs a a having ears which embrace said block, the pivot-screws c c connecting
said ears with the block, the rod d, a connection between said rod and the legs,
and the screw passing centrally through the block 6, between the ends of the
screws c c, and engaging the rod d.
WILLIAM CURTIS DAY.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.