Improvements in Dividers, Calipers, Compasses, or like Instruments.
Year: 1896

page_text: Date of Application, 24th Nov., 1896-Accepted, 3rd Apr.. 1897
COMPLETE SPECIFICATION.
Improvements in Dividers, Calipers, Compasses, or like Instruments.
I, JOHN NUTTER PEAVEY, Junior, of Manchester, County of Hillsborough, and
State of New Hampshire, one of the United States of America, Blacksmith, 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 the pivot joint of dividers, calipers, or like instruments,
the object being to provide means whereby such instruments may be "set" to any
described measurement and firmly fixed at the joint.
The invention consists essentially in pivoting the legs of dividers independently
to a suitable yoke, and providing a rack and pinion mechanism connecting the legs
and adjusting and controlling the same by one or more nuts threaded to a stud,
as fully set forth in the following specification and claims, and clearly illustrated
in the accompanying drawings forming a part of the same, of which-
Figure 1, is an elevation showing an instrument of the character above named
provided with my improved joint:
Figure 2, being a broken edge view of a similar instrument provided with my
improved joint:
Figure 3, is a sectional elevation showing a pair of calipers having my improved
joint as when partly open:
Figure 4, is an elevation of the retaining yoke within which the legs of dividers
or calipers are pivoted :
Figure 5, is a cross section of the same:
Figure 6, being a plan view of same:
Figure 7, is an elevation of a threaded stud within which is secured a rack for
engaging the pinion teeth with which the legs are supplied:
Figure 8, shows the threaded stud having the rack removed.
Similar reference letters designate corresponding parts in all the views..
A, represents the legs of my improved dividers or calipers, and B, is a yoke
piece in which the legs are independently pivoted by the screws or rivets C.
The yoke B is also provided with a rivet or screw as shown at c for preventing
the extreme lower edges of said yoke from springing out of place or spreading; the
perforations 6' which have a central location being formed for this purpose. Each
leg A is provided at its top with spur teeth a' formed in a segment of a circle a, in
which the leg pivot C is concentric, and these teeth mesh with a rack D having
teeth d on its edge, said rack being rigidly secured within a slot e formed for the
purpose in the lower portion of a threaded stud E which rests in a perforation b of
the yoke B, said perforation having a smooth bore so that said stud E may be free
to move longitudinally therein without being rotated, as the spur teeth a, of the
legs A, rest within the slot e of the stud E; the rack D being narrower than the said
stud. Rectangular openings 62 are formed one in each side of the yoke B in which
rests a nut F which is threaded to fit the stud E, and by rotating said nut the stud
is raised or lowered within the perforation 6 of the yoke, which causes the legs to
move by engagement with the teeth of the rack; an upward movement of the stud E
causing the legs to close and vice versa. G is a check nut threaded to said stud E
above the yoke B, which must be turned down hard onto the top of said yoke as a
means of more firmly setting the joint at a given measurement after the legs A have

page_text: been set, but this check nut is by no means essential or in any way an important
feature of my invention. The top of the yoke B may be thickened by forming a
boss or hub at the point where the perforation is formed, as seen in Figures 4 and 6,
so as to provide a longer bearing for the stud E. The yoke B is preferably provided
with curvilinear end portions 6' whose surface correspond with the circular portion a
of the top of the legs A in which the teeth a' are formed, and a curvilinear slot a² is
formed in each leg for the reception of said curved portions of the yoke,
which forms for each leg an interlocking joint and keeps out considerable dust
and dirt.
The instrument may be made so as to be readily converted into either dividers or
calipers by forming each leg short and providing mean for connecting det ichable
extensions as in the case of ordinary dividers, or the short on of the legs may be
formed partly hollow and provided with a slot as seen at in Figure 2, the end of
the leg being tapered slightly and provided with an external thread a to which a
tapered nut H may be fitted, and after inserting either form of leg as may be desired
as at A' in Figure 3, in the socket or hollow portion of the short leg of the instrument,
the nut H may turned up and thus secure the two sections A-A¹ firmly together.
In place of the extension leg a common lead pencil may be placed in the short leg
and secured in the same manner by the nut H.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performe, I declare that what I
claim is
1. In dividers or calipers, an adjustable joint comprising independently pivoted legs
provided with a segment of a spur pinion within which the pivot of each is concentric,
a threaded stud adapted for longitudinal movement between the pinion portions of
said legs, a double rack secured to said stud and engaging the pinion portions of said
legs, and a nut threaded to the stud for adjusting the same.
2. In dividers or calipers, an adjustable joint comprising a yoke carrying
independently pivoted legs provided with a segment of a spur pinion within which
the pivot of each is concentric, a threaded stud adapted for longitudinal movement
between the pinion portions of said legs, a double rack engaging the pinions of said
legs and secured to said stud, and a nut resting in slots formed in said yoke and
threaded to said stud for adjusting the same.
3. In dividers or calipers, an adjustable joint comprising a yoke piece carrying
independently pivoted legs having each a segment of a spur pinion within which the
pivot is concentric, a threaded stud adapted for longitudinal movement between the
pinion portions of said legs, a double rack engaging the pinions of said legs and
secured to said stud, and a pair of nuts threaded to said stud, one resting in slots
formed for the purpose in the yoke and the other placed above and adapted to be
turned down upon said yoke, all substantially for the purpose set forth.
D
ALLISON BROS.,
Agents for the Applicant.