Improvements in Squares for Carpenters' and other Uses.
Year: 1890

page_text: Date of Application, 26th Aug., 1890
Complete Specification Left, 16th Feb., 1891-Accepted, 21st Mar., 1891
PROVISIONAL SPECIFICATION.
Improvements in Squares for Carpenters' and other Uses.
I, CHARLES LEONARD BRONK, of No. 373, Bergen Street, in the City of
Brooklyn, and State of New York, United States of America, Carpenter, do
hereby declare the nature of this invention to be as follows:-
My invention relates to an improvement in steel squares, in which the arms are
pivotally secured together, so that one may be swung with relation to the other
throughout an arc of 90°.
The object is to so construct the joint between the two arms, that the strain upon
the pivotal point may be materially reduced, and a bearing of such extent formed,
that there will be little or no liability of the arms wearing, so as to be thrown out
of a true perpendicular to each other when opened, and to further provide for a
true lateral seat of the two arms, and for automatically locking them in opened
adjustment.
The square consists of two arms. The fixed arm is provided with a shallow
recess, extending for a considerable distance from its end, somewhat more than twice
the width of the moveable arm, and terminating at its lower end in a curve,
corresponding to a quarter of the circumference or more.
This curved portion is provided with graduated division marks to designate the
different angles from 1° to 90°, and subdivisions thereof, as may be desired. Said
recess occupies two-thirds or more of the width of the arm, thereby forming not
only an elongated bearing in the direction of the length of the arm, but also an
extended bearing widthwise of the same.
The wall of the recess is provided with an undercut extending throughout both
its curved and straight portions. The end of the arm is further cut away along the
edge of the recess, toward the moveable arm, forming an elongated notch,
terminating in a curved lower portion.
The edge of this notch, throughout both its straight and curved portions, is
beveled to enter a corresponding undercut, as will hereinafter appear.
The arm is provided, on its opposite face from that on which the recess is located,
with an elongated shallow recess, for the reception of a flat bar spring, having a
nose which projects through the arm, and forms a lock to secure the member or
moveable arm in its extended adjustment with relation to the fixed arm.
The movable arm is provided, on its end toward the fixed arm, with a plate of
substantially the shape and thickness of the recess hereinbefore referred to, and its
edge, throughout both the straight and curved portions, is beveled to correspond to
the undercut herein-before referred to, in the wall of the recess.
The plate is further provided with a lateral projecting portion, corresponding in
shape and thickness to the notch or cut-away portion in the fixed arm.
The moveable arm is pivotally secured to the fixed arm by means of a pivotal
screw, or other suitable pivotal connection, which extends through the plate near
its lower or curved edge, and a considerable distance back from the front or inner
edge of the fixed arm and the plate. Between the pivotal connection and the
curved end of the plate, there is provided a curved, closed-ended slot to receive a
set screw.
The two arms, when thus assembled, have an extended bearing one upon the other,
and upon opposite sides of the fixed arm, tending to prevent any displacement of the
relative position of the two arms when under strain, and the point where the nose of
the spring locks the two arms together, is at such a distance from the pivotal point

page_text: of the two arms, that the said arms are effectually locked against any liability of
displacement when under strain, in a direction to close them.
Dated this 26th day of August 1890.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Squares for Carpenters' and other Uses.
I, CHARLES LEONARD BRONK, of No. 373, Bergen Street, in the City of
Brooklyn, and State of New York, 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:-
My invention relates to an improvement in steel squares in which the arms are
pivotally secured together so that one may be swung with relation to the other
throughout an arc of 90°.
The object is to so construct the joint between the two arms, that the strain upon
the pivotal point may be materially reduced, and a bearing of such extent formed
that there will be little or no liability of the arms wearing, so as to be thrown out
of a true perpendicular to each other when opened, and to further provide for a
true lateral seat of the two arms, and for automatically locking them in opened
adjustment.
With these ends in view, my invention consists in certain features of construction
and combination of parts as will be hereinafter described and pointed out in claims.
A practical embodiment of my invention is shown in the accompanying drawing,
in which,
Fig. is a view of the square in side elevation, the arms being broken and
shortened, in order to show the joint upon a larger scale.
Fig. 2 is a view of the joint portion of the square in side elevation upon the
reverse side from Fig. 1, the arins in Figs. 1 and 2 being shown as in extended
adjustment.
Fig. 3 is a view of the joint and portions of the arms contiguous thereto in side
elevation, showing the position of the joint when the arms are partially opened, and
Fig. 4 is a transverse section through line of Fig. 1.
A represents the wider and thicker of the two arms, and B represents the
narrower and shorter of the two arms of a square of the general form in common
use. The two arms A and B are here shown graduated for a short distance from
the joint only, but it is intended that they shall be graduated throughout their
entire lengths, as in common. The arm A is provided with a shallow recess a
extending for a considerable distance from its end, somewhat more than twice the
width of the arm B, and terminating at its lower end in a curve a¹, corresponding
to a quarter of the circumference or more. This curved portion is provided with
graduated-division marks to designate the different angles from 1° to 90°, and sub-
divisions thereof, as may be desired. Said recess a occupies two thirds or more of
the width of the arm A, thereby forming not only an elongated bearing in the
direction of the length of the arm A, but also an extended bearing widthwise of the
same. The wall of the recess a is provided with an undercut a² extending
throughout both its curved and straight portions. The end of the arm A is further
cut away along the edge of the recess a toward the arm B, forming an elongated
notch, as shown at a³, the said notch terminating in a curved lower portion a. The
edge of the notch a³, throughout both its straight and curved portions, is bevelled to
enter a corresponding undercut, as will hereinafter appear.
The arm A is provided, on its opposite face from that on which the recess a is
located, with an elongated shallow recess a³, for the reception of a flat bar spring C.

page_text: The portion as of said recess a³, near the end of the arm A, extends through the
arm A into the recess a hereinbefore referred to for the reception of the nose c of
the said spring C, which nose c projects through the said portion a, and forms a
lock to secure the member or arm B in its extended adjustment with relation to the
arm A.
I prefer to form the nose e of substantially rectangular shape, as shown, and
bevel one of its corners, as shown at c', for the purpose of gradually forcing it
backward by the opening movement of the arm B. The spring C is secured with
its back flush with the surface of the arm A, conveniently by means of a pair of
short screws c². It is intended that the recess a in the arm A shall have a depth
equal to about one half the thickness of the arm A.
The arm B is provided, on its end, toward the arm A, with a plate 6 of substan-
tially the shape and thickness of the recess a hereinbefore referred to, and its.
edge, throughout both the straight and curved portions, is beveled to correspond
to the undercut hereinbefore referred to in the wall of the recess a.
The plate b
is further provided with a lateral projecting portion 62, corresponding in shape and
thickness to the notch or cut-away portion a³ in the arm A, and is provided along
the straight and curved portions of its edge with an undercut 3, adapted to receive
the beveled edge at of the notch a³.
I find it convenient, as herein shown, to form the plate b, and the projection b²,
integral with the arm B. The plate is provided, near its upper end, with an
opening, adapted to receive, with a close fit, the nose e of the spring C. I
further provide the beveled edge 1 of the plate & with an oblique shoulder b³ at the
point where it first engages with the nose c of the spring C, for the purpose of
gradually depressing the spring out of the way of the plate b, as it slides into
position within the recess a, without the necessity of operating the spring by the
pressure of the hand.
The arm B is pivotally secured to the arm A by means of a pivotal screw or
other suitable pivotal connection D, which extends through the plate 6 near its
lower or curved edge, and a considerable distance back from the front or inner edge
of the arm A and the plate b. Between the pivotal connection D and the curved
end of the plate 6, in the form of my invention shown, there is provided a curved,
closed-ended slot E through the end of the plate b. A. set screw d extends through
the curved slot E into the arm A, preferably with its head flush with the face of the
plate b.
It will be observed that the two arms A and B, when thus assembled, have an
extended bearing one upon the other, and upon opposite sides of the arm A, tending
to prevent any displacement of the relative position of the two arms when under
strain. It will also be observed, that the point where the nose of the spring locks
the two arms together, is at such a distance from the pivotal point of the two arms,
that the said arms are effectually locked against any liability of displacement, when
under strain in a direction to close them.
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 is :-
1. The combination with the arms of a square, the one provided with an elongated
shallow recess and the other with an elongated thin plate corresponding to said
recess, of a pivotal connection between the two arms at a considerable distance
from the angle formed by the inner edges of the two arms, and a locking device
near the opposite end of said corresponding recess and plate from the pivotal
connection, substantially as set forth.
2. The herein described square, one of the arms being provided with an elongated
wide shallow recess a, having a curved end, and the other with a plate corresponding
in shape and thickness to said recess, a pivotal connection between the two arms at
a point near the said curved ends, one of the arms being provided with a curved

page_text: slot, and the other with a set screw extending within the curved slot, a spring
seated in the arm provided with a. shallow recess and having its nose projected
within the recess, to engage an opening in the opposite arm, the two arms being
further provided the one with an elongated notch and the other with an elongated
lateral projection to correspond with the notch, and located upon the opposite side
of the square from the recess and plate hereinbefore referred to; substantially as
set forth.
NEWTON & SON,
Agents for the Applicant.