Improvements in Bolts and Nuts and similar Fastening Devices.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Bolts and Nuts and similar Fastening Devices.
I, CLINTON ALLEN HIGBEE, residing at 1615 North Twenty-third Street, in
the City of Philadelphia, in the County of Philadelphia, in the State of
Pennsylvania, one of the United States of America, Manufacturer, 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 the construction of nuts and bolts, and has for its object
to so improve their construction as to avoid the risk of jamming and crushing the
threads. In the Patent of the United States, No. 447,775, granted to me on the
10th day of March, 1891, I bave shown and described an improvement having
the same object in view, and in which the threads are cut off so as to have their
ends of a substantially symmetrical section on each side of the centre line. My
present invention relates to threads which taper toward the ends as is usually the
case, and has for its object to secure at the same time the loose fit on entering the
bolt in the nut and to avoid the danger of jamming incident to such nuts and bolts
as heretofore constructed. This I accomplish by so cutting the ends of the tapered
threads that at their extreme ends their aggregate height will equal or exceed the
total height of a single thread, by so forming the threads I effectually prevent
them from tapping on each other, and insure that each shall enter its corresponding
groove in correct position.
Reference being now had to the drawings in which my invention is illustrated, and
in which
Figure 1 is an end view of a nut; and
Figure 2 an end view of a bolt constructed in accordance with my invention.
Figures 3 and 4 show ends of a nut and bolt of a modified construction, but still
embodying my invention.
Figure 5 is an elevation of the bolt Figure 4.
Figure 6 shows the nut and bolt together illustrating how the described
construction prevents jamming or false engagement.
Figure 7 shows the bevelling of the ends which I prefer to employ, and
Figure 8 is a diagram illustrating the principle of construction.
A is the uut, a the full sized thread, a' the tapered section of the thread end,
a² the butt end of the thread in the nut; B is the bolt, b its full sized thread, b¹ the
tapered end and the butt or extreme end of the bolt thread. The essential
feature of my new construction is that the height of the tapered thread sections ab
at their ends a² b2 should in the aggregate equal the height of the thread a or b.
Thus referring to diagram Figure 8, the distance C C₁ we will take to be the
height of a thread, and the diagonal line C C or C₁ C' to represent the taper of
the end a¹ or b¹. The cross lines at 1, 4, 7 &c., will represent points where the
taper threads are terminated, then it will be seen that if the bolt thread is at its
end as high as indicated at 1-2 the nut thread at its end must be as high as from
2 to 3 and so on.
To facilitate the engagement of the tapered threads the ends a² and 6 one or
both should be bevelled as shown in Figure 7, the nut thread bevelled in and the
bolt thread bevelled out.
It will be understood that by bolt and nut I refer to and include male and female
screw couplings in general.

page_text: 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 :-
First. As a new article of manufacture, a nut and bolt, the threads of which are
tapered at the end so as to be of less height than the total height of the thread,
and the aggregate height of the thread ends of which is equal to or greater than
the total height of the thread.
Second. As a new article of manufacture, a nut and bolt, the threads of which
are tapered at the end so as to be of less height than the total height of the thread
and bevelled as described to facilitate engagement, and the aggregate height of the
thread ends of which is equal to or greater than the total height of the thread.
Dated this 25th day of July 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.