IMPROVEMENTS IN NUT LOCKS
Year: 1885

page_text: I, FRANK GASPER STARK, of Sinclair House, No 752 Broadway New York City,
in the County and State of New York, one of the United States of America,
Engineer, do hereby declare the nature of this invention for IMPROVEMENTS IN
NUT LOCKS and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
I produce a longitudinal groove sometimes denominated a spline, in the bolt.
I make no groove or spline in the nut, but produce a set of inclined notches of
rectangular section on the back face or working face of the nut, arranged around
the hole.
In what I esteem the most complete form of the invention, I also correspondingly
notch the opposite or front face of the nut. The hole through the nut is fully
screw-threaded as usual, including these notched ends. I provide a device, com-
posed of two branches, which I term a spring key, inserted in the spline, and
engaging by its elasticity in the notches in the nut. The outer branch of the key
bas two sufficient swells or arms, which, when it is allowed to spring outward after
the key is driven fully home, engage on each face of the nut. The nut will be held
in place under all ordinary or extraordinary conditions so long as no force is applied
with the intent to remove the key; but when it is desired to unlock the nut, a
sufficient force applied to draw the spring-key end-wise will induce its prompt
removal.
The accompanying drawings form a part of this specification and represent what
I consider the best means of carrying out the invention.
Figure 1 is a side view,
Fig. 2 an end view, and
Fig. 3 a longitudinal section.
These figures show the parts fully engaged.
Fig. 4 is a longitudinal section showing the parts in the act of being engaged or
released.
Fig. 5 is the spring key detached.
Fig. 6 is a cross-section of the bolt showing a face of the nut in elevation.
Similar letters of reference indicate corresponding parts in all the figures where

page_text: :
A is the bolt, and a is a deep spline groove, milled or otherwise produced therein.
It will be observed that this groove is considerably deeper than the threads of the
screw.
B is the nut and B¹ B¹ a series of notches in one face thereof. These notches
extend inward or longitudinally of the nut only a little distance, say across one
thread of the screw.
B B are corresponding notches or short inclined recesses on the opposite face of
the nut, coïnciding in position exactly with the notches B¹.
I employ a branched key with two inclined arms adapted to engage in the
notches or recesses in the nut, the outer branch with its arms being urged outward
by the elastic force of the metal, which may be of uniform section. The two
branches, that is to say, what I term the key body, the branch having the two
arms, and the other branch which serves to urge the key proper outward,-are
connected by a loop which makes an elastic connection. This loop also serves as a
means by which the key may be conveniently seized to be withdrawn when
required. I will use the letter D to indicate the outer branch or main body of the
key, additional portions being designated, when necessary, by additional marks,
as D¹; D and D*.
One branch, D*, lies in the bottom of the spline a, in the bolt.
What I term the main body, marked D, has an inclined bend at its free end,
adapted to engage in the proper notch B¹. This is marked D¹. The loop which
connects the branch D* with D, one side of which loop serves as an arm to engage
in the proper notch B2, is marked D². The face of the loop D' which is presented
towards the nut, is inclined and adapts the loop to serve as an arm to engage the
proper notch B
I have in my experiments made all parts of the spring key of uniform width, a
little less than that of the spline groove a. In such case the notches B, B*, should
be about the same width as the spline. This condition may be varied.
In operating the invention the nut is turned by a suitable wrench or other means
until it is tightened, or is in the position it is desired it shall maintain. Then the
spring key is inserted with its branch B* downward, in the spline a.
The notches B2 on the outer or front face indicate to the eye the position of the
corresponding notches B¹ on the back face. The spring key may be driven end wise
by any suitable force, the inclined end or arm D¹ being deflected inward by the
screw-threads, and riding along under them without serious obstruction. The
length of the key is such that when it is fully home the free bent end or incline D¹
coïncides with one of the notches B¹ in the back face of the nut, and by the
elasticity of the parts engages in such notch and holds firmly. The incline D¹,
taking hold of the nut prevents the key from slipping out. The loop D serves as
an arm at the opposite end of the key, and by engaging with the proper notch B',
on the front face of the nut prevents the key from moving too far inward.
The nut cannot turn on the bolt with the key in position without shearing the
metal of the key at the points D¹ D³. It will remain reliably locked for any length
of time.
No accidental force can remove the key by gravity or concussion. So long as the
key remains in position the nut is locked; but whenever it is desired to liberate
the key it may be drawn out by any suitable hook device engaged in the loop D*,
or by tongs firmly grasping said loop. The arm D! rides under the threads of the
nut both in the act of being inserted and in the act of being removed.
The absence of longitudinal grooves or splines in the interior of the nut, insures
that there is always a proper threaded surface engaged with the partial threads of
the bolt. The groove or spline a in the bolt must be sufficiently deep to accom-
modate both branches of the spring key entirely below or within the innermost
edges of the threads, leaving only the arms D¹, D', extending outward to engage in
the nut.

page_text: Modifications may be made in the forms and proportions. I can make the
arms D D narrower than the main body of the key. In such case narrower
notches B B may serve.
I can dispense with the notches B' on the front or outer face of the nut,
substituting simply marks there, to aid in determining the correct position of the
nut, and allow the notches B¹ on the opposite face to serve alone. It may be
practicable to realize some of the advantages of the invention without any notches
or marks on the front face, allowing the loop constituting the arm D³ of the key to
press against a smooth face of the nut. I prefer the two sets of notches B¹, B³, as
shown.
I can duplicate the spline a in the bolt. One spline is sufficient for all ordinary
cases.
I am aware that grooves have been made in the threaded portions of both nut
and bolt to receive a spring locking-key. But when the nut is thus grooved the
grooves are either so distant from each other that they do not allow a nice adjust-
ment of the nut, or, being numerous, they greatly impair the holding strength of
the nut. Instead of locating my key-engaging recesses in the barrel of the nut,
I place them upon one or both of its faces.
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. The combination with a nut having radial recesses upon its inner face,
arranged at approximate right angles with the bore of the nut, and with a grooved
bolt as shown, of a spring key having an arm to engage said recesses upon one face
of the nut, and an arm to engage the opposite face of the nut, and limit the end-
wise movement of the key as set forth.
2. The combination with a nut having radial recesses B¹ upon one face, and
corresponding marks or recesses B³ upon the other face, of a grooved bolt, and a key
having an arm with opposing inclines, as D¹, D³, to engage opposite recesses upon
both faces of the nut, as set forth.
3. The combination with the nut B, having recesses B¹, arranged around the bore
of the nut, and with the bolt A having a groove a, of a spring key, having
inclines D', D, arranged to engage the nut in opposite directions simultaneously,
as set forth.
D:
100K