IMPROVED MEANS OF LOCKING NUTS TO SCREW-BOLTS
Year: 1882

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "IMPROVED MEANS
OF LOCKING NUTS TO SCREW-BOLTS." A communication from abroad by
Solon Pattee, General Accountant, and Alphonso Budd Smith, Ship Master,
both of San Francisco, in the County of San Francisco, and State of
California, United States of America."
COMPLETE SPECIFICATION filed by the said Alexander Melville Clark at the
Office of the Commissioners of Patents on the 21st February 1882.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
" IMPROVED MEANS OF LOCKING NUTS TO SCREW-BOLTS."
A communication from abroad by Solon Pattee, General Accountant, and Alphonso
Budd Smith, Ship Master, both of San Francisco, in the County of San Francisco,
and State of California, United States of America.
This Invention relates to a new means of locking, a nut to its bolt so that it
cannot be jarred loose or thrown entirely off the bult. On fish plates of railroad
rails, on vehicles of all kinds, and also on machinery, great inconvenience is at
present experienced owing to the loosening and even loss of nuts caused by the
motion of vehicles, jarring of machinery, and from other causes.
The present Invention attains the desired result by threading the bolt with a
right handed and left handed thread, the two threads crossing each other, and by
applying thereto two nuts, the one matching the one thread, the other the reverse
thread. Between these two nuts is interposed a plate with projecting ears that
lap over the edges of both nuts and are in contact with both. If the outer nut
should begin to turn loose, it will by its movement cause the interposed plate, and
thereby also the other nut, to turn with it in the same direction. This movement
of the second nut however is longitudinally in the reverse direction to that of the
outer nut. Hence the inner nut is tightened by the loosening of the outer nut,
and counteracts therefore in satisfactory manner the tendency of the latter to
work loose.

page_text: In the accompanying Drawing, A is the bolt having a right and left thread cut
upon it. These threads cross each other and may either be single threads, as in
Figures 1 and 2, or double threads, as in Figure 3; B is the outer nut, and C the
inner nut; D is the plate of sheet metal or the like interposed between the nuts on
the bolt; b are outwardly projecting ears formed on the plate D, and bearing
against the edge of the nut B; c, are inwardly projecting ears formed on the
plate D, and bearing against the edge of the nut C; Only one ear b and one ear c
are necessary. The outer nut B may match the left thread, and the inner nut C
the right thread on the bolt A, or vice versa.
When these nuts with their interposed plate are on a bolt of the construction
stated and both contiguous to said plate, as in Figure 1, it will be impossible to
screw the nut B outward without at the same time screwing the nut C inward and
tightening it against the object that is between the head a of the bolt and the
nut c.
That this is necessarily true results from the fact that when both nuts are
turned in the same direction they move lengthwise in opposite directions, and that
owing to the grasping plate D neither nut can be turned without the other. To
unfasten the bolt the ears 6 of the plate D must first be bent to entirely clear the
nut B, whereupon said nut can be easily unscrewed, the plate D taken off, and then
the nut C unscrewed.
Further description seems needless. The Drawings show the Invention clearly,
Figure 1 being a side view of the bolt with its nuts and plate D; Figure 2, a side
view of the bolt showing the nuts and plate in section; Figure 3, a side view of &
double threaded bolt; Figures 4 and 5, central sections of the two pairs of nuts;
Figure 6, face view of plate D flattened; Figure 7, perspective view of said plate
bent to have ears 6 and c; Figure 8, a top or face view of an hexagonal nut B with
plate D below; Figure 9, face view; and Figure 10, perspective view of another
form of plate D; Figure 11, face view of a four-sided nut B on a plate D of the
form shown in Figure 10.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as new and desire to secure by Letters
Patent is,―
The bolt A having crossed threads combined with nuts B and C that are adapted
to match said threads respectively, and with the interposed plate D having ear or
ears b and ear or ears c to operate, substantially as herein shown and described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal; this Twenty first day of February, A.D. 1882.
A M. CLARK
(L.S.)