An Improved Arrangement of Lock-nuts.
Year: 1893

page_text: Date of Application, 10th Oct., 1893
Complete Specification Left, 9th July, 1894-Accepted, 11th Aug., 1894
PROVISIONAL SPECIFICATION.
An Improved Arrangement of Lock-nuts.
We, PATENT RIVET COMPANY LIMITED, of Rolfe Street, Smethwick, in the
County of Stafford, Manufacturers, and JOHN SMITH, of 195, Windmill Lane,
Smethwick, aforesaid, Foreman Engineer, do hereby declare the nature of this
invention to be as follows:--
This invention has reference to lock-nuts of the kind described in the
Specification of Letters Patent No. 7116 of A.D. 1886 granted to Armand
Flamache and Einile Picard for "Improvements in or appertaining to lock-nuts."
A lock-nut of this kind has on one face one or more helicoidal inclined planes of a
different pitch to the pitch of the screw thread in the nut, this inclined plane or
each of these inclined planes terminating in a straight portion which forms a stop
and as described in the Specification above referred to engages with a corresponding
portion of the washer which has one or more helicoidal inclined planes on its face
corresponding with the said inclined plane or inclined planes on the nut. By
referring to this Specification of Flamache and Picard it will be seen that the
perfect locking of the nut depends to a large extent upon the frictional surface
with which the underside of the washer is in contact and that if there is very little
friction as is the case when the surface is true and smooth the nut is liable to jar
loose. Moreover the uses to which this combined lock-nut and its washer can be
put are limited to those cases where the nut is required to screw the bolt up tightly
as there must be a solid surface for the washer to bear against.
By our invention we are enabled to securely lock the nut on to the belt under
all conditions whether the nut is required to screw up against a surface or not.
In carrying out this invention we dispense with the washer described in Flamache
and Picard's Specification above referred to and we use two of the said lock nuts
fitting close together on a bolt the helicoidal inclined plane face of one nut matching
the helicoidal inclined plane face of the other nut. To lock the two nuts on a bolt
they are first placed together face to face the stop portion or stop portions of the
one nut being in contact with the stop portion or stop portions of the other nut
and the nuts are screwed together along the bolt to the desired position or until
the bolt has been screwed up as tightly as required; the bottom nut is then by a
spanner held stationary whilst the top nut is turned in the direction to unscrew the
nut off the bolt, when the inclined plane face of one nut will ride on the inclined
plane face of the other nut and as these inclined planes are of a greater or less
inclination than the screw thread in the nuts the two nuts will be firmly locked
together on the bolt. To unlock the nuts one nut has to be turned in the direction
to bring the stops together whilst the other nut is held stationary.
Dated this 7th day of October 1902
CHARLES BOSWORTH KETLEY,
Agent for the Applicants.

page_text: COMPLETE SPECIFICATION.
An Improved Arrangement of Lock-nuts.
We, PATENT RIVET COMPANY, LIMITED, of Rolfe Street, Smethwick, in the
County of Stafford, Manufacturers, and JOHN SMITH, of 195 Windmill Lane,
Smethwick, aforesaid, Foreman Engineer, do bereby 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 has reference to lock-nuts of the kind described in the Specification
of Letters Patent No. 7116 of A.D. 1886 granted to Armand Flamache and
Emile Picard, for "Improvements in or appertaining to lock-nuts." A locknut of
this kind has on one face one or moré helicoidal inclined planes of a different pitch
to the pitch of the screw thread in the nut, this inclined plane or each of these
inclined planes terminating in a straight portion which forms a stop and as described
in the Specification above referred to engages with a corresponding portion of the
washer which has one or more helicoidal inclined planes on its face corresponding
with the said inclined plane or inclined planes on the nut. By referring to this
Specification of Flamache and Picard it will be seen that the perfect locking of
the nut depends to a large extent upon the frictional surface with which the
underside of the washer is in contact and that if there is very little friction as is
Moreover
the case when the surface is true and smooth the nut is liable to jar loose.
the uses to which this combined lock-nut and its washer can be put are limited to
those cases where the nut is required to screw the bolt up tightly as there must be
a solid surface for the washer to bear against.
By our invention we are enabled to securely lock the nut on to the bolt under all
conditions whether the nut is required to screw up against a surface or not.
In carrying out this invention we dispense with the washer described in Flamache
and Picard's Specification above referred to and we use two of the said lock-nuts
fitting close together on a bolt the helicoidal inclined plane face of one nut matching
the helicoidal inclined plane face of the other nut.
On the accompanying drawings Fig. 1 shews two of the said lock-nuts marked
respectively A and B arranged together in accordance with this invention;
Fig. 2 shews the said two nuts in use locked together on a bolt marked C and
Fig. 3 shews the two nuts A and B separately. It will be seen that the nut A has
a helicoidal inclined plane face a the angle of which is greater than the angle of
the screw thread in the nut and the nut B has a helicoidal inclined plane face b of
the same angle as the inclined face a of the other nut A. We find that we
obtain the best results by employing one helicoidal inclined plane face on each of
the nuts and made of an angle which is about double the angle of the screw thread
in the nuts, but it is to be understood that our invention is not limited to any
particular angle of the inclines ab nor to the number of helicoidal inclined plane
faces which are formed on the nuts as there may be two or more of these helicoidal
inclined plane faces on each nut.
°
To lock the two nuts A and B on the bolt C they are first placed together face
to face as shewn in Fig. 1 the stop portion a' of the nut A. being in contact with
or adjacent to the stop portion of the other nut B and the nuts are then screwed
together along the bolt C to the desired position or until the bolt has been screwed
up as tightly as required; the two nuts are then turned in opposite directions (or
one of the nuts is held stationary whilst the other nut is turned in the direction to
separate the nuts) when the inclined plane face of one nut will ride on the inclined
plane face of the other nut and as these inclines ab are of a greater inclination
than the screw thread in the nuts the two nuts will be firmly locked together on
the bolt as shewn in Fig. 2.
To unlock the nuts A B they have, or one of them has, to be turned in the
to huing the stan nantions 11 tomthori

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
On screwed bolts and other screws the combination of two lock nuts the meeting
faces of which are formed in corresponding helicoidal inclined planes of a greater
angle than the angle of the screw thread in the nut so that when the nuts are
turned, or one of the nuts is turned, in the direction to separate the nuts they will
be locked together on the bolt or other screw as hereinbefore set forth.
Dated this 7th day of July 1894.
CHARLES BOSWORTH KETLEY,
Agent for the Applicants.