Improvements in Lock-nut Washers.
Year: 1893

page_text: Date of Application, 13th Apr.. 1893
Complete Specification Left, 13th Feb., 1894-Accepted, 17th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Lock-nut Washers.
I, PERCY ALBERT CRAVEN, of 9 Kings Road, Wimbledon, in the County of
Surrey, Gentleman, do hereby declare the nature of this invention to be as
follows:-
My present invention consists of certain improvements upon, or modifications of
my previous invention, for which I received Letters Patent No. 11837 dated
June 24th 1892, and in which I describe and claim a washer having circumferential
slits or cuts, each being provided with a right angled or radial slit by which a like
number of pairs of tongues are formed, each pair being bent or curled in opposite
directions, so that each face of the washer has a like number of spring tongues
extending outwardly therefrom.
The principle involved in my present invention, is identically the same as that of
my previous invention before mentioned, the difference lying in the mechanical
construction of the washer, by which I am enabled to acquire advantages not
attainable by the methods and means employed in my said previous invention.
In carrying my present invention into effect I stamp or otherwise form a washer
from suitable metal, in which I cut or otherwise provide during the manufacture of
same, two or more circumferential slits, centrally or thereabouts between the inner
and outer peripheries thereof, and at the centre or thereabouts of the length of
each of said slits, and preferably at right angles thereto, I cut or otherwise provide
a cross slit or division, which extends therefrom through the substance of the
washer, terminating at the inner or outer periphery, so that one pair of tongues
are thus formed to each circumferential slit, the ends of each pair being bevelled
in opposite directions for the purpose of giving a sharp cutting or knife edge to
each tongue, and each pair I bend or curve in opposite directions to each other, so
that each tongue points in a right handed direction, with its cutting edge farthest
from the body of the washer, thus one spring tongue appears upon, and extends
in an upward direction from, each face of the washer, for each circumferential
elit made therein.
Any desired number of tongues may be thus formed in each washer, but I find
in practice that the number of tongues, to some extent, must be regulated by the
size of the washer, that is to say, the smaller the washer the less the number of
tongues therein, for the reason that, the shorter the tongues are, the less elasticity
or spring they must necessarily possess, and as I make it an indispensable condition
that the upward thrust imparted by said spring tongues to the nut when being
screwed home, must be equal over the whole of the area of the under surface
thereof, in order to avoid side or uneven strain upon the thread of the bolt, and
the thread of the nut, I wish it understood that I in no case use less than four of
said tongues, so that two would impinge upon the under surface of the nut, and two
upon the face of the substance or material at the opposite side of the washer, I
therefore, to obtain the necessary elasticity of the tongues essential in carrying out
the principle of my invention, may construct the said washers as follows.
I form the said washer in two parts that is to say, I use two washers rivetted or
otherwise fastened together face to face, in which case I prefer to make two
circumferential slits in each washer, (although any number required may be made
when this method of construction is employed in connection with large washers)
the cross cut slit being arranged at the right hand end thereof, instead of centrally,
as in the previous method, such cross slit being toward either the inner or outer
periphery, preferably the former, and the tongues thus formed are all bent upward

page_text: from the same face of the washer, thereby leaving the back or under face perfectly
plain, and by rivetting or otherwise fastening these together in pairs, with their
plain surfaces together, and in such a manner that the tongues upon the one are
opposed to those upon the other, I am enabled to produce a washer with spring
tongues on each face identically the same as that previously described, but with
tongues of greater length, and consequently possessing more elasticity, that would
be the case if cut from one piece of metal.
The washer when constructed in either of the manners described, and properly
tempered, would be placed upon the bolt, and interposed between an ordinary nut
and the substance or material being bolted together, in the usual way, either side
being used next the nut, and as the tongues upon the nut side would all point in
the direction of the rotation of the nut, while those upon the opposite side would
point in the contrary direction, the whole of the tongues would be depressed
towards and into the substance of the washer from which they have been formed,
as the nut was screwed home, and when this is effected, the nut is prevented from
returning spontaneously through vibration or otherwise, for the reason that, upon
the slightest backward movement of the nut, the tension of the tongues would
cause the knife like ends thereof to cut into the substance of the nut and the
material being bolted together, simultaneously, thus firmly locking the nut in
position, until force, greater than any possible vibration is used to remove the
same, but when a spanner or other force is used to remove the nut, the knife like
edges of the tongues would take a clean shaving off the under face of the nut,
without injury to it or themselves, whereby the same washer may be used again
and again with the same or other nut.
I have found in practice some difficulty, especially in very small washers, in
tempering the tongues that these may, after being wholly depressed by the screwing
home of the nut, return to their normal position when the nut is removed there-
from, and to overcome this difficulty I provide a rim or raised edges upon the outer
periphery of the washer, (the tongues in this case being of course forined upon the
inner periphery, which may be either attached thereto, or formed integrally there-
with, and upon this impinges the nut upon the one side, and the material or
substance being bolted together upon the other, when the nut is screwed home,
which has the effect of preventing the entire depression of the tongues, this being
regulated by the width of the said rim or raised edges, and this method also
provides that, by reason of the tension of the tongues, their knife like ends are
kept constantly at such an angle as to more readily bite or cut into the surfaces
against which they impinge upon the slightest backward movement of the nut by
vibration.
I wish it understood that I may employ either of the methods of constructing
the said washers herein described, or any desired combination thereof, and with
any suitable or required number of tongues thereon, without departing from the
principle of my invention.
DL 191
.. 1000
GEO. THOS. HYDE,
4, Moorfields, Fore Street, London, E.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Lock-nut Washers.
I, PERCY ALBERT CRAVEN, of 9 Kings Road, Wimbledon, in the County of
Surrey, Gentleman, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained '50
in and by the following statement :—
My present invention consists of certain improvements upon, or modifications of,
my previous invention for improvements in lock-nut washers, and for which Letters

page_text: Patent were granted unto me dated June 24th 1892, No. 11837, and the principle
involved in my present invention is identical with that described in my said previous
invention, the difference lying in the mechanical construction of the washer, by
which I acquire advantages not attainable by the methods and means set forth in
my said previous Patent.
In order that my present invention may be fully and clearly understood I have
hereunto appended a sheet of drawings, in which
Figs. 1 and 2 are plan views of my improved lock nut washer, the difference
between which relatively to each other and those of my said previous Patent will be
hereinafter explained.
Fig. 3 is a section of Fig. 1 upon the line A. B, while Fig. 4 is a front edge view
of Fig. 2.
Figs. 5 and 6 are plan views of washers according to my present invention,
similar to, but differing in detail and application to those shewn in Figs. 1
and 2.
Fig. 7 is a section of Fig. 5 upon the line C D as this would appear when
duplicated as hereinafter explained.
Fig. 8 is an edge front view of Fig. 6, as this would appear when duplicated.
Fig. 9 is a plan view of a lock-nut washer according to my present invention, and
hereinafter explained.
Fig. 10 is a section of Fig. 9 upon the line E F.
In my previous Patent hereinbefore referred to, I describe and show lock nut
washers having four or more spring tongues formed by making circumferential
"slits" in the substance of the washers, but according to my present invention I
reserve to myself the right to form two or more spring tongues in each washer,
which I may produce by similar slits, but I prefer to punch or otherwise remove a
certain portion of the substance of the washer, in lieu of making the said slits, as I
find in practice that in certain size washers this is desirable, and with this in view,
I carry my present invention into effect as follows.
Referring to Figs. 1, 2, 3 and 4, I stamp or otherwise form of any suitable metal,
a washer A, in which I form by punching or otherwise, two or more circumferential
openings or spaces a centrally or thereabouts between the inner and outer peripheries
of A, and centrally or thereabouts of the length of each of these, I form cuts or
divisions b in the substance of A, which may extend from a through the inner
periphery of the washer as at Fig. 1, or through the outer periphery thereof as at
Fig. 2, by which, in the case of Fig. 1, I form upon the inner periphery, two pairs
of tongues e and e³, and d and d¹, while in the case of Fig. 2 similar tongues are
formed upon the outer periphery, and by reason of the slits 6 being angled, a knife
like edge is formed upon the ends of said tongues, as shown at Fig. 4, and each
pair of tongues I bend or curve in opposite directions from each other, that is to
say, c and d would be raised, while c and d would be depressed, so that each
tongue points in a right handed direction with its cutting or knife like edge
farthest from the body of the washer, thus one spring tongue appears upon, and
extends in an upward direction from, each face of the washer, for each circum-
ferential slit or punching made therein.
Any desired number of tongues may be thus formed in either of said washers, but
I find in practice that the number of tongues must, to some extent, be regulated by the
size of the washer, that is to say, the smaller the washer the less must be the number of
tongues therein, for the reason, that the shorter the tongues are, the less elasticity
or spring they must necessarily possess, and as I make it an indispensable condition
that the upward thrust imparted by said spring tongues to the nut when being
screwed home, must be equal over the whole of the area of the under surface
thereof, in order to avoid side or uneven strain upon the threads of the bolt and
nut, I wish it understood that in no case do I use less than four of said tongues for
a complete washer, so that two would impinge upon the under surface of the nut,
and two upon the face of the substance or material at the opposite side of the
washer, therefore, in certain washers of small dimensions, or insufficient to admit of

page_text: four tongues being formed therein, I maintain the principle of my invention by
constructing a washer as at Figs. 5 6, 7 and 8.
In this method the washer is formed in two parts, or in other words consists of
two washers rivetted or otherwise fastened together face to face, in which case I
prefer to form two circumferential slits or punchings a' in each washer, (although
any number required may be made when the size of the washer will permit more)
the cross cut bevelled slit being arranged at the right hand end of a, instead of
centrally as in the previous method, and either towards the inner periphery of A
as at Fig. 5, or the outer as at Fig. 6, preferably the former, and both the tongues c
and d thus formed, are bent "up" from the same face of the washer, thereby
leaving the back or under face perfectly plane. If the tongues c d be upon the
inner periphery of the washer as at Fig. 5, and two such washers be rivetted or
otherwise connected together back to back, these would, if sectioned as at C D
Fig. 5, appear as at Fig. 7, in which the two are for clearness designated by the
letters A A', and in like manner, if the tongues be upon the outer periphery as at
Fig. 6, two such washers, when connected in the same way, and viewed from the
front edge, would appear as at Fig. 8, and by this means I am enabled to produce
a washer with spring tongues upon each face, identically the same in effect as that
of Figs. 1 or 2, but with tongues of greater length, and consequently more
elasticity, than would be the case if all were cut from one piece of metal, and as
both or all the tongues upon either face of the said duplex washer point in a right
handed direction, either face may be placed next to the nut.
The washer constructed in either of the foregoing methods, would, when properly
tempered, be placed upon the bolt between any ordinary nut and the substance or
material being bolted together, in the usual way, with either face next the nut, and
as all the tongues upon the nut side would point in the direction of its rotation when
being screwed home, it follows that those upon the opposite side would point in the
contrary direction, and during the screwing home of the nut the whole of the
tongues would be depressed towards and into the substance of the washer from
which they have been formed, and when the nut has been screwed home, this would
be prevented from returning spontaneously through vibration, for the reason that,
upon the slightest backward movement thereof, the tension of the spring tongues
would cause their knife like ends to cut into the substance of the nut and the
material bolted together simultaneously, thus firmly locking the nut in position,
until a spanner or other means of force were used to remove the same, when
the sharp edges of the tongues in contact therewith would take a clean shaving off
the undersurface thereof,, without injury to themselves or the nut, thus permitting
that the same washer may be used again and again with the same or other nut.
I have found in practice, and especially with very small washers, some difficulty
in tempering the tongues, that these may, after being wholly depressed by the
screwing home of the nut, return to their normal position when the nut has been
removed, and to overcome this difficulty I construct the washer as at Figs. 9
and 10. In this method I provide a rim or raised edge e upon the outer periphery
of the washer, or connected thereto (the tongues in this case being of course upon
the inner periphery) and upon the said rim e the nut would impinge upon the one
side, and the substance or material being bolted together upon the other, when the
nut is screwed home, which would have the effect of preventing the entire
depression of the tongues, the extent of this being regulated by the thickness of e,
and this method also provides, that by reason of the tension of the tongues, their
knife like ends are kept constantly at such an angle as to more readily bite or cut
into the surfaces opposed thereto, upon the slightest backward movement of the nut
through vibration.
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
1st. The construction and use of lock nut washers, in either of the manners

page_text: herein described and shewn, or any combination thereof, and having any desired
number of spring tongues with knife like ends, substantially as herein set forth and
shewn by the appended drawings.
2nd. The combination of a lock nut washer A having two or more circumferential
slits or divisions a, and a like number of cross bevelled cuts b, thereby forming twice
their number of knife edged spring tongues c, c'd d' upon the inner or outer
periphery of A, bent or curved in opposite directions, so that a like number of these
appear upon each face of A, substantially as and for the purposes herein described
and shewn by Figs. 1, 2, 3 and 4 of the accompanying drawings.
3rd. The combination of two washers A and A¹ rivetted or otherwise connected
back to back, and each having two or more slits or divisions a and a like number of
bevelled cross cuts 6 at the right hand end of a, whereby a like number of knife
edged spring tongues c d are formed upon the inner or outer periphery of A and A',
turned up or curved from the outer faces thereof, substantially as and for the
purposes herein described and shewn by Figs. 5, 6, 7 and 8 of the accompanying
drawings.
4th. The combination of a washer A having a rim or raised edge e formed thereon
or connected thereto, and provided with two or more slits or divisions a, and a like
number of bevelled cross cuts 6, thereby forming twice their number of knife edged
spring tongues c cd and d¹ upon the inner periphery of A, bent or curved in
opposite directions, so that a like number of these appear upon each face of A,
substantially as and for the purposes herein described, and shewn by Figs. 9 and 10
of the accompanying drawings.
Dated this 12th day of Wabun 1894
GEO. THOS. HYDE,
4, Moorfields, Fore Street, London, E.C., Agent for the Applicant.