Improvements in and relating to Metal Washers.
Year: 1889

page_text: Date of Application, 28th May, 1889
Complete Specification Left, 14th June, 1889-Accepted, 20th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in and relating to Metal Washers.
I, ROBERT JOSEPH HOOPER-RASTRICK of 30 Lavender Gardens, Lavender Hill,
Wandsworth, in the County of Surrey, Gentleman do hereby declare the nature of
this invention to be as follows:-
My invention relates to the type of metal washers having tongues or denticulations
and serrations for the locking of bolts and nuts and is devised with the object of
ensuring greater strength to said tongues or denticulations as also to the depression
or projection employed to lock the washer in position.
According to my invention the tongues and serrations are curved or rounded in
such a manner that each tongue shall gradually increase in width towards the base,
the part at which, by reason of the necessary bending up to lock the bolt or nut,
the greatest strength is required.
The locking projection for locking the washer when the nut is screwed home is
formed of a double curve, the upper part being nearly flat; at the centre it becomes
of semi-ovoid configuration, until at the inner extremity it assumes the form in
section of an inverted cone.
Dated this 24th day of May 1889
EDGAR GEORGE,
27, Bow Lane, Cannon Street, E.C., Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Metal Washers.
I, ROBERT JOSEPH HOOPER-RASTRICK of 30 Lavender Gardens Lavender Hill
Wandsworth 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 in and by the following statement:-
Hitherto in washers having tongues or denticulations and serrations these have
been of rectangular form. This is an element of weakness inasmuch as when any
one of the serrations or tongues are turned up for the purpose of locking a bolt head
or nut it becomes in the act of bending much weakened at the base and consequently
very liable to fracture. This is especially the case when the washers are adapted to
bolts subjected to considerable vibration.
Another point of weakness is in that part of the washers where the depression or
projection is made. The formation of the latter is usually that of a distinct and
sharply defined triangle in section extending beyond the base of the tongues or
serrations the particular tongue under which such projection is made is thus greatly
weakened so that not only is a fracture probable in the process of manufacture but
such fracture is likely to be further extended in screwing the nut "home." Under
these circumstances the locking device would obviously become inoperative.
'
My invention is designed with the object of remedying such disadvantages by
materially strengthening the washers on th particular parts previously referred to.
In reference to the accompanying sheet of drawings :
Figure 1 represents a washer A formed in accordance with iny invention. It will
be observed that the tongues or denticulations a or serrations 6 being curved there
are no sharp angles consequently the risk of fracture during the manufacturing process
is avoided further by virtue of the curved conformation of the serrations b, the
tongues a are strongest at the base, thus when bent up against the face of the bolt-
head or nut B, figures 2, 3 & 4 the possibility of sneh tongues a being fractured or
broken off is reduced to a minimum.

page_text: In prior inventions of a similar type the locking device of the washer has usually
been formed by pressing or stamping a diametral depression or projection on the
washer extending from the interior to the extremity of one of the tongues; the
strength of the latter is not only being considerably reduced in consequence, but a
resulting fracture also almost inevitable-to obviate this, I prefer to form the
depression in the manner shown to enlarged scale in Figures 5 and 6, from which
it will be seen that the depression curves from the upper face of the washer A at c
gradually tapering inwards and downwards in a double curve to the inner edge at d,
at which point it assumes the shape of an inverted cone, the point of depression
between c and d being somewhat of an ovoid configuration.
C
The part of the washer in which the depression is made is preferably broader
than an ordinary tongue by which means greater strength is secured to the locking
depression than in the case of a washer having all the tongues of equal size.
By the adoption of a depression formed in the manner above described there is
little probability of fracture occurring during the process of manufacture.
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
1
1. The improved washer having curved tongues or denticulations and serrations
substantially as and for the purposes herein set forth and shown.
2. In a washer having denticulations and serrations as herein described one tongue
of greater width than the others wherein is formed a depression or projection
substantially as herein described.
Dated this 14th day of June 1889.
EDGAR GEORGE,
27, Bow Lane, Cannon Street, E.C., Agent for Applicant.