Improvements in Split-pins.
Year: 1899

page_text: Date of Application, 21st July, 1899-Accepted, 26th Aug., 1899
COMPLETE SPECIFICATION.
Improvements in Split-pins.
I, HENRY HARINGTON LEIGH, Assoc.M.Inst.C.E., Fel.Ch.Inst.P.A., F.I.Inst.,
practising as Phillips and Leigh, of No. 22, Southampton Buildings, Chancery
Lane, in the Administrative County of London, Engineer and Patent Agent do
hereby declare the nature of this invention (a communication from Joseph Henry
Johnson, of The Pioneer Lock Works and General Metal Foundry, Aligarh,
North West Province, India), and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:-
This invention relates to the construction of the fastenings known as split-
pins, and the object of it is to prevent their becoming accidentally retracted from
the hole in which they are inserted when in use; thus rendering them safety
split-pins.
I will now proceed to describe my invention with the aid of the accompanying
drawings, in which:-
Figure 1 is an ordinary split-pin as used to fasten buttons or badges on
uniforms etc.
Figure 2 is an ordinary split-pin such as used in engineering.
Figure 3 is my improved form of split-pin as used to fasten buttons or badges
on uniforms.
Figure 4 is my improved split-pin as used for engineering purposes.
The split-pin as heretofore inanufactured for engineering and other uses (see
Figures 1 and 2) has been formed of a piece of slightly springy wire bent double
so as to form an eye or head a at one end and two legs b, b; another form consist-
ing of a solid tapering pin split longitudinally from the smaller end to near the
other end, thus dividing it into two legs and leaving the unsplit part to form the
head. Both these forms however, have the same disadvantage which is that the
legs being plain, that is, without projections of any kind the pin is apt to become
gradually retracted from the hole by vibration, as they are only held in place
by the slight spring with which they are endowed.
I am aware that to prevent them falling out from vibration or other causes
the projecting ends of the legs are forced apart after inserting the pin in the
hole, but this also carries the disadvantage that its legs have to be closed again
perfectly in order to remove it, and as this is of frequent occurrence with
machines where the pin serves to hold in place some wheel or part which is
required to be removed after each use of the machine, by the proper attendant,
in order to prevent others from tampering with or working it, the pin would soon
become broken by the frequent bending.
My new or improved split-pin is so constructed as to entirely overcome the
above disadvantages, and whilst it can be easily and quickly removed at any time
it is absolutely prevented from accidental retraction. It is constructed
follows-
as
At the extreme ends of the legs (see Figures 3 and 4) are formed outwardly-
turned projections e, which engage with the outer edges of the holes when the

page_text: pin is inserted, and so prevents it from falling out or becoming accidentally
dislodged by vibration and the like.
.
In the construction of split-pins of 18 inch diameter and upwards, it will be well
to have them tapered towards the ends on the inside of the split or on the out-
side as shown at din Figures 3 and 4, with the projections c below the tapered
part, so that the springiness of the pin acting in conjunction with these pro-
jections prevent it from leaving the hole.
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:
A split-pin having outwardly-turned projections at the ends of its legs sub-
stantially as and for the purpose herein before described and set forth.
Dated the 21st day of July 1899
HENRY H. LEIGH, C.P.A.