Improvements in Step Ladders.
Year: 1897

page_text: Date of Application, 21st Sept., 1897-Accepted, 13th Nov., 1897
COMPLETE SPECIFICATION.
Improvements in Step Ladders.
I, CHARLES ARTHUR ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by Reginald Wilmer Vaughan, of
Chula Vista, California, United States of America, Fruit Grower), and in what
nanner the same is to be performed, to be particularly described and ascertained
in and by the following statement: —
The object of the invention is to provide a step-ladder that while convenient for
more general purposes is especially adapted for out-door use, for example, in
gathering fruit from trees of moderate size. With such ends in view, lightness,
rigidity, and adapability for service in, many situations, are important. The
step-ladder consists of two parts, a ladder proper, or set of steps, and devices for
supporting such set in an inclined position. Preferably the two parts are not
hinged together nor in any other way actually united, yet they are adapted to
interlock and become a very rigid whole under the weight of the user and to be
entirely free to separate the instant such weight is removed. Since where the
ground is uneven it is more convenient to have but a single leg as a support, since
for some other reasons such form is preferable, and since the invention can be thus
fairly disclosed, a construction involving but a single supporting bar has been
chosen for illustration.
In the accompanying drawings,
Fig. 1 is a perspective view of the complete apparatus when ready to be mounted
by the user.
Fig. 2 is a partial section perpendicular to the planes of the steps or treads at
their middle points.
Fig. 3 is a bottom plan of a certain metal piece usually secured to one of the
steps.
As shown, the set of steps constituting one part of the apparatus, consists of the
steps proper carried by the usual side pieces, B, which are held together by rods, C,
and suitably braced to the steps. The other part of the apparatus or the device
for supporting the set of steps in an inclined position, consists of a simple cross
formed by securing a cross-bar, E, to a bar, D, at a short distance from the upper
end of the latter, which serves as a supporting leg and which, when in operative
position, makes about the usual angle with the set of steps. The parts are so
proportioned that when the bar D is in proper operative position it extends from
rear to front through the set of steps, its upper end portion bearing against the
front edge of the step next above it and the arms of the crossbar resting against
the rear edges of the two side pleces, B, respectively. The two parts are then
mutually self-supporting, for their weight tends to diminish the angle between
them and thus causes the support to grip the other member by biting against its
front and rear faces at points not in the same horizontal plane. If the weight of
a person be allowed to rest upon any step, his cramping force is greatly increased
and the two parts become temporarily a very rigid whole. To facilitate the use

page_text: of the ladder among tree branches, the side pieces are bent inward until they meet,
above the steps proper and are there united by a clip, H, or other suitable device.
When the support is a. single bar, as shown, the front edge of the step next
above it is-notched to receive it, and the notch is preferably provided with a metal
lining F.
By taking hold of both parts at once, the apparatus may be moved from place to
place as a whole quite as easily as the usual step ladder; yet the parts may be
instantly detached or separated and used alone.
The species of the invention selected for illustration has certain advantages
over other forms, but any arrangement wherein the two parts of a step ladder are
united solely by the gripping of one by the other due to force tending to lessen
the angle made by the two, is obviously within the invention.
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:-
1. A step ladder consisting of two members, a set of steps and a support for the
same, said members being adapted to pass one through the plane of the other and
to be rigidly interlocked solely by the gripping of one by the other due to force
tending to lessen the angle made by the two.
2. The combination with a normally inclined set of steps, of a support adapted
to pass obliquely through said set between its steps and to grip it by biting against
its opposite sides.at points not exactly opposite, when force tends to lessen the
angle made by the steps and support.
3. The combination with a normally inclined set of steps, of a support resting
against the front edge of a step, passing rearwardly downward through the set,
and provided below the rear edge of said step with lateral projections adapted to
rest against the rear edges of the side pieces of said set.
4. The combination with the normally inclined set of steps, of the supporting
bar making an acute angle with the set and having its upper end resting against
the front of the step next above it, and the crossbar fixed to said supporting bar
in position to meet the rear edges of the side pieces of said set when the bar is
in proper supporting position.
Dated this 91st love of Canton 1907