Improvements in Hinges Specially Applicable to Step-ladders and Trestles.
Year: 1886

page_text: Date of Application, 14th Dec., 1886.
Complete Left, 14th Sept., 1887.
Complete Accepted, 14th Oct., 1887.
PROVISIONAL DIFCITICATION.
Improvements in Hinges Specially Applicable to Step-ladders
and Trestles.
We, ROBERT SMITH and SHEM PAGET both of Parker Street Ironworks, Keighley,
in the County of York, Machine Makers, and GEORGE MOORE of Villa Mona,
Cressingham Road, Lewisham, in the County of Kent, Engineer, do hereby declare
the nature of this invention to be as follows:-
Our invention for improvements in hinges specially applicable to step ladders and
trestles has for object to construct a hinge in such manner that when applied to a
step-ladder, it shall, when the step-ladder is opened retain the said ladder in its
opened position and thus prevent any liability of injuring any person using it from
slipping of the ladder or from other similar cause and that the ladder can readily be
closed by a person at its foot when no weight is upon the ladder no matter what its
height may be.
In a hinge constructed according to our invention, one part consists of a bracket
comprising a flat bar to be secured to one part of the ladder and an open quadrant
bar projecting from the upper end of the flat bar and having a notch or recess formed
at the inner end of the slot and in its upper side. Another part of the hinge consists
of a lever to be secured to the other part of the ladder and having a stud secured in
its upper end to work in the slot in the quadrant bar. The bracket and the lever are
further connected by a short link hinged to the lower end of the flat bar of the
bracket and to the lever preferably at or near the centre of its length.
It will readily be seen that when the ladder is in its closed position, the stud on the
lever will be at the outer end of the slot in the quadrant bar and that the bracket
will form with the lever approximately a triangle; and when the ladder is opened to
its greatest extent the stud on the lever will be at the inner end of the slot of the.
quadrant bar and will enter the aforesaid notch or recess and so lock the parts of the
hinge in position. It will also be seen that the greater the weight on the ladder,
the more firmly will the stud be forced into the notch or recess. In order to close
the ladder, it is only necessary to turn the ladder on the foot of that part to which the

page_text: bracket is secured so as to raise the other part of the ladder from off the ground,
when the weight of this latter part will draw the stud out of the notch or recess and
allow the two parts of the ladder to close together.
It will also be evident that the construction and arrangement of our hinge may be
modified in various ways without departing from the nature of our said invention.
For example, the link may be replaced by a projection from the bracket, a stud on
the projection taking into a short slot in the lever.
In another arrangement, the hinge may be with slight obvious modifications-
placed upside down on the ladder in which case the axis on which the two parts of
the ladder turn will be nearer the top of the ladder.
Dated this 14th day of December 1886.
WHEATLEY & MACKENZIE,
156, Strand, London, W.C.,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Hinges Specially Applicable to Step Ladders
and Trestles.
We, ROBERT SMITH and SHEM PAGET both of Parker Street Ironworks, Keighley,
in the county of York, Machine Makers, and GEORGE MOORE of Villa Mona,
Cressingham Road, Lewisham, in the county of Kent, Engineer, 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 :-
Our invention for improvements in hinges specially applicable to step ladders and
trestles has for its object to construct a hinge in such manner that, when applied to a
step ladder, it shall, when the step ladder is opened retain the said ladder in its open
position and thus prevent any liability of injuring any person using it from slipping of
the ladder, or from other similar cause, and that the ladder can readily be closed by a
person at its foot when'no weight is upon the ladder no matter what its height may be.
In the accompanying sheet of drawings, Figs. 1 and 2 are respectively side and
back elevations of a hinge constructed according to this invention and shown applied
to a step ladder. Figs. 3, 4, 5 and 6 are similar views to fig. 1 showing modified
constructions of hinges.
Referring to figs. 1 and 2, one part of the hinge consists of a bracket comprising
a flat bar a secured to the part of the ladder and having an open quadrant har e
projecting from its upper end, and provided with a notch or recess d formed in the
upper side at its inner end.
Another part of the hinge comprises a lever e secured to the part of the ladder
and having a stud 9
at its upper end adapted to work in the slot in the quadrant
bar c, the flat bar a and lever e are further connected by a short link h hinged to the
lower end of the bar a and to the lever e preferably at or near the centre of its length.
It will readily be seen that in opening the part band of the ladder, the study will
slide in the quadrant bar e until, when the hinge is fully open it will enter the recess d
and lock the part in position.
In order to close the ladder it is only necessary to turn the ladder on the foot of
the part so as to raise the part from off the ground, when the stud 9 will be
drawn out of the notch by the weight of the part and the parts of the ladder will
fall together.
In fig. the link (fig. 1) is replaced by a pin in the bracket a working in a
slot m in the lever e, and the quadrant bar c is not slotted, the upper end of the
lever e acting as the projection to lock the hinge, and sliding against the lower edge
of the quadrant bar.
In Figs. 4 and 5 the hinges shown in Figs. 1 and 3 are modified so that the axis on
which the two parts of the ladder turn is nearer the top of the ladder; the principle of
the construction being the same as shown in these Figs.

page_text: Fig. 6 is a modification of fig. 4. The quadrant bar e is made part of the piece on
the part of the ladder and projects therefrom, and the stud g is made part of the
piece on the part f of the ladder.
It will clearly be seen that the hinges can thus be readily unlocked from the foot
of the ladder.
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 :-
1. The construction of a hinge in such manner that the parts in addition to the
ordinary or angular motion are capable of a slight longitudinal or shifting movement
relatively to one another, so that, when the hinge is fully opened, a projection on one
part takes into a recess on the other part, and locks the hinge in its open position,
until by turning the ladder on one of its feet or otherwise the pressure on the hinge
of the ladder is relieved and allows the projections and recesses to be disengaged by
the weight of one of the parts substantially as described.
2. The construction of a hinge in two parts joined together by a short link, or by
a stud on one part working in a short slot in the other part so that when the hinge is
fully opened a projection on one part engages with a recess on the other part and
firmly locks the parts in position, the parts being further retained in this position by
the weight on the ladder, and being unlocked by allowing the weight of one of the
parts to withdraw the stud out of the recess substantially as described.
3. The construction of hinges substantially as described with reference to figs. 1
and 2, or to fig. 3, or to fig. 4, or to fig. 5, or to fig. 6.
Dated this 14th day of September 1887.
WHEATLEY & MACKENZIE,
156, Strand, W.C.