Improved Means for Controlling the Extent of Spread between the Tread Frame and Legs of Step Ladders.
Year: 1896

page_text: Date of Application, 23rd May, 1896
Complete Specification Left, 17th Feb., 1897-Accepted. 20th Mar.. 1897
Improved Means for Controlling the Extent of Spread between the
Tread Frame and Legs of Step Ladders.
I, EDWIN HART, of Weston Birt, Tetbury, Gloucestershire, Gardener, do hereby
declare the nature of this invention to be as follows:-
This invention relates to step ladders such as are commonly used in households in
hanging curtains and for other uses, that is to say, step ladders consisting of a ladder
of treads or steps, and legs hinged to the ladder towards the top thereof.
According to this invention, connection between the ladder and the legs is made
by iron or steel arms arranged in the manner following.
To a suitable lug fixed to one of the treads is pivotted a single arm set on edge
and slotted towards its other end at which it carries a crosshead. Through the slot
is passed a pin which unites transversely a pair of arms also set on edge and
pivotted in lugs fixed to a crosspiece uniting the ladder legs. The single arm
aforesaid has play between the other two arms which are notched or recessed on
their upper edges.
When the ladder and legs are folded, that is to say, when they are closed on
each other, the single and double arms assume an approximately vertical position.
When the ladder and legs are moved apart the arms are drawn down on their
pivots until they are horizontal. The crosshead of the single arm then drops into
one of the recesses of the double arms and the ladder and legs are thus made rigid
and cannot move either away from or towards one another, until the crosshead is
freed from the recess.
The use of cords, chains or ropes is dispensed with..
Improved Means for Controlling the Extent of Spread between the
Tread Frame and Legs of Step Ladders.
I, EDWIN HART, of Weston Birt, Tetbury, Gloucestershire, Gardener, 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:-
This invention relates to step ladders such as are commonly used in households
in hanging curtains, and for other uses, that is to say, step ladders consisting of a
ladder of treads or steps, and legs hinged to the ladder towards the top thereof.
According to this invention, connection between the ladder and legs is made, in

page_text: addition. to the usual hinges, by iron or steel arms arranged in the manner
following-To lugs fixed to one of the treads is pivotted, at one end, a single arm
set on edge and slotted towards its other end at which it carries a crosshead.
Through this slot is passed a pin which unites transversely a pair of arms also set
on edge and pivotted in lugs fixed to a cross piece uniting the ladder legs. The
single arm aforesaid has play between the other two arms which are notched or
recessed on their upper edges. When the ladder and legs are folded that is to say,
when they are closed on each other, the single and double arms assume an
approximately vertical position. When the ladder and legs are moved apart the
arms are drawn down on their pivots until they are horizontal. The crosshead of
the single arm then drops into one of the recesses of the double arms and the ladder
'and legs are thus made rigid and cannot move either away from or towards one
another, until the crosshead is freed from the recess.
The use of cords, chains, or ropes, is dispensed with.
Referring to the accompanying sheet of illustrative drawings,
Fig. 1 thereon represents, in vertical section, a step ladder constructed and
arranged in accordance with this invention. The ladder is represented as folded,
that is to say, the legs are closed on the tread frame.
Fig. 2 shows, also in vertical section, the step ladder with the legs as moved on
their hinges a short distance apart from the frame.
Fig. 3 shows, also in vertical section, the step ladder spread to its full extent.
Fig. 4 is a plan of the connection by the arins aforesaid between the tread frame
and the legs, and illustrates the same in the position occupied when the legs are
moved apart to the full extent from the tread frame.
The connection, besides the usual binges, between the tread frame a and the
legs b, is made in the manner following: Pivottel on the pin e passed through the
lugs c of the bracket c, fixed to one of the treads, is an arm d of iron, steel, or
,other suitable metal. In the arm d is a slot d' through which is passed a pin e
which unites transversely the pair of arms set at opposite sides of the arm and
pivotted at f' to lugs g bolted to the crosspiece h extending from one leg to the
other. The arm d which carries a crosshead d is capable of sliding between the
arins which latter are recessed at 12 and 13. When the legs bare closed on
the tread frame a as shown at Fig. 1, the arms d and fassume an approximately
vertical position. When the legs and tread frame are moved apart on the hinges i,
the arms d and are drawn down on their pivots, and, when fully drawn down,
they assume a horizontal position. The crosshead d² is made to enter either one
of the recesses in the rack according to the extent of spread required, and
no further movement apart of the legs from the frame or the frame from the
legs is possible until the crosshead d² is raised clear of the recess which it has been
made to enter. Accordingly, the extent of spread is variable and under control, and
thus the ladder is capable of being adapted and locked for use safely at the full
extent of spread, and in places where the space is less than that required for the full
extent of spread. The number of recesses in the rack f may vary, as also may the
distances between them.
Obviously, the arm and rack arrangement constituting this invention, renders the
step ladder stronger and safer than ropes with their greater liability to decay and
break.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
Means for adjusting variable extent of spread, that is of distance between the
legs and the frame, of step ladders and for locking in the adjusted spread position;
consisting of a slotted arm such as d pivotted either indirectly or directly to the
tread frame and a rack such as pivotted either indirectly or directly to the legs frame
and coupled to the arm by a pin passes transversely through the slot aforesaid, the
said arm having a crosshead by engagement of which with recesses in the rack, the

page_text: extent of spread is determined and the legs and tread frame are locked in the adjusted
position, substantially as hereinabove described with reference to the accompanying
drawings.