Improvements in the Construction of Hinges for Step-ladders and other similar Contrivances.
Year: 1893

page_text: Date of Application, 2nd Sept., 1893
Complete Specification Left, 1st June, 1894-Accepted, 14th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Hinges for Step-ladders and
other similar Contrivances.
I HUGO EWALD WOLLMER of 32 Manley Road Manchester in the County
of Lancaster, Manager, do hereby declare the nature of this invention to be as
follows:
1
This invention relates to the construction of hinges to be used for step-ladders
folding trestles, and other similar contrivances, for the purpose of keeping them in
position when extended and preventing them from slipping.
According to my invention I make the hinge of two plates hinged together by a
stud or pivot, one plate being of a fan-shaped form, and the other a plain straight
strip of metal. In the latter I fix (or form with it) two studs or pins one at or
near each end, the upper one connecting the two parts together and forming the
pivot on which the hinge works, and the lower one passes through a curved slot
made for that purpose in the fan-shaped plate.
At one end of this curved slot is formed a short notch in a direction pointing
towards the upper pivot and the pivot hole in the fan plate is slotted similarly in
the same direction.
The two plates are provided with holes so that they can be attached by screws
one to the main frame and the other to the legs of the step-ladder.
In the folded position of the ladder the lower stud or pin will be at the end of
the curved slot furthest from the short notch, and as the lugs are extended this
stud or pin moves along the curved slot until it arrives at the other end when the
frame will fall slightly so as to bring the pin or stud into the short notch thereby
locking the hinge in this position.
Before folding the legs it will be necessary to slightly raise the frame of the
step-ladder so as to bring the stud or pin out of the short notch and in a line with
the curved slot, and the two parts can then be folded together. If preferred the
notch at the end of the curved slot and the short slot at the pivot end may be
dispensed with as the weight will keep the legs fully extended.
As a modification I sometimes make the two parts of the hinge somewhat in the
ordinary form, but on that part or flap attached to the frame I continue the plate
above the hinge joint and in a line therewith, and I also continue the part or flap
attached to the legs above the joint, but at such an angle as will allow the hinge to
open and the legs to be extended to the desired degree, when this angular
continuation of one flap will abut or come against the straight continuation of the
other flap and thus prevent the further extension of the legs. To prevent any
side movement one flap may be made wider than the other and so formed as
to embrace the sides of the other flap and thus give a greater firmness to the
hinge.
Dated this 1st day of September 1893.

page_text: COMPLETE SPECIFICATION.
Improvements in the Construction of Hinges for Step-ladders and
other similar Contrivances.
I HUGO EWALD WOLLMER of 32 Manley Road Manchester in the County
of Lancaster, Manager, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to the construction of hinges to be used for step-ladders,
folding trestles, and other similar contrivances, for the purpose of keeping them in
position when extended and preventing them from slipping.
The nature of my said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference
to the sheet of drawings hereunto annexed and the following explanation thereof.
Fig. 1 on the annexed drawings is a side elevation of my improved hinge
showing its application to a step-ladder.
Fig. 1 is a detached view of part of the hinge and Fig. 2 is a plan view of the
same.
Figs. 3 and 4 are similar views of a slight modification thereof.
According to my invention (as shown at Figs. 1, 1 and 2) I make the hinge of
two plates a and b hinged together by a stud or pivot d, one plate a being of a
fan-shaped form, and the other bra plain straight strip of metal. In the latter I
fix (or form with it) two studs or pins d and e one at or near each end, the upper
one d connecting the two parts together and forming the pivot on which the hinge
works, and the lower one passing through a curved slot made for that purpose in
the fan-shaped plate a.
At one end of this curved slot f is formed a short notch g in a direction pointing
towards the upper pivot d and the pivot hole in the fan plate a is slotted
similarly in the same direction.
The two plates a and b are provided with holes so that they can be attached by
screws one to the main frame and the other to the legs k of the step-ladder.
In the folded position or the ladder shown by dotted lines at Fig. 1 the lower
stud or pin e will be at the end of the curved slot f furthest from the short notch h
and as the legs are extended this stud or pin moves along the curved slot f until it
arrives at the other end when the frame will fall slightly so as to bring the pin or
stud e into the short notch g thereby locking the hinge in this position.
Before folding the legs it will be necessary to slightly raise the frame of the
step-ladder so as to bring the stud or pine out of the short notch and in a line with
the curved slot f and the two parts can then be folded together.
Instead of casting the pins d and e onto the plate b as shown the pins may be
screwed into the legs k, the plate b being dispensed with, and in either case the
projecting ends of the pins may be screwed and fitted with winged nuts to prevent
their slipping out of place when the steps are moved.
As a modification I sometimes make the two parts of the hinge somewhat in the
ordinary form as shown at Figs. 3 and 4 but on that part or flap a attached to
the frame I continue the plate above the hinge joint and in a line therewith or with
the frame as shown at a and I also continue the part or flap (attached to the
legs) above the joint, but at such an angle as will allow the hinge to open and the
legs to be extended to the desired degree and remain in that position when this
angular continuation of one flap will abut or come against the straight continuation
of the other flap and thus prevent the further extension of the legs. To prevent
any side movement one flap may be made wider than the other and so formed as
to embrace the sides of the other flap and thus give a greater firmness to the
hinge, as seen at Fig. 4.

page_text: 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 :-
First The improved hinge for step-ladders and other similar contivances.
consisting chiefly in the combination of a plate having a radial slot and a curved
slot with a short radial notch, with two pins one of which works in each slot,.
substantially as hereinbefore described and represented by Figs. 1, 1ª and 2 on the
drawings annexed, and
Secondly, I claim the improved hinge substantially as illustrated by Figs. 3.
and 4 of the said drawings consisting of two abutting flaps hinged together, one
being angular and the other straight, and one of them being wider than the other
and provided with flanges embracing the latter so as to prevent sideways movement.
and give greater firmness to the hinge.
Dated thin 20th 2 Man 1004
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.