Improvements in Ladders or similar Structures.
Year: 1893

page_text: Date of Application, 17th Mar., 1893-Accepted, 2nd June, 1893
COMPLETE SPECIFICATION.
Improvements in Ladders or similar Structures.
1, WILLIAM EVARTS RICHARDS of 203 Broadway New York in the County
New York and State of New York, United States of Amerion, Patent Agent,
do hereby declare the nature of this invention, and in, what manner the same is to
e performed, to be particularly described and ascertained in and by the following
statement:-
My invention has for its object to construct a ladder or similar structure, in
which the steps or treads may be automatically maintained in a horizontal position,
irrespective of the angle at which the ladder itself may be adjusted or secured to
the structure with which it used.
My invention is particularly adapted to be applied to ships ladders, where the
ladder is pivotally attached at its upper end to a platform constructed at some
convenient part of the ship's side, the lower end of the ladder being supported by
a rope or chain passing over a block, carried by a davit aboard ship, and lowered
thereby to the water line to receive or discharge passengers or cargo.
Such ladders, it is well known, are extensively used for receiving and discharging
passengers when ships are in ports where there are no wharfs or piers.
In ladders of this kind, the angle at which it is desired to lower the ladder for
use at different times not a constant one, for as the displacement of the ship
varies as it carries a greater or less load, the distance from the gang-way or
platform to the water line is decreased or increased, and the angle at which the
ladder must be adjusted when in use, varies accordingly.
As far as I am advised, the usual form of ship's ladder consists simply of a
construction wherein flat steps or treads are rigidly secured between the sides of
the ladder. As the treads are thus rigidly secured, it follows that they are
horizontal only when the ladder is maintained in one position or angle relative to
its platform, and are out of the horizontal in every other position of the ladder,
and frequently objectionably incline so that it is difficult, and sometimes dangerous,
to use the ladder, particularly so if the ship is rolling or pitching in the sea.
Various attempts have been made to remedy this, the most usual course being to
attach additional supporting pieces or cleats to the side pieces of the ladder,
arranging them at an angle to the rigid tread-, upon which may be placed removable
steps or treads, which are used instead of the rigid treads whenever the inclination
of the latter is such that they cannot be conveniently or safely used. But this
method is objectionable as it necessitates the carriage and care of an additional set
of treads, which are apt to be mislaid or lost; the adjusting of these treads into
position whenever they are to be used, and their removal and storage at other
times whilst at the same time only a limited degree of adjustability is secured
thereby. By the use of my invention the steps are always maintained in a
horizontal position, no matter what may be the angle of inclination of the ladder
itself; the use and storage of loose parts are dispensed with, as well as the labor
necessary for their adjustinent: and a light, convenient, and durable ladder insured,
complete in itself, and capable of automatic adjustment.
I will now proceed to describe my invention in connection with the accompanying
drawings which form a part of this Specification, and in which similar letters of
The particular features of
reference indicate the same parts wherever they occur.
novelty that I claim as my invention are pointed out in the claims at the end of this
Contion

page_text: rring now to the drawings :
Figure is a front view of a ship's gang-way and ladder embodying in
improvements.
Figure 2 is a side view partly in section.
Figure 3 is a detail side view or elevation of one of the brackets to be secure
to the gangway or platform
Figure is a detail plan of one of the steps or treads.
Figure ♬ is a perspective view of the upper part of the ladder, (part of one step
and one side piece being broken away,) and suspending brackets or segment pieces
showing the relation and operation of the parts more clearly.
Figure 6 is a detail perspective view of a shoe or step support.
Figure 7 is a perspective view showing my improved ladder as applied to a ship's
gangway.
The fine A is intended to represent the side of the ship, to which is attached in
the usual or any suitable way, the gangway or platform B. The attachment of the
gangway or platform to the ship forms no part of my invention, but I may mention
here, to aid in the more complete comprehension thereof, that it is usual to
construct this platform at some convenient place upon the ship's side, and to attach
the ladder thereto in such manner that the latter may be easily unshipped and
taken aboard when not in use, while the platform itself may be closed up against
and secured to the ship's side, so that it will not be carried away in rough weather.
To the platform B. is pivotally secured one end of the ladder C, which is constructed
with the usual side pieces e and steps or treads e, which may be as many in
mumber as desired or required. To the lower end of the ladder is attached a
landing or platform C. It is customary to provide the ladder with the standards 1, 1,
add the cables 2, 2, strung thereto, anal forming handrails or guards. The lower
end of the folder is raised or lowered and supported in the desired position by a
repe or chain 3, passing over blocks 4, 4, carried by a davit 5, which is secured
aboard ship at some suitable position relative to the gangway or platform B, the
rope or chain 3 being attached to a bail or yoke ti, which is pivotally secured to
the lower end of the ladder, preferably to the side pieces thereof as shown in the
drawings.
It has been usual to secure the upper end of the ladder to the platform 13 by
a bolt passing through eyes formed in the side bars of the ladder, and carried by
bearings or straps affixed to the bottom of the platform, (not shown). This bolt
acts as a fulerum when the ladder is mounted thereon, permitting the lower end of
the ladder to be raised or lowered as desired by means of the bail ti and the rope 3,
while the upper end of the ladder remains attached to the platform B.
In carrying out my invention I secure to the underside of the gangway or
platform a pair of brackets or segments D, D', by means of bolts 7 or other
suitable fastening means. These brackets or segments are preferably of metal, and
are made sufficiently strong to support the ladder C.
can be connected by suitable bruce-rods, (not shown), with each other, or they may
If desired the brackets D, D',
be cast in one piece with a bridge piece.
Upon the inner face of these brackets or segments I form laterally projecting
ribs d, d, so disposed as to form a cam-groove, or inclined bearing &, open at one
end d³, and closed at the other end d. The outer portion, or the end of said
groove or bearing is horizontal, or nearly so, whilst the remainder thereof is down-
wardly curved, forming a cam or bearing surface. The brackets or segments D, D',
are further provided with openings or bearings, adapted to receive the trans
verse bar or bolt E, upon which the upper end of the ladder C is pivotally
supported.
Iforin my ladder with the usual side pieces e, e, between which are the steps
or treads, but instead of securing these treads or steps rigidly to the side-pieces,
I pivotally secure them between said side-pieces in such a manner that as the 5
lower end of the ladder is raised or lowered, the steps or treads will always be

page_text: automatically adjusted and retained in a horizontal position. This I accomplish
by the following construction.
I provide each of the steps or trends upon its two side edges with front and
rear lugs or pins These lugs or pins may be of metal, and be seated in
recesses or bearings formed to receive them in the side edges of the steps or
treads e, or they may be rods, which pass entirely through the steps or treads c¹.
and project beyond the edges thereof, or, if desired, the steps or trends e inay
rest upon, and be secured to such rods as last described.
The forward lugs engage in recesses or bearings formed therefor directly in
the side pieces c, c, whilst the rear lugs engage in similar recesses or bearings,
formed in an auxiliary or supplemental frame or portion, presented by a movable
pair of bars F, F'. It will be seen therefore that the foward edges of all the
steps or treads e are pivotally supported directly by the side-pieces c, c, by means
of the lugs c, whilst the rear edges of all the steps of trade are nivotally
supported by the auxiliary frame or bars F, F, by means of the lugs, and that
the rear edge of all the steps or treads may be raised or lowered relative to their
front edge, by simply raising or lowering the auxiliary frame. Instead, however,
of providing the steps with the lugs ², e, the shoe or step-support shown in
Figure 6 may be employed, which consists of an angle-plate e, the base-portion
of which is provided with openings e, through which may extend bolts or screws
to secure the step in position thereon. The side of the plate is provided with
pintles or lugs e, which are designed to engage the openings formed in the side
pieces, and the auxiliary portions, respectively, and subserve the same function as
the lugs e, c.
The upper ends of the auxiliary frame on bars F, F, are supported by, and
carried upon, a transverse rod f, which passes through slots formed in the side
bars c, c, for this purpose, and upon either end of the rod is provided a friction
roller, which engages and rides in the cam-shaped
groove d of the
his D, D', which thus apport the anxiliary frame F. F', and the rear half
of the steps or treads e¹.
As I have before stated, the Indder is supported upon a transverse bar or bolt E,
which has its bearings in the brackets D, D'. I have shown the upper ends of
the side pieces c, c, provided with a metal strap-piece e, having an opening or eye e',
through which this bar E passes.
In operating my invention, when it is desired to connect the ladder with the
platform, the ladder is brought into position, and the ends of the rod carrying
the anti-friction rollers, are introduced into the cam-shaped grooved, through the
open ends d, the ladder is then secured in place by passing the bolt E through
the eyes and the bearings ³, as shown in Figures 1 and 2, suitable nuts being
provided upon the ends of said bar to secure the same. The lower end of the
ladder is then lowered into the desired position by means of the davit 5, block
and tackle 4, 3, and bail 6.
During this operation and in all positions of the ladder, the steps or treads el
are automatically maintained in a horizontal plane, for as the main frame of the
ladder is moved upon its axis,—the bolt E-the auxiliary frame F, F, is also
moved or swung upon its axis, the rod,-which is supported in, and caused to
travel in the cam-groove d, the pitch of which is so adjusted as to elevate or lower
the auxiliary frame F, F, and therefore the rear edges of the steps or treads c³,
at the same time that the ladder itself is raised or lowered, and to just a
sufficient degree to accomplish this result. For instance, supposing the ladder to
be in the position shown in full lines in Figure 2. and it is desired to raise it to the
position shown in dotted lines, the lower end of the ladder is raised by means of
the block and tackle, and as this is done, while the front edges of the steps are
maintained in their place between the side pieces c, c, the auxiliary frame F, F.
and the rear edges of the steps or treads e, are elevated as the rod or bar f, with
its friction rollers, is caused to travel up the cam-groove de.

page_text: When it is desired to unship the la bler, all that is necessary is, to withdraw the
bar E, and pass the rod with its friction rollers out of the cam-groove d², by
way of the open ends d², when the fadder may be taken aboard ship.
It should be understood that the drawings forming part of this Specification
are not working drawings, they are sufficiently exact however to clearly illustrate
the features of novelty contained in my invention, and to enable any person
skilled in the art to which it pertains to clearly malerstand and practice the same.
It should also be understood that while I have described my invention more
particularly with reference to a ship's ladder, that its use is not confined to that
form of ladder, but that it may be used in any structure to which it may be found
applicable in which it is desired to regulate the plane of one portion of the structure
with relation to other portions.
It will also be understood that instead of a cam-grooce d that a toothed rack
might be used, the bar in this case being provided with a toothed wheel that
would gear with the teeth of the rack.
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:
1. The combination in a ladder or similar structure, of a suspending bracket,
main and auxiliary portions pivotally suspended from said bracket, steps or treads
pivotally mounted in both of said portions, the pivotal connection of one of said
portions being movable, so as to admit of the adjustment of the plane of the
steps or treads as the position of the structure is changent, substantially its set forth.
The combination in a ladder or similar structure of a suspending bracket, of
main and auxiliary portions pivotally suspended from said bracket, steps or treads
pivotally mounted in both of said portions, a variable bearing operating the
auxiliary portion as the ladder itself is moved, and means for raising and lowering
the ladder, substantially as set forth.
3. The combination with a structure of a holder mounted thereon, having a
main and an auxiliary portion, said main and auxiliary portions being pivotally
supported and separately suspended in suitable bearings, steps or treads pivotally
mounted in both the main and auxiliary portions, said auxiliary portion being
suspended in a variable hearing that imparts independent movement to the auxiliary
portion whenever the ladder is moved, substantially as set forth.
4. The combination in a ladder or similar structure, of a suspending bracket, a
main frame pivotally suspended from a rigid bearing in said bracket, an auxiliary
portion pivotally suspended therefrom, and free to move in a variable bearing in
said bracket, steps or treads pivotally mounted in both said main and auxiliary
portions, said main and auxiliary portions being capable of motion independently
of each other, whereby the position of the steps is changed as the ladder is moved
from one position to another, substantially as set forth.
5. In a ladder or similar structure such as described, a bracket provided with
a bearing, one end of which is open, substantially as set forth.
6. The combination in a ladder or similar structure, of a suspending bracket
with its bearings, main and auxiliary portions pivotally suspended from said
bracket in such bearings, and steps or treads pivotally supported between said
main and auxiliary portions, one of said portions of the ladder being provided
with suitable openings to permit the passage and operation of the shaft or bar
upon which the other of said portions of the ladder is supported, substantially as
shown and described.
7. The combination with the depending brackets adapted to be secured to a
gangway or platform, and each provided with a cam-bearing, of a ladder pivotally
suspended from said brackets, an auxiliary portion engaging said cam-bearing,
together with a series of steps pivotally mounted in the main and auxiliary portions
of the ladder as set forth.

page_text: 8. In a ladder, the segmental bracket D, D', provided with bearings to receive
the bar E for supporting the ladder, and with ribs d, d' forming an inclined
bearing for supporting and actuating an auxiliary portion, substantially as shown
and described.
Dated this Sixteenth day of March 1893.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.