IMPROVEMENTS IN SAFETY WINDOW CLEANING CHAIRS
Year: 1879

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS
IN SAFETY WINDOW CLEANING CHAIRS." A communication from abroad by
Anna Dormitzer, of the City, County, and State of New York, United States
of America.
Sealed the 19th December 1879, and dated the 5th August 1879.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 5th August 1879.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS. IN SAFETY WINDOW CLEANING CHAIRS." [A
communication from abroad by Anna Dormitzer, of the City, County, and State of
New York, United States of America.]
This Invention relates to improvements in the window cleaning chair for which
former Letters Patent were granted to me, dated 28th February 1878, No. 824.
The object of the present Invention is to still further simplify the adjustment of
the chair, and to make it more reliable and complete. The Invention consists of
the combination of a platform, folding guards, supports, steps, braces, and their
auxiliary parts and mechanism, as hereinafter more fully described.
The platform, which is of suitable size to sit or stand upon, is provided with a
raised strip fastened along its rear edge to serve as a partial support to the back
guard, that is, hinged on the face of the platform between two side guards that are
hinged on side strips securely fastened on the edges of the platform. When opened
these guards are secured in an upright position by the engagement of hooks on the
back guard in screw eyes or staples on the side guards. On the underside of
the platform and at its opposite end is secured the front strip, which is further
strengthened and supported by braces, as is also the projecting front edge of the
platform. Hinged to the underside of the platform just in the rear of the front
strip are two supports that carry the main step, and to a side of each of these
supports are pivoted flat curved iron bars, which are stiffened by a rod that connects
them, and carry the auxiliary step that swivels between them, and is held to the
main step when desired by a spring on the main step engaging in a slight depression
or socket in the underside of the auxiliary step. This step is also provided with

page_text: two pivoted legs that are folded in a slot when the step is used, as hereafter men-
tioned, and which may be unfolded and adjusted when desired. The supports have
their lower ends slotted, and eccentrics, which are provided with pins or handles to
operate them, are pivoted in the slots. These eccentrics are designed to press
springs that are secured on the rear faces of the supports against the wainscot of
the window when the chair is placed in position, the tips of the springs being faced
with leather or other soft material to avoid defacing the paint and to cause them to
hold more firmly against the wainscoat.
Passing through the side strips of the chair and under the platform is a strong
iron rod, which may be adjusted in holes in the side strips to suit the thickness of
any window sill, and swinging on this rod is the rear or outer support of one chair,
to which great strength is imparted by a cross beam plated with iron on the face,
and strengthened by a truss rod on the other. A spring is wound around the rod,
and its loop rests against the bottom of the platform, while its ends are entered into
the upper edge of the support, and thus it serves to throw open the support, as the
tension of cords which are connected thereto is relaxed. These cords are made fast
to pins on the support, and thence pass through the cross beam and over grooved
rollers through the front strip of the chair, and secured on a drum.
The grooved rollers revolve on a strong rod that passes through the side strips of
the chair, and is firmly held in place by clamps. The drum to which the cord is
secured is mounted at the front of the chair, and has a ratchet fixed on each side of
it. It is keyed on a shaft or pin between two lugs, which pin also serves as a pivot
for a fork that embraces the lugs, and has a pawl pivoted on the inside of each
prong engaging with the ratchets, and on the inside of the downward projections of
the lugs are pivoted pawls that also engage in the opposite direction in the ratchets.
To the back of a cross piece that is secured between the heads of the front supports
of the chair are fastened two springs that are bent upward around the front strip,
and lie in grooves made therein to receive them. These springs serve to bold the
supports and steps both open and closed.
The chair is put in position for use by unfolding it and placing the platform upon
the window sill with the rear outside, and drawing the cords taut so as to bring the
rear support into close contact with the outside of the wall. The cords are drawn
taut by turning the fork from the upright to the dependant position, in doing which
the pawls on the fork engage in the teeth of the ratchets, and revolve the drum to
which the cords are secured. If turning the fork down once does not suffice, the
pawls on the lugs will hold the ratchets and drum in position while the fork is
turned up again for a fresh purchase, or the pawls can be made to push the ratchets
round a few teeth at a time. When the cords have been drawn taut the eccentrics
are turned so as to press the springs against the wainscot for the purpose of securing
the chair more firmly, and sliding wedges that have their edges faced with leather or
other soft material, and are provided with handles, are pushed as tightly as possible
in between the window sill and chair in order to complete the security and stability
of the device. These wedges are held in grooves on the lower edges of the side
strips, and are prevented by stops from moving too far rearward.
When the chair is in position the back and side guards are raised and secured, as
herein before described, and a pail is secured in a loop that also serves as a catch for
a button on the opposite guard when the chair is closed. A standard is also set in
a socket in the edge of the chair, and is provided with a device from which may be
suspended a bucket or other vessel for the convenience of the person at work upon
the window.
Should it be desirable for the operator to reach higher than is possible from the
platform itself, the auxiliary step may be raised, and so secured by the insertion of
its legs in sockets made in the face and by springs that project from the sides of the
platform.
When not in use the chair may be folded up, so that it will occupy but little
63300

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
5th February 1880.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex
Patent Agent.
"IMPROVEMENTS IN SAFETY WINDOW CLEANING CHAIRS." A com-
munication from abroad by Anna Dormitzer, of the City, County, and State of New
York, United States of America.
This Invention relates to improvements in the window cleaning chair for which
former Letters Patent were granted to me in 1878 (No. 824).
The object of the present Invention is to still. further simplify the adjustment of
the chair, and to make it more reliable and complete. The Invention consists in
the combination of a platform, folding guards, supports, steps, braces, and their
auxiliary parts and mechanism, as will be hereinafter more fully described.
In the accompanying Drawings Figure 1 is a perspective view of the improved
chair, showing it in position for use; Figure 2 is a vertical sectional elevation of the
same; Figure 3 is a side elevation of the chair detached from the window and
closed; Figure 4 is a plan of the under side of the chair closed; Figure 5 is an enlarged
view of sections of the guard, showing the device for holding them together;
Figure 6 is a side elevation partly in section of a modification of the mechanism in
the front of the chair. Similar letters of reference indicate corresponding parts.
A represents a platform of suitable size to sit or stand upon, provided with a
raised strip B fastened along its rear edge to serve as a partial support to the back
guard C, that is hinged on the face of the platform between the two side guards
D, D. The side guards are hinged on the side strips E, E, which are securely
fastened on the edges of the platform, and when opened these guards are secured in
an upright position by the engagement of the hooks a¹ (Figure 5) on the back guard
in the screw eyes or staples 6' on the side guards. On the underside of the platform
and at its opposite end is secured the front strip F, which is further strengthened
and supported, as is also the projecting front edge of the platform, by the braces
c¹, c, (Figures 3 and 4). Hinged to the underside of the platform just in the rear
of the strip F are the two supports G, G, that carry the main step H, and to a side
of each of these supports are pivoted the flat curved iron supports I that carry the
auxiliary step K that swivels between them, and is held to the main step, when
desired, as shown in Figure 2, by the spring d', which is fastened on the main step,
and engaging in a slight depression or socket f¹ in the underside of K. These two
iron supports are stiffened by the rod g' that connects them. This step is also pro-
'vided with two pivoted legs r¹, r₁ (Figure 2), that are folded in a slot s¹ when the
step is used, as in Figure 1, and which are unfolded and adjusted when desired, as
shown in Figure 2. The supports G, G, have their lower ends slotted, and pivoted
in the slots are the eccentrics h¹, h¹, which are provided with pins or handles i, i¹, to
operate them; they are designed to press the springs k¹, k¹, that are secured on the
rear faces of the supports against the wainscot of the window when the chair is
placed in position, as shown in Figures 1 and 2, and the tips of these springs are
faced with leather or other soft material, so that they shall not deface the paint and
that they may hold more firmly against the wainscot.
Passing through the side strips L of the chair and under the platform is a strong
iron rod l, which may be adjusted to suit the thickness of any window sill in any
of the holes m' in the strips. .Swinging on this rod is the rear or outer support M
of the chair, to which great strength is imparted by the cross beam N, that is plated
with iron n' on one face, and strengthened by a truss rod o' on the other. The
spring O is wound around the rod 1, and its loop rests against the bottom of the
platform, while its ends are entered into the upper edge of the support M, and thus
it serves to throw open the support as the tension of the cords P is relaxed. These
cords are made fast to two of the pins p', and thence pass through the cross beam N

page_text: •
and over the grooved rollers Q through the strip F to be secured on the drum R at
the front of the chair. The rollers Q revolve on a strong rod S that passes through
the side strips of the chair, and is firmly held in place by the clamps q², q'. The
drum R has fixed on each side of it a ratchet t¹, and it is keyed on a shaft or pin u¹
between the two lugs vl, which pin also serves as a pivot for the fork T that embraces
the lugs, and has pivoted on the inside of each tine a pawl w¹ that engages with the
ratchets, and on the inside of the downward projections of the lugs are pivoted the
pawls that also engage in the opposite direction in the ratchets. To the back of
"a cross piece y¹ that is secured between the heads of the supports G, G, are fastened
the two springs 2¹ that are bent upward around the strip F, and lie in grooves made
therein to receive them. These springs serve to hold the supports and steps open
in the position shown in Figures 1 and 2, and also to hold them closed when in the
position shown in Figures 3 and 4. The chair is put in position for use by unfolding
it and placing the platform upon the window sill with the rear outside, and drawing
taut the cords P, so as to bring the rear support M into close contact with the out-
side of the wall. The cords are drawn taut by turning the fork T from the upright
to the dependent position, in doing which the pawis w¹ engage in the teeth of the
ratchets t¹, and revolve the drum R, to which the cords are secured. If turning the
fork down once does not suffice, the pawls al will hold the ratchets and drum in
position, while the fork may be turned up again for a fresh purchase of the pawls w',
:or the pawls can be made to push the ratchets round a few teeth at a time. When
the cords have been drawn taut the eccentrics h³, h¹, are turned so as to press the
springs, kl, against the wainscot for the purpose of securing the chair more firmly,
and the sliding wedges u, that have their edges faced with leather or other soft
: material, and are provided with handles 22, are pushed as tightly as possible in
between the window sill and chair in order to complete the security and stability
of the device. These wedges are held in grooves on the lower edges of the side
strips L, and are prevented from moving too far rearward by the stops 23.
When the chair is in position the back and side guards are raised and secured, as
herein before described, and the pail V is secured in the loop a² that also serves as a
catch for the button 62 on the opposite guard when the chair is closed. The
standard W is also set in a socket in the edge of the chair, and is provided with a
device c², from which may be suspended a bucket or other vessel for the convenience
of the person at work upon the window.
Should it be desirable for the operator to reach higher than is possible from the
platform itself, the auxiliary step K may be raised to the position shown in Figure 2,
and so secured by the insertion of its legs in the sockets d² (Figure 1), made in the
face of the platform, and by the springs f2 that project from the sides of the
.platform.
When not in use the chair may be folded, as shown in Figures 3 and 4, so that it
will occupy but little space.
In Figure 6 is represented a modified and equivalent device that may be sub-
⚫stituted for fork T. The fork T2, shown in this Figure, is straighter than the fork
T, and the pawls Ws are differently shaped and located from the pawls W¹; and in
addition thereto the curved spring ² connects the fork handle with the heads of the
pawls, as shown, so that the said pawls are normally held retracted from the
ratchet t¹ by the said spring, and the fork T can be raised perpendicularly, as
shown by the dotted semi-circle, without contact of the pawls with the ratchets;
but when it is desired to operate this part of the chair mechanism a slight
pressure upon the cover y² that is pivoted on the fork T3 will cause the spring 3 to
throw the pawls at once in gear with the ratchets. It is found that this device
operates with somewhat more ease and readiness than the one heretofore described.
Having described the nature of the said Invention and the manner of performing
I the same, I would observe that I am aware that it is not new to make a window
cleaning step chair with folding back, braces, front supports, and steps in connection
with a platform, and that standards for supporting paint buckets and receptacles for
tools, etc., have been applied to ladders, and that ratchets and. pawls are in common
1

page_text: use in hoisting and lifting jacks, and other combinations, and hence I do not broadly
claim them, but what I do claim as the Invention to be protected by the herein-
before in part recited Letters Patent is,-
1st. A window cleaning chair having a platform A, raised strip B, side strips
E, E, strip F supported by braces c³, c³, guards C and D, D, supports G, G, iron sup-
ports I, rod g', springs k³, k¹, eccentrics h³, h', step H, auxiliary step K, side strips L,
rod , holes m³, support M provided with plated and trussed cross beam N, spring
O, rod S, clamps q, q', drum R provided with ratchets t¹, shaft u¹, lugs v¹ provided
with pawls x, forks T provided with pawls w¹, sliding wedges u provided with
handles and stop 23, constructed and arranged substantially as herein shown and
described.
2nd. In combination with the window cleaning chair herein described, the stan
dard W provided with device c³, substantially as herein shown and described.
3rd. In the construction of a window cleaning chair, the combination of the
drum R provided with ratchets t¹, shaft u¹, lugs v provided with pawls x¹, forks T
provided with pawls w¹, and cords P, substantially as herein shown and described.
4th. In the construction of a window cleaning chair, the combination of the
spring 2, supports G, G, cross piece y', step H, springs d¹ and k¹, k¹, eccentrics h', h',
supports I, rod gl, and auxiliary-step provided with socket f¹, legs r¹, r', and slot 8¹,
substantially as herein shown and described.
5th. The stops 23, substantially as and for the purpose described.
6th. In the construction of a window cleaning chair, the rear support M provided
with cross beam N, that is furnished with an iron plate n¹, a truss rod o', and spring
O, substantially as and for the purpose described.
7th. In the construction of a window cleaning chair, the sliding wedges u held in
grooves in the side strips L, faced with leather or other soft material, and provided
with handles 2 in combination with the stops 23, substantially as herein shown and
described.
8th. The cords P that are secured at one end to the pins p', and thence passing
through the cross beam N over the grooved rollers Q and through F, have their
other ends secured to the drum R, substantially as herein shown and for the purpose
described.
9th. The spring O wound around the rod 1, with loop resting against the lower
face of the platform, and with ends entering the support M, which it serves to
throw open as the tension of the cords P is relaxed, substantially as herein shown
and described.
10th. The springs f2 in combination with the platform H and auxiliary step K,
substantially as herein shown and for the purposes described.
11th. The plated and trussed cross beam N, substantially as herein shown and
described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Fifth day of February, in the year of our Lord
A. M. CLARK. (L.S.)