An Improved Portable Scaffold.
Year: 1889

page_text: Date of Application, 18th Jan., 1889
Complete Specification Left, 12th Oct., 1889-Accepted, 16th Nov., 1889
PROVISIONAL SPECIFICATION.
An Improved Portable Scaffold.
I JOHN HARPER of 129 King's Road, Camden Town, London, N.W. Engineer do
hereby declare the nature of this invention to be as follows:-
:-
This Invention relates to a portable scaffold particularly adapted for use in repairing,
decorating, or cleaning buildings internally or externally as well as for constructional
purposes, in lieu of the ordinary cumbersome and expensive fixed scaffolding. This
portable scaffolding is entirely self-contained, and comprises an upright framing con-
structed in sections so that it may be adapted in height to the requirements of the
work, and mounted on wheels in order that it may be easily moved from place to
place; and it further comprises a rising platform fitted to move up and down in the
said framing and provided with gear operated from the platform itself whereby it
may be raised to, and maintained at, the required elevation. The framing comprises
a bottom fixed platform mounted on wheels and four corner posts or columns fixed
in shoes and constructed in sections bolted together, the four columns being braced
together by diagonal tie rods furnished with screw couplings. Upon an inner face of
each of the four posts, is a rack, and with these racks gear pinions on a pair of shafts
mounted beneath the rising platform, these shafts being geared with a worm goar
common to both, and operated through bevel gear from a winch handle mounted at a
convenient height above the platform. Upon the other inner face of each corner
post is a guide of dovetail or T section with which engages a shoe on the end of the
platform whereby all outward deflection of the corner posts is prevented and the
wheels are held in gear with the rucks. The travelling wheels on which the apparatus
is mounted, have peripheral holes in which engage locking bolts mounted beneath the
base platform and coupled to a common rock shaft operated by a lever handle for the
purpose of holding the scaffold stationary when in use.
Dated this 18th day of January 1889.
COMPLETE SPECIFICATION.
An Improved Portable Scaffold.
I, JOHN HARPER, of 129, King's Road, Camden Town, London, N.W., Engineer, do
hereby declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following statement :-
This Invention relates to a portable scaffold particularly adapted for use in repair-
ing, decorating, or cleaning buildings internally or externally as well as for construc-
tional purposes, in lien of the ordinary cumbersome and expensive fixed scaffolding.
This portable scaffolding is entirely self contained and is constructed in sections so
that it may be adapted in height to the requirements of the work, and mounted on
wheels in order that it may be easily moved from place to place; and it comprises a
rising platform fitted to move up and down in the said framing and provided with
gear operated from the platform itself whereby it may be raised to, and maintained at,
the required elevation.
Reference is to be had to the accompanying drawings forming part of this specifi-
cation, wherein figure 1 is an elevation of the lowermost section of the framing,
partly broken away to shew the rising cage or platform and its gearing. Figure 2
is a vertical cross-section of same. Figure 3 is a plan of the cage or platform
Price fid21

page_text: and figure 4 is an underside plan thereof. The same letters of reference indicate like
parts in all the figures.
The main framing comprises a bottom fixed platform A mounted on wheels B and four
corner posts or columns fixed in shoes c and constructed in lengths or sections
halved together at their abutting ends and secured by bolts, the four columns being
braced together by diagonal tie-rods or cramps D, furnished with screw-couplings at the
middle. Upon an inner face of each of the four posts C is fixed a rack E, these
racks extending the whole height of the several lengths or sections and with these
racks gear pinions F on a pair of shafts G mounted in brackets g fixed to the
underside of the floor T of the cage or platform, these shafts being geared by worm
gear H with a transverse shaft I common to both and operated through bevel gear K
from a winch handle L mounted at a convenient height to be worked by a person
standing on the platform. Upon the other inner faces of the corner posts Care
guides M. of dovetail or T-section with which engage shoes on the ends of the plat-
form whereby all outward deflection of the corner posts is prevented and the
pinions are held in gear with the racks E. The travelling wheels B on which the
framing is mounted have peripheral holes n in which engage locking bolts O mounted
to slide in guides o fixed to the underside of the base platform A, the belts being in
pairs each pair being in alignment with a pair of the wheels B and being coupled to
opposite arms P fixed on a common rock shaft Q operated by a lever handle R engaging
with a rack S for the purpose of holding the scaffold stationary when in use.
The cage comprises the platform T, uprights-U. and cross-braces V, the platform
only engaging with the guides M and the horizontality of the platform being-main-
tained by the coupling together of the two pairs of pinions F whilst the fixity of the
cage at any height to which it may be raised is ensured by the pinions being always
in gear with the racks and by the use of worm gear which prevents the cage descending
by its own weight.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is ;
1. The herein described portable scaffold consisting of the upright framing com-
posed of corner posts constructed in lengths and erected on a wheeled base and braced
together as described, the said posts being provided with racks and guides as described,
in combination with a cage or platform adapted to be moved up and down the said
guides and provided with toothed gear engaging with the racks and coupled by worm
gear to ensure horizontality and fixity of the cage, as specified.
2. The combination, with the notched travelling wheels of the herein described
portable scaffold, of pairs of bolts adapted to engage therewith and coupled to, and
operated by, a, single hand lever, as specified.
Dated this 12th day of October 1889.
J. HARPER.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.