A NEW OR IMPROVED APPARATUS FOR SUPPORTING SCAFFOLDING
Year: 1876

page_text: LETTERS PATENT to Alfred Robson, of the Borough and County of Newcastle-
upon-Tyne, for the Invention of "A NEW OR IMPROVED APPARATUS FOR
SUPPORTING SCAFFOLDING."
Scaled the 1st August 1876, and dated the 18th February 1876.
PROVISIONAL SPECIFICATION left by the said Alfred Robson at the Office of
the Commissioners of Patents on the 18th February 1876.
ALFRED ROBSON, of the Borough and County of Newcastle-upon-Tyne. "A New
OR IMPROVED APPARATUS FOR SUPPORTING SCAFFOLDING."
Hitherto in erecting scaffolding much time and labour is occupied tying with rope
the ledger poles to the upright scaffold poles. Apart from the danger attending this
operation there is likewise the probability of the ropes becoming afterwards dry and
loose, thereby endangering the stability of the structure and the lives of the
workmen.
To obviate these evils I would have a chain of suitable length to encircle the
upright scaffold poles. One end of this chain would be fastened to the head of a
bolt that passes through the shank or head of a large and strong hook. The other
or free end of the chain is, after passing round the scaffold pole, fastened by any
suitable means to the tail end of the aforesaid bolt. Consequently the large hook
is between the two ends of the chain, and capable of moving in a vertical arc,
taking the bolt for a centre. This hook is of sufficient size and strength to carry
the ledger poles, and the whole is prevented slipping down or shifting its position
by reason of the head of the hook next the upright pole being serrated and forming
a kind of cam or eccentric, that portion concentric with the before-mentioned bolt
being uppermost. When the strain is put on the hook and consequently depressing
the point the serrated and eccentric portion of the head of the hook is brought to
bear against the upright scaffold pole, and thrusting the bolt outward causes the
chain to grip round the pole with greater force.
A modification of the above may be made by substituting an iron belt with a
hinge at the back to encircle the upright pole; the head of the hook is then placed
between the two ends, which are provided with lips, and a bolt passed through the
whole and secured by a nut. The weight of the ledger poles brings the eccentric
portion of the head of the hook to bear against the upright poles, as explained in
the foregoing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Robson in the Great Seal Patent Office on the 10th August
1876.
ALFRED ROBSON, of the Borough and County of Newcastle-upon-Tyne.
OR IMPROVED APPARATUS FOR SUPPORTING SCAFFOLDING."
"A NEW
Hitherto in erecting scaffolding for building or other purposes much time and
labour is occupied tying with ropes or cords the ledger poles to the upright scaffold
poles. Apart from the danger attending this operation there is likewise the
probability of the ropes becoming afterwards dry and loose, thereby endangering
the stability of the structure and the lives of the workmen employed thereon.
To obviate these evils I would dispense with the use of ropes or cords and
substitute therefor such means of support for the ledger poles as may be readily
placed in position and secured to the upright scaffold pole for the reception and
support of the horizontal ledger poles. One of the many forms in which my new
or improved apparatus for supporting scaffolding could be made consists of a suitable
chain of sufficient length to encircle the upright scaffold pole. One end of this
chain is fastened to an eye bolt passing through the head or shank end of a large
and strong hook, which receives and acts as a support for the ledger pole. The
other or free end of the chain is after passing round the said scaffold pole fastened
by any suitable means to the tail end of the aforesaid eye bolt, which may however
be formed in the shape of a small hook and a link of the chain acting as an eye for
it, consequently the large hook which, for the sake of distinction I call the ledger
supporter, is between the two ends of the chain, and capable of moving in a vertical
arc, taking the eye bolt as a centre. The ledger supporter is prevented slipping
down or shifting its position by reason of the shank or that portion of the ledger
supporter next the upright pole being serrated and formed similar to a cam or
eccentric, that part which is concentric with the eye bolt being uppermost. When
the ledger pole is placed in its supporter the serrated and eccentric head of the
supporter is brought to bear against the upright scaffold pole and, by reason of its
eccentricity, causes the chain to grip the last mentioned pole with greater force, and
thus give stability to the apparatus.
I will now proceed to describe my Invention more fully by aid of the accom-
panying Drawing, reference being had to the letters and figures marked thereon.
Figure 1 is a side view, and Figure 2 a plan of my new or improved apparatus
for supporting scaffolding; Figures 3, 4, and 5 are modifications of the same; and
Figure 3x a front view of Figure 3. In these Figures A is the upright scaffold pole,
and B the horizontal ledger pole supported and attached to the upright scaffold pole
by the ledger supporter C, of which d is the shank or head, e the body, and the
tail end thereof; g is any suitable chain, one end of which is secured to the head of
the eye bolt (see Figure 2), the other end may be provided with more open links,
into one or other of which looks the tail end of the said eye bolt when the sup-
porter is fastened in position to receive the ledger pole. The head of the supporter
is formed, as shewn, of an eccentric or cam-like form, so that when the weight is
brought to bear upon the body of the supporter it shall make the chain grip the
upright pole A with greater force, and ensure the security of the apparatus.
+
To prevent the ledger pole becoming by an accident displaced, the tail end of the
supporter may be furnished with a thumb screw i, Figures 1, 2, and 4, and as a
further protection a forked paul k, as shewn in Figures 3 and 4, would prevent the
supporter being jerked out of its place.
The form of ledger supporter shewn in Figure 3 (a side view), and Figure 3× (a
front view), is particularly adapted to those cases where the ledger poles used may
vary in shape and size. In Figure 3 the dotted lines shew the positions taken by
ledger poles other than those of the usual size and form. In place of a thumb screw
the stop picce sliding along the parallel portion of this supporter keeps in position
tlie ledger pole of whatever shape or size it may be.
Figure is also a special form to meet those instances where planks on edge are

page_text: required to be supported. In this Figure m is an arm hinged to the supporter at f,
and carrying at the other end of the said arm a cradle n, also hinged to the afore-
said arm, in which is placed the plank o; or the arm m may be removed and the
plank laid horizontal, as shewn in dotted lines.
In place of a chain, as shewn in all the Figures, an iron belt or band with a
hinge at the back to encircle the upright pole might be substituted; the head of
the supporter is then placed between the two ends, which are provided with lips,
and a bolt passed through the whole and secured by a nut. The employment of the
chain, however, adapts the supporter for attachment to round or square scaffolding
poles, and to pillars, posts, or columns of any dimension.
My Invention is also equally adaptable for other purposes besides supporting
builders' scaffolding; for instance, a block and fall may be suspended from the
supporter, and the principle of Figure 3 might be applied to the gaff or jib used on
board ship when loading or unloading the vessel, or to the fitting up a similar
contrivance on land.
Having now described the object and nature of my said Invention, together with,
the manner of carrying the same into effect, I would observe, in conclusion, that I
claim as my Invention, a new or improved apparatus for supporting scaffolding and
for other similar purposes of the shapes and forms above described and illustrated
on the accompanying Drawing, or any mere modifications thereof.
In witness whereof, I, the said Alfred Robson, have hereunto set my hand and
seal, this Fourteenth day of August, in the year of our Lord One thousand
eight hundred and seventy-six.
ALFRED ROBSON. (L.S.)