An Improved Attachment or Device for Employment in the Con- struction of Temporary Structures, such as Scaffolding, and for other purposes.
Year: 1890

page_text: Date of Application, 29th July, 1890
Complete Specification Left, 29th Apr., 1891-Accepted, 30th May, 1891
PROVISIONAL SPECIFICATION.
An Improved Attachment or Device for Employment in the Con-
struction of Temporary Structures, such as Scaffolding, and for
other purposes.
I, FRANCIS WELDON, of Erlimount, Earley, in the County of Berks., Colonel
in the Madras Staff Corps, do hereby declare the nature of this invention to be as
follows:-
My invention relates to an improved device forming an absolutely secure, and at
the same time instantaneously adjustable "grip," or attachment, more particularly
intended for securing together the parts of temporary structures such as scaffolding,
but also applicable to other purposes.
"
::
In order to explain the nature of my invention, I will describe its application to
a "trestle transom as used in the construction of temporary river bridges for
military purposes. Each such "trestle transom consists of two posts, and a
horizontal cross-piece or transom. The posts, are provided at the lower ends with
suitable shoes, to obtain a firm hold on the bed of the river, and, when in position
are not fixed vertically, but are inclined somewhat towards each other to obtain
greater stability. The cross-piece or transom consists of two parallel beams, affixed
together with blocks or distance pieces between them, and sliding upon the posts.
A screw is provided at each end to grip the cross-piece upon the posts at any
desired height. The platform of the bridge rests upon the cross-piece, and when it
is required to move the cross-piece to suit variations in the height of the tide or
for other reasons, the screws are slackened, the said cross-piece is raised or lowered
and then suspended by chains from the top of the posts; the screws being again
tightened. This system permits of only a small range of adjustment, for as the
posts are inclined, the cross-piece jams if moved far down. The hold on the posts
is not of a secure nature and the operations of fixing or adjusting are difficult to
accomplish.
a
The principle upon which my improved device is constructed is as follows:-If
ring be slipped on a post, the ring being rather larger in diameter than the post
and the end of a bar inserted through the ring from the upper side any downward
strain or pull on the end of the bar, jams the ring on the post forming, what may be
termed a lever grip, which is immovable, as the greater the strain on the end of
the bar or lever, the tighter the grip becomes, while at the same time the grip is
instantaneously relieved by raising the end of the lever. The grip can also be
relieved by striking or tapping on the highest part of the upper side of the ring.
It is obvious that this apparatus may be reversed to act with an upward pull, or
horizontally if desired.
Such a device it will be seen can be constructed in a great variety of forms. In
the case under consideration viz.: the trestle transom it may be arranged as
follows: The two parts are placed vertically in the water and a ring formed of
two flat bars united by two bolts is placed around each, the bars are prolonged at
the outer ends and the beams of the cross-piece are hung on the said ends, by bolts
passing through both the beams and bars. These flat bars and bolts cach form a
ring and lever device, and the weight of the cross-piece causes them to jam
immovably on the posts, and so support the said cross-piece at any required height.
To prevent rocking sideways a similar set of bars connected by bolts placed
around each post, above the first set, the long ends being in this case inside. A
bar or bolt is passed through the long ends both above and below the cross-beams
and a wedge being inserted downwards between the post and upper bolt on the
inside, the whole structure is rendered rigid. At the top of each post I place a

page_text: ring and lever or levers from which to suspend a block and rope or chain. To
raise or lower the crossbeams the aforesaid wedges are knocked out and on pulling
on the said ropes the grips are immediately released and the beams can be adjusted
to the required height.
•
To stop them at such height a slight check is applied to the undersides of the
rings from which the beams are hung, when the grip again automatically comes
into force, the wedges are then replaced, and to prevent them being accidentally
disturbed, the levers may be removed from the rings at the tops of the posts, and
the said rings being allowed-to drop on to the tops of the wedges, and then knocked
down till they jam on the posts will prevent any movement taking place in the
wedges until the said rings are removed by a reversal of the process.
This application of my invention gives complete rigidity to the structure, while
as the posts can be placed vertically the cross-beams have the entire height of the
posts above the water line for their range of adjustment &c. such adjustments can
be made by persons standing on the platform of the bridge with the greatest
certainty and rapidity.
In scaffolding used for building and other purposes my invention is particularly
applicable, as it will to a great extent obviate the present cumbrous system of
fastening the various parts together with ropes and wedges, but the invention is, as
will be readily seen of almost universal application in the attachment of the parts
of temporary and other structures.
COMPLETE SPECIFICATION.
An Improved Attachment or Device for Employment in the Con-
struction of Temporary Structures, such as Scaffolding, and for
other purposes.
I, FRANCIS WELDON, of Erlimount, Earley, in the County of Berks., Colonel in
the Madras Staff Corps do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention relates to an improved device, forming an absolutely secure and at
the same time instantaneously adjustable "grip" or attachment, more particularly
intended for securing together the parts of temporary structures, such as scaffolding,
but also applicable to other purposes.
In the accompanying two sheets of drawings
Fig. 1 is an elevation, and
Fig. 2 is a plan, illustrating the simplest form, or principle of the attachment.
Fig. 3 is an elevation, shewing the application of the invention to the construction
of a
trestle transom," as used chiefly in the construction of temporary river
bridges for military purposes.
22
Fig. 4 is a plan of same, partly in section through the lines X, X, and Y, Y, in
Fig. 3.
Figs. 5 and 6 are plans of parts of the apparatus, shewn in Figs. 3 and 4.
Fig. 7 is an elevation of a modification of the invention, as applied to the con-
struction of scaffolding.
Figs. 8 and 9 are plans of part of the apparatus shewn in Fig. 7.
Fig. 10 is a modified form of the piece shewn in Fig. 8.
Figs. 11 and 12 are elevations of further modifications of the invention as applied
to scaffolding.
Similar letters of reference. denote similar parts throughout the drawings.

page_text: In the
The general object and nature of the invention may be clearly explained by
describing its application to the "trestle transom" bridge aforesaid.
ordinary method of constructing such bridges, each "trestle transom" consists of
two upright posts and a horizontal cross-piece or transom. The posts are provided
at the lower ends with suitable shoes to obtain a firm hold on the bed of the river,
and, when in position, are not fixed vertically but are inclined somewhat towards
each other to obtain greater stability. The crosspiece, or transom consists of two
parallel beams affixed together with blocks or distance pieces between them, and
sliding upon the posts. A screw is provided at each end to grip. the crosspiece
upon the posts at any required height.
The platform of the bridge rests upon the cross-piece and when it is required to
move the crosspiece to suit variations in the height of the tide, or for other reasons,
the screws are slackened, the said cross-piece is raised or lowered, and then sus-
pended by chains from the tops of the posts, the screws being again tightened.
This permits of only a small range of adjustment, for as the posts are inclined the
crosspiece jams if moved far down. The hold on the top part is not of a secure
nature, the operations of fixing or adjusting are difficult to accomplish and the
entire structure is wanting in rigidity.
The principle upon which my improved device is constructed, is shewn clearly in
Figs. 1 and 2.
If a ring A be slipped over a vertical post B, the said ring being rather larger
in diameter than the post, and the end of a bar C be inserted through the ring from
the upper side, any downward strain or pull on the end of the bar, as indicated by
the arrow, jams the ring on the post forming what may be termed a "lever grip,"
which is immovable, as the greater the strain on the end of the bar or lever, the
tighter the grip becomes, while at the same time the grip is instantaneously relieved
by raising the end of the lever. The grip can also be relieved by striking or
tapping on the highest part of the upper side of the ring, i.e. at the point D or the
lowest part of the underside, i.e. at the point D¹.
It is obvious that this apparatus may be reversed to act with an upward pull, or
horizontally, if desired.
Such a device it will be seen can be constructed in a great variety of forms. In
the case under consideration, viz. the "trestle transom," it may be arranged as
follows, see Figs. 3, 4, 5, and 6.
The two posts B, B, are placed vertically in the water, and a ring, or device,
shewn separately in plan in Fig. 5, formed of two flat bars A', A', united by two
bolts E, E, is placed around cach post. The bars are prolonged at the outer ends,
and the beams F, F, forming the cross-piece, or transom, are hung on the said
ends by bars or bolts H, H, passing through the beams F, F, and the bars A', A².
These bars A1, A2, and bolts E, E, each form a device, similar in principle to
the ring and lever shown in Figs. 1 and 2, and the weight of the cross-piece F, F,
hung on the ends causes them to jam immovably on the posts B, B, and to support
the said cross-piece at any required height. To prevent any tendency to rock
sideways, a similar set of bars J, J, shewn separately in plan in Fig. 6, connected
by bolts K, K, is placed around each post, above the first set, the long ends being
in this case inside. Bars or bolts L, L', are passed through the long ends of the
bars, both above and below the cross beams, and a wedge M, being inserted down-
wards between the post B and upper bolt on the inside the whole structure is
rendered rigid. If the posts B, B, are fixed in the ground or provided with struts
or stays to fix them in position, only the device shewn in Fig. 5 will be required.
This device, as also the device shewn in Fig. 6, is not necessarily formed of bars,
united by bolts, as it may, if preferred, be made in one piece as a forging or
casting.
At the top of each post, I place a ring lever device A³, similar to that shewn in
Fig. 8, from which to suspend a block and rope, or chain N.
To raise or lower the cross-beams, the wedges M are knocked out, and on pulling

page_text: 1
the said ropes or chains N, the grips are immediately released and the beams can
be adjusted to the required height. To stop them at such height, a slight check is
applied to the undersides of the bars A, A, from which the beams are hung, at
the point P, when the grip again automatically comes into force, and the wedges M
are replaced.
The said
The platform Q of the bridge, as shewn, rests upon joists Q¹, on the cross-
beams F, F, but may be arranged in any other suitable manner.
beams F, F, are bolted together with distance pieces F² between them.
This application of my invention gives complete rigidity to the structure, while
as the posts B, B, can be placed vertically, the cross-beams F, F1, have almost the:
entire height of the posts above the water-line for their range of adjustment, and
such adjustment can be made by persons standing on the platform of the bridge
with the greatest certainty and rapidity.
In scaffolding used for building and other purposes, my invention is particularly
applicable, as it will to a great extent obviate the present cumbrous system of
fastening the various parts together with ropes and wedges. Figs. 7, 8 and 9
represent a convenient arrangement of the invention for this purpose. B is an
ordinary scaffold pole and F³ a pole required to be supported thereon. A. modi-
fication of the ring lever shewn in plan in Fig. 8, is used, formed of a ring A', with
a lever or tail A, made in one piece. The lever is provided at the end with a
hook or a projecting lug A. A loop R, of the form shewn in plan in Fig. 9 is
placed round the pole below the ring A, the small end engaging with the end of
the lever A, and being held by the lug A. The pole F rests upon R,.and its
weight causes the ring A to jam immovably on the pole.
As the pole F³ will tend to jam between the pole B and the loop R, motion.
endways is practically prevented.
In some cases it would be inconvenient or impossible to slip the ring A' over the
pole, as for instance when it may be required to support a pole or other object
below a pole already fixed. For this purpose the modified device shewn in Fig. 10
can be employed. This ring lever is formed in two parts, the short bent ends being.
united by the ring a, and a sleeve & sliding upon the tail pieces. By removing the
sleeve the lever ring can be opened sufficiently to place it around the pole, when
the sleeve is replaced. The ring a can also be removed, when required, if the
two halves of the device are opened sufficiently wide.
This arrangement will of course require that the loop R should also be capable.
of being opened and for this purpose instead of employing a rigid loop, as shewn, I
may use a jointed loop, or a flexible loop formed of a short length of chain or rope,
provided with a ring or loop at each end to slip over the tail piece A³, or a ring
or loop at one end and a hook at the other to engage with the said ring or loop.
Figs. 11 and 12 are a modification of the arrangement shewn in Fig. 7. In place
of the loop R, a plain circular ring R (or if preferred a slightly oval ring) is
employed. In Fig. 11 the horizontal pole is shown thrust through the ring R, on
the same side of the pole B. as the tail piece A, and in Fig. 12 on the opposite side.
In both these cases the split device shewn in Fig. 10 and the chain or rope loop
above described may be employed if desired.
All these arrangements form an extremely rigid attachment, the position of which
can be instantly altered or adjusted to varying heights.
The foregoing examples shew clearly the nature of my invention, but, as will
readily be seen, it is of almost universal application in the attachment of the parts
of temporary and other structures.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim, is
1. A combined ring lever device, consisting of bars A1, A2, united by bolts E, E';
or formed·as a simple, forging or casting, the weight or strain being taken by the

page_text: bar or bolt H, and the post or other piece B, being gripped between the bolts E, E',
or other equivalent parts, substantially as set forth with reference to Figs. 3, 4
and 5.
2. The suspension of a transom, or cross-piece F, F, upon posts B, B, by the
device, as set forth in the preceding claim.
3. In the suspension of a transom, or cross-piece F, F, upon posts B, B, the
combination with the arrangement, as set forth in the preceding claims, of devices
consisting of bars J, J', united by bolts or bars K, K¹, L, L³, (or formed as a
single forging or casting) and wedges M, M, substantially as and for the purposes
set forth with reference to Figs. 3, 4, 5 and 6.
4. The combination of a ring A' with a lever A in one piece, substantially as
and for the purposes set forth with reference to Fig. 8.
5. A combined ring lever device formed in two parts, united by a ring a and
sleeve b, substantially as and for the purposes set forth with reference to Fig. 10.
6. A device for connecting two parts such as B and F3, of scaffolding, or other
required structures, consisting of the combination of a rigid or flexible loop R with
either of the devices set forth in Claims 4 and 5, substantially as described with
reference to Figs. 7, 8, 9 and 10.
7. A device for connecting two parts, such as B and F³, of scaffolding or other
required structures, consisting of the combination of a rigid or flexible ring R' with
either of the devices set forth in Claims 4 and 5, substantially as described with
reference to Figs. 11 and 12.
Dated this 29th day of April 1891.
AMBROSE MYALL,
21, Cockspur Street, London, S.W., Agent for the Applicant.