IMPROVE- MENTS IN APPARATUS FOR CONVEYING HEAVY WEIGHTS FOR BRIDGE BUILDING AND OTHER PURPOSES
Year: 1855

page_text: LETTERS PATENT to John Avery, of 32, Essex Street, Strand, London, in
the County of Middlesex, Patent Agent, for the Invention of "IMPROVE-
MENTS IN APPARATUS FOR CONVEYING HEAVY WEIGHTS FOR BRIDGE BUILDING
AND OTHER PURPOSES."-A communication.
Sealed the 4th September 1855, and dated the 26th May 1855.
PROVISIONAL SPECIFICATION left by the said John Avery at the Office
of the Commissioners of Patents, with his Petition, on the 30th May 1855.
I, JOHN AVERY, of 32, Essex Street, Strand, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN APPARATUS FOR CONVEYING HEAVY WEIGHTS FOR BRIDGE
BUILDING AND OTHER PURPOSES," a communication, to be as follows; and relates
to the raising, lowering, & transporting of heavy bodies of stone, metal, or
other substances from, in,to,or across rivers or other places difficult of access.
It consists in providing suitable cable or other tackle,stretched between fixed
points, to form a track or way over which a suitable truck or carriage may
traverse, the weight to be lifted and removed being suspended below the truck
or carriage by a series of block tackle.
In order to illustrate the Invention more fully, it will be described as in
operation for pier building, the same being applicablewith slight modifications
to various other purposes. On the banks of the stream or ravine in which
[Price 8d.]

page_text: the piers are to be buitt suitable erections are made, over which is passed a
cable suited to the weight of materials to be transported from point to point.
This cable forms a track along which a truck of improved construction passes
and repasses. This truck is composed of a frame in the central upper part
of which a main wheel is secured, and at the ends of the frame are two
smaller wheels. These wheels are grooved so that they may properly fit the
surface of the cable over which they pass. Suitable straps extend from
the main wheel to a fixed tackle, as the entire weight of the load to be
moved being intended to be carried pendant directly below the main wheel,
& being far below the centre of gravity of the truck, there is no liability of the
wheels slipping off the cable.
AL
Supposing it is desired to covey a heavy weight from some position near
one of the towers to a distant point where the workmen are employed in
building pier or other structure, the truck is brought over the spot where
the burden happens to be, and secured from running down the incline of the
cable by means of a guide fall. The weight is attached to a moveable tackle,
and by means of a purchase fall the burden is elevated & raised until the
movable tackle block clutch the fixed tackle. The clutch bars are attached
to the sides of the movable tackle block, and have hinges. The clutches are
held in a closed position by a spring fixed across the top of the movable
tackle block; they are also attached to a movable cap piece by connecting
rods. This movable cap piece works on a pin fixed in the top of the movable
tackle. At the bottom of the fix'd tackle block is a cross bar, having in its
centre a hole for the said pin to work through, & at the ends of this cross
bar are hooked catches or lips, so that when the movable tackle block is
raised by the purchase fall, the clutch bars strike the lips, and are opened
until the clutch bars' slots arrive opposite the lips, when the spring closes the
clutch bars, and they fasten on the lips; the purchase fall will then be
relieved of all strain, the weight being sustained by the clutch bars.
In order to move the weight thus elevated to the desired position above the
pier, itis only necessary to slacken the guide fall, when the truck, carrying with
it the burden, will move of its own gravity down the incline of the cable, &
when arrived over the pier the guide fall on the opposite tower is fastened,
which safely secures the truck. The clutch bars are now dotached by simply
pulling upon the purchase fall and raising the movable tackle, which causes
the before-mentioned pin to pass the opening in the cross bar, & brings the
movable cap piece in contact with the cross bar, whereby the connecting rods
of the movable cap piece are straightened & pressed down to a line even
with the centres of their joints, which causes them to remain in that position,

page_text: & hold open the clutch bars clear of the hooked catches or lips, and the
weight is lowered by slackening the purchase fall. The clutches are after-
wards brought up to their clutching position by moving up the cap piece. A
guy chain is attached between the fixed tackle block and an arm of the frame
of the truck, in order to assist in retaining the perpendicular of the fixed block
with the main wheel when power is applied to the purchase fall. A con-
siderable saving of time may be effected in raising or lowering the burden
while in transition, and to effect the lowering of the burden the purchase
fall is fastened to the tower, & while the truck is moving towards it the
weight is also lowered with a speed proportionate to the number of sheaves
in the blocks.
In the same manner the burden may be elevated during the progress of the
truck, by fastening one end of the purchase fall, and pulling the truck away
from the point where the purchase fall is secured.
When it is desired to transport unusually large burdens, more than one
suspended cable may be employed, and their strength so combined as equally
to support one burden. For this purpose four cables may be used, a truck
to each cable, with fixed and movable tackle blocks of the same form as
before mentioned. Attached to the ends of the four inovable tackles are two
equalizing beams and one central beam, which is supported by links which
rest in the centres of the two equalizing beams The burden is attached to a
link which rests in the centre of the contral beam, and is transported in the
same manner as before described.
The guide tackles are easily brought into a convenient position to be
worked by having a metallic groove upon one side of the tower over which
the cables pass, in which an eye bolt slides, and has a chain attached above
& below. The upper part of the chain passes over a pulley, & the lower
part passes down to a convenient position near the ground, where it passes
around a winch; by turning the winch the eye bolt can be raised or lowered
as may be desired.
SPECIFICATION in pursuance of the conditions of the Letters l'atent, filed
by the said John Avery in the Great Seal Patent Office on the 5th
September 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
AVERY, of 32, Essex Street, Strand, London, in the County of Middlesex,
Patent Agent, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said John Avery. Her special licence that I, the said John
Avery, my executors, administrators. and assigns, or such others as I, the
said John Avery, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there.
after during the term therein expressed, should and lawfully might make,
usc, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE.
MENTS IN APPARATUS FOR CONVEYING HEAVY WEIGHTS FOR BRIDGE BUILDING AND
OTHER PURPOSES," (a communication,) upon the condition (amongst others) that
I, the said John Avery, by an instrament in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Avery, do hereby declare the
nature of the said 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 the raising, lowering, and transportation of heavy
bodies of stone, metal, or other substances, being chiefly em,loyed in the
erection of bridges over streams or ravines. It consists in providing a suitable
cable or cables stretched across between the banks of the river, which cables
form a fixed track, over which a suitable carriage or truck traverses, the
weight to be lifted and transported being suspended below the truck by means
of a series of tackles.
Fig. in the accompanying Drawings represents in perspective the general
uses and application of my improvement in bridge building; Fig. 2 is an
enlarged side elevation of my improved truck and improved fixed and movable
clutch pulleys, as applied ready for operation; Fig. 3 is a front view of my
improved pulleys previous to and after clutching; Fig. 4 is a view of the saine
clutched together; Fig. 5 is a view of the same in the act of being detached
or uncoupled; Fig. G is a side elevation of what I term my equalizing beams;
Fig. 7 is a perspective view showing the method of combining the strength of
more than one suspension cable. Similar letters of reference indicate the
samo parts.

page_text: ;
A, A', suspension towers placed on the opposite banks of the river, over
which the bridge is to be built; B, B1, B2, B3, suspension cables passing from
tower to tower; C, frame of cable truck; D, main wheel of same; E, E. guido
wheels; F, fixed clutch tackle; G, movable clutch tackle; H, lips on fixed
tackle H, cross bar of same; I, clutch bars on the movable tackle G; J.
hinges of the clutch bars; K, connecting rods between cap piece and clutches;
K', cap piece; 1, guide pin; M, connecting spring between clutch bars;
N, O, P, guide tackles; Q, R, S, equalizing beans; U, U, guide falls; V, guy
chain; W, metallic groove on the side of towers A, A¹; W', eye bolt working
in the groove; X, friction wheel.
In the construction of bridges across rivers, when piers are to be erected in
the stream, the usual method of transporting the stones and other materials
is to employ floats or boats, and to raise the materials by the employment of
suitable derricks; stagings and scaffolds are also employed. The various
operations of raising, elevating, and depositing the stones and other materials
consume much time, and consequently involve great expense.
The object of my improvement is to facilitate the workmen in the erection
of all such structures, by providing a safe, easy, and rapid means of trans-
porting and depositing the stones and all other materials, without the employ-
ment of derricks, or any of the usual scaffold appendages
In the first place I erect upon the banks of the river in which the piers
are to be built two towers A, A', composed of wood or any other suitable
material. I then throw a suspension cable B, proportionate in size to the
weight of materials to be transported from one tower to the other, the ouds
of the cable being fastened in the ground in any suitable manner. The
cable thus stretched forms a fixed track, over which my improved truck
passes and repasses in its various errands of transportatiou. The truck is
composed of a frame C, in the central upper part of which the main wheel D
is secured. The wheel D is grooved, and so are the wheels E, E', in order
that they may properly fit the surface of the cable over which they pass.
Suitable straps extend from the wheel D to the fixed tackle F, the entire
weight of the load to be moved being intended to be carried pendant directly
below the wheel D. As the burden always remains far below the centre of
gravity of the truck, there is never any liability in the wheels of the latter to
slip off the cable.
I will now suppose that it is desired to convey a heavy weight from some
position near one of the towers to a point in the middle of the stream, where
the workinen are engaged in building a pier. The truck is brought over the
spot where the burden happens to be placed, and secured from rolling down

page_text: the incline of the cable by means of the guide fall U, as seen in Fig. 2. The
weight is attached at a on the movable tackle G, and by means of the pur-
chase fall T the burden is elevated, being raised until the tackle blocks.
F, G, clutch.
The clutch bars I are attached to the sides of the tackle block G, having
hinges J, J. The clutches are held in a closed position by means of a
spring M, Fig. 3. They are also attached to a movable cap piece K', by
means of the connecting rods K. The dotted lines in Fig. 3 indicate the
position of the clutch bars 1, in the act of passing the lips H. As the tackle
Grises, the upper ends of the clutch bars I strike the lips H, and are opened
until the slots in the clutch bars arrive opposite the lips, when the spring M
closes the clutch bars, and they fasten on the lips H, as seen in Fig. 4. The
purchase fall T. is now relieved of all strain, the weight being entirely.
sustained by the clutch bars. In order to move the weight thus elevated to
the desired position above the pier, it is only necessary to slacken the guide
fall U, when the truck, carrying with it the burden, will move of its own
gravity down the incline of the cable in the direction of arrow 1. Arrived
over the pier the guide falls U, U₁, are fastened, which secures the truck.
The clutch bars are now detached, and the burden is lowered by slacking
the purchase fall T.
The clutches are detached by simply pulling upon the purchase fall T, and
raising the movable tackle G, as seen in Fig. 5, which causes the pin L to
pass the opening in the cross bar H', and brings the cap piece K' in contact
with the cross piece H', whereby the connecting rods K, K, are straightened
and pressed down to a line even with the centres of their joints, which causes
them to remain in that position, and hold open the clutch bars I, 1, clear
of the ears H, H, as seen in Figs. 3 and 5. The clutches are afterwards
brought up to their clutching position by moving up the cap piece K'by hand.
It is obvious that the movement of the truck is controlled by the guide
falls U, U, to which the requisite force must be applied. When desired, the
weight may be raised or lowered at the same time that the truck is moving.
I will suppose the truck to be moving in the direction of arrow 2, and that
the purchase fall T (shown in dotted lines, Fig. 2) is fastened to the tower A.
It is manifest that while the truck proceeds, the weight is also lowered with
a speed proportionate to the number of sheaves in the blocks F, G. This
plan of lowering the woight during transit to its destination will be found
very convenient where the burden is to be taken from an elevated point and
deposited at a distance lower down, see Fig. 1.
In the saine manner a weight may be elevated during the progress of the

page_text: truck by fastening one end of the purchase fall, and pulling the truck away
from the point where the purchase fall is secured. A considerable saving in
time is effected by these modes of raising and lowering the burden while in
transition. The guy chain V is attached between the tackle block F and arm C,
in order to assist in retaining the perpendicularity of the block F with the
wheel D, when power is applied to the purchase fall T. When it is desired
to transport unusually large burdens, more than one suspension cable may be
employed,and their strength so combined as equally to support one burden.
For this purpose I employ equalizing beams, Q, R, S, shown in Fig. 6.
In Fig. 7 four cables are represented as in use, having a truck to each
cable. The tackle blocks attached to two of the trucks are fastened to the
beam R, and the remaining two to beam S. The ends of central beam Q
pass through links which rest in the centres of beams R, S, as shown. The
burden is attached at y. If from any cause the cables should not each bear
up its due portion of the burden, the inequality will be at once apparent,
for the equalizing beams, being balanced in their centres, will be thrown out
of line. When the weight is equally sustained the equalizing beams will all
be parallel.
Upon the side of the tower A a metallic groove W is attached, in which
the eye bolt W slides, the eye bolt having a chain attached above and below,
the upper part of the chain passing over the pulley X, and the lower part
passing down to a convenient position near the ground, where it passes around
a winch. By turning the winch the eye bolt can be raised or lowered as
desired, and the guide tackles easily brought into convenient position. The
eye bolt W and guide block P shackle together, as seen in Fig. 2.
After the piers of a bridge have been finished, my apparatus may be then
employed in laying the superstructure and all other parts of the bridge. For
this purpose it is admirably adapted,since the trusses and other portions may
be deposited in their places with very great rapidity. A glance at the sketch,
Fig.1,will show the great convenience and superiority of my improvement
over the common methods of moving the materials used in the construction of
similar works.
The expense of my apparatus is small; all the rigging and trucks are
portable,and may be carried from one point to another at convenience. The
saving in expense which the use of my improvement affords over the old
methods is immense. The same amount of work is performed with less
machinery, by fewer workinen, and in shorter time.
Having thus described the nature of the said Invention, and the manner in
which the same is or may be carried into effect, I wish it to be understood

page_text: that I do not claim a suspended cable for transporting weights of any kind
across ravines or streams, nor do I claim transporting bodies of any kind by
means of a movable cable or catenary, which is to be raised or lowered to
deliver the burden or weight at any intermediate place between its points of
suspension or fastening,as these have been essayed ; but what I do claim is,-
First, a carriage provided with suitable block and tackle, in combination
with a permanently suspended cable, by which a suspended weight of any
kind may be transported to any given point,and then lowered or raised, as it
is transporter, at pleasure, substantially as described.
Second, in combination with the said permanently suspended cable,a truck
or carriage composed of a main wheel D, guides wheel E,E', and a flexible
frame C,so that the wheels may adjust themselves to the line of the catinary
as described.
Third, the automatically coupling and uncoupling of the blocks F, G,
substantially in the mauuer and for the purpose set forth.
Fourth, the system of equalizing beans Q,R,S,when combined with two,
three, or more cables, for the purpose of evenly distributing the weight upon
the several cables, as set forth.
In witness whereof, I, the said John Avery, have hereunto set my hand
and seal, this Fifth day of September, in the year of our Lord One
thousand eight hundred and fifty-five.
JOHN AVERY. (L.S.)