Improvements in Weighing Apparatus for Cranes.
Year: 1889

page_text: Date of Application, 31st Aug., 1889
Complete Specification Left, 30th May, 1890-Accepted, 19th July, 1890
PROVISIONAL SPECIFICATION.
Improvements in Weighing Apparatus for Cranes.
I, WILLIAM SHAFTON, of 8, Great George Street, in the City of Westminster,
Engineer, do hereby declare the nature of this invention to be as follows:-
This Invention has for its object improvements in weighing apparatus for cranes.
I will describe the invention as applied to a hydraulic crane in which the lifting
ram works in the pillar. The lifting chain passes as many times as may be necessary
around pulleys upon the cylinder and the ram head and then along the jib of the
crane to the pulley at the jib head.
In order to weigh the load being lifted I cause the lifting chain, after passing
around the pulleys upon the cylinder and ram as before stated, to rise up over another
pulley at the top of the pillar and thence to descend and to pass along the jib. This
additional pulley upon the pillar of the crane which will call the weighing pulley"
is connected with a piston working in a cylinder containing liquid, and this cylinder
is connected by a small tube with another cylinder also filled with liquid. This latter
cylinder is in a weighing cabin anywhere conveniently placed.
In this cylinder
there is a piston loaded with a spring; the piston rod is connected with an arm
carrying, at its outer end, a tracing point or pencil which marks upon a travelling
paper placed beneath it.
The arrangement in the weighing cabin thus resembles to some extent the
"Indicator employed in measuring the horse power of steam engines.
The apparatus works in the following manner: The weight of the load upon the
main chain increases the pressure upon the upper side of the weighing pulley and the
pulley yields to some extent to this pressure liquid being driven from the cylinder
beneath it into the indicator cylinder and the movement continues until the indicator
spring is so far compressed as to balance the pressure of the liquid. The paper on
which the tracing point or pencil produces this indication may be lapped around a
drum driven by clock-work in which case its movement is continuous, and the indica-
tions upon it then give the times at which the weighings were performed as well as
the amount of the loads. Or the paper may be moved forward step by step one step
for each weigh, in which case the loads will be indicated on the paper in a more
compact form but no record will be kept of the times at which the weighings were
made. The paper may be in a continuous band of any desired length and may The
unwound from one roller whilst it is wound up upon another or the pressure in the
weighing pulley cylinder may be shewn by an ordinary pressure gauge which can
be graduated to shew the weight of the load.
In some cases in place of supporting the weighing pulley by liquid in a cylinder
I attach it to a spring balance or steelyard and I provide a cabin upon the pillar
of the crane in which a man may sit to record the indications of weighing apparatus:
or the indications may be mechanically recorded upon a travelling paper as already
described.
It is not essential that the weighing pulley should be upon the top of the crane
pillar it may (although less conveniently) be mounted upon the jib of the crane, in
which case care must be taken so to arrange it that the indications may not be
affected by the varying inclinations of the jib in the case of a luffing crane.
Dated this 31st day of Juous 1000
CARPMAEL & Co.,
Agents for the Applicant,

page_text: COMPLETE SPECIFICATION.
Improvements in Weighing Apparatus for Cranes.
I, WILLIAM SHAFTON, of 8, Great George Street, in the City of Westminster,
Engineer, 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:-
--
This Invention has for its object improvements in weighing apparatus for cranes.
In order to be able to weigh a load lifted by a crane I cause the lifting chain
before it is led over the pulley at the end of the crane to be passed partly around
either under or over a pulley carried by the piston or ram of a small hydraulic
cylinder upon the pillar or jih of the crane and this cylinder I connect by a small
tube with a pressure gauge or with the cylinder of recording mechanism as herein-
after described. In this way the weighing of the load is not affected by the luffing
of the crane jib.
In some cases in place of supporting the weighing pulley by liquid in a cylinder I
attach it to a spring balance or steelyard.
In the drawings hereunto annexed I have shewn examples of cranes constructed
with weighing apparatus as above described.
The crane shewn in Figure 1 is a hydraulic crane of the kind in which the lifting
chain is led over pulleys on the cylinder and ram of a hydraulic press carried by the
crane pillar. Only so much of the crane is shewn as is necessary to shew the way in
which I
carry out my Invention.
A is the crane pillar, B the hydraulic cylinder. C the ram working in the cylinder.
DD are the pulleys carried by the cylinder and by the ram. E is the lifting chain led
around these pulleys in the ordinary way. Fis the weighing pulley, carried by the
piston rod of a small hydraulic cylinder H.
This cylinder is carried by a bracket I fixed to the lower part of the pillar A. Jis
a pipe leading from this cylinder to a pressure gauge K of ordinary type fixed to the
lower part of the pillar or it might be in any convenient position in a cabin carried by
the pillar. L is a guide pulley also carried by the bracket and M a link jointed at
one end to the bracket and at the other to the axis of the weighing pulley F.
The lifting chain E after being led around the pulleys D is led under the weighing
pulley F over the guide pulley Land from thence over the pulley N at the end of
The jib 0.
When a load is suspended from the end of the lifting chain the weighing pulley F
will be drawn upwards and will put pressure upon the liquid in the upper part of the
cylinder H and the weight of the load will be indicated on the pressure gauge.
The various weighings would always be read off upon the gauge at times when
the crane was at rest and when the loads were at the same height from the
ground.
In place of using an ordinary pressure gauge I in some cases use recording
apparatus as shown by the diagram Figure 2.
In this diagram is the pipe leading from the small hydraulic cylinder -H, it is
led to a small cylinder P fitted with a piston which is pressed downwards by a spring Q,
the piston rod is connected to an arm R which at one end turns on a fulcrum at S,
and at the other end carries a pencil or marker made to bear against paper which is
carried by the circumference of a cylinder T. Preferably I give to this cylinder a
step by step rotating movement causing it to make a partial turn after the pointer has
come to rest at each time that a weighing is to be recorded. In this way it would
only be necessary to pay attention to the lines marked at right angles to the axis of
the cylinder to ascertain the weights of the various loads weighed whilst no attention
need be paid to lines marked parallel with the axis of the cylinder. The step by step
movement may be given to the cylinder by a ratchet wheel upon it, and a pawl carried
by a lever which can be worked by a man attending to the weighing or it can be done
in other convenient ways.

page_text: In place of the small hydraulic cylinder H being carried by the pillar A, it might
be carried by the jib O as illustrated in Figure 3.
In this case the tube J leading to the pressure gauge K or recording mechanism
would either be made flexible, or be led to the jib axis, and from thence to the
indicator or recorder, or the weighing pulley might be at the top of the pillar A in
the position shown in Figure 4. In place also of the weighing pulley F being carried
by the ram of a small hydraulic cylinder, it might as before stated be carried by a
spring balance, or by a steelyard, and the weights of the several loads be indicated
or recorded as may be desired. In Figure 4 I have shewn the weighing pulley as
being carried by a steelyard. I prefer however to carry the weighing pulley by a
small hydraulic cylinder as above described.
Having now particularly described and ascertained the nature of my said Luven-
tion, and in what manner the same is to be performed I declare that what I
claim is:-
1. A crane, the lifting chain of which, before it passes over the pulley at the end of
the jib is led partly around either under or over a pulley carried by the piston or ram
of a small hydraulic cylinder connected with a pressure indicator or recorder, or is
carried by a spring balance or steelyard.
2. A hydraulic crane in which there is a hydraulic cylinder and ram working in
the crane pillar and carrying pulleys over which the lifting chain is led, and in which
the chain after passing from these pulleys is led partly around either under or over
a pulley carried by the piston or ram of a small hydraulic cylinder, connected with a
pressure indicator or recorder, or carried by a spring balance or sicelyard.
3. The construction of weighing apparatus for cranes, substantially as hereinbefore
described.
Dated this 27th day of May 1890.