IMPROVEMENTS IN WEIGHING MACHINES
Year: 1884

page_text: 1 JOHN NEEDHAM of the firm of John Needham and Sons of Market Street
Manchester in the County of Lancaster Engineers, do hereby declare the nature of
the said invention for "IMPROVEMENTS IN WEIGHING MACHINES" to be as follows:-
My said invention relates to weighing machines and consists in the first place of
an improved construction of steel yard and saddle block. My improved saddle
block may be made of any suitable material but is preferably made of steel and
has the centres or knife edges fixed or formed thereon in any convenient manner
and situated either within or without the block, or I may reverse the ordinary
arrangement and form the vee hollows in the block and the knife edges on the
shackle. The steel yard or weigh beam is formed in one piece with or is attached
to the said block in such a manner as to permit of an uninterrupted passage of the
weight or weights past or through the said block and so as to keep the line of
graduation and the line of the centres in the same plane When the steel yard or
yards is or are made seperate from the block I attach them to projections or brackets
on the said block or I form a recess or recesses in the block into which the yard or
yards is or are inserted. The said steel yards may be round square or polygonal
in section or I may arrange them to turn on their own axes so as to present
different standards or scales to the index of the weights. By my improved method
of applying such steel yards it will be unnecessary to cut the marks and scales
thereon for each machine as they may be made and marked in lengths and after-
wards cut off to suit any machine. I may employ any number of steelyards
corresponding to differing standards of weights and provided with sliding weights
having spring or other catches taking into the notches in the graduated steel yards.
The zero or starting graduation may be placed either to the right or left hand of
the knife edges or centres from which the scale extends without my improved
machine where the steel yard or yards is or are contained within a bracket formed
on or attached to the saddle block at the top of the pillar provide a relieving
lever whereby the saddle block and steel yard can be lowered vertically without
displacing the knife edge bearings. In fitting the main levers beneath the weigh
plate I apply cup or cone bearings instead of the usual links and swingers by which
the transverse thrusts and displacement of bearings which arise from the deflection
of the girders and weigh plate are neutralised and the consequence falsity in the

page_text: weight registered is avoided. I also apply the said cup or cone bearings to the
ordinary swingers. I make the main levers of comparatively light sections of steel
instead of forming them of cast iron as heretofore. The said steel sections can be
bolted together so as to form light and strong substitutes for the heavy and
cumbrous cast iron levers and parts hitherto used and as they may be easily taken
apart and packed in a small space for transport a considerable economy in the cost
of carriage is effected whilst from the nature of the material employed breakages
are avoided. In the smaller class of weighing machines I make the whole of the
parts of wrought iron and steel except the plate and wheels in the case of portable
machines. The foregoing improvements or part of them are applicable to existing
machines.

page_text: I JOHN NEEDHAM of the firm of John Needham and Sons Market Street Manchester
in the County of Lancaster Engineers do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN WEIGHING MACHINES" and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement and accompanying drawings :—
My said Invention relates to weighing machines and consists in the first place of
an improved construction of steel-yard and saddle block. The steel yard or weigh
beam is formed in one piece with or is attached to the saddle block in such a manner
as to permit of an uninterrupted passage of the weight or weights past or through
the said block and so as to keep the line of graduation and the line of the centres
in the same plane. Machines constructed in accordance with any invention are self
balancing irrespective of the weight of the component parts of the machine and I
therefore do not require the tail or counter balance weights which it is customary
to apply to machines now in use. In fitting the main levers beneath the weigh
plate I apply cup or cone bearings instead of the usual links and swingers by
which the transverse thrusts and displacement of bearings which arise from the
deflection of the girders and weigh plate are neutralised and the consequent falsity
in the weight registered is avoided. I also apply the said cup or cone bearings to
the ordinary swingers. I make the main levers of comparatively light sections of
steel instead of forming them of cast iron as heretofore. In the smaller class of
weighing machines I make the whole of the parts of wrought iron and steel except
the plate and the wheels in the cases of portable machines.
In order that my Invention may be well understood I will refer to the accom-
panying sheet of drawings wherein Figs: 1. 2 and 3. illustrate the construction of
my improved saddle block. The saddle block a is represented in cross section in
Fig: 1. and in longitudinal section in Fig: 2. In this example the centres b. b¹.
are inside the hollow block and to the outside of the block are secured two steel-
yards or weigh beams c. c. These steel-yards are secured by means of screws d. to
flanges which project from the saddle block so that the weights will clear the block.
The steel-yards extend in both directions from the centre of suspension b. so that
either of the weights can be brought into a neutral position or can be carried to
the rear side of the centre so as to add to the load. In Fig: 3. the saddle block a
is of a forked shape and the centres b. b. are on the two limbs of the fork. These
centres may be made either male or female The steel-yard c is secured in a jaw
formed in the centre of the fork or is otherwise secured in a central position.
This forked form of the saddle block permits the weight e. to pass clear through
the block and between the centres into position on either side of the centre
of suspension or into a neutral position as desired. The said weight carries a

page_text: ८
supplementary graduated beam f. on which is mounted a supplementary weight f¹.
for finer graduations of weight. I do not confine myself to forming the steel-
yards separately from the saddle block, and attaching them thereto although I
prefer to do 80. I may vary the method of attaching the steel-yards to the saddle
blocks as found to be most suitable. The steel-yards may be round square. or
polygonal in section and in some cases I may so mount them as that they may be
rotated so as to present different standards or scales to the indexes of the weights.
By making the steel-yards separately from the saddle blocks it is not necessary to
cut the marks and scales thereon for each machine as they may be made and
marked in lengths and be afterwards cut off to suit any machine. I may employ
any required number of steel-yards corresponding to differing standards of weights
and provided with sliding weights having spring or other catches taking into the
notches in the graduated steel-yards. The zero or starting point of the graduation
may be situated either to the right or to the left hand of the centre of suspension
and the graduation extend without interruption up to the maximum weight.
Machines constructed in accordance with Figs: 1 to 3 may be self-balancing so
that the ordinary tail or balance weights may be dispensed with. I do not confine
myself to the hollow or forked form of the saddle block as the formation may be
A solid block
greatly varied so long as the steelyards extend past the centres.
might be used such for example as indicated in Fig: 4 the steel-yards being secured
on each side with the requisite clearance for the passage of the weights. Figs: 5
and 6 illustrate my methods of mounting the bearings for the main lever centres.
In Fig 5. the bearing 9. rests upon a ball h which is seated in a recess in the
casting or bearing block i. In Fig: 6 the bearing g. is made of a rounded conical
or egg shaped form and is seated in a cup formed in the bearing block i. In both
examples the bearings are capable of a limited amount of self adjustment the
ordinary links or swingers being dispensed with or these bearings may be used in
conjunction therewith. Fig: 7. illustrates the improved formation of the main
levers. In this example each lever is composed of two bars or plates k. k. of rolled
steel which are connected together at intervals by means of bolts and stays l. l.
These bars k. may be rolled to any suitable section as for example angle, tee or
channel section or they may be built up that is to say be composed of two angle
steel members connected together by means of plate or sheet metal or of stay and
struts as in the building up of a girder so that they may be made to taper in
depth or they may be simple plates of steel bent to the required forms. The levers
so constructed are much lighter and less cumbersome than the ordinary cast metal
levers and as they can be taken to pieces and packed in a small compass as
compared with the ordinary levers they are much better adapted for transport to a
distance as the cost of carriage is much less and owing to the employment of less
fragile material breakages are obviated. As hereinbefore mentioned in the
construction of the smaller class of weighing machines I employ wrought iron and
steel in the construction of the frame and of all parts with the exception of the
plate or table and in the cases of portable machines of the wheels.
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. The formation of the saddle block and the attachment thereto of the steel
yards substantially as and for the purpose set forth and indicated with reference
to Figs 1 to 4 of the drawings.
2. Providing weighing machines with two steel yards secured one on each side
of the saddle block substantially as set forth and indicated.
3. Extending the steel-yard or steel yards of a weighing machine past the
centres so that the weight or weights can be moved into position on either side of
the centre of suspension substantially as set forth and indicated.

page_text: 4. Forming the steelyards of weighing machines as separate bars which are
bolted or attached to the saddle blocks or are marked with different scales and are
mounted to be revolved substantially as set forth.
5. The self adjusting bearings for the main levers of weighing machines
substantially as set forth and indicated.
6. The main levers of weighing machines constructed substantially as set forth
and indicated.