IMPROVEMENTS IN WEIGHING APPARATUS
Year: 1884

page_text: I JOHN NEEDHAM of the firm of John Needham and. Sons of Market Street
Manchester in the County of Lancastor Engineers do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN WEIGHING APPARATUS "
to be as
follows:-
My Invention consists of additions to an invention for which I made an
application for Letters Patent on the first day of May in the current year such
application bearing the number 7070. My present invention has for a part of its
object to effect the ready adjustment of the leverage of the steel yard, scale beam
or balance or of any of the levers or beams according to the class of apparatus.
I form the knife edges or the hollow centres as the case may be in separate pieces
which can be adjusted in any position upon the lever, index, arın or scale beam or
one centre in a pair may be fixed and the other be adjustable. The pieces carrying
or containing the centres may be adjusted by means of screws or cottars or other
means and secured when adjusted by means of turned steady pins or of bolts or set
screws or by means of cottars or wedges or by other suitable means. In some cases
I form or fix the hollow centres upon the levers or beams in contradistinction to
the ordinary practice. In some cases with a view to obtain accuracy throughout
a machine or number of machines I secure a number of levers or of centre pieces or
blocks side by side and cut all the centre hollows with one adjustment so that all
sliall be exactly alike. In some cases I make the knife edge centres of agate the
said centres being cemented or bedded in boxes or holders to give the necessary
strength to the material, I also use self hardening steel in the formation of edge
centres or of hollow centres or of both. The foregoing improvements are wholly
or partly applicable to scale beams and equal weight weighing machines. To
relieve the knife edges from the load in the cases of lever and equal weight
weighing machines, I apply a rocking shaft at or near each end or side of the table
and I either actuate the two shafts separately or I connect together the two shafts
by means of levers and links or of a shaft and gearing or by suitable means so that
the two shafts will act in unison and I provide the shafts with cams or excentrics
which act upon parts to raise the load when the shafts or one of the shafts are or
is acted upon. In the cases of large machines I make the under framing in sections
built one upon another iron or steel sections in some cases taking the places of the
ordinary stone or stone and brick foundations. The lever adjustment is readily

page_text: effected by packing up the upper section or by making it of the required depth.
In practice the web of the girder which supports the weigh plate has to be made of
considerable depth to resist deflection. In making the said supporting girder
I prefer to use two comparatively shallow girder sections of rolled steel and placed
side by side. I fill in the space between the said steel sections with timber
packing the timber being brought up flush with the upper surfaces of the flanges of
the sections or a little above the same. The steel girder sections and interposed
timber packing are held together by bolts or the tie bars connecting the pairs of
girders have their screwed ends passed through the timber and sections, which they
bind together by means of jamb nuts By this construction I obtain a strong and
rigid girder having a sufficiently broad bearing surface with considerably reduced
depth. The said composite girders are also lighter and more easily handled during
transport and erection.

page_text: CORT LEIM
DELCIFICATION,
"
I 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 APPARATUS 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 Invention consists of additions to an invention for which I made application
for Letters Patent on the first day of May in the current year such application
bearing the number of 7070. My present invention has for a part of its object
to effect the ready adjustment of the leverage of the steel yard, scale béam
or beams according to the class of apparatus. I form the knife edges or the
hollow centres as the case may be in separate pieces which can be adjusted in any
position upon the lever, index arm or scale beam or one centre in a pair may be
fixed and the other be adjustable. In some cases I form or fix the hollow centres
upon the levers or beams in contradistinction to the ordinary practice. In some
cases with a view to obtain accuracy throughout a machine or number of machines
I secure a number of levers or of centre pieces or blocks side by side and cut all
the centre hollows with one adjustment so that all shall be exactly alike. In some
cases I make the knife edge centres of agate. I also use self hardening steel in the
formation of edge centres or of hollow centres or of both. To relieve the knife edges
from the load in the cases of lever and equal weight weighing machines I apply a
rocking shaft at or near each end or side of the table and I either actuate the two
shafts separately or I connect together the two shafts so that the two shafts will act
in unison and 1 form or provide the shafts with cams or excentrics which act upon
parts to raise the load when the shafts or one of the shafts are or is acted upon. In
the cases of large machines I make the under framing in sections built one upon
another, iron or steel sections in some cases taking the places of the ordinary stone
or stone and brick foundations. In practice the web of the girder which supports
the weigh plate has to be made of considerable depth to resist deflection. In
making the said supporting girder I prefer to use two or more comparatively
shallow girder sections of rolled steel and placed side by side and having the
intermediate space filled with timber packing.
In the accompanying drawings are illustrated the different parts of weighing
machines to which my Invention relates. Fig: 1 represents my method of adjusting
the beam centres. In the said Fig: a. a. are the centres which are fitted to slide upon
the opposite sides of a block b. which is bolted or secured to the side of the weigh
beam or which might be formed in one piece with the same. The centres a can be
adjusted upon the block b by means of taper cottars c. c. and when adjusted be fixed
by means of turned steady pins, screws, bolts, cottars or other suitable fastenings.
Screws or other means for adjusting the centres may take the place of the cottars.
In the example the centres a. which are so fixed and adjusted upon both sides of
the weigh beam are hollow in accordance with my Invention. Figs: 2. 3 and 4
illustrate other formations of beams and levers having hollow centres. Figs: 2 and 3
=
:

page_text: representing scale beams and Fig: 4 an equal weight lever for a weighing machine.
In Fig 2 the centres are formed in parts d. which are adjustable upon the beam.
This formation facilitates construction as a number of these centres can be planed
and shaped together and after being suitably hardened can be attached to the beams
and after careful adjustment thereon be fixed by means of screws or pins or by
Buitable means. In the case of the lever represented by Fig: 4 I can also secure a
number of such levers side by side upon the table or bed of a machine and plane
or cut and finish all the hollow centres with the one adjustment and thereby ensure
as absolute uniformity in all such levers in a machine as is possible of attainment.
Fig 5 illustrates the manner in which I employ agate or self hardening steel in
the formation of the knife edge centres. In this example the suitably shaped piece of
agate or steel e. is cemented or bedded in a recess formed in a holder f. which is
made of a form suitable to the requirements according to the size or description of the
machine or to the position of the centre. Fig: 6 illustrates my improved method of
relieving the knife edges from the load in the cases of lever and equal weighing
machines. At or near each end or side of the table or platform I mount a shaft g.
each shaft being mounted to rock upon its axis in suitable bearings the shafts
being parallel one with the other or thereabouts. I connect the two shafts together
by means of levers and connecting links or by means of a connecting shaft and
level gearing or by ordinary or suitable means so that the two shafts turn or rock
in their bearings in unison when one of the two shafts is operated upon by means
of a hand lever or of gearing. Upon each shaft are formed two swells g¹ which
act as cams when the shaft is turned. Fig. 7 represents a cross section of the shaft
at the part where this swell is formed. If preferred cams or excentrics may be
fixed upon the shafts. The swells glare arranged to come below the principal
girders of the platform one of these girders being represented in section by h. or
the four swells or cams on the two shafts are otherwise arranged to act
simultaneously upon four corners or parts of the table or platform. The effect of
this arrangement is that when one of the shafts is acted upon the two shafts turn
in their bearings and the four swells g¹ act in unison upon four points on the table
or platform and raise the same uniformly and to an equal extent at all points.
Fig: 8 illustrates my method of forming the foundation for the underframing of
large machines. The said foundation is composed of sections i. i. made of iron or
steel having timber packings k. introduced. Lead or other suitable packing or
bedding material may take the place of the timber or the sections may be otherwise
suitably bedded one upon another. The said sections take the place of the ordinary
brickwork or stone foundations or of the upper part of the same and furnish a
firm and reliable foundation to carry the underframing of the machine indicated
by . The level adjustment is readily effected by packing up the upper section 1. or
by making it of the required depth. I do not confine myself to the form or to the
number of sections employed. Fig: 9 illustrates my improved formation of the
girders which support the weigh plate or platform the said Fig: representing a
section of such a girder. The girder is composed of two members m. m. made of
rolled steel of any suitable section an ordinary girder or double headed tee section
being shown in the drawing. Between these two members is interposed a filling in
of timber which entirely fills the space between the two members and is brought
flush with their top and bottom flanges or it may be that in some cases I may
cause the timber to project a little beyond the metal. The steel members or girder
sections and the interposed timber packing are held together by means of bolts or
the tie rods connecting together the pairs of girders have their screwed ends passed
through the timber and the members or girders as indicated by o. so that the whole
can be bound together by means of nuts p. p. The illustrated method of securing
the parts together may be supplemented by the employment of other bolts. By
this construction I obtain a strong and rigid girder having a sufficiently broad
bearing surface with considerably reduced depth. The said composite girders
are also lighter and more easily handled during transport and erection.

page_text: 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. In a weighing apparatus the centres separately attached to the weigh or
scale beam and adjustable in distance apart thereon substantially as set forth and
indicated.
2. The weigh or scale beams and weighing machine levers formed or provided
with hollow centres substantially as set forth and indicated.
3. The method of obtaining uniformity in the levers of weighing machines by
fixing or arranging all the levers side by side and cutting the centres in all by the
same operation as set forth.
4. The centres and bearings of weighing apparatus made of so termed self
hardening steel.
5. The knife edge centres made of agate and mounted in holders substantially as
and for the purpose set forth and indicated.
6. The employment of a coupled pair of cam shafts to raise the table or platform
of a weighing machine substantially as set forth and indicated.
7. The foundations for weighing machines constructed substantially as set forth
and indicated with reference to Fig: 8 of the drawings.
8. The composite girder beam or lever composed and constructed substantially
as and for the purpose set forth and indicated with reference to Fig. 9 of the
drawings,