Improvements in or applicable to Weighing Machines.
Year: 1891

page_text: Date of Application, 10th Jan., 1891
Complete Specification Left, 12th Oct., 1891-Accepted, 14th Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in or applicable to Weighing Machines.
I, CEMER THOMAS COLEBROOK, of Union Square, Islington, in the County of
London, Engineer, do hereby declare the nature of the said invention to be as
follows:-
This invention relates to certain improvements in weighing machines, and has
especial reference to that class of such machines known as platform weighing
machines and weigh-bridges, in which there are one or more levers within a box or
frame, the lever or levers having affixed thereto properly proportioned knife-edge
centres on which is supported a table or platform for the reception of goods to be
weighed, and the box or frame having a projecting part on which is placed a
standard or pillar for the purpose of carrying or supporting the steelyard or
indicating beam on which is marked or engraved the various divisions of weight of
any required standard.
These machines are usually of a somewhat complicated construction, and although
many attempts have been made by various manufacturers to produce a simple
single lever machine of the platform class, such machines are still very limited in
their application, while their reliability and sensitiveness leave much to be desired.
The object of this invention is to produce a single lever platform weighing
machine of a more simple construction than such machines as at present con-
structed, and, at the same time, of more accurate weighing capabilities than have
hitherto been attained in this class of machine.
To this end the invention has reference, mainly, to means for securing the
platform in such a position on the knife-edges of the lever that any given weight of
goods placed on the platform will cause the same indication on the registering
beam or steelyard when adjusted by weights (either moving or loose) attached
thereto for that purpose, no matter on what part of the platform the goods are
placed.
In carrying out the invention, two horizontally disposed diaphragms or guide plates
of sheet iron, steel or other material and of such thickness as to be flexible in the
centre part, are placed within the usual box or frame, one of these diaphragms
or guide plates being placed adjacent to the bottom of the box or frame and the other
thereof being placed adjacent to the top of the box or frame, and each having a
guiding hole in or near the centre by preference and in common line with the knife
edge centres of the lever on which the platform or table is supported.
On the underside of the usual table or platform there is formed or attached a
stem preferably of a squared or rectangular shape in cross section, and of such a
length as to reach through the said guiding holes in the diaphragms, which holes
are preferably of a shape corresponding with that of the stem. The platform is
also provided with depending supports which pass freely through other holes, in
alignment therewith, made in the upper diaphragm, and rest on knife edge centres of
steel carried by the lever.
The stem on the underside of the platform or table being free to move in a
vertical direction through the guide holes, the flexibility of the diaphragms allows
of the most delicate movement being obtained and consequently a most accurate
weighing being obtained.
In lieu of the diaphragms or in conjunction therewith any equivalent means may
be used to guide the stem on the platform or table, such, for example, as one or
more spring radiating arms through or between which the said stem is free to pass,
the arrangement being such as to ensure the stem being kept in such a position

page_text: that the weight exerted on the lever will be practically constant no matter on what
part of the platform the goods are placed.
The stem may be provided with projections or equivalent means to ensure its
coming in contact with the diaphragms, the sides of the apertures in which act as
buttresses to the stem in all directions on whatever part of the platform the goods
are placed, the platform being, by the aforesaid means, effectually prevented from
tipping, thus avoiding the necessity of additional appliances as ordinarily used to
prevent such tipping.
The platform may be freely removed or replaced without disturbing any other
part of the machine.
When the entire diaphragms are used, the lower one may form the bottom of
the box or frame, the upper one acting as a cover to the working centres and
thereby protecting them from dust and dirt.
Dated this 10th day of January 1891.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or applicable to Weighing Machines.
I, CEMER THOMAS COLEBROOK, of Union Square, Islington, in the County of
London, 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 relates to certain improvements in weighing machines, and has
especial reference to that class of such machines known as platform-weighing-
machines and weigh-bridges, in which, as usually constructed, there are one or
more levers arranged within a box or frame and fitted with properly proportioned
knife-edge centres supporting the table or platform on which the goods to be
weighed are placed, the box or frame being formed with a projecting part
supporting a standard or pillar carrying the steelyard or indicating beam on
which the various divisions of weight (which may be of any required standard)
are engraved or otherwise suitably marked.
Such machines are usually of a somewhat complicated construction, and although
many attempts have been made by various manufacturers to produce a simple
single-lever machine of the platform class, such machines are still very limited in
their application, while their reliability and sensitiveness leave much to be desired.
The object of this invention is to produce a single-lever platform-weighing-
machine of a more simple construction than such machines as at present con-
structed, and, at the same time, of more accurate weighing capabilities than have
hitherto been attained in this class of machine.
To this end the invention consists in the application of means of the nature
hereinafter described for so securing the platform relatively to the knife-edges of
the lever that any given weight of goods placed on the platform will cause the
same indication on the registering beam or steelyard, when adjusted by the usual
moving or loose weights, no matter on what part of the platform the goods are
placed.
On the accompanying drawings,
Fig. 1. represents a longitudinal sectional elevation of sufficient of a weighing
machine to illustrate the application of the improvements.
Fig. 2. represents a plan view with part of the platform and part of one of the
diaphragms hereinafter referred to removed, and
Fig. 3. represents a transverse sectional elevation, both sections being taken
through the centre of the machine.
In carrying out the invention, two horizontally disposed flexible diaphragms or
guide plates 4, 5, of sheet iron, steel or other material, are supported by ledges 6,

page_text: or otherwise in any suitable manner, within the usual box or frame 7. One of
these diaphragms is placed adjacent to the bottom of the box, and the other
thereof is placed adjacent to the top of the box. In each diaphragm is formed a
guiding hole 8, in or near the centre by preference, the centres of both such holes
being disposed in the same vertical plane as that wherein the steel knife-edge
centres 9, of the lever 10, (on which the platform or table 11, is supported) are
also disposed.
On the underside of the platform 11, is formed or attached a stem 12, preferably
of a squared or rectangular shape in cross section to prevent any movement of
rotation about its axis, and made of such a length as to extend through both of
the said holes 8, in the diaphragms, 4, 5, such holes being preferably made of a
shape corresponding with that of the stem 12. The platform is or may be also
provided with other depending supports 13, which pass freely through other holes
or apertures 14, in alignment therewith, made in the upper diaphragm 5, and rest
on the knife-edge centres 9, of the lever 10. Such lever, at the one end, is formed
with knife-edge centres 16, which are suitably supported as by standards or
ledges 21, and at the other end 17, is connected in a usual manner to the weight
indicating beam or steelyard.
The diaphragms are kept equidistant by a tubular spacing piece 18, surrounding
the stem 12, and the platform and stem are caused to move, in being depressed,
together with the diaphragms by a like tubular spacing piece 19, fitting between
the upper diaphragm and the platform.
The diaphragms are made of such a thinness and flexibility as to allow of the
most delicate movement and consequently of a most accurate weighing being
obtained.
The peripheries of the holes or apertures 8, are preferably thickened up by
attached steel rings 20, and act as buttresses to the stem in all directions, so that on
whatever part of the platform the goods are placed, the platform is effectually
prevented from tipping, thus avoiding the necessity of additional appliances as
ordinarily used to prevent such tipping.
The platform may be freely removed or replaced without disturbing any other
part of the machine.
The lower diaphragm may form the bottom of the box or frame, and the upper
one may act as a cover to the working centres and parts so as to protect them from
dust and dirt.
In lieu of entire diaphragms, any equivalent means may be used to guide the
stem on the platform, such, for example, as one or more flexible radiating arms
through or between which the said stem would be passed, the arrangement being
such as to ensure the stem being kept in such a position that the weight exerted on
and recorded through the instrumentality of the lever will be practically constant,
no matter on what part of the platform the goods should be placed.
In lieu of providing the platform with the depending supports 13, I may hang
a link on each of the centres 9, and connect such link by a cross bar supported
thereby and running below and being borne on by the lower end of the stem 12,
the weight being thus transferred to the lever 10, through the instrumentality of
the stem.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
The application to platform weighing machines of means of the nature herein-
before described for the purpose aforesaid.
10th day of October 1891.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.