IMPROVEMENTS IN WEIGHING MACHINES
Year: 1867

page_text: LETTERS PATENT to John Silvester, of the Firm of George Salter and
Company, of West Bromwich, in the County of Stafford, Manufacturers,
for the Invention of "IMPROVEMENTS IN WEIGHING MACHINES."
Sealed the 31st May 1867, and dated the 11th January 1867.
PROVISIONAL SPECIFICATION left by the said John Silvester at the
Office of the Commissioners of Patents, with his Petition, on the
11th January 1867.
I, JOHN SILVESTER, of the Firm of George Salter and Company, of West
Bromwich, in the County of Stafford, Manufacturers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN WEIGHING MACHINES," to be
as follows:-
My Invention consists of the arrangement or combination of the parts of
spring weighing machine, herein-after described, whereby the machine is made
very compact and portable.
A weighing machine constructed according to my Invention consists
essentially of the following parts -A nearly rectangular frame capable of a
vertical motion carries at its top a rod on which is the platform or scale pan
for receiving the article to be weighed; at the bottom of the said frame is
a rod similar to that at its top; the said frame and lower rod are concealed
in the case of the machine; the said frame is suspended in the case by two
coiled springs, to the lower ends of which the frame is attached; the upper

page_text: ends of the springs are connected to a fixed cross bar in the case of the machine.
The article to be weighed on being placed on the platform or scale pan
depresses the frame and elongates the springs to an extent greater or less
according to the weight of the article. The distance to which the frame is
depressed and consequently the weight of the article is indicated on a vertical
graduated plate in front of the machine by means of an index finger which
traverses the said graduated plate. The axis of the said index finger carries
pinion with which a rack carried by the frame engages. The frame is
guided in its motion by means of four nearly horizontal guide rods. Two of
the said guide rods are situated in a vertical plane parallel to the dial plate
of the machine, and the other two in a vertical plane at right angles to the
dial plate of the machine. Two of the guide bars are jointed at one end to the
top rod and the other two are jointed at one end to the bottom of the lower
rod. The other ends of the guide bars are jointed to the case of the machine.
The case of the machine is supported on a foot.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Silvester in the Great Seal Patent Office on the 5th
July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
SILVESTER, of the Firm of George Salter and Company, of West Bromwich,
in the County of Stafford, Manufacturers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eleventh day of January, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Silvester, Her special licence that I, the said John Silvester,
my executors, administrators, and assigns, or such others as I, the said
John Silvester, 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, use,
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 WEIGHING MACHINES," upon the condition (amongst others) that I,
the said John Silvester, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what

page_text: manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calenilar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Silvester, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
My Invention consists of the arrangement or combination of the parts of a
spring weighing machine, herein-after described, whereby the machine is made
very compact and portable.
A weighing machine constructed according to my Invention consists
essentially of the following parts:-A nearly rectangular frame capable of a
vertical motion carries at its top a rod, on which is the platform or scale pan
for receiving the article to be weighed. At the bottom of the said frame is a
rod similar to that at its top; the said frame and lower rod are concealed in the
case of the machine; the said frame is suspended in the case by two coiled
springs, to the lower ends of which the frame is attached. The upper ends of
the springs are connected to a fixed cross bar in the case of the machine.
The article to be weighed on being placed on the platform or scale pan
depresses the frame and elongates the springs to an extent greater or less
according to the weight of the article. The distance to which the frame is
depressed, and consequently the weight of the article, is indicated on a vertical
graduated plate in front of the machine by means of an index finger which
traverses the said graduated plate. The axis of the said index finger carries
a pinion with which a rack carried by the frame engages. The frame is
guided in its motion by means of four horizontal guide rods; two of the said
guide rods are situated in a vertical plane parallel to the dial plate of the
machine, and the other two in a vertical plane at right angles to the dial plate
of the machine. Two of the guide bars are jointed at one end to the top rod,
and the other two are jointed at one end to the bottom of the lower rod. The
other ends of the guide bars are jointed to the case of the machine. The case
of the machine is supported on a foot.
Having explained the nature of my Invention I will proceed to describe,
with reference to the accompanying Drawing, the manner in which the same
is to be performed.
Figure 1 represents in front elevation, Figure 2 in side elevation, Figure 3
in front elevation (with the dial plate removed), and Figure 4 in transverse
vertical section, a spring weighing machine constructed according to my
Invention.

page_text: The same letters of reference indicate the same parts in each Figure of the
Drawing.
a is the case of the weighing machine provided with a foot b; in the said
case a is a nearly rectangular frame c, c, capable of a vertical motion in the
said case; the said frame c, c, carries at its top a rod d on which is a
platform e, upon which platform a scale panf (see Figures 1 and 2) may be
placed for receiving the article to be weighed. To the bottom of the frame c, c,
is a similar rod g; the frame c, c, is suspended in the case a by two coiled
springs h, h, the lower ends of which are attached to the said frame, and their
upper ends to the fixed projections i, i, (or a cross bar) on the case a (see
Figures 3 and 4). The frame c, c, is guided in its vertical motion in the
case a by means of the four nearly horizontal guide rods k, l, m, n. The
guide rods k, l, are jointed at one end to the case a of the machine, and at
the other end to the bottom of the rod d and top of the frame c, c, respectively,
and the guide rods m, n, are jointed at one end to the case a, and at the other
end to the bottom rod 9 of the frame c, c. The guide rods l, m, are situated
in a vertical plane parallel with the dial plate p of the weighing machine, and
the guide rods k, n, are situated in a vertical plane at right angles to the said
dial plate p. The guide rod k is forked, the forked end embracing the rod d.
The positions of the said guide rods k, l, m, and n, and the manner in which
they are jointed to the rods d, g, frame c, c, and to the case a of the machine
will be readily seen by an examination of Figures 3 and 4 of the Drawing.
The guide rods k, n, work in recesses a³, a², at the back of the case a. The
article to be weighed on being placed in the scale pan ƒ (or on the platform e)
depresses the frame c, c, and elongates the springs h, h, to an extent dependant
upon the weight of the article in the scale pan or on the platform. The
distance to which the frame c, c, is depressed, and consequently the weight of
the article, is indicated in the following manner :-Within the frame c, c, is a
rack 9 jointed to the said frame at ; gearing. with the rack q is a pinion »,
the axis of which pinion works at one end in the case of the machine, and at
the other end in a cross plates (represented broken off in Figure 3) at the
front of the machine. The outer projecting end of the axis of the pinion »
carries an index finger or pointer t which traverses the vertical graduated dial
plate p. On the depressing of the frame c, c, by the weight of the article in
the scale pan for on the platform e, its motion is transmitted through the said
rack and pinion q, r, to the pointer t, which pointer traverses the graduated
dial plate p, and after a few oscillations comes to rest and indicates on the dial
plate the weight of the article in the scale pan or on the platform. The teeth
of the rack q are maintained in gear with the teeth of the pinion by the

page_text: small coiled spring u (see Figure 3). The upward motion of the frame c, c,
is limited by the stop v.
Having now described the nature of my Invention, and the manner in
which the same is to be performed, I wish it to be understood that I do not
limit myself to the precise details herein described and illustrated, as the same
may be varied without departing from the nature of my Invention; but I
claim as my Invention the improvements in weighing machines herein-before
described and illustrated in the accompanying Drawing, that is to say,
arranging or combining the parts of spring weighing machines, substantially
in the manner described and illustrated, whereby the said machines are made
very compact and portable.
In witness whereof, I, the said John Silvester, have hereunto set my
band and seal, this Fourth day of July, in the year of our Lord One
thousand eight hundred and sixty-seven.
Witness,
THOMAS BACHE,
West Bromwich.
JOHN SILVESTER. (L.S.)