IMPROVEMENTS IN THE MANUFACTURE OF SPRING BALANCES
Year: 1884

page_text: We THOMAS BACHE SALTER of the firm of George Salter and Company of
West Bromwich in the County of Stafford Manufacturers and JOHN HUGHES
of West Bromwich aforesaid Manger of Works to the said firm do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF SPRING BALANCES" to be as follows:―
Our Invention relates to spring balances in which a coiled steel spring is
suspended vertically at top to a fixed support and at bottom has a hook or scale
for carrying the article to be weighed.
The spring is protected by a sheet metal case and a pointer connected with the
lower end of the spring traverses a graduated plate on which it indicates the
weight of the article suspended to the balance.
In the ordinary method of manufacturing the case of the balance a piece of thin
sheet iron is stamped into a trough shape and the top to which the loop of the
suspending ring of the balance is connected is formed of a separate piece of metal
brazed in the open top of the trough shaped case. A slot is made in the said top
for the insertion of the loop. In manufacturing the case according to our Invention
we make the case by stamping but the blank we employ has at the end from
which the top of the case is formed three projections or ears which when turned
inwards form the top of the case in which top the slot required for the reception of
the loop is cut. The loop has a slot in which a plate of the shape of the top of the
case engages and the loop with the said plate engaged in it is passed into the slot
in the top of the case the plate engaged in the loop passing under the top of the
case. The loop and engaged plate are fixed in position by the brass graduated
plate of the balance. The loop at the bottom of the spring (which loop carries the
tongue having at its top the pointer) is made in a somewhat similar manner.
slight depression or notch is made on the inner edge of the loop and the cross piece
has small projections which when it has been put in its place in the loop are
pressed into the said depression or slot and the said cross piece is thereby fixed in
its place.
A
Instead of making the pointer separate from the tongue and attaching it thereto
by riveting and brazing we make the pointer of the same piece of metal as the

page_text: tongue.
We form the top of the tongue of the same shape as the pointer and bend
it at right angles to the other portion of the tongue.
By our improvements all brazing is dispensed with in the manufacture of the
loops and case of the balance and the riveting and brazing of the pointer to the
tongue is also dispensed with. Our improvements consequently effect great
economy in and simplify the manufacture of spring balances.
We THOMAS BACHE SALTER of the firm of George Salter and Company of West
Bromwich in the County of Stafford Manufacturers and JOHN HUGHES of West
Bromwich, aforesaid, Manager of Works to the said firm, do hereby declare the
nature of our Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SPRING
BALANCES" and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
Our Invention relates to spring balances in which a coiled steel spring is
suspended vertically at top to a fixed support and at bottom has a hook or scale
for carrying the article to be weighed.
The spring is protected by a sheet metal case and a pointer connected with the
lower end of the spring traverses a graduated plate on which it indicates the
weight of the article suspended to the balance.
In the ordinary method of manufacturing the case of the balance, a piece of
thin sheet iron is stamped into a trough shape and the top to which the loop of the
suspending ring of the balance is connected is formed of a separate piece of metal
brazed in the open top of the trough shaped case. A slot is made in the said top
for the insertion of the loop. In manufacturing the case according to our Invention
we make the case by stamping but the blank we employ has at the end from
which the top of the case is formed three projections or ears which when turned
inwards form the top of the case, in which top the slot required for the reception
of the loop is cut. The loop has a slot in which a plate of the shape of the top of
the case engages and the loop with the said plate engaged in it is passed into the
slot in the top of the case, the plate engaged in the loop passing under the top of
the case.
The loop and engaged plate are fixed in position by the brass graduated plate of
the balance. The loop at the bottom of the spring (which loop carries the tongue
having at its top the pointer) is made in a somewhat similar manner. A slight
depression or notch is made on the inner edge of the loop and the cross piece has
small projections which when it has been put in its place in the loop are pressed
into the said depression or slot and the said cross piece is thereby fixed in its place.
Instead of making the pointer separate from the tongue and attaching it thereto
by riveting and brazing we make the pointer of the same piece of metal as the

page_text: tongue. We form the top of the tongue of the same shape as the pointer and
bend it at right angles to the other. portion of the tongue.
Figure 1 of the accompanying Drawing represents in front elevation and
Figure 2 in side elevation a spring balance the parts herein before described of the
said balance being manufactured according to our Invention.
The same letters of reference indicate the same parts in the several Figures of
the Drawing.
a is the sheet metal trough shaped case of the balance; b is the top loop carrying
the suspending ring c and d is the bottom loop carrying the hook f to which the
article to be weighed is suspended. The bottom loop & has fixed to it the cross
piece or plate t by which the bottom of the case a is closed when the spring is in
its normal position and the said loop & has also fixed to it the tongue g which has
at its upper end the pointer / working in a slot in the brass graduated plate i of
tho balance.
In making the trough shaped case a of the balance we take a blank of the form
represented in Figure 3 the said blank having at its top end three projections or
ears k, l, k, a middle ear and two side ears k, l. By a shaping operation effected
in the ordinary way a trough form is given to the blank as represented in front
elevation, side elevation and end elevation in Figure 4. The cars or projections k,
l, k are next bent or turned inwards so as to form a closed top to the case a as
shown in end elevation in Figure 5, the closed middle projection being marked
and the closed side projections being marked k, k. A slot marked n in Figure 6 is
next cut by press tools in the closed top of the case for the reception of the top
loop b of the balance. Or the side ears or projections, kinay be made narrower
than those represented so that when they are closed inwards a slot similar to that
at n is left in the closed top of the case.
The top loop b is shown separately together with a strengthening plate in
Figure 7 and is shown fixed to the case a in Figures 8 and 9. The said top loop b
has a slot 62 in it for engaging with the uncut away portion of the top of the
case. We use with the said top loop for the purpose of strengthening the thin
sheet metal top of the case, a slotted plate p as seen in Figure 7. The slot in the
plate p can be engaged with the uncut away part of the top loop b so as to cross
the said loop b. After the slotted plate p has been engaged with the loop b the
loop and plate are passed into the slot n in the top of the case, the said plate p
passing under the top of the case as represented in section in Figure 8 and front
elevation in Figure 9. The loop b and engaged plate p are fixed in their places by
the brass graduated plate i (shown detached in Figure 10) which is secured to the
front of the trough shaped case a. To the bottom of the loop 6 the spring q of
the balance represented in Figure 11 is hooked the said spring being connected to
the bottom loop d.
The bottom loop d shown separately in Figure 12 has notches and 8 made in
its opposite edges and the slotted plate or cross piece t (which constitutes the
closing plate for the bottom of the case) is provided with small projectious u u.
After the slotted plate or cross piece t has been engaged with the back notch r in
the bottom loop d, the small projections u, u at the front of the plate t are
pressed into the front notch or depression 8 in the loop d and the said plate or
cross piece t is thereby fixed in its place. The tongue or slide 9 carrying
the pointer his rivetted to the end of the bottom loop d. The pointer / is made
in one piece with the tongue g. This is effected by giving the top of the tongue g
the same shape as the pointer as represented in Figure 14 and marked h³ and then
bending the shaped end hat right angles to the other portion of the tongue so as
to form the pointer has represented in back elevation in Figure 15 and side
elevation in Figure 16, the tongue g carrying the pointer being represented in
conjunction with the bottom loop d and its cross piece or closing plate t.
By our improvements all brazing is dispensed with in the manufacture of the
loops and case of the balance and the riveting and brazing of the pointer to the

page_text: tongue is also dispensed with. Our improvements consequently effect great
economy in and simplify the manufacture of spring balances.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is of improvements in the manufacture of spring balances of the kind
described and represented in the accompanying Drawing:
First. Closing the top of the trough shaped case of the balance by means of
projections or ears k, l, k made in one piece with the blank and leaving or cutting
a slot in the said closed top of the case for receiving the top loop substantially as
herein before described and illustrated in the accompanying Drawing.
Secondly. Strengthening the sheet metal top of the case by means of the slotted
plate p engaged with the top loop and also passed under the top of the case, the
top loop and its engaged plate being fixed in position by the graduated plate of
the balance substantially as herein before described and illustrated in the
accompanying Drawing.
Thirdly. Fixing the cross piece of the bottom loop (which cross piece constitutes
the bottom of the trough case when the spring is not elongated) by pressing small
projections on the front of the said cross piece into a depression or notch at the
front of the said bottom loop substantially as herein before described and
illustrated in the accompanying Drawing.
Fourthly. Making the pointer in one piece with the tongue of the balance as
herein before described and illustrated in the accompanying Drawing,
Dated this Sixth day of June 1884.
THOMAS BACHE SALTER.
JOHN HUGHES.