Year: 1888

page_text: I, ALEXANDER MARTINIUS GJESTVANG of No. 9 Övre Slotsgade Christiania Merchant
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:
The object of this invention is to provide a spring for use in chairs and other
upholstered seat furniture, of a strong and yet light and elastic construction with the
special purpose in view of giving the spring such a form, that it may easily be placed
and secured to the seat.
To this end the spring or springs are given such a shape and are put together in
such manner, that a single bolt may hold the spring in position, when a chair seat is
in question and when a seat of an oblong form is in question a small number of bolts
will suffice.
The invention consists in a spring of wire, which diverging from a centre or a
central line in a lesser or greater number of radiating branches is gradually bent
upwards having its smallest radius at a point lying near the frame of the seat and
from this point converging to the middle of the seat, its curvature of this latter part
in the side elevation being one, that will give the seat a neat, rounded form.
From this it will be understood, that the improved furniture spring constructed
according to the principles of this invention, will consist of several sections or pieces
of wire springs, whose form substantially is that of a parabolic or half-elliptic curve,
connected at the lower end and there adapted to be secured in a centrepiece, making
one spring.
In annexed drawing figures 1 to 8 shew in side view the single sections of the
spring from its simplest form of a half-ellipse and to the more complicated forms,
which latter arise by forming one or a number of convolutions in different places of
the curve, for increasing the elasticity and strength of the spring. In the drawing
are shown only single convolutions but they may of course be made double or
manifold. The lower extremity of the spring sections may be made horizontal or
may be bent down, which latter is preferable.
The sections may be made each of a separate single wire, or which is to be
preferred; two sections may be united and formed from one wire; instances of this

page_text: are shown in figures 9 to 11. In figures 10 and 11 two adjoining sections are con-
nected, in figure 10 at the top, in figure 11 at the bottom; in figure 9 two
diametrically placed sections are united at the upper end; this also may of course be
reversed.
When the spring is formed according to figures 10 and 11, the whole spring, that is
to say, all sections may be made from a single wire, the sections alternately being
united at the top and alternately at the lower end.
The sections, whether made single or double or all from one wire and whether bent
one way or the other or whether made with or without convolutions are held together
at their lower end by means of a centre piece, or retaining piece. This centrepiece
consists simply in a bolt preferably with a round head and a washer between which
and the bolthead the spring bent horizontally or nearly so--ends are held; if the spring
ends are bent downward the boltheadh is made tapered and the washer is substituted
by a ring with a tapered bore Figure 12. The bolt which holds the sections together
in the centrepiece, serves at the same time to secure the spring to the chair or the
other kind of seat to which the spring is used; some kind of brace being arranged to
cross the legs or in the frame of the said piece of furniture.
Figures 13 and 14 shew plans of springs constructed according to the above
principles, figure 13 showing a spring composed of sections formed as in figure 4 and
figure 10. Figure 14 one formed according to figures 4 and 9. This latter figure
also shows how the wires at their upper part, may be provided with horizontal bends
for purpose of better covering the surface of the seat.
The upper ends or bends of the spring may also be held together, preferably by
means of a cord tying them together.
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 -
A furniture spring composed of sections of wire springs diverging from a common
centre or central line, being substantially the centre or central line of the furniture
seat, to which the spring is applied, and gradually bent upwards, in a substantially
half-elliptic or parabolic form in elevation, each section terminating at a point right
above or substantially right above the issue or being at such point united to each
other, two and two sections or more thereby being made from one wire, said springs
being provided with or not provided with a lesser or greater number of convolutions,
and said springs being held at their lower ends in a common centrepiece adapted to
be secured to the furniture by a singlo bolt or for the case, an oblong seat is in
question, a small number of bolts, substantially as described and shewn.
1121 LSM.... 1000
ALEXANDER MARTINIUS GJESTVANG.
By Jensen & Son,
77, Chancery Lane, London, W.C.,
Patent Agents.