Improvements in the Construction of Base Castings and Spindles of Revoluble Chairs.
Year: 1896

page_text: Date of Application, 25th June, 1896
Complete Specification Left, 18th Mar., 1897-4ccepted, 24th Apr., 1897
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Base Castings and Spindles
of Revoluble Chairs.
I, PETER JENSEN of 77 Chancery Lane, in the County of Middlesex, Chartered
Patent Agent, do hereby declare the nature of this invention, which has been
communicated to me from abroad by The Gilson Manufacturing Company, of the
City of Port Washington, in the County of Ozaukee, and State of Wisconsin,
United States of America, to be as follows:-
This invention consists, primarily, in providing the chair-base casting which
receives the legs of the chair with a waved annular surface at one end thereof and
with a longitudinal smooth bore, and a longitudinal spline or feather projecting
into said bore, and combining therewith a longitudinally grooved screw-spindle, the
said groove receiving the said spline or feather, and a nut having a screw-threaded
bore in engagement with the screw-threads.on the spindle, and provided with a
waved annular surface in opposition to the similar surface on the casting, whereby,
when the parts are organized and put together in a chair, with the opposing wave-
surfaced ends of the nut and base-casting fitted together, the spindle will be
prevented from working down, incidental to the movement of a person occupying
the chair of which said spindle forms a part, by reason of the engagement between
the elevations on one of said waved surfaces with the depressions on the other, this
construction serving to lock the said nut against automatic rotation; secondly,
this invention consists in forming an annular flange on the described nut, and
providing suitable means for limiting the longitudinal play of the nut, such as an
opposing guard projecting from the adjacent face of said base-casting, which would
prevent the nut and spindle from being lifted up away from the base-casting; and
finally, in various details of construction, such as providing the described nut with
a hand-wheel to facilitate its rotation, so that, incidental to its rotation the spindle
will have a direct longitudinal adjustment because of the engagement of the
or feather and groove above specified.
Dated this 25th day of June 1896.
spline
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
Improvements in the Construction of Base Castings and Spindles
of Revoluble Chairs.
I, PETER JENSEN, of 77 Chancery Lane in the County of Middlesex, Chartered
Patent Agent, do hereby declare the nature of this invention, which has been
communicated to me from abroad by The Gilson Manufacturing Company, of the
City of Port Washington, in the County of Ozaukee, and State of Wisconsin,
United States of America, and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
This invention consists, primarily, in providing the chair-base casting which
[Price 8d.1

page_text: receives the legs of the chair with a waved annular surface at one end thereof and
with a longitudinal smooth bore, and a longitudinal spline or feather projecting
into said bore, and combining therewith a longitudinally grooved screw-spindle,
the said groove receiving the said spline or feather, and a nut having a screw-
threaded bore in engagement with the screw-threads on the spindle, and provided
with a waved annular surface in opposition to the similar surface on the casting,
whereby, when the parts are organized and put together in a chair, with the
opposing wave-surfaced ends of the nut and base-casting fitted together, the spindle
will be prevented from working down, incidental to the movement of a person
occupying the chair of which said spindle forms a part, by reason of the engage-
ment between the elevations on one of said waved surfaces with the depressions on
the other, this construction serving to lock the said nut against automatic rotation;
secondly, this invention consists in forming an annular flange on the described nut,
and providing suitable means for limiting the longitudinal play of the nut, such as
an opposing guard projecting from the adjacent face of said base-casting, which
would prevent the nut and spindle from being lifted up away from the base-casting;
and finally, in various details of construction, such as providing the described nut
with a hand-wheel to facilitate its rotation, so that, incidental to its rotation the
spindle will have a direct longitudinal adjustment because of the engagement of
the spline or feather and groove above specified, all as hereinafter more fully
described in connection with the accompanying drawings, and subsequently
claimed.
DESCRIPTION OF THE DRAWINGS :
Figure 1 represents a vertical transverse section of assembled parts in a chair-iron
embodying the present invention;
Figure 2, an elevation of the same.
Figures 3 and 4, horizontal sections respectively taken on lines 3-3 and 4-4,
of Figure 1, and
Figure 5, an elevation of a portion of a longitudinally-grooved screw-spindle that
constitutes a detail of one feature of the said invention.
Referring by letter to the drawings, A represents a chair-base casting having a
smooth bore provided with a spline 6 for engagement with a longitudinal groove c
in a screw-threaded spindle B, that has free play in said bore.
As herein shown, a nut C engages the spindle B above the base-casting A and
an annular flange d of the nut is opposed by a guard e, projecting from the adjacent
face of said base-casting. This guard acts to prevent the nut and spindle from
being lifted up away from the base-casting. Although the nut is shown above
the base-casting, it would be no departure from the invention to arrange it below
the same, and in such a case the guard would be correspondingly arranged to keep
said nut in working position.
As herein shown, the nut C may be provided with a hand-wheel D to facilitate
its rotation, and incidental to this rotation the spindle B will have a direct
longitudinal adjustment because of the engagement of the spline and groove above
specified.
To prevent the spindle working down, incidental to movement of a person
occupying the chair of which said spindle forms a part, the opposing ends of the
nut and base casting are waved, the elevations of one engaging the depressions of
the other to thereby lock said nut against automatic rotation, this being an important
feature of the structure thus far described.
In order to obtain the best results, it is necessary that the casting present a series
of waves arranged on a circle and that the nut present a like series and
arrangement of waves that interlock with those of said casting.
The spindle herein shown has its upper end provided with a socket for a pivot E,
that depends from the seat-iron F, and the chamber shown in communication
with the socket, may serve as a receptacle for pivot-lubricant.
4
As shown in the drawings and above specified, the opposing ends of the adjusting-

page_text: nut and base-casting are waved, the former of these parts being above the other,
but in case of reversal the waving would be preferably transferred to the nut-
flange d and guard e, this being a structural variation not involving any departure
from that feature of the invention that contemplates prevention of automatic
rotation on the part of the aforesaid nut.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what.
I claim is :-
1. A chair-base casting presenting a waved annular surface, a longitudinally-
grooved screw-spindle splined in the casting, and a nut on the spindle presenting a
waved annular surface in opposition to that of said casting.
2. A chair-base casting presenting a waved annular surface, a longitudinally-
grooved screw-spindle splined in the casting, a nut on the spindle presenting a
waved annular surface in opposition to that of said casting, and suitable means for
limiting longitudinal play of the nut.
3. A chair-base casting presenting a waved annular surface, a longitudinally-
grooved screw-spindle splined in the casting, a nut on the spindle presenting a
waved annular surface in opposition to that of said casting, a flange extending from
the nut, and a guard on said casting arranged to overlap the nut-flange.
Dated this 18th day of March 1907
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.