IMPROVEMENTS IN MUSIC STOOLS AND OTHER SEATS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office of the
Commissioners of Patents on the 9th August 1880. A communication from
abroad by Henry Jullien, of Marseilles, France.
WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex, Patent
Agent. "IMPROVEMENTS IN MUSIC STOOLS AND OTHER SEATS." [A communication
from abroad by Henry Jullien, of Marseilles, France.]
This Invention relates to improvements in music stools and other seats, and has
for its object to obtain perfect stability of the seat of the stool when raised to its
highest position, and thereby avoid the unsteadiness which is so objectionable in
stools provided with a single central elevating screw.
According to this Invention, three elevating screws are employed, disposed in an
equilateral triangle, so that the seat is always supported at three points, and may
be thus raised and lowered with great regularity; the seat always remains perfectly
firm and without any tendency to oscillate when raised.
In the accompanying Drawing Figure 1 shows in elevation a music stool
provided with three screws, the seat being in its lowered position. Figure 2 is an
elevation showing seat A partly raised; V, V, V, are the elevating screws; B is a
frame in which are mounted the nuts that work upon and raise the screws; G is
the lower stationary frame to which the legs P are fixed, and from the underside
of which a central sheath D depends. The dotted lines in the legs P and sheath D
represent cavities in which the screws and the square spindle T are received when
the seat is lowered. Figure 3 is an under side plan of the part B; E are three
nuts fitted to turn in sockets in frame B, and through which the three screws V, V, V,
pass respectively. These nuts have sprockets on their periphery, and an endless
chain m passes, as shown, around them and round a central sprocket pinion F,
through a square hole in which slides the spindle T which turns pinion F and
through chain m the nuts E. By the rotation of the pinion F and nuts E to the
right or left the screws passing through them are raised or lowered, as the case may
be. Figure 4 shows a vertical section of the elevating mechanism. The spindle T
is fixed at j to the seat A, which is hollowed on the underside to receive an
annular plate L which is fixed to the top ends of the screws V. This plate L is
hollowed at M to receive the central boss of the seat A, which rests and is free to
rotate upon L. The parts L and A are connected by a circular plate H on the

page_text: underside of L, screwed at h¹ to the seat A by screws h. When thus connected by
rotating seat A it turns spindle T, which turns pinion F, which, through chain m,
turns nuts E, whereby the screws V are raised or lowered and the part A raised
from or lowered on to part B. u is a cross pin to limit the range of upward motion
and prevent the nuts running off the threads of the screws.
For piano-stools the screws may be made of boxwood, which combines lightness
with a sufficient degree of strength. The central chain pinion is bushed with
iron where the iron spindle by which the seat is raised or lowered passes
through it.
It will be evident that the number of supporting screws may be greater than
that shown, but three are amply sufficient in the case of music stools.
The central chain pinion may also, in some cases, be replaced by a gear wheel,
which would be made to gear with the pinions of the nuts.