Improvements in Ball and Socket Joints.
Year: 1892

page_text: Date of Application, 1st Nov., 1892-Accepted, 1st Apr., 1893
COMPLETE SPECIFICATION.
Improvements in Ball and Socket Joints.
I WILLIAM HENRY MORRISON of Holmesburg, City of Philadelphia, and
State of Pennsylvania United States of America, Physician, 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 :-
My invention has relation to constructions of ball and socket joints, principally
for book supports, and consists in a casing or socket provided with adjustable
screw-threaded cap adjusted on the casing or socket by means of screw-threads, a
ball provided therein and shank secured to said ball or integral therewith protruding
through an orifice provided in the cap for the purpose large enough to allow of the
universal movement of the ball, a concave seat or cushion constructed as a seat for
the ball provided within the casing, said ball seat being preferably supported upon
a bed or cushion of soft rubber provided below said seat within said casing or
having an elastic base integral with the said seat, as hereinafter particularly
described.
The object of my invention is to provide an improved tension-regulated ball and
socket joint adapted principally in the construction of book supports so that the
book or support may, when the tension is properly regulated, be shifted to any
desired angle or position and retained in that position by a mere adjustment of the
table proper without manipulating any thumb-screw or any other adjustable device,
or even adjusting the tension device.
In the accompanying drawing similar letters of reference refer to similar parts.
Fig. 1 is a perspective view of a book support attached to a chair containing
my improved tension regulated ball and socket joint.
Fig. 2 is a sectional view of the parts detached.
Fig. 3 represents the parts of the preferred form of clamp detached for clamping
the book support to the chair.
Fig. 4 represents in detail the preferred form of adjustable stop for regulating
the height of the rest relatively to the seat of the chair.
A the casing or socket properly supported upon a sleeve, S, adapted to slide
and be secured upon the supporting arm, B', by the thumb-screw, s; the adjustable
cap or upper section, A¹, of the casing, A, is provided internally with screw-
threads, a', which are adapted to engage with the screw-threads, a, provided on
the exterior of the casing, A, the lugs or projections, U, are provided on the
exterior of the cap or section, A¹, for readily turning it and tightening or releasing
the tension when engaged on the casing, A; the ball, B, adjusted in the
casing, A, A', is provided rigidly with a shank, b, which protrudes through an
orifice, a², provided in the upper portion of the cap or section, A', of a diameter
sufficiently large to allow of a universal movement of the ball, B, the ball, B, is
seated in a concave seat, C, of hard compressible material, while the seat, C, is
supported within the casing, A, on an elastic cushion, E, preferably constructed of
soft rubber; a washer, e, is provided in the upper part of the cap or section, A¹,
above the ball, B, engaged in position by the upper portion of the cap, A', forming
a shoulder, the orifice in the washer, e, being preferably equal to or slightly
smaller than the orifice, a², of the cap, A'.
The shank, b, is secured to the table, F, of the book support, as through the
medium of the plate, p, and the lower end of the supporting arm, B', is secured to
the seat of the chair, D, by means of a clamp, d, or other suitable means.
When in position the cap or section, A¹, is turned down on to the screw-
threads, a, a¹ until the ball, B, binds between the compressible seat, C, and the

page_text: upper washer, e. If a heavy book is placed on the table, F, or if the same is to
be used for writing the tension is increased by screwing the cap section, A', upon
the casing, A, more tightly thus compressing the ball, B, upon the compressible
seat C, and indirectly upon the elastic cushion, E, binding the said ball, B, tightly
between said seat, C, and the washer, e. The friction between the outer surface of
the ball, B, and the surface of the compressible seat, C, and washer, e, increased
by the elasticity of the cushion, E, will retain the table, F, in any desired position,
though at the same time the table and book may be shifted by a simple movement
of the hand to any other possible position without changing the tension, when
once properly adjusted; the table or support is thus held firmly in that position
as the compressible seat, C, and the elastic cushion, E, will give as the table is
moved by the hand, but immediately when released will retain the ball frictionally
in any given position. The washer, e, is preferably employed so that it may move
with the ball, B, upon being shifted without moving the cap section, A', and thus
releasing the tension, as would occasionally occur where the ball is moved when
bearing directly against the upper shoulders of the sections, A'; though the
washer, e, may be eliminated.
I have described the compressible seat and elastic cushion to be in two parts,
this is not an absolute necessity as they may be composed of a single part if
desired. I have also described my invention as particularly applicable to book
supports but I do not limit myself to this use, as my invention may be applied to
other uses.
A preferred form of construction for clamping the arm, B', to the chair is that
shown in detail in Figs. 3 and 4; the main casting, d, is provided with projecting
lugs, d', d', to the lower one of which a thumb screw, t¹, is provided for securing
the device to the chair seat; the plate, ², is loosely screwed to the plate, d, at d³,
and a thumb screw t, is provided through the plate, d, at the other end and screwed
into the plate, d; the arm, B', passes through the orifices provided in the lugs, 1,
on the plate, d, and the semi-circular enlargement, ", provided upon the plate, d,
engages around the arm, B', and as the thumb screw, t, is tightened the arm, B', is
firmly clamped in the desired position. In order to allow the arm, B', to turn in
the clamp, d, as is sometimes desirable, without slipping down, I preferably provide
a stop consisting of the screw threaded conical parts, y, in two sections, these
sections are brought together around the arm, B', above the plate, d, and clamped
to the arm by means of the conically screw threaded nut, h, which when turned
upon the sectional parts g, will firmly bind them to the arın, B¹ and the base of the
parts, g, bearing upon the upper lug, l, will support the entire rest in any desired
position, and allow it to be turned around at will."
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A tension regulated ball and socket joint having the case or socket in two
parts adjusted one upon the other by means of screw-threads, a ball provided
therein having a rigid shank secured thereto protruding through the upper section
of the casing and a compressible seat provided in the lower section concaved to
receive the ball and compressible to hold the ball rigidly in position within the
casing when the tension is properly regulated substantially as described.
2. A ball and socket joint having the screw-threaded casing, sections, A, A', a
ball, B, provided therein, and rigid shank, b, attached thereto protruding through
an orifice, a², in the upper section, A', concaved ball seat provided within the
lower section for adjustably compressing the ball in the upper section substantially
as described.
3. In a tension regulated ball and socket joint the combination of a concaved
elastic seat provided in the casing constructed to yield under compression, and at
the same time to frictionally adhere to the surface of the ball provided in the
_concave to securely hold the ball in any given position and a washer loosely

page_text: provided upon the ball above its centre and within the casing substantially as
described.
4. A tension regulated ball and socket joint having the adjustable casing
section, A, A', adjustable upon each other through the medium of the screw
threads, a, a', and lugs, b', provided on the casing, A', for regulating the adjust-
ment, ball, B, having rigid shank, b, secured thereto provided within the casing
and elastic concave seat, C, supported upon the elastic cushion or bed, E, provided
in the casing, A, substantially as described.
5. A tension-regulated ball and socket joint having the adjustable sections, A, A',
adjusted upon each other through the medium of screw-threads, a ball provided
within said sections having rigid shank, b, protruding through an orifice, a³, com-
pressible concave seat, C, provided within the casing, A, rigid lugs, b, provided
on the casing, A', and washer, e, provided in the casing, A, above the ball, B,
substantially as described.
6. A tension-regulated ball and socket joint having the adjustable casing-
sections, A, A', adjustable upon each other through the medium of the screw-
threads, a, a', and lugs, b', provided on the casing, A', for regulating the adjustment,
ball, B, having rigid shank, b, provided within the casing and compressible concaved
Beat, C, supported upon an elastic cushion or bed provided in the casing, A, sub-
stantially as described.
7. A tension regulated ball and socket joint having the adjustable sections, A, A',
adjustable upon each other through the medium of the screw-threads, and the rigid
lugs, b, ball, B, having rigid shank, b, provided therein, said shank protruding
through orifice, a², provided in the upper section, A¹, compressible concaved seat, C,
and supporting elastic cushion, E, provided within the casing, A, and washer, e,
secured within the casing, A', above the ball, B, substantially as and for the
purposes set forth.
This 1st dow of November 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.