Device for Adjusting and Fixing the Length of a Connection between Two Pieces.
Year: 1895

page_text: Date of Application, 30th Nov., 1895
Complete Specification Left, 28th Aug., 1896-Accepted, 24th Oct.,
1896
Device for Adjusting and Fixing the Length of a Connection
between Two Pieces.
We, ARCHIBALD BARR, Professor of Engineering in the University of Glasgow,
North Britain, and WILLIAM STROUD, Professor of Physics, The Yorkshire
College, Leeds, England, do hereby declare the nature of this invention to be as
follows:-
The object of our invention is to provide improved means for adjusting and
fixing the length of a connection between two pieces, as for example, for adjusting
the height of a stand or the length of an arm supporting any object.
We accomplish the desired end by constructing the support, arm, or other part
to be adjustible in length of two or more pieces, one at least of which is tubular,
so that another may slide inside of it. The tubular piece and the other piece
which slides inside of it are made slightly elliptical in section, or of other form
deviating somewhat from circular. The relative dimensions of these pieces are
such that when their sections are turned in a direction of conformity as for example
when the major axes of the ellipses are coincident the one part slides more or less
freely inside the other; but when the one is turned somewhat relatively to the
other the parts become jammed, and such sliding is prevented.
When relative turning of the two ends is not objectionable one pair of such
pieces is sufficient. When we desire to keep the ends fixed as regards relative
rotation we use three pieces, one of which turns relatively to the others, and is
either controlled longitudinally on one of the other pieces and jams the third on
being partially rotated relatively to it, or it may slide relatively to both the
others and be constructed to jam both.
We may construct the apparatus in other modified ways, retaining the essential
feature of longitudinal fixing by means of jamming produced by the relative
rotation of two pieces one of which surrounds or embraces the other, and which
pieces are constructed of other than circular section.. Thus, for example, we
may construct an adjustable rod or stand of two tubes, or of a tube and a rod
of circular, square, or any other section, one sliding inside the other, and provide
upon the outer one a collar having an elliptical or other form deviating from the
circular, which collar is encircled or embraced by another piece which upon
rotation relatively to the collar produces jamming of the outer piece upon the
inner. The outer piece where encircled by the collar, and the collar itself may,
when necessary, be slotted to give greater freedom of change of form. In some
cases the jamming may be produced by alteration of form of the inner piece by
means of a plug of other than circular form rotated inside it in contact with a
section of such inner piece, also of other than circular form.
Dated this
day of November 1895
BOTTOMLEY & LIDDLE,
154 St. Vincent Street, Glasgow, Applicants' Agents.

page_text: Device for Adjusting and Fixing the Length of a Connection
between Two Pieces.
We, ARCHIBALD BARR, Professor of Engineering in the University of Glasgow,
North Britain, and WILLIAM STROUD, Professor of Physics, The Yorkshire
College, Leeds, England, 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 our invention is to provide improved means for adjusting and fixing
the length of a connection between two pieces, as for example for adjusting the
height of a stand or the length of an arm supporting any object.
We accomplish the desired end by constructing the support, arm, or other part
to be adjustable in length of two or more pieces, one at least of which is tubular,
so that another may slide inside of it. The tubular piece and the other piece'
which slides inside of it are made slightly elliptical in section or of other form
deviating somewhat from circular. The relative dimensions of these pieces are
such that when their sections are turned in a direction of conformity as for example
when the major axes of the ellipses are coincident the one part slides more or less
freely inside the other; but when the one is turned somewhat relatively to the
other the parts become jammed and such sliding is prevented.
When relative turning of the two ends is not objectionable one pair of such
pieces is sufficient. When we desire to keep the ends fixed as regards relative
rotation we use three pieces, one of which turns relatively to the others and is
either controlled longitudinally on one of the other pieces and jams the third on
being partially rotated relatively to it or it may slide relatively to both the others
and be constructed to jam both.
We may construct the apparatus in other modified ways, retaining the essential
feature of longitudinal fixing by means of jamming produced by the relative
rotation of two pieces one of which surrounds or embraces the other, and which
pieces are constructed of other than circular section.
Thus for example, we may construct an adjustable rod or stand of two tubes, or
of a tube and a rod of circular square or any other section, one sliding inside the
other, and provide upon the outer one a collar having an elliptical or other form
deviating from the circular, which collar is encircled or embraced by another piece
which upon rotation relatively to the collar produces jamming of the outer piece
upon the inner. The outer piece where encircled by the collar, and the collar
itself may, when necessary be slotted to give greater freedom of change of form.
In some cases the jamming may be produced by alteration of form of the inner
piece by means of a plug of other than circular form rotated inside it in contact
with a section of such inner piece also of other than circular form.
In order that the nature of our invention and the manner in which the same
may be carried into effect may be more clearly and fully understood we will now
describe it with reference to the accompanying drawings and to the letters and
marks thereon.
In the various figures the same letters are used to indicate the same or like parts
where they occur. The figures show the invention applied to stands for chemical,
physical and other apparatus but the invention may obviously be applied to other
apparatus and appliances such as book and music rests in which the height is
wanted to be adjustable and it is also applicable to the adjustment of the length of
an arm projecting horizontally or at any angle as well as to vertical pieces.
There are several modified ways of carrying this invention into effect retaining
the essential features claimed.

page_text: Figures 1 and 2 show the application of the invention to a stand in which
relative rotation of the two portions forming it is not objectionable.
A is a tube of elliptical or other section deviating somewhat from a circular
form, attached to a base C. A tube B of similar section and carrying a top D for
supporting apparatus slides inside or outside the first tube A when the two sections
are in conformity (that is when the major axes are coincident) bat when the tubes.
are turned relatively to one another jamming takes place and further sliding is
prevented.
The tubes may be slotted to allow freer change of form when desirable.
Figures 3 and 4 show another mode of carrying the invention into effect and
may be adopted especially when relative rotation of the top and base is.
objectionable.
As in Figures 1 and 2 the stand consists of two tubes A and B one sliding
within the other, but in this case the tubes may have square sections, or such other
sections as will prevent relative rotation. The free end of the fixed tube has
blocks of metal E, E, E, E, fixed to it. The outer surfaces of these blocks are
curved eccentrically and the blocks are, encircled by a ring F which has corre-
sponding curves on its inner surface. As the ring is rotated the sides of the outer
tube are pressed tightly against the inner jamming being thus produced and
sliding prevented. The special form of surfaces shown is not the only one by
which the result may be attained. Thus the inner surface of the ring may be
made elliptical and the blocks formed accordingly so that rotation of the ring
would produce jamming as before.
The tube or tubes where the blocks are fixed may be slotted to allow freer
change of shape if necessary.
In some cases (Figures 5 and 6) the jamming may be produced by alteration of
form of an inner piece by means of a plug G of other than circular form rotated
inside it in contact with a section of such inner piece also of other than circular
section. The plug G is connected to a rod g provided with a small handle K by
means of which it can be rotated inside the inner piece.
It is to be noted that it is in the nature of our invention that longitudinal motion
of one part relatively to another is not necessary for the production of jamming..
We do not claim any arrangement of screw motion between auy of the parts. The
part H shown in the drawing is merely intended to indicate a ring or other part
for the support of chemical or other apparatus so as to indicate one application
of the invention.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The arrangement of parts constituting a support or arm adjustable in length and
constructed of two tubes or of one tube and a rod having on the outside of the
outer part or on the inside of the inner part a piece or pieces of other than circular
form together with a ring or block capable of rotation relatively thereto so
arranged that for one relative position of the parts longitudinal sliding is freely
possible while when the ring or block is rotated slightly from that position jamming
is produced and free sliding prevented.
Dated this 27th dow of Avant 1906
BOTTOMLEY & LIDDLE,
154 St. Vincent Street, Glasgow, Applicants' Agents..