Improvements in Crutches.
Year: 1894

page_text: Date of Application, 20th Jan., 1894
Compl-te Specification Left, 20th Oct., 1894-Accepted, 24th Nov., 1894
PROVISIONAL DI MULTICATION.
Improvements in Crutches.
1, GEORGE BAILLIE MAIN, of Springvale Mills, Cowlairs, Glasgow, North
Britain, Oil Manufacturer and Refiner do hereby declare the nature of this invention
to be as follows :--
This invention relates to improvements in crutches, and has a threefold object;
the first being to remove from under the arm the friction presently existing and
caused by the forward and backward movement of the crutch when in use; the
second to so construct the cushion as to allow a continual circulation of air between
it and the arm whereby greater ease and comfort is secured to the user; and the
third to prevent slipping and concussion with the ground.
Hitherto the head or crosspiece of crutches have been made in one piece, that
is to say without separate movement or mechanism, so that when the crutch is
moved forward or backward as in actual use friction takes place under the arm
between the head or cushion of the crutch on the one part and the arm on the
other part, and so long as the crutch is being used this friction exists.
In carrying out my invention I cause the point of frictional contact to be
removed from the body or arm by making the head or crosspiece of the crutch in
two movable parts, which allows the cushion or arm-rest to remain stationary during
the forward and backward movement of the crutch, and thereby transferring the
friction from between the arm and the cushion to the lower point of contact
between the two parts of the head or crosspiece. The under portion of the head
or crosspiece is in the form of a section of a circle or curve, and fits into a
corresponding groove on the top or upper portion of the head of the crutch. This
curve allows the crutch the natural travelling movement required.
There are many ways or forms of adjustment for carrying out my invention,
and I do not confine myself to any, but the simplest methods, at least so far as I
at present am aware are the following. The under or fixed portion of the head
or crosspiece can be advantageously made of any suitable metal of a smooth surface
and with an elongated slot for the guiding pins to travel in, these pius being
screwed or fitted into the upper or arm-rest, and having heads larger than the
diameter of the slot to keep the working parts together, and prevent the pins from
coming through the slot, and also to act as guides in the movement.
The circle or
curve is regulated if necessary according to the length of the crutch.
Another way of uniting the two sections or portions of the head or crosspiece
of the crutch is by having inverted sides of the one part working in a similar
groove in the other.
To cause ventilation, the cushion for top of crutch which may be made on the
pneumatic principle, or of hollow rubber, or solid tube, or flat web rubber cloth
padded or similar material is provided with a corrugated surface, or raised or
indented straight or waved lines, or other form, thus preventing the whole surface
of the cushion coming in contact with the arm of the wearer, and so allowing a
continuous circulation of air between the cushion and the arm.
To prevent slipping and concussion of the crutch, I provide the lower end, that
is to say, the part which comes in contact with the ground, with a knob of india
rubber, or other suitable material the lower part of which is hollow or solid of

page_text: cup-shape form, so that it can slip over the end of the clutch, or the knob may be
a solid or hollow piece glued or otherwise fixed thereto.
Dated this 19th day of January 1894.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.
Improvements in Crutches.
I, GEORGE BAILLIE MAIN, of Orleans, Pollokshields, in the County of Lanark,.
North Britain, Oil Manufacturer and Refiner 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 relates to improvements in crutches and has a two-fold object;
the first being to remove from under the arm the friction presently existing and
caused by the forward and backward movement of the crutch when in use, and the
second to so construct the cushion as to allow a continual circulation of air between
it and the arm, whereby greater ease and comfort is secured to the user.
In carrying out my invention I cause the point of frictional contact to be removed
from the body or arm by making the head or crosspiece of the crutch in two parts-
one part being stationary and the other part slidable on the stationary part,-which
allows the cushion or arm rest to remain stationary during the forward and
backward movement of the crutch and thereby transferring the friction from
between the arm and the cushion to the lower point of contact between the two
parts of the head or crosspiece.
There are many ways or forms of slidable adjustment for carrying out my
invention, and I do not confine myself to any; but the simplest methods at least
so far as I at present am aware of-are the following, reference being made to the
accompanying sheet of drawings, of which-
Figure 1 represents in side elevation a head or crosspiece of a crutch made in
accordance with my invention.
Figure 2 is a transverse section of the same.
Figure 3 is a similar view to Figure 1 illustrating a somewhat modified form of
slidable piece provided with slotted sides in order to ensure lightness in the lower
or slidable portion of the head or crosspiece.
Figure 4 is a transverse section of the same.
Figure 5 illustrates a further modification both in giving motion to the crutch
and providing a pneumatic cushion, as will be hereinafter more fully referred
to; and
Figure 6 is a transverse section of the same.
Figure 7 gives a general view of a crutch showing my improvements applied
thereto.
The upper or stationary portion of the head is marked A, and the lower or
slidable portion B. The lower edge of the said stationary piece A forms a sector
of a circle, and in cross section (reference being had to Figure 2) constitutes a
dovetail projection a. This dovetail projection a works in the dovetail recess of
the lower slidable portion B of the crutch, which is also made a sector of a circle
and concentric with that of the upper portion A. Stops A' are formed to limit
the movement of the slidable portion B. The slidable portion B is provided with
two sockets C for connecting the bead or crosspiece to the crutch. In Figure 3 the
slidable portion B has slots formed in the sides of the dovetail recess so as to
minimise its weight. The part of the head or crosspiece which comes in contact
with the armpit is covered over with a covering of hollow rubber, solid tube, flat
web rubber cloth padded, or other resilient material to form a pad or cushion c.

page_text: This pad or cushion c is provided with a corrugated surface, or raised or indented,
straight or waved lines, or other form, thus preventing the whole surface of the
cushion coming in contact with the arm of the user and so allowing a continuous
circulation of air between the cushion and armpit.
In Figure 5 the dovetail arrangement is reversed; the dovetail recess or groove b
is formed in the portion A, and the dovetail projection a in the lower portion B.
In this form of head or crosspiece a pneumatic pad is provided consisting of a
tube d fitted into the hollowed portion e of the portion A. This tube d may either
be filled with compressed air or air at the atmospheric pressure. A covering of
rubber similar to that described with reference to Figures 3 and 4 is placed over
the tube.
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 crutch comprising a head having a stationary upper part and a laterally
slidable lower part, substantially as and for the purposes hereinbefore described
and shown on the accompanying sheet of drawings.
2. A crutch comprising a head, having a stationary upper part and a laterally
slidable lower part connected together by a longitudinal tongue and groove joint,
substantially as described.
3. A crutch comprising a head having a stationary upper part and a laterally
slidable lower part and stops located on the upper part for limiting the movement
of the lower part upon the upper part, substantially as described.
4. A crutch comprising a head having a corrugated surface of rubber or analogous
material for permitting the circulation of the air thereabove substantially as
described.
Dated this 19th day of October 1894.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.