Improvements in Calks or Hobnails for the Shoes of Horses and other Animals, or for Boots and Shoes.
Year: 1893

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by GEORGES DE ROUSSY DE SALES, of
Sainte Ménehould (Marne), France, Lieutenant in the 7th Regiment of
Cuirassiers.]
Improvements in Calks or Hobnails for the Shoes of Horses and
other Animals, or for Boots and Shoes.
I, ERNEST DE PASS, of 78, Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being had to the
accompanying drawings and to the letters and figures marked thereon, that is
to say:
This invention relates to improved metal calks, or hobnails, adapted to be
sured to the under side of horses shoes, or to shoes of other animals, or to boots
and shoes for personal wear, to prevent slipping in frosty weather, or on ice, or on
other slippery surfaces.
The main or distinguishing features of these calks are, that they are so con-
structed as to present a very small bearing surface, and to retain sharp angles up
to their last degree of wear. They, therefore, at all times, firmly bite or grip the
surface of the road, and do not become less efficient as time proceeds. This result
has not been attained by any of the nails or calks hitherto employed, the great
inconvenience of which was that they became rapidly rounded off by wear and
thus soon lost the property of penetrating the ground.
And in order that this invention may be readily understood, I will describe the
same fully with reference to the accompanying drawings which represent some calks
and hobnails constructed in accordance therewith.
Figs. 1, 2, and 3 are, respectively, an elevation, a plan, and an underside view of
a calk, or hobnail, adapted for use in shoeing draught horses, or such as are
employed in heavy cavalry.
Figs. 4, 5, and 6 are similar views of a screw calk for lighter horses.
Figs. 7, 8, and 9 are, respectively, a front view, a side view, and an underside
view of a nail with a calk head for draught or heavy cavalry horses.
Figs. 10, 11 and 12 are similar views of a nail of the same description for horses
of better breed.
Figs. 13, 14, 15, and 16 represent some cross or star-shaped calks constructed in
accordance with this invention.
.
The calk proper, that is to say, the part which projects from the lower face of
the shoe, is constituted by a solid body of prismatic or slightly truncated pyramidal
shape, while at the base, and in cross section, it presents crossed or star-shaped
surfaces, having generally four branches or wings, as shown in Figs. 2, 5, 9, 12
and 13.
These sections, which are of special form, are given to the calk because they
offer the two following and most important advantages:-
(1.) The area of the star-shaped base of the prism is considerably less than that
of the geometrical figure (a square or circle) in which the star inscribed. Con-
sequently the pressure per unit of surface exerted by the calk upon the ground is
far greater than with calks whose base is that of a square, or a circle, of the same
dimensions as the square or circle circumscribed in the star-shaped figures
distinguishing the calks of this invention.
It follows that, given an equal number of calks of the same size, these improved

page_text: ones will be capable of cutting or gripping a much harder road surface than will
the ordinary calks, and will offer a second advantage, which is the following:
(2.) By way of example I will take the case of a prismatic calk having a square
base. In a very short time the angles and the sharp edges which it had, when new,
will become blunt or rounded, just as do those of dice through prolonged playing ;
that is to say they wear into facets with very obtuse angles, or tend to become
hemispherical, according to the more or less defective shape of the horse's legs, or
to the manner in which he walks. In each of these cases the rounded surfaces
thus formed slide upon the ice instead of cutting or gripping it, and fail to afford
the animal sufficient support to enable him to retain his balance. This incon-
venience is chiefly noticeable when the calks only touch the ground with their
blunt corners, as they will do, for example, when the horse makes a side movement,
or turns at a quick pace. Falls, due to this circumstance are entirely avoided by
these improved calks. The bearing surfaces of the wings are, indeed, sufficiently
narrow to always wear flatwise in straight lines, so that in spite of wear, the calk
either remains plane, or assumes a pointed shape if the wings do not wear equally
at all points. In either case, the calks preserve their sharp edges and corners,
and hence continue to bite or grip the ice, thereby protecting the horse from falls.
As shown in the drawings, these calks may be secured to horse shoes by various
means, the two most common being represented by way of example:
(a.) A screw shank 1 (Figs. 1 to 6) may be formed integral with the calk by
forging, moulding, stamping, or otherwise, and be screwed into a correspondingly
tapped hole in the shoe; in this case the screw calk is made entirely of
tempered steel, or other very hard metal, well capable of resisting wear and
crushing; or
(b.) Ordinary horse shoe nails with flat shanks 2, and heads, 3, in the shape of a
truncated quadrangular pyramid, fitting exactly the hole in the shoe, may be used.
At the end of the head the calk 4 is forged which is similar in shape to the screw
calks. In this case, the entire nail is made of very malleable Swedish iron, or
other suitable metal, capable of facilitating the shoeing operation. It will of
course be understood that the size and proportions of such nails, or calks, may and
should vary to a slight extent, according to the size of the horse to be rough shod,
and the nature of the work they are to perform. I therefore do not strictly limit
myself to the proportions and dimensions indicated in the drawings.
These improved calks, or hobnails, may likewise be made as screws, or as nails,
of star-shaped section, with any desired number of branches (three, five, or six
for instance as shown in Figs. 13 to 16), each branch or wing, taken individually,
having a shape somewhat similar to that shown, by way of example, in the
drawings.
These calks can likewise be secured to the shoes by rivetting, soldering, or by
any other convenient means, or they may be secured to the hoofs of the animal,
either directly, or by the intervention of a shoe, the means of attachment being, of
course, independent of the result to be obtained.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same may be performed, I declare that what
I claim is :-
The improved calks or hobnails for the shoes of horses and other animals, or for
boots and shoes for personal wear, having their heads formed like a cross or star
in cross section, and thereby enabling them to present a minimum bearing surface
while constantly retaining their sharp edges and angles to prevent slipping, sub-
stantially as herein described, said calks, or hobnails, being secured to the animals
hoof either directly, or by means of a shoe, or to boots and shoes, by screwing,
nailing, rivetting, soldering, or otherwise, as set forth.