Improvements in the Manufacture of Calkins for Horse Shoes.
Year: 1894

page_text: Date of Application, 16th Nov., 1894-Accepted, 2nd Feb., 1895
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Calkins for Horse Shoes.
We, WILHELM DONNERSTAG, and GEORG LEISEGANG both of 6 Cosliner
Strasse Berlin, Germany, Gentlemen, 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 :-
The endeavours hitherto made and gradually perfected for providing horse shoes
with interchangeable parts or calkins have all had for their object to prevent such
parts or calkins from dropping off and also to enable horses to gain an easier an
safer foothold
Hitherto the object has not been fulfilled with the aid of screw tips, in fact no
means have yet been found for preventing in an absolutely safe manner the
loosening and dropping of tips, calkins, etc., whatever be the cause determining
such effect.
Under this invention, the peculiar motion of the feet, when the horse is walking,
is utilized to create new means for attaining in the best possible manner the object
sought after by all.
It is well known, as can be particularly observed by watching the hind feet of
horses, that, when pulling, they first bear upon the ground with their front calkins
and when they subsequently stand erect their rear hoofs turn to a great extent
towards the out sides, that is to say, the hoofs of the right as well as of the left
legs turn with their rear part upon the front calkins in an outward direction.
These observations have been utilized in the construction of the shoe tips or
calkins forming the subject of this invention, and the novelty of the contrivance
consists essentially in imparting a somewhat twisted triangular form to the bearing
surfaces of the tips or calkins. The projections or studs of the calkins are screw
threaded those for the right foot being left-handed and those for the left foot
right-handed. The studs fit into tapped holes in the shoes.
With this arrange-
ment, when the horse is moving forward, the studs of the calkins have a tendency
to become more and more firmly screwed into their tapped holes thereby obviating
any loosening effect.
The accompanying drawings show the method of practically carrying out my
improvements.
Fig. 1 is a side view of a horse shoe a provided with screwed rear tips or
calkins having a triangular pyramidal form and Fig. 2 is an underside view of
the shoe.
Fig. 3 is a diagram illustrating the action of the tips.
Figs. 4 and 4 which show the shape of the tips also show their studs 62
furnished respectively with a right hand and a left hand screw thread.
In Fig. 3 which illustrates the action of the shoe of the right foot, is the
turning point of the front tip or calkin and the arrow y indicates the direction of
the motion performed by one of the rear tips. In this motion, the lower triangular
surfaces 1 and 2 meet with a resistance on the ground which gives rise to a turning
movement in the directions indicated by the arrows p' and p2, while the frictional
resistance of the triangular surface 3 produces a turning movement in the opposite
direction p³. In each position of the edges, we have therefore p² + p² - p³ which
gives as a result a turning movement in the direction of the dotted arrow 2; as a
consequence, the stud b (which in the case in point is furnished with a left handed
thread) is screwed tighter into its corresponding tapped hole in the shoe.

page_text: The tips or calkins are preferably made of the hardest cast steel and could be
provided with three or more sides or surfaces. The calkins may be made inter-
changeable if so desired.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
consider novel aud desire to claim is :-
Calkins for horse shoes having tapered heads (6) the surfaces or edges of which
are twisted, the studs (62) of the calkins for the shoe of the right foot being cut
with a left handed screw thread and those of the calkins for the shoe of the left
foot being cut with a right handed screw thread, substantially as hereinbefore
described with reference to the drawings annexed and for the advantages set
forth.
Dated this 15th day of November 1894.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.