Improved Draw-bar Mechanism for Vehicles.
Year: 1897

page_text: Date of Application, 9th Sept., 1897-Accepted, 9th Oct., 1897
.
COMPLETE SPECIFICATION.
Improved Draw-bar Mechanism for Vehicles.
I, HERMANN LEONHARDT of 43 Uhlandstrasse, Hamburg-Hohenfelde in the
German Empire Manufacturer, 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 present application relates to a spring drawbar for vehicles which has for its
object to render the work of the animals yoked to the vehicle less onerous. To
the main cross bar, 2 levers are pivotally fixed which levers stand under the
control of a powerful spiral spring, so that the draught animal experiences no
excessive strain upon the sudden change of the resistance or increase of the load
or upon endeavouring to put the standing vehicle into motion.
The apparatus is illustrated in the accompanying two sheets of drawing in
which
Figure 1 shows the same in plan.
Figure 2 is a view from behind.
Figures 3 and 4 show modifications of the same principle in two different
positions.
Upon the draw bar pin a attached to the front of the vehicle in the usual manner
are pivoted two double armed levers b c. The swingle-trees d d are attached
either to the forked ends of the longer arms of the said levers which arms are bent
forward in a suitable shape, (see Figure 1) or they may be secured to the hooks h h¹
(see Figures 3 and 4). In single harness vehicles the traces might also be hooked
directly upon these hooks. The ends of the short lever arms of the levers b c
are also bent forwards and turned in at the ends. The said ends are each secured
to one end of the powerful spiral spring Feither in the manner shown in Figure 1 or in
that shown in Figure 3. The said spring is, as may be seen from the drawing
placed transversely to the direction of the draught so that a one-sided pull is
immediately compensated and in the case of a suddenly increased resistance the
spring is gradually extended, whereby no jerk is caused and consequent injury of
the draught animal is prevented. For waggons which require a specially strong
spring the modification illustrated in Sheet 2 and in Figure 3 in the unloaded
and Figure 4 in the loaded condition is the best form as at present known. In
this case there are attached to the shorter arms of the levers b and c check
loops e and el secured to the ends of the spring, and surrounding the levers b and c.
These loops e e¹ serve on the one hand to limit the extension of the spring F and
on the other hand to prevent any shaking or bending of the levers bc in the
perpendicular direction.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
-
A spring drawbar mechanism consisting essentially of two double armed
levers be pivotally fixed upon the main pin a of the drawbar, said levers having
their arms bent forwards, the longer arms of which are connected to the swingle-

page_text: trees dd, whilst the inwardly turned ends of the shorter arms of the said levers
are connected to the ends of a powerful spiral spring F so placed that it is
extensible at right angles to the direction of the draught, and the longer lever
arms bc are embraced by the pieces e e¹ which, limit their movement and prevent
them from bending sideways, substantially as described.
Dated this Oth dow of Santambo 1907
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.