An Improved Hay Tedder.
Year: 1891

page_text: Date of Application, 21st July, 1891
Complete Specification Left, 10th Dec., 1891-Accepted, 16th Jan., 1892
PROVISIONAL SPECIFICATION.
An Improved Hay Tedder.
We, JOSEPH STENNER of Fore Street Tiverton, and ROBERT STENNER of
Barrington Street Tiverton, Engineers and Ironmongers, do hereby declare the
nature of this invention to be as follows:-
This invention relates to certain new and useful improvements in hay tedders
having for its object light draught, rigid construction and safety from breakage
when in action.
First; To accomplish this, we make each road-wheel to drive two motions, by
which we equalise and distribute better the strain on the frame, thus giving less
vibration and consequently less wear and tear of the machine, and with a simple
device working a clutch we arrange to throw the machine in and out of gear.
We adopt for this purpose a spring lever which is self acting when turning the
machine at the ends.
Our second and very important improvement is as follows. Hitherto tedders
when being used on rough and uneven bottoms or gutters have proved unsatis-
factory owing to the prongs or forks breaking when coming into contact with these
hard substances in the ground.
We therefore introduce a most important and novel joint with a self acting
spiral spring allowing the points of the forks or prongs to turn back to an angle
of ninety degrees. Thus instantly the fork has passed over any hard substance
which has forced it back, the said self acting spring throws the fork again into its
working position.
This is effected by attaching each prong to a pivotted plate of nearly triangular
shape. The pivot on which the plate turns occupies one angle of the plate, the
prong projects from another angle while the spring presses against a sliding pin
in a horizontal slot at the third angle. We thus obtain a kind of crank action
which works so that when the prong is forced back the spring is momentarily
compressed and the plate swinging back on the pivot brings the slot in which
the pin of the spring slides from the horizontal into the vertical position bringing
also the prong with it. As soon as the obstruction is passed the spring re-asserts
its power, gently at first, on account of the vertical position of the slot, and more
firmly as the slot re-assumes its horizontal position which gives more leverage to
the springs pressure.
The upper or reverse end of the spring is attached to a suitable bracket placed
above the prong. The strength of the spring is sufficient to withstand the weight
of the heaviest crops when the prong is at work, but it yields at once to the blow
from a hard substance.
In lieu of the sliding pin a fixed pin can be used when preferred, but we do not
think it will be so effective.
COMPLETE SPECIFICATION.
An Improved Hay Tedder.
We, JOSEPH STENNER of Fore Street Tiverton, and ROBERT STENNER of
45 Barrington Street, Tiverton, Engineers and Ironmongers, 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 :-
This invention is designed to obviate certain practical defects in hay tedders by

page_text: means of new and useful improvements having for object safety from breakage
without impairing the utility of the machine.
Hitherto hay tedders when being used on stony ground, or on rough and uneven
land or gutters, have often proved very unsatisfactory, owing to the prongs or
forks breaking when coming into violent contact with the ground or with hard
substances upon it.
We therefore construct our improved hay tedder with our novel automatic joint
between the forks and the crank shafts to which they are attached as shewn in
Figs. 1. 2. 3. 4 which joint being furnished with a selfacting spiral spring k, allows
the tines of the forks (which can be made separate and detachable or otherwise) to
turn back so as to become entirely free of any hard substance.
The action of this joint is such that instantly the fork has passed over any hard
substance or obstacle which has forced it back, the said self acting spring throws
the fork again into its working position.
Figures 1 and 2 are front and back elevations respectively of our automatic joint
attached to a fork and shaft.
Fig. 3 is a side elevation of the joint with the fork in working position.
Fig. 4 shews the same with the fork deflected backwards and the spring k,
compressed.
It will be seen that we attach cach prong of the fork to a pivotted plate p, of
nearly triangular shape. The pivot r, on which the plate turns, occupies one angle
of the plate.
The prong is bolted to and projects from another angle t, while the spring k,
presses against a pin v, which slides in two horizontal slots, one in each plate,
these slots being placed in the third angle of the triangular plate.
We thus obtain a kind of bell-crank action, which works so that when the
prong is forced back as shewn in Fig. 4, the spring k, is momentarily compressed,
and the plates, swinging back on the pivots r, bring the slots in which the spring
pins v, slide, from the nearly horizontal into the vertical position, and bring also.
the prongs 2, with them.
As soon as the obstacle is passed the spring re-asserts its power over the fork,
gently at first, on account of the vertical position of the slot, and more firmly as
the slot resumes its horizontal position, as the changing position of the slot affords
more leverage to the spring's pressure.
The upper end, of the spring is attached to a suitable bracket y, there being a 3
tubular guide rod w, to keep it in place.
The strength of the spring is sufficient to withstand the weight of the heaviest
crops when at work but it yields at once when coming in contact with a hard or
fixed substance such as a stone, root of a tree or gutter.
Our automatic joint is applicable to other agricultural implements having a 4
similar mode of working to hay tedders, and the precise arrangement of parts may
be varied without affecting the principle of the invention.
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 claim is :—
1. In a hay tedder or similar implement, the automatic spring-fork-joint, con-
sisting of a combination of the pivotted slotted plates p, the pivot r, spring k, guide
rod น, bracket y, and fitted with or without separate detachable tines, as herein
lescribed and set forth.
Dated this 10th d... T
45
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.