An Improved Grapple Fork for Elevating and Discharging or Unloading and Reloading in Bulk, Hay, Straw, or the like Materials, including Ensilage and Manure.
Year: 1893

page_text: Date of Application, 25th July, 1893
Complete Specification Left, 25th Apr., 1894-Accepted, 2nd June, 1894
PROVISIONAL SPECIFICATION.
An Improved Grapple Fork for Elevating and Discharging or
Unloading and Reloading in Bulk, Hay, Straw, or the like
Materials, including Ensilage and Manure.
[, JOHN ROBERT ROBINSON of Acklam, in the County of York, Farmer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to grapple forks which are slung from the hoisting chain of
a derrick crane or other lifting apparatus to be used in substitution for hand forks
for elevating and discharging or unloading and reloading in bulk, such materials as
hay and straw, including ensilage and manure if sufficiently fibrous in their
composition to hold together between the prongs of a fork.
My invention is more especially intended to provide grapple forks, that is forks
which consist of two levers pivotted to one fulcrum with releasing mechanism of a
more simple and reliable character than has hitherto been in use so that when a
bundle of straw or other material is to be discharged therefrom the forks can be
readily pulled apart in the manner required.
In carrying my invention into effect I furnish each arm of the fork with an upper
and lower pulley placed at suitable positions above and below the fulcrum so that
releasing tackle secured to the upper part of each arm is led down under the lower
pulley of the other arm and up over the upper pulley of the arm to which it is
secured. The ends of the releasing tackle cords are then connected to one delivery
or tip cord, a pull from which opens out both arms of the fork simultaneously and
in the manner required to discharge the contents thereof. The derrick or lifting
chain is secured to both arms of the fork in the usual manner so that the arms of
the fork are closed together to take their hold of the material to be lifted by the
same pull of the lifting chain by which the material so grappled is lifted up.
The forks are varied in their prongs to suit the special purpose for which they
are intended, as for instance two pronged arms would be suitable for long fibred
materials such as straw and hay and four prongs would be required for shorter
fibred material such as ensilage and ordinary manure whereas fourteen prongs to
each arm would not be too many for very short fibred manure.
Dated this 21th dow of Lu.1., 1902
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.
COMPLETE SPECIFICATION.
An Improved Grapple Fork for Elevating and Discharging or
Unloading and Reloading in Bulk, Hay, Straw, or the like
Materials, including Ensilage and Manure.
I, JOHN ROBERT ROBINSON, of Acklam, in the County of York, Farmer, 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 grapple forks which are slung from the hoisting chain or
rope of a derrick crane or other lifting apparatus to be used in substitution for

page_text: hand forks for elevating and discharging or unloading and reloading in bulk such
materials as hay and straw, including ensilage and manure if sufficiently fibrous in
their composition to hold together between the prongs of a fork.
My invention is more especially intended to provide grapple forks, that is, forks
which consist of two levers furnished with prongs and pivotted to one fulcrum with
releasing mechanism of a more simple and reliable character than has hitherto been
in use, so that when a bundle of straw or other material is to be discharged there-
from the forks can be readily pulled apart or otherwise opened out in the manner
required.
Suitable mechanism for carrying my invention into effect is illustrated in the
accompanying drawings, in which Figures 1 and 2 illustrate the grapple fork as
constructed to be discharged of its contents by means of a delivery or tip cord to
be pulled by hand, and Figures 3, 4 and 5 illustrate the grapple fork when modified
in certain details of construction to enable the contents thereof to be discharged
either by a delivery or tip cord or automatically, and the same letters of reference
are used to indicate the same or corresponding parts in all the figures.
But in
Referring to Figures 1 and 2, Figure 1 illustrates the grapple fork in vertical
elevation as slung from the lifting chain with the prongs closed together in the
manner required to take their hold of the material to be lifted, and Figure 2
similarly illustrates the grapple fork with the prongs opened out in the manner
required to discharge the material from the grip of the fork. The parts being
constructed and arranged as shown in these two figures, they are intended to be
operated as follows:-The lifting chain a being permanently attached to the
arms bb' of the levers b¹ 62, 61 62, at suitable points of connection above the
fulcrum C9 it will be seen that the prongs d are closed together to take their grip
of the material to be lifted by the same pull of the lifting chain a by which the
material so grappled is lifted up, that is to say that the fork takes its grip of
the material to be lifted automatically and in the well known manner.
order to release the material so grappled and to discharge the fork of its load
releasing tackle is brought into operation consisting of a cord or chain e secured to
the upper part of each upper arm of the levers 12. Each cord e is led down
under a pulley f¹ secured to the lower part of the lower arm 62 of the other lever
and up over a pulley f² secured to the upper part of the arm b¹ of the lever to
which the cord itself is secured and thence to its connection with the delivery or
tip cord g so that a pull from the said cord g draws the cords e in the direction
indicated by the arrows and opens out the prongs to the position shown in Figure 2
in which position the prongs are retained only by sustaining the pull on the cord
and the fork kept ready to grapple another charge of the material to be lifted and
discharged as before.
But in order to make the grapple fork discharge itself automatically as well as
by a tip cord the fork is modified in certain details of construction as shown in
Figures 3, 4 and 5 of which Figure 3 illustrates a vertical elevation of the fork as
slung from the lifting rope with the prongs closed and Figure 4 is a corresponding
internal and vertical side view elevation showing a special arrangement of prongs
as hereinafter described; Figure 5 is a vertical elevation of the fork as slung from
the lifting rope and check chains with the prongs opened out, but instead of the
permanent connection of the lifting chain or rope a to the upper arms 6'6' of the
pronged levers 61 62, 162, I provide a detachable connection by means of a device
which when detached from and thereby relieved of the strain of the lifting rope is
free to enable the prongs to fly open and discharge their load, when the weight of
the unloaded fork is transferred to the check chains a¹ a¹ which are permanently
connected to the cross bar of the lifting tackle and to the lower arms 6² of the
pronged levers 6162. Referring to the Figures 3 and 5 it will be observed that the
prongs d d are closed by the strain taken up by the lifting rope a when transmitted
to the upper arms 6'' of the pronged levers as shown in Figure 3 and the said
prongs remain wide open when the weight of the unloaded fork is transferred to
the check chains a¹ a¹ as shown in Figure 5.

page_text: But although in order to make the connection between the lifting rope a and the
pronged levers 162, 61 63 self-detaching I avail myself of any suitable contrivance.
I have also designed for this purpose the device illustrated in Figures 3, and 5
which consists as follows:-a link, shackle or hook is attached to the under
frame of the lifting block h¹; j is a lock or lock case mounted on legs k hinged both
to the lock j and the lever arins 6' 6' so that the lock j is permanently attached to
the pronged levers b¹62, 61 62, in a manner which leaves these pronged levers free
to open and close sufficiently for the purposes of my invention. On the upper side
of the lock is provided a slot or recess 2 for the reception of the link or hook /;
is the holdfast the lower limb of which extends across the slot 2 when the
holdfast is out of gear as shown in Figure 5, so that when the link or hook h drops
into the recess it strikes and sends down the lower limb l', and consequently brings
over the holdfast 7 which is so adjusted in length that in falling down it strikes the
lower part of the catch m, and brings up the catch to the locking position in which
it is retained by the weighted lever n which falls down and inserts itself in the form
of a chock between the said catch m and the back plate or lug o. The weighted
lever n now occupies the horizontal or cross-wise position with its tail end extending
in the manner shown in Figure 4 until it is pulled over by the tip cord g or comes
in contact with the stop piece p which is a fixture attached to the lifting appliance;
the further ascent of the tail of the lever n being thus intercepted, the lever is
caused to turn about its centre towards the position shown in dotted lines and is
thus withdrawn from between the catch_m and lug o when the catch m falls back
and allows the holdfast / to fly open and the grapple fork is at once detached from
the lifting link or shackle and discharged by gravity and its weight is transferred
to and fall regulated by the check chains a¹ a¹ for which purpose the outer ends of
the levers 66 are forked or otherwise adapted to enable them to slide up and
down the said check chains as guides without undue sideward movement. The
forks are varied in their prongs to suit the special purpose for which they are
intended as for instance two or three pronged arms would be suitable for long
fibred materials such as straw and hay, and four or six prongs would be required
for shorter fibred material such as ensilage and ordinary manure, whereas fourteen
prongs to each lever set close together would not be too many for very short fibred
manure. I have therefore made provision for varying the number of prongs.
Referring more particularly to Figure 4 in which a series of prongs d are shown
attached to one crosshead d¹ it will be observed that each prong d is furnished with
a tee head through which it is bolted to the crosshead each prong being thus
detachable or attachable in position independently of the other prongs and in this
way their number and pitch in each crosshead can be readily varied. The end or
outside prongs d³ are preferably turned in or set to an angle sufficient to close in
short fibred material endwise.
Having now particularly described and ascertained the nature of my said inven-
tion and the manner in which the same is to be performed, I declare that what
I claim is :-
Firstly. In grapple forks the construction and arrangement of parts by which
the forks which are operated by suitable grappling leverage are also provided
with hand releasing tackle all combined and operating together substantially as
hereinbefore described and illustrated in Figures 1 and 2 of the accompanying
drawings.
Secondly. In grapple forks the arrangement and combination of parts by which
the forks which are operated by suitable grappling leverage are also provided with
cleasing tackle whether automatic in its action or worked by hand, all combined
and operating together, substantially as and for the purpose as hereinbefore
described and illustrated in Figures 3, 4 and 5 of the accompanying drawings.
Thirdly. In grappling forks of the double lever type, the use in combination
herewith of the detaching mechanism whether working automatically or by hand,
the said detaching mechanism being constructed, arranged and operating sub-

page_text: stantially as and for the purpose as hereinbefore described and illustrated in
Figures 3, 4 and 5 of the accompanying drawings.
Dated this 94th day of Anril 1894
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.