IMPROVEMENTS IN AND RELATING TO CRANES, MORE PARTICULARLY APPLICABLE FOR WORKING SELF-ACTING GRAPPLE BUCKETS, GRABS, SKEPS, AND LIKE DEVICES." PROVISIONAL SPECIFICATION
Year: 1881

page_text: LETTERS PATENT to William Dent Priestman, of the Town and County of
'
Kingston-upon-Hull, Engineer, for an Invention of "IMPROVEMENTS IN AND
RELATING TO CRANES, MORE PARTICULARLY APPLICABLE FOR WORKING
SELF-ACTING GRAPPLE BUCKETS, GRABS, SKEPS, AND LIKE DEVICES."
PROVISIONAL SPECIFICATION left by the said William Dent Priestman at
the Office of the Commissioners of Patents on the 3rd December 1881.
WILLIAM DENT PRIESTMAN, of the Town and County of Kingston upon Hull,
Engineer. "IMPROVEMENTS IN AND RELATING TO CRANES, MORE PARTICULARLY
APPLICABLE FOR WORKING SELF ACTING GRAPPLE BUCKETS, GRABS, SKEPS, AND
LIKE DEVICES."
My Invention relates to a novel construction of crane, being a duplex and self
balancing crane, more particularly applicablo for working self acting grapple
buckets, grabs, skeps, and like devices. The construction of crane, according to my
Invention, is alike applicable as a barge or other floating crane, a travelling or
truck crane, or a stationary crane.
My Invention consists in mounting two jibs, or the mechanical equivalent of two
jibs, on a moveable or rotating platform. The jibs are set on the platform in such
position as to balance each other, and thus constitute a duplex crane arranged to
turn round one central pillar common to both, the whole being carried on a suitable
bed plate, which bed plate may be fixed or moveable on the deck of a barge, or
may form part of a travelling mechanism or apparatus, or be mounted on or form
the carriage of a wheel truck suited for rail or road, or the bed plate may be a
stationary bed plate fixed in any required position.
The cranes may be of hand, stenam, or hydraulic type. The jibs and engines and
their platform are arranged to swing together rotating round a central pillar or
pivot, and working round one foundation or bed plate. The jibs may be stayed in
any convenient manner, and stays may extend from the centre pillar to support
the outer portions of the platform, which platform is provided with the usual bevel
or equivalent gear for effecting the rotation round the foundation.
ID 07

page_text: In the case of barges and when steam is used as the motive agent for the crane,
the steam can be supplied from an independent boiler in the barge, namely, from
the boiler in connection with the barge propelling engines, or in connection with
any other apparatus that the barge may be fitted with.
In like manner with the stationary and travelling cranes of my Invention the
steam to work them can be supplied from any independent source, or the steam
may be supplied from a boiler or boilers fixed on the platform between the two jibs
or cranes.
The essential advantage attained by my Invention is, that I obtain a self
balanced crane as the weight of one jib balances the other. I am thus enabled to
dispense with the necessity of using back balance weights, and in the case of steam
cranes I dispense with the necessity of using the boiler as the back balance or
counter balance to the jib, thus any independent boiler can be utilized for working
the crane. Iain also enabled to work the crane faster, as when one jib is lifting
the other is lowering, or in other words one jib may be loading and the other
discharging,
.
In arranging a duplex crane according to my Invention to work self acting grapple
buckets, grabs, skeps, and like devices, where it is necessary to provide a means for
taking in the slack, applying a break, and otherwise working the discharging chain
of such devices, I prefer to use the block and sheave gear patented to mo jointly
with Samuel Priestman on the 6th June 1877, No. 2196. This gear I arrango in
any convenient position on the platform, preferably against and fixed to the central
pillar; but I do not confine myself to the use of this gear for working the dis-
charging chain, as any known suitable gear may be used. For example, each crane
may have double barrels, one for the lifting and the other for the discharging chain.
It will be evident that by a crane according to my Invention, namely, a crane
having two jibs working from one platform with engines as described, I obtain an
appliance especially applicable for working grapple buckets, grabs, and like
appliances, inasmuch as the discharge is mainly at a fixed position, and the matter
to be lifted in a fixed position, thus I am enabled to lift with one jib whilo I am
discharging with the other.
In the case of barges my arrangement is very convenient, as it becomes an
athwart ship appliance capable of lifting on side of the barge and discharging
at the other. Steain as the motive agent is supplied from the barge's own boiler,
or a boiler fixed on the barge especially for working the crane, or a boiler or boilers
fixed at the side or sides of the centre pillar between the two cranes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Dent Priestman in the Great Seal Patent Office on
the 2nd June 1882.
WILLIAM DENT PRIESTMAN, of the Town and County of Kingston-upon-Hull,
Engineer. "IMPROVEMENTS IN AND RELATING TO CRANES, MORE PARTICULARLY
APPLICABLE FOR WORKING SELF-ACTING GRAPPLE BUCKETS, GRABS, SKEPS, AND
LIKE DEVICES."
My Invention relates to a novel construction of crane, being a duplex and self
balancing crane, more particularly applicable for working self acting grapple
buckets, grabs, skeps, and like devices. The construction of crane according to
my Invention is alike applicable as a barge or other floating crane, a travelling
or truck crane, or a stationary crane.
In carrying out my Invention I mount two jibs, or the mechanical equivalent of
two jibs, on a moveable or rotating platform. The jibs are set on the platform in
such position as to balance each other, and thus constitute a duplex crane arranged
to turn around one central pillar common to both, the whole being carried on a
suitable bed plate, which bed plate may be fixed or moveable on the deck of a
barge, or may forin part of a travelling mechanism or apparatus, or bo mounted
on or form the carriage of a wheel truck suited for rail or road, or the bed plate
may be a stationary bed plate fixed in any required position. The cranes may be
of hand, steam, or hydraulic type. The jibs and engines and their platform are
arranged to swing together rotating round a central pillar or pivot, and working
round one foundation or bed plate. The jibs may be stayed in any convenient
manner, and stays may extend from the centre pillar to support the outer portions
of the platform, which platform is provided with tho usual bevel or equivalent gear
for effecting the rotation round the foundation.
In the case of barges and when steam is used as the motive agent for the crane,
the steam can be supplied from an independent boiler in the barge, namely, from
the boiler in connection with the barge propelling engines, or in connection with
any other apparatus that the barge may be fitted with.
In like manner with the stationary and travelling cranes of my Invention, the
steain to work them can be supplied froin any independent source, or the steam
may be supplied from a boiler or boilers fixed on the platform between the two
jibs or cranes.
The essential advantage attained by my Invention is, that I obtain a self
balanced crane as the weight of one jib balances the other. I am thus enabled to
dispense with the necessity of using back balance weights, and in the case of steam
cranes I dispense with the necessity of using the boiler as the back balance or
counter balance to the jib, thus any independent boiler can be utilized for working
the crane.
I am also enabled to work the crane faster, as when one jib is lifting
the other is lowering, or in other words one jib may be loading and the other
discharging.
In arranging a duplex crane according to my Invention to work self acting
grapple buckets, grabs, skeps, and like devices, where it is necessary to provide a
means for taking in the slack, applying a brake, and otherwise working the dis-
charging chain of such devices, I prefer to use the block and sheave gear patented
to me jointly with Samuel Priestman, on 6th June 1877, No. 2196. This gear
I arrange in any convenient position on the platform, preferably against and fixed
to the central pillar; but I do not confine myself to the use of this gear for
working the discharging chain as any known suitable gear may be used. For

page_text: In Figures 1 and 2 the jibs or their mechanical equivalent A, A¹, are mounted
on the base plate or "platform B, which rotates on the base or foundation C being
centred on the spindle D. It will be seen that the jibs A, A¹, are so mounted on
the platform B as to balance each other, and constitute a duplex crane arranged to
turn round the centre pillar or spindle D. The barrels E, E, are arranged, as
shown, to work the lifting chains a, a', of the jibs A, A'. These barrels E, E¹, aro
driven by the friction or toothed wheels F, F, operated by the friction or toothed
pinions H, H, these pinions H, H', receiving motion from the steam cylinders J, J',
through suitable shafting and connections. The whole of these duplex working
parts are carried by the frame K; b, b', are the discharging or accessory chains
used to effect the opening of the grapple buckets or grabs X, X'. These accessory
chains b, b', are operated by the sliding weights d, d, which are arranged to move
up and down in the guides L, the weights d, d', operating the accessory chains b, b',
through the system of sheaves e, e, one set of which is arranged for each weight,
and being the block and sheave gear patented to me jointly with Samuel Priestman,
on 6th June 1877, No. 2196. Suitable brakes are provided to control the working
of the barrels E, E, and also to arrest the motion of the accessory chains b, br,
when required, such as shown in the Specification of Letters Patent No. 2196/
The levers and appliances for working the duplex crane are arranged to be operated
from the platforms R, R¹.
77°
It will be seen that the arrangement shown at Figure 1 can be mounted athwart
ships on the barge M, and is applicable for lifting from one side of the barge and
discharging on the other, being self balancing, or it may be mounted at the side or end
of the barge to work, namely, discharge or lift into or from the hold or interior of
the barge. Steam for supplying the motive power is led through the pipe N¹ from

page_text: the barges own boiler or from a boiler fixed on the barge especially for working
the crane.
In the example shown at Figure 3 it will be seen that two independent
frames K, K, are used to carry the crane mechanism; the platform B also carries
the boiler N, the discharging chain sheave gear e, e, being carried on the centre
pillar D.
In the example shown at Figure 4, a similar arrangement to that shown at
Figure 3 is illustrated. The duplex crane in this instance being mounted on the
carriage or truck P.
My Invention is capable of general application in the construction of steam or
like cranes where it is an advantage to have a double action, and to dispense with
the necessity of having to use a counter or balance weight, and is especially
applicable to be used for working self acting grapple buckets, forks, or like devices,
and I would have it clearly understood that my Invention is not limited to the
precise form and arrangement of of parts shown in the Drawings, so long as its
essential feature is retained, that is to say, the use of duplex jibs arranged on a
platform common to both, which also carries tho chain barrels and engines and the
accessory appliances for working the discharging chain in the case of self acting
grapple buckets, grabs, and like appliances.
What I claim as my Invention and secured to me by Letters Patent as aforesaid
is,―
First. In constructing duplex cranes, arranging the jibs thereof on one platform
common to both and moveable round a central pillar, which platform also carries
crane barrels, engines, and accessory appliances for effecting the various functions
of the crane, substantially as described and shown in the Drawings hereto
annexed.
Second. The arrangement and construction of duplex cranes, as herein described
and shown at Figures 1 --d 2 of the Drawings hereto annexed.
Third. The arrangement and construction of duplex cranes, as herein described
and shown at Figure 3 of the Drawings bereto annexed.
Fourth. The arrangement and construction of duplex cranes, as herein described
and shown at Figure 4 of the Drawings hereto annexed.
In witness whereof, I, the said William Dent Priestman, have hereunto set
my hand and scal, this Twenty ninth day of May, in the year of our Lord
One thousand eight hundred and eighty two.
1173 DENT
DRIESTIN
117M DENT
DRIESTS LAT