Improvements in or relating to Boats' Chocks.
Year: 1899

page_text: Date of Application, 21st July, 1899
Complete Specification I aft 10th Ann 4000 Accented
02-31.... 1000
Improvements in or relating to Boats' Chocks.
I, WILLIAM MORE BURNETT, of 20, Watson Street, Dundee, in the County
of Forfar, Shipwright, do hereby declare the nature of this invention to be as
follows:
This invention relates to chocks for supporting ships' boats, the object being
to construct such chocks so that while improving the character of the support
the freeing or disengaging of the boat therefrom may be simplified, facilitated,
and rendered mort certain, than hitherto.
In carrying my invention into effect or practice, I form the chocks for receiv-
ing the under part of a boat of two arms crossing each other in X fashion, or
otherwise of the type known as "shear chocks.' These arms are pivoted
together at their crossing, and may be formed of angle or tee iron or like
section for stiffness. Both arms are attached by pins or pivots at their lower
ends or extremities,--the one to a forked jaw or the like attached to or incor-
porated with the fixed base or skid of the chock; and the other to a similar jaw
attached to or incorporated with a slipper or sliding bar, moving in or upon
such base or skid. When any weight, as for instance that of the imposed boat,
is brought to bear on the arms so disposed and connected, the downward thrust
thereby induced is transmitted by the crossing pivot and resisted by the fixed
pivot, so as to compel the slide to move outwards and the arms to collapse or
flatten out, unless suitably restrained.
At one end of the sliding bar or the like which carries the free arm, I form
upon or attach thereto a projecting piece, which, when the chock is in proper
supporting position, engages with or is disposed to another piece or pieces on
the fixed framing, in such a manner that a pin or cotter or their equivalent
passing through each, supplies the restraint above mentioned; effectually pre-
venting the outward movement of the slide until the desired moment, and
allowing of such movement being instantly induced by the simple knocking
out or equivalent removal of the pin or cotter.
The slipper or sliding bar extends across the entire width of the fixed base
or skid, and at each of its extremities, carries a releasing device for the grips
or "grepts." One modification of this device consists of a fixed fork or socket,
formed to receive the end link of the grip, and having a hole or slot formed
in each of its arms or prongs so that the ends of the slide or projections there-
upon pass through the said fork and link to hold the latter to the former when
the boat is on the chocks, but at the moment of collapse and movement of the
slide, the withdrawal of the latter frees the grips from their forks or sockets.
In another modification I substitute for such fork a hook for receiving the end
link of the grip, hinged to the fixed base, and carrying on its under side a tail
piece which is canted by the slide or projections thereon, to free it from the
grip on the movement of the slide as before.
The pin or cotter aforesaid is placed for convenience of access, at the inner
end of the base or skid. Two chocks formed and furnished as above described

page_text: being provided for bow and stern of a boat, in the known way, its complete
release from chocks and grips is obtained by simply knocking out or otherwise
conveniently removing the pins or cotters of each; when it is left hanging upon
its davits, ready to be swung out for use.
Each chock may be braced or sustained against longitudinal thrust or
pressure by being guyed to the deck or other convenient adjacent part; or a tie
rod, hinged to allow of the independent action of each chock, may connect the
one with the other.
Dated this 19th day of July 1899.
Improvements in or relating to Boats' Chocks.
I, WILLIAM MORE BURNETT, of 20, Watson Street, Dundee, in the County
of Forfar, Shipwright, 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 relates to chocks for supporting ships' boats, the object being
to construct such chocks so that while improving the character of the support,
the freeing or disengaging of the boat therefrom may be simplified, facilitated,
and rendered mort certain than hitherto.
In order that my said invention may be the better understood, I have here-
unto appended an explanatory sheet of drawings, in which the same reference
numerals are employed to denote the same or like parts where shown.
Figs. 1, and 2, of these drawings illustrate in end and side elevation respec-
tively, the application and use of my improved chock in supporting a boat.
Fig. 3, is an end view of my improved chock with the base in vertical
section to show the internal construction more clearly; while Figs. 4, and 5,
are side view and plan respectively projected from Fig. 3.
Figs. 6, 7, 8, and 9, are cross sections at A A, BB, CC, and DD, respectively
of Fig. 3.
Fig. 10, is an end view showing. the position of my improved chock when
collapsed to free the boat; while Fig. 11, illustrates an alternative method of
engaging and releasing the grips.
In carrying my invention into effect or practice, form the chocks 20, for
receiving the under part of a boat 21, of two arms 22, and 23, crossing each
other in X fashion, or otherwise of the type known as shear chocks." These
arms are pivoted together at their crossing and may be formed of angle or tee
iron or like section for stiffness. Both arms are attached by pins or
pivots 24, and 25, at their lower extremities, the one 22, to a forked jaw 26,
or the like attached to or incorporated with the fixed base or skid 27, of the
chock; and the other 23, to a similar jaw 28, attached to or incorporated with
a slipper or sliding bar 29, moving in or upon such base or skid.
When any weight, as for instance that of the imposed boat 21, is
brought to bear on the arms so disposed and connected, the downward thrust
thereby induced is transmitted by the crossing pivot 30, and resisted by the
fixed pivot 24, so as to compel the slide to move outwards in the direction of
the arrow M, and the arms to collapse or flatten out as shown in Fig. 10, unless
suitably restrained.
At one end of the sliding bar 29, or the like, which carries the free arm 23,
I form upon or attach thereto a projecting piece 31, which, when the chock

page_text: is in proper supporting position, as shown more particularly by Fig. 3, engages
with or is disposed to another piece 27, or pieces on the fixed framing 27, in
such a manner that a pin or cotter 32, or their equivalent, passing through each
or otherwise passing through one and bearing on the other, applies the restraint
above mentioned; effectually preventing the movement of the slide 29, until
the desired moment, and allowing of such movement being instantly induced
by the simple knocking out or equivalent removal of the pin or cotter 32.
The slipper or sliding bar 29, extends across the entire width of the fixed base
or skid 27, and at each of its extremities carries a releasing device for the
grips or "grepts" 33. One modification of this device, as shown more parti-
cularly by Figs. 3, and 6, consists of a fixed fork or socket 34, formed to receive
the end link 35, of the grips 33, and having a hole or slot 36, formed in each
of its arms or prongs, so that the end of the slide or projections 37, thereupon,
pass through the said fork or socket and link, to hold the latter to the former
when the boat 21, is on the chocks 20, but at the moment of collapse and move-
ment of the slide 29, the withdrawal of the latter frees the grips 33 from their
forks or sockets 34. In another modification as shown by Fig. 11, I substitute
for such fork 34, a hook 38, for receiving the end link 35, of the grip, hinged
at 39, to the fixed base 27, and carrying on its under side a tail piece 40, which
is canted in the direction of the arrow N, by the slide 29, or projections thereon,
to free it from the grip on the movement of the slide as before.
The pin or cotter 32, aforesaid, is placed for convenience of access, at the
inner end 27b, of the base or skid 27. Two chocks 20, formed and furnished
as above described being provided for the bow and stern of a boat 21, in the
known way and as shown more particularly by Fig. 2; its complete release
from chocks 20, and grips 33, is obtained by simply knocking out or otherwise
conveniently relieving the pins or cotters 32, of each; when it is left hanging
upon the davits, ready to be swung out for use.
Each chock may be braced or sustained against longitudinal thrust or pres-
sure, by being guyed to the deck 41, or other convenient part, as indicated by
the dotted lines 42, in Fig. 2, or in any other known way: or a tie rod 43,
hinged at 44, to allow of the independent action of each chock, may connect the
one with the other.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I wish it to be clearly
understood that I do not limit myself to the precise details of construction
herein set forth, but that I hold myself free to make such modifications thereof
as conform with the spirit and scope of my invention, and I declare that what
I claim is:-
(1) The construction, combination, and arrangement of parts constituting my
improved boat chock, substantially as herein before described and illustrated in
the appended sheet of drawings.
(2) In boats' shear chocks the combination of a supporting arm working on
a fixed pivot, and a similar arm pivoted to a moving slide or the like, substan-
tially as and for the purposes herein before described and illustrated in the
appended sheet of drawings.
(3) In boats' chocks the improved means for directly engaging and releasing
the grips, substantially as and for the purposes herein set forth and illustrated
in the appended sheet of drawings.
Dated this 18th day of April 1900.