Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a cargo hook for use on
cranes and other lifting apparatus where heavy loads
are lifted and moved, as for example by slings around the
loads.
Most prior devices for this purpose are too complicated I-
and expensive to be practical and most are not designed for
very heavy loads. The conventional devices have an excessive
- number of moving parts to provide release in different ways
as may be desired. This makes them expensive to manufacture
and keep in good working order. Failure of a load hook may
result in expensive loss of time in a large loading or us- -
loading operation. also, most prior load hooks are not
suitable for use with the now common flat web slings.
The present load hook is of very simple and rugged con-
I struction designed to lift and move heavy loads. There are
relatively few moving parts to assemble and manufacture and
keep in good working order.
In the present construction a horizontal load carrying Jo
pin is rotatable on a horizontal pivot and has a free end
supported on a saddle on a latch arm which may be withdrawn
to release the load. Upon release of the load a counter-
weight on the opposite end of the pin returns the pin to
horizontal position.
The latch arm is spring opened and held in closed
; position by a paw which may be released by a remote con-
i trolled fluid pressure cylinder and piston or by a manually
operated lever in the housing of the hook or, if desired, -`
by a pull cord or electrical release. The load carrying
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pin is of generally cylindrical shape to carry flat web type
slings as well as steel rings.
i Thus the present cargo hook comprises a housing,
suspension means for said housing in an upper portion of said
housing, a load support pin mounted on a horizontal pivot in
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one side of a lower portion of said housing, a latch arm ^
mounted on a horizontal pivot in the opposite side of said
housing, a saddle on said latch arm movable into engagement
with a free end of said pin to support said pin in horizontal
position, means for opening said latch arm to disengage said
saddle from said pin, a paw arranged to hold said latch arm
in a closed position supporting said pin, and means to
', release said paw allowing said latch arm to release said
pin.
I, The invention will be better understood and additional
features and advantages will become apparent from the follow-
in description of the preferred embodiment illustrated in
the accompanying drawings. Various changes may be made in
; the details of construction and arrangement of parts and
Jo 20 certain features may be used without others. All such
modifications within the scope of the appended claims are
; included in the invention
In the drawings,
Fig. 1 is an isometric view of the present cargo hook.
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Fig. 2 is an elevation view with the front face plate
of the housing removed and parts shown in section, the parts
being shown in lifting positions.
it. 3 is a view similar to Fig. 2 with the parts shown
in solid lines in position existing after release of a load.
;; The housing 10 comprises a pair of spaced apart face
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- plates 11 and 12 which enclose most of the operating
mechanism. In the upper part of the housing, opening 13 in
the face plates 11 and 12 contains a half bearing 14 for
supporting the housing on a pin 15 in a Levis 16. Levis
16 is suspended by a cable or chain from a crane or other
lifting device, normally putting the face plates 11 and 12
in vertical positions as shown.
;, The load to be lifted and moved by the crane is
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suspended from a releasable horizontal load pin 20 which is
` pivotal mounted at one end on a horizontal bolt 21 in the
face plates 11 and 12. Load pin 20 is adapted to receive a
loop or eye 22 on one end of a flat web sling 23 on one side
of the load to be lifted or carried. Sling 23 passes under
the load and has a similar eye or loop 22 on its other end
supported by a similar load hook on the opposite side of
the load.
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-I Load pin 20 has a free end 25 which in load carrying 'I
position is supported on a saddle 26 on the lower end of a
' latch arm 27 which is pivotal mounted at its upper end
on a bolt 28 in the face plates 11 and 12. In the present
I- embodiment the end portion 25 of the pin 20 is cylindrical
and the saddle 26 has a semi-cylindrical supporting surface
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in the lower portion of an opening 29 in the lower end of
latch arm 27.
Load pin 20 may be cylindrical throughout its length
between pivot 21 and its free end 25 but in the present
embodiment at least a portion of the length of the pin
adjacent its saddle supported free end portion 25 has a
slight conical taper in the region 30. If the load is
supported by a steel ring or a Levis loop similar to the
present Levis 16 the tapered portion 30 of the pin will
tend to shift the load supporting ring or Levis loop
away from the end of the pin supported by pivot bolt 21 and
toward the free end 25 of the pin supported by saddle 26,
; which is desirable.
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On the opposite side of pivot bolt 21 extension 31
I; of the pin 20 projects out from between face plates 11 and
12 to provide a handle for manual manipulation. Handle 31 -
carries a pair of counter weights 32 to return the pin back
to horizontal position after release of the load sling 23
-I when the housing 10 is in vertical position as shown.
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Above its pivot bolt 28 the upper end of latch arm
27 has an abutment surface 35 which is engaged by an abutment ;
surface 36 on one end of a paw 40 which is pivotal mounted
: on a bolt 41 in the face plates if and 12. In an upward no-
lease movement limited by stop 42 the paw abutment surface
36 disengages latch abutment surface 35 and a second paw
abutment surface 43 engages latch arm abutment surface 35
; to limit the clockwise release movement of latch arm 27.
I, Openings 44 in face plates if and 12 provide for observation
., lo of the abutment surfaces 35, 36 and 43.
Latch arm 27 is constantly urged toward release position
: by a compression spring 45. One end of spring 45 bears
against a stationary guide block 46 between face plates
11 and 12 and the opposite end of the spring holds an end
of a pin 47 seated in a recess 48 in latch arm 27.
On the opposite side of pivot bolt 41 the paw 40 has
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. a manual manipulating arm 50 enclosed between face plates -I
., if and 12 so that it cannot be engaged and moved uninten-
tonally by some exterior object. The space between face I.
. 20 plates if and 12 provides an access opening as indicated
I; at 51 in Fig. 1 for insertion of an operator's finger for :.`
manual manipulation of arm 50. I'
.. ; Paw arm 50 is constantly urged in counter-clockwise
Jo rotation by a compression spring 52 confined between a
stationary spring seat 53 and the underside of handle arm
50. Latch arm 27 is released by remote control by a piston
55 in cylinder 56 supplied by a gas pressure hose 57 at
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cylinder connection 58. Piston 55 bears against the upper
side of paw release arm 50. A guard plate 59 projects
upward from housing 10 between hose 57 and Levis 16.
Connection 58 is protected by face plates 11 and 12~
Above the load pin 20 the space between face plates
11 and 12 is closed by guard plates 60. Above the pivot
bolt 21 there is a spacer block and handle stop 61 between
the face plates. The half bearing 14, stop 42, guide block
46, spring seat 53, guard plates 58, 60 and spacing block 61
are all welded to the face plates 11 and 12 to maintain the
face plates in parallel spaced apart relation as shown.
With the cargo hook hanging in vertical position after
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release of a load, the parts assume the positions shown in
solid lines in Fig. 3. After the sling has slipped off load
pin 20 momentarily in broken line position, counterweights
32 return the load pin to horizontal position. Spring 45
holds latch arm 27 at the limit of its clockwise rotation
with its abutment surface 35 engaged by the abutment surface
43 on paw 40, this engagement holding paw 40 in actuated
position.
A sling loop or metal ring may then be placed over
the free end of load pin 20 and retained thereon by manually
rotating latch arm 27 counter-clockwise to enclose end
portion 25 of the load pin in opening 29 in the latch arm.
This counter-clockwise rotation of latch arm 27 releases
paw 40 to rotate counter-clockwise and engage paw abutment
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surface 36 with latch arm abutment surface 35 as shown in
Fig. 2. The hook and load are then lifted by the crane and
moved to a desired position.
The load is released by remote control piston 55 or
manually by paw handle arm 50. Clockwise rotation of paw
40 disengages paw abutment surface 36 from latch arm
abutment surface 35 allowing spring 45 to rotate the latch
arm clockwise and disengage supporting saddle 26 from the l,
end portion 25 of the load arm.
If there is any tension on the sling 23 the load pin
20 will be rotated counterclockwise to its broken line
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position in Fig. 3 to release the sling. If there is no
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tension on the sling the load pin 20 may be rotated to 'I
release position manually by handle 31 or by operating the
crane to lift housing 10. This returns the parts to their
solid line positions in Fig. 3 if housing 10 is hanging
in vertical position so that counterweights 32 can return
load pin 20 to its horizontal position. The cargo hook is
then ready to receive another load.
A safety feature is that spring 45 does not apply
sufficient force against latch arm 27 to release load pin
20 when sling 23 is carrying a load. The latch arm will
release the load pin only after the load has been set down
and the only weight on the load pin is that of the sling in
slack condition.
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