U.S. patent number 3,883,170 [Application Number 05/378,029] was granted by the patent office on 1975-05-13 for hoisting shackle with quick release attachment means.
This patent grant is currently assigned to Siegfried Fricker. Invention is credited to Siegfried Fricker, Horst Reinkensmeier.
United States Patent |
3,883,170 |
Fricker , et al. |
May 13, 1975 |
Hoisting shackle with quick release attachment means
Abstract
A hoisting shackle with quick release attachment means
cooperating with non-recoverable anchoring elements in the load
e.g., a prefab building component, the closed hollow shackle body
having a slot across which a locking bolt can be engaged with the
anchoring element. Retraction of the locking bolt for remote
release can be accomplished by means of a Bowden cable.
Inventors: |
Fricker; Siegfried (Wiernsheim,
DT), Reinkensmeier; Horst (Neifern-Oschelbronn,
DT) |
Assignee: |
Fricker; Siegfried (Wiernsheim,
DT)
|
Family
ID: |
5853668 |
Appl.
No.: |
05/378,029 |
Filed: |
July 10, 1973 |
Foreign Application Priority Data
|
|
|
|
|
Aug 16, 1972 [DT] |
|
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22401714 |
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Current U.S.
Class: |
294/82.35;
294/82.24; 24/600.7; 294/89 |
Current CPC
Class: |
E04G
21/142 (20130101); B66C 1/666 (20130101); A44C
5/2014 (20130101); Y10T 24/45398 (20150115) |
Current International
Class: |
E04G
21/14 (20060101); B66C 1/66 (20060101); B66C
1/62 (20060101); B66c 001/36 () |
Field of
Search: |
;294/78R,82R,83R,89
;24/232,238,239,240,241R,241SL,241PL,233 ;52/698,699,700
;59/85,89,93 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Marbert; James R.
Assistant Examiner: Cherry; Johnny D.
Attorney, Agent or Firm: Geiger; Joseph A.
Claims
What is claimed is:
1. A hoisting shackle system with a quick release attachment device
for attaching a hoisting harness to a load at one or more
attachment points, comprising in combination:
a ring-shaped closed shackle body having an annular cavity giving
it a shape similar to that of an upright hollow torus and being
thus adapted to form an articulated, chain-link-type end member of
a hoisting harness or the like of which a hook or end loop can
reach through the central aperture of the torus, the shackle body
having an upper arcuate portion in which the outer peripheral wall
of the hollow torus structure is removed so as to leave a radially
open, U-shaped cross-sectional wall profile around its annular
cavity;
an arcuate locking bolt received in the annular cavity of the
shackle body so as to be guided therein for movement along the
curvature of said annular cavity;
a transverse radial slot in the lowermost portion of the shackle
body which reaches upwardly a distance beyond the cross-sectional
space occupied by the locking bolt inside the annular cavity;
an anchoring element capable of being fixedly attached to a load
and having an upstanding eye portion with a transverse opening, the
eye portion fitting into the radial slot of the shackle body in
such a way that the locking bolt can be inserted through its
opening, thereby attaching the anchoring element to the shackle
body; and
means for releasing the anchoring element from the shackle body, by
retracting the locking bolt from its locked position in which it
traverses said radial slot to a position outside the slot
region.
2. A hoisting shackle system as defined in claim 1, wherein:
the load is a concrete body, such as a building component or the
like; and
the anchoring element is permanently embedded in the concrete of
the load in such a way that only its upstanding eye portion
protrudes from the concrete.
3. A hoisting shackle system as defined in claim 1, wherein:
the load is a prefabricated building component of concrete;
the anchoring element is permanently embedded in the concrete of
the building component in such a way that only its upstanding eye
portion protrudes from the concrete; and
the building component includes a recess in its surface surrounding
said eye portion, the recess having an outline which matches
approximately that portion of the shackle body which reaches into
the recess when the shackle body is attached to the anchoring
element.
4. A hoisting shackle system as defined in claim 3, wherein:
the anchoring element is a steel bar of flat section whose upper
end portion forms the eye portion and whose lower end portion
includes at least one laterally extending extremity by which it is
retained in the concrete of the building component.
5. A hoisting shackle system as defined in claim 3, wherein:
the anchoring element is a bent steel rod in the shape of a twin
hook, with a central hairpin-type loop forming the upwardly
extending eye portion and two hook portions on its lower end
retaining it in the concrete of the building component.
6. A hoisting shackle system as defined inclaim 1, wherein:
the eye portion of the anchoring element has a converging outline
at its uppermost extremity, and the radial slot in the shackle body
has a matchingly shaped bottom portion which, when pressed against
the extremity of the anchoring element, centers the latter inside
the slot for alignment of its transverse opening with the locking
bolt.
7. A hoisting shackle system as defined in claim 1, wherein:
the locking bolt is of such a length that one of its extremities
reaches upwardly into the open, U-shaped portion of the shackle
body when the other end portion traverses its radial slot in the
locked position; and
the releasing means includes a radially extending actuating nose on
the upper end portion of the locking bolt.
8. A hoisting shackle system as defined in claim 1, wherein:
the releasing means includes means for remotely actuating the
reaction of the locking bolt from its locked position.
9. A hoisting shackle system as defined in claim 8, wherein:
the remote actuating means includes a Bowden-type pull cable, a
sheath bracket on the shackle body for the abutment and positioning
of the near end of the cable sheath, and a cable attachment between
the corresponding end of the cable and one end of the locking bolt;
the sheath bracket being so positioned in relation to the cable
attachment that a pulling action on the Bowden cable causes the
locking bolt to be retracted from its locked position.
10. A hoisting shackle system as defined in claim 9, wherein:
the remote-actuating means further includes a return spring
surrounding the cable between the sheath bracket and the cable
attachment, the return spring urging the locking bolt into its
locked position.
11. A hoisting shackle for releasably attaching a hoisting harness
to a load, the shackle comprising:
a generally torus-shaped, unitary shackle body having a central
annular cavity of circular outline arranged therein; a hook or end
link of the hoisting harness being engageable through the center
opening of the torus shape;
an arcuate locking bolt received in the annular cavity of the
shackle body so as to be guided therein for movement along the
center circle of the cavity;
a radial opening in the shackle body of such width and arcuate
length that the locking bolt can be inserted therethrough;
a wall reinforcement on that portion of the shackle body which is
located diametrally opposite its radial opening, the wall
reinforcement occupying a generally segment-shaped portion of the
center opening of the torus; and
a radial slot in the shackle body in angular alignment with its
wall reinforcement the slot having opposing slot flanks which
extend substantially perpendicularly to said annular cavity from
the periphery of the torus towards said reinforcment, without
cutting across the latter; and wherein
the locking bolt is movable between a locked position in which a
portion thereof extends across said radial slot, serving as a
load-carrying member, and a release position in which the bolt is
positioned outside said slot.
12. A hoisting shackle as defined in claim 11, wherein
the arcuate length of the locking bolt is substantially one-half of
the length of the annular cavity of the shackle body; and
the radial opening in the shackle body occupies approximately
one-half of the torus circumference, the torus cross section in the
area of said opening having the shape of a U-channel.
13. A hoisting shackle as defined in claim 11, further
comprising:
means for retracting the locking bolt to its release position from
a remote location.
14. A hoisting shackle as defined in claim 13, wherein
the retracting means includes a Bowden cable attached by one end to
the locking bolt and a sheath bracket on the shackle body
positioning one end of the Bowden cable sheath at a distance from
where the cable is attached to the locking bolt.
15. A hoisting shackle as defined in claim 14, wherein
the retracting means further includes a return spring surrounding
the Bowden cable end portion between the sheath bracket and the
cable attachment, the spring urging the locking bolt into its
locked position.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hoisting attachments, and in
particular to hoisting shackles which have quick release
attachments cooperating with special anchoring elements arranged in
the load itself, or attachable thereto, and which are especially
suitable for hoisting operations in connection with prefabricated
building elements in the construction industry.
2. Description of the Prior Art
Modern construction technology not only requires the transportation
and hoisting of increasingly heavier prefabricated building
components, it also requires such material handling operations to
be efficient and safe. It is therefore no longer adequate to use
ropes or cables for the attachment of these prefabricated building
components to a hoisting crane, because it is often difficult and
risky to remove the ropes or cables.
It has therefore already been suggested to incorporate
non-recoverable anchoring elements in the building components
themselves during prefabrication and to attach these components
directly to the crane by means of hooks or shackles which engage
the anchoring elements. One shortcoming of this prior art
suggestion is that the anchoring elements remaining on the prefab
components either form permanent protrusions thereon, or have to be
removed by cutting them with a blow torch, for example.
In order to avoid this problem, it has also been suggested to
provide recessed anchoring elements in the prefabricated building
components which do not project over the adjacent surface of the
part and can therefore be left in place after emplacement of the
building component. Where called for, the recesses surrounding the
anchoring elements are filled in, thereby removing any trace of the
anchoring elements. For a satisfactory operation of these recessed
anchoring elements or "lost anchors" it is necessary that they be
accurately positioned within their recesses. It has therefore also
been suggested to produce these recesses and the positioning of the
anchoring elements during the concrete pouring operation of the
building component by inserting a core piece of rubber or foam
plastic into the mold which then forms the recess around the
anchoring element and also positions the latter. Once the concrete
in the mold is set, the core elements can be removed from the
prefab component.
In many cases the use of recessed anchoring elements also offers
cost economies. On the other hand, however, the recesses themselves
may represent a structural problem in that they are either too
small for convenient access with conventional hooks, or are so
large that they entail structural stress problems by reducing the
overall bending resistence of the prefabricated building
component.
SUMMARY OF THE INVENTION
It is a primary objective of the present invention to overcome the
above shortcomings by suggesting a novel hoisting shackle with a
quick release attachment which is capable of cooperating with
special, recessed anchoring elements which require a minimal recess
space in the prefab components.
The present invention proposes to attain the above objective by
suggesting a hoisting shackle whose main body is in the form of a
closed hollow ring comparable to a tubular torus, with a portion of
the outer ring wall removed, and including an arcuate attachment
bolt which is received in the annular cavity of the shackle
body.
In a preferred embodiment the arcuate locking bolt has a
semi-annular outline and a circular cross section, the similarly
curved annular cavity of the shackle body being likewise circular
in cross section. At its lowest point the shackle body has a
transverse slot into which the eye portion of a cooperating
anchoring element can be inserted to be retained therein by the
locking bolt which traverses this slot. The semi-annular locking
bolt, when not clamped in place by the forces acting on the
anchoring element, tends to assume a position in the lower portion
of the shackle body under the influence of gravity, thereby
normally locking the shackle.
The preferred embodiment of the invention also offers an
advantageous feature in regard to the release operation on the
shackle, which merely requires a comparatively simple angular
displacement of the locking bolt inside the annular cavity of the
shackle. This release operation is very safe and positive, because
the shackle body itself is positioned against the eye portion of
the anchoring element while the locking bolt is retracted inside
the shackle body.
A still further advantageous feature of the present invention
relates to the possibility of remotely actuating the release
movement of the locking bolt. This result is obtained in a very
simple way by adding to the hoisting shackle of the invention a
cable pull, for example a Bowden cable, which permits the release
of the hoisting shackle from its anchoring element from a distance,
for instance from the ground or from a safe place on the
construction site. Accidental or premature release of the locking
bolt is practically impossible, because the load acting on the
anchoring element creates a clamping action between the locking
bolt and the cavity wall of the shackle body.
BRIEF DESCRIPTION OF THE DRAWINGS
Further special features and advantages of the invention will
become apparent from the description following below, when taken
together with the accompanying drawings which illustrate, by way of
example, several embodiments of the invention, represented in the
various figures as follows:
FIG. 1 shows in an elevational front view a hoisting shackle with
manual release and a cooperating anchoring element representing a
first embodiment of the invention;
FIG. 2 shows an elevational cross section of a hoisting shackle
similar to that of FIG. 1, but arranged for remotely controlled
release representing a second embodiment of the invention;
FIG. 3 shows a sectional side view of the hoisting shackle of FIGS.
1 or 2; and
FIG. 4 shows the three different versions of anchoring elements,
designated as 4a, 4b, and 4c, as part of the preferred embodiments
of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As illustrated in FIGS. 1 and 2, the hoisting shackle of the
invention consists of a shackle body 1 of cast steel, the general
outline of the shackle body being that of a ring, or more precisely
of a hollow torus. The shackle body 1 has an annular cavity 10
which is open to the outside in the upper half of the shackle body,
where the outer wall portion of the hollow torus profile is
removed. The upper half of the shackle body 1 thus has a U-shaped
cross section, as can be seen in FIG. 3. In the area of this
U-shaped profile the shackle body is engaged by the eye of a
connecting element 7, which may be a closed ring, a hook, or the
loop of a cable. Since the inner profile of the aperture 6 of the
shackle body 1 is rounded in at least the upper half of the body,
the connecting element 7 is allowed to swing sideways in both
directions from the vertical plane to accommodate conditions in
which the direction of cable pull or chain pull is inclined up to
approximately 60.degree. from the vertical. Such a condition may
obtain, when the hoisting harness includes two or more cables with
hoisting shackles at their extremities.
Inside the circular cavity 10 of the shackle body 1 is arranged an
arcuate locking bolt 11 which occupies approximately one-half of
the channel circumference and is guided inside the channel 10 for
motion along a circular path. The locking bolt 11 is introduced
into cavity 10 of the shackle body 1 through the open upper half of
the channel 10 and, because of the effect of gravity, will normally
slide into the lower half of shackle body 1. A nose 12 which
extends radially from one end portion of the locking bolt 11 serves
as an abutment element between bolt 11 and shackle body 1 and can
also be used to move the locking bolt 11 upwardly out of the lower
half of the cavity 10.
In the mid-portion of the lower half of the shackle body 1 is
further arranged a vertical slot 13 which traverses the circular
channel 10 of the body in that area without separating it
structurally. This slot 13 is adapted to receive the free extremity
of a matching anchoring element 17 (FIGS. 1 and 3) which has a hole
18 through which the locking bolt 11 can be engaged, when the eye
portion of the anchoring element 17 is brought into alignment with
slot 13 of shackle body 1. Thus, the shackle body 1 and locking
bolt 11 cooperate with a matching anchoring element 17 in a manner
comparable to a known necklace lock, any load or pull on the
anchoring element 17 having the tendency of clamping the locking
bolt 11 in place, thereby preventing an inadvertent or accidental
release motion.
The hoisting shackle of the invention is designed to be used for
the transportation of very heavy loads, such as prefabricated
building components which are to be hoisted into place, and
following which the hoisting harness is to be released from the
component. For this purpose, it has been found to be advantageous
and convenient to incorporate the anchoring element 17 in the
prefab building component as an integral non-recoverable part or
so-called lost anchor which need not be removed from the prefab
component during building assembly.
The hoisting shackle of the invention lends itself very
advantageously to the use of such lost anchors, because it requires
a minimum of space around the eye portion of the anchoring element.
This can best be seen in the lower portion of FIG. 1 and in the
three illustrations of FIG. 4 where several comparable embodiments
of anchoring elements are illustrated. On the one hand, it is
necessary that the eye portion of each anchoring element 17 is
recessed in relation to the upper surface of a building component
20 so that it does not interfere with other building components
during and after assembly. On the other hand, it is also important
to minimize the depth and width of the recess 19 around the free
portion of the anchoring element 17, in order to keep the
cross-sectional weakening of the prefabricated element 20 to a
minimum. This feature is clearly illustrated in FIGS. 1 and 4 which
show that the recess 19 required for the proposed lost anchor of
the invention is shallow and advantageously rounded in all
directions. The latter thus also serves to positively guide the
hoisting shackle into engagement with the eye portion of the
anchoring element 17.
The entry guidance between the hoisting shackle 1 and the free eye
portion of the anchoring element 17 can be further enhanced by
providing a pointed shape at the extremity of the anchoring element
17 and by giving the hole 18 of its eye portion an elongated
configuration. The reinforced connection web 2 which forms that
portion of the shackle body 1 which is located above slot 13 may be
provided with a matching configuration so that, when the hoisting
shackle 1 is forcibly set onto the free end of the anchoring
element 17, the hole 18 of the latter is automatically placed in
alignment with the locking bolt 11 inside the circular channel 10
of the shackle body 1.
Of the three versions of the anchoring element 17 shown in FIG. 4,
version a shows a pointed upper end, version b shows a bevelled end
portion, and version c has the rounded configuration of a loop. The
first two versions of the anchoring element are conveniently
produced as stampings, the lower end portion of the stamping being
longitudinally split so as to form two anchoring legs which are
bent in opposite directions. As an alternative, the embodiment c
shows an anchoring element 17 obtained from a rod which is bent
into the shape of a twin hook, the loop portion on its upper end
providing both the rounded entry configuration for its guidance
into slot 13 of shackle body 1 and an opening equivalent to the
hole 18 for cooperation with the locking bolt 11.
The anchoring element 17 is in each case incorporated in the
prefabricated building component by placing it into the component
mold after the concrete has been poured, but before the latter has
set. The recess 19 around the high portion of the anchoring element
17 is preferably obtained by using a core piece having the shape of
the recess, the core piece being attached to the eye portion of the
anchoring element 17. This recess core piece may be of rubber or
plastic, for example, and it may have a flat end face which, when
aligned with the corresponding end face of the building component
properly positions the anchoring element 17 as to its depth and
orientation.
In FIG. 2 is further illustrated a modified embodiment of the
invention in which the locking bolt 11 can be withdrawn into its
released position by a remotely controlled release mechanism. This
release mechanism may for instance be in the form of a Bowden-type
cable pull which includes a cable which is attached to the nose 12
of locking bolt 11 and a removable sheath bracket 22 which is
mounted on the shackle body 1 in the area of the annular cavity 10.
Thus, the release of the hoisting shackle from the anchoring
element 17 can be controlled from a remote position by means of the
release cable, thereby eliminating the need for a worker to be in
the immediate vicinity of the hoisting shackle to affect its
release. The remote release feature thus eliminates risky climbing
and balancing maneuvers which may otherwise be necessary for the
release of the hoisting harness from the building component after
emplacement of the latter.
As long as the load is suspended on the hoisting harness, the
inadvertent or accidental retraction and release of the locking
bolt 11 is effectively prevented by the load itself, which causes
the locking bolt 11 to be firmly clamped inside the annular cavity
10 of the shackle body 1. On the other hand, the locking bolt 11
can be retracted with little effort, once the load has been set
down and the hoisting harness is slack.
The Bowden cable release mechanism may further include a return
spring (not shown in drawing) which surrounds the exposed cable
position in the space between the nose 12 and the sheath bracket 22
and which urges the locking bolt 11 into its locking position.
The safety advantages of the remote release feature are
particularly advantageous in the case where large and heavy
prefabricated wall panels are to be installed, and where it would
be difficult for a worker to reach the hoisting attachments on the
upper end of the installed panel with his hand. The hoisting
shackle of the invention is suitable for application with the
heaviest building components, including components weighing up to
12 Mp (12,000 tons). It should be understood, that the
remote-controlled release mechanism may include means other than
the Bowden cable, such as, for example, release means which are
operable through the movement of the hoisting harness itself, or
which are operable by means of a long rod or the like. The latter
may include a cocked release spring arranged inside the annular
cavity 10 of shackle body 1 and a trigger mechanism which when
actuated, allows the release spring to retract the locking bolt
11.
It should be understood, of course, that the foregoing disclosure
describes only preferred embodiments of the invention and that it
is intended to cover all changes and modifications of these
examples of the invention which fall within the scope of the
appended claims.
* * * * *