Note: Descriptions are shown in the official language in which they were submitted.
1846
~ACKG~OUND OF THE I~V~N'~ION
The subject invention concerns a li~ting sling in the
form of a rnat which is particularly designed to lift
cylindrical objects, such as pipes or rollers.
~ifting mats of this kind are used when it is
desirable to distribute the lifting stress overa large
area of engagement to avoid deformation of the lifted
object. At the same time lifting with the aid of a mat
improves the balance of the lifted object æupported in the
li~ting mat compared with when conventional roundslings
or web straps are used.
When large cylindrical objects are being lifted, it
is therefore common practice to use lifting mats
consisting of two or several woven and comparatively thin
fibrous webs which are positioned side by side. At their
ends, the woven fibrous webs are interconnected by means
of a lifting element, so as to form a lifting mat.
When lifting means of this kind are used, e.g. when
drainage pipes or pipelines are deposited in the ground,
the fibrous straps, and quite particularly the load-
carrying warp threads therein, are exposed to extreme wear
owing to their direct contact with the lifted objects as
well as with earth, gravel and water. In addition, lifting
means of this type are difficult to handle when the web
ends are to be connected to the end lifting elements,
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since sorne kind of locking arral~ement is necessary.
SUI,~fAR~ Ol~' T~IE SUl~J[~.C'Il I~VEN'~ION
'~he subject invention provides a lifting mat which
possesses a higher lifting capacity than conventional
lifting means of comparable weight, and which is more
simple to handle and more resistant to wear than are
prior-ar-t lifting mats. In add:ition, the lifting mat in
accordance with the invention does not require locking
means to attach the lifting mat to a lifting element.
'lhe lifting mat in accordance with the invention is
also cheaper to manufacture than are lifting mats of
conventional design which consist of woven fibrous straps
the ends of which must be attached to the strap to form
lifting loops. '~he requirements on strength on such joints
are considerable and they are therefore often provided
with reinforcement means.
'rhe lifting mat ln accordance with the invention is
characterised in that it is composed of two or several
slings which are positioned side by side, each such sling
consisting of an elongate loop of parallel threads and
extending inside its individual channel, which channels
are formed by a wrapping enclosing the slings, a portion
of each sling protroding from its respective channel at
each channel end, said protroding portions being
individually enclosed by protective coverings and forming
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lif-ting loops.
BRIEF DES~RIPTION OF T~-L~ D~ WLNGS
The invention will be described in closer detail in
the following with reference to the accompanying drawings
on which are represented several embodiments of the
inventive object. In -the drawings,
Fig, 1 shows the lifting mat in accordance with the
invention while in use,
Fig. 2 is an end view of the lifting mat together
with its lifting element,
Fig, 3 shows the lifting mat in extended position in
a broken perspective view,
Fig. 4 illustrates a liftingloop on an enlarged scale
and
Fig. 5 and 6 show a part of the lifting mat in
accordance with two different embodiments thereof.
DETAI~ED DESCRIPTION OP A PREFE~RED E~ODIMENT
The lifting device illustrated in Fig. 1 consists of a
lifting element 1 and a lifting mat 2 laid around a tube 3.
The lifting element 1 is suspended from the lifting hook 4
of a hoisting crane and is in the form of a flat iron 5
which is fitted on each side with a number of hooks 6. The
ends of the lifting mat 2 are provided with loops 7, the
number of which corresponds to the number of hooks 6,
Fig. 2 illustrates the lifting hooks 6 of the lifting
element 1 more clearly. As appears from this drawing
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846
figure, the hool~s 6' on one side are formed with a wider
opening or loop-receiving aperture than are the hooks on
the opposite side. r~his is done in order to facilitate
hooking-on and hookin-off of the lifting loops 7 at one
end of the lifting mat while at the same time this
arrangement ensures that the lifting loops at the oppo~ite
end of the mat are securely retained in position in the
hooks when the lifting mat is applied around or is removed
from the object to be lifted.
~he lifting mat 2 illustrated in Fig 3 i8 provided
with a wrapping which is in the form of a doubled cloth 8
made from a water-repellant and wear-resistant material,
preferably polyester of nylon-reinforced PVC plastics. ~he
lengthwise marginal edges of the cloth are interconnected,
preferably at the centre of the lifting mat, by means of a
seam, which could be made either by welding or sewing or
be some other suitable type of seam.
Elongate slings 9 made from parallel strands of
synthetic fibre yarns are sandwiched between the walls of
the cloth 8 in such a manner that a portion of each ~ling
projects beyond the transverse marginal edges of the cloth,
thus forming the lifting loops 7.
Lengthwise seams 10, formed by e.g, welding or sewing,
interconnect the walls of the cloth 8, whereby channels 11
are formed which separate the individual slings 9 from
184~;
each o-ther. ~ach lifting loop 7 is provided with its
individual protective covering 12 which i9 made from a
woven synthetic-fibre cloth and i8 provided with a leather
lining 13 in the areas of the ]oop intended to engage with
the hooks 6.
Fig. 5 illustrates a second embodiment of the sling
in accordance with the invention, according to which the
wrapping consists of a number of hoses 14 forming the
channels 11 of the wrapping. ~engthwise seams 15
interconnect the hoses in parallel relationship. As in the
first embodiment, the slings extend lengthwise inside the
channels 11 in such a manner that their ends protrude
beyond the channels, forming the lifting loops 7 at the
channel ends.
~he third embodiment illustrated in Fig. 6 is
distinguished from the previous embodiment only in that the
hoses 14 are interconnected by means of straps 16 extending
lengthwise intermediate neighbouring hoses, ~his embodiment
makes it possible to manufacture lifting mats with identical
lifting capacity but of different ~idths.
Because the synthetic-fibre yarns making up the slings
9 are able to move freely inside the channels 11, the load
is distributed more e~enly over the fibres, with the result
that the lifting mat as a whole is able to take heavier
load in relation to its weight than do wo~en lifting mats
11~1846
of equivalent wei~!~t. `i~ereas loops of conventional fibrous
webs extend in a line of engagernent which is parallel to
the plane of the lifting mat and therefore require the use
of special melnbers or locking means to attach the lifting
loops to the lifting element, this i~ not necessary in the
lifting mat in accordance with the subject invention. On the
contrary, the lifting loops 7 on the mat may be hooked
directly onto the hooks 6 formed on the lifting element 1.
Because the wrapping encloses the strands forming the
slings, the latter are protected from wear and from the
detrimental effects of dirt and water. Worn-out patches
of the wrapping are easily mended which can be done without
impairing the strength of the lifting mat,
Fig, 6 shows the slings 9 fitted with a protective
covering 12 that eætends along the entire length of each
sling. This arrangement gives the lifting mat additional
wear resistance. Obviou~ly, the slings 9 illustrated in
~igs 3 and 5 could be similarly fitted with protective
coverings of this kind.
The invention is not limited to the embodiments
illustrated and described above but a number of
modifications are possible within the scope of the appended
claims. '~he lengthwise seams 10 need not extend along the
entire length of the wrapping. The essential feature is that
the slings 9 are kept separated from each other.
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The invention is not either limited to be used in
connection with tubes or rollers but could be u~ed also to
li~t other objects, e.g. bulk commodity packages, such
as sack loads.
