PINCE SUR CORDE

ROPE CLAMP

Abrégé anglais

ABSTRACT OF THE DISCLOSURE
The present invention provides a rope clamp comprising
a sleeve of plastic malleable material arranged to be firmly
pressed around one or more rope parts, the improvement wherein
the sleeve is provided with an axial center hole having sub-
stantially the same cross-section over the entire sleeve length
and with a wall thickness which is thinnest at the mid-portion
of the sleeve and thickest at the end portions of the sleeve said
wall thickness varying continuously over the whole length of
the sleeve increasing from the mid-portion to each of the end
portions of the sleeve in a substantially uniform and progressive
manner, and, whereby a substantially uniform pressure is applied
to each rope part when the sleeve is pressed firmly around it.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A rope clamp comprising a sleeve of plastic
malleable material arranged to be firmly pressed around one or
more rope parts, the improvement wherein the sleeve is provided
with an axial center hole having substantially the same cross-
section over the entire sleeve length and with a wall thickness
which is thinnest at the mid-portion of the sleeve and thickest
at the end portions of the sleeve said wall thickness varying
continuously over the whole length of the sleeve in a substantially
uniform and progressive manner and increasing from the mid-portion
to each of the end portions of the sleeve, whereby a sub-
stantially uniform pressure is applied to each rope part when
the sleeve is pressed firmly around it.
2. A clamp as claimed in claim 1, in which the wall
thickness of the sleeve increases stepwise from the middle towards
the ends thereof.
3. A clamp as claimed in claim 1 or 2, including a
ferrule attached to one end of said sleeve.
4. A clamp as claimed in claim 1, in which the wall
thickness of the sleeve increases smoothly from the middle towards
the ends thereof.

Description

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C~ This invention concerns a rope clamp in shape of a -
sleeve or a ferrule with a sleeve-shaped part of plastic
malleable material, which sleeve or sleeve part is made to be
pressed firmly around one or several rope parts. Rope clamps of
such kind are applied to ropes in several manners. For instance
the connection can be made by pressing of the whole sleeve
length simultaneously or by pressing in sections or by rolling
longitudinally of the sleeve. The pressing can be made with
one or several rope parts inserted in the sleeve and independently
if the sleeve consists of the sleeve part, which at one end
turns into a fork, tap or some other part. The method of
pressing sleeves on to ropes sectionwise is time-wasting and
complicated. It requires in addition to this the utmost
exactitude to obtain a good result. The application by rolling
has disadvantages as the sleeve easily gets banana-shaped with
the consequence that the solidity of the rope connection is
reduced at straight load by this shape.
The pressing of a cylindrical sleeve or sleeve-shaped
part around a rope simultaneously in one stage over the whole
sleeve length is also connected with disadvantages.
When pressing the sleeve together there is an
accumulation of excess in the middle zone of the sleeve while
there is no such accumulation at the sleeve ends as the
material there has the possibility to flow in the axial ~ -~
direction. The rope part or the rope parts therefore are
subject to the highest compression strain in the middle zone
of the rope sleeve and to a lesser extent at the end parts of
the sleeve. This means that there is an undesirable irregular
pressure distribution in the rope clamp. The longer the sleeve
or the sleeve-shaped part is, which is to be pressed in one
stage, the more difference there will be between the pressure
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0363Z4
strain in the mentioned middle zone and the end parts of the
sleeve, When usin~ ferrules for only one rope part in contrary
to what is the case when making a loop, the load is transferred
entirely from the rope to the clamp as the rope is inserted only
at one end of the ferrule. In such a case the sleeve-sha~ed
part has to be extremely long especially if the rope exists of
thin wires on the surface. This makes the above mentioned
problem with different flows of the material in different parts
of the sleeve part during the compression and consequently the
irregular pressure distribution in the rope clamp especially
obvious, ~ :
Accordingly, the present invention provides a rope
clamp comprising a sleeve of plastic malleable material arranged
to be firmly pressed around one or more rope parts, the improve-
ment wherein the sleeve is provided with an axial center hole
having substantially the same cross-section over the entire
sleeve length and with a wall thickness which is thinnest at
the mid-portion of the sleeve and thickest at the end portions
of the sleeve said wall thickness varying continuously over the
whole length of the sleeve increasing from the mid-portion to
each of the end portions of the sleeve in a substantially uniform
I and progressive manner, and, whereby a substantially uniform
pressure is applied to each rope part when the sleeve is pressed
firmly around it, ~ .
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In one embodiment the wall thickness of the sleeve
or sleeve part increases continuously from the middle towards
the ends. In another embodiment the wall thickness of the sleeve
or sleeve part increases step by step from the middle towards -
the ends.
The present invention will be further illustrated
by way of the accompanying drawings of which:
Fig. 1 is a side-view of a sleeve according to one
embodiment of the present invention.
Fig. 2 is an end-view of the sleeve of Fig. 1;
Fig. 3 a cross-section along the lines III-III of
Fig. l;
Fig. 4 shows the sleeve of Fig. 1 applied as a rope
clamp with a loop before compression;
Fig. 5 the rope clamp of Fig. 4 after compression;
Fig. 6 is a side-view of a sleeve according to another
embodiment of the present invention;
Fig. 7 is a side-view of a ferrule with a sleeve part
in accordance with one embodiment of the present invention;
Fig. 8 is an end-view of the ferrule of Fig. 7 and
Fig. 9 a cross-section along the lines IX-IX of Fig. 7.
Referring to Figs. 1 to 3, there is shown a sleeve 1
for rope clamps of plastic malleable material, which has an -
axial centre hole 2 with oval cross-section for accommodating
two adjacent rope parts. The centre hole 2 has the same cross- ,-
sectional dimensions over the whole sleeve length. The jacket
surface 3 of the sleeve 1 is concave, the wall of the sleeve being
thinnest at the middle part 4 of the sleeve and thickest at
the end parts 5. This embodiment of the present invention has
a lot of advantages when applying the sleeve as a rope clamp.
For example a loop as per Fig. 4 has been chosen where the oval
sleeve 1 has been mounted over two rope parts 6 and 7 for making
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1036324
the loop 8. When compressing the sleeve 1 with a set of jaws
around the rope parts 6 and 7 the material of the sleeve will
flow in both axial and radial direction as described above.
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Due to the design of the sleeve 1 with the largest wall ~ -
thickness at the end parts 5 however there will be no
exceptional high pressure in the middle zone 4. On the contrary
after compression an even pressure will result along the
whole length of the sleeve 1 and because of the material flow
the sleeve will assume a more or less cylindrical shape as
per Fig. 5. In Fig. 6 there is shown an embodiment where the
jacket surface 10 of the sleeve 9 has a step-like configuration
to achieve the largest wall thickness at the end parts 11
of the sleeve 9. With this design the desirable result will
also be achieved during compression. In Fig. 7 there is shown
a ferrule 12 with a sleeve-shaped part 13 which according to
the present invention is formed with the smallest wall thickness ~ -
at the middle part 14 and the largest wall thickness at its
end parts lS. This rope clamp ha9 a circular centre hole
16 to take up only one rope part. Due to this the sleeve-
shaped part 13 is proportionately long to be able to take up ;
existing strains applied on the rope clamp. ~ -
In this embodiment, the aim of the invention becomes
still more obvious with regard to the achieving of an even
pressure on the rope part along the whole length of the sleeve
part 13. The invention naturally also can be used for other
typesof rope clamps or ferrules.
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