Note: Descriptions are shown in the official language in which they were submitted.
1~4~S92
The inventioll relates to a tensionillg device particularly for tie
down chains.
DE OS 26 23 827 discloses a device, to be used in conj~mction with a
releasable locking means for tensioning tyre chains. This tensioning device
has proven satisfactory in use, al~hough locking and unlockillg it requires
more than one step. For instance at least one safety-pin must be released
and the chain must be lifted out of a hooked hinge-member. This known
tensioning device is too complex under certain circumstances, for example
in emergency conditions. This applies more particularly when the device is
to be used to tension chains~ for tying goods down, since it often becomes
necessary to release a number of locking means in a very short time. Further-
more, locking and unlocking this known tensioning device requires not only
sufficient room but also under certain circumstances, the use of tools.
It is the purpose of the invention to provide a tensioning device
designed in such a manner that it can be easily connected to and disconnected
from a chain even when there is very little room and without the use of tools.
According to the invention there is p-rovided a tensioning device that
fulfills three functions including a coarse shortening of a chain, a tension-
ing thereof and a rapid opening thereof, especially for lashing chains having
chain links in a chain strand of chain members, which comprises in combination:
a housing, a double nut rotatably journalled over a part of the length thereof
being protected in said housing, two link members for receiving chain links,
at least one link member having a receiving opening in which at least sub-
stantially each chain member of the chain strand can be connected, said link
members being movable relative to one another and having a releasable latch
means including a securing member associated with the receiving opening of
at least one link member with which a chain member located in the receiving
opening is to be secured, said securing member being mounted at least
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partially yieldably shiftable in a released position as journalled on the
tensioning device, at least one of said link members having a fork-like
shape with two freely projecting legs which extend parallel to one another
and are interconnected by a transverse piece, said link members being
adapted to be held in a closure position under tension, with at least one
link member, under the force of a connected tensioned chain, being adapted
to be movable rapidly into a release position, two spindles with a left
thread and a right thread journalled in said double nut so that said spindles
simultaneously can be adjusted oppositely relative to each other with said
double nut including both tensioning and coarse shortening therewith,
without any additional auxiliary tools, and an actuating element rigidly
connected upon said double nut for rotation of said double nut, said
spindles projecting with ends thereof away from each other out of said
double nut and being provided at these ends with a connection link member
providing one receiving opening for the chain member.
The design according to the invention permits rapid and reliable
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locking, tensioning and ~mlocking of a tie-down chain, without the use of
additional tools. It is also possible to use the device where there is little
room for rotating a turnbuckle where one of the connectors or hingc members
opens automatically, under chain tension, after the relevant locking means have
been released. All parts are easily accessible and operate reliably, and this
allows the tensioning device according to the invention to be used under emergeny
conditions also.
In order to ensure that the hinge members are not twisted during the
tie-down, but maintain their position in relation to the tensioning device while
the chains are being tensioned, one preferred characteristic of the invention
provides two spindles, having right, left-hand threads respectively for moving
the hinge members. The spindles are adjustable in opposite directions by means
of a double nut. A slotted tube to guide the spindles is arranged between them
and the double nut. The spindles are guided longitudinally in the slotted tube
during tying-down, so that the hinge members connected to the said spindles
maintain their positions in relation to the tensioning device during the adjust-
ing process. The slotted tube also achieves compulsory opening of the syindles,
so that the latter are adjusted simultaneously in opposite directions under all
circumstances.
In the accompanying drawings, which illustrate exemplary embodiments
of the present invention:
Figure 1 is a plan view of a tensioning device according to the
invention, comprising pivotable hooks, a safety-sleeve, and a forked hinge-member;
Figure 2 is a section along the line I-[ in Figure l;
Figure 3 is a plan view of a variant of the releasable locking means,
with pivotable hooks;
Figure 4 is a section along the line III-III in Figure 3;
Figure 5 is an enlarged view of point A in Figure 1, partly in section;
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Figure 6 is an enlarged view of point B in Figure 2, partly in
section;
Figure 7 is a plan view of another variant of the locking means, with
a spring-loaded support-piece;
Figure 8 is a section along the line VII-VII in Figure 7, with an
adjoining tensioning device having a ratchet;
Figure 9 is a side elevation in direction C according to Figure 7
and is fou~d~on t~e $ame sheet as Figure 7;
Figure 10 is a vertical section through the built-in ratchet;
Figure 11 is a longitudinal section through another variant of the
tensioning device;
Figure 12 is a section along the line XI-XI in Figure 11.
Referring to the drawings, and particularly to Figures 1 and 2,
the tensioning device has two spindles 13, each having a self-locking thread
22. The threads are right and left-hand on the respective spindles. The two
spindles 13 are mounted in a double nut 6. Tensioning is effected by means
of serrated hand-tube 10, permitting the transfer of a force of about 4000 N.
For larger preload forces, a ratchet, to be described hereinafter, replaces
the tube 10, see Figure 8. A tensioning stoke of up to 75 mm to right and
ZO left is provided by rotating tube 10. Tube 10 is secured to double nut 6
by means of a locking pin 11. The rota-l~ motion for tensioning the device
is indicated by a mark "ON" or the like made on tube 10. A tube 5 protects
spindles 13 from dust and dirt. Numeral 21 indicates a stop pin.
All parts of the tensioning device are rsplaceable and above all
maintenance-free. Parts in direct engagement with outside parts are heat-
treated to promote wear-resistance. The tensioning device is reliable even
when dirty and covered with dust. The material used may be 16 ~fn Cr 5.
The tensioning device has, at one end, a pivotable hook 1. The
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opening for the accommodatlon of the chain, formed by this hook, is bridged
by lever 2. Hook 1 is arranged between the two parallel freely projecting
legs of a forked connector 3 and is adapted to pivot about the axis of
a pin 4.
The configuration of hook 1 is such that a moment arm x is formed
between axis 4 of rotation of hook 1 and the line of action of the force exerted
by a chain 16 on the hook, i.e. the tension of the chain must be applied
eccentrically with respect to the pin 4. The moment produced acts in a direct-
ion tending to open the hook 1. This configuration of the hook leads to
faster unlocking. After the locking means of pivotable hook 1 has been released
the latter pivots downwardly and thus immediately releases the chain. This
release of the chain is assisted by the eccentric point of application of
the chain tension in hook 1. Rapid and easy unlocking is thus assured.
As shown in Figures 1 and 2, lever 2 also pivots about the pin 4
but it may also be rigidly attached. The lever 2 consists of two parts
adjoining the legs of forked connector 3 and lying in the plane of those
legs. It may be straight or curved in a direction opposite to that of hook 1.
What is important is that the opening formed by hook 1, for the accommodation
of the chain, be bridged. When curved, lever 2 forms a ring with hook 1,
as shown in Figure 2.
As shown in Figures 3 and 4, the two parallel legs of forked connector
3 may be bent obliquely upwards, thus bridging the opening formed by hook l
for the accommodation of the chain. In this case, the bent legs serve as a
rigid lever 2 and the free end of pivotable hook 1 is connected detachably
to the said lever. Any suitable means of attachment may be used for this
detachable connection. In the example in question, use is made of a locking
pin 1~. As may be gathered from Figures 3 and 4, the hinged members may be
incorporated alone, without any tensioning device, as independent elements
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in$o the tie-down system.
I`t is also possible, to lock the pivotable hook without loading the
lever 2. To this end, hook 1 is extended beyond pin 4 and the extended port-
ion is locked to the tensioning device - Figure 2. This locking is effected
by means of a sliding sleeve 7 mounted displaceably upon the said tensioning
device. With hook 1 in the locked position, sleeve 7 is pushed over the end
of the extension of hook 1. ~his end of hook 1 has a recess in which a
correspondingly designed part of sliding sleeve 7 is engaged. Since
the sleeve 7 is displaceable upon the tensioning device, recess 15 in hook
1 must run parallel, or almost parallel, with the outer wall of the tensioning
device. Sleeve 7 is mounted upon a compressi~n-spring 9. Spring clips 8
retain the sleeve 7 and spring 9 on the tube 5. Rapid unlocking is achieved
merely by pushing sleeve 7 back. This releases the extension of pivotable
hook 1, allowing the latter to pivot downwardly under the load. This releases
chain 16 and the tie-down point.
According to Figures 1 and 2, forked connection 3 and forked hinge-
member 3' are located at the ends of the tensioning device and are displaceable
in relation to each other. Locking pin 12 in hinge-member 3' allows chain 16
to be roughly shortened very rapid]y. As may be gathered from Figures 5 and
6, pin 12 may be secured in forked hinge-member 3', preferably by two
balls 17 acted upon by compression springs. Each ball 17 has a compression
spring 18 mounted in a guide 20 accessible from the outside. Suitable counter-
pressure causes the said balls to move in the direction of spring-guide 20, thus
allowing locking pin 12 to be inserted into the aligned apertures in the paral-
lel legs of forked hinge-member 3'. If the counter-pressure acting upon balls
17 ceases or is reduced, compression springs 18 cause a part of the surface
of each ball to project out of ~pring-guide 20. The projecting parts of the
balls engage in corresponding recesses in pin 12. A spring-loaded ball 17 is
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preferably provided in each leg of hinge-member 3', to ensure that the said
pin does not inadvertently fall out. Appropriate tension applied to pin 12
forces the balls back in the direction of spring-guide 20, provided that
the said tension is greater than the force of the springs.
Spring-guide 20 is preferably at an angle of 45 to the axis of
pin 12. In order to facilitate introduction, the diameter of pin 12 is
somewhat smaller than that of the apertures provided for the accommodation
thereof. Play 14 therefore remains between the walls of the said apertures
and the pin.
As already indicated, the tensioning device with the hand-tube 10~
illustrated in Figures 1 and 2, is suitable for small preload forces of up
to about 4000 N. For larger preloads, it is preferable to use a ratchet 23.
As may be gathered from Figure 8, the ratchet is arranged centrally of the
tensioning device. It has hitherto been usual to use tommy-bars for large
tensioning forces. However, in contrast to ratchets, tommy-bars can be used
only when enough room is available to rotating the tensioning device. Ratchet-
bar 24 is arranged to fold and has a detent arrangement ~not shown). If the
said bar were to project, there would be a danger of injury and tripping.
The tension achieved is maintained by a locking means 29.
The quick-release mechanism arranged at one end of the tensioning
device comprises a spring-loaded element 25 which is free to pivot in all
directions. One end of spring 26 thereof is guided upon a stud 27 fitted to
end-plate 28 of the tensioning device. The other end of the said spring
is accommodated in a recess in element 25. Fitted to the other end of the
tensioning device is the forked hinge-member 3' described above.
The tensioning device according to Figures 11 and 12 has two spindles
13a with right and left-hand threads respectively. A double nut 6a is mounted
on each spindle, preferably by means of a threaded bush 30. Part of the length
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of the double nut is covered with a hand-tube lOa which is prevented from
rotating, in relation to the said double nut, by a locking pin lla. In the
area between the two bushes 30, spindles 13a are surrounded by tubes 31 loc-
ated between the spindles and double nut. Tubes 31 are spaced from spindles
13a and bear against the inner walls of the said double nuts. Each of the
spindles is provided near the end facing the other spindle, with a guide-pin
32 engaging in a slot 33 running lengthwise of tube 31.
Rotating hand-tube lOa causes the double nuts and, through threaded
bushes 30, the two spindles 13a, to move simultaneously in opposite directions.
Since the said spindles are guided by pins 32 in slots 33, this produces
very uniform simultaneous adjustment of the spindles. This guidance also
prevents the spindles from rotating about their axes, and thus prevents the
hinge-members ~Figures 1 and 2), which are secured thereto, from being
rotated.
