WO2022162576A1

WO2022162576A1 - Lifeline

Info

Publication number: WO2022162576A1
Application number: PCT/IB2022/050717
Authority: WO
Inventors: Giorgio CUCE'; Davide MAZZINI; Michele Lombardi; Emanuele BIAGI
Original assignee: Seares S.R.L.
Priority date: 2021-01-28
Filing date: 2022-01-27
Publication date: 2022-08-04

Abstract

It is provided a lifeline (1) comprising: a cable (2); a tensioner (4) of the cable (2) defining a first coupling (4b) to an external structure and a second coupling of the cable (2) to the tensioner (4) and comprising a cylinder (41) defining the first coupling (4b), a piston (42) sliding in the cylinder (41); a stem (43) defining a first end constrained to the piston (42) and a second end defining the second coupling (4c) and a constraint (44) constraining the piston (42) to the cylinder (42) so as to prevent their mutual motion unless a tensile force at least equal to a safety threshold is applied.

Description

DESCRIPTION

LIFELINE

The present invention relates to a lifeline of the type specified in the preamble to the first claim.

In particular, the object of the present invention relates to a safety device identifiable as a path at height (usually horizontal or with slight slopes) to which one or more operators attach themselves by means of harnesses and related lanyards to move safely along said path.

As is well known, lifelines (also known as "coupling lines", "linear couplings", "linear coupling systems" or "lifelines") consist of flexible and rigid horizontal coupling systems obtained with metal cables in the case of permanent lines or textile cables in the case of temporary lines.

The cables are usually straight, but in some cases, they may have curves, cross with other lines, follow the course of the ridge of a roof or the articulated course of a wall.

The well-known lifelines consist of a rope (e.g. a steel cable) defining the route, a rope tensioner, and a series of couplings configured to tie the rope and the tensioner to an external structure such as a roof or wall.

The stretcher consists of a threaded sleeve with opposite threads at both ends, and two tie stems tied to the rope, each of which is engaged at one end so that the sleeve, as it rotates, brings the tie stems closer together or further apart and thus allows the tension of the rope to be adjusted.

If the rope is particularly long, the lifelines may have one or more section-breaking couplings with a hole through the rope to hold the rope in place.

Finally, lifelines may have clamps used by the operator to attach himself to the rope by means of slings. Examples of lifelines are described in US20191 18011 A1 , JPH0584317A, GB343610A, EP2581115A1 , EP2316535A1 and AU2019257490A1 .

The known technique described includes some important drawbacks.

In particular, the known lifelines have high installation and operating costs. In fact, due to deterioration of the rope or the tensioner, for example, they require a periodic check of the rope tension in order to guarantee the necessary safety. This operation is complex and therefore difficult to perform.

In order to solve this problem, some lifelines have a tension indicator, which makes it easier to monitor the tension, but increases the cost of the lifeline and the complexity of installation. This increase is so significant that it often leads to the tension indicators not being used, which increases the risks for the operator.

In this situation, the technical task at the basis of the present invention is to design a lifeline capable of substantially obviating at least part of the aforementioned drawbacks. In the context of said technical task, it is an important aim of the invention to obtain a lifeline with reduced installation and management costs and procedures.

It is also an important scope of the invention to achieve a lifeline capable of providing high safety without the need for complex control operations and the adoption of expensive tools.

The specified technical task and purposes are achieved by a lifeline as claimed in the appended claim 1 . Examples of preferred embodiments are described in the dependent claims.

The features and advantages of the invention are hereinafter clarified by the detailed description of preferred embodiments of the invention, with reference to the appended drawings, wherein: the Fig. 1 shows, to scale, a sectional assembly of the lifeline according to the invention; the Fig. 2 illustrates, to scale, the assembly of Fig. 1 in a different position; the Fig. 3 shows, to scale, the assembly of Fig. 1 in a further position; and the Fig. 4 illustrates, to scale, a lifeline according to the invention.

In the present document, the measurements, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words like “about” or other similar terms such as “approximately” or “substantially”, are to be considered as except for measurement errors or inaccuracies due to production and/or manufacturing errors, and, above all, except for a slight divergence from the value, measurements, shape, or geometric reference with which it is associated. For instance, these terms, if associated with a value, preferably indicate a divergence of not more than 10% of the value.

Moreover, when used, terms such as “first”, “second”, “higher”, “lower”, “main” and “secondary” do not necessarily identify an order, a priority of relationship or a relative position, but can simply be used to clearly distinguish between their different components.

The measurements and data reported in this text are to be considered, unless otherwise indicated, as performed in the International Standard Atmosphere ICAO (ISO 2533:1975).

With reference to the Figures, the lifeline according to the invention is globally indicated by number 1.

It is configured to allow safe working and to which an operator can constrain himself by means of appropriate safety equipment (such as harnesses and lanyards) to, for example, prevent falls.

Such equipment may be of a known type and for example wearable. Lifeline 1 may include at least one cable 2.

The cable 2 may define the safe route, i.e. a route along which an operator can move safely while remaining constrained to the lifeline by said safety equipment.

In use, the cable 2 may be tensioned and define a working tension. The working tension may be substantially at least 500 N in detail substantially between 500N and 1500N and, for example, substantially 1000N.

The cable 2 may be metallic.

The safe path and thus the cable 2 may be straight.

Alternatively, the safe path may define a broken line or polyline and thus the cable 2 may identify a finite and ordered set of neatly oriented and consecutive segments of cable 2. To this end, the lifeline 1 may comprise at least one diverter 3 configured to vary the direction of development of the route.

The diverter 3 may be of a known type.

The lifeline 1 may comprise a tensioner 4 of the cable 2.

The tensioner 4 may define a longitudinal axis 4a. It is shown that at least one portion of the cable 2 adjoining the tensioner 4 defines a direction of development of the path substantially parallel and in detail substantially coinciding with the longitudinal axis 4a. The tensioner 4 may define a first coupling 4b of the tensioner 4 to an external structure 1 a (for example a wall or a roof) and a second coupling 4c of the cable 2 to the tensioner 4.

It is shown that when the tensioner 4 is constrained to the external structure 1 a the cable 2 is configured to subject said tensioner 4 to a tensile force (i.e. pushing the anchors 4b and 4c away from each other.

The tensioner 4 may comprise a cylinder 41 defining the first coupling 4b, a piston 42 sliding in the cylinder 41 and a stem 43 integral with said piston 42 and defining the second anchor 4c.

The stem 43 may protrude at least partially from the cylinder 41 regardless of the position of the piston 42 in the cylinder 41 .

The cylinder 41 develops substantially along the longitudinal axis 4a.

It may comprise a hollow cylinder 411 defining a sliding chamber of the piston 42 developing along the axis 4a; a base 412 closing a base surface of the cylinder 411 ; a coupling 413 defining the first coupling 4b; and in some cases, an additional base 414 closing the other base surface of the cylinder 41 .

The additional base 414 may define a stem 42 passage section.

The chamber may be hermetically sealed. Therefore, the coupling of the cylinder 411 with the base 412 and if present with the additional base 414 can be hermetic. Furthermore, the supplementary base 414 may comprise O-rings or other similar means for hermetically sealing the passageway section with respect to the stem 43.

The chamber may be filled at least partially (in detail totally) by a fluid, in detail a viscous fluid and more in detail a liquid such as oil.

The fluid may have a dynamic viscosity substantially at least equal to 25 centipoises, in detail to 50 centipoises and more in detail to 100 centipoises. The dynamic viscosity is measured with a viscometer in an ICAO International Standard atmosphere preferably according to the George Gabriel Stokes method.

The coupling 413 may comprise a shackle (or handle) preferably threaded.

The base 412 and the hollow cylinder 411 are mutually constrained in a resolvable manner by, for example threaded coupling.

The piston 42 is configured to slide in the chamber of the cylinder 411 .

It may have a cross-section substantially equal to that of the chamber.

The piston 42 is configured to divide the cylinder 41 and thus the chamber into two sub- chambers. It may comprise at least one through-hole configured to allow a fluid passage between said sub-chambers when piston 42 flows in the chamber; and preferably a valve for each through-hole configured to allow a fluid passage between said sub-chambers only when the fluid in one of said sub-chambers reaches a limiting pressure.

The stem 43 develops substantially along the longitudinal axis 4a.

It may define a first end and a second end.

The first end is constrained to the piston 42 so as to allow the piston 43 to slide in the cylinder by translating said stem along said longitudinal axis and

The second end defines the second coupling.

The stem 43 may comprise a tensioner configured to adjust the tension of the cable 2. In detail, it may comprise a first body 431 engaging the piston 42; a second body 432 defining the second coupling 4c; and a third body 433 interposed between the first body 431 and the second body 432 and suitably constrained thereto.

The first body 431 is integral with the piston 42. They may be constrained in a resolvable manner by, for example, threaded coupling.

The second body 432 may comprise an additional attachment defining the second anchor 4c and identifiable in a preferably threaded shackle.

The third body 433 may be constrained by means of a threaded coupling to at least one between the second body (432) and the first body 431 such that the third body 433 rotates controlling an approach or departure between the first body 431 and the second body 432 along the axis 4a. In detail, the third body 433 may be constrained to the second body 432 by means of a threaded coupling. In some cases, it is constrained to the second body 432 by means of a threaded coupling and to the first body 431 by means of an additional threaded coupling characterised by a threading opposite to that of the threaded coupling with the second body 432.

The third body 433 may have at least the proximal part to the second body 432 protruding from the cylinder 41 irrespective of the position of the piston 42 in the cylinder 41 so as to always allow a reciprocal motion control between the bodies 431 and 432. The third body 433 may comprise in correspondence to the portion proximal to the second body 432 a gripping portion which, therefore, is external to the cylinder 41 appropriately independent of the position of the piston 42.

Said gripping portion may comprise a key grip.

The tensioner 4 may comprise a constraint 44 constraining, suitably in solidarity, the piston 42 to the cylinder 41 so as to prevent a mutual motion thereof.

The constraint 44 may be configured to break when a tensile force at least equal to a safety threshold is present between the couplings 4b and 4c and thus between the piston 42 and the cylinder 41 . In particular, the constraint 44 is configured to break when the cable 2 exerts on the tensioner 4 a force at least equal to the safety threshold.

The safety threshold may be substantially greater than the working tension. In detail it is at least equal to 200% in detail 500% and to be precise 1000% of the working voltage. The safety threshold may be at least equal to 5000N in detail substantially between 5000N and 15000N and, for example, substantially equal to 10000N.

The constraint 44 may be along the longitudinal axis 4a so as to be subjected only to the tensile force avoiding torques/moments that could alter the operation.

For example, the constraint 44 may be a screw configured to engage to the piston 42 via threaded coupling and to the cylinder 41 by tightening the base 412 between the screw head (i.e. , the constraint 44) and piston 42. The base 412 may provide a through hole and in detail a positioning through hole so as to accommodate the screw head identifying the constraint 44. The constraint 44 may be detachably constrained to the cylinder 41 for example by means of a threaded coupling.

It may be detachably constrained to the piston 42 for example by threaded coupling. The tensioner 4 may comprise a cable 2 tension recuperator 45.

The recuperator 45 may be configured to oppose a reciprocal motion between the couplings 4b and 4c by counteracting a change in the tensile force acting on the piston 4 and thus between the couplings 4b and 4c. It can thus be configured to keep the tension of the cable 2 substantially constant by absorbing tension variation given, for example, by a change in temperature. More in detail, it is configured to absorb a variation in voltage of the cable 2 by absorbing the variation in length of the cable itself. More in detail it is configured to absorb a variation in length of the cable 2 substantially at least 0.5%.and in detail 1%.

In reality, without the recuperator the voltage on the cable could vary greatly, for example from 0 (slack cable) to more than 10,000 N, or rather by 1000%. In detail, the maximum cable voltage variation absorbed is basically 1%.

In conclusion, the recuperator 45 is able to absorb the variation of the length of the cable 2. Preferably, the maximum variation of the length of the cable absorbed by the recuperator 45 is at least 1%.

It is noted that the maximum voltage that can be absorbed by the recuperator 45 is lower than the safety threshold. Therefore, a variation in the voltage of the cable 2 (and therefore of the traction force on the piston 4), if lower than the safety threshold, is absorbed by the recuperator 45 restoring the working voltage (therefore the correct length of the cable 2), whereas if it is at least equal to the safety threshold it cannot be absorbed by the recuperator 45 and is discharged on the constraint 44 causing it to break. The recuperator 45 can be configured to exert a force of approach between said couplings 4b and 4c opposing to a variation of said pulling force and therefore of tension/length in the cable 2.

The approach force may be nearly parallel to the longitudinal axis 4a.

The pulling force is substantially equal to the tension in the cable 2 and consequently to the tensile force. Preferably it is substantially equal to the working tension.

Furthermore, it is pointed out that, in contrast to the cylinder-piston-stem system which opposes a reciprocal motion between the couplings 4b and 4c by damping it (i.e. not elastically), the recuperator 45 can elastically oppose the reciprocal motion between the couplings 4b and 4c. It may thus comprise elastic means suitably pre-loaded so as to exert said force of approach. The elastic means may be one or more springs.

The recuperator 45 may be kinematically interposed between the couplings 4b and 4c. In a non-limiting example, the recuperator 45 may be integrated in the stem 43, more precisely in the first body 431 . The first body 431 may thus comprise a connector 431a engaging the third body 433, a rod 431b integral with the piston 42 and sliding with respect to the connector 431 a and a stop 341 c integral with the stem 413b and enclosing the recuperator 45 between the connector 431 a and the same stop 341c.

The aforementioned additional threaded coupling may be made between third body 433 and connector 431 a.

Finally, the tensioner 4 may comprise a limit switch 46 of the piston 42 with respect to the cylinder 41 .

The limit switch 46 is configured to limit the travel of the piston 42 away from the first coupling 4b. In particular, it is configured to interpose itself between piston 42 and additional base 414 by slowing down the travel of piston 42 when it reaches the vicinity of additional base 414. The limit switch 46 may comprise at least one spring, preferably a compression spring. The operation of the lifeline 1 described above in structural terms is as follows.

The lifeline 1 is initially set up for example on a roof. The operator has cable 2 by defining the path in safety and then tension the cable 2 with the tensioner 4. In particular, as shown in Fig. 1 , he constrains the tensioner 4 to the external structure 1 a through the first coupling 4b and to cable 2 via the second coupling 4c.

Then, the operator brings the cable 2 to the desired working tension by exploiting the tensioner, i.e. the stem 43 (Fig. 2). In detail, he rotates around the longitudinal axis 4a the third body 433 which, thanks to the opposite threads, varies the distance along the longitudinal axis 4a between the first body 431 and the second body 432. This action varies the distance between connector 431 a and stop 341 c with consequent charging of the recuperator 45.

At this point the operator constrains himself by means of appropriate safety equipment to the cable 2 and thus safely performs a job.

If, during the work, the operator falls, the safety equipment discharges the operator's weight onto cable 2 causing a sudden increase in tension. If the tension and therefore the traction force on the tensioner 4 exceeds the safety threshold, the constraint 44 breaks (Fig. 3) and the cable 2 pulls the piston-stem assembly, which slides in the cylinder 41 until it compresses the limit switch 46, which slows down and stops the stroke.

This movement of the stem 43 and the piston 42 discharges the increase in tension on the fluid in the cylinder 41 which, exploiting its own viscosity, dissipates it, bringing the cable back to the working tension.

At this point it is possible to restore lifeline 1 simply by replacing the broken constraint

44 with a new constraint 44. It should be noted that lifeline 1 , remaining in place for the duration of the work, may be subject to a variation in temperature (for example determined by a change of season or weather variation). This causes a lengthening or contraction of cable 2 with a consequent variation in tension and therefore in the length of the cable itself. This variation would determine a reciprocal movement between the couplings 4b and 4c (therefore between the stem 43 and the cylinder 41 and in particular between the connector 431 a and the stop 341 c) which is however absorbed by the recuperator 45 without altering the tension of the cable 2.

The lifeline 1 according to the invention achieves important advantages.

In fact, the lifeline, compared to known solutions, presents a relatively reduced installation procedure and costs thanks, above all, to a particular tensioner 4 which allows in a simple way to put the cable 2 under tension and, moreover, to maintain the desired tension independently from the environmental conditions.

This latter aspect also makes it possible to avoid monitoring the tension of cable 2 and therefore simplifies maintenance operations on lifeline 1 .

This is accentuated by the integration of the tensioner in the stem 43 and then in the tensioner 4, which has made it possible to reduce the number of lifeline 1 components, simplifying installation and reducing costs.

Another important advantage is the high level of safety guaranteed by lifeline 1 .

In fact, the introduction of the constraint 44, defining a safety threshold, allows piston 42 and cylinder 41 to slide only when necessary, such as when the operator falls. In fact, this aspect allows the tensioner 4 to absorb the forces resulting from the caution without affecting the operator.

Another advantage is that the constraint 44 is replaceable, allowing the lifeline 1 to be quickly reinstalled and thus reducing the costs of using lifeline 1 . without the need for complex control operations and the adoption of expensive tools. The invention is susceptible to variations within the scope of the inventive concept as defined by the claims.

For example, the recuperator 45 may be integrated into the piston 42. In this case, the piston 42 may comprise a first head integral with the stem 43 and a second head sliding relative to the stem 43, and the recuperator 45 may be interposed between the first head and the second head so as to oppose a reciprocal motion of the two heads along the longitudinal axis 4a while keeping the cable tension 2 substantially constant. The constraint 44 may make the second head of the piston 42 integral with the cylinder 41.

In this respect, all details are substitutable by equivalent elements and the materials, shapes and dimensions can be any.

Claims

1. Lifeline (1 ) comprising:

- a cable (2);

- a tensioner (4) of said cable (2) defining a longitudinal axis (4a), a first coupling (4b) of an external structure to said tensioner (4) and a second coupling of said cable (2) to said tensioner (4); and characterised by said tensioner (4) comprises

- a cylinder (41 ) defining said first coupling (4b);

- a piston (42) sliding in said cylinder (41 ) along said longitudinal axis (4a);

- a stem (43) defining o a first end constrained to said piston (42) so as to allow said piston (42) to slide in said cylinder (41 ) translating said stem (41 ) along said longitudinal axis (4a), and o a second end defining said second coupling (4c);

- a constraint (44) constraining said piston (42) to said cylinder (42) so as to prevent them from moving reciprocally; said constraint (44) being configured to break when a tensile force at least equal to a safety threshold occurs between said couplings (4b, 4c) and therefore between said piston (42) and said cylinder (42).

2. Lifeline (1 ) according to claim 1 , wherein said cable (2) defines a working tension and said safety threshold is substantially greater than said working tension.

3. Lifeline (1 ) according to at least one preceding claim, wherein said constraint (44) detachably constrains said piston (42) to said cylinder (42).

4. Lifeline (1 ) according to at least one preceding claim, wherein said cylinder

(41 ) defines a sliding chamber of said piston (42) housing a fluid; wherein said piston

(42) divides said chamber into two sub-chambers and comprises at least one through- hole configured to allow a fluid passage between said sub-chambers.

5. Lifeline (1 ) the preceding claim, wherein said piston (42) comprises for each bore a valve configured to allow a fluid passage between said sub-chambers only when the fluid in one of said sub-chambers reaches a limiting pressure.

6. Lifeline (1 ) according to at least one claim 5-6, wherein said fluid has a dynamic viscosity substantially at least equal to 50 centipoises.

7. Lifeline (1 ) according to at least one preceding claim, wherein said tensioner (4) comprises an limit switch (46) of said piston (42) relative to said cylinder (41 ); and wherein said limit switch (46) comprises at least one compression spring configured to be compressed by said piston (42).

8. Lifeline (1 ) comprising:

- a cable (2);

- a cylinder (41 ) defining said first coupling (4b);

- a constraint (44) constraining said piston (42) to said cylinder (42) so as to prevent them from moving reciprocally; said constraint (44) being configured to break when a tensile force at least equal to a safety threshold occurs between said couplings (4b, 4c) and therefore between said piston (42) and said cylinder (42); and

- a recuperator (45) of tension of said cable (2) configured to oppose a reciprocal motion between said couplings (4b, 4c) counteracting a variation of tension of said cable (2) and therefore keeping substantially constant said tension of said cable (2).

9. Lifeline (1 ) according to claim 8, wherein said cable (2) defines a working voltage and wherein said recuperator (45) is integrated in said stem (43) and configured to absorb a variation in length of said substantially at least 1% of said length of said cable.

10. Lifeline (1 ) according to at least one claim 8-9, wherein said recuperator (45) comprises elastic means preloaded so as to exert an approaching force between said couplings (4b, 4c).

11. Lifeline (1 ) according to at least one claim 8-10, wherein said stem (43) comprises a tensioner configured to adjust said tension of said cable (2); and wherein said stem (43) comprises a first body (431 ) engaging said piston (42); a second body (432) defining said second coupling (4c); a third body (433) interposed between said first body (431 ) and said second body (432), and engaged to said first body (431 ) and said second body (432) with opposite threads; wherein said recuperator (45) is integrated in said first body (431 ); and wherein said first body (431 ) includes a connector (431 a) engaged to said third body (433), a rod (431 b) integral with said piston (42) and a stop (341 c) integral with said rod (413b) and enclosing said recuperator (45) between said connector (431 a) and said stop (341 c).

12. Life line (1 ) comprising

- a cable (2);

- a tensioner (4) of said cable (2) defining a longitudinal axis (4a), a first coupling (4b)

15 of an external structure to said tensioner (4) and a second coupling of said cable (2) to said tensioner (4); and characterised by said tensioner (4) comprises

- a cylinder (41 ) defining said first coupling (4b);

- a constraint (44) constraining said piston (42) to said cylinder (42) so as to prevent their reciprocal motion; said constraint (44) being configured to break when a traction force at least equal to a safety threshold is present between said couplings (4b, 4c) and therefore between said piston (42) and said cylinder (42); and by that said stem (43) comprises

- a first body (431 ) engaging said piston (42)

- a second body (432) defining said second coupling (4c); and

- a third body (433) interposed and constrained to said first body (431 ) and said second body (432), said third body being constrained by a threaded coupling to at least one of said first body (431 ) and said second body (432) so as to rotate controlling an approach or a departure between said first body (431 ) and said second body (432).

13. Lifeline (1 ) according to claim 12, wherein said third body (433) protrudes at least partially from said cylinder (41 ) irrespective of the position in said cylinder (41 ) of said piston (42) and therefore of said stem (43); and wherein said third body (433) comprises at least a grip portion proximal to said second body (432) and therefore to

16 said second coupling (4c).

14. Lifeline (1 ) according to at least one claim 12-13, wherein said tensioner (4) comprises a tension recuperator (45) of said cable (2) integrated into said first body (431 ) and configured to oppose a reciprocal motion between said couplings (4b, 4c) by counteracting a variation in the length of said cable (2) and thereby maintaining said length of said cable (2) substantially constant.

15. Life line (1 ) according to any preceding claim, wherein said first body (431 ) comprises a connector (431 a) engaging said third body (433), a rod (431 b) integral with said piston (42) and a stop (341 c) integral with said rod (413b) and enclosing said recuperator (45) between said connector (431 a) and said stop (341 c).

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