EP4711263A1

EP4711263A1 - Block with a textile axle

Info

Publication number: EP4711263A1
Application number: EP25201995.5A
Authority: EP
Inventors: Roberto Carraro; Bernardo Jacopo ZIN; Roberto FAVERO
Original assignee: Antal Srl
Current assignee: Antal Srl
Priority date: 2024-09-13
Filing date: 2025-09-12
Publication date: 2026-03-18
Also published as: AU2025230783A1

Abstract

A block (1) with a textile axle, comprising a unitary body (2) which is substantially toroidal and which has an external annular groove (3) which is provided to receive a first rope (25) to be redirected and a central passage (4) which is provided to receive in direct contact a second rope (26) which acts as a textile axle of the block, as well as a partial closure element (11) of the external annular groove rotatable with respect to the unitary body. The partial closure element is rotatably supported on the unitary body by means of bearings (15) interposed between the partial closure element and the unitary body coaxially with the central passage and comprises two walls (9, 10) which are parallel and spaced apart from each other. The bearings comprise rolling elements (16) received in rolling tracks (7, 8), the internal ring (12) of which is formed on the unitary body and the external ring (13) of which is formed on the respective wall. The walls are axially retained by the bearings as a result of the effect of the connection between the rolling elements and the respective internal ring and external ring. The rolling tracks are removably closed by a respective flange (17) for retaining the rolling elements in the corresponding rolling tracks.

Description

The invention relates to a block with a textile axle, i.e. a low-friction ring for redirecting ropes.
Rings of this type are widely used in the nautical sector for redirecting textile rigging, ropes and sheets, particularly on sailing boats.
These rings differ from the more common blocks in that they are made solely of an essentially toroidal unitary body, generally made of light alloy with a thick anodised surface that is particularly hardened and slippery, having an external annular groove provided to slidably house a first rope to be redirected and a central passage arranged to accommodate in direct contact a second rope generally used for retaining the ring. The ring functionally replaces the pulley of a block and the second (retaining) rope acts as a textile axle so that the ring can rotate around the second rope, usually a loop of Dyneema^® or similar low-friction, high-strength material.
In these rings, there is the problem of preventing the first rope from derailing, which would cause it to rub directly against the second rope with very rapid wear and tear and consequent failure of the system. In other words, the derailing would cause the redirect rigging (first rope) to slide over the fastening (second rope), bypassing the ring, which would thereby lose its function.
This problem is addressed by applying a partial closure element to the external groove that prevents it from derailing.
A low-friction ring with partial closure is described for example in IT202000032444A1 on behalf of the Applicant. The solution described therein provides that the partial closure element is rotatably supported on the unitary body by means of bearings interposed between the partial closure element and the unitary body coaxially to the central passage. Specifically, the partial closure element comprises two parallel walls spaced apart from each other, and the bearings are interposed between the walls and a respective flange of the unitary body outside the annular groove.
The above solution lends itself well to the construction of low-friction rings of medium and large size, but has the drawback that the walls must be permanently joined by at least one bridge extending between them radially outside the unitary body; if the bridge is removed, the walls separate and the bearings come out of their seats. This means that, during use, the closure element cannot be opened to afford access to the external annular groove. As a result, the structure of this known ring is impractical for redirecting rigging lines that are rigged before positioning the block, such as genoa or spinnaker sheets or mainsail halyards.
Other types of rings with partial closure are described, for example, in EP3939877A1 , EP3016848 , US10322918 or ES2599393 .
FR2923451 , on the other hand, describes a conventional block (not a block with a textile axle) comprising a pulley that is supported by ball bearings between two walls, which in turn are interconnected by a central portion with a passage for a textile retaining element. In turn, the pulley is supported on the central portion by a roller bearing. This is not a block with a textile axle but a conventional block whose structure is better described in FR2945603 . It is also clear from the dissymmetry of the block that it does not allow the use of the retaining rope as the textile axle of the pulley, the latter being supported instead by a roller bearing as well as a bushing. It also requires a multiplicity of components of considerable cost and complexity, subject to coupling and relative rotation, thus losing the main advantage of low-friction rings, which consists in their unparalleled simplicity of construction.
The problem underlying the present invention is to provide a block with a textile axle that is structurally and functionally designed to overcome at least some of the drawbacks complained of with reference to the aforementioned prior art.
Within this general scope, it is a purpose of the invention to enable the construction of a block with a textile axle with a minimal number of components.
A further purpose of the invention is to provide a block with a textile axle that simplifies assembly and maintenance.
It is also a purpose of the invention to provide a versatile block with a textile axle suitable for redirecting different types of rigging lines. A further purpose of the invention is to provide a highly efficient block with a textile axle.
This problem is solved and these purposes are achieved, at least in part, by the invention by means of a block with a textile axle comprising an essentially toroidal unitary body having an external annular groove provided to receive a first rope to be redirected and a central passage provided to receive in direct contact a second rope acting as the textile axle of the block.
Preferably, the block further comprises a partial closure element of the external annular groove ratable with respect to the unitary body. Advantageously, the partial closure element prevents the derailing of the rope to redirect.
Preferably, the partial closure element is rotatably supported on the unitary body by bearings. This minimises rotational friction and also minimises rotational play. As will be evident from the following description, play-free rotation facilitates the closing of the closure element.
Preferably the bearings are interposed between the partial closure element and the unitary body coaxially to the central passage. Preferably the partial closure element comprises two parallel walls spaced apart from each other.
Preferably, the bearings comprise rolling elements received in rolling tracks, the internal ring of which is formed on the unitary body and the external ring of which is formed on the respective wall.
Preferably, the walls are axially retained by the bearings as a result of the effect of the connection between the rolling elements and the respective internal ring and external ring.
Preferably, the rolling tracks are removably closed by a respective flange for retaining the rolling elements in the corresponding rolling tracks.
In this way, both the walls and the respective bearings are axially retained on the unitary body of the block regardless of whether the walls are joined together or not. This means that, during use, it is possible to open the closure element to afford access to the external annular groove without losing the bearings. Thanks to this arrangement, the block of the invention facilitates the redirecting of rigging lines that are rigged before the block is positioned, such as genoa or spinnaker sheets or mainsail halyards.
The present invention may also have one or more of the following preferred features in addition to those mentioned above.
Preferably the central passage is flanked by respective axially projecting shoulders on which the internal ring of the respective rolling tracks is formed. In this way, a compact and resistant structure is obtained.
Preferably, the external ring is formed partly on the respective wall and partly on the respective flange. This feature simplifies the assembly and maintenance of the bearings.
Preferably the flanges are fixed to the respective walls by way of releasable connection means, particularly of the threaded type. Also this feature simplifies assembly and maintenance operations.
Preferably the walls can be opened to afford access to the external annular groove by rotating one wall with respect to the other. In this way, the external annular groove can accommodate rigging lines that are rigged before the block is positioned.
It is preferred that the walls are structurally independent from each other. Further preferred is that the walls are joined in a releasable manner via a bridge extending between them radially outside the unitary body. Advantageously, the bridge acts as a partial closure of the groove to prevent a rope engaged in it from derailing from the groove. In addition, the bridge prevents the walls from closing on the unitary body under stress, hindering its rotation.
Preferably, the bridge comprises a first and a second portion integral to one and the other of said walls respectively, and preferably connection means configured to releasably join the first portion to the second portion, preferably by rotation of one wall relative to the other. Advantageously, the joining of the two portions of the bridge by means of the connection means prevents the accidental opening of the closure element and makes it more solid and less deformable.
Preferably the two portions of the bridge are configured to be joined in a releasable manner by rotation of one wall relative to the other. It is important to note that this configuration is made possible by the fact that the partial closure element is rotatably supported on the unitary body by bearings. In fact, the bearings minimise rotational play and therefore facilitate the meeting of the two portions of the bridge during the rotation of one wall with respect to the other.
Preferably, the connection means comprise a male/female coupling that is formed on mutually facing surfaces of said first and second portions. Advantageously, the male/female coupling is configured to releasably join the first portion to the second portion by rotation of one wall relative to the other. In this way, it is sufficient to turn one wall relative to the other to couple or uncouple the two portions of the bridge.
In a preferred example, the male/female coupling includes a circumferential guide with a dovetail. This provides both axial and radial coupling between the two portions of the bridge.
It is important to note that the coupling of the two portions of the bridge by means of the male/female coupling is made possible by the fact that the partial closure element is rotatably supported on the unitary body by bearings. The bearings minimise rotational play and therefore facilitate the meeting of the male and female portions of the coupling. This consideration applies all the more in the case of a precision coupling such as a dovetail coupling.
In embodiments, the connection means comprise a spring-loaded ball, also known as a ball presser, which acts between mutually facing surfaces of said first and second portions to counteract the rotation of one wall with respect to the other. The spring-loaded ball thus prevents accidental opening of the bridge, increasing the reliability of the block.
In embodiments, the connection means comprise openings formed on said first and second portions for a fastening rope to the second rope. In this way, the fastening rope binds the two portions of the bridge together and simultaneously restrains the walls from rotating together with the unitary body.
In embodiments, the connection means comprise a textile ring formed by the second rope. Preferably the textile ring is anchored to the walls by means of respective rope-stopping clamps and is preferably openable by means of a toggle type fastening. In this way, when the block is under load, the tension of the textile ring tends to keep the two portions of the bridge together (it is important to note that the two portions of the bridge serve not only to constrain the walls together but above all to maintain their correct orientation by preventing them from rotating and "touching" the rigging line); on the other hand, when the block is unloaded, the two portions of the bridge are easily separated by opening the toggle type fastening. This solution therefore increases safety and user-friendliness.
In any case, it is preferable for the second rope to be tied to the walls, possibly by means of the third rope or alternatively by means of rope-stopping clamps, so as to maintain the correct orientation of the walls and prevent them from rotating and touching the rigging line to be redirected.
According to a further advantageous aspect of the invention, the external annular groove has a diameter greater than or equal to 3 or preferably 4 times the diameter of the central passage. This dimensional ratio increases the efficiency of the block because the lever arm of the active torque exerted by the first rope to be redirected prevails over the lever arm of the passive torque exerted by the second rope in direct contact with the central passage.
Further preferred aspects are also defined in the appended claims as well as in the following description.
The features and advantages of the invention will best be seen from the following detailed description of a preferred but not exclusive embodiment thereof illustrated, by way of indication and not limitation, with reference to the accompanying drawings in which:

Fig. 1 is a perspective view of a block with a textile axle according to the invention;
Fig. 2 is a perspective view of the block in Figure 1, illustrating its operation;
Fig. 3 is a front view of the block in Figure 1;
Fig. 4 is a sectional view according to section line IV-IV of the block in Figure 3;
Fig. 5 is a side view of the block in Figure 1;
Fig. 6 is an exploded perspective view of the block in Figure 1;
Figs. 7 and 8 are perspective views of an embodiment of the block according to the invention;
Figs. 9 and 10 represent further embodiments of the block according to the invention.

In the drawings, a block with a textile axle for redirecting ropes and the like, typically used for redirecting textile rigging lines, ropes and sheets, particularly on sailing yachts, is collectively referred to as 1. The block 1 comprises a unitary body 2, i.e. a body made in a single piece or formed of interconnected parts in such a way as to create a unitary solid structure, essentially toroidal and having an external annular groove 3 preferably with a rounded profile to receive a first rope 25 to be redirected and a central passage 4 with an axis orthogonal to the median plane of the groove 3 and also rounded with a large radius of curvature R so as to be provided to receive in direct contact a second rope 26 (hereinafter also referred to as a retaining rope) which generally serves as a retaining and textile axle of the ring but which can in turn be slidable in the central passage thanks to its rounded profile.
The body 2 is preferably made of thick anodised light alloy, but can optionally be made of steel, titanium, or other metal material with high strength and a low coefficient of friction.
As shown in the example in Figure 4 on the axially opposing sides of the groove 3 respective shoulders 6 are preferably formed, extending substantially at right angles from the groove 3 to define the internal ring 12 of respective rolling tracks 7, 8 for bearings 15 with rolling elements 16. Preferably, the shoulders 6 have a respective external face (i.e. facing the groove 3) in which the internal ring 12 is formed and an opposing internal face that connects in a rounded manner to the central passage 4 to actually define the desired approximately toroidal conformation. Preferably, the internal ring 12 is also formed as a single piece in the body 2, but it is envisaged that it can be made in the form of a bearing race or the like on the shoulders 6.
Since these bearings are subject to a relatively low load, plastic balls such as Delrin^® or the like can be used. It is also envisaged that the bearing, instead of a rolling bearing, may be a sliding bearing or another type, e.g. made of Teflon^™ or another material with a low coefficient of friction.
The external ring 13 of the respective rolling track 7, 8 is formed in a position facing the internal ring 12 on a corresponding wall 9, 10 which is part of a partial closure element 11 of the external annular groove 3. Preferably, a first half of the external ring 13 proximal to the mid-plane of the block is formed as a single piece on the respective wall, while the other half of the external ring 13 distal from the mid-plane of the block is provided on a flange 17.
Advantageously, the walls 9, 10 are held axially by the bearings 15 due to the effect of the connection between the rolling elements 16 and the respective internal 12 and external 13 rings.
In a further advantageous aspect, each rolling track 7, 8 is removably closed by a respective flange 17 for retaining the rolling elements 16 in the corresponding rolling tracks.
The flange 17 is preferably fixed to the respective wall 9, 10 by releasable means 18 to simplify the assembly of the bearings. In a preferred example, each flange 17 is constrained to the external face of the respective wall 9, 10 by screws or bolts.
Coaxially to the central passage 4, the flange 17 preferably has a central hole passing through the second rope 26, through which the respective shoulders 6 can protrude axially. This allows the second rope 26 to slide over the rounded profile of the shoulders 6 without compressing the flange 17.
Preferably, the walls 9, 10 are parallel and spaced apart and preferably comprise a first and second portion 14a, 14b, respectively, radially projecting, which together form a bridge 14 acting as a partial closure of the groove 3 to prevent a rope engaged therein from derailing from the groove. In this way, the body 2 is free to rotate on the textile axle defined by the second rope 26 and the first rope 25 is retained in the groove 3 so as to prevent it from accidentally derailing.
Advantageously, the walls of the block with a textile axle, unlike those of conventional blocks, do not have a structural function. Therefore, being unloaded, the walls 9, 10 can be made of lightweight materials, e.g. plastic.
Preferably the walls 9, 10 are structurally independent from each other and joined in a releasable manner by means of the bridge 14 which extends therebetween radially outside the body 2. It is preferred that the partial closure element 11 is radially constrained to the body 2 but free to rotate with respect to it. Further preferred is that the partial closure element 11 is applied on the body 2 to cover an angular sector of the groove 3 and is openable to afford access to the external annular groove by rotation of one wall relative to the other.
In a preferred example, the partial closure element 11 can be opened by decoupling the two portions 14a, 14b of the bridge by rotation of one wall with respect to the other. Preferably, the two portions 14a, 14b are mutually releasably couplable by means of connection means 19. The connection means 19 can be of the form-fitting type, in particular for axial and/or radial coupling between the two bridge portions, by means of possible male/female coupling structures 20 (example in Figure 4). Additionally or alternatively, the connection means 19 may be of the force-fitting type, in particular for circumferential coupling between the two portions of the bridge, e.g. by means of a spring-loaded ball 23 (example in Figure 10). In any case, it is preferred that the connection means 19 a configured in such a way that, when the two portions of the bridge 14 are mutually engaged with each other, the closure element 11 covers an angular sector of the groove 3.
In embodiments, the male/female coupling 20 can be configured to be engageable and disengageable by rotation of one wall relative to the other to couple axially and/or radially the two portions 14a, 14b of the bridge. In the preferred example of Figure 2, the male/female coupling 20 comprises a circumferential guide with a dovetail including a circumferential dovetail groove 20a and a correspondingly shaped projection 20b formed on mutually facing surfaces of the two portions 14a, 14b of the bridge. By turning one wall relative to the other, it is possible to couple and uncouple the groove 20a with respect to the corresponding projection 20b.
In embodiments, is also provide a spring-loaded ball 23 which acts between the mutually facing surfaces of the two portions 14a, 14b of the bridge to counteract the rotation of one wall with respect to the other. The spring-loaded ball thus provides a force coupling between the two portions of the bridge, preventing accidental opening of the closure element 11.
In the bridge 14, openings 24 are preferably provided for a third rope 27 (also referred to as a fastening rope in the following) through which the partial closure element 11 can be constrained, for example, to the retaining rope 26 passing through the central passage 4 (example in Figures 7 and 8). Advantageously, the fastening rope 27 can also serve as circumferential coupling between the two portions 14a, 14b of the bridge.
If the second rope 26 does not require adjustment, it can, for example, be made from a loop of Dyneema^® or another high-strength, low-friction textile ring that can be made openable by means of a toggle type fastening 29. As shown in the example in Figure 9, the textile ring formed by the second rope 26 can be anchored to the walls 9, 10 by means of the respective rope-stopping clamps 30. In this way, the toggle type fastening 29 can also serve as a circumferential connection means between the two portions 14a, 14b of the bridge.
Considering that an important feature of the block 1 is the closure of the annular groove 3 to avoid derailing of the redirected rigging line with a closure element 11 which must not follow the rotation of the unitary body 2 of the block but remain stationary and well oriented without hindering the movements of the redirected rigging line, an advantage of the proposed solution is to minimise the friction between the body 2 and the closure element 11 and thus to absolutely avoid that the closure element rotates following the unitary body of the block even in the presence of deformations due to the high loads for which this solution is intended.
Preferably the central passage 4 of the unitary body has bilaterally rounded profiles with diameter d increasing outwards to define the shoulders 6, with a bilateral conformation resembling a Venturi tube. In this way, the second rope 26 can both form the textile axle of rotation of the ring and slide itself into the central passage without risk of damage.
With reference to the example in Figures 3 and 5, the external annular groove 3 can have a diameter D of at least 3 and preferably 4 times the diameter d of the central passage 4. In this way, the lever arm of the active torque exerted by the first rope 25 to be redirected prevails over the lever arm of the passive torque exerted by the second rope 26 in direct contact with the central passage 4. With reference to the example in Figures 1 and 2, the operation of the block 1 is as follows.
The first rope 25, preferably textile, is led into the annular groove 3 of the body of the block 1 and is generally the rope to be redirected. The second rope 26, also preferably textile, is instead led through the central passage 4. This rope can be used either as a simple retaining device for the block 1, to constrain its structure to the hull of a boat, for example, or as a second adjustable rigging line, in which case it can slide axially in the central passage 4. The third rope 27 (example from Figures 7 and 8) can be used to connect the block to the second rope 26, passing through the openings 24, so that the walls 9, 10 are retained from rotating together with the unitary body 2. At the same time, the unitary body 2 is free to turn on the textile axle formed by the second rope 26 as a result of the drag caused when the first rope 25 is redirected or released. This achieves the typical effect of a rotating pulley block but without its structural complication.
It will also be observed that the structure of the bridge 14 between the walls 9, 10 prevents the walls from closing on the body of the ring under stress, hindering its rotation. In fact, the main task of the bridge 14 is to prevent the redirected rigging line from derailing, but at the same time it also serves to make the closure 11 more solid and less deformable.
Finally, to insert or remove the second rope 25 in relation to the groove 3, it is sufficient to release any connection means 19 and open the bridge 14 by rotating one wall with respect to the other. In this way, the external annular groove can accommodate rigging lines that are rigged before the block is positioned, such as genoa or spinnaker sheets or mainsail halyards.
The block according to the present invention thus solves the proposed problem and achieves numerous advantages including simplicity of construction, versatility of use and high efficiency.

Claims

A block (1) with a textile axle, comprising a unitary body (2) which is substantially toroidal and which has an external annular groove (3) which is provided to receive a first rope (25) to be redirected and a central passage (4) which is provided to receive in direct contact a second rope (26) which acts as a textile axle of the block, and a partial closure element (11) of the external annular groove (3) which is rotatable with respect to the unitary body (2), the partial closure element (11) being rotatably supported on the unitary body (2) by means of bearings (15) which are interposed between the partial closure element (11) and the unitary body (2) coaxially relative to the central passage (4), the partial closure element (11) comprising two walls (9, 10) which are parallel and spaced apart from each other, the bearings (15) comprising rolling elements (16) which are received in rolling tracks (7, 8), the internal ring (12) of which is formed on the unitary body (2) and the external ring (13) of which is formed on the respective wall (9, 10), characterized in that the walls (9, 10) are axially retained by the bearings as a result of the effect of the connection between the rolling elements (16) and the respective internal ring (12) and external ring (13), the rolling tracks (7, 8) being removably closed by a respective flange (17) for retaining the rolling elements (16) in the corresponding rolling tracks.
A block (1) according to claim 1, wherein the central passage (4) is flanked by respective axially projecting shoulders (6) on which the internal ring (12) of the respective rolling tracks (7, 8) is formed.
A block (1) according to claim 1 or 2, wherein the external ring (13) is partially formed on the respective wall (9, 10) and partially formed on the respective flange (17).
A block (1) according to one or more of the preceding claims, wherein the flanges (17) are fixed to the respective walls (9, 10) by way of releasable connection means (18).
A block (1) according to one or more of the preceding claims, wherein the walls (9, 10) can be opened in order to afford access to the external annular groove (3) by rotating one wall with respect to the other wall.
A block (1) according to one or more of the preceding claims, wherein the walls (9, 10) are structurally independent of each other and joined in a releasable manner by means of a bridge (14) which extends therebetween radially outside the unitary body (2).
A block (1) according to claim 6, wherein the bridge (14) comprises a first portion and a second portion (14a, 14b) which are fixedly joined to one and the other of the walls, respectively, and connection means (19) which are configured to releasably join the first portion (14a) to the second portion (14b).
A block (1) according to claim 7, wherein the connection means (19) comprise a male/female coupling (20) which is formed on mutually facing surfaces of the first and second portions (14a, 14b) and which is configured to releasably join the first portion to the second portion by rotating one wall with respect to the other wall.
A block (1) according to claim 8, wherein the male/female coupling (2) comprises a circumferential guide (20a, 20b) with a dovetail.
A block (1) according to one or more of claims 7 to 9, wherein the connection means (19) comprise a spring-mounted ball (23) which acts between mutually facing surfaces of the first and second portions (14a, 14b) in order to act counter to the rotation of one wall with respect to the other.
A block (1) according to one or more of claims 7 to 10, wherein the connection means (19) comprise openings (24) which are formed in the first and second portions (14a, 14b) for a fastening rope (27) with respect to the second rope (26).
A block (1) according to one or more of claims 7 to 11, wherein the connection means (19) comprise a textile ring which is formed by the second rope (26), the textile ring being anchored to the walls (9, 10) by means of respective rope-stopping clamps (30) and being able to be opened by means of a toggle type fastening (29).
A block (1) according to one or more of the preceding claims, wherein the external annular groove (3) has a diameter (D) greater than or equal to 3 times the diameter (d) of the central passage (4).