EP3019430B1 - Lifting ring - Google Patents

Description

Technical area

The present invention relates to a rotating lifting ring for lifting loads. Rotating rings are used in all cases where it may be useful or necessary to allow an orientation of the ring relative to the load handled by a pivoting of the ring along a fixed axis determined by the attachment of the ring on the load, this fixed axis being generally orthogonal to the surface of the part on which the ring is fixed.

State of the art

Such rotating rings are used in particular in the case where several rings attached to the load are used and where these rings are connected to one and the same lifting member (eg a hook) by slings or chains. In such a case, the direction of the slings or lifting chains is inclined relative to the axis of the fastener, and it is important that the plane of the annular portion is oriented in the direction in which the force of the traction is applied to the ring, to avoid excessive forces transversely to the plane of the ring, and also avoid any risk of excessive tightening, and especially loosening, of the fastening screw. The orientation of the ring must be able to adapt to this direction of the lifting force, without this requires a pivoting of the fastening screw, or that it creates on it a tightening torque or loosening .

The EP 0 697 364 discloses for example a lifting ring comprising a forged body with a central passage through which a screw fastener, which allows the fixing of the ring on a load and the rotation of the body thereon. A shackle, forming the hooking loop of the ring, is pivotally mounted about two projecting radial axes formed in one piece with the body.

In such a ring, the shackle pivots freely on the projecting radial axes, and when no traction is exerted, falls systematically under his own weight. In some cases, it would be desirable for the shackle to remain in a given angular position.

The EP 0 179 733 discloses a lifting ring with a body and a screw fastener passing through a bore of the body. A shackle is pivotally mounted about a lateral pivot axis formed by a bolt. Elastic washers are threaded on the pivot axis, between the body and the inner flanks of the shackle.

The EP 2 431 620 describes a pivoting ring in which a shackle is pivotable on two salient radial axes. Washers are mounted on the ends of the radial axes to serve as an axial stop when the ring is loaded.

General description of the invention

The present invention provides a lifting ring comprising a body and a screw fastener passing through a bore of the body, to allow rotation of the body on the screw fastener along a relative axis of rotation, the body comprising two radial axes projecting around which pivots a shackle.

According to the invention, at least one positioning spring is fixed on a first radial axis projecting from the body and exerts pressure on the shackle so as to create a force for maintaining it in a desired angular position.

The positioning spring thus produces a force preventing the gravity pivoting of the shackle. The dimensioning of the spring is such that it resists the weight of the shackle itself, possibly linked to a hook or other lifting accessory, but allows the hand to move the shackle by an operator, as well as its alignment during operation. lifting. Such a positioning spring can be provided on each of the two projecting radial axes.

In practice, the positioning spring is preferably pressed against an outer surface of the shackle, in particular around the projecting radial axis on which it is mounted. The positioning spring is then arranged so as to exert pressure forces substantially parallel to the axis of pivoting of the shackle and towards it.

Preferably, the positioning spring comprises a frustoconical type spring or washer. It may be provided at its periphery with a collar, preferably notched, bearing on the shackle, if necessary via a washer to increase the contact surface and therefore the friction. The positioning spring may also consist of an assembly of 2 or more springs.

Any method of fixing the spring can be envisaged. It can be fixed simply on the end face of the projecting axis, in particular by a screw. This allows easy mounting of the positioning spring, which is not integrated into the body of the ring.

For an improved contact, the shackle comprises at its ends two lugs each traversed by one of the projecting radial axes, whose outer flanks are flattened, preferably in a plane perpendicular to its pivot axis.

Brief description of the drawings

• Fig. 1: une vue de côté d'un mode de réalisation de l'anneau de levage selon l'invention ;
• Fig. 2: une vue en perspective de l'anneau avec le ressort non-assemblé ;
• Fig. 3: une vue en coupe verticale de la Fig.1 selon un plan passant par le centre des tourillons ;
• Fig. 4: une vue du ressort ; et
• Fig. 5 : une vue du détail C de la Fig.3.

Other features and features of the invention will become apparent from the detailed description of an advantageous embodiment presented below, by way of illustration, with reference to the accompanying drawings. These show:

• Fig. 1 : a side view of an embodiment of the hoisting ring according to the invention;
• Fig. 2 : a perspective view of the ring with the unassembled spring;
• Fig. 3 : a vertical sectional view of the Fig.1 according to a plan passing through the center of the trunnions;
• Fig. 4 : a view of the spring; and
• Fig. 5 : a detail view C of the Fig.3 .

Description of a preferred execution

One embodiment of the present lifting ring 10 is shown in FIG. figure 1 . It comprises a body 12 having a central passage, generally designated bore, traversed by a screw 14, which provides the functions of fixing the ring and pivot axis, allowing the body 12 to rotate freely on the rod 16 of the screw 14 along an axis A. Conventionally, the fixing screw 14 is intended to be assembled by screwing on a load to be lifted.

A shackle 18, constituting the ring or the attachment loop of the device 10, is pivotally mounted about projecting radial axes 20, 20 '(also referred to as "trunnions") of the body 12 so as to be pivotable about an axis B generally perpendicular to the axis A.

As we see better on the Fig.3 in the present embodiment, the body 12 comprises a sleeve 22 (or "flange") threaded on the screw 12 to the underside of the head 24 of the screw (shouldered type). A bushing 26 is threaded onto the rod 16 of the screw 14 and locked thereon so that in the service position a flange 28, which is integral with the bushing 26 at one of its ends, is remote from the head 24 of the the screw 14. The inner dimensions of the sleeve 22 and outer sleeve 26, and their respective lengths are such that a functional axial and radial play (not shown) exists, allowing the sleeve 22 to rotate freely on the socket 26 mounted on the screw 13, even when the screw is fully tightened on the load to be lifted (the sleeve 22 is thus held axially between the wings formed by the underside of the screw head 14-in particular the shoulder thereof- and the inner face of the flange 16).

In this variant, the sleeve assembly 26 and flange 28, also called "base", is pressed and / or shrunk on the cylindrical part of the screw rod 16, above the screw thread 30. In other variants, the sleeve 15 may have internal threading and be locked by screwing on the screw, the threading would then rise to the underside of the screw head. Furthermore, the shoulder which axially retains the sleeve 22 on the side of the screw head (here formed by a shoulder thereof) could be formed by an intermediate piece. Also, if an intermediate part is used, the base does not necessarily have to reach under the screw head. As will be understood, the skilled person can find all kinds of configurations for the assembly of the body and the fixing screw.

The shackle 18 here has a simple U-shape, and is preferably forged in one piece. The ends 32 of the two branches 34 of the shackle are provided with holes 36, thus forming ears which serve as a pivot bearing around the journals 20, 20 '. Preferably, the ears are enlarged and have flats flattened (in the plane perpendicular to the pivot axis B), as seen best at Figs. 2 and 3 .

According to an important aspect, a positioning spring 38 is fixed on a pin 20 so as to exert on the shackle 18 braking forces / preventing the gravitational pivoting thereof and allowing its adjustment and maintenance in a desired angular position. Preferably, the spring 38 has its load axis parallel to the axis of pivoting of the shackle, so as to exert elastic forces generally parallel to the pivot axis B of the shackle. The shackle 18 is thus retained in position by the friction / frictional resistance created by the spring 38 at the interface with the shackle.

The positioning spring 38 is preferably sized and prestressed so that the forces exerted on the shackle 18 allow a given angular positioning thereof to the hand by an operator, and it remains in this rest position, it is to say that no traction is exerted (if necessary with a hook, chain or other lifting accessory).

The positioning spring 38 can be fixed simply on the end face 40 of the pin 20, 20 '. Any suitable means for fixing the spring 38 may be envisaged, for example a screw 42 screwed into a threaded hole 44 in the face 40.

The positioning spring 38 is preferably designed as a frustoconical spring or washer, for example based on a Belleville washer which may include additional contact areas.

According to an advantageous embodiment illustrated Fig.4 the spring 38 comprises a frustoconical portion 46 whose narrow side is closed by a disk 48 provided with a central hole 50 for the fixing screw 42, and the widened side (shackle side) ends with a flange 52, preferably notched .

As we see better on the Fig.2 a washer 54 may be interposed between the spring 38 and the shackle 18 to increase the contact area and / or to make up the thickness tolerances.

The skilled person may use any other type of appropriate positioning spring configuration, for example ring springs. hollow frustoconical with or without cuts, or assemblies of two or more frustoconical springs.

Thus, the spring 38 has an annular contact surface with the shackle 18, at the level of the outer flat surface 32a of its lug 32. This surface being in a plane perpendicular to the axis B, the annular contact is guaranteed whatever the angular position of the shackle 18.

For improved support of the lugs 32 on the journals 20, 20 ', circular rods 56 are advantageously partially engaged in annular grooves with semicircular section provided at the ends of the trunnions.

Reference sign 60 indicates a hexagon socket for an Allen key. Alternatively, the screw head 24 could have an outer hexagonal profile.

Claims (9)

1. Lifting ring comprising a body (12) and a screw-fixation member (14) that passes into a bore in the body, in order to allow the body to rotate on the screw-fixation member about an relative rotary axis, the body comprising two protruding radial shafts (20, 20') about which a shackle (18) pivots;
   characterised in that at least one positioning spring (38) is fixed to a first of the protruding radial shafts of the body (20, 20') so as to exert a retaining force on the shackle, the positioning spring (38) being fixed to the end face of the protruding shaft (20, 20'), in particular by means of a screw, and compressed against an outer side (32a) of the shackle.
2. Lifting ring according to claim 1, characterised in that the positioning spring (38) is arranged so as to exert pressing forces substantially in parallel with the pivot axis (B) of the shackle and in the direction thereof.
3. Lifting ring according to either claim 1 or claim 2, characterised in that the positioning spring (38) comprises a frusto-conical or washer spring.
4. Lifting ring according to claim 3, characterised in that the positioning spring (38) comprises on its circumference a rim, which is preferably notched, that abuts the shackle.
5. Lifting ring according to any of the preceding claims, characterised in that a washer is positioned between the positioning spring (38) and the outer side of shackle.
6. Lifting ring according to any of the preceding claims, characterised in that the shackle comprises, at the ends thereof, two lugs of which the outer sides are flattened, preferably in a plane that is perpendicular to the pivot axis (B) of said shackle; and in that the positioning spring abuts said flattened outer side.
7. Lifting ring according to any of the preceding claims, characterised in that another positioning spring is fixed to the second protruding radial shaft.
8. Lifting ring according to any of the preceding claims, characterised in that the positioning spring consists of an assembly of two or more springs.
9. Lifting ring according to any of the preceding claims, characterised in that the screw-fixation member (14) comprises a head (24) having an actuation portion designed to cooperate with a tightening tool.

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