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EP-4741589-A1 - TIP GROUP FOR EARTH-MOVING MACHINES

EP4741589A1EP 4741589 A1EP4741589 A1EP 4741589A1EP-4741589-A1

Abstract

A tip group (1) for earth-moving machines, which predominantly extends along a longitudinal axis (X) between a front working portion (2) and a rear portion (4) for fastening to a bucket of an earth-moving machine, and comprises a tip (6) defining a pocket (8) open at the rear, a tip holder (10) having a nosepiece (12) defining a front protrusion (13), said nosepiece (12) being suitable for geometrically coupling with the pocket (8), so as to form a male-female type coupling. The tip group is characterized in that at least one of the nosepiece (12) and the inner surface of the pocket (8) has at least one lowered or recessed zone (15; 15'), which extends at least partially in a direction incident with respect to the longitudinal axis (X); and in that at least the other of the nosepiece (12) and the inner surface of the pocket (8) has at least one relief (16; 16') suitable for engaging said lowered or recessed zone (15; 15'), so that, following said engagement, the tip (6) and the tip holder (10) are integrally coupled.

Inventors

  • BELOTTI, Francesco

Assignees

  • ESTI S.r.l.

Dates

Publication Date
20260513
Application Date
20251029

Claims (16)

  1. A tip group (1) for earth-moving machines, said tip group (1) predominantly extending along a longitudinal axis (X) between a front working portion (2) and a rear portion (4) to be fixed to a bucket of an earth-moving machine, and comprising: - a tip (6) defining a pocket (8) open at the rear; - a tip holder (10) having a nosepiece (12) defining a front protrusion (13), said nosepiece (12) suitable for being coupled geometrically to the pocket (8), so as to create a male-female type coupling; characterized in that at least one of the nosepiece (12) and the inner surface of the pocket (8) has at least one lowered or recessed zone (15; 15'), said lowered or recessed zone (15; 15') extending at least partially in an incident direction with respect to the longitudinal axis (X); and in that at least the other of the nosepiece (12) or the inner surface of the pocket (8) has at least one relief (16; 16') suitable for engaging said lowered or recessed zone (15; 15') so that, following said engagement, the tip (6) and the tip holder (10) are integrally coupled.
  2. Tip group according to claim 1, wherein the constraining reaction generated by the integral coupling between the tip (6) and the tip holder (10) balances the effect of the gravitational force acting on the tip (6), when the tip group (1) is in a vertical position with respect to the ground.
  3. Tip group according to any one of the preceding claims, wherein the integral coupling between the tip (6) and the tip holder (10) occurs by axially engaging the tip (6) in the tip holder (10) and then rotationally moving the tip (6) about the longitudinal axis (X).
  4. Tip group according to any one of the preceding claims, wherein the integral coupling between the tip (6) and the tip holder (10) is a bayonet engagement.
  5. Tip group according to any one of the preceding claims, wherein both the nosepiece (12) and the inner surface of the pocket (8) have a lowered or recessed zone (15; 15'), each of said lowered or recessed zones (15; 15') extending at least partially in an incident direction with respect to the longitudinal axis (X), and both the nosepiece (12) and the inner surface of the pocket (8) have a relief (16; 16'), each of said reliefs (16; 16') being suitable for engaging a respective one of said lowered or recessed zones (15; 15').
  6. Tip group according to any one of the preceding claims, wherein the at least one lowered or recessed zone (15; 15') consists of a groove having a much smaller dimension in the direction parallel to the longitudinal axis (X) than the dimension in the direction incident to the longitudinal axis (X).
  7. Tip group according to any one of the preceding claims, wherein the tip (6) has at least one locking element hole (18) obtained in a pair of opposite walls (20, 20') defining the pocket (8) and suitable for being engaged by a locking element (22; 23, 23'); and wherein a locking element seat (24) suitable for being engaged by said locking element (22; 23, 23') is obtained in the nosepiece (12), said locking element seat (24) being at least partially aligned with said locking element hole (18) when the tip (6) and the tip holder (10) are integrally coupled.
  8. Tip group according to claim 7, characterized in that the locking element seat (24) is defined by a lowered or recessed zone (14) obtained in the surface of the nosepiece (12).
  9. Tip group according to claim 7 or 8, wherein the locking element hole (18) and the locking element seat (24) extend along a transverse axis (Y) perpendicular to the longitudinal axis (X).
  10. Tip group according to any one of claims 7 to 9, wherein the nosepiece (12) and the pocket (8) have respective upper (26, 26') and lower (28, 28') surfaces inclined with respect to the longitudinal axis (X) and converging at the front; and wherein the nosepiece (12) and the pocket (8) have respective opposite side surfaces (30, 30', 30'', 30‴), at least said opposite side surfaces (30", 30‴) of the pocket (8) being substantially vertical.
  11. Tip group according to claim 10, the locking element seat (24) and the locking element hole (18) extending between said opposite side surfaces (30, 30', 30", 30‴).
  12. Tip group according to any one of the preceding claims, characterized in that the pocket (8) ends at the front with a substantially hemispherical bottom (32); and in that the front protrusion (13) defined by the nosepiece (12) is substantially hemispherical, so that said front protrusion (13) abuts against said bottom (32) when the tip (6) and the tip holder (10) are integrally coupled.
  13. Tip group according to any one of claims 7 to 12, further comprising a locking key (22), said locking key (22) predominantly extending along a key axis (Z), and being suitable for engaging the locking element seat (24) and the locking element hole (18).
  14. Tip group according to claim 13, wherein the locking key (22) has an intermediate portion (34) in the direction perpendicular to the key axis (Z), said intermediate portion (34) being suitable for allowing a compression insertion of the locking key (22) into the locking element hole (18) and into the locking element seat (24), so as to constrain the locking key (22) in the direction of the key axis (Z).
  15. Tip group according to any one of claims 13 or 14, wherein the intermediate portion (34) of the locking key (22) is made of an elastomeric material, for example rubber.
  16. Tip group according to any one of claims 7 to 12, further comprising a connecting pin (23) and related locking ring (23'), said connecting pin (23) predominantly extending along a pin axis (P), and being suitable for engaging the locking element seat (24) and the locking element hole (18); and said related locking ring (23') being suitable for constraining the connecting pin (23) in the direction of the pin axis (P).

Description

Field of application The present invention falls within the field of equipment and spare parts for earth-moving machines, for example excavators. In particular, the subject of the present invention is a tip group for earth-moving machines. Prior art In the field, countless examples of tip groups for earth-moving machines are known. Typically, a tip group is composed of a tip, a tip holder, and a locking element for locking the tip to the tip holder, such as for example a locking pin. Typically, the tip is provided with a pocket open at the rear, and with a locking element hole obtained in a pair of opposite walls of said pocket, suitable for being engaged by the locking element. Typically, the tip holder has a body configured to be fixed, for example by welding, screwing or bolting, to the bucket of the earth-moving machine, and a nosepiece that extends from the body and geometrically couples to the pocket of the tip, so as to form a male-female type coupling. Furthermore, the nosepiece is typically provided with a locking element seat suitable for being engaged by the locking element, which extends between two opposite surfaces of the nosepiece and is aligned with the locking element hole when the tip and the tip holder are coupled. The making of the tip group in two separable parts, tip and tip holder, advantageously allows the replacement of the tip alone when worn, allowing the tip holder to remain permanently fixed to the bucket of the earth-moving machine. The locking system of the tip to the tip holder must therefore be suitable for allowing an easy and quick replacement of the tip, without giving rise to misunderstandings about the insertion direction of the locking element, and without requiring excessive effort by the operator for the operation of inserting said locking element. However, this requirement clashes with the need to make the coupling between the tip and the tip holder as firm as possible, so as to withstand the considerable stresses to which the tip is subjected when the earth-moving machine is in operation. In some known tip groups, in order to make the replacement operation of the tip easier and quicker, it has been chosen to forego achieving an optimal constraint between the locking element and the locking element seat engaged by it, with the result that, following prolonged use of the tip, the locking element can come out of its seat, causing the decoupling of the tip from the tip holder. In other known embodiments, in order to firmly constrain the locking element, specific retaining devices have been provided in the locking element itself, for example of the elastic type, suitable for interacting with the nosepiece of the tip holder. These embodiments, in addition to making the structure of the tip group more complex, and consequently more expensive, have not completely solved the problem of avoiding the decoupling of the tip from the tip holder in demanding operating conditions. In fact, all efforts in this regard have been predominantly concentrated on the coupling between the locking element, the tip and the tip holder, and consequently limited to a restricted area of the tip group. However, the stresses to which the tip group is subjected during use are such that, if countered solely by the locking element, they can cause its breakage, and the consequent decoupling of the tip from the tip holder. Other known tip groups provide a bore in the nosepiece of the tip holder, suitable for being engaged by the locking element. Such a bore entails an inevitable structural weakening of the tip group and of its components, in addition to making an additional machining of the tip holder necessary, with a consequent increase in production costs. Other known embodiments for tip groups provide an integrated tip-tip holder locking system, without the need for a third locking element. However, such an integrated locking system entails the need for a tool such as a crowbar to lock, unlock or remove the tip, a tool not always readily available in such working environments. Furthermore, such integration also makes a further machining of the tip group necessary, with a consequent increase in production costs. Other known tip groups are based on a helical coupling system between the tip and the tip holder. In such systems, the nosepiece of the tip holder, having a helical shape, couples with the tip, reducing the workload of the locking element, which simply has the function of preventing the rotational movement of the tip in the tip holder, and the consequent disengagement. A typical problem of all these known systems consists in the fact that, in the absence of the locking element, the tip tends to come out of the tip holder when the tip group is tilted with respect to the horizontal position with respect to the ground, or if it is positioned vertically with respect to the ground. Consequently, a bucket of an earth-moving machine having a typical tip group of the prior art must always be placed