CZ20004810A3 - Coupler for excavator and similar gear - Google Patents

Abstract

The solution relates to a device for coupling teeth of excavators and the like. The coupling between the tooth (17, 49) and the tooth carrier (1, 27) is carried out by means of a combination of three successive surfaces, from the central silo of the coupling part to its free end. The first surface of stepped straight guide rails (9, 10; 45, 46; 57, 58), which are open on the lateral outer surfaces of the coupling part, is followed by a surface for guiding by means of mutually opposing rotary surfaces (20, 21), and a third end surface (24, 31) in the form of a prismatic rod, the axis of which coincides with the axis of the given part.

Description

Coupling for excavator teeth and similar equipment

Technical area

A device for coupling excavator teeth, of the type used on excavators and similar machines. These machines are intended for removing masses of earth and stones in public works and construction.

State of the art

For the removal of masses of soil and stones in civil engineering works of all kinds, excavators of various types are traditionally used, which include buckets (excavating containers), provided with working edges, which are designed to engage in masses of soil and stones during their removal. For this reason, there are problems with accelerated wear of their cutting edge, which must be provided with very hard, detachable parts with high mechanical strength, which are the so-called teeth. The teeth are made of materials that have a high degree of hardness and mechanical strength, in order to achieve their greater working life and the need for their easy replacement, since their purpose is precisely to withstand the wear of the working surface, so that for their replacement it is essential that it is easy and quick.

Teeth for excavators and the like must meet a number of conditions, which are in some cases contradictory and represent, on the one hand, reduced production costs, given the type of their intended use and the frequency of their replacement, and, on the other hand, high strength and the longest possible service life.

The reconciliation of this combination of characteristics is not easy in excavator tooth coupling devices because, firstly, due to the fact that they need to be mass-produced products at low cost, it is not possible to resort to mechanization of the parts in question to achieve more or less small tolerances in their dimensions, so it is necessary to manufacture them on the basis of economical manufacturing methods to obtain solid parts such as casting and forging. However, the use of cast or forged parts represents an important limitation on the dimensional tolerances that can be achieved on excavator teeth, which leads to limitations on good coupling (bonding) between the tooth and the so-called tooth carrier, which is the element for connecting with the active edge of the excavator bucket. The result of unsatisfactory coupling is the occurrence of various operational problems due to incorrect positioning of the tooth in its carrier, which manifests itself in high local contact pressures, with subsequent wear and an increase in the coupling clearance between the tooth and the carrier, which again accentuates wear problems and leads to a reduction in the useful life of the coupling.

For the technical reasons mentioned above, one of the constant problems in the manufacture of teeth for excavators is to achieve designs that allow an improvement in the coupling of the tooth and its carrier without excessively increasing the difficulty of manufacturing and therefore the cost of these parts. For this reason, numerous systems for connecting the tooth to the carrier have been published, all of which claim to introduce improvements in the design of these parts and therefore in the coupling of the latter part.

US Patent 4,404,760 describes a coupler with an adapter and a point element, in which the adapter has a recess with holders (or • » • · ··· ·

The essence of the invention

The present invention has holders that have a supporting function, since they are able to absorb the forces (stresses) that are transmitted from the end of a given point to the adapter. The coupling of the invention is precisely the result of the work carried out by the inventors to achieve a more balanced solution to the technical problems arising from the teeth of excavators. The result of the research carried out and the work of the inventors is the obtaining of a device for coupling the teeth (coupling) of an excavator, which satisfactorily combines the features of mechanical robustness necessary in this part, with a significant simplification of manufacture and an extended life of the coupling.

According to the present invention, its satisfactory results are achieved by a specific combination of elements for guiding and coupling the teeth in the tooth carrier, this combination consisting in: coupling of inserted special protrusions of the teeth, which are provided with a double, stepped inner strip, with complementary recesses of the tooth carrier, mutual coupling in surfaces of rotation symmetrical to the given coupling, and finally external/internal coupling in the end prismatic (prism) surface. The combination of these three types of basic coupling is achieved by creating a first coupling surface between the tooth and its carrier, which includes seats (seats) that open on the edge of the tooth carrier and have an internal double, straight guide strip that takes the form of a profile that has a double, straight stepped area in cross section and that extends along the sides of the tooth carrier parallel to the axis of this part. The tooth has protruding surfaces, complementary to said portions with a double stepped guiding structure, so that, upon insertion thereof, the above-mentioned

the projecting surfaces are suitably retained in the double guide recesses, providing multiple engagement surfaces between the tooth and the tooth carrier in a transverse arrangement at 90°, which provides a very effective engagement with multiple contact surfaces between the two parts. The immediate engagement surface between the tooth and the tooth carrier has mutually opposed, symmetrical rotating surfaces, taking the form of cylindrical or frustoconical surfaces, arranged at the beginning of the tooth engagement rod, intended to coincide (cover) in the complementary hole of the tooth carrier and, preferably, in such an arrangement that one of the rotating surfaces is arranged on the upper part of this part and the other, symmetrically opposite to the first, is arranged on the lower part of this part. The third coupling surface between the tooth and the tooth carrier, associated with those described above, forms the end, pivot pin of the tooth coupling projection, which adopts a prismatic structure with rounded edges and an axis coinciding with that of the part. The tooth has a coupling hole, the structure of which is complementary to that of the tooth carrier, where a very effective coupling between the tooth and the tooth carrier is achieved by means of the combination of the three separate surfaces mentioned, which, without altering the favorable characteristics of the casting or forging production, allows the two parts to be guided effectively with respect to each other, with the result that the contact areas between the tooth and the tooth carrier are significantly increased, leading to less individual wear and therefore to a prolonged life of the coupling.

These improvements similarly provide for the arrangement of the pin or cotter seat in the main body or portion of the tooth carrier that is not covered by the tooth, which allows for increased strength of the tooth carrier, which in turn allows for the tooth carrier to be reduced internally, which reduces the weight of the assembly. The upper and lower ends of the seat for the retaining pin or pin will optionally be closed • · · 9 9 · · 9 9 • 999 ···· · · · · « · · 9 9 9

9 9 · 9 9

9999 999 99 9999 by means of covers intended to protect the cotter pin seats as much as possible, facilitating their subsequent removal at the right moment. The retaining bolt or pin will have an assembly consisting of a base body carrying a centering extension, which is connected to the base body by vulcanization. In order to allow the correct insertion of the cotter pin to be checked and, similarly, certain manipulations that may be necessary for extraction, the tooth will have a hole in one of its lateral support attachments that coincides with the position of the bolt in question.

With respect to the outer and inner lateral guide rails, the design of the tooth assembly and its carrier can be symmetrical or asymmetrical.

Overview of images in drawings

For a better understanding, there are attached, by way of non-limiting example, descriptive drawings of a preferred embodiment of the present invention, which show:

Fig. 1 and 2 - respective elevation and plan views of a coupler for an excavator tooth according to the present invention.

Fig. 3 to 6 - cross-sections of the tooth coupling, which correspond to the area of the double, stepped guide rail.

Fig. 7 to 10 - cross-sections of the coupling surface provided with rotating surfaces.

Fig. 11 - cross-section of a prismatic, end pivot of the coupler.

Fig. 12 - a plan view of the assembly of the tooth and its carrier according to the present invention, and Fig. 13 and 14 show longitudinal sections according to the indicated section planes.

Fig. 15 - elevation view of the tooth and tooth carrier assembly.

Fig. 16 - cross-section along the section plane indicated in Fig.

15.

• · ····

Fig. 17 - perspective view of the coupling device from the right side, corresponding to the given cotter pin.

Fig. 18 - perspective view, similar to the view in Fig. 17, from the opposite side of the given cotter pin.

Fig. 19 - perspective view of the assembly of a tooth and a tooth carrier according to the present invention.

Fig. 20 - A perspective view of a tooth having therein the coupling device of the present invention.

Fig. 21 - side view of a variant of the tooth carrier shown in Fig. 1 and the following figures.

Fig. 22 to 27 - sections along the sections indicated in Fig.

21.

Fig. 28 and 29 - longitudinal section of the assembly of the tooth carrier and tooth according to the variant in Fig. 21.

Fig. 30 and 31 - respective posterior and anterior perspective views of a tooth according to the present improvements.

Fig. 32 and 33 - respective sections of the tooth retaining bolts, according to the presented improvements.

Fig. 34 - side view of an alternative version shown in Fig. 21, with an asymmetrical arrangement of lateral guide rails.

Fig. 35 to 40 - sections along the section planes indicated in Fig. 34.

Fig. 41 - perspective view of the assembly consisting of a tooth carrier and a tooth according to the variant in Fig. 34.

Fig. 42 - longitudinal section along the section plane indicated in Fig. 41.

Fig. 43 - second longitudinal section through the section plane indicated in Fig. 44, perpendicular to the section indicated in Fig. 42.

Fig. 44 - plan view of the tooth and tooth carrier assembly according to the presented improvements.

Fig. 45 - A sectional detail of a tooth and tooth carrier assembly according to the present invention, showing a variant of the edge where the tooth and its carrier overlap.

Fig. 46 - sectional detail showing the stresses generated in the coupler in Fig. 45.

Examples of embodiments of the invention

The coupling device (coupler) first comprises a tooth-bearing element, generally designated JL, which carries an internal coupling, which consists of a surface 2 for coupling with the tooth and a surface 3 for coupling with the active edge of the excavator bucket. The surface 3 has a basically fork-shaped structure with arms 4 and 5 with a straight flush recess 6 for its connection to the active edge of the bucket by welding or other means. The protruding part 3 (obviously 2, note of the translator) has, as is usual in these coupling devices, a structure with a decreasing cross-section from the initial face 7 of the protrusion 2 to the final straight end. According to the present invention, the coupling 1 has on each of its sides respective openings 9 and 10, which start at the face 7 and extend to the end 3 for coupling with the edge of the bucket. These openings are characterized in that they both have a structure based on a double internal guide rail by means of transverse straight steps, as can be seen in Fig. 3 to 6, in which it can be seen that the openings 9 and 10 have rectilinear forming lines, parallel to the axis of the part in question, taking the form in cross-section in which a double straight guide rail is formed with a step having, for example, for the opening of the guide rail 9, straight parallel walls 11 and 12 of the first straight guide rail and the walls of the straight guide rail of the lower part of the recess 9, which are indicated as 13 and 14. The straight guide rails of each side, for example, 12 and 13 and also 11 and 14, are separated by respective straight (straight) steps 15 and 16. The structure of the recess 10 is identical to that described for the recess 9, so it is not explained in further detail. The provision of a double stepped guide rail improves the engagement between the tooth and the tooth carrier by increasing the effective contact areas between these two parts in the initial assembly. Tooth 17, Fig. 15 and 16, has projecting side wings or arms 18 and 19 of complementary shape to the openings in the double stepped guide rails 9 and 10, as seen in Figs. 15 and 16, 19 and 20.

The coupling projection 2 has, after its origin from the face 2 of the part 1, a coupling surface by means of rotary surfaces, which are formed by two surfaces 20 and 21, Fig. 7 and 10, which can be formed by frustoconical or cylindrical surfaces, arranged opposite each other and symmetrical with respect to the axis of the part in question, which coincides with the axis of symmetry of the parts shown. The lateral grooves 22 and 23 extend along said coupling surfaces, and end in the outermost part, shown in Fig. 10, in which the two rotary surfaces opposite each other, indicated in this case 20' and 21', are practically connected by their ends. The third main supporting surface is formed by a bar 24 at the free end of the coupling surface 2, which adopts a straight, prismatic (prism) structure with rounded edges, as can be seen in Fig. 11.

The coupling is completed by means of a transverse pin 25 which is intended to retain the tooth 17 and which is encapsulated in a transverse opening 26 which opens in the part 2 in the immediate vicinity of the face 1.

In the variant in Fig. 21, designated overall 27, a structure can be seen that is slightly different in the rear extensions 28 and 29, the first of which is essentially a bluntly inclined structure, forming with extension 29 a recess at a certain angle with respect to the horizontal, intended for the incorporation of • · • · * • · ·

of the tooth carrier on the edge of the bucket or scoop of an earthmoving machine. In this variant, the pin or cotter pin seat 30, which, as in the version of Fig. 1, is provided in a portion of the tooth carrier body and not in a portion called the nose (or head), also has wide half-grooves or bends 32 and 33 at its ends, which, in conjunction with the more limited length of the pin, as seen in Fig. 28, 32 and 33, allows receiving in the upper and lower parts respective covers 34 and 35, which are preferably partially encapsulated in the ends of the holes for receiving the bolt 36. In this way, additional protection is achieved for the end of the bolt, which increases its protection against impacts from stones, metal objects and other parts that could cause its expulsion, especially during demolition work, and in addition significantly improves the work of dismantling it for replacement. The bolt, as can be seen in the more detailed section of Fig. 32, has a complex structure in which the body 36 is provided with a wide opening in which is encapsulated a centering insert 37, provided in its central part of the outer edge with a small centering projection 38, and which is connected to the base body 36 by means of a surface of vulcanized rubber 39, or some other flexible material.

The linear design of the bolt 36, which was shown in Fig. 32, can be modified in the form of a slightly arcuate structure, as can be seen in Fig. 33, where a bolt 40 is shown, provided with a certain longitudinal curvature, which is provided with a similar centering insert 41, with a central protrusion 42 and with a connection to a similar elastic surface 43 excluded.

The design of the tooth carrier with a seat for the bolt in its body, instead of being located in the nose of the tooth carrier, gives greater mechanical strength to the latter and allows the tooth carrier to be hollow inside, as can be seen in Fig. 22 to 26, where a cavity 44 can be seen, similarly visible in Fig. 42 and 43, which opens in the mating surface on the edge of the bucket, between the extensions 28 and 29. This design makes it possible to achieve easier assembly of the tooth carrier.

As can be seen in Fig. 22 to 26, the variant of the bucket carrier shown in Fig. 21 has lateral centering grooves of the symmetrical type 45 and 46, as corresponding to those in Fig. 1 and the following figures, a version with a double retaining bolt is also shown, with seats 47 and 48 for the latter, which can be seen in Fig. 23.

Fig. 28 and 29 show the engagement of tooth 49 in the tooth carrier according to the variant in Fig. 21.

On the tooth 49, Figs. 30 and 31, it is possible to observe the securing of the brackets 50 and 51, provided with upper and lower guide rails, such as those indicated 52 and 53 for the bracket 50. The guidance of the brackets 51 is carried out simply by means of an internally protruding block 54, which replaces the complete internal rib 55 of the variant of Fig. 1, shown for example in Fig. 20. At the same time, the bracket 51 has a hole 56, which is at the level of the bolt and which makes it possible to observe the correct coupling of the latter and, if required, to assist in some manipulation from inside said hole in the event of problems arising with the extraction of the bolt.

In the sections of Fig. 35 to 37, an arrangement of asymmetrical guide grooves is seen, such as a single dovetail groove 57 on the barley side and a double, stepped groove 58 on the opposite side, which forms a variant that can be used in some cases as a substitute for a symmetrical groove on both sides of the tooth carrier. In the case shown in Fig. 36, an arrangement of a single cotter pin 59, associated with a double stepped groove 58, is also seen.

The invention similarly provides a special edge formation where the tooth carrier and the tooth meet, as seen in the respective φ · φ φ

Φ Φ φ Φ · Φ · Φ • φ φ Φ φ φ Φ • • φ Φ φ · φ Φ · * Φ φφ φ Φ φ φ Φ φ φ φ φ φ Φ φφ ΦΦΦ 11 pictures and, especially , in Fig. 21 and on Fig. 45 and 46. According to submitted invention margin 60 carriers tooth is not perpendicular to

the central plane Ρ of the tooth, but forming a certain angle a (alpha) with respect to the perpendicular p, as shown in Fig. 45, the complementary edge of the tooth 61 has a corresponding shape so that it can make contact against said edge 60 and by the fact of the indicated angle, the vector Fi, which represents the reaction of the stress force F exerted on the tool during operation, can be decomposed into components Fi _Z and Fi _Y , the latter of which is the load transverse to the central plane of the tooth, which therefore cooperates in maintaining the tooth coupled in the tooth carrier, countering the effect of the component Fi _z , which tends to expel the tooth and thus considerably reduces the risk of breaking through its neck.

Through the explained assembly, the excavator tooth coupling, which is the subject of the present invention, has proven to be very effective, since it allows a firm coupling of the tooth in the tooth carrier by providing multiple contact surfaces in different planes, to distribute the stress over large areas for the purpose of reducing wear in the coupling and increasing its useful life.

Claims (9)

PATENT CLAIMS A coupler for teeth of an excavator or the like of the type comprising a tooth supporting portion (1, 27) for attachment to an active edge of a bucket having a protrusion (2, 31) having a cross section decreasing towards the free end and a shape substantially complementary to receiving of the tooth (17, 49) allowing its coupling, in which the coupling between the tooth (17, 49) and the tooth carrier is made by combining a plurality of successive surfaces from the central portion of the coupling portion to its free end, including a first surface of stepped straight guide rails 9, 10; 45, 46; 57, 58), which are open on the lateral outer surfaces of the portion of the tooth carrier (1, 27), which are intended to receive complementary profiles of the side wings (18, 19); 50, 51 (tooth, 17, 49), followed by a guide surface through rotatable surfaces (20, 21) opposite to each other and an end surface (24, 31) in the form of a prismatic rod whose axis coincides with the tooth bearing portion 1.27; characterized by having: an area with stepped straight guide bars / 9, 10; 45, 46; 57, 58 (taking the form of a groove closed at its rear end and open at its front end and allowing the lateral wings to slide slidably); 50, 51 (a tooth) (17, 49) having at least one of these side wings (18, 19); 50, 51) and an inner projecting block (54) that extends along the side grooves (22, 23) during assembly of the tooth (17, 49); 45, 46; 46 and 58 (a) is retained in position by a retaining bolt (25, 59), a tooth retaining surface (17, 49) formed by two cambered recesses (60) secured in the front edge (7) 99 ·· ·· · 9 9 9 9 9 9 ** 9 9 9 ** 9 9 9 9 9 The tooth-bearing parts (1, 27), the recesses (60) receive the trailing edge (61) of the tooth opening (17, 49), including an acute angle α to the perpendicular to the median plane of the tooth (17, 49), this angle is complementary to the trailing edge (61) of the tooth neck (17, 49), a guide surface which forms one of the deflection angle planes of said retaining recesses (60) and is composed of two opposing conical surfaces (20, 21) whose the axes of rotation are in the same plane, offset from each other and different from the axis of the tooth bearing portion (1, 27), the end face (24, 31), whose cross-section corresponds to an irregular hexagon with longer sides in horizontal position and one or two holes 26, 47, 48 for receiving a retaining bolt (25, 59) arranged in and extending perpendicular to the tooth-bearing portion (1, 27), interrupted by the stepped profile of the straight guide bar (9, 10); 45, 46; 57, 58 (offset) relative to the annular recesses (60) of the leading edge (7) of the tooth-bearing portion (1, 27). An excavator coupling or the like according to claim 1, characterized in that the bent recesses (60) of the front edge (7) of the tooth bearing parts (1, 27) which receive the back edge (61) of the neck or hole of the tooth (17). 48, extend along the profile of the widest part of the mating surface, which is formed by two conical surfaces (20, 21) opposed to each other, forming the rear portion of the nose of the tooth-bearing parts. An excavator coupler or the like according to claim 2, wherein the two bent recesses (60) of the front edge (7) of the tooth-bearing portions (1, 27) have upper and lower portions that are constrained at their two ends two stepped guide rails (9, 10); 45, 46; 57, 58) forming one of the mating surfaces. • · An excavator coupler or the like according to claim 2, wherein the two bowed recesses (60) of the front edge (7) of the tooth-bearing portions (1, 27) limit the widest portion of the two conical surfaces (20, 21). which form mating or coupling surfaces which in turn are directly constrained by their sides by means of stepped guides (9, 10); 45, 46; 57, 58) forming a mating surface and coincident with the surface of the end mating surface (24, 31). Excavator coupler or the like, according to claim 1, characterized in that the adjusting function performed by the bowed recesses (60) of the front edge of the tooth-bearing parts (1, 27) with respect to the back edge (61) of the hole or neck of the tooth (17). 49 is supplemented by a adjusting function performed by the rear walls of the stepped straight guide rails (9, 10); 45, 46; 57, 58) with respect to the protruding ends of the side wings (18, 19); 50, 51]. An excavator coupling or the like according to claim 1, characterized in that the pin (25, 59) for retaining the tooth (17, 49) on the tooth-bearing parts (1, 27) has a shorter length than the hole (bore). 26, 47, 48 (to accommodate it in this portion (1, 27)), thereby allowing the upper or lower removable cover (34, 35) to be received in the hole or opening. An excavator ' s coupling according to claim 6, characterized in that the studs (34, 35) closing the bolt receiving hole are partially seated in the upper and lower recesses (32, 33) of the hole or bore (26, 47). , 48 / for bolt (25, 59). Excavator coupler or the like according to claims 1 and 7, characterized in that the profile of the side wings (18, 19); 50, 51 of the tooth (17, 49) is complementary to the profile of the stepped straight guide rails (9, 10); 45, 46; 57, 58]. An excavator ' s coupling according to claim 1, characterized in that the cross section of the irregular hexagon end surface (24, 31) extends in accordance with at least one end, in a rectangular shaped extension.