GB2066729A

GB2066729A - Regrindable blade for a wood- cutting machine

Info

Publication number: GB2066729A
Application number: GB8041173A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-12-29
Filing date: 1980-12-23
Publication date: 1981-07-15
Also published as: FR2472457A1; NO147137C; NO147137B; NO803789L; GB2066729B; ATA620680A; FR2472457B1; AT372332B

Abstract

The blade comprises separate scorers (8) each of which is secured to the blade body plate (2) so as to project beyond the cutting edge (3) of the blade (1). The scorers (8) may be retained in grooves (7) in the plate (2) by adhesive or welding and are replaceable when worn instead of replacing the whole blade (1). <IMAGE>

Description

SPECIFICATION Regrindable blade for a wood-cutting machine The invention relates to a regrindable blade for a wood-cutting machine of the type comprising scorers for breaking up the chip material .transversely, the scorers being located on a chip discharge surface in the vicinity of the blade cutting edge and with their end faces in the plane .of a surface beneath the cutting edge.

A blade of this type is known from German AS 28 18 143. In contrast to a so called chaser blade, a blade of this type cuts virtually over the entire length of the cutting edge. Accordingly, the length of the chip is comparatively large. Also, chips of uniform thickness with a generally constant quality are produced. In the case of the known blade, the scorers are formed from the blade body by the punching and bending method.

For this, a parting cut must be inserted in the blade body and then a part of the material bent out to form the scorer. This production is complicated and expensive and also requires precision punching and bending tools, which are subject to considerable wear, so that excessive manufacturing tolerances may occur.

It is the object of the invention to improve a regrindable blade of the aforedescribed type so that whilst retaining its advantages, the production expenditure for the scorers is reduced and an improvement in the quality of the blade is facilitated.

The invention provides a regrindable blade for a wood-cutting machine, which comprises scorers for breaking up chip material transversely, which scorers are located on a chip discharge surface adjacent a cutting edge of the blade and with their end faces in the plane of a surface below the cutting edge, characterised in that each scorer is constructed as a separate scoring member and is attached to a blade body.

As a result of the construction of the scorers as separate scoring members, optimum adaptation of the blade and of the scorers to the respective wood material and operating conditions is possible. The scorers may be produced economically and from the most favourable quality of tool steel. It is no longer necessary for the blade body to consist completely of tool steel, solely in the region of its cutting edge. Due to this, considerable savings are achieved. It is also possible to use a laminated material for the blade body, which on the upper side, on which the cutting edge is located, consists of a layer of material which is highly resistant to wear, whereas a softer material is located therebelow, which has advantageous elasticity. With low production costs, it is thus possible to achieve a long tool life for the blade.A further advantage consists in that after hardening and tempering, the blade can be reground on the upper side with a flat grinding machine, and the scorers are only then inserted, whereas after tempering and hardening, the known blades can only be reground with special machines, which is very expensive. Also, in the case of possible damage, the scoring members of the blade according to the invention can be exchanged quite easily. Also, since the tool life of the scorer can be extended considerably by using a suitable high quality tool steel, the proportion of fine material which is undesirable during chip production is extremely small.

Further advantages and details of the invention will become apparent from the ensuing description and drawings, which illustrate preferred embodiments diagrammatically: Fig. 1 is a view of the rear side of 2 blade according to the invention; Fig. 2 is a side view of the blade according to Fig. 1 in the direction of arrow ll; Fig. 3 is a front view of the blade according to Fig. 1 in the direction of arrow Ill; Figs. 4 to 1 5 show scoring members of varying construction and attached to various blade bodies in partial view and to an enlarged scale; Fig. 16 is a view of the rear side of a blade with shorter scoring members; Fig. 17 is a side view of the blade according to Fig. 1 6 in the direction of arrow XVI I;; Fig. 1 8 is a front view of the blade according to Fig. 1 6 in the direction of arrow XVIII; Fig. 19 is a front view of another embodiment of the blade, in partial section; Fig. 20 is a side view of the blade according to Fig. 19, in partial section; Fig. 21 is a front view of a blade having a different construction, in partial section; Fig. 22 is a side view of the blade according to Fig. 21 in partial section, Fig. 23 is a view of the rear side of the blade according to Fig. 21 and 22, Fig. 24 is a front view of a further embodiment of the blade, in partial section, Fig. 25 is a view of the rear side of the blade according to Fig. 24.

The blade 1 illustrated in Figs. 1 to 3 consists of a blade body 2 with a cutting edge 3, adjoining which is a surface 4 below the cutting edge. The front side of the blade body forms a chip discharge surface 5 and is parallel to the rear side 6 of the blade body 2. The front side 5 contains retaining grooves 7, which extend over the full width of the blade body 2. Inserted in each retaining groove 7 is a scoring member 8, which likewise extends over the full width of the blade body 2. The scoring members 8 are immovably secured in the retaining grooves 7. They project beyond the cutting edge 3, their end faces being located in a common plane with the surface 4 below the cutting edge.

As one embodiment, Fig. 4 shows a scoring member 9, the cross section of which corresponds to that of an equilateral triangle, so that the scoring member has an acute-angled cutting part 10. The base part 11 of the scoring member 9 is located in the retaining grooves 7 of a blade body 14, which is made from a composite material and comprises a thin surface layer 1 5 which is highly resistant to wear and is appiied to a support 16, which is more resilient than the surface layer 1 5.

The underside of the base part 11 is soldered to the bottom of the retaining groove 7, which has a rectangular cross section and therefore has walls 13 at right angles to the bottom of the groove.

In the embodiment according to Fig. 5, a scoring member 8 is soldered in the blade body 14 in the retaining groove 7, according to Fig. 1, which scoring member likewise has an acute-angled cutting part 10, but the base part 17 of which has parallel side faces 18. The scoring member is seated with an exact fit in the groove 7, thus providing an additional support.

According to Fig. 6, a scoring member 19 is welded in the retaining groove 7 of rectangular cross-section, in the blade body 2 constructed according to Figs. 1 to 3. The base part 17 of the scoring member 1 9 likewise has parallel side faces 18, which bear against the parallel groove walls 13 of the retaining groove 7. The cutting part 20 of the scoring member 19, opposite the base part 17, is constructed as a rounded portion 21.

According to Fig. 7, a scoring member 22 is welded in the groove 7 of the blade body 14, which is constructed according to Figs. 4 and 5, whereof the cutting part 23 is constructed as a flat portion 24 (cf Fig. 6).

Fig. 8 shows a scoring member 25 of trapezoidal cross-section. The base part 26 of this scoring member is inserted in a retaining groove 27, which is constructed as a dove-tailed groove and therefore comprises side walls 28 having a back taper. These walls 28 having a back taper are bonded against the base part 26 of the scoring member 25.

According to Fig. 9, the base part 11 of the scoring member 9 of triangular cross-section is inserted with adhesive in the dove-tail shaped retaining groove 27 in the blade body 2.

Fig. 10 shows a scoring member 29 with a base part 30 of rectangular cross-section, which is inserted in a retaining groove 31 of likewise rectangular cross-section in the blade body 14 and is attached by adjesive. The scoring member 29 has a chamfer 32 and a flat portion 24 on its upper free end.

Fig. 11 shows a similar scoring member 33, which is likewise attached in the groove 31 by adhesive. The scoring member 33 has a chamfer 32, but the latter forms an acute angle at the upper free end of the scoring member 33.

In the embodiment according to Fig. 12, a scoring member 34 has a substantially rectangular cross-section and an upper flat portion 24. Two recesses 36 are provided on the base part 35. The base part 35 is inserted in the retaining groove 31 and bonded from outside so that part of the material on the chip surface 5 of the blade body 2 is pressed into the recesses 36.

Fig. 13 shows a retaining groove 37 of T shaped cross-section. Inserted in this retaining groove 37 is a scoring member 38 which has a rounded portion 21 on its upper side and the base part 39 of which likewise has a T shaped cross section. For improving the retaining forces, it is thus provided that the scoring member 38 has fluting provided on the side flanges of the base part 39. Fluting of this type may naturally be provided in the other embodiments.

Fig. 14 shows a scoring member 40 of triangular cross-section, which comprises a notch 42 on the bottom of its base part 41. The blade body 2 is deformed on the rear side 6 by indented grooving 43 so that the scoring member 40 is fixed in the dove-tail shaped retaining groove 27 with the walls 28 having a back taper.

According to Fig.15, the scoring member 9 of triangular cross-section is placed with its bottom on the chip discharge surface 5 of the blade body 2 and attached to the latter for example by means of brazing solder.

Figs. 16 to 18 show a blade 44, which is constructed substantially like the blade 1 in Figs. 1 to 3 and comprises scoring members 45 located in retaining grooves 46. One difference consists in that the scoring members 45 and retaining grooves 46 do not extend over the full width of the blade body 2, but, starting from the cutting edge 3, extend only over somewhat more than three quarters of the width of the blade body 2.

In the case of the blades illustrated in Figs. 1 9 and 20, the retaining groove 7 does not extend over the full width of the blade body 2, but, starting from the cutting edge 3, over approximately three quarters of the width of the blade body 2. Two recesses 58 are formed in the rear region of the blade body 2, which recesses in the present case are formed as bores 59. The two bores 59 are arranged one behind the other in the longitudinal direction of the retaining groove 7 and are spaced apart by a bridge 60. The bores 59 extend from the rear side 6 at right angles to the plane of the blade body 2 and open into the retaining groove 7. The diameter of the bores 59 is such that it is equal to the width of the retaining groove 7.The depth of the retaining groove 7 is somewhat less than the depth of the bores 59, measured from the rear side 6 of the body 2 to the bottom 11 of the retaining groove 7.

Located in the retaining groove 7 is the base part 62 of a scoring member 63, the width and length of which correspond substantially to the retaining groove 7 and which projects with a cutting part 64 beyond the chip discharge surface 5 and the cutting edge 3 of the blade body 2, in which case the end face of the scoring member 63 lies in the same plane as the surface 4 below the cutting edge of the blade body 2.

The cutting part 64 of the scoring member 63, projecting beyond the chip discharge surface 5, has a triangular cross-section, whereas the bass part 62 has a rectangular cross-section.

A welding or soldering metal is located as the attachment means 65 for the scoring member, in the bores 59, which metal is securely bonded to the base part 62 of the scoring member 63 and to the wall of the bores 59. Therefore, the scoring member 63 is not only located with an exact fit in the retaining groove 7, but is fixed to the blade body 2 by additional material bonding, in which case, at the time of manufacture, the bonding material 65 may advantageously be supplied from the rear side 6 of the blade body. The bonding material 65 completely fills the bores 59 and lies flush with the rear side 6 of the blade body 2, which thus has a completely flat surface.

In the embodiment illustrated in Figs. 21, 22 and 23, the recess 58 in the blade body 2 of the blade 66, which is constructed substantially like the afore-described blade 1, is constructed as a longitudinal groove 67. The width of the longitudinal groove 67 is thus exactly equal to the width of the retaining groove 7 and its length is nocsured such that it extends together with the retaining groove 7 over approximately three quarters of the width of the blade body 2. A rounded portion 68 is formed at the end of the longitudinal groove 67 so that no sharp edged grooves can be produced. The bonding material 65 consisting of welding or soldering metal completely fills the longitudinal groove 67 and connects the scoring member 63 firmly to the blade body 2.In the region of the surface 4 below the cutting edge of the blade body 2, the outer surface of the bonding material 65 extends in the same plane as the surface 4. In the same way, a completely flat surface is also provided in the region of the bonding material 65, on the rear side 6 of the blade body 2.

The blade 69 illustrated in Figs. 24 and 25 is constructed substantially like the blade 66, but in the latter, the retaining groove 70 and the recess 58 constructed as the longitudinal groove 71 extend continuously over the entire width of the blade body 72. The blade body 72 thus consists of individual pieces of plate 73, which are held together by the bonding material 65 consisting of welding or soldering metal. In this case also, the bonding material 65 completely fills the longitudinal groove 71 and forms a flat surface with the rear side 6 of the blade body 72. In particular casss it is possible to achieve rationalization of production by using the pieces of plate 73.

The embodiments according to Figs. 19 to 25 have the particular advantage that the scoring members are held securely on the blade body by way of the bonding material adhering firmly to their base part at the bottom of the retaining groove, in which case the bonding material is located outside the retaining groove in the recess provided therefor and adheres firmly to the walls thereof. The bonding material can thus be introduced easily and without difficulties from the rear side of the blade body, without causing any changes due to an accumulation of material, deformation of material or the like on the chip discharge surface of the blade body. The attachment of the scoring members consequently takes place exclusively in the rear region of the blade, so that in the working region of the chip discharge surface, the tool dimensions can be maintained exactly and no machining is required.

Claims

1. A regrindable blade for a wood-cutting machine, which comprises scorers for breaking up chip material transversely, which scorers are located on a chip discharge surface adjacent a cutting edge of the blade and with their end faces in the plane of a surface below the cutting edge, characterised in that each scorer is constructed as a separate scoring member and is attached to a blade body.

2. A blade according to claim 1, characterised in that each scoring member is inserted in a retaining groove which extends over at least a part of the blade body.

3. A blade according to claim 1 or claim 2, characterised in that each scoring member comprises a base part which is attached to the blade body by means of a bonding material.

4. A blade according to claim 3, characterised in that the cross section of the scoring member is a substantially equilateral triangle.

5. A blade according to claim 3,-characterised in that on its base part the scoring member has parallel side faces.

6. A blade according to any one of claims 3 to 5, characterised in that on the base part the scoring member comprises a recess on at least one side thereof.

7. A blade according to claim 3 characterised in that the base part of the scoring member has a T-shaped cross section.

8. A blade according to any one of claims 3 to 7, characterised in that the scoring member is inserted by its base part in a correspondingly constructed retaining groove.

9. A blade according to any one of claims 1 to 8, characterised in that a cutting part of the scoring member comprises a flat portion.

10. A blade according to any one of claims 1 to 8, characterised in that the scoring member comprises a chamfer on one side.

11. A blade according to claim 2 or any claim dependent thereon, characterised in that the blade body comprises at least one recess adjoining the retaining groove located in which recess is a bonding material adhering firmly to the scoring member and to a wall of the recess.

12. A blade according to claim 11, characterised in that the depth of the recess is not less than the depth of the retaining groove.

13. A blade according to claim 11 or 12, characterised in that the recess is constructed as a bore extending at right angles to the plane of the blade body.

14. A blade according to claim 13, characterised in that spaced in the longitudinal direction of the retaining groove are provided two bores.

15. A blade according to claim 11 or 12, characterised in that the recess is constructed as a longitudinal groove.

16. A blade according to claim 15, characterised by the fact that the longitudinal groove and the retaining groove are constructed in a continuous manner over the entire width of the blade body and that the blade body consists of individual plate pieces held together by bonding material.

17. A blade acco;ding to any one of claims 11 to 16, characterised by the fact that the bonding material substantially fills the entire cross section of the recess.

18. A regrindable blade for a wood-cutting machine substantially as hereinbefore described with reference to and as illustrated in the various figures of the accompanying drawings.