EP0080408B1 - Shingle making machine - Google Patents

Abstract

1. Device for splitting pieces of wood (9) in order to form laths by means of a blade (1) which is mounted on a support (2) and moved mechanically in a reciprocating manner, the said blade being also pivotable about an axis (3) which is adjacent to the cutting edge and substantially parallel to the latter, characterised in that the said blade (1), which is mounted pivotably on the support about the axis adjacent to and substantially parallel to its cutting edge, has an axis of articulation (3) which merges with the line of intersection between the plane of the flat surface (5) having the smaller width and that plane (15) of the blade face which is adjacent to this flat surface, in that the said blade has a substantially parallelepipedic rectangular flattenend form, its cutting edge being in the form of a dihedron situated along one of the long sides of the rectangle, in that the bisecting plane of the dihedron forming the cutting edge combines with the centre plane (7) to form such an angle that one of the flat surfaces (6) of the dihedron has a width distinctly greater than that of the other flat surface (5).

Description

The present invention relates to a machine for making shingles from pieces of wood such as logs.

It is recalled that the shingles are strips of wood intended to cover, like scales, the roofs or walls of dwellings; this covering method is very old and very effective, both from the point of view of the seal it provides, and from the point of view of thermal insulation, as from the point of view of its longevity; it is recalled, however, that the excellent characteristics mentioned above of this material are only obtained if the fibers of the wood constituting the shingle are directed in the direction of the slope.

Thus, the oldest known way of making shingles consisted of cutting slats or slats from an ax with a log; in this way, the wood fibers were practically not interrupted all along the lamella; in the event of warping of the strip, one could however plan it with the ax without too much prejudice for the quality of the shingle.

More recently, it has been proposed to manufacture shingles from boards obtained by sawing and then planing. This manufacturing method provided shingles of very strict dimensions and flattering appearance when they were new; experience has shown that shingles made in this way deteriorate fairly quickly, this rapid deterioration seems to be due to the fact that the wood fibers have been cut, thus allowing the water to flow through the fiber bundles .

Devices are also known for splitting logs intended for heating in general, in which an ax-shaped or wedge-shaped blade is moved mechanically alternately at a relatively low speed allowing manual positioning of the log at- underside of the blade; applied to the manufacture of shingles, this device only has the advantage over the manual manufacturing process of saving fatigue, the production cost remaining just as prohibitive as that of the entirely manual process.

According to the present invention, a device intended for splitting pieces of wood in order to form shingles by means of a blade mounted on a support and mechanically moved alternately, said blade being moreover pivotable about an axis close to its cutting edge and substantially parallel to the latter, is characterized in that said blade, which is pivotally mounted on a support, around an axis adjacent to its cutting edge and substantially parallel thereto, has its axis of articulation coincident with the line of intersection of the plane of the facet of smaller width with the plane of the face of the blade adjacent to this facet, in that said blade has a substantially flat rectangular parallelepiped shape, its cutting edge being in the form of a dihedron

located along one of the long sides of the rectangle, in that the bisector plane of the dihedron constituting the cutting edge forms with the median plane an angle such that one of the facets of the dihedron has a width significantly greater than that of the other facet.

More preferably, the pivoting of the blade is limited by two adjustable abutment positions, and the blade is biased lightly in the direction of the so-called first position of abutment situated on the side of the facet of greater width.

Also known from US-A-2183479 is a device for splitting pieces of wood in order to form shingles, by means of a blade mounted on a support and mechanically moved alternately;

also known from US-A-3,224,477 a similar device in which the blade is pivotable about an axis close to its cutting edge and parallel thereto;

the device of the first of these documents does not include an oscillating blade and therefore does not allow splitting along the grain of the wood; the device of the second document is designed for unwinding and although having an oscillating blade is not suitable for splitting lengthwise, a fortiori for successive splitting.

The problem which the present invention aims to solve is that of repetitive long splitting and following as much as possible the wood grain so as not to cut the fibers. Thus, the present invention also aims to provide a machine automatically reproducing the old process and allowing the obtaining of shingles of identical quality with however a considerable reduction in cost compared to the manual process.

More preferably, the blade is articulated at each of its ends on said support and the support is itself driven by an alternating rectilinear translational movement of direction substantially perpendicular to the cutting edge of the blade; care will be taken that the means for adjusting the first stop position make it possible to adjust this position so that the facet of smaller width is parallel to the plane of translation of the blade support.

Advantageously, a device of the invention further comprises a member for gripping pieces of wood to be split, said member essentially consisting of a pair of jaws intended to bite into the opposite edges of the piece and to present the latter at the end. facing the blade, the direction of the wood fibers being generally parallel to the plane of translation of the blade.

According to a particular embodiment of a device of the invention as described above, the translation plane is a horizontal plane, the gripping member is located above the translation plane, the facet of smaller width being located above the widest facet, the slight stress of the blade is a downward bias resulting from its own weight.

It will be noted that both the stressing force of the blade, or its weight in the aforementioned particular case, the respective width of the facets of the cutting edge, the thickness of the blade, as well as its width must be defined by tests following the characteristics of the wood used, namely the species, age, dryness, etc.

• la figure 1 est une illustration schématique en perspective des organes essentiels d'un dispositif de l'invention,
• la figure 2 est une coupe schématique en élévation d'une forme particulière de réalisation de la machine de l'invention,
• la figure 3 est une vue de dessus de la même,
• la figure 4 est une vue en perspective d'un chariot support de lame de la machine des figures précédentes,
• la figure 5 est une coupe partielle en élévation de celui-ci,
• la figure 6 est une vue en plan partiel du même, et
• la figure 7 est une coupe schématique en élévation d'une seconde forme de réalisation, cette vue étant analogue à celle de la fig. 2. Sur la fig. 1, on a représenté une lame 1 de forme sensiblement rectangulaire allongée, coupée vers la moitié de sa longueur pour mettre en évidence son profil ; la lame 1 est articulée à chacune de ses extrémités sur un support 2 dont sont seulement visibles des parties 2', et 2" voisines de l'axe 3 d'articulation de la lame ; l'axe d'articulation 3 est voisin au tranchant 4 de la lame et parallèle à celui-ci ; l'articulation de la lame, dont on décrira plus loin les détails, permet à la lame de pivoter autour de l'axe 3.

The present invention will be better understood and details will be apparent from the description which will be given in relation to the figures of the appended boards, of a schematic example and of a particular embodiment, appended boards in which:

• FIG. 1 is a schematic perspective illustration of the essential organs of a device of the invention,
• FIG. 2 is a diagrammatic section in elevation of a particular embodiment of the machine of the invention,
• FIG. 3 is a top view of the same,
• FIG. 4 is a perspective view of a blade support carriage of the machine of the preceding figures,
• FIG. 5 is a partial section in elevation thereof,
• FIG. 6 is a partial plan view of the same, and
• Figure 7 is a schematic sectional elevation of a second embodiment, this view being similar to that of FIG. 2. In fig. 1, there is shown a blade 1 of substantially rectangular elongated shape, cut around half its length to highlight its profile; the blade 1 is articulated at each of its ends on a support 2 of which only parts 2 'and 2 "are visible, which are close to the axis 3 of articulation of the blade; the axis of articulation 3 is close to the cutting edge 4 of the blade and parallel to it; the articulation of the blade, the details of which will be described below, allows the blade to pivot around axis 3.

The blade 1 is cut from a rectangular plate, or a flattened parallelepiped, made of a suitable steel; the edge of the blade consists of the edge of a dihedral formed by upper 5 and lower 6 facets; the facet 5 has a width 1 much less than the width L of the facet 6; the cutting edge 4 or edge of the dihedral of the facets is situated slightly above the median plane 7 of the blade; the bisector plane of the dihedral, materialized by the bisector 8, is inclined on the median plane 7 so as to give the facets the abovementioned disproportion.

The blade, by means of its support, is driven in an alternating movement of translation back and forth shown by the arrows 10; this movement takes place in a plane, called the plane of carriage, perpendicular to the cutting edge 4 of the blade; such a plan is materialized by the dashed lines 11; there is also shown in FIG. 1 a piece of wood 9 in the form of a log kept in a fixed position using jaws such as 12 making grips at each of its ends, the log is positioned so that its underside 13 is located at a distance h - below the plan of carriage; the plan of work determines on the edge of the log the line of impact of the edge of the blade and the distance h will, after splitting, the thickness of the wooden slat constituting the draft of a shingle.

Thanks to its pivoting mobility, the blade will be able to follow the wood fibers which are generally parallel to the plane of translation, or of turning of the blade. This pivoting nature of the blade appears to be one of the causes of the proper functioning of the device of the invention; however, an additional condition is required, namely: that the axis of articulation 3 of the blade on its support must be as close as possible to the line 14 of intersection of the plane of the facet 5 and the upper face 15 of the blade ; in the case of the figure, the axis is optimally coincident with line 14.

The blade 1 is pivotally held between two stop positions, respectively, a first lower 16 and upper 17 stop position; these stop positions are adjustable using means which will be described later; the stop 16 is adjusted so that the upper facet 5 of the cutting edge is substantially parallel to the turning plane which is in the case of the figure a horizontal plane; in this particular case, the cantilever weight of the blade will be used relative to its pivot axis to serve as a permanent stress on the blade towards its lower stop position. Thus before the impact of the cutting edge on the log, the plane of the upper facet 5 of the cutting edge will be approximately parallel to the fibers of the wood of the log 9.

In fig. 2 and 3, there is shown respectively in elevation and in plan a machine putting the operating principles described with the previous figures. Such a machine essentially consists of a chassis 20 supporting members 21 for positioning and holding logs such as 9, drive members 22 of a blade-holder carriage 23 which can move back and forth in upper longitudinal members 24 of the chassis, a pair of connecting rods 25 connecting large wheels 26 to the carriage 23 by means of a transverse bar 27, a conveyor belt 28, slats of split wood and a receiving hopper 29 for the slats; the means for positioning and holding the logs are constituted by a mast 30 along which can move under the action of a jack 31, a vice 32 for clamping logs by a pair of opposing jaws such as 12 under the action of a jack 34; the vertical movement of the vice 32 takes place step by step according to a pneumatic alogical control, the height of a step corresponding to the thickness h of a slat. Means for automatically supplying jaw logs can be provided. The drive members 22 essentially consist of a motor 40 'of multiplying pulleys catrices 41 ', 42', large wheels 26 and pulleys 43 for driving the carpet.

In fig. 4, 5 and 6, the blade carriage is shown in more detail. First of all, it is noted that it is mainly formed of a pair of flanges 30 and 31 secured to the crossbar 27 at the end of which the connecting rods 25 are articulated. The outer faces of the flanges are provided with a double train of rollers 32 intended to guide the rolling of the carriage on rails 33 fixed inside the upper side members 24 of the chassis; centering rollers 34 mounted on the flanges center the carriage between the rails.

The blade 1 is supported by the flanges of the carriage (similar to the elements 2 ′ and 2 "in FIG. 1) by means of a pair of supports 36 each comprising a groove 37 in which the blade is engaged at its ends each support 36 is articulated by means of a ring 38 (or a ball bearing) on the flange which supports it; each support further comprises at the rear of the groove 37 an adjustment screw 39 allowing adjust the position of the blade in the groove so that the line 14 (fig. 1, edge of the upper facet) coincides with the axis of articulation of the support on the flange; such an adjustment is necessary to compensate loss of blade width after resharpening.

In fig. 5 more particularly, it is noted that the abovementioned upper and lower stop positions are determined by means of a threaded rod 40 secured to a flange; the ends of the rod 40 are provided with rubber end caps such as 41; as shown in fig. 5, the blade 1 is in the lower stop position; if under the effect of the impact against the log for example, the blade 1 were to pivot upwards, an extension arm 42 secured to the support 36 would come into abutment against the end piece 41 and the blade would then be in the position of so-called upper stop.

In fig. 7, there is shown a device similar to that of the preceding figures in which the blade works in a vertical planing plane. The different organs of this machine have been assigned the reference numbers assigned to analogous organs of the machine in the preceding figures; we note that in this configuration case the connecting rods 25 'push the arm 27' towards the log 9 'instead of pulling it as in the previous case. It will also be noted that, failing gravity, the blade is biased into the lower stop position by a small spring not shown in the figures. Although it has been described how during a first impact of the blade against the log, the latter was split along the fibers of the wood, to give rise to a slat, and how the log was translated parallel to itself to present a second line of impact and give rise to a next batten, it will be noted that it is also possible to control the translation of the log only after several round trips of the blade; by doing so in cases where the log is knotty or the wood fibers are not for another reason substantially parallel to the axis of the log, we will perform a kind of planing in one or more passes, equivalent to manual work of planing on a coverslip; experience has shown that the planing, or planing, thus practiced with the machines of the invention is generally sufficient to provide slats of substantially constant thickness and not be detrimental to the quality thereof in order to constitute shingles.

Finally, it will be noted that, without departing from the scope of the invention according to the claims, the means for moving the carriage, instead of being mechanical means by connecting rods, could be hydraulic or pneumatic means and that the means for holding and advancement of the logs could be mechanical means, for example by screws; more generally, it should be understood that the present invention is not limited to the embodiments described or shown above but that its scope is defined by its general characteristics as they have been stated above.

Claims (7)

1. Device for splitting pieces of wood (9) in order to form laths by means of a blade (1) which is mounted on a support (2) and moved mechanically in a reciprocating manner, the said blade being also pivotable about an axis (3) which is adjacent to the cutting edge and substantially parallel to the latter, characterised in that the said blade (1), which is mounted pivotably on the support about the axis adjacent to and substantially parallel to its cutting edge, has an axis of articulation (3) which merges with the line of intersection between the plane of the flat surface (5) having the smaller width and that plane (15) of the blade face which is adjacent to this flat surface, in that the said blade has a substantially parallelepipedic rectangular flattenend form, its cutting edge being in the form of a dihedron situated along one of the long sides of the rectangle, in that the bisecting plane of the dihedron forming the cutting edge combines with the centre plane (7) to form such an angle that one of the flat surfaces (6) of the dihedron has a width distinctly greater than that of the other flat surface (5).

2. Device according to Claim 1, characterised in that the solid angle of intersection (4) of the dihedron is situated approximately between the centre plane (7) of the thickness of the blade and the plane of one of the blade faces.

3. Device according to Claim 2, characterised in that the pivoting of the blade is limited by two adjustable stop positions (40, 41), and in that the blade is pulled slightly in the direction of the so- called first stop position situated on the side of the flat surface having the greater width.

4. Device according to Claim 1, characterised in that the said blade is articulated at each of its ends on the said support, and in that the said support is actuated by a rectilinear reciprocating movement of translation having a direction substantially perpendicular to the cutting edge of the blade.

5. Device according to Claim 4, characterised in that the means of setting the first stop position permit this position to be set in such a manner that the flat surface with the smaller width is parallel to the transiationai'piane of the blade support.

6. Device according to Claim 5, characterised in that it also comprises a gripping device (21) for gripping the pieces of wood to be split, the said device being essentially formed by a pair of jaws (12) designed to bite into the opposite edges of the wood and to present the latter end on to the blade, the direction of the wood grain being completely parallel to the translational plane of the blade.

7. Device according to Claim 6, characterised in that the translational plane is a horizontal plane, in that the gripping device is situated above the translational plane, with the flat surface which has the smaller width being above the flat surface with the greater width, and in that the slight pull of the blade is a downward pull resulting from its own weight.

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