Shaving machine and shaving apparatus

Abstract

A wood chipper for obtaining wood shavings from wood chips, comprising: a closed structure having a feed port through which wood chips can be introduced into the structure; a cutter ring disposed within the structure, wherein the cutter ring has a substantially horizontal central axis and an inner surface, and includes a plurality of cutting elements projecting from within the inner surface; a rotor disposed within the cutter ring, wherein the rotor includes a plurality of impact elements disposed on a circle centered on the central axis; a drive mechanism actuated to rotate the rotor and / or the cutter ring relative to each other about the central axis, such that each impact element moves relative to the cutting elements in a corresponding tangential direction; wherein the rotor includes a plurality of clamping elements, each clamping element being associated with a corresponding impact element to project relative to the corresponding impact element in a corresponding tangential direction, and together with the corresponding impact element defining a seat adapted to receive at least one wood chip.

Description

[0001] This invention relates to a wood chipper that functions to obtain long wood or bamboo shavings by repeatedly cutting elongated wood chips (preferably referred to as "wood chips" or more specifically "large wood chips"), and to a wood chipper apparatus including such a wood chipper.

[0002] In the wood processing industry, engineered wood products made from wood shavings (such as oriented strand board (OSB) and particle board (PB)) are already well-known.

[0003] This type of engineered wood is typically made by mixing wood shavings with glue and adhesives, and then compacting the mixture using a suitable press. The wood shavings are obtained in advance through a first shaving process and a second shaving process. The first shaving process reduces the starting wood (which may consist of logs or already processed regenerated wood) into elongated wood chips, while the second shaving process further cuts the wood chips to obtain the actual wood shavings.

[0004] Wood chipping is typically performed using a wood chipper. Generally, such a wood chipper first comprises an enclosed structure with a feed inlet through which wood chips are introduced into the structure. The wood chipper then includes: a cutter ring positioned inside the enclosed structure, having a horizontal central axis and an inner surface from which cutting elements project inward, and which, once the wood chips are introduced into the structure, rest on the inner surface; and a rotor housed inside the cutter ring to allow rotation about a central axis relative to the cutter ring. The rotor specifically includes multiple support elements positioned on a circle centered on the central axis, with impact elements projecting outward from the corresponding support elements fixed to each support element.

[0005] The chipper ultimately includes a drive unit that can be actuated to rotate a rotor relative to a cutter ring: by rotating the rotor, the impact element moves the wood chip along the inner surface of the cutter ring, pushing the wood chip against the cutting element to perform cutting, which allows for the production of chips of the desired size.

[0006] However, some drawbacks have been observed with this solution. First, it has been observed that the long wood shavings obtained in this way are on average shorter than the starting wood chips; considering that the longer the long wood shavings, the greater the quality and strength of the resulting board, the long wood shavings obtained by known methods allow for the production of boards of limited quality, unless a difficult and laborious operation is carried out to select only the longest wood shavings and discard all other long wood shavings.

[0007] Furthermore, given the same number of other structural features (e.g., the same number of cutting elements and impact elements), it is desirable to increase the productivity of the planer so that more engineered wood panels can be manufactured subsequently in the same amount of time.

[0008] The purpose of this invention is to overcome the above-mentioned disadvantages, and in particular to manufacture a wood chipper and chipping equipment that can obtain wood shavings of sufficient length to produce high-quality engineered wood products, minimize waste, and increase overall productivity with the same number of other structural features.

[0009] Another objective of this invention is to achieve an effective reduction in the size of wood chips obtained from recycled timber.

[0010] According to the present invention, these and other results are achieved by manufacturing the shaving machine according to claim 1 and the shaving device according to claim 6.

[0011] Other features of the invention are the subject of the dependent claims.

[0012] The invention will now be described, by way of illustration and not limitation, with reference to the accompanying drawings, in which:

[0013] - Figure 1 This is a perspective view of the shaving device according to the present invention;

[0014] - Figure 2 This is a perspective view of the shaving machine according to the present invention;

[0015] - Figure 3 yes Figure 2 The view, in which some parts have been removed for clarity;

[0016] - Figure 4 This is an enlarged front view of the details of the blade ring of the slicer according to the present invention;

[0017] - Figure 5 This is a perspective view of the rotor of a slicing machine according to the present invention, wherein some parts have been removed for clarity;

[0018] - Figure 6 This is an enlarged front view of the rotor of the slicing machine according to the present invention;

[0019] - Figure 7 yes Figure 3 A magnified view of the details;

[0020] - Figure 8 This is a component diagram of the directional feeder of the device according to the present invention;

[0021] - Figure 9This is a component diagram of the conveyor belt of the device according to the present invention.

[0022] refer to Figure 1 100 generally refers to a shaving device that can be used to obtain wood shavings by cutting multiple wood chips in one or more steps. Each wood chip is produced by a previous shaving process (known but not described) and is generally elongated in shape, i.e., such that it has one dimension (length) greater than the other two dimensions (width and thickness); the wood chip (better referred to by the English term "chip", or more specifically "macro-chip") may have, for example, a parallelepiped or cylindrical shape, with a length of about 100 mm and a width and thickness of about 50 mm.

[0023] The device 100 specifically includes a wood chipper 1, which defines a wood chip shell inside the wood chipper 1, wherein wood chips are cut to obtain long wood shavings, and a supply device 2 actuable to introduce wood chips into the interior of the wood chipper 1.

[0024] Reference Figure 2 The wood chipper 1 first includes a machine body 13, on the front surface of which a service opening is formed. This service opening can be closed by a door 11 hinged to the machine body 13 itself by two vertical shafts. The machine body 13 and the door 11 together form a closed structure 10, within which a wood chip shell is defined. A feeding port 12 is formed in the lower part of the door 11, through which wood chips can be introduced into the wood chip shell to be ground when the wood chipper 1 is in use and the door 11 is closed.

[0025] Reference Figure 3 The slicer 1 also includes a cutter ring 20, which is positioned inside the housing 10, wherein the central axis A of the cutter ring 20 is placed substantially horizontally. In this way, a set of three mutually perpendicular reference directions can be defined point by point, including an axial direction, a radial direction, and a tangential direction parallel to the central axis A.

[0026] The cutter ring 20 has an inner surface 21, on which the wood chip is positioned once it is introduced into the housing structure 10 through the feed port 12 and extends in width along the axial direction for substantially the entire extension of the machine body 13: thus, the wood chip placed on the inner surface 21 cannot be detached laterally from the cutter ring 20.

[0027] More specifically, the cutter ring 20 is composed of a plurality of bases 22, which are placed on a circle centered on the central axis A and laterally fixed to two first closing rings 23, so as to define the inner surface 21 of the cutter ring 20 by means of corresponding inner surfaces. Reference Figure 4Each base 22 includes a cutting element 24 positioned to protrude internally relative to the inner surface 21 of the cutter ring 20, i.e., protruding from the inner surface 21 along a direction having at least a component along a corresponding radial direction; each cutting element 24 specifically consists of a cutting blade extending axially along the entire width of the cutter ring 20. The bases 22 are fixed to a first closing ring 23 such that a slit 25 is defined between each pair of adjacent bases 22, each pair of bases 22 being adjacent to each cutting element 24 and having a predetermined width measured in the tangential direction.

[0028] Still referencing Figure 3 The slicer 1 also includes a rotor 30 coaxially disposed inside the cutter ring 20, such that the rotor 30 and / or the cutter ring 20 can rotate relative to each other about a central axis A. Preferably, the cutter ring 20 is fixed to the machine body 13 during use, while the rotor 30 rotates relative to the cutter ring 20 about the central axis A; however, in an alternative embodiment, the cutter ring 20 may also rotate about the central axis A in a direction opposite to the direction of rotation of the rotor 30.

[0029] Reference Figure 5 The rotor 30 includes a support disk 31 centered on a central axis A, and a plurality of support elements 32 (also referred to as "long arms"), which are fixed at one end to the support disk 31 and at the other end to a second closed ring 33, so as to be located on a circle centered on the central axis A and equidistant from each other. Impact elements 34 (preferably in a reversible manner) project outward from the corresponding support element 32 along a corresponding radial direction: in this way, the impact elements 34 are also positioned on a circle centered on the central axis A.

[0030] More specifically, see reference Figure 7 Each impact element 34 is composed of a bottom cutter, the axial extension of which is substantially equal to the axial extension of the cutting blade, and the bottom cutter is connected to a corresponding support element 32 such that the radial distance R between the cutting blade and the bottom cutter allows for the cutting of wood chips while preventing the wood chips from being crushed between the cutting blade and the bottom cutter. Crushing would cause the wood chips to tear and grind, as well as generate dust and particles, resulting in low-quality long wood shavings.

[0031] Still referencing Figure 3 The slicer 1 includes a drive unit 40, which is driven to rotate the rotor 30 and / or the cutter ring 20 relative to each other about a central axis A, thereby moving the impact element 34 tangentially relative to the cutting element 24. The drive unit 40 may include, for example, an electric motor 41 connected to a support disc 31 of the rotor 30 via a coupling 42.

[0032] In this manner, the impact element 34 tangentially pushes the wood chips introduced into the chip shell along the inner surface 21 of the cutter ring 20, causing them to abut against the cutting element 24, which performs cutting, dividing the wood chips in question into two parts: long shavings of the desired size that escape from the cutter ring 20, which pass through the slit 25 adjacent to the cutting element 24 that performs the cutting, and the remaining wood chips that subsequently undergo further cutting to obtain more long shavings. Therefore, it is evident that the size and thus the quality of the obtained long shavings depend on the protrusion of the cutting element 24 relative to the inner surface 21 of the cutter ring 20, the tangential width of the slit 25, and the radial distance R between the impact element 34 and the cutting element 24.

[0033] Reference Figure 6 Connecting elements 35 (preferably in a reversible manner) are connected to each support element 32 to be radially inwardly positioned relative to the impact element 34 connected to the same support element 32, and clamping elements 36 (preferably in a reversible manner) protruding tangentially from their associated impact element 34 (i.e., connected to the same support element 32) are connected to each connecting element 35 in the same direction in which the support element 32 moves relative to the cutting element 24 as the rotor 30 rotates relative to the cutter ring 20. Thus, each clamping element 36, together with its associated impact element 34, defines a seat 37 (also referred to as a "groove") in which one or more wood chips to be ground can be received. In fact, it has been observed that, in known solutions, one of the reasons for the reduction in the average length of the strands obtained from the chipper 1 is that, after the wood chips are cut between the impact element 34 and the cutting element 24, the remaining wood chips inside the cutter ring 20 are usually projected in space in a random direction by the reaction force. Once they bounce once or multiple times on the inner surface 21 and return to rest on the inner surface 21 of the cutter ring 20, they themselves are randomly oriented. Therefore, the remaining wood chips are likely to be placed on the inner surface 21 with their extension direction tilted relative to the cutting element 24, and thus subsequent cutting will reduce their length.

[0034] On the other hand, the clamping element 36 prevents the remaining wood chips from being projected in a random direction after cutting, but instead clamps them in the seat 37, where their extension direction is substantially parallel to the cutting element 24, i.e., axially oriented. Therefore, subsequent cutting occurs with the cutting element 24 positioned parallel to the extension direction of the remaining wood chips, thus thinning the remaining wood chips without shortening them. This allows for the production of longer wood chips with a greater average length, and therefore allows for the subsequent production of higher quality engineered wood panels, avoiding the need to discard large quantities of long wood chips that are too short. Furthermore, it has been observed that the fact that the remaining wood chips are clamped in the seat 37 by the clamping element 36 allows for multiple consecutive cuts (by consecutively cutting the element 24) to be performed on the same material received in the same seat 37, thereby minimizing the average residence time of the material within the chip housing. This also allows for an increase in the overall productivity of the chipper 1 while having the same other structural features.

[0035] The present invention also minimizes the number of consecutive cuts each wood chip undergoes to obtain long wood shavings of the desired size. Therefore, the wood chipper 1 is particularly suitable for grinding recycled wood chips: in fact, this wood has undergone prior processing, its resistance characteristics differ from those of the logs, and excessive cuts tend to rapidly impair the final quality of the long wood shavings obtained from it.

[0036] Furthermore, the inherently higher efficiency of the planing process compared to known solutions may allow for a reduction in the total number of cutting elements 24 and impact elements 34, and allow for further spacing of them along the corresponding circles, while maintaining the high overall productivity of the planer 1. In this way, after each cut, more time is given to the remaining wood chips to reposition in the corresponding seats 37, thus allowing subsequent cuts to occur with the cutting elements 24 positioned parallel to the extension direction of the remaining wood chips.

[0037] Preferably, the clamping element 36 has a clamping surface 38 that projects tangentially from its associated impact element 34 and is inclined inwardly relative to the tangential direction. It has been observed that this configuration allows wood chips to be easily inserted into the seat 37 while still preventing them from escaping from the seat 37 after cutting. The clamping surface 38 may be smooth, or it may have a roughness of suitable shape and size to further prevent any remaining wood chips from dislodging from the seat 37. The exact shape, geometry, and size of each clamping element 36 can vary depending on the shape and size of the wood chips to be planed.

[0038] Preferably, the clamping element 36 has a wedge-shaped structure with a radial cross-section that gradually decreases as it moves away from the support element 32 to which it is fixed. In fact, this construction has been observed to be particularly robust and durable.

[0039] Still referencing Figure 1 The supply device 2 includes a conveyor belt 50 and a directional feeder 60. The conveyor belt 50 extends along a conveying direction substantially parallel to the central axis A and has a first end 51 facing the feed port 12 in the structure 10 of the slicer 1 and a second end 52 opposite to the first end 51. The directional feeder 60 has a concave shape and extends along a directional direction that is inclined upward relative to the conveying direction: the directional feeder 60 thus has an open lower end 61 positioned above the conveyor belt 50 (particularly above the second end 52) and an upper end 62 opposite to the lower end 61.

[0040] refer to Figure 8 The directional feeder 60 has a semi-circular cross-section, and the wood chips to be planed (which initially tend to be placed in a random orientation) are loaded therein. The directional feeder 60 can also be vibratory actuated: in this way, the wood chips received therein tend to autonomously orient themselves parallel to the orientation direction and move toward the lower end 61 until they fall onto the conveyor belt 50. More specifically, the directional feeder 60 is suspended from a support bracket 63 by a plurality of springs 64 and can be vibratory actuated by one or more vibration actuators (not visible in the figure).

[0041] Reference Figure 9 The conveyor belt 50 includes a belt 53 wound around two rollers between a first end 51 and a second end 52, and a conveyor actuator 54 actuated to circulate the belt 53 so as to push wood chips placed on the belt 53 toward the first end 51 and introduce them into the shaving housing through the feed port 12. Since the orientation direction is inclined perpendicularly to the conveying direction, once the wood chips, oriented along the orientation direction by the directional feeder 60, fall onto the conveyor belt 50, the wood chips are generally aligned along the conveying direction: this allows the wood chips to be introduced into the shaving machine 1, which is already axially aligned, i.e., substantially parallel to the cutting element 24. In this way, it is likely that the first cutting of the wood chips occurs when the cutting element 24 is positioned parallel to the extension direction of the wood chips, thereby maximizing the length of the resulting long shavings.

[0042] Furthermore, preferably, the directional feeder 60 allows the wood chips to be advanced at a first speed, while the conveyor belt 50 allows the wood chips to be advanced at a second speed greater than the first speed. This allows for a further increase in the possibility of axial alignment of the wood chips falling from the directional feeder 60 onto the conveyor belt 50.

[0043] In an alternative embodiment not depicted in the figure, the belt has a concave cross-section to better clamp the wood chips as they are advanced.

[0044] In an alternative embodiment not depicted in the figure, the supply device 2 includes a drop supply device actuated to introduce wood chips into the chip shell through the feed port 12 by gravity.

[0045] The present invention has been described in an illustrative rather than limiting manner according to its preferred embodiments, but it should be understood that various changes and / or modifications can be made by those skilled in the art without departing from the relevant scope of protection defined by the appended claims.

Claims

1. A wood chipper (1) for obtaining wood shavings from wood chips, comprising: - A closed structure (10) having a feeding port (12) in which the wood chips can be introduced into the interior of the structure (10) through the feeding port (12); - A blade ring (20), which is placed inside the structure (10), wherein the blade ring (20) has a substantially horizontal central axis (A) and an inner surface (21), and includes a plurality of cutting elements (24) protruding inward from the inner surface (21); - Rotor (30), the rotor (30) being placed inside the blade ring (20), wherein the rotor (30) includes a plurality of impact elements (34) placed on a circle centered on the central axis (A); - A drive device (40) capable of driving the rotor (30) and / or the cutter ring (20) to rotate relative to each other about the central axis (A), so that each impact element (34) moves relative to the cutting element (24) in the corresponding tangential direction; The rotor (30) is characterized in that it includes a plurality of clamping elements (36), wherein each clamping element (36) is associated with a corresponding impact element (34) so ​​as to protrude from the corresponding impact element (34) in a corresponding tangential direction and define a seat (37) with the corresponding impact element (34) suitable for receiving at least one piece of wood.

2. The shaving machine (1) according to claim 1, wherein, Each clamping element (36) has a clamping surface (38) protruding from the corresponding impact element (34) in the corresponding tangential direction, the clamping surface (38) being inclined toward the central axis (A) relative to the corresponding tangential direction.

3. The shaving machine (1) according to claim 2, wherein, Each clamping element (36) has a wedge-shaped structure with a radial dimension that gradually decreases as it moves away from the corresponding impact element (34) in the corresponding tangential direction.

4. The slicing machine (1) according to any one of the preceding claims, wherein, The rotor (30) includes a plurality of support elements (32), wherein each clamping element (36) is reversibly connected to the corresponding support element (32).

5. The slicing machine (1) according to any one of the preceding claims, wherein, Each cutting element (24) includes a cutting insert (24) extending substantially parallel to the central axis (A), and wherein each impact element (34) includes a bottom cutter (34) extending substantially parallel to the central axis (A).

6. A shaving apparatus (100) for obtaining wood shavings from wood chips, comprising: - A shaving machine (1) according to any one of claims 1 to 5; - A supply device (2) that can be driven to introduce the wood chips into the structure (10) through the feed port (12).

7. The device (10) according to claim 6, wherein, The supply device (2) includes: - A conveyor belt (50) extending along a conveying direction substantially parallel to the central axis (A) and having a first end (51) facing the feed inlet (12) and a second end (52) opposite to the first end (51), the conveyor belt (50) being actuable to advance the wood chips placed thereon toward the first end (51). - A concave directional feeder (60) extends along a directional direction that is inclined upward relative to the conveying direction and has an open lower end (61) positioned above the conveyor belt (50). The directional feeder (60) is shaped to receive a plurality of wood chips and is also vibratoryly actuated to orient the wood chips received therein substantially parallel to the directional direction and to advance the wood chips toward the lower end (61).

8. The device (100) according to claim 7, wherein, The directional feeder (60) has a semi-circular cross-section.

9. The device (100) according to claim 7 or 8, wherein, The directional feeder (60) is vibratory actuated to advance the wood chips received therein toward the lower end (61) at a first speed, and the conveyor belt (50) is actuated to advance the wood chips placed thereon toward the first end (51) at a second speed greater than the first speed.

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