Edge-trimming module for an electric hand-held saw and electric hand-held saw comprising such a module

Abstract

The present invention relates to an edge-trimming module (10) for an electric hand-held saw comprising a blade (16) performing a reciprocating movement and a table through which said blade moves, this edge-trimming module (10) comprising a plate (11) provided with at least one member (14) for attaching the plate to the table, this plate (11) comprising a guide fin (20) arranged downstream of said blade and aligned with this blade, this edge-trimming module (10) being characterized in that it further comprises: · an alignment flank (21) arranged upstream of said blade and aligned with this blade; · a lateral guide member (12) for guiding the blade; and · a chip guard (13). The invention further relates to a jigsaw comprising such an edge-trimming module.

Description

[0001] EDGING MODULE FOR PORTABLE ELECTRO SAW AND PORTABLE ELECTRO SAW COMPRISING SUCH A MODULE

[0002] TECHNICAL FIELD

[0003] The present invention relates in particular to the field of carpentry and portable electric machine tools used in particular in this field. It relates more particularly to a module to be attached to a portable electric saw such as a jigsaw. It also relates to a portable electric saw comprising such a module.

[0004] More particularly, the invention relates to a ripping module for a portable electric saw comprising a blade performing a reciprocating movement and a table through which said blade moves, this ripping module comprising a plate provided with at least one member for fixing the table to the ripping module, this plate comprising a guide fin arranged downstream of said blade and aligned with this blade.

[0005] PRIOR ART

[0006] Currently, there are portable electric machines such as jigsaws, which are very commonly used. These saws are practical due to their ease of use and versatility. They can be used to cut a wide variety of materials such as solid wood, chipboard panels such as OSB, MDF, melamine or laminated panels, plasterboard, synthetic materials, etc. They are also interesting because they can follow curves as well as straight lines.

[0007] However, they have drawbacks. When used to make a straight cut, it is necessary to place a guide against which a saw table can rest. Setting up the guide takes some time and can be complicated, depending on the configuration of the piece or the cut to be made. Furthermore, depending on the thickness or type of material to be cut, the blade may tend to deform and not remain perpendicular to the surface of the piece to be cut. This can produce a cut whose edge is not perpendicular to the face, which can prevent the assembly of different pieces. Generally, jigsaws produce chips on one of the faces of the piece to be cut. These chips are particularly visible and annoying on pieces covered with a coating such as a melamine panel or on pieces for which the surface is visible, such as parquet for example.In practice, it may be necessary to use the saw "upside down", i.e., with the table held on the underside of the workpiece and the blade pointing vertically upwards, so that the splintering occurs on the non-visible side of the finished piece. It may also be necessary to saw the workpiece to a size larger than the finished piece size, and then re-cut the piece with another machine that does not produce splintering, such as a planer.

[0008] It would therefore be advantageous to have a saw that allows you to make perfectly straight cuts, without using a guide and avoiding splintering.

[0009] Some tests have been carried out in particular with the aim of producing saws allowing straight cuts. One of these tests is described in particular in French patent FR2659045A1. The latter describes a "removable self-guiding device for a portable saw". This device comprises a shoe on which is fixed a fin perpendicular to the shoe and having the thickness of the saw blade. When the saw has cut a furrow, the fin is inserted into the furrow and guides the saw in a straight line.

[0010] This device has a number of disadvantages. In particular, before the blade has made a groove, there is nothing to guide it. If the start of the groove is not perfectly aligned with the desired cut, it will no longer be possible to rectify the direction of the cut, as the fin prevents this rectification. Furthermore, if the start of the cut is not completely straight, which is often the case in the absence of guidance, it may be difficult to insert the fin into the groove. In this embodiment, there is nothing to make a straight cut aligned with the desired cut, in the absence of guidance. The saw is therefore difficult to use in practice. Furthermore, since the blade of a jigsaw is generally relatively flexible, it may deviate from the ideal cutting plane and the edge or edge of the workpiece may not be perpendicular to the surface of the workpiece. In addition, such a saw will produce splinters.

[0011] German patent DE1278728B also describes a jigsaw comprising an element introduced into the groove created by the passage of the blade. The start of the cut is not guided and it is therefore not possible to guarantee that this cut is straight and aligned with the desired cut. Furthermore, the element introduced into the groove is very short, which prevents optimal guidance of the saw.

[0012] Patent GB1330328A describes a jigsaw-type saw comprising a fin arranged under the saw table and comprising a blade guide. This fin is inserted into the groove created by the passage of the blade. It prevents the blade from deviating from its straight path. Furthermore, the blade is held in a position perpendicular to the plane of the piece to be cut by the guide.

[0013] In this embodiment, the fin must be high enough to pass through the entire piece to be cut. If its thickness is small, it will not have sufficient rigidity. If it has a thickness of the order of magnitude of the thickness of the blade, it is enough for the piece to be cut to tighten slightly for this fin to get stuck in the groove, rendering the saw unusable.

[0014] Furthermore, the saw must be guided at the beginning of its use in a piece to be cut, which still requires the installation of a guide. In addition, this saw produces splinters.

[0015] US4051597A also describes a jigsaw with a rear wing. This rear wing is small, which means that the guidance is relatively imprecise. The saw also needs to be guided at the beginning of its stroke, and it produces splintering, just like the saws mentioned above. Therefore, it does not solve the problems mentioned above either.

[0016] None of the prior art saws can make a straight cut, aligned with the desired cut, without any guidance and without producing splinters.

[0017] In the examples described in the documents mentioned above, a mechanism is usually added to a conventional jigsaw. This mechanism is adapted to the shape and dimensions of the jigsaw used. Since the dimensions of the plates of existing jigsaws are not standardized, it is necessary to produce a specific mechanism for each type of jigsaw plate. As a result, in the majority of cases, it is not possible to use the same mechanism for two different jigsaws.

[0018] It would be advantageous to be able to use one mechanism on a variety of different sized saw blades. It would also be advantageous if this mechanism could be easily attached to or removed from the jigsaw and attached to a different jigsaw.

[0019] DESCRIPTION OF THE INVENTION

[0020] The present invention provides a ripping module that can be removably attached to a portable electric saw with a reciprocating blade such as a jigsaw. This ripping module allows, on the one hand, straight cuts to be made without the need for a guide. Indeed, when the saw blade has started a cut by following a certain straight line, this cut can be continued by following the same straight line, without deviating from it and without the need for a guide attached to the piece to be cut. Furthermore, it is relatively simple to ensure that the cut made will be well aligned with the desired cut, this being all the more important since the direction of this cut can no longer be rectified during use.

[0021] On the other hand, this module allows the cutting to be carried out without the blade forming chips, which allows the part to be cut directly to the dimensions of the finished part, without having to retouch it. In addition, surprisingly, the surface condition of the edge or field of the part is of very good quality and this edge is perpendicular to the surface of the part, which allows for good quality assembly, especially when two parts must be assembled either field against field or one field against a surface.

[0022] The present invention also proposes to provide a ripping module which can be attached to a jigsaw table very simply and quickly and which can also be removed therefrom very simply and quickly. Furthermore, according to an advantageous variant, this ripping module can be easily adapted to tables having different sizes and shapes.

[0023] The aims of the invention are achieved by a edging module as defined in the preamble, this edging module being characterized in that it further comprises:

[0024] • an alignment flank arranged upstream of said blade and aligned with this blade;

[0025] • a lateral blade support member; and

[0026] • a splinter-proof device.

[0027] The object of the invention is also achieved by a saw comprising such a ripping module.

[0028] The saw of the invention makes it possible to start a cut without having to set up an initial guide, while ensuring that the first part of the cut is straight and aligned with the desired cut. This ensures that the guide fin can be introduced into the furrow without being stuck due to a non-straight start to the cut.

[0029] When the blade has started a furrow, it is guided by a fin and does not deviate, thus ensuring a straight cut over a long length.

[0030] The ripping module of the invention further allows the blade to be held in a position perpendicular to the saw table, which ensures that the edge or field of the piece to be cut is perpendicular to the surface of this piece.

[0031] The module of the invention also allows for chip-free cuts, which makes it possible to use a saw equipped with such a module with materials having a fragile and visible surface, such as parquet floors, melamine panels or other materials of the same type.

[0032] This makes it possible to saw pieces to their final dimensions without having to rework them to achieve a clean finish.

[0033] According to a variant, the module of the invention can also be easily adapted to different saws, having plates of different dimensions. In addition, the installation and removal of the ripping module of the invention is particularly simple and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention and its advantages will be better understood with reference to the appended figures and to the detailed description of a particular embodiment, in which:

[0035] - Figure 1 is a bottom view of a first embodiment of an edging module according to the present invention;

[0036] - Figure 2 is a top view of the edging module of Figure 1;

[0037] - Figure 3 is a top view of a detail of the module of Figure 1, with a saw blade in section;

[0038] - figure 4 is a rear view of the module of figure 1;

[0039] - Figure 5 is a side view of an embodiment of a detail of the module of Figure 1;

[0040] - Figure 6 is a top view of a second embodiment of an edging module according to the present invention;

[0041] - Figure 7 is a side view of the edging module of Figure 6; and

[0042] - Figure 8 is a front view of the edging module of Figure 6.

[0043] METHOD OF CARRYING OUT THE INVENTION

[0044] With reference to the figures, the edging module 10 according to the invention essentially comprises a plate 11, a lateral guide member 12 for a saw blade, a splinter guard device 13 and a member 14 for fixing the plate to a jigsaw type saw. It may further comprise a sighting device 15.

[0045] This edging module 10 is intended to cooperate with a reciprocating blade saw such as a jigsaw (not shown). Such a jigsaw comprises a table through which the saw blade 16 passes. It also comprises a motor intended to move the blade in a reciprocating movement. The saw blade comprises a rear zone 17 having a first thickness and a front zone 18 comprising teeth 19. Traditionally, these teeth are set. The width of the groove formed by the passage of the saw blade in a piece to be cut corresponds to the width of the front of the saw blade and is here called the second thickness of the blade.

[0046] The plate 11 of the ripping module comprises a fin 20 aligned with the saw blade. The thickness of the fin 20 is substantially equal to the first thickness of the blade, i.e. the thickness of the rear zone 17 of the saw blade. The length of this fin 20 is preferably large enough to allow effective guidance of the saw. Preferably, this length should be at least 10 cm and at most 25 cm, with a preferred length of between 6 cm and 12 cm.

[0047] The plate 11 of the ripping module also includes an alignment flank 21 arranged to align the saw blade with the cut to be made, when the saw is positioned. It should be noted that this alignment flank 21 is particularly useful before starting to saw and until the fin 20 is sufficiently advanced in the groove formed by the passage of the saw blade in the piece to be cut. After this, the alignment flank 21 can be used to check that the saw cuts according to the selected straight line, but its usefulness is less.

[0048] This alignment flank 21 is formed by a cutout in the plate 11 of the edging module. The flank is aligned with the corresponding side of the teeth 19 of the saw blade 16.

[0049] The lateral guide member 12 of the saw blade is illustrated in Figures 1, 2, 3, 6 and 8. It is formed from a part preferably made of a relatively hard metal. For example, the plate 11 can be made of aluminum and the lateral guide member 12 can be made of steel. The lateral guide member could be a single piece with the plate. The advantage of producing this guide member and the plate as separate parts is that this makes it possible in particular to replace the guide member 12 in the event of wear or deterioration.

[0050] This guide member 12 has a slot 22 aligned with the fin 20 of the table. This slot 22 has a width slightly larger than the first width of the saw blade or the width of the rear zone 17 of the blade. This guide member is fixed to the table 11 in such a way that when the ripping module 10 is mounted on a jigsaw type saw and the blade is installed, the rear of this blade moves in the slot 22 of the lateral guide member 12 with a slight play. A slightly larger width means that the width of the slot 22 is approximately 2-3 hundredths of a millimeter larger than the first thickness of the saw, or even up to a tenth of a millimeter larger.

[0051] This lateral guide member 12 is interesting because it keeps the blade perpendicular to the saw table, which ensures that the side of the sawn piece is perpendicular to the surface of the piece to be sawn. Depending on the assemblies to be made, a lack of perpendicularity is troublesome and requires reworking the piece on another machine. Thanks to the edging module of the invention, this lack of perpendicularity is avoided.

[0052] The splinter guard 13 of the edging module 10 also preferably comprises a part made of "hard" metal or of a metal having a hardness similar to or greater than the hardness of the saw blade. It comprises a slot 24 in which the teeth 19 of the blade move when the module of the invention is used on a jigsaw. The width of the slot 24 of the splinter guard 13 is slightly greater than the second thickness of the saw blade or the thickness of the front zone 18 of this blade, so that the teeth are not in permanent contact with the flanks of the slot 24 of the splinter guard 13. According to an advantageous embodiment, a slightly greater thickness means that the slot has a width greater than the second thickness of the blade by approximately 1 tenth of a millimeter, with a maximum of 2 tenths of a millimeter more than the thickness of the blade.

[0053] According to an advantageous embodiment, the difference between the width of the slot 22 of the lateral guide member 12 and the thickness of the rear zone 17 of the blade is smaller than the difference between the width of the slot 24 of the splinter-proof device 13 and the thickness of the front zone 18 of the blade. In this way, if the rear of the blade rubs against one of the flanks of the slot 22 of the lateral guide member 12, the teeth 19 do not rub against one of the flanks of the slot 24 of the splinter-proof device 13.

[0054] The lateral guide member 12 of the blade and the splinter guard device 13 are described separately from each other since they have two distinct functions. In practice, in the illustrated embodiments, they are formed in the same part. This part can be made of a relatively strong material such as steel for example. They could also be made in a single piece with the plate of the edging module.

[0055] The length and relative position of the slot 22 are such that the saw blade does not rub against the rear of this slot when the saw is in use.

[0056] In the embodiment illustrated by Figures 1 to 5, the plate 11 of the edging module has a recess 25 provided to receive the saw blade. The part forming the splinter guard device 13 and the lateral guide member 12 of the blade is fixed above this recess 25, preferably in a removable manner. This allows this part to be changed in the event of wear or damage.

[0057] The edging module 10 of the invention comprises, as indicated above, a member 14 for fixing the plate to a jigsaw. In the embodiment illustrated by Figures 1 to 5, this fixing member is adapted to the shape and dimensions of the plate of the saw on which the module is to be placed.

[0058] In the embodiment illustrated by Figures 6 to 8, the fixing member allows the ripping module to be adapted to a wide variety of different jigsaw sizes.

[0059] In the first illustrated embodiment, the tabletop comprises two rails 26 into which the saw table slides. A securing device 27 for securing the tabletop to the ripping module of the invention makes it possible to hold the ripping module on the saw. Figure 5 illustrates a variant of such a securing device. This securing device 27 comprises a hook 28 which is forced by means of a spring 29, in the direction of the saw table. The hook 28 can be detached from the saw table by actuating a bracket 30 against the force of the spring 29.

[0060] It is clear that other fixing devices for the edging module to the tabletop can be considered and are adapted to the specific shape of the tabletop on which the module is to be mounted. The same applies to the securing device.

[0061] In the embodiment illustrated by Figures 6 to 8, the fixing member 14 comprises five eccentric mechanisms. Two eccentric mechanisms 31 are of a first type; another eccentric mechanism 32 is of a second type and the last two eccentric mechanisms 33 are of a third type.

[0062] All eccentric mechanisms comprise a disc 34 preferably having a height slightly less than the thickness of a conventional jigsaw plate. The disc 34 of an eccentric mechanism comprises an eccentric through hole, arranged to receive a screw 35, 36 and to be able to pivot around this screw.

[0063] In the eccentric mechanisms 31, 32 of the first and second type, the screw 35 passes through the disc of the eccentric mechanism and opens into a threaded bore of the plate 11 of the edging module. This screw has a head which can be actuated from the top of the plate, for example a cylindrical screw with a hexagon socket. A washer (not shown) can be placed between the head of the screw and the disc of the eccentric mechanism.

[0064] The two eccentric mechanisms 31 of the first type are placed towards the rear of the table of the edging module, respectively on the left side and on the right side. The position and the dimension of the discs of these eccentric mechanisms allow the discs to bear against the sides of the table of the saw on which this edging module is mounted.

[0065] When the ripping module 10 is placed on the table of the circular saw, the discs 34 are pivoted so that they bear against the sides of this table. The screws 35 are then tightened to ensure effective lateral support of the ripping module relative to the table.

[0066] The eccentric mechanism 32 of the second type is positioned so that the front of the saw table bears against the disc 34 of this eccentric mechanism. The position of the jigsaw table relative to the ripping module is preferably such that the saw blade 16 does not abut against the bottom of the slot 22 and the teeth 19 of this blade do not protrude from the front of the slot. When the jigsaw table is correctly positioned, the disc of the front eccentric mechanism 32 can be positioned and held in position by tightening the screw 35.

[0067] The last two eccentric mechanisms 33, of the third type, also comprise a disc 34 and a screw 36. They further comprise a wedge 37 and a spring 38, this spring being placed between the wedge 37 and the head of the screw 36.

[0068] In more detail, as previously, the screw 36 has an end which opens into a threaded bore in the plate of the edging module 10. This screw 36 is however longer than the screws 35 of the other eccentric mechanisms.

[0069] As with other eccentric mechanisms, the disc 34 has an eccentric bore, this disc being able to pivot around the screw 36. Each wedge 37 having an area in the form of an inclined plane 39 is also provided with a through bore, dimensioned so that this wedge can slide and pivot around the screw 36. The wedge is forced in the direction of the plate by the spring 35 arranged between the screw head and the disc.

[0070] The fixing member 14 preferably comprises two eccentric mechanisms 33 with wedges, arranged near the left and right sides of the table of the ripping module, so that the areas of the discs of the eccentric mechanisms 31 and 33 bearing against the saw table make it possible to keep the saw table parallel to the cutting line.

[0071] When installing a ripping module on a jigsaw, the eccentric mechanisms are adjusted so as to position the jigsaw table parallel to the side edges of the tabletop or parallel to the cutting line, and so that the front eccentric ensures correct positioning of the saw blade in the slot 22. The wedges 37 are raised against the force of the springs 38, positioned above the table so that the inclined planes rest against the top of this table, and then released. The ripping module is then ready for use. To remove the ripping module, it is sufficient to move the wedges 37 against the force of the springs 38. The ripping module can then be separated from the saw.

[0072] Eccentric mechanisms are described as having a disc. This disc could be replaced by a disc portion or a cam arranged to adapt the ripping module to the table of the specific jigsaw being used.

[0073] Furthermore, the wedges are movable on a screw around which is also placed a disc of an eccentric mechanism. It is also possible to separate the functions of lateral positioning of the saw table by means of the discs 34 and of holding the table against the plate by means of the wedges 37. Thus, the wedges could be movable along a rod independent of the screw of the eccentric mechanism.

[0074] As indicated above, the ripping module 10 may include a sighting device 15 which helps to align the saw blade with the desired cut. The sighting device is typically formed by a laser allowing the location pointed by the saw blade to be visualized.

[0075] When the ripping module 10 according to the first embodiment of the invention is to be used with a saw to make a straight cut, first of all the blade 16 is removed from the saw. The ripping module 10 is then slid onto the table of the jigsaw so that this table is arranged between the rails 26. The saw is then secured to the ripping module 10 by means of the securing device 27.

[0076] The saw blade is then put in place, the rear of this blade being placed in the slot 22 of the lateral guide member 12 and the front of the blade being arranged in the slot 24 of the splinter guard device 13.

[0077] The aiming device 15 is then engaged and the saw is placed at the start of the cut to be made. The alignment flank 21 is aligned with the cut to be made. It should be noted that the aiming device 15 is not essential. It is for example possible to draw a line to position the saw before starting the cut. The saw is positioned so that the alignment flank 21 is aligned with the line. To install the ripping module according to the second embodiment, it is not necessary to remove the saw blade. It is sufficient to correctly position the eccentrics if the ripping module is adjusted for a saw having a table of different dimensions, and to position the shims.

[0078] The alignment flank 21 allows the blade to be guided when starting the cut and the aiming device 15 allows the saw to be positioned so that the cut ends at the desired location. When the saw blade has made a groove in the workpiece to be cut, the fin 20 naturally places itself in this groove. When a sufficiently large part of this fin is in the groove, any deviation of the cut is avoided. The alignment flank 21 allows easy straight cutting until the fin 20 takes over at the guiding level.

[0079] The lateral guide member 12 ensures correct positioning of the saw blade. The latter remains perpendicular to the saw table, which ensures that the field of the workpiece to be cut is perpendicular to its face. Holding the rear of the saw blade by the slot 22 of the lateral guide member 12 reduces the vibrations of this blade, which makes it possible to obtain an excellent quality surface finish of the cut.

[0080] The splinter guard 13 prevents splintering at the cut surface. This allows a saw equipped with the ripping module 10 of the invention to be used even for fragile materials, such as melamine panels, parquet floors or the like.

[0081] The module of the invention thus makes it possible to use a jigsaw type saw for straight cuts of any length, with excellent cutting quality both in terms of the straightness and the surface condition of the cut piece, even for delicate materials. It thus significantly modifies the possibilities of using a jigsaw.

[0082] The eccentric attachment allows for installation on virtually any jigsaw, without having to adapt this ripping module to a specific size or shape of saw. Furthermore, the installation or removal of the ripping module is extremely simple and quick, which allows, for example, the ripping module of the invention to be used for a straight cut, then to remove the ripping module in a few seconds to make a curved cut, then to replace the ripping module in a few seconds also to make a new straight cut.

[0083] The invention has been presented in the form of a ripping module which can be removably placed on a jigsaw type saw. The invention also relates to a jigsaw type saw comprising such a ripping module. The invention may also relate to a saw comprising the elements of the ripping module, without the latter being removable.

Claims

Claims 1. Edging module (10) for a portable electric saw comprising a blade (16) performing a reciprocating movement and a table through which said blade moves, this edging module (10) comprising a plate (11) provided with at least one fixing member (14) of the plate (11) to the table, this plate (11) comprising a guide fin (20) arranged downstream of said blade and aligned with this blade, this edging module (10) being characterized in that it further comprises: • an alignment flank (21) arranged upstream of said blade and aligned with this blade; • a lateral guide member (12) for the blade; and • a splinter-proof device (13).

2. Edging module according to claim 1, characterized in that the fixing member (14) of the plate (11) of the edging module to the table of a saw comprises two rails (26) arranged to receive said table of the saw.

3. Edging module according to claim 1, characterized in that it comprises a securing device (27) for the plate arranged to removably fix said edging module (10) to the saw.

4. Edging module according to claim 1, characterized in that the fixing member (14) of the plate (11) of the edging module to the table of a saw comprises at least four eccentric mechanisms, these eccentric mechanisms comprise a cam arranged to bear against the table of the portable electric saw.

5. Edging module according to claim 1, characterized in that the fixing member (14) of the plate (11) of the edging module to the table of a saw comprises a wedge (37) arranged to constrain the table of said saw against the plate (11) of the edging module.

6. Edging module according to claim 1, characterized in that the guide fin (20) has a length of between 6 and 25 cm and preferably between 12 and 20 cm.

7. Edging module according to claim 1, characterized in that the lateral guide member (12) of the blade comprises a slot (22) arranged to allow a rear zone (17) of the saw blade to move.

8. Edging module according to claim 7, characterized in that the width of the slot (22) of the lateral guide member (12) is greater than the width of the rear zone (17) of the blade.

9. Edging module according to claim 1, characterized in that the splinter guard device (13) comprises a slot (24) arranged to allow teeth (19) of the saw blade to move.

10. Edging module according to claim 9, characterized in that the width of the slot (24) of the splinter guard device (13) is greater than the width of the front zone (18) of the saw blade.

11. Edging module according to claims 7 and 9, characterized in that the difference between the width of the slot (24) of the splinter guard device (13) and the width of the front zone (18) of the saw blade is greater than the difference between the width of the slot (22) of the lateral guide member (12) and the width of the rear zone (17) of the saw blade.

12. Edging module according to claim 1, characterized in that the splinter-proof device (13) and the lateral guide member (12) form the same part.

13. Edging module according to claim 1, characterized in that the splinter-proof device (13) is removable relative to the plate (11) of the edging module (10). 14 Edging module according to claim 1, characterized in that it comprises an aiming device (15).

15. Jigsaw comprising a ripping module (10) according to any one of the preceding claims.

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