DE102005025934C5 - Electric jigsaw - Google Patents

Abstract

Electric jigsaw with a saw blade (11), a machine part (13) and a plurality of base plates (15) which can each be detachably connected to the machine part (13) and are interchangeable, the base plates (15) being different from one another and being provided for different functions , the releasable connection between the base plates (15) and the machine part being designed in such a way that, with the exception of a relative movement for coupling and uncoupling the machine part (13) and the base plate (15), there is no relative adjustability between the base plate (15) and the machine part (13 ) is possible to make different cutting angles, and a base plate (15) for 90 ° cuts and another base plate (15) for bevel cuts, the latter to support the jigsaw when making the bevel cuts.

Description

The invention relates to an electric jigsaw.

Jigsaws are an indispensable tool not only for professional users, but also extremely popular with do-it-yourselfers, due to their wide range of uses and ease of use. Most of the commercially available jigsaws are tools that are intended for rather coarser work where accuracy is not the main focus. Jigsaws are not considered precision tools.

The invention has set itself the goal of changing this, and thus an electric jigsaw is to be created with which work with the highest possible accuracy is guaranteed without sacrificing versatility and manageability.

From the DE 37 17 585 C2 a jigsaw is known in which part of a cooling air flow conveyed by a motor fan is guided to the cutting area by means of a blown air duct. Sawdust can be removed by means of an external suction fan via an optional extraction channel.

The US 4665617 A discloses a jigsaw with a base plate, in which a splinter protection device, a chip catcher, a suction channel and a detachable rip fence are provided to improve the cutting guide.

The above-mentioned object is achieved by the features of claim 1.

According to the invention, an electric jigsaw comprises a saw blade, a machine part and a plurality of base plates that can each be detachably connected to the machine part, the base plates being provided for different functions.

According to the invention, the jigsaw comprises a plurality of interchangeable base plates, each of which can be connected to the machine part, in such a way that a relative adjustability between the machine part and the base plate for executing different cutting angles is deliberately dispensed with and the only possible relative movement is one for coupling and decoupling of the machine part and the base plate.

According to the invention, a base plate for 90 ° cuts and a further base plate for bevel cuts are provided, the latter being pivotable together with the machine part or having a pivotable section.

According to the invention, several functions are not implemented with the help of a single base plate, but rather divided between different base plates, which at first glance may appear to be unnecessary additional effort, but ultimately, due to the lack of adjustment options, a practically play-free and thus much more precise alignment between the saw blade and workpiece has the consequence. The prerequisite for this is the releasable coupling according to the invention between the machine part and the base plate. Such a coupling, which does not have to offer any possibility of adjustment, can be implemented with relatively little effort and extremely small tolerances. This takes into account the experience that in practice bevel cuts with jigsaws are rarely necessary. According to the invention, it is therefore avoided to worsen the precision of the 90 ° cuts in favor of seldom required bevel cuts.

The jigsaw can be provided with a stability package made up of a plurality of individual measures distributed along a system circuit that determines the behavior of the saw blade in order to achieve high-precision and clean cuts.

It is often not enough to improve the stability at just one point on the machine in order to obtain more precise cuts in this way. E.g. Even an optimal saw blade guidance with regard to the angularity does not prevent insufficient cuts if the machine comprising the saw blade and the base plate serving to rest on the workpiece are designed to be angularly adjustable relative to one another in order to set different cutting angles, since play leading to inaccuracies can practically not be avoided.

Here the approach can be helpful to start at different points of the system circle that determines the behavior of the saw blade in order to enable cuts overall that meet the highest standards in terms of angularity, evenness and cleanliness, ie freedom from tearing. With the idea of a stability pact, the jigsaw can be designed and used as a precision tool that can replace other tools - such as hand-held circular saws - for some applications. When the jigsaw is placed on a workpiece, the saw blade interacting with the workpiece, the workpiece itself, the base plate resting on the workpiece, the machine body connected to the base plate, the holder or holder for the saw blade belonging to the machine body and the saw blade guide and Finally, the saw blade itself again, as it were, forms a closed system with regard to stability components that determine each other and thus ultimately also the behavior of the saw blade.

Preferred embodiments of the invention are described in the dependent claims, the description and the drawing.

It should be expressly pointed out at this point that the exemplary embodiments described below represent fundamentally independent technical aspects that are not only practicable within a stability package, but can in principle also be used independently of other measures.

According to one aspect of the invention, a bracket is provided which can be detachably connected in particular to a base plate and has a support and / or stop function. With such a boom there is the possibility for the user to enlarge the effective support surface of the machine or the base plate and thus to increase the stability of the machine considerably. In particular, in addition to the support function, the boom can be provided with a stop function and / or coupled to a guide rail, in particular by hanging or placing. For example, the boom can serve as a rip fence for making precise longitudinal cuts. Alternatively or additionally, the boom can be used for a circular function.

According to a further aspect of the invention it is provided that a base plate is part of a combined suction and blowing system for sawdust, since chips that are not removed are detrimental to precise work. For this purpose, the base plate can be provided with integrated channels, which open into the cutting area on different sides of the saw blade and of which one has a suction opening and the other has a blow opening, which together generate a discharge flow for the sawdust in the cutting area.

Furthermore, according to one aspect of the invention, a preferably separate tear-off protection member is provided in particular on a base plate, which has a hold-down device for the cut-delimiting workpiece material which is effective directly on the saw blade. The hold-down device can in particular be an elastically deformable pressure section which protrudes with respect to the support surface of the base plate and is located at least to the side of the saw blade. This pressure section is preferably designed in such a way that the own weight of the jigsaw is already sufficient to press the pressure section into flush alignment with the support surface, this being done against the restoring force of the pressure section. Because of this restoring force, the workpiece material delimiting the cut is actively loaded and pressed down during sawing, which prevents the material from tearing out in a particularly effective manner. The anti-tear element is preferably sawed in by means of the saw blade when it is used for the first time. This ensures that the hold-down function is effective directly on the saw blade.

The tear-out protection element can be provided with a chip channel which is part of a combined suction and blowing system for sawdust. It is preferably provided that the chip channel comprises two channel sections positioned on opposite sides of the saw blade when the anti-tear element is inserted, one of which is located between a blow opening of a base plate and the saw blade and the other between the saw blade and a suction opening of the base plate.

In this way, the anti-tear element is used at the same time for an optimal flow guidance for the removal of the sawdust.

According to a further aspect of the invention, the saw blade is composed of a plurality of differently designed individual saw blades. By joining several individual saw blades together, a thicker and / or particularly stiff saw blade can be realized, the cuts of which are characterized by a high level of flatness. Due to the different design of the individual saw blades, different functions can also be specifically assigned to them. In the case of a, for example, symmetrical sandwich structure consisting of a central saw blade and two outer saw blades, the latter can be provided with fine teeth and the central saw blade with coarse teeth. The saw blades can also be arranged offset to one another in the saw blade plane. For example, a middle saw blade can protrude with its back to the rear in order to interact with a saw blade guide and / or an exciter of a pendulum stroke control. It is also possible to integrate at least one non-sawing blade into the saw blade, which thus contributes to the thickness and stability or rigidity of the saw blade as a whole, but has no sawing function. Such a blade is also regarded as a “single saw blade” within the scope of the invention.

According to a further aspect of the invention, it can be provided that the saw blade has a profiled holding section, the thickness of which varies along a perpendicular to the teeth running in the plane of the saw blade. In particular, the holding section has a cross-shaped or T-shaped profile. Such a profile has the advantage that a section extending in the plane of the saw blade - in the case of a T-profile, depending on the design, the upper crossbeam or the vertical leg of the "T" - can be designed according to the holding section of a conventional standard saw blade. A saw blade receptacle designed in accordance with the holding section is then compatible both with these standard saw blades and with the saw blades having the special thickness profile.

In general, therefore, one aspect of the invention is that a saw blade holder is provided which is compatible with saw blades whose holding sections have different thickness profiles.

According to a further aspect of the invention, a saw blade fixing is provided which has a tool-free, hand-operated clamping device and a pull-out safeguard that is decoupled therefrom. This division of the saw blade fixation means that the clamping device can easily be designed for manual operation without tools, since the pull-out protection is provided separately. In a preferred embodiment, the clamping device can simultaneously be designed as a safety device for an actuating mechanism of the pull-out safety device, in particular to the effect that when the clamping device is activated, the pull-out safety device cannot be unlocked, but the clamping device must first be released.

According to a further aspect of the invention, a saw blade guide that can swing together with the saw blade is provided. This ensures that the saw blade is optimally guided at all times during a pendulum stroke operation.

Furthermore, according to one aspect of the invention, a saw blade guide is integrated into a pendulum exciter that particularly acts directly on the saw blade. The saw blade guide and pendulum exciter thereby form a unit that moves together and engages the saw blade.

Alternatively, it can be provided that a saw blade guide and the saw blade form an integrated unit which as a whole can be excited to a pendulum movement. Such a configuration has the particular advantage that possibly disruptive relative movements between the saw blade guide and the saw blade are avoided when the pendulum movement is excited. In addition, such a configuration allows the saw blade to be guided in a relatively simple manner over a comparatively large part of its length. In particular, the saw blade guide can be brought up to the workpiece surface without any problems.

According to a further aspect of the invention, a pendulum stroke control is provided for the saw blade, in which the pendulum movement and the movement of a counter mass compensating for the stroke movement have different generators. The generators are, in particular, eccentric control cams, each of which is picked up by an actuation or excitation mechanism in order to set the saw blade or the countermass in motion according to the course of the curve. By providing different generators according to the invention, the pendulum movement and the lifting movement of the saw blade that corresponds to the movement of the countermass can be optimally coordinated with one another. This applies in particular to the timing of the movements. However, it is also advantageous that the actual path of the pendulum movement can be selected completely independently of the shape of the generators for the movement of the counter mass and thus the lifting movement.

According to a further aspect of the invention, a combined lighting and protective finger designed as a light guide is provided, into which light can be coupled and which, running in front of the saw blade, points with its free lower light exit end at the cutting area. In a technically advantageous and aesthetically interesting way, several functions are combined in one component. If necessary, the “light finger” can also fulfill other functions and, for example, serve to illuminate a company emblem integrated into the machine housing.

• 1 eine erfindungsgemäße Stichsäge mit teilweise weggelassenem Gehäuse,
• 2 die Grundplatte der Stichsäge von 1 zusammen mit einem Ausleger,
• 3 einen horizontalen Schnitt durch die Stichsäge von 1 zur Verdeutlichung der Koppelung zwischen Grundplatte und Maschinenteil,
• 4 die Unterseite der Grundplatte von 2,
• 5 eine Teilansicht der Stichsäge von 1,
• 6 den Maschinenteil von 1 in Verbindung mit einer Grundplatte und einem Ausleger zur Ausführung von Schrägschnitten,
• 7 und 8 Detailansichten zur Erläuterung eines Ausreißschutzorgans der erfindungsgemäßen Stichsäge,
• 9 verschiedene Ansichten eines erfindungsgemäßen Sägeblatts für eine erfindungsgemäße Stichsäge,
• 10 Darstellungen zur Erläuterung der Universalität einer erfindungsgemäßen Sägeblattaufnahme,
• 11 eine Teilansicht zur Erläuterung einer erfindungsgemäßen Pendelhubsteuerung,
• 12 und 13 andere Teilansichten zur Erläuterung der Pendelhubsteuerung von 11, und
• 14 eine Teilansicht zur Erläuterung einer anderen Pendelhubsteuerung gemäß der Erfindung.

The invention is described below by way of example with reference to the drawing. Show it:

• 1 a jigsaw according to the invention with a partially omitted housing,
• 2 the base plate of the jigsaw from 1 together with a boom,
• 3 a horizontal cut through the jigsaw of 1 to clarify the coupling between the base plate and the machine part,
• 4th the underside of the base plate of 2 ,
• 5 a partial view of the jigsaw of 1 ,
• 6 the machine part of 1 in connection with a base plate and a bracket for making bevel cuts,
• 7th and 8th Detailed views to explain a tear-out protection element of the jigsaw according to the invention,
• 9 different views of a saw blade according to the invention for a jigsaw according to the invention,
• 10 Representations to explain the universality of a saw blade holder according to the invention,
• 11 a partial view to explain a pendulum stroke control according to the invention,
• 12 and 13 other partial views to explain the pendulum stroke control from 11 , and
• 14th a partial view for explaining another pendulum stroke control according to the invention.

1 shows an overview of an embodiment of a jigsaw according to the invention. The jigsaw comprises a machine part 13 , which is detachable with a base plate serving to rest on a workpiece to be machined 15th is coupled. The coupling takes place by sliding on the machine part 13 on the base plate 15th for example from the front, where it would also be possible to slide it in the opposite direction. A locking mechanism is used to fix the coupled state, of which in 1 one on the machine part 13 provided locking button 16 is shown, which will be discussed in more detail below. The base plate 15th is with a suction nozzle 22nd through which the sawdust can be extracted. This is also discussed in more detail below.

According to the invention, several measures are provided to ensure a backlash and tolerance-free coupling between the machine part 13 and base plate 15th and thus to ensure high-precision work. This is the case with the base plate, for example 15th not a cast, but a machined component. In particular, the surfaces used for coupling are both on the base plate 15th as well as on the machine part 13 milled guides, which ensure extremely high precision and, in particular, angularity of the cuts to be made.

The base plate 15th is also with receiving openings 52 provided, can be inserted into the rods of a boom, which will be discussed in more detail below.

1 also shows a further aspect of the invention, namely a combined lighting and protective finger 41 , which is designed as a light guide. The finger points at the upper end of the gear housing 41 an internal coupling section 45 via which light is coupled in by means of an LED. Outside the gear housing, the one in front of the saw blade is used 11 running fingers, here having a trunk-like shape 41 as protection against intrusion. With its free light exit end 43 is the finger 41 aimed at the cutting area.

The lighting and protective finger is roughly halfway up the gearbox housing 41 with an integrated emblem section 47 in which part of the radiation coupled in via the LED is decoupled and its externally visible surface can be used for lighting or backlighting a company logo.

2 shows the base plate 15th without attached machine part. For skid-like coupling sections of the machine part, which is designed like a slide, are on the base plate 15th guides 24 formed with machined guide surfaces, which enable a practically backlash and tolerance-free coupling. On one side is the one on the base plate in the rear area 15th trained machine mount a locking mount 14th provided with that already in conjunction with 1 mentioned locking button 16 cooperates. At the end of the attachment process, the spring-loaded locking button engages 16 with a locking projection 18th ( 3 ) automatically into the locking receptacle 14th one. By pressing the locking button 16 on the side of the machine part 13 can lock to remove the machine part 13 from the base plate 15th unlocked.

The base plate 15th is also part of a combined suction and blowing system for sawdust. This is the base plate 15th on the insides of its two fork-like protruding sections at the level of the saw blade 11 ( 1 ) on one side with a blow hole 23 ( 1 ) and on the opposite side with a suction opening 25th ( 2 ) Mistake. The blow hole 23 stands with one at the top of the base plate 15th trained air inlet opening 26th connected via an internal channel. With the machine part attached 13 is an air flow generated by a machine fan over the inlet opening 26th to the blow hole 23 directed. The suction opening 25th in turn stands over an internal channel of the base plate 15th with the suction nozzle already mentioned 22nd in connection to which a hose of a suction device can be connected in a conventional manner.

This allows between the blow hole 23 and the suction opening 25th an accumulating sawdust entrained air flow perpendicular to the saw blade 11 be generated.

2 also shows a boom 17th that with poles 49 in the already associated with 1 mentioned receiving openings 52 the base plate 15th inserted and by means of special clamping screws 54 a clamping mechanism that can be operated without tools 53 on the base plate 15th is fixed. The distance one at the free end of the rod 49 attached support and stop section 51 from the base plate 15th can be adjusted continuously in this way.

In the in 2 The position shown is practiced by the section 51 a support function, whereby the effective support surface of the base plate 15th considerably enlarged and thereby an extremely stable and tilt-proof working with the jigsaw is made possible.

By repositioning the boom 17th , ie by turning or turning around 180 °, the stop function can be activated. A stop section 50 of the boom 17th then protrudes downwards and serves as a lateral rip fence for making straight cuts with high precision.

In the support and stop section 51 are also openings 48 formed, through each of which a fixing pin can be inserted, in order to provide a circular function for performing circular arc cuts in this way.

On 3 has already been explained above to explain the locking mechanism for coupling the base plate 15th and machine part 13 received. A particular advantage of the invention is that coupling and decoupling between the base plate 15th and machine part 13 can be done without tools. In this context it should also be mentioned that the guided tours 24 the base plate 15th ( 2 ) or the corresponding "runners" of the machine part 13 can be provided with in particular leaf spring-like spring elements in order to achieve even better practical freedom from play in the connection between the machine part 13 and base plate 15th to ensure.

3 also shows an adjustment knob 70 , which is part of a pendulum stroke control for the saw blade explained in more detail elsewhere 11 is. With the adjustment knob 70 can be the behavior of the pendulum motion of the saw blade 11 to be influenced.

4th shows the underside of the base plate 15th which is essentially a supporting surface 55 serves. The bottom has a central longitudinal groove 57 provided, which has a funnel-shaped extension at its front end 59 having. The depth of the groove 57 can for example be about 1 mm. Any sawdust is collected via the collecting funnel 59 the groove 57 fed in and carried away from this to the rear, which causes a so-called “riding on” of the base plate 15th on which sawdust is prevented. With a suction the groove is 57 not connected, ie there is no active suction in this area, although this would in principle be possible according to the invention in an alternative embodiment.

The supporting surface 55 can be provided with flocking or another suitable surface design in order to be able to process sensitive surfaces without the risk of damage.

5 shows part of the jigsaw according to the invention from a different perspective, namely obliquely from behind. You can see the saw blade in particular 11 , the one above the base plate 15th in front of the saw blade 11 running lighting and protective fingers 41 , the receiving openings 52 for the poles 49 of the boom 17th ( 2 ) and the locking button 16 to release the latch between the base plate 15th and machine part 13 ( 3 ).

6 shows the same machine part 13 as described above, but here coupled to another base plate 15th used to make bevel cuts. The base plate 15th is with rotatable holding sections 60 provided, through the rods 49 a double boom 17th are inserted, the support and stop sections 51 according to the boom 17th according to 2 includes.

Relative to that of the boom 17th defined plane and thus to the surface of the workpiece, not shown here, the machine part 13 together with the base plate 15th around the axis 63 the holding sections 60 pivoted and in the desired inclined position using tensioning screws 61 be established, being at the base plate 15th an angle scale 62 is provided that the angle between the by the boom 17th defined level and the here merely schematized saw blade 11 indicates.

In the embodiment of 6 consequently, an adjustment option for setting different cutting angles with respect to the workpiece surface is possible. The machine part 13 however, is firmly attached to the base plate 15th connected in each position not just across the sections 51 of the boom 17th , but is also supported itself on the workpiece surface.

According to the invention are in addition to those in connection with 2 and 6 described baseplates 15th and booms 17th further refinements and configurations of a base plate are conceivable in order to provide various functions.

In the sections 51 trained grooves 65 serve to couple the machine 13 to a guide rail system on or next to which the machine 13 can be guided to perform high precision cuts. Such a coupling groove 65 is also with the boom 17th according to 2 intended.

To connect the machine part 13 with the base plate 15th becomes the machine part 13 with the saw blade 11 through one in the base plate 15th intended opening 91 inserted and then for locking with the base plate 15th as described above in connection with 2 described manner shifted perpendicular to the insertion direction. Depending on the configuration of the locking or latching mechanism used for this, the machine part 13 relative to the base plate 15th be pushed either forward or backward.

The 7th and 8th show a special anti-tear device 19th which is used to prevent the workpiece material from tearing out during sawing. With the anti-tear device 19th it is a separate component that attaches to the base plate 15th ( 2 ) and for this purpose between the fork-like forward protruding sections of the base plate 15th is plugged. Corresponding guide grooves 28 on the base plate 15th are in 2 shown.

In the attached state of the anti-tear device 19th , in which its bottom 30th flush with the support surface 55 the base plate 15th the saw blade runs 11 of the machine part 13 through a chip channel of the pull-out protection organ 19th through that of two duct sections 21a , 21b on both sides of the saw blade 11 is formed. The canal section 21a stands with the blow hole 23 ( 1 ) in connection while the duct section 21b with the suction opening 25th ( 2 ) communicates. The pull-out protection organ ensures this additional function 19th for optimal flow guidance in the area of the saw blade 11 .

A on the underside provides the tear-off protection function 30th of the anti-tear device 19th Downholder protruding downwards, for example by about 0.5 mm 21st . This hold-down 21st is achieved in particular by pushing open the anti-tear member 19th while the machine is running using the saw blade 11 Sawn in, so that the edges of the elastically deformable hold-down sections that are created as a result 20th in the immediate vicinity of the side surfaces of the saw blade 11 lie.

When the pull-out protection element rests on the workpiece surface 19th practice the hold-down sections which can be deflected against a restoring force 20th with their edges exert pressure on the cut edges of the workpiece, which reliably prevents the cut edges from being torn out. The hold-down 21st is designed in such a way that the own weight of the jigsaw is sufficient to pre-tension the hold-down sections 20th to produce, that is, the hold-down sections 20th against their restoring force in the plane of the bottom 30th of the anti-tear device 19th to press.

The hold-down 21st can be made in one piece with the anti-tear device made of plastic, for example 19th be trained. Alternatively, it is possible to use the anti-tear element 19th to be provided in the form of a separate insert part and to be manufactured from a different material, in particular from metal. Such a metal insert can also be easily cut into an optimal hold-down configuration with respect to the respective saw blade 11 to be brought.

Another advantage of this anti-tear function according to the invention is that the saw blade is guided at the same time 11 takes place directly on the workpiece surface, which further increases the cutting precision.

The 9 and 10 show with a multi-part saw blade 11 another aspect of the jigsaw according to the invention. In the illustrated embodiment, the saw blade is 11 Manufactured in sandwich construction from three individual saw blades, namely from a central saw blade 11a and two outer saw blades 11b . The thickness of the two outer saw blades 11b decreases towards the rear, ie away from the teeth, so that the saw blade 11 has a trapezoidal cross-section (lower illustration in 9 ). This cross-sectional shape is interrupted by the rear edge of the middle saw blade 11a going backwards over the outer saw blades 11b protrudes and such a back 12 for the saw blade 11 forms whose thickness is the thickness of the middle saw blade 11a corresponds.

Im for receiving and holding the saw blade 11 serving holding section 27 the thickness of the saw blade varies 11 such that the holding portion 27 has a cruciform cross-section (upper illustration in 9 ). This profile of the holding section 27 arises from the fact that in the area of the holding section 27 the middle saw blade 11a has a larger width than the two outer saw blades 11b .

A major advantage of this embodiment is that the saw blade according to the invention 11 also and especially in the area of the holding section 27 has a high level of rigidity, which all single saw blades 11a , 11b contribute. In the area of the holding section 27 can use the outer saw blades 11b to a certain extent, as “stiffening ribs” of the central saw blade 11a be considered.

Another advantage of this embodiment according to the invention is based on 10 explained. A saw blade holder only shown schematically 29 is with a corresponding to the profile of the holding portion 27 formed, provided in cross-section cross-shaped receiving opening. A clamping screw that can be operated by hand without tools 32 acts on the holding section 27 over one of the saw blades on the side 11b , ie the wide middle saw blade 11a is not here directly, but indirectly via the saw blade on the side 11b tense. Alternatively, between clamping screw 32 and middle saw blade 11a one that of the screw 32 facing lateral saw blade 11b bridging, for example U-shaped intermediate piece can be provided, which makes it possible to clamp the middle saw blade directly 11a to apply.

The right representation in 10 shows the clamping of a conventional saw blade 11 , which typically has a standard thickness of about 1.2 mm. The sandwich saw blade according to the invention and the saw blade holder 29 are designed such that at least in the holding section 27 the middle saw blade 11a in terms of its dimensions corresponds to such a conventional standard saw blade. This means that instead of the sandwich saw blade according to the invention, there is also a conventional saw blade 11 with normal thickness can be used.

According to the illustration on the right in 10 becomes this conventional saw blade 11 Clamped in exactly the same central position as the central single saw blade 11a of the sandwich saw blade according to the invention, whereby it is from the clamping screw 32 is applied directly. It should be emphasized here in particular that this embodiment according to the invention automatically ensures that both the sandwich saw blade according to the invention and a conventional standard saw blade 11 are always centered in the same way. Because of this universality, the special sandwich saw blades and the conventional thin saw blades can be used without the need to change the settings of the machine.

In addition, the special profiling of the holding section 27 of the sandwich saw blades according to the invention 11 a kind of coding can be implemented, so to speak, which ensures that, apart from the conventional standard saw blades, only the special profile on the holding section 27 having sandwich saw blades in the saw blade holder 29 fit.

In 10 The pull-out protection for the saw blades mentioned in the introductory part is not shown 11 . Reference is made to this explanation at this point.

It should also be added that due to the fact that the sandwich saw blade according to the invention 11 its back serving to guide the saw blade 12 only from the central single saw blade 11a is formed, this saw blade guide - which will be discussed in more detail below - automatically also to guide the conventional standard saw blades according to the right illustration in 10 is designed.

Notwithstanding that in the 9 and 10 shown cross-shape of the holding portion 27 For example, a T-shape can also be provided, the transverse bar of the “T” in turn being formed by a central single saw blade and, in this variant, one of the lateral single saw blades not extending into the holding section 27 is sufficient, so that in this way, while maintaining a sandwich structure of three individual saw blades, the holding section only has a T-profile. Alternatively, a T-profile can also be created by shortening the middle single saw blade so that it is flush with the side single saw blades on one side, so that it then extends over the side single saw blades on the other side protruding section forms the leg of the "T".

The 11 to 13 show various partial views of a pendulum stroke control according to the invention. In a pendulum stroke mode that can be set by the user, the saw blade only moves up and down 11 (Lifting movement) acting on the saw blade 11 by means of a driven ram 69 is transmitted, a pendulum motion is superimposed. This pendulum movement is made by means of a directly on the back 12 of the saw blade 11 attacking pendulum exciter 35 generated around an axis 71 is pivotably attached. The plunger 69 is together with the saw blade 11 to get one in the 11 to 13 Axis not shown and referred to below as the pendulum axis can be pivoted about the pendulum movement of the saw blade 11 to enable.

In a known manner, which will not be discussed in greater detail here, the mass moved during the lifting movement, in particular of the ram 69 and the saw blade 11 compensated by a countermass, not shown here, which is also driven via a gear from the central drive shaft of the motor of the jigsaw. A component of this transmission is a control element which is embodied in one piece according to the invention 36 that is about a gear 38 is set in rotation and which conventionally has a single eccentric cam has over which both the up and down movement of the saw blade 11 corresponding movement of the countermass, i.e. the lifting movement, as well as the movement of the pendulum exciter that ensures the pendulum movement is picked up or derived.

According to the invention, the control element deviates from this principle 36 with two separate control cams 37 , 39 provided, in this embodiment, on opposite sides of the gear section 38 of the tax body 36 are located. According to the invention, therefore, the counter mass on the one hand and the pendulum exciter 35 on the other hand, each has its own generator, in this exemplary embodiment in the form of an eccentric control curve.

In addition to the control curve 39 there is a separate control curve for the counterweight (not shown) 37 for the pendulum exciter 35 intended. The course of the control curve 37 is via a lever 75 and a cylindrical pin 77 on one arm 67 of the pendulum exciter, which is designed as a rocker arm 35 transfer.

A major advantage of this embodiment according to the invention is that the control member 36 to optimize the coordination between the stroke movement on the one hand and pendulum movement on the other hand, since the control cam 37 for the pendulum exciter 35 and the control curve 39 for the counter mass can be both positioned and shaped independently of one another. Not only can the timing between lifting movement and pendulum movement be optimized, but the shape of the pendulum movement can also be designed independently.

The one over the control curve 37 acted on arm 67 of the pendulum exciter 35 is via a machine-fixed return spring 87 supported. The other arm 68 of the pendulum exciter 35 carries a saw blade guide at its free end 33 , the two side guides in the form of inserts 81 made of hard metal as well as a role 79 ( 13 ) that covers the back 12 of the saw blade 11 is applied.

A major advantage of this guide of the saw blade according to the invention 11 is that the guide section 33 together with the saw blade 11 performs the pendulum motion, which means that the saw blade 11 never leaves the lateral guide and is therefore guided to the side at all times.

Because the pivot axis 71 of the pendulum exciter 35 and the pendulum axis (not shown) of the saw blade 11 do not coincide, there is a corresponding relative movement between the saw blade guide during the pendulum stroke operation 33 and the saw blade 11 . The above and below the point of contact between the rollers can be coordinated with this relative movement 79 and back 12 of the saw blade 11 located rear sections of the hard metal guide pieces 81 be convex or curved to the rear support of the saw blade 11 through the role 79 optimally support without disturbing the mentioned relative movement.

An alternative way of guiding the saw blade is shown 14th . The creation of the pendulum motion of the saw blade 11 takes place in turn by one around an axis 71 pivotable pendulum exciter 35 . This pendulum pathogen 35 However, it is essentially only used to generate the pendulum movement and not to guide the saw blade laterally 11 . Rather, the saw blade is 11 into one as a whole around a pendulum axis 73 pivoting suspended frame 85 integrated, of a recording 29 for the saw blade 11 includes that has a drive rod 83 to perform the lifting movement can be moved up and down, relative to a fixed in the frame 85 integrated saw blade guide 33 .

With such a configuration, the saw blade 11 not only be guided over a greater length, but the saw blade guide 33 can in particular up to the workpiece surface 89 reach out.

List of reference symbols

11

Saw blade

11a, 11b

Single saw blades

12

Back of the saw blade

13

Machine part

14th

Snap recording

15th

Base plate

16

Locking button

17th

Boom, double boom

18th

Locking projection

19th

Anti-tear device

20th

Hold-down section

21st

Hold-down

21a

Chip channel section

21b

Chip channel section

22nd

Suction nozzle

23

Blow hole

24

guide

25th

Suction opening

26th

Inlet opening

27

Holding section

28

Guide groove for tear-off protection element

29

Saw blade holder

30th

Underside of the anti-tear member

32

Clamping screw

33

Saw blade guide

35

Pendulum pathogen

36

Control body

37

Generating for pendulum motion

38

gear

39

Generating for movement of the counter mass

41

Lighting and protective fingers

43

Light exit end

45

Coupling section

47

Emblem section

48

opening

49

pole

50

Stop section

51

Support and stop section

52

Receiving opening

53

Clamping mechanism

54

Clamping screw

55

Support surface

57

Groove

59

funnel-shaped extension

60

Holding section

61

Clamping screw

62

Angle scale

63

Swivel axis

65

Guide groove for guide rail

67

poor

68

poor

69

Plunger

70

Adjustment knob

71

Swivel axis

73

Swing axle

75

lever

77

pen

79

role

81

Insert made of hard metal

83

Drive rod

85

frame

87

Return spring

89

Workpiece surface

91

Opening in the base plate

Claims (16)

Electric jigsaw with a saw blade (11), a machine part (13) and a plurality of base plates (15) which can each be detachably connected to the machine part (13) and interchangeable with one another, wherein the base plates (15) are different from one another and are provided for different functions, wherein the releasable connection between the base plates (15) and the machine part is designed in such a way that, with the exception of a relative movement for coupling and decoupling the machine part (13) and the base plate (15), there is no relative adjustability between the base plate (15) and the machine part (13) for making different cutting angles is possible, and with a base plate (15) for 90 ° cuts and a further base plate (15) for bevel cuts, the latter to support the jigsaw when making the bevel cuts. Jigsaw after Claim 1 , characterized in that a bracket (17) which can be detachably connected in particular to a base plate (15) and has a support and / or stop function is provided. Jigsaw according to one of the preceding claims, characterized in that a base plate (15) is part of a combined suction and blowing system for sawdust. Jigsaw according to one of the preceding claims, characterized in that a preferably separate tear-off protection element (19) is provided in particular on a base plate (15), which has a hold-down device (21) for the cut-limiting workpiece material, which acts directly on the saw blade (11). Jigsaw after Claim 4 , characterized in that the tear-off protection element (19) is provided with a chip channel (21a, 21b) which is part of a combined suction and blowing system for sawdust. Jigsaw after Claim 5 , characterized in that the chip channel comprises two channel sections (21a, 21b) positioned on opposite sides of the saw blade (11), one of which between a blow opening (23) of a base plate (15) and the saw blade (11) and the other between the Saw blade (11) and a suction opening (25) of the base plate (15) is located. Jigsaw according to one of the preceding claims, characterized in that the saw blade (11) is composed of a plurality of differently designed individual saw blades (11a, 11b). Jigsaw according to one of the preceding claims, characterized in that the saw blade (11) has a profiled holding section (27), the thickness of which varies along a perpendicular to the teeth running in the plane of the saw blade. Jigsaw after Claim 8 , characterized in that the holding section (27) has a cross-shaped or T-shaped profile. Jigsaw according to one of the preceding claims, characterized in that a saw blade holder (29) is provided which is compatible with saw blades whose holding sections (27) have different thickness profiles, one of the thickness profiles preferably corresponding to that of a standard saw blade. Jigsaw according to one of the preceding claims, characterized in that a saw blade fixing is provided which has a tool-free, hand-operated clamping device (32) and a pull-out safeguard that is decoupled therefrom. Jigsaw according to one of the preceding claims, characterized in that a saw blade guide (33) is provided which can oscillate together with the saw blade (11) in a pendulum stroke operation. Jigsaw according to one of the preceding claims, characterized in that a saw blade guide (33) is integrated in a pendulum exciter (35) which particularly acts directly on the saw blade (11). Jigsaw after one of the Claims 1 to 12 , characterized in that a saw blade guide (33) and the saw blade (11) form an integrated unit which, as a whole, can be excited to a pendulum movement. Jigsaw according to one of the preceding claims, characterized in that a pendulum stroke control is provided for the saw blade (11), in which the pendulum movement and the movement of a counter mass compensating for the stroke movement have different generators (37, 39). Jigsaw according to one of the preceding claims, characterized in that a combined lighting and protective finger (41) designed as a light guide is provided, into which light can be coupled and which extends in front of the saw blade (11) with its free lower light exit end (43) the cutting area.

Images