AU2018275014B2

AU2018275014B2 - Saw

Info

Publication number: AU2018275014B2
Application number: AU2018275014A
Authority: AU
Inventors: Markus Bindhammer
Original assignee: Scheppach GmbH
Current assignee: Scheppach GmbH
Priority date: 2017-12-13
Filing date: 2018-12-09
Publication date: 2019-09-19
Anticipated expiration: 2038-12-09
Also published as: EP3498444A1; CN109909546A; EP3498444B1; AU2018275014A1; CN109909546B

Abstract

Warnsymbol Abstract The invention is concerned with a saw, comprising: a machine head (7) carrying a saw blade (11) and a saw blade cover (10), a workpiece support (8), and a holder, on which the machine head (7) is received pivotably relative to the workpiece support (8) in a vertical plane, between an upper saw blade position, in which the saw blade (11) is located above the workpiece support (8), and a lower saw blade position, in which the saw blade (11) can engage a workpiece resting on the workpiece support (8), wherein the saw blade cover (10) has a plurality of segments which are mounted on the machine head so as to be telescopable in and out, and which are telescoped out in the upper saw blade position as a saw blade protection and are telescoped in in the lower saw blade position in order to release the saw blade (11) for sawing, and wherein a linkage (9) connecting the holder and the saw blade cover (10) is provided which pushes the segments of the saw blade cover (10) together when the machine head (7) is pressed down, and wherein a number of luminaires are provided which are connected to a voltage source (13; 14) via a switch. The invention is characterized in that the switch is mounted above and/or below the linkage (9) on the holder so that it is actuated by the linkage (9) when the machine head (7) is pushed down from the upper saw blade position, wherein the number of luminaires are connected via the switch to a voltage source (13; 14) when the machine head (7) is pushed down from the upper saw blade position. (Fig. 5) Fig.4 0A o Fig. 5

Description

a machine head (7) carrying a saw blade (11) and a saw blade cover (10), a workpiece support (8), and a holder, on which the machine head (7) is received pivotably relative to the workpiece support (8) in a vertical plane, between an upper saw blade position, in which the saw blade (11) is located above the workpiece support (8), and a lower saw blade position, in which the saw blade (11) can engage a workpiece resting on the workpiece support (8), wherein the saw blade cover (10) has a plurality of segments which are mounted on the machine head so as to be telescopable in and out, and which are telescoped out in the upper saw blade position as a saw blade protection and are telescoped in in the lower saw blade position in order to release the saw blade (11) for sawing, and wherein a linkage (9) connecting the holder and the saw blade cover (10) is provided which pushes the segments of the saw blade cover (10) together when the machine head (7) is pressed down, and wherein a number of luminaires are provided which are connected to a voltage source (13; 14) via a switch.

The invention is characterized in that the switch is mounted above and/or below the linkage (9) on the holder so that it is actuated by the linkage (9) when the machine head (7) is pushed down from the upper saw blade position, wherein the number of luminaires are connected via the switch to a voltage source (13; 14) when the machine head (7) is pushed down from the upper saw blade position.

(Fig. 5)

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Fig. 4

Fig. 5

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P/00/011

Regulation 3.2

AUSTRALIA

Patents Act 1990

COMPLETE SPECIFICATION

FOR A STANDARD PATENT ORIGINAL

TO BE COMPLETED BY APPLICANT

Name of Applicant:	Scheppach Fabrikation von Holzbearbeitungsmaschinen GmbH
Invention Title:	Saw
Address for Service:	A.P.T. Patent and Trade Mark Attorneys PO Box 833, Blackwood, SA 5051

The following statement is a full description of this invention, including the best method of performing it known to me/us:la

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-1 Saw

The invention concerns a saw, in particular a chop saw, a sliding chop saw, a 5 mitre saw or a sliding compound mitre saw according to the preamble of claim 1.

It is known from panel saws to warn by luminaires of the rotating scoring saw blade, instead by simple markings, see for example European patent application EP 2 210 722 A2.

German patent application DE 10 2008 054 698 A1 discloses a signalling device equipped with LEDs on a circular saw. The signalling device signals whether a sensor is armed, which detects whether there is a dangerous approach of a body part of the operator to the saw blade.

US patent application US 2014/0130643 A shows a circular saw with various light sources, namely a transmitter and a laser, both of which are intended to detect whether a workpiece has reached the area of the saw blade. Independently of these two light sources, a microswitch is provided which is attached to a holder for 20 a saw blade cover and detects whether the saw blade cover is attached to the holder.

Generic chop saws, sliding chop saws, mitre saws or sliding compound mitre saws have a machine head carrying a saw blade and a saw blade cover, a workpiece 25 support generally penetrated by a through slot for a saw blade, and a holder on which the machine head is received above the workpiece support. The machine head is mounted pivotable, in most cases pivotable in a vertical plane, between an upper saw blade position, in which the saw blade is located above the workpiece support, and a lowered saw blade position, in which it penetrates at least one 30 workpiece to be machined or in most cases also the workpiece support.

The saw blade cover can have several segments attached to the machine head

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-2that can be telescoped in and out around the axis of rotation of the saw blade. However, saw blade covers with flexible, retractable and extendable sections are also conceivable. The segments or sections of the saw blade cover are telescoped in the upper saw blade position and serve as saw blade protection by largely enclosing the saw blade. If the machine head with the saw blade is pressed down to the lower saw blade position, i.e. to the working position, the segments or sections of the saw blade cover are telescoped in and release the saw blade for sawing.

A linkage of rods is conventionally provided for this purpose, which engages at one end on the holder and at the other end on the saw blade cover and telescopes in or pushes together the segments of the saw blade cover or guides them during this movement when the machine head is pressed downwards. The linkage may, for example, consist of three rods articulated to each other, the two outer rods of which are connected at their free ends to the holder or saw blade cover and the facing ends of which are articulated to opposite ends of a central rod. The end of the linkage articulated on the saw blade cover may, for example, be articulated eccentrically to the axis of rotation of the saw blade on the foremost of the saw blade cover segments, so that the linkage ensures that the saw blade cover is retracted or telescoped when the machine head is pressed down. When the sawing process is completed, the saw blade cover is then telescoped far out around the saw blade again when the machine head is lifted.

In this way, the user is effectively protected against injuries caused by unintentional reaching into the running saw blade. In particular, the combination of high speed and a sharp saw blade can cause serious injury if the saw blade is during the cutting process or while the saw blade is still rotating and the saw blade cover is not completely closed. For this reason, most common saws are equipped with stickers, imprints or embossings on the workpiece support, which warn the user not to reach into the running saw blade. However, it is often the case that the user does not notice or observe these warnings.

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-3British patent application GB 2497347 A discloses a combination of a circular table saw and a mitre saw, wherein lighting is provided for the mitre saw. The saw has a linkage of rods that telescopically swivels the saw blade cover on or off when the machine head with the saw blade is swivelled down or up. A light guide system is also shown, which has a light that is positioned above the edge of the saw blade and can direct a beam of light onto it if an operator actuates a light switch. When the motor unit is swivelled downwards towards the workpiece, the light beam shines across both sides of the saw blade onto the workpiece. The saw blade creates a shadow on the workpiece which serves as an indicator for the cutting line of the saw blade.

Startign from there, it is an object of the present invention to further develop a saw of the generic type in such a way as to increase operational safety.

This object is solved with the characteristics of claim 1.

According to the invention, a switch is attached to the holder above and/or below the linkage of rods for this purpose. The switch can preferably be designed as a microswitch. The switch is mounted on the holder in such a way that it is actuated by the linkage when the machine head is pushed down from the upper saw blade position. Furthermore, according to the invention, a number of lights are provided, which are connected to a voltage source via the switch and supplied with an operating voltage necessary for lighting when the machine head is pressed down from the upper saw blade position.

By means of the lights actuated by linkage and switch, a lighting system can be realized in a simple way, which is activated when the machine head is pivoted downwards into the working position, i.e. the lower saw blade position, and then illuminates the sawing area accordingly. In the context of the invention, however, it is preferable to implement a warning system in order to give the user a conspicuous, clearly visible warning that should warn him not to reach into the running saw blade.

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-4To this end, each of the number of lights or luminaires may include at least one light source, for example one or more LEDs or lasers, and a translucent cover arranged in front of the light source and provided with a warning symbol. When the 5 lights are energized, the lamps illuminate the cover and the warning symbol appears.

Positions at the edge of the workpiece support or on the workpiece itself are well perceived by the user. Therefore, at least one of the number of luminaires can be 10 advantageously recessed in a recess in the tool rest. Further advantageous, at least one further light can be provided which is directed from above onto the workpiece support or a workpiece placed there for sawing, in particular to project the warning symbol onto the workpiece.

In particular, in the case of the luminaire or luminaires recessed in a recess in the workpiece support, the cover can advantageously have a diffusor made of transparent plastic. The diffusor can be made of acrylic or epoxy resin, for example, and can also have a matt surface. The warning symbol may then be printed on a translucent sticker affixed to or attached to the diffusor. The diffusor 20 can be realized cost-effectively as a plastic plate. It would also be conceivable to laser or mill the warning symbol into the diffusor as long as it is clearly visible to the user.

In contrast, in particular for the light or lights directed from above onto the 25 workpiece support or a workpiece placed there for sawing, it is advantageous, if the cover comprises a diffusing lens in order to project the light of the luminaire magnified onto the workpiece support or the workpiece placed there for sawing. The warning symbol can then be lasered or milled into the diffusing lens, or a translucent sticker with the warning symbol can be affixed to the diffusing lens. In 30 order to provide the necessary luminosity for the projection of the warning symbol onto the workpiece, in particular in an enlarged form, a laser is a suitable light source.

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-5The user's attention can be further increased if at least a number or all of the lights have a microcircuit so that their light source flashes when the operating voltage is present.

If one or more LEDs, e.g. two LEDs, are provided as illuminants per luminaire, the luminaire equipped with this illuminant can advantageously have a circuit board which not only carries the LED or LEDs, but also a series resistor for each LED, which prevents the LED from burning out when the operating voltage is applied. Another advantage is that a flat conductor track can be applied to the PCB, for example a tin-plated, silver-plated or gold-plated conductor track which simultaneously serves as a reflector for the illuminant and as an electrical conductor to the illuminant or series resistor.

If the saw has a laser unit indicating the cutting direction, the illuminants of the number of luminaires can be connected to the power supply of the cutting guide laser unit. However, a battery can also be provided to power the lamps. It would also be conceivable to transform down and rectify the line voltage used to operate the saw using a transformer and a downstream rectifier in order to be able to use it to supply the illuminants.

Another advantage is that the lamps can be switched in such a way that they only light up during a warning phase lasting a few seconds, for example, when the machine head is pressed downwards from the upper saw blade position, regardless of how long the machine head remains pressed downwards from the upper saw blade position in the lower saw blade position. This avoids the need for an additional on/off switch, which would otherwise be necessary to prevent the lights from glowing continuously during transport of the saw with the machine head lowered. This can also be achieved advantageously by providing at least one capacitor or preferably one supercapacitor, in particular one capacitor or supercapacitor per luminaire, which serves as a short-term voltage source for the illuminants during the warning phase and - e.g. via the battery - is charged when

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-6the machine head is in the upper saw blade position.

It would also be conceivable to use a second switch which can be actuated by the linkage when the machine head is swiveled upwards to detect when a sawing operation has ended and to give the user an all-clear signal via the lights or other additional lights, e.g. via a delay element interposed in the switching element, to ensure that the saw blade no longer rotates. The use of LEDs or lasers of different colors, such as green instead of red, would be conceivable.

In the following, advantageous embodiments of the invention are explained in more detail using the enclosed figures.

Figure 1 shows a perspective, exploded view of two luminaires for a saw according to the embodiment of the invention shown in Figures 3 to 5, wherein one luminaire is shown with and one without supercondenser;

Figure 2 shows a perspective view of the luminaire shown in Fig. 1 with supercapacitor in assembled condition;

Figure 3 is a perspective partial view of a cross-cut mitre saw, according to an embodiment of the invention;

Figure 4 is a detailed view of a side area of a workpiece support of the mitre saw shown in Fig. 3;

Figure 5 is a top view of the mitre saw shown in figures 3 and 4;

Figure 6 shows a switching diagram for the luminaire shown in Figure 1 with supercapacitor;

Figure 7 shows a wiring diagram for the luminaire shown in Figure 1 without supercapacitor; and

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-7Figure 8 shows the principle of a luminaire projecting a warning symbol onto a workpiece.

Figs. 3 to 5 show a mitre saw with a machine head 7 pivotably mounted above a workpiece support 8, which carries a saw blade 11 with a saw blade cover 10 and, as shown in particular in Fig. 5, is equipped with a handle to pivot the saw blade 11 from an upper saw blade position/rest position to a lower saw blade position/working position and back.

The machine head 7 is hinged to an unspecified holder which connects the machine head 7 to a machine frame. The machine frame has the form of a rotary table rotatable relative to the two lateral sections of the workpiece support 8 in order to produce mitre cuts.

When lowering the saw blade 11, i.e. when swiveling the machine head 7 downwards, the saw blade cover 10, which at least largely covers the saw blade 11 in the rest position, must be opened to allow a saw cut through the workpiece. When the saw blade 11 is raised again after the sawing process, i.e. when the machine head 7 is swiveled upwards, the saw blade cover should extend around the saw blade again as quickly as possible in order to protect a user of the mitre saw from unintentional injuries caused by the still rotating saw blade 11. For this purpose, a linkage 9 as shown in Fig. 3 is provided, which connects the saw blade cover 10 with the holder to which the machine head 7 is hinged.

A microswitch 12 is provided below the arm of the linkage 9 which is hinged to the holder. When lowering the saw blade 11, i.e. when swiveling the machine head 7 downwards, the microswitch 12 is actuated by force of the linkage 9 or its arm which is hinged to the holder.

The switch 12 is connected in an electrical circuit with two luminaires embedded in the workpiece support 8 to the left and right of the saw blade 11, which, when

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-8energised, backlight a warning symbol, in the example shown a crossed-out hand. If the linkage 9 is moved in vertical direction when lowering the machine head 7 or the saw blade 11 and presses on the micro switch 12, each of the two luminaires is connected to a power source via a circuit and supplied with an operating voltage so that the luminaires light up as soon as the machine head 7 of the cross-cut mitre saw is pressed down.

Figs. 6 and 7 show two possible circuits for one of the two luminaires.

Fig. 7 shows the simplest possible wiring. As long as the machine head 7 remains pressed down, both LEDs 1 of the respective luminaire light up (or flash). An on/off switch designated here with 15 is necessary, as otherwise the LEDs 1 would light up continuously or flash if the machine head 7 is locked in the lower position, e.g. for transporting the mitre saw.

In the circuit shown in Fig. 6, in addition to a battery 13 serving as voltage source, a supercapacitor 14 is provided which is charged as long as the linkage 9 does not press the micro switch 12. If the machine head 7 is now pressed down and with it the linkage 9, the micro switch 12 is actuated, whereby the supercapacitor 14 is conductively connected to the LEDs 1. The supercapacitor 14 then serves as a short-term voltage source, so that the LEDs 1 only light for a few seconds or flash as soon as the machine head 7 is pressed down. To prevent the LEDS 1 from burning out, series resistors 3 are connected upstream.

The luminaires equipped with supercapacitor 14 may have the structure shown in Fig. 1 on the left and in Fig. 2. The luminaires without supercapacitor may have the structure shown in Fig. 1 on the right.

The LEDs 1 are preferably of SMD design to ensure a flat structure and are positioned opposite each other on a circular PCB 2. The LEDs 1 can be equipped with an integrated microcircuit so that they flash when the operating voltage is applied. The wavelength of LEDs 1 is preferably 620 to 780 nm. The PCB 2

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-9contains the two resistors 3 necessary for the two LEDs 1. A wide tin-plated, silver-plated or gold-plated conductor track 4 on the PCB 2 serves as reflector.

A diffusor 5 made of acrylic or epoxy resin, whose surface is matt, sits above the circuit board. On the diffusor 5 the warning symbol consisting of a crossed-out hand is affixed as a translucent sticker 6. The warning symbol can also be integrated directly into the diffusor, e.g. lasered or milled into it.

Furthermore, Fig. 8 shows a principle sketch for an additional light that can project the warning symbol onto the workpiece surface. A laser 101 is provided as the illuminant, which illuminates an upstream scattering lens 105, on the back of which a sticker 106 with the warning symbol is affixed. The wiring of the additional luminaire can again be carried out as shown in Fig. 6 or 7. The additional luminaire could, for example, be attached to the holder or near the handle of the machine head.

Modifications and variations of the shown embodiment are possible without leaving the scope of the invention.

For example, it would also be conceivable within the scope of the invention to use a sensor, e.g. a light barrier, as a switch actuated by the linkage, which detects the lowering of the linkage and triggers the power supply to the luminaires. The sensor could also directly detect the lowering of the machine head or the saw blade or the telescoping of the saw blade cover. A microswitch on the saw blade cover instead of on the linkage would also be possible within the scope of the invention.

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Claims

1. Saw, in particular a chop saw, a sliding chop saw, a mitre saw or a sliding compound mitre saw, comprising:

2. Saw according to claim 1, characterized in that at least one of the number of

2018275014 09 Dec 2018 luminaires is embedded in a recess in the workpiece support (8).

3. Saw according to claim 1 or 2, characterized in that at least one of the number of luminaires is directed from above onto the workpiece support (8) or a

4. Saw according to claim 1, 2 or 3, characterized in that the number of luminaires each comprises at least one illuminant, in particular a number of LEDs (1) or lasers (101), and a transparent cover (5, 6; 105, 106) arranged in front of the

10 illuminant and provided with a warning symbol.

5 14. Saw according to one of the preceding claims, characterized in that the illuminants are wired in such away that they illuminate only in a warning phase, for example a few seconds long, irrespective of how long the machine head (7) is pressed down from the upper saw blade position.

5. Saw according to claim 4, characterized in that at at least one of the number of luminaires the cover (5, 6) has a diffusor (5) made of transparent plastic, in particular of acrylic or epoxy resin, in particular with a matt surface, into which the 15 warning symbol is lasered or milled or on which a translucent sticker (6) with the warning symbol is applied.

5 workpiece placed there for sawing.

5 a machine head (7) carrying a saw blade (11) and a saw blade cover (10), a workpiece support (8), which is preferably penetrated by a through passage for the saw blade (11), and a holder, on which the machine head (7) is received pivotably relative to the workpiece support (8) in a vertical plane, between an upper saw blade position, in which the saw blade (11) is located above the workpiece support 10 (8), and a lower saw blade position, in which the saw blade (11) can engage a workpiece resting on the workpiece support (8), wherein the saw blade cover (10) has a plurality of segments which are mounted on the machine head so as to be telescopable in and out, preferably about the axis of rotation of the saw blade (11), and which are telescoped out in the upper saw 15 blade position as a saw blade protection and are telescoped in in the lower saw blade position in order to release the saw blade (11) for sawing, and wherein a linkage (9) connecting the holder and the saw blade cover (10) is provided which pushes the segments of the saw blade cover (10) together when the machine head (7) is pressed down, and wherein a number of luminaires are provided which 20 are connected to a voltage source (13; 14) via a switch, characterized in that the switch, preferably microswitch (12), is mounted above and/or below the linkage (9) on the holder so that it is actuated by the linkage (9) when the machine head (7) is pushed down from the upper saw blade position, wherein the number of 25 luminaires are connected via the switch to a voltage source (13; 14) when the machine head (7) is pushed down from the upper saw blade position.

6. Saw according to claim 4 or 5, characterized in that at at least one of the numbers of luminaires directed from above onto the workpiece support (8) or a 20 workpiece placed there for sawing, the cover (105, 106) comprises a diffusor lens (105) in order to project the light of the luminaire magnified onto the workpiece support (8) or a workpiece placed there for sawing, into which diffusor lens (105) the warning symbol is lasered or milled or on which a translucent sticker (106) with the warning symbol is attached.

7. Saw according to one of the preceding claims, characterized in that at least

2018275014 09 Dec 2018 one of the number of luminaires has a microcircuit so that its illuminant flashes when the operating voltage is applied.

8. Saw according to one of the preceding claims, characterized in that at least 5 one of the number of luminaires comprises a reflector arranged behind the illuminant.

9. Saw according to claim 8, characterised in that the reflector is constructed as a tinned, silver-plated or gold-plated, flat conductor track (4) on a printed circuit

10 board (2).

10. Saw according to claim 9, characterized in that at least one, preferably two LEDs, are provided as illuminants, wherein the printed circuit board (2) carries a series resistor (3) for each LED.

11. Saw according to one of the preceding claims, characterized in that a battery (13) or a transformer with a rectifier connected downstream is provided for supplying the illuminants, which transform down and rectify a line voltage used to operate the saw.

12. Saw according to one of the preceding claims, characterized in that it comprises a cutting guide laser unit, wherein the lighting means being connected to the power supply of the cutting guide laser unit.

13. Saw according to one of the preceding claims, characterized in that the

2018275014 09 Dec 2018 illuminants are wired in such a way that they illuminate for an entire period of time during which the machine head (7) is pressed down from the upper saw blade position.

10 15. Saw according to claim 14, characterized in that at least one capacitor or supercapacitor (14) is provided, preferably one capacitor or supercapacitor (14) per luminaire, which during the warning phase serves as a short-term voltage source for the illuminants and which is charged when the machine head (7) is in the upper saw blade position.

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Fig. 1

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Fig. 2

Fig. 3

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Fig. 4

Fig. 5

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Fig. 6

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