Saw device with an emergency brake unit, and method for preparing a triggered emergency brake unit for operation

Abstract

The invention relates to a saw device (10) comprising a frame, a circular disc-shaped sawblade (12) which is rotatably mounted with respect to the frame, and an emergency brake unit (24). The emergency brake unit (24) comprises a blocking element (26), an actuator unit (32), and a control unit (34). The blocking element (26) has a bearing section (38) and a head section (42) which is designed to selectively engage into the sawblade (12) in order to brake same. The actuator unit (32) is coupled to the blocking element (26) at least in a normal position of the blocking element (26) such that the blocking element (26) can selectively be brought into engagement with the sawblade (12) by means of the actuator unit (32). Additionally, the blocking element (26) can be uninstalled from the frame separately from the actuator unit (32) and / or separately from the control unit (34) in a selective manner. The invention additionally relates to a method for preparing a triggered emergency brake unit (24) of a saw device (10) for operation. In this context, a blocking element (26) is uninstalled separately from the actuator unit (32) and / or separately from the control unit (34) and an unused blocking element (26) is installed.

Description

[0001] Sawing device with an emergency brake unit and method for making a triggered emergency brake unit ready for use

[0002] The invention relates to a sawing device comprising a frame, a circular disk-shaped saw blade mounted rotatably with respect to the frame, and an emergency brake unit.

[0003] Furthermore, the invention is directed to a method for making a triggered emergency brake unit of a sawing device ready for use.

[0004] Sawing devices with emergency braking units are known from the state of the art.

[0005] The emergency brake unit is designed to stop the saw blade from rotating if there is a risk of injury or if there is an imminent risk of injury. This prevents injuries to saw users or at least reduces their severity. In other words, safe operation of the saw is ensured.

[0006] Particularly in applications where relatively frequent activation of the emergency brake unit is expected, it is important for work efficiency that a saw with a triggered emergency brake unit can be quickly and easily made ready for use again. Only then can work on the task be continued promptly. In this way, safe operation of the sawing device can be combined with high work efficiency. From an economic perspective, the costs of triggering the emergency brake unit and making a triggered emergency brake unit ready for use should be as low as possible.

[0007] It is therefore the object of the present invention to improve sawing devices and associated methods for making a triggered emergency brake unit ready for use in such a way that increased work efficiency can be achieved with known high operational reliability.

[0008] The problem is solved by a sawing device with a frame, a circular disk-shaped saw blade that is rotatably mounted with respect to the frame, and an emergency brake unit. The emergency brake unit comprises a blocking element, an actuator unit, and a control unit that is integrally formed with the actuator unit or coupled to the actuator unit for signaling purposes. The blocking element comprises a bearing section, via which the blocking element is mounted on the frame, and a head section. The head section is designed to selectively engage with the saw blade for braking. At least in a normal position of the blocking element, the actuator unit is coupled to the blocking element in such a way that the blocking element can be selectively brought into engagement with the saw blade by means of the actuator unit. Furthermore, the blocking element can be selectively removed from the frame separately from the actuator unit and / or separately from the control unit.In this case, the normal position of the blocking element is to be understood as the position in which it has not yet engaged the saw blade. The normal position can therefore also be referred to as the non-triggered position. Furthermore, “removable separately from the actuator unit and / or separately from the control unit” means that the blocking element can be removed from the sawing device without the actuator unit and / or the control unit of the emergency brake unit having to be removed at the same time. This does not include, of course, assembly elements, bearing elements, holding elements and fastening elements by means of which the blocking element is mounted. In other words, the blocking element can be removed individually with respect to the actuator unit and / or the control unit. The blocking element can therefore be replaced on its own or individually. The actuator unit and / or the control unit remain or are replaced separately.remains mounted on the sawing device during such a replacement. This means that the blocking element can be removed quickly and easily. This applies in principle to all operating states of the sawing device and the emergency brake unit, but in particular to a state after the emergency brake unit has been triggered, i.e. when the blocking element engages or has engaged the saw blade. This means that the emergency brake unit and the sawing device can be put back into operation quickly and easily after the emergency brake unit has been triggered. A machining task can therefore be continued and completed promptly. The fact that the blocking element can be replaced individually also means that triggering the emergency brake unit and making the triggered emergency brake unit ready for use incurs comparatively little cost.

[0009] In a preferred embodiment, the blocking element can be removed separately from all other components of the emergency brake unit. In other words, the blocking element can be removed individually with respect to all other components of the emergency brake unit. The described effects and advantages are thereby achieved to a particularly high degree.

[0010] In a further preferred embodiment, the blocking element, the actuator unit, and the control unit of the emergency brake unit can each be removed separately from all other components of the emergency brake unit. In other words, the blocking element can be removed individually with respect to all other components of the emergency brake unit. In addition, the actuator unit can be removed individually with respect to all other components of the emergency brake unit. Furthermore, the control unit of the emergency brake unit can be removed individually with respect to all other components of the emergency brake unit. Thus, individual components of the emergency brake unit can be easily replaced, repaired, and / or maintained.

[0011] In a first alternative, the control unit of the emergency brake unit can be designed integrally with a motor control unit, which serves to control a drive motor designed to drive the saw blade. In a second alternative, the motor control unit and the control unit of the emergency brake unit are designed separately. However, they can be connected to each other via signaling, so that the drive motor can be deactivated easily and reliably when the emergency brake unit is triggered.

[0012] The aforementioned effects and advantages of the invention become particularly clear when compared to known emergency brake units for sawing devices. In such emergency brake units, the blocking element, the associated actuator unit, and the control unit are designed as a module. After the emergency brake unit is triggered, the entire module—that is, both the blocking element and the actuator unit and the control unit—must always be replaced.

[0013] In this context, a sawing device with a circular disk-shaped saw blade can also be referred to as a circular sawing device or simply a circular saw. Examples of such sawing devices include miter saws, table saws, hand-held circular saws, and plunge-cut saws.

[0014] Locking elements for emergency brake units of sawing devices are also colloquially referred to as brake wedges. This applies regardless of whether the locking element is wedge-shaped or acts as a wedge.

[0015] It is also understood that the emergency brake unit is coupled to a sensor unit for detecting actual or imminent contact with the saw blade by a user and is operated based on the sensor unit's detection result. This allows the emergency brake unit to be triggered in a timely and targeted manner. Injury to the user of the sawing device can thus be completely prevented or at least limited in severity.

[0016] In this context, the actuator unit of the emergency brake unit can comprise an actuator that can be triggered selectively, particularly depending on the detection result. By means of the actuator, the blocking element, or more precisely the associated head section, can be brought into engagement with the saw blade quickly and reliably. The actuator comprises, for example, a lifting magnet or a shape memory alloy actuator. It is also possible to use a preloaded spring, which can be released by means of a fuse wire, as the actuator.

[0017] The sawing device can comprise a guide element. The guide element is designed to guide the blocking element at least along a guide direction that runs at least partially parallel to a circumferential direction of the saw blade. This is particularly important when the blocking element engages the saw blade with its head section. In such a situation, the kinetic energy of the saw blade's rotation must be specifically introduced into the blocking element and absorbed by the blocking element. The guide element prevents the blocking element from undesired deformation or displacement. Guidance along a guide direction that runs at least partially parallel to a circumferential direction of the saw blade allows movement of the blocking element parallel to the circumferential direction. Movement parallel to an axial direction of the saw blade is prevented by the guide element.Depending on the application, movement in a direction radial to the saw blade can be permitted or prevented. The guide element thus ensures that the saw blade is braked with high reliability by means of the locking element.

[0018] According to one embodiment, the blocking element is connected to the frame via a bearing element. The bearing element can be removed individually from the sawing device, i.e. from the frame. In this embodiment, both the bearing element and the blocking element can be removed individually. The ability of the bearing element to be removed individually results in the blocking element being removed individually. In other words, the bearing element must be removed in order to be able to remove the blocking element. Other components of the emergency brake unit do not have to be removed. Thanks to the individually removable bearing element, the blocking element can be reliably mounted on the frame, so that even comparatively high forces can be transmitted between the blocking element and the frame. On the other hand, the blocking element can be removed quickly and easily.

[0019] The sawing device can include a locking mechanism by which the bearing element can be selectively locked to the frame and selectively unlocked from the frame. The bearing element is thus secured to the frame in such a way that it cannot be undesirably separated from the frame. Examples of locking mechanisms include a thread into which the bearing element is screwed, an eccentric mechanism by which the bearing element is clamped, and locking wings arranged at one end of the bearing element and positively engage behind an associated frame section when locked.

[0020] In one variant, the guide element is mounted on the frame by means of a bearing element. The bearing element thus serves to support both the blocking element and the guide element. Compared to mounting the blocking element and the guide element with separate, dedicated bearing elements, this allows for fewer components. This allows for a comparatively simple and compact design of the sawing device.

[0021] In another alternative, the blocking element is mounted on the frame by means of a stationary bearing element. A retaining element is also provided to hold the blocking element to the bearing element. The blocking element can be reliably mounted on the frame via the stationary bearing element. In particular, comparatively high forces can be transmitted between the blocking element and the frame. To remove the blocking element, only the retaining element needs to be removed or moved into a release position. This allows the blocking element to be removed quickly and easily.

[0022] The retaining element can also be optionally individually removable from the bearing element. In this embodiment, both the retaining element and the blocking element are individually removable. The individual detachability of the retaining element results in the individual detachability of the blocking element. In other words, the retaining element must be removed in order to remove the blocking element. Other components of the emergency brake unit do not need to be removed.

[0023] Examples of retaining elements include a nut that is screwed onto the bearing element and retaining rings that are positively or non-positively coupled to the bearing element.

[0024] In one embodiment, the holding element is formed by a section of the guide element. Thus, a section of the guide element is designed to hold the blocking element on the bearing element. In particular, such a section of the guide element blocks movement of the blocking element along an extension direction of the bearing element, i.e., along an axial direction of the bearing element. In this context, the guide element can be mounted separately on the frame, so that it can optionally assume an operating position in which it holds the blocking element on the bearing element, and a release position in which it allows disassembly of the blocking element from the bearing element.

[0025] The bearing element can be a bearing pin. The blocking element can be rotatably mounted via the bearing pin. Such a bearing element is comparatively simple in design and can reliably support the blocking element. The rotatable mounting ensures that the blocking element can be easily and reliably brought into engagement with the saw blade.

[0026] In one embodiment, the blocking element comprises a coupling section, via which the blocking element is coupled to the actuator unit, at least in the normal position. The coupling section can be positioned at an end of the blocking element opposite the bearing section. The blocking element can thus be selectively brought into engagement with the saw blade by means of the actuator unit via the coupling section. By positioning the coupling section at an end of the blocking element opposite the bearing section, the blocking element can engage the saw blade with high reliability and precision. Undesirable interactions between the coupling section and the bearing section are thereby eliminated or at least reduced to a minimal level.

[0027] In this context, a clamping element can be provided that couples the actuator unit to the blocking element in a force-locking manner, at least in the normal position. Alternatively, a form-locking element can be provided that couples the actuator unit to the blocking element in a form-locking manner, at least in the normal position. The actuator unit and the blocking element are thus coupled in a simple and reliable manner, at least in the normal position. Such a coupling can also be quickly and easily released and re-established when replacing the blocking element.

[0028] In an end position, the blocking element can be decoupled from at least a portion of the actuator unit. This end position refers to the position of the blocking element after it has been brought into engagement with the saw blade by the actuator unit, i.e., a position after the emergency brake unit has been triggered. Because the coupling to the actuator unit has already been released, the blocking element can be particularly easily removed from the emergency brake unit and replaced with an unused blocking element.

[0029] The actuator unit can also be optionally individually removable from the frame. Again, this individual detachability refers to the remaining components of the emergency brake unit. This allows the actuator unit to be replaced on its own if necessary, without having to simultaneously disassemble other components of the emergency brake unit. The emergency brake unit is therefore particularly easy to repair. It should be emphasized that in a preferred embodiment, the actuator unit is designed to be used in multiple activation processes of the emergency brake unit. As a standard, the actuator unit does not need to be replaced after the emergency brake unit has been activated.

[0030] Preferably, at least one of the blocking element and the actuator unit can be disassembled without tools. In other words, at least one of the blocking element and the actuator unit can be disassembled manually, in particular without tools. This makes disassembly particularly simple.

[0031] According to one variant, in the normal position, the bearing section and the head section are essentially the same distance from a center axis of the saw blade. Consequently, the blocking element is arranged in a space-saving manner within the sawing device, while also being positioned so that the head section of the blocking element only has to overcome a comparatively small distance to engage the saw blade. Furthermore, such an arrangement allows forces introduced into the blocking element to be reliably supported via its bearing section. Overall, the saw blade can be brought to a standstill relatively quickly and reliably.

[0032] Furthermore, it can be provided that the blocking element comprises a deformation section that lies between the bearing section and the head section and / or connects the bearing section and the head section to one another. The deformation section can be arc-shaped and designed to be plastically shortened along an arc-circumferential direction to brake the saw blade. The kinetic energy of the rotation of the saw blade can thus be reliably and purposefully converted into a plastic shortening of the deformation section. This is achieved in particular by the arc shape of the deformation section and its position between the bearing section and the head section. Therefore, rotation of the saw blade can be stopped in a comparatively short time.Since the deformation section is specifically designed to be plastically shortened along the circumferential direction of the arc, it can absorb a comparatively large amount of kinetic energy with respect to the installation space occupied by the deformation section and convert it into plastic shortening. This also means that forces resulting from the braking of the saw blade are reliably and specifically absorbed by the deformation section. As a result, only comparatively low forces act on the other components of the emergency braking unit. The same applies to components of the sawing device. Consequently, the functionality of the other components of the emergency braking unit and the components of the sawing device are not affected by a braking process brought about by the blocking element. This applies in particular to the saw blade, which can be reused when the sawing device is put back into operation.

[0033] Preferably, the arcuate deformation section runs concentrically to the circular disk-shaped saw blade.

[0034] Furthermore, the object is achieved by a method for preparing a triggered emergency brake unit of a sawing device. The sawing device comprises a circular disk-shaped saw blade. The emergency brake unit has a blocking element that is designed to selectively engage the saw blade to brake the saw blade. The method comprises the following steps:

[0035] - Dismantling the blocking element separately from an actuator unit of the emergency brake unit and / or separately from a control unit of the emergency brake unit, wherein the blocking element engages with the saw blade or was engaged with the saw blade,

[0036] - Mounting an unused blocking element.

[0037] In this context, a condition arises in which the blocking element engages with the saw blade or was in engagement with the saw blade when the emergency brake unit was triggered and the saw blade was braked by means of the blocking element. In emergency brake units of the type relevant here, as a result of the triggering of the emergency brake unit, the blocking element, which is damaged and / or deformed as a result of the triggering, must be replaced with an unused blocking element. As already mentioned, against this background, dismantling the blocking element separately from an actuator unit of the emergency brake unit and / or separately from a control unit of the emergency brake unit means that the blocking element can be dismantled from the sawing device without the actuator unit of the emergency brake unit and / or the control unit of the emergency brake unit having to be dismantled at the same time.As already mentioned, this does not include assembly elements, bearing elements, holding elements, and fastening elements by means of which the blocking element is mounted. In this context, one can also speak of a singular disassembly of the blocking element, where singular again refers to the actuator unit and / or the control unit of the emergency brake unit. This means that the blocking element can be replaced on its own or individually to make the sawing device ready for use. The actuator unit and / or the control unit of the emergency brake unit remain or remain mounted on the sawing device during such a replacement. The blocking element can therefore be quickly and easily replaced with an unused blocking element. This means that the emergency brake unit and the sawing device can be made ready for use quickly and easily after the emergency brake unit has been triggered. A machining task can therefore be continued and completed promptly.The fact that the blocking element can be replaced individually also means that triggering the emergency brake unit and making the triggered emergency brake unit ready for use incurs comparatively low costs.

[0038] In a preferred embodiment, the blocking element is removed separately from all other components of the emergency brake unit. In other words, the blocking element is removed singly with respect to all other components of the emergency brake unit. The described effects and advantages are thereby achieved to a particularly high degree.

[0039] In a further preferred embodiment, the blocking element, the actuator unit, and the control unit of the emergency brake unit are each disassembled separately from all other components of the emergency brake unit. In other words, the blocking element is disassembled singly with respect to all other components of the emergency brake unit. In addition, the actuator unit is disassembled singly with respect to all other components of the emergency brake unit. Furthermore, the control unit of the emergency brake unit is disassembled singly with respect to all other components of the emergency brake unit. Consequently, individual components of the emergency brake unit can be easily replaced, repaired, and / or maintained.

[0040] In one variant, the unused blocking element is coupled to an actuator unit of the emergency brake unit when mounting it. This means that the actuator unit is not replaced. This coupling allows the blocking element to be selectively engaged with the saw blade using the actuator unit during subsequent operation of the sawing device.

[0041] In one embodiment, to disassemble the blocking element, a bearing element by which the blocking element is mounted in the sawing device is removed. Alternatively, a retaining element is removed from a fixed bearing element by which the blocking element is mounted in the sawing device. In both variants, the blocking element can thus be disassembled quickly and easily. This can preferably be done without tools.

[0042] The holding element can be formed by a section of a guide element, and the removal of the holding element from the stationary bearing element can involve moving the guide element into a release position. The movement into the release position includes, for example, folding, pivoting, rotating, and / or sliding the guide element. Preferably, the guide element is not separated from the frame of the sawing device. In this way, the holding element can be removed from the stationary bearing element particularly quickly and easily. The blocking element can thus be replaced particularly quickly and easily.

[0043] The invention is explained below using various embodiments shown in the accompanying drawings. They show:

[0044] Figure 1 shows a sawing device according to the invention in a perspective

[0045] View, wherein the sawing device according to the invention comprises an emergency brake unit which is equipped with a blocking element and can be made ready for use by means of a method according to the invention,

[0046] Figure 2 shows the sawing device from Figure 1 in a side view, with a

[0047] Guide element of the emergency brake unit is omitted,

[0048] Figure 3 Parts of the sawing device from Figures 1 and 2 in a separate

[0049] Opinion,

[0050] Figure 4 shows a detailed view of the blocking element,

[0051] Figures 5 to 8 show parts of the sawing device from Figures 1 and 2 at different times after the emergency brake unit has been triggered,

[0052] Figure 9 shows a curve of a force absorbed by the blocking element over time after the emergency brake unit has been triggered, Figure 10 shows parts of the sawing device from Figures 1 and 2 during assembly of the

[0053] blocking element,

[0054] Figures 11 to 14 show alternative designs for holding the blocking element in a

[0055] Normal position,

[0056] Figure 15 parts of a sawing device according to an alternative embodiment,

[0057] Figure 16 Parts of a sawing device according to yet another alternative

[0058] embodiment,

[0059] Figure 17 Parts of a sawing device according to another alternative

[0060] embodiment, and

[0061] Figure 18 shows an additional embodiment of an inventive

[0062] Sawing device.

[0063] Figures 1 and 2 show a sawing device 10 with a circular disk-shaped

[0064] Saw blade 12. In the example shown, the sawing device 10 is a miter saw.

[0065] The sawing device 10 comprises a base assembly 14 and an arm assembly 16 rotatably mounted thereon.

[0066] The base assembly 14 has a support surface 18 on which a component to be machined, i.e. sawn off or sawn in, can be positioned.

[0067] Furthermore, the saw blade 12 can be set in rotation about a central axis A by actuating a drive motor M coupled thereto and can be brought into interaction with the component to be machined by displacing the arm assembly 16 relative to the base assembly 14.

[0068] In the example shown, the arm assembly 16 is moved relative to the base assembly 14 manually.

[0069] The arm assembly 16, or more generally the sawing device 10, comprises a frame 20 on which a drive shaft 22 is rotatably mounted. The drive shaft 22 is coupled to the drive motor M. The saw blade 12 is fixed to the drive shaft 22, so that the saw blade 12 can be driven in rotation in a known manner.

[0070] The sawing device 10 is further equipped with an emergency brake unit 24, which can be seen in detail in Figures 3 and 4.

[0071] For better visibility of the emergency brake unit 24, a housing part is not shown in Figures 1 and 2 in an area G. Such a housing part serves, on the one hand, to drain workpiece particles, e.g., sawdust or dust, generated by the use of the sawing device 10. On the other hand, such a housing part forms a portion of the handle provided at the end of the arm assembly 16 in the illustrated embodiment. Furthermore, the housing part serves to cover the saw blade 12.

[0072] The emergency brake unit 24 comprises a blocking element 26 which is rotatably mounted on the sawing device 10 via a bearing element 28 fixed to the frame 20 in the form of a fixed bearing pin 30 such that it can selectively engage with the saw blade 12 to brake the saw blade 12.

[0073] In addition, the emergency brake unit 24 comprises an actuator unit 32 which is designed to selectively bring the blocking element 26 into engagement with the saw blade 12.

[0074] In the example shown, the actuator unit 32 comprises an electrically controllable lifting magnet, which is not shown in detail in the figures.

[0075] The emergency braking unit 24 also includes an associated control unit 34.

[0076] In the illustrated embodiment, the control unit 34 is designed and arranged separately from the actuator unit 32 (see, for example, Figures 3 to 8). The actuator unit 32 and the control unit 34 are signal-coupled via a signal line.

[0077] This configuration allows the actuator unit 32 and the control unit 34 to be disassembled separately. This facilitates replacement, repair, or maintenance. The control unit 34 is coupled to a known sensor unit for detecting an actual or imminent contact with the saw blade 12 by a user.

[0078] Thus, the actuator unit 32 can be operated depending on a detection result of the sensor unit.

[0079] The emergency brake unit 24 further comprises a guide element 36 which is mounted on the frame 20 and guides a movement of the blocking element 26 along a guide direction F, as will be explained in more detail below.

[0080] The blocking element 26 is in a normal position in Figures 3 and 4. In this position, the blocking element is arranged parallel to a circumferential direction U of the saw blade 12.

[0081] The blocking element 26 is constructed from three sections.

[0082] The blocking element 26 comprises a bearing section 38.

[0083] In the illustrated embodiment, the bearing section 38 is sleeve-shaped, ie the bearing section 38 comprises a circular-cylindrical bearing opening 40 which is delimited by a wall 41 with a substantially constant wall thickness.

[0084] The fixed bearing pin 30 is received in the bearing opening 40, so that the blocking element 26 is rotatably mounted on the frame 20 of the sawing device 10 via the bearing section 38 and the bearing pin 30.

[0085] The blocking element 26 further comprises a head portion 42.

[0086] The head portion 42 is provided at an end of the blocking element 26 opposite the bearing portion 38.

[0087] The head section 42 is designed to engage the saw blade 12 when the emergency brake unit 24 is actuated, i.e. driven by the actuator unit 32, in order to ideally brake it to a standstill.

[0088] In this context, the head portion 42 comprises a coupling portion 44. The coupling portion 44 is positioned at an end of the blocking element 26 opposite the bearing portion 38.

[0089] The coupling section 44 is also positioned radially outward on the head section 42.

[0090] The coupling section 44 serves two different functions.

[0091] On the one hand, the coupling section 44 is designed to introduce an actuating force generated by the actuator unit 32 into the blocking element 26 so that the head section 42 can engage with the saw blade 12.

[0092] On the other hand, the coupling section 44 serves to fix or lock the blocking element 26 relative to the frame 20, at least in the normal position shown in Figures 3 and 4. Thus, the head section 42 is prevented from engaging the saw blade 12 in the normal position.

[0093] The force application and locking functions can be implemented separately or together, i.e., combined. The latter is the case in the embodiments shown in Figures 1 to 10.

[0094] Here, the coupling section 44 comprises two coupling openings 46.

[0095] In addition, a U-shaped form-locking element 48 is provided, which on the one hand is fastened to the actuator unit 32, e.g., in a form-fitting manner, and on the other hand has nubs complementary to the coupling openings 46, which engage in the coupling openings 46. The form-locking element 48 is thus positively coupled to both the blocking element 26 and the actuator unit 32.

[0096] Thus, on the one hand, an actuating force generated by the actuator unit 32 can be introduced into the blocking element 26 via the positive-locking element 48. On the other hand, the blocking element 26 is locked in the normal position relative to the frame 20 via the positive-locking element 48 and the actuator unit 32.

[0097] It is understood that, alternatively, the coupling openings 46 and the associated nubs can also be omitted. Instead of the U-shaped form-locking element 48, a similarly U-shaped clamping element is then used, which is clamped onto the coupling section 44, i.e., is non-positively connected to the blocking element 26 in the region of the coupling section 44. Such a clamping element can be attached to the actuator unit 32 in a form-fitting or non-positive manner.

[0098] The head portion 42 further comprises a cut zone 50.

[0099] In the illustrated embodiment, the incision zone 50 is characterized by a two-row pattern of through-openings 52. For clarity, only some of the through-openings 52 are provided with a reference symbol in the figures.

[0100] By means of the through openings 52, the material of the head section 42 is specifically weakened in the area of ​​the incision zone 50, so that after the emergency brake unit 24 is triggered, the saw blade 12 cuts gently into the head section 42 over as large an area as possible.

[0101] This results in a reliable coupling between the saw blade 12 and the blocking element 26, which is necessary for reliably braking a rotation of the saw blade 12.

[0102] A connection zone 54 is provided essentially between the coupling section 44 and the incision zone 50.

[0103] In the illustrated embodiment, the connection zone 54 also includes through-openings 56. Again, for the sake of clarity, only some of the through-openings 56 are provided with a reference symbol in the figures. However, the diameters of the through-openings 56 of the connection zone 54 are selected to be significantly larger than the diameters of the through-openings 52 of the incision zone 50.

[0104] The connection zone 54 serves, on the one hand, to transmit an actuating force from the coupling section 44 to the notch zone 50. On the other hand, the notch zone 50 is coupled to the deformation section, which will be explained below, via the connection zone 54. In this context, the through-openings 56 of the connection zone 54 serve to ensure sufficient rigidity of the connection zone 54 with the lowest possible mass and thus the lowest possible mass inertia.

[0105] In addition, the head section 42 is equipped with a guide surface 58.

[0106] The guide surface 58 rests against a guide counter surface 60 of the guide element 36.

[0107] Due to the geometry of the head portion 42 and the guide counter surface 60, the head portion 42 is subjected to a force in the direction of the saw blade 12 when it is moved clockwise along the circumferential direction U of the saw blade 12 in the illustration according to Figure 4. For this purpose, the guide surface 58 has a normal with a radially outward extension component.

[0108] As is clear from the above explanations, through-holes are used in the head section 42 shown in the figures to create areas of different stiffness and different resistance to cutting by the saw blade 12. It is understood that, as an alternative to the through-holes, this can also be achieved by providing different materials in the various areas of the head section 42. In this context, it may be particularly important to use materials of different ductility.

[0109] Located between the head portion 42 and the bearing portion 38, the blocking element 26 comprises a deformation portion 64.

[0110] The deformation section 64 connects the bearing section 38 and the head section 42 to each other.

[0111] The deformation section 64 is overall arc-shaped, in the illustrated embodiment circular arc-shaped.

[0112] In this case, an arcuate circumferential direction 66, ie the curved longitudinal extension direction of the arcuate deformation section 64, runs essentially parallel to the circumferential direction U of the saw blade 12. In the embodiment shown, an outer circumference of the saw blade 12 and the arcuate deformation section 64 also run concentrically, with the central axis A representing the center.

[0113] In the embodiment shown in Figure 4, the deformation section 64 extends over a section of the arc circumferential direction 66 with a center angle of approximately 60 degrees.

[0114] The circumferential extent of the deformation section 64 is thus essentially twice the circumferential extent of the head section 42. The head section 42 is consequently circumferentially shorter than the deformation section 64.

[0115] Also with respect to a circumferential extension of the bearing section 38, the deformation section 64 is several times longer.

[0116] In addition, the deformation section 64 is spaced further from the outer circumference of the saw blade 12 in a radial direction with respect to the central axis A of the saw blade 12 than the head section 42 and the bearing section 38.

[0117] In other words, both the head portion 42 and the bearing portion 38 project radially inward relative to the arc circumferential direction 66 relative to the deformation portion 64.

[0118] In this context, the radial distance D of the deformation section 64 from the saw blade 12 is selected such that it is greater than zero in all operating situations of the emergency brake unit 24. This applies in particular to an end position of the blocking element 26, which will be explained later.

[0119] In other words, the distance D of the deformation section 64 is selected such that it does not contact the outer circumference of the saw blade 12 in any operating situation.

[0120] The deformation section 64 further comprises a structure 68 which is plastically deformable in the arc circumferential direction 66. In the embodiment shown in Figure 4, this structure 68 is formed from a total of eleven ring segments 70.

[0121] The ring segments 70 are arranged adjacent to one another along the arc circumferential direction 66 with a slight overlap.

[0122] Each of the ring segments 70 has a wall 72 with a substantially constant wall thickness t.

[0123] The walls 72 each define an axially continuous cavity 74.

[0124] For the sake of clarity, only some of the ring segments 70 as well as only some of the walls 72 and some of the cavities 74 are provided with a reference symbol in the figures.

[0125] The structure 68 which is plastically deformable in the circumferential direction 66 of the arc thus comprises a total of eleven cavities 74 arranged adjacently along the circumferential direction 66 of the arc.

[0126] Due to the slight overlap of the ring segments 70, each cavity 74 has a crescent-shaped cross-section.

[0127] Furthermore, a filling material 76 is arranged in the interior of each of the three cavities 74 which are arranged adjacent to the bearing section 38.

[0128] In the embodiment shown, the filling material is a rubber material.

[0129] Furthermore, the blocking element 26 is made of an aluminum alloy.

[0130] Due to the filling material 76, a different stiffness of the deformation section 64 results in the region of the cavities 74 provided with the filling material 76 than in the region of the unfilled cavities 74. The deformation section 64 thus comprises two regions with different stiffnesses or, more generally, a stiffness curve.

[0131] It is understood that the rigidity can be specifically adjusted by appropriately selecting the filler material 76 as well as the number and position of the cavities 74 filled with the filler material 76. Overall, the structure 68 ensures that the rigidity of the deformation section 64 along the arc circumferential direction 66 is lower than the rigidity of the head section 42.

[0132] In addition, the structure 68 has predetermined deformation points 78. In the embodiment shown in Figure 4, these are located in the radially inwardly projecting and radially outwardly projecting sections of the ring segments 70.

[0133] For the sake of clarity, only some of the desired deformation points 78 are provided with a reference symbol in the figures.

[0134] The deformation section 64 is therefore designed to be plastically shortened along the arc circumferential direction 66 to brake the saw blade 12. This is explained below with reference to Figures 5 to 8.

[0135] In this context, Figure 5 shows the emergency brake unit 24, and in particular the blocking element 26, in the previously described normal position. This means that the actuator unit 32 has not yet been actuated to effect emergency braking.

[0136] Accordingly, no force acts on the blocking element 26 (see Figure 9).

[0137] As already explained, the blocking element 26 is held in the normal position via the form-locking element 48 and the actuator unit 32.

[0138] The position in Figure 5 corresponds to the situation at 0 milliseconds in the diagram in Figure 9.

[0139] It is now assumed that the emergency brake unit 24 is triggered at time zero milliseconds (0 ms). This results in the actuator unit 32 being actuated and the head section 42 being forced toward the saw blade 12. In the illustrated embodiment, this is done via the positive locking element 48.

[0140] It is understood that at the same time, the drive motor M is deactivated and / or decoupled from the drive shaft 22. Figure 6 shows a situation that occurs one millisecond (1 ms) after triggering. Again, the force curve at 1 ms in Figure 9 can be associated with the situation in Figure 6.

[0141] In this situation, the saw blade 12 has cut into the incision zone 50, creating a force coupling between the saw blade 12 and the blocking element 26. Due to the clockwise rotation of the saw blade 12, at the time shown in Figure 6, the head section 42 has already been moved a certain circumferential distance along the circumferential direction U of the saw blade 12 compared to the initial situation in Figure 5.

[0142] This resulted in the connection between the form-locking element 48 and the actuator unit 32 being released.

[0143] The coupling between the form-locking element 48 and the head section 42 has remained intact in the present case.

[0144] It is understood that alternatively, the connection between the form-locking element 48 and the head portion 42 can be separated and the connection between the form-locking element 48 and the actuator unit 32 can be maintained.

[0145] In this context, the guide element 36 ensures that the blocking element 26 cannot escape the drive of the saw blade 12 either in the radial direction or in the axial direction. The blocking element 26 is thus guided along the guide direction F by means of the guide element 36.

[0146] The entrainment by the saw blade 12 has further caused at least those three ring segments 70 which are arranged adjacent to the head section 42 to be deformed.

[0147] More precisely, these ring segments were compressed along the arc circumferential direction 66.

[0148] In Figure 7, the emergency brake unit 24 is shown after a further millisecond, ie 2 milliseconds after triggering.

[0149] The head section 42 remains coupled to the saw blade 12. However, all ring segments 70 are now compressed along the arc circumferential direction 66, so that the deformation section 64 is already significantly plastically shortened along the arc circumferential direction 66.

[0150] The kinetic energy of the rotation of the saw blade 12 is converted into the plastic shortening of the deformation section 64 in order to slow down the saw blade 12.

[0151] Figure 8 shows the emergency brake unit 24 five milliseconds (5 ms) after activation. At this point, the saw blade 12 is essentially stationary, i.e., it is no longer rotating.

[0152] The deformation section 64 is now substantially completely compressed, ie the cavities 74 are substantially closed by pushing the deformation section 64 together along the arc circumferential direction 66.

[0153] Figure 8 shows the emergency brake unit 24 at the end of an emergency braking operation. The corresponding position of the blocking element 26 is also referred to as the end position.

[0154] In order to be able to put the emergency brake unit 24 and the sawing device 10 as a whole back into operation, ie in order to make a sawing device 10 whose emergency brake unit 24 has been triggered ready for use again, the blocking element 26 must now be replaced.

[0155] For this purpose, the blocking element 26 can optionally be removed from the frame 20 separately from the actuator unit 32. The blocking element 26 can thus be removed individually. This is explained in connection with Figure 10.

[0156] As already mentioned, the blocking element 26 is rotatably mounted on the frame 20 via the fixed bearing pin 30.

[0157] In order to prevent the blocking element 26 from being separated from the bearing pin 30 along an axial direction, a holding element 80 is provided for holding the blocking element 26 on the bearing pin 30.

[0158] In the illustrated embodiment, this holding element 80 is a side wall portion of the guide element 36, i.e., a portion of a wall of the guide element 36 that prevents axial displacement of the blocking element 26. Consequently, when the guide element 36 is in its operating position shown in dashed lines in Figure 10, the blocking element 26 is held on the bearing pin 30.

[0159] The guide element 36 is rotatably mounted on the frame 20 via a further bearing element 82, which is also designed as a bearing pin.

[0160] This allows the guide element 36 to be moved into a release position for disassembling the blocking element 26, which is shown in solid lines in Figure 10. In the release position, the retaining element 80 is removed from the bearing element, i.e., from the bearing pin 30.

[0161] To prevent the guide element 36 from undesirably assuming the release position, it can be locked in the operating position by means of a locking mechanism 84 (see Figure 10 and Figure 3).

[0162] The locking mechanism 84 includes a first through-opening 86 on the guide element 36 and a second through-opening 88 on the frame 20.

[0163] Furthermore, the locking mechanism 84 has a locking pin 90.

[0164] At a first end, the locking pin 90 is equipped with locking wings 92 and at a second end opposite the first end with an operating lever 93.

[0165] The locking pin 90 can thus be inserted into the through openings 86 and 88 and moved by means of the operating lever 93 into a rotational position in which the locking wings 92 engage behind a section of the frame 20.

[0166] In another rotational position, the engagement is released so that the locking pin can be pulled out axially from the through openings 86 and 88.

[0167] By means of the locking mechanism 84, the guide element 36 can be selectively locked to the frame 20 and selectively unlocked from the frame 20. This naturally also applies to the holding element 80 formed by the guide element 36. No tools are required to operate the locking pin 90 and thus to disassemble the blocking element 26.

[0168] For the singular disassembly of the blocking element 26, only the locking pin 90 is unlocked and removed from the frame 20. The guide element 36 is then moved into the release position, and the blocking element 26 is pulled off the bearing pin 30 along an axial direction, i.e., disassembled from the frame.

[0169] An unused blocking element 26 is then mounted.

[0170] For this purpose, the bearing section 38 of the unused blocking element 26 is placed on the fixed bearing pin 30.

[0171] Furthermore, the unused blocking element 26 is coupled to the actuator unit 32.

[0172] The guide element 36 is then moved back into the operating position and locked there by means of the locking pin 90.

[0173] Furthermore, the actuator unit 32 must be reset to its original position. This can be done using the control unit 34.

[0174] The sawing device 10 is now ready for operation again and the emergency brake unit 24 is ready for use again.

[0175] In the emergency brake unit 24 shown in Figures 1 to 10, the head section 42 is always selectively brought into engagement with the saw blade 12 by the actuator unit 32 and is also held in the normal position by the actuator unit 32 in such a way that the head section 42 does not inadvertently come into contact with the saw blade 12.

[0176] Figures 11 to 14 show alternatives for locking the blocking element 26 in the normal position. As usual, the force is applied via a pressure piece coupled to the solenoid of the actuator unit 32, which is designed to apply an actuating force to the head portion 42 in the direction of the saw blade 12. The pressure piece can be designed as a plunger. In this context, in the alternative according to Figure 11, the blocking element 26 is held in the normal position by means of a spring-loaded pin 94. For this purpose, the spring-loaded pin 94 engages in an associated recess 96 on a circumferential end face of the blocking element 26.

[0177] The actuator unit 32 corresponds to the actuator unit 32 of the embodiment from Figures 1 to 10. When triggered, it pushes the blocking element 26 in the direction of the saw blade 12. As a result, the pin 94 is pressed out of the recess 96 against the spring force.

[0178] In the alternative according to Figure 12, a magnet 98 and a counterpart 100 made of ferromagnetic material are provided. In the example shown, the magnet is attached to the guide element 36 and the counterpart 100 is attached to the head section 42 of the blocking element 26.

[0179] The pairing of magnet 98 and counterpart 100 is selected such that by means of the actuator unit 32 the head section 42 and thus the counterpart 100 can be detached from the magnet 98 against a magnetic force when the emergency brake unit 24 is actuated.

[0180] In the alternative according to Figure 13, a leaf spring element 102 is attached to the frame 20 via a first end. A second end of the leaf spring element 102 is received in a recess 104 arranged on the front side of the blocking element 26. This holds the blocking element 26 in the normal position.

[0181] The actuator unit 32 again corresponds to the actuator unit 32 of the embodiment from Figures 1 to 10. If this is triggered, it presses the blocking element 26 in the direction of the saw blade 12. This deforms the leaf spring element 102 so that its free end jumps out of the recess 104 and releases the blocking element.

[0182] In the alternative shown in Figure 14, two balls 106, 108 are provided, each engaging at different ends of one of the coupling openings 46. The balls 106, 108 are spring-loaded, so that they can be forced out of the coupling openings 46 upon actuation of the actuator unit 32, thus releasing the blocking element 26.

[0183] Figure 15 shows sections of an alternative sawing device 10.

[0184] In the following, only the differences from the previously explained sawing devices 10 will be discussed. Identical or corresponding elements are provided with the same reference numerals.

[0185] The differences concern the blocking element 26.

[0186] Unlike in the previous embodiments, the deformation section 64 now comprises hexagonal ring segments 70. This means that the walls 72 of the ring segments 70 each form hexagons and the through openings 74 defined by these walls 72 each have a hexagonal cross-section.

[0187] A further difference is that two radially adjacent rows of ring segments 70 are now provided. Each of these rows of ring segments 70 also has 16 ring segments 70. Thus, more ring segments 70 are provided in each row than, for example, in the blocking element 26 of Figure 4.

[0188] The plastically deformable structure 68 of the blocking element 26 from Figure 15 can also be referred to as a honeycomb structure.

[0189] For the sake of clarity, only some of the ring segments 70 as well as only some of the walls 72 and some of the cavities 74 are provided with a reference symbol.

[0190] The desired deformation points 78 are now formed by those sections of the walls 72 of each ring segment 70 which comprise the radially inwardly projecting corner of the hexagonal cross-section and the radially outwardly projecting corner of the hexagonal cross-section.

[0191] Each ring segment 70 thus comprises two desired deformation points 78, one radially inner and one radially outer. The through-openings in the head section 42, more precisely the through-openings 56 in the connection zone 54, now also have hexagonal cross-sections. Furthermore, they are arranged slightly differently than in the blocking element 26 shown in Figure 4.

[0192] Another alternative sawing device 10 is shown in sections in Figure 16.

[0193] Again, only the differences to the previous embodiments are explained.

[0194] The sawing device 10 from Figure 16 has a significantly smaller saw blade 12 than the previously explained sawing devices.

[0195] The blocking element 26 does not differ in its shape from the blocking element 26 in Figure 10. It has only been scaled proportionally.

[0196] This can be seen in particular by comparing the size of the blocking element 26 and the actuator unit 32, which is identical in the embodiments according to Figures 10 and 16.

[0197] Another alternative sawing device 10 is shown in sections in Figure 17.

[0198] Again, only the differences from the previous embodiments will be discussed. These again concern the blocking element 26.

[0199] In the embodiment according to Figure 17, the head portion 42 of the blocking element 26 is designed differently.

[0200] On the one hand, its front side is no longer pointed, but blunt.

[0201] On the other hand, compared to the previous head sections 42, this is longer along the arc circumferential direction 66.

[0202] This also entails an increased number as well as changes in the size and position of the through holes 56 in the connecting section 54.

[0203] Since the total length of the blocking element 26 along the arc circumferential direction 66 has remained the same, the deformation section 64 is now shorter. It now comprises only a total of seven ring segments 70. The wall thickness t of the associated walls 72 has been increased compared to the embodiment shown in Figure 4.

[0204] For the sake of clarity, only some of the ring segments 70, as well as some of the walls 72 and some of the cavities 74, are provided with a reference symbol. Figure 18 shows an additional embodiment of a sawing device 10.

[0205] The sawing device 10 is now designed as a table saw.

[0206] Furthermore, in particular with regard to the emergency braking unit 24, the above explanations apply analogously.

[0207] It should be noted that in all of the aforementioned embodiments, the actuator unit 32 can also be selectively and individually detachable from the frame 20. This allows for easy repair of the emergency brake unit 24 in the event that a defect occurs in the actuator unit 32.

[0208] The actuator unit 32 can also be disassembled without tools.

[0209] List of reference symbols

[0210] 10 sawing device

[0211] 12 saw blades

[0212] 14 Basic assembly

[0213] 16 Arm assembly

[0214] 18 support surface

[0215] 20 frames

[0216] 22 Drive shaft

[0217] 24 emergency braking unit

[0218] 26 Blocking element

[0219] 28 bearing element

[0220] 30 bearing bolts

[0221] 32 Actuator unit

[0222] 34 Control unit

[0223] 36 Guide element

[0224] 38 Storage section

[0225] 40 Warehouse opening

[0226] 41 wall

[0227] 42 head section

[0228] 44 coupling section

[0229] 46 coupling openings

[0230] 48 Form-locking element

[0231] 50 incision zone

[0232] 52 passage opening

[0233] 54 Connection zone

[0234] 56 passage opening

[0235] 58 guide surface

[0236] 60 Guide counter surface 64 Deformation section

[0237] 66 Arc circumferential direction

[0238] 68 plastically deformable structure

[0239] 70 ring segment

[0240] 72 Wall

[0241] 74 Cavity

[0242] 76 Filling material

[0243] 78 Target deformation point

[0244] 80 holding element

[0245] 82 bearing element

[0246] 84 Locking mechanism

[0247] 86 first passage opening

[0248] 88 second passage opening

[0249] 90 locking pin

[0250] 92 locking wings

[0251] 93 Control lever

[0252] 94 pen

[0253] 96 Deepening

[0254] 98 Magnet

[0255] 100 counterpart

[0256] 102 leaf spring element

[0257] 104 Deepening

[0258] 106 ball

[0259] 108 ball

[0260] A Center axis of the saw blade

[0261] D radial distance of the deformation section from the saw blade

[0262] M drive motor

[0263] U Circumferential direction of the saw blade F Guide direction

[0264] G Area for a housing part not shown t Wall thickness

Claims

Claims: Sawing device (10) with a frame (20), a circular disk-shaped saw blade (12) rotatably mounted with respect to the frame (20), and an emergency braking unit (24), wherein the emergency braking unit (24) comprises a locking element (26), an actuator unit (32), and a control unit (34) which is integrally formed with the actuator unit (32) or is coupled to the actuator unit (32) via signaling, wherein the locking element (26) comprises a bearing section (38) via which the locking element (26) is mounted on the frame (20), and a head section (42) which is configured to selectively engage the saw blade (12) for braking, wherein the actuator unit (32) is coupled to the locking element (26) at least in a normal position of the locking element (26) such that the locking element (26) can be controlled by means of the actuator unit (32). can optionally be brought into engagement with the saw blade (12),and wherein the locking element (26) can be selectively removed from the frame (20) separately from the actuator unit (32) and / or separately from the control unit (34). Sawing device (10) according to claim 1, comprising a guide element (36) for guiding the locking element (26) at least along a guide direction (F) which runs at least partially parallel to a circumferential direction (U) of the saw blade (12). Sawing device (10) according to claim 1 or 2, wherein the locking element (26) is connected to the frame (20) via a bearing element, the bearing element being singularly removable from the sawing device (10). Sawing device (10) according to claim 3, comprising a locking mechanism by means of which the bearing element can be selectively locked to the frame (20) and selectively unlocked from the frame (20). Sawing device (10) according to claim 2 and claim 3 or 4, wherein the guide element (36) is mounted on the frame (20) by means of the bearing element.

6. Sawing device (10) according to claim 1 or 2, wherein the locking element (26) is mounted on the frame (20) by means of a fixed bearing element (28) and a holding element (80) is provided for holding the locking element (26) on the bearing element (28).

7. Sawing device (10) according to claim 6, wherein the holding element (80) can optionally be removed singularly from the bearing element (28).

8. Sawing device (10) according to claim 2 and claim 6 or 7, wherein the holding element (80) is formed by a section of the guide element (36).

9. Sawing device (10) according to one of the preceding claims, wherein the blocking element (26) comprises a coupling section (44) via which the blocking element (26) is coupled to the actuator unit (32) at least in the normal position, wherein the coupling section (44) is positioned at an end of the blocking element (26) opposite the bearing section (38).

10. Sawing device (10) according to one of the preceding claims, wherein in an end position the blocking element (26) is decoupled from at least a section of the actuator unit (32).

11. Sawing device (10) according to one of the preceding claims, wherein the blocking element (26) comprises a deformation section (64) which lies between the bearing section (38) and the head section (42) and / or connects the bearing section (38) and the head section (42), wherein the deformation section (64) is arc-shaped and is designed to be plastically shortened along an arc circumferential direction (66) for braking the saw blade (12).

12. Method for making a triggered emergency braking unit (24) of a sawing device (10) ready for use, wherein the sawing device (10) comprises a circular disk-shaped saw blade (12) and the emergency braking unit (24) has a locking element (26) configured to selectively engage the saw blade (12) in order to brake the saw blade (12), wherein the method comprises the following steps: - Disassembling the locking element (26) separately from an actuator unit (32) of the emergency braking unit (24) and / or separately from a control unit (34) of the emergency braking unit (24), wherein the locking element (26) engages in or was engaged with the saw blade (12), - Assembling an unused locking element (26). Method according to claim 12, wherein, when assembling the unused locking element (26), the unused locking element (26) is coupled to an actuator unit (32) of the emergency braking unit (24). Method according to claim 12 or 13, wherein, for disassembling the locking element (26), a bearing element (28) by means of which the locking element is held in the sawing device is used. (10) is mounted, is disassembled, or a retaining element (80) is removed from a stationary bearing element (28) by means of which the blocking element (26) is mounted in the sawing device (10). Method according to claim 14, wherein the retaining element (80) is formed by a section of a guide element (36) and removing the retaining element (80) from the stationary bearing element (28) comprises moving the guide element (36) into a release position.

Images