Blocking element for emergency brake unit of sawing device, and sawing device

Abstract

The invention relates to a blocking element (26) for an emergency braking unit (24) of a sawing device (10) having a disc-shaped saw blade (12). The blocking element (26) comprises a bearing portion (38) via which the blocking element (26) can be supported on the sawing device (10), a head portion (42) designed to selectively engage into the saw blade (12) for braking the saw blade, and a deformation portion (64). The deformation portion (64) is located between the bearing portion (38) and the head portion (42) and / or connects the bearing portion (38) and the head portion (42) together. The deformation portion (64) is arcuate and is designed to be contoured and shortened in the arc circumferential direction (66) in order to brake the saw blade (12). Furthermore, the sawing device (10) is provided with a disc-shaped saw blade (12) and an emergency brake unit (24). The emergency braking unit (24) comprises such a blocking element (26), and the blocking element (26) is mounted on the sawing device (10) such that the blocking device can be selectively incorporated into the saw blade (12) in order to brake the saw blade (12).

Description

Technical Field

[0001] The invention relates to a blocking element for an emergency brake unit of a sawing device having a disc-shaped saw blade.

[0002] The invention further relates to a sawing device having a disc-shaped saw blade and an emergency brake unit, wherein the emergency brake unit comprises such a blocking element. Background Art

[0003] Sawing devices comprising an emergency brake unit are known from the prior art.

[0004] The emergency brake unit and in particular the blocking element it comprises serves to stop the rotation of the saw blade in the event of a sign of a risk of injury or a risk of injury. In this way, injuries to a user of the sawing device are avoided or at least their severity is reduced. In other words, safe operation of the sawing device is ensured.

[0005] In this respect, it is important to stop the rotation of the saw blade within a relatively short time. However, this means that the kinetic energy of the saw blade must be absorbed by the components of the emergency brake unit and / or the remaining components of the sawing device within this short time. Therefore, relatively large forces act on the components of the emergency brake unit and / or the remaining components of the sawing device.

[0006] This may lead to the fact that after use of the emergency brake unit, one or more parts thereof and one or more parts of the sawing device are deformed or damaged in another way, so that they have to be replaced before the sawing device can be returned to operation. Summary of the invention

[0007] It is therefore an object of the present invention to provide an emergency brake unit by means of which the rotation of a saw blade can be stopped in a relatively short time, wherein at the same time the functionality of as few components of the emergency brake unit and / or of the associated sawing device as possible is impaired.

[0008] The above-mentioned purpose is achieved by a blocking element of an emergency brake unit of a sawing device with a disc-shaped saw blade. The blocking element includes a bearing portion, and the blocking element can be supported on the sawing device via the bearing portion, in particular in a rotatable manner. In addition, the blocking element includes a head portion, which is designed to selectively engage in the saw blade for braking purposes. In addition, the blocking element includes a deformation portion located between the bearing portion and the head portion and / or connecting the bearing portion and the head portion to each other. The deformation portion is arched and is designed to be plastically shortened so as to brake the saw blade in the arc circumferential direction. Therefore, the rotational kinetic energy of the saw blade can be reliably and purposefully converted into the plastic shortening of the deformation portion. This is particularly achieved by the arc shape of the deformation portion and its position between the bearing portion and the head portion. Therefore, the rotation of the saw blade can be stopped in a relatively short time. Since the deformation portion is specifically designed to be plastically shortened in the arc circumferential direction, it can absorb a relatively large amount of kinetic energy relative to the installation space occupied by the deformation portion, and can convert it into plastic shortening. This also means that the forces generated by the braking of the saw blade are absorbed by the deformed part in a reliable and targeted manner. As a result, only relatively small forces act on the remaining components of the emergency brake unit. The same applies to the associated components of the sawing device. As a result, the remaining components of the emergency brake unit and the components of the sawing device are not affected in terms of their functional efficiency by the emergency braking procedure brought about by the blocking element. This applies in particular to the saw blade that can continue to be used when the sawing device is put back into operation.

[0009] With regard to the arcuate configuration of the deformation portion, it should be noted that even a partially arcuate deformation portion is considered to be arcuate. Thus, a deformation portion consisting of an arcuate segment and a straight segment is also an arcuate deformation portion.

[0010] The arc shape includes, for example, a circular arc shape or an elliptical arc shape. The portion of a circular line associated with a circular surface sector is called a circular arc. Similarly, the portion of an elliptical line associated with an elliptical surface sector is called an elliptical arc.

[0011] Preferably, the bearing portion and the head portion of the blocking element are arranged at two opposite ends of the blocking element.

[0012] The bearing part may have a receiver for a bearing element (e.g. a bearing pin). Preferably, the center axis of such a receiver extends parallel to the center axis of the arc circumferential direction assigned to the deformation part. Thus, the blocking element is rotatably mounted on the bearing pin via the bearing part.

[0013] Furthermore, an interface for coupling the blocking element to the actuator can be provided on the head portion. Thus, the blocking element (more precisely, the associated head portion) can be quickly and reliably engaged with the saw blade.

[0014] Furthermore, an interface for holding the blocking element in a normal position, which will be explained below, can be provided on the head portion. This holding ensures that the head portion does not engage with the saw blade in an undesirable manner.

[0015] The interface for coupling the blocking element to the actuator and the interface for holding the blocking element in the normal position may be formed in a combined or integrated manner.

[0016] In this respect, sawing devices with disc-shaped saw blades may also be referred to as circular sawing devices or simply circular saws. Examples of such sawing devices are miter saws, circular table saws, circular hand saws and plunge saws.

[0017] The blocking element of the emergency brake unit for sawing devices is also colloquially referred to as a brake wedge. This is independent of whether the blocking element is wedge-shaped or acts as a wedge.

[0018] In the state in which the blocking element is mounted in the sawing device, the arcuate deformation part can be arranged in particular concentrically with the disc-shaped saw blade. In this way, the blocking element can be quickly and reliably engaged in the saw blade. In addition, the rotational kinetic energy of the saw blade can thus be introduced simply and reliably into the blocking element, in particular into the deformation part. In addition, such an arrangement of the deformation part is space-saving.

[0019] Preferably, the blocking element is designed and / or manufactured in one piece. For example, the blocking element can be designed as a cast component or an injection molded component.

[0020] The barrier element designed as one piece can be easily recycled after use (ie, when the deformed portion is plastically shortened). For example, the used barrier element can be melted and processed to form a new barrier element.

[0021] The blocking element can be made of a synthetic material or a metallic material, for example an aluminum alloy.

[0022] In one embodiment, the deformed portion extends over a portion of the arc circumferential direction at a center point angle of 15 to 90 degrees. Therefore, depending on the application, a suitable circumference of the deformed portion can be set. In other words, a suitable braking distance length can be set for the saw blade. This ensures that the saw blade stops reliably within a specified time.

[0023] Exemplary deformed portions extend over a portion of the arc circumferential direction at a center point angle of about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, or about 60 degrees. In another example, the deformed portion extends over a portion of the arc circumferential direction at a center point angle of about 65 degrees, about 70 degrees, or about 75 degrees.

[0024] The head portion can be shorter than the deformation portion in the arc circumferential direction. Therefore, a relatively large installation space can be provided for the deformation portion. Therefore, the energy to be absorbed by the deformation portion can be absorbed in a relatively long time. This reduces the mechanical load on the remaining components of the sawing device.

[0025] In this regard, an exemplary head portion extends over a portion of the arc circumferential direction at a centerpoint angle of about 20 degrees, about 25 degrees, about 30 degrees, about 35 degrees, or about 40 degrees.

[0026] In one example, the head portion extends over a portion of the arc circumferential direction at a center point angle of about 30 degrees, and the deformed portion and the bearing portion together extend over a portion of the arc circumferential direction at a center point angle of about 60 degrees. Therefore, the deformed portion and the bearing portion together are twice as long as the head portion. In this example, the blocking element as a whole extends over a portion of the arc circumferential direction at a center point angle of about 90 degrees.

[0027] According to one variant, the head portion protrudes radially inwardly relative to the deformation portion in terms of the arc circumferential direction. When the blocking element is in the installed state, the distance between the deformation portion and the outer periphery of the saw blade is greater than the distance between the head portion and the outer periphery of the saw blade. Due to the relatively short distance, the head portion can be quickly and reliably engaged in the saw blade. In addition, the distance between the deformation portion and the outer periphery of the saw blade can be selected so that even if the deformation portion is in a plastic deformation state, it is still spaced apart from the saw blade. In this way, the plastic shortening of the deformation portion will not be hindered by any contact between the deformation portion and the outer periphery of the saw blade (in particular the teeth). The distance between the deformation portion and the outer periphery of the saw blade and / or the drive shaft of the saw blade can be designed to different sizes for different blocking elements provided for different sawing devices. Therefore, the blocking element can be suitable for different sawing devices with different saw blades.

[0028] In a specific area of ​​the head portion protruding radially inwards relative to the deformed portion, an engagement portion or sawing portion can be provided for the saw blade. This portion is particularly suitable for reliably coupling the saw blade to the head portion. To this end, the engagement portion or sawing portion can include a material that can be sawed particularly easily. This results in a smooth coupling between the saw blade and the head portion, i.e. a smooth transition from an uncoupled state of the saw blade and the head portion to a coupled state.

[0029] Furthermore, it can be provided that the head portion comprises regions of different rigidity and / or different ductility. This can be achieved by a corresponding arrangement of cavities and / or materials. The cavity can be designed as a hole or a bore. Alternatively, the different rigidities can be achieved by a corresponding shaping of the head portion. Thus, in both variants, the region of the head portion which is sawn first when the head portion is engaged in the saw blade can have a relatively low rigidity and / or ductility. The region which is sawn subsequently can have a greater rigidity and / or a greater ductility. Thus, the coupling of the saw blade to the head portion is produced in a smooth manner. At the same time, the coupling is relatively strong once it has been produced, so that large forces can be transmitted.

[0030] In one embodiment, the head portion comprises areas of different materials. As already explained, the different materials provide areas of different rigidity and / or different ductility within the head portion. In this respect, a relatively soft material, such as a synthetic material, can be used, for example, in the area of ​​the end of the head portion facing the saw blade and / or in the area located in the plane of the saw blade. Thus, a relatively small cutting force is required to saw into this area, resulting in a smooth sawing action. The additional area may comprise a metallic material.

[0031] In one example, the head portion has a guide surface for pushing the head portion in the direction of the saw blade. The guide surface has a normal with a radially outer extension component. The radial direction is defined relative to the arc circumferential direction. The push particularly includes applying a force. Thus, the head portion can be pushed by a force in the direction of the saw blade, thereby generating a reliable coupling between the saw blade and the head portion in order to brake the saw blade. The guide surface can be planar. Alternatively, the guide surface includes a portion of the side surface of the cylinder. Thus, the guide surface is curved. In both cases, the guide surface can be designed so that when the head portion is coupled to the saw blade, self-reinforcement occurs, i.e. the guide surface continues to push the head portion in the direction of the saw blade.

[0032] The head portion may have a greater rigidity in the arc circumferential direction than the deformed portion. Therefore, when the blocking element is used, the deformed portion is deformed in a targeted manner. Therefore, the rotational kinetic energy of the saw blade is absorbed by the deformed portion in a targeted manner. In contrast, the head portion is deformed to a lesser extent. In particular, the rigidity of the head portion and the deformed portion may be set so that the head portion is substantially not deformed. In one example, the rigidity of the head portion is twice the rigidity of the deformed portion.

[0033] It will be appreciated that the deformation portion is designed to absorb substantially all of the rotational kinetic energy of the saw blade. However, of course, a certain proportion of the kinetic energy is also absorbed by the sawing of the head portion and by the deformation of the head portion. However, the proportion of the kinetic energy absorbed by the head portion is relatively small or even negligible compared to the proportion absorbed by the deformation portion.

[0034] According to one variant, the deformable portion comprises a structure with a desired deformation point, which is plastically deformable in the arc circumferential direction. Thus, plastic shortening of the deformable portion is achieved by the fact that the deformable structure is plastically deformed. In particular, the deformation occurs in the region of the desired deformation point. This produces a well-defined deformation of the deformable portion. In other words, the deformable portion is prevented from being displaced into undesirable regions during its plastic shortening, for example, the deformable portion is prevented from expanding or buckling in an undesirable manner.

[0035] In particular, the plastically deformable structure comprises a structural element designed to fold, fold or collapse when a force is applied. Such a structural element can extend along the flow of force and / or obliquely and / or laterally relative to the flow of force. The plastically deformable structure can also include a plastically compressible material. An example of a plastically compressible material is a porous material, such as a foam material.

[0036] The deformation part can have a plurality of cavities. The cavities are arranged adjacent to each other in the arc circumferential direction. The cavities are to be understood as macroscopic cavities. Therefore, the cavities form a row in the arc circumferential direction. Of course, two or more rows of cavities can also be provided. In addition, the cavities are used to fold or collapse in the arc circumferential direction and thus convert the kinetic energy generated by the rotation of the saw blade into plastic deformation of the deformation part. By means of the number, arrangement, shape and size of the cavities, the deformation behavior of the deformation part can be set in a targeted manner.

[0037] In a design alternative, the cavity is continuous in a direction extending axially relative to the arc circumferential direction. Thus, the cavity is open on two axial sides and thus constitutes a through opening. Such a cavity can be made particularly easily. In addition, such a cavity can be folded or collapsed in a particularly effective manner to absorb energy.

[0038] On the one hand, the cavity can be produced subtractively. In this respect, the cavity is provided by means of material removal starting from an at least partially solid deformation part. The cavity can be produced by perforating, perforating, milling, drilling or other suitable production methods. On the other hand, the cavity can also be introduced into the deformation part even during the production of the deformation part. In the case of production of the deformation part by means of a casting or injection molding method, the cavity can also be provided by means of such a casting or injection molding method.

[0039] In this regard, a group of cavities may also be referred to as a cavity pattern or a pattern of cavities.

[0040] In one variant, at least one cavity is defined by a wall with a constant wall thickness. Such a cavity can collapse or fold in a particularly reliable manner. This depends on the direction of application of the force, the shape of the cavity and the wall thickness. In particular, the wall thickness can be used to set the force required to collapse or fold the cavity. Thus, the wall thickness can be varied in order to adapt the blocking element to different sawing devices. Furthermore, a constant wall thickness is particularly advantageous for producing the deformation part by means of a casting or injection molding method.

[0041] The fact that the cavity or cavities have a constant wall thickness does not in each case exclude the provision of cavities with different wall thicknesses within the deformation section. In particular, in this respect, the wall thickness can be varied in order to set the rigidity of the deformation section. A rigidity progression can also be provided within the deformation section.

[0042] The cavity can be formed by means of adjacently arranged annular segments. Such annular segments can be folded or collapsed in a defined manner in the arc circumferential direction, and thus kinetic energy can be converted into plastic deformation in a defined manner. The annular segments can be spaced apart from each other, directly adjacent to each other or nested in each other.

[0043] In one example, the deformation portion provided with a single row of cavities comprises 5 to 20 annular segments. The first preferred embodiment has seven annular segments. The second preferred embodiment comprises eleven annular segments.

[0044] In one exemplary embodiment, at least one cavity has a circular, crescent-shaped or polygonal cross section. In this respect, a crescent shape is understood to be a differential surface of two overlapping circular surfaces. The cross-sectional shape of the cavity defines the length ratio of the deformed portion in the undeformed state and in the plastically deformed state. Thus, by selecting the cross-sectional shape, the extent to which the deformed portion is plastically shortened when a force is applied accordingly can be set.

[0045] In this respect, the cavity of an annular segment with a cross section in the shape of a circle or a circle segment is defined by a wall which is at least partially in the shape of a cylindrical sleeve. In the case of a cavity with a polygonal cross section, the associated wall has the shape of a sleeve of a cylinder whose bottom surface is polygonal. In the case of such an annular segment, it is particularly advantageous if at least one corner of the cross section faces radially inwards or radially outwards relative to the arc circumferential direction. Such an annular segment can be folded with a certain precision in the arc circumferential direction.

[0046] In the case where the deformed portion comprises a row of ring segments and the deformed portion while in the plastically deformed state (i.e. in the final position of the blocking element) is intended to be at a distance greater than zero from the outer periphery of the saw blade, the radial extension of the deformed portion relative to the arc circumferential direction can be calculated as the sum of half the inner periphery of the cavity and twice the wall thickness of the associated ring segment. This is based on the concept that the ring segments are compressed in the circumferential direction so that the cavity is completely closed. In order to ensure the distance from the outer periphery of the saw blade, the radial extension of the deformed portion in its deformed state must be smaller than the radial distance between the outer periphery of the saw blade and the guide element.

[0047] A filling material may be arranged inside at least one of the cavities. The filling material may also be referred to as an inlay. Preferably, the filling material is different from the specific material from which the deformation portion is itself made. The filling material may be elastically deformable and / or plastically deformable. Thus, the filling material may be used to further set the rigidity of the deformation portion and thus its deformation behavior. The filling material may be arranged in a single cavity, in a group of cavities or in all cavities.

[0048] In addition, the deformation portion can have a rigidity gradient. Therefore, the rigidity of the deformation portion is not constant in the arc circumferential direction. This can be achieved by the fact that adjacent parts of the plastic deformation structure of the deformation portion (for example, adjacent annular segments) have different rigidities. In the first example, the deformation portion has a lower rigidity at the end facing the head portion than at the end facing the bearing portion. In the second example, it is the opposite, that is, the deformation portion has a higher rigidity at the end facing the head portion than at the end facing the bearing portion. In both cases, the rigidity gradient is used to smoothly and without any jerking of the movement introduced into the deformation portion by the kinetic energy and the associated forces generated by the rotation of the saw blade. Therefore, the saw blade is braked smoothly. At the same time, a strong braking effect can be guaranteed by means of a rigidity curve with a large gradient.

[0049] The above-mentioned object is also achieved by a sawing device having a disc-shaped saw blade and an emergency brake unit. The emergency brake unit includes a blocking element according to the present invention. The blocking element is mounted on the sawing device so that it can selectively engage in the saw blade in order to brake the saw blade. Therefore, the rotational kinetic energy of the saw blade can be selectively and reliably and purposefully converted into the plastic shortening of the deformed part. Therefore, the rotation of the saw blade can be stopped in a relatively short time. The force generated by the braking of the saw blade is absorbed in a reliable and targeted manner by the deformed part of the blocking element. Therefore, only relatively small forces act on the remaining components of the emergency brake unit. The same applies to the components of the associated sawing device. Therefore, the remaining components of the emergency brake unit and the components of the sawing device are not affected by the emergency brake procedure brought about by the blocking element in terms of their functional efficiency. This is particularly suitable for saw blades that can continue to be used when the sawing device returns to operation.

[0050] The emergency brake unit is coupled to a sensor unit for detecting actual or imminent contact by a user in the installed state and operates according to the detection result of the sensor unit. In this way, the emergency brake unit can be triggered in a timely and targeted manner, so that injuries to the user can be completely prevented or at least their severity can be limited.

[0051] Furthermore, the emergency brake unit comprises an actuator which can be selectively triggered, in particular depending on the detection result. The actuator is coupled to the blocking element, or more precisely to the associated head portion, so that it can quickly and reliably engage with the saw blade. The actuator comprises, for example, a lifting magnet or a shape memory alloy actuator.

[0052] In the normal position, the blocking element can be arranged parallel to the circumference of the saw blade. This means that the parts forming the blocking element are each at a constant radial distance from the saw blade along the outer periphery of the saw blade. In particular, the head portion and the bearing portion of the blocking element are substantially at the same radial distance from the central axis of the saw blade and the outer periphery of the saw blade along the outer periphery of the saw blade. In addition, in this respect, the central axis of the arcuate deformation portion and the rotation axis of the saw blade are preferably substantially coincident. The normal position is defined by the fact that the blocking element is in a position ready for operation, but has not yet engaged with the saw blade, that is, the emergency brake unit has not yet been triggered. Therefore, as a whole, the blocking element is positioned in a space-saving manner in the sawing device on the one hand, and is arranged on the other hand so that the head portion of the blocking element only has to overcome a relatively small distance in order to engage in the saw blade. As a result, the saw blade can be stopped relatively quickly.

[0053] In the normal position, the radial distance of the deformed portion from the saw blade may be greater than the radial distance of the head portion from the saw blade. As already explained, this prevents undesired interactions between the deformed portion and the saw blade.

[0054] In the final position of the blocking element, the deformed portion can be radially spaced apart from the saw blade. The final position of the blocking element is to be understood as the position which the blocking element occupies after it has engaged in the saw blade and has braked its rotation until the saw blade has stopped. The final position therefore relates to the position after emergency braking has been achieved. The deformed portion is therefore not in contact with the saw blade. In this way, the deformed portion can be plastically deformed without being influenced by the saw blade. Furthermore, no sawing is performed on or in the deformed portion. It therefore remains structurally intact, so that it can effectively convert kinetic energy into plastic deformation.

[0055] Furthermore, the blocking element can be selectively removed separately from the actuator unit of the emergency brake unit and / or separately from the control unit of the emergency brake unit of the sawing device. The expression "can be removed 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 having to remove the actuator unit and / or the control unit of the emergency brake unit at the same time. Of course, this does not include the mounting elements, bearing elements, retaining elements and fastening elements by means of which the blocking element is mounted. In other words, the blocking element can also be removed separately relative to the actuator unit and / or the control unit. Therefore, the blocking element can be replaced by itself or separately. When such replacement occurs, the actuator unit and / or the control unit of the emergency brake unit remain mounted on the sawing device. As a result, the blocking element can be removed quickly and simply. In principle, this applies to all operating states of the sawing device and the emergency brake unit, but in particular to the state after the emergency brake unit is triggered, i.e., when the blocking element engages in the saw blade or has engaged in the saw blade. Therefore, the emergency brake unit and the sawing device can be quickly and simply put back into operation after the triggering of the emergency brake unit. Thus, the machining task can be continued and completed quickly.The fact that the blocking elements can be replaced individually also ensures that the triggering of the emergency brake unit and the action of making the triggered emergency brake unit ready for operation result in relatively low costs.

[0056] 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 separately from all other components of the emergency brake unit. The explained effects and advantages are particularly evident.

[0057] In another 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 separately from all other components of the emergency brake unit. In addition, the actuator unit can be removed separately from all other components of the emergency brake unit. In addition, the control unit of the emergency brake unit can be removed separately from all other components of the emergency brake unit. Therefore, the individual components of the emergency brake unit can be replaced, repaired and / or maintained in a simple manner.

[0058] In a first alternative, the control unit of the emergency brake unit can be integrated with a motor control unit for controlling a drive motor configured to drive the saw blade. In a second alternative, the motor control unit and the control unit of the emergency brake unit are formed separately. However, they can be connected to each other via signal technology so that the drive motor can be simply and reliably deactivated when the emergency brake unit is triggered. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The invention will be explained below with the aid of various exemplary embodiments shown in the accompanying drawings. In the drawings:

[0060] Figure 1 shows a perspective view of a sawing device according to the invention, wherein the sawing device according to the invention comprises an emergency brake unit which is equipped with a blocking element according to the invention,

[0061] Figure 2 Shown in side view Figure 1 A sawing device in which the guide element of the emergency brake unit is omitted,

[0062] Figure 3 Shown in a separate view Figure 1 and Figure 2 Components of a sawing device,

[0063] Figure 4 shows a detailed view of the blocking element,

[0064] Figures 5 to 8 The diagram shows the emergency brake unit at different times after triggering. Figure 1 and Figure 2 Components of a sawing device,

[0065] Fig. 9 shows the force absorbed by the blocking element over time after triggering the emergency brake unit,

[0066] Fig.10 shows the process during installation of the blocking element Figure 1 and Figure 2 Components of a sawing device,

[0067] Figures 11 to 14 An alternative embodiment for holding the blocking element in the normal position is shown.

[0068] Fig.15 shows components of a sawing device according to an alternative embodiment,

[0069] Fig.16 shows components of a sawing device according to another alternative embodiment,

[0070] Fig.17 shows components of a sawing device according to yet another alternative embodiment, and

[0071] Fig.18 An additional embodiment of a sawing device according to the invention is shown. DETAILED DESCRIPTION

[0072] Figure 1 and Figure 2A sawing device 10 is shown having a disc-shaped saw blade 12. In the example shown, the sawing device 10 is a miter saw.

[0073] The sawing device 10 includes a base assembly 14 and an arm assembly 16 rotatably mounted thereon.

[0074] The base assembly 14 has a support surface 18 upon which a component to be processed (ie, to be sawn or cut) may be positioned.

[0075] Furthermore, the saw blade 12 may be rotated about the central axis A by actuating a drive motor M coupled to the saw blade 12 , and the saw blade 12 may be caused to interact with a component to be processed by displacing the arm assembly 16 relative to the base assembly 14 .

[0076] In the example shown, displacement of the arm assembly 16 relative to the base assembly 14 is accomplished manually.

[0077] The arm assembly 16 or more generally the sawing device 10 comprises a frame 20 on which a drive shaft 22 is mounted in a rotationally drivable manner. The drive shaft 22 is drivingly coupled to a drive motor M. The saw blade 12 is fixed to the drive shaft 22 so that the saw blade 12 can be rotationally driven in a known manner.

[0078] Furthermore, the sawing device 10 is equipped with an emergency brake unit 24, which can Figure 3 and Figure 4 See in detail.

[0079] In order to be able to see the emergency brake unit 24 more clearly, Figure 1 and Figure 2 In the embodiment shown, no housing component is shown in the area G. On the one hand, such a housing component serves to remove workpiece particles, such as sawdust or dust generated by the use of the sawing device 10. On the other hand, in the embodiment shown, a part of the handle provided at the end of the arm assembly 16 is formed by means of such a housing component. Furthermore, the housing component serves to cover the saw blade 12.

[0080] 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 and in the form of a fixed bearing pin 30 , such that it can selectively engage into the saw blade 12 in order to brake the saw blade 12 .

[0081] Furthermore, the emergency brake unit 24 includes an actuator unit 32 which is configured to selectively engage the blocking element 26 with the saw blade 12 .

[0082] In the example shown, the actuator unit 32 comprises for this purpose an electrically activatable lifting magnet which is not shown in greater detail in the drawing.

[0083] The emergency brake unit 24 also comprises an associated control unit 34 .

[0084] In the embodiment shown, 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 coupled by signal technology via a signal line.

[0085] This configuration ensures that the actuator unit 32 and the control unit 34 can be removed separately from each other. This makes replacement, repair or maintenance easier.

[0086] The control unit 34 is coupled to a sensor unit known per se in order to detect when a user actually touches the saw blade 12 or is about to touch the saw blade 12 .

[0087] Therefore, the actuator unit 32 can operate according to the detection result of the sensor unit.

[0088] Furthermore, the emergency brake unit 24 has a guide element 36 which is mounted on the frame 20 and which guides a movement of the blocking element 26 in a guide direction F, as will also be explained in detail below.

[0089] The blocking element 26 is located at Figure 3 and Figure 4 In this position, the blocking element is arranged parallel to the circumferential direction U of the saw blade 12.

[0090] The blocking element 26 consists of three parts 26 .

[0091] The blocking element 26 comprises a bearing portion 38 .

[0092] In the embodiment shown, the bearing portion 38 is sleeve-shaped, ie the bearing portion 38 comprises a cylindrical bearing opening 40 which is defined by a wall 41 having a substantially constant wall thickness.

[0093] The fixed bearing pin 30 is received in the bearing opening 40 and the blocking element 26 is therefore rotatably mounted on the frame 20 of the sawing device 10 via the bearing portion 38 and the bearing pin 30 .

[0094] Furthermore, the blocking element 26 comprises a head portion 42 .

[0095] The head portion 42 is provided at the end of the blocking element 26 opposite to the bearing portion 38 .

[0096] The head portion 42 is designed to engage into the saw blade 12 in case the emergency brake unit 24 is actuated (ie driven by the actuator unit 32) so as to desirably brake said saw blade until it stops.

[0097] In this regard, the head portion 42 includes a coupling portion 44 .

[0098] The coupling portion 44 is positioned at the end of the blocking element 26 opposite to the bearing portion 38 .

[0099] Furthermore, the coupling portion 44 is positioned on the radially outer side of the head portion 42 .

[0100] The coupling portion 44 has two different functions.

[0101] Firstly, the coupling section 44 is designed to introduce the actuating force generated by the actuator unit 32 into the blocking element 26 and thus the head section 42 can engage into the saw blade 12 .

[0102] Secondly, the coupling portion 44 is used at least in Figure 3 and Figure 4 The normal position shown secures or holds the blocking member 26 relative to the frame 20. Thus, the head portion 42 is prevented from engaging into the saw blade 12 in the normal position.

[0103] The force introduction function and the holding function can be realized separately from each other or together (ie, combined). Figures 1 to 10 This is the case in the embodiment shown.

[0104] In this case, the coupling portion 44 includes two coupling openings 46 .

[0105] In addition, a U-shaped form-fit element 48 is provided, which is fastened, for example, in a form-fitting manner to the actuator unit 32 on the one hand and which, on the other hand, has a projection which is complementary to the coupling opening 46 and engages in the coupling opening 46. The form-fit element 48 is thus coupled to the blocking element 26 and the actuator unit 32 in a form-fitting manner.

[0106] Thus, on the one hand, the actuation force generated by the actuator unit 32 can be introduced into the blocking element 26 via the form-fit element 48. On the other hand, the blocking element 26 is held in a normal position relative to the frame 20 via the form-fit element 48 and the actuator unit 32.

[0107] It is understood that, alternatively, the coupling opening 46 and the associated projection can also be omitted. Then, instead of the U-shaped form-fit element 48, a likewise U-shaped clamping element is used, which is fixedly clamped on the coupling part 44, i.e., connected to the blocking element 26 in a force-fitting manner in the region of the coupling part 44. The fastening of this clamping element to the actuator unit 32 can be achieved by a form-fitting or force-fitting manner.

[0108] Furthermore, the head portion 42 includes a cutting region 50 .

[0109] In the embodiment shown, the cutting zone 50 features a pattern of two rows of through openings 52. To improve clarity, only some of the through openings 52 have been provided with reference numerals in the Figures.

[0110] The material of the head part 42 is weakened by means of the through-opening 52 , in particular in the region of the cutting zone 50 , so that after triggering the emergency brake unit 24 the saw blade 12 penetrates smoothly into the head part 42 and cuts over the largest possible area of ​​the head part.

[0111] This results in a secure coupling between the saw blade 12 and the blocking element 26 , which is necessary to reliably brake the rotation of the saw blade 12 .

[0112] The connection region 54 is substantially disposed between the coupling portion 44 and the cutting region 50 .

[0113] In the embodiment shown, the connecting region 54 also comprises through openings 56. Again, for improved clarity, only some of the through openings 56 are provided with reference numerals in the figure. However, the diameter of the through openings 56 of the connecting region 54 is selected to be significantly larger than the diameter of the through openings 52 of the cutting region 50.

[0114] On the one hand, the connecting area 54 is used to transmit the actuation force from the coupling portion 44 to the cutting area 50. On the other hand, the cutting area 50 is coupled to a deformation portion via the connecting area 54, which will be explained below.

[0115] In this respect, the through-opening 56 of the connecting region 54 serves to ensure that the connecting region 54 has sufficient rigidity with the lowest possible mass and thus with the lowest possible mass inertia.

[0116] Furthermore, the head portion 42 is provided with a guide surface 58 .

[0117] The guide surface 58 bears against a counter-guide surface 60 of the guide element 36 .

[0118] Due to the geometry of the head portion 42 and the opposing guide surface 60, when the head portion is Figure 4 In the illustrated view, during a clockwise movement in the circumferential direction U of the saw blade 12, a force is exerted on the head section 42 in the direction of the saw blade 12. For this purpose, the guide surface 58 has a normal with a radially outer extension component.

[0119] It is apparent from the above explanation that in the case of the head portion 42 shown in the figures, through-openings are used to create areas of different rigidity and different cutting resistance to the saw blade 12. It will be appreciated that, as an alternative to through-openings, this can also be achieved by providing different materials in different areas of the head portion 42. In this regard, the use of materials of different ductility may be particularly important.

[0120] The blocking element 26 positioned between the head portion 42 and the bearing portion 38 includes a deformed portion 64 .

[0121] The deformation portion 64 connects the bearing portion 38 and the head portion 42 to each other.

[0122] Overall, the deformed portion 64 is arcuate, and in the exemplary embodiment shown, the deformed portion 64 is arcuate.

[0123] In this case, the arc circumferential direction 66 , ie the curved longitudinal extension direction of the arc-shaped deformation portion 64 , extends substantially parallel to the circumferential direction U of the saw blade 12 .

[0124] In the embodiment shown, the saw blade 12 and the outer circumference of the arcuate deformation 64 also extend concentrically, with the central axis A forming the center.

[0125] exist Figure 4 In the illustrated embodiment, the deformed portion 64 extends over a portion of the arc circumferential direction 66 at a centerpoint angle of approximately 60 degrees.

[0126] Thus, the circumferential extension of the deformation portion 64 is substantially twice the circumferential extension of the head portion 42. Thus, the head portion 42 is circumferentially shorter than the deformation portion 64.

[0127] The deformation section 64 also has a multiple of the circumferential extension of the bearing section 38 .

[0128] Furthermore, in the radial direction relative to the central axis A of the saw blade 12 , the deformed portion 64 is further away from the outer periphery of the saw blade 12 than the head portion 42 and the bearing portion 38 .

[0129] In other words, with respect to the arc circumferential direction 66 , the head portion 42 and the bearing portion 38 protrude radially inward relative to the deformation portion 64 .

[0130] In this respect, 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 also applies in particular to the end position of the blocking element 26 which will be explained later.

[0131] In other words, the distance D of the deformed portion 64 is selected so that it does not contact the periphery of the saw blade 12 under any operating conditions.

[0132] The deformation portion 64 further includes a structure 68 that is plastically deformable in an arc circumferential direction 66 .

[0133] exist Figure 4 In the embodiment shown, the structure 68 is formed by a total of eleven ring segments 70 .

[0134] The ring segments 70 are arranged adjacent to each other in the arc circumferential direction 66 and slightly overlap each other.

[0135] Each annular segment 70 has a wall 72 with a substantially constant wall thickness t.

[0136] The walls 72 define in each case an axially continuous cavity 74 .

[0137] To improve clarity, only some of the ring segments 70 are provided with reference numerals and only some of the walls 72 and some of the cavities 74 are provided with reference numerals in the figures.

[0138] Therefore, the structure 68 that can be plastically deformed in the arc circumferential direction 66 includes a total of eleven cavities 74 , and the cavities 74 are arranged in an adjacent manner in the arc circumferential direction 66 .

[0139] The slight overlap of the ring segments 70 creates a crescent-shaped cross-section for each cavity 74 .

[0140] Furthermore, a filling material 76 is arranged in each case inside three cavities 74 arranged adjacent to the bearing section 38 .

[0141] In the illustrated embodiment, the filling material is a rubber material.

[0142] For the remainder, the blocking element 26 is made of an aluminum alloy.

[0143] The filling material 76 causes the deformed portion 64 to have a different stiffness in the area of ​​the cavity 74 having the filling material 76 than in the area of ​​the unfilled cavity 74. The deformed portion 64 thus includes two areas of different stiffness or more generally a stiffness gradient.

[0144] It should be understood that the rigidity can be set in a targeted manner by correspondingly selecting the filling material 76 and the number and position of the cavities 74 filled with the filling material 76 .

[0145] The overall effect of the structure 68 is that the rigidity of the deformation portion 64 in the arc circumferential direction 66 is less than the rigidity of the head portion 42 .

[0146] In addition, the structure 68 has a desired inflection point 78. Figure 4In the embodiment shown, they are located in each case in the portion of the ring segment 70 which projects radially inwards to the furthest extent and in the portion of the ring segment 70 which projects radially outwards to the furthest extent.

[0147] Again, to improve clarity, only some of the desired inflection points 78 are provided with reference numerals in the figure.

[0148] The deformed portion 64 is therefore designed to be plastically shortened in order to brake the saw blade 12 in the arc circumferential direction 66. This will be referred to below. Figures 5 to 8 To explain.

[0149] in this regard, Figure 5 The emergency brake unit 24 is shown, in particular the blocking element 26 is shown in the normal position already described. This means that the actuator unit 32 has not yet been actuated in order to achieve emergency braking.

[0150] Therefore, no force is yet acting on the blocking element 26 (see Fig. 9 ).

[0151] As already explained, the blocking element 26 is held in the normal position via the form-fit element 48 and the actuator unit 32 .

[0152] Figure 5 The position in corresponds to Fig. 9 The situation at 0 milliseconds in the curve graph.

[0153] It is now assumed that at time zero milliseconds (0 ms) the emergency brake unit 24 is triggered. As a result, the actuator unit 32 is actuated and the head section 42 is pushed in the direction of the saw blade 12. In the exemplary embodiment shown, this is achieved via a form-fitting element 48.

[0154] It will be appreciated that at the same time the drive motor M is deactivated and / or disconnected from the drive shaft 22 .

[0155] Figure 6 shows what happens one millisecond (1ms) after the trigger. Fig. 9 The force curve at 1ms can be assigned to Figure 6 The situation in.

[0156] In this case, the saw blade 12 has already cut into the cutting zone 50, so that a force-based coupling is produced between the saw blade 12 and the blocking element 26. Due to the clockwise rotation of the saw blade 12, Figure 6 The time shown is Figure 5 Compared to the initial situation, the head portion 42 has been dragged a certain circumferential distance in the circumferential direction U of the saw blade 12 .

[0157] This results in the connection between the form-fit element 48 and the actuator unit 32 being released.

[0158] In the present case, the coupling between the form-fit element 48 and the head part 42 remains.

[0159] It is understood that, alternatively, the connection between the form-fit element 48 and the head portion 42 can also be disconnected, while the connection between the form-fit element 48 and the actuator unit 32 is maintained.

[0160] In this respect, the guide element 36 ensures that the blocking element 26 cannot prevent itself from being dragged in the radial direction or in the axial direction by the saw blade 12. The blocking element 26 is thus guided in the guide direction F by means of the guide element 36.

[0161] Furthermore, the dragging of the saw blade 12 has deformed at least three ring segments 70 disposed adjacent the head portion 42 .

[0162] More precisely, the annular segments have been compressed in the arc circumferential direction 66 .

[0163] Figure 7 The emergency brake unit 24 is shown after another millisecond has passed, ie 2 milliseconds have passed after being triggered.

[0164] The head portion 42 continues to be coupled to the saw blade 12 .

[0165] However, now all the ring segments 70 are compressed in the arc circumferential direction 66 , so that the deformed portion 64 has been plastically shortened significantly in the arc circumferential direction 66 .

[0166] The rotational kinetic energy of the saw blade 12 is converted into plastic shortening of the deformed portion 64 so as to brake the saw blade 12 .

[0167] Figure 8 The emergency brake unit 24 is shown five milliseconds (5 ms) after being triggered. At this point, the saw blade 12 is substantially stationary, ie, it is no longer rotating.

[0168] The deformed portions 64 are now substantially fully compressed, ie, the cavity 74 is substantially closed by pushing the deformed portions 64 together in the arcuate circumferential direction 66 .

[0169] therefore, Figure 8 The emergency brake unit 24 is shown at the end of the emergency brake procedure. The associated position of the blocking element 26 is also referred to as the end position.

[0170] 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 the sawing device 10 in which the emergency brake unit 24 has been triggered ready for operation again, the blocking element 26 now has to be replaced.

[0171] To this end, the blocking element 26 can be selectively removed from the frame 20 separately from the actuator unit 32. Thus, the blocking element 26 can be removed separately. This will be combined with Fig.10 To explain.

[0172] As already explained, the blocking element 26 is rotatably mounted on the frame 20 via a fixed bearing pin 30 .

[0173] In order to prevent the blocking element 26 from being separated from the bearing pin 30 in the axial direction of the bearing pin, a retaining element 80 is provided for retaining the blocking element 26 on the bearing pin 30 .

[0174] In the embodiment shown, the retaining element 80 is a side wall portion of the guide element 36 , ie a portion of the wall of the guide element 36 which prevents an axial displacement of the blocking element 26 .

[0175] Therefore, if the guide element 36 is in its Fig.10 In the operating position shown in dashed lines in FIG. 2 , the blocking element 26 is held on the bearing pin 30 .

[0176] The guide element 36 is rotatably mounted on the frame 20 via a further bearing element 82 which is likewise designed as a bearing pin.

[0177] This allows the guide element 36 to be transferred to a release position to remove the blocking element 26, which is Fig.10 In the release position, the retaining element 80 is removed from the bearing element, ie from the bearing pin 30 .

[0178] In order to prevent the guide element 36 from assuming the release position in an undesired manner, it can be locked in the operating position by means of a locking mechanism 84 (except for Fig.10 In addition, see Figure 3 ).

[0179] The locking mechanism 84 includes a first through-opening 86 in the guide element 36 and a second through-opening 88 in the frame 20 .

[0180] Furthermore, the locking mechanism 84 has a locking pin 90 .

[0181] At a first end, the locking pin 90 is provided with a locking wing 92 , and at a second end opposite to the first end, the locking pin 90 is provided with an operating lever 93 .

[0182] The locking pin 90 can thus be inserted into the through-openings 86 and 88 and can be transferred by means of the actuating lever 93 into a rotational position in which the locking wing 92 engages behind a part of the frame 20 .

[0183] In another rotational position, the rear engagement is released and thus the locking pin can be pulled axially out through the openings 86 and 88 .

[0184] Thus, by means of the locking mechanism 84, the guide element 36 can be selectively locked on the frame 20 and selectively unlocked from the frame 20. Of course, this also applies to the retaining element 80 formed by the guide element 36.

[0185] Therefore, no tools are required to operate the locking pin 90 and thus no tools are required to remove the blocking element 26 .

[0186] Therefore, to remove the blocking element 26 alone, only the locking pin 90 is unlocked and removed from the frame 20. The guide element 36 is then transferred to the release position and the blocking element 26 is removed from the bearing pin 30 in its axial direction, ie removed from the frame.

[0187] Then, the unused blocking element 26 is installed.

[0188] For this purpose, the bearing section 38 of the unused blocking element 26 is placed onto the fixed bearing pin 30 .

[0189] Furthermore, unused blocking elements 26 are coupled to the actuator unit 32 .

[0190] The guide element 36 is then moved back into the operating position and locked in this position by means of the locking pin 90 .

[0191] Furthermore, the actuator unit 32 must be returned to its starting position. This can be achieved with the aid of the control unit 34.

[0192] The sawing device 10 is now ready for operation again and the emergency brake unit 24 is ready for operation again.

[0193] exist Figures 1 to 10 In the case of the illustrated emergency brake unit 24 , the head portion 42 is always selectively engaged with the saw blade 12 by the actuator unit 32 and is also held in a normal position by the actuator unit 32 so that the head portion 32 does not inadvertently come into contact with the saw blade 12 .

[0194] Figures 11 to 14 An alternative for holding the blocking element 26 in the normal position is shown. Typically, the force is applied via a pressure piece coupled to a lifting magnet of the actuator unit 32, which is formed to apply an actuating force to the head portion 42 in the direction of the saw blade 12. The pressure piece can be formed as a push rod.

[0195] In this regard, according to Fig.11In an alternative embodiment, 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 the circumferential end side of the blocking element 26.

[0196] The actuator unit 32 corresponds to Figures 1 to 10 The actuator unit 32 of the embodiment of the present invention is provided. If the actuator unit is triggered, it pushes the blocking element 26 in the direction of the saw blade 12. As a result, the pin 94 is pushed out of the recess 96 against the spring force.

[0197] exist Fig.12 In an alternative, a magnet 98 and a counter-piece 100 consisting of a ferromagnetic material are provided. In the example shown, the magnet is fastened to the guide element 36 and the counter-piece is fastened to the head portion 42 of the blocking element 26.

[0198] The pairing of magnet 98 and counter-piece 100 is selected such that when the emergency brake unit 24 is actuated, by means of the actuator unit 32 , the head portion 42 and thus the counter-piece 100 can be separated from the magnet 98 against the magnetic force.

[0199] exist Fig.13 In an alternative, the leaf spring element 102 is fastened to the frame 20 via a first end. The second end of the leaf spring element 102 is received in a recess 104 arranged on the end side on the blocking element 26. The blocking element 26 is thereby held in the normal position.

[0200] The actuator unit 32 again corresponds to the Figures 1 to 10 The actuator unit 32 of the embodiment of the present invention is provided. If the actuator unit is triggered, it pushes the blocking element 26 in the direction of the saw blade 12. The leaf spring element 102 is deformed thereby, so that its free end pops out of the recess 104 and releases the blocking element.

[0201] exist Fig.14 In an alternative, two balls 106 , 108 are provided, each ball engaging at a different end of one coupling opening 46 .

[0202] The balls 106 , 108 are spring-loaded so that they can be pushed out of the coupling opening 46 when the actuator unit 32 is actuated and can thus release the blocking element 26 .

[0203] Fig.15 Part of an alternative sawing device 10 is shown.

[0204] Only the differences with respect to the already explained sawing device 10 will be discussed below. Identical or mutually corresponding elements are denoted by the same reference numerals.

[0205] The difference relates to the blocking element 26 .

[0206] In contrast to the previous embodiment, the deformation 64 now comprises a hexagonal ring segment 70. This means that the walls 72 of the ring segment 70 each form a hexagon and the through openings 74 defined by these walls 72 each form a hexagonal cross section.

[0207] Another difference is that now two radially adjacent rows of ring segments 70 are provided. In addition, each of these rows of ring segments 70 has 16 ring segments 70. Thus, there are more ring segments 70 in each row than, for example, Figure 4 The annular segment in the blocking element 26.

[0208] Fig.15 The plastically deformable structure 68 of the blocking element 26 may also be referred to as a honeycomb structure.

[0209] To increase clarity, only some of the ring segments 70 are provided with reference numerals and only some of the walls 72 and some of the cavities 74 are provided with reference numerals.

[0210] The desired deformation points 78 are now formed by those parts of the wall 72 of each ring segment 70 which comprise the corners of the hexagonal cross section which protrude radially inwards to the furthest extent and the corners of the hexagonal cross section which protrude radially outwards to the furthest extent.

[0211] Therefore, each annular segment 70 includes two desired deformation points 78 , namely a radially inner deformation point and a radially outer deformation point.

[0212] The through openings 56 of the head portion 42 or more precisely of the connecting region 54 now also have a hexagonal cross section. In addition, they are arranged in a manner similar to Figure 4 The blocking element 26 is slightly different.

[0213] Fig.16 Portions of yet another alternative sawing device 10 are shown.

[0214] Again, only the differences with respect to the preceding embodiment are explained.

[0215] Fig.16 The sawing device 10 in the embodiment has a much smaller saw blade 12 than the sawing devices described above.

[0216] The blocking element 26 does not differ in shape from Fig.10 The blocking element 26 is shown only to scale.

[0217] This can be seen in particular by comparing Fig.10 and Fig.16 The illustrated embodiment is shown by the identical dimensions of the blocking element 26 and the actuator unit 32 .

[0218] Fig.17 Part of another alternative sawing device 10 is shown.

[0219] Again, only the differences with respect to the previous embodiment are discussed. The differences again relate to the blocking element 26 .

[0220] exist Fig.17 In the embodiment shown, the head section 42 of the blocking element 26 is designed differently.

[0221] On the one hand, its end sides are no longer pointed but blunt.

[0222] On the other hand, this head portion is longer in the arc circumferential direction 66 than the previous head portion 42 .

[0223] This also leads to an increase in the number of through-holes 56 in the connecting portion 54 and a change in the size and position of the through-holes 56 .

[0224] Since the total length of the blocking element 26 in the arc circumferential direction 66 remains the same, the deformed portion 64 is now shorter. It now comprises only seven annular segments 70 in total. Figure 4 Compared to the embodiment shown, the wall thickness t of the associated wall 72 is increased.

[0225] To increase clarity, only some of the ring segments 70 are provided with reference numerals and only some of the walls 72 and some of the cavities 74 are provided with reference numerals.

[0226] Fig.18 Additional embodiments of the sawing device 10 are shown.

[0227] The sawing device 10 is now designed as a circular table saw.

[0228] For the remainder, the above explanations apply analogously, in particular with regard to the emergency brake unit 24 .

[0229] It is worth noting that in all the aforementioned embodiments, the actuator unit 32 can also be selectively removed individually from the frame 20. This makes it easy to repair the emergency brake unit 24 in the event of a defect in the actuator unit 32.

[0230] The actuator unit 32 can also be removed in a tool-free manner.

[0231] Reference numerals list

[0232] 10 Sawing device

[0233] 12 Saw Blade

[0234] 14 Base assembly

[0235] 16 Arm assembly

[0236] 18 Support surface

[0237] 20 Framework

[0238] 22 Drive shaft

[0239] 24 Emergency brake unit

[0240] 26 Blocking element

[0241] 28 Bearing elements

[0242] 30 Bearing pin

[0243] 32 Actuator unit

[0244] 34 Control Unit

[0245] 36 Guide element

[0246] 38 bearing part

[0247] 40 Bearing opening

[0248] 41 wall

[0249] 42 Head

[0250] 44 Coupling section

[0251] 46 Coupling opening

[0252] 48 Form-fitting elements

[0253] 50 Cutting Area

[0254] 52 Through opening

[0255] 54 Connection Zone

[0256] 56 Through opening

[0257] 58 Guide Surface

[0258] 60 Relative guide surface

[0259] 64 Deformed part

[0260] 66 Arc circumferential direction

[0261] 68 Plastic deformation structure

[0262] 70 Ring segment

[0263] 72 wall

[0264] 74 Cavity

[0265] 76 Filling material

[0266] 78 Expected deformation point

[0267] 80 Holding element

[0268] 82 Bearing elements

[0269] 84 Locking mechanism

[0270] 86 First penetration opening

[0271] 88 Second through opening

[0272] 90 Locking pin

[0273] 92 Locking Wing

[0274] 93 Joystick

[0275] 94 Pins

[0276] 96 Depression

[0277] 98 Magnet

[0278] 100 relative pieces

[0279] 102 Leaf spring element

[0280] 104 Depression

[0281] 106 Ball

[0282] 108 Ball

[0283] A The center axis of the saw blade

[0284] D Radial distance between the deformed part and the saw blade

[0285] M Drive motor

[0286] U Circumferential direction of saw blade

[0287] F Guidance direction

[0288] G Area of ​​the housing component not shown

[0289] Wall thickness

Claims

1. A blocking element (26) for an emergency brake unit (24) of a sawing device (10) having a disc-shaped saw blade (12), wherein the blocking element (26) include: a bearing portion (38), via which the blocking element (26) can be mounted on the sawing device (10), a head portion (42) designed to selectively engage the saw blade (12) for braking purposes, and a deformation portion (64) located between the bearing portion (38) and the head portion (42) and / or connecting the bearing portion (38) and the head portion (42) to each other; The deformed portion (64) is arcuate and is designed to be plastically shortened so as to brake the saw blade (12) in an arc circumferential direction (66).

2. The blocking element (26) according to any one of the preceding claims, wherein the head portion (42) is shorter than the deformation portion (64) in the arc circumferential direction (66).

3. The blocking element (26) according to any one of the preceding claims, in, With respect to the arc circumferential direction (66), the head portion (42) protrudes radially inward relative to the deformation portion (64).

4. The blocking element (26) according to any one of the preceding claims, in, The head portion (42) has greater rigidity in the arc circumferential direction (66) than the deformation portion (64).

5. The blocking element (26) according to any one of the preceding claims, in, The deformation portion (64) includes a structure (68) having a desired deformation point (78), and the structure (68) is plastically deformable in the arc circumferential direction (66).

6. The blocking element (26) according to any one of the preceding claims, in, The deformation portion (64) has a plurality of cavities (74) arranged adjacent to each other in the arc circumferential direction (66).

7. The blocking element (26) according to claim 6, wherein the cavity (74) is continuous in a direction extending axially relative to the arc circumferential direction (66).

8. The barrier element (26) according to claim 6 or 7, wherein at least one cavity (74) is defined by a wall (72) having a constant wall thickness (t).

9. The blocking element (26) according to any one of claims 6 to 8, in, The cavity (74) is formed by adjacently arranged annular segments (70).

10. The blocking element (26) according to any one of the preceding claims, in, The deformed portion (64) has a stiffness gradient.

11. A sawing device (10) having a disc-shaped saw blade (12) and an emergency brake unit (24), wherein the emergency brake unit (24) comprises a blocking element (26) according to any of the preceding claims, the blocking element (26) being mounted on the sawing device (10) such that it can selectively engage in the saw blade (12) in order to brake the saw blade (12).

12. The sawing device (10) according to claim 11, in, The blocking element (26) is arranged parallel to the circumference of the saw blade (12) in a normal position.

13. The sawing device (10) according to claim 12, in, In the normal position, the radial distance (D) between the deformed portion (64) and the saw blade (12) is greater than the radial distance between the head portion (42) and the saw blade (12).

14. The sawing device (10) according to any one of claims 11 to 13, in, In the final position of the blocking element (26), the deformed portion (64) is radially spaced apart from the saw blade (12).

15. The sawing device (10) according to any one of claims 11 to 14, in, The blocking element (26) can be selectively removed from the sawing device (10) separately from the actuator unit (32).

Images