Sawing device with hand position detection

Abstract

Sawing device (10), comprising: a sawing machine (20) comprising a workbench (22), a saw blade housing (26) pivotally connected to the workbench (22), a motor (27) mounted on the saw blade housing (26), a saw blade (28) connected to the motor (27) to be rotated by the motor (27) and partially received in the saw blade housing (26) to be driven by the saw blade housing (28) to move closer to or away from the workbench (22), and a protective cover (29) pivotally connected to the saw blade housing (26) and covering part of the saw blade (28); a safety module (40) having a positioning mark (41) and a visual element (43) arranged on the same side of the saw blade (28) as the positioning mark (41), wherein the visual element (43) detects the positioning mark (41) to determine a relative position between the positioning mark (41) and a center point (C) of the saw blade (28) in order to define a saw blade warning area (W1) around the saw blade (28) based on the relative position, wherein the visual element (43) detects a position of a hand (50) to define a hand warning area (W2) around the hand (50) when the hand (50) approaches the sawing machine (20); and a control unit (45) electrically connected to the motor (27) and the visual element (43); wherein, when the visual element (43) detects that the saw blade warning area (W1) and the hand warning area (W2) partially overlap, the visual element (43) sends a brake signal to the control unit (45), whereby the control unit (45) stops the motor (27).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates to sawing devices and, in particular, to a sawing device with which a position of a hand can be detected. 2. Description of the state of the art

[0002] Due to the high risk of injury to users during the operation of cutting tools, industry professionals have continuously improved safety mechanisms to increase user protection. For example, the machine tool monitoring device disclosed in US 8,386,067 uses at least one projection unit to define at least one area to be monitored in order to alert users that approaching the monitored area could be dangerous. Furthermore, the safety system disclosed in US 11,187,378 uses a sensor assembly to monitor a specific hazard area near a moving component of a power tool and generate data related to the hazard area. The data generated by the sensor assembly is received and analyzed by a control unit to determine whether the user's hand is within the specific hazard area.If it is confirmed that the user's hand is in the danger zone, the control unit sends a signal to the braking system to stop the operation of the moving component of the power tool. SUMMARY OF THE INVENTION

[0003] An object of the present invention is to provide a sawing device or a sawing apparatus with which operational safety can be improved.

[0004] To achieve the above object, the sawing device of the present invention comprises a sawing machine, a safety module, and a control unit. The sawing machine includes a worktable, a saw blade housing pivotably connected to the worktable, a motor mounted on the saw blade housing, a saw blade connected to the motor, rotated by the motor and partially housed in the saw blade housing to be driven by the saw blade housing to move closer to or away from the worktable, and a protective cover pivotably connected to the saw blade housing and covering a part of the saw blade. The safety module includes a positioning mark and a visual / optical element arranged on the same side of the saw blade as the positioning mark.The visual / optical element detects the positioning mark to determine a relative position between the positioning mark and a center of the sawblade, and defines a sawblade warning zone around the sawblade based on the relative position. When a hand approaches the sawing machine, the visual / optical element detects a hand position to define a hand warning zone around the hand. The control unit is electrically connected to the motor and the visual / optical element to receive a signal generated by the visual / optical element and stop the motor based on the signal.

[0005] From the above, it can be seen that if the visual / optical element detects that the saw blade warning area and the hand warning area do not overlap, there is no risk of hand injury from the saw blade. In this case, the control unit maintains the motor's operation so that the saw blade can continue cutting. If the visual / optical element detects that the saw blade warning area and the hand warning area partially overlap, this indicates that there is a risk of hand injury from the saw blade. In this case, the visual / optical element sends a brake signal to the control unit, causing the control unit to stop the motor. This can prevent hand injury from the saw blade and increase operational safety for the user.

[0006] The positioning mark is preferably attached to the workbench, the saw blade housing, or the protective cover. This ensures that the visual / optical element can accurately detect the positioning mark.

[0007] The visual / optical element preferably defines the warning area for the saw blade as follows: an area extending 2 cm to 5 cm radially outward from the teeth of the saw blade, an area extending 2 cm to 5 cm axially outward from both opposite sides of the saw blade, and an area 5 cm to 10 cm in front of the saw blade.

[0008] The visual / optical element can preferably determine a hand movement speed so that the controller can apply different braking modes to the motor accordingly. If the visual / optical element detects that the hand movement speed is close to 100 cm / s, the controller stops the motor when the hand is approximately 10 cm from the sawblade. If the visual / optical element detects that the hand movement speed is below 100 cm / s, the controller stops the motor when the hand is approximately 2 cm to 5 cm from the sawblade.

[0009] Preferably, the visual / optical element can be mounted together with the sawing machine or installed separately as a standalone unit. In the first case, since its installation position is fixed, the visual / optical element can directly and unambiguously capture a complete image of the positioning mark. In the second case, the visual / optical element may not be able to capture a complete image of the positioning mark due to an angular deviation between the visual element and the positioning mark. At this point, the visual / optical element first captures the lengths of the sides of the positioning mark and calculates the position of the positioning mark based on these side lengths. In this way, the visual / optical element can determine the relative position between the center of the positioning saw blade and the positioning mark.

[0010] Further advantages and features of the present invention will become fully understood from the following description taken in conjunction with the accompanying drawings in which like reference numerals designate like components. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a sawing apparatus of the present invention. Fig. 2 is similar to Fig. 1 and shows that the positioning mark is attached to the saw blade housing. Fig. 3 is similar to Fig. 1 and shows that the positioning mark is attached to the workbench. Fig. 4 is a front view of the sawing device of the present invention. Fig. 5 is a block diagram, another perspective view of the sawing apparatus of the present invention. Fig. Figure 6 is a schematic drawing of the sawing apparatus of the present invention showing that the visual / optical element defines the saw blade warning area around the saw blade and defines the hand warning area around the hand. Fig. 7 is a side view of Fig. 6. Fig. 8 is a plan view of Fig. 6. Fig. 9 is similar to Fig. 7 and shows that the saw blade warning area and the hand warning area partially overlap. Fig. 10 is similar to Fig. 8 and shows that the saw blade warning area and the hand warning area partially overlap. DETAILED DESCRIPTION OF THE INVENTION

[0011] With reference to the Fig. 1 and Fig. 2, a sawing device 10 of the present invention includes a sawing machine 20, a safety module 40, and a controller 45. The sawing machine 20 may be a miter saw, a band saw, or a table saw. A miter saw is used here as an example, but is not limited to this type. In this embodiment, the sawing machine 20 includes a base 21, a workbench 22, a guide pin seat 23, two guide pins 24, an angle seat 25, a saw blade housing 26, a motor 27, a saw blade 28, a protective cover 29, a handle 30, and a handle 31. The worktable 22 is rotatably mounted on the base 21 and includes a work surface 32 for placing a workpiece (not shown) and a slot 33 located on the work surface 32. The guide rod seat 23 is connected to the back of the worktable 22.The guide rods 24 are parallel to each other and mounted in the guide rod seat 23 so that they can move in a forward and backward direction relative to the worktable 22. The angle seat 25 is connected to the front ends of the guide rods 24 so that it can move together with the guide rods 24. The saw blade housing 26 is pivotally connected to the angle seat 25 so that the saw blade housing 26 can be rotated both vertically and horizontally relative to the work surface 32, while simultaneously moving forward and backward together with the guide rods 24 through the angle seat 25. The motor 27 is connected to the right side of the saw blade housing 26 to provide the power source.The saw blade 28 is connected to the motor 27 and partially housed in the saw blade housing 26 so that the saw blade 28 can be driven by the motor 27 to work, and the saw blade 28 can also be driven by the saw blade housing 26 to tilt up and down, forward and backward, and left and right relative to the work surface 32. The protective cover 29 is pivotally connected to the saw blade housing 26 and covers the lower half of the saw blade 28 when the saw blade 28 is not in use, thereby preventing the saw blade 28 from being exposed when not in use. The handle 30 is attached to the outer surface of the motor 27 to allow a user to easily drive the saw blade 28. The handle 31 is provided on the top of the saw blade housing 26 to allow the user to easily lift and transport the entire machine.

[0012] The safety module 40 comprises a positioning marker 41, a bracket 42, a visual element 43, a brake 44, and a controller 45. The positioning marker 41 (in this embodiment, a QR code is used) is attached to the left side of the protective cover 29 in this example. In fact, however, the positioning marker 41 can be attached via a bracket 47 (as in Fig. 2) on the left side of the saw blade housing 26 or on the work surface 32 of the workbench 22 (as shown in Fig. 3). The lower end of the bracket 42 is connected to the left side of the saw blade housing 26, and the upper end of the bracket 42 extends to the top of the workbench 22. The visual / optical element 43 (a depth camera is used in this embodiment) is installed at the upper end of the bracket 42 and arranged above the workbench 22 such that the visual / optical element 43 and the positioning mark 41 are both located on the left side of the saw blade 28.

[0013] The visual / optical element 43 detects the positioning mark 41 to determine a relative position between the positioning mark 41 and a center point C of the saw blade 28 and, based on this relative position, to define a saw blade warning area W1 (as shown in Fig. 6) around the saw blade 28. The saw blade 28 can be operated in various ways depending on the actual requirements, for example, it can be moved up and down relative to the work table 22, it can be moved both up and down and forwards and backwards relative to the work table 22, or it can be tilted at an angle and then moved up and down and forwards and backwards relative to the work table 22 according to this angle.Therefore, in this embodiment, the visual / optical element 43 defines the saw blade warning area W1 as follows: an area extending 2 cm to 5 cm outward from the teeth 282 of the saw blade 28 along a radial direction D1 of the saw blade 28, an area extending 2 cm to 5 cm outward from both opposite sides of the saw blade 28 along an axial direction D2 of the saw blade 28, and an area 5 cm to 10 cm in front of the saw blade 28; that is, the saw blade warning area W1 is a three-dimensional virtual space formed around the saw blade 28. In addition, as shown in FIG. Fig. As shown in Figure 6, the visual / optical element 43 detects a position of a hand 50 to define a hand warning area W2 around the hand 50. The hand warning area W2 is a three-dimensional virtual space formed around the hand 50.

[0014] The brake 44 (an electromagnetic brake is used in this embodiment) is assembled with the motor 27 and enclosed together with the motor 27 by an outer casing 46 to stop the motor 27. The control unit 45 is installed behind the handle 30 and is electrically connected to the motor 27, the visual element 43, and the brake 44 to receive a signal generated by the visual element 43 and drive the brake 44 to stop the motor 27 based on the signal. Before starting operation, the visual / optical element 43 first detects the position mark 41 to locate the position of the saw blade 28 and simultaneously defines the saw blade warning area W1 around the saw blade 28. Next, the visual / optical element 43 detects the position of the hand 50 to define the hand warning area W2 around the hand 50.This allows the relative distance d between the saw blade warning area W1 and the hand warning area W2 to be determined.

[0015] If the visual / optical element 43 detects during operation that the saw blade warning area W1 and the hand warning area W2 do not overlap, as shown in the Fig. 7 and Fig. 8, it indicates that there is no danger of the hand 50 being injured by the saw blade 28. In this case, the control unit 45 maintains the operation of the motor 27 so that the saw blade 28 can continue the sawing process. As soon as the visual / optical element 43 detects that the saw blade warning area W1 and the hand warning area W2 partially overlap, i.e. the relative distance d ≦ 0, as shown in the Fig. 9 and Fig.10, it indicates that there is a risk of injury to the hand 50 by the saw blade 28. At this point, the visual / optical element 43 sends a brake signal (which can be transmitted via either a wired or wireless transmission) to the controller 45, causing the controller 45 to actuate the brake 44 to stop the motor 27. This can prevent injury to the hand 50 by the saw blade 28 and increase operational safety for the user.

[0016] In addition, even if the saw blade warning area W1 and the hand warning area W2 do not overlap, the visual / optical element 43 determines whether the hand 50 may be injured by the saw blade 28 based on the movement speed of the hand 50. The visual / optical element 43 then sends a brake signal to the controller 45. For example, if the hand 50 can move 10 cm in 0.1 seconds, which corresponds to a preset speed of the hand 50 of 100 cm / s, and if the visual / optical element 43 detects that the movement speed of the hand 50 is approaching this preset speed, the controller 45 activates the brake 44 to stop the motor 27 when the hand 50 is approximately 10 cm away from the saw blade 28.Conversely, the control unit 45 activates the brake 44 to stop the motor 27 when the hand element 50 is approximately 2 cm to 5 cm away from the saw blade 28 if the visual / optical element 43 detects that the movement speed of the hand element 50 is below the preset speed.

[0017] It should be noted here that the visual / optical element 43 does not necessarily have to be attached to the sawing machine 20 via the bracket 42. The visual / optical element 43 can also be set up independently and separately from the sawing machine 20. In this case, angular deviations may occur between the visual element 43 and the positioning mark 41, so that the visual / optical element 43 may not be able to capture a complete image of the positioning mark 41. Therefore, the visual / optical element 43 first captures the lengths of the sides of the positioning mark 41 and then calculates the position of the positioning mark 41 based on these side lengths. In this way, the visual / optical element 43 can obtain a complete image of the positioning mark 41.In this way, the relative position between the center point C of the saw blade 28 and the positioning mark 41 can be determined, which then allows the saw blade warning area W1 to be defined.

[0018] As explained above, the sawing device 10 of the present invention uses the visual / optical element 43 to determine whether the saw blade warning area W1 and the hand warning area W2 overlap. Once the two areas overlap, the control unit 45 stops the operation of the motor 27 via the brake 44 to prevent the hand 50 from being injured by the saw blade 28, thereby increasing operational safety.

[0019] From the description of the invention, it will be apparent that the same may be varied in many respects. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all modifications obvious to one skilled in the art are intended to be included within the scope of the following claims.

[0020] A sawing device comprises a sawing machine, a safety module, and a controller. The sawing machine has a saw blade. The safety module has a positioning mark and a visual / optical element arranged on the same side of the saw blade as the positioning mark. The visual / optical element detects the positioning mark to determine a relative position between the positioning mark and a center of the saw blade to define a saw blade warning zone based on the relative position. When a hand approaches the sawing machine, the visual / optical element detects the position of the hand to define a hand warning zone. The controller is electrically connected to a motor and the visual element.When the visual / optical element detects that the saw blade warning area and the hand warning area partially overlap, the visual / optical element sends a brake signal to the controller, causing the controller to stop the motor. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 8,386,067

[0002] US 11,187,378

[0002]

Claims

[1] Sawing device (10), comprising: a sawing machine (20) comprising a workbench (22), a saw blade housing (26) pivotally connected to the workbench (22), a motor (27) mounted on the saw blade housing (26), a saw blade (28) connected to the motor (27) to be rotated by the motor (27) and partially received in the saw blade housing (26) to be driven by the saw blade housing (28) to move closer to or away from the workbench (22), and a protective cover (29) pivotally connected to the saw blade housing (26) and covering part of the saw blade (28); a safety module (40) having a positioning mark (41) and a visual element (43) arranged on the same side of the saw blade (28) as the positioning mark (41), wherein the visual element (43) detects the positioning mark (41) to determine a relative position between the positioning mark (41) and a center point (C) of the saw blade (28) in order to define a saw blade warning area (W1) around the saw blade (28) based on the relative position, wherein the visual element (43) detects a position of a hand (50) to define a hand warning area (W2) around the hand (50) when the hand (50) approaches the sawing machine (20); and a control unit (45) electrically connected to the motor (27) and the visual element (43); wherein, when the visual element (43) detects that the saw blade warning area (W1) and the hand warning area (W2) partially overlap, the visual element (43) sends a brake signal to the control unit (45), whereby the control unit (45) stops the motor (27). [2] Sawing device (10) according to claim 1, wherein the positioning mark (41) is alternatively attached to the workbench (22), the saw blade housing (26) or the protective cover (29). [3] Sawing device (10) according to claim 1 or 2, wherein the visual element (43) defines the saw blade warning area (W1) as follows: an area extending 2 cm to 5 cm radially outward from the teeth (282) of the saw blade (28), an area extending 2 cm to 5 cm axially outward from both opposite sides of the saw blade (28), and an area of 5 cm to 10 cm in front of the saw blade (28). [4] Sawing device (10) according to one of claims 1 to 3, wherein the control unit (45) stops the motor (27) when the visual element (43) detects that a movement speed of the hand (50) is close to 100 cm / s and the hand (50) is about 10 cm away from the saw blade (28), and the control unit (45) stops the motor (27) when the visual / optical element (43) detects that the movement speed of the hand (50) is below 100 cm / s and the hand (50) is about 2 cm to 5 cm away from the saw blade (28). [5] Sawing device (10) according to claim 1, wherein the visual element (43) is mounted on a bracket (42) which is fastened to one side of the saw blade housing (26) and positioned above the workbench (22). [6] Sawing device (10) according to claim 1 or 5, wherein the visual element (43) and the sawing machine (20) are installed separately and independently of each other. [7] Sawing device (10) according to claim 6, wherein the visual element (43) detects lengths of sides of the positioning mark (41) to determine the relative position between the positioning mark (41) and the center (C) of the saw blade (28). [8] The sawing device (10) according to any one of claims 1 to 7, further comprising a brake (44) provided on the motor (27) and electrically connected to the controller (45); wherein when the visual element (43) sends the brake signal to the controller (45), the brake (44) is controlled by the controller (45) to stop the motor (27).

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