Signal switchers for power tools

Abstract

A signal switch for a power tool has a paddle supported by a rocker that extends into the switch housing to pivot an actuating member. A circuit board is attached to the bottom of the switch. Depending on the position of the paddle, at least one microswitch extends from the circuit board into the switch in a position to be actuated by the actuating member. The circuit board includes a connector configured to connect to a cable (e.g., a ribbon cable). Circuit traces on the circuit board are electrically connected to the microswitch and the electrical connector. The interior of the switch housing is sealed from the external environment so that the mechanical components of the switch are protected from the environment.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS.

[0002] This application claims priority to U.S. Provisional Application Serial No. 62 / 942,812 filed on December 3, 2019, by Andrew Frolov, entitled “SIGNALSWITCH FOR POWER TOOLS,” the disclosure of which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present application relates generally to power tools and, in particular, to power switches for power tools. Background Art

[0004] Some power tools and other types of devices have specific requirements for power switches or on / off switches. For example, with power tools (e.g., table saws), the user should not be able to accidentally start the power tool. The switch should also be able to be turned off blindly, meaning the user should not be required to see the switch to turn it off, and should be able to be turned off by the user's hand, knee, or other body part.

[0005] Generally, two types of switches are widely used on table saws and similar types of power tools. One type of switch is a rocker switch, which has a large paddle joystick, such as Figure 5 and Figure 6 Another type of switch is a push button switch, which has two buttons (on / off) provided on a large pad, such as Figure 7 A problem faced by power switches in power tools is oxidation buildup on exposed conductors, which can shorten service life. Electrical switches for power tools that receive power from an AC outlet are less susceptible to oxidation due to the high AC voltage and current flowing through the switch contacts, which prevents oxidation buildup. However, battery-operated power tools typically have very low DC voltage and current flowing through the contacts, which may not be sufficient to prevent oxidation buildup. Harsh environments (e.g., high temperature and humidity) can exacerbate this problem.

[0006] Contact oxidation and harsh environments have a greater impact on battery-powered tools. Battery-powered tools often use microswitches that can handle DC voltage and current and have an IP rating, protecting them from harsh environments. However, it is difficult to utilize microswitches in power tools (such as table saws) that are configured to be actuated blindly by bumping the switch with a hand, knee, or other body part. For example, a typical switch for a table saw can generate a large amount of kinetic energy, which is transferred from the switch lever to the contacts when the switch is closed. If actuated in this manner, the microswitches can be easily damaged.

[0007] What is needed is a switch configuration that enables miniature switches to be used in power switches for power tools (e.g., table saws) while still allowing blind actuation by hand, knee, or other body part and being less susceptible to oxidation and harsh environments. Summary of the Invention

[0008] A signal switch for a power tool is provided, comprising a lower housing assembly having a plurality of side walls connected together to define an interior space; and a bottom wall attached to bottom portions of the plurality of side walls and covering the bottom portion of the interior space, the bottom wall defining at least one opening. An actuating member having a first end and a second end is pivotally supported within the interior space. The signal switch also comprises an upper housing assembly having an upper wall attached to top portions of the plurality of side walls and covering the upper portion of the interior space. A paddle extends through the opening in the upper wall. The paddle has an arm positioned within the interior space. A rocker mechanism is configured to enable the paddle to pivot between an on position and an off position. A spring-loaded pressure member is provided at the end of the arm. The signal switch also comprises a micro-switch circuit board attached to the bottom wall. At least one micro-switch is provided on the inner side of the circuit board in a position extending through the at least one opening in the bottom wall and protruding into the interior space. At least two micro-switches can be used to meet safety requirements. An electrical connector is provided on the outer side of the circuit board and is configured to connect to an electrical cable. Circuit traces on the circuit board are electrically connected to the micro-switches and the electrical connector. When the paddle is in the on position, the arm is positioned such that the pressing member presses the second end of the actuating member into engagement with at least one micro-switch protruding into the interior space. When the paddle is in the off position, the arm is positioned such that the pressing member presses the first end of the actuating member downwardly, causing the second end of the actuating member to move away from the at least one micro-switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a perspective view of a table saw including a signal switch according to the present disclosure.

[0010] Figure 2 yes Figure 1 An exploded view of some of the components of a table saw.

[0011] Figure 3 yes Figure 1 Schematic depiction of the electrical system of a table saw.

[0012] Figure 4 Yes Display Figure 1 A partial perspective view of a power switch for a table saw.

[0013] Figure 5-Figure 7 An embodiment of a power switch according to the prior art is shown.

[0014] Figure 8 is a front view of a signal switch according to the present disclosure.

[0015] Figure 9 yes Figure 8 Bottom perspective view of the signal switcher.

[0016] Figure 10 yes Figure 8 A perspective view of the micro-switch circuit board of a signal switcher.

[0017] Figure 11 yes Figure 8 Schematic cross-sectional view of a signal switch, showing the switch in an off position.

[0018] Figure 12 yes Figure 8 Schematic cross-sectional view of a signal switch, showing the switch in the on position.

[0019] Figure 13 is a perspective view of a micro switch circuit board of a signal switch according to another embodiment.

[0020] Figure 14 is a schematic cross-sectional view of a signal switch having another embodiment of fixed terminals. DETAILED DESCRIPTION

[0021] To facilitate understanding of the principles of the apparatus described herein, reference is made to the embodiment(s) illustrated in the drawings and described in the following written description. It should be understood that no limitation of the scope of the apparatus is intended thereby. It should be further understood that the apparatus encompasses any changes and modifications to the illustrated embodiment(s), and includes further applications of the principles of the apparatus, as would normally occur to one of ordinary skill in the art to which the apparatus pertains.

[0022] The present disclosure relates to a power switch for a power tool (e.g., a table saw) that enables a micro switch to be used as an on / off power switch for the power tool while still allowing easy / blind manipulation actuation using the user's hand, knee, or other body part, and is not susceptible to oxidation and harsh environments. As discussed below, the power switch has a rocker switch configuration, wherein the micro switch extends into the switch to be actuated by the rocker. The micro switch is provided on a circuit board mounted on the bottom of the switch. The circuit board has circuit traces that connect the micro switch to a connector provided on the circuit board. The connector enables a cable (e.g., a ribbon cable) to be used to provide signals from the switch to a signal board, and from the signal board to the main board of the power tool. The interior of the switch housing is sealed from the external environment so that the mechanical components of the switch are protected from the environment.

[0023] In the embodiments described herein, the power tool comprises a table saw, although the power switch may be used with any type of power tool or device. Figure 1 , the table saw assembly 100 includes a base 104 and a table top 102. Figure 1 and Figure 2 , a power tool in the form of a table saw 100 includes a blade assembly 101, a table structure 102, and a base 104. The table 102 includes an opening or slot 106 through which a top portion of the blade assembly 101 extends. The table 102 has a generally flat upper surface, which may be referred to as a work surface. A frame 104 is connected to a bottom portion of the table 102 and is configured to define an interior space 105 in which the bottom portion of the blade assembly 101 is positioned. Figure 1 In an embodiment, the table structure 102 and the frame 104 may be formed from sheet metal, plastic, aluminum, a composite material, or the like. The table 102 and the frame 104 may include a handle (eg, handle 108 ) that enables a user to conveniently carry the table saw 100 .

[0024] In some embodiments, the blade assembly 101 has a fixed position along the longitudinal axis L of the table 102 or along the length of the slot 106. In other embodiments, the blade assembly 101 may be mounted to a slide assembly (not shown) that enables the blade assembly to be moved longitudinally relative to the table 102, commonly referred to as a "push-pull" saw.

[0025] The blade assembly 101 of the table saw 100 includes an adjustment mechanism 110 for adjusting the angular and vertical position of the blade. The mechanism 110 is adapted to allow the blade assembly 101 to rotate about a longitudinal axis L so that the blade can make angled cuts in a workpiece. The mechanism can further be adapted to raise and lower the cutting blade relative to the table 102 to adjust the depth of the cut into the workpiece.

[0026] like Figure 2 , the blade assembly 101 generally includes a blade 120, an electric motor assembly 122, and a carrier assembly 124 including a cover assembly 126. The carrier assembly 124 includes a pivot mount 125 that is pivotally mounted to the underside of the table 102 to allow the blade assembly, and therefore the blade 120, to pivot about a longitudinal axis L ( Figure 1 ). The motor assembly 122 is supported within a channel 128 in a carrier assembly that is configured to allow the motor assembly, and therefore the blade 120, to move up and down relative to the table 102 and the slot 106. Depending on the nature of the table saw 100, the blade 120 may be configured for rotational or reciprocating motion, with the motor assembly 122 configured to drive the blade in a rotational motion.

[0027] The adjustment mechanism 110 incorporates a mechanism for controlled pivoting of the carriage assembly 124 relative to the table 102 and for controlled up and down movement of the motor assembly 122 relative to the table, which ultimately provides controlled positioning of the cutting blade 120. It will be appreciated that various adjustment mechanisms may be utilized to provide angle adjustment and up and down adjustment for the blade 120. For example, a screw mechanism may be provided to move the motor assembly 122, and therefore the blade 120, up and down relative to the carriage assembly 124 and, therefore, relative to the table 102 and the work surface. The angle adjustment mechanism may incorporate a shaft 112 that engages within a curved slot 113 in a sidewall 114 of the frame 104. The shaft 112 may form part of a gear mechanism for driving a height adjustment screw. Other mechanisms are contemplated, provided that they are capable of at least adjusting the angle of the blade 120 relative to the table 102 and the slot 106.

[0028] The signal switch 200 according to the present disclosure is provided on the front portion of the table saw 100, where it is easily accessible to the user during operation of the table saw. The power signal is preferably a low-voltage signal, although any voltage and / or current level may be used for the power signal. The power signal is used to send signals to the control system when activating and deactivating the table saw and is not used to supply power to the control system.

[0029] refer to Figure 4 The signal switch 200 includes a housing 220 that is attached to a housing 222 of a power tool. The switch housing 220 is attached to the power tool housing by fasteners 224 (e.g., screws). The switch 200 includes a toggle 226 for opening and closing a circuit that supplies power signals to a control system. The circuit can receive power from an interface circuit power distribution system or connect signals to a control system.

[0030] An embodiment of the electrical system is Figure 3. The electrical system includes a control system 202, a safety system 204, and a power distribution system 206. The control system 202 includes components for controlling the console saw, such as a processor, memory, and the like. The control system 202 can be implemented on a printed circuit board (PCB). The safety system 204 includes electrical components and circuitry configured to detect operating conditions that could cause damage to the saw or to the operator of the tool and implement strategies to prevent such damage, for example, by stopping the blade, cutting off power, etc. The safety system 204 can be implemented on the same PCB as the control system or on a PCB separate from the control system. The power distribution system 206 includes components and circuitry that provides power to the drive system of the power tool.

[0031] Power is provided by a power supply 210. The power supply can be an AC outlet or a battery. In the embodiment described herein, the power tool is a battery-operated table saw, so Figure 3 The power supply 210 depicted in FIG is a battery. The signal switch 200 is configured to manually open and close a signal circuit to indicate to the control system 202 when to supply or cut off power to the various systems of the power tool.

[0032] Figures 8-12 An embodiment of a signal switch 200 is shown in greater detail. The signal switch 200 includes an upper housing assembly 228 and a lower housing assembly 230. The lower housing assembly 230 includes a plurality of side walls surrounding and defining an interior space. The upper housing assembly 228 is mounted on top of the lower housing assembly 230 and encloses an upper portion of the interior space. The lower housing assembly 230 includes a bottom wall 232 ( Figure 11 ), the bottom wall 232 closes the bottom part of the internal space.

[0033] like Figure 11 and Figure 12 As can be seen in the bottom wall 232, the bottom wall 232 defines an opening through which the micro switches 238 for the signal switch 200 extend into the interior space. The number of micro switch openings 236 depends on the number of micro switches 238 utilized. As illustrated, two micro switches 238 are utilized, and therefore two openings are provided in the bottom wall 232. An actuating member 240 for actuating the micro switches 238 is provided in the interior space of the lower housing assembly 230. A micro switch circuit board 242 is mounted to the lower housing assembly 230 above the bottom wall 232. The micro switch circuit board 242 can be implemented as a printed circuit board assembly (PCBA) and can be mounted to the lower housing assembly 230 in any suitable manner.

[0034] The micro switches 238 are provided on the upper side of the circuit board 242 in a position extending through corresponding openings 236 provided in the bottom wall 232 of the lower housing assembly 230. Figures 8-12 In the embodiment of the present invention, two micro switches 238 are utilized, although any suitable number of micro switches may be used. The micro switches 238 protrude into the interior space of the lower housing assembly 230 by a sufficient amount to be actuated by the actuation member 240. In one embodiment, the micro switches 238 are configured to extend into the interior space so that only the actuation button on the top of the switch 238 protrudes above the inner surface of the bottom wall 232, as shown in FIG. Figure 11 and Figure 12 Can be seen in.

[0035] The actuating member 240 is pivotally supported in position, for example, to actuate the micro-switch 238 by pressing a button on the top of the micro-switch 238. The actuating member 240 includes a first end 246 and a second end 248. The actuating member 240 is pivotally supported on the bottom wall by the pivot assembly 250 in a position in which one end of the actuating member 240 (e.g., the second end 248) can be pivoted into engagement with the micro-switch 238 or out of engagement with the micro-switch 238. In particular, the actuating member 240 is configured to pivot between a first position and a second position. In the first position, the second end 248 of the actuating member 240 is spaced apart from the micro-switch 238 such that the micro-switch 238 is not actuated, as shown in FIG. Figure 11 This corresponds to the disconnected position for the signal switch. In order to pivot the actuating member to the second position, the second end of the actuating member 240 is pivoted downwardly into contact with the micro switch 238, as shown. Figure 12 This corresponds to the on position for the signal switch.

[0036] Upper housing assembly 228 includes a toggle 226, a rocker mechanism 252, and a spring assembly 254. The toggle 226 is manually moved by a user to activate and deactivate the table saw. The toggle 226 includes a large actuation portion to facilitate access by the user. The actuation portion may also include indicia (e.g., arrows, alphanumeric characters, and symbols) to indicate on and off positions, direction of movement, or any other information to assist and guide the user.

[0037] The toggle button 226 is attached to the upper housing assembly 228 by a rocker mechanism 252 that enables the toggle button 226 to be in the off position ( Figure 11 ) and the on position ( Figure 12). Rocker mechanism 252 can be configured in the same manner as rocker switches known in the art. In the off position, paddle button 226 is oriented downward and positioned proximate to the side of the power tool. The position and orientation of paddle button 226 in the off position are selected to substantially prevent and / or reduce the likelihood of accidental contact between the paddle button and the switch, causing the paddle button to move to the on position.

[0038] The toggle button 226 pivots outwardly from the side of the power tool to activate the power tool. Figure 12 In the on position, the toggle 226 extends outward from the power tool to a position that is easily accessible during operation. The toggle 226 can then be easily moved to the off position by contacting the toggle with a hand, knee, or other body part without having to see the toggle. The toggle 226 includes an arm portion 256 that extends into the interior space. A spring assembly is provided on the arm. For example, in one embodiment, the arm 256 includes a hollow tube in which a pressing member 260 (e.g., a ball or plunger) is retained. A spring (not shown) is provided in the arm 256 to bias the pressing member to an extended position in which the pressing member protrudes from the end of the arm so that it can resiliently bear against the actuating member 240.

[0039] When the toggle button 226 is moved to the on position, Figure 12 As shown in FIG, the pressing member 260 moves into engagement with the second end 248 of the actuating member 240, which causes the actuating member 240 to pivot into engagement with the micro-switch 238, thereby actuating the micro-switch. Figure 11 As shown in FIG, the pressing member 260 moves into engagement with the first end 246 of the actuating member 240 , which causes the actuating member 240 to pivot to the non-actuated position where the second end 248 of the actuating member 240 is spaced apart from the micro-switch 238 .

[0040] The micro switch circuit board 242 includes an electrical connector 262 and a circuit trace 264. The circuit trace 264 is electrically connected to the micro switch 238 and the electrical connector 262. The circuit trace 264 is used to route signals from the micro switch 238 to the electrical connector 262. Although not shown in FIG. Figures 8-12 , but other electrical components may be provided on the micro-switch circuit board 242 as needed to assist in processing and routing signals through the micro-switch circuit board 242.

[0041] The electrical connector 262 is configured to connect to a complementary connector 270 provided on a cable 272 (e.g., a ribbon cable or other suitable type of cable). As is known in the art, a ribbon cable comprises a plurality of individual insulated conductors arranged in a flat, parallel pattern. Connectors with a predetermined configuration are provided on each end of the cable. The ribbon cable extends from the micro-switch circuit board and is connected at its other end to a signal board on the table saw's main board. Thus, the cable forms part of the table saw's signal circuitry and enables simple and easy routing of signals from the switch to the power tool's systems.

[0042] The interior space of the power switch is sealed from the external environment by using seals and sealing materials in appropriate locations within the switch. For example, signal switch 200 includes seals 266 at locations where the paddles extend through upper housing assembly 228 into the interior space. A sealant 268 is also provided to seal the interface between the microswitch circuit board 242 and the lower housing assembly 230. Thus, the interior space is sealed from the environment, protecting the switch's mechanical components (e.g., actuating member 240 and the pushbuttons of microswitch 238) from dust and contamination.

[0043] refer to Figure 13 and Figure 14 The signal switch 200 can be implemented by adding a circuit board and a micro switch to a rocker switch, so that the rocker assembly of the switch can be used to actuate the micro switch. Figure 14 As can be seen in FIG, the power switch may include fixed terminals that are mounted to the bottom surface of the bottom wall 232 and are used to connect the switch to the power circuit. Fixed terminals 234 can be used for accurate positioning of the micro switch circuit board. Figure 13 As best seen in FIG, the micro-switch circuit board 242 may include openings or slots 244 through which the fixed terminals 234 extend for accurate positioning when the micro-switch circuit board 242 is mounted to the lower housing assembly 230.

[0044] Although the present disclosure has been shown and described in detail in the drawings and foregoing description, it should be considered as illustrative rather than restrictive in nature. It should be understood that only preferred embodiments have been presented and that all changes, modifications, and further applications that fall within the spirit of the present disclosure are intended to be protected.

Claims

1. A signal switch for an electric tool, comprising: Lower housing assembly, including: a plurality of side walls connected together to define an interior space; a bottom wall attached to bottom portions of the plurality of side walls and covering a bottom portion of the interior space, the bottom wall defining at least one opening; an actuation member pivotably supported within the interior space, the actuation member having a first end and a second end; Upper housing assembly, including: an upper wall attached to top portions of the plurality of side walls and covering an upper portion of the interior space, the upper wall defining an opening; a paddle extending through the opening and having an arm positioned within the interior space; a rocker mechanism configured to enable the toggle to pivot between an on position and an off position; and a spring-loaded pressing member on the end of the arm; and Micro switcher circuit board, including: a circuit board attached to the bottom wall, the circuit board defining at least two slots through which at least two fixed terminals extend; at least one microswitch on an interior side of the circuit board and positioned to extend through the at least one opening in the bottom wall and protrude into the interior space; an electrical connector on an outer side of the circuit board, the electrical connector being configured to connect to an electrical cable; and a circuit trace electrically connected to the microswitch and the electrical connector, wherein, when the toggle is in the on position, the arm is positioned such that the pressing member presses the second end portion of the actuating member into engagement with the at least one micro-switch protruding into the interior space, and Wherein, when the toggle is in the off position, the arm is positioned such that the pressing member presses downwardly on the first end of the actuating member, which moves the second end of the actuating member away from the at least one micro-switch.

2. The signal switch according to claim 1, wherein: The interior space is sealed from the external environment.

3. The signal switch according to claim 1, wherein: The electrical cable comprises a ribbon cable.

4. The signal switch according to claim 1, wherein: The power tool is a table saw.

5. The signal switch according to claim 1, wherein: The circuit traces are configured to route signals from the at least one microswitch to the electrical connector.

6. Power tools, including: Tool components, configured to perform work; a drive system configured to drive the tool member; a power source configured to provide power to the drive system; a power circuit for supplying power from the power source to the drive system; A signal switch is electrically connected to the power circuit, and the signal switch includes: Lower housing assembly, including: a plurality of side walls connected together to define an interior space; a bottom wall attached to bottom portions of the plurality of side walls and covering a bottom portion of the interior space, the bottom wall defining at least one opening; an actuation member pivotably supported within the interior space, the actuation member having a first end and a second end; Upper housing assembly, including: an upper wall attached to top portions of the plurality of side walls and covering an upper portion of the interior space, the upper wall defining an opening; a paddle extending through the opening and having an arm positioned within the interior space; a rocker mechanism configured to enable the toggle to pivot between an on position and an off position; and a spring-loaded pressing member on the end of the arm; and Micro switcher circuit board, including: a circuit board, attached to the bottom wall, at least one microswitch on an interior side of the circuit board and positioned to extend through the at least one opening in the bottom wall and protrude into the interior space; an electrical connector on an outer side of the circuit board, the electrical connector being configured to connect to an electrical cable; and a circuit trace electrically connected to the microswitch and the electrical connector; and an electrical cable having a first connection end connected to the electrical connector and a second connection end connected to a signal board of a main power board of the power tool, wherein, when the toggle is in the on position, the arm is positioned such that the pressing member presses the second end portion of the actuating member into engagement with the at least one micro-switch protruding into the interior space, and Wherein, when the toggle is in the off position, the arm is positioned such that the pressing member presses downwardly on the first end of the actuating member, which moves the second end of the actuating member away from the at least one micro-switch.

7. The electric power tool according to claim 6, wherein: The interior space is sealed from the external environment.

8. The electric power tool according to claim 6, wherein: The electrical cable comprises a ribbon cable.

9. The electric power tool according to claim 6, wherein: The power tool is a table saw.

10. The electric power tool according to claim 6, wherein The circuit traces are configured to route signals from the at least one microswitch to the electrical connector.

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