Table saw and push stick for the table saw

Abstract

A push stick for a table saw and a table saw with the push stick are provided. The push stick includes a gripping possibility for a machine operator at its operator-side end. A workpiece engagement notch is formed at the push stick's workpiece-side end. The notch includes a push surface facing in an intended feed direction of the workpiece and a holding-down surface protruding therefrom at the top under a preferably right angle. The push stick includes a detection device which detects whether the push surface and the holding-down surface lie flat against the workpiece. The push stick further includes a signaling device which emits a flat contact signal when the detection device has detected a flat contact of the push surface and the holding-down surface on the workpiece. The signal therefore signals whether the push surface and the holding-down surface lie flat against the workpiece.

Claims

1. A push stick for a table saw, comprising: a grip end for a machine operator at an operator-side end of the push stick; a workpiece engagement notch suitable for acting on a workpiece being formed at a workpiece-side end of the push stick, and being spaced apart from the grip end, wherein the workpiece engagement notch comprises a push surface facing in an intended feed direction of the workpiece and a holding-down surface protruding from a top of the push surface; a detection device which detects whether the push surface and the holding-down surface lie flat against the workpiece; and a signaling device which emits a respective flat contact signal in response to when the detection device has detected a flat contact of the push surface and the holding-down surface on the workpiece, wherein the flat contact signal signals that the push surface and the holding-down surface lie flat against the workpiece.

2. The push stick according to claim 1, wherein the detection device on the push surface and on the holding-down surface each comprise at least one pushbutton switch which is recessed in such a way that actuation of the respective pushbutton switch takes place only when the respective surface lies flat against the workpiece.

3. The push stick (3) according to claim 2, wherein the detection device comprises a respective micro-switch on the push surface and on the holding-down surface, and wherein the two micro-switches are switched in an AND gate to permit the detection device to detect flat contact only when both micro-switches are actuated.

4. The push stick according to claim 1, wherein the detection device has an electro-optical or electro-acoustic scanning device which detects whether the push surface and the holding-down surface lie flat against the workpiece.

5. The push stick according to claim 1, wherein the signaling device comprises an LED which is illuminated under flat contact.

6. The push stick according to claim 2, wherein the signaling device comprises an LED which is illuminated under flat contact.

7. The push stick according to claim 1, wherein the signaling device comprises a wire-bound or a wireless communication interface, via which the flat contact signal can be transmitted.

8. The push stick according to claim 2, wherein the signaling device comprises a wire-bound or a wireless communication interface, via which the flat contact signal can be transmitted.

9. The push stick according to claim 4, wherein the signaling device comprises a wire-bound or a wireless communication interface, via which the flat contact signal can be transmitted.

10. The push stick according to claim 1, wherein the signaling device comprises a debouncing device for debouncing the flat contact signal, and wherein the debouncing device comprises a low-pass filter, a flip-flop and/or a microcontroller with debouncing software.

11. The push stick according to claim 2, wherein the signaling device comprises a debouncing device for debouncing the flat contact signal, and wherein the debouncing device comprises a low-pass filter, a flip-flop and/or a microcontroller with debouncing software.

12. The push stick according to claim 3, wherein the signaling device comprises a debouncing device for debouncing the flat contact signal, and wherein the debouncing device comprises a low-pass filter, a flip-flop and/or a microcontroller with debouncing software.

13. The push stick according to claim 6, wherein the signaling device comprises a debouncing device for debouncing the flat contact signal, and wherein the debouncing device comprises a low-pass filter, a flip-flop and/or a microcontroller with debouncing software.

14. A table saw comprising: a push stick including a grip end for a machine operator at an operator-side end, and a workpiece engagement notch suitable for acting on a workpiece, the workpiece engagement notch being formed at a workpiece-side end of the push stick and being spaced apart from the grip end, wherein the workpiece engagement notch comprises a push surface facing in an intended feed direction of the workpiece and a holding-down surface protruding from a top of the push surface under a right angle, and wherein the push stick comprises a detection device and a signaling device, wherein the detection device detects whether the push surface and the holding-down surface lie flat against the workpiece, wherein the signaling device emits a respective flat contact signal in response to when the detection device has detected a flat contact of the push surface and the holding-down surface on the workpiece, and wherein the flat contact signal signals that the push surface and the holding-down surface lie flat against the workpiece.

15. The table saw according to claim 14, wherein the push stick comprises a wire-bound or a wireless communication interface, via which the flat contact signal can be transmitted, and a machine controller of the table saw comprises a respective wire-bound or a respective wireless communication interface, via which the flat contact signal can be received, wherein the machine controller comprises an actuator and an actuating device for the actuator, wherein the actuating device actuates the actuator in response to when the flat contact signal signals that the sliding surface and the holding-down surface lie flat against the workpiece.

16. The table saw according to claim 15, wherein the actuator is an ON/OFF switch for driving the saw blade.

17. The table saw according to claim 14, wherein the detection device on the push surface and on the holding-down surface each comprise at least one pushbutton switch which is recessed in such a way that actuation of the respective pushbutton switch takes place only when the respective surface lies flat against the workpiece.

18. The table saw according to claim 17, wherein the detection device comprises a respective micro-switch on the push surface and on the holding-down surface, wherein the two micro-switches are switched in an AND gate to permit the detection device to detect flat contact only when both micro-switches are actuated.

19. The table saw according to claim 14, wherein the detection device has an electro-optical or electro-acoustic scanning device which detects whether the push surface and the holding-down surface lie flat against the workpiece.

20. The table saw according to claim 14, wherein the signaling device comprises an LED, which is illuminated under flat contact.

21. The push stick according to claim 1, wherein the holding-down surface protrudes with a right angle from the top of the push surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described with reference to the drawings wherein:

(2) FIG. 1 shows a side view of an exemplary embodiment of a push stick;

(3) FIG. 2 shows a perspective front view of the push stick shown in FIG. 1;

(4) FIG. 3 shows a circuit diagram of the push stick shown in FIGS. 1 and 2.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

(5) Reference is made firstly to FIGS. 1 and 2, which show a push stick 3 which can be gripped at its right end in FIG. 1 by a machine operator of a table circular saw or a table saw so that, with its left end in FIG. 1, a workpiece engagement notch can be brought into engagement with a workpiece to be pushed past a saw blade of the table circular saw/table band saw. For this purpose, the workpiece engagement notch has a push surface 1 and a holding-down surface 2 protruding therefrom at a right angle to the workpiece, so that the push stick 3 with its push surface 1 and its holding-down surface 2 is arranged in a planar manner on a workpiece which is constructed for example as a board with side surfaces adjoining at right angles.

(6) Two micro-buttons or micro-switches 4 are disposed on the push surface 1 and on the holding-down surface 2 of the push stick 3. The scanning could also take place by electro-optical or electro-acoustic scanning instead of or in addition to these electromechanical components, as long as the detection device 4 formed thereby detects whether the push surface 1 and the holding-down surface 2 lie flat against the workpiece.

(7) Furthermore, the push stick 3 has an LED 5, which serves as signalling device 5 which, in response to whether or not the detection device 4 formed by the two micro-switches 4 detects the flat contact of the sliding surface 1 and the holding-down surface 2 on the workpiece, emits a flat contact signal which signals whether or not the push surface 1 and the holding-down surface 2 rest flat against the workpiece. In the exemplary embodiment, the LED 5 thus lights up in the case of flat contact. It could, of course, also be the case that the LED 5 is illuminated as a warning light when there is no flat contact on both sides. Furthermore, the signalling device 5 could also comprise a different signal transmitter alternatively or additionally to the LED 5, for example an acoustic signalling device or a vibration alarm. Furthermore, it would be conceivable for the signalling device to have a communication module or a communication interface, for example a Bluetooth or WLAN transmitter/receiver, via which it is connected to a machine controller of the table circular saw. Thus, for example, it would be possible for the table circular saw to be put into operation only when the push surface 1 and the holding-down surface 2 of the push stick 3 abut or lie flat against the workpiece.

(8) FIG. 3 shows the circuit diagram of the push stick 3 and thus the electrical connection of the micro-switches 4 with the LED 5 and the button cell 7 provided as a power supply which is inserted into a button cell holder 8 shown in FIG. 1. The two micro-switches 4 are connected as AND gates, i.e., the LED 5 is only illuminated when both micro-switches 4 are actuated, i.e., when both surfaces 1, 2 lie flat against the workpiece. The illuminating LED 5 thus indicates to the machine operator using the push stick 3 that the workpiece can be fed to the saw blade of the table saw with the greatest possible safety.

(9) In order to be able to utilize the flat contact signal output by the two micro-switches 4 also for sensitive signal processing devices, e.g., on the machine controller of the circular saw, it is advantageous to debounce the micro-switches 4. This can be done, for example, by a low-pass filter, a flip-flop or by a microcontroller with corresponding software.

(10) Variations and modifications of the embodiments shown are possible without departing from the scope of the invention.

(11) It is understood that the foregoing description is that of the exemplary embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.