Power tool with pyrotechnic lockout

• US 9,868,166 B2
• Filed: 03/04/2016
• Issued: 01/16/2018
• Est. Priority Date: 03/12/2015
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH, Robert Bosch Tool Corporation (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH, Robert Bosch Tool Corporation (Robert Bosch GmbH)
• Inventors: Hendrickson, Eric, Szweda, Timothy
• Primary Examiner(s): Alie, Ghassem
• Assistant Examiner(s): Grosselin, III, John E
• Application Number:
  US15/060,705
• Publication Number:
  US 20160263676A1
• Time in Patent Office: 683 Days
• Field of Search: None
• CPC Class Codes: B23D 45/06 with a circular saw blade arranged underneath a stationary work-table
• CPC Class Codes: B23D 47/08 of devices for bringing the circular saw blade to the workpiece or removing same therefrom
• CPC Class Codes: B23D 59/002 for the position of the saw blade B27B5/36 and B27B9/02 take precedence
• CPC Class Codes: B27G 19/02 for circular saws

Abstract

A power tool assembly includes a workpiece support surface, a latch movable between a first latch position whereat a drop arm assembly cannot be moved from a first position whereat a shaping device does not extend above the workpiece support surface to a second position whereat the shaping device extends above the workpiece support surface, to a second latch position whereat the drop arm assembly can be moved from the first position to the second position, an actuator housing configured to receive an actuator device, and a reaction plug configured to be selectively seated with the actuator housing, the reaction plug configured such that when an actuator device is installed in the actuator housing and the reaction plug is moved from an unseated position to a fully seated position, the reaction plug forces the actuator device to move the latch from the first latch position to the second latch position.

Claims

1. A power tool assembly comprising:

a workpiece support surface;

a drop arm assembly movable along a drop path between a first drop arm assembly position whereat a portion of a shaping device supported by the drop arm assembly extends above the workpiece support surface and a second drop arm assembly position whereat the portion of the shaping device does not extend above the workpiece support surface;

a latch movable between a first latch position whereat the drop arm assembly cannot be moved from the second drop arm assembly position to the first drop arm assembly position, and a second latch position whereat the drop arm assembly can be moved from the second drop arm assembly position to the first drop arm assembly position;

an actuator housing configured to receive an actuator device;

and a reaction plug configured to be selectively seated with the actuator housing, the reaction plug configured such that when the actuator device is installed in the actuator housing and the reaction plug is moved from an unseated position to a fully seated position, the reaction plug forces the actuator device to move the latch from the first latch position to the second latch position.

2. The power tool assembly of claim 1, further comprising:

a biasing device configured to bias the latch toward the first latch position.

3. The power tool assembly of claim 2, wherein the biasing device and latch are configured such that as the reaction plug is moved from a fully seated position to an unseated position, the biasing device forces the latch against an actuator device positioned within the actuator housing thereby moving the actuator device in a direction outwardly from the actuator housing.

4. The power tool assembly of claim 3, wherein:

the actuator housing includes a slit on a motor side of the actuator housing configured to receive a portion of an actuator cartridge therein, and movement of the actuator device in the direction outwardly from the actuator housing causes a portion of the actuator cartridge outside of the actuator housing to be elevated above a finger plate portion of the actuator housing.

5. The power tool assembly of claim 3, wherein the reaction plug is configured to threadedly engage the actuator housing.

6. The power tool assembly of claim 1, wherein the latch comprises:

a latch pin receiving area configured to receive a latch pin of the drop arm assembly; and

a lower portion located beneath the latch pin receiving area, the lower portion configured such that when the latch is in the second latch position, the lower portion is located within the drop path such that movement of the drop arm assembly from the second drop arm assembly position toward the first drop arm assembly position causes the latch pin to contact the lower portion, thereby moving the latch from the second latch position in a direction away from the first latch position.

7. The power tool assembly of claim 6, wherein the lower portion is configured such that when the latch is in the first latch position, the lower portion is located within the drop path such that movement of the drop arm assembly from the second drop arm assembly position toward the first drop arm assembly position causes the latch pin to contact the lower portion, thereby precluding further movement of the drop arm assembly toward the first drop arm assembly position.

8. The power tool assembly of claim 7, wherein the actuator device comprises a pyrotechnic device.

9. The power tool assembly of claim 8, further comprising:

a control system configured to actuate the pyrotechnic device in response to a sensed unsafe condition.

10. The power tool of claim 9, further comprising:

an electrical connector configured to connect to a plug of the activating device; and

a connecting wire including a first end permanently attached at one end to the electrical connector and a second end permanently attached to the control system.

11. The power tool of claim 10, wherein:

the connecting wire extends through an opening in the reaction plug; and

the electrical connector is sized such that the electrical connector cannot move through the opening.

12. A method of operating a power tool assembly having a drop arm assembly movable along a drop path between a first drop arm assembly position whereat a portion of a shaping device supported by the drop arm assembly extends above a workpiece support surface and a second drop arm assembly position whereat the portion of the shaping device does not extend above the workpiece support surface comprising:

inserting an actuator device into an actuator housing;

moving a reaction plug configured to be selectively seated with the actuator housing from an unseated position to a fully seated position with the actuator inserted;

causing the actuator device to move a latch from a first latch position whereat the drop arm assembly cannot be moved from the second drop arm assembly position to the first drop arm assembly position, to a second latch position whereat the drop arm assembly can be moved from the second drop arm assembly position to the first drop arm assembly position, by movement of the reaction plug from the unseated position to the fully seated position; and

moving the drop arm assembly from the second drop arm assembly position to the first drop arm assembly position after moving the reaction plug from the unseated position to the fully seated position.

13. The method of claim 12, wherein forcing the actuator device to move the latch comprises forcing the actuator device to move the latch against a bias produced by a biasing device configured to bias the latch toward the first position.

14. The method of claim 13, wherein inserting the actuator device into the actuator housing comprises:

inserting a portion of an actuator cartridge supporting the actuator device into a slit on a motor side of the actuator housing.

15. The method of claim 14, wherein moving the reaction plug from the unseated position to the fully seated position comprises:

causing a portion of the actuator cartridge outside of the actuator housing to move downwardly from a position above a finger plate portion of the actuator housing.

16. The method of claim 14, wherein moving the reaction plug from the unseated position to the fully seated position comprises:

threadedly engaging the actuator housing with the reaction plug.

17. The method of claim 12, wherein moving the drop arm assembly from the second drop arm assembly position to the first drop arm assembly position comprises:

moving the latch from the second latch position in a direction away from the first latch position by forcing a latch pin of the drop arm assembly against a lower portion of the latch with the latch in the second latch position; and

moving the latch pin into a latch pin receiving area of the latch after moving the latch from the second latch position in the direction away from the first latch position.