Handheld work apparatus having an electric motor and method for activating the same

Patent metadata

Field	Value
Publication number	US-10293445-B2
Application number	US-201615266988-A
Country	US
Kind code	B2
Filing date	Sep 15, 2016
Priority date	Sep 15, 2015
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A handheld work apparatus has an electric motor and a voltage source for operating the motor. A manual actuation element provided on a handle of the apparatus is operated by a user and is provided for activating the motor. The actuation element is connected to a control unit which controls the energy supply from the source to the motor as a function of an operating signal of the actuation element. If the control unit is in a blocking state, the energy supply to the motor is blocked independently of the operating signal of the actuation element. After receiving a control signal, the control unit switches from the blocking state to a standby state to release an energy supply to the motor. The control signal is derived from a combination of an actuation stroke and an actuation time (ΔTB) of the actuation element. A method for activating the apparatus is also disclosed.

First claim

What is claimed is:

1. A method for activating a handheld work apparatus having an electric motor; a voltage source for operating the electric motor; a handle; a manual actuation member disposed on said handle and configured to be operated by a user for activating the work apparatus; a control unit; the manual actuation member being connected to the control unit and configured to output an operating signal; the control unit being configured to control the energy supply from the voltage source to the electric motor in dependence upon the operating signal of the manual actuation member; the control unit having a blocking state wherein the control unit is configured to block the supply of energy to the electric motor regardless of the operating signal of the manual actuation member; the method comprising the steps of:
deriving a control signal from a combination of an actuating stroke of the actuating member and an actuating time (ΔT B ) of the actuating member;
generating the control signal when, within the predefined actuating time (ΔT B ), the actuating member has performed a predefined actuating stroke in an actuating direction beyond a stroke threshold (H S ) and a predefined return stroke in a return direction opposite to the actuating direction; and,
switching the control unit out of the blocking state and into a standby state after receiving the control signal so as to enable an energy supply to the electric motor.

2. The method of claim 1 , wherein the stroke threshold (H S ) is crossed within the predefined return stroke.

3. The method of claim 1 , wherein the control signal is only generated when the stroke threshold (H S ) is crossed a second time in the actuating direction after the return stroke.

4. The method of claim 3 , wherein the control signal is only generated when the second time crossing the stroke threshold (HS) occurs within a predefined pause-time (ΔT P ) after the crossing of the stroke threshold (H S ) in the return direction.

5. The method of claim 1 , wherein the actuating time (ΔT B ) lies in a range from 50 milliseconds to 1 second.

6. The method of claim 1 , wherein the actuating stroke corresponds to 40% to 90% of a composite actuating stroke (I; III) of the actuating member.

7. The method of claim 1 further comprising the step of switching the control unit back to the blocking state when no operating signal is received within a predefined pause-time (ΔT P ) after the occurrence of the control signal.

8. The method of claim 7 , wherein the pause-time (ΔT P ) lies in a range between 1 and 5 seconds.

9. The method of claim 1 , wherein:
the handle has a grip sensor configured to output a presence signal when a hand of the user is present; and,
the control signal is only generated when the grip sensor is outputting a presence signal.

10. The method of claim 9 further comprising the step of:
switching the control unit back into the blocking state when the presence signal of the grip sensor ceases.

11. The method of claim 10 , wherein the control unit only switches back to the blocking state after a predefined amount of time has passed and the presence signal of the grip sensor remains dormant.

12. The method of claim 1 , wherein the actuating stroke of the actuating member and the return stroke of the actuating member are the same.

13. The method of claim 1 further comprising the step of displaying the standby state via an optical display.

14. The method of claim 13 , wherein the optical display is an LED.

15. A handheld work apparatus comprising:
an electric motor;
a voltage source configured to supply energy to said electric motor;
a handle;
a manual actuating member disposed on said handle and configured to be operated by a user of the work apparatus for activation of the work apparatus;
a control unit;
said manual actuating member being connected to said control unit and configured to output an operating signal;
said control unit being configured to control the energy supply from said voltage source to said electric motor in dependence upon said operating signal;
said control unit being further configured to block the energy supply to said electric motor independently of said operating signal of said manual actuating member;
said control unit being further configured to switch out of said blocking state into a standby state after receiving a control signal so as to allow an energy supply to said electric motor;
said control signal being derived from a combination of an actuating stroke of said manual actuating member and an actuating time (ΔT B ) of said manual actuating member; and,
said control signal being generated when said manual actuating member has performed a predefined actuating stroke beyond a stroke threshold (H S ) in an actuating direction and a predefined return stroke counter to said actuating direction within the predefined actuating time (ΔT B ).

16. The work apparatus of claim 15 , wherein said manual actuating member is configured to have an increased spring force acting thereagainst at said stroke threshold (H S ).

17. The work apparatus of claim 15 , wherein:
said handle includes a handle housing having a switching depression formed therein; and,
said switching depression is associated with said stroke threshold (H S ) of said manual actuating member.

18. The work apparatus of claim 15 further comprising a grip sensor associated with said manual actuating member and configured to detect a hand of a user.

19. The work apparatus of claim 18 , wherein said grip sensor is configured as an actuating lock for said manual actuating member.

20. The work apparatus of claim 15 , wherein said manual actuating member defines a positioning path; and, the work apparatus further comprising:
at least one of a switch and a potentiometer configured to determine said positioning path.

Assignees

• Stihl Ag & Co Kg Andreas

Inventors

• Gerstenberger Oliver
• Hoche Florian
• Gurr Kay-Steffen
• Gwosdz Fabian

Classifications

• B23Q11/0078 Primary

  Safety devices protecting the operator, e.g. against accident or noise (protecting the machine tool B23Q5/58; protecting people, in general F16P1/00, F16P3/00) · CPC title

• B25F5/00 Primary

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• F16P3/00

  Safety devices acting in conjunction with the control or operation of a machine; Control arrangements requiring the simultaneous use of two or more parts of the body (F16P5/00 takes precedence) · CPC title