Impact Tools With Rigidly Coupled Impact Mechanisms

• US 20190321958A1
• Filed: 04/20/2018
• Published: 10/24/2019
• Est. Priority Date: 04/20/2018
• Status: Active Grant

• Current Assignee: Ingersoll-Rand Industrial U.S., Inc. (Ingersoll Rand, Inc.)
• Original Assignee: Ingersoll-Rand Company (Trane Technologies plc)
• Inventors: Cooper, Timothy R., Linehan, John J., Eardley, Edward Charles
• Granted Patent: US 11,247,321 B2
• Time in Patent Office: Days
• CPC Class Codes: B25B 21/02 with means for imparting impact to screwdriver blade or nut socket
• CPC Class Codes: B25B 21/026 Impact clutches
• CPC Class Codes: B25D 11/068 in which the tool bit or anvil is hit by a rotary impulse member
• CPC Class Codes: B25D 11/106 cam member and cam follower having the same shape B25D11/104 takes precedence
• CPC Class Codes: B25D 17/06 Hammer pistons; Anvils ; Guide-sleeves for pistons
• CPC Class Codes: B25D 2211/062 Cam-actuated impulse-driving mechanisms
• CPC Class Codes: B25D 2250/095 Electric motors
• CPC Class Codes: B25D 2250/195 Regulation means
• CPC Class Codes: B25D 2250/221 Sensors

Abstract

Illustrative embodiments of impact tools with impact mechanisms rigidly coupled to electric motors are disclosed. In at least one illustrative embodiment, an impact tool may comprise an impact mechanism, an electric motor, and a control circuit. The impact mechanism may comprise a hammer and an anvil, the hammer being configured to rotate about a first axis and to periodically impact the anvil to drive rotation of the anvil about the first axis. The electric motor may comprise a rotor that is rigidly coupled to the impact mechanism, the electric motor being configured to drive rotation of the hammer about the first axis. The control circuit may be configured to supply a current to the electric motor and to prevent the current from exceeding a threshold in response to the hammer impacting the anvil.

Claims

1. An impact tool comprising:

an impact mechanism comprising a hammer and an anvil, the hammer being configured to rotate about a first axis and to periodically impact the anvil to drive rotation of the anvil about the first axis;

an electric motor comprising a rotor that is directly coupled to the impact mechanism, the electric motor being configured to drive rotation of the hammer about the first axis;

wherein the motor rotates the hammer in a first direction, and the hammer causes the rotor to periodically stop rotating in the first direction when the hammer periodically impacts the anvil; and

a control circuit that supplies a current to the electric motor and limits the current supplied to the electric motor.

2. The impact tool of claim 1, wherein the control circuit limits the current supplied to the electric motor by disabling the supply of current when the current exceeds a threshold.

3. The impact tool of claim 1, wherein the control circuit limits the current supplied to the electric motor in response to the hammer impacting the anvil.

4. The impact tool of claim 1, wherein the control circuit includes a pulse width modulation circuit, and a current measurement circuit, that disables the supply of current to the electric motor for each successive cycle the current exceeds a specified threshold for the electric motor.

5. The impact tool of claim 1, wherein the control circuit dictates a current limit for the electric motor.

6. The impact tool of claim 1, wherein the control circuit comprises an electronic controller to determine whether the hammer has impacted the anvil and to prevent the current from exceeding the threshold.

7. The impact tool of claim 1, wherein the control circuit comprises an electronic controller to determine a desired parameter of the impact mechanism and to adjust the threshold to a level associated with achieving the desired parameter of the impact mechanism.

8. The impact tool of claim 7, wherein the desired parameter is at least one of a rotational speed achieved by the hammer, a torque delivered by the hammer to the anvil upon impact, a rebound angle of the hammer after impacting the anvil, or a frequency at which the hammer impacts the anvil.

9. The impact tool of claim 1, wherein the hammer is directly coupled to the rotor for rotation therewith about the first axis and the hammer comprises a hammer jaw configured to translate parallel to the first axis between a disengaged position and an engaged position such that the hammer jaw impacts the anvil when in the engaged position.

10. The impact tool of claim 1, wherein the impact mechanism further comprises a hammer frame supporting the hammer for rotation about the first axis, the hammer being pivotably coupled to the hammer frame such that the hammer is further configured to pivot about a second axis different from the first axis.

11. The impact tool of claim 10, wherein the hammer frame is directly coupled to the rotor by a connection selected from the group consisting of a splined connection between the hammer frame and the rotor, and the hammer frame and the rotor integrally formed as a monolithic component.

12. The impact tool of claim 9, wherein the impact mechanism further comprises a camming plate configured to drive rotation of the hammer about the first axis, the camming plate being rigidly coupled to the rotor by a splined connection between the camming plate and the rotor.

13. The impact tool of claim 9, wherein the impact mechanism further comprises a camming plate configured to drive rotation of the hammer about the first axis, the camming plate and the rotor being integrally formed as a monolithic component.

14. An impact tool comprising:

a swinging weight impact mechanism comprising a hammer frame supporting a hammer that rotates about a first axis, the hammer being pivotably coupled to the hammer frame such that the hammer is also configured to pivot about a second axis different from the first axis, and an anvil configured to rotate about the first axis when impacted by the hammer; and

an electric motor comprising a rotor that is directly coupled to the swinging weight impact mechanism, the electric motor being configured to drive rotation of the hammer about the first axis in a first direction;

wherein the rotor is directly coupled to the swinging weight impact mechanism such that rotation of the rotor in the first direction rotates the hammer in the first direction, and when the hammer stops rotating in the first direction the rotor is concurrently stopped rotating in the first direction.

15. The impact tool of claim 14, wherein the hammer frame is directly coupled to the rotor by a connection selected from the group consisting of a splined, hex, star, D, and square connection between the hammer frame and the rotor, and the hammer frame and the rotor integrally formed as a monolithic component.

16. The impact tool of claim 14, wherein the swinging weight impact mechanism further comprises a camming plate configured to drive rotation of the hammer about the first axis, the camming plate being rigidly coupled to the rotor by a splined connection between the camming plate and the rotor.

17. The impact tool of claim 14, wherein the swinging weight impact mechanism further comprises a camming plate to drive rotation of the hammer about the first axis, the camming plate and the rotor being integrally formed as a monolithic component.

18. An impact tool comprising:

an electric motor comprising a rotor configured to rotate about a first axis; and

an impact mechanism comprising a hammer configured to rotate about the first axis and an anvil configured to rotate about the first axis when impacted by the hammer;

wherein the hammer comprises a hammer base directly coupled to the rotor to rotate therewith about the first axis and a hammer jaw configured to translate parallel to the first axis between a disengaged position and an engaged position in response to rotation of the hammer base about the first axis such that the hammer jaw rotates about the first axis without impacting the anvil when in the disengaged position and impacts the anvil when in the engaged position;

wherein the rotor is directly coupled to the hammer base such that rotation of the rotor in a first direction about the first axis rotates the hammer in the first direction about the first axis, and when the hammer stops rotating in the first direction about the first axis the rotor is concurrently stopped rotating in the first direction about the first axis.

19. The impact tool of claim 18, wherein the hammer base and the hammer jaw are integrally formed as a monolithic component.

20. The impact tool of claim 18, wherein the hammer further comprises a pin supported by the hammer base and configured to translate parallel to the first axis in response to rotation of the hammer base about the first axis, the hammer jaw being formed on the pin.

21. The impact tool of claim 18, further comprising a control circuit that supplies a current to the electric motor and limits the current supplied to the electric motor in response to the hammer impacting the anvil.