Electric cutting system

Patent metadata

Field	Value
Publication number	US-9656336-B2
Application number	US-201314407534-A
Country	US
Kind code	B2
Filing date	Jun 12, 2013
Priority date	Jun 12, 2012
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An electric power saw/cutter includes a rotatable saw structure, a rear handle with a switch/speed control, a front handle and a drive unit for rotating the saw structure. The drive unit itself including a saw structure drive arrangement to which the saw structure is attachable, a transmission for driving the saw drive arrangement, an electric motor for driving an input shaft of the transmission, and a support structure for holding/carrying the saw structure drive arrangement, the transmission and the electric motor. The front handle and the rear handle are directly connected to each other to form a handle unit, which unit is resiliently connected to the drive unit, so that vibrations from the saw blade and drive unit will be reduced in the handle unit.

First claim

The invention claimed is:

1. An electric power saw comprising:
a rotatable saw structure
a rear handle with a switch control
a front handle
a drive unit for rotating the saw structure, the drive unit comprising:
a saw structure drive arrangement to which the saw structure is attachable
a transmission for driving the saw drive arrangement
an electric motor for driving the transmission
a support structure for holding the saw structure drive arrangement, the transmission and the electric motor, and
a fluid control unit arranged to regulate and distribute a fluid through a plurality of conduits, wherein the front handle and the rear handle are directly connected to each other to form a handle unit, which is resiliently connected to the drive unit, so that vibrations from the saw structure and drive unit are reduced in the handle unit, and the power saw includes a cooling fluid system comprising:
at least one the cooling path in the motor, having an inlet for connecting to a fluid source and an outlet, said cooling path running within a side wall of a motor housing that is parallel to a rotor axis of the motor,
wherein the motor housing comprises an inner tubular part and an outer tubular part, wherein the cooling path is disposed between the inner tubular part and the outer tubular part,
wherein the rear handle further includes a trigger lock opposite to the switch control, the trigger lock activating the switch control when the trigger lock is actuated, the trigger lock further opening an inlet valve of the fluid control unit when being actuated and returning the inlet valve to a closed position when the trigger lock is not actuated, and
wherein the fluid control unit includes a transfer conduit which connects to the outlet and includes a fluid valve configured to direct fluid from the motor to a tool conduit leading to at least one nozzle at the rotatable saw structure and/or to a return conduit to discard or return a remaining flow to the fluid source.

2. An electric power saw according to claim 1 , wherein the rotatable saw structure is one circular saw blade and the saw structure drive arrangement is a saw blade drive shaft.

3. An electric power saw according to claim 1 , wherein the rotatable saw structure is formed by two circular saw blades at an axial distance from each other and the saw structure drive arrangement is a common saw blade drive shaft driving both saw blades.

4. An electric power saw according to claim 1 , wherein the rotatable saw structure is a ring saw blade and the saw structure drive arrangement is a ring saw aggregate.

5. An electric power saw according to claim 1 , comprising an anti-vibration handle system comprising vibration-damping elements positioned between the handle unit and the drive unit.

6. An electric power saw according to claim 5 , wherein said anti-vibration handle system comprises at least three vibration-damping elements.

7. An electric power saw according to claim 5 , wherein at least one of the vibration-damping elements is a resilient element.

8. An electric power saw according to claim 1 , wherein the electric motor is a high frequency, permanent magnet motor having the motor housing surrounding a stator and a rotor.

9. An electric power saw according to claim 1 , wherein the cooling path runs in the side wall in a circular helix around the stator housed in the motor housing.

10. An electric power saw according to claim 1 , wherein the fluid control unit includes a tool conduit valve downstream the inlet valve that can be gradually adjusted by an operator between a fully closed position and a fully opened position, said tool conduit valve leading to the tool conduit.

11. An electric power saw according to claim 1 , wherein the fluid control unit includes a return conduit valve downstream the inlet valve that can be set in at least two modes by an operator, an open mode for returning fluid to the return conduit and a closed mode for blocking fluid flow to the return conduit.

12. An electric power saw according to claim 1 , wherein the transmission is a belt transmission.

13. An electric power saw according to claim 1 , wherein the cooling path is formed by a groove in the inner tubular part.

14. An electric power saw according to claim 1 , wherein an outer diameter of the inner tubular part is substantially equal to an inner diameter of the outer tubular part, such that the inner tubular part is insertable into the second tubular part.

15. An electric power saw comprising:
a rotatable saw structure
a rear handle with a switch control a front handle
a drive unit for rotating the saw structure, the drive unit comprising: a saw structure drive arrangement to which the saw structure is attachable a transmission for driving the saw drive arrangement an electric motor for driving the transmission
a support structure for holding the saw structure drive arrangement, the transmission and the electric motor, and
a fluid control unit arranged to regulate and distribute a fluid through a plurality of conduits, wherein the power saw includes a cooling fluid system comprising:
a cooling path in the motor, having an inlet for connecting to a fluid source and an outlet, said cooling path running within a side wall of a motor housing that is parallel to a rotor axis of the motor,
wherein the motor housing comprises an inner tubular part and an outer tubular part, wherein the cooling path is disposed between the inner tubular part and the outer tubular part,
wherein the rear handle further includes a trigger lock opposite to the switch control, the trigger lock activating the switch control when the trigger lock is actuated, the trigger lock further opening an inlet valve of the fluid control unit when being actuated and returning the inlet valve to a closed position when the trigger lock is not actuated, and
wherein the fluid control unit includes a transfer conduit which connects to the outlet and includes a fluid valve configured to direct fluid from the motor to a tool conduit leading to at least one nozzle at the rotatable saw structure and/or to a return conduit to discard or return a remaining flow to the fluid source.

16. An electric power saw comprising:
a rotatable saw structure
a rear handle with a switch control
a front handle
a drive unit for rotating the saw structure, the drive unit comprising:
a saw structure drive arrangement to which the saw structure is attachable
a transmission for driving the saw drive arrangement
an electric motor for driving the transmission
a support structure for holding the saw structure drive arrangement, the transmission and the electric motor, and
a fluid control unit arranged to regulate and distribute a fluid through a plurality of conduits, wherein the power saw includes a cooling fluid system comprising:
a cooling path in the motor, having an inlet for connecting to a fluid source and an outlet, said cooling path running within a side wall of a motor housing,
wherein the rear handle further includes a trigger lock opposite to the switch control, the trigger lock activating the switch control when the trigger lock is actuated, the trigger lock further opening an inlet valve of the fluid control unit when being actuated and the trigger lock returning the inlet valve to a closed position when the trigger lock is not actuated, and
wherein the fluid control unit includes a transfer conduit which connects to the outlet and includes a fluid valve configured to direct fluid from the motor to a tool conduit leading to at least one nozzle at the rotatable saw structure and/or to a return condu

Assignees

• Husqvarna Ab

Inventors

• Petersson Ulf
• Bergvall Bengt Allan
• Pinzani Håkan
• Carlsson Pär
• Vidlund Adam
• Berg Johan
• Bennehag Anders

Classifications

• H02K9/19

  for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil · CPC title

• B23D59/02

  Devices for lubricating or cooling circular saw blades · CPC title

• B23B45/02

  driven by electric power · CPC title

• B28D7/02

  for removing or laying dust, e.g. by spraying liquids; for cooling work · CPC title

• B23D47/12

  of drives for circular saw blades · CPC title