Knockout tools
Power-driven knockout tools are provided, including knockout tool accessory devices for power-driven tools. A plurality of different die sets can be coupled to the knockout tools, for forming openings through rigid plate or sheet material. The knockout tool portion of the tools may include a transmission that provides for sufficient speed reduction and corresponding increase in output torque from an input speed/torque associated with a rotary force input to the transmission to an output speed and an output torque for the pulling of a punch portion of the die set through the rigid sheet or plate material.
1 . A knockout tool comprising:
a housing;
a transmission received in the housing;
an input shaft at least partially received in the housing and configured to transmit an input torque to the transmission;
a driving member at least partially received in the housing and configured to be rotatably driven about a first axis by the transmission, the driving member including a threaded first portion and a second portion proximate the threaded first portion; and
a driven member at least partially received in the housing and configured to be axially moveable along a second axis, the driven member including a coupling portion configured to be coupled to a punch of a die set and a threaded portion engageable with the threaded first portion;
wherein, during operation, in response to rotation of the input shaft in a first direction, the threaded first portion is rotatably driven by the transmission to engage the threaded portion such that rotation of the driving member about the first axis causes axial movement of the driven member and the punch in a first axial direction along the second axis to form a hole in a workpiece; and
wherein, in response to further rotation of the input shaft, the threaded portion is positioned proximate the second portion causing the threaded first portion and the threaded portion to disengage such that further rotation of the driving member about the first axis does not cause axial movement of the driven member along the second axis.
2 . The knockout tool of claim 1 , wherein at least one of the driving member or the driven member includes an unthreaded portion.
3 . The knockout tool of claim 1 , further comprising a spring that biases at least one of the threaded first portion and the threaded portion toward being in engagement with each other.
4 . The knockout tool of claim 3 , wherein, in response to disengagement of the threaded first portion and the threaded portion, rotation of the input shaft in a second direction opposite the first direction and a biasing force of the spring cause the threaded first portion and the threaded portion to re-engage.
5 . The knockout tool of claim 3 , wherein the spring is positioned between an end portion of the driven member and a bearing coupling the driving member to the transmission, wherein the spring exerts a biasing force on the driven member that urges re-engagement of the threaded first portion of the driving member with the threaded portion of the driven member.
6 . The knockout tool of claim 1 , wherein the transmission includes a gear assembly including a plurality of gears to provide a speed reduction and torque increase from the input shaft to the driving member.
7 . The knockout tool of claim 6 , wherein the gear assembly includes at least one planetary gear set configured to transmit torque from the input shaft to an output member of the at least one planetary gear set.
8 . The knockout tool of claim 7 , wherein the gear assembly further includes a first spur gear configured to be driven by the output member of the at least one planetary gear set and a second spur gear configured to be driven by the first spur gear.
9 . The knockout tool of claim 6 , wherein the gear assembly includes:
an input spur gear;
an intermediate spur gear mounted on an intermediate shaft and in meshed engagement with the input spur gear, and configured to rotate in response to rotation of the input spur gear;
a worm gear formed on an outer portion of the intermediate shaft and configured to rotate together with the intermediate spur gear and the intermediate shaft; and
an output gear in meshed engagement with the worm gear and configured to rotate in response to rotation of the worm gear.
10 . The knockout tool of claim 6 , wherein the gear assembly includes:
an input bevel gear;
an output bevel gear in meshed engagement with the input bevel gear, wherein the output bevel gear is configured to rotate in response to rotation of the input bevel gear;
at least one planetary gear set configured to transmit torque in response to rotation of the output bevel gear;
an input spur gear configured to rotate in response to rotation of an output member of the at least one planetary gear set; and
an output spur gear in meshed engagement with the input spur gear and configured to rotate in response to rotation of the input spur gear.
11 . The knockout tool of claim 1 , further comprising:
a punch of a die set coupleable to the driven member and movable axially along the second axis with the driven member.
12 . The knockout tool of claim 6 , wherein a speed reduction ratio of the transmission is between 500:1 and 1500:1.
13 . The knockout tool of claim 1 , wherein the knockout tool is configured to generate at least 50 kN of axial pulling force at the driven member.
14 . The knockout tool of claim 1 , wherein a volume of the housing is between 352 cm 3 and 1220 cm 3 .
15 . The knockout tool of claim 1 , wherein a ratio of an axial pulling force at the driven member to a volume of the housing is between 0.03 kN/cm 3 and 0.15 kN/cm 3 .
16 . The knockout tool of claim 1 , wherein the input shaft is configured to be driven by an output tool holder of a separate rotary power tool.
17 . The knockout tool of claim 16 , further comprising a brace assembly configured to support the housing relative to the rotary power tool, the brace assembly including an arm configured to be removeably attached to athe power tool and a collar coupled to the arm and configured to be coupled to the housing.
18 . The knockout tool of claim 1 , further comprising an electric motor received in the housing and configured to rotatably drive the input shaft.
19 . The knockout tool of claim 18 , further comprising a handle coupled to the housing and a battery configured to provide power to the electric motor.
20 . The knockout tool of claim 1 ,
wherein the transmission includes a planetary gear set;
wherein the housing includes:
opposing front and rear sides;
a handle portion;
a motor and transmission portion located above the handle portion that contains a motor and the planetary gear set; and
a punch portion located above the motor and transmission portion that contains the driving member and the driven member;
wherein the motor includes a shaft that rotates about a third axis, wherein the second axis and the third axis are offset and parallel and each extend between the front and rear sides of the housing.
21 . The knockout tool of claim 20 , wherein the motor and the punch portion are each located forward of the handle portion.
22 . The knockout tool of claim 1 ,
wherein the knockout tool is configured to generate at least 50 kN of axial pulling force at the driven member for forming the hole in the workpiece with the die set.
23 . The knockout tool of claim 22 , wherein a ratio of an axial pulling force at the driven member to a volume of the housing is between 0.08 kN/cm 3 and 0.09 kN/cm 3 .