Impact wrench

Claim 2

In a power tool, a combination comprising a fluid-actuated motor; means for supplying pressurized fluid to said motor; actuator means driven by said motor and generating a series of impacts; means for sensing the occurrence of each impact and for generating a pressure pulse in response thereto; and means for interrupting the supply of said pressurized fluid to said motor when a predetermined cumulative number of said pulses has been generated.

Claim 3

Apparatus as defined in claim 1 wherein said sensing means comprises a control duct and a valve and valve plug in said duct for controllably admitting fluid pressure to the duct; and a push rod interconnecting the valve plug with the actuator means.

Claim 4

Apparatus as defined in claim 2 wherein said valve has a seat surface, a port aperture in said surface for admitting fluid pressure thereto, a further port aperture in said surface for transmitting pressure therefrom to the control duct, and the valve plug is a disc-shaped plate movable onto and away from said seat by said push rod.

Claim 5

Apparatus as defined in claim 1, wherein said sensing means includes a control duct, a throttle therein, and vent means connectable with said motor and the control duct.

Claim 6

Apparatus as defined in claim 4 wherein the throttle is disposed between said vent means and said sensing means.

Claim 7

Apparatus as defined in claim 4 wherein said throttle has a throttle valve body and means are provided for selectively connecting the throttle valve to the control duct and disconnecting it therefrom.

Claim 8

Apparatus as defined in claim 4 wherein the throttle has means for adjusting the same to thereby modify the number of pulses needed for controlling said fluid power motor.

Claim 9

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct and a valve and valve plug in said duct for controllably admitting fluid pressure to the duct, and a push rod interconnecting the valve plug with the impactor, said valve having a seat surface, a port aperture in said surface for admitting fluid pressure thereto, a further port aperture in said surface for transmitting pressure therefrom to the control duct, and the valve plug being discshaped plate movable onto and away from said seat by said push rod; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.

Claim 10

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct and a valve and valve plug in said duct for controllably admitting fluid pressure to the duct, and a push rod interconnecting the valve plug with the impactor, said valve having a seat surface, a port aperture in said surface for admitting fluid pressure thereto, a further port aperture in said surface for transmitting pressure therefrom to the control duct, and the valve plug being discshaped plate movable onto and away from said seat by said push rod; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.

Claim 11

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses, and including a duct for admitting fluid pressure to said motor, a slider movable between a first position outside said duct and a second position across said duct, means operable by fluid pressure impulses derived from said fluid pressure for moving said slider to said second position, and a spring for normally biassing said slider to said first position.

Claim 12

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses, and including a duct for admitting fluid pressure to said motor, a slider movable between a first position outside said duct and a second position across said duct, means operable by fluid pressure impulses derived from said fluid pressure for moving said slider to said second position, and a spring for normally biassing said slider to said first position.

Claim 13

Apparatus as defined in claim 9 wherein said slider has a cylindrical portion movable longitudinally of the axis thereof and said spring is a compression spring coaxial with said cylinder.

Claim 14

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct; vent means connectable with the fluid power motor and the control duct, and a throttle in said control duct between said vent means and said means for generating said fluid control impulses; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.

Claim 15

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct; vent means connectable with the fluid power motor and the control duct, and a throttle in said control duct between said vent means and said means for generating said fluid control impulses; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.

Claim 16

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct, a throttle therein having a throttle valve body, means for selectively connecting the throttle valve to the control duct and disconnecting it therefrom, and vent means connectable with the fluid power motor and the control duct; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.

Claim 17

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct, a throttle therein having a throttle valve body, means for selectively connecting the throttle valve to the control duct and disconnecting it therefrom, and vent means connectable with the fluid power motor and the control duct; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.

Claim 18

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct; a throttle therein; means for adjusting said throttle to therEby modify the numer of control impulses needed for controlling said fluid power motor, and vent means connectable with the fluid power motor and the control duct; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.

Claim 19

An impact wrench comprising a fluid power motor and an impactor driven thereby for effecting rotary motion of a tool; means for axially reciprocating said impactor during such rotary motion to rotate the tool by impacts in response to a torque resistance; means for generating a fluid control impulse in response to an axial reciprocation of said impactor and including a control duct; a throttle therein; means for adjusting said throttle to therEby modify the numer of control impulses needed for controlling said fluid power motor, and vent means connectable with the fluid power motor and the control duct; and means controlled by said torque resistance for controlling said fluid power motor by such fluid control impulses.