Fluid-driven tool with built-in work control mechanism

Claim 2

In A fluid driven apparatus of the type having a fluid input and a fluid driven motor in communication with said input, improved means for controlling fluid flow from said input to said motor to control the work output of said motor, comprising, in combination: a fluid flow line from said input to said motor; first fluid valve means in said line upstream from said motor, said first fluid valve means having a normally open position to prevent fluid flow to said motor and an actuable closed position to permit fluid flow to said motor, timing means, and fluid pressure sensing means upstream from said first fluid valve means for sensing increased back pressure in said fluid flow line after said first fluid valve means is closed and said motor encounters increased resistance to fluid driven operation, said sensing means operating to then provide a fluid signal to said timing means which, in turn, after a predetermined increment of time, provides a fluid signal to open said first fluid valve means and discontinue operation of said motor.

Claim 3

The improvement of claim 1 wherein said timing means is adjustable to provide for adjustment of said predetermined time increment.

Claim 4

The improvement of claim 1 including restrictor means between said fluid pressure sensing means and said first fluid valve means.

Claim 5

The improvement of claim 1 including manual valve means for opening and closing said fluid flow line to said motor through said first fluid valve means, said manual means in said fluid flow line upstream said first fluid valve means and comprising a portion of said fluid pressure sensing means.

Claim 6

The improvement of claim 1 wherein said first fluid valve means includes a first fluid valve for receiving a fluid flow line signal and a timing means fluid signal, said signals being algebraically summed by said first fluid valve to control fluid flow to said motor.

Claim 7

The improvement of claim 1 wherein said timing means includes a timing restrictor.

Claim 8

The improvement of claim 1 including exhaust means for exhausting said timing means whenever said motor does not receive fluid flow.

Claim 9

The improvement of claim 1 wherein said fluid pressure sensing means includes fluid restrictor means in said fluid flow line upstream said first fluid valve means, means for providing a first fluid pressure signal, said first signal being initially indicative of the line pressure in said fluid flow line when said first fluid valve means is open, means for providing a second fluid pressure signal indicative of the line pressure in said fluid flow line downstream said restrictor means when said first fluid valve means is closed, means for algebraically summing said first signal with said second signal, the algebraic sum of said signals providing an output signal to said timing means whenever the algebraic sum of said first and second signals changes from a first sign to a second sign.

Claim 10

The improvement of claim 8 wherein said means for providing a first signal includes a first conduit from said fluid flow line to said second valve means, and a restrictor intermediate said second valve means and connection of said first conduit to said fluid flow line.

Claim 11

The improvement of claim 8 wherein said means for providing a first signal includes exhaust means for diminishing said first signal whenever fluid flows through said restrictor means.

Claim 12

The improvement of claim 10 wherein said exhaust means includes means for controlling the rate of exhaust.

Claim 13

The improvement of claim 11 wherein said means for controlling the rate of exhaust is adjustable.

Claim 14

The improvement of claim 8 wherein said means for providing a first signal includes means for delaying any change in said first signal.

Claim 15

The improvement of claim 13 wherein said means for delaying change in said first signal includes reservoir means.

Claim 16

The improvement of claim 8 wherein said second valve means includes a pressure responsive diaphragm, one portion of said diaphragm being responsive to Said first signal and another portion of said diaphragm being responsive to said second signal, said diaphragm being movable to effect switching whenever the algebraic sum of said signals sensed by said diaphragm changes from a first sign to a second sign.

Claim 17

The improvement of claim 1 wherein said timing means includes timing reservoir means for receiving fluid, the increment of time being a function of the volume of said timing reservoir means.

Claim 18

The improvement of claim 16 wherein said timing restrictor is adjustable.

Claim 19

The improvement of claim 16 wherein said timing means includes timing reservoir means and said timing restrictor is upstream said timing reservoir means.

Claim 20

The improvement of claim 18 wherein said time increment is adjustable.

Claim 21

The improvement of claim 18 wherein said fluid pressure sensing means is adjustable to sense a desired back pressure before effecting closure of said first fluid valve means.

Claim 22

The improvement of claim 18 wherein said fluid pressure sensing means includes a first fluid conduit from the upstream side of said manual valve means in said fluid flow line connected to said second fluid valve means, said conduit carrying a fluid pressure signal, said signal being initially indicative of said line pressure in said fluid flow line when said manually operable valve is open, said signal being algebraically summed with a second fluid pressure signal indicative of the line pressure in said fluid flow line downstream of said manually operable valve to thereby operate said second valve means whenever the algebraic sum of said signals changes sign.

Claim 23

In a fluid driven apparatus of the type having a fluid input and a fluid driven motor in communication with said input, the improvement comprising, in combination: improved means for controlling fluid flow from said input to said motor to thereby control the work output of said motor comprising, in combination: a fluid flow line from said input to said motor, first fluid valve means in said line upstream from said motor, said first fluid valve means having a closed position to permit fluid flow to said motor, a manually operable valve in said line upstream from said first fluid valve means, said manual valve having a closed position to permit fluid flow to said motor, restrictor means in said fluid flow line interposed between said first valve means and said manually operable valve means, and fluid pressure sensing means for sensing the back pressure in said fluid flow line upon increased resistance to fluid driven operation of said motor, said fluid pressure sensing means including second fluid valve means connected with said fluid flow line upstream said restrictor, said second fluid valve means also connected with said first fluid valve means and operable to provide fluid flow to and thereby position said first fluid valve means in open position subsequent to a time increment following sensing of said back pressure.

Claim 24

In a fluid driven apparatus of the type having a fluid input and a fluid driven motor in communication with said input, the improvement comprising, in combination: improved means for controlling fluid flow from said input to said motor to thereby control the work output of said motor comprising, in combination: a fluid flow line from said input to said motor, first fluid valve means in said line upstream from said motor, said first fluid valve means having a closed position to permit fluid flow to said motor, a manually operable valve in said line upstream from said first fluid valve means, said manual valve having a closed position to permit fluid flow to said motor, restrictor means in said fluid flow line interposed between said first valve means and said manually operable valve means, and fluid pressure sensing means for sensing the back pressure in said fluid flow line upon increased resistance to fluid driven operation of said motor, said fluid pressure sensing means including second fluid valve means connected with said fluid flow line upstream said restrictor, said second fluid valve means also connected with said first fluid valve means and operable to provide fluid flow to and thereby position said first fluid valve means in open position subsequent to a time increment following sensing of said back pressure.

Claim 25

In a fluid driven apparatus of the type having a fluid inlet and a fluid driven motor in communication with said inlet, improved means for controlling fluid flow from said inlet to said motor to control the work output of said motor comprising, in combination: a fluid flow line from said inlet to said motor; first fluid valve means in said line upstream from said motor, said first fluid valve means having a normally open position to prevent fluid flow to said motor and an actuable closed position to permit fluid flow to said motor; timing means; a manually operable valve in said line upstream from said first fluid valve means, said manual valve having a closed position to permit fluid flow to said motor; and fluid pressure sensing means upstream from said first fluid valve means and downstream from said manually operable valve, said fluid pressure sensing means operable for sensing increased back pressure in said fluid flow line after said first fluid valve means is closed and said manual valve is Closed and said motor encounters increased resistance to a fluid driven operation, said sensing means operating to then provide a fluid signal to said timing means which, in turn, after a predetermined increment of time provides a fluid signal to open said first fluid valve means and discontinue operation of said motor.

Claim 26

In a fluid driven apparatus of the type having a fluid inlet and a fluid driven motor in communication with said inlet, improved means for controlling fluid flow from said inlet to said motor to control the work output of said motor comprising, in combination: a fluid flow line from said inlet to said motor; first fluid valve means in said line upstream from said motor, said first fluid valve means having a normally open position to prevent fluid flow to said motor and an actuable closed position to permit fluid flow to said motor; timing means; a manually operable valve in said line upstream from said first fluid valve means, said manual valve having a closed position to permit fluid flow to said motor; and fluid pressure sensing means upstream from said first fluid valve means and downstream from said manually operable valve, said fluid pressure sensing means operable for sensing increased back pressure in said fluid flow line after said first fluid valve means is closed and said manual valve is Closed and said motor encounters increased resistance to a fluid driven operation, said sensing means operating to then provide a fluid signal to said timing means which, in turn, after a predetermined increment of time provides a fluid signal to open said first fluid valve means and discontinue operation of said motor.

Claim 27

In a fluid driven apparatus of the type having a fluid input and a fluid driven motor in communication with said input, improved means for controlling fluid flow from said input to said motor to control the work output of said motor, comprising in combination: a fluid flow line from said input to said motor; first fluid flow valve means in said line upstream from said motor, said first fluid valve means having a normally open position to prevent fluid flow to said motor and an actuable closed position to permit fluid flow to said motor; timing means; and fluid pressure sensing means upstream from said first fluid valve means, said fluid pressuring sensing means including fluid restrictor means in said fluid flow line upstream from said first fluid valve means, means for providing a first fluid pressure signal, said first signal being initially indicative of the line pressure in said fluid flow line when said first fluid valve means is open, means for providing a second fluid pressure signal indicative of the line pressure in said fluid flow line downstream from said restrictor means when said first fluid valve means is closed, means for algebraically summing said first signal with said second signal, the algebraic sum of said signals providing an output signal to said timing means whenever the algebraic sum of said first and second signals changes from a first sign to a second sign.

Claim 28

In a fluid driven apparatus of the type having a fluid input and a fluid driven motor in communication with said input, improved means for controlling fluid flow from said input to said motor to control the work output of said motor, comprising in combination: a fluid flow line from said input to said motor; first fluid flow valve means in said line upstream from said motor, said first fluid valve means having a normally open position to prevent fluid flow to said motor and an actuable closed position to permit fluid flow to said motor; timing means; and fluid pressure sensing means upstream from said first fluid valve means, said fluid pressuring sensing means including fluid restrictor means in said fluid flow line upstream from said first fluid valve means, means for providing a first fluid pressure signal, said first signal being initially indicative of the line pressure in said fluid flow line when said first fluid valve means is open, means for providing a second fluid pressure signal indicative of the line pressure in said fluid flow line downstream from said restrictor means when said first fluid valve means is closed, means for algebraically summing said first signal with said second signal, the algebraic sum of said signals providing an output signal to said timing means whenever the algebraic sum of said first and second signals changes from a first sign to a second sign.