Rotary chuck installation of fluid-actuated type

Claim 2

Safe work grip mechanism for a rotary chuck having a power drive with a manual start control operative on manipulation to start the power drive, and companion fixed and rotary coupling members having a port in the fixed member, a cylinder in the rotary member with a piston defining in the cylinder a chuckclosing end and being shiftable into chuck-closing and chuckopening positions, and a first passage from said port to said cylinder end, said mechanism comprising first means, including a first plunger, associated with said start control and normally conditioning said control for operation on manipulation of the latter, but acting on subjection of said plunger to fluid pressure to render said control inoperative; a first main conduit between said port and a fluid pressure supply source; a first main valve interposed in said conduit and dividing the latter into first and second sections, of which said first section leads to said port and forms together with said first passage a second passage from said main valve to said cylinder end, with said valve being normally urged into a first position in which to interrupt communication between said sections and vent said first section, and shiftable into a second position in which to provide communication between said sections; a first check valve in said second passage normally closed to trap fluid under pressure in said cylinder end; a differential-pressure switch having two compartments and being closed except on substantial pressure equilibrium in said compartments; second and third conduits, of which said second conduit connects one of said compartments with said second passage between said main and check valves, and said third conduit connects the other compartment with said second conduit section; a constriction in said second conduit to delay fluid pressure rise to supply pressure in said one compartment at least until on admission of fluid under pressure into said cylinder end said piston has been shifted to its chuck-closing position and in the latter position is also subjected to the full supply pressure of the fluid, with said plunger being for fluid pressure subjection in communication with said second passage between said main and check valves; a second check valve in said third conduit normally closed to trap fluid under pressure in said other compartment at the supply pressure; a main relay adapted, when energized, to shift said main valve into said second position; and control circuitry for said main relay, including said main relay, a manual start switch and said differential-pressure switch, with said circuitry being closed on closure of said start switch when said differential-pressure switch is closed, and being opened on opening of said differential-pressure switch when said start switch is open.

Claim 3

Safe work grip mechanism for a rotary chuck as in claim 1, in which said drive start control is a drive start circuit including another manual switch, said means includes a normally-closed safety switch in said drive circuit in series with said other manual switch, with said safety switch being opened by said plunger when subjected to fluid pressure, and said drive start circuit being open when either of said safety and other switches is open, and being closed when both of said safety and other switches are closed, and said control circuitry is in parallel with said drive start circuit and includes a control switch arranged to be closed when the power drive is inoperative and to be opened when the power drive is operative, with said control circuitry being open when said control switch is open.

Claim 4

Safe work grip mechanism for a rotary chuck as in claim 2, in which said control switch is a centrifugal switch operatively associated with said power drive.

Claim 5

Safe work grip mechanism for a rotary chuck as in claim 1, in which said fluid pressure supply source includes a pressure regulator settable for different output pressures of the fluid, and there is further provided a vent in said third conduit between said other compartment and second check valve, and a plunger normally closing said vent and manipulatable to open said vent.

Claim 6

Safe work grip mechanism for a rotary chuck as in claim 1, in which said constriction is provided by a valve interposed in said second conduit and adjustable to vary the size of said constriction.

Claim 7

Safe work grip mechanism for a rotary chuck as in claim 1, in which said piston defines in said cylinder another end for shifting said piston to said chuck-opening position on admission of fluid under pressure into said other cylinder end, and said coupling members have a second port in said fixed member and a third passage from said second port to said other cylinder end, and there is further provided another main conduit from said fluid pressure supply source to said second port, a second main valve interposed in said other main conduit and dividing the latter into third and fourth sections of which said third section leads to said second port, with said second main valve being normally urged into a first position in which to interrupt communication between said third and fourth conduit sections and vent said third conduit section, and shiftable into a second position in which to provide communication between said third and fourth conduit sections, a second plunger associated with said first check valve and operative on subjection to fluid pressure to open the latter, a fluid passage from said third conduit section to said second plunger for fluid pressure subjection of the latter, and unchucking means manually operable for shifting said second main valve into said second position.

Claim 8

Safe work grip mechanism for a rotary chuck as in claim 6, in which said drive start control is a drive start circuit, including another manual switch closable to close the circuit, said first means includes a normally-closed safety switch in said drive start circuit in series with said other switch, with said safety switch being opened by said first plunger when subjected to fluid pressure, said control circuitry is in parallel with said drive start circuit and includes a control switch arranged to be closed and opened when the power drive is inoperative and operative, respectively, with said control circuitry being open when said control switch is open, and said unchucking means is an unchucking circuit including a manual unchucking switch, said control switch, and a second main relay adapted, when energized, to shift said second main valve into said second position, with said unchucking circuit being closed on closure of said unchucking and control switches, and being open when either said unchucking switch or said control switch is open.

Claim 9

Safe work grip mechanism for a rotary chuck as in claim 7, in which said control circuitry includes a further normally-closed switch which, when opened, opens said control circuitry, with said further switch being ganged with said unchucking switch so that the latter is open when said further switch is closed, and is closed when said further switch is open.

Claim 10

Safe work grip mechanism for a rotary chuck having a power drive with a manual start control operative on manipulation to start the power drive, and companion fixed and rotary coupling members having first and second ports in the fixed member, a cylinder in the rotary member with a piston defining in the cylinder opposite first and second ends and being shiftable into two operating positions on admission of fluid under pressure into the respective cylinder ends, and first and second passages from said first and second ports to said first and second cylinder ends, respectively, said mechanism comprising first means, including a first plunger, associated with said drive start control and normally conditioning said control for operatioN on manipulation of the latter, but acting on subjection of said plunger to fluid pressure to render said control inoperative; first and second conduits from a fluid pressure supply source to said first and second ports; respectively; first and second main valves interposed in said first and second conduits, respectively, and dividing said first and second conduits into first and second sections and into third and fourth sections, respectively, of which said first and third sections lead to said first and second ports, respectively, and together with said first and second passages define third and fourth passages leading from said first and second main valves to said first and second cylinder ends, respectively, with said first and second main valves being normally urged into a first position in which to interrupt communication between said first and second conduit sections and between said third and fourth conduit sections, respectively, and vent said first and third conduit sections, respectively, and shiftable into a second position in which to provide communication between said first and second conduit sections and between said third and fourth conduit sections, respectively; first and second check valves in said third and fourth passages, respectively, normally closed to trap fluid under pressure in the respective first and second cylinder ends; a differential-pressure switch having two compartments and being closed except on substantial pressure equilibrium in said compartments; a shuttle valve having a chamber with opposite ends in communication with said third and fourth passages, respectively, between said first main and check valves and between said second main and check valves, and a movable valve member in said chamber acting on subjection to fluid under pressure admitted through either chamber end to close the other chamber end; third and fourth conduits, of which said third conduit leads from one of said compartments to said valve chamber, and said fourth conduit leads from said fluid pressure supply source to the other of said compartments; second and third plungers associated with said first and second check valves, respectively, and each operative on subjection to fluid pressure to open the associated valve, with said second and third plungers being exposed to fluid under pressure in said fourth and third passages, respectively; a constriction in said third conduit to delay fluid pressure rise to supply pressure in said one compartment at least until on admission of fluid under pressure to either cylinder end the piston has been shifted to the corresponding operating position and is also subjected to the full supply pressure of the fluid; a third check valve in said fourth conduit normally closed to trap fluid under pressure in said other compartment at the supply pressure; first and second main relays adapted, when energized, to shift said first and second main valves, respectively, into said second position; a first circuit branch including a normally-open control switch, second and third circuit branches including said first and second main relays, respectively, switch means manipulatable into first and second positions in which to connect said first circuit branch with said second and third circuit branches, respectively, with said first circuit branch and the therewith connected second or third circuit branch forming a chucking circuit which is closed on closure of said control switch; a control relay adapted, when energized, to close said control switch, and control circuitry for said control relay, including said control relay, a manual start switch and said differential-pressure switch, with said circuit being closed on closure of said start switch when said differential-pressure switch is closed, and being opened on opening of said differential-pressure switch when said start switch is open.

Claim 11

Safe work grip mechanism for a rotary chuck having a power drive with a manual start control operative on manipulation to start the power drive, and companion fixed and rotary coupling members having first and second ports in the fixed member, a cylinder in the rotary member with a piston defining in the cylinder opposite first and second ends and being shiftable into two operating positions on admission of fluid under pressure into the respective cylinder ends, and first and second passages from said first and second ports to said first and second cylinder ends, respectively, said mechanism comprising first means, including a first plunger, associated with said drive start control and normally conditioning said control for operatioN on manipulation of the latter, but acting on subjection of said plunger to fluid pressure to render said control inoperative; first and second conduits from a fluid pressure supply source to said first and second ports; respectively; first and second main valves interposed in said first and second conduits, respectively, and dividing said first and second conduits into first and second sections and into third and fourth sections, respectively, of which said first and third sections lead to said first and second ports, respectively, and together with said first and second passages define third and fourth passages leading from said first and second main valves to said first and second cylinder ends, respectively, with said first and second main valves being normally urged into a first position in which to interrupt communication between said first and second conduit sections and between said third and fourth conduit sections, respectively, and vent said first and third conduit sections, respectively, and shiftable into a second position in which to provide communication between said first and second conduit sections and between said third and fourth conduit sections, respectively; first and second check valves in said third and fourth passages, respectively, normally closed to trap fluid under pressure in the respective first and second cylinder ends; a differential-pressure switch having two compartments and being closed except on substantial pressure equilibrium in said compartments; a shuttle valve having a chamber with opposite ends in communication with said third and fourth passages, respectively, between said first main and check valves and between said second main and check valves, and a movable valve member in said chamber acting on subjection to fluid under pressure admitted through either chamber end to close the other chamber end; third and fourth conduits, of which said third conduit leads from one of said compartments to said valve chamber, and said fourth conduit leads from said fluid pressure supply source to the other of said compartments; second and third plungers associated with said first and second check valves, respectively, and each operative on subjection to fluid pressure to open the associated valve, with said second and third plungers being exposed to fluid under pressure in said fourth and third passages, respectively; a constriction in said third conduit to delay fluid pressure rise to supply pressure in said one compartment at least until on admission of fluid under pressure to either cylinder end the piston has been shifted to the corresponding operating position and is also subjected to the full supply pressure of the fluid; a third check valve in said fourth conduit normally closed to trap fluid under pressure in said other compartment at the supply pressure; first and second main relays adapted, when energized, to shift said first and second main valves, respectively, into said second position; a first circuit branch including a normally-open control switch, second and third circuit branches including said first and second main relays, respectively, switch means manipulatable into first and second positions in which to connect said first circuit branch with said second and third circuit branches, respectively, with said first circuit branch and the therewith connected second or third circuit branch forming a chucking circuit which is closed on closure of said control switch; a control relay adapted, when energized, to close said control switch, and control circuitry for said control relay, including said control relay, a manual start switch and said differential-pressure switch, with said circuit being closed on closure of said start switch when said differential-pressure switch is closed, and being opened on opening of said differential-pressure switch when said start switch is open.

Claim 12

Safe work grip mechanism for a rotary chuck as in claim 9, in which said control circuitry provides a starting circuit for said control relay, including said cOntrol relay and said manual start switch closable to close said starting circuit, and a holding circuit for said control relay, including said control relay, said differential-pressure switch and another normally-open switch closed by said control relay when energized, with said holding circuit being closed on closure of said other and differential-pressure switches, and being opened on opening of said differential-pressure switch; and there are further provided a fourth circuit branch including a normally-open unchucking switch, and fifth and sixth circuit branches, including said first and second main relays, respectively, with said switch means in said first and second positions also connecting said fourth circuit branch with said sixth and fifth circuit branches, respectively, and said fourth and therewith connected fifth or sixth circuit branch forming an unchucking circuit closed on closure of said unchucking switch.

Claim 13

Safe work grip mechanism for a rotary chuck as in claim 10, in which said starting and holding circuits also include a further normally-closed switch which, when opened, opens said starting and holding circuits, and said unchucking switch is ganged with said further switch so that the latter is closed and opened when said unchucking switch is open and closed, respectively.

Claim 14

Safe work grip mechanism for a rotary chuck as in claim 9, in which said fluid pressure supply source includes a pressure regulator settable for different output pressures of the fluid, and there is further provided in said fourth conduit between said other compartment and third check valve a vent, and a spring-urged plunger normally closing said vent and manipulatable to open said vent.

Claim 15

Safe work grip mechanism for a rotary chuck as in claim 9, in which said constriction is provided by a valve interposed in said third conduit and adjustable to vary the size of the constriction.

Claim 16

Safe work grip mechanism for a rotary chuck as in claim 10, in which said drive start control is a drive start circuit, including another manual switch, said first means includes a normally-closed safety switch in said drive start circuit in series with said other switch, with said safety switch being opened by said first plunger when subjected to fluid pressure, and said drive start circuit being open when either of said safety and other switches is open, and being closed when both of the latter switches are closed, and said chucking, starting, holding and unchucking circuits are in parallel with said drive start circuit and include a second control switch arranged to be closed an opened when the power drive is inoperative and operative, respectively, with said chucking, starting, holding and unchucking circuits being open when said second control switch is open.