Pipe perforating machine

Claim 2

A pipe perforating machine comprising: a. a frame operable to support a pipe in a stationary position, b. cooperating die members carried by said frame and including a male die supported by said frame for movement in a straight line radial to said pipe, said male die having a pair of generally parallel, closely spaced apart cutting edges of a length at least several times the lateral spacing therebetween, the central portions of said cutting edges extending generally at right angles to the radial movement of said die, and the end portions thereof being inclined obtusely away from a plane established by the central portions of said cutting edges, and away from the confronting wall surface of said pipe, to a radial distance from said plane greater than the wall thickness of said pipe, and c. power means operable to move said male die radially of said pipe to engage a wall of said pipe and to form a perforation in said wall, the radial movement of said die, after it initially engages said pipe wall, being greater than the wall thickness of said pipe, but less than the radial spacing between the central portions and the extreme ends of said die cutting edges, whereby the central portion of the strip of pipe wall between said die cutting edges is offset laterally from the pipe wall by a distance greater than the wall thickness, and the ends of said pipe wall strip are left connected to the standing portion of the pipe wall.

Claim 3

A pipe perforating machine comprising: a. a frame, b. a cantilevered arbor beam fixed in said frame, c. tracks carried fixedly by said frame in parallel relation to said arbor beam, d. a carriage movable along said tracks, e. means operable to support a pipe to be perforated on said carriage in parallel relation to said arbor beam and coaxially therewith, whereby said pipe may be moved coaxially over the free end of said beam, f. cooperating die members carried by said frame and including an internal die carried movably by said arbor beam at the free end thereof for extension radially of said beam to engage said pipe and form a perforation in the wall thereof, said pipe being movable axially over said internal die when the latter is retracted; an external die carried movably by said frame externally of said pipe for movement coaxial to the extend-retract movement of said internal die, being inwardly extendable radially of said pipe to cooperate with said internal die in forming said perforation, and radially outwardly retractable to disengage said pipe; and a back-up support member carried by said frame externally of said pipe for movement radially of said pipe in diametrically opposite relation to said external die, being extendable to engage said pipe and retractable to disengage said pipe, said arbor beam carrying a rigid member operable on very slight deflection of said beam to engage the interior wall of said pipe opposite from said internal die, and g. a control system operable to extend and retract said internal and external dies, and said back-up support member simultaneously, said control system including a double-acting hydraulic cylinder for operating each of said internal and external dies, and said back-up support, the pistons of said cylinders being operable by movement thereof in one direction to extend said dies, and said back-up support member, and by movement thereof in the opposite direction to retract said dies, and said back-up support member, means operable to deliver hydraulic fluid at a constant pressure to the die-retraction sides of the pistons of said double-acting hydraulic cylinders, whereby said dies, and said back-up support member, are biased toward their retracted positions, and means operable alternately to deliver hydraulic fluid at a still higher pressure to the die-extension sides of the pistons of said double-acting cylinders, whereby said dies, and said back-up support member are moved to their extended positions, and to exhaust said higher pressure fluid.

Claim 4

A pipe perforating machine comprising: a. a frame, b. a cantilevered arbor beam fixed in said frame, c. tracks carried fixedly by said frame in parallel relation to said arbor beam, d. a carriage movable along said tracks, e. means operable to support a pipe to be perforated on said carriage in parallel relation to said arbor beam and coaxially therewith, whereby said pipe may be moved coaxially over the free end of said beam, f. cooperating die members carried by said frame and including an internal die carried movably by said arbor beam at the free end thereof for extension radially of said beam to engage said pipe and form a perforation in the wall thereof, said pipe being movable axially over said internal die when the latter is retracted; an external die carried movably by said frame externally of said pipe for movement coaxial to the extend-retract movement of said internal die, being inwardly extendable radially of said pipe to cooperate with said internal die in forming said perforation, and radially outwardly retractable to disengage said pipe; and a back-up support member carried by said frame externally of said pipe for movement radially of said pipe in diametrically opposite relation to said external die, being extendable to engage said pipe and retractable to disengage said pipe, said arbor beam carrying a rigid member operable on very slight deflection of said beam to engage the interior wall of said pipe opposite from said internal die, and g. a control system operable to extend and retract said internal and external dies, and said back-up support member simultaneously, said control system including a double-acting hydraulic cylinder for operating each of said internal and external dies, and said back-up support, the pistons of said cylinders being operable by movement thereof in one direction to extend said dies, and said back-up support member, and by movement thereof in the opposite direction to retract said dies, and said back-up support member, means operable to deliver hydraulic fluid at a constant pressure to the die-retraction sides of the pistons of said double-acting hydraulic cylinders, whereby said dies, and said back-up support member, are biased toward their retracted positions, and means operable alternately to deliver hydraulic fluid at a still higher pressure to the die-extension sides of the pistons of said double-acting cylinders, whereby said dies, and said back-up support member are moved to their extended positions, and to exhaust said higher pressure fluid.

Claim 5

A pipe perforating machine comprising: a. a frame, b. a cantilevered arbor beam fixed in said frame, c. tracks carried fixedly by said frame in parallel relation to said arbor beam, d. a carriage movable along said tracks, e. means operable to support a pipe to be perforated on said carriage in parallel relation to said arbor beam and coaxially therewith, whereby said pipe may be moved coaxially over the free end of said beam, f. cooperating die members carried by said frame and including an internal die carried movably by said arbor beam at the free end thereof for extension radially of said beam to engage said pipe and form a perforation in the wall thereof, said pipe being axially movable over said internal die when the latter is retracted, and g. a control system operable to extend and retract said internal die alternately, as said pipe is moved axially over said arbor beam, whereby a series of perforations are formed in the wall of said pipe, said control system comprising die-extending means operable when actuated to extend said cooperating die members to form a perforation in the wall of said pipe, die-retracting means operable when actuated to retract said die members out of engagement with said pipe, pipe advancing means operable each time it is actuated to advance said carriage and pipe axially by a distance equal to the desired longitudinal spacing between successive perforations in said pipe, a first limit switch operable by extension of said cooperating die members to their fully extended positions, at which time a perforation is completed, to deactivate said die-extending means and to actuate said pipe advancing means, and a second limit switch operable by the completion of the operation of said pipe advancing means to advance the pipe by the desired distance, to deactivate said die-retraction means and said pipe advancing means, and to actuate said die-extension means, whereby the functions of die-extension, die-retraction, and advancing of the pipe are accomplished in a continuously repetitive cycle.

Claim 6

A pipe perforating machine comprising: a. a frame, b. a cantilevered arbor beam fixed in said frame, c. tracks carried fixedly by said frame in parallel relation to said arbor beam, d. a carriage movable along said tracks, e. means operable to support a pipe to be perforated on said carriage in parallel relation to said arbor beam and coaxially therewith, whereby said pipe may be moved coaxially over the free end of said beam, f. cooperating die members carried by said frame and including an internal die carried movably by said arbor beam at the free end thereof for extension radially of said beam to engage said pipe and form a perforation in the wall thereof, said pipe being axially movable over said internal die when the latter is retracted, and g. a control system operable to extend and retract said internal die alternately, as said pipe is moved axially over said arbor beam, whereby a series of perforations are formed in the wall of said pipe, said control system comprising die-extending means operable when actuated to extend said cooperating die members to form a perforation in the wall of said pipe, die-retracting means operable when actuated to retract said die members out of engagement with said pipe, pipe advancing means operable each time it is actuated to advance said carriage and pipe axially by a distance equal to the desired longitudinal spacing between successive perforations in said pipe, a first limit switch operable by extension of said cooperating die members to their fully extended positions, at which time a perforation is completed, to deactivate said die-extending means and to actuate said pipe advancing means, and a second limit switch operable by the completion of the operation of said pipe advancing means to advance the pipe by the desired distance, to deactivate said die-retraction means and said pipe advancing means, and to actuate said die-extension means, whereby the functions of die-extension, die-retraction, and advancing of the pipe are accomplished in a continuously repetitive cycle.

Claim 7

A pipe perforating machine as recited in claim 3 wherein said die-extending means and said die-retracting means for each of said cooperating die members constitutes: a. a double-acting hydraulic cylinder the piston of which is movable in one direction to extend said die member, and in the opposite direction to retract said die member, b. means operable to supply a continuous lower hydraulic pressure to the die-retraction side of said piston, c. means controlled by said second limit switch to supply a higher hydraulic pressure to the die-extension side of said piston, and d. means controlled by said first limit switch to exhaust said higher hydraulic pressure from the die-extension side of said piston.

Claim 8

A pipe perforating machine as recited in claim 4 wherein the die-extension side of said piston is of greater effective area than the die-retraction side thereof.

Claim 9

A pipe perforating machine as recited in claim 3 wherein said control system additionally includes: a. pipe return means operable when actuated to move said carriage and pipe continuously in a direction opposite to that in which it is moved by said pipe advancing means, b. a third limit switch operable by the arrival of said carriage at the advancing limit of its travel, at which time a full longitudinal row of perforations in said pipe will have been completed, to deactuate side die-extension means, whereby said die members remain in their retracted positions, to deactuate said pipe advancing means, and to actuate said pipe return means, whereby said pipe is returned to its starting position, and c. a fourth limit switch operable by arrival of said carriage at its return limit to deactuate said pipe return means.

Claim 10

A pipe perforating machine as recited in claim 6 wherein said pipe is supported on said carriage by means permitting rotation of said pipe about its axis, whereby it may be turned angularly to position another longitudinal line thereof in alignment with said die members, when it is in its return limit position.

Claim 11

A pipe perforating machine as recited in claim 7 with the addition of pipe indexing means operable automatically to turn said pipe about its axis by an angular distance equal to the desired angular spacing between successive longitudinal rows of perforations to be formed in said pipe, during the return movement of said carriage.

Claim 12

A pipe perforating machine as recited in claim 7 with the addition of: a. an indexing head mounted on said carriage for rotation on an axis coaxial with said pipe, b. clamp means operable to clamp said pipe to said head coaxially therewith, said indexing head having an operating member operable when deflected to turn said head rotatably by an angle equal to the desired angular spacing between successive longitudinal rows of perforations to be formed in said pipe, and c. an operator for said head consisting of a member mounted on said track and operable during the return movement of said carriage to engage and deflect the operating member of said indexing head.

Claim 13

A pipe perforating machine as recited in claim 8 wherein said fourth limit switch is operable by the arrival of said carriage at its return limit to reactuate said die-extending means and said pipe advancing means, in addition to deactuating said pipe return means, whereby successive rows of perforations are formed automatically until the pipe is completely perforated.

Claim 14

A pipe perforating machine as recited in claim 10 with the addition of a fifth limit switch operable to engage and be actuated by the first perforation of the first row of perforations formed, as the last perforation of the last row of perforations formed is completed, actuation of said fifth limit switch functioning to deactuate said die-extending means by means independent of said first and third limit switches, but not said pipe return means, whereby the machine comes to rest after the next return travel of the carriage has been completed.

Claim 15

A pipe perforating machine as recited in claim 11 with the addition of: a. manually operable means for reactuating said die-extending means whenever the latter has been deactuated by actuation of said fifth limit switch.