Gas operated single stroke servo-motor

Claim 2

A gas operated single stroke servo-motor which comprises: a rigid body having a cavity therein open at one end and closed at the other, a tool receiving passage intermediate the ends of the cavity opening onto the outside of the body, and a wall area within said cavity opposite the tool receiving passage shaped to reinforce the adjacent wall surface of a tubular element placed thereagainst; a deformable tubular member having a hollow interior located within the body cavity with one end in abutting relation to the closed end of the latter and a portion of its exterior surface in face-to-face contacting relation with said cavity''s reinforcing area, said tubular member having at least one wall thereof deformed and folded inwardly into the interior thereof to provide a fold therein; plug means mounted in the open end of the body cavity for adjustable movement into essentially fluid-tight sealed engagement with the adjacent end of the tubular member housed therein, said plug cooperating with the closed end of said cavity and with said tubular member when held therebetween to define an essentially fluid-tight sealed chamber inside the latter, and said elements further cooperating to maintain the essentially fluid-tight sealed condition of said chamber while its volume becomes greater in response to an increase in internal fluid pressure of a magnitude sufficient to at least partially unfold the fold in the folded wall; conduit means connectable to a source of fluid under pressure communicating with the interior of the sealed chamber; and, tool means operatively associated with the tubular member responsive to the unfolding of the latter to move from a retracted position confined within the tool receiving passage into an extended position.

Claim 3

The servo-motor as set forth in claim 1 in which: the tool means comprises a blade; and, in which the tool receiving passage comprises a slit sized to guide the latter during its excursion from retracted into extended position.

Claim 4

A gas operated single stroke servo-motor which comprises: a rigid body having a cavity therein open at one end and closed at the other, a tool receiving passage intermediate the ends of the cavity opening onto the outside of the body, and a wall area within said cavity opposite the tool receiving passage shaped to reinforce the adjacent wall surface of a tubular element placed thereagainst; a deformable hollow tubular member located within the body cavity with one end in abutting relation to the closed end of the latter and a portion of its exterior surface in face-to-face contacting relation with said cavity''s reinforcing area, said tubular member having its wall nearest the tool receiving passage folded inwardly toward the reinforced wall to provide a fold therein; plug means mounted in the open end of the body cavity for adjustable movement into essentially fluid-tight sealed engagement with the adjacent end of the tubular member housed therein, said plug cooperating with the closed end of said cavity and with said tubular member when held therebetween to define an essentially fluid-tight sealed chamber inside the latter, and said elements further cooperating to maintain the essentially fluid-tight sealeD condition of said chamber while its volume becomes greater in response to an increase in internal fluid pressure of a magnitude sufficient to at least partially unfold the fold in the folded wall; conduit means connectable to a source of fluid under pressure communicating with the interior of the sealed chamber; and, tool means operatively associated with the folded wall of the tubular member responsive to the unfolding of the latter to move from a retracted position confined within the tool receiving passage into an extended position adapted to engage a workpiece located in the path thereof.

Claim 5

A gas operated single stroke servo-motor which comprises: a rigid body having a cavity therein open at one end and closed at the other, a tool receiving passage intermediate the ends of the cavity opening onto the outside of the body, and a wall area within said cavity opposite the tool receiving passage shaped to reinforce the adjacent wall surface of a tubular element placed thereagainst; a deformable hollow tubular member located within the body cavity with one end in abutting relation to the closed end of the latter and a portion of its exterior surface in face-to-face contacting relation with said cavity''s reinforcing area, said tubular member having its wall nearest the tool receiving passage folded inwardly toward the reinforced wall to provide a fold therein; plug means mounted in the open end of the body cavity for adjustable movement into essentially fluid-tight sealed engagement with the adjacent end of the tubular member housed therein, said plug cooperating with the closed end of said cavity and with said tubular member when held therebetween to define an essentially fluid-tight sealed chamber inside the latter, and said elements further cooperating to maintain the essentially fluid-tight sealeD condition of said chamber while its volume becomes greater in response to an increase in internal fluid pressure of a magnitude sufficient to at least partially unfold the fold in the folded wall; conduit means connectable to a source of fluid under pressure communicating with the interior of the sealed chamber; and, tool means operatively associated with the folded wall of the tubular member responsive to the unfolding of the latter to move from a retracted position confined within the tool receiving passage into an extended position adapted to engage a workpiece located in the path thereof.

Claim 6

The servo-motor as set forth in claim 3 in which: the tool means comprises a blade; and, in which the tool receiving passage comprises a slit sized to guide the latter during its excursion from retracted into extended position.

Claim 7

The servo-motor as set forth in claim 1 in which: the tool means is releasably held in retracted position.

Claim 8

The servo-motor as set forth in claim 1 in which: a shear pin depending from the body releasably holds the tool means in retracted position.

Claim 9

The servo-motor as set forth in claim 1 in which: the folded wall section lies in spaced relation to the opposed surface of the reinforced wall portion so as to define therewith a partially collapsed condition wherein generally pear shaped lobes are produced on opposite sides of the fold communicating with one another across the latter.

Claim 10

The servo-motor as set forth in claim 1 in which: the fold in the folded wall is loose and rounded.

Claim 11

The servo-motor as set forth in claim 1 in which: the body includes a passage intersecting the path of movement of the tool means and adapted to receive a workpiece and maintain same in position for engagement by the latter.

Claim 12

The servo-motor as set forth in claim 1 in which: the reinforcing wall area of the body cavity is semi-cylindrical; and, in which the tubular member has a cylindrical wall surface in engagement therewith.

Claim 13

The servo-motor as set forth in claim 1 in which: the opposed surfaces of the plug means and closed end of the body cavity in engagement with the tubular member are planar and essentially parallel to one another; and, in which the opposite open ends of the tubular member are cut off normal to its longitudinal axis.

Claim 14

The servo-motor as set forth in claim 1 in which: the body includes a surface located beyond the tool receiving passage positioned and adapted to receive the tool means and stop same in its extended position.

Claim 15

The servo-motor as set forth in claim 2 in which: the sharpened edge of the blade is essentially straight and extends at right angles to the direction of its movement; and, in which the body includes a planar surface located in the path of blade movement positioned to define a support for a workpiece to be cut by the latter.

Claim 16

The servo-motor as set forth in claim 6 in which: the shear pin passes through the tool means.

Claim 17

The servo-motor as set forth in claim 4 in which: the conduit means opens into the end of at least one of said lobes.

Claim 18

The servo-motor as set forth in claim 4 in which: the conduit means includes branches opening into both of said lobes.

Claim 19

The servo-motor as set forth in claim 7 in which: the body includes a surface positioned and adapted to support a workpiece located within said workpiece receiving passage and support same in the path of the tool means.