Frictional lock for retaining a rotatable piston against axial displacement

Claim 2

In a fluidic system for imparting intermittent axial displacement to a piston slidably disposed in a cylinder, means for locking the piston in a stationary position at the conclusion of each displacement thereof, comprising, a housing fixed within the interior of the cylinder, said housing having a tapered interior portion and a port for the entry therein of a flow of fluid, a hollow carrier slidably fitted between said housing and the piston in position to be axially displaced by said flow of fluid, a pair of arcuate locking elements seated in said carrier for transverse movement into and out of locking engagement with the piston, a ball rotatably mounted in the exterior of each of said locking elements for protrusion from said carrier, first spring means seated between said locking elements for urging said balls into rolling contact with said tapered interior portion of said housing, and second spring means normally urging said carrier toward said entry port whereby said tapered interior portion of said housing cams said balls inwardly to force said locking elements into frictional locking engagement with the piston.

Claim 3

The piston locking means defined in claim 1 wherein said carrier is provided with diametrically opposed openings of spherical contour for rotatably retaining said balls therein.

Claim 4

The piston locking means defined in claim 1 wherein said first spring means comprises a pair of compression springs seated between said locking elements at diametrically opposed locations.

Claim 5

The piston locking means defined in claim 1 wherein said second spring means comprises a plurality of alternately stacked concave and convex spring washers selected to impart a predetermined bias against said carrier.

Claim 6

In a fluidic control system responsive to the recoil displacement of the firing tube of a mortar for actuating a piston rod to return the tube to the original sighting inclination thereof, means for locking the piston rod against axial displacement following each actuation thereof, comprising, a fixed cylindrical housing surrounding the piston rod, said housing having an entry port for admitting a flow of fluid therein and a tapered interior portion spaced from the piston rod, a hollow carrier slidably disposed intermediate the interior of said housing and the exterior of the piston rod in the path of said flow of fluid from said entry port, said carrier having diametrically opposed transverse openings therethrough, a pair of semi-annular locking elements seated in opposed relation in said carrier for transverse movement into and out of locking engagement with the piston rod, a ball rotatably mounted in the exterior of each of said locking elements to protrude through said transverse openings in said carrier. a pair of compression springs seated between said locking elements at diametrically opposed locations for urging said balls into rolling contact with said tapered interior portion of said housing, and a plurality of alternately stacked concave and convex spring washers adjacent the end of said carrier remote from said entry port in said housing for imparting axial displacement thereto whereby said tapered interior portion of said housing cams said balls inwardly to force said locking elements into frictional engagement with the exterior periphery of the piston rod.

Claim 7

In a fluidic control system responsive to the recoil displacement of the firing tube of a mortar for actuating a piston rod to return the tube to the original sighting inclination thereof, means for locking the piston rod against axial displacement following each actuation thereof, comprising, a fixed cylindrical housing surrounding the piston rod, said housing having an entry port for admitting a flow of fluid therein and a tapered interior portion spaced from the piston rod, a hollow carrier slidably disposed intermediate the interior of said housing and the exterior of the piston rod in the path of said flow of fluid from said entry port, said carrier having diametrically opposed transverse openings therethrough, a pair of semi-annular locking elements seated in opposed relation in said carrier for transverse movement into and out of locking engagement with the piston rod, a ball rotatably mounted in the exterior of each of said locking elements to protrude through said transverse openings in said carrier. a pair of compression springs seated between said locking elements at diametrically opposed locations for urging said balls into rolling contact with said tapered interior portion of said housing, and a plurality of alternately stacked concave and convex spring washers adjacent the end of said carrier remote from said entry port in said housing for imparting axial displacement thereto whereby said tapered interior portion of said housing cams said balls inwardly to force said locking elements into frictional engagement with the exterior periphery of the piston rod.

Claim 8

The piston rod locking means definEd in claim 5 wherein said carrier is rotatably disposed in said housing for rotation together with the piston rod when said locking elements are in frictional engagement therewith.

Claim 9

The piston rod locking means defined in claim 5 including an insert adjustably threaded into said housing to impart a predetermined degree of compression to said stack of spring washers.

Claim 10

The piston rod locking means defined in claim 5 wherein said transverse openings are spherically contoured with the end thereof at the interior of said carrier diametrically larger than the end at the exterior thereof to thereby retain said balls for rolling contact with said tapered interior of said housing.

Claim 11

In a tripod mount having a pison rod rotatably and slidably disposed in a cylinder for supporting the firing tube of a mortar at a desired inclination and a fluidic control system responsive to the recoil displacement of the firing tube in both azimuth and elevation for actuating the piston rod to restore the tube to the original inclination thereof, the combination of, a cylindrical housing fixed in the cylinder to surround a portion of the piston rod, said housing having a port in the upper end thereof for entry of fluid from the control system and an interior portion of upwardly decreasing taper disposed below said port, a hollow carrier rotatably disposed in said housing in the flow path of the fluid from said entry port for axial displacement relative to said housing and to the piston rod, said carrier having opposed openings extending transversely therethrough, a pair of semi-annular oppositely disposed locking elements seated in said carrier for transverse movement into and out of locking engagement with the piston rod, a ball rotatably mounted in the exterior of each of said locking elements in position to protrude through said transverse openings in said carrier, a pair of compression springs seated between said locking elements for urging said balls into rolling contact with said tapered interior portion of said housing, an insert adjustably threaded into the end of said housing remote from said entry port, and a plurality of alternately stacked concave and convex spring washers seated between said insert and the underside of said carrier whereby the flow of fluid through said entry port in said housing at the beginning of each actuation of the piston rod forces said carrier downwardly against said spring washers to thereby permit said compression springs to urge said locking elements out of frictional engagement with the piston rod and whereby said spring washers urge said carrier upwardly at the conclusion of each actuation of the piston rod to thereby permit said tapered interior portion of said housing to cam said balls inwardly and return said locking elements into locking engagement with the piston rod.

Claim 12

In a tripod mount having a pison rod rotatably and slidably disposed in a cylinder for supporting the firing tube of a mortar at a desired inclination and a fluidic control system responsive to the recoil displacement of the firing tube in both azimuth and elevation for actuating the piston rod to restore the tube to the original inclination thereof, the combination of, a cylindrical housing fixed in the cylinder to surround a portion of the piston rod, said housing having a port in the upper end thereof for entry of fluid from the control system and an interior portion of upwardly decreasing taper disposed below said port, a hollow carrier rotatably disposed in said housing in the flow path of the fluid from said entry port for axial displacement relative to said housing and to the piston rod, said carrier having opposed openings extending transversely therethrough, a pair of semi-annular oppositely disposed locking elements seated in said carrier for transverse movement into and out of locking engagement with the piston rod, a ball rotatably mounted in the exterior of each of said locking elements in position to protrude through said transverse openings in said carrier, a pair of compression springs seated between said locking elements for urging said balls into rolling contact with said tapered interior portion of said housing, an insert adjustably threaded into the end of said housing remote from said entry port, and a plurality of alternately stacked concave and convex spring washers seated between said insert and the underside of said carrier whereby the flow of fluid through said entry port in said housing at the beginning of each actuation of the piston rod forces said carrier downwardly against said spring washers to thereby permit said compression springs to urge said locking elements out of frictional engagement with the piston rod and whereby said spring washers urge said carrier upwardly at the conclusion of each actuation of the piston rod to thereby permit said tapered interior portion of said housing to cam said balls inwardly and return said locking elements into locking engagement with the piston rod.

Claim 13

The combination defined in claim 9 including, a slabbed surface extending along the exterior periphery of the piston rod beyond the ends of said housing, a plurality of chordal inserts secured to the interior of said carrier in contact with said slabbed surface for completing the exterior periphery of the piston rod, means for sealing the interior of said housing against leakage of the flow of fluid directed against said carrier, and an exit passage through the housing and the cylinder positioned to permit the escape of the air trapped between said carrier and said threaded insert during the downward displacement of said carrier.