Dereefing cutter

A dereefing cutter comprising:

• a housing having an aperture therein to accommodate a reefing line;
• a knife slidably mounted in said housing;
• a piston slidable along the longitudinal axis of said housing and operable to move said knife across said aperture and sever a reefing line located therein;
• spring means located between said housing and said piston in a direction to move said knife across said aperture;
• detent means operable between said housing and said piston, and including a support member fixed to said housing and a detent member carried by said support member and slidable relative thereto in a direction perpendicular to said longitudinal axis;
• a release member operable on said detent member and slidable relative to said housing from a first position in which said detent member is engaged with said piston to retain stored energy in said spring and a second position in which said detent member is moveable relative to said support member to release said piston for movement under the influence of said spring, the sliding movement of said release member from said first to said second position being in a direction opposite to the direction of movement of said piston under the influence of said spring;
• and said support member preventing movement of said detent member in a direction along said longitudinal axis, timing means to control movement of said release means and initiating means operable to initiate said timing means for deployment of a parachute to which said reefing line is attached, said timing means delaying operation of said release means for a predetermined period and beng interposed between said initiating means and said release means to prevent movement of said piston prior to the expiry of said predetermined period.

A dereefing cutter comprising:

• a housing having an aperture therein to accommodate a reefing line;
• a knife slidably mounted in said housing;
• a piston slidable along the longitudinal axis of said housing and operable to move said knife across said aperture and sever a reefing line located therein, spring means located between said housing and said piston to bias said piston in a direction to move said knife across said aperture, detent means operable between said housing and said piston, and including a support member fixed to said housing and a detent member carried by said support member and slidable relative thereto in a direction perpendicular to said longitudinal axis, said support member comprising a cylindrical projection on said housing and said piston is slidably mounted on said projection, said detent member comprising a plurality of plungers supported in apertures on said projection for movement transverse to said longitudinal axis, said piston including a groove alignable with said apertures to receive said plungers, a release member operable on said detent member to control transverse movement of said plungers, said release member being slidable relative to said housing from a first position in which said plungers are held in said groove to retain stored energy in said spring and a second position in which said plungers are moveable relative to said support member to release said piston for movement under the influence of said spring said support member preventing movement of said plungers in a direction along said longitudinal axis;
• and timing means to control movement of said release member and initiating means operable to initiate said timing means, said timing means delaying operation of said release means for a predetermined period and being interposed between said initiating means and said release member to prevent movement of said piston prior to the expiry of said predetermined period.

A dereefing cutter for a parachute comprising a housing, an aperture in said housing to receive a reefing line, a knife to sever said reefing line and positioned to one side of said aperture, biasing means to bias said knife toward and across said aperture to sever a reefing line located in said aperture, latch means to oppose said biasing means and retain said knife to said one side, said latch means including a detent member slidably supported by a fixed member associated with said housing and operable upon a moveable member associated with said knife means, to hold said moveable member in a latched position against said biasing means, release means to release said latch means and permit movement of said knife means by said biasing means, said release means being operable to permit relative movement between said detent member and said fixed member to move said detent member out of latching engagement with said moveable member to permit relative movement, under the influence of said biasing means between said detent member and said moveable member, said release means including a release member moveable relative to said detent member from a first position in which said detent member prevents movement between said fixed and moveable members to a second position in which said detent member permits such relative movement, movement of said release member from said first to second position being in a direction opposite to that imparted to said moveable member by said biasing means.