Worm drive mechanism

Claim 2

A drive mechanism comprising: an elongated worm; a nut having at least one internal groove engaging said worm; a sleeve surrounding said nut; motor means for rotating said sleeve; locking means for locking said nut to said sleeve for rotation therewith; and release means for normally preventing longitudinal movement of said nut relative to said sleeve and for releasing said nut for longitudinal movement upon actuation thereof, said release means comprising (1) a blocking member having a retaining position in which it engages an end of said nut and a release position in which it does not engage said nut and (2) a release spring biasing said blocking member toward said retaining position.

Claim 3

The drive mechanism of claim 1 wherein said worm includes a member wound in the shape of a helix and received by the threads of said nut.

Claim 4

The drive mechanism of claim 2 further comprising a plurality of telescopically internested members arranged to receive said worm, thereby enabling said wound member to resist compressive forces.

Claim 5

The drive mechanism of claim 2 further comprising magazine means for bending and receiving said worm.

Claim 6

The drive mechanism of claim 2 further comprising: a plurality of rigid telescopically internested members arranged to receive said worm as it moves in a first direction, thereby enabling said worm to resist compressive forces; and magazine means for bending said worm and receiving it in a coiled configuration as it moves in a second direction.

Claim 7

The drive mechanism of claim 2 wherein said worm further includes at least one elongated restrainer connected to said wound member adjacent the ends of said wound member and also connected thereto at a plurality of intermediate points.

Claim 8

The drive mechanism of claim 1 further comprising a support member on which said sleeve is rotatably mounted, said release means also being mounted on said support member.

Claim 9

A drive mechanism comprising an elongated worm; a nut having at least one internal groove engaging said worm; a sleeve surrounding said nut; motor means for rotating said sleeve; locking means for locking said nut to said sleeve for rotation therewith, said locking means comprising a recess on the outer surface of said nut, a drive member carried by said sleeve, and a locking spring arranged to bias said drive member toward and into said recess; and release means for normally preventing longitudinal movement of said nut relative to said sleeve and for releasing said nut for longitudinal movement upon actuation thereof.

Claim 10

A drive mechanism comprising an elongated worm; a nut having at least one internal groove engaging said worm; a sleeve surrounding said nut; motor means for rotating said sleeve; locking means for locking said nut to said sleeve for rotation therewith, said locking means comprising a recess on the outer surface of said nut, a drive member carried by said sleeve, and a locking spring arranged to bias said drive member toward and into said recess; and release means for normally preventing longitudinal movement of said nut relative to said sleeve and for releasing said nut for longitudinal movement upon actuation thereof.

Claim 11

The drive mechanism of claim 8 wherein said release means comprises a pair of blocking members disposed at opposite ends of said nut, each of said blocking members having a retaining position in which it engages said nut and a release position in which it does not engage said nut, whereby movement of one of said blocking members to its release position permits free longitudinal movement of said nut with said worm member in one direction.

Claim 12

The drive mechanism of claim 8 wherein said recess extends longitudinally along said nut and is tapered to allow disengagement of said drive member from said recess upon longitudinal movement of said nut.

Claim 13

The drive mechanism of claim 8 wherein said worm includes a member wound in the shape of a helix received by said thread groove of said nut.

Claim 14

The drive mechanism of claim 11 wherein said worm further includes at least one elongated restrainer connected at its ends to said wound member to prevent elongation of said worm and also connected intermediate its ends to restrict axial displacement of said worm.

Claim 15

A drive mechanism comprising: an elongated worm including a flexible steel member wound in the shape of a helix and a flexible restrainer extending internally through said helix, said restrainer member being connected at and intermediate its ends to said wound member; an internally threaded plastic nut surrounding said worm and having a threaded internal surface that receives said wound member to produce longitudinal movement of said worm in response to rotational movement of said nut, said nut having a cylindrical outer surface; a plurality of rigid telescopically internested members arranged to receive said worm as it moves in a first direction, thereby enabling said worm to resist compressive forces; magazine means for receiving and storing said worm in a coiled configuration as it moves in a second direction, said magazine means including a flexible tube; a sleeve having a cylindrical inner surface surrounding said nut; a yoke on which said sleeve is rotatably mounted; motor means for causing rotation of said sleeve; clutch means for operatively connecting said motor means to said sleeve and permitting relative rotation between said motor means and said sleeve, said clutch means comprising a first clutch plate secured to said sleeve for rotation therewith and a second clutch plate axially slidable on said sleeve to engage said first clutch plate; locking means carried by said sleeve for locking said nut to said sleeve for rotation therewith, said locking means comprising a longitudinal groove defined by the outer surface of said nut, a drive pin carried by said sleeve, and a locking spring arranged to bias said drive pin toward and into said groove, said groove being tapered for maximum depth at the center thereof to allow disengagement of said drive pin from said groove upon longitudinal movement of said nut in either of two opposite directions; and release means for normally preventing longitudinal movement of said worm without corresponding rotation of said nut and for releasing said worm for free longitudinal movement upon actuation thereof, said release means including a pair of blocking members disposed at opposite ends of said nut, each of said blocking members having a retaining position in which it engages said nut and a release position in which it does not engage said nut, whereby movement of one of said blocking members to its release position permits free longitudinal movement of said nut and said worm member in one direction, said release means further including a pair of springs biasing said blocking members toward said retaining positions.

Claim 16

A drive mechanism comprising: an elongated worm including a flexible steel member wound in the shape of a helix and a flexible restrainer extending internally through said helix, said restrainer member being connected at and intermediate its ends to said wound member; an internally threaded plastic nut surrounding said worm and having a threaded internal surface that receives said wound member to produce longitudinal movement of said worm in response to rotational movement of said nut, said nut having a cylindrical outer surface; a plurality of rigid telescopically internested members arranged to receive said worm as it moves in a first direction, thereby enabling said worm to resist compressive forces; magazine means for receiving and storing said worm in a coiled configuration as it moves in a second direction, said magazine means including a flexible tube; a sleeve having a cylindrical inner surface surrounding said nut; a yoke on which said sleeve is rotatably mounted; motor means for causing rotation of said sleeve; clutch means for operatively connecting said motor means to said sleeve and permitting relative rotation between said motor means and said sleeve, said clutch means comprising a first clutch plate secured to said sleeve for rotation therewith and a second clutch plate axially slidable on said sleeve to engage said first clutch plate; locking means carried by said sleeve for locking said nut to said sleeve for rotation therewith, said locking means comprising a longitudinal groove defined by the outer surface of said nut, a drive pin carried by said sleeve, and a locking spring arranged to bias said drive pin toward and into said groove, said groove being tapered for maximum depth at the center thereof to allow disengagement of said drive pin from said groove upon longitudinal movement of said nut in either of two opposite directions; and release means for normally preventing longitudinal movement of said worm without corresponding rotation of said nut and for releasing said worm for free longitudinal movement upon actuation thereof, said release means including a pair of blocking members disposed at opposite ends of said nut, each of said blocking members having a retaining position in which it engages said nut and a release position in which it does not engage said nut, whereby movement of one of said blocking members to its release position permits free longitudinal movement of said nut and said worm member in one direction, said release means further including a pair of springs biasing said blocking members toward said retaining positions.

Claim 17

A drive mechanism comprising: an elongated worm; a nut having at least one internal groove engaging said worm; a sleeve surrounding said nut; motor means for rotating said sleeve; locking means for locking said nut to said sleeve for rotation therewith, said locking means comprises a recess defined by the outer surface of said nut, a drive member carried by said sleeve, and a locking spring arranged to bias said drive member toward and into said recess, said recess extending longitudinally along said nut and being tapered for maximum depth at the center thereof to allow disengagement of said drive member from said recess upon longitudinal movement of said nut in either of two opposite directions; and release means for normally preventing longitudinal movement of said nut relative to said sleeve and for releasing said nut for longitudinal movement upon actuation thereof, said release means comprising a pair of blocking members disposed at opposite ends of said nut, each of said blocking members having a retaining position in which it engages said nut and a release position in which it does not engage said nut, whereby movement of one of said blocking members to its release position permits free longitudinal movement of said nut with said worm member in one direction.

Claim 18

A drive mechanism comprising: an elongated worm; a nut having at least one internal groove engaging said worm; a sleeve surrounding said nut; motor means for rotating said sleeve; locking means for locking said nut to said sleeve for rotation therewith, said locking means comprises a recess defined by the outer surface of said nut, a drive member carried by said sleeve, and a locking spring arranged to bias said drive member toward and into said recess, said recess extending longitudinally along said nut and being tapered for maximum depth at the center thereof to allow disengagement of said drive member from said recess upon longitudinal movement of said nut in either of two opposite directions; and release means for normally preventing longitudinal movement of said nut relative to said sleeve and for releasing said nut for longitudinal movement upon actuation thereof, said release means comprising a pair of blocking members disposed at opposite ends of said nut, each of said blocking members having a retaining position in which it engages said nut and a release position in which it does not engage said nut, whereby movement of one of said blocking members to its release position permits free longitudinal movement of said nut with said worm member in one direction.