US 4,180,194 A · Web transport mechanism and method

Abstract

A rolling loop camera has a rotor which is arranged to clamp successive frames of the film against the surface of a fiber optic device. The rotor comprises a number of clamping devices with gaps between them, which devices roll over the film on the said surface. The gaps between the clamping devices receive the film which has been formed into a loop by supply means and the movement of the rotor causes the loop to roll across the said surface, thus placing the next frame on the surface for exposure. The film between the supply means and the loop is essentially supported by only the resilience of the film, and thus sliding of the film along a stationary surface while the loop is being formed is avoided. Each clamping device comprises a group of rollers and may include a belt supported by the rollers. As the rotor is operated, the clamping devices move around an endless path which in one embodiment is circular and in another embodiment is oval. A track defining the path is provided, and the clamping devices are maintained in engagement with the track by a drive member which causes the devices to roll along the track, thereby causing rotation of the rotor. The invention is applicable also to film projectors, in which case locator means is preferably provided for ensuring correct registration of the film frames in the device.

Claims42

Dependent claims

A mechanism for transporting a web through a work zone and intermittently holding successive portions of said web stationary in said work zone, comprising:

(a) a support member having a web support surface in said work zone;
(b) clamping means including a plurality of clamping members spaced apart from each other to define a plurality of gaps, each of said clamping members including a clamping surface which is arranged to roll across said web at said work zone;
(c) track means defining an endless path with which said clamping means are engaged and about which said clamping means are movable so that said clamping surfaces and said gaps alternately traverse said support surface, said clamping surfaces being adapted when traversing said support surface to hold portions of the web between the support and clamping surfaces stationary with respect to the support surface;
(d) drive means operable to rotate said clamping members to cause said clamping members to roll along said track means to thereby cause said movement of said clamping members around said endless path;
(e) supply means for supplying web to an input zone upstream of said support surface for forming a first loop of said web in said input zone, said clamping means being arranged to receive said first loop in said gap as said gap approaches said support surface and to transfer said loop across said support surface so that the portion of web previously clamped in said work zone is transferred to an input zone downstream of said support surface in the form of a second loop and web from said first loop is transferred into said work zone;
and
(f) take-up means for removing web from said second loop.

4 more elements

A mechanism for transporting a web through a work zone and holding successive portions of said web stationary in said work zone during intermittent work periods, comprising:

(a) a support member having a web support surface in said work zone;
(b) clamping means having a clamping surface and at least one gap therein;
(c) means for moving said clamping means around an endless path so that said clamping surface said clamping surface traversing said support surface during said work periods and said gap traversing said support surface during intervening periods and said gap alternately traverse said support surface, said clamping surface being adapted when traversing said support surface to cooperate with said support surface to clamp a portion of the web therebetween to thereby hold said web portion stationary with respect to said support surface, said clamping surface having a length in the direction of movement of the clamping member not less than the length of said work zone in said direction so that said clamping is effective throughout each of said work periods;
(d) supply means for supplying web to an input zone upstream of said support surface for forming a first loop of said web in said input zone, said clamping means being arranged to receive said first loop in said gap as said gap approaches said support surface and to transfer said loop across said support surface so that the portion of web previously clamped in said work zone is transferred to an input zone downstream of said support surface in the form of a second loop and web from said first loop is transferred into said work zone;
and
(e) take-up means for removing web from said second loop.

3 more elements

A mechanism for transporting a web through a work zone and intermittently holding successive portions of said web stationary in said work zone, comprising:

(a) a support member having a web support surface in said work zone;
(b) clamping means having a clamping surface and at least one gap therein;
(c) track means defining an endless path around which said clamping means is movable, said clamping means being in rolling engagement with said track means;
(d) drive means operable to rotate said clamping means to cause said clamping means to roll along said track means thereby causing said clamping means to move around said endless path so that said clamping surface and said gap alternately traverse said support surface, said clamping surface being adapted when traversing said support surface to roll over portions of the web between the support and clamping surfaces to hold said web portions stationary with respect to the support surface;
(e) supply means for supplying web to an input zone upstream of said support surface for forming a first loop of said web in said input zone, said clamping means being arranged to receive said first loop in said gap as said gap approaches said support surface and to transfer said loop across said support surfaace so that the portion of web previously clamped in said work zone is transferred to an output zone downstream of said support surface in the form of a second loop and web from said first loop is transferred into said work zone;
and
(f) take-up means for removing web from said second loop.

4 more elements

Dependencies are inferred from the claim text.

Web transport mechanism and method

Life of this patent

Web transport mechanism and method

Life of this patent

Abstract

Claims42