Patent Application
20250122044
The present invention relates to a variable tension control film dispenser with a locking mechanism that is manually activated by squeezing pressure on the outside of the skin.
Stretch wrap is used in many applications, including securing loads on a pallet, wrapping products to protect them from damage, and bundling various items together. Typically, a roll of stretch wrap is made up of a core (usually made of paperboard) around which the plastic wrap is wound. Coreless versions exist where the film is wound around itself without an inner core.
To facilitate applying the film by hand, the core in the film roll may be extended beyond the film edge (extended core), or a mandrel can be inserted inside the roll to enable the operator to unwind the film. However, it is difficult to control the film tension when wrapping items with these products.
Most of the prior art designs rely on either regulating friction between an extended core and an outside skin, or by regulating the friction between a mandrel, which is wedged in the core, and an outside skin. Regulating friction is done by varying the amount of squeezing action by the hand on the outside surface.
A problem with dispensers is that they rely on friction alone to regulate tension in the film and that the amount of friction required to achieve a certain tension in the film is very different when the roll is large compared to when the roll is almost used up. As the roll diameter gets smaller, the friction required to stop the roll becomes proportionally smaller as well. The practical implication is that a design which is optimized for a larger roll diameter is not functional when the roll is almost used up. On the other hand, a dispenser design that is optimized for a small roll diameter requires an extraordinary amount of friction, and thus squeezing action, to stop the roll from unwinding when used with a larger diameter roll.
U.S. Pat. No. 4,477,037 relates to stretch wrap film wound on a mandrel or core which is longer than the roll of film to extend out both ends. A rotatable handle is mounted on the core outboard of the film. Braking between the handle and core is adjusted by a screw thread which tightens a friction brake.
U.S. Pat. No. 4,484,717 relates to a stretch wrap film on a roll utilized by manual grasp on handles mounted on each end of the roll and freely rotatable. A brake-ring is positioned under the index finger clamped onto a spindle running with stretch wrap film roll to apply braking.
U.S. Pat. No. 4,575,020 relates to a portable chuck dispensing under tension roll of wrap material wound on a tubular core, that includes expandable spindle insertable in one end of the tubular core. An adjustable brake through two pieces are squeezed together and through a fulcrum creates expanding collar inside the core.
U.S. Pat. No. 4,784,348 relates to a head and spindle projecting outwardly, with head mounting on a roll of web. A wrap envelope of web is wound about a spindle, tension and speed of unrolling the web is done by manually squeezing wrap envelope on the spindle causing the brake.
U.S. Pat. No. 5,203,517 relates to a dispenser for stretch wrap film having a spindle that forms a hub that attaches to a core of film roll, rotates with the roll as film is unwound. The spindle extends coaxially from the core and partially surrounded by flexible hand grip. Bearings are beneath hand grip. Part of the hand grip engages spindle without bearings so hand pressure cause friction to brake.
U.S. Pat. No. 5,915,642 relates to handle having insert portion having plurality of radially extending fins and grip surface. Handle is inserted into a hollow core. Fins provide a fit allows core to rotate relative to the handle. The fins can deform when subjected to rotation. Grip positioned allows user to squeeze handle against core to slow or stop rotation. Fins extending outward from insert portion to be inserted into core and fingers to fit inside handle. Braking force is applied by repositioning fingers inside handle to deform fins against the core. Core is large enough to fit fingers inside.
U.S. Pat. No. 9,272,870 relates to a film dispensing apparatus that has an exterior holding surface of a holding member that is concentric with axis of rotation of rotating member. Film dispensing apparatus includes brake portion found in interior of holding member associated with interior holding surface with sufficient force, causes brake portion to flex and contact the rotating member to provide more tension.
U.S. Pat. No. 11,584,610 relates to rotating member for wrap dispenser, includes a first portion defining first outer surface and first inner surface, first inner surface define first inner diameter, second portion define second inner surface, second inner surface define second inner diameter; first inner diameter less than second inner diameter; an upset radially outwardly from first outer surface of first portion, upset oriented distal to second portion, slot extends longitudinally through upset allow upset flex inward.
US patent publication 20090308968 relates to dispenser for coreless rolls of film. Mandrels of dispenser can move between retracted position where dispenser has reduced diameter, when dispenser inserted in roll of film and increased diameter when film dispensed. Mandrel sections joined by spring configurations and slidable. Lug elements deflect spring configurations outwardly.
US patent publication 20120181369 relates to film dispenser for stretch wrap. Film dispenser comprised of separate inner and outer mold. Inner mold comprised of slots and extensions, and a collar which fits into outer mold, and inner ridges of inner mold fit into groove on extended core. Outer mold comprised of ribs which fit into slots of inner mold.
US patent publication 20130074446 relates to stretch film dispenser to wrap film up to 12″ in width, consist of stopper ring secured at beginning of extended core followed by semi-compressible sleeve with embedded guide rings encircling core extension, contoured guide rings followed by second stripper ring secured one inch from remote end of core extension.
US patent publication 20140116004 relates to device for handling a roll of wrap material having tube handle, tube extension connected to tube handle, top end cap on tube handle, bottom end cap on tube extension, tensioning means, bottom end cap holds roll of wrapping on tube extension against tensioning means that is adjustable.
US patent publication 20150183542 relates to a film dispenser comprised of inner and outer mold. Inner mold comprised of slots and extensions, and a collar fits into outer mold, inner ridges of inner mold fit into groove on extended core. Outer mold comprised of ribs which fit into slots of inner mold.
US patent publication 20160264277 relates to dispenser include rotating member, holding member, collar at first end of holding member, inner surface enclosing engaging portion of rotating member, cap attached to end of rotating member and holding the holding member collar positioned between end surface at first end rotating member and stop surface of cap.
US patent publication 20160289033 relates to film dispenser for coreless film rolls. First dispenser member matable with second dispenser member, in at least two angular positions. Dispenser can engage film rolls of varying internal dimensions. Support walls define complementary interlocking formations. Engaged support walls support central region of film roll.
US patent publication 2021014717 relates to dispenser comprising rotating member and holding member. Diameter cylindrical inner surface of second portion greater than diameter of cylindrical inner surface of first portion. Plurality of ribs extend inwardly from cylindrical inner surface of second portion. Holding member located outwardly of first portion.
U.S. design Pat. 823,905 relates to a braking film dispenser with lobes.
The present invention relates to a system for stopping the release of wrapping material from a stretch wrap dispenser by using a locking mechanism.
It is an object of the present invention to use a combination of ridges or protrusions and slots that when in a fully locked position, instantly stop the roll, thus not relying on excessive squeezing force.
It is an object of the present invention for the stretch wrap dispenser to comprise a mandrel and a flexible skin, wherein the mandrel has slots and the flexible skin has protrusions.
It is an object of the present invention for the stretch wrap dispenser to comprise a mandrel and a flexible skin, wherein the mandrel has protrusions and the flexible skin has slots.
It is an object of the present invention for the stretch wrap dispenser to comprise a mandrel and a flexible skin, wherein the mandrel has protrusions and the flexible skin has protrusions. In this manner when trying to turn the dispenser, it will not turn when squeezed since the protrusions will make contact with each other.
It is an object of the present invention for the stretch wrap dispenser to comprise an extended core and a flexible skin, wherein the extended core has slots and the flexible skin has protrusions.
It is an object of the present invention for the stretch wrap dispenser to comprise an extended core and a flexible skin, wherein the extended core has protrusions and the flexible skin has slots.
It is an object of the present invention for the stretch wrap dispenser to comprise an extended core and a flexible skin, wherein the extended core has protrusions and the flexible skin has protrusions.
It is an object of the present invention for the mandrel and the flexible skin comprise a plastic material.
It is an object of the present invention for the extended core and the flexible skin to comprise a plastic material.
It is an object of the present invention for the extended core to be comprised of a paper material and the flexible skin to be comprised of a plastic material.
It is an object of the present invention for the stretch wrap dispenser to comprise at least two parts; a mandrel, which is solidly wedged into the core, and a flexible skin. It is an object of the present invention for the mandrel to comprise either ridges protruding outwardly longitudinally along the outside of the mandrel or slots protruding inwardly along the outside of the mandrel. It is an object of the present invention for the skin to exhibit protrusions longitudinally along the side of the skin, the position of which are laterally matched with the ridges or slots on the mandrel. By putting a minimum amount of squeezing action on the skin, the skin will deflect from a round shape into a slightly oval shape. This causes the protrusions on the inside of the skin to lock behind the ridges or latch into slots in the mandrel. With the mandrel being wedged inside of the film core, the locking mechanism will prevent the roll from unwinding any further. The present invention does not rely solely on friction, but is based on an interlocking mechanism.
It is an object of the present invention for the mandrel to have outward ridges and skin to have inward ridges.
It is an object of the present invention for the mandrel to have inward slots on the outside and the skin to have inward ridges to lock inside slots.
It is an object of the present invention for the mandrel to have outward ridges that will lock into inward slots on the inside of the skin.
It is an object of the present invention for the ridges to cover only part of the length of the mandrel and skin.
It is an object of the present invention for the part of the mandrel that is not covered by the ridges to have an idler made of a low friction plastic to facilitate easy unwinding when the skin is not being squeezed.
It is an object of the present invention for the ridges to cover the entire length of the part of the mandrel sticking outside the core and along the entire skin.
It is an object of the present invention for the mandrel to have a mandrel extension which when in use is wedged inside the core of the stretch wrap film.
It is an object of the present invention for the mandrel to have a flange which extends radially from the mandrel.
It is an object of the present invention for the flange to be locked into an undercut on the inside of the flexible skin to lock the film in place on the mandrel.
It is an object of the present invention for the flexible skin to have a textured surface to improve the grip of a user.
It is an object of the flexible skin to have a flange flaring out radially to protect a user's hand, located on the top side of the flexible skin.
With regards to the operation of the device, normally the skin will rotate freely around the mandrel. However, when the skin is being squeezed, the shape will become oval, thus starting to engage the ridges on the inside of the skin behind the ridges on the outside of the mandrel, and ultimately locking the skin on the mandrel which stops the film from unwinding any further.
The present invention teaches further methods of operating the device where the skin is locked onto the mandrel that includes slots on the inside of the skin engaging with ridges on the outside of the mandrel, or ridges located on the inside of the skin engaging with slots located on the outside of the mandrel. The invention further teaches any other type of protrusion on the inside of the skin engaging with matching slots in the outside of the mandrel, or protrusions on the outside of the mandrel engaging with matching slots on the inside of the skin.
